From 08944810f3b9632de38ae92499c63464f212e0fe Mon Sep 17 00:00:00 2001 From: Lorry Tar Creator Date: Thu, 24 Aug 2017 16:58:43 +0000 Subject: sqlite-autoconf-3200100 --- sqlite3.c | 141769 ++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 96420 insertions(+), 45349 deletions(-) (limited to 'sqlite3.c') diff --git a/sqlite3.c b/sqlite3.c index cae0c4a..ea5ba16 100644 --- a/sqlite3.c +++ b/sqlite3.c @@ -1,6 +1,6 @@ /****************************************************************************** ** This file is an amalgamation of many separate C source files from SQLite -** version 3.8.8.1. By combining all the individual C code files into this +** version 3.20.1. By combining all the individual C code files into this ** single large file, the entire code can be compiled as a single translation ** unit. This allows many compilers to do optimizations that would not be ** possible if the files were compiled separately. Performance improvements @@ -9,7 +9,7 @@ ** ** This file is all you need to compile SQLite. To use SQLite in other ** programs, you need this file and the "sqlite3.h" header file that defines -** the programming interface to the SQLite library. (If you do not have +** the programming interface to the SQLite library. (If you do not have ** the "sqlite3.h" header file at hand, you will find a copy embedded within ** the text of this file. Search for "Begin file sqlite3.h" to find the start ** of the embedded sqlite3.h header file.) Additional code files may be needed @@ -22,9 +22,758 @@ #ifndef SQLITE_PRIVATE # define SQLITE_PRIVATE static #endif -#ifndef SQLITE_API -# define SQLITE_API +/************** Begin file ctime.c *******************************************/ +/* +** 2010 February 23 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** This file implements routines used to report what compile-time options +** SQLite was built with. +*/ + +#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS + +/* +** Include the configuration header output by 'configure' if we're using the +** autoconf-based build +*/ +#if defined(_HAVE_SQLITE_CONFIG_H) && !defined(SQLITECONFIG_H) +#include "config.h" +#define SQLITECONFIG_H 1 +#endif + +/* These macros are provided to "stringify" the value of the define +** for those options in which the value is meaningful. */ +#define CTIMEOPT_VAL_(opt) #opt +#define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt) + +/* +** An array of names of all compile-time options. This array should +** be sorted A-Z. +** +** This array looks large, but in a typical installation actually uses +** only a handful of compile-time options, so most times this array is usually +** rather short and uses little memory space. +*/ +static const char * const sqlite3azCompileOpt[] = { + +/* +** BEGIN CODE GENERATED BY tool/mkctime.tcl +*/ +#if SQLITE_32BIT_ROWID + "32BIT_ROWID", +#endif +#if SQLITE_4_BYTE_ALIGNED_MALLOC + "4_BYTE_ALIGNED_MALLOC", +#endif +#if SQLITE_64BIT_STATS + "64BIT_STATS", +#endif +#if SQLITE_ALLOW_COVERING_INDEX_SCAN + "ALLOW_COVERING_INDEX_SCAN", +#endif +#if SQLITE_ALLOW_URI_AUTHORITY + "ALLOW_URI_AUTHORITY", +#endif +#ifdef SQLITE_BITMASK_TYPE + "BITMASK_TYPE=" CTIMEOPT_VAL(SQLITE_BITMASK_TYPE), +#endif +#if SQLITE_BUG_COMPATIBLE_20160819 + "BUG_COMPATIBLE_20160819", +#endif +#if SQLITE_CASE_SENSITIVE_LIKE + "CASE_SENSITIVE_LIKE", +#endif +#if SQLITE_CHECK_PAGES + "CHECK_PAGES", +#endif +#if defined(__clang__) && defined(__clang_major__) + "COMPILER=clang-" CTIMEOPT_VAL(__clang_major__) "." + CTIMEOPT_VAL(__clang_minor__) "." + CTIMEOPT_VAL(__clang_patchlevel__), +#elif defined(_MSC_VER) + "COMPILER=msvc-" CTIMEOPT_VAL(_MSC_VER), +#elif defined(__GNUC__) && defined(__VERSION__) + "COMPILER=gcc-" __VERSION__, +#endif +#if SQLITE_COVERAGE_TEST + "COVERAGE_TEST", +#endif +#if SQLITE_DEBUG + "DEBUG", +#endif +#if SQLITE_DEFAULT_AUTOMATIC_INDEX + "DEFAULT_AUTOMATIC_INDEX", +#endif +#if SQLITE_DEFAULT_AUTOVACUUM + "DEFAULT_AUTOVACUUM", +#endif +#ifdef SQLITE_DEFAULT_CACHE_SIZE + "DEFAULT_CACHE_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_CACHE_SIZE), +#endif +#if SQLITE_DEFAULT_CKPTFULLFSYNC + "DEFAULT_CKPTFULLFSYNC", +#endif +#ifdef SQLITE_DEFAULT_FILE_FORMAT + "DEFAULT_FILE_FORMAT=" CTIMEOPT_VAL(SQLITE_DEFAULT_FILE_FORMAT), +#endif +#ifdef SQLITE_DEFAULT_FILE_PERMISSIONS + "DEFAULT_FILE_PERMISSIONS=" CTIMEOPT_VAL(SQLITE_DEFAULT_FILE_PERMISSIONS), +#endif +#if SQLITE_DEFAULT_FOREIGN_KEYS + "DEFAULT_FOREIGN_KEYS", +#endif +#ifdef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT + "DEFAULT_JOURNAL_SIZE_LIMIT=" CTIMEOPT_VAL(SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT), +#endif +#ifdef SQLITE_DEFAULT_LOCKING_MODE + "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE), +#endif +#ifdef SQLITE_DEFAULT_LOOKASIDE + "DEFAULT_LOOKASIDE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOOKASIDE), +#endif +#if SQLITE_DEFAULT_MEMSTATUS + "DEFAULT_MEMSTATUS", +#endif +#ifdef SQLITE_DEFAULT_MMAP_SIZE + "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE), +#endif +#ifdef SQLITE_DEFAULT_PAGE_SIZE + "DEFAULT_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_PAGE_SIZE), +#endif +#ifdef SQLITE_DEFAULT_PCACHE_INITSZ + "DEFAULT_PCACHE_INITSZ=" CTIMEOPT_VAL(SQLITE_DEFAULT_PCACHE_INITSZ), +#endif +#ifdef SQLITE_DEFAULT_PROXYDIR_PERMISSIONS + "DEFAULT_PROXYDIR_PERMISSIONS=" CTIMEOPT_VAL(SQLITE_DEFAULT_PROXYDIR_PERMISSIONS), +#endif +#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS + "DEFAULT_RECURSIVE_TRIGGERS", +#endif +#ifdef SQLITE_DEFAULT_ROWEST + "DEFAULT_ROWEST=" CTIMEOPT_VAL(SQLITE_DEFAULT_ROWEST), +#endif +#ifdef SQLITE_DEFAULT_SECTOR_SIZE + "DEFAULT_SECTOR_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_SECTOR_SIZE), +#endif +#ifdef SQLITE_DEFAULT_SYNCHRONOUS + "DEFAULT_SYNCHRONOUS=" CTIMEOPT_VAL(SQLITE_DEFAULT_SYNCHRONOUS), +#endif +#ifdef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT + "DEFAULT_WAL_AUTOCHECKPOINT=" CTIMEOPT_VAL(SQLITE_DEFAULT_WAL_AUTOCHECKPOINT), +#endif +#ifdef SQLITE_DEFAULT_WAL_SYNCHRONOUS + "DEFAULT_WAL_SYNCHRONOUS=" CTIMEOPT_VAL(SQLITE_DEFAULT_WAL_SYNCHRONOUS), +#endif +#ifdef SQLITE_DEFAULT_WORKER_THREADS + "DEFAULT_WORKER_THREADS=" CTIMEOPT_VAL(SQLITE_DEFAULT_WORKER_THREADS), +#endif +#if SQLITE_DIRECT_OVERFLOW_READ + "DIRECT_OVERFLOW_READ", +#endif +#if SQLITE_DISABLE_DIRSYNC + "DISABLE_DIRSYNC", +#endif +#if SQLITE_DISABLE_FTS3_UNICODE + "DISABLE_FTS3_UNICODE", +#endif +#if SQLITE_DISABLE_FTS4_DEFERRED + "DISABLE_FTS4_DEFERRED", +#endif +#if SQLITE_DISABLE_INTRINSIC + "DISABLE_INTRINSIC", +#endif +#if SQLITE_DISABLE_LFS + "DISABLE_LFS", +#endif +#if SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS + "DISABLE_PAGECACHE_OVERFLOW_STATS", +#endif +#if SQLITE_DISABLE_SKIPAHEAD_DISTINCT + "DISABLE_SKIPAHEAD_DISTINCT", +#endif +#ifdef SQLITE_ENABLE_8_3_NAMES + "ENABLE_8_3_NAMES=" CTIMEOPT_VAL(SQLITE_ENABLE_8_3_NAMES), +#endif +#if SQLITE_ENABLE_API_ARMOR + "ENABLE_API_ARMOR", +#endif +#if SQLITE_ENABLE_ATOMIC_WRITE + "ENABLE_ATOMIC_WRITE", +#endif +#if SQLITE_ENABLE_CEROD + "ENABLE_CEROD", +#endif +#if SQLITE_ENABLE_COLUMN_METADATA + "ENABLE_COLUMN_METADATA", +#endif +#if SQLITE_ENABLE_COLUMN_USED_MASK + "ENABLE_COLUMN_USED_MASK", +#endif +#if SQLITE_ENABLE_COSTMULT + "ENABLE_COSTMULT", +#endif +#if SQLITE_ENABLE_CURSOR_HINTS + "ENABLE_CURSOR_HINTS", +#endif +#if SQLITE_ENABLE_DBSTAT_VTAB + "ENABLE_DBSTAT_VTAB", +#endif +#if SQLITE_ENABLE_EXPENSIVE_ASSERT + "ENABLE_EXPENSIVE_ASSERT", +#endif +#if SQLITE_ENABLE_FTS1 + "ENABLE_FTS1", +#endif +#if SQLITE_ENABLE_FTS2 + "ENABLE_FTS2", +#endif +#if SQLITE_ENABLE_FTS3 + "ENABLE_FTS3", +#endif +#if SQLITE_ENABLE_FTS3_PARENTHESIS + "ENABLE_FTS3_PARENTHESIS", +#endif +#if SQLITE_ENABLE_FTS3_TOKENIZER + "ENABLE_FTS3_TOKENIZER", +#endif +#if SQLITE_ENABLE_FTS4 + "ENABLE_FTS4", +#endif +#if SQLITE_ENABLE_FTS5 + "ENABLE_FTS5", +#endif +#if SQLITE_ENABLE_HIDDEN_COLUMNS + "ENABLE_HIDDEN_COLUMNS", +#endif +#if SQLITE_ENABLE_ICU + "ENABLE_ICU", +#endif +#if SQLITE_ENABLE_IOTRACE + "ENABLE_IOTRACE", +#endif +#if SQLITE_ENABLE_JSON1 + "ENABLE_JSON1", +#endif +#if SQLITE_ENABLE_LOAD_EXTENSION + "ENABLE_LOAD_EXTENSION", +#endif +#ifdef SQLITE_ENABLE_LOCKING_STYLE + "ENABLE_LOCKING_STYLE=" CTIMEOPT_VAL(SQLITE_ENABLE_LOCKING_STYLE), +#endif +#if SQLITE_ENABLE_MEMORY_MANAGEMENT + "ENABLE_MEMORY_MANAGEMENT", +#endif +#if SQLITE_ENABLE_MEMSYS3 + "ENABLE_MEMSYS3", +#endif +#if SQLITE_ENABLE_MEMSYS5 + "ENABLE_MEMSYS5", +#endif +#if SQLITE_ENABLE_MULTIPLEX + "ENABLE_MULTIPLEX", +#endif +#if SQLITE_ENABLE_NULL_TRIM + "ENABLE_NULL_TRIM", +#endif +#if SQLITE_ENABLE_OVERSIZE_CELL_CHECK + "ENABLE_OVERSIZE_CELL_CHECK", +#endif +#if SQLITE_ENABLE_PREUPDATE_HOOK + "ENABLE_PREUPDATE_HOOK", +#endif +#if SQLITE_ENABLE_QPSG + "ENABLE_QPSG", +#endif +#if SQLITE_ENABLE_RBU + "ENABLE_RBU", +#endif +#if SQLITE_ENABLE_RTREE + "ENABLE_RTREE", +#endif +#if SQLITE_ENABLE_SELECTTRACE + "ENABLE_SELECTTRACE", +#endif +#if SQLITE_ENABLE_SESSION + "ENABLE_SESSION", +#endif +#if SQLITE_ENABLE_SNAPSHOT + "ENABLE_SNAPSHOT", +#endif +#if SQLITE_ENABLE_SQLLOG + "ENABLE_SQLLOG", +#endif +#if defined(SQLITE_ENABLE_STAT4) + "ENABLE_STAT4", +#elif defined(SQLITE_ENABLE_STAT3) + "ENABLE_STAT3", +#endif +#if SQLITE_ENABLE_STMTVTAB + "ENABLE_STMTVTAB", +#endif +#if SQLITE_ENABLE_STMT_SCANSTATUS + "ENABLE_STMT_SCANSTATUS", +#endif +#if SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION + "ENABLE_UNKNOWN_SQL_FUNCTION", +#endif +#if SQLITE_ENABLE_UNLOCK_NOTIFY + "ENABLE_UNLOCK_NOTIFY", +#endif +#if SQLITE_ENABLE_UPDATE_DELETE_LIMIT + "ENABLE_UPDATE_DELETE_LIMIT", +#endif +#if SQLITE_ENABLE_URI_00_ERROR + "ENABLE_URI_00_ERROR", +#endif +#if SQLITE_ENABLE_VFSTRACE + "ENABLE_VFSTRACE", +#endif +#if SQLITE_ENABLE_WHERETRACE + "ENABLE_WHERETRACE", +#endif +#if SQLITE_ENABLE_ZIPVFS + "ENABLE_ZIPVFS", +#endif +#if SQLITE_EXPLAIN_ESTIMATED_ROWS + "EXPLAIN_ESTIMATED_ROWS", +#endif +#if SQLITE_EXTRA_IFNULLROW + "EXTRA_IFNULLROW", +#endif +#ifdef SQLITE_EXTRA_INIT + "EXTRA_INIT=" CTIMEOPT_VAL(SQLITE_EXTRA_INIT), +#endif +#ifdef SQLITE_EXTRA_SHUTDOWN + "EXTRA_SHUTDOWN=" CTIMEOPT_VAL(SQLITE_EXTRA_SHUTDOWN), +#endif +#ifdef SQLITE_FTS3_MAX_EXPR_DEPTH + "FTS3_MAX_EXPR_DEPTH=" CTIMEOPT_VAL(SQLITE_FTS3_MAX_EXPR_DEPTH), +#endif +#if SQLITE_FTS5_ENABLE_TEST_MI + "FTS5_ENABLE_TEST_MI", +#endif +#if SQLITE_FTS5_NO_WITHOUT_ROWID + "FTS5_NO_WITHOUT_ROWID", +#endif +#if SQLITE_HAS_CODEC + "HAS_CODEC", +#endif +#if HAVE_ISNAN || SQLITE_HAVE_ISNAN + "HAVE_ISNAN", +#endif +#if SQLITE_HOMEGROWN_RECURSIVE_MUTEX + "HOMEGROWN_RECURSIVE_MUTEX", +#endif +#if SQLITE_IGNORE_AFP_LOCK_ERRORS + "IGNORE_AFP_LOCK_ERRORS", +#endif +#if SQLITE_IGNORE_FLOCK_LOCK_ERRORS + "IGNORE_FLOCK_LOCK_ERRORS", +#endif +#if SQLITE_INLINE_MEMCPY + "INLINE_MEMCPY", +#endif +#if SQLITE_INT64_TYPE + "INT64_TYPE", +#endif +#ifdef SQLITE_INTEGRITY_CHECK_ERROR_MAX + "INTEGRITY_CHECK_ERROR_MAX=" CTIMEOPT_VAL(SQLITE_INTEGRITY_CHECK_ERROR_MAX), +#endif +#if SQLITE_LIKE_DOESNT_MATCH_BLOBS + "LIKE_DOESNT_MATCH_BLOBS", +#endif +#if SQLITE_LOCK_TRACE + "LOCK_TRACE", +#endif +#if SQLITE_LOG_CACHE_SPILL + "LOG_CACHE_SPILL", +#endif +#ifdef SQLITE_MALLOC_SOFT_LIMIT + "MALLOC_SOFT_LIMIT=" CTIMEOPT_VAL(SQLITE_MALLOC_SOFT_LIMIT), +#endif +#ifdef SQLITE_MAX_ATTACHED + "MAX_ATTACHED=" CTIMEOPT_VAL(SQLITE_MAX_ATTACHED), +#endif +#ifdef SQLITE_MAX_COLUMN + "MAX_COLUMN=" CTIMEOPT_VAL(SQLITE_MAX_COLUMN), +#endif +#ifdef SQLITE_MAX_COMPOUND_SELECT + "MAX_COMPOUND_SELECT=" CTIMEOPT_VAL(SQLITE_MAX_COMPOUND_SELECT), +#endif +#ifdef SQLITE_MAX_DEFAULT_PAGE_SIZE + "MAX_DEFAULT_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_DEFAULT_PAGE_SIZE), +#endif +#ifdef SQLITE_MAX_EXPR_DEPTH + "MAX_EXPR_DEPTH=" CTIMEOPT_VAL(SQLITE_MAX_EXPR_DEPTH), +#endif +#ifdef SQLITE_MAX_FUNCTION_ARG + "MAX_FUNCTION_ARG=" CTIMEOPT_VAL(SQLITE_MAX_FUNCTION_ARG), +#endif +#ifdef SQLITE_MAX_LENGTH + "MAX_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_LENGTH), +#endif +#ifdef SQLITE_MAX_LIKE_PATTERN_LENGTH + "MAX_LIKE_PATTERN_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_LIKE_PATTERN_LENGTH), +#endif +#ifdef SQLITE_MAX_MEMORY + "MAX_MEMORY=" CTIMEOPT_VAL(SQLITE_MAX_MEMORY), +#endif +#ifdef SQLITE_MAX_MMAP_SIZE + "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE), +#endif +#ifdef SQLITE_MAX_MMAP_SIZE_ + "MAX_MMAP_SIZE_=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE_), +#endif +#ifdef SQLITE_MAX_PAGE_COUNT + "MAX_PAGE_COUNT=" CTIMEOPT_VAL(SQLITE_MAX_PAGE_COUNT), +#endif +#ifdef SQLITE_MAX_PAGE_SIZE + "MAX_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_PAGE_SIZE), +#endif +#ifdef SQLITE_MAX_SCHEMA_RETRY + "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY), +#endif +#ifdef SQLITE_MAX_SQL_LENGTH + "MAX_SQL_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_SQL_LENGTH), +#endif +#ifdef SQLITE_MAX_TRIGGER_DEPTH + "MAX_TRIGGER_DEPTH=" CTIMEOPT_VAL(SQLITE_MAX_TRIGGER_DEPTH), +#endif +#ifdef SQLITE_MAX_VARIABLE_NUMBER + "MAX_VARIABLE_NUMBER=" CTIMEOPT_VAL(SQLITE_MAX_VARIABLE_NUMBER), +#endif +#ifdef SQLITE_MAX_VDBE_OP + "MAX_VDBE_OP=" CTIMEOPT_VAL(SQLITE_MAX_VDBE_OP), +#endif +#ifdef SQLITE_MAX_WORKER_THREADS + "MAX_WORKER_THREADS=" CTIMEOPT_VAL(SQLITE_MAX_WORKER_THREADS), +#endif +#if SQLITE_MEMDEBUG + "MEMDEBUG", +#endif +#if SQLITE_MIXED_ENDIAN_64BIT_FLOAT + "MIXED_ENDIAN_64BIT_FLOAT", +#endif +#if SQLITE_MMAP_READWRITE + "MMAP_READWRITE", +#endif +#if SQLITE_MUTEX_NOOP + "MUTEX_NOOP", +#endif +#if SQLITE_MUTEX_NREF + "MUTEX_NREF", +#endif +#if SQLITE_MUTEX_OMIT + "MUTEX_OMIT", +#endif +#if SQLITE_MUTEX_PTHREADS + "MUTEX_PTHREADS", +#endif +#if SQLITE_MUTEX_W32 + "MUTEX_W32", +#endif +#if SQLITE_NEED_ERR_NAME + "NEED_ERR_NAME", +#endif +#if SQLITE_NOINLINE + "NOINLINE", +#endif +#if SQLITE_NO_SYNC + "NO_SYNC", +#endif +#if SQLITE_OMIT_ALTERTABLE + "OMIT_ALTERTABLE", +#endif +#if SQLITE_OMIT_ANALYZE + "OMIT_ANALYZE", +#endif +#if SQLITE_OMIT_ATTACH + "OMIT_ATTACH", +#endif +#if SQLITE_OMIT_AUTHORIZATION + "OMIT_AUTHORIZATION", +#endif +#if SQLITE_OMIT_AUTOINCREMENT + "OMIT_AUTOINCREMENT", #endif +#if SQLITE_OMIT_AUTOINIT + "OMIT_AUTOINIT", +#endif +#if SQLITE_OMIT_AUTOMATIC_INDEX + "OMIT_AUTOMATIC_INDEX", +#endif +#if SQLITE_OMIT_AUTORESET + "OMIT_AUTORESET", +#endif +#if SQLITE_OMIT_AUTOVACUUM + "OMIT_AUTOVACUUM", +#endif +#if SQLITE_OMIT_BETWEEN_OPTIMIZATION + "OMIT_BETWEEN_OPTIMIZATION", +#endif +#if SQLITE_OMIT_BLOB_LITERAL + "OMIT_BLOB_LITERAL", +#endif +#if SQLITE_OMIT_BTREECOUNT + "OMIT_BTREECOUNT", +#endif +#if SQLITE_OMIT_CAST + "OMIT_CAST", +#endif +#if SQLITE_OMIT_CHECK + "OMIT_CHECK", +#endif +#if SQLITE_OMIT_COMPLETE + "OMIT_COMPLETE", +#endif +#if SQLITE_OMIT_COMPOUND_SELECT + "OMIT_COMPOUND_SELECT", +#endif +#if SQLITE_OMIT_CONFLICT_CLAUSE + "OMIT_CONFLICT_CLAUSE", +#endif +#if SQLITE_OMIT_CTE + "OMIT_CTE", +#endif +#if SQLITE_OMIT_DATETIME_FUNCS + "OMIT_DATETIME_FUNCS", +#endif +#if SQLITE_OMIT_DECLTYPE + "OMIT_DECLTYPE", +#endif +#if SQLITE_OMIT_DEPRECATED + "OMIT_DEPRECATED", +#endif +#if SQLITE_OMIT_DISKIO + "OMIT_DISKIO", +#endif +#if SQLITE_OMIT_EXPLAIN + "OMIT_EXPLAIN", +#endif +#if SQLITE_OMIT_FLAG_PRAGMAS + "OMIT_FLAG_PRAGMAS", +#endif +#if SQLITE_OMIT_FLOATING_POINT + "OMIT_FLOATING_POINT", +#endif +#if SQLITE_OMIT_FOREIGN_KEY + "OMIT_FOREIGN_KEY", +#endif +#if SQLITE_OMIT_GET_TABLE + "OMIT_GET_TABLE", +#endif +#if SQLITE_OMIT_HEX_INTEGER + "OMIT_HEX_INTEGER", +#endif +#if SQLITE_OMIT_INCRBLOB + "OMIT_INCRBLOB", +#endif +#if SQLITE_OMIT_INTEGRITY_CHECK + "OMIT_INTEGRITY_CHECK", +#endif +#if SQLITE_OMIT_LIKE_OPTIMIZATION + "OMIT_LIKE_OPTIMIZATION", +#endif +#if SQLITE_OMIT_LOAD_EXTENSION + "OMIT_LOAD_EXTENSION", +#endif +#if SQLITE_OMIT_LOCALTIME + "OMIT_LOCALTIME", +#endif +#if SQLITE_OMIT_LOOKASIDE + "OMIT_LOOKASIDE", +#endif +#if SQLITE_OMIT_MEMORYDB + "OMIT_MEMORYDB", +#endif +#if SQLITE_OMIT_OR_OPTIMIZATION + "OMIT_OR_OPTIMIZATION", +#endif +#if SQLITE_OMIT_PAGER_PRAGMAS + "OMIT_PAGER_PRAGMAS", +#endif +#if SQLITE_OMIT_PARSER_TRACE + "OMIT_PARSER_TRACE", +#endif +#if SQLITE_OMIT_POPEN + "OMIT_POPEN", +#endif +#if SQLITE_OMIT_PRAGMA + "OMIT_PRAGMA", +#endif +#if SQLITE_OMIT_PROGRESS_CALLBACK + "OMIT_PROGRESS_CALLBACK", +#endif +#if SQLITE_OMIT_QUICKBALANCE + "OMIT_QUICKBALANCE", +#endif +#if SQLITE_OMIT_REINDEX + "OMIT_REINDEX", +#endif +#if SQLITE_OMIT_SCHEMA_PRAGMAS + "OMIT_SCHEMA_PRAGMAS", +#endif +#if SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS + "OMIT_SCHEMA_VERSION_PRAGMAS", +#endif +#if SQLITE_OMIT_SHARED_CACHE + "OMIT_SHARED_CACHE", +#endif +#if SQLITE_OMIT_SHUTDOWN_DIRECTORIES + "OMIT_SHUTDOWN_DIRECTORIES", +#endif +#if SQLITE_OMIT_SUBQUERY + "OMIT_SUBQUERY", +#endif +#if SQLITE_OMIT_TCL_VARIABLE + "OMIT_TCL_VARIABLE", +#endif +#if SQLITE_OMIT_TEMPDB + "OMIT_TEMPDB", +#endif +#if SQLITE_OMIT_TEST_CONTROL + "OMIT_TEST_CONTROL", +#endif +#if SQLITE_OMIT_TRACE + "OMIT_TRACE", +#endif +#if SQLITE_OMIT_TRIGGER + "OMIT_TRIGGER", +#endif +#if SQLITE_OMIT_TRUNCATE_OPTIMIZATION + "OMIT_TRUNCATE_OPTIMIZATION", +#endif +#if SQLITE_OMIT_UTF16 + "OMIT_UTF16", +#endif +#if SQLITE_OMIT_VACUUM + "OMIT_VACUUM", +#endif +#if SQLITE_OMIT_VIEW + "OMIT_VIEW", +#endif +#if SQLITE_OMIT_VIRTUALTABLE + "OMIT_VIRTUALTABLE", +#endif +#if SQLITE_OMIT_WAL + "OMIT_WAL", +#endif +#if SQLITE_OMIT_WSD + "OMIT_WSD", +#endif +#if SQLITE_OMIT_XFER_OPT + "OMIT_XFER_OPT", +#endif +#if SQLITE_PCACHE_SEPARATE_HEADER + "PCACHE_SEPARATE_HEADER", +#endif +#if SQLITE_PERFORMANCE_TRACE + "PERFORMANCE_TRACE", +#endif +#if SQLITE_POWERSAFE_OVERWRITE + "POWERSAFE_OVERWRITE", +#endif +#if SQLITE_PREFER_PROXY_LOCKING + "PREFER_PROXY_LOCKING", +#endif +#if SQLITE_PROXY_DEBUG + "PROXY_DEBUG", +#endif +#if SQLITE_REVERSE_UNORDERED_SELECTS + "REVERSE_UNORDERED_SELECTS", +#endif +#if SQLITE_RTREE_INT_ONLY + "RTREE_INT_ONLY", +#endif +#if SQLITE_SECURE_DELETE + "SECURE_DELETE", +#endif +#if SQLITE_SMALL_STACK + "SMALL_STACK", +#endif +#ifdef SQLITE_SORTER_PMASZ + "SORTER_PMASZ=" CTIMEOPT_VAL(SQLITE_SORTER_PMASZ), +#endif +#if SQLITE_SOUNDEX + "SOUNDEX", +#endif +#ifdef SQLITE_STAT4_SAMPLES + "STAT4_SAMPLES=" CTIMEOPT_VAL(SQLITE_STAT4_SAMPLES), +#endif +#ifdef SQLITE_STMTJRNL_SPILL + "STMTJRNL_SPILL=" CTIMEOPT_VAL(SQLITE_STMTJRNL_SPILL), +#endif +#if SQLITE_SUBSTR_COMPATIBILITY + "SUBSTR_COMPATIBILITY", +#endif +#if SQLITE_SYSTEM_MALLOC + "SYSTEM_MALLOC", +#endif +#if SQLITE_TCL + "TCL", +#endif +#ifdef SQLITE_TEMP_STORE + "TEMP_STORE=" CTIMEOPT_VAL(SQLITE_TEMP_STORE), +#endif +#if SQLITE_TEST + "TEST", +#endif +#if defined(SQLITE_THREADSAFE) + "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE), +#elif defined(THREADSAFE) + "THREADSAFE=" CTIMEOPT_VAL(THREADSAFE), +#else + "THREADSAFE=1", +#endif +#if SQLITE_UNLINK_AFTER_CLOSE + "UNLINK_AFTER_CLOSE", +#endif +#if SQLITE_UNTESTABLE + "UNTESTABLE", +#endif +#if SQLITE_USER_AUTHENTICATION + "USER_AUTHENTICATION", +#endif +#if SQLITE_USE_ALLOCA + "USE_ALLOCA", +#endif +#if SQLITE_USE_FCNTL_TRACE + "USE_FCNTL_TRACE", +#endif +#if SQLITE_USE_URI + "USE_URI", +#endif +#if SQLITE_VDBE_COVERAGE + "VDBE_COVERAGE", +#endif +#if SQLITE_WIN32_MALLOC + "WIN32_MALLOC", +#endif +#if SQLITE_ZERO_MALLOC + "ZERO_MALLOC", +#endif +/* +** END CODE GENERATED BY tool/mkctime.tcl +*/ +}; + +SQLITE_PRIVATE const char **sqlite3CompileOptions(int *pnOpt){ + *pnOpt = sizeof(sqlite3azCompileOpt) / sizeof(sqlite3azCompileOpt[0]); + return (const char**)sqlite3azCompileOpt; +} + +#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */ + +/************** End of ctime.c ***********************************************/ /************** Begin file sqliteInt.h ***************************************/ /* ** 2001 September 15 @@ -40,8 +789,51 @@ ** Internal interface definitions for SQLite. ** */ -#ifndef _SQLITEINT_H_ -#define _SQLITEINT_H_ +#ifndef SQLITEINT_H +#define SQLITEINT_H + +/* Special Comments: +** +** Some comments have special meaning to the tools that measure test +** coverage: +** +** NO_TEST - The branches on this line are not +** measured by branch coverage. This is +** used on lines of code that actually +** implement parts of coverage testing. +** +** OPTIMIZATION-IF-TRUE - This branch is allowed to alway be false +** and the correct answer is still obtained, +** though perhaps more slowly. +** +** OPTIMIZATION-IF-FALSE - This branch is allowed to alway be true +** and the correct answer is still obtained, +** though perhaps more slowly. +** +** PREVENTS-HARMLESS-OVERREAD - This branch prevents a buffer overread +** that would be harmless and undetectable +** if it did occur. +** +** In all cases, the special comment must be enclosed in the usual +** slash-asterisk...asterisk-slash comment marks, with no spaces between the +** asterisks and the comment text. +*/ + +/* +** Make sure the Tcl calling convention macro is defined. This macro is +** only used by test code and Tcl integration code. +*/ +#ifndef SQLITE_TCLAPI +# define SQLITE_TCLAPI +#endif + +/* +** Make sure that rand_s() is available on Windows systems with MSVC 2005 +** or higher. +*/ +#if defined(_MSC_VER) && _MSC_VER>=1400 +# define _CRT_RAND_S +#endif /* ** Include the header file used to customize the compiler options for MSVC. @@ -65,14 +857,15 @@ ** ** This file contains code that is specific to MSVC. */ -#ifndef _MSVC_H_ -#define _MSVC_H_ +#ifndef SQLITE_MSVC_H +#define SQLITE_MSVC_H #if defined(_MSC_VER) #pragma warning(disable : 4054) #pragma warning(disable : 4055) #pragma warning(disable : 4100) #pragma warning(disable : 4127) +#pragma warning(disable : 4130) #pragma warning(disable : 4152) #pragma warning(disable : 4189) #pragma warning(disable : 4206) @@ -85,11 +878,52 @@ #pragma warning(disable : 4706) #endif /* defined(_MSC_VER) */ -#endif /* _MSVC_H_ */ +#endif /* SQLITE_MSVC_H */ /************** End of msvc.h ************************************************/ /************** Continuing where we left off in sqliteInt.h ******************/ +/* +** Special setup for VxWorks +*/ +/************** Include vxworks.h in the middle of sqliteInt.h ***************/ +/************** Begin file vxworks.h *****************************************/ +/* +** 2015-03-02 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +****************************************************************************** +** +** This file contains code that is specific to Wind River's VxWorks +*/ +#if defined(__RTP__) || defined(_WRS_KERNEL) +/* This is VxWorks. Set up things specially for that OS +*/ +#include +#include /* amalgamator: dontcache */ +#define OS_VXWORKS 1 +#define SQLITE_OS_OTHER 0 +#define SQLITE_HOMEGROWN_RECURSIVE_MUTEX 1 +#define SQLITE_OMIT_LOAD_EXTENSION 1 +#define SQLITE_ENABLE_LOCKING_STYLE 0 +#define HAVE_UTIME 1 +#else +/* This is not VxWorks. */ +#define OS_VXWORKS 0 +#define HAVE_FCHOWN 1 +#define HAVE_READLINK 1 +#define HAVE_LSTAT 1 +#endif /* defined(_WRS_KERNEL) */ + +/************** End of vxworks.h *********************************************/ +/************** Continuing where we left off in sqliteInt.h ******************/ + /* ** These #defines should enable >2GB file support on POSIX if the ** underlying operating system supports it. If the OS lacks @@ -122,6 +956,30 @@ # define _LARGEFILE_SOURCE 1 #endif +/* The GCC_VERSION and MSVC_VERSION macros are used to +** conditionally include optimizations for each of these compilers. A +** value of 0 means that compiler is not being used. The +** SQLITE_DISABLE_INTRINSIC macro means do not use any compiler-specific +** optimizations, and hence set all compiler macros to 0 +** +** There was once also a CLANG_VERSION macro. However, we learn that the +** version numbers in clang are for "marketing" only and are inconsistent +** and unreliable. Fortunately, all versions of clang also recognize the +** gcc version numbers and have reasonable settings for gcc version numbers, +** so the GCC_VERSION macro will be set to a correct non-zero value even +** when compiling with clang. +*/ +#if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC) +# define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__) +#else +# define GCC_VERSION 0 +#endif +#if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC) +# define MSVC_VERSION _MSC_VER +#else +# define MSVC_VERSION 0 +#endif + /* Needed for various definitions... */ #if defined(__GNUC__) && !defined(_GNU_SOURCE) # define _GNU_SOURCE @@ -170,7 +1028,7 @@ /************** Include sqlite3.h in the middle of sqliteInt.h ***************/ /************** Begin file sqlite3.h *****************************************/ /* -** 2001 September 15 +** 2001-09-15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: @@ -194,15 +1052,15 @@ ** ** The official C-language API documentation for SQLite is derived ** from comments in this file. This file is the authoritative source -** on how SQLite interfaces are suppose to operate. +** on how SQLite interfaces are supposed to operate. ** ** The name of this file under configuration management is "sqlite.h.in". ** The makefile makes some minor changes to this file (such as inserting ** the version number) and changes its name to "sqlite3.h" as ** part of the build process. */ -#ifndef _SQLITE3_H_ -#define _SQLITE3_H_ +#ifndef SQLITE3_H +#define SQLITE3_H #include /* Needed for the definition of va_list */ /* @@ -214,16 +1072,29 @@ extern "C" { /* -** Add the ability to override 'extern' +** Provide the ability to override linkage features of the interface. */ #ifndef SQLITE_EXTERN # define SQLITE_EXTERN extern #endif - #ifndef SQLITE_API # define SQLITE_API #endif - +#ifndef SQLITE_CDECL +# define SQLITE_CDECL +#endif +#ifndef SQLITE_APICALL +# define SQLITE_APICALL +#endif +#ifndef SQLITE_STDCALL +# define SQLITE_STDCALL SQLITE_APICALL +#endif +#ifndef SQLITE_CALLBACK +# define SQLITE_CALLBACK +#endif +#ifndef SQLITE_SYSAPI +# define SQLITE_SYSAPI +#endif /* ** These no-op macros are used in front of interfaces to mark those @@ -266,32 +1137,33 @@ extern "C" { ** be held constant and Z will be incremented or else Y will be incremented ** and Z will be reset to zero. ** -** Since version 3.6.18, SQLite source code has been stored in the +** Since [version 3.6.18] ([dateof:3.6.18]), +** SQLite source code has been stored in the ** Fossil configuration management ** system. ^The SQLITE_SOURCE_ID macro evaluates to ** a string which identifies a particular check-in of SQLite ** within its configuration management system. ^The SQLITE_SOURCE_ID -** string contains the date and time of the check-in (UTC) and an SHA1 -** hash of the entire source tree. +** string contains the date and time of the check-in (UTC) and a SHA1 +** or SHA3-256 hash of the entire source tree. ** ** See also: [sqlite3_libversion()], ** [sqlite3_libversion_number()], [sqlite3_sourceid()], ** [sqlite_version()] and [sqlite_source_id()]. */ -#define SQLITE_VERSION "3.8.8.1" -#define SQLITE_VERSION_NUMBER 3008008 -#define SQLITE_SOURCE_ID "2015-01-20 16:51:25 f73337e3e289915a76ca96e7a05a1a8d4e890d55" +#define SQLITE_VERSION "3.20.1" +#define SQLITE_VERSION_NUMBER 3020001 +#define SQLITE_SOURCE_ID "2017-08-24 16:21:36 8d3a7ea6c5690d6b7c3767558f4f01b511c55463e3f9e64506801fe9b74dce34" /* ** CAPI3REF: Run-Time Library Version Numbers -** KEYWORDS: sqlite3_version, sqlite3_sourceid +** KEYWORDS: sqlite3_version sqlite3_sourceid ** ** These interfaces provide the same information as the [SQLITE_VERSION], ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros ** but are associated with the library instead of the header file. ^(Cautious ** programmers might include assert() statements in their application to ** verify that values returned by these interfaces match the macros in -** the header, and thus insure that the application is +** the header, and thus ensure that the application is ** compiled with matching library and header files. ** ** 
@@ -416,7 +1288,11 @@ typedef struct sqlite3 sqlite3;
 */
 #ifdef SQLITE_INT64_TYPE
   typedef SQLITE_INT64_TYPE sqlite_int64;
-  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
+# ifdef SQLITE_UINT64_TYPE
+    typedef SQLITE_UINT64_TYPE sqlite_uint64;
+# else  
+    typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
+# endif
 #elif defined(_MSC_VER) || defined(__BORLANDC__)
   typedef __int64 sqlite_int64;
   typedef unsigned __int64 sqlite_uint64;
@@ -437,6 +1313,7 @@ typedef sqlite_uint64 sqlite3_uint64;
 
 /*
 ** CAPI3REF: Closing A Database Connection
+** DESTRUCTOR: sqlite3
 **
 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
 ** for the [sqlite3] object.
@@ -488,6 +1365,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 
 /*
 ** CAPI3REF: One-Step Query Execution Interface
+** METHOD: sqlite3
 **
 ** The sqlite3_exec() interface is a convenience wrapper around
 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
@@ -512,7 +1390,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
 ** on error message strings returned through the 5th parameter of
-** of sqlite3_exec() after the error message string is no longer needed.
+** sqlite3_exec() after the error message string is no longer needed.
 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
 ** NULL before returning.
@@ -539,7 +1417,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 ** Restrictions:
 **
 ** 
    
-** 
  •  The application must insure that the 1st parameter to sqlite3_exec()
+** 
  •  The application must ensure that the 1st parameter to sqlite3_exec()
 **      is a valid and open [database connection].
 ** 
  •  The application must not close the [database connection] specified by
 **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
@@ -568,7 +1446,7 @@ SQLITE_API int sqlite3_exec(
 */
 #define SQLITE_OK           0   /* Successful result */
 /* beginning-of-error-codes */
-#define SQLITE_ERROR        1   /* SQL error or missing database */
+#define SQLITE_ERROR        1   /* Generic error */
 #define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
 #define SQLITE_PERM         3   /* Access permission denied */
 #define SQLITE_ABORT        4   /* Callback routine requested an abort */
@@ -583,7 +1461,7 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_FULL        13   /* Insertion failed because database is full */
 #define SQLITE_CANTOPEN    14   /* Unable to open the database file */
 #define SQLITE_PROTOCOL    15   /* Database lock protocol error */
-#define SQLITE_EMPTY       16   /* Database is empty */
+#define SQLITE_EMPTY       16   /* Not used */
 #define SQLITE_SCHEMA      17   /* The database schema changed */
 #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
 #define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
@@ -591,7 +1469,7 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_MISUSE      21   /* Library used incorrectly */
 #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
 #define SQLITE_AUTH        23   /* Authorization denied */
-#define SQLITE_FORMAT      24   /* Auxiliary database format error */
+#define SQLITE_FORMAT      24   /* Not used */
 #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
 #define SQLITE_NOTADB      26   /* File opened that is not a database file */
 #define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
@@ -608,7 +1486,8 @@ SQLITE_API int sqlite3_exec(
 ** [result codes].  However, experience has shown that many of
 ** these result codes are too coarse-grained.  They do not provide as
 ** much information about problems as programmers might like.  In an effort to
-** address this, newer versions of SQLite (version 3.3.8 and later) include
+** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
+** and later) include
 ** support for additional result codes that provide more detailed information
 ** about errors. These [extended result codes] are enabled or disabled
 ** on a per database connection basis using the
@@ -642,6 +1521,8 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
 #define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
 #define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
+#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
+#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
 #define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
@@ -669,6 +1550,7 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
 #define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
 #define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
+#define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))
 
 /*
 ** CAPI3REF: Flags For File Open Operations
@@ -723,7 +1605,7 @@ SQLITE_API int sqlite3_exec(
 ** file that were written at the application level might have changed
 ** and that adjacent bytes, even bytes within the same sector are
 ** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
-** flag indicate that a file cannot be deleted when open.  The
+** flag indicates that a file cannot be deleted when open.  The
 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
 ** read-only media and cannot be changed even by processes with
 ** elevated privileges.
@@ -873,6 +1755,9 @@ struct sqlite3_file {
 ** 
  •  [SQLITE_IOCAP_ATOMIC64K]
 ** 
  •  [SQLITE_IOCAP_SAFE_APPEND]
 ** 
  •  [SQLITE_IOCAP_SEQUENTIAL]
+** 
  •  [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
+** 
  •  [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
+** 
  •  [SQLITE_IOCAP_IMMUTABLE]
 ** 

 **
 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
@@ -927,14 +1812,16 @@ struct sqlite3_io_methods {
 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
 ** interface.
 **
+** 
    
+** 
  • [[SQLITE_FCNTL_LOCKSTATE]]
 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
 ** opcode causes the xFileControl method to write the current state of
 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
 ** into an integer that the pArg argument points to. This capability
-** is used during testing and only needs to be supported when SQLITE_TEST
-** is defined.
-** 
      
+** is used during testing and is only available when the SQLITE_TEST
+** compile-time option is used.
+**
 ** 
    • [[SQLITE_FCNTL_SIZE_HINT]]
 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
 ** layer a hint of how large the database file will grow to be during the
@@ -955,8 +1842,13 @@ struct sqlite3_io_methods {
 ** 
    • [[SQLITE_FCNTL_FILE_POINTER]]
 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
 ** to the [sqlite3_file] object associated with a particular database
-** connection.  See the [sqlite3_file_control()] documentation for
-** additional information.
+** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
+**
+** 
    • [[SQLITE_FCNTL_JOURNAL_POINTER]]
+** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
+** to the [sqlite3_file] object associated with the journal file (either
+** the [rollback journal] or the [write-ahead log]) for a particular database
+** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
 **
 ** 
    • [[SQLITE_FCNTL_SYNC_OMITTED]]
 ** No longer in use.
@@ -994,7 +1886,7 @@ struct sqlite3_io_methods {
 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
 ** to be adjusted.  The values are changed for all database connections
 ** within the same process.  The argument is a pointer to an array of two
-** integers where the first integer i the new retry count and the second
+** integers where the first integer is the new retry count and the second
 ** integer is the delay.  If either integer is negative, then the setting
 ** is not changed but instead the prior value of that setting is written
 ** into the array entry, allowing the current retry settings to be
@@ -1043,6 +1935,15 @@ struct sqlite3_io_methods {
 ** pointer in case this file-control is not implemented.  This file-control
 ** is intended for diagnostic use only.
 **
+** 
    • [[SQLITE_FCNTL_VFS_POINTER]]
+** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
+** [VFSes] currently in use.  ^(The argument X in
+** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
+** of type "[sqlite3_vfs] **".  This opcodes will set *X
+** to a pointer to the top-level VFS.)^
+** ^When there are multiple VFS shims in the stack, this opcode finds the
+** upper-most shim only.
+**
 ** 
    • [[SQLITE_FCNTL_PRAGMA]]
 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
 ** file control is sent to the open [sqlite3_file] object corresponding
@@ -1059,7 +1960,9 @@ struct sqlite3_io_methods {
 ** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
 ** file control returns [SQLITE_OK], then the parser assumes that the
 ** VFS has handled the PRAGMA itself and the parser generates a no-op
-** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
+** prepared statement if result string is NULL, or that returns a copy
+** of the result string if the string is non-NULL.
+** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
 ** that the VFS encountered an error while handling the [PRAGMA] and the
 ** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
@@ -1111,18 +2014,39 @@ struct sqlite3_io_methods {
 ** on whether or not the file has been renamed, moved, or deleted since it
 ** was first opened.
 **
+** 
    • [[SQLITE_FCNTL_WIN32_GET_HANDLE]]
+** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
+** underlying native file handle associated with a file handle.  This file
+** control interprets its argument as a pointer to a native file handle and
+** writes the resulting value there.
+**
 ** 
    • [[SQLITE_FCNTL_WIN32_SET_HANDLE]]
 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
 ** opcode causes the xFileControl method to swap the file handle with the one
 ** pointed to by the pArg argument.  This capability is used during testing
 ** and only needs to be supported when SQLITE_TEST is defined.
 **
+** 
    • [[SQLITE_FCNTL_WAL_BLOCK]]
+** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
+** be advantageous to block on the next WAL lock if the lock is not immediately
+** available.  The WAL subsystem issues this signal during rare
+** circumstances in order to fix a problem with priority inversion.
+** Applications should not use this file-control.
+**
+** 
    • [[SQLITE_FCNTL_ZIPVFS]]
+** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
+** VFS should return SQLITE_NOTFOUND for this opcode.
+**
+** 
    • [[SQLITE_FCNTL_RBU]]
+** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
+** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
+** this opcode.  
 ** 
    
 */
 #define SQLITE_FCNTL_LOCKSTATE               1
-#define SQLITE_GET_LOCKPROXYFILE             2
-#define SQLITE_SET_LOCKPROXYFILE             3
-#define SQLITE_LAST_ERRNO                    4
+#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
+#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
+#define SQLITE_FCNTL_LAST_ERRNO              4
 #define SQLITE_FCNTL_SIZE_HINT               5
 #define SQLITE_FCNTL_CHUNK_SIZE              6
 #define SQLITE_FCNTL_FILE_POINTER            7
@@ -1141,6 +2065,19 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_SYNC                   21
 #define SQLITE_FCNTL_COMMIT_PHASETWO        22
 #define SQLITE_FCNTL_WIN32_SET_HANDLE       23
+#define SQLITE_FCNTL_WAL_BLOCK              24
+#define SQLITE_FCNTL_ZIPVFS                 25
+#define SQLITE_FCNTL_RBU                    26
+#define SQLITE_FCNTL_VFS_POINTER            27
+#define SQLITE_FCNTL_JOURNAL_POINTER        28
+#define SQLITE_FCNTL_WIN32_GET_HANDLE       29
+#define SQLITE_FCNTL_PDB                    30
+
+/* deprecated names */
+#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
+#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
+#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO
+
 
 /*
 ** CAPI3REF: Mutex Handle
@@ -1154,6 +2091,16 @@ struct sqlite3_io_methods {
 */
 typedef struct sqlite3_mutex sqlite3_mutex;
 
+/*
+** CAPI3REF: Loadable Extension Thunk
+**
+** A pointer to the opaque sqlite3_api_routines structure is passed as
+** the third parameter to entry points of [loadable extensions].  This
+** structure must be typedefed in order to work around compiler warnings
+** on some platforms.
+*/
+typedef struct sqlite3_api_routines sqlite3_api_routines;
+
 /*
 ** CAPI3REF: OS Interface Object
 **
@@ -1347,7 +2294,7 @@ struct sqlite3_vfs {
   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
   /*
   ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
-  ** New fields may be appended in figure versions.  The iVersion
+  ** New fields may be appended in future versions.  The iVersion
   ** value will increment whenever this happens. 
   */
 };
@@ -1503,9 +2450,11 @@ SQLITE_API int sqlite3_os_end(void);
 ** applications and so this routine is usually not necessary.  It is
 ** provided to support rare applications with unusual needs.
 **
-** The sqlite3_config() interface is not threadsafe.  The application
-** must insure that no other SQLite interfaces are invoked by other
-** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
+** The sqlite3_config() interface is not threadsafe. The application
+** must ensure that no other SQLite interfaces are invoked by other
+** threads while sqlite3_config() is running.
+**
+** The sqlite3_config() interface
 ** may only be invoked prior to library initialization using
 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
@@ -1527,6 +2476,7 @@ SQLITE_API int sqlite3_config(int, ...);
 
 /*
 ** CAPI3REF: Configure database connections
+** METHOD: sqlite3
 **
 ** The sqlite3_db_config() interface is used to make configuration
 ** changes to a [database connection].  The interface is similar to
@@ -1701,7 +2651,7 @@ struct sqlite3_mem_methods {
 **   
  •  [sqlite3_memory_used()]
 **   
  •  [sqlite3_memory_highwater()]
 **   
  •  [sqlite3_soft_heap_limit64()]
-**   
  •  [sqlite3_status()]
+**   
  •  [sqlite3_status64()]
 **   
)^
 ** ^Memory allocation statistics are enabled by default unless SQLite is
 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
@@ -1731,29 +2681,34 @@ struct sqlite3_mem_methods {
 ** 
 **
 ** [[SQLITE_CONFIG_PAGECACHE]] 
SQLITE_CONFIG_PAGECACHE

-** 
 ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer
+** 
 ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
 ** that SQLite can use for the database page cache with the default page
 ** cache implementation.  
-** This configuration should not be used if an application-define page
-** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]
-** configuration option.
+** This configuration option is a no-op if an application-define page
+** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
-** 8-byte aligned
-** memory, the size of each page buffer (sz), and the number of pages (N).
+** 8-byte aligned memory (pMem), the size of each page cache line (sz),
+** and the number of cache lines (N).
 ** The sz argument should be the size of the largest database page
 ** (a power of two between 512 and 65536) plus some extra bytes for each
 ** page header.  ^The number of extra bytes needed by the page header
-** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 
-** to [sqlite3_config()].
+** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
 ** ^It is harmless, apart from the wasted memory,
-** for the sz parameter to be larger than necessary.  The first
-** argument should pointer to an 8-byte aligned block of memory that
-** is at least sz*N bytes of memory, otherwise subsequent behavior is
-** undefined.
-** ^SQLite will use the memory provided by the first argument to satisfy its
-** memory needs for the first N pages that it adds to cache.  ^If additional
-** page cache memory is needed beyond what is provided by this option, then
-** SQLite goes to [sqlite3_malloc()] for the additional storage space.

+** for the sz parameter to be larger than necessary.  The pMem
+** argument must be either a NULL pointer or a pointer to an 8-byte
+** aligned block of memory of at least sz*N bytes, otherwise
+** subsequent behavior is undefined.
+** ^When pMem is not NULL, SQLite will strive to use the memory provided
+** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
+** a page cache line is larger than sz bytes or if all of the pMem buffer
+** is exhausted.
+** ^If pMem is NULL and N is non-zero, then each database connection
+** does an initial bulk allocation for page cache memory
+** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
+** of -1024*N bytes if N is negative, . ^If additional
+** page cache memory is needed beyond what is provided by the initial
+** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
+** additional cache line. 
 **
 ** [[SQLITE_CONFIG_HEAP]] 
SQLITE_CONFIG_HEAP

 ** 
 ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 
@@ -1912,7 +2867,6 @@ struct sqlite3_mem_methods {
 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
 ** that specifies the maximum size of the created heap.
-** 
 **
 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
 ** 
SQLITE_CONFIG_PCACHE_HDRSZ
@@ -1932,6 +2886,20 @@ struct sqlite3_mem_methods {
 ** is enabled (using the [PRAGMA threads] command) and the amount of content
 ** to be sorted exceeds the page size times the minimum of the
 ** [PRAGMA cache_size] setting and this value.
+**
+** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
+** 
SQLITE_CONFIG_STMTJRNL_SPILL
+** 
^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
+** becomes the [statement journal] spill-to-disk threshold.  
+** [Statement journals] are held in memory until their size (in bytes)
+** exceeds this threshold, at which point they are written to disk.
+** Or if the threshold is -1, statement journals are always held
+** exclusively in memory.
+** Since many statement journals never become large, setting the spill
+** threshold to a value such as 64KiB can greatly reduce the amount of
+** I/O required to support statement rollback.
+** The default value for this setting is controlled by the
+** [SQLITE_STMTJRNL_SPILL] compile-time option.
 ** 
 */
 #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
@@ -1959,6 +2927,7 @@ struct sqlite3_mem_methods {
 #define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
 #define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
 #define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
+#define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
 
 /*
 ** CAPI3REF: Database Connection Configuration Options
@@ -2016,15 +2985,83 @@ struct sqlite3_mem_methods {
 ** following this call.  The second parameter may be a NULL pointer, in
 ** which case the trigger setting is not reported back. 

 **
+** 
SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER

+** 
 ^This option is used to enable or disable the two-argument
+** version of the [fts3_tokenizer()] function which is part of the
+** [FTS3] full-text search engine extension.
+** There should be two additional arguments.
+** The first argument is an integer which is 0 to disable fts3_tokenizer() or
+** positive to enable fts3_tokenizer() or negative to leave the setting
+** unchanged.
+** The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
+** following this call.  The second parameter may be a NULL pointer, in
+** which case the new setting is not reported back. 

+**
+** 
SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION

+** 
 ^This option is used to enable or disable the [sqlite3_load_extension()]
+** interface independently of the [load_extension()] SQL function.
+** The [sqlite3_enable_load_extension()] API enables or disables both the
+** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
+** There should be two additional arguments.
+** When the first argument to this interface is 1, then only the C-API is
+** enabled and the SQL function remains disabled.  If the first argument to
+** this interface is 0, then both the C-API and the SQL function are disabled.
+** If the first argument is -1, then no changes are made to state of either the
+** C-API or the SQL function.
+** The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
+** is disabled or enabled following this call.  The second parameter may
+** be a NULL pointer, in which case the new setting is not reported back.
+** 

+**
+** 
SQLITE_DBCONFIG_MAINDBNAME

+** 
 ^This option is used to change the name of the "main" database
+** schema.  ^The sole argument is a pointer to a constant UTF8 string
+** which will become the new schema name in place of "main".  ^SQLite
+** does not make a copy of the new main schema name string, so the application
+** must ensure that the argument passed into this DBCONFIG option is unchanged
+** until after the database connection closes.
+** 

+**
+** 
SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE

+** 
 Usually, when a database in wal mode is closed or detached from a 
+** database handle, SQLite checks if this will mean that there are now no 
+** connections at all to the database. If so, it performs a checkpoint 
+** operation before closing the connection. This option may be used to
+** override this behaviour. The first parameter passed to this operation
+** is an integer - non-zero to disable checkpoints-on-close, or zero (the
+** default) to enable them. The second parameter is a pointer to an integer
+** into which is written 0 or 1 to indicate whether checkpoints-on-close
+** have been disabled - 0 if they are not disabled, 1 if they are.
+** 

+**
+** 
SQLITE_DBCONFIG_ENABLE_QPSG

+** 
^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
+** the [query planner stability guarantee] (QPSG).  When the QPSG is active,
+** a single SQL query statement will always use the same algorithm regardless
+** of values of [bound parameters].)^ The QPSG disables some query optimizations
+** that look at the values of bound parameters, which can make some queries
+** slower.  But the QPSG has the advantage of more predictable behavior.  With
+** the QPSG active, SQLite will always use the same query plan in the field as
+** was used during testing in the lab.
+** 

+**
 ** 
 */
-#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
-#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
-#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
+#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
+#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
+#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
+#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
 
 
 /*
 ** CAPI3REF: Enable Or Disable Extended Result Codes
+** METHOD: sqlite3
 **
 ** ^The sqlite3_extended_result_codes() routine enables or disables the
 ** [extended result codes] feature of SQLite. ^The extended result
@@ -2034,6 +3071,7 @@ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
 
 /*
 ** CAPI3REF: Last Insert Rowid
+** METHOD: sqlite3
 **
 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
 ** has a unique 64-bit signed
@@ -2043,20 +3081,30 @@ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
 ** is another alias for the rowid.
 **
-** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 
-** most recent successful [INSERT] into a rowid table or [virtual table]
-** on database connection D.
-** ^Inserts into [WITHOUT ROWID] tables are not recorded.
-** ^If no successful [INSERT]s into rowid tables
-** have ever occurred on the database connection D, 
-** then sqlite3_last_insert_rowid(D) returns zero.
-**
-** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
-** method, then this routine will return the [rowid] of the inserted
-** row as long as the trigger or virtual table method is running.
-** But once the trigger or virtual table method ends, the value returned 
-** by this routine reverts to what it was before the trigger or virtual
-** table method began.)^
+** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
+** the most recent successful [INSERT] into a rowid table or [virtual table]
+** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
+** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 
+** on the database connection D, then sqlite3_last_insert_rowid(D) returns 
+** zero.
+**
+** As well as being set automatically as rows are inserted into database
+** tables, the value returned by this function may be set explicitly by
+** [sqlite3_set_last_insert_rowid()]
+**
+** Some virtual table implementations may INSERT rows into rowid tables as
+** part of committing a transaction (e.g. to flush data accumulated in memory
+** to disk). In this case subsequent calls to this function return the rowid
+** associated with these internal INSERT operations, which leads to 
+** unintuitive results. Virtual table implementations that do write to rowid
+** tables in this way can avoid this problem by restoring the original 
+** rowid value using [sqlite3_set_last_insert_rowid()] before returning 
+** control to the user.
+**
+** ^(If an [INSERT] occurs within a trigger then this routine will 
+** return the [rowid] of the inserted row as long as the trigger is 
+** running. Once the trigger program ends, the value returned 
+** by this routine reverts to what it was before the trigger was fired.)^
 **
 ** ^An [INSERT] that fails due to a constraint violation is not a
 ** successful [INSERT] and does not change the value returned by this
@@ -2083,8 +3131,19 @@ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
 */
 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
 
+/*
+** CAPI3REF: Set the Last Insert Rowid value.
+** METHOD: sqlite3
+**
+** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
+** set the value returned by calling sqlite3_last_insert_rowid(D) to R 
+** without inserting a row into the database.
+*/
+SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
+
 /*
 ** CAPI3REF: Count The Number Of Rows Modified
+** METHOD: sqlite3
 **
 ** ^This function returns the number of rows modified, inserted or
 ** deleted by the most recently completed INSERT, UPDATE or DELETE
@@ -2137,6 +3196,7 @@ SQLITE_API int sqlite3_changes(sqlite3*);
 
 /*
 ** CAPI3REF: Total Number Of Rows Modified
+** METHOD: sqlite3
 **
 ** ^This function returns the total number of rows inserted, modified or
 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
@@ -2160,6 +3220,7 @@ SQLITE_API int sqlite3_total_changes(sqlite3*);
 
 /*
 ** CAPI3REF: Interrupt A Long-Running Query
+** METHOD: sqlite3
 **
 ** ^This function causes any pending database operation to abort and
 ** return at its earliest opportunity. This routine is typically
@@ -2191,9 +3252,6 @@ SQLITE_API int sqlite3_total_changes(sqlite3*);
 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
 ** SQL statements is a no-op and has no effect on SQL statements
 ** that are started after the sqlite3_interrupt() call returns.
-**
-** If the database connection closes while [sqlite3_interrupt()]
-** is running then bad things will likely happen.
 */
 SQLITE_API void sqlite3_interrupt(sqlite3*);
 
@@ -2236,6 +3294,7 @@ SQLITE_API int sqlite3_complete16(const void *sql);
 /*
 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
 ** KEYWORDS: {busy-handler callback} {busy handler}
+** METHOD: sqlite3
 **
 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
 ** that might be invoked with argument P whenever
@@ -2291,10 +3350,11 @@ SQLITE_API int sqlite3_complete16(const void *sql);
 ** A busy handler must not close the database connection
 ** or [prepared statement] that invoked the busy handler.
 */
-SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
+SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
 
 /*
 ** CAPI3REF: Set A Busy Timeout
+** METHOD: sqlite3
 **
 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
 ** for a specified amount of time when a table is locked.  ^The handler
@@ -2317,6 +3377,7 @@ SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
 
 /*
 ** CAPI3REF: Convenience Routines For Running Queries
+** METHOD: sqlite3
 **
 ** This is a legacy interface that is preserved for backwards compatibility.
 ** Use of this interface is not recommended.
@@ -2402,6 +3463,10 @@ SQLITE_API void sqlite3_free_table(char **result);
 **
 ** These routines are work-alikes of the "printf()" family of functions
 ** from the standard C library.
+** These routines understand most of the common K&R formatting options,
+** plus some additional non-standard formats, detailed below.
+** Note that some of the more obscure formatting options from recent
+** C-library standards are omitted from this implementation.
 **
 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
 ** results into memory obtained from [sqlite3_malloc()].
@@ -2434,7 +3499,7 @@ SQLITE_API void sqlite3_free_table(char **result);
 ** These routines all implement some additional formatting
 ** options that are useful for constructing SQL statements.
 ** All of the usual printf() formatting options apply.  In addition, there
-** is are "%q", "%Q", and "%z" options.
+** is are "%q", "%Q", "%w" and "%z" options.
 **
 ** ^(The %q option works like %s in that it substitutes a nul-terminated
 ** string from the argument list.  But %q also doubles every '\'' character.
@@ -2487,6 +3552,12 @@ SQLITE_API void sqlite3_free_table(char **result);
 ** The code above will render a correct SQL statement in the zSQL
 ** variable even if the zText variable is a NULL pointer.
 **
+** ^(The "%w" formatting option is like "%q" except that it expects to
+** be contained within double-quotes instead of single quotes, and it
+** escapes the double-quote character instead of the single-quote
+** character.)^  The "%w" formatting option is intended for safely inserting
+** table and column names into a constructed SQL statement.
+**
 ** ^(The "%z" formatting option works like "%s" but with the
 ** addition that after the string has been read and copied into
 ** the result, [sqlite3_free()] is called on the input string.)^
@@ -2642,12 +3713,15 @@ SQLITE_API void sqlite3_randomness(int N, void *P);
 
 /*
 ** CAPI3REF: Compile-Time Authorization Callbacks
+** METHOD: sqlite3
+** KEYWORDS: {authorizer callback}
 **
 ** ^This routine registers an authorizer callback with a particular
 ** [database connection], supplied in the first argument.
 ** ^The authorizer callback is invoked as SQL statements are being compiled
 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
-** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
+** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
+** and [sqlite3_prepare16_v3()].  ^At various
 ** points during the compilation process, as logic is being created
 ** to perform various actions, the authorizer callback is invoked to
 ** see if those actions are allowed.  ^The authorizer callback should
@@ -2669,8 +3743,10 @@ SQLITE_API void sqlite3_randomness(int N, void *P);
 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
 ** the particular action to be authorized. ^The third through sixth parameters
-** to the callback are zero-terminated strings that contain additional
-** details about the action to be authorized.
+** to the callback are either NULL pointers or zero-terminated strings
+** that contain additional details about the action to be authorized.
+** Applications must always be prepared to encounter a NULL pointer in any
+** of the third through the sixth parameters of the authorization callback.
 **
 ** ^If the action code is [SQLITE_READ]
 ** and the callback returns [SQLITE_IGNORE] then the
@@ -2679,6 +3755,10 @@ SQLITE_API void sqlite3_randomness(int N, void *P);
 ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
 ** return can be used to deny an untrusted user access to individual
 ** columns of a table.
+** ^When a table is referenced by a [SELECT] but no column values are
+** extracted from that table (for example in a query like
+** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
+** is invoked once for that table with a column name that is an empty string.
 ** ^If the action code is [SQLITE_DELETE] and the callback returns
 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
 ** [truncate optimization] is disabled and all rows are deleted individually.
@@ -2798,6 +3878,10 @@ SQLITE_API int sqlite3_set_authorizer(
 
 /*
 ** CAPI3REF: Tracing And Profiling Functions
+** METHOD: sqlite3
+**
+** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
+** instead of the routines described here.
 **
 ** These routines register callback functions that can be used for
 ** tracing and profiling the execution of SQL statements.
@@ -2824,12 +3908,107 @@ SQLITE_API int sqlite3_set_authorizer(
 ** sqlite3_profile() function is considered experimental and is
 ** subject to change in future versions of SQLite.
 */
-SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
-SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
+SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
+   void(*xTrace)(void*,const char*), void*);
+SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
 
+/*
+** CAPI3REF: SQL Trace Event Codes
+** KEYWORDS: SQLITE_TRACE
+**
+** These constants identify classes of events that can be monitored
+** using the [sqlite3_trace_v2()] tracing logic.  The third argument
+** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of
+** the following constants.  ^The first argument to the trace callback
+** is one of the following constants.
+**
+** New tracing constants may be added in future releases.
+**
+** ^A trace callback has four arguments: xCallback(T,C,P,X).
+** ^The T argument is one of the integer type codes above.
+** ^The C argument is a copy of the context pointer passed in as the
+** fourth argument to [sqlite3_trace_v2()].
+** The P and X arguments are pointers whose meanings depend on T.
+**
+** 

+** [[SQLITE_TRACE_STMT]] 
SQLITE_TRACE_STMT

+** 
^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
+** first begins running and possibly at other times during the
+** execution of the prepared statement, such as at the start of each
+** trigger subprogram. ^The P argument is a pointer to the
+** [prepared statement]. ^The X argument is a pointer to a string which
+** is the unexpanded SQL text of the prepared statement or an SQL comment 
+** that indicates the invocation of a trigger.  ^The callback can compute
+** the same text that would have been returned by the legacy [sqlite3_trace()]
+** interface by using the X argument when X begins with "--" and invoking
+** [sqlite3_expanded_sql(P)] otherwise.
+**
+** [[SQLITE_TRACE_PROFILE]] 
SQLITE_TRACE_PROFILE

+** 
^An SQLITE_TRACE_PROFILE callback provides approximately the same
+** information as is provided by the [sqlite3_profile()] callback.
+** ^The P argument is a pointer to the [prepared statement] and the
+** X argument points to a 64-bit integer which is the estimated of
+** the number of nanosecond that the prepared statement took to run.
+** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
+**
+** [[SQLITE_TRACE_ROW]] 
SQLITE_TRACE_ROW

+** 
^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
+** statement generates a single row of result.  
+** ^The P argument is a pointer to the [prepared statement] and the
+** X argument is unused.
+**
+** [[SQLITE_TRACE_CLOSE]] 
SQLITE_TRACE_CLOSE

+** 
^An SQLITE_TRACE_CLOSE callback is invoked when a database
+** connection closes.
+** ^The P argument is a pointer to the [database connection] object
+** and the X argument is unused.
+** 

+*/
+#define SQLITE_TRACE_STMT       0x01
+#define SQLITE_TRACE_PROFILE    0x02
+#define SQLITE_TRACE_ROW        0x04
+#define SQLITE_TRACE_CLOSE      0x08
+
+/*
+** CAPI3REF: SQL Trace Hook
+** METHOD: sqlite3
+**
+** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
+** function X against [database connection] D, using property mask M
+** and context pointer P.  ^If the X callback is
+** NULL or if the M mask is zero, then tracing is disabled.  The
+** M argument should be the bitwise OR-ed combination of
+** zero or more [SQLITE_TRACE] constants.
+**
+** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 
+** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
+**
+** ^The X callback is invoked whenever any of the events identified by 
+** mask M occur.  ^The integer return value from the callback is currently
+** ignored, though this may change in future releases.  Callback
+** implementations should return zero to ensure future compatibility.
+**
+** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
+** ^The T argument is one of the [SQLITE_TRACE]
+** constants to indicate why the callback was invoked.
+** ^The C argument is a copy of the context pointer.
+** The P and X arguments are pointers whose meanings depend on T.
+**
+** The sqlite3_trace_v2() interface is intended to replace the legacy
+** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
+** are deprecated.
+*/
+SQLITE_API int sqlite3_trace_v2(
+  sqlite3*,
+  unsigned uMask,
+  int(*xCallback)(unsigned,void*,void*,void*),
+  void *pCtx
+);
+
 /*
 ** CAPI3REF: Query Progress Callbacks
+** METHOD: sqlite3
 **
 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
 ** function X to be invoked periodically during long running calls to
@@ -2863,6 +4042,7 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 
 /*
 ** CAPI3REF: Opening A New Database Connection
+** CONSTRUCTOR: sqlite3
 **
 ** ^These routines open an SQLite database file as specified by the 
 ** filename argument. ^The filename argument is interpreted as UTF-8 for
@@ -3148,12 +4328,15 @@ SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int
 
 /*
 ** CAPI3REF: Error Codes And Messages
-**
-** ^The sqlite3_errcode() interface returns the numeric [result code] or
-** [extended result code] for the most recent failed sqlite3_* API call
-** associated with a [database connection]. If a prior API call failed
-** but the most recent API call succeeded, the return value from
-** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
+** METHOD: sqlite3
+**
+** ^If the most recent sqlite3_* API call associated with 
+** [database connection] D failed, then the sqlite3_errcode(D) interface
+** returns the numeric [result code] or [extended result code] for that
+** API call.
+** If the most recent API call was successful,
+** then the return value from sqlite3_errcode() is undefined.
+** ^The sqlite3_extended_errcode()
 ** interface is the same except that it always returns the 
 ** [extended result code] even when extended result codes are
 ** disabled.
@@ -3191,33 +4374,34 @@ SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
 SQLITE_API const char *sqlite3_errstr(int);
 
 /*
-** CAPI3REF: SQL Statement Object
+** CAPI3REF: Prepared Statement Object
 ** KEYWORDS: {prepared statement} {prepared statements}
 **
-** An instance of this object represents a single SQL statement.
-** This object is variously known as a "prepared statement" or a
-** "compiled SQL statement" or simply as a "statement".
+** An instance of this object represents a single SQL statement that
+** has been compiled into binary form and is ready to be evaluated.
+**
+** Think of each SQL statement as a separate computer program.  The
+** original SQL text is source code.  A prepared statement object 
+** is the compiled object code.  All SQL must be converted into a
+** prepared statement before it can be run.
 **
-** The life of a statement object goes something like this:
+** The life-cycle of a prepared statement object usually goes like this:
 **
 ** 
    
-** 
  1.  Create the object using [sqlite3_prepare_v2()] or a related
-**      function.
-** 
  2.  Bind values to [host parameters] using the sqlite3_bind_*()
+** 
  3.  Create the prepared statement object using [sqlite3_prepare_v2()].
+** 
  4.  Bind values to [parameters] using the sqlite3_bind_*()
 **      interfaces.
 ** 
  5.  Run the SQL by calling [sqlite3_step()] one or more times.
-** 
  6.  Reset the statement using [sqlite3_reset()] then go back
+** 
  7.  Reset the prepared statement using [sqlite3_reset()] then go back
 **      to step 2.  Do this zero or more times.
 ** 
  8.  Destroy the object using [sqlite3_finalize()].
 ** 

-**
-** Refer to documentation on individual methods above for additional
-** information.
 */
 typedef struct sqlite3_stmt sqlite3_stmt;
 
 /*
 ** CAPI3REF: Run-time Limits
+** METHOD: sqlite3
 **
 ** ^(This interface allows the size of various constructs to be limited
 ** on a connection by connection basis.  The first parameter is the
@@ -3286,9 +4470,9 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 **
 ** [[SQLITE_LIMIT_VDBE_OP]] ^(
SQLITE_LIMIT_VDBE_OP

 ** 
The maximum number of instructions in a virtual machine program
-** used to implement an SQL statement.  This limit is not currently
-** enforced, though that might be added in some future release of
-** SQLite.
)^
+** used to implement an SQL statement.  If [sqlite3_prepare_v2()] or
+** the equivalent tries to allocate space for more than this many opcodes
+** in a single prepared statement, an SQLITE_NOMEM error is returned.)^
 **
 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(
SQLITE_LIMIT_FUNCTION_ARG

 ** 
The maximum number of arguments on a function.
)^
@@ -3326,32 +4510,68 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 #define SQLITE_LIMIT_TRIGGER_DEPTH            10
 #define SQLITE_LIMIT_WORKER_THREADS           11
 
+/*
+** CAPI3REF: Prepare Flags
+**
+** These constants define various flags that can be passed into
+** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
+** [sqlite3_prepare16_v3()] interfaces.
+**
+** New flags may be added in future releases of SQLite.
+**
+** 

+** [[SQLITE_PREPARE_PERSISTENT]] ^(
SQLITE_PREPARE_PERSISTENT

+** 
The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
+** that the prepared statement will be retained for a long time and
+** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
+** and [sqlite3_prepare16_v3()] assume that the prepared statement will 
+** be used just once or at most a few times and then destroyed using
+** [sqlite3_finalize()] relatively soon. The current implementation acts
+** on this hint by avoiding the use of [lookaside memory] so as not to
+** deplete the limited store of lookaside memory. Future versions of
+** SQLite may act on this hint differently.
+** 

+*/
+#define SQLITE_PREPARE_PERSISTENT              0x01
+
 /*
 ** CAPI3REF: Compiling An SQL Statement
 ** KEYWORDS: {SQL statement compiler}
+** METHOD: sqlite3
+** CONSTRUCTOR: sqlite3_stmt
+**
+** To execute an SQL statement, it must first be compiled into a byte-code
+** program using one of these routines.  Or, in other words, these routines
+** are constructors for the [prepared statement] object.
 **
-** To execute an SQL query, it must first be compiled into a byte-code
-** program using one of these routines.
+** The preferred routine to use is [sqlite3_prepare_v2()].  The
+** [sqlite3_prepare()] interface is legacy and should be avoided.
+** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
+** for special purposes.
+**
+** The use of the UTF-8 interfaces is preferred, as SQLite currently
+** does all parsing using UTF-8.  The UTF-16 interfaces are provided
+** as a convenience.  The UTF-16 interfaces work by converting the
+** input text into UTF-8, then invoking the corresponding UTF-8 interface.
 **
 ** The first argument, "db", is a [database connection] obtained from a
 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
 ** [sqlite3_open16()].  The database connection must not have been closed.
 **
 ** The second argument, "zSql", is the statement to be compiled, encoded
-** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
-** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
-** use UTF-16.
-**
-** ^If the nByte argument is less than zero, then zSql is read up to the
-** first zero terminator. ^If nByte is non-negative, then it is the maximum
-** number of  bytes read from zSql.  ^When nByte is non-negative, the
-** zSql string ends at either the first '\000' or '\u0000' character or
-** the nByte-th byte, whichever comes first. If the caller knows
-** that the supplied string is nul-terminated, then there is a small
-** performance advantage to be gained by passing an nByte parameter that
-** is equal to the number of bytes in the input string including
-** the nul-terminator bytes as this saves SQLite from having to
-** make a copy of the input string.
+** as either UTF-8 or UTF-16.  The sqlite3_prepare(), sqlite3_prepare_v2(),
+** and sqlite3_prepare_v3()
+** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
+** and sqlite3_prepare16_v3() use UTF-16.
+**
+** ^If the nByte argument is negative, then zSql is read up to the
+** first zero terminator. ^If nByte is positive, then it is the
+** number of bytes read from zSql.  ^If nByte is zero, then no prepared
+** statement is generated.
+** If the caller knows that the supplied string is nul-terminated, then
+** there is a small performance advantage to passing an nByte parameter that
+** is the number of bytes in the input string including
+** the nul-terminator.
 **
 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
 ** past the end of the first SQL statement in zSql.  These routines only
@@ -3369,10 +4589,11 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
 ** otherwise an [error code] is returned.
 **
-** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
-** recommended for all new programs. The two older interfaces are retained
-** for backwards compatibility, but their use is discouraged.
-** ^In the "v2" interfaces, the prepared statement
+** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
+** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
+** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
+** are retained for backwards compatibility, but their use is discouraged.
+** ^In the "vX" interfaces, the prepared statement
 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
 ** original SQL text. This causes the [sqlite3_step()] interface to
 ** behave differently in three ways:
@@ -3405,6 +4626,12 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 ** or [GLOB] operator or if the parameter is compared to an indexed column
 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
 ** 
+**
+** 
^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
+** the extra prepFlags parameter, which is a bit array consisting of zero or
+** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags.  ^The
+** sqlite3_prepare_v2() interface works exactly the same as
+** sqlite3_prepare_v3() with a zero prepFlags parameter.
 ** 
 */
 SQLITE_API int sqlite3_prepare(
@@ -3421,6 +4648,14 @@ SQLITE_API int sqlite3_prepare_v2(
   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
 );
+SQLITE_API int sqlite3_prepare_v3(
+  sqlite3 *db,            /* Database handle */
+  const char *zSql,       /* SQL statement, UTF-8 encoded */
+  int nByte,              /* Maximum length of zSql in bytes. */
+  unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
+  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
+);
 SQLITE_API int sqlite3_prepare16(
   sqlite3 *db,            /* Database handle */
   const void *zSql,       /* SQL statement, UTF-16 encoded */
@@ -3435,18 +4670,53 @@ SQLITE_API int sqlite3_prepare16_v2(
   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
 );
+SQLITE_API int sqlite3_prepare16_v3(
+  sqlite3 *db,            /* Database handle */
+  const void *zSql,       /* SQL statement, UTF-16 encoded */
+  int nByte,              /* Maximum length of zSql in bytes. */
+  unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
+  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
+  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
+);
 
 /*
 ** CAPI3REF: Retrieving Statement SQL
-**
-** ^This interface can be used to retrieve a saved copy of the original
-** SQL text used to create a [prepared statement] if that statement was
-** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
+** METHOD: sqlite3_stmt
+**
+** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
+** SQL text used to create [prepared statement] P if P was
+** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
+** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
+** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
+** string containing the SQL text of prepared statement P with
+** [bound parameters] expanded.
+**
+** ^(For example, if a prepared statement is created using the SQL
+** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
+** and parameter :xyz is unbound, then sqlite3_sql() will return
+** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
+** will return "SELECT 2345,NULL".)^
+**
+** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
+** is available to hold the result, or if the result would exceed the
+** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
+**
+** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
+** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
+** option causes sqlite3_expanded_sql() to always return NULL.
+**
+** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
+** automatically freed when the prepared statement is finalized.
+** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
+** is obtained from [sqlite3_malloc()] and must be free by the application
+** by passing it to [sqlite3_free()].
 */
 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
+SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Determine If An SQL Statement Writes The Database
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
 ** and only if the [prepared statement] X makes no direct changes to
@@ -3473,15 +4743,21 @@ SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
 ** sqlite3_stmt_readonly() to return true since, while those statements
 ** change the configuration of a database connection, they do not make 
 ** changes to the content of the database files on disk.
+** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
+** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
+** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
+** sqlite3_stmt_readonly() returns false for those commands.
 */
 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
 ** [prepared statement] S has been stepped at least once using 
-** [sqlite3_step(S)] but has not run to completion and/or has not 
+** [sqlite3_step(S)] but has neither run to completion (returned
+** [SQLITE_DONE] from [sqlite3_step(S)]) nor
 ** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
 ** interface returns false if S is a NULL pointer.  If S is not a 
 ** NULL pointer and is not a pointer to a valid [prepared statement]
@@ -3508,7 +4784,9 @@ SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
 ** Some interfaces require a protected sqlite3_value.  Other interfaces
 ** will accept either a protected or an unprotected sqlite3_value.
 ** Every interface that accepts sqlite3_value arguments specifies
-** whether or not it requires a protected sqlite3_value.
+** whether or not it requires a protected sqlite3_value.  The
+** [sqlite3_value_dup()] interface can be used to construct a new 
+** protected sqlite3_value from an unprotected sqlite3_value.
 **
 ** The terms "protected" and "unprotected" refer to whether or not
 ** a mutex is held.  An internal mutex is held for a protected
@@ -3532,7 +4810,7 @@ SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
 ** interfaces require protected sqlite3_value objects.
 */
-typedef struct Mem sqlite3_value;
+typedef struct sqlite3_value sqlite3_value;
 
 /*
 ** CAPI3REF: SQL Function Context Object
@@ -3552,6 +4830,7 @@ typedef struct sqlite3_context sqlite3_context;
 ** CAPI3REF: Binding Values To Prepared Statements
 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
+** METHOD: sqlite3_stmt
 **
 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
 ** literals may be replaced by a [parameter] that matches one of following
@@ -3633,6 +4912,15 @@ typedef struct sqlite3_context sqlite3_context;
 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
 ** ^A negative value for the zeroblob results in a zero-length BLOB.
 **
+** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
+** [prepared statement] S to have an SQL value of NULL, but to also be
+** associated with the pointer P of type T.  ^D is either a NULL pointer or
+** a pointer to a destructor function for P. ^SQLite will invoke the
+** destructor D with a single argument of P when it is finished using
+** P.  The T parameter should be a static string, preferably a string
+** literal. The sqlite3_bind_pointer() routine is part of the
+** [pointer passing interface] added for SQLite 3.20.0.
+**
 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
 ** for the [prepared statement] or with a prepared statement for which
 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
@@ -3666,10 +4954,13 @@ SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)
 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
                          void(*)(void*), unsigned char encoding);
 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
+SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
+SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
 
 /*
 ** CAPI3REF: Number Of SQL Parameters
+** METHOD: sqlite3_stmt
 **
 ** ^This routine can be used to find the number of [SQL parameters]
 ** in a [prepared statement].  SQL parameters are tokens of the
@@ -3690,6 +4981,7 @@ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Name Of A Host Parameter
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
@@ -3706,8 +4998,8 @@ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
 ** ^If the value N is out of range or if the N-th parameter is
 ** nameless, then NULL is returned.  ^The returned string is
 ** always in UTF-8 encoding even if the named parameter was
-** originally specified as UTF-16 in [sqlite3_prepare16()] or
-** [sqlite3_prepare16_v2()].
+** originally specified as UTF-16 in [sqlite3_prepare16()],
+** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
 **
 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
 ** [sqlite3_bind_parameter_count()], and
@@ -3717,22 +5009,25 @@ SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
 
 /*
 ** CAPI3REF: Index Of A Parameter With A Given Name
+** METHOD: sqlite3_stmt
 **
 ** ^Return the index of an SQL parameter given its name.  ^The
 ** index value returned is suitable for use as the second
 ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
 ** is returned if no matching parameter is found.  ^The parameter
 ** name must be given in UTF-8 even if the original statement
-** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
+** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
+** [sqlite3_prepare16_v3()].
 **
 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
 ** [sqlite3_bind_parameter_count()], and
-** [sqlite3_bind_parameter_index()].
+** [sqlite3_bind_parameter_name()].
 */
 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
 
 /*
 ** CAPI3REF: Reset All Bindings On A Prepared Statement
+** METHOD: sqlite3_stmt
 **
 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
@@ -3742,10 +5037,15 @@ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Number Of Columns In A Result Set
+** METHOD: sqlite3_stmt
 **
 ** ^Return the number of columns in the result set returned by the
-** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
-** statement that does not return data (for example an [UPDATE]).
+** [prepared statement]. ^If this routine returns 0, that means the 
+** [prepared statement] returns no data (for example an [UPDATE]).
+** ^However, just because this routine returns a positive number does not
+** mean that one or more rows of data will be returned.  ^A SELECT statement
+** will always have a positive sqlite3_column_count() but depending on the
+** WHERE clause constraints and the table content, it might return no rows.
 **
 ** See also: [sqlite3_data_count()]
 */
@@ -3753,6 +5053,7 @@ SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Column Names In A Result Set
+** METHOD: sqlite3_stmt
 **
 ** ^These routines return the name assigned to a particular column
 ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
@@ -3782,6 +5083,7 @@ SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
 
 /*
 ** CAPI3REF: Source Of Data In A Query Result
+** METHOD: sqlite3_stmt
 **
 ** ^These routines provide a means to determine the database, table, and
 ** table column that is the origin of a particular result column in
@@ -3834,6 +5136,7 @@ SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
 
 /*
 ** CAPI3REF: Declared Datatype Of A Query Result
+** METHOD: sqlite3_stmt
 **
 ** ^(The first parameter is a [prepared statement].
 ** If this statement is a [SELECT] statement and the Nth column of the
@@ -3866,17 +5169,20 @@ SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
 
 /*
 ** CAPI3REF: Evaluate An SQL Statement
+** METHOD: sqlite3_stmt
 **
-** After a [prepared statement] has been prepared using either
-** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
+** After a [prepared statement] has been prepared using any of
+** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
+** or [sqlite3_prepare16_v3()] or one of the legacy
 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
 ** must be called one or more times to evaluate the statement.
 **
 ** The details of the behavior of the sqlite3_step() interface depend
-** on whether the statement was prepared using the newer "v2" interface
-** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
-** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
-** new "v2" interface is recommended for new applications but the legacy
+** on whether the statement was prepared using the newer "vX" interfaces
+** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
+** [sqlite3_prepare16_v2()] or the older legacy
+** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
+** new "vX" interface is recommended for new applications but the legacy
 ** interface will continue to be supported.
 **
 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
@@ -3922,7 +5228,8 @@ SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
 ** other than [SQLITE_ROW] before any subsequent invocation of
 ** sqlite3_step().  Failure to reset the prepared statement using 
 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
-** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
+** sqlite3_step().  But after [version 3.6.23.1] ([dateof:3.6.23.1]),
+** sqlite3_step() began
 ** calling [sqlite3_reset()] automatically in this circumstance rather
 ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
 ** break because any application that ever receives an SQLITE_MISUSE error
@@ -3936,15 +5243,17 @@ SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
 ** specific [error codes] that better describes the error.
 ** We admit that this is a goofy design.  The problem has been fixed
 ** with the "v2" interface.  If you prepare all of your SQL statements
-** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
+** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
+** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
 ** then the more specific [error codes] are returned directly
-** by sqlite3_step().  The use of the "v2" interface is recommended.
+** by sqlite3_step().  The use of the "vX" interfaces is recommended.
 */
 SQLITE_API int sqlite3_step(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Number of columns in a result set
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
 ** current row of the result set of [prepared statement] P.
@@ -3998,8 +5307,29 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 /*
 ** CAPI3REF: Result Values From A Query
 ** KEYWORDS: {column access functions}
-**
-** These routines form the "result set" interface.
+** METHOD: sqlite3_stmt
+**
+** Summary:
+** 

+** 
sqlite3_column_blob→BLOB result
+** 
sqlite3_column_double→REAL result
+** 
sqlite3_column_int→32-bit INTEGER result
+** 
sqlite3_column_int64→64-bit INTEGER result
+** 
sqlite3_column_text→UTF-8 TEXT result
+** 
sqlite3_column_text16→UTF-16 TEXT result
+** 
sqlite3_column_value→The result as an 
+** [sqlite3_value|unprotected sqlite3_value] object.
+** 
   
+** 
sqlite3_column_bytes→Size of a BLOB
+** or a UTF-8 TEXT result in bytes
+** 
sqlite3_column_bytes16  
+** →  Size of UTF-16
+** TEXT in bytes
+** 
sqlite3_column_type→Default
+** datatype of the result
+** 

+**
+** Details:
 **
 ** ^These routines return information about a single column of the current
 ** result row of a query.  ^In every case the first argument is a pointer
@@ -4022,16 +5352,29 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** are called from a different thread while any of these routines
 ** are pending, then the results are undefined.
 **
+** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
+** each return the value of a result column in a specific data format.  If
+** the result column is not initially in the requested format (for example,
+** if the query returns an integer but the sqlite3_column_text() interface
+** is used to extract the value) then an automatic type conversion is performed.
+**
 ** ^The sqlite3_column_type() routine returns the
 ** [SQLITE_INTEGER | datatype code] for the initial data type
 ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
-** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
-** returned by sqlite3_column_type() is only meaningful if no type
-** conversions have occurred as described below.  After a type conversion,
-** the value returned by sqlite3_column_type() is undefined.  Future
+** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
+** The return value of sqlite3_column_type() can be used to decide which
+** of the first six interface should be used to extract the column value.
+** The value returned by sqlite3_column_type() is only meaningful if no
+** automatic type conversions have occurred for the value in question.  
+** After a type conversion, the result of calling sqlite3_column_type()
+** is undefined, though harmless.  Future
 ** versions of SQLite may change the behavior of sqlite3_column_type()
 ** following a type conversion.
 **
+** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
+** or sqlite3_column_bytes16() interfaces can be used to determine the size
+** of that BLOB or string.
+**
 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
 ** routine returns the number of bytes in that BLOB or string.
 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
@@ -4060,16 +5403,21 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** even empty strings, are always zero-terminated.  ^The return
 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
 **
-** ^The object returned by [sqlite3_column_value()] is an
-** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
-** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
+** Warning: ^The object returned by [sqlite3_column_value()] is an
+** [unprotected sqlite3_value] object.  In a multithreaded environment,
+** an unprotected sqlite3_value object may only be used safely with
+** [sqlite3_bind_value()] and [sqlite3_result_value()].
 ** If the [unprotected sqlite3_value] object returned by
 ** [sqlite3_column_value()] is used in any other way, including calls
 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
-** or [sqlite3_value_bytes()], then the behavior is undefined.
-**
-** These routines attempt to convert the value where appropriate.  ^For
-** example, if the internal representation is FLOAT and a text result
+** or [sqlite3_value_bytes()], the behavior is not threadsafe.
+** Hence, the sqlite3_column_value() interface
+** is normally only useful within the implementation of 
+** [application-defined SQL functions] or [virtual tables], not within
+** top-level application code.
+**
+** The these routines may attempt to convert the datatype of the result.
+** ^For example, if the internal representation is FLOAT and a text result
 ** is requested, [sqlite3_snprintf()] is used internally to perform the
 ** conversion automatically.  ^(The following table details the conversions
 ** that are applied:
@@ -4097,12 +5445,6 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** 
 **
)^ ** -** The table above makes reference to standard C library functions atoi() -** and atof(). SQLite does not really use these functions. It has its -** own equivalent internal routines. The atoi() and atof() names are -** used in the table for brevity and because they are familiar to most -** C programmers. -** ** Note that when type conversions occur, pointers returned by prior ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or ** sqlite3_column_text16() may be invalidated. @@ -4127,7 +5469,7 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); ** of conversion are done in place when it is possible, but sometimes they ** are not possible and in those cases prior pointers are invalidated. ** -** The safest and easiest to remember policy is to invoke these routines +** The safest policy is to invoke these routines ** in one of the following ways: ** **
    @@ -4147,7 +5489,7 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); ** ^The pointers returned are valid until a type conversion occurs as ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or ** [sqlite3_finalize()] is called. ^The memory space used to hold strings -** and BLOBs is freed automatically. Do not pass the pointers returned +** and BLOBs is freed automatically. Do not pass the pointers returned ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into ** [sqlite3_free()]. ** @@ -4158,18 +5500,19 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); ** [SQLITE_NOMEM].)^ */ SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); -SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); -SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); -SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); +SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); /* ** CAPI3REF: Destroy A Prepared Statement Object +** DESTRUCTOR: sqlite3_stmt ** ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. ** ^If the most recent evaluation of the statement encountered no errors @@ -4197,6 +5540,7 @@ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); /* ** CAPI3REF: Reset A Prepared Statement Object +** METHOD: sqlite3_stmt ** ** The sqlite3_reset() function is called to reset a [prepared statement] ** object back to its initial state, ready to be re-executed. @@ -4226,6 +5570,7 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); ** KEYWORDS: {function creation routines} ** KEYWORDS: {application-defined SQL function} ** KEYWORDS: {application-defined SQL functions} +** METHOD: sqlite3 ** ** ^These functions (collectively known as "function creation routines") ** are used to add SQL functions or aggregates or to redefine the behavior @@ -4380,8 +5725,8 @@ SQLITE_API int sqlite3_create_function_v2( ** These functions are [deprecated]. In order to maintain ** backwards compatibility with older code, these functions continue ** to be supported. However, new applications should avoid -** the use of these functions. To help encourage people to avoid -** using these functions, we are not going to tell you what they do. +** the use of these functions. To encourage programmers to avoid +** these functions, we will not explain what they do. */ #ifndef SQLITE_OMIT_DEPRECATED SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); @@ -4394,23 +5739,43 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6 #endif /* -** CAPI3REF: Obtaining SQL Function Parameter Values -** -** The C-language implementation of SQL functions and aggregates uses -** this set of interface routines to access the parameter values on -** the function or aggregate. -** -** The xFunc (for scalar functions) or xStep (for aggregates) parameters -** to [sqlite3_create_function()] and [sqlite3_create_function16()] -** define callbacks that implement the SQL functions and aggregates. -** The 3rd parameter to these callbacks is an array of pointers to -** [protected sqlite3_value] objects. There is one [sqlite3_value] object for -** each parameter to the SQL function. These routines are used to -** extract values from the [sqlite3_value] objects. +** CAPI3REF: Obtaining SQL Values +** METHOD: sqlite3_value +** +** Summary: +**
    +**
    sqlite3_value_blob→BLOB value +**
    sqlite3_value_double→REAL value +**
    sqlite3_value_int→32-bit INTEGER value +**
    sqlite3_value_int64→64-bit INTEGER value +**
    sqlite3_value_pointer→Pointer value +**
    sqlite3_value_text→UTF-8 TEXT value +**
    sqlite3_value_text16→UTF-16 TEXT value in +** the native byteorder +**
    sqlite3_value_text16be→UTF-16be TEXT value +**
    sqlite3_value_text16le→UTF-16le TEXT value +**
        +**
    sqlite3_value_bytes→Size of a BLOB +** or a UTF-8 TEXT in bytes +**
    sqlite3_value_bytes16   +** →  Size of UTF-16 +** TEXT in bytes +**
    sqlite3_value_type→Default +** datatype of the value +**
    sqlite3_value_numeric_type   +** →  Best numeric datatype of the value +**
    +** +** Details: +** +** These routines extract type, size, and content information from +** [protected sqlite3_value] objects. Protected sqlite3_value objects +** are used to pass parameter information into implementation of +** [application-defined SQL functions] and [virtual tables]. ** ** These routines work only with [protected sqlite3_value] objects. ** Any attempt to use these routines on an [unprotected sqlite3_value] -** object results in undefined behavior. +** is not threadsafe. ** ** ^These routines work just like the corresponding [column access functions] ** except that these routines take a single [protected sqlite3_value] object @@ -4421,6 +5786,24 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces ** extract UTF-16 strings as big-endian and little-endian respectively. ** +** ^If [sqlite3_value] object V was initialized +** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] +** and if X and Y are strings that compare equal according to strcmp(X,Y), +** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, +** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() +** routine is part of the [pointer passing interface] added for SQLite 3.20.0. +** +** ^(The sqlite3_value_type(V) interface returns the +** [SQLITE_INTEGER | datatype code] for the initial datatype of the +** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], +** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ +** Other interfaces might change the datatype for an sqlite3_value object. +** For example, if the datatype is initially SQLITE_INTEGER and +** sqlite3_value_text(V) is called to extract a text value for that +** integer, then subsequent calls to sqlite3_value_type(V) might return +** SQLITE_TEXT. Whether or not a persistent internal datatype conversion +** occurs is undefined and may change from one release of SQLite to the next. +** ** ^(The sqlite3_value_numeric_type() interface attempts to apply ** numeric affinity to the value. This means that an attempt is ** made to convert the value to an integer or floating point. If @@ -4439,20 +5822,51 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6 ** the SQL function that supplied the [sqlite3_value*] parameters. */ SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); -SQLITE_API int sqlite3_value_bytes(sqlite3_value*); -SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); SQLITE_API double sqlite3_value_double(sqlite3_value*); SQLITE_API int sqlite3_value_int(sqlite3_value*); SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); +SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); +SQLITE_API int sqlite3_value_bytes(sqlite3_value*); +SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); SQLITE_API int sqlite3_value_type(sqlite3_value*); SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); +/* +** CAPI3REF: Finding The Subtype Of SQL Values +** METHOD: sqlite3_value +** +** The sqlite3_value_subtype(V) function returns the subtype for +** an [application-defined SQL function] argument V. The subtype +** information can be used to pass a limited amount of context from +** one SQL function to another. Use the [sqlite3_result_subtype()] +** routine to set the subtype for the return value of an SQL function. +*/ +SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); + +/* +** CAPI3REF: Copy And Free SQL Values +** METHOD: sqlite3_value +** +** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] +** object D and returns a pointer to that copy. ^The [sqlite3_value] returned +** is a [protected sqlite3_value] object even if the input is not. +** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a +** memory allocation fails. +** +** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object +** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer +** then sqlite3_value_free(V) is a harmless no-op. +*/ +SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); +SQLITE_API void sqlite3_value_free(sqlite3_value*); + /* ** CAPI3REF: Obtain Aggregate Function Context +** METHOD: sqlite3_context ** ** Implementations of aggregate SQL functions use this ** routine to allocate memory for storing their state. @@ -4497,6 +5911,7 @@ SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); /* ** CAPI3REF: User Data For Functions +** METHOD: sqlite3_context ** ** ^The sqlite3_user_data() interface returns a copy of ** the pointer that was the pUserData parameter (the 5th parameter) @@ -4511,6 +5926,7 @@ SQLITE_API void *sqlite3_user_data(sqlite3_context*); /* ** CAPI3REF: Database Connection For Functions +** METHOD: sqlite3_context ** ** ^The sqlite3_context_db_handle() interface returns a copy of ** the pointer to the [database connection] (the 1st parameter) @@ -4522,6 +5938,7 @@ SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); /* ** CAPI3REF: Function Auxiliary Data +** METHOD: sqlite3_context ** ** These functions may be used by (non-aggregate) SQL functions to ** associate metadata with argument values. If the same value is passed to @@ -4534,10 +5951,11 @@ SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); ** the compiled regular expression can be reused on multiple ** invocations of the same function. ** -** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata -** associated by the sqlite3_set_auxdata() function with the Nth argument -** value to the application-defined function. ^If there is no metadata -** associated with the function argument, this sqlite3_get_auxdata() interface +** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata +** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument +** value to the application-defined function. ^N is zero for the left-most +** function argument. ^If there is no metadata +** associated with the function argument, the sqlite3_get_auxdata(C,N) interface ** returns a NULL pointer. ** ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th @@ -4549,12 +5967,13 @@ SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); ** SQLite will invoke the destructor function X with parameter P exactly ** once, when the metadata is discarded. ** SQLite is free to discard the metadata at any time, including:
      -**
    • when the corresponding function parameter changes, or -**
    • when [sqlite3_reset()] or [sqlite3_finalize()] is called for the -** SQL statement, or -**
    • when sqlite3_set_auxdata() is invoked again on the same parameter, or -**
    • during the original sqlite3_set_auxdata() call when a memory -** allocation error occurs.
    )^ +**
  • ^(when the corresponding function parameter changes)^, or +**
  • ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the +** SQL statement)^, or +**
  • ^(when sqlite3_set_auxdata() is invoked again on the same +** parameter)^, or +**
  • ^(during the original sqlite3_set_auxdata() call when a memory +** allocation error occurs.)^
** ** Note the last bullet in particular. The destructor X in ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the @@ -4567,6 +5986,10 @@ SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); ** function parameters that are compile-time constants, including literal ** values and [parameters] and expressions composed from the same.)^ ** +** The value of the N parameter to these interfaces should be non-negative. +** Future enhancements may make use of negative N values to define new +** kinds of function caching behavior. +** ** These routines must be called from the same thread in which ** the SQL function is running. */ @@ -4594,6 +6017,7 @@ typedef void (*sqlite3_destructor_type)(void*); /* ** CAPI3REF: Setting The Result Of An SQL Function +** METHOD: sqlite3_context ** ** These routines are used by the xFunc or xFinal callbacks that ** implement SQL functions and aggregates. See @@ -4609,9 +6033,9 @@ typedef void (*sqlite3_destructor_type)(void*); ** to by the second parameter and which is N bytes long where N is the ** third parameter. ** -** ^The sqlite3_result_zeroblob() interfaces set the result of -** the application-defined function to be a BLOB containing all zero -** bytes and N bytes in size, where N is the value of the 2nd parameter. +** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) +** interfaces set the result of the application-defined function to be +** a BLOB containing all zero bytes and N bytes in size. ** ** ^The sqlite3_result_double() interface sets the result from ** an application-defined function to be a floating point value specified @@ -4689,11 +6113,11 @@ typedef void (*sqlite3_destructor_type)(void*); ** when it has finished using that result. ** ^If the 4th parameter to the sqlite3_result_text* interfaces ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT -** then SQLite makes a copy of the result into space obtained from +** then SQLite makes a copy of the result into space obtained ** from [sqlite3_malloc()] before it returns. ** ** ^The sqlite3_result_value() interface sets the result of -** the application-defined function to be a copy the +** the application-defined function to be a copy of the ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] ** so that the [sqlite3_value] specified in the parameter may change or @@ -4702,6 +6126,17 @@ typedef void (*sqlite3_destructor_type)(void*); ** [unprotected sqlite3_value] object is required, so either ** kind of [sqlite3_value] object can be used with this interface. ** +** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an +** SQL NULL value, just like [sqlite3_result_null(C)], except that it +** also associates the host-language pointer P or type T with that +** NULL value such that the pointer can be retrieved within an +** [application-defined SQL function] using [sqlite3_value_pointer()]. +** ^If the D parameter is not NULL, then it is a pointer to a destructor +** for the P parameter. ^SQLite invokes D with P as its only argument +** when SQLite is finished with P. The T parameter should be a static +** string and preferably a string literal. The sqlite3_result_pointer() +** routine is part of the [pointer passing interface] added for SQLite 3.20.0. +** ** If these routines are called from within the different thread ** than the one containing the application-defined function that received ** the [sqlite3_context] pointer, the results are undefined. @@ -4725,10 +6160,28 @@ SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(* SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); +SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); +SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); + + +/* +** CAPI3REF: Setting The Subtype Of An SQL Function +** METHOD: sqlite3_context +** +** The sqlite3_result_subtype(C,T) function causes the subtype of +** the result from the [application-defined SQL function] with +** [sqlite3_context] C to be the value T. Only the lower 8 bits +** of the subtype T are preserved in current versions of SQLite; +** higher order bits are discarded. +** The number of subtype bytes preserved by SQLite might increase +** in future releases of SQLite. +*/ +SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); /* ** CAPI3REF: Define New Collating Sequences +** METHOD: sqlite3 ** ** ^These functions add, remove, or modify a [collation] associated ** with the [database connection] specified as the first argument. @@ -4831,6 +6284,7 @@ SQLITE_API int sqlite3_create_collation16( /* ** CAPI3REF: Collation Needed Callbacks +** METHOD: sqlite3 ** ** ^To avoid having to register all collation sequences before a database ** can be used, a single callback function may be registered with the @@ -5038,6 +6492,7 @@ SQLITE_API char *sqlite3_data_directory; /* ** CAPI3REF: Test For Auto-Commit Mode ** KEYWORDS: {autocommit mode} +** METHOD: sqlite3 ** ** ^The sqlite3_get_autocommit() interface returns non-zero or ** zero if the given database connection is or is not in autocommit mode, @@ -5060,6 +6515,7 @@ SQLITE_API int sqlite3_get_autocommit(sqlite3*); /* ** CAPI3REF: Find The Database Handle Of A Prepared Statement +** METHOD: sqlite3_stmt ** ** ^The sqlite3_db_handle interface returns the [database connection] handle ** to which a [prepared statement] belongs. ^The [database connection] @@ -5072,6 +6528,7 @@ SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); /* ** CAPI3REF: Return The Filename For A Database Connection +** METHOD: sqlite3 ** ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename ** associated with database N of connection D. ^The main database file @@ -5088,6 +6545,7 @@ SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); /* ** CAPI3REF: Determine if a database is read-only +** METHOD: sqlite3 ** ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N ** of connection D is read-only, 0 if it is read/write, or -1 if N is not @@ -5097,6 +6555,7 @@ SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); /* ** CAPI3REF: Find the next prepared statement +** METHOD: sqlite3 ** ** ^This interface returns a pointer to the next [prepared statement] after ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL @@ -5112,6 +6571,7 @@ SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); /* ** CAPI3REF: Commit And Rollback Notification Callbacks +** METHOD: sqlite3 ** ** ^The sqlite3_commit_hook() interface registers a callback ** function to be invoked whenever a transaction is [COMMIT | committed]. @@ -5161,11 +6621,12 @@ SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); /* ** CAPI3REF: Data Change Notification Callbacks +** METHOD: sqlite3 ** ** ^The sqlite3_update_hook() interface registers a callback function ** with the [database connection] identified by the first argument ** to be invoked whenever a row is updated, inserted or deleted in -** a rowid table. +** a [rowid table]. ** ^Any callback set by a previous call to this function ** for the same database connection is overridden. ** @@ -5186,7 +6647,7 @@ SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. ** ** ^In the current implementation, the update hook -** is not invoked when duplication rows are deleted because of an +** is not invoked when conflicting rows are deleted because of an ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook ** invoked when rows are deleted using the [truncate optimization]. ** The exceptions defined in this paragraph might change in a future @@ -5204,8 +6665,8 @@ SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); ** on the same [database connection] D, or NULL for ** the first call on D. ** -** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] -** interfaces. +** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], +** and [sqlite3_preupdate_hook()] interfaces. */ SQLITE_API void *sqlite3_update_hook( sqlite3*, @@ -5222,7 +6683,8 @@ SQLITE_API void *sqlite3_update_hook( ** and disabled if the argument is false.)^ ** ** ^Cache sharing is enabled and disabled for an entire process. -** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, +** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). +** In prior versions of SQLite, ** sharing was enabled or disabled for each thread separately. ** ** ^(The cache sharing mode set by this interface effects all subsequent @@ -5237,6 +6699,11 @@ SQLITE_API void *sqlite3_update_hook( ** future releases of SQLite. Applications that care about shared ** cache setting should set it explicitly. ** +** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 +** and will always return SQLITE_MISUSE. On those systems, +** shared cache mode should be enabled per-database connection via +** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. +** ** This interface is threadsafe on processors where writing a ** 32-bit integer is atomic. ** @@ -5262,6 +6729,7 @@ SQLITE_API int sqlite3_release_memory(int); /* ** CAPI3REF: Free Memory Used By A Database Connection +** METHOD: sqlite3 ** ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap ** memory as possible from database connection D. Unlike the @@ -5310,7 +6778,8 @@ SQLITE_API int sqlite3_db_release_memory(sqlite3*); ** from the heap. ** )^ ** -** Beginning with SQLite version 3.7.3, the soft heap limit is enforced +** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), +** the soft heap limit is enforced ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], ** the soft heap limit is enforced on every memory allocation. Without @@ -5339,6 +6808,7 @@ SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); /* ** CAPI3REF: Extract Metadata About A Column Of A Table +** METHOD: sqlite3 ** ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns ** information about column C of table T in database D @@ -5348,9 +6818,11 @@ SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); ** column exists. ^The sqlite3_table_column_metadata() interface returns ** SQLITE_ERROR and if the specified column does not exist. ** ^If the column-name parameter to sqlite3_table_column_metadata() is a -** NULL pointer, then this routine simply checks for the existance of the +** NULL pointer, then this routine simply checks for the existence of the ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it -** does not. +** does not. If the table name parameter T in a call to +** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is +** undefined behavior. ** ** ^The column is identified by the second, third and fourth parameters to ** this function. ^(The second parameter is either the name of the database @@ -5417,6 +6889,7 @@ SQLITE_API int sqlite3_table_column_metadata( /* ** CAPI3REF: Load An Extension +** METHOD: sqlite3 ** ** ^This interface loads an SQLite extension library from the named file. ** @@ -5444,9 +6917,18 @@ SQLITE_API int sqlite3_table_column_metadata( ** should free this memory by calling [sqlite3_free()]. ** ** ^Extension loading must be enabled using -** [sqlite3_enable_load_extension()] prior to calling this API, +** [sqlite3_enable_load_extension()] or +** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) +** prior to calling this API, ** otherwise an error will be returned. ** +** Security warning: It is recommended that the +** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this +** interface. The use of the [sqlite3_enable_load_extension()] interface +** should be avoided. This will keep the SQL function [load_extension()] +** disabled and prevent SQL injections from giving attackers +** access to extension loading capabilities. +** ** See also the [load_extension() SQL function]. */ SQLITE_API int sqlite3_load_extension( @@ -5458,6 +6940,7 @@ SQLITE_API int sqlite3_load_extension( /* ** CAPI3REF: Enable Or Disable Extension Loading +** METHOD: sqlite3 ** ** ^So as not to open security holes in older applications that are ** unprepared to deal with [extension loading], and as a means of disabling @@ -5468,6 +6951,17 @@ SQLITE_API int sqlite3_load_extension( ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 ** to turn extension loading on and call it with onoff==0 to turn ** it back off again. +** +** ^This interface enables or disables both the C-API +** [sqlite3_load_extension()] and the SQL function [load_extension()]. +** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) +** to enable or disable only the C-API.)^ +** +** Security warning: It is recommended that extension loading +** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method +** rather than this interface, so the [load_extension()] SQL function +** remains disabled. This will prevent SQL injections from giving attackers +** access to extension loading capabilities. */ SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); @@ -5481,7 +6975,7 @@ SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); ** ** ^(Even though the function prototype shows that xEntryPoint() takes ** no arguments and returns void, SQLite invokes xEntryPoint() with three -** arguments and expects and integer result as if the signature of the +** arguments and expects an integer result as if the signature of the ** entry point where as follows: ** ** 
@@ -5507,7 +7001,7 @@ SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
 ** See also: [sqlite3_reset_auto_extension()]
 ** and [sqlite3_cancel_auto_extension()]
 */
-SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
+SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
 
 /*
 ** CAPI3REF: Cancel Automatic Extension Loading
@@ -5519,7 +7013,7 @@ SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
 ** unregistered and it returns 0 if X was not on the list of initialization
 ** routines.
 */
-SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
+SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
 
 /*
 ** CAPI3REF: Reset Automatic Extension Loading
@@ -5629,6 +7123,17 @@ struct sqlite3_module {
 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
 **
+** The colUsed field indicates which columns of the virtual table may be
+** required by the current scan. Virtual table columns are numbered from
+** zero in the order in which they appear within the CREATE TABLE statement
+** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
+** the corresponding bit is set within the colUsed mask if the column may be
+** required by SQLite. If the table has at least 64 columns and any column
+** to the right of the first 63 is required, then bit 63 of colUsed is also
+** set. In other words, column iCol may be required if the expression
+** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 
+** non-zero.
+**
 ** The [xBestIndex] method must fill aConstraintUsage[] with information
 ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
 ** the right-hand side of the corresponding aConstraint[] is evaluated
@@ -5654,19 +7159,39 @@ struct sqlite3_module {
 ** ^The estimatedRows value is an estimate of the number of rows that
 ** will be returned by the strategy.
 **
+** The xBestIndex method may optionally populate the idxFlags field with a 
+** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
+** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
+** assumes that the strategy may visit at most one row. 
+**
+** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
+** SQLite also assumes that if a call to the xUpdate() method is made as
+** part of the same statement to delete or update a virtual table row and the
+** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
+** any database changes. In other words, if the xUpdate() returns
+** SQLITE_CONSTRAINT, the database contents must be exactly as they were
+** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
+** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
+** the xUpdate method are automatically rolled back by SQLite.
+**
 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
-** structure for SQLite version 3.8.2. If a virtual table extension is
+** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 
+** If a virtual table extension is
 ** used with an SQLite version earlier than 3.8.2, the results of attempting 
 ** to read or write the estimatedRows field are undefined (but are likely 
 ** to included crashing the application). The estimatedRows field should
 ** therefore only be used if [sqlite3_libversion_number()] returns a
-** value greater than or equal to 3008002.
+** value greater than or equal to 3008002. Similarly, the idxFlags field
+** was added for [version 3.9.0] ([dateof:3.9.0]). 
+** It may therefore only be used if
+** sqlite3_libversion_number() returns a value greater than or equal to
+** 3009000.
 */
 struct sqlite3_index_info {
   /* Inputs */
   int nConstraint;           /* Number of entries in aConstraint */
   struct sqlite3_index_constraint {
-     int iColumn;              /* Column on left-hand side of constraint */
+     int iColumn;              /* Column constrained.  -1 for ROWID */
      unsigned char op;         /* Constraint operator */
      unsigned char usable;     /* True if this constraint is usable */
      int iTermOffset;          /* Used internally - xBestIndex should ignore */
@@ -5688,8 +7213,17 @@ struct sqlite3_index_info {
   double estimatedCost;           /* Estimated cost of using this index */
   /* Fields below are only available in SQLite 3.8.2 and later */
   sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
+  /* Fields below are only available in SQLite 3.9.0 and later */
+  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
+  /* Fields below are only available in SQLite 3.10.0 and later */
+  sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
 };
 
+/*
+** CAPI3REF: Virtual Table Scan Flags
+*/
+#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */
+
 /*
 ** CAPI3REF: Virtual Table Constraint Operator Codes
 **
@@ -5698,15 +7232,19 @@ struct sqlite3_index_info {
 ** an operator that is part of a constraint term in the wHERE clause of
 ** a query that uses a [virtual table].
 */
-#define SQLITE_INDEX_CONSTRAINT_EQ    2
-#define SQLITE_INDEX_CONSTRAINT_GT    4
-#define SQLITE_INDEX_CONSTRAINT_LE    8
-#define SQLITE_INDEX_CONSTRAINT_LT    16
-#define SQLITE_INDEX_CONSTRAINT_GE    32
-#define SQLITE_INDEX_CONSTRAINT_MATCH 64
+#define SQLITE_INDEX_CONSTRAINT_EQ      2
+#define SQLITE_INDEX_CONSTRAINT_GT      4
+#define SQLITE_INDEX_CONSTRAINT_LE      8
+#define SQLITE_INDEX_CONSTRAINT_LT     16
+#define SQLITE_INDEX_CONSTRAINT_GE     32
+#define SQLITE_INDEX_CONSTRAINT_MATCH  64
+#define SQLITE_INDEX_CONSTRAINT_LIKE   65
+#define SQLITE_INDEX_CONSTRAINT_GLOB   66
+#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
 
 /*
 ** CAPI3REF: Register A Virtual Table Implementation
+** METHOD: sqlite3
 **
 ** ^These routines are used to register a new [virtual table module] name.
 ** ^Module names must be registered before
@@ -5764,7 +7302,7 @@ SQLITE_API int sqlite3_create_module_v2(
 */
 struct sqlite3_vtab {
   const sqlite3_module *pModule;  /* The module for this virtual table */
-  int nRef;                       /* NO LONGER USED */
+  int nRef;                       /* Number of open cursors */
   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
   /* Virtual table implementations will typically add additional fields */
 };
@@ -5803,6 +7341,7 @@ SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
 
 /*
 ** CAPI3REF: Overload A Function For A Virtual Table
+** METHOD: sqlite3
 **
 ** ^(Virtual tables can provide alternative implementations of functions
 ** using the [xFindFunction] method of the [virtual table module].  
@@ -5845,6 +7384,8 @@ typedef struct sqlite3_blob sqlite3_blob;
 
 /*
 ** CAPI3REF: Open A BLOB For Incremental I/O
+** METHOD: sqlite3
+** CONSTRUCTOR: sqlite3_blob
 **
 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
 ** in row iRow, column zColumn, table zTable in database zDb;
@@ -5890,6 +7431,12 @@ typedef struct sqlite3_blob sqlite3_blob;
 ** [database connection] error code and message accessible via 
 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 
 **
+** A BLOB referenced by sqlite3_blob_open() may be read using the
+** [sqlite3_blob_read()] interface and modified by using
+** [sqlite3_blob_write()].  The [BLOB handle] can be moved to a
+** different row of the same table using the [sqlite3_blob_reopen()]
+** interface.  However, the column, table, or database of a [BLOB handle]
+** cannot be changed after the [BLOB handle] is opened.
 **
 ** ^(If the row that a BLOB handle points to is modified by an
 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
@@ -5913,6 +7460,10 @@ typedef struct sqlite3_blob sqlite3_blob;
 **
 ** To avoid a resource leak, every open [BLOB handle] should eventually
 ** be released by a call to [sqlite3_blob_close()].
+**
+** See also: [sqlite3_blob_close()],
+** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
+** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
 */
 SQLITE_API int sqlite3_blob_open(
   sqlite3*,
@@ -5926,12 +7477,13 @@ SQLITE_API int sqlite3_blob_open(
 
 /*
 ** CAPI3REF: Move a BLOB Handle to a New Row
+** METHOD: sqlite3_blob
 **
-** ^This function is used to move an existing blob handle so that it points
+** ^This function is used to move an existing [BLOB handle] so that it points
 ** to a different row of the same database table. ^The new row is identified
 ** by the rowid value passed as the second argument. Only the row can be
 ** changed. ^The database, table and column on which the blob handle is open
-** remain the same. Moving an existing blob handle to a new row can be
+** remain the same. Moving an existing [BLOB handle] to a new row is
 ** faster than closing the existing handle and opening a new one.
 **
 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
@@ -5946,10 +7498,11 @@ SQLITE_API int sqlite3_blob_open(
 **
 ** ^This function sets the database handle error code and message.
 */
-SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
+SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
 
 /*
 ** CAPI3REF: Close A BLOB Handle
+** DESTRUCTOR: sqlite3_blob
 **
 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
 ** unconditionally.  Even if this routine returns an error code, the 
@@ -5972,6 +7525,7 @@ SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
 
 /*
 ** CAPI3REF: Return The Size Of An Open BLOB
+** METHOD: sqlite3_blob
 **
 ** ^Returns the size in bytes of the BLOB accessible via the 
 ** successfully opened [BLOB handle] in its only argument.  ^The
@@ -5987,6 +7541,7 @@ SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
 
 /*
 ** CAPI3REF: Read Data From A BLOB Incrementally
+** METHOD: sqlite3_blob
 **
 ** ^(This function is used to read data from an open [BLOB handle] into a
 ** caller-supplied buffer. N bytes of data are copied into buffer Z
@@ -6015,6 +7570,7 @@ SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
 
 /*
 ** CAPI3REF: Write Data Into A BLOB Incrementally
+** METHOD: sqlite3_blob
 **
 ** ^(This function is used to write data into an open [BLOB handle] from a
 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
@@ -6138,6 +7694,9 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 ** 
  •   SQLITE_MUTEX_STATIC_APP1
 ** 
  •   SQLITE_MUTEX_STATIC_APP2
 ** 
  •   SQLITE_MUTEX_STATIC_APP3
+** 
  •   SQLITE_MUTEX_STATIC_VFS1
+** 
  •   SQLITE_MUTEX_STATIC_VFS2
+** 
  •   SQLITE_MUTEX_STATIC_VFS3
 ** 
 **
 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
@@ -6332,16 +7891,20 @@ SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
 #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
 #define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
 #define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
-#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
+#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_randomness() */
 #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
 #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
 #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
 #define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
 #define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
 #define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
+#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
+#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
+#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */
 
 /*
 ** CAPI3REF: Retrieve the mutex for a database connection
+** METHOD: sqlite3
 **
 ** ^This interface returns a pointer the [sqlite3_mutex] object that 
 ** serializes access to the [database connection] given in the argument
@@ -6353,6 +7916,7 @@ SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
 
 /*
 ** CAPI3REF: Low-Level Control Of Database Files
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_file_control()] interface makes a direct call to the
 ** xFileControl method for the [sqlite3_io_methods] object associated
@@ -6431,17 +7995,19 @@ SQLITE_API int sqlite3_test_control(int op, ...);
 #define SQLITE_TESTCTRL_SCRATCHMALLOC           17
 #define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
 #define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
+#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD    19
 #define SQLITE_TESTCTRL_NEVER_CORRUPT           20
 #define SQLITE_TESTCTRL_VDBE_COVERAGE           21
 #define SQLITE_TESTCTRL_BYTEORDER               22
 #define SQLITE_TESTCTRL_ISINIT                  23
 #define SQLITE_TESTCTRL_SORTER_MMAP             24
-#define SQLITE_TESTCTRL_LAST                    24
+#define SQLITE_TESTCTRL_IMPOSTER                25
+#define SQLITE_TESTCTRL_LAST                    25
 
 /*
 ** CAPI3REF: SQLite Runtime Status
 **
-** ^This interface is used to retrieve runtime status information
+** ^These interfaces are used to retrieve runtime status information
 ** about the performance of SQLite, and optionally to reset various
 ** highwater marks.  ^The first argument is an integer code for
 ** the specific parameter to measure.  ^(Recognized integer codes
@@ -6455,19 +8021,22 @@ SQLITE_API int sqlite3_test_control(int op, ...);
 ** ^(Other parameters record only the highwater mark and not the current
 ** value.  For these latter parameters nothing is written into *pCurrent.)^
 **
-** ^The sqlite3_status() routine returns SQLITE_OK on success and a
-** non-zero [error code] on failure.
+** ^The sqlite3_status() and sqlite3_status64() routines return
+** SQLITE_OK on success and a non-zero [error code] on failure.
 **
-** This routine is threadsafe but is not atomic.  This routine can be
-** called while other threads are running the same or different SQLite
-** interfaces.  However the values returned in *pCurrent and
-** *pHighwater reflect the status of SQLite at different points in time
-** and it is possible that another thread might change the parameter
-** in between the times when *pCurrent and *pHighwater are written.
+** If either the current value or the highwater mark is too large to
+** be represented by a 32-bit integer, then the values returned by
+** sqlite3_status() are undefined.
 **
 ** See also: [sqlite3_db_status()]
 */
 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
+SQLITE_API int sqlite3_status64(
+  int op,
+  sqlite3_int64 *pCurrent,
+  sqlite3_int64 *pHighwater,
+  int resetFlag
+);
 
 
 /*
@@ -6546,7 +8115,8 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 ** The value written into the *pCurrent parameter is undefined.)^
 **
 ** [[SQLITE_STATUS_PARSER_STACK]] ^(
    SQLITE_STATUS_PARSER_STACK
    
-** 
    This parameter records the deepest parser stack.  It is only
+** 
    The *pHighwater parameter records the deepest parser stack. 
+** The *pCurrent value is undefined.  The *pHighwater value is only
 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].
    )^
 ** 
 **
@@ -6565,6 +8135,7 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 
 /*
 ** CAPI3REF: Database Connection Status
+** METHOD: sqlite3
 **
 ** ^This interface is used to retrieve runtime status information 
 ** about a single [database connection].  ^The first argument is the
@@ -6631,6 +8202,18 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 ** memory used by all pager caches associated with the database connection.)^
 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
 **
+** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 
+** ^(
    SQLITE_DBSTATUS_CACHE_USED_SHARED
    
+** 
    This parameter is similar to DBSTATUS_CACHE_USED, except that if a
+** pager cache is shared between two or more connections the bytes of heap
+** memory used by that pager cache is divided evenly between the attached
+** connections.)^  In other words, if none of the pager caches associated
+** with the database connection are shared, this request returns the same
+** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
+** shared, the value returned by this call will be smaller than that returned
+** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
+** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
+**
 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(
    SQLITE_DBSTATUS_SCHEMA_USED
    
 ** 
    This parameter returns the approximate number of bytes of heap
 ** memory used to store the schema for all databases associated
@@ -6688,11 +8271,13 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 #define SQLITE_DBSTATUS_CACHE_MISS           8
 #define SQLITE_DBSTATUS_CACHE_WRITE          9
 #define SQLITE_DBSTATUS_DEFERRED_FKS        10
-#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
+#define SQLITE_DBSTATUS_CACHE_USED_SHARED   11
+#define SQLITE_DBSTATUS_MAX                 11   /* Largest defined DBSTATUS */
 
 
 /*
 ** CAPI3REF: Prepared Statement Status
+** METHOD: sqlite3_stmt
 **
 ** ^(Each prepared statement maintains various
 ** [SQLITE_STMTSTATUS counters] that measure the number
@@ -6750,6 +8335,24 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 ** used as a proxy for the total work done by the prepared statement.
 ** If the number of virtual machine operations exceeds 2147483647
 ** then the value returned by this statement status code is undefined.
+**
+** [[SQLITE_STMTSTATUS_REPREPARE]] 
    SQLITE_STMTSTATUS_REPREPARE
    
+** 
    ^This is the number of times that the prepare statement has been
+** automatically regenerated due to schema changes or change to 
+** [bound parameters] that might affect the query plan.
+**
+** [[SQLITE_STMTSTATUS_RUN]] 
    SQLITE_STMTSTATUS_RUN
    
+** 
    ^This is the number of times that the prepared statement has
+** been run.  A single "run" for the purposes of this counter is one
+** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
+** The counter is incremented on the first [sqlite3_step()] call of each
+** cycle.
+**
+** [[SQLITE_STMTSTATUS_MEMUSED]] 
    SQLITE_STMTSTATUS_MEMUSED
    
+** 
    ^This is the approximate number of bytes of heap memory
+** used to store the prepared statement.  ^This value is not actually
+** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
+** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
 ** 
    
 ** 
 */
@@ -6757,6 +8360,9 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 #define SQLITE_STMTSTATUS_SORT              2
 #define SQLITE_STMTSTATUS_AUTOINDEX         3
 #define SQLITE_STMTSTATUS_VM_STEP           4
+#define SQLITE_STMTSTATUS_REPREPARE         5
+#define SQLITE_STMTSTATUS_RUN               6
+#define SQLITE_STMTSTATUS_MEMUSED           99
 
 /*
 ** CAPI3REF: Custom Page Cache Object
@@ -7041,7 +8647,7 @@ typedef struct sqlite3_backup sqlite3_backup;
 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
 ** an error.
 **
-** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 
+** ^A call to sqlite3_backup_init() will fail, returning NULL, if 
 ** there is already a read or read-write transaction open on the 
 ** destination database.
 **
@@ -7137,20 +8743,20 @@ typedef struct sqlite3_backup sqlite3_backup;
 ** is not a permanent error and does not affect the return value of
 ** sqlite3_backup_finish().
 **
-** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
+** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
 ** sqlite3_backup_remaining() and sqlite3_backup_pagecount()
 **
-** ^Each call to sqlite3_backup_step() sets two values inside
-** the [sqlite3_backup] object: the number of pages still to be backed
-** up and the total number of pages in the source database file.
-** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
-** retrieve these two values, respectively.
-**
-** ^The values returned by these functions are only updated by
-** sqlite3_backup_step(). ^If the source database is modified during a backup
-** operation, then the values are not updated to account for any extra
-** pages that need to be updated or the size of the source database file
-** changing.
+** ^The sqlite3_backup_remaining() routine returns the number of pages still
+** to be backed up at the conclusion of the most recent sqlite3_backup_step().
+** ^The sqlite3_backup_pagecount() routine returns the total number of pages
+** in the source database at the conclusion of the most recent
+** sqlite3_backup_step().
+** ^(The values returned by these functions are only updated by
+** sqlite3_backup_step(). If the source database is modified in a way that
+** changes the size of the source database or the number of pages remaining,
+** those changes are not reflected in the output of sqlite3_backup_pagecount()
+** and sqlite3_backup_remaining() until after the next
+** sqlite3_backup_step().)^
 **
 ** Concurrent Usage of Database Handles
 **
@@ -7196,6 +8802,7 @@ SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
 
 /*
 ** CAPI3REF: Unlock Notification
+** METHOD: sqlite3
 **
 ** ^When running in shared-cache mode, a database operation may fail with
 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
@@ -7329,18 +8936,43 @@ SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
 /*
 ** CAPI3REF: String Globbing
 *
-** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
-** the glob pattern P, and it returns non-zero if string X does not match
-** the glob pattern P.  ^The definition of glob pattern matching used in
+** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
+** string X matches the [GLOB] pattern P.
+** ^The definition of [GLOB] pattern matching used in
 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
-** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
-** sensitive.
+** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
+** is case sensitive.
 **
 ** Note that this routine returns zero on a match and non-zero if the strings
 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
+**
+** See also: [sqlite3_strlike()].
 */
 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
 
+/*
+** CAPI3REF: String LIKE Matching
+*
+** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
+** string X matches the [LIKE] pattern P with escape character E.
+** ^The definition of [LIKE] pattern matching used in
+** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
+** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
+** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
+** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
+** insensitive - equivalent upper and lower case ASCII characters match
+** one another.
+**
+** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
+** only ASCII characters are case folded.
+**
+** Note that this routine returns zero on a match and non-zero if the strings
+** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
+**
+** See also: [sqlite3_strglob()].
+*/
+SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
+
 /*
 ** CAPI3REF: Error Logging Interface
 **
@@ -7366,6 +8998,7 @@ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
 
 /*
 ** CAPI3REF: Write-Ahead Log Commit Hook
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
 ** is invoked each time data is committed to a database in wal mode.
@@ -7395,7 +9028,7 @@ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
 ** previously registered write-ahead log callback. ^Note that the
 ** [sqlite3_wal_autocheckpoint()] interface and the
 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
-** those overwrite any prior [sqlite3_wal_hook()] settings.
+** overwrite any prior [sqlite3_wal_hook()] settings.
 */
 SQLITE_API void *sqlite3_wal_hook(
   sqlite3*, 
@@ -7405,6 +9038,7 @@ SQLITE_API void *sqlite3_wal_hook(
 
 /*
 ** CAPI3REF: Configure an auto-checkpoint
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
@@ -7435,6 +9069,7 @@ SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
 
 /*
 ** CAPI3REF: Checkpoint a database
+** METHOD: sqlite3
 **
 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
@@ -7456,6 +9091,7 @@ SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
 
 /*
 ** CAPI3REF: Checkpoint a database
+** METHOD: sqlite3
 **
 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
 ** operation on database X of [database connection] D in mode M.  Status
@@ -7710,6 +9346,7 @@ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
 
 /*
 ** CAPI3REF: Prepared Statement Scan Status
+** METHOD: sqlite3_stmt
 **
 ** This interface returns information about the predicted and measured
 ** performance for pStmt.  Advanced applications can use this
@@ -7738,7 +9375,7 @@ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
 **
 ** See also: [sqlite3_stmt_scanstatus_reset()]
 */
-SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus(
+SQLITE_API int sqlite3_stmt_scanstatus(
   sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
   int idx,                  /* Index of loop to report on */
   int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
@@ -7747,14 +9384,339 @@ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus(
 
 /*
 ** CAPI3REF: Zero Scan-Status Counters
+** METHOD: sqlite3_stmt
 **
 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
 **
 ** This API is only available if the library is built with pre-processor
 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
 */
-SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
+SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
+
+/*
+** CAPI3REF: Flush caches to disk mid-transaction
+**
+** ^If a write-transaction is open on [database connection] D when the
+** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
+** pages in the pager-cache that are not currently in use are written out 
+** to disk. A dirty page may be in use if a database cursor created by an
+** active SQL statement is reading from it, or if it is page 1 of a database
+** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]
+** interface flushes caches for all schemas - "main", "temp", and
+** any [attached] databases.
+**
+** ^If this function needs to obtain extra database locks before dirty pages 
+** can be flushed to disk, it does so. ^If those locks cannot be obtained 
+** immediately and there is a busy-handler callback configured, it is invoked
+** in the usual manner. ^If the required lock still cannot be obtained, then
+** the database is skipped and an attempt made to flush any dirty pages
+** belonging to the next (if any) database. ^If any databases are skipped
+** because locks cannot be obtained, but no other error occurs, this
+** function returns SQLITE_BUSY.
+**
+** ^If any other error occurs while flushing dirty pages to disk (for
+** example an IO error or out-of-memory condition), then processing is
+** abandoned and an SQLite [error code] is returned to the caller immediately.
+**
+** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
+**
+** ^This function does not set the database handle error code or message
+** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
+*/
+SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
+
+/*
+** CAPI3REF: The pre-update hook.
+**
+** ^These interfaces are only available if SQLite is compiled using the
+** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
+**
+** ^The [sqlite3_preupdate_hook()] interface registers a callback function
+** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
+** on a database table.
+** ^At most one preupdate hook may be registered at a time on a single
+** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
+** the previous setting.
+** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
+** with a NULL pointer as the second parameter.
+** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
+** the first parameter to callbacks.
+**
+** ^The preupdate hook only fires for changes to real database tables; the
+** preupdate hook is not invoked for changes to [virtual tables] or to
+** system tables like sqlite_master or sqlite_stat1.
+**
+** ^The second parameter to the preupdate callback is a pointer to
+** the [database connection] that registered the preupdate hook.
+** ^The third parameter to the preupdate callback is one of the constants
+** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
+** kind of update operation that is about to occur.
+** ^(The fourth parameter to the preupdate callback is the name of the
+** database within the database connection that is being modified.  This
+** will be "main" for the main database or "temp" for TEMP tables or 
+** the name given after the AS keyword in the [ATTACH] statement for attached
+** databases.)^
+** ^The fifth parameter to the preupdate callback is the name of the
+** table that is being modified.
+**
+** For an UPDATE or DELETE operation on a [rowid table], the sixth
+** parameter passed to the preupdate callback is the initial [rowid] of the 
+** row being modified or deleted. For an INSERT operation on a rowid table,
+** or any operation on a WITHOUT ROWID table, the value of the sixth 
+** parameter is undefined. For an INSERT or UPDATE on a rowid table the
+** seventh parameter is the final rowid value of the row being inserted
+** or updated. The value of the seventh parameter passed to the callback
+** function is not defined for operations on WITHOUT ROWID tables, or for
+** INSERT operations on rowid tables.
+**
+** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
+** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
+** provide additional information about a preupdate event. These routines
+** may only be called from within a preupdate callback.  Invoking any of
+** these routines from outside of a preupdate callback or with a
+** [database connection] pointer that is different from the one supplied
+** to the preupdate callback results in undefined and probably undesirable
+** behavior.
+**
+** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
+** in the row that is being inserted, updated, or deleted.
+**
+** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row before it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
+** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row after it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
+** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
+** callback was invoked as a result of a direct insert, update, or delete
+** operation; or 1 for inserts, updates, or deletes invoked by top-level 
+** triggers; or 2 for changes resulting from triggers called by top-level
+** triggers; and so forth.
+**
+** See also:  [sqlite3_update_hook()]
+*/
+#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+SQLITE_API void *sqlite3_preupdate_hook(
+  sqlite3 *db,
+  void(*xPreUpdate)(
+    void *pCtx,                   /* Copy of third arg to preupdate_hook() */
+    sqlite3 *db,                  /* Database handle */
+    int op,                       /* SQLITE_UPDATE, DELETE or INSERT */
+    char const *zDb,              /* Database name */
+    char const *zName,            /* Table name */
+    sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */
+    sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */
+  ),
+  void*
+);
+SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
+SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
+SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
+SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
+#endif
+
+/*
+** CAPI3REF: Low-level system error code
+**
+** ^Attempt to return the underlying operating system error code or error
+** number that caused the most recent I/O error or failure to open a file.
+** The return value is OS-dependent.  For example, on unix systems, after
+** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
+** called to get back the underlying "errno" that caused the problem, such
+** as ENOSPC, EAUTH, EISDIR, and so forth.  
+*/
+SQLITE_API int sqlite3_system_errno(sqlite3*);
+
+/*
+** CAPI3REF: Database Snapshot
+** KEYWORDS: {snapshot} {sqlite3_snapshot}
+** EXPERIMENTAL
+**
+** An instance of the snapshot object records the state of a [WAL mode]
+** database for some specific point in history.
+**
+** In [WAL mode], multiple [database connections] that are open on the
+** same database file can each be reading a different historical version
+** of the database file.  When a [database connection] begins a read
+** transaction, that connection sees an unchanging copy of the database
+** as it existed for the point in time when the transaction first started.
+** Subsequent changes to the database from other connections are not seen
+** by the reader until a new read transaction is started.
+**
+** The sqlite3_snapshot object records state information about an historical
+** version of the database file so that it is possible to later open a new read
+** transaction that sees that historical version of the database rather than
+** the most recent version.
+**
+** The constructor for this object is [sqlite3_snapshot_get()].  The
+** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
+** to an historical snapshot (if possible).  The destructor for 
+** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
+*/
+typedef struct sqlite3_snapshot {
+  unsigned char hidden[48];
+} sqlite3_snapshot;
+
+/*
+** CAPI3REF: Record A Database Snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
+** new [sqlite3_snapshot] object that records the current state of
+** schema S in database connection D.  ^On success, the
+** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
+** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
+** If there is not already a read-transaction open on schema S when
+** this function is called, one is opened automatically. 
+**
+** The following must be true for this function to succeed. If any of
+** the following statements are false when sqlite3_snapshot_get() is
+** called, SQLITE_ERROR is returned. The final value of *P is undefined
+** in this case. 
+**
+** 
      
+**   
    •  The database handle must be in [autocommit mode].
+**
+**   
    •  Schema S of [database connection] D must be a [WAL mode] database.
+**
+**   
    •  There must not be a write transaction open on schema S of database
+**        connection D.
+**
+**   
    •  One or more transactions must have been written to the current wal
+**        file since it was created on disk (by any connection). This means
+**        that a snapshot cannot be taken on a wal mode database with no wal 
+**        file immediately after it is first opened. At least one transaction
+**        must be written to it first.
+** 
    
+**
+** This function may also return SQLITE_NOMEM.  If it is called with the
+** database handle in autocommit mode but fails for some other reason, 
+** whether or not a read transaction is opened on schema S is undefined.
+**
+** The [sqlite3_snapshot] object returned from a successful call to
+** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
+** to avoid a memory leak.
+**
+** The [sqlite3_snapshot_get()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
+  sqlite3 *db,
+  const char *zSchema,
+  sqlite3_snapshot **ppSnapshot
+);
+
+/*
+** CAPI3REF: Start a read transaction on an historical snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
+** read transaction for schema S of
+** [database connection] D such that the read transaction
+** refers to historical [snapshot] P, rather than the most
+** recent change to the database.
+** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
+** or an appropriate [error code] if it fails.
+**
+** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
+** the first operation following the [BEGIN] that takes the schema S
+** out of [autocommit mode].
+** ^In other words, schema S must not currently be in
+** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
+** database connection D must be out of [autocommit mode].
+** ^A [snapshot] will fail to open if it has been overwritten by a
+** [checkpoint].
+** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
+** database connection D does not know that the database file for
+** schema S is in [WAL mode].  A database connection might not know
+** that the database file is in [WAL mode] if there has been no prior
+** I/O on that database connection, or if the database entered [WAL mode] 
+** after the most recent I/O on the database connection.)^
+** (Hint: Run "[PRAGMA application_id]" against a newly opened
+** database connection in order to make it ready to use snapshots.)
+**
+** The [sqlite3_snapshot_open()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
+  sqlite3 *db,
+  const char *zSchema,
+  sqlite3_snapshot *pSnapshot
+);
 
+/*
+** CAPI3REF: Destroy a snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
+** The application must eventually free every [sqlite3_snapshot] object
+** using this routine to avoid a memory leak.
+**
+** The [sqlite3_snapshot_free()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
+
+/*
+** CAPI3REF: Compare the ages of two snapshot handles.
+** EXPERIMENTAL
+**
+** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
+** of two valid snapshot handles. 
+**
+** If the two snapshot handles are not associated with the same database 
+** file, the result of the comparison is undefined. 
+**
+** Additionally, the result of the comparison is only valid if both of the
+** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
+** last time the wal file was deleted. The wal file is deleted when the
+** database is changed back to rollback mode or when the number of database
+** clients drops to zero. If either snapshot handle was obtained before the 
+** wal file was last deleted, the value returned by this function 
+** is undefined.
+**
+** Otherwise, this API returns a negative value if P1 refers to an older
+** snapshot than P2, zero if the two handles refer to the same database
+** snapshot, and a positive value if P1 is a newer snapshot than P2.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
+  sqlite3_snapshot *p1,
+  sqlite3_snapshot *p2
+);
+
+/*
+** CAPI3REF: Recover snapshots from a wal file
+** EXPERIMENTAL
+**
+** If all connections disconnect from a database file but do not perform
+** a checkpoint, the existing wal file is opened along with the database
+** file the next time the database is opened. At this point it is only
+** possible to successfully call sqlite3_snapshot_open() to open the most
+** recent snapshot of the database (the one at the head of the wal file),
+** even though the wal file may contain other valid snapshots for which
+** clients have sqlite3_snapshot handles.
+**
+** This function attempts to scan the wal file associated with database zDb
+** of database handle db and make all valid snapshots available to
+** sqlite3_snapshot_open(). It is an error if there is already a read
+** transaction open on the database, or if the database is not a wal mode
+** database.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
 
 /*
 ** Undo the hack that converts floating point types to integer for
@@ -7767,8 +9729,9 @@ SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*)
 #if 0
 }  /* End of the 'extern "C"' block */
 #endif
-#endif /* _SQLITE3_H_ */
+#endif /* SQLITE3_H */
 
+/******** Begin file sqlite3rtree.h *********/
 /*
 ** 2010 August 30
 **
@@ -7868,6 +9831,8 @@ struct sqlite3_rtree_query_info {
   int eParentWithin;                /* Visibility of parent node */
   int eWithin;                      /* OUT: Visiblity */
   sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
+  /* The following fields are only available in 3.8.11 and later */
+  sqlite3_value **apSqlParam;       /* Original SQL values of parameters */
 };
 
 /*
@@ -7884,6 +9849,1878 @@ struct sqlite3_rtree_query_info {
 
 #endif  /* ifndef _SQLITE3RTREE_H_ */
 
+/******** End of sqlite3rtree.h *********/
+/******** Begin file sqlite3session.h *********/
+
+#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
+#define __SQLITESESSION_H_ 1
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#if 0
+extern "C" {
+#endif
+
+
+/*
+** CAPI3REF: Session Object Handle
+*/
+typedef struct sqlite3_session sqlite3_session;
+
+/*
+** CAPI3REF: Changeset Iterator Handle
+*/
+typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
+
+/*
+** CAPI3REF: Create A New Session Object
+**
+** Create a new session object attached to database handle db. If successful,
+** a pointer to the new object is written to *ppSession and SQLITE_OK is
+** returned. If an error occurs, *ppSession is set to NULL and an SQLite
+** error code (e.g. SQLITE_NOMEM) is returned.
+**
+** It is possible to create multiple session objects attached to a single
+** database handle.
+**
+** Session objects created using this function should be deleted using the
+** [sqlite3session_delete()] function before the database handle that they
+** are attached to is itself closed. If the database handle is closed before
+** the session object is deleted, then the results of calling any session
+** module function, including [sqlite3session_delete()] on the session object
+** are undefined.
+**
+** Because the session module uses the [sqlite3_preupdate_hook()] API, it
+** is not possible for an application to register a pre-update hook on a
+** database handle that has one or more session objects attached. Nor is
+** it possible to create a session object attached to a database handle for
+** which a pre-update hook is already defined. The results of attempting 
+** either of these things are undefined.
+**
+** The session object will be used to create changesets for tables in
+** database zDb, where zDb is either "main", or "temp", or the name of an
+** attached database. It is not an error if database zDb is not attached
+** to the database when the session object is created.
+*/
+SQLITE_API int sqlite3session_create(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of db (e.g. "main") */
+  sqlite3_session **ppSession     /* OUT: New session object */
+);
+
+/*
+** CAPI3REF: Delete A Session Object
+**
+** Delete a session object previously allocated using 
+** [sqlite3session_create()]. Once a session object has been deleted, the
+** results of attempting to use pSession with any other session module
+** function are undefined.
+**
+** Session objects must be deleted before the database handle to which they
+** are attached is closed. Refer to the documentation for 
+** [sqlite3session_create()] for details.
+*/
+SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
+
+
+/*
+** CAPI3REF: Enable Or Disable A Session Object
+**
+** Enable or disable the recording of changes by a session object. When
+** enabled, a session object records changes made to the database. When
+** disabled - it does not. A newly created session object is enabled.
+** Refer to the documentation for [sqlite3session_changeset()] for further
+** details regarding how enabling and disabling a session object affects
+** the eventual changesets.
+**
+** Passing zero to this function disables the session. Passing a value
+** greater than zero enables it. Passing a value less than zero is a 
+** no-op, and may be used to query the current state of the session.
+**
+** The return value indicates the final state of the session object: 0 if 
+** the session is disabled, or 1 if it is enabled.
+*/
+SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
+
+/*
+** CAPI3REF: Set Or Clear the Indirect Change Flag
+**
+** Each change recorded by a session object is marked as either direct or
+** indirect. A change is marked as indirect if either:
+**
+** 
      
+**   
    •  The session object "indirect" flag is set when the change is
+**        made, or
+**   
    •  The change is made by an SQL trigger or foreign key action 
+**        instead of directly as a result of a users SQL statement.
+** 
    
+**
+** If a single row is affected by more than one operation within a session,
+** then the change is considered indirect if all operations meet the criteria
+** for an indirect change above, or direct otherwise.
+**
+** This function is used to set, clear or query the session object indirect
+** flag.  If the second argument passed to this function is zero, then the
+** indirect flag is cleared. If it is greater than zero, the indirect flag
+** is set. Passing a value less than zero does not modify the current value
+** of the indirect flag, and may be used to query the current state of the 
+** indirect flag for the specified session object.
+**
+** The return value indicates the final state of the indirect flag: 0 if 
+** it is clear, or 1 if it is set.
+*/
+SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
+
+/*
+** CAPI3REF: Attach A Table To A Session Object
+**
+** If argument zTab is not NULL, then it is the name of a table to attach
+** to the session object passed as the first argument. All subsequent changes 
+** made to the table while the session object is enabled will be recorded. See 
+** documentation for [sqlite3session_changeset()] for further details.
+**
+** Or, if argument zTab is NULL, then changes are recorded for all tables
+** in the database. If additional tables are added to the database (by 
+** executing "CREATE TABLE" statements) after this call is made, changes for 
+** the new tables are also recorded.
+**
+** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
+** defined as part of their CREATE TABLE statement. It does not matter if the 
+** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
+** KEY may consist of a single column, or may be a composite key.
+** 
+** It is not an error if the named table does not exist in the database. Nor
+** is it an error if the named table does not have a PRIMARY KEY. However,
+** no changes will be recorded in either of these scenarios.
+**
+** Changes are not recorded for individual rows that have NULL values stored
+** in one or more of their PRIMARY KEY columns.
+**
+** SQLITE_OK is returned if the call completes without error. Or, if an error 
+** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
+*/
+SQLITE_API int sqlite3session_attach(
+  sqlite3_session *pSession,      /* Session object */
+  const char *zTab                /* Table name */
+);
+
+/*
+** CAPI3REF: Set a table filter on a Session Object.
+**
+** The second argument (xFilter) is the "filter callback". For changes to rows 
+** in tables that are not attached to the Session object, the filter is called
+** to determine whether changes to the table's rows should be tracked or not. 
+** If xFilter returns 0, changes is not tracked. Note that once a table is 
+** attached, xFilter will not be called again.
+*/
+SQLITE_API void sqlite3session_table_filter(
+  sqlite3_session *pSession,      /* Session object */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of third arg to _filter_table() */
+    const char *zTab              /* Table name */
+  ),
+  void *pCtx                      /* First argument passed to xFilter */
+);
+
+/*
+** CAPI3REF: Generate A Changeset From A Session Object
+**
+** Obtain a changeset containing changes to the tables attached to the 
+** session object passed as the first argument. If successful, 
+** set *ppChangeset to point to a buffer containing the changeset 
+** and *pnChangeset to the size of the changeset in bytes before returning
+** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
+** zero and return an SQLite error code.
+**
+** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
+** each representing a change to a single row of an attached table. An INSERT
+** change contains the values of each field of a new database row. A DELETE
+** contains the original values of each field of a deleted database row. An
+** UPDATE change contains the original values of each field of an updated
+** database row along with the updated values for each updated non-primary-key
+** column. It is not possible for an UPDATE change to represent a change that
+** modifies the values of primary key columns. If such a change is made, it
+** is represented in a changeset as a DELETE followed by an INSERT.
+**
+** Changes are not recorded for rows that have NULL values stored in one or 
+** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
+** no corresponding change is present in the changesets returned by this
+** function. If an existing row with one or more NULL values stored in
+** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
+** only an INSERT is appears in the changeset. Similarly, if an existing row
+** with non-NULL PRIMARY KEY values is updated so that one or more of its
+** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
+** DELETE change only.
+**
+** The contents of a changeset may be traversed using an iterator created
+** using the [sqlite3changeset_start()] API. A changeset may be applied to
+** a database with a compatible schema using the [sqlite3changeset_apply()]
+** API.
+**
+** Within a changeset generated by this function, all changes related to a
+** single table are grouped together. In other words, when iterating through
+** a changeset or when applying a changeset to a database, all changes related
+** to a single table are processed before moving on to the next table. Tables
+** are sorted in the same order in which they were attached (or auto-attached)
+** to the sqlite3_session object. The order in which the changes related to
+** a single table are stored is undefined.
+**
+** Following a successful call to this function, it is the responsibility of
+** the caller to eventually free the buffer that *ppChangeset points to using
+** [sqlite3_free()].
+**
+** 
    Changeset Generation
    
+**
+** Once a table has been attached to a session object, the session object
+** records the primary key values of all new rows inserted into the table.
+** It also records the original primary key and other column values of any
+** deleted or updated rows. For each unique primary key value, data is only
+** recorded once - the first time a row with said primary key is inserted,
+** updated or deleted in the lifetime of the session.
+**
+** There is one exception to the previous paragraph: when a row is inserted,
+** updated or deleted, if one or more of its primary key columns contain a
+** NULL value, no record of the change is made.
+**
+** The session object therefore accumulates two types of records - those
+** that consist of primary key values only (created when the user inserts
+** a new record) and those that consist of the primary key values and the
+** original values of other table columns (created when the users deletes
+** or updates a record).
+**
+** When this function is called, the requested changeset is created using
+** both the accumulated records and the current contents of the database
+** file. Specifically:
+**
+** 
      
+**   
    •  For each record generated by an insert, the database is queried
+**        for a row with a matching primary key. If one is found, an INSERT
+**        change is added to the changeset. If no such row is found, no change 
+**        is added to the changeset.
+**
+**   
    •  For each record generated by an update or delete, the database is 
+**        queried for a row with a matching primary key. If such a row is
+**        found and one or more of the non-primary key fields have been
+**        modified from their original values, an UPDATE change is added to 
+**        the changeset. Or, if no such row is found in the table, a DELETE 
+**        change is added to the changeset. If there is a row with a matching
+**        primary key in the database, but all fields contain their original
+**        values, no change is added to the changeset.
+** 
    
+**
+** This means, amongst other things, that if a row is inserted and then later
+** deleted while a session object is active, neither the insert nor the delete
+** will be present in the changeset. Or if a row is deleted and then later a 
+** row with the same primary key values inserted while a session object is
+** active, the resulting changeset will contain an UPDATE change instead of
+** a DELETE and an INSERT.
+**
+** When a session object is disabled (see the [sqlite3session_enable()] API),
+** it does not accumulate records when rows are inserted, updated or deleted.
+** This may appear to have some counter-intuitive effects if a single row
+** is written to more than once during a session. For example, if a row
+** is inserted while a session object is enabled, then later deleted while 
+** the same session object is disabled, no INSERT record will appear in the
+** changeset, even though the delete took place while the session was disabled.
+** Or, if one field of a row is updated while a session is disabled, and 
+** another field of the same row is updated while the session is enabled, the
+** resulting changeset will contain an UPDATE change that updates both fields.
+*/
+SQLITE_API int sqlite3session_changeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Load The Difference Between Tables Into A Session 
+**
+** If it is not already attached to the session object passed as the first
+** argument, this function attaches table zTbl in the same manner as the
+** [sqlite3session_attach()] function. If zTbl does not exist, or if it
+** does not have a primary key, this function is a no-op (but does not return
+** an error).
+**
+** Argument zFromDb must be the name of a database ("main", "temp" etc.)
+** attached to the same database handle as the session object that contains 
+** a table compatible with the table attached to the session by this function.
+** A table is considered compatible if it:
+**
+** 
      
+**   
    •  Has the same name,
+**   
    •  Has the same set of columns declared in the same order, and
+**   
    •  Has the same PRIMARY KEY definition.
+** 
    
+**
+** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
+** are compatible but do not have any PRIMARY KEY columns, it is not an error
+** but no changes are added to the session object. As with other session
+** APIs, tables without PRIMARY KEYs are simply ignored.
+**
+** This function adds a set of changes to the session object that could be
+** used to update the table in database zFrom (call this the "from-table") 
+** so that its content is the same as the table attached to the session 
+** object (call this the "to-table"). Specifically:
+**
+** 
      
+**   
    •  For each row (primary key) that exists in the to-table but not in 
+**     the from-table, an INSERT record is added to the session object.
+**
+**   
    •  For each row (primary key) that exists in the to-table but not in 
+**     the from-table, a DELETE record is added to the session object.
+**
+**   
    •  For each row (primary key) that exists in both tables, but features 
+**     different non-PK values in each, an UPDATE record is added to the
+**     session.  
+** 
    
+**
+** To clarify, if this function is called and then a changeset constructed
+** using [sqlite3session_changeset()], then after applying that changeset to 
+** database zFrom the contents of the two compatible tables would be 
+** identical.
+**
+** It an error if database zFrom does not exist or does not contain the
+** required compatible table.
+**
+** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
+** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
+** may be set to point to a buffer containing an English language error 
+** message. It is the responsibility of the caller to free this buffer using
+** sqlite3_free().
+*/
+SQLITE_API int sqlite3session_diff(
+  sqlite3_session *pSession,
+  const char *zFromDb,
+  const char *zTbl,
+  char **pzErrMsg
+);
+
+
+/*
+** CAPI3REF: Generate A Patchset From A Session Object
+**
+** The differences between a patchset and a changeset are that:
+**
+** 
      
+**   
    •  DELETE records consist of the primary key fields only. The 
+**        original values of other fields are omitted.
+**   
    •  The original values of any modified fields are omitted from 
+**        UPDATE records.
+** 
    
+**
+** A patchset blob may be used with up to date versions of all 
+** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 
+** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
+** attempting to use a patchset blob with old versions of the
+** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 
+**
+** Because the non-primary key "old.*" fields are omitted, no 
+** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
+** is passed to the sqlite3changeset_apply() API. Other conflict types work
+** in the same way as for changesets.
+**
+** Changes within a patchset are ordered in the same way as for changesets
+** generated by the sqlite3session_changeset() function (i.e. all changes for
+** a single table are grouped together, tables appear in the order in which
+** they were attached to the session object).
+*/
+SQLITE_API int sqlite3session_patchset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnPatchset,                /* OUT: Size of buffer at *ppChangeset */
+  void **ppPatchset               /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Test if a changeset has recorded any changes.
+**
+** Return non-zero if no changes to attached tables have been recorded by 
+** the session object passed as the first argument. Otherwise, if one or 
+** more changes have been recorded, return zero.
+**
+** Even if this function returns zero, it is possible that calling
+** [sqlite3session_changeset()] on the session handle may still return a
+** changeset that contains no changes. This can happen when a row in 
+** an attached table is modified and then later on the original values 
+** are restored. However, if this function returns non-zero, then it is
+** guaranteed that a call to sqlite3session_changeset() will return a 
+** changeset containing zero changes.
+*/
+SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
+
+/*
+** CAPI3REF: Create An Iterator To Traverse A Changeset 
+**
+** Create an iterator used to iterate through the contents of a changeset.
+** If successful, *pp is set to point to the iterator handle and SQLITE_OK
+** is returned. Otherwise, if an error occurs, *pp is set to zero and an
+** SQLite error code is returned.
+**
+** The following functions can be used to advance and query a changeset 
+** iterator created by this function:
+**
+** 
      
+**   
    •  [sqlite3changeset_next()]
+**   
    •  [sqlite3changeset_op()]
+**   
    •  [sqlite3changeset_new()]
+**   
    •  [sqlite3changeset_old()]
+** 
    
+**
+** It is the responsibility of the caller to eventually destroy the iterator
+** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
+** changeset (pChangeset) must remain valid until after the iterator is
+** destroyed.
+**
+** Assuming the changeset blob was created by one of the
+** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
+** [sqlite3changeset_invert()] functions, all changes within the changeset 
+** that apply to a single table are grouped together. This means that when 
+** an application iterates through a changeset using an iterator created by 
+** this function, all changes that relate to a single table are visited 
+** consecutively. There is no chance that the iterator will visit a change 
+** the applies to table X, then one for table Y, and then later on visit 
+** another change for table X.
+*/
+SQLITE_API int sqlite3changeset_start(
+  sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */
+  int nChangeset,                 /* Size of changeset blob in bytes */
+  void *pChangeset                /* Pointer to blob containing changeset */
+);
+
+
+/*
+** CAPI3REF: Advance A Changeset Iterator
+**
+** This function may only be used with iterators created by function
+** [sqlite3changeset_start()]. If it is called on an iterator passed to
+** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
+** is returned and the call has no effect.
+**
+** Immediately after an iterator is created by sqlite3changeset_start(), it
+** does not point to any change in the changeset. Assuming the changeset
+** is not empty, the first call to this function advances the iterator to
+** point to the first change in the changeset. Each subsequent call advances
+** the iterator to point to the next change in the changeset (if any). If
+** no error occurs and the iterator points to a valid change after a call
+** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 
+** Otherwise, if all changes in the changeset have already been visited,
+** SQLITE_DONE is returned.
+**
+** If an error occurs, an SQLite error code is returned. Possible error 
+** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 
+** SQLITE_NOMEM.
+*/
+SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
+** is not the case, this function returns [SQLITE_MISUSE].
+**
+** If argument pzTab is not NULL, then *pzTab is set to point to a
+** nul-terminated utf-8 encoded string containing the name of the table
+** affected by the current change. The buffer remains valid until either
+** sqlite3changeset_next() is called on the iterator or until the 
+** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 
+** set to the number of columns in the table affected by the change. If
+** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
+** is an indirect change, or false (0) otherwise. See the documentation for
+** [sqlite3session_indirect()] for a description of direct and indirect
+** changes. Finally, if pOp is not NULL, then *pOp is set to one of 
+** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 
+** type of change that the iterator currently points to.
+**
+** If no error occurs, SQLITE_OK is returned. If an error does occur, an
+** SQLite error code is returned. The values of the output variables may not
+** be trusted in this case.
+*/
+SQLITE_API int sqlite3changeset_op(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  const char **pzTab,             /* OUT: Pointer to table name */
+  int *pnCol,                     /* OUT: Number of columns in table */
+  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
+  int *pbIndirect                 /* OUT: True for an 'indirect' change */
+);
+
+/*
+** CAPI3REF: Obtain The Primary Key Definition Of A Table
+**
+** For each modified table, a changeset includes the following:
+**
+** 
      
+**   
    •  The number of columns in the table, and
+**   
    •  Which of those columns make up the tables PRIMARY KEY.
+** 
    
+**
+** This function is used to find which columns comprise the PRIMARY KEY of
+** the table modified by the change that iterator pIter currently points to.
+** If successful, *pabPK is set to point to an array of nCol entries, where
+** nCol is the number of columns in the table. Elements of *pabPK are set to
+** 0x01 if the corresponding column is part of the tables primary key, or
+** 0x00 if it is not.
+**
+** If argument pnCol is not NULL, then *pnCol is set to the number of columns
+** in the table.
+**
+** If this function is called when the iterator does not point to a valid
+** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
+** SQLITE_OK is returned and the output variables populated as described
+** above.
+*/
+SQLITE_API int sqlite3changeset_pk(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
+  int *pnCol                      /* OUT: Number of entries in output array */
+);
+
+/*
+** CAPI3REF: Obtain old.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** original row values stored as part of the UPDATE or DELETE change and
+** returns SQLITE_OK. The name of the function comes from the fact that this 
+** is similar to the "old.*" columns available to update or delete triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+SQLITE_API int sqlite3changeset_old(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain new.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** new row values stored as part of the UPDATE or INSERT change and
+** returns SQLITE_OK. If the change is an UPDATE and does not include
+** a new value for the requested column, *ppValue is set to NULL and 
+** SQLITE_OK returned. The name of the function comes from the fact that 
+** this is similar to the "new.*" columns available to update or delete 
+** triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+SQLITE_API int sqlite3changeset_new(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
+**
+** This function should only be used with iterator objects passed to a
+** conflict-handler callback by [sqlite3changeset_apply()] with either
+** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
+** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
+** is set to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the 
+** "conflicting row" associated with the current conflict-handler callback
+** and returns SQLITE_OK.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+SQLITE_API int sqlite3changeset_conflict(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Value from conflicting row */
+);
+
+/*
+** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
+**
+** This function may only be called with an iterator passed to an
+** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
+** it sets the output variable to the total number of known foreign key
+** violations in the destination database and returns SQLITE_OK.
+**
+** In all other cases this function returns SQLITE_MISUSE.
+*/
+SQLITE_API int sqlite3changeset_fk_conflicts(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int *pnOut                      /* OUT: Number of FK violations */
+);
+
+
+/*
+** CAPI3REF: Finalize A Changeset Iterator
+**
+** This function is used to finalize an iterator allocated with
+** [sqlite3changeset_start()].
+**
+** This function should only be called on iterators created using the
+** [sqlite3changeset_start()] function. If an application calls this
+** function with an iterator passed to a conflict-handler by
+** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
+** call has no effect.
+**
+** If an error was encountered within a call to an sqlite3changeset_xxx()
+** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 
+** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
+** to that error is returned by this function. Otherwise, SQLITE_OK is
+** returned. This is to allow the following pattern (pseudo-code):
+**
+**   sqlite3changeset_start();
+**   while( SQLITE_ROW==sqlite3changeset_next() ){
+**     // Do something with change.
+**   }
+**   rc = sqlite3changeset_finalize();
+**   if( rc!=SQLITE_OK ){
+**     // An error has occurred 
+**   }
+*/
+SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Invert A Changeset
+**
+** This function is used to "invert" a changeset object. Applying an inverted
+** changeset to a database reverses the effects of applying the uninverted
+** changeset. Specifically:
+**
+** 
      
+**   
    •  Each DELETE change is changed to an INSERT, and
+**   
    •  Each INSERT change is changed to a DELETE, and
+**   
    •  For each UPDATE change, the old.* and new.* values are exchanged.
+** 
    
+**
+** This function does not change the order in which changes appear within
+** the changeset. It merely reverses the sense of each individual change.
+**
+** If successful, a pointer to a buffer containing the inverted changeset
+** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
+** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
+** zeroed and an SQLite error code returned.
+**
+** It is the responsibility of the caller to eventually call sqlite3_free()
+** on the *ppOut pointer to free the buffer allocation following a successful 
+** call to this function.
+**
+** WARNING/TODO: This function currently assumes that the input is a valid
+** changeset. If it is not, the results are undefined.
+*/
+SQLITE_API int sqlite3changeset_invert(
+  int nIn, const void *pIn,       /* Input changeset */
+  int *pnOut, void **ppOut        /* OUT: Inverse of input */
+);
+
+/*
+** CAPI3REF: Concatenate Two Changeset Objects
+**
+** This function is used to concatenate two changesets, A and B, into a 
+** single changeset. The result is a changeset equivalent to applying
+** changeset A followed by changeset B. 
+**
+** This function combines the two input changesets using an 
+** sqlite3_changegroup object. Calling it produces similar results as the
+** following code fragment:
+**
+**   sqlite3_changegroup *pGrp;
+**   rc = sqlite3_changegroup_new(&pGrp);
+**   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
+**   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
+**   if( rc==SQLITE_OK ){
+**     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
+**   }else{
+**     *ppOut = 0;
+**     *pnOut = 0;
+**   }
+**
+** Refer to the sqlite3_changegroup documentation below for details.
+*/
+SQLITE_API int sqlite3changeset_concat(
+  int nA,                         /* Number of bytes in buffer pA */
+  void *pA,                       /* Pointer to buffer containing changeset A */
+  int nB,                         /* Number of bytes in buffer pB */
+  void *pB,                       /* Pointer to buffer containing changeset B */
+  int *pnOut,                     /* OUT: Number of bytes in output changeset */
+  void **ppOut                    /* OUT: Buffer containing output changeset */
+);
+
+
+/*
+** CAPI3REF: Changegroup Handle
+*/
+typedef struct sqlite3_changegroup sqlite3_changegroup;
+
+/*
+** CAPI3REF: Create A New Changegroup Object
+**
+** An sqlite3_changegroup object is used to combine two or more changesets
+** (or patchsets) into a single changeset (or patchset). A single changegroup
+** object may combine changesets or patchsets, but not both. The output is
+** always in the same format as the input.
+**
+** If successful, this function returns SQLITE_OK and populates (*pp) with
+** a pointer to a new sqlite3_changegroup object before returning. The caller
+** should eventually free the returned object using a call to 
+** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
+** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
+**
+** The usual usage pattern for an sqlite3_changegroup object is as follows:
+**
+** 
      
+**   
    •  It is created using a call to sqlite3changegroup_new().
+**
+**   
    •  Zero or more changesets (or patchsets) are added to the object
+**        by calling sqlite3changegroup_add().
+**
+**   
    •  The result of combining all input changesets together is obtained 
+**        by the application via a call to sqlite3changegroup_output().
+**
+**   
    •  The object is deleted using a call to sqlite3changegroup_delete().
+** 
    
+**
+** Any number of calls to add() and output() may be made between the calls to
+** new() and delete(), and in any order.
+**
+** As well as the regular sqlite3changegroup_add() and 
+** sqlite3changegroup_output() functions, also available are the streaming
+** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
+*/
+SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
+
+/*
+** CAPI3REF: Add A Changeset To A Changegroup
+**
+** Add all changes within the changeset (or patchset) in buffer pData (size
+** nData bytes) to the changegroup. 
+**
+** If the buffer contains a patchset, then all prior calls to this function
+** on the same changegroup object must also have specified patchsets. Or, if
+** the buffer contains a changeset, so must have the earlier calls to this
+** function. Otherwise, SQLITE_ERROR is returned and no changes are added
+** to the changegroup.
+**
+** Rows within the changeset and changegroup are identified by the values in
+** their PRIMARY KEY columns. A change in the changeset is considered to
+** apply to the same row as a change already present in the changegroup if
+** the two rows have the same primary key.
+**
+** Changes to rows that do not already appear in the changegroup are
+** simply copied into it. Or, if both the new changeset and the changegroup
+** contain changes that apply to a single row, the final contents of the
+** changegroup depends on the type of each change, as follows:
+**
+** 
+**   
+**       
+**       
    Existing Change  New Change       Output Change
+**   
    INSERT INSERT 
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   
    INSERT UPDATE 
+**       The INSERT change remains in the changegroup. The values in the 
+**       INSERT change are modified as if the row was inserted by the
+**       existing change and then updated according to the new change.
+**   
    INSERT DELETE 
+**       The existing INSERT is removed from the changegroup. The DELETE is
+**       not added.
+**   
    UPDATE INSERT 
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   
    UPDATE UPDATE 
+**       The existing UPDATE remains within the changegroup. It is amended 
+**       so that the accompanying values are as if the row was updated once 
+**       by the existing change and then again by the new change.
+**   
    UPDATE DELETE 
+**       The existing UPDATE is replaced by the new DELETE within the
+**       changegroup.
+**   
    DELETE INSERT 
+**       If one or more of the column values in the row inserted by the
+**       new change differ from those in the row deleted by the existing 
+**       change, the existing DELETE is replaced by an UPDATE within the
+**       changegroup. Otherwise, if the inserted row is exactly the same 
+**       as the deleted row, the existing DELETE is simply discarded.
+**   
    DELETE UPDATE 
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   
    DELETE DELETE 
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+** 
    
+**
+** If the new changeset contains changes to a table that is already present
+** in the changegroup, then the number of columns and the position of the
+** primary key columns for the table must be consistent. If this is not the
+** case, this function fails with SQLITE_SCHEMA. If the input changeset
+** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
+** returned. Or, if an out-of-memory condition occurs during processing, this
+** function returns SQLITE_NOMEM. In all cases, if an error occurs the
+** final contents of the changegroup is undefined.
+**
+** If no error occurs, SQLITE_OK is returned.
+*/
+SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
+
+/*
+** CAPI3REF: Obtain A Composite Changeset From A Changegroup
+**
+** Obtain a buffer containing a changeset (or patchset) representing the
+** current contents of the changegroup. If the inputs to the changegroup
+** were themselves changesets, the output is a changeset. Or, if the
+** inputs were patchsets, the output is also a patchset.
+**
+** As with the output of the sqlite3session_changeset() and
+** sqlite3session_patchset() functions, all changes related to a single
+** table are grouped together in the output of this function. Tables appear
+** in the same order as for the very first changeset added to the changegroup.
+** If the second or subsequent changesets added to the changegroup contain
+** changes for tables that do not appear in the first changeset, they are
+** appended onto the end of the output changeset, again in the order in
+** which they are first encountered.
+**
+** If an error occurs, an SQLite error code is returned and the output
+** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
+** is returned and the output variables are set to the size of and a 
+** pointer to the output buffer, respectively. In this case it is the
+** responsibility of the caller to eventually free the buffer using a
+** call to sqlite3_free().
+*/
+SQLITE_API int sqlite3changegroup_output(
+  sqlite3_changegroup*,
+  int *pnData,                    /* OUT: Size of output buffer in bytes */
+  void **ppData                   /* OUT: Pointer to output buffer */
+);
+
+/*
+** CAPI3REF: Delete A Changegroup Object
+*/
+SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
+
+/*
+** CAPI3REF: Apply A Changeset To A Database
+**
+** Apply a changeset to a database. This function attempts to update the
+** "main" database attached to handle db with the changes found in the
+** changeset passed via the second and third arguments.
+**
+** The fourth argument (xFilter) passed to this function is the "filter
+** callback". If it is not NULL, then for each table affected by at least one
+** change in the changeset, the filter callback is invoked with
+** the table name as the second argument, and a copy of the context pointer
+** passed as the sixth argument to this function as the first. If the "filter
+** callback" returns zero, then no attempt is made to apply any changes to 
+** the table. Otherwise, if the return value is non-zero or the xFilter
+** argument to this function is NULL, all changes related to the table are
+** attempted.
+**
+** For each table that is not excluded by the filter callback, this function 
+** tests that the target database contains a compatible table. A table is 
+** considered compatible if all of the following are true:
+**
+** 
      
+**   
    •  The table has the same name as the name recorded in the 
+**        changeset, and
+**   
    •  The table has at least as many columns as recorded in the 
+**        changeset, and
+**   
    •  The table has primary key columns in the same position as 
+**        recorded in the changeset.
+** 
    
+**
+** If there is no compatible table, it is not an error, but none of the
+** changes associated with the table are applied. A warning message is issued
+** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
+** one such warning is issued for each table in the changeset.
+**
+** For each change for which there is a compatible table, an attempt is made 
+** to modify the table contents according to the UPDATE, INSERT or DELETE 
+** change. If a change cannot be applied cleanly, the conflict handler 
+** function passed as the fifth argument to sqlite3changeset_apply() may be 
+** invoked. A description of exactly when the conflict handler is invoked for 
+** each type of change is below.
+**
+** Unlike the xFilter argument, xConflict may not be passed NULL. The results
+** of passing anything other than a valid function pointer as the xConflict
+** argument are undefined.
+**
+** Each time the conflict handler function is invoked, it must return one
+** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 
+** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
+** if the second argument passed to the conflict handler is either
+** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
+** returns an illegal value, any changes already made are rolled back and
+** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 
+** actions are taken by sqlite3changeset_apply() depending on the value
+** returned by each invocation of the conflict-handler function. Refer to
+** the documentation for the three 
+** [SQLITE_CHANGESET_OMIT|available return values] for details.
+**
+** 
    
+** 
    DELETE Changes
    
+**   For each DELETE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all non-primary key columns also match the values stored in 
+**   the changeset the row is deleted from the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the non-primary key fields contains a value different from the original
+**   row value stored in the changeset, the conflict-handler function is
+**   invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
+**   database table has more columns than are recorded in the changeset,
+**   only the values of those non-primary key fields are compared against
+**   the current database contents - any trailing database table columns
+**   are ignored.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
+**   (which can only happen if a foreign key constraint is violated), the
+**   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
+**   passed as the second argument. This includes the case where the DELETE
+**   operation is attempted because an earlier call to the conflict handler
+**   function returned [SQLITE_CHANGESET_REPLACE].
+**
+** 
    INSERT Changes
    
+**   For each INSERT change, an attempt is made to insert the new row into
+**   the database. If the changeset row contains fewer fields than the
+**   database table, the trailing fields are populated with their default
+**   values.
+**
+**   If the attempt to insert the row fails because the database already 
+**   contains a row with the same primary key values, the conflict handler
+**   function is invoked with the second argument set to 
+**   [SQLITE_CHANGESET_CONFLICT].
+**
+**   If the attempt to insert the row fails because of some other constraint
+**   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 
+**   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
+**   This includes the case where the INSERT operation is re-attempted because 
+**   an earlier call to the conflict handler function returned 
+**   [SQLITE_CHANGESET_REPLACE].
+**
+** 
    UPDATE Changes
    
+**   For each UPDATE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all modified non-primary key columns also match the values
+**   stored in the changeset the row is updated within the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the modified non-primary key fields contains a value different from an
+**   original row value stored in the changeset, the conflict-handler function
+**   is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
+**   UPDATE changes only contain values for non-primary key fields that are
+**   to be modified, only those fields need to match the original values to
+**   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the UPDATE operation is attempted, but SQLite returns 
+**   SQLITE_CONSTRAINT, the conflict-handler function is invoked with 
+**   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
+**   This includes the case where the UPDATE operation is attempted after 
+**   an earlier call to the conflict handler function returned
+**   [SQLITE_CHANGESET_REPLACE].  
+** 
    
+**
+** It is safe to execute SQL statements, including those that write to the
+** table that the callback related to, from within the xConflict callback.
+** This can be used to further customize the applications conflict
+** resolution strategy.
+**
+** All changes made by this function are enclosed in a savepoint transaction.
+** If any other error (aside from a constraint failure when attempting to
+** write to the target database) occurs, then the savepoint transaction is
+** rolled back, restoring the target database to its original state, and an 
+** SQLite error code returned.
+*/
+SQLITE_API int sqlite3changeset_apply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+
+/* 
+** CAPI3REF: Constants Passed To The Conflict Handler
+**
+** Values that may be passed as the second argument to a conflict-handler.
+**
+** 
    
+** 
    SQLITE_CHANGESET_DATA
    
+**   The conflict handler is invoked with CHANGESET_DATA as the second argument
+**   when processing a DELETE or UPDATE change if a row with the required
+**   PRIMARY KEY fields is present in the database, but one or more other 
+**   (non primary-key) fields modified by the update do not contain the 
+**   expected "before" values.
+** 
+**   The conflicting row, in this case, is the database row with the matching
+**   primary key.
+** 
+** 
    SQLITE_CHANGESET_NOTFOUND
    
+**   The conflict handler is invoked with CHANGESET_NOTFOUND as the second
+**   argument when processing a DELETE or UPDATE change if a row with the
+**   required PRIMARY KEY fields is not present in the database.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+** 
+** 
    SQLITE_CHANGESET_CONFLICT
    
+**   CHANGESET_CONFLICT is passed as the second argument to the conflict
+**   handler while processing an INSERT change if the operation would result 
+**   in duplicate primary key values.
+** 
+**   The conflicting row in this case is the database row with the matching
+**   primary key.
+**
+** 
    SQLITE_CHANGESET_FOREIGN_KEY
    
+**   If foreign key handling is enabled, and applying a changeset leaves the
+**   database in a state containing foreign key violations, the conflict 
+**   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
+**   exactly once before the changeset is committed. If the conflict handler
+**   returns CHANGESET_OMIT, the changes, including those that caused the
+**   foreign key constraint violation, are committed. Or, if it returns
+**   CHANGESET_ABORT, the changeset is rolled back.
+**
+**   No current or conflicting row information is provided. The only function
+**   it is possible to call on the supplied sqlite3_changeset_iter handle
+**   is sqlite3changeset_fk_conflicts().
+** 
+** 
    SQLITE_CHANGESET_CONSTRAINT
    
+**   If any other constraint violation occurs while applying a change (i.e. 
+**   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 
+**   invoked with CHANGESET_CONSTRAINT as the second argument.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+**
+** 
    
+*/
+#define SQLITE_CHANGESET_DATA        1
+#define SQLITE_CHANGESET_NOTFOUND    2
+#define SQLITE_CHANGESET_CONFLICT    3
+#define SQLITE_CHANGESET_CONSTRAINT  4
+#define SQLITE_CHANGESET_FOREIGN_KEY 5
+
+/* 
+** CAPI3REF: Constants Returned By The Conflict Handler
+**
+** A conflict handler callback must return one of the following three values.
+**
+** 
    
+** 
    SQLITE_CHANGESET_OMIT
    
+**   If a conflict handler returns this value no special action is taken. The
+**   change that caused the conflict is not applied. The session module 
+**   continues to the next change in the changeset.
+**
+** 
    SQLITE_CHANGESET_REPLACE
    
+**   This value may only be returned if the second argument to the conflict
+**   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
+**   is not the case, any changes applied so far are rolled back and the 
+**   call to sqlite3changeset_apply() returns SQLITE_MISUSE.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
+**   handler, then the conflicting row is either updated or deleted, depending
+**   on the type of change.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
+**   handler, then the conflicting row is removed from the database and a
+**   second attempt to apply the change is made. If this second attempt fails,
+**   the original row is restored to the database before continuing.
+**
+** 
    SQLITE_CHANGESET_ABORT
    
+**   If this value is returned, any changes applied so far are rolled back 
+**   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
+** 
    
+*/
+#define SQLITE_CHANGESET_OMIT       0
+#define SQLITE_CHANGESET_REPLACE    1
+#define SQLITE_CHANGESET_ABORT      2
+
+/*
+** CAPI3REF: Streaming Versions of API functions.
+**
+** The six streaming API xxx_strm() functions serve similar purposes to the 
+** corresponding non-streaming API functions:
+**
+** 
+**   
+**   
    Streaming functionNon-streaming equivalent
    sqlite3changeset_apply_str[sqlite3changeset_apply] 
+**   
    sqlite3changeset_concat_str[sqlite3changeset_concat] 
+**   
    sqlite3changeset_invert_str[sqlite3changeset_invert] 
+**   
    sqlite3changeset_start_str[sqlite3changeset_start] 
+**   
    sqlite3session_changeset_str[sqlite3session_changeset] 
+**   
    sqlite3session_patchset_str[sqlite3session_patchset] 
+** 
    
+**
+** Non-streaming functions that accept changesets (or patchsets) as input
+** require that the entire changeset be stored in a single buffer in memory. 
+** Similarly, those that return a changeset or patchset do so by returning 
+** a pointer to a single large buffer allocated using sqlite3_malloc(). 
+** Normally this is convenient. However, if an application running in a 
+** low-memory environment is required to handle very large changesets, the
+** large contiguous memory allocations required can become onerous.
+**
+** In order to avoid this problem, instead of a single large buffer, input
+** is passed to a streaming API functions by way of a callback function that
+** the sessions module invokes to incrementally request input data as it is
+** required. In all cases, a pair of API function parameters such as
+**
+**  
    +**        int nChangeset,
+**        void *pChangeset,
+**  
    
+**
+** Is replaced by:
+**
+**  
    +**        int (*xInput)(void *pIn, void *pData, int *pnData),
+**        void *pIn,
+**  
    
+**
+** Each time the xInput callback is invoked by the sessions module, the first
+** argument passed is a copy of the supplied pIn context pointer. The second 
+** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 
+** error occurs the xInput method should copy up to (*pnData) bytes of data 
+** into the buffer and set (*pnData) to the actual number of bytes copied 
+** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 
+** should be set to zero to indicate this. Or, if an error occurs, an SQLite 
+** error code should be returned. In all cases, if an xInput callback returns
+** an error, all processing is abandoned and the streaming API function
+** returns a copy of the error code to the caller.
+**
+** In the case of sqlite3changeset_start_strm(), the xInput callback may be
+** invoked by the sessions module at any point during the lifetime of the
+** iterator. If such an xInput callback returns an error, the iterator enters
+** an error state, whereby all subsequent calls to iterator functions 
+** immediately fail with the same error code as returned by xInput.
+**
+** Similarly, streaming API functions that return changesets (or patchsets)
+** return them in chunks by way of a callback function instead of via a
+** pointer to a single large buffer. In this case, a pair of parameters such
+** as:
+**
+**  
    +**        int *pnChangeset,
+**        void **ppChangeset,
+**  
    
+**
+** Is replaced by:
+**
+**  
    +**        int (*xOutput)(void *pOut, const void *pData, int nData),
+**        void *pOut
+**  
    
+**
+** The xOutput callback is invoked zero or more times to return data to
+** the application. The first parameter passed to each call is a copy of the
+** pOut pointer supplied by the application. The second parameter, pData,
+** points to a buffer nData bytes in size containing the chunk of output
+** data being returned. If the xOutput callback successfully processes the
+** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
+** it should return some other SQLite error code. In this case processing
+** is immediately abandoned and the streaming API function returns a copy
+** of the xOutput error code to the application.
+**
+** The sessions module never invokes an xOutput callback with the third 
+** parameter set to a value less than or equal to zero. Other than this,
+** no guarantees are made as to the size of the chunks of data returned.
+*/
+SQLITE_API int sqlite3changeset_apply_strm(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
+  void *pIn,                                          /* First arg for xInput */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+SQLITE_API int sqlite3changeset_concat_strm(
+  int (*xInputA)(void *pIn, void *pData, int *pnData),
+  void *pInA,
+  int (*xInputB)(void *pIn, void *pData, int *pnData),
+  void *pInB,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+SQLITE_API int sqlite3changeset_invert_strm(
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+SQLITE_API int sqlite3changeset_start_strm(
+  sqlite3_changeset_iter **pp,
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn
+);
+SQLITE_API int sqlite3session_changeset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+SQLITE_API int sqlite3session_patchset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 
+    int (*xInput)(void *pIn, void *pData, int *pnData),
+    void *pIn
+);
+SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
+    int (*xOutput)(void *pOut, const void *pData, int nData), 
+    void *pOut
+);
+
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#if 0
+}
+#endif
+
+#endif  /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
+
+/******** End of sqlite3session.h *********/
+/******** Begin file fts5.h *********/
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Interfaces to extend FTS5. Using the interfaces defined in this file, 
+** FTS5 may be extended with:
+**
+**     * custom tokenizers, and
+**     * custom auxiliary functions.
+*/
+
+
+#ifndef _FTS5_H
+#define _FTS5_H
+
+
+#if 0
+extern "C" {
+#endif
+
+/*************************************************************************
+** CUSTOM AUXILIARY FUNCTIONS
+**
+** Virtual table implementations may overload SQL functions by implementing
+** the sqlite3_module.xFindFunction() method.
+*/
+
+typedef struct Fts5ExtensionApi Fts5ExtensionApi;
+typedef struct Fts5Context Fts5Context;
+typedef struct Fts5PhraseIter Fts5PhraseIter;
+
+typedef void (*fts5_extension_function)(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+);
+
+struct Fts5PhraseIter {
+  const unsigned char *a;
+  const unsigned char *b;
+};
+
+/*
+** EXTENSION API FUNCTIONS
+**
+** xUserData(pFts):
+**   Return a copy of the context pointer the extension function was 
+**   registered with.
+**
+** xColumnTotalSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the FTS5 table. Or, if iCol is
+**   non-negative but less than the number of columns in the table, return
+**   the total number of tokens in column iCol, considering all rows in 
+**   the FTS5 table.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+** xColumnCount(pFts):
+**   Return the number of columns in the table.
+**
+** xColumnSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the current row. Or, if iCol is
+**   non-negative but less than the number of columns in the table, set
+**   *pnToken to the number of tokens in column iCol of the current row.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+**   This function may be quite inefficient if used with an FTS5 table
+**   created with the "columnsize=0" option.
+**
+** xColumnText:
+**   This function attempts to retrieve the text of column iCol of the
+**   current document. If successful, (*pz) is set to point to a buffer
+**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
+**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
+**   if an error occurs, an SQLite error code is returned and the final values
+**   of (*pz) and (*pn) are undefined.
+**
+** xPhraseCount:
+**   Returns the number of phrases in the current query expression.
+**
+** xPhraseSize:
+**   Returns the number of tokens in phrase iPhrase of the query. Phrases
+**   are numbered starting from zero.
+**
+** xInstCount:
+**   Set *pnInst to the total number of occurrences of all phrases within
+**   the query within the current row. Return SQLITE_OK if successful, or
+**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always returns 0.
+**
+** xInst:
+**   Query for the details of phrase match iIdx within the current row.
+**   Phrase matches are numbered starting from zero, so the iIdx argument
+**   should be greater than or equal to zero and smaller than the value
+**   output by xInstCount().
+**
+**   Usually, output parameter *piPhrase is set to the phrase number, *piCol
+**   to the column in which it occurs and *piOff the token offset of the
+**   first token of the phrase. The exception is if the table was created
+**   with the offsets=0 option specified. In this case *piOff is always
+**   set to -1.
+**
+**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
+**   if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. 
+**
+** xRowid:
+**   Returns the rowid of the current row.
+**
+** xTokenize:
+**   Tokenize text using the tokenizer belonging to the FTS5 table.
+**
+** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
+**   This API function is used to query the FTS table for phrase iPhrase
+**   of the current query. Specifically, a query equivalent to:
+**
+**       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
+**
+**   with $p set to a phrase equivalent to the phrase iPhrase of the
+**   current query is executed. Any column filter that applies to
+**   phrase iPhrase of the current query is included in $p. For each 
+**   row visited, the callback function passed as the fourth argument 
+**   is invoked. The context and API objects passed to the callback 
+**   function may be used to access the properties of each matched row.
+**   Invoking Api.xUserData() returns a copy of the pointer passed as 
+**   the third argument to pUserData.
+**
+**   If the callback function returns any value other than SQLITE_OK, the
+**   query is abandoned and the xQueryPhrase function returns immediately.
+**   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
+**   Otherwise, the error code is propagated upwards.
+**
+**   If the query runs to completion without incident, SQLITE_OK is returned.
+**   Or, if some error occurs before the query completes or is aborted by
+**   the callback, an SQLite error code is returned.
+**
+**
+** xSetAuxdata(pFts5, pAux, xDelete)
+**
+**   Save the pointer passed as the second argument as the extension functions 
+**   "auxiliary data". The pointer may then be retrieved by the current or any
+**   future invocation of the same fts5 extension function made as part of
+**   of the same MATCH query using the xGetAuxdata() API.
+**
+**   Each extension function is allocated a single auxiliary data slot for
+**   each FTS query (MATCH expression). If the extension function is invoked 
+**   more than once for a single FTS query, then all invocations share a 
+**   single auxiliary data context.
+**
+**   If there is already an auxiliary data pointer when this function is
+**   invoked, then it is replaced by the new pointer. If an xDelete callback
+**   was specified along with the original pointer, it is invoked at this
+**   point.
+**
+**   The xDelete callback, if one is specified, is also invoked on the
+**   auxiliary data pointer after the FTS5 query has finished.
+**
+**   If an error (e.g. an OOM condition) occurs within this function, an
+**   the auxiliary data is set to NULL and an error code returned. If the
+**   xDelete parameter was not NULL, it is invoked on the auxiliary data
+**   pointer before returning.
+**
+**
+** xGetAuxdata(pFts5, bClear)
+**
+**   Returns the current auxiliary data pointer for the fts5 extension 
+**   function. See the xSetAuxdata() method for details.
+**
+**   If the bClear argument is non-zero, then the auxiliary data is cleared
+**   (set to NULL) before this function returns. In this case the xDelete,
+**   if any, is not invoked.
+**
+**
+** xRowCount(pFts5, pnRow)
+**
+**   This function is used to retrieve the total number of rows in the table.
+**   In other words, the same value that would be returned by:
+**
+**        SELECT count(*) FROM ftstable;
+**
+** xPhraseFirst()
+**   This function is used, along with type Fts5PhraseIter and the xPhraseNext
+**   method, to iterate through all instances of a single query phrase within
+**   the current row. This is the same information as is accessible via the
+**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
+**   to use, this API may be faster under some circumstances. To iterate 
+**   through instances of phrase iPhrase, use the following code:
+**
+**       Fts5PhraseIter iter;
+**       int iCol, iOff;
+**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
+**           iCol>=0;
+**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
+**       ){
+**         // An instance of phrase iPhrase at offset iOff of column iCol
+**       }
+**
+**   The Fts5PhraseIter structure is defined above. Applications should not
+**   modify this structure directly - it should only be used as shown above
+**   with the xPhraseFirst() and xPhraseNext() API methods (and by
+**   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always iterates
+**   through an empty set (all calls to xPhraseFirst() set iCol to -1).
+**
+** xPhraseNext()
+**   See xPhraseFirst above.
+**
+** xPhraseFirstColumn()
+**   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
+**   and xPhraseNext() APIs described above. The difference is that instead
+**   of iterating through all instances of a phrase in the current row, these
+**   APIs are used to iterate through the set of columns in the current row
+**   that contain one or more instances of a specified phrase. For example:
+**
+**       Fts5PhraseIter iter;
+**       int iCol;
+**       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
+**           iCol>=0;
+**           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
+**       ){
+**         // Column iCol contains at least one instance of phrase iPhrase
+**       }
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" option. If the FTS5 table is created with either 
+**   "detail=none" "content=" option (i.e. if it is a contentless table), 
+**   then this API always iterates through an empty set (all calls to 
+**   xPhraseFirstColumn() set iCol to -1).
+**
+**   The information accessed using this API and its companion
+**   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
+**   (or xInst/xInstCount). The chief advantage of this API is that it is
+**   significantly more efficient than those alternatives when used with
+**   "detail=column" tables.  
+**
+** xPhraseNextColumn()
+**   See xPhraseFirstColumn above.
+*/
+struct Fts5ExtensionApi {
+  int iVersion;                   /* Currently always set to 3 */
+
+  void *(*xUserData)(Fts5Context*);
+
+  int (*xColumnCount)(Fts5Context*);
+  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
+  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
+
+  int (*xTokenize)(Fts5Context*, 
+    const char *pText, int nText, /* Text to tokenize */
+    void *pCtx,                   /* Context passed to xToken() */
+    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
+  );
+
+  int (*xPhraseCount)(Fts5Context*);
+  int (*xPhraseSize)(Fts5Context*, int iPhrase);
+
+  int (*xInstCount)(Fts5Context*, int *pnInst);
+  int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
+
+  sqlite3_int64 (*xRowid)(Fts5Context*);
+  int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
+  int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
+
+  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
+    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
+  );
+  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
+  void *(*xGetAuxdata)(Fts5Context*, int bClear);
+
+  int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
+  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
+
+  int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
+  void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
+};
+
+/* 
+** CUSTOM AUXILIARY FUNCTIONS
+*************************************************************************/
+
+/*************************************************************************
+** CUSTOM TOKENIZERS
+**
+** Applications may also register custom tokenizer types. A tokenizer 
+** is registered by providing fts5 with a populated instance of the 
+** following structure. All structure methods must be defined, setting
+** any member of the fts5_tokenizer struct to NULL leads to undefined
+** behaviour. The structure methods are expected to function as follows:
+**
+** xCreate:
+**   This function is used to allocate and initialize a tokenizer instance.
+**   A tokenizer instance is required to actually tokenize text.
+**
+**   The first argument passed to this function is a copy of the (void*)
+**   pointer provided by the application when the fts5_tokenizer object
+**   was registered with FTS5 (the third argument to xCreateTokenizer()). 
+**   The second and third arguments are an array of nul-terminated strings
+**   containing the tokenizer arguments, if any, specified following the
+**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
+**   to create the FTS5 table.
+**
+**   The final argument is an output variable. If successful, (*ppOut) 
+**   should be set to point to the new tokenizer handle and SQLITE_OK
+**   returned. If an error occurs, some value other than SQLITE_OK should
+**   be returned. In this case, fts5 assumes that the final value of *ppOut 
+**   is undefined.
+**
+** xDelete:
+**   This function is invoked to delete a tokenizer handle previously
+**   allocated using xCreate(). Fts5 guarantees that this function will
+**   be invoked exactly once for each successful call to xCreate().
+**
+** xTokenize:
+**   This function is expected to tokenize the nText byte string indicated 
+**   by argument pText. pText may or may not be nul-terminated. The first
+**   argument passed to this function is a pointer to an Fts5Tokenizer object
+**   returned by an earlier call to xCreate().
+**
+**   The second argument indicates the reason that FTS5 is requesting
+**   tokenization of the supplied text. This is always one of the following
+**   four values:
+**
+**   
    •  FTS5_TOKENIZE_DOCUMENT - A document is being inserted into
+**            or removed from the FTS table. The tokenizer is being invoked to
+**            determine the set of tokens to add to (or delete from) the
+**            FTS index.
+**
+**       
    •  FTS5_TOKENIZE_QUERY - A MATCH query is being executed 
+**            against the FTS index. The tokenizer is being called to tokenize 
+**            a bareword or quoted string specified as part of the query.
+**
+**       
    •  (FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX) - Same as
+**            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
+**            followed by a "*" character, indicating that the last token
+**            returned by the tokenizer will be treated as a token prefix.
+**
+**       
    •  FTS5_TOKENIZE_AUX - The tokenizer is being invoked to 
+**            satisfy an fts5_api.xTokenize() request made by an auxiliary
+**            function. Or an fts5_api.xColumnSize() request made by the same
+**            on a columnsize=0 database.  
+**   
    
+**
+**   For each token in the input string, the supplied callback xToken() must
+**   be invoked. The first argument to it should be a copy of the pointer
+**   passed as the second argument to xTokenize(). The third and fourth
+**   arguments are a pointer to a buffer containing the token text, and the
+**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
+**   of the first byte of and first byte immediately following the text from
+**   which the token is derived within the input.
+**
+**   The second argument passed to the xToken() callback ("tflags") should
+**   normally be set to 0. The exception is if the tokenizer supports 
+**   synonyms. In this case see the discussion below for details.
+**
+**   FTS5 assumes the xToken() callback is invoked for each token in the 
+**   order that they occur within the input text.
+**
+**   If an xToken() callback returns any value other than SQLITE_OK, then
+**   the tokenization should be abandoned and the xTokenize() method should
+**   immediately return a copy of the xToken() return value. Or, if the
+**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
+**   if an error occurs with the xTokenize() implementation itself, it
+**   may abandon the tokenization and return any error code other than
+**   SQLITE_OK or SQLITE_DONE.
+**
+** SYNONYM SUPPORT
+**
+**   Custom tokenizers may also support synonyms. Consider a case in which a
+**   user wishes to query for a phrase such as "first place". Using the 
+**   built-in tokenizers, the FTS5 query 'first + place' will match instances
+**   of "first place" within the document set, but not alternative forms
+**   such as "1st place". In some applications, it would be better to match
+**   all instances of "first place" or "1st place" regardless of which form
+**   the user specified in the MATCH query text.
+**
+**   There are several ways to approach this in FTS5:
+**
+**   
    1.  By mapping all synonyms to a single token. In this case, the 
+**            In the above example, this means that the tokenizer returns the
+**            same token for inputs "first" and "1st". Say that token is in
+**            fact "first", so that when the user inserts the document "I won
+**            1st place" entries are added to the index for tokens "i", "won",
+**            "first" and "place". If the user then queries for '1st + place',
+**            the tokenizer substitutes "first" for "1st" and the query works
+**            as expected.
+**
+**       
    2.  By adding multiple synonyms for a single term to the FTS index.
+**            In this case, when tokenizing query text, the tokenizer may 
+**            provide multiple synonyms for a single term within the document.
+**            FTS5 then queries the index for each synonym individually. For
+**            example, faced with the query:
+**
+**   
+**     ... MATCH 'first place'
+**
+**            the tokenizer offers both "1st" and "first" as synonyms for the
+**            first token in the MATCH query and FTS5 effectively runs a query 
+**            similar to:
+**
+**   
+**     ... MATCH '(first OR 1st) place'
+**
+**            except that, for the purposes of auxiliary functions, the query
+**            still appears to contain just two phrases - "(first OR 1st)" 
+**            being treated as a single phrase.
+**
+**       
    3.  By adding multiple synonyms for a single term to the FTS index.
+**            Using this method, when tokenizing document text, the tokenizer
+**            provides multiple synonyms for each token. So that when a 
+**            document such as "I won first place" is tokenized, entries are
+**            added to the FTS index for "i", "won", "first", "1st" and
+**            "place".
+**
+**            This way, even if the tokenizer does not provide synonyms
+**            when tokenizing query text (it should not - to do would be
+**            inefficient), it doesn't matter if the user queries for 
+**            'first + place' or '1st + place', as there are entires in the
+**            FTS index corresponding to both forms of the first token.
+**   
    
+**
+**   Whether it is parsing document or query text, any call to xToken that
+**   specifies a tflags argument with the FTS5_TOKEN_COLOCATED bit
+**   is considered to supply a synonym for the previous token. For example,
+**   when parsing the document "I won first place", a tokenizer that supports
+**   synonyms would call xToken() 5 times, as follows:
+**
+**   
+**       xToken(pCtx, 0, "i",                      1,  0,  1);
+**       xToken(pCtx, 0, "won",                    3,  2,  5);
+**       xToken(pCtx, 0, "first",                  5,  6, 11);
+**       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
+**       xToken(pCtx, 0, "place",                  5, 12, 17);
+**
+**
+**   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
+**   xToken() is called. Multiple synonyms may be specified for a single token
+**   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 
+**   There is no limit to the number of synonyms that may be provided for a
+**   single token.
+**
+**   In many cases, method (1) above is the best approach. It does not add 
+**   extra data to the FTS index or require FTS5 to query for multiple terms,
+**   so it is efficient in terms of disk space and query speed. However, it
+**   does not support prefix queries very well. If, as suggested above, the
+**   token "first" is subsituted for "1st" by the tokenizer, then the query:
+**
+**   
+**     ... MATCH '1s*'
+**
+**   will not match documents that contain the token "1st" (as the tokenizer
+**   will probably not map "1s" to any prefix of "first").
+**
+**   For full prefix support, method (3) may be preferred. In this case, 
+**   because the index contains entries for both "first" and "1st", prefix
+**   queries such as 'fi*' or '1s*' will match correctly. However, because
+**   extra entries are added to the FTS index, this method uses more space
+**   within the database.
+**
+**   Method (2) offers a midpoint between (1) and (3). Using this method,
+**   a query such as '1s*' will match documents that contain the literal 
+**   token "1st", but not "first" (assuming the tokenizer is not able to
+**   provide synonyms for prefixes). However, a non-prefix query like '1st'
+**   will match against "1st" and "first". This method does not require
+**   extra disk space, as no extra entries are added to the FTS index. 
+**   On the other hand, it may require more CPU cycles to run MATCH queries,
+**   as separate queries of the FTS index are required for each synonym.
+**
+**   When using methods (2) or (3), it is important that the tokenizer only
+**   provide synonyms when tokenizing document text (method (2)) or query
+**   text (method (3)), not both. Doing so will not cause any errors, but is
+**   inefficient.
+*/
+typedef struct Fts5Tokenizer Fts5Tokenizer;
+typedef struct fts5_tokenizer fts5_tokenizer;
+struct fts5_tokenizer {
+  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
+  void (*xDelete)(Fts5Tokenizer*);
+  int (*xTokenize)(Fts5Tokenizer*, 
+      void *pCtx,
+      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
+      const char *pText, int nText, 
+      int (*xToken)(
+        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
+        int tflags,         /* Mask of FTS5_TOKEN_* flags */
+        const char *pToken, /* Pointer to buffer containing token */
+        int nToken,         /* Size of token in bytes */
+        int iStart,         /* Byte offset of token within input text */
+        int iEnd            /* Byte offset of end of token within input text */
+      )
+  );
+};
+
+/* Flags that may be passed as the third argument to xTokenize() */
+#define FTS5_TOKENIZE_QUERY     0x0001
+#define FTS5_TOKENIZE_PREFIX    0x0002
+#define FTS5_TOKENIZE_DOCUMENT  0x0004
+#define FTS5_TOKENIZE_AUX       0x0008
+
+/* Flags that may be passed by the tokenizer implementation back to FTS5
+** as the third argument to the supplied xToken callback. */
+#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
+
+/*
+** END OF CUSTOM TOKENIZERS
+*************************************************************************/
+
+/*************************************************************************
+** FTS5 EXTENSION REGISTRATION API
+*/
+typedef struct fts5_api fts5_api;
+struct fts5_api {
+  int iVersion;                   /* Currently always set to 2 */
+
+  /* Create a new tokenizer */
+  int (*xCreateTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_tokenizer *pTokenizer,
+    void (*xDestroy)(void*)
+  );
+
+  /* Find an existing tokenizer */
+  int (*xFindTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void **ppContext,
+    fts5_tokenizer *pTokenizer
+  );
+
+  /* Create a new auxiliary function */
+  int (*xCreateFunction)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_extension_function xFunction,
+    void (*xDestroy)(void*)
+  );
+};
+
+/*
+** END OF REGISTRATION API
+*************************************************************************/
+
+#if 0
+}  /* end of the 'extern "C"' block */
+#endif
+
+#endif /* _FTS5_H */
+
+/******** End of fts5.h *********/
 
 /************** End of sqlite3.h *********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -7892,8 +11729,9 @@ struct sqlite3_rtree_query_info {
 ** Include the configuration header output by 'configure' if we're using the
 ** autoconf-based build
 */
-#ifdef _HAVE_SQLITE_CONFIG_H
-#include "config.h"
+#if defined(_HAVE_SQLITE_CONFIG_H) && !defined(SQLITECONFIG_H)
+/* #include "config.h" */
+#define SQLITECONFIG_H 1
 #endif
 
 /************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
@@ -7987,7 +11825,7 @@ struct sqlite3_rtree_query_info {
 ** Not currently enforced.
 */
 #ifndef SQLITE_MAX_VDBE_OP
-# define SQLITE_MAX_VDBE_OP 25000
+# define SQLITE_MAX_VDBE_OP 250000000
 #endif
 
 /*
@@ -7998,14 +11836,16 @@ struct sqlite3_rtree_query_info {
 #endif
 
 /*
-** The maximum number of in-memory pages to use for the main database
-** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
+** The suggested maximum number of in-memory pages to use for
+** the main database table and for temporary tables.
+**
+** IMPLEMENTATION-OF: R-30185-15359 The default suggested cache size is -2000,
+** which means the cache size is limited to 2048000 bytes of memory.
+** IMPLEMENTATION-OF: R-48205-43578 The default suggested cache size can be
+** altered using the SQLITE_DEFAULT_CACHE_SIZE compile-time options.
 */
 #ifndef SQLITE_DEFAULT_CACHE_SIZE
-# define SQLITE_DEFAULT_CACHE_SIZE  2000
-#endif
-#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
-# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
+# define SQLITE_DEFAULT_CACHE_SIZE  -2000
 #endif
 
 /*
@@ -8018,8 +11858,9 @@ struct sqlite3_rtree_query_info {
 
 /*
 ** The maximum number of attached databases.  This must be between 0
-** and 62.  The upper bound on 62 is because a 64-bit integer bitmap
-** is used internally to track attached databases.
+** and 125.  The upper bound of 125 is because the attached databases are
+** counted using a signed 8-bit integer which has a maximum value of 127
+** and we have to allow 2 extra counts for the "main" and "temp" databases.
 */
 #ifndef SQLITE_MAX_ATTACHED
 # define SQLITE_MAX_ATTACHED 10
@@ -8054,7 +11895,7 @@ struct sqlite3_rtree_query_info {
 ** The default size of a database page.
 */
 #ifndef SQLITE_DEFAULT_PAGE_SIZE
-# define SQLITE_DEFAULT_PAGE_SIZE 1024
+# define SQLITE_DEFAULT_PAGE_SIZE 4096
 #endif
 #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
 # undef SQLITE_DEFAULT_PAGE_SIZE
@@ -8135,7 +11976,7 @@ struct sqlite3_rtree_query_info {
 ** to the next, so we have developed the following set of #if statements
 ** to generate appropriate macros for a wide range of compilers.
 **
-** The correct "ANSI" way to do this is to use the intptr_t type. 
+** The correct "ANSI" way to do this is to use the intptr_t type.
 ** Unfortunately, that typedef is not available on all compilers, or
 ** if it is available, it requires an #include of specific headers
 ** that vary from one machine to the next.
@@ -8171,6 +12012,25 @@ struct sqlite3_rtree_query_info {
 #  define SQLITE_NOINLINE
 #endif
 
+/*
+** Make sure that the compiler intrinsics we desire are enabled when
+** compiling with an appropriate version of MSVC unless prevented by
+** the SQLITE_DISABLE_INTRINSIC define.
+*/
+#if !defined(SQLITE_DISABLE_INTRINSIC)
+#  if defined(_MSC_VER) && _MSC_VER>=1400
+#    if !defined(_WIN32_WCE)
+#      include 
+#      pragma intrinsic(_byteswap_ushort)
+#      pragma intrinsic(_byteswap_ulong)
+#      pragma intrinsic(_byteswap_uint64)
+#      pragma intrinsic(_ReadWriteBarrier)
+#    else
+#      include 
+#    endif
+#  endif
+#endif
+
 /*
 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
 ** 0 means mutexes are permanently disable and the library is never
@@ -8181,6 +12041,11 @@ struct sqlite3_rtree_query_info {
 **
 ** Older versions of SQLite used an optional THREADSAFE macro.
 ** We support that for legacy.
+**
+** To ensure that the correct value of "THREADSAFE" is reported when querying
+** for compile-time options at runtime (e.g. "PRAGMA compile_options"), this
+** logic is partially replicated in ctime.c. If it is updated here, it should
+** also be updated there.
 */
 #if !defined(SQLITE_THREADSAFE)
 # if defined(THREADSAFE)
@@ -8269,7 +12134,7 @@ struct sqlite3_rtree_query_info {
 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
 ** feature.
 */
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
 # define NDEBUG 1
 #endif
 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
@@ -8284,7 +12149,7 @@ struct sqlite3_rtree_query_info {
 #endif
 
 /*
-** The testcase() macro is used to aid in coverage testing.  When 
+** The testcase() macro is used to aid in coverage testing.  When
 ** doing coverage testing, the condition inside the argument to
 ** testcase() must be evaluated both true and false in order to
 ** get full branch coverage.  The testcase() macro is inserted
@@ -8330,7 +12195,7 @@ SQLITE_PRIVATE   void sqlite3Coverage(int);
 #endif
 
 /*
-** The ALWAYS and NEVER macros surround boolean expressions which 
+** The ALWAYS and NEVER macros surround boolean expressions which
 ** are intended to always be true or false, respectively.  Such
 ** expressions could be omitted from the code completely.  But they
 ** are included in a few cases in order to enhance the resilience
@@ -8344,7 +12209,7 @@ SQLITE_PRIVATE   void sqlite3Coverage(int);
 ** be true and false so that the unreachable code they specify will
 ** not be counted as untested code.
 */
-#if defined(SQLITE_COVERAGE_TEST)
+#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
 # define ALWAYS(X)      (1)
 # define NEVER(X)       (0)
 #elif !defined(NDEBUG)
@@ -8355,6 +12220,54 @@ SQLITE_PRIVATE   void sqlite3Coverage(int);
 # define NEVER(X)       (X)
 #endif
 
+/*
+** Some malloc failures are only possible if SQLITE_TEST_REALLOC_STRESS is
+** defined.  We need to defend against those failures when testing with
+** SQLITE_TEST_REALLOC_STRESS, but we don't want the unreachable branches
+** during a normal build.  The following macro can be used to disable tests
+** that are always false except when SQLITE_TEST_REALLOC_STRESS is set.
+*/
+#if defined(SQLITE_TEST_REALLOC_STRESS)
+# define ONLY_IF_REALLOC_STRESS(X)  (X)
+#elif !defined(NDEBUG)
+# define ONLY_IF_REALLOC_STRESS(X)  ((X)?(assert(0),1):0)
+#else
+# define ONLY_IF_REALLOC_STRESS(X)  (0)
+#endif
+
+/*
+** Declarations used for tracing the operating system interfaces.
+*/
+#if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \
+    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
+  extern int sqlite3OSTrace;
+# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
+# define SQLITE_HAVE_OS_TRACE
+#else
+# define OSTRACE(X)
+# undef  SQLITE_HAVE_OS_TRACE
+#endif
+
+/*
+** Is the sqlite3ErrName() function needed in the build?  Currently,
+** it is needed by "mutex_w32.c" (when debugging), "os_win.c" (when
+** OSTRACE is enabled), and by several "test*.c" files (which are
+** compiled using SQLITE_TEST).
+*/
+#if defined(SQLITE_HAVE_OS_TRACE) || defined(SQLITE_TEST) || \
+    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
+# define SQLITE_NEED_ERR_NAME
+#else
+# undef  SQLITE_NEED_ERR_NAME
+#endif
+
+/*
+** SQLITE_ENABLE_EXPLAIN_COMMENTS is incompatible with SQLITE_OMIT_EXPLAIN
+*/
+#ifdef SQLITE_OMIT_EXPLAIN
+# undef SQLITE_ENABLE_EXPLAIN_COMMENTS
+#endif
+
 /*
 ** Return true (non-zero) if the input is an integer that is too large
 ** to fit in 32-bits.  This macro is used inside of various testcase()
@@ -8388,8 +12301,8 @@ SQLITE_PRIVATE   void sqlite3Coverage(int);
 ** This is the header file for the generic hash-table implementation
 ** used in SQLite.
 */
-#ifndef _SQLITE_HASH_H_
-#define _SQLITE_HASH_H_
+#ifndef SQLITE_HASH_H
+#define SQLITE_HASH_H
 
 /* Forward declarations of structures. */
 typedef struct Hash Hash;
@@ -8469,7 +12382,7 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 */
 /* #define sqliteHashCount(H)  ((H)->count) // NOT USED */
 
-#endif /* _SQLITE_HASH_H_ */
+#endif /* SQLITE_HASH_H */
 
 /************** End of hash.h ************************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -8502,75 +12415,75 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 #define TK_WITHOUT                         25
 #define TK_COMMA                           26
 #define TK_ID                              27
-#define TK_INDEXED                         28
-#define TK_ABORT                           29
-#define TK_ACTION                          30
-#define TK_AFTER                           31
-#define TK_ANALYZE                         32
-#define TK_ASC                             33
-#define TK_ATTACH                          34
-#define TK_BEFORE                          35
-#define TK_BY                              36
-#define TK_CASCADE                         37
-#define TK_CAST                            38
-#define TK_COLUMNKW                        39
-#define TK_CONFLICT                        40
-#define TK_DATABASE                        41
-#define TK_DESC                            42
-#define TK_DETACH                          43
-#define TK_EACH                            44
-#define TK_FAIL                            45
-#define TK_FOR                             46
-#define TK_IGNORE                          47
-#define TK_INITIALLY                       48
-#define TK_INSTEAD                         49
-#define TK_LIKE_KW                         50
-#define TK_MATCH                           51
-#define TK_NO                              52
-#define TK_KEY                             53
-#define TK_OF                              54
-#define TK_OFFSET                          55
-#define TK_PRAGMA                          56
-#define TK_RAISE                           57
-#define TK_RECURSIVE                       58
-#define TK_REPLACE                         59
-#define TK_RESTRICT                        60
-#define TK_ROW                             61
-#define TK_TRIGGER                         62
-#define TK_VACUUM                          63
-#define TK_VIEW                            64
-#define TK_VIRTUAL                         65
-#define TK_WITH                            66
-#define TK_REINDEX                         67
-#define TK_RENAME                          68
-#define TK_CTIME_KW                        69
-#define TK_ANY                             70
-#define TK_OR                              71
-#define TK_AND                             72
-#define TK_IS                              73
-#define TK_BETWEEN                         74
-#define TK_IN                              75
-#define TK_ISNULL                          76
-#define TK_NOTNULL                         77
-#define TK_NE                              78
-#define TK_EQ                              79
-#define TK_GT                              80
-#define TK_LE                              81
-#define TK_LT                              82
-#define TK_GE                              83
-#define TK_ESCAPE                          84
-#define TK_BITAND                          85
-#define TK_BITOR                           86
-#define TK_LSHIFT                          87
-#define TK_RSHIFT                          88
-#define TK_PLUS                            89
-#define TK_MINUS                           90
-#define TK_STAR                            91
-#define TK_SLASH                           92
-#define TK_REM                             93
-#define TK_CONCAT                          94
-#define TK_COLLATE                         95
-#define TK_BITNOT                          96
+#define TK_ABORT                           28
+#define TK_ACTION                          29
+#define TK_AFTER                           30
+#define TK_ANALYZE                         31
+#define TK_ASC                             32
+#define TK_ATTACH                          33
+#define TK_BEFORE                          34
+#define TK_BY                              35
+#define TK_CASCADE                         36
+#define TK_CAST                            37
+#define TK_COLUMNKW                        38
+#define TK_CONFLICT                        39
+#define TK_DATABASE                        40
+#define TK_DESC                            41
+#define TK_DETACH                          42
+#define TK_EACH                            43
+#define TK_FAIL                            44
+#define TK_FOR                             45
+#define TK_IGNORE                          46
+#define TK_INITIALLY                       47
+#define TK_INSTEAD                         48
+#define TK_LIKE_KW                         49
+#define TK_MATCH                           50
+#define TK_NO                              51
+#define TK_KEY                             52
+#define TK_OF                              53
+#define TK_OFFSET                          54
+#define TK_PRAGMA                          55
+#define TK_RAISE                           56
+#define TK_RECURSIVE                       57
+#define TK_REPLACE                         58
+#define TK_RESTRICT                        59
+#define TK_ROW                             60
+#define TK_TRIGGER                         61
+#define TK_VACUUM                          62
+#define TK_VIEW                            63
+#define TK_VIRTUAL                         64
+#define TK_WITH                            65
+#define TK_REINDEX                         66
+#define TK_RENAME                          67
+#define TK_CTIME_KW                        68
+#define TK_ANY                             69
+#define TK_OR                              70
+#define TK_AND                             71
+#define TK_IS                              72
+#define TK_BETWEEN                         73
+#define TK_IN                              74
+#define TK_ISNULL                          75
+#define TK_NOTNULL                         76
+#define TK_NE                              77
+#define TK_EQ                              78
+#define TK_GT                              79
+#define TK_LE                              80
+#define TK_LT                              81
+#define TK_GE                              82
+#define TK_ESCAPE                          83
+#define TK_BITAND                          84
+#define TK_BITOR                           85
+#define TK_LSHIFT                          86
+#define TK_RSHIFT                          87
+#define TK_PLUS                            88
+#define TK_MINUS                           89
+#define TK_STAR                            90
+#define TK_SLASH                           91
+#define TK_REM                             92
+#define TK_CONCAT                          93
+#define TK_COLLATE                         94
+#define TK_BITNOT                          95
+#define TK_INDEXED                         96
 #define TK_STRING                          97
 #define TK_JOIN_KW                         98
 #define TK_CONSTRAINT                      99
@@ -8606,9 +12519,9 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 #define TK_LIMIT                          129
 #define TK_WHERE                          130
 #define TK_INTO                           131
-#define TK_INTEGER                        132
-#define TK_FLOAT                          133
-#define TK_BLOB                           134
+#define TK_FLOAT                          132
+#define TK_BLOB                           133
+#define TK_INTEGER                        134
 #define TK_VARIABLE                       135
 #define TK_CASE                           136
 #define TK_WHEN                           137
@@ -8624,16 +12537,28 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 #define TK_TO_REAL                        147
 #define TK_ISNOT                          148
 #define TK_END_OF_FILE                    149
-#define TK_ILLEGAL                        150
-#define TK_SPACE                          151
-#define TK_UNCLOSED_STRING                152
-#define TK_FUNCTION                       153
-#define TK_COLUMN                         154
-#define TK_AGG_FUNCTION                   155
-#define TK_AGG_COLUMN                     156
-#define TK_UMINUS                         157
-#define TK_UPLUS                          158
-#define TK_REGISTER                       159
+#define TK_UNCLOSED_STRING                150
+#define TK_FUNCTION                       151
+#define TK_COLUMN                         152
+#define TK_AGG_FUNCTION                   153
+#define TK_AGG_COLUMN                     154
+#define TK_UMINUS                         155
+#define TK_UPLUS                          156
+#define TK_REGISTER                       157
+#define TK_VECTOR                         158
+#define TK_SELECT_COLUMN                  159
+#define TK_IF_NULL_ROW                    160
+#define TK_ASTERISK                       161
+#define TK_SPAN                           162
+#define TK_SPACE                          163
+#define TK_ILLEGAL                        164
+
+/* The token codes above must all fit in 8 bits */
+#define TKFLG_MASK           0xff  
+
+/* Flags that can be added to a token code when it is not
+** being stored in a u8: */
+#define TKFLG_DONTFOLD       0x100  /* Omit constant folding optimizations */
 
 /************** End of parse.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -8643,6 +12568,18 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 #include 
 #include 
 
+/*
+** Use a macro to replace memcpy() if compiled with SQLITE_INLINE_MEMCPY.
+** This allows better measurements of where memcpy() is used when running
+** cachegrind.  But this macro version of memcpy() is very slow so it
+** should not be used in production.  This is a performance measurement
+** hack only.
+*/
+#ifdef SQLITE_INLINE_MEMCPY
+# define memcpy(D,S,N) {char*xxd=(char*)(D);const char*xxs=(const char*)(S);\
+                        int xxn=(N);while(xxn-->0)*(xxd++)=*(xxs++);}
+#endif
+
 /*
 ** If compiling for a processor that lacks floating point support,
 ** substitute integer for floating-point
@@ -8665,7 +12602,7 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 
 /*
 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
-** afterward. Having this macro allows us to cause the C compiler 
+** afterward. Having this macro allows us to cause the C compiler
 ** to omit code used by TEMP tables without messy #ifndef statements.
 */
 #ifdef SQLITE_OMIT_TEMPDB
@@ -8699,12 +12636,11 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 */
 #ifndef SQLITE_TEMP_STORE
 # define SQLITE_TEMP_STORE 1
-# define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
 #endif
 
 /*
 ** If no value has been provided for SQLITE_MAX_WORKER_THREADS, or if
-** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it 
+** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it
 ** to zero.
 */
 #if SQLITE_TEMP_STORE==3 || SQLITE_THREADSAFE==0
@@ -8722,6 +12658,18 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 # define SQLITE_MAX_WORKER_THREADS SQLITE_DEFAULT_WORKER_THREADS
 #endif
 
+/*
+** The default initial allocation for the pagecache when using separate
+** pagecaches for each database connection.  A positive number is the
+** number of pages.  A negative number N translations means that a buffer
+** of -1024*N bytes is allocated and used for as many pages as it will hold.
+**
+** The default value of "20" was choosen to minimize the run-time of the
+** speedtest1 test program with options: --shrink-memory --reprepare
+*/
+#ifndef SQLITE_DEFAULT_PCACHE_INITSZ
+# define SQLITE_DEFAULT_PCACHE_INITSZ 20
+#endif
 
 /*
 ** GCC does not define the offsetof() macro so we'll have to do it
@@ -8734,8 +12682,12 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 /*
 ** Macros to compute minimum and maximum of two numbers.
 */
-#define MIN(A,B) ((A)<(B)?(A):(B))
-#define MAX(A,B) ((A)>(B)?(A):(B))
+#ifndef MIN
+# define MIN(A,B) ((A)<(B)?(A):(B))
+#endif
+#ifndef MAX
+# define MAX(A,B) ((A)>(B)?(A):(B))
+#endif
 
 /*
 ** Swap two objects of type TYPE.
@@ -8843,45 +12795,83 @@ typedef INT8_TYPE i8;              /* 1-byte signed integer */
 **      4 -> 20           1000 -> 99        1048576 -> 200
 **     10 -> 33           1024 -> 100    4294967296 -> 320
 **
-** The LogEst can be negative to indicate fractional values. 
+** The LogEst can be negative to indicate fractional values.
 ** Examples:
 **
 **    0.5 -> -10           0.1 -> -33        0.0625 -> -40
 */
 typedef INT16_TYPE LogEst;
 
+/*
+** Set the SQLITE_PTRSIZE macro to the number of bytes in a pointer
+*/
+#ifndef SQLITE_PTRSIZE
+# if defined(__SIZEOF_POINTER__)
+#   define SQLITE_PTRSIZE __SIZEOF_POINTER__
+# elif defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
+       defined(_M_ARM)   || defined(__arm__)    || defined(__x86)
+#   define SQLITE_PTRSIZE 4
+# else
+#   define SQLITE_PTRSIZE 8
+# endif
+#endif
+
+/* The uptr type is an unsigned integer large enough to hold a pointer
+*/
+#if defined(HAVE_STDINT_H)
+  typedef uintptr_t uptr;
+#elif SQLITE_PTRSIZE==4
+  typedef u32 uptr;
+#else
+  typedef u64 uptr;
+#endif
+
+/*
+** The SQLITE_WITHIN(P,S,E) macro checks to see if pointer P points to
+** something between S (inclusive) and E (exclusive).
+**
+** In other words, S is a buffer and E is a pointer to the first byte after
+** the end of buffer S.  This macro returns true if P points to something
+** contained within the buffer S.
+*/
+#define SQLITE_WITHIN(P,S,E) (((uptr)(P)>=(uptr)(S))&&((uptr)(P)<(uptr)(E)))
+
+
 /*
 ** Macros to determine whether the machine is big or little endian,
 ** and whether or not that determination is run-time or compile-time.
 **
 ** For best performance, an attempt is made to guess at the byte-order
 ** using C-preprocessor macros.  If that is unsuccessful, or if
-** -DSQLITE_RUNTIME_BYTEORDER=1 is set, then byte-order is determined
+** -DSQLITE_BYTEORDER=0 is set, then byte-order is determined
 ** at run-time.
 */
-#ifdef SQLITE_AMALGAMATION
-SQLITE_PRIVATE const int sqlite3one = 1;
-#else
-SQLITE_PRIVATE const int sqlite3one;
-#endif
-#if (defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
+#ifndef SQLITE_BYTEORDER
+# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
      defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
      defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
-     defined(__arm__)) && !defined(SQLITE_RUNTIME_BYTEORDER)
-# define SQLITE_BYTEORDER    1234
-# define SQLITE_BIGENDIAN    0
-# define SQLITE_LITTLEENDIAN 1
-# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
+     defined(__arm__)
+#   define SQLITE_BYTEORDER    1234
+# elif defined(sparc)    || defined(__ppc__)
+#   define SQLITE_BYTEORDER    4321
+# else
+#   define SQLITE_BYTEORDER 0
+# endif
 #endif
-#if (defined(sparc)    || defined(__ppc__))  \
-    && !defined(SQLITE_RUNTIME_BYTEORDER)
-# define SQLITE_BYTEORDER    4321
+#if SQLITE_BYTEORDER==4321
 # define SQLITE_BIGENDIAN    1
 # define SQLITE_LITTLEENDIAN 0
 # define SQLITE_UTF16NATIVE  SQLITE_UTF16BE
-#endif
-#if !defined(SQLITE_BYTEORDER)
-# define SQLITE_BYTEORDER    0     /* 0 means "unknown at compile-time" */
+#elif SQLITE_BYTEORDER==1234
+# define SQLITE_BIGENDIAN    0
+# define SQLITE_LITTLEENDIAN 1
+# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
+#else
+# ifdef SQLITE_AMALGAMATION
+  const int sqlite3one = 1;
+# else
+  extern const int sqlite3one;
+# endif
 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
 # define SQLITE_UTF16NATIVE  (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
@@ -8895,7 +12885,7 @@ SQLITE_PRIVATE const int sqlite3one;
 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
 
-/* 
+/*
 ** Round up a number to the next larger multiple of 8.  This is used
 ** to force 8-byte alignment on 64-bit architectures.
 */
@@ -8934,21 +12924,18 @@ SQLITE_PRIVATE const int sqlite3one;
 */
 #ifdef __APPLE__
 # include 
-# if TARGET_OS_IPHONE
-#   undef SQLITE_MAX_MMAP_SIZE
-#   define SQLITE_MAX_MMAP_SIZE 0
-# endif
 #endif
 #ifndef SQLITE_MAX_MMAP_SIZE
 # if defined(__linux__) \
   || defined(_WIN32) \
   || (defined(__APPLE__) && defined(__MACH__)) \
-  || defined(__sun)
+  || defined(__sun) \
+  || defined(__FreeBSD__) \
+  || defined(__DragonFly__)
 #   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
 # else
 #   define SQLITE_MAX_MMAP_SIZE 0
 # endif
-# define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
 #endif
 
 /*
@@ -8958,7 +12945,6 @@ SQLITE_PRIVATE const int sqlite3one;
 */
 #ifndef SQLITE_DEFAULT_MMAP_SIZE
 # define SQLITE_DEFAULT_MMAP_SIZE 0
-# define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
 #endif
 #if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
 # undef SQLITE_DEFAULT_MMAP_SIZE
@@ -8991,7 +12977,7 @@ SQLITE_PRIVATE const int sqlite3one;
 
 /*
 ** An instance of the following structure is used to store the busy-handler
-** callback for a given sqlite handle. 
+** callback for a given sqlite handle.
 **
 ** The sqlite.busyHandler member of the sqlite struct contains the busy
 ** callback for the database handle. Each pager opened via the sqlite
@@ -9036,9 +13022,9 @@ struct BusyHandler {
 
 /*
 ** The following value as a destructor means to use sqlite3DbFree().
-** The sqlite3DbFree() routine requires two parameters instead of the 
-** one parameter that destructors normally want.  So we have to introduce 
-** this magic value that the code knows to handle differently.  Any 
+** The sqlite3DbFree() routine requires two parameters instead of the
+** one parameter that destructors normally want.  So we have to introduce
+** this magic value that the code knows to handle differently.  Any
 ** pointer will work here as long as it is distinct from SQLITE_STATIC
 ** and SQLITE_TRANSIENT.
 */
@@ -9062,19 +13048,19 @@ struct BusyHandler {
   #define SQLITE_WSD const
   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
-SQLITE_API   int sqlite3_wsd_init(int N, int J);
-SQLITE_API   void *sqlite3_wsd_find(void *K, int L);
+SQLITE_API int sqlite3_wsd_init(int N, int J);
+SQLITE_API void *sqlite3_wsd_find(void *K, int L);
 #else
-  #define SQLITE_WSD 
+  #define SQLITE_WSD
   #define GLOBAL(t,v) v
   #define sqlite3GlobalConfig sqlite3Config
 #endif
 
 /*
 ** The following macros are used to suppress compiler warnings and to
-** make it clear to human readers when a function parameter is deliberately 
+** make it clear to human readers when a function parameter is deliberately
 ** left unused within the body of a function. This usually happens when
-** a function is called via a function pointer. For example the 
+** a function is called via a function pointer. For example the
 ** implementation of an SQL aggregate step callback may not use the
 ** parameter indicating the number of arguments passed to the aggregate,
 ** if it knows that this is enforced elsewhere.
@@ -9117,6 +13103,7 @@ typedef struct LookasideSlot LookasideSlot;
 typedef struct Module Module;
 typedef struct NameContext NameContext;
 typedef struct Parse Parse;
+typedef struct PreUpdate PreUpdate;
 typedef struct PrintfArguments PrintfArguments;
 typedef struct RowSet RowSet;
 typedef struct Savepoint Savepoint;
@@ -9139,8 +13126,16 @@ typedef struct Walker Walker;
 typedef struct WhereInfo WhereInfo;
 typedef struct With With;
 
+/* A VList object records a mapping between parameters/variables/wildcards
+** in the SQL statement (such as $abc, @pqr, or :xyz) and the integer
+** variable number associated with that parameter.  See the format description
+** on the sqlite3VListAdd() routine for more information.  A VList is really
+** just an array of integers.
+*/
+typedef int VList;
+
 /*
-** Defer sourcing vdbe.h and btree.h until after the "u8" and 
+** Defer sourcing vdbe.h and btree.h until after the "u8" and
 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
 ** pointer types (i.e. FuncDef) defined above.
 */
@@ -9161,8 +13156,8 @@ typedef struct With With;
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 */
-#ifndef _BTREE_H_
-#define _BTREE_H_
+#ifndef SQLITE_BTREE_H
+#define SQLITE_BTREE_H
 
 /* TODO: This definition is just included so other modules compile. It
 ** needs to be revisited.
@@ -9187,6 +13182,7 @@ typedef struct With With;
 typedef struct Btree Btree;
 typedef struct BtCursor BtCursor;
 typedef struct BtShared BtShared;
+typedef struct BtreePayload BtreePayload;
 
 
 SQLITE_PRIVATE int sqlite3BtreeOpen(
@@ -9211,20 +13207,18 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 
 SQLITE_PRIVATE int sqlite3BtreeClose(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree*,int);
+SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree*,int);
 #if SQLITE_MAX_MMAP_SIZE>0
 SQLITE_PRIVATE   int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);
 #endif
 SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(Btree*,unsigned);
-SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
 SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree*,int);
 SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree*,int);
-SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree*);
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
+SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p);
-#endif
 SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int);
 SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *);
 SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int);
@@ -9239,7 +13233,9 @@ SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeIsInBackup(Btree*);
 SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
 SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *pBtree);
+#ifndef SQLITE_OMIT_SHARED_CACHE
 SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock);
+#endif
 SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *, int, int);
 
 SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *);
@@ -9300,10 +13296,75 @@ SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p);
 #define BTREE_DATA_VERSION        15  /* A virtual meta-value */
 
 /*
-** Values that may be OR'd together to form the second argument of an
-** sqlite3BtreeCursorHints() call.
+** Kinds of hints that can be passed into the sqlite3BtreeCursorHint()
+** interface.
+**
+** BTREE_HINT_RANGE  (arguments: Expr*, Mem*)
+**
+**     The first argument is an Expr* (which is guaranteed to be constant for
+**     the lifetime of the cursor) that defines constraints on which rows
+**     might be fetched with this cursor.  The Expr* tree may contain
+**     TK_REGISTER nodes that refer to values stored in the array of registers
+**     passed as the second parameter.  In other words, if Expr.op==TK_REGISTER
+**     then the value of the node is the value in Mem[pExpr.iTable].  Any
+**     TK_COLUMN node in the expression tree refers to the Expr.iColumn-th
+**     column of the b-tree of the cursor.  The Expr tree will not contain
+**     any function calls nor subqueries nor references to b-trees other than
+**     the cursor being hinted.
+**
+**     The design of the _RANGE hint is aid b-tree implementations that try
+**     to prefetch content from remote machines - to provide those
+**     implementations with limits on what needs to be prefetched and thereby
+**     reduce network bandwidth.
+**
+** Note that BTREE_HINT_FLAGS with BTREE_BULKLOAD is the only hint used by
+** standard SQLite.  The other hints are provided for extentions that use
+** the SQLite parser and code generator but substitute their own storage
+** engine.
+*/
+#define BTREE_HINT_RANGE 0       /* Range constraints on queries */
+
+/*
+** Values that may be OR'd together to form the argument to the
+** BTREE_HINT_FLAGS hint for sqlite3BtreeCursorHint():
+**
+** The BTREE_BULKLOAD flag is set on index cursors when the index is going
+** to be filled with content that is already in sorted order.
+**
+** The BTREE_SEEK_EQ flag is set on cursors that will get OP_SeekGE or
+** OP_SeekLE opcodes for a range search, but where the range of entries
+** selected will all have the same key.  In other words, the cursor will
+** be used only for equality key searches.
+**
+*/
+#define BTREE_BULKLOAD 0x00000001  /* Used to full index in sorted order */
+#define BTREE_SEEK_EQ  0x00000002  /* EQ seeks only - no range seeks */
+
+/* 
+** Flags passed as the third argument to sqlite3BtreeCursor().
+**
+** For read-only cursors the wrFlag argument is always zero. For read-write
+** cursors it may be set to either (BTREE_WRCSR|BTREE_FORDELETE) or just
+** (BTREE_WRCSR). If the BTREE_FORDELETE bit is set, then the cursor will
+** only be used by SQLite for the following:
+**
+**   * to seek to and then delete specific entries, and/or
+**
+**   * to read values that will be used to create keys that other
+**     BTREE_FORDELETE cursors will seek to and delete.
+**
+** The BTREE_FORDELETE flag is an optimization hint.  It is not used by
+** by this, the native b-tree engine of SQLite, but it is available to
+** alternative storage engines that might be substituted in place of this
+** b-tree system.  For alternative storage engines in which a delete of
+** the main table row automatically deletes corresponding index rows,
+** the FORDELETE flag hint allows those alternative storage engines to
+** skip a lot of work.  Namely:  FORDELETE cursors may treat all SEEK
+** and DELETE operations as no-ops, and any READ operation against a
+** FORDELETE cursor may return a null row: 0x01 0x00.
 */
-#define BTREE_BULKLOAD 0x00000001
+#define BTREE_WRCSR     0x00000004     /* read-write cursor */
+#define BTREE_FORDELETE 0x00000008     /* Cursor is for seek/delete only */
 
 SQLITE_PRIVATE int sqlite3BtreeCursor(
   Btree*,                              /* BTree containing table to open */
@@ -9314,6 +13375,10 @@ SQLITE_PRIVATE int sqlite3BtreeCursor(
 );
 SQLITE_PRIVATE int sqlite3BtreeCursorSize(void);
 SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor*);
+SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor*, unsigned);
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor*, int, ...);
+#endif
 
 SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
@@ -9325,36 +13390,72 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
 );
 SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor*, int*);
-SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*);
-SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
-                                  const void *pData, int nData,
-                                  int nZero, int bias, int seekResult);
+SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*, u8 flags);
+
+/* Allowed flags for sqlite3BtreeDelete() and sqlite3BtreeInsert() */
+#define BTREE_SAVEPOSITION 0x02  /* Leave cursor pointing at NEXT or PREV */
+#define BTREE_AUXDELETE    0x04  /* not the primary delete operation */
+#define BTREE_APPEND       0x08  /* Insert is likely an append */
+
+/* An instance of the BtreePayload object describes the content of a single
+** entry in either an index or table btree.
+**
+** Index btrees (used for indexes and also WITHOUT ROWID tables) contain
+** an arbitrary key and no data.  These btrees have pKey,nKey set to their
+** key and pData,nData,nZero set to zero.
+**
+** Table btrees (used for rowid tables) contain an integer rowid used as
+** the key and passed in the nKey field.  The pKey field is zero.  
+** pData,nData hold the content of the new entry.  nZero extra zero bytes
+** are appended to the end of the content when constructing the entry.
+**
+** This object is used to pass information into sqlite3BtreeInsert().  The
+** same information used to be passed as five separate parameters.  But placing
+** the information into this object helps to keep the interface more 
+** organized and understandable, and it also helps the resulting code to
+** run a little faster by using fewer registers for parameter passing.
+*/
+struct BtreePayload {
+  const void *pKey;       /* Key content for indexes.  NULL for tables */
+  sqlite3_int64 nKey;     /* Size of pKey for indexes.  PRIMARY KEY for tabs */
+  const void *pData;      /* Data for tables.  NULL for indexes */
+  sqlite3_value *aMem;    /* First of nMem value in the unpacked pKey */
+  u16 nMem;               /* Number of aMem[] value.  Might be zero */
+  int nData;              /* Size of pData.  0 if none. */
+  int nZero;              /* Extra zero data appended after pData,nData */
+};
+
+SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,
+                       int flags, int seekResult);
 SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);
 SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);
-SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int *pRes);
+SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int flags);
 SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);
-SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int *pRes);
-SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
-SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
-SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor*, u32 *pAmt);
-SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor*, u32 *pAmt);
-SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
-SQLITE_PRIVATE int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);
+SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int flags);
+SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor*);
+SQLITE_PRIVATE int sqlite3BtreePayload(BtCursor*, u32 offset, u32 amt, void*);
+SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor*, u32 *pAmt);
+SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor*);
 
 SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
 SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);
+SQLITE_PRIVATE i64 sqlite3BtreeRowCountEst(BtCursor*);
 
+#ifndef SQLITE_OMIT_INCRBLOB
+SQLITE_PRIVATE int sqlite3BtreePayloadChecked(BtCursor*, u32 offset, u32 amt, void*);
 SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
 SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *);
+#endif
 SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *);
 SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
-SQLITE_PRIVATE void sqlite3BtreeCursorHints(BtCursor *, unsigned int mask);
+SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor*, unsigned int mask);
 SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *pBt);
 SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void);
 
 #ifndef NDEBUG
 SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor*);
 #endif
+SQLITE_PRIVATE int sqlite3BtreeCursorIsValidNN(BtCursor*);
 
 #ifndef SQLITE_OMIT_BTREECOUNT
 SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *, i64 *);
@@ -9377,15 +13478,19 @@ SQLITE_PRIVATE   int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);
 #ifndef SQLITE_OMIT_SHARED_CACHE
 SQLITE_PRIVATE   void sqlite3BtreeEnter(Btree*);
 SQLITE_PRIVATE   void sqlite3BtreeEnterAll(sqlite3*);
+SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);
+SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
+SQLITE_PRIVATE   int sqlite3BtreeConnectionCount(Btree*);
 #else
 # define sqlite3BtreeEnter(X) 
 # define sqlite3BtreeEnterAll(X)
+# define sqlite3BtreeSharable(X) 0
+# define sqlite3BtreeEnterCursor(X)
+# define sqlite3BtreeConnectionCount(X) 1
 #endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
-SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);
 SQLITE_PRIVATE   void sqlite3BtreeLeave(Btree*);
-SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
 SQLITE_PRIVATE   void sqlite3BtreeLeaveCursor(BtCursor*);
 SQLITE_PRIVATE   void sqlite3BtreeLeaveAll(sqlite3*);
 #ifndef NDEBUG
@@ -9396,9 +13501,7 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 #endif
 #else
 
-# define sqlite3BtreeSharable(X) 0
 # define sqlite3BtreeLeave(X)
-# define sqlite3BtreeEnterCursor(X)
 # define sqlite3BtreeLeaveCursor(X)
 # define sqlite3BtreeLeaveAll(X)
 
@@ -9408,7 +13511,7 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 #endif
 
 
-#endif /* _BTREE_H_ */
+#endif /* SQLITE_BTREE_H */
 
 /************** End of btree.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -9431,8 +13534,8 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 ** or VDBE.  The VDBE implements an abstract machine that runs a
 ** simple program to access and modify the underlying database.
 */
-#ifndef _SQLITE_VDBE_H_
-#define _SQLITE_VDBE_H_
+#ifndef SQLITE_VDBE_H
+#define SQLITE_VDBE_H
 /* #include  */
 
 /*
@@ -9446,7 +13549,7 @@ typedef struct Vdbe Vdbe;
 ** The names of the following types declared in vdbeInt.h are required
 ** for the VdbeOp definition.
 */
-typedef struct Mem Mem;
+typedef struct sqlite3_value Mem;
 typedef struct SubProgram SubProgram;
 
 /*
@@ -9457,25 +13560,29 @@ typedef struct SubProgram SubProgram;
 struct VdbeOp {
   u8 opcode;          /* What operation to perform */
   signed char p4type; /* One of the P4_xxx constants for p4 */
-  u8 opflags;         /* Mask of the OPFLG_* flags in opcodes.h */
-  u8 p5;              /* Fifth parameter is an unsigned character */
+  u16 p5;             /* Fifth parameter is an unsigned 16-bit integer */
   int p1;             /* First operand */
   int p2;             /* Second parameter (often the jump destination) */
   int p3;             /* The third parameter */
-  union {             /* fourth parameter */
+  union p4union {     /* fourth parameter */
     int i;                 /* Integer value if p4type==P4_INT32 */
     void *p;               /* Generic pointer */
     char *z;               /* Pointer to data for string (char array) types */
     i64 *pI64;             /* Used when p4type is P4_INT64 */
     double *pReal;         /* Used when p4type is P4_REAL */
     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
+    sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */
     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
     Mem *pMem;             /* Used when p4type is P4_MEM */
     VTable *pVtab;         /* Used when p4type is P4_VTAB */
     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
     int *ai;               /* Used when p4type is P4_INTARRAY */
     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
-    int (*xAdvance)(BtCursor *, int *);
+    Table *pTab;           /* Used when p4type is P4_TABLE */
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+    Expr *pExpr;           /* Used when p4type is P4_EXPR */
+#endif
+    int (*xAdvance)(BtCursor *, int);
   } p4;
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   char *zComment;          /* Comment to improve readability */
@@ -9499,7 +13606,7 @@ struct SubProgram {
   int nOp;                      /* Elements in aOp[] */
   int nMem;                     /* Number of memory cells required */
   int nCsr;                     /* Number of cursors required */
-  int nOnce;                    /* Number of OP_Once instructions */
+  u8 *aOnce;                    /* Array of OP_Once flags */
   void *token;                  /* id that may be used to recursive triggers */
   SubProgram *pNext;            /* Next sub-program already visited */
 };
@@ -9519,22 +13626,26 @@ typedef struct VdbeOpList VdbeOpList;
 /*
 ** Allowed values of VdbeOp.p4type
 */
-#define P4_NOTUSED    0   /* The P4 parameter is not used */
-#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
-#define P4_STATIC   (-2)  /* Pointer to a static string */
-#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
-#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
-#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
-#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
-#define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
-#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
-#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
-#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
-#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
-#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
-#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
-#define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
-#define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
+#define P4_NOTUSED      0   /* The P4 parameter is not used */
+#define P4_TRANSIENT    0   /* P4 is a pointer to a transient string */
+#define P4_STATIC     (-1)  /* Pointer to a static string */
+#define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */
+#define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */
+#define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */
+#define P4_ADVANCE    (-5)  /* P4 is a pointer to BtreeNext() or BtreePrev() */
+#define P4_TABLE      (-6)  /* P4 is a pointer to a Table structure */
+/* Above do not own any resources.  Must free those below */
+#define P4_FREE_IF_LE (-7)
+#define P4_DYNAMIC    (-7)  /* Pointer to memory from sqliteMalloc() */
+#define P4_FUNCDEF    (-8)  /* P4 is a pointer to a FuncDef structure */
+#define P4_KEYINFO    (-9)  /* P4 is a pointer to a KeyInfo structure */
+#define P4_EXPR       (-10) /* P4 is a pointer to an Expr tree */
+#define P4_MEM        (-11) /* P4 is a pointer to a Mem*    structure */
+#define P4_VTAB       (-12) /* P4 is a pointer to an sqlite3_vtab structure */
+#define P4_REAL       (-13) /* P4 is a 64-bit floating point value */
+#define P4_INT64      (-14) /* P4 is a 64-bit signed integer */
+#define P4_INTARRAY   (-15) /* P4 is a vector of 32-bit integers */
+#define P4_FUNCCTX    (-16) /* P4 is a pointer to an sqlite3_context object */
 
 /* Error message codes for OP_Halt */
 #define P5_ConstraintNotNull 1
@@ -9576,200 +13687,227 @@ typedef struct VdbeOpList VdbeOpList;
 /************** Include opcodes.h in the middle of vdbe.h ********************/
 /************** Begin file opcodes.h *****************************************/
 /* Automatically generated.  Do not edit */
-/* See the mkopcodeh.awk script for details */
-#define OP_Function        1 /* synopsis: r[P3]=func(r[P2@P5])             */
-#define OP_Savepoint       2
-#define OP_AutoCommit      3
-#define OP_Transaction     4
-#define OP_SorterNext      5
-#define OP_PrevIfOpen      6
-#define OP_NextIfOpen      7
-#define OP_Prev            8
-#define OP_Next            9
-#define OP_AggStep        10 /* synopsis: accum=r[P3] step(r[P2@P5])       */
-#define OP_Checkpoint     11
-#define OP_JournalMode    12
-#define OP_Vacuum         13
-#define OP_VFilter        14 /* synopsis: iplan=r[P3] zplan='P4'           */
-#define OP_VUpdate        15 /* synopsis: data=r[P3@P2]                    */
-#define OP_Goto           16
-#define OP_Gosub          17
-#define OP_Return         18
+/* See the tool/mkopcodeh.tcl script for details */
+#define OP_Savepoint       0
+#define OP_AutoCommit      1
+#define OP_Transaction     2
+#define OP_SorterNext      3
+#define OP_PrevIfOpen      4
+#define OP_NextIfOpen      5
+#define OP_Prev            6
+#define OP_Next            7
+#define OP_Checkpoint      8
+#define OP_JournalMode     9
+#define OP_Vacuum         10
+#define OP_VFilter        11 /* synopsis: iplan=r[P3] zplan='P4'           */
+#define OP_VUpdate        12 /* synopsis: data=r[P3@P2]                    */
+#define OP_Goto           13
+#define OP_Gosub          14
+#define OP_InitCoroutine  15
+#define OP_Yield          16
+#define OP_MustBeInt      17
+#define OP_Jump           18
 #define OP_Not            19 /* same as TK_NOT, synopsis: r[P2]= !r[P1]    */
-#define OP_InitCoroutine  20
-#define OP_EndCoroutine   21
-#define OP_Yield          22
-#define OP_HaltIfNull     23 /* synopsis: if r[P3]=null halt               */
-#define OP_Halt           24
-#define OP_Integer        25 /* synopsis: r[P2]=P1                         */
-#define OP_Int64          26 /* synopsis: r[P2]=P4                         */
-#define OP_String         27 /* synopsis: r[P2]='P4' (len=P1)              */
-#define OP_Null           28 /* synopsis: r[P2..P3]=NULL                   */
-#define OP_SoftNull       29 /* synopsis: r[P1]=NULL                       */
-#define OP_Blob           30 /* synopsis: r[P2]=P4 (len=P1)                */
-#define OP_Variable       31 /* synopsis: r[P2]=parameter(P1,P4)           */
-#define OP_Move           32 /* synopsis: r[P2@P3]=r[P1@P3]                */
-#define OP_Copy           33 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
-#define OP_SCopy          34 /* synopsis: r[P2]=r[P1]                      */
-#define OP_ResultRow      35 /* synopsis: output=r[P1@P2]                  */
-#define OP_CollSeq        36
-#define OP_AddImm         37 /* synopsis: r[P1]=r[P1]+P2                   */
-#define OP_MustBeInt      38
-#define OP_RealAffinity   39
-#define OP_Cast           40 /* synopsis: affinity(r[P1])                  */
-#define OP_Permutation    41
-#define OP_Compare        42 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
-#define OP_Jump           43
-#define OP_Once           44
-#define OP_If             45
-#define OP_IfNot          46
-#define OP_Column         47 /* synopsis: r[P3]=PX                         */
-#define OP_Affinity       48 /* synopsis: affinity(r[P1@P2])               */
-#define OP_MakeRecord     49 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
-#define OP_Count          50 /* synopsis: r[P2]=count()                    */
-#define OP_ReadCookie     51
-#define OP_SetCookie      52
-#define OP_ReopenIdx      53 /* synopsis: root=P2 iDb=P3                   */
-#define OP_OpenRead       54 /* synopsis: root=P2 iDb=P3                   */
-#define OP_OpenWrite      55 /* synopsis: root=P2 iDb=P3                   */
-#define OP_OpenAutoindex  56 /* synopsis: nColumn=P2                       */
-#define OP_OpenEphemeral  57 /* synopsis: nColumn=P2                       */
-#define OP_SorterOpen     58
-#define OP_SequenceTest   59 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
-#define OP_OpenPseudo     60 /* synopsis: P3 columns in r[P2]              */
-#define OP_Close          61
-#define OP_SeekLT         62 /* synopsis: key=r[P3@P4]                     */
-#define OP_SeekLE         63 /* synopsis: key=r[P3@P4]                     */
-#define OP_SeekGE         64 /* synopsis: key=r[P3@P4]                     */
-#define OP_SeekGT         65 /* synopsis: key=r[P3@P4]                     */
-#define OP_Seek           66 /* synopsis: intkey=r[P2]                     */
-#define OP_NoConflict     67 /* synopsis: key=r[P3@P4]                     */
-#define OP_NotFound       68 /* synopsis: key=r[P3@P4]                     */
-#define OP_Found          69 /* synopsis: key=r[P3@P4]                     */
-#define OP_NotExists      70 /* synopsis: intkey=r[P3]                     */
-#define OP_Or             71 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
-#define OP_And            72 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
-#define OP_Sequence       73 /* synopsis: r[P2]=cursor[P1].ctr++           */
-#define OP_NewRowid       74 /* synopsis: r[P2]=rowid                      */
-#define OP_Insert         75 /* synopsis: intkey=r[P3] data=r[P2]          */
-#define OP_IsNull         76 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
-#define OP_NotNull        77 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
-#define OP_Ne             78 /* same as TK_NE, synopsis: if r[P1]!=r[P3] goto P2 */
-#define OP_Eq             79 /* same as TK_EQ, synopsis: if r[P1]==r[P3] goto P2 */
-#define OP_Gt             80 /* same as TK_GT, synopsis: if r[P1]>r[P3] goto P2 */
-#define OP_Le             81 /* same as TK_LE, synopsis: if r[P1]<=r[P3] goto P2 */
-#define OP_Lt             82 /* same as TK_LT, synopsis: if r[P1]=r[P3] goto P2 */
-#define OP_InsertInt      84 /* synopsis: intkey=P3 data=r[P2]             */
-#define OP_BitAnd         85 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
-#define OP_BitOr          86 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
-#define OP_ShiftLeft      87 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<>r[P1] */
-#define OP_Add            89 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
-#define OP_Subtract       90 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
-#define OP_Multiply       91 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
-#define OP_Divide         92 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
-#define OP_Remainder      93 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
-#define OP_Concat         94 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
-#define OP_Delete         95
-#define OP_BitNot         96 /* same as TK_BITNOT, synopsis: r[P1]= ~r[P1] */
+#define OP_Once           20
+#define OP_If             21
+#define OP_IfNot          22
+#define OP_IfNullRow      23 /* synopsis: if P1.nullRow then r[P3]=NULL, goto P2 */
+#define OP_SeekLT         24 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekLE         25 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekGE         26 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekGT         27 /* synopsis: key=r[P3@P4]                     */
+#define OP_NoConflict     28 /* synopsis: key=r[P3@P4]                     */
+#define OP_NotFound       29 /* synopsis: key=r[P3@P4]                     */
+#define OP_Found          30 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekRowid      31 /* synopsis: intkey=r[P3]                     */
+#define OP_NotExists      32 /* synopsis: intkey=r[P3]                     */
+#define OP_Last           33
+#define OP_IfSmaller      34
+#define OP_SorterSort     35
+#define OP_Sort           36
+#define OP_Rewind         37
+#define OP_IdxLE          38 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxGT          39 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxLT          40 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxGE          41 /* synopsis: key=r[P3@P4]                     */
+#define OP_RowSetRead     42 /* synopsis: r[P3]=rowset(P1)                 */
+#define OP_RowSetTest     43 /* synopsis: if r[P3] in rowset(P1) goto P2   */
+#define OP_Program        44
+#define OP_FkIfZero       45 /* synopsis: if fkctr[P1]==0 goto P2          */
+#define OP_IfPos          46 /* synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
+#define OP_IfNotZero      47 /* synopsis: if r[P1]!=0 then r[P1]--, goto P2 */
+#define OP_DecrJumpZero   48 /* synopsis: if (--r[P1])==0 goto P2          */
+#define OP_IncrVacuum     49
+#define OP_VNext          50
+#define OP_Init           51 /* synopsis: Start at P2                      */
+#define OP_Return         52
+#define OP_EndCoroutine   53
+#define OP_HaltIfNull     54 /* synopsis: if r[P3]=null halt               */
+#define OP_Halt           55
+#define OP_Integer        56 /* synopsis: r[P2]=P1                         */
+#define OP_Int64          57 /* synopsis: r[P2]=P4                         */
+#define OP_String         58 /* synopsis: r[P2]='P4' (len=P1)              */
+#define OP_Null           59 /* synopsis: r[P2..P3]=NULL                   */
+#define OP_SoftNull       60 /* synopsis: r[P1]=NULL                       */
+#define OP_Blob           61 /* synopsis: r[P2]=P4 (len=P1)                */
+#define OP_Variable       62 /* synopsis: r[P2]=parameter(P1,P4)           */
+#define OP_Move           63 /* synopsis: r[P2@P3]=r[P1@P3]                */
+#define OP_Copy           64 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
+#define OP_SCopy          65 /* synopsis: r[P2]=r[P1]                      */
+#define OP_IntCopy        66 /* synopsis: r[P2]=r[P1]                      */
+#define OP_ResultRow      67 /* synopsis: output=r[P1@P2]                  */
+#define OP_CollSeq        68
+#define OP_AddImm         69 /* synopsis: r[P1]=r[P1]+P2                   */
+#define OP_Or             70 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
+#define OP_And            71 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
+#define OP_RealAffinity   72
+#define OP_Cast           73 /* synopsis: affinity(r[P1])                  */
+#define OP_Permutation    74
+#define OP_IsNull         75 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
+#define OP_NotNull        76 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
+#define OP_Ne             77 /* same as TK_NE, synopsis: IF r[P3]!=r[P1]   */
+#define OP_Eq             78 /* same as TK_EQ, synopsis: IF r[P3]==r[P1]   */
+#define OP_Gt             79 /* same as TK_GT, synopsis: IF r[P3]>r[P1]    */
+#define OP_Le             80 /* same as TK_LE, synopsis: IF r[P3]<=r[P1]   */
+#define OP_Lt             81 /* same as TK_LT, synopsis: IF r[P3]=r[P1]   */
+#define OP_ElseNotEq      83 /* same as TK_ESCAPE                          */
+#define OP_BitAnd         84 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
+#define OP_BitOr          85 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
+#define OP_ShiftLeft      86 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<>r[P1] */
+#define OP_Add            88 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
+#define OP_Subtract       89 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
+#define OP_Multiply       90 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
+#define OP_Divide         91 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
+#define OP_Remainder      92 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
+#define OP_Concat         93 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
+#define OP_Compare        94 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
+#define OP_BitNot         95 /* same as TK_BITNOT, synopsis: r[P1]= ~r[P1] */
+#define OP_Column         96 /* synopsis: r[P3]=PX                         */
 #define OP_String8        97 /* same as TK_STRING, synopsis: r[P2]='P4'    */
-#define OP_ResetCount     98
-#define OP_SorterCompare  99 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
-#define OP_SorterData    100 /* synopsis: r[P2]=data                       */
-#define OP_RowKey        101 /* synopsis: r[P2]=key                        */
-#define OP_RowData       102 /* synopsis: r[P2]=data                       */
-#define OP_Rowid         103 /* synopsis: r[P2]=rowid                      */
-#define OP_NullRow       104
-#define OP_Last          105
-#define OP_SorterSort    106
-#define OP_Sort          107
-#define OP_Rewind        108
-#define OP_SorterInsert  109
-#define OP_IdxInsert     110 /* synopsis: key=r[P2]                        */
-#define OP_IdxDelete     111 /* synopsis: key=r[P2@P3]                     */
-#define OP_IdxRowid      112 /* synopsis: r[P2]=rowid                      */
-#define OP_IdxLE         113 /* synopsis: key=r[P3@P4]                     */
-#define OP_IdxGT         114 /* synopsis: key=r[P3@P4]                     */
-#define OP_IdxLT         115 /* synopsis: key=r[P3@P4]                     */
-#define OP_IdxGE         116 /* synopsis: key=r[P3@P4]                     */
-#define OP_Destroy       117
-#define OP_Clear         118
-#define OP_ResetSorter   119
-#define OP_CreateIndex   120 /* synopsis: r[P2]=root iDb=P1                */
-#define OP_CreateTable   121 /* synopsis: r[P2]=root iDb=P1                */
-#define OP_ParseSchema   122
-#define OP_LoadAnalysis  123
-#define OP_DropTable     124
-#define OP_DropIndex     125
-#define OP_DropTrigger   126
-#define OP_IntegrityCk   127
-#define OP_RowSetAdd     128 /* synopsis: rowset(P1)=r[P2]                 */
-#define OP_RowSetRead    129 /* synopsis: r[P3]=rowset(P1)                 */
-#define OP_RowSetTest    130 /* synopsis: if r[P3] in rowset(P1) goto P2   */
-#define OP_Program       131
-#define OP_Param         132
-#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
-#define OP_FkCounter     134 /* synopsis: fkctr[P1]+=P2                    */
-#define OP_FkIfZero      135 /* synopsis: if fkctr[P1]==0 goto P2          */
-#define OP_MemMax        136 /* synopsis: r[P1]=max(r[P1],r[P2])           */
-#define OP_IfPos         137 /* synopsis: if r[P1]>0 goto P2               */
-#define OP_IfNeg         138 /* synopsis: r[P1]+=P3, if r[P1]<0 goto P2    */
-#define OP_IfZero        139 /* synopsis: r[P1]+=P3, if r[P1]==0 goto P2   */
-#define OP_AggFinal      140 /* synopsis: accum=r[P1] N=P2                 */
-#define OP_IncrVacuum    141
-#define OP_Expire        142
-#define OP_TableLock     143 /* synopsis: iDb=P1 root=P2 write=P3          */
-#define OP_VBegin        144
-#define OP_VCreate       145
-#define OP_VDestroy      146
-#define OP_VOpen         147
-#define OP_VColumn       148 /* synopsis: r[P3]=vcolumn(P2)                */
-#define OP_VNext         149
-#define OP_VRename       150
-#define OP_Pagecount     151
-#define OP_MaxPgcnt      152
-#define OP_Init          153 /* synopsis: Start at P2                      */
-#define OP_Noop          154
-#define OP_Explain       155
-
+#define OP_Affinity       98 /* synopsis: affinity(r[P1@P2])               */
+#define OP_MakeRecord     99 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
+#define OP_Count         100 /* synopsis: r[P2]=count()                    */
+#define OP_ReadCookie    101
+#define OP_SetCookie     102
+#define OP_ReopenIdx     103 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenRead      104 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenWrite     105 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenDup       106
+#define OP_OpenAutoindex 107 /* synopsis: nColumn=P2                       */
+#define OP_OpenEphemeral 108 /* synopsis: nColumn=P2                       */
+#define OP_SorterOpen    109
+#define OP_SequenceTest  110 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
+#define OP_OpenPseudo    111 /* synopsis: P3 columns in r[P2]              */
+#define OP_Close         112
+#define OP_ColumnsUsed   113
+#define OP_Sequence      114 /* synopsis: r[P2]=cursor[P1].ctr++           */
+#define OP_NewRowid      115 /* synopsis: r[P2]=rowid                      */
+#define OP_Insert        116 /* synopsis: intkey=r[P3] data=r[P2]          */
+#define OP_InsertInt     117 /* synopsis: intkey=P3 data=r[P2]             */
+#define OP_Delete        118
+#define OP_ResetCount    119
+#define OP_SorterCompare 120 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
+#define OP_SorterData    121 /* synopsis: r[P2]=data                       */
+#define OP_RowData       122 /* synopsis: r[P2]=data                       */
+#define OP_Rowid         123 /* synopsis: r[P2]=rowid                      */
+#define OP_NullRow       124
+#define OP_SorterInsert  125 /* synopsis: key=r[P2]                        */
+#define OP_IdxInsert     126 /* synopsis: key=r[P2]                        */
+#define OP_IdxDelete     127 /* synopsis: key=r[P2@P3]                     */
+#define OP_DeferredSeek  128 /* synopsis: Move P3 to P1.rowid if needed    */
+#define OP_IdxRowid      129 /* synopsis: r[P2]=rowid                      */
+#define OP_Destroy       130
+#define OP_Clear         131
+#define OP_Real          132 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
+#define OP_ResetSorter   133
+#define OP_CreateIndex   134 /* synopsis: r[P2]=root iDb=P1                */
+#define OP_CreateTable   135 /* synopsis: r[P2]=root iDb=P1                */
+#define OP_SqlExec       136
+#define OP_ParseSchema   137
+#define OP_LoadAnalysis  138
+#define OP_DropTable     139
+#define OP_DropIndex     140
+#define OP_DropTrigger   141
+#define OP_IntegrityCk   142
+#define OP_RowSetAdd     143 /* synopsis: rowset(P1)=r[P2]                 */
+#define OP_Param         144
+#define OP_FkCounter     145 /* synopsis: fkctr[P1]+=P2                    */
+#define OP_MemMax        146 /* synopsis: r[P1]=max(r[P1],r[P2])           */
+#define OP_OffsetLimit   147 /* synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1) */
+#define OP_AggStep0      148 /* synopsis: accum=r[P3] step(r[P2@P5])       */
+#define OP_AggStep       149 /* synopsis: accum=r[P3] step(r[P2@P5])       */
+#define OP_AggFinal      150 /* synopsis: accum=r[P1] N=P2                 */
+#define OP_Expire        151
+#define OP_TableLock     152 /* synopsis: iDb=P1 root=P2 write=P3          */
+#define OP_VBegin        153
+#define OP_VCreate       154
+#define OP_VDestroy      155
+#define OP_VOpen         156
+#define OP_VColumn       157 /* synopsis: r[P3]=vcolumn(P2)                */
+#define OP_VRename       158
+#define OP_Pagecount     159
+#define OP_MaxPgcnt      160
+#define OP_PureFunc0     161
+#define OP_Function0     162 /* synopsis: r[P3]=func(r[P2@P5])             */
+#define OP_PureFunc      163
+#define OP_Function      164 /* synopsis: r[P3]=func(r[P2@P5])             */
+#define OP_CursorHint    165
+#define OP_Noop          166
+#define OP_Explain       167
 
 /* Properties such as "out2" or "jump" that are specified in
 ** comments following the "case" for each opcode in the vdbe.c
 ** are encoded into bitvectors as follows:
 */
-#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
-#define OPFLG_OUT2_PRERELEASE 0x0002  /* out2-prerelease: */
-#define OPFLG_IN1             0x0004  /* in1:   P1 is an input */
-#define OPFLG_IN2             0x0008  /* in2:   P2 is an input */
-#define OPFLG_IN3             0x0010  /* in3:   P3 is an input */
-#define OPFLG_OUT2            0x0020  /* out2:  P2 is an output */
-#define OPFLG_OUT3            0x0040  /* out3:  P3 is an output */
+#define OPFLG_JUMP        0x01  /* jump:  P2 holds jmp target */
+#define OPFLG_IN1         0x02  /* in1:   P1 is an input */
+#define OPFLG_IN2         0x04  /* in2:   P2 is an input */
+#define OPFLG_IN3         0x08  /* in3:   P3 is an input */
+#define OPFLG_OUT2        0x10  /* out2:  P2 is an output */
+#define OPFLG_OUT3        0x20  /* out3:  P3 is an output */
 #define OPFLG_INITIALIZER {\
-/*   0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01,\
-/*   8 */ 0x01, 0x01, 0x00, 0x00, 0x02, 0x00, 0x01, 0x00,\
-/*  16 */ 0x01, 0x01, 0x04, 0x24, 0x01, 0x04, 0x05, 0x10,\
-/*  24 */ 0x00, 0x02, 0x02, 0x02, 0x02, 0x00, 0x02, 0x02,\
-/*  32 */ 0x00, 0x00, 0x20, 0x00, 0x00, 0x04, 0x05, 0x04,\
-/*  40 */ 0x04, 0x00, 0x00, 0x01, 0x01, 0x05, 0x05, 0x00,\
-/*  48 */ 0x00, 0x00, 0x02, 0x02, 0x10, 0x00, 0x00, 0x00,\
-/*  56 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x11,\
-/*  64 */ 0x11, 0x11, 0x08, 0x11, 0x11, 0x11, 0x11, 0x4c,\
-/*  72 */ 0x4c, 0x02, 0x02, 0x00, 0x05, 0x05, 0x15, 0x15,\
-/*  80 */ 0x15, 0x15, 0x15, 0x15, 0x00, 0x4c, 0x4c, 0x4c,\
-/*  88 */ 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x00,\
-/*  96 */ 0x24, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,\
-/* 104 */ 0x00, 0x01, 0x01, 0x01, 0x01, 0x08, 0x08, 0x00,\
-/* 112 */ 0x02, 0x01, 0x01, 0x01, 0x01, 0x02, 0x00, 0x00,\
-/* 120 */ 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
-/* 128 */ 0x0c, 0x45, 0x15, 0x01, 0x02, 0x02, 0x00, 0x01,\
-/* 136 */ 0x08, 0x05, 0x05, 0x05, 0x00, 0x01, 0x00, 0x00,\
-/* 144 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,\
-/* 152 */ 0x02, 0x01, 0x00, 0x00,}
+/*   0 */ 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01,\
+/*   8 */ 0x00, 0x10, 0x00, 0x01, 0x00, 0x01, 0x01, 0x01,\
+/*  16 */ 0x03, 0x03, 0x01, 0x12, 0x01, 0x03, 0x03, 0x01,\
+/*  24 */ 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,\
+/*  32 */ 0x09, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,\
+/*  40 */ 0x01, 0x01, 0x23, 0x0b, 0x01, 0x01, 0x03, 0x03,\
+/*  48 */ 0x03, 0x01, 0x01, 0x01, 0x02, 0x02, 0x08, 0x00,\
+/*  56 */ 0x10, 0x10, 0x10, 0x10, 0x00, 0x10, 0x10, 0x00,\
+/*  64 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x02, 0x26, 0x26,\
+/*  72 */ 0x02, 0x02, 0x00, 0x03, 0x03, 0x0b, 0x0b, 0x0b,\
+/*  80 */ 0x0b, 0x0b, 0x0b, 0x01, 0x26, 0x26, 0x26, 0x26,\
+/*  88 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x00, 0x12,\
+/*  96 */ 0x00, 0x10, 0x00, 0x00, 0x10, 0x10, 0x00, 0x00,\
+/* 104 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
+/* 112 */ 0x00, 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00,\
+/* 120 */ 0x00, 0x00, 0x00, 0x10, 0x00, 0x04, 0x04, 0x00,\
+/* 128 */ 0x00, 0x10, 0x10, 0x00, 0x10, 0x00, 0x10, 0x10,\
+/* 136 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06,\
+/* 144 */ 0x10, 0x00, 0x04, 0x1a, 0x00, 0x00, 0x00, 0x00,\
+/* 152 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,\
+/* 160 */ 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
+}
+
+/* The sqlite3P2Values() routine is able to run faster if it knows
+** the value of the largest JUMP opcode.  The smaller the maximum
+** JUMP opcode the better, so the mkopcodeh.tcl script that
+** generated this include file strives to group all JUMP opcodes
+** together near the beginning of the list.
+*/
+#define SQLITE_MX_JUMP_OPCODE  83  /* Maximum JUMP opcode */
 
 /************** End of opcodes.h *********************************************/
 /************** Continuing where we left off in vdbe.h ***********************/
 
+/*
+** Additional non-public SQLITE_PREPARE_* flags
+*/
+#define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
+#define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
+
 /*
 ** Prototypes for the VDBE interface.  See comments on the implementation
 ** for a description of what each of these routines does.
@@ -9778,24 +13916,39 @@ SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse*);
 SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe*,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
+SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe*,int);
+SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe*,int,const char*);
+SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
 SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
+SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
-SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
+SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe*,int);
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
+SQLITE_PRIVATE   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
+SQLITE_PRIVATE   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
+#else
+# define sqlite3VdbeVerifyNoMallocRequired(A,B)
+# define sqlite3VdbeVerifyNoResultRow(A)
+#endif
+SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
 SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
+SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
 SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
-SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
+SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
 SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
-SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
+SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
 SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
+SQLITE_PRIVATE void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
 SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
 SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
 SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*);
+SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,Parse*);
@@ -9812,7 +13965,8 @@ SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int);
 SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
 SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*);
 SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);
-SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
+SQLITE_PRIVATE u8 sqlite3VdbePrepareFlags(Vdbe*);
+SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
 SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
 SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
@@ -9824,7 +13978,8 @@ SQLITE_PRIVATE int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
 
 SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 SQLITE_PRIVATE int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
-SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);
+SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
+SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
 
 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
 SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
@@ -9833,6 +13988,8 @@ SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
 SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 #endif
 
+SQLITE_PRIVATE int sqlite3NotPureFunc(sqlite3_context*);
+
 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
 ** each VDBE opcode.
 **
@@ -9899,7 +14056,7 @@ SQLITE_PRIVATE void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const ch
 # define sqlite3VdbeScanStatus(a,b,c,d,e)
 #endif
 
-#endif
+#endif /* SQLITE_VDBE_H */
 
 /************** End of vdbe.h ************************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -9921,8 +14078,8 @@ SQLITE_PRIVATE void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const ch
 ** at a time and provides a journal for rollback.
 */
 
-#ifndef _PAGER_H_
-#define _PAGER_H_
+#ifndef SQLITE_PAGER_H
+#define SQLITE_PAGER_H
 
 /*
 ** Default maximum size for persistent journal files. A negative 
@@ -9975,7 +14132,11 @@ typedef struct PgHdr DbPage;
 #define PAGER_LOCKINGMODE_EXCLUSIVE   1
 
 /*
-** Numeric constants that encode the journalmode.  
+** Numeric constants that encode the journalmode.
+**
+** The numeric values encoded here (other than PAGER_JOURNALMODE_QUERY)
+** are exposed in the API via the "PRAGMA journal_mode" command and
+** therefore cannot be changed without a compatibility break.
 */
 #define PAGER_JOURNALMODE_QUERY     (-1)  /* Query the value of journalmode */
 #define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
@@ -9986,22 +14147,28 @@ typedef struct PgHdr DbPage;
 #define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */
 
 /*
-** Flags that make up the mask passed to sqlite3PagerAcquire().
+** Flags that make up the mask passed to sqlite3PagerGet().
 */
 #define PAGER_GET_NOCONTENT     0x01  /* Do not load data from disk */
 #define PAGER_GET_READONLY      0x02  /* Read-only page is acceptable */
 
 /*
 ** Flags for sqlite3PagerSetFlags()
+**
+** Value constraints (enforced via assert()):
+**    PAGER_FULLFSYNC      == SQLITE_FullFSync
+**    PAGER_CKPT_FULLFSYNC == SQLITE_CkptFullFSync
+**    PAGER_CACHE_SPILL    == SQLITE_CacheSpill
 */
 #define PAGER_SYNCHRONOUS_OFF       0x01  /* PRAGMA synchronous=OFF */
 #define PAGER_SYNCHRONOUS_NORMAL    0x02  /* PRAGMA synchronous=NORMAL */
 #define PAGER_SYNCHRONOUS_FULL      0x03  /* PRAGMA synchronous=FULL */
-#define PAGER_SYNCHRONOUS_MASK      0x03  /* Mask for three values above */
-#define PAGER_FULLFSYNC             0x04  /* PRAGMA fullfsync=ON */
-#define PAGER_CKPT_FULLFSYNC        0x08  /* PRAGMA checkpoint_fullfsync=ON */
-#define PAGER_CACHESPILL            0x10  /* PRAGMA cache_spill=ON */
-#define PAGER_FLAGS_MASK            0x1c  /* All above except SYNCHRONOUS */
+#define PAGER_SYNCHRONOUS_EXTRA     0x04  /* PRAGMA synchronous=EXTRA */
+#define PAGER_SYNCHRONOUS_MASK      0x07  /* Mask for four values above */
+#define PAGER_FULLFSYNC             0x08  /* PRAGMA fullfsync=ON */
+#define PAGER_CKPT_FULLFSYNC        0x10  /* PRAGMA checkpoint_fullfsync=ON */
+#define PAGER_CACHESPILL            0x20  /* PRAGMA cache_spill=ON */
+#define PAGER_FLAGS_MASK            0x38  /* All above except SYNCHRONOUS */
 
 /*
 ** The remainder of this file contains the declarations of the functions
@@ -10019,14 +14186,18 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   int,
   void(*)(DbPage*)
 );
-SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager);
+SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager, sqlite3*);
 SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
 
 /* Functions used to configure a Pager object. */
 SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(Pager*, int(*)(void *), void *);
 SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u32*, int);
+#ifdef SQLITE_HAS_CODEC
+SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager*,Pager*);
+#endif
 SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int);
 SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);
+SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager*, int);
 SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
 SQLITE_PRIVATE void sqlite3PagerShrink(Pager*);
 SQLITE_PRIVATE void sqlite3PagerSetFlags(Pager*,unsigned);
@@ -10036,10 +14207,10 @@ SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager*);
 SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager*);
 SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
 SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
+SQLITE_PRIVATE int sqlite3PagerFlush(Pager*);
 
 /* Functions used to obtain and release page references. */ 
-SQLITE_PRIVATE int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
-#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
+SQLITE_PRIVATE int sqlite3PagerGet(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
 SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
 SQLITE_PRIVATE void sqlite3PagerRef(DbPage*);
 SQLITE_PRIVATE void sqlite3PagerUnref(DbPage*);
@@ -10066,11 +14237,21 @@ SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
 SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager);
 
 #ifndef SQLITE_OMIT_WAL
-SQLITE_PRIVATE   int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*);
+SQLITE_PRIVATE   int sqlite3PagerCheckpoint(Pager *pPager, sqlite3*, int, int*, int*);
 SQLITE_PRIVATE   int sqlite3PagerWalSupported(Pager *pPager);
 SQLITE_PRIVATE   int sqlite3PagerWalCallback(Pager *pPager);
 SQLITE_PRIVATE   int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
-SQLITE_PRIVATE   int sqlite3PagerCloseWal(Pager *pPager);
+SQLITE_PRIVATE   int sqlite3PagerCloseWal(Pager *pPager, sqlite3*);
+# ifdef SQLITE_DIRECT_OVERFLOW_READ
+SQLITE_PRIVATE   int sqlite3PagerUseWal(Pager *pPager, Pgno);
+# endif
+# ifdef SQLITE_ENABLE_SNAPSHOT
+SQLITE_PRIVATE   int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot);
+SQLITE_PRIVATE   int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot);
+SQLITE_PRIVATE   int sqlite3PagerSnapshotRecover(Pager *pPager);
+# endif
+#else
+# define sqlite3PagerUseWal(x,y) 0
 #endif
 
 #ifdef SQLITE_ENABLE_ZIPVFS
@@ -10080,17 +14261,19 @@ SQLITE_PRIVATE   int sqlite3PagerWalFramesize(Pager *pPager);
 /* Functions used to query pager state and configuration. */
 SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager*);
 SQLITE_PRIVATE u32 sqlite3PagerDataVersion(Pager*);
-SQLITE_PRIVATE int sqlite3PagerRefcount(Pager*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE   int sqlite3PagerRefcount(Pager*);
+#endif
 SQLITE_PRIVATE int sqlite3PagerMemUsed(Pager*);
 SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*, int);
-SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager*);
+SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager*);
 SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*);
+SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager*);
 SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*);
-SQLITE_PRIVATE int sqlite3PagerNosync(Pager*);
 SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*);
 SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager*);
 SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *, int, int, int *);
-SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *);
+SQLITE_PRIVATE void sqlite3PagerClearCache(Pager*);
 SQLITE_PRIVATE int sqlite3SectorSize(sqlite3_file *);
 
 /* Functions used to truncate the database file. */
@@ -10117,7 +14300,7 @@ SQLITE_PRIVATE   void sqlite3PagerRefdump(Pager*);
 # define enable_simulated_io_errors()
 #endif
 
-#endif /* _PAGER_H_ */
+#endif /* SQLITE_PAGER_H */
 
 /************** End of pager.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -10151,7 +14334,8 @@ struct PgHdr {
   sqlite3_pcache_page *pPage;    /* Pcache object page handle */
   void *pData;                   /* Page data */
   void *pExtra;                  /* Extra content */
-  PgHdr *pDirty;                 /* Transient list of dirty pages */
+  PCache *pCache;                /* PRIVATE: Cache that owns this page */
+  PgHdr *pDirty;                 /* Transient list of dirty sorted by pgno */
   Pager *pPager;                 /* The pager this page is part of */
   Pgno pgno;                     /* Page number for this page */
 #ifdef SQLITE_CHECK_PAGES
@@ -10160,25 +14344,25 @@ struct PgHdr {
   u16 flags;                     /* PGHDR flags defined below */
 
   /**********************************************************************
-  ** Elements above are public.  All that follows is private to pcache.c
-  ** and should not be accessed by other modules.
+  ** Elements above, except pCache, are public.  All that follow are 
+  ** private to pcache.c and should not be accessed by other modules.
+  ** pCache is grouped with the public elements for efficiency.
   */
   i16 nRef;                      /* Number of users of this page */
-  PCache *pCache;                /* Cache that owns this page */
-
   PgHdr *pDirtyNext;             /* Next element in list of dirty pages */
   PgHdr *pDirtyPrev;             /* Previous element in list of dirty pages */
 };
 
 /* Bit values for PgHdr.flags */
-#define PGHDR_DIRTY             0x002  /* Page has changed */
-#define PGHDR_NEED_SYNC         0x004  /* Fsync the rollback journal before
-                                       ** writing this page to the database */
-#define PGHDR_NEED_READ         0x008  /* Content is unread */
-#define PGHDR_REUSE_UNLIKELY    0x010  /* A hint that reuse is unlikely */
-#define PGHDR_DONT_WRITE        0x020  /* Do not write content to disk */
+#define PGHDR_CLEAN           0x001  /* Page not on the PCache.pDirty list */
+#define PGHDR_DIRTY           0x002  /* Page is on the PCache.pDirty list */
+#define PGHDR_WRITEABLE       0x004  /* Journaled and ready to modify */
+#define PGHDR_NEED_SYNC       0x008  /* Fsync the rollback journal before
+                                     ** writing this page to the database */
+#define PGHDR_DONT_WRITE      0x010  /* Do not write content to disk */
+#define PGHDR_MMAP            0x020  /* This is an mmap page object */
 
-#define PGHDR_MMAP              0x040  /* This is an mmap page object */
+#define PGHDR_WAL_APPEND      0x040  /* Appended to wal file */
 
 /* Initialize and shutdown the page cache subsystem */
 SQLITE_PRIVATE int sqlite3PcacheInitialize(void);
@@ -10222,6 +14406,7 @@ SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr*);         /* Remove page from cache
 SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr*);    /* Make sure page is marked dirty */
 SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr*);    /* Mark a single page as clean */
 SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache*);    /* Mark all dirty list pages as clean */
+SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache*);
 
 /* Change a page number.  Used by incr-vacuum. */
 SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr*, Pgno);
@@ -10260,6 +14445,11 @@ SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*);
 SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *));
 #endif
 
+#if defined(SQLITE_DEBUG)
+/* Check invariants on a PgHdr object */
+SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr*);
+#endif
+
 /* Set and get the suggested cache-size for the specified pager-cache.
 **
 ** If no global maximum is configured, then the system attempts to limit
@@ -10271,6 +14461,13 @@ SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *, int);
 SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *);
 #endif
 
+/* Set or get the suggested spill-size for the specified pager-cache.
+**
+** The spill-size is the minimum number of pages in cache before the cache
+** will attempt to spill dirty pages by calling xStress.
+*/
+SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *, int);
+
 /* Free up as much memory as possible from the page cache */
 SQLITE_PRIVATE void sqlite3PcacheShrink(PCache*);
 
@@ -10289,11 +14486,13 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);
 SQLITE_PRIVATE int sqlite3HeaderSizePcache(void);
 SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void);
 
+/* Number of dirty pages as a percentage of the configured cache size */
+SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache*);
+
 #endif /* _PCACHE_H_ */
 
 /************** End of pcache.h **********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
-
 /************** Include os.h in the middle of sqliteInt.h ********************/
 /************** Begin file os.h **********************************************/
 /*
@@ -10339,8 +14538,8 @@ SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void);
 ** This file contains pre-processor directives related to operating system
 ** detection and/or setup.
 */
-#ifndef _OS_SETUP_H_
-#define _OS_SETUP_H_
+#ifndef SQLITE_OS_SETUP_H
+#define SQLITE_OS_SETUP_H
 
 /*
 ** Figure out if we are dealing with Unix, Windows, or some other operating
@@ -10380,7 +14579,7 @@ SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void);
 #  endif
 #endif
 
-#endif /* _OS_SETUP_H_ */
+#endif /* SQLITE_OS_SETUP_H */
 
 /************** End of os_setup.h ********************************************/
 /************** Continuing where we left off in os.h *************************/
@@ -10519,7 +14718,7 @@ SQLITE_PRIVATE int sqlite3OsInit(void);
 /* 
 ** Functions for accessing sqlite3_file methods 
 */
-SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file*);
+SQLITE_PRIVATE void sqlite3OsClose(sqlite3_file*);
 SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);
 SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);
 SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file*, i64 size);
@@ -10556,6 +14755,7 @@ SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *, void *);
 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
 SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *, int);
+SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs*);
 SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*);
 
 /*
@@ -10563,7 +14763,7 @@ SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*);
 ** sqlite3_malloc() to obtain space for the file-handle structure.
 */
 SQLITE_PRIVATE int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);
-SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
+SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *);
 
 #endif /* _SQLITE_OS_H_ */
 
@@ -10645,6 +14845,36 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 /************** End of mutex.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
 
+/* The SQLITE_EXTRA_DURABLE compile-time option used to set the default
+** synchronous setting to EXTRA.  It is no longer supported.
+*/
+#ifdef SQLITE_EXTRA_DURABLE
+# warning Use SQLITE_DEFAULT_SYNCHRONOUS=3 instead of SQLITE_EXTRA_DURABLE
+# define SQLITE_DEFAULT_SYNCHRONOUS 3
+#endif
+
+/*
+** Default synchronous levels.
+**
+** Note that (for historcal reasons) the PAGER_SYNCHRONOUS_* macros differ
+** from the SQLITE_DEFAULT_SYNCHRONOUS value by 1.
+**
+**           PAGER_SYNCHRONOUS       DEFAULT_SYNCHRONOUS
+**   OFF           1                         0
+**   NORMAL        2                         1
+**   FULL          3                         2
+**   EXTRA         4                         3
+**
+** The "PRAGMA synchronous" statement also uses the zero-based numbers.
+** In other words, the zero-based numbers are used for all external interfaces
+** and the one-based values are used internally.
+*/
+#ifndef SQLITE_DEFAULT_SYNCHRONOUS
+# define SQLITE_DEFAULT_SYNCHRONOUS 2
+#endif
+#ifndef SQLITE_DEFAULT_WAL_SYNCHRONOUS
+# define SQLITE_DEFAULT_WAL_SYNCHRONOUS SQLITE_DEFAULT_SYNCHRONOUS
+#endif
 
 /*
 ** Each database file to be accessed by the system is an instance
@@ -10654,9 +14884,10 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 ** databases may be attached.
 */
 struct Db {
-  char *zName;         /* Name of this database */
+  char *zDbSName;      /* Name of this database. (schema name, not filename) */
   Btree *pBt;          /* The B*Tree structure for this database file */
   u8 safety_level;     /* How aggressive at syncing data to disk */
+  u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */
   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
 };
 
@@ -10667,7 +14898,7 @@ struct Db {
 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
 ** In shared cache mode, a single Schema object can be shared by multiple
 ** Btrees that refer to the same underlying BtShared object.
-** 
+**
 ** Schema objects are automatically deallocated when the last Btree that
 ** references them is destroyed.   The TEMP Schema is manually freed by
 ** sqlite3_close().
@@ -10692,7 +14923,7 @@ struct Schema {
 };
 
 /*
-** These macros can be used to test, set, or clear bits in the 
+** These macros can be used to test, set, or clear bits in the
 ** Db.pSchema->flags field.
 */
 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->schemaFlags&(P))==(P))
@@ -10741,8 +14972,8 @@ struct Schema {
 ** lookaside allocations are not used to construct the schema objects.
 */
 struct Lookaside {
+  u32 bDisable;           /* Only operate the lookaside when zero */
   u16 sz;                 /* Size of each buffer in bytes */
-  u8 bEnabled;            /* False to disable new lookaside allocations */
   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
   int nOut;               /* Number of buffers currently checked out */
   int mxOut;              /* Highwater mark for nOut */
@@ -10756,13 +14987,15 @@ struct LookasideSlot {
 };
 
 /*
-** A hash table for function definitions.
+** A hash table for built-in function definitions.  (Application-defined
+** functions use a regular table table from hash.h.)
 **
 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
-** Collisions are on the FuncDef.pHash chain.
+** Collisions are on the FuncDef.u.pHash chain.
 */
+#define SQLITE_FUNC_HASH_SZ 23
 struct FuncDefHash {
-  FuncDef *a[23];       /* Hash table for functions */
+  FuncDef *a[SQLITE_FUNC_HASH_SZ];       /* Hash table for functions */
 };
 
 #ifdef SQLITE_USER_AUTHENTICATION
@@ -10803,6 +15036,15 @@ SQLITE_PRIVATE void sqlite3CryptFunc(sqlite3_context*,int,sqlite3_value**);
                                const char*);
 #endif
 
+#ifndef SQLITE_OMIT_DEPRECATED
+/* This is an extra SQLITE_TRACE macro that indicates "legacy" tracing
+** in the style of sqlite3_trace()
+*/
+#define SQLITE_TRACE_LEGACY  0x80
+#else
+#define SQLITE_TRACE_LEGACY  0
+#endif /* SQLITE_OMIT_DEPRECATED */
+
 
 /*
 ** Each database connection is an instance of the following structure.
@@ -10820,16 +15062,21 @@ struct sqlite3 {
   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
   int errCode;                  /* Most recent error code (SQLITE_*) */
   int errMask;                  /* & result codes with this before returning */
+  int iSysErrno;                /* Errno value from last system error */
   u16 dbOptFlags;               /* Flags to enable/disable optimizations */
   u8 enc;                       /* Text encoding */
   u8 autoCommit;                /* The auto-commit flag. */
   u8 temp_store;                /* 1: file 2: memory 0: default */
   u8 mallocFailed;              /* True if we have seen a malloc failure */
+  u8 bBenignMalloc;             /* Do not require OOMs if true */
   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
   u8 suppressErr;               /* Do not issue error messages if true */
   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
+  u8 mTrace;                    /* zero or more SQLITE_TRACE flags */
+  u8 skipBtreeMutex;            /* True if no shared-cache backends */
+  u8 nSqlExec;                  /* Number of pending OP_SqlExec opcodes */
   int nextPagesize;             /* Pagesize after VACUUM if >0 */
   u32 magic;                    /* Magic number for detect library misuse */
   int nChange;                  /* Value returned by sqlite3_changes() */
@@ -10841,23 +15088,32 @@ struct sqlite3 {
     u8 iDb;                     /* Which db file is being initialized */
     u8 busy;                    /* TRUE if currently initializing */
     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
+    u8 imposterTable;           /* Building an imposter table */
   } init;
   int nVdbeActive;              /* Number of VDBEs currently running */
   int nVdbeRead;                /* Number of active VDBEs that read or write */
   int nVdbeWrite;               /* Number of active VDBEs that read and write */
   int nVdbeExec;                /* Number of nested calls to VdbeExec() */
+  int nVDestroy;                /* Number of active OP_VDestroy operations */
   int nExtension;               /* Number of loaded extensions */
   void **aExtension;            /* Array of shared library handles */
-  void (*xTrace)(void*,const char*);        /* Trace function */
+  int (*xTrace)(u32,void*,void*,void*);     /* Trace function */
   void *pTraceArg;                          /* Argument to the trace function */
   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
   void *pProfileArg;                        /* Argument to profile function */
-  void *pCommitArg;                 /* Argument to xCommitCallback() */   
+  void *pCommitArg;                 /* Argument to xCommitCallback() */
   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
-  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
+  void *pRollbackArg;               /* Argument to xRollbackCallback() */
   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
   void *pUpdateArg;
   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  void *pPreUpdateArg;          /* First argument to xPreUpdateCallback */
+  void (*xPreUpdateCallback)(   /* Registered using sqlite3_preupdate_hook() */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64
+  );
+  PreUpdate *pPreUpdate;        /* Context for active pre-update callback */
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
 #ifndef SQLITE_OMIT_WAL
   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
   void *pWalArg;
@@ -10887,7 +15143,7 @@ struct sqlite3 {
   VTable **aVTrans;             /* Virtual tables with open transactions */
   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
 #endif
-  FuncDefHash aFunc;            /* Hash table of connection functions */
+  Hash aFunc;                   /* Hash table of connection functions */
   Hash aCollSeq;                /* All collating sequences */
   BusyHandler busyHandler;      /* Busy callback */
   Db aDbStatic[2];              /* Static space for the 2 default backends */
@@ -10899,8 +15155,8 @@ struct sqlite3 {
   i64 nDeferredImmCons;         /* Net deferred immediate constraints */
   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
-  /* The following variables are all protected by the STATIC_MASTER 
-  ** mutex, not by sqlite3.mutex. They are used by code in notify.c. 
+  /* The following variables are all protected by the STATIC_MASTER
+  ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
   **
   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
   ** unlock so that it can proceed.
@@ -10928,37 +15184,52 @@ struct sqlite3 {
 
 /*
 ** Possible values for the sqlite3.flags.
-*/
-#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
-#define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
-#define SQLITE_FullFSync      0x00000004  /* Use full fsync on the backend */
-#define SQLITE_CkptFullFSync  0x00000008  /* Use full fsync for checkpoint */
-#define SQLITE_CacheSpill     0x00000010  /* OK to spill pager cache */
-#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
+**
+** Value constraints (enforced via assert()):
+**      SQLITE_FullFSync     == PAGER_FULLFSYNC
+**      SQLITE_CkptFullFSync == PAGER_CKPT_FULLFSYNC
+**      SQLITE_CacheSpill    == PAGER_CACHE_SPILL
+*/
+#define SQLITE_WriteSchema    0x00000001  /* OK to update SQLITE_MASTER */
+#define SQLITE_LegacyFileFmt  0x00000002  /* Create new databases in format 1 */
+#define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
+#define SQLITE_FullFSync      0x00000008  /* Use full fsync on the backend */
+#define SQLITE_CkptFullFSync  0x00000010  /* Use full fsync for checkpoint */
+#define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */
 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                           /*   DELETE, or UPDATE and return */
                                           /*   the count using a callback. */
 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                           /*   result set is empty */
-#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
-#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
-#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
-#define SQLITE_VdbeAddopTrace 0x00001000  /* Trace sqlite3VdbeAddOp() calls */
-#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
-#define SQLITE_ReadUncommitted 0x0004000  /* For shared-cache mode */
-#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
-#define SQLITE_RecoveryMode   0x00010000  /* Ignore schema errors */
-#define SQLITE_ReverseOrder   0x00020000  /* Reverse unordered SELECTs */
-#define SQLITE_RecTriggers    0x00040000  /* Enable recursive triggers */
-#define SQLITE_ForeignKeys    0x00080000  /* Enforce foreign key constraints  */
-#define SQLITE_AutoIndex      0x00100000  /* Enable automatic indexes */
-#define SQLITE_PreferBuiltin  0x00200000  /* Preference to built-in funcs */
-#define SQLITE_LoadExtension  0x00400000  /* Enable load_extension */
-#define SQLITE_EnableTrigger  0x00800000  /* True to enable triggers */
-#define SQLITE_DeferFKs       0x01000000  /* Defer all FK constraints */
-#define SQLITE_QueryOnly      0x02000000  /* Disable database changes */
-#define SQLITE_VdbeEQP        0x04000000  /* Debug EXPLAIN QUERY PLAN */
+#define SQLITE_IgnoreChecks   0x00000200  /* Do not enforce check constraints */
+#define SQLITE_ReadUncommit   0x00000400  /* READ UNCOMMITTED in shared-cache */
+#define SQLITE_NoCkptOnClose  0x00000800  /* No checkpoint on close()/DETACH */
+#define SQLITE_ReverseOrder   0x00001000  /* Reverse unordered SELECTs */
+#define SQLITE_RecTriggers    0x00002000  /* Enable recursive triggers */
+#define SQLITE_ForeignKeys    0x00004000  /* Enforce foreign key constraints  */
+#define SQLITE_AutoIndex      0x00008000  /* Enable automatic indexes */
+#define SQLITE_LoadExtension  0x00010000  /* Enable load_extension */
+#define SQLITE_EnableTrigger  0x00020000  /* True to enable triggers */
+#define SQLITE_DeferFKs       0x00040000  /* Defer all FK constraints */
+#define SQLITE_QueryOnly      0x00080000  /* Disable database changes */
+#define SQLITE_CellSizeCk     0x00100000  /* Check btree cell sizes on load */
+#define SQLITE_Fts3Tokenizer  0x00200000  /* Enable fts3_tokenizer(2) */
+#define SQLITE_EnableQPSG     0x00400000  /* Query Planner Stability Guarantee */
+/* The next four values are not used by PRAGMAs or by sqlite3_dbconfig() and
+** could be factored out into a separate bit vector of the sqlite3 object. */
+#define SQLITE_InternChanges  0x00800000  /* Uncommitted Hash table changes */
+#define SQLITE_LoadExtFunc    0x01000000  /* Enable load_extension() SQL func */
+#define SQLITE_PreferBuiltin  0x02000000  /* Preference to built-in funcs */
+#define SQLITE_Vacuum         0x04000000  /* Currently in a VACUUM */
+/* Flags used only if debugging */
+#ifdef SQLITE_DEBUG
+#define SQLITE_SqlTrace       0x08000000  /* Debug print SQL as it executes */
+#define SQLITE_VdbeListing    0x10000000  /* Debug listings of VDBE programs */
+#define SQLITE_VdbeTrace      0x20000000  /* True to trace VDBE execution */
+#define SQLITE_VdbeAddopTrace 0x40000000  /* Trace sqlite3VdbeAddOp() calls */
+#define SQLITE_VdbeEQP        0x80000000  /* Debug EXPLAIN QUERY PLAN */
+#endif
 
 
 /*
@@ -10978,18 +15249,15 @@ struct sqlite3 {
 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
 #define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
 #define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
+#define SQLITE_CountOfView    0x1000   /* The count-of-view optimization */
+#define SQLITE_CursorHints    0x2000   /* Add OP_CursorHint opcodes */
 #define SQLITE_AllOpts        0xffff   /* All optimizations */
 
 /*
 ** Macros for testing whether or not optimizations are enabled or disabled.
 */
-#ifndef SQLITE_OMIT_BUILTIN_TEST
 #define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
 #define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)
-#else
-#define OptimizationDisabled(db, mask)  0
-#define OptimizationEnabled(db, mask)   1
-#endif
 
 /*
 ** Return true if it OK to factor constant expressions into the initialization
@@ -11011,28 +15279,33 @@ struct sqlite3 {
 
 /*
 ** Each SQL function is defined by an instance of the following
-** structure.  A pointer to this structure is stored in the sqlite.aFunc
-** hash table.  When multiple functions have the same name, the hash table
-** points to a linked list of these structures.
+** structure.  For global built-in functions (ex: substr(), max(), count())
+** a pointer to this structure is held in the sqlite3BuiltinFunctions object.
+** For per-connection application-defined functions, a pointer to this
+** structure is held in the db->aHash hash table.
+**
+** The u.pHash field is used by the global built-ins.  The u.pDestructor
+** field is used by per-connection app-def functions.
 */
 struct FuncDef {
-  i16 nArg;            /* Number of arguments.  -1 means unlimited */
+  i8 nArg;             /* Number of arguments.  -1 means unlimited */
   u16 funcFlags;       /* Some combination of SQLITE_FUNC_* */
   void *pUserData;     /* User data parameter */
   FuncDef *pNext;      /* Next function with same name */
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
-  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
-  void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
-  char *zName;         /* SQL name of the function. */
-  FuncDef *pHash;      /* Next with a different name but the same hash */
-  FuncDestructor *pDestructor;   /* Reference counted destructor function */
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**); /* func or agg-step */
+  void (*xFinalize)(sqlite3_context*);                  /* Agg finalizer */
+  const char *zName;   /* SQL name of the function. */
+  union {
+    FuncDef *pHash;      /* Next with a different name but the same hash */
+    FuncDestructor *pDestructor;   /* Reference counted destructor function */
+  } u;
 };
 
 /*
 ** This structure encapsulates a user-function destructor callback (as
 ** configured using create_function_v2()) and a reference counter. When
 ** create_function_v2() is called to create a function with a destructor,
-** a single object of this type is allocated. FuncDestructor.nRef is set to 
+** a single object of this type is allocated. FuncDestructor.nRef is set to
 ** the number of FuncDef objects created (either 1 or 3, depending on whether
 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
 ** member of each of the new FuncDef objects is set to point to the allocated
@@ -11050,36 +15323,60 @@ struct FuncDestructor {
 
 /*
 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
-** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
+** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And
+** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There
 ** are assert() statements in the code to verify this.
-*/
-#define SQLITE_FUNC_ENCMASK  0x003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
-#define SQLITE_FUNC_LIKE     0x004 /* Candidate for the LIKE optimization */
-#define SQLITE_FUNC_CASE     0x008 /* Case-sensitive LIKE-type function */
-#define SQLITE_FUNC_EPHEM    0x010 /* Ephemeral.  Delete with VDBE */
-#define SQLITE_FUNC_NEEDCOLL 0x020 /* sqlite3GetFuncCollSeq() might be called */
-#define SQLITE_FUNC_LENGTH   0x040 /* Built-in length() function */
-#define SQLITE_FUNC_TYPEOF   0x080 /* Built-in typeof() function */
-#define SQLITE_FUNC_COUNT    0x100 /* Built-in count(*) aggregate */
-#define SQLITE_FUNC_COALESCE 0x200 /* Built-in coalesce() or ifnull() */
-#define SQLITE_FUNC_UNLIKELY 0x400 /* Built-in unlikely() function */
-#define SQLITE_FUNC_CONSTANT 0x800 /* Constant inputs give a constant output */
-#define SQLITE_FUNC_MINMAX  0x1000 /* True for min() and max() aggregates */
+**
+** Value constraints (enforced via assert()):
+**     SQLITE_FUNC_MINMAX    ==  NC_MinMaxAgg      == SF_MinMaxAgg
+**     SQLITE_FUNC_LENGTH    ==  OPFLAG_LENGTHARG
+**     SQLITE_FUNC_TYPEOF    ==  OPFLAG_TYPEOFARG
+**     SQLITE_FUNC_CONSTANT  ==  SQLITE_DETERMINISTIC from the API
+**     SQLITE_FUNC_ENCMASK   depends on SQLITE_UTF* macros in the API
+*/
+#define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
+#define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */
+#define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */
+#define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */
+#define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/
+#define SQLITE_FUNC_LENGTH   0x0040 /* Built-in length() function */
+#define SQLITE_FUNC_TYPEOF   0x0080 /* Built-in typeof() function */
+#define SQLITE_FUNC_COUNT    0x0100 /* Built-in count(*) aggregate */
+#define SQLITE_FUNC_COALESCE 0x0200 /* Built-in coalesce() or ifnull() */
+#define SQLITE_FUNC_UNLIKELY 0x0400 /* Built-in unlikely() function */
+#define SQLITE_FUNC_CONSTANT 0x0800 /* Constant inputs give a constant output */
+#define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */
+#define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
+                                    ** single query - might change over time */
+#define SQLITE_FUNC_AFFINITY 0x4000 /* Built-in affinity() function */
 
 /*
 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
 ** used to create the initializers for the FuncDef structures.
 **
 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
-**     Used to create a scalar function definition of a function zName 
+**     Used to create a scalar function definition of a function zName
 **     implemented by C function xFunc that accepts nArg arguments. The
 **     value passed as iArg is cast to a (void*) and made available
-**     as the user-data (sqlite3_user_data()) for the function. If 
+**     as the user-data (sqlite3_user_data()) for the function. If
 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
 **
 **   VFUNCTION(zName, nArg, iArg, bNC, xFunc)
 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.
 **
+**   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
+**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
+**     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
+**     and functions like sqlite_version() that can change, but not during
+**     a single query.  The iArg is ignored.  The user-data is always set
+**     to a NULL pointer.  The bNC parameter is not used.
+**
+**   PURE_DATE(zName, nArg, iArg, bNC, xFunc)
+**     Used for "pure" date/time functions, this macro is like DFUNCTION
+**     except that it does set the SQLITE_FUNC_CONSTANT flags.  iArg is
+**     ignored and the user-data for these functions is set to an 
+**     arbitrary non-NULL pointer.  The bNC parameter is not used.
+**
 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
 **     Used to create an aggregate function definition implemented by
 **     the C functions xStep and xFinal. The first four parameters
@@ -11087,8 +15384,8 @@ struct FuncDestructor {
 **     FUNCTION().
 **
 **   LIKEFUNC(zName, nArg, pArg, flags)
-**     Used to create a scalar function definition of a function zName 
-**     that accepts nArg arguments and is implemented by a call to C 
+**     Used to create a scalar function definition of a function zName
+**     that accepts nArg arguments and is implemented by a call to C
 **     function likeFunc. Argument pArg is cast to a (void *) and made
 **     available as the function user-data (sqlite3_user_data()). The
 **     FuncDef.flags variable is set to the value passed as the flags
@@ -11096,25 +15393,31 @@ struct FuncDestructor {
 */
 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
-   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
 #define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
   {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
-   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \
+   0, 0, xFunc, 0, #zName, {0} }
+#define PURE_DATE(zName, nArg, iArg, bNC, xFunc) \
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \
+   (void*)&sqlite3Config, 0, xFunc, 0, #zName, {0} }
 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
   {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
-   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
-  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
-   pArg, 0, xFunc, 0, 0, #zName, 0, 0}
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
+   pArg, 0, xFunc, 0, #zName, }
 #define LIKEFUNC(zName, nArg, arg, flags) \
   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
-   (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
+   (void *)arg, 0, likeFunc, 0, #zName, {0} }
 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
-   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
+   SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
 #define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
-   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
+   SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
 
 /*
 ** All current savepoints are stored in a linked list starting at
@@ -11148,6 +15451,7 @@ struct Module {
   const char *zName;                   /* Name passed to create_module() */
   void *pAux;                          /* pAux passed to create_module() */
   void (*xDestroy)(void *);            /* Module destructor function */
+  Table *pEpoTab;                      /* Eponymous table for this module */
 };
 
 /*
@@ -11155,14 +15459,12 @@ struct Module {
 ** of this structure.
 */
 struct Column {
-  char *zName;     /* Name of this column */
+  char *zName;     /* Name of this column, \000, then the type */
   Expr *pDflt;     /* Default value of this column */
-  char *zDflt;     /* Original text of the default value */
-  char *zType;     /* Data type for this column */
   char *zColl;     /* Collating sequence.  If NULL, use the default */
   u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */
   char affinity;   /* One of the SQLITE_AFF_... values */
-  u8 szEst;        /* Estimated size of this column.  INT==1 */
+  u8 szEst;        /* Estimated size of value in this column. sizeof(INT)==1 */
   u8 colFlags;     /* Boolean properties.  See COLFLAG_ defines below */
 };
 
@@ -11170,6 +15472,7 @@ struct Column {
 */
 #define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */
 #define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */
+#define COLFLAG_HASTYPE  0x0004    /* Type name follows column name */
 
 /*
 ** A "Collating Sequence" is defined by an instance of the following
@@ -11193,22 +15496,23 @@ struct CollSeq {
 */
 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
+#define SQLITE_SO_UNDEFINED -1 /* No sort order specified */
 
 /*
 ** Column affinity types.
 **
 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
-** the speed a little by numbering the values consecutively.  
+** the speed a little by numbering the values consecutively.
 **
 ** But rather than start with 0 or 1, we begin with 'A'.  That way,
 ** when multiple affinity types are concatenated into a string and
 ** used as the P4 operand, they will be more readable.
 **
 ** Note also that the numeric types are grouped together so that testing
-** for a numeric type is a single comparison.  And the NONE type is first.
+** for a numeric type is a single comparison.  And the BLOB type is first.
 */
-#define SQLITE_AFF_NONE     'A'
+#define SQLITE_AFF_BLOB     'A'
 #define SQLITE_AFF_TEXT     'B'
 #define SQLITE_AFF_NUMERIC  'C'
 #define SQLITE_AFF_INTEGER  'D'
@@ -11218,7 +15522,7 @@ struct CollSeq {
 
 /*
 ** The SQLITE_AFF_MASK values masks off the significant bits of an
-** affinity value. 
+** affinity value.
 */
 #define SQLITE_AFF_MASK     0x47
 
@@ -11231,6 +15535,7 @@ struct CollSeq {
 ** operator is NULL.  It is added to certain comparison operators to
 ** prove that the operands are always NOT NULL.
 */
+#define SQLITE_KEEPNULL     0x08  /* Used by vector == or <> */
 #define SQLITE_JUMPIFNULL   0x10  /* jumps if either operand is NULL */
 #define SQLITE_STOREP2      0x20  /* Store result in reg[P2] rather than jump */
 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
@@ -11238,20 +15543,20 @@ struct CollSeq {
 
 /*
 ** An object of this type is created for each virtual table present in
-** the database schema. 
+** the database schema.
 **
 ** If the database schema is shared, then there is one instance of this
 ** structure for each database connection (sqlite3*) that uses the shared
 ** schema. This is because each database connection requires its own unique
-** instance of the sqlite3_vtab* handle used to access the virtual table 
-** implementation. sqlite3_vtab* handles can not be shared between 
-** database connections, even when the rest of the in-memory database 
+** instance of the sqlite3_vtab* handle used to access the virtual table
+** implementation. sqlite3_vtab* handles can not be shared between
+** database connections, even when the rest of the in-memory database
 ** schema is shared, as the implementation often stores the database
 ** connection handle passed to it via the xConnect() or xCreate() method
 ** during initialization internally. This database connection handle may
-** then be used by the virtual table implementation to access real tables 
-** within the database. So that they appear as part of the callers 
-** transaction, these accesses need to be made via the same database 
+** then be used by the virtual table implementation to access real tables
+** within the database. So that they appear as part of the callers
+** transaction, these accesses need to be made via the same database
 ** connection as that used to execute SQL operations on the virtual table.
 **
 ** All VTable objects that correspond to a single table in a shared
@@ -11263,19 +15568,19 @@ struct CollSeq {
 ** sqlite3_vtab* handle in the compiled query.
 **
 ** When an in-memory Table object is deleted (for example when the
-** schema is being reloaded for some reason), the VTable objects are not 
-** deleted and the sqlite3_vtab* handles are not xDisconnect()ed 
+** schema is being reloaded for some reason), the VTable objects are not
+** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
 ** immediately. Instead, they are moved from the Table.pVTable list to
 ** another linked list headed by the sqlite3.pDisconnect member of the
-** corresponding sqlite3 structure. They are then deleted/xDisconnected 
+** corresponding sqlite3 structure. They are then deleted/xDisconnected
 ** next time a statement is prepared using said sqlite3*. This is done
 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
 ** Refer to comments above function sqlite3VtabUnlockList() for an
 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
 ** list without holding the corresponding sqlite3.mutex mutex.
 **
-** The memory for objects of this type is always allocated by 
-** sqlite3DbMalloc(), using the connection handle stored in VTable.db as 
+** The memory for objects of this type is always allocated by
+** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
 ** the first argument.
 */
 struct VTable {
@@ -11289,34 +15594,8 @@ struct VTable {
 };
 
 /*
-** Each SQL table is represented in memory by an instance of the
-** following structure.
-**
-** Table.zName is the name of the table.  The case of the original
-** CREATE TABLE statement is stored, but case is not significant for
-** comparisons.
-**
-** Table.nCol is the number of columns in this table.  Table.aCol is a
-** pointer to an array of Column structures, one for each column.
-**
-** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
-** the column that is that key.   Otherwise Table.iPKey is negative.  Note
-** that the datatype of the PRIMARY KEY must be INTEGER for this field to
-** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
-** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
-** is generated for each row of the table.  TF_HasPrimaryKey is set if
-** the table has any PRIMARY KEY, INTEGER or otherwise.
-**
-** Table.tnum is the page number for the root BTree page of the table in the
-** database file.  If Table.iDb is the index of the database table backend
-** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
-** holds temporary tables and indices.  If TF_Ephemeral is set
-** then the table is stored in a file that is automatically deleted
-** when the VDBE cursor to the table is closed.  In this case Table.tnum 
-** refers VDBE cursor number that holds the table open, not to the root
-** page number.  Transient tables are used to hold the results of a
-** sub-query that appears instead of a real table name in the FROM clause 
-** of a SELECT statement.
+** The schema for each SQL table and view is represented in memory
+** by an instance of the following structure.
 */
 struct Table {
   char *zName;         /* Name of the table or view */
@@ -11325,26 +15604,25 @@ struct Table {
   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
   FKey *pFKey;         /* Linked list of all foreign keys in this table */
   char *zColAff;       /* String defining the affinity of each column */
-#ifndef SQLITE_OMIT_CHECK
   ExprList *pCheck;    /* All CHECK constraints */
-#endif
-  LogEst nRowLogEst;   /* Estimated rows in table - from sqlite_stat1 table */
-  int tnum;            /* Root BTree node for this table (see note above) */
-  i16 iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
+                       /*   ... also used as column name list in a VIEW */
+  int tnum;            /* Root BTree page for this table */
+  u32 nTabRef;         /* Number of pointers to this Table */
+  u32 tabFlags;        /* Mask of TF_* values */
+  i16 iPKey;           /* If not negative, use aCol[iPKey] as the rowid */
   i16 nCol;            /* Number of columns in this table */
-  u16 nRef;            /* Number of pointers to this Table */
+  LogEst nRowLogEst;   /* Estimated rows in table - from sqlite_stat1 table */
   LogEst szTabRow;     /* Estimated size of each table row in bytes */
 #ifdef SQLITE_ENABLE_COSTMULT
   LogEst costMult;     /* Cost multiplier for using this table */
 #endif
-  u8 tabFlags;         /* Mask of TF_* values */
   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
 #ifndef SQLITE_OMIT_ALTERTABLE
   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
 #endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   int nModuleArg;      /* Number of arguments to the module */
-  char **azModuleArg;  /* Text of all module args. [0] is module name */
+  char **azModuleArg;  /* 0: module 1: schema 2: vtab name 3...: args */
   VTable *pVTable;     /* List of VTable objects. */
 #endif
   Trigger *pTrigger;   /* List of triggers stored in pSchema */
@@ -11354,14 +15632,24 @@ struct Table {
 
 /*
 ** Allowed values for Table.tabFlags.
-*/
-#define TF_Readonly        0x01    /* Read-only system table */
-#define TF_Ephemeral       0x02    /* An ephemeral table */
-#define TF_HasPrimaryKey   0x04    /* Table has a primary key */
-#define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
-#define TF_Virtual         0x10    /* Is a virtual table */
-#define TF_WithoutRowid    0x20    /* No rowid used. PRIMARY KEY is the key */
-
+**
+** TF_OOOHidden applies to tables or view that have hidden columns that are
+** followed by non-hidden columns.  Example:  "CREATE VIRTUAL TABLE x USING
+** vtab1(a HIDDEN, b);".  Since "b" is a non-hidden column but "a" is hidden,
+** the TF_OOOHidden attribute would apply in this case.  Such tables require
+** special handling during INSERT processing.
+*/
+#define TF_Readonly        0x0001    /* Read-only system table */
+#define TF_Ephemeral       0x0002    /* An ephemeral table */
+#define TF_HasPrimaryKey   0x0004    /* Table has a primary key */
+#define TF_Autoincrement   0x0008    /* Integer primary key is autoincrement */
+#define TF_HasStat1        0x0010    /* nRowLogEst set from sqlite_stat1 */
+#define TF_WithoutRowid    0x0020    /* No rowid.  PRIMARY KEY is the key */
+#define TF_NoVisibleRowid  0x0040    /* No user-visible "rowid" column */
+#define TF_OOOHidden       0x0080    /* Out-of-Order hidden columns */
+#define TF_StatsUsed       0x0100    /* Query planner decisions affected by
+                                     ** Index.aiRowLogEst[] values */
+#define TF_HasNotNull      0x0200    /* Contains NOT NULL constraints */
 
 /*
 ** Test to see whether or not a table is a virtual table.  This is
@@ -11369,15 +15657,32 @@ struct Table {
 ** table support is omitted from the build.
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-#  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
-#  define IsHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#  define IsVirtual(X)      ((X)->nModuleArg)
 #else
 #  define IsVirtual(X)      0
-#  define IsHiddenColumn(X) 0
 #endif
 
+/*
+** Macros to determine if a column is hidden.  IsOrdinaryHiddenColumn()
+** only works for non-virtual tables (ordinary tables and views) and is
+** always false unless SQLITE_ENABLE_HIDDEN_COLUMNS is defined.  The
+** IsHiddenColumn() macro is general purpose.
+*/
+#if defined(SQLITE_ENABLE_HIDDEN_COLUMNS)
+#  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#  define IsOrdinaryHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#elif !defined(SQLITE_OMIT_VIRTUALTABLE)
+#  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#  define IsOrdinaryHiddenColumn(X) 0
+#else
+#  define IsHiddenColumn(X)         0
+#  define IsOrdinaryHiddenColumn(X) 0
+#endif
+
+
 /* Does the table have a rowid */
 #define HasRowid(X)     (((X)->tabFlags & TF_WithoutRowid)==0)
+#define VisibleRowid(X) (((X)->tabFlags & TF_NoVisibleRowid)==0)
 
 /*
 ** Each foreign key constraint is an instance of the following structure.
@@ -11445,7 +15750,7 @@ struct FKey {
 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
 ** referenced table row is propagated into the row that holds the
 ** foreign key.
-** 
+**
 ** The following symbolic values are used to record which type
 ** of action to take.
 */
@@ -11466,7 +15771,7 @@ struct FKey {
 
 /*
 ** An instance of the following structure is passed as the first
-** argument to sqlite3VdbeKeyCompare and is used to control the 
+** argument to sqlite3VdbeKeyCompare and is used to control the
 ** comparison of the two index keys.
 **
 ** Note that aSortOrder[] and aColl[] have nField+1 slots.  There
@@ -11484,9 +15789,8 @@ struct KeyInfo {
 };
 
 /*
-** An instance of the following structure holds information about a
-** single index record that has already been parsed out into individual
-** values.
+** This object holds a record which has been parsed out into individual
+** fields, for the purposes of doing a comparison.
 **
 ** A record is an object that contains one or more fields of data.
 ** Records are used to store the content of a table row and to store
@@ -11494,20 +15798,40 @@ struct KeyInfo {
 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
 ** OP_Column opcode.
 **
-** This structure holds a record that has already been disassembled
-** into its constituent fields.
-**
-** The r1 and r2 member variables are only used by the optimized comparison
-** functions vdbeRecordCompareInt() and vdbeRecordCompareString().
+** An instance of this object serves as a "key" for doing a search on
+** an index b+tree. The goal of the search is to find the entry that
+** is closed to the key described by this object.  This object might hold
+** just a prefix of the key.  The number of fields is given by
+** pKeyInfo->nField.
+**
+** The r1 and r2 fields are the values to return if this key is less than
+** or greater than a key in the btree, respectively.  These are normally
+** -1 and +1 respectively, but might be inverted to +1 and -1 if the b-tree
+** is in DESC order.
+**
+** The key comparison functions actually return default_rc when they find
+** an equals comparison.  default_rc can be -1, 0, or +1.  If there are
+** multiple entries in the b-tree with the same key (when only looking
+** at the first pKeyInfo->nFields,) then default_rc can be set to -1 to
+** cause the search to find the last match, or +1 to cause the search to
+** find the first match.
+**
+** The key comparison functions will set eqSeen to true if they ever
+** get and equal results when comparing this structure to a b-tree record.
+** When default_rc!=0, the search might end up on the record immediately
+** before the first match or immediately after the last match.  The
+** eqSeen field will indicate whether or not an exact match exists in the
+** b-tree.
 */
 struct UnpackedRecord {
   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
+  Mem *aMem;          /* Values */
   u16 nField;         /* Number of entries in apMem[] */
   i8 default_rc;      /* Comparison result if keys are equal */
   u8 errCode;         /* Error detected by xRecordCompare (CORRUPT or NOMEM) */
-  Mem *aMem;          /* Values */
-  int r1;             /* Value to return if (lhs > rhs) */
-  int r2;             /* Value to return if (rhs < lhs) */
+  i8 r1;              /* Value to return if (lhs > rhs) */
+  i8 r2;              /* Value to return if (rhs < lhs) */
+  u8 eqSeen;          /* True if an equality comparison has been seen */
 };
 
 
@@ -11525,7 +15849,7 @@ struct UnpackedRecord {
 ** In the Table structure describing Ex1, nCol==3 because there are
 ** three columns in the table.  In the Index structure describing
 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
-** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the 
+** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
 ** The second column to be indexed (c1) has an index of 0 in
 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
@@ -11533,9 +15857,17 @@ struct UnpackedRecord {
 ** The Index.onError field determines whether or not the indexed columns
 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
 ** it means this is not a unique index.  Otherwise it is a unique index
-** and the value of Index.onError indicate the which conflict resolution 
+** and the value of Index.onError indicate the which conflict resolution
 ** algorithm to employ whenever an attempt is made to insert a non-unique
 ** element.
+**
+** While parsing a CREATE TABLE or CREATE INDEX statement in order to
+** generate VDBE code (as opposed to parsing one read from an sqlite_master
+** table as part of parsing an existing database schema), transient instances
+** of this structure may be created. In this case the Index.tnum variable is
+** used to store the address of a VDBE instruction, not a database page
+** number (it cannot - the database page is not allocated until the VDBE
+** program is executed). See convertToWithoutRowidTable() for details.
 */
 struct Index {
   char *zName;             /* Name of this index */
@@ -11546,8 +15878,9 @@ struct Index {
   Index *pNext;            /* The next index associated with the same table */
   Schema *pSchema;         /* Schema containing this index */
   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
-  char **azColl;           /* Array of collation sequence names for index */
+  const char **azColl;     /* Array of collation sequence names for index */
   Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
+  ExprList *aColExpr;      /* Column expressions */
   int tnum;                /* DB Page containing root of this index */
   LogEst szIdxRow;         /* Estimated average row size in bytes */
   u16 nKeyCol;             /* Number of columns forming the key */
@@ -11559,6 +15892,7 @@ struct Index {
   unsigned isResized:1;    /* True if resizeIndexObject() has been called */
   unsigned isCovering:1;   /* True if this is a covering index */
   unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
+  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   int nSample;             /* Number of elements in aSample[] */
   int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
@@ -11582,8 +15916,14 @@ struct Index {
 /* Return true if index X is a UNIQUE index */
 #define IsUniqueIndex(X)      ((X)->onError!=OE_None)
 
+/* The Index.aiColumn[] values are normally positive integer.  But
+** there are some negative values that have special meaning:
+*/
+#define XN_ROWID     (-1)     /* Indexed column is the rowid */
+#define XN_EXPR      (-2)     /* Indexed column is an expression */
+
 /*
-** Each sample stored in the sqlite_stat3 table is represented in memory 
+** Each sample stored in the sqlite_stat3 table is represented in memory
 ** using a structure of this type.  See documentation at the top of the
 ** analyze.c source file for additional information.
 */
@@ -11678,9 +16018,9 @@ typedef int ynVar;
 ** to represent the greater-than-or-equal-to operator in the expression
 ** tree.
 **
-** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB, 
+** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
-** the expression is a variable (TK_VARIABLE), then Expr.token contains the 
+** the expression is a variable (TK_VARIABLE), then Expr.token contains the
 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
 ** then Expr.token contains the name of the function.
 **
@@ -11691,7 +16031,7 @@ typedef int ynVar;
 ** a CASE expression or an IN expression of the form " IN (, ...)".
 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
 ** the form " IN (SELECT ...)". If the EP_xIsSelect bit is set in the
-** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is 
+** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
 ** valid.
 **
 ** An expression of the form ID or ID.ID refers to a column in a table.
@@ -11702,8 +16042,8 @@ typedef int ynVar;
 ** value is also stored in the Expr.iAgg column in the aggregate so that
 ** it can be accessed after all aggregates are computed.
 **
-** If the expression is an unbound variable marker (a question mark 
-** character '?' in the original SQL) then the Expr.iTable holds the index 
+** If the expression is an unbound variable marker (a question mark
+** character '?' in the original SQL) then the Expr.iTable holds the index
 ** number for that variable.
 **
 ** If the expression is a subquery then Expr.iColumn holds an integer
@@ -11742,7 +16082,7 @@ struct Expr {
 
   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
   ** space is allocated for the fields below this point. An attempt to
-  ** access them will result in a segfault or malfunction. 
+  ** access them will result in a segfault or malfunction.
   *********************************************************************/
 
   Expr *pLeft;           /* Left subnode */
@@ -11763,9 +16103,11 @@ struct Expr {
   int iTable;            /* TK_COLUMN: cursor number of table holding column
                          ** TK_REGISTER: register number
                          ** TK_TRIGGER: 1 -> new, 0 -> old
-                         ** EP_Unlikely:  134217728 times likelihood */
+                         ** EP_Unlikely:  134217728 times likelihood
+                         ** TK_SELECT: 1st register of result vector */
   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
-                         ** TK_VARIABLE: variable number (always >= 1). */
+                         ** TK_VARIABLE: variable number (always >= 1).
+                         ** TK_SELECT_COLUMN: column of the result vector */
   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
   u8 op2;                /* TK_REGISTER: original value of Expr.op
@@ -11780,8 +16122,8 @@ struct Expr {
 */
 #define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
 #define EP_Agg       0x000002 /* Contains one or more aggregate functions */
-#define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
-#define EP_Error     0x000008 /* Expression contains one or more errors */
+                  /* 0x000004 // available for use */
+                  /* 0x000008 // available for use */
 #define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
 #define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
 #define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
@@ -11797,11 +16139,19 @@ struct Expr {
 #define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
 #define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
 #define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
-#define EP_Constant  0x080000 /* Node is a constant */
+#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
 #define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
+#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
+#define EP_Alias     0x400000 /* Is an alias for a result set column */
+#define EP_Leaf      0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */
 
 /*
-** These macros can be used to test, set, or clear bits in the 
+** Combinations of two or more EP_* flags
+*/
+#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */
+
+/*
+** These macros can be used to test, set, or clear bits in the
 ** Expr.flags field.
 */
 #define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
@@ -11820,8 +16170,8 @@ struct Expr {
 #endif
 
 /*
-** Macros to determine the number of bytes required by a normal Expr 
-** struct, an Expr struct with the EP_Reduced flag set in Expr.flags 
+** Macros to determine the number of bytes required by a normal Expr
+** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
 ** and an Expr struct with the EP_TokenOnly flag set.
 */
 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
@@ -11829,7 +16179,7 @@ struct Expr {
 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
 
 /*
-** Flags passed to the sqlite3ExprDup() function. See the header comment 
+** Flags passed to the sqlite3ExprDup() function. See the header comment
 ** above sqlite3ExprDup() for details.
 */
 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
@@ -11852,8 +16202,9 @@ struct Expr {
 */
 struct ExprList {
   int nExpr;             /* Number of expressions on the list */
+  int nAlloc;            /* Number of a[] slots allocated */
   struct ExprList_item { /* For each expression in the list */
-    Expr *pExpr;            /* The list of expressions */
+    Expr *pExpr;            /* The parse tree for this expression */
     char *zName;            /* Token associated with this expression */
     char *zSpan;            /* Original text of the expression */
     u8 sortOrder;           /* 1 for DESC or 0 for ASC */
@@ -11867,7 +16218,7 @@ struct ExprList {
       } x;
       int iConstExprReg;      /* Register in which Expr value is cached */
     } u;
-  } *a;                  /* Alloc a power of two greater or equal to nExpr */
+  } a[1];                  /* One slot for each expression in the list */
 };
 
 /*
@@ -11911,7 +16262,11 @@ struct IdList {
 ** tables in a join to 32 instead of 64.  But it also reduces the size
 ** of the library by 738 bytes on ix86.
 */
-typedef u64 Bitmask;
+#ifdef SQLITE_BITMASK_TYPE
+  typedef SQLITE_BITMASK_TYPE Bitmask;
+#else
+  typedef u64 Bitmask;
+#endif
 
 /*
 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
@@ -11923,6 +16278,7 @@ typedef u64 Bitmask;
 */
 #define MASKBIT(n)   (((Bitmask)1)<<(n))
 #define MASKBIT32(n) (((unsigned int)1)<<(n))
+#define ALLBITS      ((Bitmask)-1)
 
 /*
 ** The following structure describes the FROM clause of a SELECT statement.
@@ -11956,11 +16312,15 @@ struct SrcList {
     int addrFillSub;  /* Address of subroutine to manifest a subquery */
     int regReturn;    /* Register holding return address of addrFillSub */
     int regResult;    /* Registers holding results of a co-routine */
-    u8 jointype;      /* Type of join between this able and the previous */
-    unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
-    unsigned isCorrelated :1;  /* True if sub-query is correlated */
-    unsigned viaCoroutine :1;  /* Implemented as a co-routine */
-    unsigned isRecursive :1;   /* True for recursive reference in WITH */
+    struct {
+      u8 jointype;      /* Type of join between this table and the previous */
+      unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
+      unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
+      unsigned isTabFunc :1;     /* True if table-valued-function syntax */
+      unsigned isCorrelated :1;  /* True if sub-query is correlated */
+      unsigned viaCoroutine :1;  /* Implemented as a co-routine */
+      unsigned isRecursive :1;   /* True for recursive reference in WITH */
+    } fg;
 #ifndef SQLITE_OMIT_EXPLAIN
     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
 #endif
@@ -11968,8 +16328,11 @@ struct SrcList {
     Expr *pOn;        /* The ON clause of a join */
     IdList *pUsing;   /* The USING clause of a join */
     Bitmask colUsed;  /* Bit N (1<" clause */
-    Index *pIndex;    /* Index structure corresponding to zIndex, if any */
+    union {
+      char *zIndexedBy;    /* Identifier from "INDEXED BY " clause */
+      ExprList *pFuncArg;  /* Arguments to table-valued-function */
+    } u1;
+    Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
   } a[1];             /* One entry for each identifier on the list */
 };
 
@@ -11988,21 +16351,28 @@ struct SrcList {
 /*
 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
 ** and the WhereInfo.wctrlFlags member.
+**
+** Value constraints (enforced via assert()):
+**     WHERE_USE_LIMIT  == SF_FixedLimit
 */
 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
-#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
-#define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
-#define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
-#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
-                          /*   0x0080 // not currently used */
-#define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
-#define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
-#define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
-#define WHERE_SORTBYGROUP      0x0800 /* Support sqlite3WhereIsSorted() */
-#define WHERE_REOPEN_IDX       0x1000 /* Try to use OP_ReopenIdx */
+#define WHERE_ONEPASS_MULTIROW 0x0008 /* ONEPASS is ok with multiple rows */
+#define WHERE_DUPLICATES_OK    0x0010 /* Ok to return a row more than once */
+#define WHERE_OR_SUBCLAUSE     0x0020 /* Processing a sub-WHERE as part of
+                                      ** the OR optimization  */
+#define WHERE_GROUPBY          0x0040 /* pOrderBy is really a GROUP BY */
+#define WHERE_DISTINCTBY       0x0080 /* pOrderby is really a DISTINCT clause */
+#define WHERE_WANT_DISTINCT    0x0100 /* All output needs to be distinct */
+#define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */
+#define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */
+#define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */
+#define WHERE_SEEK_UNIQ_TABLE  0x1000 /* Do not defer seeks if unique */
+                        /*     0x2000    not currently used */
+#define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */
+                        /*     0x8000    not currently used */
 
 /* Allowed return values from sqlite3WhereIsDistinct()
 */
@@ -12020,12 +16390,12 @@ struct SrcList {
 ** pEList corresponds to the result set of a SELECT and is NULL for
 ** other statements.
 **
-** NameContexts can be nested.  When resolving names, the inner-most 
+** NameContexts can be nested.  When resolving names, the inner-most
 ** context is searched first.  If no match is found, the next outer
 ** context is checked.  If there is still no match, the next context
 ** is checked.  This process continues until either a match is found
 ** or all contexts are check.  When a match is found, the nRef member of
-** the context containing the match is incremented. 
+** the context containing the match is incremented.
 **
 ** Each subquery gets a new NameContext.  The pNext field points to the
 ** NameContext in the parent query.  Thus the process of scanning the
@@ -12046,15 +16416,18 @@ struct NameContext {
 /*
 ** Allowed values for the NameContext, ncFlags field.
 **
-** Note:  NC_MinMaxAgg must have the same value as SF_MinMaxAgg and
-** SQLITE_FUNC_MINMAX.
-** 
+** Value constraints (all checked via assert()):
+**    NC_HasAgg    == SF_HasAgg
+**    NC_MinMaxAgg == SF_MinMaxAgg == SQLITE_FUNC_MINMAX
+**
 */
 #define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
-#define NC_HasAgg    0x0002  /* One or more aggregate functions seen */
+#define NC_PartIdx   0x0002  /* True if resolving a partial index WHERE */
 #define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
 #define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
-#define NC_PartIdx   0x0010  /* True if resolving a partial index WHERE */
+#define NC_HasAgg    0x0010  /* One or more aggregate functions seen */
+#define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
+#define NC_VarSelect 0x0040  /* A correlated subquery has been seen */
 #define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
 
 /*
@@ -12080,13 +16453,13 @@ struct NameContext {
 struct Select {
   ExprList *pEList;      /* The fields of the result */
   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
-  u16 selFlags;          /* Various SF_* values */
+  LogEst nSelectRow;     /* Estimated number of result rows */
+  u32 selFlags;          /* Various SF_* values */
   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
 #if SELECTTRACE_ENABLED
   char zSelName[12];     /* Symbolic name of this SELECT use for debugging */
 #endif
   int addrOpenEphm[2];   /* OP_OpenEphem opcodes related to this select */
-  u64 nSelectRow;        /* Estimated number of result rows */
   SrcList *pSrc;         /* The FROM clause */
   Expr *pWhere;          /* The WHERE clause */
   ExprList *pGroupBy;    /* The GROUP BY clause */
@@ -12102,20 +16475,30 @@ struct Select {
 /*
 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
 ** "Select Flag".
-*/
-#define SF_Distinct        0x0001  /* Output should be DISTINCT */
-#define SF_Resolved        0x0002  /* Identifiers have been resolved */
-#define SF_Aggregate       0x0004  /* Contains aggregate functions */
-#define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
-#define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
-#define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
-#define SF_Compound        0x0040  /* Part of a compound query */
-#define SF_Values          0x0080  /* Synthesized from VALUES clause */
-#define SF_AllValues       0x0100  /* All terms of compound are VALUES */
-#define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
-#define SF_MaybeConvert    0x0400  /* Need convertCompoundSelectToSubquery() */
-#define SF_Recursive       0x0800  /* The recursive part of a recursive CTE */
-#define SF_MinMaxAgg       0x1000  /* Aggregate containing min() or max() */
+**
+** Value constraints (all checked via assert())
+**     SF_HasAgg     == NC_HasAgg
+**     SF_MinMaxAgg  == NC_MinMaxAgg     == SQLITE_FUNC_MINMAX
+**     SF_FixedLimit == WHERE_USE_LIMIT
+*/
+#define SF_Distinct       0x00001  /* Output should be DISTINCT */
+#define SF_All            0x00002  /* Includes the ALL keyword */
+#define SF_Resolved       0x00004  /* Identifiers have been resolved */
+#define SF_Aggregate      0x00008  /* Contains agg functions or a GROUP BY */
+#define SF_HasAgg         0x00010  /* Contains aggregate functions */
+#define SF_UsesEphemeral  0x00020  /* Uses the OpenEphemeral opcode */
+#define SF_Expanded       0x00040  /* sqlite3SelectExpand() called on this */
+#define SF_HasTypeInfo    0x00080  /* FROM subqueries have Table metadata */
+#define SF_Compound       0x00100  /* Part of a compound query */
+#define SF_Values         0x00200  /* Synthesized from VALUES clause */
+#define SF_MultiValue     0x00400  /* Single VALUES term with multiple rows */
+#define SF_NestedFrom     0x00800  /* Part of a parenthesized FROM clause */
+#define SF_MinMaxAgg      0x01000  /* Aggregate containing min() or max() */
+#define SF_Recursive      0x02000  /* The recursive part of a recursive CTE */
+#define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */
+#define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */
+#define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */
+#define SF_IncludeHidden  0x20000  /* Include hidden columns in output */
 
 
 /*
@@ -12123,7 +16506,7 @@ struct Select {
 ** by one of the following macros.  The "SRT" prefix means "SELECT Result
 ** Type".
 **
-**     SRT_Union       Store results as a key in a temporary index 
+**     SRT_Union       Store results as a key in a temporary index
 **                     identified by pDest->iSDParm.
 **
 **     SRT_Except      Remove results from the temporary index pDest->iSDParm.
@@ -12147,7 +16530,7 @@ struct Select {
 **                     of the query.  This destination implies "LIMIT 1".
 **
 **     SRT_Set         The result must be a single column.  Store each
-**                     row of result as the key in table pDest->iSDParm. 
+**                     row of result as the key in table pDest->iSDParm.
 **                     Apply the affinity pDest->affSdst before storing
 **                     results.  Used to implement "IN (SELECT ...)".
 **
@@ -12207,19 +16590,19 @@ struct Select {
 */
 struct SelectDest {
   u8 eDest;            /* How to dispose of the results.  On of SRT_* above. */
-  char affSdst;        /* Affinity used when eDest==SRT_Set */
   int iSDParm;         /* A parameter used by the eDest disposal method */
   int iSdst;           /* Base register where results are written */
   int nSdst;           /* Number of registers allocated */
+  char *zAffSdst;      /* Affinity used when eDest==SRT_Set */
   ExprList *pOrderBy;  /* Key columns for SRT_Queue and SRT_DistQueue */
 };
 
 /*
-** During code generation of statements that do inserts into AUTOINCREMENT 
+** During code generation of statements that do inserts into AUTOINCREMENT
 ** tables, the following information is attached to the Table.u.autoInc.p
 ** pointer of each autoincrement table to record some side information that
 ** the code generator needs.  We have to keep per-table autoincrement
-** information in case inserts are down within triggers.  Triggers do not
+** information in case inserts are done within triggers.  Triggers do not
 ** normally coordinate their activities, but we do need to coordinate the
 ** loading and saving of autoincrement information.
 */
@@ -12238,7 +16621,7 @@ struct AutoincInfo {
 #endif
 
 /*
-** At least one instance of the following structure is created for each 
+** At least one instance of the following structure is created for each
 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
 ** statement. All such objects are stored in the linked list headed at
 ** Parse.pTriggerPrg and deleted once statement compilation has been
@@ -12251,7 +16634,7 @@ struct AutoincInfo {
 ** values for both pTrigger and orconf.
 **
 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
-** accessed (or set to 0 for triggers fired as a result of INSERT 
+** accessed (or set to 0 for triggers fired as a result of INSERT
 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
 ** a mask of new.* columns used by the program.
 */
@@ -12292,7 +16675,7 @@ struct TriggerPrg {
 ** is constant but the second part is reset at the beginning and end of
 ** each recursion.
 **
-** The nTableLock and aTableLock variables are only used if the shared-cache 
+** The nTableLock and aTableLock variables are only used if the shared-cache
 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
 ** used to store the set of table-locks required by the statement being
 ** compiled. Function sqlite3TableLock() is used to add entries to the
@@ -12311,35 +16694,25 @@ struct Parse {
   u8 mayAbort;         /* True if statement may throw an ABORT exception */
   u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
   u8 okConstFactor;    /* OK to factor out constants */
-  int aTempReg[8];     /* Holding area for temporary registers */
+  u8 disableLookaside; /* Number of times lookaside has been disabled */
+  u8 nColCache;        /* Number of entries in aColCache[] */
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */
   int nErr;            /* Number of errors seen */
   int nTab;            /* Number of previously allocated VDBE cursors */
   int nMem;            /* Number of memory cells used so far */
-  int nSet;            /* Number of sets used so far */
-  int nOnce;           /* Number of OP_Once instructions so far */
   int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
-  int iFixedOp;        /* Never back out opcodes iFixedOp-1 or earlier */
-  int ckBase;          /* Base register of data during check constraints */
-  int iPartIdxTab;     /* Table corresponding to a partial index */
+  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
+  int iSelfTab;        /* Table for associated with an index on expr, or negative
+                       ** of the base register during check-constraint eval */
   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
   int nLabel;          /* Number of labels used */
   int *aLabel;         /* Space to hold the labels */
-  struct yColCache {
-    int iTable;           /* Table cursor number */
-    i16 iColumn;          /* Table column number */
-    u8 tempReg;           /* iReg is a temp register that needs to be freed */
-    int iLevel;           /* Nesting level */
-    int iReg;             /* Reg with value of this column. 0 means none. */
-    int lru;              /* Least recently used entry has the smallest value */
-  } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
   ExprList *pConstExpr;/* Constant expressions */
   Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */
-  int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
   int regRoot;         /* Register holding root page number for new objects */
   int nMaxArg;         /* Max args passed to user function by sub-program */
@@ -12352,12 +16725,9 @@ struct Parse {
   TableLock *aTableLock; /* Required table locks for shared-cache mode */
 #endif
   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
-
-  /* Information used while coding trigger programs. */
   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
   Table *pTriggerTab;  /* Table triggers are being coded for */
   int addrCrTab;       /* Address of OP_CreateTable opcode on CREATE TABLE */
-  int addrSkipPK;      /* Address of instruction to skip PRIMARY KEY index */
   u32 nQueryLoop;      /* Est number of iterations of a query (10*log2(N)) */
   u32 oldmask;         /* Mask of old.* columns referenced */
   u32 newmask;         /* Mask of new.* columns referenced */
@@ -12365,36 +16735,50 @@ struct Parse {
   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
   u8 disableTriggers;  /* True to disable triggers */
 
+  /**************************************************************************
+  ** Fields above must be initialized to zero.  The fields that follow,
+  ** down to the beginning of the recursive section, do not need to be
+  ** initialized as they will be set before being used.  The boundary is
+  ** determined by offsetof(Parse,aColCache).
+  **************************************************************************/
+
+  struct yColCache {
+    int iTable;           /* Table cursor number */
+    i16 iColumn;          /* Table column number */
+    u8 tempReg;           /* iReg is a temp register that needs to be freed */
+    int iLevel;           /* Nesting level */
+    int iReg;             /* Reg with value of this column. 0 means none. */
+    int lru;              /* Least recently used entry has the smallest value */
+  } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
+  int aTempReg[8];        /* Holding area for temporary registers */
+  Token sNameToken;       /* Token with unqualified schema object name */
+
   /************************************************************************
   ** Above is constant between recursions.  Below is reset before and after
   ** each recursion.  The boundary between these two regions is determined
-  ** using offsetof(Parse,nVar) so the nVar field must be the first field
-  ** in the recursive region.
+  ** using offsetof(Parse,sLastToken) so the sLastToken field must be the
+  ** first field in the recursive region.
   ************************************************************************/
 
-  int nVar;                 /* Number of '?' variables seen in the SQL so far */
-  int nzVar;                /* Number of available slots in azVar[] */
+  Token sLastToken;       /* The last token parsed */
+  ynVar nVar;               /* Number of '?' variables seen in the SQL so far */
   u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
-  u8 bFreeWith;             /* True if pWith should be freed with parser */
   u8 explain;               /* True if the EXPLAIN flag is found on the query */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
   int nVtabLock;            /* Number of virtual tables to lock */
 #endif
-  int nAlias;               /* Number of aliased result set columns */
   int nHeight;              /* Expression tree height of current sub-select */
 #ifndef SQLITE_OMIT_EXPLAIN
   int iSelectId;            /* ID of current select for EXPLAIN output */
   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
 #endif
-  char **azVar;             /* Pointers to names of parameters */
+  VList *pVList;            /* Mapping between variable names and numbers */
   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
   const char *zTail;        /* All SQL text past the last semicolon parsed */
   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
-  Token sNameToken;         /* Token with unqualified schema object name */
-  Token sLastToken;         /* The last token parsed */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   Token sArg;               /* Complete text of a module argument */
   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
@@ -12402,8 +16786,17 @@ struct Parse {
   Table *pZombieTab;        /* List of Table objects to delete after code gen */
   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
   With *pWith;              /* Current WITH clause, or NULL */
+  With *pWithToFree;        /* Free this WITH object at the end of the parse */
 };
 
+/*
+** Sizes and pointers of various parts of the Parse object.
+*/
+#define PARSE_HDR_SZ offsetof(Parse,aColCache) /* Recursive part w/o aColCache*/
+#define PARSE_RECURSE_SZ offsetof(Parse,sLastToken)    /* Recursive part */
+#define PARSE_TAIL_SZ (sizeof(Parse)-PARSE_RECURSE_SZ) /* Non-recursive part */
+#define PARSE_TAIL(X) (((char*)(X))+PARSE_RECURSE_SZ)  /* Pointer to tail */
+
 /*
 ** Return true if currently inside an sqlite3_declare_vtab() call.
 */
@@ -12424,25 +16817,40 @@ struct AuthContext {
 
 /*
 ** Bitfield flags for P5 value in various opcodes.
-*/
-#define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
+**
+** Value constraints (enforced via assert()):
+**    OPFLAG_LENGTHARG    == SQLITE_FUNC_LENGTH
+**    OPFLAG_TYPEOFARG    == SQLITE_FUNC_TYPEOF
+**    OPFLAG_BULKCSR      == BTREE_BULKLOAD
+**    OPFLAG_SEEKEQ       == BTREE_SEEK_EQ
+**    OPFLAG_FORDELETE    == BTREE_FORDELETE
+**    OPFLAG_SAVEPOSITION == BTREE_SAVEPOSITION
+**    OPFLAG_AUXDELETE    == BTREE_AUXDELETE
+*/
+#define OPFLAG_NCHANGE       0x01    /* OP_Insert: Set to update db->nChange */
+                                     /* Also used in P2 (not P5) of OP_Delete */
 #define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
-#define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
+#define OPFLAG_LASTROWID     0x20    /* Set to update db->lastRowid */
 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
+#define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */
 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
 #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
-#define OPFLAG_P2ISREG       0x02    /* P2 to OP_Open** is a register number */
+#define OPFLAG_SEEKEQ        0x02    /* OP_Open** cursor uses EQ seek only */
+#define OPFLAG_FORDELETE     0x08    /* OP_Open should use BTREE_FORDELETE */
+#define OPFLAG_P2ISREG       0x10    /* P2 to OP_Open** is a register number */
 #define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */
+#define OPFLAG_SAVEPOSITION  0x02    /* OP_Delete/Insert: save cursor pos */
+#define OPFLAG_AUXDELETE     0x04    /* OP_Delete: index in a DELETE op */
 
 /*
  * Each trigger present in the database schema is stored as an instance of
- * struct Trigger. 
+ * struct Trigger.
  *
  * Pointers to instances of struct Trigger are stored in two ways.
- * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
+ * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
  *    database). This allows Trigger structures to be retrieved by name.
  * 2. All triggers associated with a single table form a linked list, using the
  *    pNext member of struct Trigger. A pointer to the first element of the
@@ -12468,7 +16876,7 @@ struct Trigger {
 
 /*
 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
-** determine which. 
+** determine which.
 **
 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
 ** In that cases, the constants below can be ORed together.
@@ -12478,48 +16886,48 @@ struct Trigger {
 
 /*
  * An instance of struct TriggerStep is used to store a single SQL statement
- * that is a part of a trigger-program. 
+ * that is a part of a trigger-program.
  *
  * Instances of struct TriggerStep are stored in a singly linked list (linked
- * using the "pNext" member) referenced by the "step_list" member of the 
+ * using the "pNext" member) referenced by the "step_list" member of the
  * associated struct Trigger instance. The first element of the linked list is
  * the first step of the trigger-program.
- * 
+ *
  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
- * "SELECT" statement. The meanings of the other members is determined by the 
+ * "SELECT" statement. The meanings of the other members is determined by the
  * value of "op" as follows:
  *
  * (op == TK_INSERT)
  * orconf    -> stores the ON CONFLICT algorithm
  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
  *              this stores a pointer to the SELECT statement. Otherwise NULL.
- * target    -> A token holding the quoted name of the table to insert into.
+ * zTarget   -> Dequoted name of the table to insert into.
  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
  *              this stores values to be inserted. Otherwise NULL.
- * pIdList   -> If this is an INSERT INTO ... () VALUES ... 
+ * pIdList   -> If this is an INSERT INTO ... () VALUES ...
  *              statement, then this stores the column-names to be
  *              inserted into.
  *
  * (op == TK_DELETE)
- * target    -> A token holding the quoted name of the table to delete from.
+ * zTarget   -> Dequoted name of the table to delete from.
  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
  *              Otherwise NULL.
- * 
+ *
  * (op == TK_UPDATE)
- * target    -> A token holding the quoted name of the table to update rows of.
+ * zTarget   -> Dequoted name of the table to update.
  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
  *              Otherwise NULL.
  * pExprList -> A list of the columns to update and the expressions to update
  *              them to. See sqlite3Update() documentation of "pChanges"
  *              argument.
- * 
+ *
  */
 struct TriggerStep {
   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
   u8 orconf;           /* OE_Rollback etc. */
   Trigger *pTrig;      /* The trigger that this step is a part of */
-  Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
-  Token target;        /* Target table for DELETE, UPDATE, INSERT */
+  Select *pSelect;     /* SELECT statement or RHS of INSERT INTO SELECT ... */
+  char *zTarget;       /* Target table for DELETE, UPDATE, INSERT */
   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
   ExprList *pExprList; /* SET clause for UPDATE. */
   IdList *pIdList;     /* Column names for INSERT */
@@ -12530,7 +16938,7 @@ struct TriggerStep {
 /*
 ** The following structure contains information used by the sqliteFix...
 ** routines as they walk the parse tree to make database references
-** explicit.  
+** explicit.
 */
 typedef struct DbFixer DbFixer;
 struct DbFixer {
@@ -12550,14 +16958,20 @@ struct StrAccum {
   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
   char *zBase;         /* A base allocation.  Not from malloc. */
   char *zText;         /* The string collected so far */
-  int  nChar;          /* Length of the string so far */
-  int  nAlloc;         /* Amount of space allocated in zText */
-  int  mxAlloc;        /* Maximum allowed string length */
-  u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
+  u32  nChar;          /* Length of the string so far */
+  u32  nAlloc;         /* Amount of space allocated in zText */
+  u32  mxAlloc;        /* Maximum allowed allocation.  0 for no malloc usage */
   u8   accError;       /* STRACCUM_NOMEM or STRACCUM_TOOBIG */
+  u8   printfFlags;    /* SQLITE_PRINTF flags below */
 };
 #define STRACCUM_NOMEM   1
 #define STRACCUM_TOOBIG  2
+#define SQLITE_PRINTF_INTERNAL 0x01  /* Internal-use-only converters allowed */
+#define SQLITE_PRINTF_SQLFUNC  0x02  /* SQL function arguments to VXPrintf */
+#define SQLITE_PRINTF_MALLOCED 0x04  /* True if xText is allocated space */
+
+#define isMalloced(X)  (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)
+
 
 /*
 ** A pointer to this structure is used to communicate information
@@ -12585,6 +16999,7 @@ struct Sqlite3Config {
   int neverCorrupt;                 /* Database is always well-formed */
   int szLookaside;                  /* Default lookaside buffer size */
   int nLookaside;                   /* Default lookaside buffer count */
+  int nStmtSpill;                   /* Stmt-journal spill-to-disk threshold */
   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
@@ -12624,10 +17039,11 @@ struct Sqlite3Config {
   void (*xVdbeBranch)(void*,int iSrcLine,u8 eThis,u8 eMx);  /* Callback */
   void *pVdbeBranchArg;                                     /* 1st argument */
 #endif
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
   int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
 #endif
   int bLocaltimeFault;              /* True to fail localtime() calls */
+  int iOnceResetThreshold;          /* When to reset OP_Once counters */
 };
 
 /*
@@ -12652,18 +17068,24 @@ struct Sqlite3Config {
 ** Context pointer passed down through the tree-walk.
 */
 struct Walker {
+  Parse *pParse;                            /* Parser context.  */
   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
   void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
-  Parse *pParse;                            /* Parser context.  */
   int walkerDepth;                          /* Number of subqueries */
   u8 eCode;                                 /* A small processing code */
   union {                                   /* Extra data for callback */
-    NameContext *pNC;                          /* Naming context */
-    int n;                                     /* A counter */
-    int iCur;                                  /* A cursor number */
-    SrcList *pSrcList;                         /* FROM clause */
-    struct SrcCount *pSrcCount;                /* Counting column references */
+    NameContext *pNC;                         /* Naming context */
+    int n;                                    /* A counter */
+    int iCur;                                 /* A cursor number */
+    SrcList *pSrcList;                        /* FROM clause */
+    struct SrcCount *pSrcCount;               /* Counting column references */
+    struct CCurHint *pCCurHint;               /* Used by codeCursorHint() */
+    int *aiCol;                               /* array of column indexes */
+    struct IdxCover *pIdxCover;               /* Check for index coverage */
+    struct IdxExprTrans *pIdxTrans;           /* Convert indexed expr to column */
+    ExprList *pGroupBy;                       /* GROUP BY clause */
+    struct HavingToWhereCtx *pHavingCtx;      /* HAVING to WHERE clause ctx */
   } u;
 };
 
@@ -12673,6 +17095,11 @@ SQLITE_PRIVATE int sqlite3WalkExprList(Walker*, ExprList*);
 SQLITE_PRIVATE int sqlite3WalkSelect(Walker*, Select*);
 SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker*, Select*);
 SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker*, Select*);
+SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker*, Expr*);
+SQLITE_PRIVATE int sqlite3SelectWalkNoop(Walker*, Select*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE void sqlite3SelectWalkAssert2(Walker*, Select*);
+#endif
 
 /*
 ** Return code from the parse-tree walking primitives and their
@@ -12693,7 +17120,7 @@ struct With {
     char *zName;                    /* Name of this CTE */
     ExprList *pCols;                /* List of explicit column names, or NULL */
     Select *pSelect;                /* The definition of this CTE */
-    const char *zErr;               /* Error message for circular references */
+    const char *zCteErr;            /* Error message for circular references */
   } a[1];
 };
 
@@ -12731,7 +17158,26 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE   int sqlite3NomemError(int);
+SQLITE_PRIVATE   int sqlite3IoerrnomemError(int);
+SQLITE_PRIVATE   int sqlite3CorruptPgnoError(int,Pgno);
+# define SQLITE_NOMEM_BKPT sqlite3NomemError(__LINE__)
+# define SQLITE_IOERR_NOMEM_BKPT sqlite3IoerrnomemError(__LINE__)
+# define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptPgnoError(__LINE__,(P))
+#else
+# define SQLITE_NOMEM_BKPT SQLITE_NOMEM
+# define SQLITE_IOERR_NOMEM_BKPT SQLITE_IOERR_NOMEM
+# define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptError(__LINE__)
+#endif
 
+/*
+** FTS3 and FTS4 both require virtual table support
+*/
+#if defined(SQLITE_OMIT_VIRTUALTABLE)
+# undef SQLITE_ENABLE_FTS3
+# undef SQLITE_ENABLE_FTS4
+#endif
 
 /*
 ** FTS4 is really an extension for FTS3.  It is enabled using the
@@ -12764,6 +17210,7 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
+# define sqlite3Isquote(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x80)
 #else
 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
@@ -12772,14 +17219,18 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
+# define sqlite3Isquote(x)   ((x)=='"'||(x)=='\''||(x)=='['||(x)=='`')
 #endif
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
 SQLITE_PRIVATE int sqlite3IsIdChar(u8);
+#endif
 
 /*
 ** Internal function prototypes
 */
-#define sqlite3StrICmp sqlite3_stricmp
+SQLITE_PRIVATE int sqlite3StrICmp(const char*,const char*);
 SQLITE_PRIVATE int sqlite3Strlen30(const char*);
+SQLITE_PRIVATE char *sqlite3ColumnType(Column*,char*);
 #define sqlite3StrNICmp sqlite3_strnicmp
 
 SQLITE_PRIVATE int sqlite3MallocInit(void);
@@ -12788,12 +17239,14 @@ SQLITE_PRIVATE void *sqlite3Malloc(u64);
 SQLITE_PRIVATE void *sqlite3MallocZero(u64);
 SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, u64);
 SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, u64);
+SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3*, u64);
 SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3*,const char*);
 SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, u64);
 SQLITE_PRIVATE void *sqlite3Realloc(void*, u64);
 SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);
 SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, u64);
 SQLITE_PRIVATE void sqlite3DbFree(sqlite3*, void*);
+SQLITE_PRIVATE void sqlite3DbFreeNN(sqlite3*, void*);
 SQLITE_PRIVATE int sqlite3MallocSize(void*);
 SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3*, void*);
 SQLITE_PRIVATE void *sqlite3ScratchMalloc(int);
@@ -12801,7 +17254,9 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void*);
 SQLITE_PRIVATE void *sqlite3PageMalloc(int);
 SQLITE_PRIVATE void sqlite3PageFree(void*);
 SQLITE_PRIVATE void sqlite3MemSetDefault(void);
+#ifndef SQLITE_UNTESTABLE
 SQLITE_PRIVATE void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
+#endif
 SQLITE_PRIVATE int sqlite3HeapNearlyFull(void);
 
 /*
@@ -12815,18 +17270,22 @@ SQLITE_PRIVATE int sqlite3HeapNearlyFull(void);
 #ifdef SQLITE_USE_ALLOCA
 # define sqlite3StackAllocRaw(D,N)   alloca(N)
 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
-# define sqlite3StackFree(D,P)       
+# define sqlite3StackFree(D,P)
 #else
 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
 #endif
 
-#ifdef SQLITE_ENABLE_MEMSYS3
-SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
-#endif
+/* Do not allow both MEMSYS5 and MEMSYS3 to be defined together.  If they
+** are, disable MEMSYS3
+*/
 #ifdef SQLITE_ENABLE_MEMSYS5
 SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
+#undef SQLITE_ENABLE_MEMSYS3
+#endif
+#ifdef SQLITE_ENABLE_MEMSYS3
+SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
 #endif
 
 
@@ -12837,10 +17296,20 @@ SQLITE_PRIVATE   sqlite3_mutex *sqlite3MutexAlloc(int);
 SQLITE_PRIVATE   int sqlite3MutexInit(void);
 SQLITE_PRIVATE   int sqlite3MutexEnd(void);
 #endif
+#if !defined(SQLITE_MUTEX_OMIT) && !defined(SQLITE_MUTEX_NOOP)
+SQLITE_PRIVATE   void sqlite3MemoryBarrier(void);
+#else
+# define sqlite3MemoryBarrier()
+#endif
 
-SQLITE_PRIVATE int sqlite3StatusValue(int);
-SQLITE_PRIVATE void sqlite3StatusAdd(int, int);
-SQLITE_PRIVATE void sqlite3StatusSet(int, int);
+SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int);
+SQLITE_PRIVATE void sqlite3StatusUp(int, int);
+SQLITE_PRIVATE void sqlite3StatusDown(int, int);
+SQLITE_PRIVATE void sqlite3StatusHighwater(int, int);
+
+/* Access to mutexes used by sqlite3_status() */
+SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void);
+SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void);
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
 SQLITE_PRIVATE   int sqlite3IsNaN(double);
@@ -12858,14 +17327,11 @@ struct PrintfArguments {
   sqlite3_value **apArg;   /* The argument values */
 };
 
-#define SQLITE_PRINTF_INTERNAL 0x01
-#define SQLITE_PRINTF_SQLFUNC  0x02
-SQLITE_PRIVATE void sqlite3VXPrintf(StrAccum*, u32, const char*, va_list);
-SQLITE_PRIVATE void sqlite3XPrintf(StrAccum*, u32, const char*, ...);
+SQLITE_PRIVATE void sqlite3VXPrintf(StrAccum*, const char*, va_list);
+SQLITE_PRIVATE void sqlite3XPrintf(StrAccum*, const char*, ...);
 SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3*,const char*, ...);
 SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
-SQLITE_PRIVATE char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
-#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
 SQLITE_PRIVATE   void sqlite3DebugPrintf(const char*, ...);
 #endif
 #if defined(SQLITE_TEST)
@@ -12873,19 +17339,18 @@ SQLITE_PRIVATE   void *sqlite3TestTextToPtr(const char*);
 #endif
 
 #if defined(SQLITE_DEBUG)
-SQLITE_PRIVATE   TreeView *sqlite3TreeViewPush(TreeView*,u8);
-SQLITE_PRIVATE   void sqlite3TreeViewPop(TreeView*);
-SQLITE_PRIVATE   void sqlite3TreeViewLine(TreeView*, const char*, ...);
-SQLITE_PRIVATE   void sqlite3TreeViewItem(TreeView*, const char*, u8);
 SQLITE_PRIVATE   void sqlite3TreeViewExpr(TreeView*, const Expr*, u8);
+SQLITE_PRIVATE   void sqlite3TreeViewBareExprList(TreeView*, const ExprList*, const char*);
 SQLITE_PRIVATE   void sqlite3TreeViewExprList(TreeView*, const ExprList*, u8, const char*);
 SQLITE_PRIVATE   void sqlite3TreeViewSelect(TreeView*, const Select*, u8);
+SQLITE_PRIVATE   void sqlite3TreeViewWith(TreeView*, const With*, u8);
 #endif
 
 
-SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*, ...);
+SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);
 SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);
-SQLITE_PRIVATE int sqlite3Dequote(char*);
+SQLITE_PRIVATE void sqlite3Dequote(char*);
+SQLITE_PRIVATE void sqlite3TokenInit(Token*,char*);
 SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);
 SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, char **);
 SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);
@@ -12894,45 +17359,60 @@ SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);
 SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);
 SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);
 SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse*,int,int);
+#endif
 SQLITE_PRIVATE Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
 SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*,int,const char*);
 SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
-SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
+SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*);
+SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse*, Expr*, Select*);
 SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
 SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
-SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*);
+SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*, u32);
 SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3*, Expr*);
 SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
+SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);
+SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList*,int);
 SQLITE_PRIVATE void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
 SQLITE_PRIVATE void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
 SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);
+SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);
 SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
 SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
 SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3*,const char *zName);
+#endif
 SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3*);
 SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3*,int);
 SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3*);
-SQLITE_PRIVATE void sqlite3BeginParse(Parse*,int);
 SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);
+SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3*,Table*);
+SQLITE_PRIVATE int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);
+SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(Parse*,Table*,Select*);
 SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,Select*);
 SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *, int);
 SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table*);
 SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index*, i16);
 SQLITE_PRIVATE void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
-SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*);
+#if SQLITE_ENABLE_HIDDEN_COLUMNS
+SQLITE_PRIVATE   void sqlite3ColumnPropertiesFromName(Table*, Column*);
+#else
+# define sqlite3ColumnPropertiesFromName(T,C) /* no-op */
+#endif
+SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*,Token*);
 SQLITE_PRIVATE void sqlite3AddNotNull(Parse*, int);
 SQLITE_PRIVATE void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
 SQLITE_PRIVATE void sqlite3AddCheckConstraint(Parse*, Expr*);
-SQLITE_PRIVATE void sqlite3AddColumnType(Parse*,Token*);
 SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse*,ExprSpan*);
 SQLITE_PRIVATE void sqlite3AddCollateType(Parse*, Token*);
 SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,u8,Select*);
 SQLITE_PRIVATE int sqlite3ParseUri(const char*,const char*,unsigned int*,
                     sqlite3_vfs**,char**,char **);
 SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
-SQLITE_PRIVATE int sqlite3CodeOnce(Parse *);
 
-#ifdef SQLITE_OMIT_BUILTIN_TEST
+#ifdef SQLITE_UNTESTABLE
 # define sqlite3FaultSim(X) SQLITE_OK
 #else
 SQLITE_PRIVATE   int sqlite3FaultSim(int);
@@ -12940,11 +17420,14 @@ SQLITE_PRIVATE   int sqlite3FaultSim(int);
 
 SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32);
 SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec*, u32);
+SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec*, u32);
 SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec*, u32);
 SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec*, u32, void*);
 SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec*);
 SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec*);
+#ifndef SQLITE_UNTESTABLE
 SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int,int*);
+#endif
 
 SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
 SQLITE_PRIVATE void sqlite3RowSetClear(RowSet*);
@@ -12952,7 +17435,7 @@ SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet*, i64);
 SQLITE_PRIVATE int sqlite3RowSetTest(RowSet*, int iBatch, i64);
 SQLITE_PRIVATE int sqlite3RowSetNext(RowSet*, i64*);
 
-SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
+SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,ExprList*,Select*,int,int);
 
 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
 SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
@@ -12982,18 +17465,19 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*)
 SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                       Token*, Select*, Expr*, IdList*);
 SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
+SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);
 SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
 SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);
 SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);
 SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3*, IdList*);
 SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3*, SrcList*);
 SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);
-SQLITE_PRIVATE Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
-                          Expr*, int, int);
+SQLITE_PRIVATE void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
+                          Expr*, int, int, u8);
 SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);
 SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*);
 SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
-                         Expr*,ExprList*,u16,Expr*,Expr*);
+                         Expr*,ExprList*,u32,Expr*,Expr*);
 SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3*, Select*);
 SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);
 SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, int);
@@ -13005,14 +17489,20 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
 SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
 SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
 SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);
-SQLITE_PRIVATE u64 sqlite3WhereOutputRowCount(WhereInfo*);
+SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereOrderedInnerLoop(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo*);
 SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo*, int*);
+#define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */
+#define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */
+#define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */
+SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
 SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
+SQLITE_PRIVATE void sqlite3ExprCodeGetColumnToReg(Parse*, Table*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse*, int, int, int);
@@ -13022,59 +17512,78 @@ SQLITE_PRIVATE void sqlite3ExprCacheRemove(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3ExprCacheClear(Parse*);
 SQLITE_PRIVATE void sqlite3ExprCacheAffinityChange(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3ExprCode(Parse*, Expr*, int);
+SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse*, Expr*, int);
 SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
-SQLITE_PRIVATE void sqlite3ExprCodeAtInit(Parse*, Expr*, int, u8);
+SQLITE_PRIVATE int sqlite3ExprCodeAtInit(Parse*, Expr*, int);
 SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
 SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse*, Expr*, int);
 SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse*, Expr*, int);
-SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, u8);
+SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
 #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
+#define SQLITE_ECEL_REF      0x04  /* Use ExprList.u.x.iOrderByCol */
+#define SQLITE_ECEL_OMITREF  0x08  /* Omit if ExprList.u.x.iOrderByCol */
 SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
 SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
+SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);
 SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3*,const char*, const char*);
-SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
-SQLITE_PRIVATE Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
+#define LOCATE_VIEW    0x01
+#define LOCATE_NOERR   0x02
+SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,u32 flags,const char*, const char*);
+SQLITE_PRIVATE Table *sqlite3LocateTableItem(Parse*,u32 flags,struct SrcList_item *);
 SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
 SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
 SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
-SQLITE_PRIVATE void sqlite3Vacuum(Parse*);
-SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*);
+SQLITE_PRIVATE void sqlite3Vacuum(Parse*,Token*);
+SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*, int);
 SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3*, Token*);
-SQLITE_PRIVATE int sqlite3ExprCompare(Expr*, Expr*, int);
+SQLITE_PRIVATE int sqlite3ExprCompare(Parse*,Expr*, Expr*, int);
+SQLITE_PRIVATE int sqlite3ExprCompareSkip(Expr*, Expr*, int);
 SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList*, ExprList*, int);
-SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Expr*, Expr*, int);
+SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Parse*,Expr*, Expr*, int);
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
+SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(Expr*, int iCur, Index *pIdx);
 SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
 SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse*);
+#ifndef SQLITE_UNTESTABLE
 SQLITE_PRIVATE void sqlite3PrngSaveState(void);
 SQLITE_PRIVATE void sqlite3PrngRestoreState(void);
+#endif
 SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3*,int);
 SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse*, int);
 SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
 SQLITE_PRIVATE void sqlite3BeginTransaction(Parse*, int);
-SQLITE_PRIVATE void sqlite3CommitTransaction(Parse*);
-SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse*);
+SQLITE_PRIVATE void sqlite3EndTransaction(Parse*,int);
 SQLITE_PRIVATE void sqlite3Savepoint(Parse*, int, Token*);
 SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *);
 SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
 SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr*);
 SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr*);
 SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*, u8);
+SQLITE_PRIVATE int sqlite3ExprIsConstantOrGroupBy(Parse*, Expr*, ExprList*);
 SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr*,int);
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr*);
+#endif
 SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr*, int*);
 SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr*);
 SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
 SQLITE_PRIVATE int sqlite3IsRowid(const char*);
-SQLITE_PRIVATE void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8);
-SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
+SQLITE_PRIVATE void sqlite3GenerateRowDelete(
+    Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
+SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
 SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
 SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse*,int);
 SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
-                                     u8,u8,int,int*);
+                                     u8,u8,int,int*,int*);
+#ifdef SQLITE_ENABLE_NULL_TRIM
+SQLITE_PRIVATE   void sqlite3SetMakeRecordP5(Vdbe*,Table*);
+#else
+# define sqlite3SetMakeRecordP5(A,B)
+#endif
 SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
-SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, int, u8*, int*, int*);
+SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, u8, int, u8*, int*, int*);
 SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3MultiWrite(Parse*);
 SQLITE_PRIVATE void sqlite3MayAbort(Parse*);
@@ -13091,11 +17600,11 @@ SQLITE_PRIVATE void sqlite3SelectSetName(Select*,const char*);
 #else
 # define sqlite3SelectSetName(A,B)
 #endif
-SQLITE_PRIVATE void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
-SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
-SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3*);
+SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(FuncDef*,int);
+SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,u8,u8);
+SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void);
 SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void);
-SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void);
+SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
 SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3*);
 SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3*);
 SQLITE_PRIVATE void sqlite3ChangeCookie(Parse*, int);
@@ -13126,6 +17635,7 @@ SQLITE_PRIVATE   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
 SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
 SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
+# define sqlite3IsToplevel(p) ((p)->pToplevel==0)
 #else
 # define sqlite3TriggersExist(B,C,D,E,F) 0
 # define sqlite3DeleteTrigger(A,B)
@@ -13135,6 +17645,7 @@ SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Tab
 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
 # define sqlite3TriggerList(X, Y) 0
 # define sqlite3ParseToplevel(p) p
+# define sqlite3IsToplevel(p) 1
 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
 #endif
 
@@ -13164,7 +17675,9 @@ SQLITE_PRIVATE int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
 SQLITE_PRIVATE int sqlite3AtoF(const char *z, double*, int, u8);
 SQLITE_PRIVATE int sqlite3GetInt32(const char *, int*);
 SQLITE_PRIVATE int sqlite3Atoi(const char*);
+#ifndef SQLITE_OMIT_UTF16
 SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *pData, int nChar);
+#endif
 SQLITE_PRIVATE int sqlite3Utf8CharLen(const char *pData, int nByte);
 SQLITE_PRIVATE u32 sqlite3Utf8Read(const u8**);
 SQLITE_PRIVATE LogEst sqlite3LogEst(u64);
@@ -13172,7 +17685,14 @@ SQLITE_PRIVATE LogEst sqlite3LogEstAdd(LogEst,LogEst);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double);
 #endif
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
 SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst);
+#endif
+SQLITE_PRIVATE VList *sqlite3VListAdd(sqlite3*,VList*,const char*,int,int);
+SQLITE_PRIVATE const char *sqlite3VListNumToName(VList*,int);
+SQLITE_PRIVATE int sqlite3VListNameToNum(VList*,const char*,int);
 
 /*
 ** Routines to read and write variable-length integers.  These used to
@@ -13198,20 +17718,22 @@ SQLITE_PRIVATE int sqlite3VarintLen(u64 v);
 #define putVarint    sqlite3PutVarint
 
 
-SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
+SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3*, Index*);
 SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe*, Table*, int);
 SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2);
 SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
+SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table*,int);
 SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr);
 SQLITE_PRIVATE int sqlite3Atoi64(const char*, i64*, int, u8);
 SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char*, i64*);
 SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3*, int, const char*,...);
 SQLITE_PRIVATE void sqlite3Error(sqlite3*,int);
+SQLITE_PRIVATE void sqlite3SystemError(sqlite3*,int);
 SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
 SQLITE_PRIVATE u8 sqlite3HexToInt(int h);
 SQLITE_PRIVATE int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
 
-#if defined(SQLITE_TEST) 
+#if defined(SQLITE_NEED_ERR_NAME)
 SQLITE_PRIVATE const char *sqlite3ErrName(int);
 #endif
 
@@ -13220,7 +17742,7 @@ SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse);
 SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
 SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
 SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
-SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*);
+SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
 SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
 SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr*);
 SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *, CollSeq *);
@@ -13239,21 +17761,24 @@ SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z,u8);
 
 SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
 SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
-SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
+SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
                         void(*)(void*));
 SQLITE_PRIVATE void sqlite3ValueSetNull(sqlite3_value*);
 SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
 SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
+#ifndef SQLITE_OMIT_UTF16
 SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
+#endif
 SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
 SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
 #ifndef SQLITE_AMALGAMATION
 SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
+SQLITE_PRIVATE const char sqlite3StrBINARY[];
 SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
 SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[];
 SQLITE_PRIVATE const Token sqlite3IntTokens[];
 SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config;
-SQLITE_PRIVATE SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
+SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;
 #ifndef SQLITE_OMIT_WSD
 SQLITE_PRIVATE int sqlite3PendingByte;
 #endif
@@ -13265,10 +17790,12 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
 SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);
 SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
 SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*);
-SQLITE_PRIVATE int sqlite3CodeSubselect(Parse *, Expr *, int, int);
+SQLITE_PRIVATE int sqlite3CodeSubselect(Parse*, Expr *, int, int);
 SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);
+SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
 SQLITE_PRIVATE int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
 SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);
+SQLITE_PRIVATE int sqlite3ResolveExprListNames(NameContext*, ExprList*);
 SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
 SQLITE_PRIVATE void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
 SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
@@ -13286,7 +17813,6 @@ SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3*,Index*);
 SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
 SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
 SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
-SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3SchemaClear(void *);
 SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
@@ -13297,15 +17823,17 @@ SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);
 #ifdef SQLITE_DEBUG
 SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo*);
 #endif
-SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
+SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
   void (*)(sqlite3_context*,int,sqlite3_value **),
   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
   FuncDestructor *pDestructor
 );
+SQLITE_PRIVATE void sqlite3OomFault(sqlite3*);
+SQLITE_PRIVATE void sqlite3OomClear(sqlite3*);
 SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);
 SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);
 
-SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, char*, int, int);
+SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
 SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum*,const char*,int);
 SQLITE_PRIVATE void sqlite3StrAccumAppendAll(StrAccum*,const char*);
 SQLITE_PRIVATE void sqlite3AppendChar(StrAccum*,int,char);
@@ -13317,19 +17845,29 @@ SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
 SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);
 SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
 
+#ifndef SQLITE_OMIT_SUBQUERY
+SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse*, Expr*);
+#else
+# define sqlite3ExprCheckIN(x,y) SQLITE_OK
+#endif
+
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void);
-SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(Parse*,Index*,UnpackedRecord**,Expr*,u8,int,int*);
+SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
+    Parse*,Index*,UnpackedRecord**,Expr*,int,int,int*);
 SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);
 SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);
 SQLITE_PRIVATE int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
+SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3*, Index*, int);
 #endif
 
 /*
 ** The interface to the LEMON-generated parser
 */
-SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(u64));
-SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));
+#ifndef SQLITE_AMALGAMATION
+SQLITE_PRIVATE   void *sqlite3ParserAlloc(void*(*)(u64));
+SQLITE_PRIVATE   void sqlite3ParserFree(void*, void(*)(void*));
+#endif
 SQLITE_PRIVATE void sqlite3Parser(void*, int, Token, Parse*);
 #ifdef YYTRACKMAXSTACKDEPTH
 SQLITE_PRIVATE   int sqlite3ParserStackPeak(void*);
@@ -13358,7 +17896,7 @@ SQLITE_PRIVATE   int sqlite3Utf8To8(unsigned char*);
 #  define sqlite3VtabRollback(X)
 #  define sqlite3VtabCommit(X)
 #  define sqlite3VtabInSync(db) 0
-#  define sqlite3VtabLock(X) 
+#  define sqlite3VtabLock(X)
 #  define sqlite3VtabUnlock(X)
 #  define sqlite3VtabUnlockList(X)
 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
@@ -13375,8 +17913,17 @@ SQLITE_PRIVATE    void sqlite3VtabUnlockList(sqlite3*);
 SQLITE_PRIVATE    int sqlite3VtabSavepoint(sqlite3 *, int, int);
 SQLITE_PRIVATE    void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);
 SQLITE_PRIVATE    VTable *sqlite3GetVTable(sqlite3*, Table*);
+SQLITE_PRIVATE    Module *sqlite3VtabCreateModule(
+     sqlite3*,
+     const char*,
+     const sqlite3_module*,
+     void*,
+     void(*)(void*)
+   );
 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
 #endif
+SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse*,Module*);
+SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3*,Module*);
 SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse*,Table*);
 SQLITE_PRIVATE void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
 SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse*, Token*);
@@ -13414,7 +17961,7 @@ SQLITE_PRIVATE   void sqlite3WithPush(Parse*, With*, u8);
 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
 ** key functionality is available. If OMIT_TRIGGER is defined but
 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
-** this case foreign keys are parsed, but no other functionality is 
+** this case foreign keys are parsed, but no other functionality is
 ** provided (enforcement of FK constraints requires the triggers sub-system).
 */
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
@@ -13430,6 +17977,7 @@ SQLITE_PRIVATE   FKey *sqlite3FkReferences(Table *);
   #define sqlite3FkDropTable(a,b,c)
   #define sqlite3FkOldmask(a,b)         0
   #define sqlite3FkRequired(a,b,c,d)    0
+  #define sqlite3FkReferences(a)        0
 #endif
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 SQLITE_PRIVATE   void sqlite3FkDelete(sqlite3 *, Table*);
@@ -13448,10 +17996,10 @@ SQLITE_PRIVATE   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
 
 /*
 ** The interface to the code in fault.c used for identifying "benign"
-** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
+** malloc failures. This is only present if SQLITE_UNTESTABLE
 ** is not defined.
 */
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
 SQLITE_PRIVATE   void sqlite3BeginBenignMalloc(void);
 SQLITE_PRIVATE   void sqlite3EndBenignMalloc(void);
 #else
@@ -13473,28 +18021,22 @@ SQLITE_PRIVATE   void sqlite3EndBenignMalloc(void);
 #define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
 #define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
 #define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
-SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*);
+SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*);
 
+SQLITE_PRIVATE int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
+SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *);
 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
-SQLITE_PRIVATE   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
-SQLITE_PRIVATE   int sqlite3JournalSize(sqlite3_vfs *);
 SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
-SQLITE_PRIVATE   int sqlite3JournalExists(sqlite3_file *p);
-#else
-  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
-  #define sqlite3JournalExists(p) 1
 #endif
 
+SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p);
 SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *);
-SQLITE_PRIVATE int sqlite3MemJournalSize(void);
-SQLITE_PRIVATE int sqlite3IsMemJournal(sqlite3_file *);
 
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);
 #if SQLITE_MAX_EXPR_DEPTH>0
-SQLITE_PRIVATE   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
 SQLITE_PRIVATE   int sqlite3SelectExprHeight(Select *);
 SQLITE_PRIVATE   int sqlite3ExprCheckHeight(Parse*, int);
 #else
-  #define sqlite3ExprSetHeight(x,y)
   #define sqlite3SelectExprHeight(x) 0
   #define sqlite3ExprCheckHeight(x,y)
 #endif
@@ -13519,12 +18061,12 @@ SQLITE_PRIVATE   void sqlite3ParserTrace(FILE*, char *);
 /*
 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
 ** sqlite3IoTrace is a pointer to a printf-like routine used to
-** print I/O tracing messages. 
+** print I/O tracing messages.
 */
 #ifdef SQLITE_ENABLE_IOTRACE
 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
 SQLITE_PRIVATE   void sqlite3VdbeIOTraceSql(Vdbe*);
-void (*sqlite3IoTrace)(const char*,...);
+SQLITE_API SQLITE_EXTERN void (SQLITE_CDECL *sqlite3IoTrace)(const char*,...);
 #else
 # define IOTRACE(A)
 # define sqlite3VdbeIOTraceSql(X)
@@ -13553,7 +18095,7 @@ void (*sqlite3IoTrace)(const char*,...);
 ** that allocations that might have been satisfied by lookaside are not
 ** passed back to non-lookaside free() routines.  Asserts such as the
 ** example above are placed on the non-lookaside free() routines to verify
-** this constraint. 
+** this constraint.
 **
 ** All of this is no-op for a production build.  It only comes into
 ** play when the SQLITE_MEMDEBUG compile-time option is used.
@@ -13580,7 +18122,21 @@ SQLITE_PRIVATE int sqlite3ThreadCreate(SQLiteThread**,void*(*)(void*),void*);
 SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread*, void**);
 #endif
 
-#endif /* _SQLITEINT_H_ */
+#if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
+SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3*);
+#endif
+
+SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr);
+SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr);
+SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr*, int);
+SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(Parse*,Expr*,int);
+SQLITE_PRIVATE void sqlite3VectorErrorMsg(Parse*, Expr*);
+
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+SQLITE_PRIVATE const char **sqlite3CompileOptions(int *pnOpt);
+#endif
+
+#endif /* SQLITEINT_H */
 
 /************** End of sqliteInt.h *******************************************/
 /************** Begin file global.c ******************************************/
@@ -13598,6 +18154,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread*, void**);
 **
 ** This file contains definitions of global variables and constants.
 */
+/* #include "sqliteInt.h" */
 
 /* An array to map all upper-case characters into their corresponding
 ** lower-case character. 
@@ -13631,16 +18188,16 @@ SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {
      48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
      64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
      80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
-     96, 97, 66, 67, 68, 69, 70, 71, 72, 73,106,107,108,109,110,111, /* 6x */
-    112, 81, 82, 83, 84, 85, 86, 87, 88, 89,122,123,124,125,126,127, /* 7x */
+     96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111, /* 6x */
+    112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127, /* 7x */
     128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
-    144,145,146,147,148,149,150,151,152,153,154,155,156,157,156,159, /* 9x */
+    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159, /* 9x */
     160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
     176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
     192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
     208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
-    224,225,162,163,164,165,166,167,168,169,232,203,204,205,206,207, /* Ex */
-    239,240,241,242,243,244,245,246,247,248,249,219,220,221,222,255, /* Fx */
+    224,225,162,163,164,165,166,167,168,169,234,235,236,237,238,239, /* Ex */
+    240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255, /* Fx */
 #endif
 };
 
@@ -13655,6 +18212,7 @@ SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {
 **   isxdigit()                       0x08
 **   toupper()                        0x20
 **   SQLite identifier character      0x40
+**   Quote character                  0x80
 **
 ** Bit 0x20 is set if the mapped character requires translation to upper
 ** case. i.e. if the character is a lower-case ASCII character.
@@ -13663,16 +18221,13 @@ SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {
 **
 **   (x & ~(map[x]&0x20))
 **
-** Standard function tolower() is implemented using the sqlite3UpperToLower[]
+** The equivalent of tolower() is implemented using the sqlite3UpperToLower[]
 ** array. tolower() is used more often than toupper() by SQLite.
 **
-** Bit 0x40 is set if the character non-alphanumeric and can be used in an 
+** Bit 0x40 is set if the character is non-alphanumeric and can be used in an 
 ** SQLite identifier.  Identifiers are alphanumerics, "_", "$", and any
 ** non-ASCII UTF character. Hence the test for whether or not a character is
 ** part of an identifier is 0x46.
-**
-** SQLite's versions are identical to the standard versions assuming a
-** locale of "C". They are implemented as macros in sqliteInt.h.
 */
 #ifdef SQLITE_ASCII
 SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
@@ -13680,7 +18235,7 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
   0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */
-  0x01, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,  /* 20..27     !"#$%&' */
+  0x01, 0x00, 0x80, 0x00, 0x40, 0x00, 0x00, 0x80,  /* 20..27     !"#$%&' */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 28..2f    ()*+,-./ */
   0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,  /* 30..37    01234567 */
   0x0c, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 38..3f    89:;<=>? */
@@ -13688,8 +18243,8 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
   0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x02,  /* 40..47    @ABCDEFG */
   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 48..4f    HIJKLMNO */
   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 50..57    PQRSTUVW */
-  0x02, 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
-  0x00, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
+  0x02, 0x02, 0x02, 0x80, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
+  0x80, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 68..6f    hijklmno */
   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 70..77    pqrstuvw */
   0x22, 0x22, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 78..7f    xyz{|}~. */
@@ -13724,9 +18279,16 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
 ** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
 ** disabled. The default value may be changed by compiling with the
 ** SQLITE_USE_URI symbol defined.
+**
+** URI filenames are enabled by default if SQLITE_HAS_CODEC is
+** enabled.
 */
 #ifndef SQLITE_USE_URI
-# define  SQLITE_USE_URI 0
+# ifdef SQLITE_HAS_CODEC
+#  define SQLITE_USE_URI 1
+# else
+#  define SQLITE_USE_URI 0
+# endif
 #endif
 
 /* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
@@ -13744,6 +18306,31 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
 # define SQLITE_SORTER_PMASZ 250
 #endif
 
+/* Statement journals spill to disk when their size exceeds the following
+** threshold (in bytes). 0 means that statement journals are created and
+** written to disk immediately (the default behavior for SQLite versions
+** before 3.12.0).  -1 means always keep the entire statement journal in
+** memory.  (The statement journal is also always held entirely in memory
+** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this
+** setting.)
+*/
+#ifndef SQLITE_STMTJRNL_SPILL 
+# define SQLITE_STMTJRNL_SPILL (64*1024)
+#endif
+
+/*
+** The default lookaside-configuration, the format "SZ,N".  SZ is the
+** number of bytes in each lookaside slot (should be a multiple of 8)
+** and N is the number of slots.  The lookaside-configuration can be
+** changed as start-time using sqlite3_config(SQLITE_CONFIG_LOOKASIDE)
+** or at run-time for an individual database connection using
+** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);
+*/
+#ifndef SQLITE_DEFAULT_LOOKASIDE
+# define SQLITE_DEFAULT_LOOKASIDE 1200,100
+#endif
+
+
 /*
 ** The following singleton contains the global configuration for
 ** the SQLite library.
@@ -13756,8 +18343,8 @@ SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */
    0x7ffffffe,                /* mxStrlen */
    0,                         /* neverCorrupt */
-   128,                       /* szLookaside */
-   500,                       /* nLookaside */
+   SQLITE_DEFAULT_LOOKASIDE,  /* szLookaside, nLookaside */
+   SQLITE_STMTJRNL_SPILL,     /* nStmtSpill */
    {0,0,0,0,0,0,0,0},         /* m */
    {0,0,0,0,0,0,0,0,0},       /* mutex */
    {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */
@@ -13771,7 +18358,7 @@ SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    0,                         /* nScratch */
    (void*)0,                  /* pPage */
    0,                         /* szPage */
-   0,                         /* nPage */
+   SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */
    0,                         /* mxParserStack */
    0,                         /* sharedCacheEnabled */
    SQLITE_SORTER_PMASZ,       /* szPma */
@@ -13793,10 +18380,11 @@ SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    0,                         /* xVdbeBranch */
    0,                         /* pVbeBranchArg */
 #endif
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
    0,                         /* xTestCallback */
 #endif
-   0                          /* bLocaltimeFault */
+   0,                         /* bLocaltimeFault */
+   0x7ffffffe                 /* iOnceResetThreshold */
 };
 
 /*
@@ -13804,7 +18392,7 @@ SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
 ** database connections.  After initialization, this table is
 ** read-only.
 */
-SQLITE_PRIVATE SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
+SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;
 
 /*
 ** Constant tokens for values 0 and 1.
@@ -13819,7 +18407,7 @@ SQLITE_PRIVATE const Token sqlite3IntTokens[] = {
 ** The value of the "pending" byte must be 0x40000000 (1 byte past the
 ** 1-gibabyte boundary) in a compatible database.  SQLite never uses
 ** the database page that contains the pending byte.  It never attempts
-** to read or write that page.  The pending byte page is set assign
+** to read or write that page.  The pending byte page is set aside
 ** for use by the VFS layers as space for managing file locks.
 **
 ** During testing, it is often desirable to move the pending byte to
@@ -13837,6 +18425,7 @@ SQLITE_PRIVATE const Token sqlite3IntTokens[] = {
 SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;
 #endif
 
+/* #include "opcodes.h" */
 /*
 ** Properties of opcodes.  The OPFLG_INITIALIZER macro is
 ** created by mkopcodeh.awk during compilation.  Data is obtained
@@ -13845,436 +18434,12 @@ SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;
 */
 SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;
 
-/************** End of global.c **********************************************/
-/************** Begin file ctime.c *******************************************/
 /*
-** 2010 February 23
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-**
-** This file implements routines used to report what compile-time options
-** SQLite was built with.
-*/
-
-#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
-
-
-/*
-** An array of names of all compile-time options.  This array should 
-** be sorted A-Z.
-**
-** This array looks large, but in a typical installation actually uses
-** only a handful of compile-time options, so most times this array is usually
-** rather short and uses little memory space.
+** Name of the default collating sequence
 */
-static const char * const azCompileOpt[] = {
+SQLITE_PRIVATE const char sqlite3StrBINARY[] = "BINARY";
 
-/* These macros are provided to "stringify" the value of the define
-** for those options in which the value is meaningful. */
-#define CTIMEOPT_VAL_(opt) #opt
-#define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt)
-
-#if SQLITE_32BIT_ROWID
-  "32BIT_ROWID",
-#endif
-#if SQLITE_4_BYTE_ALIGNED_MALLOC
-  "4_BYTE_ALIGNED_MALLOC",
-#endif
-#if SQLITE_CASE_SENSITIVE_LIKE
-  "CASE_SENSITIVE_LIKE",
-#endif
-#if SQLITE_CHECK_PAGES
-  "CHECK_PAGES",
-#endif
-#if SQLITE_COVERAGE_TEST
-  "COVERAGE_TEST",
-#endif
-#if SQLITE_DEBUG
-  "DEBUG",
-#endif
-#if SQLITE_DEFAULT_LOCKING_MODE
-  "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE),
-#endif
-#if defined(SQLITE_DEFAULT_MMAP_SIZE) && !defined(SQLITE_DEFAULT_MMAP_SIZE_xc)
-  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
-#endif
-#if SQLITE_DISABLE_DIRSYNC
-  "DISABLE_DIRSYNC",
-#endif
-#if SQLITE_DISABLE_LFS
-  "DISABLE_LFS",
-#endif
-#if SQLITE_ENABLE_API_ARMOR
-  "ENABLE_API_ARMOR",
-#endif
-#if SQLITE_ENABLE_ATOMIC_WRITE
-  "ENABLE_ATOMIC_WRITE",
-#endif
-#if SQLITE_ENABLE_CEROD
-  "ENABLE_CEROD",
-#endif
-#if SQLITE_ENABLE_COLUMN_METADATA
-  "ENABLE_COLUMN_METADATA",
-#endif
-#if SQLITE_ENABLE_EXPENSIVE_ASSERT
-  "ENABLE_EXPENSIVE_ASSERT",
-#endif
-#if SQLITE_ENABLE_FTS1
-  "ENABLE_FTS1",
-#endif
-#if SQLITE_ENABLE_FTS2
-  "ENABLE_FTS2",
-#endif
-#if SQLITE_ENABLE_FTS3
-  "ENABLE_FTS3",
-#endif
-#if SQLITE_ENABLE_FTS3_PARENTHESIS
-  "ENABLE_FTS3_PARENTHESIS",
-#endif
-#if SQLITE_ENABLE_FTS4
-  "ENABLE_FTS4",
-#endif
-#if SQLITE_ENABLE_ICU
-  "ENABLE_ICU",
-#endif
-#if SQLITE_ENABLE_IOTRACE
-  "ENABLE_IOTRACE",
-#endif
-#if SQLITE_ENABLE_LOAD_EXTENSION
-  "ENABLE_LOAD_EXTENSION",
-#endif
-#if SQLITE_ENABLE_LOCKING_STYLE
-  "ENABLE_LOCKING_STYLE=" CTIMEOPT_VAL(SQLITE_ENABLE_LOCKING_STYLE),
-#endif
-#if SQLITE_ENABLE_MEMORY_MANAGEMENT
-  "ENABLE_MEMORY_MANAGEMENT",
-#endif
-#if SQLITE_ENABLE_MEMSYS3
-  "ENABLE_MEMSYS3",
-#endif
-#if SQLITE_ENABLE_MEMSYS5
-  "ENABLE_MEMSYS5",
-#endif
-#if SQLITE_ENABLE_OVERSIZE_CELL_CHECK
-  "ENABLE_OVERSIZE_CELL_CHECK",
-#endif
-#if SQLITE_ENABLE_RTREE
-  "ENABLE_RTREE",
-#endif
-#if defined(SQLITE_ENABLE_STAT4)
-  "ENABLE_STAT4",
-#elif defined(SQLITE_ENABLE_STAT3)
-  "ENABLE_STAT3",
-#endif
-#if SQLITE_ENABLE_UNLOCK_NOTIFY
-  "ENABLE_UNLOCK_NOTIFY",
-#endif
-#if SQLITE_ENABLE_UPDATE_DELETE_LIMIT
-  "ENABLE_UPDATE_DELETE_LIMIT",
-#endif
-#if SQLITE_HAS_CODEC
-  "HAS_CODEC",
-#endif
-#if HAVE_ISNAN || SQLITE_HAVE_ISNAN
-  "HAVE_ISNAN",
-#endif
-#if SQLITE_HOMEGROWN_RECURSIVE_MUTEX
-  "HOMEGROWN_RECURSIVE_MUTEX",
-#endif
-#if SQLITE_IGNORE_AFP_LOCK_ERRORS
-  "IGNORE_AFP_LOCK_ERRORS",
-#endif
-#if SQLITE_IGNORE_FLOCK_LOCK_ERRORS
-  "IGNORE_FLOCK_LOCK_ERRORS",
-#endif
-#ifdef SQLITE_INT64_TYPE
-  "INT64_TYPE",
-#endif
-#if SQLITE_LOCK_TRACE
-  "LOCK_TRACE",
-#endif
-#if defined(SQLITE_MAX_MMAP_SIZE) && !defined(SQLITE_MAX_MMAP_SIZE_xc)
-  "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),
-#endif
-#ifdef SQLITE_MAX_SCHEMA_RETRY
-  "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
-#endif
-#if SQLITE_MEMDEBUG
-  "MEMDEBUG",
-#endif
-#if SQLITE_MIXED_ENDIAN_64BIT_FLOAT
-  "MIXED_ENDIAN_64BIT_FLOAT",
-#endif
-#if SQLITE_NO_SYNC
-  "NO_SYNC",
-#endif
-#if SQLITE_OMIT_ALTERTABLE
-  "OMIT_ALTERTABLE",
-#endif
-#if SQLITE_OMIT_ANALYZE
-  "OMIT_ANALYZE",
-#endif
-#if SQLITE_OMIT_ATTACH
-  "OMIT_ATTACH",
-#endif
-#if SQLITE_OMIT_AUTHORIZATION
-  "OMIT_AUTHORIZATION",
-#endif
-#if SQLITE_OMIT_AUTOINCREMENT
-  "OMIT_AUTOINCREMENT",
-#endif
-#if SQLITE_OMIT_AUTOINIT
-  "OMIT_AUTOINIT",
-#endif
-#if SQLITE_OMIT_AUTOMATIC_INDEX
-  "OMIT_AUTOMATIC_INDEX",
-#endif
-#if SQLITE_OMIT_AUTORESET
-  "OMIT_AUTORESET",
-#endif
-#if SQLITE_OMIT_AUTOVACUUM
-  "OMIT_AUTOVACUUM",
-#endif
-#if SQLITE_OMIT_BETWEEN_OPTIMIZATION
-  "OMIT_BETWEEN_OPTIMIZATION",
-#endif
-#if SQLITE_OMIT_BLOB_LITERAL
-  "OMIT_BLOB_LITERAL",
-#endif
-#if SQLITE_OMIT_BTREECOUNT
-  "OMIT_BTREECOUNT",
-#endif
-#if SQLITE_OMIT_BUILTIN_TEST
-  "OMIT_BUILTIN_TEST",
-#endif
-#if SQLITE_OMIT_CAST
-  "OMIT_CAST",
-#endif
-#if SQLITE_OMIT_CHECK
-  "OMIT_CHECK",
-#endif
-#if SQLITE_OMIT_COMPLETE
-  "OMIT_COMPLETE",
-#endif
-#if SQLITE_OMIT_COMPOUND_SELECT
-  "OMIT_COMPOUND_SELECT",
-#endif
-#if SQLITE_OMIT_CTE
-  "OMIT_CTE",
-#endif
-#if SQLITE_OMIT_DATETIME_FUNCS
-  "OMIT_DATETIME_FUNCS",
-#endif
-#if SQLITE_OMIT_DECLTYPE
-  "OMIT_DECLTYPE",
-#endif
-#if SQLITE_OMIT_DEPRECATED
-  "OMIT_DEPRECATED",
-#endif
-#if SQLITE_OMIT_DISKIO
-  "OMIT_DISKIO",
-#endif
-#if SQLITE_OMIT_EXPLAIN
-  "OMIT_EXPLAIN",
-#endif
-#if SQLITE_OMIT_FLAG_PRAGMAS
-  "OMIT_FLAG_PRAGMAS",
-#endif
-#if SQLITE_OMIT_FLOATING_POINT
-  "OMIT_FLOATING_POINT",
-#endif
-#if SQLITE_OMIT_FOREIGN_KEY
-  "OMIT_FOREIGN_KEY",
-#endif
-#if SQLITE_OMIT_GET_TABLE
-  "OMIT_GET_TABLE",
-#endif
-#if SQLITE_OMIT_INCRBLOB
-  "OMIT_INCRBLOB",
-#endif
-#if SQLITE_OMIT_INTEGRITY_CHECK
-  "OMIT_INTEGRITY_CHECK",
-#endif
-#if SQLITE_OMIT_LIKE_OPTIMIZATION
-  "OMIT_LIKE_OPTIMIZATION",
-#endif
-#if SQLITE_OMIT_LOAD_EXTENSION
-  "OMIT_LOAD_EXTENSION",
-#endif
-#if SQLITE_OMIT_LOCALTIME
-  "OMIT_LOCALTIME",
-#endif
-#if SQLITE_OMIT_LOOKASIDE
-  "OMIT_LOOKASIDE",
-#endif
-#if SQLITE_OMIT_MEMORYDB
-  "OMIT_MEMORYDB",
-#endif
-#if SQLITE_OMIT_OR_OPTIMIZATION
-  "OMIT_OR_OPTIMIZATION",
-#endif
-#if SQLITE_OMIT_PAGER_PRAGMAS
-  "OMIT_PAGER_PRAGMAS",
-#endif
-#if SQLITE_OMIT_PRAGMA
-  "OMIT_PRAGMA",
-#endif
-#if SQLITE_OMIT_PROGRESS_CALLBACK
-  "OMIT_PROGRESS_CALLBACK",
-#endif
-#if SQLITE_OMIT_QUICKBALANCE
-  "OMIT_QUICKBALANCE",
-#endif
-#if SQLITE_OMIT_REINDEX
-  "OMIT_REINDEX",
-#endif
-#if SQLITE_OMIT_SCHEMA_PRAGMAS
-  "OMIT_SCHEMA_PRAGMAS",
-#endif
-#if SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
-  "OMIT_SCHEMA_VERSION_PRAGMAS",
-#endif
-#if SQLITE_OMIT_SHARED_CACHE
-  "OMIT_SHARED_CACHE",
-#endif
-#if SQLITE_OMIT_SUBQUERY
-  "OMIT_SUBQUERY",
-#endif
-#if SQLITE_OMIT_TCL_VARIABLE
-  "OMIT_TCL_VARIABLE",
-#endif
-#if SQLITE_OMIT_TEMPDB
-  "OMIT_TEMPDB",
-#endif
-#if SQLITE_OMIT_TRACE
-  "OMIT_TRACE",
-#endif
-#if SQLITE_OMIT_TRIGGER
-  "OMIT_TRIGGER",
-#endif
-#if SQLITE_OMIT_TRUNCATE_OPTIMIZATION
-  "OMIT_TRUNCATE_OPTIMIZATION",
-#endif
-#if SQLITE_OMIT_UTF16
-  "OMIT_UTF16",
-#endif
-#if SQLITE_OMIT_VACUUM
-  "OMIT_VACUUM",
-#endif
-#if SQLITE_OMIT_VIEW
-  "OMIT_VIEW",
-#endif
-#if SQLITE_OMIT_VIRTUALTABLE
-  "OMIT_VIRTUALTABLE",
-#endif
-#if SQLITE_OMIT_WAL
-  "OMIT_WAL",
-#endif
-#if SQLITE_OMIT_WSD
-  "OMIT_WSD",
-#endif
-#if SQLITE_OMIT_XFER_OPT
-  "OMIT_XFER_OPT",
-#endif
-#if SQLITE_PERFORMANCE_TRACE
-  "PERFORMANCE_TRACE",
-#endif
-#if SQLITE_PROXY_DEBUG
-  "PROXY_DEBUG",
-#endif
-#if SQLITE_RTREE_INT_ONLY
-  "RTREE_INT_ONLY",
-#endif
-#if SQLITE_SECURE_DELETE
-  "SECURE_DELETE",
-#endif
-#if SQLITE_SMALL_STACK
-  "SMALL_STACK",
-#endif
-#if SQLITE_SOUNDEX
-  "SOUNDEX",
-#endif
-#if SQLITE_SYSTEM_MALLOC
-  "SYSTEM_MALLOC",
-#endif
-#if SQLITE_TCL
-  "TCL",
-#endif
-#if defined(SQLITE_TEMP_STORE) && !defined(SQLITE_TEMP_STORE_xc)
-  "TEMP_STORE=" CTIMEOPT_VAL(SQLITE_TEMP_STORE),
-#endif
-#if SQLITE_TEST
-  "TEST",
-#endif
-#if defined(SQLITE_THREADSAFE)
-  "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE),
-#endif
-#if SQLITE_USE_ALLOCA
-  "USE_ALLOCA",
-#endif
-#if SQLITE_USER_AUTHENTICATION
-  "USER_AUTHENTICATION",
-#endif
-#if SQLITE_WIN32_MALLOC
-  "WIN32_MALLOC",
-#endif
-#if SQLITE_ZERO_MALLOC
-  "ZERO_MALLOC"
-#endif
-};
-
-/*
-** Given the name of a compile-time option, return true if that option
-** was used and false if not.
-**
-** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
-** is not required for a match.
-*/
-SQLITE_API int sqlite3_compileoption_used(const char *zOptName){
-  int i, n;
-
-#if SQLITE_ENABLE_API_ARMOR
-  if( zOptName==0 ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
-#endif
-  if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
-  n = sqlite3Strlen30(zOptName);
-
-  /* Since ArraySize(azCompileOpt) is normally in single digits, a
-  ** linear search is adequate.  No need for a binary search. */
-  for(i=0; i=0 && NaDb[] (or -1) */
+  u8 nullRow;             /* True if pointing to a row with no data */
+  u8 deferredMoveto;      /* A call to sqlite3BtreeMoveto() is needed */
+  u8 isTable;             /* True for rowid tables.  False for indexes */
 #ifdef SQLITE_DEBUG
-  u8 seekOp;            /* Most recent seek operation on this cursor */
-#endif
-  i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
-  u8 nullRow;           /* True if pointing to a row with no data */
-  u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */
-  Bool isEphemeral:1;   /* True for an ephemeral table */
-  Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
-  Bool isTable:1;       /* True if a table requiring integer keys */
-  Bool isOrdered:1;     /* True if the underlying table is BTREE_UNORDERED */
-  Pgno pgnoRoot;        /* Root page of the open btree cursor */
-  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
-  i64 seqCount;         /* Sequence counter */
-  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
-  VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
-
-  /* Cached information about the header for the data record that the
-  ** cursor is currently pointing to.  Only valid if cacheStatus matches
+  u8 seekOp;              /* Most recent seek operation on this cursor */
+  u8 wrFlag;              /* The wrFlag argument to sqlite3BtreeCursor() */
+#endif
+  Bool isEphemeral:1;     /* True for an ephemeral table */
+  Bool useRandomRowid:1;  /* Generate new record numbers semi-randomly */
+  Bool isOrdered:1;       /* True if the table is not BTREE_UNORDERED */
+  Btree *pBtx;            /* Separate file holding temporary table */
+  i64 seqCount;           /* Sequence counter */
+  int *aAltMap;           /* Mapping from table to index column numbers */
+
+  /* Cached OP_Column parse information is only valid if cacheStatus matches
   ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of
-  ** CACHE_STALE and so setting cacheStatus=CACHE_STALE guarantees that
-  ** the cache is out of date.
-  **
-  ** aRow might point to (ephemeral) data for the current row, or it might
-  ** be NULL.
-  */
-  u32 cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
-  u32 payloadSize;      /* Total number of bytes in the record */
-  u32 szRow;            /* Byte available in aRow */
-  u32 iHdrOffset;       /* Offset to next unparsed byte of the header */
-  const u8 *aRow;       /* Data for the current row, if all on one page */
-  u32 *aOffset;         /* Pointer to aType[nField] */
-  u32 aType[1];         /* Type values for all entries in the record */
+  ** CACHE_STALE (0) and so setting cacheStatus=CACHE_STALE guarantees that
+  ** the cache is out of date. */
+  u32 cacheStatus;        /* Cache is valid if this matches Vdbe.cacheCtr */
+  int seekResult;         /* Result of previous sqlite3BtreeMoveto() or 0
+                          ** if there have been no prior seeks on the cursor. */
+  /* NB: seekResult does not distinguish between "no seeks have ever occurred
+  ** on this cursor" and "the most recent seek was an exact match". */
+
+  /* When a new VdbeCursor is allocated, only the fields above are zeroed.
+  ** The fields that follow are uninitialized, and must be individually
+  ** initialized prior to first use. */
+  VdbeCursor *pAltCursor; /* Associated index cursor from which to read */
+  union {
+    BtCursor *pCursor;          /* CURTYPE_BTREE.  Btree cursor */
+    sqlite3_vtab_cursor *pVCur; /* CURTYPE_VTAB.   Vtab cursor */
+    int pseudoTableReg;         /* CURTYPE_PSEUDO. Reg holding content. */
+    VdbeSorter *pSorter;        /* CURTYPE_SORTER. Sorter object */
+  } uc;
+  KeyInfo *pKeyInfo;      /* Info about index keys needed by index cursors */
+  u32 iHdrOffset;         /* Offset to next unparsed byte of the header */
+  Pgno pgnoRoot;          /* Root page of the open btree cursor */
+  i16 nField;             /* Number of fields in the header */
+  u16 nHdrParsed;         /* Number of header fields parsed so far */
+  i64 movetoTarget;       /* Argument to the deferred sqlite3BtreeMoveto() */
+  u32 *aOffset;           /* Pointer to aType[nField] */
+  const u8 *aRow;         /* Data for the current row, if all on one page */
+  u32 payloadSize;        /* Total number of bytes in the record */
+  u32 szRow;              /* Byte available in aRow */
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+  u64 maskUsed;           /* Mask of columns used by this cursor */
+#endif
+
   /* 2*nField extra array elements allocated for aType[], beyond the one
   ** static element declared in the structure.  nField total array slots for
   ** aType[] and nField+1 array slots for aOffset[] */
+  u32 aType[1];           /* Type values record decode.  MUST BE LAST */
 };
-typedef struct VdbeCursor VdbeCursor;
+
+
+/*
+** A value for VdbeCursor.cacheStatus that means the cache is always invalid.
+*/
+#define CACHE_STALE 0
 
 /*
 ** When a sub-program is executed (OP_Program), a structure of this type
@@ -14429,15 +18624,15 @@ struct VdbeFrame {
   Op *aOp;                /* Program instructions for parent frame */
   i64 *anExec;            /* Event counters from parent frame */
   Mem *aMem;              /* Array of memory cells for parent frame */
-  u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
+  u8 *aOnce;              /* Bitmask used by OP_Once */
   void *token;            /* Copy of SubProgram.token */
   i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
+  AuxData *pAuxData;      /* Linked list of auxdata allocations */
   int nCursor;            /* Number of entries in apCsr */
   int pc;                 /* Program Counter in parent (calling) frame */
   int nOp;                /* Size of aOp array */
   int nMem;               /* Number of entries in aMem */
-  int nOnceFlag;          /* Number of entries in aOnceFlag */
   int nChildMem;          /* Number of memory cells for child frame */
   int nChildCsr;          /* Number of cursors for child frame */
   int nChange;            /* Statement changes (Vdbe.nChange)     */
@@ -14446,27 +18641,24 @@ struct VdbeFrame {
 
 #define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])
 
-/*
-** A value for VdbeCursor.cacheValid that means the cache is always invalid.
-*/
-#define CACHE_STALE 0
-
 /*
 ** Internally, the vdbe manipulates nearly all SQL values as Mem
 ** structures. Each Mem struct may cache multiple representations (string,
 ** integer etc.) of the same value.
 */
-struct Mem {
+struct sqlite3_value {
   union MemValue {
     double r;           /* Real value used when MEM_Real is set in flags */
     i64 i;              /* Integer value used when MEM_Int is set in flags */
-    int nZero;          /* Used when bit MEM_Zero is set in flags */
+    int nZero;          /* Extra zero bytes when MEM_Zero and MEM_Blob set */
+    const char *zPType; /* Pointer type when MEM_Term|MEM_Subtype|MEM_Null */
     FuncDef *pDef;      /* Used only when flags==MEM_Agg */
     RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
     VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
   } u;
   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
+  u8  eSubtype;       /* Subtype for this value */
   int n;              /* Number of characters in string value, excluding '\0' */
   char *z;            /* String or BLOB value */
   /* ShallowCopy only needs to copy the information above */
@@ -14481,11 +18673,18 @@ struct Mem {
 #endif
 };
 
+/*
+** Size of struct Mem not including the Mem.zMalloc member or anything that
+** follows.
+*/
+#define MEMCELLSIZE offsetof(Mem,zMalloc)
+
 /* One or more of the following flags are set to indicate the validOK
 ** representations of the value stored in the Mem struct.
 **
 ** If the MEM_Null flag is set, then the value is an SQL NULL value.
-** No other flags may be set in this case.
+** For a pointer type created using sqlite3_bind_pointer() or
+** sqlite3_result_pointer() the MEM_Term and MEM_Subtype flags are also set.
 **
 ** If the MEM_Str flag is set then Mem.z points at a string representation.
 ** Usually this is encoded in the same unicode encoding as the main
@@ -14493,7 +18692,7 @@ struct Mem {
 ** set, then the string is nul terminated. The MEM_Int and MEM_Real 
 ** flags may coexist with the MEM_Str flag.
 */
-#define MEM_Null      0x0001   /* Value is NULL */
+#define MEM_Null      0x0001   /* Value is NULL (or a pointer) */
 #define MEM_Str       0x0002   /* Value is a string */
 #define MEM_Int       0x0004   /* Value is an integer */
 #define MEM_Real      0x0008   /* Value is a real number */
@@ -14503,7 +18702,7 @@ struct Mem {
 #define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
 #define MEM_Undefined 0x0080   /* Value is undefined */
 #define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
-#define MEM_TypeMask  0x01ff   /* Mask of type bits */
+#define MEM_TypeMask  0xc1ff   /* Mask of type bits */
 
 
 /* Whenever Mem contains a valid string or blob representation, one of
@@ -14511,17 +18710,24 @@ struct Mem {
 ** policy for Mem.z.  The MEM_Term flag tells us whether or not the
 ** string is \000 or \u0000 terminated
 */
-#define MEM_Term      0x0200   /* String rep is nul terminated */
+#define MEM_Term      0x0200   /* String in Mem.z is zero terminated */
 #define MEM_Dyn       0x0400   /* Need to call Mem.xDel() on Mem.z */
 #define MEM_Static    0x0800   /* Mem.z points to a static string */
 #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
 #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
 #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
+#define MEM_Subtype   0x8000   /* Mem.eSubtype is valid */
 #ifdef SQLITE_OMIT_INCRBLOB
   #undef MEM_Zero
   #define MEM_Zero 0x0000
 #endif
 
+/* Return TRUE if Mem X contains dynamically allocated content - anything
+** that needs to be deallocated to avoid a leak.
+*/
+#define VdbeMemDynamic(X)  \
+  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))!=0)
+
 /*
 ** Clear any existing type flags from a Mem and replace them with f
 */
@@ -14544,11 +18750,11 @@ struct Mem {
 ** when the VM is halted (if not before).
 */
 struct AuxData {
-  int iOp;                        /* Instruction number of OP_Function opcode */
-  int iArg;                       /* Index of function argument. */
+  int iAuxOp;                     /* Instruction number of OP_Function opcode */
+  int iAuxArg;                    /* Index of function argument. */
   void *pAux;                     /* Aux data pointer */
-  void (*xDelete)(void *);        /* Destructor for the aux data */
-  AuxData *pNext;                 /* Next element in list */
+  void (*xDeleteAux)(void*);      /* Destructor for the aux data */
+  AuxData *pNextAux;              /* Next element in list */
 };
 
 /*
@@ -14565,26 +18771,16 @@ struct AuxData {
 ** (Mem) which are only defined there.
 */
 struct sqlite3_context {
-  Mem *pOut;            /* The return value is stored here */
-  FuncDef *pFunc;       /* Pointer to function information */
-  Mem *pMem;            /* Memory cell used to store aggregate context */
-  Vdbe *pVdbe;          /* The VM that owns this context */
-  int iOp;              /* Instruction number of OP_Function */
-  int isError;          /* Error code returned by the function. */
-  u8 skipFlag;          /* Skip accumulator loading if true */
-  u8 fErrorOrAux;       /* isError!=0 or pVdbe->pAuxData modified */
-};
-
-/*
-** An Explain object accumulates indented output which is helpful
-** in describing recursive data structures.
-*/
-struct Explain {
-  Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
-  StrAccum str;      /* The string being accumulated */
-  int nIndent;       /* Number of elements in aIndent */
-  u16 aIndent[100];  /* Levels of indentation */
-  char zBase[100];   /* Initial space */
+  Mem *pOut;              /* The return value is stored here */
+  FuncDef *pFunc;         /* Pointer to function information */
+  Mem *pMem;              /* Memory cell used to store aggregate context */
+  Vdbe *pVdbe;            /* The VM that owns this context */
+  int iOp;                /* Instruction number of OP_Function */
+  int isError;            /* Error code returned by the function. */
+  u8 skipFlag;            /* Skip accumulator loading if true */
+  u8 fErrorOrAux;         /* isError!=0 or pVdbe->pAuxData modified */
+  u8 argc;                /* Number of arguments */
+  sqlite3_value *argv[1]; /* Argument set */
 };
 
 /* A bitfield type for use inside of structures.  Always follow with :N where
@@ -14608,62 +18804,59 @@ struct ScanStatus {
 **
 ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
 ** is really a pointer to an instance of this structure.
-**
-** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
-** any virtual table method invocations made by the vdbe program. It is
-** set to 2 for xDestroy method calls and 1 for all other methods. This
-** variable is used for two purposes: to allow xDestroy methods to execute
-** "DROP TABLE" statements and to prevent some nasty side effects of
-** malloc failure when SQLite is invoked recursively by a virtual table 
-** method function.
 */
 struct Vdbe {
   sqlite3 *db;            /* The database connection that owns this statement */
+  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
+  Parse *pParse;          /* Parsing context used to create this Vdbe */
+  ynVar nVar;             /* Number of entries in aVar[] */
+  u32 magic;              /* Magic number for sanity checking */
+  int nMem;               /* Number of memory locations currently allocated */
+  int nCursor;            /* Number of slots in apCsr[] */
+  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
+  int pc;                 /* The program counter */
+  int rc;                 /* Value to return */
+  int nChange;            /* Number of db changes made since last reset */
+  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
+  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
+  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
+  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
+  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
+
+  /* When allocating a new Vdbe object, all of the fields below should be
+  ** initialized to zero or NULL */
+
   Op *aOp;                /* Space to hold the virtual machine's program */
   Mem *aMem;              /* The memory locations */
   Mem **apArg;            /* Arguments to currently executing user function */
   Mem *aColName;          /* Column names to return */
   Mem *pResultSet;        /* Pointer to an array of results */
-  Parse *pParse;          /* Parsing context used to create this Vdbe */
-  int nMem;               /* Number of memory locations currently allocated */
-  int nOp;                /* Number of instructions in the program */
-  int nCursor;            /* Number of slots in apCsr[] */
-  u32 magic;              /* Magic number for sanity checking */
   char *zErrMsg;          /* Error message written here */
-  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
   VdbeCursor **apCsr;     /* One element of this array for each open cursor */
   Mem *aVar;              /* Values for the OP_Variable opcode. */
-  char **azVar;           /* Name of variables */
-  ynVar nVar;             /* Number of entries in aVar[] */
-  ynVar nzVar;            /* Number of entries in azVar[] */
-  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
-  int pc;                 /* The program counter */
-  int rc;                 /* Value to return */
+  VList *pVList;          /* Name of variables */
+#ifndef SQLITE_OMIT_TRACE
+  i64 startTime;          /* Time when query started - used for profiling */
+#endif
+  int nOp;                /* Number of instructions in the program */
+#ifdef SQLITE_DEBUG
+  int rcApp;              /* errcode set by sqlite3_result_error_code() */
+#endif
   u16 nResColumn;         /* Number of columns in one row of the result set */
   u8 errorAction;         /* Recovery action to do in case of an error */
   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
+  u8 prepFlags;           /* SQLITE_PREPARE_* flags */
+  bft expired:1;          /* True if the VM needs to be recompiled */
+  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
   bft explain:2;          /* True if EXPLAIN present on SQL command */
-  bft inVtabMethod:2;     /* See comments above */
   bft changeCntOn:1;      /* True to update the change-counter */
-  bft expired:1;          /* True if the VM needs to be recompiled */
   bft runOnlyOnce:1;      /* Automatically expire on reset */
   bft usesStmtJournal:1;  /* True if uses a statement journal */
   bft readOnly:1;         /* True for statements that do not write */
   bft bIsReader:1;        /* True for statements that read */
-  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
-  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
-  int nChange;            /* Number of db changes made since last reset */
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
-  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
-  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
-#ifndef SQLITE_OMIT_TRACE
-  i64 startTime;          /* Time when query started - used for profiling */
-#endif
-  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
-  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
-  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
-  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
+  u32 aCounter[7];        /* Counters used by sqlite3_stmt_status() */
   char *zSql;             /* Text of the SQL statement that generated this */
   void *pFree;            /* Free this when deleting the vdbe */
   VdbeFrame *pFrame;      /* Parent frame */
@@ -14671,8 +18864,6 @@ struct Vdbe {
   int nFrame;             /* Number of frames in pFrame list */
   u32 expmask;            /* Binding to these vars invalidates VM */
   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
-  int nOnceFlag;          /* Size of array aOnceFlag[] */
-  u8 *aOnceFlag;          /* Flags for OP_Once */
   AuxData *pAuxData;      /* Linked list of auxdata allocations */
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
   i64 *anExec;            /* Number of times each op has been executed */
@@ -14684,26 +18875,49 @@ struct Vdbe {
 /*
 ** The following are allowed values for Vdbe.magic
 */
-#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
-#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
-#define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
-#define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
+#define VDBE_MAGIC_INIT     0x16bceaa5    /* Building a VDBE program */
+#define VDBE_MAGIC_RUN      0x2df20da3    /* VDBE is ready to execute */
+#define VDBE_MAGIC_HALT     0x319c2973    /* VDBE has completed execution */
+#define VDBE_MAGIC_RESET    0x48fa9f76    /* Reset and ready to run again */
+#define VDBE_MAGIC_DEAD     0x5606c3c8    /* The VDBE has been deallocated */
+
+/*
+** Structure used to store the context required by the 
+** sqlite3_preupdate_*() API functions.
+*/
+struct PreUpdate {
+  Vdbe *v;
+  VdbeCursor *pCsr;               /* Cursor to read old values from */
+  int op;                         /* One of SQLITE_INSERT, UPDATE, DELETE */
+  u8 *aRecord;                    /* old.* database record */
+  KeyInfo keyinfo;
+  UnpackedRecord *pUnpacked;      /* Unpacked version of aRecord[] */
+  UnpackedRecord *pNewUnpacked;   /* Unpacked version of new.* record */
+  int iNewReg;                    /* Register for new.* values */
+  i64 iKey1;                      /* First key value passed to hook */
+  i64 iKey2;                      /* Second key value passed to hook */
+  Mem *aNew;                      /* Array of new.* values */
+  Table *pTab;                    /* Schema object being upated */          
+  Index *pPk;                     /* PK index if pTab is WITHOUT ROWID */
+};
 
 /*
 ** Function prototypes
 */
+SQLITE_PRIVATE void sqlite3VdbeError(Vdbe*, const char *, ...);
 SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
 void sqliteVdbePopStack(Vdbe*,int);
-SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor*);
+SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor**, int*);
 SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor*);
 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
 SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, Op*);
 #endif
 SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32);
-SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int);
+SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8);
+SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int, u32*);
 SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);
 SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
-SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(Vdbe*, int, int);
+SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3*, AuxData**, int, int);
 
 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
 SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*);
@@ -14724,6 +18938,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem*, i64);
 #else
 SQLITE_PRIVATE   void sqlite3VdbeMemSetDouble(Mem*, double);
 #endif
+SQLITE_PRIVATE void sqlite3VdbeMemSetPointer(Mem*, void*, const char*, void(*)(void*));
 SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem*,sqlite3*,u16);
 SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem*);
 SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem*,int);
@@ -14737,10 +18952,8 @@ SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
 SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem*,u8,u8);
-SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,int,Mem*);
+SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,Mem*);
 SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
-#define VdbeMemDynamic(X)  \
-  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))!=0)
 SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
 SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
 SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
@@ -14748,22 +18961,29 @@ SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
 SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
 SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*);
 SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(Vdbe*,VdbeCursor*,int,const char*,Table*,i64,int);
+#endif
 SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p);
 
 SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, int, VdbeCursor *);
 SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *, VdbeSorter *);
 SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
 SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
-SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
+SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *);
 SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *, int *);
 SQLITE_PRIVATE int sqlite3VdbeSorterWrite(const VdbeCursor *, Mem *);
 SQLITE_PRIVATE int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int, int *);
 
-#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
+#if !defined(SQLITE_OMIT_SHARED_CACHE) 
 SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
-SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
 #else
 # define sqlite3VdbeEnter(X)
+#endif
+
+#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
+SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
+#else
 # define sqlite3VdbeLeave(X)
 #endif
 
@@ -14778,12 +18998,14 @@ SQLITE_PRIVATE int sqlite3VdbeCheckFk(Vdbe *, int);
 # define sqlite3VdbeCheckFk(p,i) 0
 #endif
 
-SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem*, u8);
 #ifdef SQLITE_DEBUG
 SQLITE_PRIVATE   void sqlite3VdbePrintSql(Vdbe*);
 SQLITE_PRIVATE   void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
 #endif
-SQLITE_PRIVATE int sqlite3VdbeMemHandleBom(Mem *pMem);
+#ifndef SQLITE_OMIT_UTF16
+SQLITE_PRIVATE   int sqlite3VdbeMemTranslate(Mem*, u8);
+SQLITE_PRIVATE   int sqlite3VdbeMemHandleBom(Mem *pMem);
+#endif
 
 #ifndef SQLITE_OMIT_INCRBLOB
 SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);
@@ -14793,7 +19015,7 @@ SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);
   #define ExpandBlob(P) SQLITE_OK
 #endif
 
-#endif /* !defined(_VDBEINT_H_) */
+#endif /* !defined(SQLITE_VDBEINT_H) */
 
 /************** End of vdbeInt.h *********************************************/
 /************** Continuing where we left off in status.c *********************/
@@ -14801,12 +19023,34 @@ SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);
 /*
 ** Variables in which to record status information.
 */
+#if SQLITE_PTRSIZE>4
+typedef sqlite3_int64 sqlite3StatValueType;
+#else
+typedef u32 sqlite3StatValueType;
+#endif
 typedef struct sqlite3StatType sqlite3StatType;
 static SQLITE_WSD struct sqlite3StatType {
-  int nowValue[10];         /* Current value */
-  int mxValue[10];          /* Maximum value */
+  sqlite3StatValueType nowValue[10];  /* Current value */
+  sqlite3StatValueType mxValue[10];   /* Maximum value */
 } sqlite3Stat = { {0,}, {0,} };
 
+/*
+** Elements of sqlite3Stat[] are protected by either the memory allocator
+** mutex, or by the pcache1 mutex.  The following array determines which.
+*/
+static const char statMutex[] = {
+  0,  /* SQLITE_STATUS_MEMORY_USED */
+  1,  /* SQLITE_STATUS_PAGECACHE_USED */
+  1,  /* SQLITE_STATUS_PAGECACHE_OVERFLOW */
+  0,  /* SQLITE_STATUS_SCRATCH_USED */
+  0,  /* SQLITE_STATUS_SCRATCH_OVERFLOW */
+  0,  /* SQLITE_STATUS_MALLOC_SIZE */
+  0,  /* SQLITE_STATUS_PARSER_STACK */
+  1,  /* SQLITE_STATUS_PAGECACHE_SIZE */
+  0,  /* SQLITE_STATUS_SCRATCH_SIZE */
+  0,  /* SQLITE_STATUS_MALLOC_COUNT */
+};
+
 
 /* The "wsdStat" macro will resolve to the status information
 ** state vector.  If writable static data is unsupported on the target,
@@ -14823,47 +19067,82 @@ static SQLITE_WSD struct sqlite3StatType {
 #endif
 
 /*
-** Return the current value of a status parameter.
+** Return the current value of a status parameter.  The caller must
+** be holding the appropriate mutex.
 */
-SQLITE_PRIVATE int sqlite3StatusValue(int op){
+SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int op){
   wsdStatInit;
   assert( op>=0 && op=0 && op=0 && op=0 && opwsdStat.mxValue[op] ){
     wsdStat.mxValue[op] = wsdStat.nowValue[op];
   }
 }
+SQLITE_PRIVATE void sqlite3StatusDown(int op, int N){
+  wsdStatInit;
+  assert( N>=0 );
+  assert( op>=0 && op=0 && op=0 );
+  newValue = (sqlite3StatValueType)X;
   assert( op>=0 && opwsdStat.mxValue[op] ){
-    wsdStat.mxValue[op] = wsdStat.nowValue[op];
+  assert( op>=0 && opwsdStat.mxValue[op] ){
+    wsdStat.mxValue[op] = newValue;
   }
 }
 
 /*
 ** Query status information.
-**
-** This implementation assumes that reading or writing an aligned
-** 32-bit integer is an atomic operation.  If that assumption is not true,
-** then this routine is not threadsafe.
 */
-SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
+SQLITE_API int sqlite3_status64(
+  int op,
+  sqlite3_int64 *pCurrent,
+  sqlite3_int64 *pHighwater,
+  int resetFlag
+){
+  sqlite3_mutex *pMutex;
   wsdStatInit;
   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
     return SQLITE_MISUSE_BKPT;
@@ -14871,13 +19150,30 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
 #endif
+  pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
+  sqlite3_mutex_enter(pMutex);
   *pCurrent = wsdStat.nowValue[op];
   *pHighwater = wsdStat.mxValue[op];
   if( resetFlag ){
     wsdStat.mxValue[op] = wsdStat.nowValue[op];
   }
+  sqlite3_mutex_leave(pMutex);
+  (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */
   return SQLITE_OK;
 }
+SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
+  sqlite3_int64 iCur = 0, iHwtr = 0;
+  int rc;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
+  if( rc==0 ){
+    *pCurrent = (int)iCur;
+    *pHighwater = (int)iHwtr;
+  }
+  return rc;
+}
 
 /*
 ** Query status information for a single database connection
@@ -14927,6 +19223,7 @@ SQLITE_API int sqlite3_db_status(
     ** by all pagers associated with the given database connection.  The
     ** highwater mark is meaningless and is returned as zero.
     */
+    case SQLITE_DBSTATUS_CACHE_USED_SHARED:
     case SQLITE_DBSTATUS_CACHE_USED: {
       int totalUsed = 0;
       int i;
@@ -14935,7 +19232,11 @@ SQLITE_API int sqlite3_db_status(
         Btree *pBt = db->aDb[i].pBt;
         if( pBt ){
           Pager *pPager = sqlite3BtreePager(pBt);
-          totalUsed += sqlite3PagerMemUsed(pPager);
+          int nByte = sqlite3PagerMemUsed(pPager);
+          if( op==SQLITE_DBSTATUS_CACHE_USED_SHARED ){
+            nByte = nByte / sqlite3BtreeConnectionCount(pBt);
+          }
+          totalUsed += nByte;
         }
       }
       sqlite3BtreeLeaveAll(db);
@@ -14966,10 +19267,10 @@ SQLITE_API int sqlite3_db_status(
             + pSchema->idxHash.count
             + pSchema->fkeyHash.count
           );
-          nByte += sqlite3MallocSize(pSchema->tblHash.ht);
-          nByte += sqlite3MallocSize(pSchema->trigHash.ht);
-          nByte += sqlite3MallocSize(pSchema->idxHash.ht);
-          nByte += sqlite3MallocSize(pSchema->fkeyHash.ht);
+          nByte += sqlite3_msize(pSchema->tblHash.ht);
+          nByte += sqlite3_msize(pSchema->trigHash.ht);
+          nByte += sqlite3_msize(pSchema->idxHash.ht);
+          nByte += sqlite3_msize(pSchema->fkeyHash.ht);
 
           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
@@ -15100,59 +19401,87 @@ SQLITE_API int sqlite3_db_status(
 **      Willmann-Bell, Inc
 **      Richmond, Virginia (USA)
 */
+/* #include "sqliteInt.h" */
 /* #include  */
 /* #include  */
 #include 
 
 #ifndef SQLITE_OMIT_DATETIME_FUNCS
 
+/*
+** The MSVC CRT on Windows CE may not have a localtime() function.
+** So declare a substitute.  The substitute function itself is
+** defined in "os_win.c".
+*/
+#if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
+    (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
+struct tm *__cdecl localtime(const time_t *);
+#endif
 
 /*
 ** A structure for holding a single date and time.
 */
 typedef struct DateTime DateTime;
 struct DateTime {
-  sqlite3_int64 iJD; /* The julian day number times 86400000 */
-  int Y, M, D;       /* Year, month, and day */
-  int h, m;          /* Hour and minutes */
-  int tz;            /* Timezone offset in minutes */
-  double s;          /* Seconds */
-  char validYMD;     /* True (1) if Y,M,D are valid */
-  char validHMS;     /* True (1) if h,m,s are valid */
-  char validJD;      /* True (1) if iJD is valid */
-  char validTZ;      /* True (1) if tz is valid */
+  sqlite3_int64 iJD;  /* The julian day number times 86400000 */
+  int Y, M, D;        /* Year, month, and day */
+  int h, m;           /* Hour and minutes */
+  int tz;             /* Timezone offset in minutes */
+  double s;           /* Seconds */
+  char validJD;       /* True (1) if iJD is valid */
+  char rawS;          /* Raw numeric value stored in s */
+  char validYMD;      /* True (1) if Y,M,D are valid */
+  char validHMS;      /* True (1) if h,m,s are valid */
+  char validTZ;       /* True (1) if tz is valid */
+  char tzSet;         /* Timezone was set explicitly */
+  char isError;       /* An overflow has occurred */
 };
 
 
 /*
-** Convert zDate into one or more integers.  Additional arguments
-** come in groups of 5 as follows:
+** Convert zDate into one or more integers according to the conversion
+** specifier zFormat.
+**
+** zFormat[] contains 4 characters for each integer converted, except for
+** the last integer which is specified by three characters.  The meaning
+** of a four-character format specifiers ABCD is:
 **
-**       N       number of digits in the integer
-**       min     minimum allowed value of the integer
-**       max     maximum allowed value of the integer
-**       nextC   first character after the integer
-**       pVal    where to write the integers value.
+**    A:   number of digits to convert.  Always "2" or "4".
+**    B:   minimum value.  Always "0" or "1".
+**    C:   maximum value, decoded as:
+**           a:  12
+**           b:  14
+**           c:  24
+**           d:  31
+**           e:  59
+**           f:  9999
+**    D:   the separator character, or \000 to indicate this is the
+**         last number to convert.
+**
+** Example:  To translate an ISO-8601 date YYYY-MM-DD, the format would
+** be "40f-21a-20c".  The "40f-" indicates the 4-digit year followed by "-".
+** The "21a-" indicates the 2-digit month followed by "-".  The "20c" indicates
+** the 2-digit day which is the last integer in the set.
 **
-** Conversions continue until one with nextC==0 is encountered.
 ** The function returns the number of successful conversions.
 */
-static int getDigits(const char *zDate, ...){
+static int getDigits(const char *zDate, const char *zFormat, ...){
+  /* The aMx[] array translates the 3rd character of each format
+  ** spec into a max size:    a   b   c   d   e     f */
+  static const u16 aMx[] = { 12, 14, 24, 31, 59, 9999 };
   va_list ap;
-  int val;
-  int N;
-  int min;
-  int max;
-  int nextC;
-  int *pVal;
   int cnt = 0;
-  va_start(ap, zDate);
+  char nextC;
+  va_start(ap, zFormat);
   do{
-    N = va_arg(ap, int);
-    min = va_arg(ap, int);
-    max = va_arg(ap, int);
-    nextC = va_arg(ap, int);
-    pVal = va_arg(ap, int*);
+    char N = zFormat[0] - '0';
+    char min = zFormat[1] - '0';
+    int val = 0;
+    u16 max;
+
+    assert( zFormat[2]>='a' && zFormat[2]<='f' );
+    max = aMx[zFormat[2] - 'a'];
+    nextC = zFormat[3];
     val = 0;
     while( N-- ){
       if( !sqlite3Isdigit(*zDate) ){
@@ -15161,12 +19490,13 @@ static int getDigits(const char *zDate, ...){
       val = val*10 + *zDate - '0';
       zDate++;
     }
-    if( valmax || (nextC!=0 && nextC!=*zDate) ){
+    if( val<(int)min || val>(int)max || (nextC!=0 && nextC!=*zDate) ){
       goto end_getDigits;
     }
-    *pVal = val;
+    *va_arg(ap,int*) = val;
     zDate++;
     cnt++;
+    zFormat += 4;
   }while( nextC );
 end_getDigits:
   va_end(ap);
@@ -15207,13 +19537,14 @@ static int parseTimezone(const char *zDate, DateTime *p){
     return c!=0;
   }
   zDate++;
-  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
+  if( getDigits(zDate, "20b:20e", &nHr, &nMn)!=2 ){
     return 1;
   }
   zDate += 5;
   p->tz = sgn*(nMn + nHr*60);
 zulu_time:
   while( sqlite3Isspace(*zDate) ){ zDate++; }
+  p->tzSet = 1;
   return *zDate!=0;
 }
 
@@ -15227,13 +19558,13 @@ zulu_time:
 static int parseHhMmSs(const char *zDate, DateTime *p){
   int h, m, s;
   double ms = 0.0;
-  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
+  if( getDigits(zDate, "20c:20e", &h, &m)!=2 ){
     return 1;
   }
   zDate += 5;
   if( *zDate==':' ){
     zDate++;
-    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
+    if( getDigits(zDate, "20e", &s)!=1 ){
       return 1;
     }
     zDate += 2;
@@ -15251,6 +19582,7 @@ static int parseHhMmSs(const char *zDate, DateTime *p){
     s = 0;
   }
   p->validJD = 0;
+  p->rawS = 0;
   p->validHMS = 1;
   p->h = h;
   p->m = m;
@@ -15260,6 +19592,14 @@ static int parseHhMmSs(const char *zDate, DateTime *p){
   return 0;
 }
 
+/*
+** Put the DateTime object into its error state.
+*/
+static void datetimeError(DateTime *p){
+  memset(p, 0, sizeof(*p));
+  p->isError = 1;
+}
+
 /*
 ** Convert from YYYY-MM-DD HH:MM:SS to julian day.  We always assume
 ** that the YYYY-MM-DD is according to the Gregorian calendar.
@@ -15279,6 +19619,10 @@ static void computeJD(DateTime *p){
     M = 1;
     D = 1;
   }
+  if( Y<-4713 || Y>9999 || p->rawS ){
+    datetimeError(p);
+    return;
+  }
   if( M<=2 ){
     Y--;
     M += 12;
@@ -15321,7 +19665,7 @@ static int parseYyyyMmDd(const char *zDate, DateTime *p){
   }else{
     neg = 0;
   }
-  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
+  if( getDigits(zDate, "40f-21a-21d", &Y, &M, &D)!=3 ){
     return 1;
   }
   zDate += 10;
@@ -15359,6 +19703,21 @@ static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
   }
 }
 
+/*
+** Input "r" is a numeric quantity which might be a julian day number,
+** or the number of seconds since 1970.  If the value if r is within
+** range of a julian day number, install it as such and set validJD.
+** If the value is a valid unix timestamp, put it in p->s and set p->rawS.
+*/
+static void setRawDateNumber(DateTime *p, double r){
+  p->s = r;
+  p->rawS = 1;
+  if( r>=0.0 && r<5373484.5 ){
+    p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
+    p->validJD = 1;
+  }
+}
+
 /*
 ** Attempt to parse the given string into a julian day number.  Return
 ** the number of errors.
@@ -15385,16 +19744,33 @@ static int parseDateOrTime(
     return 0;
   }else if( parseHhMmSs(zDate, p)==0 ){
     return 0;
-  }else if( sqlite3StrICmp(zDate,"now")==0){
+  }else if( sqlite3StrICmp(zDate,"now")==0 && sqlite3NotPureFunc(context) ){
     return setDateTimeToCurrent(context, p);
   }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8) ){
-    p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
-    p->validJD = 1;
+    setRawDateNumber(p, r);
     return 0;
   }
   return 1;
 }
 
+/* The julian day number for 9999-12-31 23:59:59.999 is 5373484.4999999.
+** Multiplying this by 86400000 gives 464269060799999 as the maximum value
+** for DateTime.iJD.
+**
+** But some older compilers (ex: gcc 4.2.1 on older Macs) cannot deal with 
+** such a large integer literal, so we have to encode it.
+*/
+#define INT_464269060799999  ((((i64)0x1a640)<<32)|0x1072fdff)
+
+/*
+** Return TRUE if the given julian day number is within range.
+**
+** The input is the JulianDay times 86400000.
+*/
+static int validJulianDay(sqlite3_int64 iJD){
+  return iJD>=0 && iJD<=INT_464269060799999;
+}
+
 /*
 ** Compute the Year, Month, and Day from the julian day number.
 */
@@ -15405,13 +19781,16 @@ static void computeYMD(DateTime *p){
     p->Y = 2000;
     p->M = 1;
     p->D = 1;
+  }else if( !validJulianDay(p->iJD) ){
+    datetimeError(p);
+    return;
   }else{
     Z = (int)((p->iJD + 43200000)/86400000);
     A = (int)((Z - 1867216.25)/36524.25);
     A = Z + 1 + A - (A/4);
     B = A + 1524;
     C = (int)((B - 122.1)/365.25);
-    D = (36525*C)/100;
+    D = (36525*(C&32767))/100;
     E = (int)((B-D)/30.6001);
     X1 = (int)(30.6001*E);
     p->D = B - D - X1;
@@ -15436,6 +19815,7 @@ static void computeHMS(DateTime *p){
   s -= p->h*3600;
   p->m = s/60;
   p->s += s - p->m*60;
+  p->rawS = 0;
   p->validHMS = 1;
 }
 
@@ -15456,6 +19836,7 @@ static void clearYMD_HMS_TZ(DateTime *p){
   p->validTZ = 0;
 }
 
+#ifndef SQLITE_OMIT_LOCALTIME
 /*
 ** On recent Windows platforms, the localtime_s() function is available
 ** as part of the "Secure CRT". It is essentially equivalent to 
@@ -15474,7 +19855,6 @@ static void clearYMD_HMS_TZ(DateTime *p){
 #define HAVE_LOCALTIME_S 1
 #endif
 
-#ifndef SQLITE_OMIT_LOCALTIME
 /*
 ** The following routine implements the rough equivalent of localtime_r()
 ** using whatever operating-system specific localtime facility that
@@ -15497,14 +19877,14 @@ static int osLocaltime(time_t *t, struct tm *pTm){
 #endif
   sqlite3_mutex_enter(mutex);
   pX = localtime(t);
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
   if( sqlite3GlobalConfig.bLocaltimeFault ) pX = 0;
 #endif
   if( pX ) *pTm = *pX;
   sqlite3_mutex_leave(mutex);
   rc = pX==0;
 #else
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
   if( sqlite3GlobalConfig.bLocaltimeFault ) return 1;
 #endif
 #if HAVE_LOCALTIME_R
@@ -15575,13 +19955,38 @@ static sqlite3_int64 localtimeOffset(
   y.validYMD = 1;
   y.validHMS = 1;
   y.validJD = 0;
+  y.rawS = 0;
   y.validTZ = 0;
+  y.isError = 0;
   computeJD(&y);
   *pRc = SQLITE_OK;
   return y.iJD - x.iJD;
 }
 #endif /* SQLITE_OMIT_LOCALTIME */
 
+/*
+** The following table defines various date transformations of the form
+**
+**            'NNN days'
+**
+** Where NNN is an arbitrary floating-point number and "days" can be one
+** of several units of time.
+*/
+static const struct {
+  u8 eType;           /* Transformation type code */
+  u8 nName;           /* Length of th name */
+  char *zName;        /* Name of the transformation */
+  double rLimit;      /* Maximum NNN value for this transform */
+  double rXform;      /* Constant used for this transform */
+} aXformType[] = {
+  { 0, 6, "second", 464269060800.0, 86400000.0/(24.0*60.0*60.0) },
+  { 0, 6, "minute", 7737817680.0,   86400000.0/(24.0*60.0)      },
+  { 0, 4, "hour",   128963628.0,    86400000.0/24.0             },
+  { 0, 3, "day",    5373485.0,      86400000.0                  },
+  { 1, 5, "month",  176546.0,       30.0*86400000.0             },
+  { 2, 4, "year",   14713.0,        365.0*86400000.0            },
+};
+
 /*
 ** Process a modifier to a date-time stamp.  The modifiers are
 ** as follows:
@@ -15606,17 +20011,15 @@ static sqlite3_int64 localtimeOffset(
 ** to context pCtx. If the error is an unrecognized modifier, no error is
 ** written to pCtx.
 */
-static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
+static int parseModifier(
+  sqlite3_context *pCtx,      /* Function context */
+  const char *z,              /* The text of the modifier */
+  int n,                      /* Length of zMod in bytes */
+  DateTime *p                 /* The date/time value to be modified */
+){
   int rc = 1;
-  int n;
   double r;
-  char *z, zBuf[30];
-  z = zBuf;
-  for(n=0; niJD += localtimeOffset(p, pCtx, &rc);
         clearYMD_HMS_TZ(p);
@@ -15636,23 +20039,33 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
       /*
       **    unixepoch
       **
-      ** Treat the current value of p->iJD as the number of
+      ** Treat the current value of p->s as the number of
       ** seconds since 1970.  Convert to a real julian day number.
       */
-      if( strcmp(z, "unixepoch")==0 && p->validJD ){
-        p->iJD = (p->iJD + 43200)/86400 + 21086676*(i64)10000000;
-        clearYMD_HMS_TZ(p);
-        rc = 0;
+      if( sqlite3_stricmp(z, "unixepoch")==0 && p->rawS ){
+        r = p->s*1000.0 + 210866760000000.0;
+        if( r>=0.0 && r<464269060800000.0 ){
+          clearYMD_HMS_TZ(p);
+          p->iJD = (sqlite3_int64)r;
+          p->validJD = 1;
+          p->rawS = 0;
+          rc = 0;
+        }
       }
 #ifndef SQLITE_OMIT_LOCALTIME
-      else if( strcmp(z, "utc")==0 ){
-        sqlite3_int64 c1;
-        computeJD(p);
-        c1 = localtimeOffset(p, pCtx, &rc);
-        if( rc==SQLITE_OK ){
-          p->iJD -= c1;
-          clearYMD_HMS_TZ(p);
-          p->iJD += c1 - localtimeOffset(p, pCtx, &rc);
+      else if( sqlite3_stricmp(z, "utc")==0 && sqlite3NotPureFunc(pCtx) ){
+        if( p->tzSet==0 ){
+          sqlite3_int64 c1;
+          computeJD(p);
+          c1 = localtimeOffset(p, pCtx, &rc);
+          if( rc==SQLITE_OK ){
+            p->iJD -= c1;
+            clearYMD_HMS_TZ(p);
+            p->iJD += c1 - localtimeOffset(p, pCtx, &rc);
+          }
+          p->tzSet = 1;
+        }else{
+          rc = SQLITE_OK;
         }
       }
 #endif
@@ -15666,7 +20079,7 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
       ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the
       ** date is already on the appropriate weekday, this is a no-op.
       */
-      if( strncmp(z, "weekday ", 8)==0
+      if( sqlite3_strnicmp(z, "weekday ", 8)==0
                && sqlite3AtoF(&z[8], &r, sqlite3Strlen30(&z[8]), SQLITE_UTF8)
                && (n=(int)r)==r && n>=0 && r<7 ){
         sqlite3_int64 Z;
@@ -15689,23 +20102,24 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
       ** Move the date backwards to the beginning of the current day,
       ** or month or year.
       */
-      if( strncmp(z, "start of ", 9)!=0 ) break;
+      if( sqlite3_strnicmp(z, "start of ", 9)!=0 ) break;
+      if( !p->validJD && !p->validYMD && !p->validHMS ) break;
       z += 9;
       computeYMD(p);
       p->validHMS = 1;
       p->h = p->m = 0;
       p->s = 0.0;
+      p->rawS = 0;
       p->validTZ = 0;
       p->validJD = 0;
-      if( strcmp(z,"month")==0 ){
+      if( sqlite3_stricmp(z,"month")==0 ){
         p->D = 1;
         rc = 0;
-      }else if( strcmp(z,"year")==0 ){
-        computeYMD(p);
+      }else if( sqlite3_stricmp(z,"year")==0 ){
         p->M = 1;
         p->D = 1;
         rc = 0;
-      }else if( strcmp(z,"day")==0 ){
+      }else if( sqlite3_stricmp(z,"day")==0 ){
         rc = 0;
       }
       break;
@@ -15723,6 +20137,7 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
     case '8':
     case '9': {
       double rRounder;
+      int i;
       for(n=1; z[n] && z[n]!=':' && !sqlite3Isspace(z[n]); n++){}
       if( !sqlite3AtoF(z, &r, n, SQLITE_UTF8) ){
         rc = 1;
@@ -15751,46 +20166,48 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
         rc = 0;
         break;
       }
+
+      /* If control reaches this point, it means the transformation is
+      ** one of the forms like "+NNN days".  */
       z += n;
       while( sqlite3Isspace(*z) ) z++;
       n = sqlite3Strlen30(z);
       if( n>10 || n<3 ) break;
-      if( z[n-1]=='s' ){ z[n-1] = 0; n--; }
+      if( sqlite3UpperToLower[(u8)z[n-1]]=='s' ) n--;
       computeJD(p);
-      rc = 0;
+      rc = 1;
       rRounder = r<0 ? -0.5 : +0.5;
-      if( n==3 && strcmp(z,"day")==0 ){
-        p->iJD += (sqlite3_int64)(r*86400000.0 + rRounder);
-      }else if( n==4 && strcmp(z,"hour")==0 ){
-        p->iJD += (sqlite3_int64)(r*(86400000.0/24.0) + rRounder);
-      }else if( n==6 && strcmp(z,"minute")==0 ){
-        p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0)) + rRounder);
-      }else if( n==6 && strcmp(z,"second")==0 ){
-        p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0*60.0)) + rRounder);
-      }else if( n==5 && strcmp(z,"month")==0 ){
-        int x, y;
-        computeYMD_HMS(p);
-        p->M += (int)r;
-        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
-        p->Y += x;
-        p->M -= x*12;
-        p->validJD = 0;
-        computeJD(p);
-        y = (int)r;
-        if( y!=r ){
-          p->iJD += (sqlite3_int64)((r - y)*30.0*86400000.0 + rRounder);
-        }
-      }else if( n==4 && strcmp(z,"year")==0 ){
-        int y = (int)r;
-        computeYMD_HMS(p);
-        p->Y += y;
-        p->validJD = 0;
-        computeJD(p);
-        if( y!=r ){
-          p->iJD += (sqlite3_int64)((r - y)*365.0*86400000.0 + rRounder);
+      for(i=0; i-aXformType[i].rLimit && rM += (int)r;
+              x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
+              p->Y += x;
+              p->M -= x*12;
+              p->validJD = 0;
+              r -= (int)r;
+              break;
+            }
+            case 2: { /* Special processing to add years */
+              int y = (int)r;
+              computeYMD_HMS(p);
+              p->Y += y;
+              p->validJD = 0;
+              r -= (int)r;
+              break;
+            }
+          }
+          computeJD(p);
+          p->iJD += (sqlite3_int64)(r*aXformType[i].rXform + rRounder);
+          rc = 0;
+          break;
         }
-      }else{
-        rc = 1;
       }
       clearYMD_HMS_TZ(p);
       break;
@@ -15817,7 +20234,7 @@ static int isDate(
   sqlite3_value **argv, 
   DateTime *p
 ){
-  int i;
+  int i, n;
   const unsigned char *z;
   int eType;
   memset(p, 0, sizeof(*p));
@@ -15826,8 +20243,7 @@ static int isDate(
   }
   if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT
                    || eType==SQLITE_INTEGER ){
-    p->iJD = (sqlite3_int64)(sqlite3_value_double(argv[0])*86400000.0 + 0.5);
-    p->validJD = 1;
+    setRawDateNumber(p, sqlite3_value_double(argv[0]));
   }else{
     z = sqlite3_value_text(argv[0]);
     if( !z || parseDateOrTime(context, (char*)z, p) ){
@@ -15836,8 +20252,11 @@ static int isDate(
   }
   for(i=1; iisError || !validJulianDay(p->iJD) ) return 1;
   return 0;
 }
 
@@ -16000,7 +20419,7 @@ static void strftimeFunc(
     sqlite3_result_error_toobig(context);
     return;
   }else{
-    z = sqlite3DbMallocRaw(db, (int)n);
+    z = sqlite3DbMallocRawNN(db, (int)n);
     if( z==0 ){
       sqlite3_result_error_nomem(context);
       return;
@@ -16136,7 +20555,6 @@ static void currentTimeFunc(
 ){
   time_t t;
   char *zFormat = (char *)sqlite3_user_data(context);
-  sqlite3 *db;
   sqlite3_int64 iT;
   struct tm *pTm;
   struct tm sNow;
@@ -16169,29 +20587,23 @@ static void currentTimeFunc(
 ** external linkage.
 */
 SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void){
-  static SQLITE_WSD FuncDef aDateTimeFuncs[] = {
+  static FuncDef aDateTimeFuncs[] = {
 #ifndef SQLITE_OMIT_DATETIME_FUNCS
-    FUNCTION(julianday,        -1, 0, 0, juliandayFunc ),
-    FUNCTION(date,             -1, 0, 0, dateFunc      ),
-    FUNCTION(time,             -1, 0, 0, timeFunc      ),
-    FUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
-    FUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
-    FUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
-    FUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
-    FUNCTION(current_date,      0, 0, 0, cdateFunc     ),
+    PURE_DATE(julianday,        -1, 0, 0, juliandayFunc ),
+    PURE_DATE(date,             -1, 0, 0, dateFunc      ),
+    PURE_DATE(time,             -1, 0, 0, timeFunc      ),
+    PURE_DATE(datetime,         -1, 0, 0, datetimeFunc  ),
+    PURE_DATE(strftime,         -1, 0, 0, strftimeFunc  ),
+    DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
+    DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
+    DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),
 #else
     STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
     STR_FUNCTION(current_date,      0, "%Y-%m-%d",          0, currentTimeFunc),
     STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
 #endif
   };
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aDateTimeFuncs);
-
-  for(i=0; ipMethods ){
-    rc = pId->pMethods->xClose(pId);
+    pId->pMethods->xClose(pId);
     pId->pMethods = 0;
   }
-  return rc;
 }
 SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
   DO_OS_MALLOC_TEST(id);
@@ -16307,8 +20738,8 @@ SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
 #ifdef SQLITE_TEST
   if( op!=SQLITE_FCNTL_COMMIT_PHASETWO ){
     /* Faults are not injected into COMMIT_PHASETWO because, assuming SQLite
-    ** is using a regular VFS, it is called after the corresponding 
-    ** transaction has been committed. Injecting a fault at this point 
+    ** is using a regular VFS, it is called after the corresponding
+    ** transaction has been committed. Injecting a fault at this point
     ** confuses the test scripts - the COMMIT comand returns SQLITE_NOMEM
     ** but the transaction is committed anyway.
     **
@@ -16377,10 +20808,10 @@ SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
 ** VFS methods.
 */
 SQLITE_PRIVATE int sqlite3OsOpen(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  sqlite3_file *pFile, 
-  int flags, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  sqlite3_file *pFile,
+  int flags,
   int *pFlagsOut
 ){
   int rc;
@@ -16399,18 +20830,18 @@ SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dir
   return pVfs->xDelete(pVfs, zPath, dirSync);
 }
 SQLITE_PRIVATE int sqlite3OsAccess(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int flags, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  int flags,
   int *pResOut
 ){
   DO_OS_MALLOC_TEST(0);
   return pVfs->xAccess(pVfs, zPath, flags, pResOut);
 }
 SQLITE_PRIVATE int sqlite3OsFullPathname(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int nPathOut, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  int nPathOut,
   char *zPathOut
 ){
   DO_OS_MALLOC_TEST(0);
@@ -16437,6 +20868,9 @@ SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufO
 SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
   return pVfs->xSleep(pVfs, nMicro);
 }
+SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs *pVfs){
+  return pVfs->xGetLastError ? pVfs->xGetLastError(pVfs, 0, 0) : 0;
+}
 SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
   int rc;
   /* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64()
@@ -16456,13 +20890,13 @@ SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p
 }
 
 SQLITE_PRIVATE int sqlite3OsOpenMalloc(
-  sqlite3_vfs *pVfs, 
-  const char *zFile, 
-  sqlite3_file **ppFile, 
+  sqlite3_vfs *pVfs,
+  const char *zFile,
+  sqlite3_file **ppFile,
   int flags,
   int *pOutFlags
 ){
-  int rc = SQLITE_NOMEM;
+  int rc;
   sqlite3_file *pFile;
   pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);
   if( pFile ){
@@ -16472,15 +20906,15 @@ SQLITE_PRIVATE int sqlite3OsOpenMalloc(
     }else{
       *ppFile = pFile;
     }
+  }else{
+    rc = SQLITE_NOMEM_BKPT;
   }
   return rc;
 }
-SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *pFile){
-  int rc = SQLITE_OK;
+SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *pFile){
   assert( pFile );
-  rc = sqlite3OsClose(pFile);
+  sqlite3OsClose(pFile);
   sqlite3_free(pFile);
-  return rc;
 }
 
 /*
@@ -16491,7 +20925,7 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *pFile){
 */
 SQLITE_PRIVATE int sqlite3OsInit(void){
   void *p = sqlite3_malloc(10);
-  if( p==0 ) return SQLITE_NOMEM;
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   sqlite3_free(p);
   return sqlite3_os_init();
 }
@@ -16618,8 +21052,9 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
 ** during a hash table resize is a benign fault.
 */
 
+/* #include "sqliteInt.h" */
 
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
 
 /*
 ** Global variables.
@@ -16677,7 +21112,7 @@ SQLITE_PRIVATE void sqlite3EndBenignMalloc(void){
   }
 }
 
-#endif   /* #ifndef SQLITE_OMIT_BUILTIN_TEST */
+#endif   /* #ifndef SQLITE_UNTESTABLE */
 
 /************** End of fault.c ***********************************************/
 /************** Begin file mem0.c ********************************************/
@@ -16699,6 +21134,7 @@ SQLITE_PRIVATE void sqlite3EndBenignMalloc(void){
 ** are merely placeholders.  Real drivers must be substituted using
 ** sqlite3_config() before SQLite will operate.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is the default.  It is
@@ -16785,6 +21221,7 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 **                                be necessary when compiling for Delphi,
 **                                for example.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is the default.  It is
@@ -16800,7 +21237,9 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 */
 #include 
 #include 
+#ifdef SQLITE_MIGHT_BE_SINGLE_CORE
 #include 
+#endif /* SQLITE_MIGHT_BE_SINGLE_CORE */
 static malloc_zone_t* _sqliteZone_;
 #define SQLITE_MALLOC(x) malloc_zone_malloc(_sqliteZone_, (x))
 #define SQLITE_FREE(x) malloc_zone_free(_sqliteZone_, (x));
@@ -16868,7 +21307,9 @@ static malloc_zone_t* _sqliteZone_;
 */
 static void *sqlite3MemMalloc(int nByte){
 #ifdef SQLITE_MALLOCSIZE
-  void *p = SQLITE_MALLOC( nByte );
+  void *p;
+  testcase( ROUND8(nByte)==nByte );
+  p = SQLITE_MALLOC( nByte );
   if( p==0 ){
     testcase( sqlite3GlobalConfig.xLog!=0 );
     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte);
@@ -16877,7 +21318,7 @@ static void *sqlite3MemMalloc(int nByte){
 #else
   sqlite3_int64 *p;
   assert( nByte>0 );
-  nByte = ROUND8(nByte);
+  testcase( ROUND8(nByte)!=nByte );
   p = SQLITE_MALLOC( nByte+8 );
   if( p ){
     p[0] = nByte;
@@ -16915,10 +21356,11 @@ static void sqlite3MemFree(void *pPrior){
 */
 static int sqlite3MemSize(void *pPrior){
 #ifdef SQLITE_MALLOCSIZE
-  return pPrior ? (int)SQLITE_MALLOCSIZE(pPrior) : 0;
+  assert( pPrior!=0 );
+  return (int)SQLITE_MALLOCSIZE(pPrior);
 #else
   sqlite3_int64 *p;
-  if( pPrior==0 ) return 0;
+  assert( pPrior!=0 );
   p = (sqlite3_int64*)pPrior;
   p--;
   return (int)p[0];
@@ -16990,19 +21432,10 @@ static int sqlite3MemInit(void *NotUsed){
   }else{
     /* only 1 core, use our own zone to contention over global locks, 
     ** e.g. we have our own dedicated locks */
-    bool success;
-    malloc_zone_t* newzone = malloc_create_zone(4096, 0);
-    malloc_set_zone_name(newzone, "Sqlite_Heap");
-    do{
-      success = OSAtomicCompareAndSwapPtrBarrier(NULL, newzone, 
-                                 (void * volatile *)&_sqliteZone_);
-    }while(!_sqliteZone_);
-    if( !success ){
-      /* somebody registered a zone first */
-      malloc_destroy_zone(newzone);
-    }
+    _sqliteZone_ = malloc_create_zone(4096, 0);
+    malloc_set_zone_name(_sqliteZone_, "Sqlite_Heap");
   }
-#endif
+#endif /*  defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) */
   UNUSED_PARAMETER(NotUsed);
   return SQLITE_OK;
 }
@@ -17060,6 +21493,7 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 ** This file contains implementations of the low-level memory allocation
 ** routines specified in the sqlite3_mem_methods object.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is used only if the
@@ -17594,6 +22028,7 @@ SQLITE_PRIVATE int sqlite3MemdebugMallocCount(){
 ** This version of the memory allocation subsystem is included
 ** in the build only if SQLITE_ENABLE_MEMSYS3 is defined.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is only built into the library
@@ -18046,7 +22481,7 @@ static void memsys3FreeUnsafe(void *pOld){
 */
 static int memsys3Size(void *p){
   Mem3Block *pBlock;
-  if( p==0 ) return 0;
+  assert( p!=0 );
   pBlock = (Mem3Block*)p;
   assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
   return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
@@ -18285,7 +22720,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
 **
 ** This memory allocator uses the following algorithm:
 **
-**   1.  All memory allocations sizes are rounded up to a power of 2.
+**   1.  All memory allocation sizes are rounded up to a power of 2.
 **
 **   2.  If two adjacent free blocks are the halves of a larger block,
 **       then the two blocks are coalesced into the single larger block.
@@ -18308,6 +22743,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
 ** The sqlite3_status() logic tracks the maximum values of n and M so
 ** that an application can, at any time, verify this constraint.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is used only when 
@@ -18361,6 +22797,7 @@ static SQLITE_WSD struct Mem5Global {
   */
   sqlite3_mutex *mutex;
 
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /*
   ** Performance statistics
   */
@@ -18372,11 +22809,12 @@ static SQLITE_WSD struct Mem5Global {
   u32 maxOut;         /* Maximum instantaneous currentOut */
   u32 maxCount;       /* Maximum instantaneous currentCount */
   u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */
+#endif
   
   /*
   ** Lists of free blocks.  aiFreelist[0] is a list of free blocks of
   ** size mem5.szAtom.  aiFreelist[1] holds blocks of size szAtom*2.
-  ** and so forth.
+  ** aiFreelist[2] holds free blocks of size szAtom*4.  And so forth.
   */
   int aiFreelist[LOGMAX+1];
 
@@ -18442,9 +22880,7 @@ static void memsys5Link(int i, int iLogsize){
 }
 
 /*
-** If the STATIC_MEM mutex is not already held, obtain it now. The mutex
-** will already be held (obtained by code in malloc.c) if
-** sqlite3GlobalConfig.bMemStat is true.
+** Obtain or release the mutex needed to access global data structures.
 */
 static void memsys5Enter(void){
   sqlite3_mutex_enter(mem5.mutex);
@@ -18454,17 +22890,15 @@ static void memsys5Leave(void){
 }
 
 /*
-** Return the size of an outstanding allocation, in bytes.  The
-** size returned omits the 8-byte header overhead.  This only
-** works for chunks that are currently checked out.
+** Return the size of an outstanding allocation, in bytes.
+** This only works for chunks that are currently checked out.
 */
 static int memsys5Size(void *p){
-  int iSize = 0;
-  if( p ){
-    int i = (int)(((u8 *)p-mem5.zPool)/mem5.szAtom);
-    assert( i>=0 && i=0 && i0 );
 
+  /* No more than 1GiB per allocation */
+  if( nByte > 0x40000000 ) return 0;
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /* Keep track of the maximum allocation request.  Even unfulfilled
   ** requests are counted */
   if( (u32)nByte>mem5.maxRequest ){
     mem5.maxRequest = nByte;
   }
+#endif
 
-  /* Abort if the requested allocation size is larger than the largest
-  ** power of two that we can represent using 32-bit signed integers.
-  */
-  if( nByte > 0x40000000 ){
-    return 0;
-  }
 
   /* Round nByte up to the next valid power of two */
-  for(iFullSz=mem5.szAtom, iLogsize=0; iFullSz0 );
   assert( mem5.currentOut>=(size*mem5.szAtom) );
   mem5.currentCount--;
   mem5.currentOut -= size*mem5.szAtom;
   assert( mem5.currentOut>0 || mem5.currentCount==0 );
   assert( mem5.currentCount>0 || mem5.currentOut==0 );
+#endif
 
   mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;
   while( ALWAYS(iLogsize>iLogsize) & 1 ){
       iBuddy = iBlock - size;
+      assert( iBuddy>=0 );
     }else{
       iBuddy = iBlock + size;
+      if( iBuddy>=mem5.nBlock ) break;
     }
-    assert( iBuddy>=0 );
-    if( (iBuddy+(1<mem5.nBlock ) break;
     if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
     memsys5Unlink(iBuddy, iLogsize);
     iLogsize++;
@@ -18658,13 +23096,11 @@ static void *memsys5Realloc(void *pPrior, int nBytes){
   if( nBytes<=nOld ){
     return pPrior;
   }
-  memsys5Enter();
-  p = memsys5MallocUnsafe(nBytes);
+  p = memsys5Malloc(nBytes);
   if( p ){
     memcpy(p, pPrior, nOld);
-    memsys5FreeUnsafe(pPrior);
+    memsys5Free(pPrior);
   }
-  memsys5Leave();
   return p;
 }
 
@@ -18851,6 +23287,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){
 **
 ** This file contains code that is common across all mutex implementations.
 */
+/* #include "sqliteInt.h" */
 
 #if defined(SQLITE_DEBUG) && !defined(SQLITE_MUTEX_OMIT)
 /*
@@ -18859,7 +23296,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){
 ** allocate a mutex while the system is uninitialized.
 */
 static SQLITE_WSD int mutexIsInit = 0;
-#endif /* SQLITE_DEBUG */
+#endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */
 
 
 #ifndef SQLITE_MUTEX_OMIT
@@ -18882,11 +23319,18 @@ SQLITE_PRIVATE int sqlite3MutexInit(void){
     }else{
       pFrom = sqlite3NoopMutex();
     }
-    memcpy(pTo, pFrom, offsetof(sqlite3_mutex_methods, xMutexAlloc));
-    memcpy(&pTo->xMutexFree, &pFrom->xMutexFree,
-           sizeof(*pTo) - offsetof(sqlite3_mutex_methods, xMutexFree));
+    pTo->xMutexInit = pFrom->xMutexInit;
+    pTo->xMutexEnd = pFrom->xMutexEnd;
+    pTo->xMutexFree = pFrom->xMutexFree;
+    pTo->xMutexEnter = pFrom->xMutexEnter;
+    pTo->xMutexTry = pFrom->xMutexTry;
+    pTo->xMutexLeave = pFrom->xMutexLeave;
+    pTo->xMutexHeld = pFrom->xMutexHeld;
+    pTo->xMutexNotheld = pFrom->xMutexNotheld;
+    sqlite3MemoryBarrier();
     pTo->xMutexAlloc = pFrom->xMutexAlloc;
   }
+  assert( sqlite3GlobalConfig.mutex.xMutexInit );
   rc = sqlite3GlobalConfig.mutex.xMutexInit();
 
 #ifdef SQLITE_DEBUG
@@ -18921,6 +23365,7 @@ SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int id){
   if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;
   if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;
 #endif
+  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
 }
 
@@ -18929,6 +23374,7 @@ SQLITE_PRIVATE sqlite3_mutex *sqlite3MutexAlloc(int id){
     return 0;
   }
   assert( GLOBAL(int, mutexIsInit) );
+  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
 }
 
@@ -18937,6 +23383,7 @@ SQLITE_PRIVATE sqlite3_mutex *sqlite3MutexAlloc(int id){
 */
 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexFree );
     sqlite3GlobalConfig.mutex.xMutexFree(p);
   }
 }
@@ -18947,6 +23394,7 @@ SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
 */
 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexEnter );
     sqlite3GlobalConfig.mutex.xMutexEnter(p);
   }
 }
@@ -18958,6 +23406,7 @@ SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
   int rc = SQLITE_OK;
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexTry );
     return sqlite3GlobalConfig.mutex.xMutexTry(p);
   }
   return rc;
@@ -18971,6 +23420,7 @@ SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
 */
 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexLeave );
     sqlite3GlobalConfig.mutex.xMutexLeave(p);
   }
 }
@@ -18981,9 +23431,11 @@ SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
 ** intended for use inside assert() statements.
 */
 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
+  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexHeld );
   return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);
 }
 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
+  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld );
   return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
 }
 #endif
@@ -19019,6 +23471,7 @@ SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
 ** that does error checking on mutexes to make sure they are being
 ** called correctly.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_MUTEX_OMIT
 
@@ -19100,7 +23553,7 @@ static int debugMutexEnd(void){ return SQLITE_OK; }
 ** that means that a mutex could not be allocated. 
 */
 static sqlite3_mutex *debugMutexAlloc(int id){
-  static sqlite3_debug_mutex aStatic[SQLITE_MUTEX_STATIC_APP3 - 1];
+  static sqlite3_debug_mutex aStatic[SQLITE_MUTEX_STATIC_VFS3 - 1];
   sqlite3_debug_mutex *pNew = 0;
   switch( id ){
     case SQLITE_MUTEX_FAST:
@@ -19113,8 +23566,12 @@ static sqlite3_mutex *debugMutexAlloc(int id){
       break;
     }
     default: {
-      assert( id-2 >= 0 );
-      assert( id-2 < (int)(sizeof(aStatic)/sizeof(aStatic[0])) );
+#ifdef SQLITE_ENABLE_API_ARMOR
+      if( id-2<0 || id-2>=ArraySize(aStatic) ){
+        (void)SQLITE_MISUSE_BKPT;
+        return 0;
+      }
+#endif
       pNew = &aStatic[id-2];
       pNew->id = id;
       break;
@@ -19129,8 +23586,13 @@ static sqlite3_mutex *debugMutexAlloc(int id){
 static void debugMutexFree(sqlite3_mutex *pX){
   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;
   assert( p->cnt==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-  sqlite3_free(p);
+  if( p->id==SQLITE_MUTEX_RECURSIVE || p->id==SQLITE_MUTEX_FAST ){
+    sqlite3_free(p);
+  }else{
+#ifdef SQLITE_ENABLE_API_ARMOR
+    (void)SQLITE_MISUSE_BKPT;
+#endif
+  }
 }
 
 /*
@@ -19213,6 +23675,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 *************************************************************************
 ** This file contains the C functions that implement mutexes for pthreads
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** The code in this file is only used if we are compiling threadsafe
@@ -19241,15 +23704,19 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 */
 struct sqlite3_mutex {
   pthread_mutex_t mutex;     /* Mutex controlling the lock */
-#if SQLITE_MUTEX_NREF
+#if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)
   int id;                    /* Mutex type */
+#endif
+#if SQLITE_MUTEX_NREF
   volatile int nRef;         /* Number of entrances */
   volatile pthread_t owner;  /* Thread that is within this mutex */
   int trace;                 /* True to trace changes */
 #endif
 };
 #if SQLITE_MUTEX_NREF
-#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0, 0 }
+#define SQLITE3_MUTEX_INITIALIZER {PTHREAD_MUTEX_INITIALIZER,0,0,(pthread_t)0,0}
+#elif defined(SQLITE_ENABLE_API_ARMOR)
+#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0 }
 #else
 #define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
 #endif
@@ -19279,6 +23746,19 @@ static int pthreadMutexNotheld(sqlite3_mutex *p){
 }
 #endif
 
+/*
+** Try to provide a memory barrier operation, needed for initialization
+** and also for the implementation of xShmBarrier in the VFS in cases
+** where SQLite is compiled without mutexes.
+*/
+SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
+#if defined(SQLITE_MEMORY_BARRIER)
+  SQLITE_MEMORY_BARRIER;
+#elif defined(__GNUC__) && GCC_VERSION>=4001000
+  __sync_synchronize();
+#endif
+}
+
 /*
 ** Initialize and deinitialize the mutex subsystem.
 */
@@ -19304,6 +23784,9 @@ static int pthreadMutexEnd(void){ return SQLITE_OK; }
 ** 
  •   SQLITE_MUTEX_STATIC_APP1
 ** 
  •   SQLITE_MUTEX_STATIC_APP2
 ** 
  •   SQLITE_MUTEX_STATIC_APP3
+** 
  •   SQLITE_MUTEX_STATIC_VFS1
+** 
  •   SQLITE_MUTEX_STATIC_VFS2
+** 
  •   SQLITE_MUTEX_STATIC_VFS3
 ** 
 **
 ** The first two constants cause sqlite3_mutex_alloc() to create
@@ -19332,6 +23815,9 @@ static int pthreadMutexEnd(void){ return SQLITE_OK; }
 */
 static sqlite3_mutex *pthreadMutexAlloc(int iType){
   static sqlite3_mutex staticMutexes[] = {
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER,
@@ -19358,9 +23844,6 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
         pthread_mutexattr_settype(&recursiveAttr, PTHREAD_MUTEX_RECURSIVE);
         pthread_mutex_init(&p->mutex, &recursiveAttr);
         pthread_mutexattr_destroy(&recursiveAttr);
-#endif
-#if SQLITE_MUTEX_NREF
-        p->id = iType;
 #endif
       }
       break;
@@ -19368,9 +23851,6 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
     case SQLITE_MUTEX_FAST: {
       p = sqlite3MallocZero( sizeof(*p) );
       if( p ){
-#if SQLITE_MUTEX_NREF
-        p->id = iType;
-#endif
         pthread_mutex_init(&p->mutex, 0);
       }
       break;
@@ -19383,12 +23863,12 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
       }
 #endif
       p = &staticMutexes[iType-2];
-#if SQLITE_MUTEX_NREF
-      p->id = iType;
-#endif
       break;
     }
   }
+#if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)
+  if( p ) p->id = iType;
+#endif
   return p;
 }
 
@@ -19400,9 +23880,18 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
 */
 static void pthreadMutexFree(sqlite3_mutex *p){
   assert( p->nRef==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-  pthread_mutex_destroy(&p->mutex);
-  sqlite3_free(p);
+#if SQLITE_ENABLE_API_ARMOR
+  if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE )
+#endif
+  {
+    pthread_mutex_destroy(&p->mutex);
+    sqlite3_free(p);
+  }
+#ifdef SQLITE_ENABLE_API_ARMOR
+  else{
+    (void)SQLITE_MISUSE_BKPT;
+  }
+#endif
 }
 
 /*
@@ -19576,6 +24065,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 *************************************************************************
 ** This file contains the C functions that implement mutexes for Win32.
 */
+/* #include "sqliteInt.h" */
 
 #if SQLITE_OS_WIN
 /*
@@ -19614,24 +24104,14 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
 /*
 ** Macros for performance tracing.  Normally turned off.  Only works
 ** on i486 hardware.
 */
 #ifdef SQLITE_PERFORMANCE_TRACE
 
-/* 
-** hwtime.h contains inline assembler code for implementing 
+/*
+** hwtime.h contains inline assembler code for implementing
 ** high-performance timing routines.
 */
 /************** Include hwtime.h in the middle of os_common.h ****************/
@@ -19651,8 +24131,8 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -19720,7 +24200,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in os_common.h ******************/
@@ -19741,14 +24221,14 @@ static sqlite_uint64 g_elapsed;
 ** of code will give us the ability to simulate a disk I/O error.  This
 ** is used for testing the I/O recovery logic.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
 #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
 #define SimulateIOError(CODE)  \
   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
@@ -19774,17 +24254,17 @@ static void local_ioerr(){
 #define SimulateIOErrorBenign(X)
 #define SimulateIOError(A)
 #define SimulateDiskfullError(A)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** When testing, keep a count of the number of open files.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
 #define OpenCounter(X)  sqlite3_open_file_count+=(X)
 #else
 #define OpenCounter(X)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 #endif /* !defined(_OS_COMMON_H_) */
 
@@ -19810,8 +24290,8 @@ SQLITE_API int sqlite3_open_file_count = 0;
 **
 ** This file contains code that is specific to Windows.
 */
-#ifndef _OS_WIN_H_
-#define _OS_WIN_H_
+#ifndef SQLITE_OS_WIN_H
+#define SQLITE_OS_WIN_H
 
 /*
 ** Include the primary Windows SDK header file.
@@ -19872,7 +24352,18 @@ SQLITE_API int sqlite3_open_file_count = 0;
 # define SQLITE_WIN32_VOLATILE volatile
 #endif
 
-#endif /* _OS_WIN_H_ */
+/*
+** For some Windows sub-platforms, the _beginthreadex() / _endthreadex()
+** functions are not available (e.g. those not using MSVC, Cygwin, etc).
+*/
+#if SQLITE_OS_WIN && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
+    SQLITE_THREADSAFE>0 && !defined(__CYGWIN__)
+# define SQLITE_OS_WIN_THREADS 1
+#else
+# define SQLITE_OS_WIN_THREADS 0
+#endif
+
+#endif /* SQLITE_OS_WIN_H */
 
 /************** End of os_win.h **********************************************/
 /************** Continuing where we left off in mutex_w32.c ******************/
@@ -19930,10 +24421,30 @@ static int winMutexNotheld(sqlite3_mutex *p){
 }
 #endif
 
+/*
+** Try to provide a memory barrier operation, needed for initialization
+** and also for the xShmBarrier method of the VFS in cases when SQLite is
+** compiled without mutexes (SQLITE_THREADSAFE=0).
+*/
+SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
+#if defined(SQLITE_MEMORY_BARRIER)
+  SQLITE_MEMORY_BARRIER;
+#elif defined(__GNUC__)
+  __sync_synchronize();
+#elif MSVC_VERSION>=1300
+  _ReadWriteBarrier();
+#elif defined(MemoryBarrier)
+  MemoryBarrier();
+#endif
+}
+
 /*
 ** Initialize and deinitialize the mutex subsystem.
 */
 static sqlite3_mutex winMutex_staticMutexes[] = {
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
@@ -20013,6 +24524,9 @@ static int winMutexEnd(void){
 ** 
  •   SQLITE_MUTEX_STATIC_APP1
 ** 
  •   SQLITE_MUTEX_STATIC_APP2
 ** 
  •   SQLITE_MUTEX_STATIC_APP3
+** 
  •   SQLITE_MUTEX_STATIC_VFS1
+** 
  •   SQLITE_MUTEX_STATIC_VFS2
+** 
  •   SQLITE_MUTEX_STATIC_VFS3
 ** 
 **
 ** The first two constants cause sqlite3_mutex_alloc() to create
@@ -20047,8 +24561,8 @@ static sqlite3_mutex *winMutexAlloc(int iType){
     case SQLITE_MUTEX_RECURSIVE: {
       p = sqlite3MallocZero( sizeof(*p) );
       if( p ){
-#ifdef SQLITE_DEBUG
         p->id = iType;
+#ifdef SQLITE_DEBUG
 #ifdef SQLITE_WIN32_MUTEX_TRACE_DYNAMIC
         p->trace = 1;
 #endif
@@ -20068,12 +24582,9 @@ static sqlite3_mutex *winMutexAlloc(int iType){
         return 0;
       }
 #endif
-      assert( iType-2 >= 0 );
-      assert( iType-2 < ArraySize(winMutex_staticMutexes) );
-      assert( winMutex_isInit==1 );
       p = &winMutex_staticMutexes[iType-2];
-#ifdef SQLITE_DEBUG
       p->id = iType;
+#ifdef SQLITE_DEBUG
 #ifdef SQLITE_WIN32_MUTEX_TRACE_STATIC
       p->trace = 1;
 #endif
@@ -20092,13 +24603,15 @@ static sqlite3_mutex *winMutexAlloc(int iType){
 */
 static void winMutexFree(sqlite3_mutex *p){
   assert( p );
-#ifdef SQLITE_DEBUG
   assert( p->nRef==0 && p->owner==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ){
+    DeleteCriticalSection(&p->mutex);
+    sqlite3_free(p);
+  }else{
+#ifdef SQLITE_ENABLE_API_ARMOR
+    (void)SQLITE_MISUSE_BKPT;
 #endif
-  assert( winMutex_isInit==1 );
-  DeleteCriticalSection(&p->mutex);
-  sqlite3_free(p);
+  }
 }
 
 /*
@@ -20129,8 +24642,8 @@ static void winMutexEnter(sqlite3_mutex *p){
   p->owner = tid;
   p->nRef++;
   if( p->trace ){
-    OSTRACE(("ENTER-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n",
-             tid, p, p->trace, p->nRef));
+    OSTRACE(("ENTER-MUTEX tid=%lu, mutex(%d)=%p (%d), nRef=%d\n",
+             tid, p->id, p, p->trace, p->nRef));
   }
 #endif
 }
@@ -20172,8 +24685,8 @@ static int winMutexTry(sqlite3_mutex *p){
 #endif
 #ifdef SQLITE_DEBUG
   if( p->trace ){
-    OSTRACE(("TRY-MUTEX tid=%lu, mutex=%p (%d), owner=%lu, nRef=%d, rc=%s\n",
-             tid, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc)));
+    OSTRACE(("TRY-MUTEX tid=%lu, mutex(%d)=%p (%d), owner=%lu, nRef=%d, rc=%s\n",
+             tid, p->id, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc)));
   }
 #endif
   return rc;
@@ -20201,8 +24714,8 @@ static void winMutexLeave(sqlite3_mutex *p){
   LeaveCriticalSection(&p->mutex);
 #ifdef SQLITE_DEBUG
   if( p->trace ){
-    OSTRACE(("LEAVE-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n",
-             tid, p, p->trace, p->nRef));
+    OSTRACE(("LEAVE-MUTEX tid=%lu, mutex(%d)=%p (%d), nRef=%d\n",
+             tid, p->id, p, p->trace, p->nRef));
   }
 #endif
 }
@@ -20245,6 +24758,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 **
 ** Memory allocation functions used throughout sqlite.
 */
+/* #include "sqliteInt.h" */
 /* #include  */
 
 /*
@@ -20277,16 +24791,7 @@ typedef struct ScratchFreeslot {
 */
 static SQLITE_WSD struct Mem0Global {
   sqlite3_mutex *mutex;         /* Mutex to serialize access */
-
-  /*
-  ** The alarm callback and its arguments.  The mem0.mutex lock will
-  ** be held while the callback is running.  Recursive calls into
-  ** the memory subsystem are allowed, but no new callbacks will be
-  ** issued.
-  */
-  sqlite3_int64 alarmThreshold;
-  void (*alarmCallback)(void*, sqlite3_int64,int);
-  void *alarmArg;
+  sqlite3_int64 alarmThreshold; /* The soft heap limit */
 
   /*
   ** Pointers to the end of sqlite3GlobalConfig.pScratch memory
@@ -20303,54 +24808,32 @@ static SQLITE_WSD struct Mem0Global {
   ** sqlite3_soft_heap_limit() setting.
   */
   int nearlyFull;
-} mem0 = { 0, 0, 0, 0, 0, 0, 0, 0 };
+} mem0 = { 0, 0, 0, 0, 0, 0 };
 
 #define mem0 GLOBAL(struct Mem0Global, mem0)
 
 /*
-** This routine runs when the memory allocator sees that the
-** total memory allocation is about to exceed the soft heap
-** limit.
-*/
-static void softHeapLimitEnforcer(
-  void *NotUsed, 
-  sqlite3_int64 NotUsed2,
-  int allocSize
-){
-  UNUSED_PARAMETER2(NotUsed, NotUsed2);
-  sqlite3_release_memory(allocSize);
-}
-
-/*
-** Change the alarm callback
+** Return the memory allocator mutex. sqlite3_status() needs it.
 */
-static int sqlite3MemoryAlarm(
-  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
-  void *pArg,
-  sqlite3_int64 iThreshold
-){
-  int nUsed;
-  sqlite3_mutex_enter(mem0.mutex);
-  mem0.alarmCallback = xCallback;
-  mem0.alarmArg = pArg;
-  mem0.alarmThreshold = iThreshold;
-  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
-  mem0.nearlyFull = (iThreshold>0 && iThreshold<=nUsed);
-  sqlite3_mutex_leave(mem0.mutex);
-  return SQLITE_OK;
+SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void){
+  return mem0.mutex;
 }
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
-** Deprecated external interface.  Internal/core SQLite code
-** should call sqlite3MemoryAlarm.
+** Deprecated external interface.  It used to set an alarm callback
+** that was invoked when memory usage grew too large.  Now it is a
+** no-op.
 */
 SQLITE_API int sqlite3_memory_alarm(
   void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
   void *pArg,
   sqlite3_int64 iThreshold
 ){
-  return sqlite3MemoryAlarm(xCallback, pArg, iThreshold);
+  (void)xCallback;
+  (void)pArg;
+  (void)iThreshold;
+  return SQLITE_OK;
 }
 #endif
 
@@ -20361,19 +24844,21 @@ SQLITE_API int sqlite3_memory_alarm(
 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){
   sqlite3_int64 priorLimit;
   sqlite3_int64 excess;
+  sqlite3_int64 nUsed;
 #ifndef SQLITE_OMIT_AUTOINIT
   int rc = sqlite3_initialize();
   if( rc ) return -1;
 #endif
   sqlite3_mutex_enter(mem0.mutex);
   priorLimit = mem0.alarmThreshold;
-  sqlite3_mutex_leave(mem0.mutex);
-  if( n<0 ) return priorLimit;
-  if( n>0 ){
-    sqlite3MemoryAlarm(softHeapLimitEnforcer, 0, n);
-  }else{
-    sqlite3MemoryAlarm(0, 0, 0);
+  if( n<0 ){
+    sqlite3_mutex_leave(mem0.mutex);
+    return priorLimit;
   }
+  mem0.alarmThreshold = n;
+  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+  mem0.nearlyFull = (n>0 && n<=nUsed);
+  sqlite3_mutex_leave(mem0.mutex);
   excess = sqlite3_memory_used() - n;
   if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff));
   return priorLimit;
@@ -20387,13 +24872,12 @@ SQLITE_API void sqlite3_soft_heap_limit(int n){
 ** Initialize the memory allocation subsystem.
 */
 SQLITE_PRIVATE int sqlite3MallocInit(void){
+  int rc;
   if( sqlite3GlobalConfig.m.xMalloc==0 ){
     sqlite3MemSetDefault();
   }
   memset(&mem0, 0, sizeof(mem0));
-  if( sqlite3GlobalConfig.bCoreMutex ){
-    mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
-  }
+  mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
   if( sqlite3GlobalConfig.pScratch && sqlite3GlobalConfig.szScratch>=100
       && sqlite3GlobalConfig.nScratch>0 ){
     int i, n, sz;
@@ -20417,12 +24901,13 @@ SQLITE_PRIVATE int sqlite3MallocInit(void){
     sqlite3GlobalConfig.nScratch = 0;
   }
   if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512
-      || sqlite3GlobalConfig.nPage<1 ){
+      || sqlite3GlobalConfig.nPage<=0 ){
     sqlite3GlobalConfig.pPage = 0;
     sqlite3GlobalConfig.szPage = 0;
-    sqlite3GlobalConfig.nPage = 0;
   }
-  return sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);
+  rc = sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);
+  if( rc!=SQLITE_OK ) memset(&mem0, 0, sizeof(mem0));
+  return rc;
 }
 
 /*
@@ -20448,10 +24933,8 @@ SQLITE_PRIVATE void sqlite3MallocEnd(void){
 ** Return the amount of memory currently checked out.
 */
 SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
-  int n, mx;
-  sqlite3_int64 res;
-  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, 0);
-  res = (sqlite3_int64)n;  /* Work around bug in Borland C. Ticket #3216 */
+  sqlite3_int64 res, mx;
+  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, 0);
   return res;
 }
 
@@ -20461,44 +24944,48 @@ SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
 ** or since the most recent reset.
 */
 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
-  int n, mx;
-  sqlite3_int64 res;
-  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, resetFlag);
-  res = (sqlite3_int64)mx;  /* Work around bug in Borland C. Ticket #3216 */
-  return res;
+  sqlite3_int64 res, mx;
+  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag);
+  return mx;
 }
 
 /*
 ** Trigger the alarm 
 */
 static void sqlite3MallocAlarm(int nByte){
-  void (*xCallback)(void*,sqlite3_int64,int);
-  sqlite3_int64 nowUsed;
-  void *pArg;
-  if( mem0.alarmCallback==0 ) return;
-  xCallback = mem0.alarmCallback;
-  nowUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
-  pArg = mem0.alarmArg;
-  mem0.alarmCallback = 0;
+  if( mem0.alarmThreshold<=0 ) return;
   sqlite3_mutex_leave(mem0.mutex);
-  xCallback(pArg, nowUsed, nByte);
+  sqlite3_release_memory(nByte);
   sqlite3_mutex_enter(mem0.mutex);
-  mem0.alarmCallback = xCallback;
-  mem0.alarmArg = pArg;
 }
 
 /*
 ** Do a memory allocation with statistics and alarms.  Assume the
 ** lock is already held.
 */
-static int mallocWithAlarm(int n, void **pp){
-  int nFull;
+static void mallocWithAlarm(int n, void **pp){
   void *p;
+  int nFull;
   assert( sqlite3_mutex_held(mem0.mutex) );
+  assert( n>0 );
+
+  /* In Firefox (circa 2017-02-08), xRoundup() is remapped to an internal
+  ** implementation of malloc_good_size(), which must be called in debug
+  ** mode and specifically when the DMD "Dark Matter Detector" is enabled
+  ** or else a crash results.  Hence, do not attempt to optimize out the
+  ** following xRoundup() call. */
   nFull = sqlite3GlobalConfig.m.xRoundup(n);
-  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
-  if( mem0.alarmCallback!=0 ){
-    int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+
+#ifdef SQLITE_MAX_MEMORY
+  if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)+nFull>SQLITE_MAX_MEMORY ){
+    *pp = 0;
+    return;
+  }
+#endif
+
+  sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n);
+  if( mem0.alarmThreshold>0 ){
+    sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
     if( nUsed >= mem0.alarmThreshold - nFull ){
       mem0.nearlyFull = 1;
       sqlite3MallocAlarm(nFull);
@@ -20508,18 +24995,17 @@ static int mallocWithAlarm(int n, void **pp){
   }
   p = sqlite3GlobalConfig.m.xMalloc(nFull);
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
-  if( p==0 && mem0.alarmCallback ){
+  if( p==0 && mem0.alarmThreshold>0 ){
     sqlite3MallocAlarm(nFull);
     p = sqlite3GlobalConfig.m.xMalloc(nFull);
   }
 #endif
   if( p ){
     nFull = sqlite3MallocSize(p);
-    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull);
-    sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, 1);
+    sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);
+    sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);
   }
   *pp = p;
-  return nFull;
 }
 
 /*
@@ -20588,19 +25074,19 @@ SQLITE_PRIVATE void *sqlite3ScratchMalloc(int n){
   assert( n>0 );
 
   sqlite3_mutex_enter(mem0.mutex);
-  sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+  sqlite3StatusHighwater(SQLITE_STATUS_SCRATCH_SIZE, n);
   if( mem0.nScratchFree && sqlite3GlobalConfig.szScratch>=n ){
     p = mem0.pScratchFree;
     mem0.pScratchFree = mem0.pScratchFree->pNext;
     mem0.nScratchFree--;
-    sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
+    sqlite3StatusUp(SQLITE_STATUS_SCRATCH_USED, 1);
     sqlite3_mutex_leave(mem0.mutex);
   }else{
     sqlite3_mutex_leave(mem0.mutex);
     p = sqlite3Malloc(n);
     if( sqlite3GlobalConfig.bMemstat && p ){
       sqlite3_mutex_enter(mem0.mutex);
-      sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, sqlite3MallocSize(p));
+      sqlite3StatusUp(SQLITE_STATUS_SCRATCH_OVERFLOW, sqlite3MallocSize(p));
       sqlite3_mutex_leave(mem0.mutex);
     }
     sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
@@ -20632,7 +25118,7 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void *p){
     scratchAllocOut--;
 #endif
 
-    if( p>=sqlite3GlobalConfig.pScratch && p=db->lookaside.pStart && plookaside.pEnd;
+  return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pEnd);
 }
 #else
 #define isLookaside(A,B) 0
@@ -20683,25 +25169,27 @@ SQLITE_PRIVATE int sqlite3MallocSize(void *p){
   return sqlite3GlobalConfig.m.xSize(p);
 }
 SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3 *db, void *p){
-  if( db==0 ){
-    assert( sqlite3MemdebugNoType(p, ~MEMTYPE_HEAP) );
-    assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
-    return sqlite3MallocSize(p);
-  }else{
-    assert( sqlite3_mutex_held(db->mutex) );
-    if( isLookaside(db, p) ){
-      return db->lookaside.sz;
+  assert( p!=0 );
+  if( db==0 || !isLookaside(db,p) ){
+#ifdef SQLITE_DEBUG
+    if( db==0 ){
+      assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
+      assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
     }else{
       assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
-      assert( sqlite3MemdebugNoType(p, ~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
-      return sqlite3GlobalConfig.m.xSize(p);
+      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
     }
+#endif
+    return sqlite3GlobalConfig.m.xSize(p);
+  }else{
+    assert( sqlite3_mutex_held(db->mutex) );
+    return db->lookaside.sz;
   }
 }
 SQLITE_API sqlite3_uint64 sqlite3_msize(void *p){
-  assert( sqlite3MemdebugNoType(p, ~MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
-  return (sqlite3_uint64)sqlite3GlobalConfig.m.xSize(p);
+  return p ? sqlite3GlobalConfig.m.xSize(p) : 0;
 }
 
 /*
@@ -20710,11 +25198,11 @@ SQLITE_API sqlite3_uint64 sqlite3_msize(void *p){
 SQLITE_API void sqlite3_free(void *p){
   if( p==0 ) return;  /* IMP: R-49053-54554 */
   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
-  assert( sqlite3MemdebugNoType(p, ~MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
   if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
-    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -sqlite3MallocSize(p));
-    sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, -1);
+    sqlite3StatusDown(SQLITE_STATUS_MEMORY_USED, sqlite3MallocSize(p));
+    sqlite3StatusDown(SQLITE_STATUS_MALLOC_COUNT, 1);
     sqlite3GlobalConfig.m.xFree(p);
     sqlite3_mutex_leave(mem0.mutex);
   }else{
@@ -20732,11 +25220,12 @@ static SQLITE_NOINLINE void measureAllocationSize(sqlite3 *db, void *p){
 
 /*
 ** Free memory that might be associated with a particular database
-** connection.
+** connection.  Calling sqlite3DbFree(D,X) for X==0 is a harmless no-op.
+** The sqlite3DbFreeNN(D,X) version requires that X be non-NULL.
 */
-SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
+SQLITE_PRIVATE void sqlite3DbFreeNN(sqlite3 *db, void *p){
   assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  if( p==0 ) return;
+  assert( p!=0 );
   if( db ){
     if( db->pnBytesFreed ){
       measureAllocationSize(db, p);
@@ -20744,7 +25233,7 @@ SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
     }
     if( isLookaside(db, p) ){
       LookasideSlot *pBuf = (LookasideSlot*)p;
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
       /* Trash all content in the buffer being freed */
       memset(p, 0xaa, db->lookaside.sz);
 #endif
@@ -20755,11 +25244,15 @@ SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
     }
   }
   assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
-  assert( sqlite3MemdebugNoType(p, ~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+  assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
   assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
   sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
   sqlite3_free(p);
 }
+SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
+  assert( db==0 || sqlite3_mutex_held(db->mutex) );
+  if( p ) sqlite3DbFreeNN(db, p);
+}
 
 /*
 ** Change the size of an existing memory allocation
@@ -20768,7 +25261,7 @@ SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, u64 nBytes){
   int nOld, nNew, nDiff;
   void *pNew;
   assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) );
-  assert( sqlite3MemdebugNoType(pOld, ~MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugNoType(pOld, (u8)~MEMTYPE_HEAP) );
   if( pOld==0 ){
     return sqlite3Malloc(nBytes); /* IMP: R-04300-56712 */
   }
@@ -20789,20 +25282,20 @@ SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, u64 nBytes){
     pNew = pOld;
   }else if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
-    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
+    sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
     nDiff = nNew - nOld;
-    if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
+    if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
           mem0.alarmThreshold-nDiff ){
       sqlite3MallocAlarm(nDiff);
     }
     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
-    if( pNew==0 && mem0.alarmCallback ){
+    if( pNew==0 && mem0.alarmThreshold>0 ){
       sqlite3MallocAlarm((int)nBytes);
       pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
     }
     if( pNew ){
       nNew = sqlite3MallocSize(pNew);
-      sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
+      sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
     }
     sqlite3_mutex_leave(mem0.mutex);
   }else{
@@ -20847,16 +25340,31 @@ SQLITE_PRIVATE void *sqlite3MallocZero(u64 n){
 ** the mallocFailed flag in the connection pointer.
 */
 SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, u64 n){
-  void *p = sqlite3DbMallocRaw(db, n);
-  if( p ){
-    memset(p, 0, (size_t)n);
-  }
+  void *p;
+  testcase( db==0 );
+  p = sqlite3DbMallocRaw(db, n);
+  if( p ) memset(p, 0, (size_t)n);
+  return p;
+}
+
+
+/* Finish the work of sqlite3DbMallocRawNN for the unusual and
+** slower case when the allocation cannot be fulfilled using lookaside.
+*/
+static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){
+  void *p;
+  assert( db!=0 );
+  p = sqlite3Malloc(n);
+  if( !p ) sqlite3OomFault(db);
+  sqlite3MemdebugSetType(p, 
+         (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
   return p;
 }
 
 /*
-** Allocate and zero memory.  If the allocation fails, make
-** the mallocFailed flag in the connection pointer.
+** Allocate memory, either lookaside (if possible) or heap.  
+** If the allocation fails, set the mallocFailed flag in
+** the connection pointer.
 **
 ** If db!=0 and db->mallocFailed is true (indicating a prior malloc
 ** failure on the same database connection) then always return 0.
@@ -20871,78 +25379,87 @@ SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, u64 n){
 **
 ** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
 ** that all prior mallocs (ex: "a") worked too.
+**
+** The sqlite3MallocRawNN() variant guarantees that the "db" parameter is
+** not a NULL pointer.
 */
 SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){
   void *p;
-  assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  assert( db==0 || db->pnBytesFreed==0 );
+  if( db ) return sqlite3DbMallocRawNN(db, n);
+  p = sqlite3Malloc(n);
+  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
+  return p;
+}
+SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
 #ifndef SQLITE_OMIT_LOOKASIDE
-  if( db ){
-    LookasideSlot *pBuf;
-    if( db->mallocFailed ){
-      return 0;
-    }
-    if( db->lookaside.bEnabled ){
-      if( n>db->lookaside.sz ){
-        db->lookaside.anStat[1]++;
-      }else if( (pBuf = db->lookaside.pFree)==0 ){
-        db->lookaside.anStat[2]++;
-      }else{
-        db->lookaside.pFree = pBuf->pNext;
-        db->lookaside.nOut++;
-        db->lookaside.anStat[0]++;
-        if( db->lookaside.nOut>db->lookaside.mxOut ){
-          db->lookaside.mxOut = db->lookaside.nOut;
-        }
-        return (void*)pBuf;
+  LookasideSlot *pBuf;
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->lookaside.bDisable==0 ){
+    assert( db->mallocFailed==0 );
+    if( n>db->lookaside.sz ){
+      db->lookaside.anStat[1]++;
+    }else if( (pBuf = db->lookaside.pFree)==0 ){
+      db->lookaside.anStat[2]++;
+    }else{
+      db->lookaside.pFree = pBuf->pNext;
+      db->lookaside.nOut++;
+      db->lookaside.anStat[0]++;
+      if( db->lookaside.nOut>db->lookaside.mxOut ){
+        db->lookaside.mxOut = db->lookaside.nOut;
       }
+      return (void*)pBuf;
     }
+  }else if( db->mallocFailed ){
+    return 0;
   }
 #else
-  if( db && db->mallocFailed ){
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->mallocFailed ){
     return 0;
   }
 #endif
-  p = sqlite3Malloc(n);
-  if( !p && db ){
-    db->mallocFailed = 1;
-  }
-  sqlite3MemdebugSetType(p, 
-         (db && db->lookaside.bEnabled) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
-  return p;
+  return dbMallocRawFinish(db, n);
 }
 
+/* Forward declaration */
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n);
+
 /*
 ** Resize the block of memory pointed to by p to n bytes. If the
 ** resize fails, set the mallocFailed flag in the connection object.
 */
 SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
-  void *pNew = 0;
   assert( db!=0 );
+  if( p==0 ) return sqlite3DbMallocRawNN(db, n);
   assert( sqlite3_mutex_held(db->mutex) );
+  if( isLookaside(db,p) && n<=db->lookaside.sz ) return p;
+  return dbReallocFinish(db, p, n);
+}
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
+  void *pNew = 0;
+  assert( db!=0 );
+  assert( p!=0 );
   if( db->mallocFailed==0 ){
-    if( p==0 ){
-      return sqlite3DbMallocRaw(db, n);
-    }
     if( isLookaside(db, p) ){
-      if( n<=db->lookaside.sz ){
-        return p;
-      }
-      pNew = sqlite3DbMallocRaw(db, n);
+      pNew = sqlite3DbMallocRawNN(db, n);
       if( pNew ){
         memcpy(pNew, p, db->lookaside.sz);
         sqlite3DbFree(db, p);
       }
     }else{
       assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
-      assert( sqlite3MemdebugNoType(p, ~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
       sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
       pNew = sqlite3_realloc64(p, n);
       if( !pNew ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
       sqlite3MemdebugSetType(pNew,
-            (db->lookaside.bEnabled ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
+            (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
     }
   }
   return pNew;
@@ -20974,9 +25491,8 @@ SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3 *db, const char *z){
   if( z==0 ){
     return 0;
   }
-  n = sqlite3Strlen30(z) + 1;
-  assert( (n&0x7fffffff)==n );
-  zNew = sqlite3DbMallocRaw(db, (int)n);
+  n = strlen(z) + 1;
+  zNew = sqlite3DbMallocRaw(db, n);
   if( zNew ){
     memcpy(zNew, z, n);
   }
@@ -20984,11 +25500,12 @@ SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3 *db, const char *z){
 }
 SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
   char *zNew;
+  assert( db!=0 );
   if( z==0 ){
     return 0;
   }
   assert( (n&0x7fffffff)==n );
-  zNew = sqlite3DbMallocRaw(db, n+1);
+  zNew = sqlite3DbMallocRawNN(db, n+1);
   if( zNew ){
     memcpy(zNew, z, (size_t)n);
     zNew[n] = 0;
@@ -20997,28 +25514,52 @@ SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
 }
 
 /*
-** Create a string from the zFromat argument and the va_list that follows.
-** Store the string in memory obtained from sqliteMalloc() and make *pz
-** point to that string.
+** Free any prior content in *pz and replace it with a copy of zNew.
 */
-SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zFormat, ...){
-  va_list ap;
-  char *z;
-
-  va_start(ap, zFormat);
-  z = sqlite3VMPrintf(db, zFormat, ap);
-  va_end(ap);
+SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
   sqlite3DbFree(db, *pz);
-  *pz = z;
+  *pz = sqlite3DbStrDup(db, zNew);
+}
+
+/*
+** Call this routine to record the fact that an OOM (out-of-memory) error
+** has happened.  This routine will set db->mallocFailed, and also
+** temporarily disable the lookaside memory allocator and interrupt
+** any running VDBEs.
+*/
+SQLITE_PRIVATE void sqlite3OomFault(sqlite3 *db){
+  if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
+    db->mallocFailed = 1;
+    if( db->nVdbeExec>0 ){
+      db->u1.isInterrupted = 1;
+    }
+    db->lookaside.bDisable++;
+  }
+}
+
+/*
+** This routine reactivates the memory allocator and clears the
+** db->mallocFailed flag as necessary.
+**
+** The memory allocator is not restarted if there are running
+** VDBEs.
+*/
+SQLITE_PRIVATE void sqlite3OomClear(sqlite3 *db){
+  if( db->mallocFailed && db->nVdbeExec==0 ){
+    db->mallocFailed = 0;
+    db->u1.isInterrupted = 0;
+    assert( db->lookaside.bDisable>0 );
+    db->lookaside.bDisable--;
+  }
 }
 
 /*
 ** Take actions at the end of an API call to indicate an OOM error
 */
 static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
-  db->mallocFailed = 0;
+  sqlite3OomClear(db);
   sqlite3Error(db, SQLITE_NOMEM);
-  return SQLITE_NOMEM;
+  return SQLITE_NOMEM_BKPT;
 }
 
 /*
@@ -21030,17 +25571,16 @@ static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
 ** function. However, if a malloc() failure has occurred since the previous
 ** invocation SQLITE_NOMEM is returned instead. 
 **
-** If the first argument, db, is not NULL and a malloc() error has occurred,
-** then the connection error-code (the value returned by sqlite3_errcode())
-** is set to SQLITE_NOMEM.
+** If an OOM as occurred, then the connection error-code (the value
+** returned by sqlite3_errcode()) is set to SQLITE_NOMEM.
 */
 SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){
-  /* If the db handle is not NULL, then we must hold the connection handle
-  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
+  /* If the db handle must hold the connection handle mutex here.
+  ** Otherwise the read (and possible write) of db->mallocFailed 
   ** is unsafe, as is the call to sqlite3Error().
   */
-  assert( !db || sqlite3_mutex_held(db->mutex) );
-  if( db==0 ) return rc & 0xff;
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
   if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
     return apiOomError(db);
   }
@@ -21051,43 +25591,42 @@ SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){
 /************** Begin file printf.c ******************************************/
 /*
 ** The "printf" code that follows dates from the 1980's.  It is in
-** the public domain.  The original comments are included here for
-** completeness.  They are very out-of-date but might be useful as
-** an historical reference.  Most of the "enhancements" have been backed
-** out so that the functionality is now the same as standard printf().
+** the public domain. 
 **
 **************************************************************************
 **
 ** This file contains code for a set of "printf"-like routines.  These
 ** routines format strings much like the printf() from the standard C
 ** library, though the implementation here has enhancements to support
-** SQLlite.
+** SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Conversion types fall into various categories as defined by the
 ** following enumeration.
 */
-#define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
-#define etFLOAT       2 /* Floating point.  %f */
-#define etEXP         3 /* Exponentional notation. %e and %E */
-#define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
-#define etSIZE        5 /* Return number of characters processed so far. %n */
-#define etSTRING      6 /* Strings. %s */
-#define etDYNSTRING   7 /* Dynamically allocated strings. %z */
-#define etPERCENT     8 /* Percent symbol. %% */
-#define etCHARX       9 /* Characters. %c */
+#define etRADIX       0 /* non-decimal integer types.  %x %o */
+#define etFLOAT       1 /* Floating point.  %f */
+#define etEXP         2 /* Exponentional notation. %e and %E */
+#define etGENERIC     3 /* Floating or exponential, depending on exponent. %g */
+#define etSIZE        4 /* Return number of characters processed so far. %n */
+#define etSTRING      5 /* Strings. %s */
+#define etDYNSTRING   6 /* Dynamically allocated strings. %z */
+#define etPERCENT     7 /* Percent symbol. %% */
+#define etCHARX       8 /* Characters. %c */
 /* The rest are extensions, not normally found in printf() */
-#define etSQLESCAPE  10 /* Strings with '\'' doubled.  %q */
-#define etSQLESCAPE2 11 /* Strings with '\'' doubled and enclosed in '',
+#define etSQLESCAPE   9 /* Strings with '\'' doubled.  %q */
+#define etSQLESCAPE2 10 /* Strings with '\'' doubled and enclosed in '',
                           NULL pointers replaced by SQL NULL.  %Q */
-#define etTOKEN      12 /* a pointer to a Token structure */
-#define etSRCLIST    13 /* a pointer to a SrcList */
-#define etPOINTER    14 /* The %p conversion */
-#define etSQLESCAPE3 15 /* %w -> Strings with '\"' doubled */
-#define etORDINAL    16 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
+#define etTOKEN      11 /* a pointer to a Token structure */
+#define etSRCLIST    12 /* a pointer to a SrcList */
+#define etPOINTER    13 /* The %p conversion */
+#define etSQLESCAPE3 14 /* %w -> Strings with '\"' doubled */
+#define etORDINAL    15 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
+#define etDECIMAL    16 /* %d or %u, but not %x, %o */
 
-#define etINVALID     0 /* Any unrecognized conversion type */
+#define etINVALID    17 /* Any unrecognized conversion type */
 
 
 /*
@@ -21111,9 +25650,8 @@ typedef struct et_info {   /* Information about each format field */
 /*
 ** Allowed values for et_info.flags
 */
-#define FLAG_SIGNED  1     /* True if the value to convert is signed */
-#define FLAG_INTERN  2     /* True if for internal use only */
-#define FLAG_STRING  4     /* Allow infinity precision */
+#define FLAG_SIGNED    1     /* True if the value to convert is signed */
+#define FLAG_STRING    4     /* Allow infinite precision */
 
 
 /*
@@ -21123,7 +25661,7 @@ typedef struct et_info {   /* Information about each format field */
 static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
 static const char aPrefix[] = "-x0\000X0";
 static const et_info fmtinfo[] = {
-  {  'd', 10, 1, etRADIX,      0,  0 },
+  {  'd', 10, 1, etDECIMAL,    0,  0 },
   {  's',  0, 4, etSTRING,     0,  0 },
   {  'g',  0, 1, etGENERIC,    30, 0 },
   {  'z',  0, 4, etDYNSTRING,  0,  0 },
@@ -21132,7 +25670,7 @@ static const et_info fmtinfo[] = {
   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
   {  'c',  0, 0, etCHARX,      0,  0 },
   {  'o',  8, 0, etRADIX,      0,  2 },
-  {  'u', 10, 0, etRADIX,      0,  0 },
+  {  'u', 10, 0, etDECIMAL,    0,  0 },
   {  'x', 16, 0, etRADIX,      16, 1 },
   {  'X', 16, 0, etRADIX,      0,  4 },
 #ifndef SQLITE_OMIT_FLOATING_POINT
@@ -21141,16 +25679,15 @@ static const et_info fmtinfo[] = {
   {  'E',  0, 1, etEXP,        14, 0 },
   {  'G',  0, 1, etGENERIC,    14, 0 },
 #endif
-  {  'i', 10, 1, etRADIX,      0,  0 },
+  {  'i', 10, 1, etDECIMAL,    0,  0 },
   {  'n',  0, 0, etSIZE,       0,  0 },
   {  '%',  0, 0, etPERCENT,    0,  0 },
   {  'p', 16, 0, etPOINTER,    0,  1 },
 
-/* All the rest have the FLAG_INTERN bit set and are thus for internal
-** use only */
-  {  'T',  0, 2, etTOKEN,      0,  0 },
-  {  'S',  0, 2, etSRCLIST,    0,  0 },
-  {  'r', 10, 3, etORDINAL,    0,  0 },
+  /* All the rest are undocumented and are for internal use only */
+  {  'T',  0, 0, etTOKEN,      0,  0 },
+  {  'S',  0, 0, etSRCLIST,    0,  0 },
+  {  'r', 10, 1, etORDINAL,    0,  0 },
 };
 
 /*
@@ -21188,6 +25725,7 @@ static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
 ** Set the StrAccum object to an error mode.
 */
 static void setStrAccumError(StrAccum *p, u8 eError){
+  assert( eError==STRACCUM_NOMEM || eError==STRACCUM_TOOBIG );
   p->accError = eError;
   p->nAlloc = 0;
 }
@@ -21223,7 +25761,6 @@ static char *getTextArg(PrintfArguments *p){
 */
 SQLITE_PRIVATE void sqlite3VXPrintf(
   StrAccum *pAccum,          /* Accumulate results here */
-  u32 bFlags,                /* SQLITE_PRINTF_* flags */
   const char *fmt,           /* Format string */
   va_list ap                 /* arguments */
 ){
@@ -21234,17 +25771,15 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
   int idx;                   /* A general purpose loop counter */
   int width;                 /* Width of the current field */
   etByte flag_leftjustify;   /* True if "-" flag is present */
-  etByte flag_plussign;      /* True if "+" flag is present */
-  etByte flag_blanksign;     /* True if " " flag is present */
+  etByte flag_prefix;        /* '+' or ' ' or 0 for prefix */
   etByte flag_alternateform; /* True if "#" flag is present */
   etByte flag_altform2;      /* True if "!" flag is present */
   etByte flag_zeropad;       /* True if field width constant starts with zero */
-  etByte flag_long;          /* True if "l" flag is present */
-  etByte flag_longlong;      /* True if the "ll" flag is present */
+  etByte flag_long;          /* 1 for the "l" flag, 2 for "ll", 0 by default */
   etByte done;               /* Loop termination flag */
-  etByte xtype = 0;          /* Conversion paradigm */
+  etByte cThousand;          /* Thousands separator for %d and %u */
+  etByte xtype = etINVALID;  /* Conversion paradigm */
   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
-  u8 useIntern;              /* Ok to use internal conversions (ex: %T) */
   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
   sqlite_uint64 longvalue;   /* Value for integer types */
   LONGDOUBLE_TYPE realvalue; /* Value for real types */
@@ -21262,21 +25797,12 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
   char buf[etBUFSIZE];       /* Conversion buffer */
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( ap==0 ){
-    (void)SQLITE_MISUSE_BKPT;
-    sqlite3StrAccumReset(pAccum);
-    return;
-  }
-#endif
   bufpt = 0;
-  if( bFlags ){
-    if( (bArgList = (bFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
-      pArgList = va_arg(ap, PrintfArguments*);
-    }
-    useIntern = bFlags & SQLITE_PRINTF_INTERNAL;
+  if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){
+    pArgList = va_arg(ap, PrintfArguments*);
+    bArgList = 1;
   }else{
-    bArgList = useIntern = 0;
+    bArgList = 0;
   }
   for(; (c=(*fmt))!=0; ++fmt){
     if( c!='%' ){
@@ -21294,22 +25820,22 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       break;
     }
     /* Find out what flags are present */
-    flag_leftjustify = flag_plussign = flag_blanksign = 
+    flag_leftjustify = flag_prefix = cThousand =
      flag_alternateform = flag_altform2 = flag_zeropad = 0;
     done = 0;
     do{
       switch( c ){
         case '-':   flag_leftjustify = 1;     break;
-        case '+':   flag_plussign = 1;        break;
-        case ' ':   flag_blanksign = 1;       break;
+        case '+':   flag_prefix = '+';        break;
+        case ' ':   flag_prefix = ' ';        break;
         case '#':   flag_alternateform = 1;   break;
         case '!':   flag_altform2 = 1;        break;
         case '0':   flag_zeropad = 1;         break;
+        case ',':   cThousand = ',';          break;
         default:    done = 1;                 break;
       }
     }while( !done && (c=(*++fmt))!=0 );
     /* Get the field width */
-    width = 0;
     if( c=='*' ){
       if( bArgList ){
         width = (int)getIntArg(pArgList);
@@ -21318,18 +25844,27 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       }
       if( width<0 ){
         flag_leftjustify = 1;
-        width = -width;
+        width = width >= -2147483647 ? -width : 0;
       }
       c = *++fmt;
     }else{
+      unsigned wx = 0;
       while( c>='0' && c<='9' ){
-        width = width*10 + c - '0';
+        wx = wx*10 + c - '0';
         c = *++fmt;
       }
+      testcase( wx>0x7fffffff );
+      width = wx & 0x7fffffff;
+    }
+    assert( width>=0 );
+#ifdef SQLITE_PRINTF_PRECISION_LIMIT
+    if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
+      width = SQLITE_PRINTF_PRECISION_LIMIT;
     }
+#endif
+
     /* Get the precision */
     if( c=='.' ){
-      precision = 0;
       c = *++fmt;
       if( c=='*' ){
         if( bArgList ){
@@ -21337,29 +25872,40 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         }else{
           precision = va_arg(ap,int);
         }
-        if( precision<0 ) precision = -precision;
         c = *++fmt;
+        if( precision<0 ){
+          precision = precision >= -2147483647 ? -precision : -1;
+        }
       }else{
+        unsigned px = 0;
         while( c>='0' && c<='9' ){
-          precision = precision*10 + c - '0';
+          px = px*10 + c - '0';
           c = *++fmt;
         }
+        testcase( px>0x7fffffff );
+        precision = px & 0x7fffffff;
       }
     }else{
       precision = -1;
     }
+    assert( precision>=(-1) );
+#ifdef SQLITE_PRINTF_PRECISION_LIMIT
+    if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
+      precision = SQLITE_PRINTF_PRECISION_LIMIT;
+    }
+#endif
+
+
     /* Get the conversion type modifier */
     if( c=='l' ){
       flag_long = 1;
       c = *++fmt;
       if( c=='l' ){
-        flag_longlong = 1;
+        flag_long = 2;
         c = *++fmt;
-      }else{
-        flag_longlong = 0;
       }
     }else{
-      flag_long = flag_longlong = 0;
+      flag_long = 0;
     }
     /* Fetch the info entry for the field */
     infop = &fmtinfo[0];
@@ -21367,11 +25913,7 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     for(idx=0; idxflags & FLAG_INTERN)==0 ){
-          xtype = infop->type;
-        }else{
-          return;
-        }
+        xtype = infop->type;
         break;
       }
     }
@@ -21381,15 +25923,11 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     **
     **   flag_alternateform          TRUE if a '#' is present.
     **   flag_altform2               TRUE if a '!' is present.
-    **   flag_plussign               TRUE if a '+' is present.
+    **   flag_prefix                 '+' or ' ' or zero
     **   flag_leftjustify            TRUE if a '-' is present or if the
     **                               field width was negative.
     **   flag_zeropad                TRUE if the width began with 0.
-    **   flag_long                   TRUE if the letter 'l' (ell) prefixed
-    **                               the conversion character.
-    **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
-    **                               the conversion character.
-    **   flag_blanksign              TRUE if a ' ' is present.
+    **   flag_long                   1 for "l", 2 for "ll"
     **   width                       The specified field width.  This is
     **                               always non-negative.  Zero is the default.
     **   precision                   The specified precision.  The default
@@ -21399,19 +25937,24 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     */
     switch( xtype ){
       case etPOINTER:
-        flag_longlong = sizeof(char*)==sizeof(i64);
-        flag_long = sizeof(char*)==sizeof(long int);
+        flag_long = sizeof(char*)==sizeof(i64) ? 2 :
+                     sizeof(char*)==sizeof(long int) ? 1 : 0;
         /* Fall through into the next case */
       case etORDINAL:
-      case etRADIX:
+      case etRADIX:      
+        cThousand = 0;
+        /* Fall through into the next case */
+      case etDECIMAL:
         if( infop->flags & FLAG_SIGNED ){
           i64 v;
           if( bArgList ){
             v = getIntArg(pArgList);
-          }else if( flag_longlong ){
-            v = va_arg(ap,i64);
           }else if( flag_long ){
-            v = va_arg(ap,long int);
+            if( flag_long==2 ){
+              v = va_arg(ap,i64) ;
+            }else{
+              v = va_arg(ap,long int);
+            }
           }else{
             v = va_arg(ap,int);
           }
@@ -21424,17 +25967,17 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
             prefix = '-';
           }else{
             longvalue = v;
-            if( flag_plussign )        prefix = '+';
-            else if( flag_blanksign )  prefix = ' ';
-            else                       prefix = 0;
+            prefix = flag_prefix;
           }
         }else{
           if( bArgList ){
             longvalue = (u64)getIntArg(pArgList);
-          }else if( flag_longlong ){
-            longvalue = va_arg(ap,u64);
           }else if( flag_long ){
-            longvalue = va_arg(ap,unsigned long int);
+            if( flag_long==2 ){
+              longvalue = va_arg(ap,u64);
+            }else{
+              longvalue = va_arg(ap,unsigned long int);
+            }
           }else{
             longvalue = va_arg(ap,unsigned int);
           }
@@ -21444,16 +25987,17 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         if( flag_zeropad && precision0 );
         }
         length = (int)(&zOut[nOut-1]-bufpt);
-        for(idx=precision-length; idx>0; idx--){
+        while( precision>length ){
           *(--bufpt) = '0';                             /* Zero pad */
+          length++;
+        }
+        if( cThousand ){
+          int nn = (length - 1)/3;  /* Number of "," to insert */
+          int ix = (length - 1)%3 + 1;
+          bufpt -= nn;
+          for(idx=0; nn>0; idx++){
+            bufpt[idx] = bufpt[idx+nn];
+            ix--;
+            if( ix==0 ){
+              bufpt[++idx] = cThousand;
+              nn--;
+              ix = 3;
+            }
+          }
         }
         if( prefix ) *(--bufpt) = prefix;               /* Add sign */
         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
@@ -21502,12 +26061,11 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           realvalue = -realvalue;
           prefix = '-';
         }else{
-          if( flag_plussign )          prefix = '+';
-          else if( flag_blanksign )    prefix = ' ';
-          else                         prefix = 0;
+          prefix = flag_prefix;
         }
         if( xtype==etGENERIC && precision>0 ) precision--;
-        for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
+        testcase( precision>0xfff );
+        for(idx=precision&0xfff, rounder=0.5; idx>0; idx--, rounder*=0.1){}
         if( xtype==etFLOAT ) realvalue += rounder;
         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
         exp = 0;
@@ -21519,21 +26077,16 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         if( realvalue>0.0 ){
           LONGDOUBLE_TYPE scale = 1.0;
           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
-          while( realvalue>=1e64*scale && exp<=350 ){ scale *= 1e64; exp+=64; }
-          while( realvalue>=1e8*scale && exp<=350 ){ scale *= 1e8; exp+=8; }
+          while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
           realvalue /= scale;
           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
           if( exp>350 ){
-            if( prefix=='-' ){
-              bufpt = "-Inf";
-            }else if( prefix=='+' ){
-              bufpt = "+Inf";
-            }else{
-              bufpt = "Inf";
-            }
-            length = sqlite3Strlen30(bufpt);
+            bufpt = buf;
+            buf[0] = prefix;
+            memcpy(buf+(prefix!=0),"Inf",4);
+            length = 3+(prefix!=0);
             break;
           }
         }
@@ -21562,8 +26115,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         }else{
           e2 = exp;
         }
-        if( MAX(e2,0)+precision+width > etBUFSIZE - 15 ){
-          bufpt = zExtra = sqlite3Malloc( MAX(e2,0)+precision+width+15 );
+        if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
+          bufpt = zExtra 
+              = sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
           if( bufpt==0 ){
             setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
@@ -21681,12 +26235,13 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       case etDYNSTRING:
         if( bArgList ){
           bufpt = getTextArg(pArgList);
+          xtype = etSTRING;
         }else{
           bufpt = va_arg(ap,char*);
         }
         if( bufpt==0 ){
           bufpt = "";
-        }else if( xtype==etDYNSTRING && !bArgList ){
+        }else if( xtype==etDYNSTRING ){
           zExtra = bufpt;
         }
         if( precision>=0 ){
@@ -21695,9 +26250,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           length = sqlite3Strlen30(bufpt);
         }
         break;
-      case etSQLESCAPE:
-      case etSQLESCAPE2:
-      case etSQLESCAPE3: {
+      case etSQLESCAPE:           /* Escape ' characters */
+      case etSQLESCAPE2:          /* Escape ' and enclose in '...' */
+      case etSQLESCAPE3: {        /* Escape " characters */
         int i, j, k, n, isnull;
         int needQuote;
         char ch;
@@ -21716,7 +26271,7 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           if( ch==q )  n++;
         }
         needQuote = !isnull && xtype==etSQLESCAPE2;
-        n += i + 1 + needQuote*2;
+        n += i + 3;
         if( n>etBUFSIZE ){
           bufpt = zExtra = sqlite3Malloc( n );
           if( bufpt==0 ){
@@ -21742,7 +26297,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         break;
       }
       case etTOKEN: {
-        Token *pToken = va_arg(ap, Token*);
+        Token *pToken;
+        if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
+        pToken = va_arg(ap, Token*);
         assert( bArgList==0 );
         if( pToken && pToken->n ){
           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
@@ -21751,9 +26308,13 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         break;
       }
       case etSRCLIST: {
-        SrcList *pSrc = va_arg(ap, SrcList*);
-        int k = va_arg(ap, int);
-        struct SrcList_item *pItem = &pSrc->a[k];
+        SrcList *pSrc;
+        int k;
+        struct SrcList_item *pItem;
+        if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
+        pSrc = va_arg(ap, SrcList*);
+        k = va_arg(ap, int);
+        pItem = &pSrc->a[k];
         assert( bArgList==0 );
         assert( k>=0 && knSrc );
         if( pItem->zDatabase ){
@@ -21775,12 +26336,16 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     ** the output.
     */
     width -= length;
-    if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
-    sqlite3StrAccumAppend(pAccum, bufpt, length);
-    if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
+    if( width>0 ){
+      if( !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
+      sqlite3StrAccumAppend(pAccum, bufpt, length);
+      if( flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
+    }else{
+      sqlite3StrAccumAppend(pAccum, bufpt, length);
+    }
 
     if( zExtra ){
-      sqlite3_free(zExtra);
+      sqlite3DbFree(pAccum->db, zExtra);
       zExtra = 0;
     }
   }/* End for loop over the format string */
@@ -21795,19 +26360,20 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
 */
 static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
   char *zNew;
-  assert( p->nChar+N >= p->nAlloc ); /* Only called if really needed */
+  assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */
   if( p->accError ){
     testcase(p->accError==STRACCUM_TOOBIG);
     testcase(p->accError==STRACCUM_NOMEM);
     return 0;
   }
-  if( !p->useMalloc ){
+  if( p->mxAlloc==0 ){
     N = p->nAlloc - p->nChar - 1;
     setStrAccumError(p, STRACCUM_TOOBIG);
     return N;
   }else{
-    char *zOld = (p->zText==p->zBase ? 0 : p->zText);
+    char *zOld = isMalloced(p) ? p->zText : 0;
     i64 szNew = p->nChar;
+    assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
     szNew += N + 1;
     if( szNew+p->nChar<=p->mxAlloc ){
       /* Force exponential buffer size growth as long as it does not overflow,
@@ -21821,16 +26387,17 @@ static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
     }else{
       p->nAlloc = (int)szNew;
     }
-    if( p->useMalloc==1 ){
+    if( p->db ){
       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
     }else{
-      zNew = sqlite3_realloc(zOld, p->nAlloc);
+      zNew = sqlite3_realloc64(zOld, p->nAlloc);
     }
     if( zNew ){
       assert( p->zText!=0 || p->nChar==0 );
-      if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
+      if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
       p->zText = zNew;
       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
+      p->printfFlags |= SQLITE_PRINTF_MALLOCED;
     }else{
       sqlite3StrAccumReset(p);
       setStrAccumError(p, STRACCUM_NOMEM);
@@ -21844,7 +26411,11 @@ static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
 ** Append N copies of character c to the given string buffer.
 */
 SQLITE_PRIVATE void sqlite3AppendChar(StrAccum *p, int N, char c){
-  if( p->nChar+N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ) return;
+  testcase( p->nChar + (i64)N > 0x7fffffff );
+  if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
+    return;
+  }
+  assert( (p->zText==p->zBase)==!isMalloced(p) );
   while( (N--)>0 ) p->zText[p->nChar++] = c;
 }
 
@@ -21862,6 +26433,7 @@ static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
     memcpy(&p->zText[p->nChar], z, N);
     p->nChar += N;
   }
+  assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
 }
 
 /*
@@ -21869,13 +26441,13 @@ static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
 ** size of the memory allocation for StrAccum if necessary.
 */
 SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
-  assert( z!=0 );
+  assert( z!=0 || N==0 );
   assert( p->zText!=0 || p->nChar==0 || p->accError );
   assert( N>=0 );
   assert( p->accError==0 || p->nAlloc==0 );
   if( p->nChar+N >= p->nAlloc ){
     enlargeAndAppend(p,z,N);
-  }else{
+  }else if( N ){
     assert( p->zText );
     p->nChar += N;
     memcpy(&p->zText[p->nChar-N], z, N);
@@ -21895,20 +26467,23 @@ SQLITE_PRIVATE void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
 ** Return a pointer to the resulting string.  Return a NULL
 ** pointer if any kind of error was encountered.
 */
+static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){
+  assert( p->mxAlloc>0 && !isMalloced(p) );
+  p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
+  if( p->zText ){
+    memcpy(p->zText, p->zBase, p->nChar+1);
+    p->printfFlags |= SQLITE_PRINTF_MALLOCED;
+  }else{
+    setStrAccumError(p, STRACCUM_NOMEM);
+  }
+  return p->zText;
+}
 SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){
   if( p->zText ){
+    assert( (p->zText==p->zBase)==!isMalloced(p) );
     p->zText[p->nChar] = 0;
-    if( p->useMalloc && p->zText==p->zBase ){
-      if( p->useMalloc==1 ){
-        p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
-      }else{
-        p->zText = sqlite3_malloc(p->nChar+1);
-      }
-      if( p->zText ){
-        memcpy(p->zText, p->zBase, p->nChar+1);
-      }else{
-        setStrAccumError(p, STRACCUM_NOMEM);
-      }
+    if( p->mxAlloc>0 && !isMalloced(p) ){
+      return strAccumFinishRealloc(p);
     }
   }
   return p->zText;
@@ -21918,27 +26493,36 @@ SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){
 ** Reset an StrAccum string.  Reclaim all malloced memory.
 */
 SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum *p){
-  if( p->zText!=p->zBase ){
-    if( p->useMalloc==1 ){
-      sqlite3DbFree(p->db, p->zText);
-    }else{
-      sqlite3_free(p->zText);
-    }
+  assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
+  if( isMalloced(p) ){
+    sqlite3DbFree(p->db, p->zText);
+    p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
   }
   p->zText = 0;
 }
 
 /*
-** Initialize a string accumulator
+** Initialize a string accumulator.
+**
+** p:     The accumulator to be initialized.
+** db:    Pointer to a database connection.  May be NULL.  Lookaside
+**        memory is used if not NULL. db->mallocFailed is set appropriately
+**        when not NULL.
+** zBase: An initial buffer.  May be NULL in which case the initial buffer
+**        is malloced.
+** n:     Size of zBase in bytes.  If total space requirements never exceed
+**        n then no memory allocations ever occur.
+** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
+**        allocations will ever occur.
 */
-SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
+SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
   p->zText = p->zBase = zBase;
-  p->db = 0;
+  p->db = db;
   p->nChar = 0;
   p->nAlloc = n;
   p->mxAlloc = mx;
-  p->useMalloc = 1;
   p->accError = 0;
+  p->printfFlags = 0;
 }
 
 /*
@@ -21950,13 +26534,13 @@ SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list a
   char zBase[SQLITE_PRINT_BUF_SIZE];
   StrAccum acc;
   assert( db!=0 );
-  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
+  sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
                       db->aLimit[SQLITE_LIMIT_LENGTH]);
-  acc.db = db;
-  sqlite3VXPrintf(&acc, SQLITE_PRINTF_INTERNAL, zFormat, ap);
+  acc.printfFlags = SQLITE_PRINTF_INTERNAL;
+  sqlite3VXPrintf(&acc, zFormat, ap);
   z = sqlite3StrAccumFinish(&acc);
   if( acc.accError==STRACCUM_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return z;
 }
@@ -21974,24 +26558,6 @@ SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
   return z;
 }
 
-/*
-** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
-** the string and before returning.  This routine is intended to be used
-** to modify an existing string.  For example:
-**
-**       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
-**
-*/
-SQLITE_PRIVATE char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
-  va_list ap;
-  char *z;
-  va_start(ap, zFormat);
-  z = sqlite3VMPrintf(db, zFormat, ap);
-  va_end(ap);
-  sqlite3DbFree(db, zStr);
-  return z;
-}
-
 /*
 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
 ** %-conversion extensions.
@@ -22010,9 +26576,8 @@ SQLITE_API char *sqlite3_vmprintf(const char *zFormat, va_list ap){
 #ifndef SQLITE_OMIT_AUTOINIT
   if( sqlite3_initialize() ) return 0;
 #endif
-  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
-  acc.useMalloc = 2;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   z = sqlite3StrAccumFinish(&acc);
   return z;
 }
@@ -22052,14 +26617,14 @@ SQLITE_API char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_li
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( zBuf==0 || zFormat==0 ) {
     (void)SQLITE_MISUSE_BKPT;
-    if( zBuf && n>0 ) zBuf[0] = 0;
+    if( zBuf ) zBuf[0] = 0;
     return zBuf;
   }
 #endif
-  sqlite3StrAccumInit(&acc, zBuf, n, 0);
-  acc.useMalloc = 0;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
-  return sqlite3StrAccumFinish(&acc);
+  sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
+  sqlite3VXPrintf(&acc, zFormat, ap);
+  zBuf[acc.nChar] = 0;
+  return zBuf;
 }
 SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
   char *z;
@@ -22078,14 +26643,18 @@ SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
 ** allocate memory because it might be called while the memory allocator
 ** mutex is held.
+**
+** sqlite3VXPrintf() might ask for *temporary* memory allocations for
+** certain format characters (%q) or for very large precisions or widths.
+** Care must be taken that any sqlite3_log() calls that occur while the
+** memory mutex is held do not use these mechanisms.
 */
 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
   StrAccum acc;                          /* String accumulator */
   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
 
-  sqlite3StrAccumInit(&acc, zMsg, sizeof(zMsg), 0);
-  acc.useMalloc = 0;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
                            sqlite3StrAccumFinish(&acc));
 }
@@ -22102,7 +26671,7 @@ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...){
   }
 }
 
-#if defined(SQLITE_DEBUG)
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
 /*
 ** A version of printf() that understands %lld.  Used for debugging.
 ** The printf() built into some versions of windows does not understand %lld
@@ -22112,10 +26681,9 @@ SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){
   va_list ap;
   StrAccum acc;
   char zBuf[500];
-  sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
-  acc.useMalloc = 0;
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
   va_start(ap,zFormat);
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   va_end(ap);
   sqlite3StrAccumFinish(&acc);
   fprintf(stdout,"%s", zBuf);
@@ -22123,24 +26691,49 @@ SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){
 }
 #endif
 
-#ifdef SQLITE_DEBUG
-/*************************************************************************
-** Routines for implementing the "TreeView" display of hierarchical
-** data structures for debugging.
+
+/*
+** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
+** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
+*/
+SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, const char *zFormat, ...){
+  va_list ap;
+  va_start(ap,zFormat);
+  sqlite3VXPrintf(p, zFormat, ap);
+  va_end(ap);
+}
+
+/************** End of printf.c **********************************************/
+/************** Begin file treeview.c ****************************************/
+/*
+** 2015-06-08
 **
-** The main entry points (coded elsewhere) are:
-**     sqlite3TreeViewExpr(0, pExpr, 0);
-**     sqlite3TreeViewExprList(0, pList, 0, 0);
-**     sqlite3TreeViewSelect(0, pSelect, 0);
-** Insert calls to those routines while debugging in order to display
-** a diagram of Expr, ExprList, and Select objects.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
 **
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains C code to implement the TreeView debugging routines.
+** These routines print a parse tree to standard output for debugging and
+** analysis. 
+**
+** The interfaces in this file is only available when compiling
+** with SQLITE_DEBUG.
 */
-/* Add a new subitem to the tree.  The moreToFollow flag indicates that this
-** is not the last item in the tree. */
-SQLITE_PRIVATE TreeView *sqlite3TreeViewPush(TreeView *p, u8 moreToFollow){
+/* #include "sqliteInt.h" */
+#ifdef SQLITE_DEBUG
+
+/*
+** Add a new subitem to the tree.  The moreToFollow flag indicates that this
+** is not the last item in the tree.
+*/
+static TreeView *sqlite3TreeViewPush(TreeView *p, u8 moreToFollow){
   if( p==0 ){
-    p = sqlite3_malloc( sizeof(*p) );
+    p = sqlite3_malloc64( sizeof(*p) );
     if( p==0 ) return 0;
     memset(p, 0, sizeof(*p));
   }else{
@@ -22150,21 +26743,26 @@ SQLITE_PRIVATE TreeView *sqlite3TreeViewPush(TreeView *p, u8 moreToFollow){
   if( p->iLevelbLine) ) p->bLine[p->iLevel] = moreToFollow;
   return p;
 }
-/* Finished with one layer of the tree */
-SQLITE_PRIVATE void sqlite3TreeViewPop(TreeView *p){
+
+/*
+** Finished with one layer of the tree
+*/
+static void sqlite3TreeViewPop(TreeView *p){
   if( p==0 ) return;
   p->iLevel--;
   if( p->iLevel<0 ) sqlite3_free(p);
 }
-/* Generate a single line of output for the tree, with a prefix that contains
-** all the appropriate tree lines */
-SQLITE_PRIVATE void sqlite3TreeViewLine(TreeView *p, const char *zFormat, ...){
+
+/*
+** Generate a single line of output for the tree, with a prefix that contains
+** all the appropriate tree lines
+*/
+static void sqlite3TreeViewLine(TreeView *p, const char *zFormat, ...){
   va_list ap;
   int i;
   StrAccum acc;
   char zBuf[500];
-  sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
-  acc.useMalloc = 0;
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
   if( p ){
     for(i=0; iiLevel && ibLine)-1; i++){
       sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|   " : "    ", 4);
@@ -22172,31 +26770,474 @@ SQLITE_PRIVATE void sqlite3TreeViewLine(TreeView *p, const char *zFormat, ...){
     sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|-- " : "'-- ", 4);
   }
   va_start(ap, zFormat);
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   va_end(ap);
+  assert( acc.nChar>0 );
   if( zBuf[acc.nChar-1]!='\n' ) sqlite3StrAccumAppend(&acc, "\n", 1);
   sqlite3StrAccumFinish(&acc);
   fprintf(stdout,"%s", zBuf);
   fflush(stdout);
 }
-/* Shorthand for starting a new tree item that consists of a single label */
-SQLITE_PRIVATE void sqlite3TreeViewItem(TreeView *p, const char *zLabel, u8 moreToFollow){
-  p = sqlite3TreeViewPush(p, moreToFollow);
+
+/*
+** Shorthand for starting a new tree item that consists of a single label
+*/
+static void sqlite3TreeViewItem(TreeView *p, const char *zLabel,u8 moreFollows){
+  p = sqlite3TreeViewPush(p, moreFollows);
   sqlite3TreeViewLine(p, "%s", zLabel);
 }
-#endif /* SQLITE_DEBUG */
 
 /*
-** variable-argument wrapper around sqlite3VXPrintf().
+** Generate a human-readable description of a WITH clause.
 */
-SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, u32 bFlags, const char *zFormat, ...){
-  va_list ap;
-  va_start(ap,zFormat);
-  sqlite3VXPrintf(p, bFlags, zFormat, ap);
-  va_end(ap);
+SQLITE_PRIVATE void sqlite3TreeViewWith(TreeView *pView, const With *pWith, u8 moreToFollow){
+  int i;
+  if( pWith==0 ) return;
+  if( pWith->nCte==0 ) return;
+  if( pWith->pOuter ){
+    sqlite3TreeViewLine(pView, "WITH (0x%p, pOuter=0x%p)",pWith,pWith->pOuter);
+  }else{
+    sqlite3TreeViewLine(pView, "WITH (0x%p)", pWith);
+  }
+  if( pWith->nCte>0 ){
+    pView = sqlite3TreeViewPush(pView, 1);
+    for(i=0; inCte; i++){
+      StrAccum x;
+      char zLine[1000];
+      const struct Cte *pCte = &pWith->a[i];
+      sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
+      sqlite3XPrintf(&x, "%s", pCte->zName);
+      if( pCte->pCols && pCte->pCols->nExpr>0 ){
+        char cSep = '(';
+        int j;
+        for(j=0; jpCols->nExpr; j++){
+          sqlite3XPrintf(&x, "%c%s", cSep, pCte->pCols->a[j].zName);
+          cSep = ',';
+        }
+        sqlite3XPrintf(&x, ")");
+      }
+      sqlite3XPrintf(&x, " AS");
+      sqlite3StrAccumFinish(&x);
+      sqlite3TreeViewItem(pView, zLine, inCte-1);
+      sqlite3TreeViewSelect(pView, pCte->pSelect, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    sqlite3TreeViewPop(pView);
+  }
 }
 
-/************** End of printf.c **********************************************/
+
+/*
+** Generate a human-readable description of a Select object.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){
+  int n = 0;
+  int cnt = 0;
+  if( p==0 ){
+    sqlite3TreeViewLine(pView, "nil-SELECT");
+    return;
+  } 
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  if( p->pWith ){
+    sqlite3TreeViewWith(pView, p->pWith, 1);
+    cnt = 1;
+    sqlite3TreeViewPush(pView, 1);
+  }
+  do{
+    sqlite3TreeViewLine(pView, "SELECT%s%s (0x%p) selFlags=0x%x nSelectRow=%d",
+      ((p->selFlags & SF_Distinct) ? " DISTINCT" : ""),
+      ((p->selFlags & SF_Aggregate) ? " agg_flag" : ""), p, p->selFlags,
+      (int)p->nSelectRow
+    );
+    if( cnt++ ) sqlite3TreeViewPop(pView);
+    if( p->pPrior ){
+      n = 1000;
+    }else{
+      n = 0;
+      if( p->pSrc && p->pSrc->nSrc ) n++;
+      if( p->pWhere ) n++;
+      if( p->pGroupBy ) n++;
+      if( p->pHaving ) n++;
+      if( p->pOrderBy ) n++;
+      if( p->pLimit ) n++;
+      if( p->pOffset ) n++;
+    }
+    sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");
+    if( p->pSrc && p->pSrc->nSrc ){
+      int i;
+      pView = sqlite3TreeViewPush(pView, (n--)>0);
+      sqlite3TreeViewLine(pView, "FROM");
+      for(i=0; ipSrc->nSrc; i++){
+        struct SrcList_item *pItem = &p->pSrc->a[i];
+        StrAccum x;
+        char zLine[100];
+        sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
+        sqlite3XPrintf(&x, "{%d,*}", pItem->iCursor);
+        if( pItem->zDatabase ){
+          sqlite3XPrintf(&x, " %s.%s", pItem->zDatabase, pItem->zName);
+        }else if( pItem->zName ){
+          sqlite3XPrintf(&x, " %s", pItem->zName);
+        }
+        if( pItem->pTab ){
+          sqlite3XPrintf(&x, " tabname=%Q", pItem->pTab->zName);
+        }
+        if( pItem->zAlias ){
+          sqlite3XPrintf(&x, " (AS %s)", pItem->zAlias);
+        }
+        if( pItem->fg.jointype & JT_LEFT ){
+          sqlite3XPrintf(&x, " LEFT-JOIN");
+        }
+        sqlite3StrAccumFinish(&x);
+        sqlite3TreeViewItem(pView, zLine, ipSrc->nSrc-1); 
+        if( pItem->pSelect ){
+          sqlite3TreeViewSelect(pView, pItem->pSelect, 0);
+        }
+        if( pItem->fg.isTabFunc ){
+          sqlite3TreeViewExprList(pView, pItem->u1.pFuncArg, 0, "func-args:");
+        }
+        sqlite3TreeViewPop(pView);
+      }
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pWhere ){
+      sqlite3TreeViewItem(pView, "WHERE", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pWhere, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pGroupBy ){
+      sqlite3TreeViewExprList(pView, p->pGroupBy, (n--)>0, "GROUPBY");
+    }
+    if( p->pHaving ){
+      sqlite3TreeViewItem(pView, "HAVING", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pHaving, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pOrderBy ){
+      sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");
+    }
+    if( p->pLimit ){
+      sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pLimit, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pOffset ){
+      sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pOffset, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pPrior ){
+      const char *zOp = "UNION";
+      switch( p->op ){
+        case TK_ALL:         zOp = "UNION ALL";  break;
+        case TK_INTERSECT:   zOp = "INTERSECT";  break;
+        case TK_EXCEPT:      zOp = "EXCEPT";     break;
+      }
+      sqlite3TreeViewItem(pView, zOp, 1);
+    }
+    p = p->pPrior;
+  }while( p!=0 );
+  sqlite3TreeViewPop(pView);
+}
+
+/*
+** Generate a human-readable explanation of an expression tree.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){
+  const char *zBinOp = 0;   /* Binary operator */
+  const char *zUniOp = 0;   /* Unary operator */
+  char zFlgs[60];
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  if( pExpr==0 ){
+    sqlite3TreeViewLine(pView, "nil");
+    sqlite3TreeViewPop(pView);
+    return;
+  }
+  if( pExpr->flags ){
+    if( ExprHasProperty(pExpr, EP_FromJoin) ){
+      sqlite3_snprintf(sizeof(zFlgs),zFlgs,"  flags=0x%x iRJT=%d",
+                       pExpr->flags, pExpr->iRightJoinTable);
+    }else{
+      sqlite3_snprintf(sizeof(zFlgs),zFlgs,"  flags=0x%x",pExpr->flags);
+    }
+  }else{
+    zFlgs[0] = 0;
+  }
+  switch( pExpr->op ){
+    case TK_AGG_COLUMN: {
+      sqlite3TreeViewLine(pView, "AGG{%d:%d}%s",
+            pExpr->iTable, pExpr->iColumn, zFlgs);
+      break;
+    }
+    case TK_COLUMN: {
+      if( pExpr->iTable<0 ){
+        /* This only happens when coding check constraints */
+        sqlite3TreeViewLine(pView, "COLUMN(%d)%s", pExpr->iColumn, zFlgs);
+      }else{
+        sqlite3TreeViewLine(pView, "{%d:%d}%s",
+                             pExpr->iTable, pExpr->iColumn, zFlgs);
+      }
+      break;
+    }
+    case TK_INTEGER: {
+      if( pExpr->flags & EP_IntValue ){
+        sqlite3TreeViewLine(pView, "%d", pExpr->u.iValue);
+      }else{
+        sqlite3TreeViewLine(pView, "%s", pExpr->u.zToken);
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    case TK_FLOAT: {
+      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_STRING: {
+      sqlite3TreeViewLine(pView,"%Q", pExpr->u.zToken);
+      break;
+    }
+    case TK_NULL: {
+      sqlite3TreeViewLine(pView,"NULL");
+      break;
+    }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case TK_BLOB: {
+      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_VARIABLE: {
+      sqlite3TreeViewLine(pView,"VARIABLE(%s,%d)",
+                          pExpr->u.zToken, pExpr->iColumn);
+      break;
+    }
+    case TK_REGISTER: {
+      sqlite3TreeViewLine(pView,"REGISTER(%d)", pExpr->iTable);
+      break;
+    }
+    case TK_ID: {
+      sqlite3TreeViewLine(pView,"ID \"%w\"", pExpr->u.zToken);
+      break;
+    }
+#ifndef SQLITE_OMIT_CAST
+    case TK_CAST: {
+      /* Expressions of the form:   CAST(pLeft AS token) */
+      sqlite3TreeViewLine(pView,"CAST %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+#endif /* SQLITE_OMIT_CAST */
+    case TK_LT:      zBinOp = "LT";     break;
+    case TK_LE:      zBinOp = "LE";     break;
+    case TK_GT:      zBinOp = "GT";     break;
+    case TK_GE:      zBinOp = "GE";     break;
+    case TK_NE:      zBinOp = "NE";     break;
+    case TK_EQ:      zBinOp = "EQ";     break;
+    case TK_IS:      zBinOp = "IS";     break;
+    case TK_ISNOT:   zBinOp = "ISNOT";  break;
+    case TK_AND:     zBinOp = "AND";    break;
+    case TK_OR:      zBinOp = "OR";     break;
+    case TK_PLUS:    zBinOp = "ADD";    break;
+    case TK_STAR:    zBinOp = "MUL";    break;
+    case TK_MINUS:   zBinOp = "SUB";    break;
+    case TK_REM:     zBinOp = "REM";    break;
+    case TK_BITAND:  zBinOp = "BITAND"; break;
+    case TK_BITOR:   zBinOp = "BITOR";  break;
+    case TK_SLASH:   zBinOp = "DIV";    break;
+    case TK_LSHIFT:  zBinOp = "LSHIFT"; break;
+    case TK_RSHIFT:  zBinOp = "RSHIFT"; break;
+    case TK_CONCAT:  zBinOp = "CONCAT"; break;
+    case TK_DOT:     zBinOp = "DOT";    break;
+
+    case TK_UMINUS:  zUniOp = "UMINUS"; break;
+    case TK_UPLUS:   zUniOp = "UPLUS";  break;
+    case TK_BITNOT:  zUniOp = "BITNOT"; break;
+    case TK_NOT:     zUniOp = "NOT";    break;
+    case TK_ISNULL:  zUniOp = "ISNULL"; break;
+    case TK_NOTNULL: zUniOp = "NOTNULL"; break;
+
+    case TK_SPAN: {
+      sqlite3TreeViewLine(pView, "SPAN %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+
+    case TK_COLLATE: {
+      sqlite3TreeViewLine(pView, "COLLATE %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+
+    case TK_AGG_FUNCTION:
+    case TK_FUNCTION: {
+      ExprList *pFarg;       /* List of function arguments */
+      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
+        pFarg = 0;
+      }else{
+        pFarg = pExpr->x.pList;
+      }
+      if( pExpr->op==TK_AGG_FUNCTION ){
+        sqlite3TreeViewLine(pView, "AGG_FUNCTION%d %Q",
+                             pExpr->op2, pExpr->u.zToken);
+      }else{
+        sqlite3TreeViewLine(pView, "FUNCTION %Q", pExpr->u.zToken);
+      }
+      if( pFarg ){
+        sqlite3TreeViewExprList(pView, pFarg, 0, 0);
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_EXISTS: {
+      sqlite3TreeViewLine(pView, "EXISTS-expr flags=0x%x", pExpr->flags);
+      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      break;
+    }
+    case TK_SELECT: {
+      sqlite3TreeViewLine(pView, "SELECT-expr flags=0x%x", pExpr->flags);
+      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      break;
+    }
+    case TK_IN: {
+      sqlite3TreeViewLine(pView, "IN flags=0x%x", pExpr->flags);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      }else{
+        sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
+      }
+      break;
+    }
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+    /*
+    **    x BETWEEN y AND z
+    **
+    ** This is equivalent to
+    **
+    **    x>=y AND x<=z
+    **
+    ** X is stored in pExpr->pLeft.
+    ** Y is stored in pExpr->pList->a[0].pExpr.
+    ** Z is stored in pExpr->pList->a[1].pExpr.
+    */
+    case TK_BETWEEN: {
+      Expr *pX = pExpr->pLeft;
+      Expr *pY = pExpr->x.pList->a[0].pExpr;
+      Expr *pZ = pExpr->x.pList->a[1].pExpr;
+      sqlite3TreeViewLine(pView, "BETWEEN");
+      sqlite3TreeViewExpr(pView, pX, 1);
+      sqlite3TreeViewExpr(pView, pY, 1);
+      sqlite3TreeViewExpr(pView, pZ, 0);
+      break;
+    }
+    case TK_TRIGGER: {
+      /* If the opcode is TK_TRIGGER, then the expression is a reference
+      ** to a column in the new.* or old.* pseudo-tables available to
+      ** trigger programs. In this case Expr.iTable is set to 1 for the
+      ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
+      ** is set to the column of the pseudo-table to read, or to -1 to
+      ** read the rowid field.
+      */
+      sqlite3TreeViewLine(pView, "%s(%d)", 
+          pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
+      break;
+    }
+    case TK_CASE: {
+      sqlite3TreeViewLine(pView, "CASE");
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+      sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
+      break;
+    }
+#ifndef SQLITE_OMIT_TRIGGER
+    case TK_RAISE: {
+      const char *zType = "unk";
+      switch( pExpr->affinity ){
+        case OE_Rollback:   zType = "rollback";  break;
+        case OE_Abort:      zType = "abort";     break;
+        case OE_Fail:       zType = "fail";      break;
+        case OE_Ignore:     zType = "ignore";    break;
+      }
+      sqlite3TreeViewLine(pView, "RAISE %s(%Q)", zType, pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_MATCH: {
+      sqlite3TreeViewLine(pView, "MATCH {%d:%d}%s",
+                          pExpr->iTable, pExpr->iColumn, zFlgs);
+      sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
+      break;
+    }
+    case TK_VECTOR: {
+      sqlite3TreeViewBareExprList(pView, pExpr->x.pList, "VECTOR");
+      break;
+    }
+    case TK_SELECT_COLUMN: {
+      sqlite3TreeViewLine(pView, "SELECT-COLUMN %d", pExpr->iColumn);
+      sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
+      break;
+    }
+    case TK_IF_NULL_ROW: {
+      sqlite3TreeViewLine(pView, "IF-NULL-ROW %d", pExpr->iTable);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+    default: {
+      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
+      break;
+    }
+  }
+  if( zBinOp ){
+    sqlite3TreeViewLine(pView, "%s%s", zBinOp, zFlgs);
+    sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+    sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
+  }else if( zUniOp ){
+    sqlite3TreeViewLine(pView, "%s%s", zUniOp, zFlgs);
+    sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+  }
+  sqlite3TreeViewPop(pView);
+}
+
+
+/*
+** Generate a human-readable explanation of an expression list.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewBareExprList(
+  TreeView *pView,
+  const ExprList *pList,
+  const char *zLabel
+){
+  if( zLabel==0 || zLabel[0]==0 ) zLabel = "LIST";
+  if( pList==0 ){
+    sqlite3TreeViewLine(pView, "%s (empty)", zLabel);
+  }else{
+    int i;
+    sqlite3TreeViewLine(pView, "%s", zLabel);
+    for(i=0; inExpr; i++){
+      int j = pList->a[i].u.x.iOrderByCol;
+      if( j ){
+        sqlite3TreeViewPush(pView, 0);
+        sqlite3TreeViewLine(pView, "iOrderByCol=%d", j);
+      }
+      sqlite3TreeViewExpr(pView, pList->a[i].pExpr, inExpr-1);
+      if( j ) sqlite3TreeViewPop(pView);
+    }
+  }
+}
+SQLITE_PRIVATE void sqlite3TreeViewExprList(
+  TreeView *pView,
+  const ExprList *pList,
+  u8 moreToFollow,
+  const char *zLabel
+){
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  sqlite3TreeViewBareExprList(pView, pList, zLabel);
+  sqlite3TreeViewPop(pView);
+}
+
+#endif /* SQLITE_DEBUG */
+
+/************** End of treeview.c ********************************************/
 /************** Begin file random.c ******************************************/
 /*
 ** 2001 September 15
@@ -22215,6 +27256,7 @@ SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, u32 bFlags, const char *zFormat,
 ** Random numbers are used by some of the database backends in order
 ** to generate random integer keys for tables or random filenames.
 */
+/* #include "sqliteInt.h" */
 
 
 /* All threads share a single random number generator.
@@ -22305,7 +27347,7 @@ SQLITE_API void sqlite3_randomness(int N, void *pBuf){
   sqlite3_mutex_leave(mutex);
 }
 
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
 /*
 ** For testing purposes, we sometimes want to preserve the state of
 ** PRNG and restore the PRNG to its saved state at a later time, or
@@ -22330,7 +27372,7 @@ SQLITE_PRIVATE void sqlite3PrngRestoreState(void){
     sizeof(sqlite3Prng)
   );
 }
-#endif /* SQLITE_OMIT_BUILTIN_TEST */
+#endif /* SQLITE_UNTESTABLE */
 
 /************** End of random.c **********************************************/
 /************** Begin file threads.c *****************************************/
@@ -22361,7 +27403,9 @@ SQLITE_PRIVATE void sqlite3PrngRestoreState(void){
 ** of multiple cores can do so, while also allowing applications to stay
 ** single-threaded if desired.
 */
+/* #include "sqliteInt.h" */
 #if SQLITE_OS_WIN
+/* #  include "os_win.h" */
 #endif
 
 #if SQLITE_MAX_WORKER_THREADS>0
@@ -22397,10 +27441,14 @@ SQLITE_PRIVATE int sqlite3ThreadCreate(
 
   *ppThread = 0;
   p = sqlite3Malloc(sizeof(*p));
-  if( p==0 ) return SQLITE_NOMEM;
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   memset(p, 0, sizeof(*p));
   p->xTask = xTask;
   p->pIn = pIn;
+  /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 
+  ** function that returns SQLITE_ERROR when passed the argument 200, that
+  ** forces worker threads to run sequentially and deterministically 
+  ** for testing purposes. */
   if( sqlite3FaultSim(200) ){
     rc = 1;
   }else{    
@@ -22419,7 +27467,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
   int rc;
 
   assert( ppOut!=0 );
-  if( NEVER(p==0) ) return SQLITE_NOMEM;
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
   if( p->done ){
     *ppOut = p->pOut;
     rc = SQLITE_OK;
@@ -22435,7 +27483,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
 
 
 /********************************* Win32 Threads ****************************/
-#if SQLITE_OS_WIN && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_THREADSAFE>0
+#if SQLITE_OS_WIN_THREADS
 
 #define SQLITE_THREADS_IMPLEMENTED 1  /* Prevent the single-thread code below */
 #include 
@@ -22484,8 +27532,13 @@ SQLITE_PRIVATE int sqlite3ThreadCreate(
   assert( xTask!=0 );
   *ppThread = 0;
   p = sqlite3Malloc(sizeof(*p));
-  if( p==0 ) return SQLITE_NOMEM;
-  if( sqlite3GlobalConfig.bCoreMutex==0 ){
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 
+  ** function that returns SQLITE_ERROR when passed the argument 200, that
+  ** forces worker threads to run sequentially and deterministically 
+  ** (via the sqlite3FaultSim() term of the conditional) for testing
+  ** purposes. */
+  if( sqlite3GlobalConfig.bCoreMutex==0 || sqlite3FaultSim(200) ){
     memset(p, 0, sizeof(*p));
   }else{
     p->xTask = xTask;
@@ -22511,9 +27564,9 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
   BOOL bRc;
 
   assert( ppOut!=0 );
-  if( NEVER(p==0) ) return SQLITE_NOMEM;
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
   if( p->xTask==0 ){
-    assert( p->id==GetCurrentThreadId() );
+    /* assert( p->id==GetCurrentThreadId() ); */
     rc = WAIT_OBJECT_0;
     assert( p->tid==0 );
   }else{
@@ -22528,7 +27581,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
   return (rc==WAIT_OBJECT_0) ? SQLITE_OK : SQLITE_ERROR;
 }
 
-#endif /* SQLITE_OS_WIN && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT */
+#endif /* SQLITE_OS_WIN_THREADS */
 /******************************** End Win32 Threads *************************/
 
 
@@ -22559,7 +27612,7 @@ SQLITE_PRIVATE int sqlite3ThreadCreate(
   assert( xTask!=0 );
   *ppThread = 0;
   p = sqlite3Malloc(sizeof(*p));
-  if( p==0 ) return SQLITE_NOMEM;
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   if( (SQLITE_PTR_TO_INT(p)/17)&1 ){
     p->xTask = xTask;
     p->pIn = pIn;
@@ -22575,7 +27628,7 @@ SQLITE_PRIVATE int sqlite3ThreadCreate(
 SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
 
   assert( ppOut!=0 );
-  if( NEVER(p==0) ) return SQLITE_NOMEM;
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
   if( p->xTask ){
     *ppOut = p->xTask(p->pIn);
   }else{
@@ -22586,7 +27639,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
 #if defined(SQLITE_TEST)
   {
     void *pTstAlloc = sqlite3Malloc(10);
-    if (!pTstAlloc) return SQLITE_NOMEM;
+    if (!pTstAlloc) return SQLITE_NOMEM_BKPT;
     sqlite3_free(pTstAlloc);
   }
 #endif
@@ -22635,15 +27688,17 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
 **     0xfe 0xff   big-endian utf-16 follows
 **
 */
+/* #include "sqliteInt.h" */
 /* #include  */
+/* #include "vdbeInt.h" */
 
-#ifndef SQLITE_AMALGAMATION
+#if !defined(SQLITE_AMALGAMATION) && SQLITE_BYTEORDER==0
 /*
 ** The following constant value is used by the SQLITE_BIGENDIAN and
 ** SQLITE_LITTLEENDIAN macros.
 */
 SQLITE_PRIVATE const int sqlite3one = 1;
-#endif /* SQLITE_AMALGAMATION */
+#endif /* SQLITE_AMALGAMATION && SQLITE_BYTEORDER==0 */
 
 /*
 ** This lookup table is used to help decode the first byte of
@@ -22831,7 +27886,7 @@ SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desired
     rc = sqlite3VdbeMemMakeWriteable(pMem);
     if( rc!=SQLITE_OK ){
       assert( rc==SQLITE_NOMEM );
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     zIn = (u8*)pMem->z;
     zTerm = &zIn[pMem->n&~1];
@@ -22873,7 +27928,7 @@ SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desired
   zTerm = &zIn[pMem->n];
   zOut = sqlite3DbMallocRaw(pMem->db, len);
   if( !zOut ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   z = zOut;
 
@@ -22916,7 +27971,7 @@ SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desired
 
   c = pMem->flags;
   sqlite3VdbeMemRelease(pMem);
-  pMem->flags = MEM_Str|MEM_Term|(c&MEM_AffMask);
+  pMem->flags = MEM_Str|MEM_Term|(c&(MEM_AffMask|MEM_Subtype));
   pMem->enc = desiredEnc;
   pMem->z = (char*)zOut;
   pMem->zMalloc = pMem->z;
@@ -22932,7 +27987,9 @@ translate_out:
 #endif
   return SQLITE_OK;
 }
+#endif /* SQLITE_OMIT_UTF16 */
 
+#ifndef SQLITE_OMIT_UTF16
 /*
 ** This routine checks for a byte-order mark at the beginning of the 
 ** UTF-16 string stored in *pMem. If one is present, it is removed and
@@ -23148,6 +28205,7 @@ SQLITE_PRIVATE void sqlite3UtfSelfTest(void){
 ** strings, and stuff like that.
 **
 */
+/* #include "sqliteInt.h" */
 /* #include  */
 #if HAVE_ISNAN || SQLITE_HAVE_ISNAN
 # include 
@@ -23174,7 +28232,7 @@ SQLITE_PRIVATE void sqlite3Coverage(int x){
 ** Return whatever integer value the test callback returns, or return
 ** SQLITE_OK if no test callback is installed.
 */
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
 SQLITE_PRIVATE int sqlite3FaultSim(int iTest){
   int (*xCallback)(int) = sqlite3GlobalConfig.xTestCallback;
   return xCallback ? xCallback(iTest) : SQLITE_OK;
@@ -23237,19 +28295,53 @@ SQLITE_PRIVATE int sqlite3IsNaN(double x){
 ** than 1GiB) the value returned might be less than the true string length.
 */
 SQLITE_PRIVATE int sqlite3Strlen30(const char *z){
-  const char *z2 = z;
   if( z==0 ) return 0;
-  while( *z2 ){ z2++; }
-  return 0x3fffffff & (int)(z2 - z);
+  return 0x3fffffff & (int)strlen(z);
+}
+
+/*
+** Return the declared type of a column.  Or return zDflt if the column 
+** has no declared type.
+**
+** The column type is an extra string stored after the zero-terminator on
+** the column name if and only if the COLFLAG_HASTYPE flag is set.
+*/
+SQLITE_PRIVATE char *sqlite3ColumnType(Column *pCol, char *zDflt){
+  if( (pCol->colFlags & COLFLAG_HASTYPE)==0 ) return zDflt;
+  return pCol->zName + strlen(pCol->zName) + 1;
+}
+
+/*
+** Helper function for sqlite3Error() - called rarely.  Broken out into
+** a separate routine to avoid unnecessary register saves on entry to
+** sqlite3Error().
+*/
+static SQLITE_NOINLINE void  sqlite3ErrorFinish(sqlite3 *db, int err_code){
+  if( db->pErr ) sqlite3ValueSetNull(db->pErr);
+  sqlite3SystemError(db, err_code);
 }
 
 /*
 ** Set the current error code to err_code and clear any prior error message.
+** Also set iSysErrno (by calling sqlite3System) if the err_code indicates
+** that would be appropriate.
 */
 SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code){
   assert( db!=0 );
   db->errCode = err_code;
-  if( db->pErr ) sqlite3ValueSetNull(db->pErr);
+  if( err_code || db->pErr ) sqlite3ErrorFinish(db, err_code);
+}
+
+/*
+** Load the sqlite3.iSysErrno field if that is an appropriate thing
+** to do based on the SQLite error code in rc.
+*/
+SQLITE_PRIVATE void sqlite3SystemError(sqlite3 *db, int rc){
+  if( rc==SQLITE_IOERR_NOMEM ) return;
+  rc &= 0xff;
+  if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){
+    db->iSysErrno = sqlite3OsGetLastError(db->pVfs);
+  }
 }
 
 /*
@@ -23276,6 +28368,7 @@ SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code){
 SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){
   assert( db!=0 );
   db->errCode = err_code;
+  sqlite3SystemError(db, err_code);
   if( zFormat==0 ){
     sqlite3Error(db, err_code);
   }else if( db->pErr || (db->pErr = sqlite3ValueNew(db))!=0 ){
@@ -23339,18 +28432,13 @@ SQLITE_PRIVATE void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
 ** brackets from around identifiers.  For example:  "[a-b-c]" becomes
 ** "a-b-c".
 */
-SQLITE_PRIVATE int sqlite3Dequote(char *z){
+SQLITE_PRIVATE void sqlite3Dequote(char *z){
   char quote;
   int i, j;
-  if( z==0 ) return -1;
+  if( z==0 ) return;
   quote = z[0];
-  switch( quote ){
-    case '\'':  break;
-    case '"':   break;
-    case '`':   break;                /* For MySQL compatibility */
-    case '[':   quote = ']';  break;  /* For MS SqlServer compatibility */
-    default:    return -1;
-  }
+  if( !sqlite3Isquote(quote) ) return;
+  if( quote=='[' ) quote = ']';
   for(i=1, j=0;; i++){
     assert( z[i] );
     if( z[i]==quote ){
@@ -23365,7 +28453,14 @@ SQLITE_PRIVATE int sqlite3Dequote(char *z){
     }
   }
   z[j] = 0;
-  return j;
+}
+
+/*
+** Generate a Token object from a string
+*/
+SQLITE_PRIVATE void sqlite3TokenInit(Token *p, char *z){
+  p->z = z;
+  p->n = sqlite3Strlen30(z);
 }
 
 /* Convenient short-hand */
@@ -23382,16 +28477,25 @@ SQLITE_PRIVATE int sqlite3Dequote(char *z){
 ** independence" that SQLite uses internally when comparing identifiers.
 */
 SQLITE_API int sqlite3_stricmp(const char *zLeft, const char *zRight){
-  register unsigned char *a, *b;
   if( zLeft==0 ){
     return zRight ? -1 : 0;
   }else if( zRight==0 ){
     return 1;
   }
+  return sqlite3StrICmp(zLeft, zRight);
+}
+SQLITE_PRIVATE int sqlite3StrICmp(const char *zLeft, const char *zRight){
+  unsigned char *a, *b;
+  int c;
   a = (unsigned char *)zLeft;
   b = (unsigned char *)zRight;
-  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
-  return UpperToLower[*a] - UpperToLower[*b];
+  for(;;){
+    c = (int)UpperToLower[*a] - (int)UpperToLower[*b];
+    if( c || *a==0 ) break;
+    a++;
+    b++;
+  }
+  return c;
 }
 SQLITE_API int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
   register unsigned char *a, *b;
@@ -23441,7 +28545,7 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   int eValid = 1;  /* True exponent is either not used or is well-formed */
   double result;
   int nDigits = 0;
-  int nonNum = 0;
+  int nonNum = 0;  /* True if input contains UTF16 with high byte non-zero */
 
   assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
   *pResult = 0.0;   /* Default return value, in case of an error */
@@ -23454,7 +28558,7 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
     assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
     for(i=3-enc; i=zEnd ) goto do_atof_calc;
 
@@ -23502,7 +28604,12 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   if( *z=='e' || *z=='E' ){
     z+=incr;
     eValid = 0;
-    if( z>=zEnd ) goto do_atof_calc;
+
+    /* This branch is needed to avoid a (harmless) buffer overread.  The 
+    ** special comment alerts the mutation tester that the correct answer
+    ** is obtained even if the branch is omitted */
+    if( z>=zEnd ) goto do_atof_calc;              /*PREVENTS-HARMLESS-OVERREAD*/
+
     /* get sign of exponent */
     if( *z=='-' ){
       esign = -1;
@@ -23519,9 +28626,7 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   }
 
   /* skip trailing spaces */
-  if( nDigits && eValid ){
-    while( z0 ){
-      while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
-    }else{
-      while( !(s%10) && e>0 ) e--,s/=10;
+    /* Attempt to reduce exponent.
+    **
+    ** Branches that are not required for the correct answer but which only
+    ** help to obtain the correct answer faster are marked with special
+    ** comments, as a hint to the mutation tester.
+    */
+    while( e>0 ){                                       /*OPTIMIZATION-IF-TRUE*/
+      if( esign>0 ){
+        if( s>=(LARGEST_INT64/10) ) break;             /*OPTIMIZATION-IF-FALSE*/
+        s *= 10;
+      }else{
+        if( s%10!=0 ) break;                           /*OPTIMIZATION-IF-FALSE*/
+        s /= 10;
+      }
+      e--;
     }
 
     /* adjust the sign of significand */
     s = sign<0 ? -s : s;
 
-    /* if exponent, scale significand as appropriate
-    ** and store in result. */
-    if( e ){
+    if( e==0 ){                                         /*OPTIMIZATION-IF-TRUE*/
+      result = (double)s;
+    }else{
       LONGDOUBLE_TYPE scale = 1.0;
       /* attempt to handle extremely small/large numbers better */
-      if( e>307 && e<342 ){
-        while( e%308 ) { scale *= 1.0e+1; e -= 1; }
-        if( esign<0 ){
-          result = s / scale;
-          result /= 1.0e+308;
-        }else{
-          result = s * scale;
-          result *= 1.0e+308;
-        }
-      }else if( e>=342 ){
-        if( esign<0 ){
-          result = 0.0*s;
-        }else{
-          result = 1e308*1e308*s;  /* Infinity */
+      if( e>307 ){                                      /*OPTIMIZATION-IF-TRUE*/
+        if( e<342 ){                                    /*OPTIMIZATION-IF-TRUE*/
+          while( e%308 ) { scale *= 1.0e+1; e -= 1; }
+          if( esign<0 ){
+            result = s / scale;
+            result /= 1.0e+308;
+          }else{
+            result = s * scale;
+            result *= 1.0e+308;
+          }
+        }else{ assert( e>=342 );
+          if( esign<0 ){
+            result = 0.0*s;
+          }else{
+            result = 1e308*1e308*s;  /* Infinity */
+          }
         }
       }else{
         /* 1.0e+22 is the largest power of 10 than can be 
@@ -23580,8 +28695,6 @@ do_atof_calc:
           result = s * scale;
         }
       }
-    } else {
-      result = (double)s;
     }
   }
 
@@ -23589,7 +28702,7 @@ do_atof_calc:
   *pResult = result;
 
   /* return true if number and no extra non-whitespace chracters after */
-  return z>=zEnd && nDigits>0 && eValid && nonNum==0;
+  return z==zEnd && nDigits>0 && eValid && nonNum==0;
 #else
   return !sqlite3Atoi64(z, pResult, length, enc);
 #endif /* SQLITE_OMIT_FLOATING_POINT */
@@ -23651,7 +28764,7 @@ SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc
   int neg = 0; /* assume positive */
   int i;
   int c = 0;
-  int nonNum = 0;
+  int nonNum = 0;  /* True if input contains UTF16 with high byte non-zero */
   const char *zStart;
   const char *zEnd = zNum + length;
   assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
@@ -23662,7 +28775,7 @@ SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc
     assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
     for(i=3-enc; i19*incr || nonNum ){
+  if( &zNum[i]19*incr                  /* Too many digits */
+   || nonNum                     /* UTF16 with high-order bytes non-zero */
+  ){
     /* zNum is empty or contains non-numeric text or is longer
     ** than 19 digits (thus guaranteeing that it is too large) */
     return 1;
@@ -23731,7 +28848,6 @@ SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char *z, i64 *pOut){
 #ifndef SQLITE_OMIT_HEX_INTEGER
   if( z[0]=='0'
    && (z[1]=='x' || z[1]=='X')
-   && sqlite3Isxdigit(z[2])
   ){
     u64 u = 0;
     int i, k;
@@ -23787,6 +28903,8 @@ SQLITE_PRIVATE int sqlite3GetInt32(const char *zNum, int *pValue){
     }
   }
 #endif
+  if( !sqlite3Isdigit(zNum[0]) ) return 0;
+  while( zNum[0]=='0' ) zNum++;
   for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
     v = v*10 + c;
   }
@@ -23977,7 +29095,8 @@ SQLITE_PRIVATE u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   /* a: p0<<28 | p2<<14 | p4 (unmasked) */
   if (!(a&0x80))
   {
-    /* we can skip these cause they were (effectively) done above in calc'ing s */
+    /* we can skip these cause they were (effectively) done above
+    ** while calculating s */
     /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
     /* b &= (0x7f<<14)|(0x7f); */
     b = b<<7;
@@ -24198,11 +29317,8 @@ SQLITE_PRIVATE u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){
 ** 64-bit integer.
 */
 SQLITE_PRIVATE int sqlite3VarintLen(u64 v){
-  int i = 0;
-  do{
-    i++;
-    v >>= 7;
-  }while( v!=0 && ALWAYS(i<9) );
+  int i;
+  for(i=1; (v >>= 7)!=0; i++){ assert( i<10 ); }
   return i;
 }
 
@@ -24211,14 +29327,38 @@ SQLITE_PRIVATE int sqlite3VarintLen(u64 v){
 ** Read or write a four-byte big-endian integer value.
 */
 SQLITE_PRIVATE u32 sqlite3Get4byte(const u8 *p){
+#if SQLITE_BYTEORDER==4321
+  u32 x;
+  memcpy(&x,p,4);
+  return x;
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  u32 x;
+  memcpy(&x,p,4);
+  return __builtin_bswap32(x);
+#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+  u32 x;
+  memcpy(&x,p,4);
+  return _byteswap_ulong(x);
+#else
   testcase( p[0]&0x80 );
   return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+#endif
 }
 SQLITE_PRIVATE void sqlite3Put4byte(unsigned char *p, u32 v){
+#if SQLITE_BYTEORDER==4321
+  memcpy(p,&v,4);
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  u32 x = __builtin_bswap32(v);
+  memcpy(p,&x,4);
+#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+  u32 x = _byteswap_ulong(v);
+  memcpy(p,&x,4);
+#else
   p[0] = (u8)(v>>24);
   p[1] = (u8)(v>>16);
   p[2] = (u8)(v>>8);
   p[3] = (u8)v;
+#endif
 }
 
 
@@ -24250,7 +29390,7 @@ SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){
   char *zBlob;
   int i;
 
-  zBlob = (char *)sqlite3DbMallocRaw(db, n/2 + 1);
+  zBlob = (char *)sqlite3DbMallocRawNN(db, n/2 + 1);
   n--;
   if( zBlob ){
     for(i=0; i=5004000
+  return __builtin_add_overflow(*pA, iB, pA);
+#else
   i64 iA = *pA;
   testcase( iA==0 ); testcase( iA==1 );
   testcase( iB==-1 ); testcase( iB==0 );
@@ -24340,8 +29483,12 @@ SQLITE_PRIVATE int sqlite3AddInt64(i64 *pA, i64 iB){
   }
   *pA += iB;
   return 0; 
+#endif
 }
 SQLITE_PRIVATE int sqlite3SubInt64(i64 *pA, i64 iB){
+#if GCC_VERSION>=5004000
+  return __builtin_sub_overflow(*pA, iB, pA);
+#else
   testcase( iB==SMALLEST_INT64+1 );
   if( iB==SMALLEST_INT64 ){
     testcase( (*pA)==(-1) ); testcase( (*pA)==0 );
@@ -24351,38 +29498,28 @@ SQLITE_PRIVATE int sqlite3SubInt64(i64 *pA, i64 iB){
   }else{
     return sqlite3AddInt64(pA, -iB);
   }
+#endif
 }
-#define TWOPOWER32 (((i64)1)<<32)
-#define TWOPOWER31 (((i64)1)<<31)
 SQLITE_PRIVATE int sqlite3MulInt64(i64 *pA, i64 iB){
+#if GCC_VERSION>=5004000
+  return __builtin_mul_overflow(*pA, iB, pA);
+#else
   i64 iA = *pA;
-  i64 iA1, iA0, iB1, iB0, r;
-
-  iA1 = iA/TWOPOWER32;
-  iA0 = iA % TWOPOWER32;
-  iB1 = iB/TWOPOWER32;
-  iB0 = iB % TWOPOWER32;
-  if( iA1==0 ){
-    if( iB1==0 ){
-      *pA *= iB;
-      return 0;
-    }
-    r = iA0*iB1;
-  }else if( iB1==0 ){
-    r = iA1*iB0;
-  }else{
-    /* If both iA1 and iB1 are non-zero, overflow will result */
-    return 1;
-  }
-  testcase( r==(-TWOPOWER31)-1 );
-  testcase( r==(-TWOPOWER31) );
-  testcase( r==TWOPOWER31 );
-  testcase( r==TWOPOWER31-1 );
-  if( r<(-TWOPOWER31) || r>=TWOPOWER31 ) return 1;
-  r *= TWOPOWER32;
-  if( sqlite3AddInt64(&r, iA0*iB0) ) return 1;
-  *pA = r;
+  if( iB>0 ){
+    if( iA>LARGEST_INT64/iB ) return 1;
+    if( iA0 ){
+      if( iBLARGEST_INT64/-iB ) return 1;
+    }
+  }
+  *pA = iA*iB;
   return 0;
+#endif
 }
 
 /*
@@ -24466,7 +29603,7 @@ SQLITE_PRIVATE LogEst sqlite3LogEst(u64 x){
     if( x<2 ) return 0;
     while( x<8 ){  y -= 10; x <<= 1; }
   }else{
-    while( x>255 ){ y += 40; x >>= 4; }
+    while( x>255 ){ y += 40; x >>= 4; }  /*OPTIMIZATION-IF-TRUE*/
     while( x>15 ){  y += 10; x >>= 1; }
   }
   return a[x&7] + y - 10;
@@ -24489,20 +29626,134 @@ SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double x){
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
 /*
 ** Convert a LogEst into an integer.
+**
+** Note that this routine is only used when one or more of various
+** non-standard compile-time options is enabled.
 */
 SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst x){
   u64 n;
-  if( x<10 ) return 1;
   n = x%10;
   x /= 10;
   if( n>=5 ) n -= 2;
   else if( n>=1 ) n -= 1;
-  if( x>=3 ){
-    return x>60 ? (u64)LARGEST_INT64 : (n+8)<<(x-3);
-  }
-  return (n+8)>>(3-x);
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
+  if( x>60 ) return (u64)LARGEST_INT64;
+#else
+  /* If only SQLITE_ENABLE_STAT3_OR_STAT4 is on, then the largest input
+  ** possible to this routine is 310, resulting in a maximum x of 31 */
+  assert( x<=60 );
+#endif
+  return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x);
+}
+#endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */
+
+/*
+** Add a new name/number pair to a VList.  This might require that the
+** VList object be reallocated, so return the new VList.  If an OOM
+** error occurs, the original VList returned and the
+** db->mallocFailed flag is set.
+**
+** A VList is really just an array of integers.  To destroy a VList,
+** simply pass it to sqlite3DbFree().
+**
+** The first integer is the number of integers allocated for the whole
+** VList.  The second integer is the number of integers actually used.
+** Each name/number pair is encoded by subsequent groups of 3 or more
+** integers.
+**
+** Each name/number pair starts with two integers which are the numeric
+** value for the pair and the size of the name/number pair, respectively.
+** The text name overlays one or more following integers.  The text name
+** is always zero-terminated.
+**
+** Conceptually:
+**
+**    struct VList {
+**      int nAlloc;   // Number of allocated slots 
+**      int nUsed;    // Number of used slots 
+**      struct VListEntry {
+**        int iValue;    // Value for this entry
+**        int nSlot;     // Slots used by this entry
+**        // ... variable name goes here
+**      } a[0];
+**    }
+**
+** During code generation, pointers to the variable names within the
+** VList are taken.  When that happens, nAlloc is set to zero as an 
+** indication that the VList may never again be enlarged, since the
+** accompanying realloc() would invalidate the pointers.
+*/
+SQLITE_PRIVATE VList *sqlite3VListAdd(
+  sqlite3 *db,           /* The database connection used for malloc() */
+  VList *pIn,            /* The input VList.  Might be NULL */
+  const char *zName,     /* Name of symbol to add */
+  int nName,             /* Bytes of text in zName */
+  int iVal               /* Value to associate with zName */
+){
+  int nInt;              /* number of sizeof(int) objects needed for zName */
+  char *z;               /* Pointer to where zName will be stored */
+  int i;                 /* Index in pIn[] where zName is stored */
+
+  nInt = nName/4 + 3;
+  assert( pIn==0 || pIn[0]>=3 );  /* Verify ok to add new elements */
+  if( pIn==0 || pIn[1]+nInt > pIn[0] ){
+    /* Enlarge the allocation */
+    int nAlloc = (pIn ? pIn[0]*2 : 10) + nInt;
+    VList *pOut = sqlite3DbRealloc(db, pIn, nAlloc*sizeof(int));
+    if( pOut==0 ) return pIn;
+    if( pIn==0 ) pOut[1] = 2;
+    pIn = pOut;
+    pIn[0] = nAlloc;
+  }
+  i = pIn[1];
+  pIn[i] = iVal;
+  pIn[i+1] = nInt;
+  z = (char*)&pIn[i+2];
+  pIn[1] = i+nInt;
+  assert( pIn[1]<=pIn[0] );
+  memcpy(z, zName, nName);
+  z[nName] = 0;
+  return pIn;
+}
+
+/*
+** Return a pointer to the name of a variable in the given VList that
+** has the value iVal.  Or return a NULL if there is no such variable in
+** the list
+*/
+SQLITE_PRIVATE const char *sqlite3VListNumToName(VList *pIn, int iVal){
+  int i, mx;
+  if( pIn==0 ) return 0;
+  mx = pIn[1];
+  i = 2;
+  do{
+    if( pIn[i]==iVal ) return (char*)&pIn[i+2];
+    i += pIn[i+1];
+  }while( i */
 
 /* Turn bulk memory into a hash table object by initializing the
@@ -24563,8 +29815,12 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash *pH){
 static unsigned int strHash(const char *z){
   unsigned int h = 0;
   unsigned char c;
-  while( (c = (unsigned char)*z++)!=0 ){
-    h = (h<<3) ^ h ^ sqlite3UpperToLower[c];
+  while( (c = (unsigned char)*z++)!=0 ){     /*OPTIMIZATION-IF-TRUE*/
+    /* Knuth multiplicative hashing.  (Sorting & Searching, p. 510).
+    ** 0x9e3779b1 is 2654435761 which is the closest prime number to
+    ** (2**32)*golden_ratio, where golden_ratio = (sqrt(5) - 1)/2. */
+    h += sqlite3UpperToLower[c];
+    h *= 0x9e3779b1;
   }
   return h;
 }
@@ -24644,8 +29900,9 @@ static int rehash(Hash *pH, unsigned int new_size){
 }
 
 /* This function (for internal use only) locates an element in an
-** hash table that matches the given key.  The hash for this key is
-** also computed and returned in the *pH parameter.
+** hash table that matches the given key.  If no element is found,
+** a pointer to a static null element with HashElem.data==0 is returned.
+** If pH is not NULL, then the hash for this key is written to *pH.
 */
 static HashElem *findElementWithHash(
   const Hash *pH,     /* The pH to be searched */
@@ -24655,8 +29912,9 @@ static HashElem *findElementWithHash(
   HashElem *elem;                /* Used to loop thru the element list */
   int count;                     /* Number of elements left to test */
   unsigned int h;                /* The computed hash */
+  static HashElem nullElement = { 0, 0, 0, 0 };
 
-  if( pH->ht ){
+  if( pH->ht ){   /*OPTIMIZATION-IF-TRUE*/
     struct _ht *pEntry;
     h = strHash(pKey) % pH->htsize;
     pEntry = &pH->ht[h];
@@ -24667,7 +29925,7 @@ static HashElem *findElementWithHash(
     elem = pH->first;
     count = pH->count;
   }
-  *pHash = h;
+  if( pHash ) *pHash = h;
   while( count-- ){
     assert( elem!=0 );
     if( sqlite3StrICmp(elem->pKey,pKey)==0 ){ 
@@ -24675,7 +29933,7 @@ static HashElem *findElementWithHash(
     }
     elem = elem->next;
   }
-  return 0;
+  return &nullElement;
 }
 
 /* Remove a single entry from the hash table given a pointer to that
@@ -24717,13 +29975,9 @@ static void removeElementGivenHash(
 ** found, or NULL if there is no match.
 */
 SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey){
-  HashElem *elem;    /* The element that matches key */
-  unsigned int h;    /* A hash on key */
-
   assert( pH!=0 );
   assert( pKey!=0 );
-  elem = findElementWithHash(pH, pKey, &h);
-  return elem ? elem->data : 0;
+  return findElementWithHash(pH, pKey, 0)->data;
 }
 
 /* Insert an element into the hash table pH.  The key is pKey
@@ -24748,7 +30002,7 @@ SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, void *data){
   assert( pH!=0 );
   assert( pKey!=0 );
   elem = findElementWithHash(pH,pKey,&h);
-  if( elem ){
+  if( elem->data ){
     void *old_data = elem->data;
     if( data==0 ){
       removeElementGivenHash(pH,elem,h);
@@ -24777,170 +30031,185 @@ SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, void *data){
 /************** End of hash.c ************************************************/
 /************** Begin file opcodes.c *****************************************/
 /* Automatically generated.  Do not edit */
-/* See the mkopcodec.awk script for details. */
-#if !defined(SQLITE_OMIT_EXPLAIN) || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+/* See the tool/mkopcodec.tcl script for details. */
+#if !defined(SQLITE_OMIT_EXPLAIN) \
+ || defined(VDBE_PROFILE) \
+ || defined(SQLITE_DEBUG)
 #if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) || defined(SQLITE_DEBUG)
 # define OpHelp(X) "\0" X
 #else
 # define OpHelp(X)
 #endif
 SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
- static const char *const azName[] = { "?",
-     /*   1 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),
-     /*   2 */ "Savepoint"        OpHelp(""),
-     /*   3 */ "AutoCommit"       OpHelp(""),
-     /*   4 */ "Transaction"      OpHelp(""),
-     /*   5 */ "SorterNext"       OpHelp(""),
-     /*   6 */ "PrevIfOpen"       OpHelp(""),
-     /*   7 */ "NextIfOpen"       OpHelp(""),
-     /*   8 */ "Prev"             OpHelp(""),
-     /*   9 */ "Next"             OpHelp(""),
-     /*  10 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
-     /*  11 */ "Checkpoint"       OpHelp(""),
-     /*  12 */ "JournalMode"      OpHelp(""),
-     /*  13 */ "Vacuum"           OpHelp(""),
-     /*  14 */ "VFilter"          OpHelp("iplan=r[P3] zplan='P4'"),
-     /*  15 */ "VUpdate"          OpHelp("data=r[P3@P2]"),
-     /*  16 */ "Goto"             OpHelp(""),
-     /*  17 */ "Gosub"            OpHelp(""),
-     /*  18 */ "Return"           OpHelp(""),
-     /*  19 */ "Not"              OpHelp("r[P2]= !r[P1]"),
-     /*  20 */ "InitCoroutine"    OpHelp(""),
-     /*  21 */ "EndCoroutine"     OpHelp(""),
-     /*  22 */ "Yield"            OpHelp(""),
-     /*  23 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
-     /*  24 */ "Halt"             OpHelp(""),
-     /*  25 */ "Integer"          OpHelp("r[P2]=P1"),
-     /*  26 */ "Int64"            OpHelp("r[P2]=P4"),
-     /*  27 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
-     /*  28 */ "Null"             OpHelp("r[P2..P3]=NULL"),
-     /*  29 */ "SoftNull"         OpHelp("r[P1]=NULL"),
-     /*  30 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
-     /*  31 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),
-     /*  32 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
-     /*  33 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
-     /*  34 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
-     /*  35 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
-     /*  36 */ "CollSeq"          OpHelp(""),
-     /*  37 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
-     /*  38 */ "MustBeInt"        OpHelp(""),
-     /*  39 */ "RealAffinity"     OpHelp(""),
-     /*  40 */ "Cast"             OpHelp("affinity(r[P1])"),
-     /*  41 */ "Permutation"      OpHelp(""),
-     /*  42 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
-     /*  43 */ "Jump"             OpHelp(""),
-     /*  44 */ "Once"             OpHelp(""),
-     /*  45 */ "If"               OpHelp(""),
-     /*  46 */ "IfNot"            OpHelp(""),
-     /*  47 */ "Column"           OpHelp("r[P3]=PX"),
-     /*  48 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
-     /*  49 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
-     /*  50 */ "Count"            OpHelp("r[P2]=count()"),
-     /*  51 */ "ReadCookie"       OpHelp(""),
-     /*  52 */ "SetCookie"        OpHelp(""),
-     /*  53 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),
-     /*  54 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
-     /*  55 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),
-     /*  56 */ "OpenAutoindex"    OpHelp("nColumn=P2"),
-     /*  57 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
-     /*  58 */ "SorterOpen"       OpHelp(""),
-     /*  59 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
-     /*  60 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
-     /*  61 */ "Close"            OpHelp(""),
-     /*  62 */ "SeekLT"           OpHelp("key=r[P3@P4]"),
-     /*  63 */ "SeekLE"           OpHelp("key=r[P3@P4]"),
-     /*  64 */ "SeekGE"           OpHelp("key=r[P3@P4]"),
-     /*  65 */ "SeekGT"           OpHelp("key=r[P3@P4]"),
-     /*  66 */ "Seek"             OpHelp("intkey=r[P2]"),
-     /*  67 */ "NoConflict"       OpHelp("key=r[P3@P4]"),
-     /*  68 */ "NotFound"         OpHelp("key=r[P3@P4]"),
-     /*  69 */ "Found"            OpHelp("key=r[P3@P4]"),
-     /*  70 */ "NotExists"        OpHelp("intkey=r[P3]"),
-     /*  71 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),
-     /*  72 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),
-     /*  73 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),
-     /*  74 */ "NewRowid"         OpHelp("r[P2]=rowid"),
-     /*  75 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
-     /*  76 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
-     /*  77 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
-     /*  78 */ "Ne"               OpHelp("if r[P1]!=r[P3] goto P2"),
-     /*  79 */ "Eq"               OpHelp("if r[P1]==r[P3] goto P2"),
-     /*  80 */ "Gt"               OpHelp("if r[P1]>r[P3] goto P2"),
-     /*  81 */ "Le"               OpHelp("if r[P1]<=r[P3] goto P2"),
-     /*  82 */ "Lt"               OpHelp("if r[P1]=r[P3] goto P2"),
-     /*  84 */ "InsertInt"        OpHelp("intkey=P3 data=r[P2]"),
-     /*  85 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
-     /*  86 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
-     /*  87 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<>r[P1]"),
-     /*  89 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
-     /*  90 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
-     /*  91 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
-     /*  92 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
-     /*  93 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
-     /*  94 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
-     /*  95 */ "Delete"           OpHelp(""),
-     /*  96 */ "BitNot"           OpHelp("r[P1]= ~r[P1]"),
-     /*  97 */ "String8"          OpHelp("r[P2]='P4'"),
-     /*  98 */ "ResetCount"       OpHelp(""),
-     /*  99 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
-     /* 100 */ "SorterData"       OpHelp("r[P2]=data"),
-     /* 101 */ "RowKey"           OpHelp("r[P2]=key"),
-     /* 102 */ "RowData"          OpHelp("r[P2]=data"),
-     /* 103 */ "Rowid"            OpHelp("r[P2]=rowid"),
-     /* 104 */ "NullRow"          OpHelp(""),
-     /* 105 */ "Last"             OpHelp(""),
-     /* 106 */ "SorterSort"       OpHelp(""),
-     /* 107 */ "Sort"             OpHelp(""),
-     /* 108 */ "Rewind"           OpHelp(""),
-     /* 109 */ "SorterInsert"     OpHelp(""),
-     /* 110 */ "IdxInsert"        OpHelp("key=r[P2]"),
-     /* 111 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),
-     /* 112 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
-     /* 113 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
-     /* 114 */ "IdxGT"            OpHelp("key=r[P3@P4]"),
-     /* 115 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
-     /* 116 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
-     /* 117 */ "Destroy"          OpHelp(""),
-     /* 118 */ "Clear"            OpHelp(""),
-     /* 119 */ "ResetSorter"      OpHelp(""),
-     /* 120 */ "CreateIndex"      OpHelp("r[P2]=root iDb=P1"),
-     /* 121 */ "CreateTable"      OpHelp("r[P2]=root iDb=P1"),
-     /* 122 */ "ParseSchema"      OpHelp(""),
-     /* 123 */ "LoadAnalysis"     OpHelp(""),
-     /* 124 */ "DropTable"        OpHelp(""),
-     /* 125 */ "DropIndex"        OpHelp(""),
-     /* 126 */ "DropTrigger"      OpHelp(""),
-     /* 127 */ "IntegrityCk"      OpHelp(""),
-     /* 128 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
-     /* 129 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
-     /* 130 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
-     /* 131 */ "Program"          OpHelp(""),
-     /* 132 */ "Param"            OpHelp(""),
-     /* 133 */ "Real"             OpHelp("r[P2]=P4"),
-     /* 134 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
-     /* 135 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
-     /* 136 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
-     /* 137 */ "IfPos"            OpHelp("if r[P1]>0 goto P2"),
-     /* 138 */ "IfNeg"            OpHelp("r[P1]+=P3, if r[P1]<0 goto P2"),
-     /* 139 */ "IfZero"           OpHelp("r[P1]+=P3, if r[P1]==0 goto P2"),
-     /* 140 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
-     /* 141 */ "IncrVacuum"       OpHelp(""),
-     /* 142 */ "Expire"           OpHelp(""),
-     /* 143 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
-     /* 144 */ "VBegin"           OpHelp(""),
-     /* 145 */ "VCreate"          OpHelp(""),
-     /* 146 */ "VDestroy"         OpHelp(""),
-     /* 147 */ "VOpen"            OpHelp(""),
-     /* 148 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
-     /* 149 */ "VNext"            OpHelp(""),
-     /* 150 */ "VRename"          OpHelp(""),
-     /* 151 */ "Pagecount"        OpHelp(""),
-     /* 152 */ "MaxPgcnt"         OpHelp(""),
-     /* 153 */ "Init"             OpHelp("Start at P2"),
-     /* 154 */ "Noop"             OpHelp(""),
-     /* 155 */ "Explain"          OpHelp(""),
+ static const char *const azName[] = {
+    /*   0 */ "Savepoint"        OpHelp(""),
+    /*   1 */ "AutoCommit"       OpHelp(""),
+    /*   2 */ "Transaction"      OpHelp(""),
+    /*   3 */ "SorterNext"       OpHelp(""),
+    /*   4 */ "PrevIfOpen"       OpHelp(""),
+    /*   5 */ "NextIfOpen"       OpHelp(""),
+    /*   6 */ "Prev"             OpHelp(""),
+    /*   7 */ "Next"             OpHelp(""),
+    /*   8 */ "Checkpoint"       OpHelp(""),
+    /*   9 */ "JournalMode"      OpHelp(""),
+    /*  10 */ "Vacuum"           OpHelp(""),
+    /*  11 */ "VFilter"          OpHelp("iplan=r[P3] zplan='P4'"),
+    /*  12 */ "VUpdate"          OpHelp("data=r[P3@P2]"),
+    /*  13 */ "Goto"             OpHelp(""),
+    /*  14 */ "Gosub"            OpHelp(""),
+    /*  15 */ "InitCoroutine"    OpHelp(""),
+    /*  16 */ "Yield"            OpHelp(""),
+    /*  17 */ "MustBeInt"        OpHelp(""),
+    /*  18 */ "Jump"             OpHelp(""),
+    /*  19 */ "Not"              OpHelp("r[P2]= !r[P1]"),
+    /*  20 */ "Once"             OpHelp(""),
+    /*  21 */ "If"               OpHelp(""),
+    /*  22 */ "IfNot"            OpHelp(""),
+    /*  23 */ "IfNullRow"        OpHelp("if P1.nullRow then r[P3]=NULL, goto P2"),
+    /*  24 */ "SeekLT"           OpHelp("key=r[P3@P4]"),
+    /*  25 */ "SeekLE"           OpHelp("key=r[P3@P4]"),
+    /*  26 */ "SeekGE"           OpHelp("key=r[P3@P4]"),
+    /*  27 */ "SeekGT"           OpHelp("key=r[P3@P4]"),
+    /*  28 */ "NoConflict"       OpHelp("key=r[P3@P4]"),
+    /*  29 */ "NotFound"         OpHelp("key=r[P3@P4]"),
+    /*  30 */ "Found"            OpHelp("key=r[P3@P4]"),
+    /*  31 */ "SeekRowid"        OpHelp("intkey=r[P3]"),
+    /*  32 */ "NotExists"        OpHelp("intkey=r[P3]"),
+    /*  33 */ "Last"             OpHelp(""),
+    /*  34 */ "IfSmaller"        OpHelp(""),
+    /*  35 */ "SorterSort"       OpHelp(""),
+    /*  36 */ "Sort"             OpHelp(""),
+    /*  37 */ "Rewind"           OpHelp(""),
+    /*  38 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
+    /*  39 */ "IdxGT"            OpHelp("key=r[P3@P4]"),
+    /*  40 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
+    /*  41 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
+    /*  42 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
+    /*  43 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
+    /*  44 */ "Program"          OpHelp(""),
+    /*  45 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
+    /*  46 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
+    /*  47 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]--, goto P2"),
+    /*  48 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
+    /*  49 */ "IncrVacuum"       OpHelp(""),
+    /*  50 */ "VNext"            OpHelp(""),
+    /*  51 */ "Init"             OpHelp("Start at P2"),
+    /*  52 */ "Return"           OpHelp(""),
+    /*  53 */ "EndCoroutine"     OpHelp(""),
+    /*  54 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
+    /*  55 */ "Halt"             OpHelp(""),
+    /*  56 */ "Integer"          OpHelp("r[P2]=P1"),
+    /*  57 */ "Int64"            OpHelp("r[P2]=P4"),
+    /*  58 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
+    /*  59 */ "Null"             OpHelp("r[P2..P3]=NULL"),
+    /*  60 */ "SoftNull"         OpHelp("r[P1]=NULL"),
+    /*  61 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
+    /*  62 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),
+    /*  63 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
+    /*  64 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
+    /*  65 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
+    /*  66 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),
+    /*  67 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
+    /*  68 */ "CollSeq"          OpHelp(""),
+    /*  69 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
+    /*  70 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),
+    /*  71 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),
+    /*  72 */ "RealAffinity"     OpHelp(""),
+    /*  73 */ "Cast"             OpHelp("affinity(r[P1])"),
+    /*  74 */ "Permutation"      OpHelp(""),
+    /*  75 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
+    /*  76 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
+    /*  77 */ "Ne"               OpHelp("IF r[P3]!=r[P1]"),
+    /*  78 */ "Eq"               OpHelp("IF r[P3]==r[P1]"),
+    /*  79 */ "Gt"               OpHelp("IF r[P3]>r[P1]"),
+    /*  80 */ "Le"               OpHelp("IF r[P3]<=r[P1]"),
+    /*  81 */ "Lt"               OpHelp("IF r[P3]=r[P1]"),
+    /*  83 */ "ElseNotEq"        OpHelp(""),
+    /*  84 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
+    /*  85 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
+    /*  86 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<>r[P1]"),
+    /*  88 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
+    /*  89 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
+    /*  90 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
+    /*  91 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
+    /*  92 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
+    /*  93 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
+    /*  94 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
+    /*  95 */ "BitNot"           OpHelp("r[P1]= ~r[P1]"),
+    /*  96 */ "Column"           OpHelp("r[P3]=PX"),
+    /*  97 */ "String8"          OpHelp("r[P2]='P4'"),
+    /*  98 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
+    /*  99 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
+    /* 100 */ "Count"            OpHelp("r[P2]=count()"),
+    /* 101 */ "ReadCookie"       OpHelp(""),
+    /* 102 */ "SetCookie"        OpHelp(""),
+    /* 103 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),
+    /* 104 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
+    /* 105 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),
+    /* 106 */ "OpenDup"          OpHelp(""),
+    /* 107 */ "OpenAutoindex"    OpHelp("nColumn=P2"),
+    /* 108 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
+    /* 109 */ "SorterOpen"       OpHelp(""),
+    /* 110 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
+    /* 111 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
+    /* 112 */ "Close"            OpHelp(""),
+    /* 113 */ "ColumnsUsed"      OpHelp(""),
+    /* 114 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),
+    /* 115 */ "NewRowid"         OpHelp("r[P2]=rowid"),
+    /* 116 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
+    /* 117 */ "InsertInt"        OpHelp("intkey=P3 data=r[P2]"),
+    /* 118 */ "Delete"           OpHelp(""),
+    /* 119 */ "ResetCount"       OpHelp(""),
+    /* 120 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
+    /* 121 */ "SorterData"       OpHelp("r[P2]=data"),
+    /* 122 */ "RowData"          OpHelp("r[P2]=data"),
+    /* 123 */ "Rowid"            OpHelp("r[P2]=rowid"),
+    /* 124 */ "NullRow"          OpHelp(""),
+    /* 125 */ "SorterInsert"     OpHelp("key=r[P2]"),
+    /* 126 */ "IdxInsert"        OpHelp("key=r[P2]"),
+    /* 127 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),
+    /* 128 */ "DeferredSeek"     OpHelp("Move P3 to P1.rowid if needed"),
+    /* 129 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
+    /* 130 */ "Destroy"          OpHelp(""),
+    /* 131 */ "Clear"            OpHelp(""),
+    /* 132 */ "Real"             OpHelp("r[P2]=P4"),
+    /* 133 */ "ResetSorter"      OpHelp(""),
+    /* 134 */ "CreateIndex"      OpHelp("r[P2]=root iDb=P1"),
+    /* 135 */ "CreateTable"      OpHelp("r[P2]=root iDb=P1"),
+    /* 136 */ "SqlExec"          OpHelp(""),
+    /* 137 */ "ParseSchema"      OpHelp(""),
+    /* 138 */ "LoadAnalysis"     OpHelp(""),
+    /* 139 */ "DropTable"        OpHelp(""),
+    /* 140 */ "DropIndex"        OpHelp(""),
+    /* 141 */ "DropTrigger"      OpHelp(""),
+    /* 142 */ "IntegrityCk"      OpHelp(""),
+    /* 143 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
+    /* 144 */ "Param"            OpHelp(""),
+    /* 145 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
+    /* 146 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
+    /* 147 */ "OffsetLimit"      OpHelp("if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)"),
+    /* 148 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
+    /* 149 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
+    /* 150 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
+    /* 151 */ "Expire"           OpHelp(""),
+    /* 152 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
+    /* 153 */ "VBegin"           OpHelp(""),
+    /* 154 */ "VCreate"          OpHelp(""),
+    /* 155 */ "VDestroy"         OpHelp(""),
+    /* 156 */ "VOpen"            OpHelp(""),
+    /* 157 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
+    /* 158 */ "VRename"          OpHelp(""),
+    /* 159 */ "Pagecount"        OpHelp(""),
+    /* 160 */ "MaxPgcnt"         OpHelp(""),
+    /* 161 */ "PureFunc0"        OpHelp(""),
+    /* 162 */ "Function0"        OpHelp("r[P3]=func(r[P2@P5])"),
+    /* 163 */ "PureFunc"         OpHelp(""),
+    /* 164 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),
+    /* 165 */ "CursorHint"       OpHelp(""),
+    /* 166 */ "Noop"             OpHelp(""),
+    /* 167 */ "Explain"          OpHelp(""),
   };
   return azName[i];
 }
@@ -24993,6 +30262,7 @@ SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
 **   *  Definitions of sqlite3_vfs objects for all locking methods
 **      plus implementations of sqlite3_os_init() and sqlite3_os_end().
 */
+/* #include "sqliteInt.h" */
 #if SQLITE_OS_UNIX              /* This file is used on unix only */
 
 /*
@@ -25020,16 +30290,17 @@ SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
 #  endif
 #endif
 
-/*
-** Define the OS_VXWORKS pre-processor macro to 1 if building on 
-** vxworks, or 0 otherwise.
-*/
-#ifndef OS_VXWORKS
-#  if defined(__RTP__) || defined(_WRS_KERNEL)
-#    define OS_VXWORKS 1
-#  else
-#    define OS_VXWORKS 0
-#  endif
+/* Use pread() and pwrite() if they are available */
+#if defined(__APPLE__)
+# define HAVE_PREAD 1
+# define HAVE_PWRITE 1
+#endif
+#if defined(HAVE_PREAD64) && defined(HAVE_PWRITE64)
+# undef USE_PREAD
+# define USE_PREAD64 1
+#elif defined(HAVE_PREAD) && defined(HAVE_PWRITE)
+# undef USE_PREAD64
+# define USE_PREAD 1
 #endif
 
 /*
@@ -25046,18 +30317,30 @@ SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
 # include 
 #endif
 
-#if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE
 # include 
-# if OS_VXWORKS
-#  include 
-#  include 
-# else
-#  include 
-#  include 
-# endif
+# include 
+# include 
 #endif /* SQLITE_ENABLE_LOCKING_STYLE */
 
-#if defined(__APPLE__) || (SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS)
+#if defined(__APPLE__) && ((__MAC_OS_X_VERSION_MIN_REQUIRED > 1050) || \
+                           (__IPHONE_OS_VERSION_MIN_REQUIRED > 2000))
+#  if (!defined(TARGET_OS_EMBEDDED) || (TARGET_OS_EMBEDDED==0)) \
+       && (!defined(TARGET_IPHONE_SIMULATOR) || (TARGET_IPHONE_SIMULATOR==0))
+#    define HAVE_GETHOSTUUID 1
+#  else
+#    warning "gethostuuid() is disabled."
+#  endif
+#endif
+
+
+#if OS_VXWORKS
+/* # include  */
+# include 
+# include 
+#endif /* OS_VXWORKS */
+
+#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
 # include 
 #endif
 
@@ -25098,6 +30381,15 @@ SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
 */
 #define MAX_PATHNAME 512
 
+/*
+** Maximum supported symbolic links
+*/
+#define SQLITE_MAX_SYMLINKS 100
+
+/* Always cast the getpid() return type for compatibility with
+** kernel modules in VxWorks. */
+#define osGetpid(X) (pid_t)getpid()
+
 /*
 ** Only set the lastErrno if the error code is a real error and not 
 ** a normal expected return code of SQLITE_BUSY or SQLITE_OK
@@ -25186,7 +30478,7 @@ struct unixFile {
 ** method was called.  If xOpen() is called from a different process id,
 ** indicating that a fork() has occurred, the PRNG will be reset.
 */
-static int randomnessPid = 0;
+static pid_t randomnessPid = 0;
 
 /*
 ** Allowed values for the unixFile.ctrlFlags bitmask:
@@ -25203,7 +30495,6 @@ static int randomnessPid = 0;
 #define UNIXFILE_DELETE      0x20     /* Delete on close */
 #define UNIXFILE_URI         0x40     /* Filename might have query parameters */
 #define UNIXFILE_NOLOCK      0x80     /* Do no file locking */
-#define UNIXFILE_WARNED    0x0100     /* verifyDbFile() warnings have been issued */
 
 /*
 ** Include code that is common to all os_*.c files
@@ -25241,24 +30532,14 @@ static int randomnessPid = 0;
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
 /*
 ** Macros for performance tracing.  Normally turned off.  Only works
 ** on i486 hardware.
 */
 #ifdef SQLITE_PERFORMANCE_TRACE
 
-/* 
-** hwtime.h contains inline assembler code for implementing 
+/*
+** hwtime.h contains inline assembler code for implementing
 ** high-performance timing routines.
 */
 /************** Include hwtime.h in the middle of os_common.h ****************/
@@ -25278,8 +30559,8 @@ static int randomnessPid = 0;
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -25347,7 +30628,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in os_common.h ******************/
@@ -25368,14 +30649,14 @@ static sqlite_uint64 g_elapsed;
 ** of code will give us the ability to simulate a disk I/O error.  This
 ** is used for testing the I/O recovery logic.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
 #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
 #define SimulateIOError(CODE)  \
   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
@@ -25401,17 +30682,17 @@ static void local_ioerr(){
 #define SimulateIOErrorBenign(X)
 #define SimulateIOError(A)
 #define SimulateDiskfullError(A)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** When testing, keep a count of the number of open files.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
 #define OpenCounter(X)  sqlite3_open_file_count+=(X)
 #else
 #define OpenCounter(X)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 #endif /* !defined(_OS_COMMON_H_) */
 
@@ -25476,19 +30757,6 @@ static int posixOpen(const char *zFile, int flags, int mode){
   return open(zFile, flags, mode);
 }
 
-/*
-** On some systems, calls to fchown() will trigger a message in a security
-** log if they come from non-root processes.  So avoid calling fchown() if
-** we are not running as root.
-*/
-static int posixFchown(int fd, uid_t uid, gid_t gid){
-#if OS_VXWORKS
-  return 0;
-#else
-  return geteuid() ? 0 : fchown(fd,uid,gid);
-#endif
-}
-
 /* Forward reference */
 static int openDirectory(const char*, int*);
 static int unixGetpagesize(void);
@@ -25542,7 +30810,7 @@ static struct unix_syscall {
   { "read",         (sqlite3_syscall_ptr)read,       0  },
 #define osRead      ((ssize_t(*)(int,void*,size_t))aSyscall[8].pCurrent)
 
-#if defined(USE_PREAD) || (SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS)
+#if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE
   { "pread",        (sqlite3_syscall_ptr)pread,      0  },
 #else
   { "pread",        (sqlite3_syscall_ptr)0,          0  },
@@ -25554,12 +30822,12 @@ static struct unix_syscall {
 #else
   { "pread64",      (sqlite3_syscall_ptr)0,          0  },
 #endif
-#define osPread64   ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[10].pCurrent)
+#define osPread64 ((ssize_t(*)(int,void*,size_t,off64_t))aSyscall[10].pCurrent)
 
   { "write",        (sqlite3_syscall_ptr)write,      0  },
 #define osWrite     ((ssize_t(*)(int,const void*,size_t))aSyscall[11].pCurrent)
 
-#if defined(USE_PREAD) || (SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS)
+#if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE
   { "pwrite",       (sqlite3_syscall_ptr)pwrite,     0  },
 #else
   { "pwrite",       (sqlite3_syscall_ptr)0,          0  },
@@ -25572,10 +30840,10 @@ static struct unix_syscall {
 #else
   { "pwrite64",     (sqlite3_syscall_ptr)0,          0  },
 #endif
-#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
+#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off64_t))\
                     aSyscall[13].pCurrent)
 
-  { "fchmod",       (sqlite3_syscall_ptr)fchmod,     0  },
+  { "fchmod",       (sqlite3_syscall_ptr)fchmod,          0  },
 #define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)
 
 #if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
@@ -25597,29 +30865,74 @@ static struct unix_syscall {
   { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
 #define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)
 
-  { "fchown",       (sqlite3_syscall_ptr)posixFchown,     0 },
+#if defined(HAVE_FCHOWN)
+  { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },
+#else
+  { "fchown",       (sqlite3_syscall_ptr)0,               0 },
+#endif
 #define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)
 
+  { "geteuid",      (sqlite3_syscall_ptr)geteuid,         0 },
+#define osGeteuid   ((uid_t(*)(void))aSyscall[21].pCurrent)
+
 #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
-  { "mmap",       (sqlite3_syscall_ptr)mmap,     0 },
-#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[21].pCurrent)
+  { "mmap",         (sqlite3_syscall_ptr)mmap,            0 },
+#else
+  { "mmap",         (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)
 
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
   { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
-#define osMunmap ((void*(*)(void*,size_t))aSyscall[22].pCurrent)
+#else
+  { "munmap",       (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMunmap ((void*(*)(void*,size_t))aSyscall[23].pCurrent)
 
-#if HAVE_MREMAP
+#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
   { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
 #else
   { "mremap",       (sqlite3_syscall_ptr)0,               0 },
 #endif
-#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[23].pCurrent)
+#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)
+
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
   { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },
-#define osGetpagesize ((int(*)(void))aSyscall[24].pCurrent)
+#else
+  { "getpagesize",  (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osGetpagesize ((int(*)(void))aSyscall[25].pCurrent)
+
+#if defined(HAVE_READLINK)
+  { "readlink",     (sqlite3_syscall_ptr)readlink,        0 },
+#else
+  { "readlink",     (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)
 
+#if defined(HAVE_LSTAT)
+  { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },
+#else
+  { "lstat",         (sqlite3_syscall_ptr)0,              0 },
 #endif
+#define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)
 
 }; /* End of the overrideable system calls */
 
+
+/*
+** On some systems, calls to fchown() will trigger a message in a security
+** log if they come from non-root processes.  So avoid calling fchown() if
+** we are not running as root.
+*/
+static int robustFchown(int fd, uid_t uid, gid_t gid){
+#if defined(HAVE_FCHOWN)
+  return osGeteuid() ? 0 : osFchown(fd,uid,gid);
+#else
+  return 0;
+#endif
+}
+
 /*
 ** This is the xSetSystemCall() method of sqlite3_vfs for all of the
 ** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
@@ -25781,19 +31094,19 @@ static int robust_open(const char *z, int f, mode_t m){
 **   unixEnterLeave()
 */
 static void unixEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 static void unixLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #ifdef SQLITE_DEBUG
 static int unixMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #endif
 
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
+#ifdef SQLITE_HAVE_OS_TRACE
 /*
 ** Helper function for printing out trace information from debugging
 ** binaries. This returns the string representation of the supplied
@@ -25874,9 +31187,9 @@ static int lockTrace(int fd, int op, struct flock *p){
 /*
 ** Retry ftruncate() calls that fail due to EINTR
 **
-** All calls to ftruncate() within this file should be made through this wrapper.
-** On the Android platform, bypassing the logic below could lead to a corrupt
-** database.
+** All calls to ftruncate() within this file should be made through
+** this wrapper.  On the Android platform, bypassing the logic below
+** could lead to a corrupt database.
 */
 static int robust_ftruncate(int h, sqlite3_int64 sz){
   int rc;
@@ -25904,23 +31217,12 @@ static int robust_ftruncate(int h, sqlite3_int64 sz){
 ** should handle ENOLCK, ENOTSUP, EOPNOTSUPP separately.
 */
 static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
+  assert( (sqliteIOErr == SQLITE_IOERR_LOCK) || 
+          (sqliteIOErr == SQLITE_IOERR_UNLOCK) || 
+          (sqliteIOErr == SQLITE_IOERR_RDLOCK) ||
+          (sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) );
   switch (posixError) {
-#if 0
-  /* At one point this code was not commented out. In theory, this branch
-  ** should never be hit, as this function should only be called after
-  ** a locking-related function (i.e. fcntl()) has returned non-zero with
-  ** the value of errno as the first argument. Since a system call has failed,
-  ** errno should be non-zero.
-  **
-  ** Despite this, if errno really is zero, we still don't want to return
-  ** SQLITE_OK. The system call failed, and *some* SQLite error should be
-  ** propagated back to the caller. Commenting this branch out means errno==0
-  ** will be handled by the "default:" case below.
-  */
-  case 0: 
-    return SQLITE_OK;
-#endif
-
+  case EACCES: 
   case EAGAIN:
   case ETIMEDOUT:
   case EBUSY:
@@ -25930,41 +31232,9 @@ static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
      * introspection, in which it actually means what it says */
     return SQLITE_BUSY;
     
-  case EACCES: 
-    /* EACCES is like EAGAIN during locking operations, but not any other time*/
-    if( (sqliteIOErr == SQLITE_IOERR_LOCK) || 
-        (sqliteIOErr == SQLITE_IOERR_UNLOCK) || 
-        (sqliteIOErr == SQLITE_IOERR_RDLOCK) ||
-        (sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) ){
-      return SQLITE_BUSY;
-    }
-    /* else fall through */
   case EPERM: 
     return SQLITE_PERM;
     
-#if EOPNOTSUPP!=ENOTSUP
-  case EOPNOTSUPP: 
-    /* something went terribly awry, unless during file system support 
-     * introspection, in which it actually means what it says */
-#endif
-#ifdef ENOTSUP
-  case ENOTSUP: 
-    /* invalid fd, unless during file system support introspection, in which 
-     * it actually means what it says */
-#endif
-  case EIO:
-  case EBADF:
-  case EINVAL:
-  case ENOTCONN:
-  case ENODEV:
-  case ENXIO:
-  case ENOENT:
-#ifdef ESTALE                     /* ESTALE is not defined on Interix systems */
-  case ESTALE:
-#endif
-  case ENOSYS:
-    /* these should force the client to close the file and reconnect */
-    
   default: 
     return sqliteIOErr;
   }
@@ -26056,7 +31326,7 @@ static struct vxworksFileId *vxworksFindFileId(const char *zAbsoluteName){
 
   assert( zAbsoluteName[0]=='/' );
   n = (int)strlen(zAbsoluteName);
-  pNew = sqlite3_malloc( sizeof(*pNew) + (n+1) );
+  pNew = sqlite3_malloc64( sizeof(*pNew) + (n+1) );
   if( pNew==0 ) return 0;
   pNew->zCanonicalName = (char*)&pNew[1];
   memcpy(pNew->zCanonicalName, zAbsoluteName, n+1);
@@ -26208,7 +31478,14 @@ struct unixFileId {
 #if OS_VXWORKS
   struct vxworksFileId *pId;  /* Unique file ID for vxworks. */
 #else
-  ino_t ino;                  /* Inode number */
+  /* We are told that some versions of Android contain a bug that
+  ** sizes ino_t at only 32-bits instead of 64-bits. (See
+  ** https://android-review.googlesource.com/#/c/115351/3/dist/sqlite3.c)
+  ** To work around this, always allocate 64-bits for the inode number.  
+  ** On small machines that only have 32-bit inodes, this wastes 4 bytes,
+  ** but that should not be a big deal. */
+  /* WAS:  ino_t ino;   */
+  u64 ino;                   /* Inode number */
 #endif
 };
 
@@ -26248,7 +31525,7 @@ static unixInodeInfo *inodeList = 0;
 
 /*
 **
-** This function - unixLogError_x(), is only ever called via the macro
+** This function - unixLogErrorAtLine(), is only ever called via the macro
 ** unixLogError().
 **
 ** It is invoked after an error occurs in an OS function and errno has been
@@ -26335,6 +31612,14 @@ static void robust_close(unixFile *pFile, int h, int lineno){
   }
 }
 
+/*
+** Set the pFile->lastErrno.  Do this in a subroutine as that provides
+** a convenient place to set a breakpoint.
+*/
+static void storeLastErrno(unixFile *pFile, int error){
+  pFile->lastErrno = error;
+}
+
 /*
 ** Close all file descriptors accumuated in the unixInodeInfo->pUnused list.
 */ 
@@ -26408,8 +31693,8 @@ static int findInodeInfo(
   fd = pFile->h;
   rc = osFstat(fd, &statbuf);
   if( rc!=0 ){
-    pFile->lastErrno = errno;
-#ifdef EOVERFLOW
+    storeLastErrno(pFile, errno);
+#if defined(EOVERFLOW) && defined(SQLITE_DISABLE_LFS)
     if( pFile->lastErrno==EOVERFLOW ) return SQLITE_NOLFS;
 #endif
     return SQLITE_IOERR;
@@ -26429,12 +31714,12 @@ static int findInodeInfo(
   if( statbuf.st_size==0 && (pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS)!=0 ){
     do{ rc = osWrite(fd, "S", 1); }while( rc<0 && errno==EINTR );
     if( rc!=1 ){
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       return SQLITE_IOERR;
     }
     rc = osFstat(fd, &statbuf);
     if( rc!=0 ){
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       return SQLITE_IOERR;
     }
   }
@@ -26445,16 +31730,16 @@ static int findInodeInfo(
 #if OS_VXWORKS
   fileId.pId = pFile->pId;
 #else
-  fileId.ino = statbuf.st_ino;
+  fileId.ino = (u64)statbuf.st_ino;
 #endif
   pInode = inodeList;
   while( pInode && memcmp(&fileId, &pInode->fileId, sizeof(fileId)) ){
     pInode = pInode->pNext;
   }
   if( pInode==0 ){
-    pInode = sqlite3_malloc( sizeof(*pInode) );
+    pInode = sqlite3_malloc64( sizeof(*pInode) );
     if( pInode==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset(pInode, 0, sizeof(*pInode));
     memcpy(&pInode->fileId, &fileId, sizeof(fileId));
@@ -26479,7 +31764,8 @@ static int fileHasMoved(unixFile *pFile){
 #else
   struct stat buf;
   return pFile->pInode!=0 &&
-      (osStat(pFile->zPath, &buf)!=0 || buf.st_ino!=pFile->pInode->fileId.ino);
+      (osStat(pFile->zPath, &buf)!=0 
+         || (u64)buf.st_ino!=pFile->pInode->fileId.ino);
 #endif
 }
 
@@ -26496,30 +31782,25 @@ static int fileHasMoved(unixFile *pFile){
 static void verifyDbFile(unixFile *pFile){
   struct stat buf;
   int rc;
-  if( pFile->ctrlFlags & UNIXFILE_WARNED ){
-    /* One or more of the following warnings have already been issued.  Do not
-    ** repeat them so as not to clutter the error log */
-    return;
-  }
+
+  /* These verifications occurs for the main database only */
+  if( pFile->ctrlFlags & UNIXFILE_NOLOCK ) return;
+
   rc = osFstat(pFile->h, &buf);
   if( rc!=0 ){
     sqlite3_log(SQLITE_WARNING, "cannot fstat db file %s", pFile->zPath);
-    pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
   }
-  if( buf.st_nlink==0 && (pFile->ctrlFlags & UNIXFILE_DELETE)==0 ){
+  if( buf.st_nlink==0 ){
     sqlite3_log(SQLITE_WARNING, "file unlinked while open: %s", pFile->zPath);
-    pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
   }
   if( buf.st_nlink>1 ){
     sqlite3_log(SQLITE_WARNING, "multiple links to file: %s", pFile->zPath);
-    pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
   }
   if( fileHasMoved(pFile) ){
     sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);
-    pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
   }
 }
@@ -26539,6 +31820,7 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
 
   assert( pFile );
+  assert( pFile->eFileLock<=SHARED_LOCK );
   unixEnterMutex(); /* Because pFile->pInode is shared across threads */
 
   /* Check if a thread in this process holds such a lock */
@@ -26557,7 +31839,7 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
     lock.l_type = F_WRLCK;
     if( osFcntl(pFile->h, F_GETLK, &lock) ){
       rc = SQLITE_IOERR_CHECKRESERVEDLOCK;
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
     } else if( lock.l_type!=F_UNLCK ){
       reserved = 1;
     }
@@ -26595,9 +31877,7 @@ static int unixFileLock(unixFile *pFile, struct flock *pLock){
   unixInodeInfo *pInode = pFile->pInode;
   assert( unixMutexHeld() );
   assert( pInode!=0 );
-  if( ((pFile->ctrlFlags & UNIXFILE_EXCL)!=0 || pInode->bProcessLock)
-   && ((pFile->ctrlFlags & UNIXFILE_RDONLY)==0)
-  ){
+  if( (pFile->ctrlFlags & (UNIXFILE_EXCL|UNIXFILE_RDONLY))==UNIXFILE_EXCL ){
     if( pInode->bProcessLock==0 ){
       struct flock lock;
       assert( pInode->nLock==0 );
@@ -26647,7 +31927,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** lock transitions in terms of the POSIX advisory shared and exclusive
   ** lock primitives (called read-locks and write-locks below, to avoid
   ** confusion with SQLite lock names). The algorithms are complicated
-  ** slightly in order to be compatible with windows systems simultaneously
+  ** slightly in order to be compatible with Windows95 systems simultaneously
   ** accessing the same database file, in case that is ever required.
   **
   ** Symbols defined in os.h indentify the 'pending byte' and the 'reserved
@@ -26655,8 +31935,14 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** range', a range of 510 bytes at a well known offset.
   **
   ** To obtain a SHARED lock, a read-lock is obtained on the 'pending
-  ** byte'.  If this is successful, a random byte from the 'shared byte
-  ** range' is read-locked and the lock on the 'pending byte' released.
+  ** byte'.  If this is successful, 'shared byte range' is read-locked
+  ** and the lock on the 'pending byte' released.  (Legacy note:  When
+  ** SQLite was first developed, Windows95 systems were still very common,
+  ** and Widnows95 lacks a shared-lock capability.  So on Windows95, a
+  ** single randomly selected by from the 'shared byte range' is locked.
+  ** Windows95 is now pretty much extinct, but this work-around for the
+  ** lack of shared-locks on Windows95 lives on, for backwards
+  ** compatibility.)
   **
   ** A process may only obtain a RESERVED lock after it has a SHARED lock.
   ** A RESERVED lock is implemented by grabbing a write-lock on the
@@ -26675,11 +31961,6 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** range'. Since all other locks require a read-lock on one of the bytes
   ** within this range, this ensures that no other locks are held on the
   ** database. 
-  **
-  ** The reason a single byte cannot be used instead of the 'shared byte
-  ** range' is that some versions of windows do not support read-locks. By
-  ** locking a random byte from a range, concurrent SHARED locks may exist
-  ** even if the locking primitive used is always a write-lock.
   */
   int rc = SQLITE_OK;
   unixFile *pFile = (unixFile*)id;
@@ -26690,7 +31971,8 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   assert( pFile );
   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (unix)\n", pFile->h,
       azFileLock(eFileLock), azFileLock(pFile->eFileLock),
-      azFileLock(pFile->pInode->eFileLock), pFile->pInode->nShared , getpid()));
+      azFileLock(pFile->pInode->eFileLock), pFile->pInode->nShared,
+      osGetpid(0)));
 
   /* If there is already a lock of this type or more restrictive on the
   ** unixFile, do nothing. Don't use the end_lock: exit path, as
@@ -26757,7 +32039,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
       tErrno = errno;
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
       goto end_lock;
     }
@@ -26792,7 +32074,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
 
     if( rc ){
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
       goto end_lock;
     }else{
@@ -26825,7 +32107,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
       tErrno = errno;
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
     }
   }
@@ -26898,7 +32180,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (unix)\n", pFile->h, eFileLock,
       pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,
-      getpid()));
+      osGetpid(0)));
 
   assert( eFileLock<=SHARED_LOCK );
   if( pFile->eFileLock<=eFileLock ){
@@ -26932,7 +32214,6 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
     **  4:   [RRRR.]
     */
     if( eFileLock==SHARED_LOCK ){
-
 #if !defined(__APPLE__) || !SQLITE_ENABLE_LOCKING_STYLE
       (void)handleNFSUnlock;
       assert( handleNFSUnlock==0 );
@@ -26949,9 +32230,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         if( unixFileLock(pFile, &lock)==(-1) ){
           tErrno = errno;
           rc = SQLITE_IOERR_UNLOCK;
-          if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
-          }
+          storeLastErrno(pFile, tErrno);
           goto end_unlock;
         }
         lock.l_type = F_RDLCK;
@@ -26962,7 +32241,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
           tErrno = errno;
           rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_RDLOCK);
           if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
+            storeLastErrno(pFile, tErrno);
           }
           goto end_unlock;
         }
@@ -26973,9 +32252,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         if( unixFileLock(pFile, &lock)==(-1) ){
           tErrno = errno;
           rc = SQLITE_IOERR_UNLOCK;
-          if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
-          }
+          storeLastErrno(pFile, tErrno);
           goto end_unlock;
         }
       }else
@@ -26993,7 +32270,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
           ** SQLITE_BUSY would confuse the upper layer (in practice it causes 
           ** an assert to fail). */ 
           rc = SQLITE_IOERR_RDLOCK;
-          pFile->lastErrno = errno;
+          storeLastErrno(pFile, errno);
           goto end_unlock;
         }
       }
@@ -27006,7 +32283,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
       pInode->eFileLock = SHARED_LOCK;
     }else{
       rc = SQLITE_IOERR_UNLOCK;
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       goto end_unlock;
     }
   }
@@ -27024,7 +32301,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         pInode->eFileLock = NO_LOCK;
       }else{
         rc = SQLITE_IOERR_UNLOCK;
-        pFile->lastErrno = errno;
+        storeLastErrno(pFile, errno);
         pInode->eFileLock = NO_LOCK;
         pFile->eFileLock = NO_LOCK;
       }
@@ -27226,17 +32503,7 @@ static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
   
   assert( pFile );
-
-  /* Check if a thread in this process holds such a lock */
-  if( pFile->eFileLock>SHARED_LOCK ){
-    /* Either this connection or some other connection in the same process
-    ** holds a lock on the file.  No need to check further. */
-    reserved = 1;
-  }else{
-    /* The lock is held if and only if the lockfile exists */
-    const char *zLockFile = (const char*)pFile->lockingContext;
-    reserved = osAccess(zLockFile, 0)==0;
-  }
+  reserved = osAccess((const char*)pFile->lockingContext, 0)==0;
   OSTRACE(("TEST WR-LOCK %d %d %d (dotlock)\n", pFile->h, rc, reserved));
   *pResOut = reserved;
   return rc;
@@ -27298,8 +32565,8 @@ static int dotlockLock(sqlite3_file *id, int eFileLock) {
       rc = SQLITE_BUSY;
     } else {
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
-      if( IS_LOCK_ERROR(rc) ){
-        pFile->lastErrno = tErrno;
+      if( rc!=SQLITE_BUSY ){
+        storeLastErrno(pFile, tErrno);
       }
     }
     return rc;
@@ -27326,7 +32593,7 @@ static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
 
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (dotlock)\n", pFile->h, eFileLock,
-           pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -27345,15 +32612,13 @@ static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
   /* To fully unlock the database, delete the lock file */
   assert( eFileLock==NO_LOCK );
   rc = osRmdir(zLockFile);
-  if( rc<0 && errno==ENOTDIR ) rc = osUnlink(zLockFile);
   if( rc<0 ){
     int tErrno = errno;
-    rc = 0;
-    if( ENOENT != tErrno ){
+    if( tErrno==ENOENT ){
+      rc = SQLITE_OK;
+    }else{
       rc = SQLITE_IOERR_UNLOCK;
-    }
-    if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc; 
   }
@@ -27365,14 +32630,11 @@ static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file.  Make sure the lock has been released before closing.
 */
 static int dotlockClose(sqlite3_file *id) {
-  int rc = SQLITE_OK;
-  if( id ){
-    unixFile *pFile = (unixFile*)id;
-    dotlockUnlock(id, NO_LOCK);
-    sqlite3_free(pFile->lockingContext);
-    rc = closeUnixFile(id);
-  }
-  return rc;
+  unixFile *pFile = (unixFile*)id;
+  assert( id!=0 );
+  dotlockUnlock(id, NO_LOCK);
+  sqlite3_free(pFile->lockingContext);
+  return closeUnixFile(id);
 }
 /****************** End of the dot-file lock implementation *******************
 ******************************************************************************/
@@ -27389,10 +32651,9 @@ static int dotlockClose(sqlite3_file *id) {
 ** still works when you do this, but concurrency is reduced since
 ** only a single process can be reading the database at a time.
 **
-** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off or if
-** compiling for VXWORKS.
+** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off
 */
-#if SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE
 
 /*
 ** Retry flock() calls that fail with EINTR
@@ -27439,10 +32700,8 @@ static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){
         int tErrno = errno;
         /* unlock failed with an error */
         lrc = SQLITE_IOERR_UNLOCK; 
-        if( IS_LOCK_ERROR(lrc) ){
-          pFile->lastErrno = tErrno;
-          rc = lrc;
-        }
+        storeLastErrno(pFile, tErrno);
+        rc = lrc;
       }
     } else {
       int tErrno = errno;
@@ -27450,7 +32709,7 @@ static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){
       /* someone else might have it reserved */
       lrc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK); 
       if( IS_LOCK_ERROR(lrc) ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
         rc = lrc;
       }
     }
@@ -27516,7 +32775,7 @@ static int flockLock(sqlite3_file *id, int eFileLock) {
     /* didn't get, must be busy */
     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
   } else {
     /* got it, set the type and return ok */
@@ -27545,7 +32804,7 @@ static int flockUnlock(sqlite3_file *id, int eFileLock) {
   
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (flock)\n", pFile->h, eFileLock,
-           pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -27575,12 +32834,9 @@ static int flockUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file.
 */
 static int flockClose(sqlite3_file *id) {
-  int rc = SQLITE_OK;
-  if( id ){
-    flockUnlock(id, NO_LOCK);
-    rc = closeUnixFile(id);
-  }
-  return rc;
+  assert( id!=0 );
+  flockUnlock(id, NO_LOCK);
+  return closeUnixFile(id);
 }
 
 #endif /* SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORK */
@@ -27606,7 +32862,7 @@ static int flockClose(sqlite3_file *id) {
 ** to a non-zero value otherwise *pResOut is set to zero.  The return value
 ** is set to SQLITE_OK unless an I/O error occurs during lock checking.
 */
-static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
+static int semXCheckReservedLock(sqlite3_file *id, int *pResOut) {
   int rc = SQLITE_OK;
   int reserved = 0;
   unixFile *pFile = (unixFile*)id;
@@ -27628,7 +32884,7 @@ static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
       int tErrno = errno;
       if( EAGAIN != tErrno ){
         rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_CHECKRESERVEDLOCK);
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       } else {
         /* someone else has the lock when we are in NO_LOCK */
         reserved = (pFile->eFileLock < SHARED_LOCK);
@@ -27673,7 +32929,7 @@ static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
 ** This routine will only increase a lock.  Use the sqlite3OsUnlock()
 ** routine to lower a locking level.
 */
-static int semLock(sqlite3_file *id, int eFileLock) {
+static int semXLock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
   sem_t *pSem = pFile->pInode->pSem;
   int rc = SQLITE_OK;
@@ -27706,14 +32962,14 @@ static int semLock(sqlite3_file *id, int eFileLock) {
 ** If the locking level of the file descriptor is already at or below
 ** the requested locking level, this routine is a no-op.
 */
-static int semUnlock(sqlite3_file *id, int eFileLock) {
+static int semXUnlock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
   sem_t *pSem = pFile->pInode->pSem;
 
   assert( pFile );
   assert( pSem );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (sem)\n", pFile->h, eFileLock,
-           pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -27732,7 +32988,7 @@ static int semUnlock(sqlite3_file *id, int eFileLock) {
     int rc, tErrno = errno;
     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc; 
   }
@@ -27743,10 +32999,10 @@ static int semUnlock(sqlite3_file *id, int eFileLock) {
 /*
  ** Close a file.
  */
-static int semClose(sqlite3_file *id) {
+static int semXClose(sqlite3_file *id) {
   if( id ){
     unixFile *pFile = (unixFile*)id;
-    semUnlock(id, NO_LOCK);
+    semXUnlock(id, NO_LOCK);
     assert( pFile );
     unixEnterMutex();
     releaseInodeInfo(pFile);
@@ -27834,7 +33090,7 @@ static int afpSetLock(
                     setLockFlag ? SQLITE_IOERR_LOCK : SQLITE_IOERR_UNLOCK);
 #endif /* SQLITE_IGNORE_AFP_LOCK_ERRORS */
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc;
   } else {
@@ -27927,7 +33183,7 @@ static int afpLock(sqlite3_file *id, int eFileLock){
   assert( pFile );
   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (afp)\n", pFile->h,
            azFileLock(eFileLock), azFileLock(pFile->eFileLock),
-           azFileLock(pInode->eFileLock), pInode->nShared , getpid()));
+           azFileLock(pInode->eFileLock), pInode->nShared , osGetpid(0)));
 
   /* If there is already a lock of this type or more restrictive on the
   ** unixFile, do nothing. Don't use the afp_end_lock: exit path, as
@@ -28017,7 +33273,7 @@ static int afpLock(sqlite3_file *id, int eFileLock){
     lrc2 = afpSetLock(context->dbPath, pFile, PENDING_BYTE, 1, 0);
     
     if( IS_LOCK_ERROR(lrc1) ) {
-      pFile->lastErrno = lrc1Errno;
+      storeLastErrno(pFile, lrc1Errno);
       rc = lrc1;
       goto afp_end_lock;
     } else if( IS_LOCK_ERROR(lrc2) ){
@@ -28113,7 +33369,7 @@ static int afpUnlock(sqlite3_file *id, int eFileLock) {
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (afp)\n", pFile->h, eFileLock,
            pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,
-           getpid()));
+           osGetpid(0)));
 
   assert( eFileLock<=SHARED_LOCK );
   if( pFile->eFileLock<=eFileLock ){
@@ -28205,23 +33461,22 @@ static int afpUnlock(sqlite3_file *id, int eFileLock) {
 */
 static int afpClose(sqlite3_file *id) {
   int rc = SQLITE_OK;
-  if( id ){
-    unixFile *pFile = (unixFile*)id;
-    afpUnlock(id, NO_LOCK);
-    unixEnterMutex();
-    if( pFile->pInode && pFile->pInode->nLock ){
-      /* If there are outstanding locks, do not actually close the file just
-      ** yet because that would clear those locks.  Instead, add the file
-      ** descriptor to pInode->aPending.  It will be automatically closed when
-      ** the last lock is cleared.
-      */
-      setPendingFd(pFile);
-    }
-    releaseInodeInfo(pFile);
-    sqlite3_free(pFile->lockingContext);
-    rc = closeUnixFile(id);
-    unixLeaveMutex();
+  unixFile *pFile = (unixFile*)id;
+  assert( id!=0 );
+  afpUnlock(id, NO_LOCK);
+  unixEnterMutex();
+  if( pFile->pInode && pFile->pInode->nLock ){
+    /* If there are outstanding locks, do not actually close the file just
+    ** yet because that would clear those locks.  Instead, add the file
+    ** descriptor to pInode->aPending.  It will be automatically closed when
+    ** the last lock is cleared.
+    */
+    setPendingFd(pFile);
   }
+  releaseInodeInfo(pFile);
+  sqlite3_free(pFile->lockingContext);
+  rc = closeUnixFile(id);
+  unixLeaveMutex();
   return rc;
 }
 
@@ -28291,7 +33546,6 @@ static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
   TIMER_START;
   assert( cnt==(cnt&0x1ffff) );
   assert( id->h>2 );
-  cnt &= 0x1ffff;
   do{
 #if defined(USE_PREAD)
     got = osPread(id->h, pBuf, cnt, offset);
@@ -28301,13 +33555,9 @@ static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
     SimulateIOError( got = -1 );
 #else
     newOffset = lseek(id->h, offset, SEEK_SET);
-    SimulateIOError( newOffset-- );
-    if( newOffset!=offset ){
-      if( newOffset == -1 ){
-        ((unixFile*)id)->lastErrno = errno;
-      }else{
-        ((unixFile*)id)->lastErrno = 0;
-      }
+    SimulateIOError( newOffset = -1 );
+    if( newOffset<0 ){
+      storeLastErrno((unixFile*)id, errno);
       return -1;
     }
     got = osRead(id->h, pBuf, cnt);
@@ -28316,7 +33566,7 @@ static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
     if( got<0 ){
       if( errno==EINTR ){ got = 1; continue; }
       prior = 0;
-      ((unixFile*)id)->lastErrno = errno;
+      storeLastErrno((unixFile*)id,  errno);
       break;
     }else if( got>0 ){
       cnt -= got;
@@ -28381,7 +33631,7 @@ static int unixRead(
     /* lastErrno set by seekAndRead */
     return SQLITE_IOERR_READ;
   }else{
-    pFile->lastErrno = 0; /* not a system error */
+    storeLastErrno(pFile, 0);   /* not a system error */
     /* Unread parts of the buffer must be zero-filled */
     memset(&((char*)pBuf)[got], 0, amt-got);
     return SQLITE_IOERR_SHORT_READ;
@@ -28406,21 +33656,21 @@ static int seekAndWriteFd(
 
   assert( nBuf==(nBuf&0x1ffff) );
   assert( fd>2 );
+  assert( piErrno!=0 );
   nBuf &= 0x1ffff;
   TIMER_START;
 
 #if defined(USE_PREAD)
-  do{ rc = osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
+  do{ rc = (int)osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
 #elif defined(USE_PREAD64)
-  do{ rc = osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
+  do{ rc = (int)osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
 #else
   do{
     i64 iSeek = lseek(fd, iOff, SEEK_SET);
-    SimulateIOError( iSeek-- );
-
-    if( iSeek!=iOff ){
-      if( piErrno ) *piErrno = (iSeek==-1 ? errno : 0);
-      return -1;
+    SimulateIOError( iSeek = -1 );
+    if( iSeek<0 ){
+      rc = -1;
+      break;
     }
     rc = osWrite(fd, pBuf, nBuf);
   }while( rc<0 && errno==EINTR );
@@ -28429,7 +33679,7 @@ static int seekAndWriteFd(
   TIMER_END;
   OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));
 
-  if( rc<0 && piErrno ) *piErrno = errno;
+  if( rc<0 ) *piErrno = errno;
   return rc;
 }
 
@@ -28492,7 +33742,7 @@ static int unixWrite(
   }
 #endif
 
-#if SQLITE_MAX_MMAP_SIZE>0
+#if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
   /* Deal with as much of this write request as possible by transfering
   ** data from the memory mapping using memcpy().  */
   if( offsetmmapSize ){
@@ -28508,8 +33758,8 @@ static int unixWrite(
     }
   }
 #endif
-
-  while( amt>0 && (wrote = seekAndWrite(pFile, offset, pBuf, amt))>0 ){
+ 
+  while( (wrote = seekAndWrite(pFile, offset, pBuf, amt))0 ){
     amt -= wrote;
     offset += wrote;
     pBuf = &((char*)pBuf)[wrote];
@@ -28517,12 +33767,12 @@ static int unixWrite(
   SimulateIOError(( wrote=(-1), amt=1 ));
   SimulateDiskfullError(( wrote=0, amt=1 ));
 
-  if( amt>0 ){
+  if( amt>wrote ){
     if( wrote<0 && pFile->lastErrno!=ENOSPC ){
       /* lastErrno set by seekAndWrite */
       return SQLITE_IOERR_WRITE;
     }else{
-      pFile->lastErrno = 0; /* not a system error */
+      storeLastErrno(pFile, 0); /* not a system error */
       return SQLITE_FULL;
     }
   }
@@ -28613,10 +33863,15 @@ static int full_fsync(int fd, int fullSync, int dataOnly){
 #endif
 
   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
-  ** no-op
+  ** no-op.  But go ahead and call fstat() to validate the file
+  ** descriptor as we need a method to provoke a failure during
+  ** coverate testing.
   */
 #ifdef SQLITE_NO_SYNC
-  rc = SQLITE_OK;
+  {
+    struct stat buf;
+    rc = osFstat(fd, &buf);
+  }
 #elif HAVE_FULLFSYNC
   if( fullSync ){
     rc = osFcntl(fd, F_FULLFSYNC, 0);
@@ -28682,16 +33937,20 @@ static int openDirectory(const char *zFilename, int *pFd){
   char zDirname[MAX_PATHNAME+1];
 
   sqlite3_snprintf(MAX_PATHNAME, zDirname, "%s", zFilename);
-  for(ii=(int)strlen(zDirname); ii>1 && zDirname[ii]!='/'; ii--);
+  for(ii=(int)strlen(zDirname); ii>0 && zDirname[ii]!='/'; ii--);
   if( ii>0 ){
     zDirname[ii] = '\0';
-    fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
-    if( fd>=0 ){
-      OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
-    }
+  }else{
+    if( zDirname[0]!='/' ) zDirname[0] = '.';
+    zDirname[1] = 0;
+  }
+  fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
+  if( fd>=0 ){
+    OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
   }
   *pFd = fd;
-  return (fd>=0?SQLITE_OK:unixLogError(SQLITE_CANTOPEN_BKPT, "open", zDirname));
+  if( fd>=0 ) return SQLITE_OK;
+  return unixLogError(SQLITE_CANTOPEN_BKPT, "openDirectory", zDirname);
 }
 
 /*
@@ -28731,7 +33990,7 @@ static int unixSync(sqlite3_file *id, int flags){
   rc = full_fsync(pFile->h, isFullsync, isDataOnly);
   SimulateIOError( rc=1 );
   if( rc ){
-    pFile->lastErrno = errno;
+    storeLastErrno(pFile, errno);
     return unixLogError(SQLITE_IOERR_FSYNC, "full_fsync", pFile->zPath);
   }
 
@@ -28744,10 +34003,11 @@ static int unixSync(sqlite3_file *id, int flags){
     OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
             HAVE_FULLFSYNC, isFullsync));
     rc = osOpenDirectory(pFile->zPath, &dirfd);
-    if( rc==SQLITE_OK && dirfd>=0 ){
+    if( rc==SQLITE_OK ){
       full_fsync(dirfd, 0, 0);
       robust_close(pFile, dirfd, __LINE__);
-    }else if( rc==SQLITE_CANTOPEN ){
+    }else{
+      assert( rc==SQLITE_CANTOPEN );
       rc = SQLITE_OK;
     }
     pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
@@ -28775,7 +34035,7 @@ static int unixTruncate(sqlite3_file *id, i64 nByte){
 
   rc = robust_ftruncate(pFile->h, nByte);
   if( rc ){
-    pFile->lastErrno = errno;
+    storeLastErrno(pFile, errno);
     return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
   }else{
 #ifdef SQLITE_DEBUG
@@ -28815,7 +34075,7 @@ static int unixFileSize(sqlite3_file *id, i64 *pSize){
   rc = osFstat(((unixFile*)id)->h, &buf);
   SimulateIOError( rc=1 );
   if( rc!=0 ){
-    ((unixFile*)id)->lastErrno = errno;
+    storeLastErrno((unixFile*)id, errno);
     return SQLITE_IOERR_FSTAT;
   }
   *pSize = buf.st_size;
@@ -28851,7 +34111,9 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
     i64 nSize;                    /* Required file size */
     struct stat buf;              /* Used to hold return values of fstat() */
    
-    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;
+    if( osFstat(pFile->h, &buf) ){
+      return SQLITE_IOERR_FSTAT;
+    }
 
     nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;
     if( nSize>(i64)buf.st_size ){
@@ -28877,18 +34139,14 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
       int nWrite = 0;             /* Number of bytes written by seekAndWrite */
       i64 iWrite;                 /* Next offset to write to */
 
-      iWrite = ((buf.st_size + 2*nBlk - 1)/nBlk)*nBlk-1;
+      iWrite = (buf.st_size/nBlk)*nBlk + nBlk - 1;
       assert( iWrite>=buf.st_size );
-      assert( (iWrite/nBlk)==((buf.st_size+nBlk-1)/nBlk) );
       assert( ((iWrite+1)%nBlk)==0 );
-      for(/*no-op*/; iWrite=nSize ) iWrite = nSize - 1;
         nWrite = seekAndWrite(pFile, iWrite, "", 1);
         if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
       }
-      if( nWrite==0 || (nSize%nBlk) ){
-        nWrite = seekAndWrite(pFile, nSize-1, "", 1);
-        if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
-      }
 #endif
     }
   }
@@ -28898,7 +34156,7 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
     int rc;
     if( pFile->szChunk<=0 ){
       if( robust_ftruncate(pFile->h, nByte) ){
-        pFile->lastErrno = errno;
+        storeLastErrno(pFile, errno);
         return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
       }
     }
@@ -28940,7 +34198,7 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       *(int*)pArg = pFile->eFileLock;
       return SQLITE_OK;
     }
-    case SQLITE_LAST_ERRNO: {
+    case SQLITE_FCNTL_LAST_ERRNO: {
       *(int*)pArg = pFile->lastErrno;
       return SQLITE_OK;
     }
@@ -28968,7 +34226,7 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_TEMPFILENAME: {
-      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
+      char *zTFile = sqlite3_malloc64( pFile->pVfs->mxPathname );
       if( zTFile ){
         unixGetTempname(pFile->pVfs->mxPathname, zTFile);
         *(char**)pArg = zTFile;
@@ -29009,8 +34267,8 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
     }
 #endif
 #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
-    case SQLITE_SET_LOCKPROXYFILE:
-    case SQLITE_GET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_SET_LOCKPROXYFILE:
+    case SQLITE_FCNTL_GET_LOCKPROXYFILE: {
       return proxyFileControl(id,op,pArg);
     }
 #endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
@@ -29150,7 +34408,9 @@ static int unixDeviceCharacteristics(sqlite3_file *id){
 ** Instead, it should be called via macro osGetpagesize().
 */
 static int unixGetpagesize(void){
-#if defined(_BSD_SOURCE)
+#if OS_VXWORKS
+  return 1024;
+#elif defined(_BSD_SOURCE)
   return getpagesize();
 #else
   return (int)sysconf(_SC_PAGESIZE);
@@ -29243,22 +34503,24 @@ struct unixShm {
 ** otherwise.
 */
 static int unixShmSystemLock(
-  unixShmNode *pShmNode, /* Apply locks to this open shared-memory segment */
+  unixFile *pFile,       /* Open connection to the WAL file */
   int lockType,          /* F_UNLCK, F_RDLCK, or F_WRLCK */
   int ofst,              /* First byte of the locking range */
   int n                  /* Number of bytes to lock */
 ){
-  struct flock f;       /* The posix advisory locking structure */
-  int rc = SQLITE_OK;   /* Result code form fcntl() */
+  unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */
+  struct flock f;        /* The posix advisory locking structure */
+  int rc = SQLITE_OK;    /* Result code form fcntl() */
 
   /* Access to the unixShmNode object is serialized by the caller */
+  pShmNode = pFile->pInode->pShmNode;
   assert( sqlite3_mutex_held(pShmNode->mutex) || pShmNode->nRef==0 );
 
   /* Shared locks never span more than one byte */
   assert( n==1 || lockType!=F_RDLCK );
 
   /* Locks are within range */
-  assert( n>=1 && n=1 && n<=SQLITE_SHM_NLOCK );
 
   if( pShmNode->h>=0 ){
     /* Initialize the locking parameters */
@@ -29336,7 +34598,7 @@ static int unixShmRegionPerMap(void){
 static void unixShmPurge(unixFile *pFd){
   unixShmNode *p = pFd->pInode->pShmNode;
   assert( unixMutexHeld() );
-  if( p && p->nRef==0 ){
+  if( p && ALWAYS(p->nRef==0) ){
     int nShmPerMap = unixShmRegionPerMap();
     int i;
     assert( p->pInode==pFd->pInode );
@@ -29402,8 +34664,8 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
   int nShmFilename;               /* Size of the SHM filename in bytes */
 
   /* Allocate space for the new unixShm object. */
-  p = sqlite3_malloc( sizeof(*p) );
-  if( p==0 ) return SQLITE_NOMEM;
+  p = sqlite3_malloc64( sizeof(*p) );
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   memset(p, 0, sizeof(*p));
   assert( pDbFd->pShm==0 );
 
@@ -29415,12 +34677,15 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
   pShmNode = pInode->pShmNode;
   if( pShmNode==0 ){
     struct stat sStat;                 /* fstat() info for database file */
+#ifndef SQLITE_SHM_DIRECTORY
+    const char *zBasePath = pDbFd->zPath;
+#endif
 
     /* Call fstat() to figure out the permissions on the database file. If
     ** a new *-shm file is created, an attempt will be made to create it
     ** with the same permissions.
     */
-    if( osFstat(pDbFd->h, &sStat) && pInode->bProcessLock==0 ){
+    if( osFstat(pDbFd->h, &sStat) ){
       rc = SQLITE_IOERR_FSTAT;
       goto shm_open_err;
     }
@@ -29428,11 +34693,11 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
 #ifdef SQLITE_SHM_DIRECTORY
     nShmFilename = sizeof(SQLITE_SHM_DIRECTORY) + 31;
 #else
-    nShmFilename = 6 + (int)strlen(pDbFd->zPath);
+    nShmFilename = 6 + (int)strlen(zBasePath);
 #endif
-    pShmNode = sqlite3_malloc( sizeof(*pShmNode) + nShmFilename );
+    pShmNode = sqlite3_malloc64( sizeof(*pShmNode) + nShmFilename );
     if( pShmNode==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto shm_open_err;
     }
     memset(pShmNode, 0, sizeof(*pShmNode)+nShmFilename);
@@ -29442,16 +34707,18 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
                      SQLITE_SHM_DIRECTORY "/sqlite-shm-%x-%x",
                      (u32)sStat.st_ino, (u32)sStat.st_dev);
 #else
-    sqlite3_snprintf(nShmFilename, zShmFilename, "%s-shm", pDbFd->zPath);
+    sqlite3_snprintf(nShmFilename, zShmFilename, "%s-shm", zBasePath);
     sqlite3FileSuffix3(pDbFd->zPath, zShmFilename);
 #endif
     pShmNode->h = -1;
     pDbFd->pInode->pShmNode = pShmNode;
     pShmNode->pInode = pDbFd->pInode;
-    pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-    if( pShmNode->mutex==0 ){
-      rc = SQLITE_NOMEM;
-      goto shm_open_err;
+    if( sqlite3GlobalConfig.bCoreMutex ){
+      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+      if( pShmNode->mutex==0 ){
+        rc = SQLITE_NOMEM_BKPT;
+        goto shm_open_err;
+      }
     }
 
     if( pInode->bProcessLock==0 ){
@@ -29470,19 +34737,19 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
       ** is owned by the same user that owns the original database.  Otherwise,
       ** the original owner will not be able to connect.
       */
-      osFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
+      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
   
       /* Check to see if another process is holding the dead-man switch.
       ** If not, truncate the file to zero length. 
       */
       rc = SQLITE_OK;
-      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
+      if( unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
         if( robust_ftruncate(pShmNode->h, 0) ){
           rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
         }
       }
       if( rc==SQLITE_OK ){
-        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
+        rc = unixShmSystemLock(pDbFd, F_RDLCK, UNIX_SHM_DMS, 1);
       }
       if( rc ) goto shm_open_err;
     }
@@ -29607,7 +34874,8 @@ static int unixShmMap(
           /* Write to the last byte of each newly allocated or extended page */
           assert( (nByte % pgsz)==0 );
           for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
-            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, 0)!=1 ){
+            int x = 0;
+            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, &x)!=1 ){
               const char *zFile = pShmNode->zFilename;
               rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);
               goto shmpage_out;
@@ -29622,7 +34890,7 @@ static int unixShmMap(
         pShmNode->apRegion, nReqRegion*sizeof(char *)
     );
     if( !apNew ){
-      rc = SQLITE_IOERR_NOMEM;
+      rc = SQLITE_IOERR_NOMEM_BKPT;
       goto shmpage_out;
     }
     pShmNode->apRegion = apNew;
@@ -29640,9 +34908,9 @@ static int unixShmMap(
           goto shmpage_out;
         }
       }else{
-        pMem = sqlite3_malloc(szRegion);
+        pMem = sqlite3_malloc64(szRegion);
         if( pMem==0 ){
-          rc = SQLITE_NOMEM;
+          rc = SQLITE_NOMEM_BKPT;
           goto shmpage_out;
         }
         memset(pMem, 0, szRegion);
@@ -29714,7 +34982,7 @@ static int unixShmLock(
 
     /* Unlock the system-level locks */
     if( (mask & allMask)==0 ){
-      rc = unixShmSystemLock(pShmNode, F_UNLCK, ofst+UNIX_SHM_BASE, n);
+      rc = unixShmSystemLock(pDbFd, F_UNLCK, ofst+UNIX_SHM_BASE, n);
     }else{
       rc = SQLITE_OK;
     }
@@ -29742,7 +35010,7 @@ static int unixShmLock(
     /* Get shared locks at the system level, if necessary */
     if( rc==SQLITE_OK ){
       if( (allShared & mask)==0 ){
-        rc = unixShmSystemLock(pShmNode, F_RDLCK, ofst+UNIX_SHM_BASE, n);
+        rc = unixShmSystemLock(pDbFd, F_RDLCK, ofst+UNIX_SHM_BASE, n);
       }else{
         rc = SQLITE_OK;
       }
@@ -29767,7 +35035,7 @@ static int unixShmLock(
     ** also mark the local connection as being locked.
     */
     if( rc==SQLITE_OK ){
-      rc = unixShmSystemLock(pShmNode, F_WRLCK, ofst+UNIX_SHM_BASE, n);
+      rc = unixShmSystemLock(pDbFd, F_WRLCK, ofst+UNIX_SHM_BASE, n);
       if( rc==SQLITE_OK ){
         assert( (p->sharedMask & mask)==0 );
         p->exclMask |= mask;
@@ -29776,7 +35044,7 @@ static int unixShmLock(
   }
   sqlite3_mutex_leave(pShmNode->mutex);
   OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x\n",
-           p->id, getpid(), p->sharedMask, p->exclMask));
+           p->id, osGetpid(0), p->sharedMask, p->exclMask));
   return rc;
 }
 
@@ -29790,7 +35058,8 @@ static void unixShmBarrier(
   sqlite3_file *fd                /* Database file holding the shared memory */
 ){
   UNUSED_PARAMETER(fd);
-  unixEnterMutex();
+  sqlite3MemoryBarrier();         /* compiler-defined memory barrier */
+  unixEnterMutex();               /* Also mutex, for redundancy */
   unixLeaveMutex();
 }
 
@@ -29835,7 +35104,9 @@ static int unixShmUnmap(
   assert( pShmNode->nRef>0 );
   pShmNode->nRef--;
   if( pShmNode->nRef==0 ){
-    if( deleteFlag && pShmNode->h>=0 ) osUnlink(pShmNode->zFilename);
+    if( deleteFlag && pShmNode->h>=0 ){
+      osUnlink(pShmNode->zFilename);
+    }
     unixShmPurge(pDbFd);
   }
   unixLeaveMutex();
@@ -29898,7 +35169,9 @@ static void unixRemapfile(
   assert( pFd->mmapSizeActual>=pFd->mmapSize );
   assert( MAP_FAILED!=0 );
 
+#ifdef SQLITE_MMAP_READWRITE
   if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;
+#endif
 
   if( pOrig ){
 #if HAVE_MREMAP
@@ -29970,17 +35243,14 @@ static void unixRemapfile(
 ** recreated as a result of outstanding references) or an SQLite error
 ** code otherwise.
 */
-static int unixMapfile(unixFile *pFd, i64 nByte){
-  i64 nMap = nByte;
-  int rc;
-
+static int unixMapfile(unixFile *pFd, i64 nMap){
   assert( nMap>=0 || pFd->nFetchOut==0 );
+  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
   if( pFd->nFetchOut>0 ) return SQLITE_OK;
 
   if( nMap<0 ){
     struct stat statbuf;          /* Low-level file information */
-    rc = osFstat(pFd->h, &statbuf);
-    if( rc!=SQLITE_OK ){
+    if( osFstat(pFd->h, &statbuf) ){
       return SQLITE_IOERR_FSTAT;
     }
     nMap = statbuf.st_size;
@@ -29989,12 +35259,9 @@ static int unixMapfile(unixFile *pFd, i64 nByte){
     nMap = pFd->mmapSizeMax;
   }
 
+  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
   if( nMap!=pFd->mmapSize ){
-    if( nMap>0 ){
-      unixRemapfile(pFd, nMap);
-    }else{
-      unixUnmapfile(pFd);
-    }
+    unixRemapfile(pFd, nMap);
   }
 
   return SQLITE_OK;
@@ -30112,7 +35379,7 @@ static int unixUnfetch(sqlite3_file *fd, i64 iOff, void *p){
 **   *  An I/O method finder function called FINDER that returns a pointer
 **      to the METHOD object in the previous bullet.
 */
-#define IOMETHODS(FINDER, METHOD, VERSION, CLOSE, LOCK, UNLOCK, CKLOCK, SHMMAP) \
+#define IOMETHODS(FINDER,METHOD,VERSION,CLOSE,LOCK,UNLOCK,CKLOCK,SHMMAP)     \
 static const sqlite3_io_methods METHOD = {                                   \
    VERSION,                    /* iVersion */                                \
    CLOSE,                      /* xClose */                                  \
@@ -30177,7 +35444,7 @@ IOMETHODS(
   0                         /* xShmMap method */
 )
 
-#if SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE
 IOMETHODS(
   flockIoFinder,            /* Finder function name */
   flockIoMethods,           /* sqlite3_io_methods object name */
@@ -30195,10 +35462,10 @@ IOMETHODS(
   semIoFinder,              /* Finder function name */
   semIoMethods,             /* sqlite3_io_methods object name */
   1,                        /* shared memory is disabled */
-  semClose,                 /* xClose method */
-  semLock,                  /* xLock method */
-  semUnlock,                /* xUnlock method */
-  semCheckReservedLock,     /* xCheckReservedLock method */
+  semXClose,                /* xClose method */
+  semXLock,                 /* xLock method */
+  semXUnlock,               /* xUnlock method */
+  semXCheckReservedLock,    /* xCheckReservedLock method */
   0                         /* xShmMap method */
 )
 #endif
@@ -30322,15 +35589,13 @@ static const sqlite3_io_methods
 
 #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
 
-#if OS_VXWORKS && SQLITE_ENABLE_LOCKING_STYLE
-/* 
-** This "finder" function attempts to determine the best locking strategy 
-** for the database file "filePath".  It then returns the sqlite3_io_methods
-** object that implements that strategy.
-**
-** This is for VXWorks only.
+#if OS_VXWORKS
+/*
+** This "finder" function for VxWorks checks to see if posix advisory
+** locking works.  If it does, then that is what is used.  If it does not
+** work, then fallback to named semaphore locking.
 */
-static const sqlite3_io_methods *autolockIoFinderImpl(
+static const sqlite3_io_methods *vxworksIoFinderImpl(
   const char *filePath,    /* name of the database file */
   unixFile *pNew           /* the open file object */
 ){
@@ -30356,9 +35621,9 @@ static const sqlite3_io_methods *autolockIoFinderImpl(
   }
 }
 static const sqlite3_io_methods 
-  *(*const autolockIoFinder)(const char*,unixFile*) = autolockIoFinderImpl;
+  *(*const vxworksIoFinder)(const char*,unixFile*) = vxworksIoFinderImpl;
 
-#endif /* OS_VXWORKS && SQLITE_ENABLE_LOCKING_STYLE */
+#endif /* OS_VXWORKS */
 
 /*
 ** An abstract type for a pointer to an IO method finder function:
@@ -30423,7 +35688,7 @@ static int fillInUnixFile(
   pNew->pId = vxworksFindFileId(zFilename);
   if( pNew->pId==0 ){
     ctrlFlags |= UNIXFILE_NOLOCK;
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
 #endif
 
@@ -30477,9 +35742,9 @@ static int fillInUnixFile(
     ** the afpLockingContext.
     */
     afpLockingContext *pCtx;
-    pNew->lockingContext = pCtx = sqlite3_malloc( sizeof(*pCtx) );
+    pNew->lockingContext = pCtx = sqlite3_malloc64( sizeof(*pCtx) );
     if( pCtx==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       /* NB: zFilename exists and remains valid until the file is closed
       ** according to requirement F11141.  So we do not need to make a
@@ -30507,9 +35772,9 @@ static int fillInUnixFile(
     int nFilename;
     assert( zFilename!=0 );
     nFilename = (int)strlen(zFilename) + 6;
-    zLockFile = (char *)sqlite3_malloc(nFilename);
+    zLockFile = (char *)sqlite3_malloc64(nFilename);
     if( zLockFile==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       sqlite3_snprintf(nFilename, zLockFile, "%s" DOTLOCK_SUFFIX, zFilename);
     }
@@ -30532,7 +35797,7 @@ static int fillInUnixFile(
         if( zSemName[n]=='/' ) zSemName[n] = '_';
       pNew->pInode->pSem = sem_open(zSemName, O_CREAT, 0666, 1);
       if( pNew->pInode->pSem == SEM_FAILED ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
         pNew->pInode->aSemName[0] = '\0';
       }
     }
@@ -30540,7 +35805,7 @@ static int fillInUnixFile(
   }
 #endif
   
-  pNew->lastErrno = 0;
+  storeLastErrno(pNew, 0);
 #if OS_VXWORKS
   if( rc!=SQLITE_OK ){
     if( h>=0 ) robust_close(pNew, h, __LINE__);
@@ -30565,29 +35830,31 @@ static int fillInUnixFile(
 */
 static const char *unixTempFileDir(void){
   static const char *azDirs[] = {
-     0,
      0,
      0,
      "/var/tmp",
      "/usr/tmp",
      "/tmp",
-     0        /* List terminator */
+     "."
   };
-  unsigned int i;
+  unsigned int i = 0;
   struct stat buf;
-  const char *zDir = 0;
-
-  azDirs[0] = sqlite3_temp_directory;
-  if( !azDirs[1] ) azDirs[1] = getenv("SQLITE_TMPDIR");
-  if( !azDirs[2] ) azDirs[2] = getenv("TMPDIR");
-  for(i=0; i=sizeof(azDirs)/sizeof(azDirs[0]) ) break;
+    zDir = azDirs[i++];
   }
-  return zDir;
+  return 0;
 }
 
 /*
@@ -30596,38 +35863,26 @@ static const char *unixTempFileDir(void){
 ** pVfs->mxPathname bytes.
 */
 static int unixGetTempname(int nBuf, char *zBuf){
-  static const unsigned char zChars[] =
-    "abcdefghijklmnopqrstuvwxyz"
-    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-    "0123456789";
-  unsigned int i, j;
   const char *zDir;
+  int iLimit = 0;
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
   ** function failing. 
   */
+  zBuf[0] = 0;
   SimulateIOError( return SQLITE_IOERR );
 
   zDir = unixTempFileDir();
-  if( zDir==0 ) zDir = ".";
-
-  /* Check that the output buffer is large enough for the temporary file 
-  ** name. If it is not, return SQLITE_ERROR.
-  */
-  if( (strlen(zDir) + strlen(SQLITE_TEMP_FILE_PREFIX) + 18) >= (size_t)nBuf ){
-    return SQLITE_ERROR;
-  }
-
+  if( zDir==0 ) return SQLITE_IOERR_GETTEMPPATH;
   do{
-    sqlite3_snprintf(nBuf-18, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX, zDir);
-    j = (int)strlen(zBuf);
-    sqlite3_randomness(15, &zBuf[j]);
-    for(i=0; i<15; i++, j++){
-      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
-    }
-    zBuf[j] = 0;
-    zBuf[j+1] = 0;
+    u64 r;
+    sqlite3_randomness(sizeof(r), &r);
+    assert( nBuf>2 );
+    zBuf[nBuf-2] = 0;
+    sqlite3_snprintf(nBuf, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX"%llx%c",
+                     zDir, r, 0);
+    if( zBuf[nBuf-2]!=0 || (iLimit++)>10 ) return SQLITE_ERROR;
   }while( osAccess(zBuf,0)==0 );
   return SQLITE_OK;
 }
@@ -30682,7 +35937,7 @@ static UnixUnusedFd *findReusableFd(const char *zPath, int flags){
     unixEnterMutex();
     pInode = inodeList;
     while( pInode && (pInode->fileId.dev!=sStat.st_dev
-                     || pInode->fileId.ino!=sStat.st_ino) ){
+                     || pInode->fileId.ino!=(u64)sStat.st_ino) ){
        pInode = pInode->pNext;
     }
     if( pInode ){
@@ -30699,6 +35954,27 @@ static UnixUnusedFd *findReusableFd(const char *zPath, int flags){
   return pUnused;
 }
 
+/*
+** Find the mode, uid and gid of file zFile. 
+*/
+static int getFileMode(
+  const char *zFile,              /* File name */
+  mode_t *pMode,                  /* OUT: Permissions of zFile */
+  uid_t *pUid,                    /* OUT: uid of zFile. */
+  gid_t *pGid                     /* OUT: gid of zFile. */
+){
+  struct stat sStat;              /* Output of stat() on database file */
+  int rc = SQLITE_OK;
+  if( 0==osStat(zFile, &sStat) ){
+    *pMode = sStat.st_mode & 0777;
+    *pUid = sStat.st_uid;
+    *pGid = sStat.st_gid;
+  }else{
+    rc = SQLITE_IOERR_FSTAT;
+  }
+  return rc;
+}
+
 /*
 ** This function is called by unixOpen() to determine the unix permissions
 ** to create new files with. If no error occurs, then SQLITE_OK is returned
@@ -30734,7 +36010,6 @@ static int findCreateFileMode(
   if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
     char zDb[MAX_PATHNAME+1];     /* Database file path */
     int nDb;                      /* Number of valid bytes in zDb */
-    struct stat sStat;            /* Output of stat() on database file */
 
     /* zPath is a path to a WAL or journal file. The following block derives
     ** the path to the associated database file from zPath. This block handles
@@ -30749,28 +36024,34 @@ static int findCreateFileMode(
     ** used by the test_multiplex.c module.
     */
     nDb = sqlite3Strlen30(zPath) - 1; 
-#ifdef SQLITE_ENABLE_8_3_NAMES
-    while( nDb>0 && sqlite3Isalnum(zPath[nDb]) ) nDb--;
-    if( nDb==0 || zPath[nDb]!='-' ) return SQLITE_OK;
-#else
     while( zPath[nDb]!='-' ){
+#ifndef SQLITE_ENABLE_8_3_NAMES
+      /* In the normal case (8+3 filenames disabled) the journal filename
+      ** is guaranteed to contain a '-' character. */
       assert( nDb>0 );
-      assert( zPath[nDb]!='\n' );
+      assert( sqlite3Isalnum(zPath[nDb]) );
+#else
+      /* If 8+3 names are possible, then the journal file might not contain
+      ** a '-' character.  So check for that case and return early. */
+      if( nDb==0 || zPath[nDb]=='.' ) return SQLITE_OK;
+#endif
       nDb--;
     }
-#endif
     memcpy(zDb, zPath, nDb);
     zDb[nDb] = '\0';
 
-    if( 0==osStat(zDb, &sStat) ){
-      *pMode = sStat.st_mode & 0777;
-      *pUid = sStat.st_uid;
-      *pGid = sStat.st_gid;
-    }else{
-      rc = SQLITE_IOERR_FSTAT;
-    }
+    rc = getFileMode(zDb, pMode, pUid, pGid);
   }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
     *pMode = 0600;
+  }else if( flags & SQLITE_OPEN_URI ){
+    /* If this is a main database file and the file was opened using a URI
+    ** filename, check for the "modeof" parameter. If present, interpret
+    ** its value as a filename and try to copy the mode, uid and gid from
+    ** that file.  */
+    const char *z = sqlite3_uri_parameter(zPath, "modeof");
+    if( z ){
+      rc = getFileMode(z, pMode, pUid, pGid);
+    }
   }
   return rc;
 }
@@ -30871,8 +36152,8 @@ static int unixOpen(
   ** the same instant might all reset the PRNG.  But multiple resets
   ** are harmless.
   */
-  if( randomnessPid!=getpid() ){
-    randomnessPid = getpid();
+  if( randomnessPid!=osGetpid(0) ){
+    randomnessPid = osGetpid(0);
     sqlite3_randomness(0,0);
   }
 
@@ -30884,9 +36165,9 @@ static int unixOpen(
     if( pUnused ){
       fd = pUnused->fd;
     }else{
-      pUnused = sqlite3_malloc(sizeof(*pUnused));
+      pUnused = sqlite3_malloc64(sizeof(*pUnused));
       if( !pUnused ){
-        return SQLITE_NOMEM;
+        return SQLITE_NOMEM_BKPT;
       }
     }
     p->pUnused = pUnused;
@@ -30899,7 +36180,7 @@ static int unixOpen(
   }else if( !zName ){
     /* If zName is NULL, the upper layer is requesting a temp file. */
     assert(isDelete && !syncDir);
-    rc = unixGetTempname(MAX_PATHNAME+2, zTmpname);
+    rc = unixGetTempname(pVfs->mxPathname, zTmpname);
     if( rc!=SQLITE_OK ){
       return rc;
     }
@@ -30932,7 +36213,8 @@ static int unixOpen(
     }
     fd = robust_open(zName, openFlags, openMode);
     OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
-    if( fd<0 && errno!=EISDIR && isReadWrite && !isExclusive ){
+    assert( !isExclusive || (openFlags & O_CREAT)!=0 );
+    if( fd<0 && errno!=EISDIR && isReadWrite ){
       /* Failed to open the file for read/write access. Try read-only. */
       flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
       openFlags &= ~(O_RDWR|O_CREAT);
@@ -30951,7 +36233,7 @@ static int unixOpen(
     ** the same as the original database.
     */
     if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
-      osFchown(fd, uid, gid);
+      robustFchown(fd, uid, gid);
     }
   }
   assert( fd>=0 );
@@ -30971,7 +36253,7 @@ static int unixOpen(
     zPath = sqlite3_mprintf("%s", zName);
     if( zPath==0 ){
       robust_close(p, fd, __LINE__);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
 #else
     osUnlink(zName);
@@ -30982,24 +36264,25 @@ static int unixOpen(
     p->openFlags = openFlags;
   }
 #endif
-
-  noLock = eType!=SQLITE_OPEN_MAIN_DB;
-
   
 #if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
   if( fstatfs(fd, &fsInfo) == -1 ){
-    ((unixFile*)pFile)->lastErrno = errno;
+    storeLastErrno(p, errno);
     robust_close(p, fd, __LINE__);
     return SQLITE_IOERR_ACCESS;
   }
   if (0 == strncmp("msdos", fsInfo.f_fstypename, 5)) {
     ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
   }
+  if (0 == strncmp("exfat", fsInfo.f_fstypename, 5)) {
+    ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
+  }
 #endif
 
   /* Set up appropriate ctrlFlags */
   if( isDelete )                ctrlFlags |= UNIXFILE_DELETE;
   if( isReadonly )              ctrlFlags |= UNIXFILE_RDONLY;
+  noLock = eType!=SQLITE_OPEN_MAIN_DB;
   if( noLock )                  ctrlFlags |= UNIXFILE_NOLOCK;
   if( syncDir )                 ctrlFlags |= UNIXFILE_DIRSYNC;
   if( flags & SQLITE_OPEN_URI ) ctrlFlags |= UNIXFILE_URI;
@@ -31017,19 +36300,6 @@ static int unixOpen(
     if( envforce!=NULL ){
       useProxy = atoi(envforce)>0;
     }else{
-      if( statfs(zPath, &fsInfo) == -1 ){
-        /* In theory, the close(fd) call is sub-optimal. If the file opened
-        ** with fd is a database file, and there are other connections open
-        ** on that file that are currently holding advisory locks on it,
-        ** then the call to close() will cancel those locks. In practice,
-        ** we're assuming that statfs() doesn't fail very often. At least
-        ** not while other file descriptors opened by the same process on
-        ** the same file are working.  */
-        p->lastErrno = errno;
-        robust_close(p, fd, __LINE__);
-        rc = SQLITE_IOERR_ACCESS;
-        goto open_finished;
-      }
       useProxy = !(fsInfo.f_flags&MNT_LOCAL);
     }
     if( useProxy ){
@@ -31089,16 +36359,12 @@ static int unixDelete(
     int fd;
     rc = osOpenDirectory(zPath, &fd);
     if( rc==SQLITE_OK ){
-#if OS_VXWORKS
-      if( fsync(fd)==-1 )
-#else
-      if( fsync(fd) )
-#endif
-      {
+      if( full_fsync(fd,0,0) ){
         rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
       }
       robust_close(0, fd, __LINE__);
-    }else if( rc==SQLITE_CANTOPEN ){
+    }else{
+      assert( rc==SQLITE_CANTOPEN );
       rc = SQLITE_OK;
     }
   }
@@ -31122,33 +36388,49 @@ static int unixAccess(
   int flags,              /* What do we want to learn about the zPath file? */
   int *pResOut            /* Write result boolean here */
 ){
-  int amode = 0;
   UNUSED_PARAMETER(NotUsed);
   SimulateIOError( return SQLITE_IOERR_ACCESS; );
-  switch( flags ){
-    case SQLITE_ACCESS_EXISTS:
-      amode = F_OK;
-      break;
-    case SQLITE_ACCESS_READWRITE:
-      amode = W_OK|R_OK;
-      break;
-    case SQLITE_ACCESS_READ:
-      amode = R_OK;
-      break;
+  assert( pResOut!=0 );
 
-    default:
-      assert(!"Invalid flags argument");
-  }
-  *pResOut = (osAccess(zPath, amode)==0);
-  if( flags==SQLITE_ACCESS_EXISTS && *pResOut ){
+  /* The spec says there are three possible values for flags.  But only
+  ** two of them are actually used */
+  assert( flags==SQLITE_ACCESS_EXISTS || flags==SQLITE_ACCESS_READWRITE );
+
+  if( flags==SQLITE_ACCESS_EXISTS ){
     struct stat buf;
-    if( 0==osStat(zPath, &buf) && buf.st_size==0 ){
-      *pResOut = 0;
-    }
+    *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
+  }else{
+    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
   }
   return SQLITE_OK;
 }
 
+/*
+**
+*/
+static int mkFullPathname(
+  const char *zPath,              /* Input path */
+  char *zOut,                     /* Output buffer */
+  int nOut                        /* Allocated size of buffer zOut */
+){
+  int nPath = sqlite3Strlen30(zPath);
+  int iOff = 0;
+  if( zPath[0]!='/' ){
+    if( osGetcwd(zOut, nOut-2)==0 ){
+      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
+    }
+    iOff = sqlite3Strlen30(zOut);
+    zOut[iOff++] = '/';
+  }
+  if( (iOff+nPath+1)>nOut ){
+    /* SQLite assumes that xFullPathname() nul-terminates the output buffer
+    ** even if it returns an error.  */
+    zOut[iOff] = '\0';
+    return SQLITE_CANTOPEN_BKPT;
+  }
+  sqlite3_snprintf(nOut-iOff, &zOut[iOff], "%s", zPath);
+  return SQLITE_OK;
+}
 
 /*
 ** Turn a relative pathname into a full pathname. The relative path
@@ -31165,6 +36447,17 @@ static int unixFullPathname(
   int nOut,                     /* Size of output buffer in bytes */
   char *zOut                    /* Output buffer */
 ){
+#if !defined(HAVE_READLINK) || !defined(HAVE_LSTAT)
+  return mkFullPathname(zPath, zOut, nOut);
+#else
+  int rc = SQLITE_OK;
+  int nByte;
+  int nLink = 1;                /* Number of symbolic links followed so far */
+  const char *zIn = zPath;      /* Input path for each iteration of loop */
+  char *zDel = 0;
+
+  assert( pVfs->mxPathname==MAX_PATHNAME );
+  UNUSED_PARAMETER(pVfs);
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
@@ -31173,21 +36466,62 @@ static int unixFullPathname(
   */
   SimulateIOError( return SQLITE_ERROR );
 
-  assert( pVfs->mxPathname==MAX_PATHNAME );
-  UNUSED_PARAMETER(pVfs);
+  do {
 
-  zOut[nOut-1] = '\0';
-  if( zPath[0]=='/' ){
-    sqlite3_snprintf(nOut, zOut, "%s", zPath);
-  }else{
-    int nCwd;
-    if( osGetcwd(zOut, nOut-1)==0 ){
-      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
+    /* Call stat() on path zIn. Set bLink to true if the path is a symbolic
+    ** link, or false otherwise.  */
+    int bLink = 0;
+    struct stat buf;
+    if( osLstat(zIn, &buf)!=0 ){
+      if( errno!=ENOENT ){
+        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "lstat", zIn);
+      }
+    }else{
+      bLink = S_ISLNK(buf.st_mode);
     }
-    nCwd = (int)strlen(zOut);
-    sqlite3_snprintf(nOut-nCwd, &zOut[nCwd], "/%s", zPath);
-  }
-  return SQLITE_OK;
+
+    if( bLink ){
+      if( zDel==0 ){
+        zDel = sqlite3_malloc(nOut);
+        if( zDel==0 ) rc = SQLITE_NOMEM_BKPT;
+      }else if( ++nLink>SQLITE_MAX_SYMLINKS ){
+        rc = SQLITE_CANTOPEN_BKPT;
+      }
+
+      if( rc==SQLITE_OK ){
+        nByte = osReadlink(zIn, zDel, nOut-1);
+        if( nByte<0 ){
+          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zIn);
+        }else{
+          if( zDel[0]!='/' ){
+            int n;
+            for(n = sqlite3Strlen30(zIn); n>0 && zIn[n-1]!='/'; n--);
+            if( nByte+n+1>nOut ){
+              rc = SQLITE_CANTOPEN_BKPT;
+            }else{
+              memmove(&zDel[n], zDel, nByte+1);
+              memcpy(zDel, zIn, n);
+              nByte += n;
+            }
+          }
+          zDel[nByte] = '\0';
+        }
+      }
+
+      zIn = zDel;
+    }
+
+    assert( rc!=SQLITE_OK || zIn!=zOut || zIn[0]=='/' );
+    if( rc==SQLITE_OK && zIn!=zOut ){
+      rc = mkFullPathname(zIn, zOut, nOut);
+    }
+    if( bLink==0 ) break;
+    zIn = zOut;
+  }while( rc==SQLITE_OK );
+
+  sqlite3_free(zDel);
+  return rc;
+#endif   /* HAVE_READLINK && HAVE_LSTAT */
 }
 
 
@@ -31273,8 +36607,8 @@ static int unixRandomness(sqlite3_vfs *NotUsed, int nBuf, char *zBuf){
   ** tests repeatable.
   */
   memset(zBuf, 0, nBuf);
-  randomnessPid = getpid();  
-#if !defined(SQLITE_TEST)
+  randomnessPid = osGetpid(0);  
+#if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
   {
     int fd, got;
     fd = robust_open("/dev/urandom", O_RDONLY, 0);
@@ -31356,11 +36690,8 @@ static int unixCurrentTimeInt64(sqlite3_vfs *NotUsed, sqlite3_int64 *piNow){
   *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_nsec/1000000;
 #else
   struct timeval sNow;
-  if( gettimeofday(&sNow, 0)==0 ){
-    *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;
-  }else{
-    rc = SQLITE_ERROR;
-  }
+  (void)gettimeofday(&sNow, 0);  /* Cannot fail given valid arguments */
+  *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;
 #endif
 
 #ifdef SQLITE_TEST
@@ -31372,6 +36703,7 @@ static int unixCurrentTimeInt64(sqlite3_vfs *NotUsed, sqlite3_int64 *piNow){
   return rc;
 }
 
+#ifndef SQLITE_OMIT_DEPRECATED
 /*
 ** Find the current time (in Universal Coordinated Time).  Write the
 ** current time and date as a Julian Day number into *prNow and
@@ -31385,19 +36717,21 @@ static int unixCurrentTime(sqlite3_vfs *NotUsed, double *prNow){
   *prNow = i/86400000.0;
   return rc;
 }
+#else
+# define unixCurrentTime 0
+#endif
 
 /*
-** We added the xGetLastError() method with the intention of providing
-** better low-level error messages when operating-system problems come up
-** during SQLite operation.  But so far, none of that has been implemented
-** in the core.  So this routine is never called.  For now, it is merely
-** a place-holder.
+** The xGetLastError() method is designed to return a better
+** low-level error message when operating-system problems come up
+** during SQLite operation.  Only the integer return code is currently
+** used.
 */
 static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
   UNUSED_PARAMETER(NotUsed);
   UNUSED_PARAMETER(NotUsed2);
   UNUSED_PARAMETER(NotUsed3);
-  return 0;
+  return errno;
 }
 
 
@@ -31455,9 +36789,10 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 **
 ** C APIs
 **
-**  sqlite3_file_control(db, dbname, SQLITE_SET_LOCKPROXYFILE,
+**  sqlite3_file_control(db, dbname, SQLITE_FCNTL_SET_LOCKPROXYFILE,
 **                        | ":auto:");
-**  sqlite3_file_control(db, dbname, SQLITE_GET_LOCKPROXYFILE, &);
+**  sqlite3_file_control(db, dbname, SQLITE_FCNTL_GET_LOCKPROXYFILE,
+**                       &);
 **
 **
 ** SQL pragmas
@@ -31550,7 +36885,7 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 ** setting the environment variable SQLITE_FORCE_PROXY_LOCKING to 1 will
 ** force proxy locking to be used for every database file opened, and 0
 ** will force automatic proxy locking to be disabled for all database
-** files (explicitly calling the SQLITE_SET_LOCKPROXYFILE pragma or
+** files (explicitly calling the SQLITE_FCNTL_SET_LOCKPROXYFILE pragma or
 ** sqlite_file_control API is not affected by SQLITE_FORCE_PROXY_LOCKING).
 */
 
@@ -31571,6 +36906,7 @@ struct proxyLockingContext {
   char *lockProxyPath;         /* Name of the proxy lock file */
   char *dbPath;                /* Name of the open file */
   int conchHeld;               /* 1 if the conch is held, -1 if lockless */
+  int nFails;                  /* Number of conch taking failures */
   void *oldLockingContext;     /* Original lockingcontext to restore on close */
   sqlite3_io_methods const *pOldMethod;     /* Original I/O methods for close */
 };
@@ -31592,7 +36928,7 @@ static int proxyGetLockPath(const char *dbPath, char *lPath, size_t maxLen){
   {
     if( !confstr(_CS_DARWIN_USER_TEMP_DIR, lPath, maxLen) ){
       OSTRACE(("GETLOCKPATH  failed %s errno=%d pid=%d\n",
-               lPath, errno, getpid()));
+               lPath, errno, osGetpid(0)));
       return SQLITE_IOERR_LOCK;
     }
     len = strlcat(lPath, "sqliteplocks", maxLen);    
@@ -31614,7 +36950,7 @@ static int proxyGetLockPath(const char *dbPath, char *lPath, size_t maxLen){
   }
   lPath[i+len]='\0';
   strlcat(lPath, ":auto:", maxLen);
-  OSTRACE(("GETLOCKPATH  proxy lock path=%s pid=%d\n", lPath, getpid()));
+  OSTRACE(("GETLOCKPATH  proxy lock path=%s pid=%d\n", lPath, osGetpid(0)));
   return SQLITE_OK;
 }
 
@@ -31641,7 +36977,7 @@ static int proxyCreateLockPath(const char *lockPath){
           if( err!=EEXIST ) {
             OSTRACE(("CREATELOCKPATH  FAILED creating %s, "
                      "'%s' proxy lock path=%s pid=%d\n",
-                     buf, strerror(err), lockPath, getpid()));
+                     buf, strerror(err), lockPath, osGetpid(0)));
             return err;
           }
         }
@@ -31650,7 +36986,7 @@ static int proxyCreateLockPath(const char *lockPath){
     }
     buf[i] = lockPath[i];
   }
-  OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n", lockPath, getpid()));
+  OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n",lockPath,osGetpid(0)));
   return 0;
 }
 
@@ -31684,9 +37020,9 @@ static int proxyCreateUnixFile(
   if( pUnused ){
     fd = pUnused->fd;
   }else{
-    pUnused = sqlite3_malloc(sizeof(*pUnused));
+    pUnused = sqlite3_malloc64(sizeof(*pUnused));
     if( !pUnused ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   }
   if( fd<0 ){
@@ -31717,9 +37053,9 @@ static int proxyCreateUnixFile(
     }
   }
   
-  pNew = (unixFile *)sqlite3_malloc(sizeof(*pNew));
+  pNew = (unixFile *)sqlite3_malloc64(sizeof(*pNew));
   if( pNew==NULL ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto end_create_proxy;
   }
   memset(pNew, 0, sizeof(unixFile));
@@ -31750,8 +37086,10 @@ SQLITE_API int sqlite3_hostid_num = 0;
 
 #define PROXY_HOSTIDLEN    16  /* conch file host id length */
 
+#ifdef HAVE_GETHOSTUUID
 /* Not always defined in the headers as it ought to be */
 extern int gethostuuid(uuid_t id, const struct timespec *wait);
+#endif
 
 /* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 
 ** bytes of writable memory.
@@ -31759,10 +37097,9 @@ extern int gethostuuid(uuid_t id, const struct timespec *wait);
 static int proxyGetHostID(unsigned char *pHostID, int *pError){
   assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
   memset(pHostID, 0, PROXY_HOSTIDLEN);
-#if defined(__MAX_OS_X_VERSION_MIN_REQUIRED)\
-               && __MAC_OS_X_VERSION_MIN_REQUIRED<1050
+#ifdef HAVE_GETHOSTUUID
   {
-    static const struct timespec timeout = {1, 0}; /* 1 sec timeout */
+    struct timespec timeout = {1, 0}; /* 1 sec timeout */
     if( gethostuuid(pHostID, &timeout) ){
       int err = errno;
       if( pError ){
@@ -31877,7 +37214,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
        */
       struct stat buf;
       if( osFstat(conchFile->h, &buf) ){
-        pFile->lastErrno = errno;
+        storeLastErrno(pFile, errno);
         return SQLITE_IOERR_LOCK;
       }
       
@@ -31897,7 +37234,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
         char tBuf[PROXY_MAXCONCHLEN];
         int len = osPread(conchFile->h, tBuf, PROXY_MAXCONCHLEN, 0);
         if( len<0 ){
-          pFile->lastErrno = errno;
+          storeLastErrno(pFile, errno);
           return SQLITE_IOERR_LOCK;
         }
         if( len>PROXY_PATHINDEX && tBuf[0]==(char)PROXY_CONCHVERSION){
@@ -31917,7 +37254,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
       if( 0==proxyBreakConchLock(pFile, myHostID) ){
         rc = SQLITE_OK;
         if( lockType==EXCLUSIVE_LOCK ){
-          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);          
+          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);
         }
         if( !rc ){
           rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
@@ -31955,11 +37292,12 @@ static int proxyTakeConch(unixFile *pFile){
     int forceNewLockPath = 0;
     
     OSTRACE(("TAKECONCH  %d for %s pid=%d\n", conchFile->h,
-             (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"), getpid()));
+             (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"),
+             osGetpid(0)));
 
     rc = proxyGetHostID(myHostID, &pError);
     if( (rc&0xff)==SQLITE_IOERR ){
-      pFile->lastErrno = pError;
+      storeLastErrno(pFile, pError);
       goto end_takeconch;
     }
     rc = proxyConchLock(pFile, myHostID, SHARED_LOCK);
@@ -31970,7 +37308,7 @@ static int proxyTakeConch(unixFile *pFile){
     readLen = seekAndRead((unixFile*)conchFile, 0, readBuf, PROXY_MAXCONCHLEN);
     if( readLen<0 ){
       /* I/O error: lastErrno set by seekAndRead */
-      pFile->lastErrno = conchFile->lastErrno;
+      storeLastErrno(pFile, conchFile->lastErrno);
       rc = SQLITE_IOERR_READ;
       goto end_takeconch;
     }else if( readLen<=(PROXY_HEADERLEN+PROXY_HOSTIDLEN) || 
@@ -32043,7 +37381,7 @@ static int proxyTakeConch(unixFile *pFile){
           rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
         }
       }else{
-        rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, EXCLUSIVE_LOCK);
+        rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
       }
       if( rc==SQLITE_OK ){
         char writeBuffer[PROXY_MAXCONCHLEN];
@@ -32052,14 +37390,15 @@ static int proxyTakeConch(unixFile *pFile){
         writeBuffer[0] = (char)PROXY_CONCHVERSION;
         memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);
         if( pCtx->lockProxyPath!=NULL ){
-          strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath, MAXPATHLEN);
+          strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath,
+                  MAXPATHLEN);
         }else{
           strlcpy(&writeBuffer[PROXY_PATHINDEX], tempLockPath, MAXPATHLEN);
         }
         writeSize = PROXY_PATHINDEX + strlen(&writeBuffer[PROXY_PATHINDEX]);
         robust_ftruncate(conchFile->h, writeSize);
         rc = unixWrite((sqlite3_file *)conchFile, writeBuffer, writeSize, 0);
-        fsync(conchFile->h);
+        full_fsync(conchFile->h,0,0);
         /* If we created a new conch file (not just updated the contents of a 
          ** valid conch file), try to match the permissions of the database 
          */
@@ -32129,7 +37468,7 @@ static int proxyTakeConch(unixFile *pFile){
         if( tempLockPath ){
           pCtx->lockProxyPath = sqlite3DbStrDup(0, tempLockPath);
           if( !pCtx->lockProxyPath ){
-            rc = SQLITE_NOMEM;
+            rc = SQLITE_NOMEM_BKPT;
           }
         }
       }
@@ -32164,7 +37503,7 @@ static int proxyReleaseConch(unixFile *pFile){
   conchFile = pCtx->conchFile;
   OSTRACE(("RELEASECONCH  %d for %s pid=%d\n", conchFile->h,
            (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"), 
-           getpid()));
+           osGetpid(0)));
   if( pCtx->conchHeld>0 ){
     rc = conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, NO_LOCK);
   }
@@ -32176,7 +37515,7 @@ static int proxyReleaseConch(unixFile *pFile){
 
 /*
 ** Given the name of a database file, compute the name of its conch file.
-** Store the conch filename in memory obtained from sqlite3_malloc().
+** Store the conch filename in memory obtained from sqlite3_malloc64().
 ** Make *pConchPath point to the new name.  Return SQLITE_OK on success
 ** or SQLITE_NOMEM if unable to obtain memory.
 **
@@ -32192,9 +37531,9 @@ static int proxyCreateConchPathname(char *dbPath, char **pConchPath){
 
   /* Allocate space for the conch filename and initialize the name to
   ** the name of the original database file. */  
-  *pConchPath = conchPath = (char *)sqlite3_malloc(len + 8);
+  *pConchPath = conchPath = (char *)sqlite3_malloc64(len + 8);
   if( conchPath==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memcpy(conchPath, dbPath, len+1);
   
@@ -32264,7 +37603,8 @@ static int proxyGetDbPathForUnixFile(unixFile *pFile, char *dbPath){
     /* afp style keeps a reference to the db path in the filePath field 
     ** of the struct */
     assert( (int)strlen((char*)pFile->lockingContext)<=MAXPATHLEN );
-    strlcpy(dbPath, ((afpLockingContext *)pFile->lockingContext)->dbPath, MAXPATHLEN);
+    strlcpy(dbPath, ((afpLockingContext *)pFile->lockingContext)->dbPath,
+            MAXPATHLEN);
   } else
 #endif
   if( pFile->pMethod == &dotlockIoMethods ){
@@ -32305,11 +37645,11 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
   }
   
   OSTRACE(("TRANSPROXY  %d for %s pid=%d\n", pFile->h,
-           (lockPath ? lockPath : ":auto:"), getpid()));
+           (lockPath ? lockPath : ":auto:"), osGetpid(0)));
 
-  pCtx = sqlite3_malloc( sizeof(*pCtx) );
+  pCtx = sqlite3_malloc64( sizeof(*pCtx) );
   if( pCtx==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memset(pCtx, 0, sizeof(*pCtx));
 
@@ -32345,7 +37685,7 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
   if( rc==SQLITE_OK ){
     pCtx->dbPath = sqlite3DbStrDup(0, dbPath);
     if( pCtx->dbPath==NULL ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
   if( rc==SQLITE_OK ){
@@ -32377,7 +37717,7 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
 */
 static int proxyFileControl(sqlite3_file *id, int op, void *pArg){
   switch( op ){
-    case SQLITE_GET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_GET_LOCKPROXYFILE: {
       unixFile *pFile = (unixFile*)id;
       if( pFile->pMethod == &proxyIoMethods ){
         proxyLockingContext *pCtx = (proxyLockingContext*)pFile->lockingContext;
@@ -32392,13 +37732,16 @@ static int proxyFileControl(sqlite3_file *id, int op, void *pArg){
       }
       return SQLITE_OK;
     }
-    case SQLITE_SET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_SET_LOCKPROXYFILE: {
       unixFile *pFile = (unixFile*)id;
       int rc = SQLITE_OK;
       int isProxyStyle = (pFile->pMethod == &proxyIoMethods);
       if( pArg==NULL || (const char *)pArg==0 ){
         if( isProxyStyle ){
-          /* turn off proxy locking - not supported */
+          /* turn off proxy locking - not supported.  If support is added for
+          ** switching proxy locking mode off then it will need to fail if
+          ** the journal mode is WAL mode. 
+          */
           rc = SQLITE_ERROR /*SQLITE_PROTOCOL? SQLITE_MISUSE?*/;
         }else{
           /* turn off proxy locking - already off - NOOP */
@@ -32528,7 +37871,7 @@ static int proxyUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file that uses proxy locks.
 */
 static int proxyClose(sqlite3_file *id) {
-  if( id ){
+  if( ALWAYS(id) ){
     unixFile *pFile = (unixFile*)id;
     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;
     unixFile *lockProxy = pCtx->lockProxy;
@@ -32643,8 +37986,10 @@ SQLITE_API int sqlite3_os_init(void){
   ** array cannot be const.
   */
   static sqlite3_vfs aVfs[] = {
-#if SQLITE_ENABLE_LOCKING_STYLE && (OS_VXWORKS || defined(__APPLE__))
+#if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
     UNIXVFS("unix",          autolockIoFinder ),
+#elif OS_VXWORKS
+    UNIXVFS("unix",          vxworksIoFinder ),
 #else
     UNIXVFS("unix",          posixIoFinder ),
 #endif
@@ -32654,11 +37999,11 @@ SQLITE_API int sqlite3_os_init(void){
 #if OS_VXWORKS
     UNIXVFS("unix-namedsem", semIoFinder ),
 #endif
-#if SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS
     UNIXVFS("unix-posix",    posixIoFinder ),
-#if !OS_VXWORKS
-    UNIXVFS("unix-flock",    flockIoFinder ),
 #endif
+#if SQLITE_ENABLE_LOCKING_STYLE
+    UNIXVFS("unix-flock",    flockIoFinder ),
 #endif
 #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
     UNIXVFS("unix-afp",      afpIoFinder ),
@@ -32670,7 +38015,7 @@ SQLITE_API int sqlite3_os_init(void){
 
   /* Double-check that the aSyscall[] array has been constructed
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
-  assert( ArraySize(aSyscall)==25 );
+  assert( ArraySize(aSyscall)==28 );
 
   /* Register all VFSes defined in the aVfs[] array */
   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
@@ -32708,6 +38053,7 @@ SQLITE_API int sqlite3_os_end(void){
 **
 ** This file contains code that is specific to Windows.
 */
+/* #include "sqliteInt.h" */
 #if SQLITE_OS_WIN               /* This file is used for Windows only */
 
 /*
@@ -32746,24 +38092,14 @@ SQLITE_API int sqlite3_os_end(void){
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
 /*
 ** Macros for performance tracing.  Normally turned off.  Only works
 ** on i486 hardware.
 */
 #ifdef SQLITE_PERFORMANCE_TRACE
 
-/* 
-** hwtime.h contains inline assembler code for implementing 
+/*
+** hwtime.h contains inline assembler code for implementing
 ** high-performance timing routines.
 */
 /************** Include hwtime.h in the middle of os_common.h ****************/
@@ -32783,8 +38119,8 @@ SQLITE_API int sqlite3_os_end(void){
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -32852,7 +38188,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in os_common.h ******************/
@@ -32873,14 +38209,14 @@ static sqlite_uint64 g_elapsed;
 ** of code will give us the ability to simulate a disk I/O error.  This
 ** is used for testing the I/O recovery logic.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
 #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
 #define SimulateIOError(CODE)  \
   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
@@ -32906,17 +38242,17 @@ static void local_ioerr(){
 #define SimulateIOErrorBenign(X)
 #define SimulateIOError(A)
 #define SimulateDiskfullError(A)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** When testing, keep a count of the number of open files.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
 #define OpenCounter(X)  sqlite3_open_file_count+=(X)
 #else
 #define OpenCounter(X)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 #endif /* !defined(_OS_COMMON_H_) */
 
@@ -32926,6 +38262,7 @@ SQLITE_API int sqlite3_open_file_count = 0;
 /*
 ** Include the header file for the Windows VFS.
 */
+/* #include "os_win.h" */
 
 /*
 ** Compiling and using WAL mode requires several APIs that are only
@@ -32978,6 +38315,10 @@ SQLITE_API int sqlite3_open_file_count = 0;
 #  define NTDDI_WINBLUE                     0x06030000
 #endif
 
+#ifndef NTDDI_WINTHRESHOLD
+#  define NTDDI_WINTHRESHOLD                0x06040000
+#endif
+
 /*
 ** Check to see if the GetVersionEx[AW] functions are deprecated on the
 ** target system.  GetVersionEx was first deprecated in Win8.1.
@@ -32990,6 +38331,19 @@ SQLITE_API int sqlite3_open_file_count = 0;
 #  endif
 #endif
 
+/*
+** Check to see if the CreateFileMappingA function is supported on the
+** target system.  It is unavailable when using "mincore.lib" on Win10.
+** When compiling for Windows 10, always assume "mincore.lib" is in use.
+*/
+#ifndef SQLITE_WIN32_CREATEFILEMAPPINGA
+#  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINTHRESHOLD
+#    define SQLITE_WIN32_CREATEFILEMAPPINGA   0
+#  else
+#    define SQLITE_WIN32_CREATEFILEMAPPINGA   1
+#  endif
+#endif
+
 /*
 ** This constant should already be defined (in the "WinDef.h" SDK file).
 */
@@ -33099,8 +38453,10 @@ WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
 #endif /* SQLITE_OS_WINRT */
 
 /*
-** This file mapping API is common to both Win32 and WinRT.
+** These file mapping APIs are common to both Win32 and WinRT.
 */
+
+WINBASEAPI BOOL WINAPI FlushViewOfFile(LPCVOID, SIZE_T);
 WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
 #endif /* SQLITE_WIN32_FILEMAPPING_API */
 
@@ -33173,6 +38529,17 @@ struct winFile {
 #endif
 };
 
+/*
+** The winVfsAppData structure is used for the pAppData member for all of the
+** Win32 VFS variants.
+*/
+typedef struct winVfsAppData winVfsAppData;
+struct winVfsAppData {
+  const sqlite3_io_methods *pMethod; /* The file I/O methods to use. */
+  void *pAppData;                    /* The extra pAppData, if any. */
+  BOOL bNoLock;                      /* Non-zero if locking is disabled. */
+};
+
 /*
 ** Allowed values for winFile.ctrlFlags
 */
@@ -33224,22 +38591,72 @@ struct winFile {
  ******************************************************************************
  */
 #ifndef SQLITE_WIN32_HEAP_CREATE
-#  define SQLITE_WIN32_HEAP_CREATE    (TRUE)
+#  define SQLITE_WIN32_HEAP_CREATE        (TRUE)
+#endif
+
+/*
+ * This is the maximum possible initial size of the Win32-specific heap, in
+ * bytes.
+ */
+#ifndef SQLITE_WIN32_HEAP_MAX_INIT_SIZE
+#  define SQLITE_WIN32_HEAP_MAX_INIT_SIZE (4294967295U)
+#endif
+
+/*
+ * This is the extra space for the initial size of the Win32-specific heap,
+ * in bytes.  This value may be zero.
+ */
+#ifndef SQLITE_WIN32_HEAP_INIT_EXTRA
+#  define SQLITE_WIN32_HEAP_INIT_EXTRA  (4194304)
+#endif
+
+/*
+ * Calculate the maximum legal cache size, in pages, based on the maximum
+ * possible initial heap size and the default page size, setting aside the
+ * needed extra space.
+ */
+#ifndef SQLITE_WIN32_MAX_CACHE_SIZE
+#  define SQLITE_WIN32_MAX_CACHE_SIZE   (((SQLITE_WIN32_HEAP_MAX_INIT_SIZE) - \
+                                          (SQLITE_WIN32_HEAP_INIT_EXTRA)) / \
+                                         (SQLITE_DEFAULT_PAGE_SIZE))
+#endif
+
+/*
+ * This is cache size used in the calculation of the initial size of the
+ * Win32-specific heap.  It cannot be negative.
+ */
+#ifndef SQLITE_WIN32_CACHE_SIZE
+#  if SQLITE_DEFAULT_CACHE_SIZE>=0
+#    define SQLITE_WIN32_CACHE_SIZE     (SQLITE_DEFAULT_CACHE_SIZE)
+#  else
+#    define SQLITE_WIN32_CACHE_SIZE     (-(SQLITE_DEFAULT_CACHE_SIZE))
+#  endif
+#endif
+
+/*
+ * Make sure that the calculated cache size, in pages, cannot cause the
+ * initial size of the Win32-specific heap to exceed the maximum amount
+ * of memory that can be specified in the call to HeapCreate.
+ */
+#if SQLITE_WIN32_CACHE_SIZE>SQLITE_WIN32_MAX_CACHE_SIZE
+#  undef SQLITE_WIN32_CACHE_SIZE
+#  define SQLITE_WIN32_CACHE_SIZE       (2000)
 #endif
 
 /*
  * The initial size of the Win32-specific heap.  This value may be zero.
  */
 #ifndef SQLITE_WIN32_HEAP_INIT_SIZE
-#  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_DEFAULT_CACHE_SIZE) * \
-                                       (SQLITE_DEFAULT_PAGE_SIZE) + 4194304)
+#  define SQLITE_WIN32_HEAP_INIT_SIZE   ((SQLITE_WIN32_CACHE_SIZE) * \
+                                         (SQLITE_DEFAULT_PAGE_SIZE) + \
+                                         (SQLITE_WIN32_HEAP_INIT_EXTRA))
 #endif
 
 /*
  * The maximum size of the Win32-specific heap.  This value may be zero.
  */
 #ifndef SQLITE_WIN32_HEAP_MAX_SIZE
-#  define SQLITE_WIN32_HEAP_MAX_SIZE  (0)
+#  define SQLITE_WIN32_HEAP_MAX_SIZE    (0)
 #endif
 
 /*
@@ -33247,7 +38664,7 @@ struct winFile {
  * zero for the default behavior.
  */
 #ifndef SQLITE_WIN32_HEAP_FLAGS
-#  define SQLITE_WIN32_HEAP_FLAGS     (0)
+#  define SQLITE_WIN32_HEAP_FLAGS       (0)
 #endif
 
 
@@ -33394,8 +38811,9 @@ static struct win_syscall {
 #define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)
 
-#if (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
-        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
+        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0) && \
+        SQLITE_WIN32_CREATEFILEMAPPINGA
   { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
 #else
   { "CreateFileMappingA",      (SYSCALL)0,                       0 },
@@ -33625,8 +39043,7 @@ static struct win_syscall {
 
 #define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)
 
-#if defined(SQLITE_WIN32_HAS_ANSI) && defined(SQLITE_WIN32_GETVERSIONEX) && \
-        SQLITE_WIN32_GETVERSIONEX
+#if defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_GETVERSIONEX
   { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
 #else
   { "GetVersionExA",           (SYSCALL)0,                       0 },
@@ -33636,7 +39053,7 @@ static struct win_syscall {
         LPOSVERSIONINFOA))aSyscall[34].pCurrent)
 
 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
-        defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
+        SQLITE_WIN32_GETVERSIONEX
   { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
 #else
   { "GetVersionExW",           (SYSCALL)0,                       0 },
@@ -33968,6 +39385,32 @@ static struct win_syscall {
         SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)
 #endif /* defined(InterlockedCompareExchange) */
 
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  { "UuidCreate",               (SYSCALL)UuidCreate,             0 },
+#else
+  { "UuidCreate",               (SYSCALL)0,                      0 },
+#endif
+
+#define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },
+#else
+  { "UuidCreateSequential",     (SYSCALL)0,                      0 },
+#endif
+
+#define osUuidCreateSequential \
+        ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)
+
+#if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0
+  { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },
+#else
+  { "FlushViewOfFile",          (SYSCALL)0,                      0 },
+#endif
+
+#define osFlushViewOfFile \
+        ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)
+
 }; /* End of the overrideable system calls */
 
 /*
@@ -34079,7 +39522,7 @@ SQLITE_API int sqlite3_win32_compact_heap(LPUINT pnLargest){
     if( lastErrno==NO_ERROR ){
       sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",
                   (void*)hHeap);
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",
                   osGetLastError(), (void*)hHeap);
@@ -34105,8 +39548,8 @@ SQLITE_API int sqlite3_win32_reset_heap(){
   int rc;
   MUTEX_LOGIC( sqlite3_mutex *pMaster; ) /* The main static mutex */
   MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
-  MUTEX_LOGIC( pMaster = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER); )
-  MUTEX_LOGIC( pMem = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM); )
+  MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
+  MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )
   sqlite3_mutex_enter(pMaster);
   sqlite3_mutex_enter(pMem);
   winMemAssertMagic();
@@ -34151,6 +39594,12 @@ SQLITE_API void sqlite3_win32_write_debug(const char *zBuf, int nBuf){
   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
   assert( nMin==-1 || nMin==0 || nMin0 ){
     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
@@ -34221,7 +39670,7 @@ SQLITE_PRIVATE DWORD sqlite3Win32Wait(HANDLE hObject){
 ** the LockFileEx() API.
 */
 
-#if !defined(SQLITE_WIN32_GETVERSIONEX) || !SQLITE_WIN32_GETVERSIONEX
+#if !SQLITE_WIN32_GETVERSIONEX
 # define osIsNT()  (1)
 #elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
 # define osIsNT()  (1)
@@ -34242,7 +39691,7 @@ SQLITE_API int sqlite3_win32_is_nt(void){
   **       kernel.
   */
   return 1;
-#elif defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
+#elif SQLITE_WIN32_GETVERSIONEX
   if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
 #if defined(SQLITE_WIN32_HAS_ANSI)
     OSVERSIONINFOA sInfo;
@@ -34399,7 +39848,7 @@ static int winMemInit(void *pAppData){
           "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",
           osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,
           dwMaximumSize);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pWinMemData->bOwned = TRUE;
     assert( pWinMemData->bOwned );
@@ -34409,7 +39858,7 @@ static int winMemInit(void *pAppData){
   if( !pWinMemData->hHeap ){
     sqlite3_log(SQLITE_NOMEM,
         "failed to GetProcessHeap (%lu)", osGetLastError());
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pWinMemData->bOwned = FALSE;
   assert( !pWinMemData->bOwned );
@@ -34476,147 +39925,244 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 #endif /* SQLITE_WIN32_MALLOC */
 
 /*
-** Convert a UTF-8 string to Microsoft Unicode (UTF-16?).
+** Convert a UTF-8 string to Microsoft Unicode.
 **
-** Space to hold the returned string is obtained from malloc.
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static LPWSTR winUtf8ToUnicode(const char *zFilename){
+static LPWSTR winUtf8ToUnicode(const char *zText){
   int nChar;
-  LPWSTR zWideFilename;
+  LPWSTR zWideText;
 
-  nChar = osMultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
+  nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, NULL, 0);
   if( nChar==0 ){
     return 0;
   }
-  zWideFilename = sqlite3MallocZero( nChar*sizeof(zWideFilename[0]) );
-  if( zWideFilename==0 ){
+  zWideText = sqlite3MallocZero( nChar*sizeof(WCHAR) );
+  if( zWideText==0 ){
     return 0;
   }
-  nChar = osMultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename,
+  nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, zWideText,
                                 nChar);
   if( nChar==0 ){
-    sqlite3_free(zWideFilename);
-    zWideFilename = 0;
+    sqlite3_free(zWideText);
+    zWideText = 0;
   }
-  return zWideFilename;
+  return zWideText;
 }
 
 /*
-** Convert Microsoft Unicode to UTF-8.  Space to hold the returned string is
-** obtained from sqlite3_malloc().
+** Convert a Microsoft Unicode string to UTF-8.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static char *winUnicodeToUtf8(LPCWSTR zWideFilename){
+static char *winUnicodeToUtf8(LPCWSTR zWideText){
   int nByte;
-  char *zFilename;
+  char *zText;
 
-  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
+  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, 0, 0, 0, 0);
   if( nByte == 0 ){
     return 0;
   }
-  zFilename = sqlite3MallocZero( nByte );
-  if( zFilename==0 ){
+  zText = sqlite3MallocZero( nByte );
+  if( zText==0 ){
     return 0;
   }
-  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
+  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, zText, nByte,
                                 0, 0);
   if( nByte == 0 ){
-    sqlite3_free(zFilename);
-    zFilename = 0;
+    sqlite3_free(zText);
+    zText = 0;
   }
-  return zFilename;
+  return zText;
 }
 
 /*
-** Convert an ANSI string to Microsoft Unicode, based on the
-** current codepage settings for file apis.
+** Convert an ANSI string to Microsoft Unicode, using the ANSI or OEM
+** code page.
 **
-** Space to hold the returned string is obtained
-** from sqlite3_malloc.
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static LPWSTR winMbcsToUnicode(const char *zFilename){
+static LPWSTR winMbcsToUnicode(const char *zText, int useAnsi){
   int nByte;
-  LPWSTR zMbcsFilename;
-  int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;
+  LPWSTR zMbcsText;
+  int codepage = useAnsi ? CP_ACP : CP_OEMCP;
 
-  nByte = osMultiByteToWideChar(codepage, 0, zFilename, -1, NULL,
+  nByte = osMultiByteToWideChar(codepage, 0, zText, -1, NULL,
                                 0)*sizeof(WCHAR);
   if( nByte==0 ){
     return 0;
   }
-  zMbcsFilename = sqlite3MallocZero( nByte*sizeof(zMbcsFilename[0]) );
-  if( zMbcsFilename==0 ){
+  zMbcsText = sqlite3MallocZero( nByte*sizeof(WCHAR) );
+  if( zMbcsText==0 ){
     return 0;
   }
-  nByte = osMultiByteToWideChar(codepage, 0, zFilename, -1, zMbcsFilename,
+  nByte = osMultiByteToWideChar(codepage, 0, zText, -1, zMbcsText,
                                 nByte);
   if( nByte==0 ){
-    sqlite3_free(zMbcsFilename);
-    zMbcsFilename = 0;
+    sqlite3_free(zMbcsText);
+    zMbcsText = 0;
   }
-  return zMbcsFilename;
+  return zMbcsText;
 }
 
 /*
-** Convert Microsoft Unicode to multi-byte character string, based on the
-** user's ANSI codepage.
+** Convert a Microsoft Unicode string to a multi-byte character string,
+** using the ANSI or OEM code page.
 **
-** Space to hold the returned string is obtained from
-** sqlite3_malloc().
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static char *winUnicodeToMbcs(LPCWSTR zWideFilename){
+static char *winUnicodeToMbcs(LPCWSTR zWideText, int useAnsi){
   int nByte;
-  char *zFilename;
-  int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;
+  char *zText;
+  int codepage = useAnsi ? CP_ACP : CP_OEMCP;
 
-  nByte = osWideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
+  nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, 0, 0, 0, 0);
   if( nByte == 0 ){
     return 0;
   }
-  zFilename = sqlite3MallocZero( nByte );
-  if( zFilename==0 ){
+  zText = sqlite3MallocZero( nByte );
+  if( zText==0 ){
     return 0;
   }
-  nByte = osWideCharToMultiByte(codepage, 0, zWideFilename, -1, zFilename,
+  nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, zText,
                                 nByte, 0, 0);
   if( nByte == 0 ){
-    sqlite3_free(zFilename);
-    zFilename = 0;
+    sqlite3_free(zText);
+    zText = 0;
   }
-  return zFilename;
+  return zText;
 }
 
 /*
-** Convert multibyte character string to UTF-8.  Space to hold the
-** returned string is obtained from sqlite3_malloc().
+** Convert a multi-byte character string to UTF-8.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-SQLITE_API char *sqlite3_win32_mbcs_to_utf8(const char *zFilename){
-  char *zFilenameUtf8;
+static char *winMbcsToUtf8(const char *zText, int useAnsi){
+  char *zTextUtf8;
   LPWSTR zTmpWide;
 
-  zTmpWide = winMbcsToUnicode(zFilename);
+  zTmpWide = winMbcsToUnicode(zText, useAnsi);
   if( zTmpWide==0 ){
     return 0;
   }
-  zFilenameUtf8 = winUnicodeToUtf8(zTmpWide);
+  zTextUtf8 = winUnicodeToUtf8(zTmpWide);
   sqlite3_free(zTmpWide);
-  return zFilenameUtf8;
+  return zTextUtf8;
 }
 
 /*
-** Convert UTF-8 to multibyte character string.  Space to hold the
-** returned string is obtained from sqlite3_malloc().
+** Convert a UTF-8 string to a multi-byte character string.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-SQLITE_API char *sqlite3_win32_utf8_to_mbcs(const char *zFilename){
-  char *zFilenameMbcs;
+static char *winUtf8ToMbcs(const char *zText, int useAnsi){
+  char *zTextMbcs;
   LPWSTR zTmpWide;
 
-  zTmpWide = winUtf8ToUnicode(zFilename);
+  zTmpWide = winUtf8ToUnicode(zText);
   if( zTmpWide==0 ){
     return 0;
   }
-  zFilenameMbcs = winUnicodeToMbcs(zTmpWide);
+  zTextMbcs = winUnicodeToMbcs(zTmpWide, useAnsi);
   sqlite3_free(zTmpWide);
-  return zFilenameMbcs;
+  return zTextMbcs;
+}
+
+/*
+** This is a public wrapper for the winUtf8ToUnicode() function.
+*/
+SQLITE_API LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToUnicode(zText);
+}
+
+/*
+** This is a public wrapper for the winUnicodeToUtf8() function.
+*/
+SQLITE_API char *sqlite3_win32_unicode_to_utf8(LPCWSTR zWideText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zWideText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUnicodeToUtf8(zWideText);
+}
+
+/*
+** This is a public wrapper for the winMbcsToUtf8() function.
+*/
+SQLITE_API char *sqlite3_win32_mbcs_to_utf8(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winMbcsToUtf8(zText, osAreFileApisANSI());
+}
+
+/*
+** This is a public wrapper for the winMbcsToUtf8() function.
+*/
+SQLITE_API char *sqlite3_win32_mbcs_to_utf8_v2(const char *zText, int useAnsi){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winMbcsToUtf8(zText, useAnsi);
+}
+
+/*
+** This is a public wrapper for the winUtf8ToMbcs() function.
+*/
+SQLITE_API char *sqlite3_win32_utf8_to_mbcs(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToMbcs(zText, osAreFileApisANSI());
+}
+
+/*
+** This is a public wrapper for the winUtf8ToMbcs() function.
+*/
+SQLITE_API char *sqlite3_win32_utf8_to_mbcs_v2(const char *zText, int useAnsi){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToMbcs(zText, useAnsi);
 }
 
 /*
@@ -34646,7 +40192,7 @@ SQLITE_API int sqlite3_win32_set_directory(DWORD type, LPCWSTR zValue){
     if( zValue && zValue[0] ){
       zValueUtf8 = winUnicodeToUtf8(zValue);
       if ( zValueUtf8==0 ){
-        return SQLITE_NOMEM;
+        return SQLITE_NOMEM_BKPT;
       }
     }
     sqlite3_free(*ppDirectory);
@@ -34718,7 +40264,7 @@ static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
     if( dwLen > 0 ){
       /* allocate a buffer and convert to UTF8 */
       sqlite3BeginBenignMalloc();
-      zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
+      zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
       sqlite3EndBenignMalloc();
       /* free the system buffer allocated by FormatMessage */
       osLocalFree(zTemp);
@@ -34851,25 +40397,26 @@ static int winRetryIoerr(int *pnRetry, DWORD *pError){
 /*
 ** Log a I/O error retry episode.
 */
-static void winLogIoerr(int nRetry){
+static void winLogIoerr(int nRetry, int lineno){
   if( nRetry ){
-    sqlite3_log(SQLITE_IOERR,
-      "delayed %dms for lock/sharing conflict",
-      winIoerrRetryDelay*nRetry*(nRetry+1)/2
+    sqlite3_log(SQLITE_NOTICE,
+      "delayed %dms for lock/sharing conflict at line %d",
+      winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
     );
   }
 }
 
-#if SQLITE_OS_WINCE
-/*************************************************************************
-** This section contains code for WinCE only.
+/*
+** This #if does not rely on the SQLITE_OS_WINCE define because the
+** corresponding section in "date.c" cannot use it.
 */
-#if !defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API
+#if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
+    (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
 /*
-** The MSVC CRT on Windows CE may not have a localtime() function.  So
-** create a substitute.
+** The MSVC CRT on Windows CE may not have a localtime() function.
+** So define a substitute.
 */
-/* #include  */
+/* #  include  */
 struct tm *__cdecl localtime(const time_t *t)
 {
   static struct tm y;
@@ -34893,6 +40440,10 @@ struct tm *__cdecl localtime(const time_t *t)
 }
 #endif
 
+#if SQLITE_OS_WINCE
+/*************************************************************************
+** This section contains code for WinCE only.
+*/
 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
 
 /*
@@ -34923,7 +40474,7 @@ static int winceCreateLock(const char *zFilename, winFile *pFile){
   zName = winUtf8ToUnicode(zFilename);
   if( zName==0 ){
     /* out of memory */
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
 
   /* Initialize the local lockdata */
@@ -35335,7 +40886,8 @@ static int winClose(sqlite3_file *id){
   assert( pFile->pShm==0 );
 #endif
   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
-  OSTRACE(("CLOSE file=%p\n", pFile->h));
+  OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
 
 #if SQLITE_MAX_MMAP_SIZE>0
   winUnmapfile(pFile);
@@ -35347,7 +40899,12 @@ static int winClose(sqlite3_file *id){
   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
 #if SQLITE_OS_WINCE
 #define WINCE_DELETION_ATTEMPTS 3
-  winceDestroyLock(pFile);
+  {
+    winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;
+    if( pAppData==NULL || !pAppData->bNoLock ){
+      winceDestroyLock(pFile);
+    }
+  }
   if( pFile->zDeleteOnClose ){
     int cnt = 0;
     while(
@@ -35364,7 +40921,8 @@ static int winClose(sqlite3_file *id){
     pFile->h = NULL;
   }
   OpenCounter(-1);
-  OSTRACE(("CLOSE file=%p, rc=%s\n", pFile->h, rc ? "ok" : "failed"));
+  OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
+           osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
   return rc ? SQLITE_OK
             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
                           "winClose", pFile->zPath);
@@ -35392,7 +40950,8 @@ static int winRead(
   assert( amt>0 );
   assert( offset>=0 );
   SimulateIOError(return SQLITE_IOERR_READ);
-  OSTRACE(("READ file=%p, buffer=%p, amount=%d, offset=%lld, lock=%d\n",
+  OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
+           "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
            pFile->h, pBuf, amt, offset, pFile->locktype));
 
 #if SQLITE_MAX_MMAP_SIZE>0
@@ -35401,7 +40960,8 @@ static int winRead(
   if( offsetmmapSize ){
     if( offset+amt <= pFile->mmapSize ){
       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
-      OSTRACE(("READ-MMAP file=%p, rc=SQLITE_OK\n", pFile->h));
+      OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
       return SQLITE_OK;
     }else{
       int nCopy = (int)(pFile->mmapSize - offset);
@@ -35415,7 +40975,8 @@ static int winRead(
 
 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
   if( winSeekFile(pFile, offset) ){
-    OSTRACE(("READ file=%p, rc=SQLITE_FULL\n", pFile->h));
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_FULL;
   }
   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
@@ -35429,19 +40990,22 @@ static int winRead(
     DWORD lastErrno;
     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
     pFile->lastErrno = lastErrno;
-    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_READ\n", pFile->h));
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
                        "winRead", pFile->zPath);
   }
-  winLogIoerr(nRetry);
+  winLogIoerr(nRetry, __LINE__);
   if( nRead<(DWORD)amt ){
     /* Unread parts of the buffer must be zero-filled */
     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
-    OSTRACE(("READ file=%p, rc=SQLITE_IOERR_SHORT_READ\n", pFile->h));
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_IOERR_SHORT_READ;
   }
 
-  OSTRACE(("READ file=%p, rc=SQLITE_OK\n", pFile->h));
+  OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 }
 
@@ -35464,16 +41028,18 @@ static int winWrite(
   SimulateIOError(return SQLITE_IOERR_WRITE);
   SimulateDiskfullError(return SQLITE_FULL);
 
-  OSTRACE(("WRITE file=%p, buffer=%p, amount=%d, offset=%lld, lock=%d\n",
+  OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
+           "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
            pFile->h, pBuf, amt, offset, pFile->locktype));
 
-#if SQLITE_MAX_MMAP_SIZE>0
+#if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
   /* Deal with as much of this write request as possible by transfering
   ** data from the memory mapping using memcpy().  */
   if( offsetmmapSize ){
     if( offset+amt <= pFile->mmapSize ){
       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
-      OSTRACE(("WRITE-MMAP file=%p, rc=SQLITE_OK\n", pFile->h));
+      OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
       return SQLITE_OK;
     }else{
       int nCopy = (int)(pFile->mmapSize - offset);
@@ -35536,17 +41102,20 @@ static int winWrite(
   if( rc ){
     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
        || ( pFile->lastErrno==ERROR_DISK_FULL )){
-      OSTRACE(("WRITE file=%p, rc=SQLITE_FULL\n", pFile->h));
+      OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
       return winLogError(SQLITE_FULL, pFile->lastErrno,
                          "winWrite1", pFile->zPath);
     }
-    OSTRACE(("WRITE file=%p, rc=SQLITE_IOERR_WRITE\n", pFile->h));
+    OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
                        "winWrite2", pFile->zPath);
   }else{
-    winLogIoerr(nRetry);
+    winLogIoerr(nRetry, __LINE__);
   }
-  OSTRACE(("WRITE file=%p, rc=SQLITE_OK\n", pFile->h));
+  OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 }
 
@@ -35560,8 +41129,8 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
 
   assert( pFile );
   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
-  OSTRACE(("TRUNCATE file=%p, size=%lld, lock=%d\n",
-           pFile->h, nByte, pFile->locktype));
+  OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
+           osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
 
   /* If the user has configured a chunk-size for this file, truncate the
   ** file so that it consists of an integer number of chunks (i.e. the
@@ -35593,7 +41162,8 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   }
 #endif
 
-  OSTRACE(("TRUNCATE file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
+  OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
+           osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -35617,7 +41187,7 @@ static int winSync(sqlite3_file *id, int flags){
   BOOL rc;
 #endif
 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
-    (defined(SQLITE_TEST) && defined(SQLITE_DEBUG))
+    defined(SQLITE_HAVE_OS_TRACE)
   /*
   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
   ** OSTRACE() macros.
@@ -35638,8 +41208,9 @@ static int winSync(sqlite3_file *id, int flags){
   */
   SimulateDiskfullError( return SQLITE_FULL );
 
-  OSTRACE(("SYNC file=%p, flags=%x, lock=%d\n",
-           pFile->h, flags, pFile->locktype));
+  OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
+           osGetCurrentProcessId(), pFile, pFile->h, flags,
+           pFile->locktype));
 
 #ifndef SQLITE_TEST
   UNUSED_PARAMETER(flags);
@@ -35654,19 +41225,38 @@ static int winSync(sqlite3_file *id, int flags){
   ** no-op
   */
 #ifdef SQLITE_NO_SYNC
-  OSTRACE(("SYNC-NOP file=%p, rc=SQLITE_OK\n", pFile->h));
+  OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 #else
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFile->pMapRegion ){
+    if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
+      OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_OK\n", osGetCurrentProcessId(),
+               pFile, pFile->pMapRegion));
+    }else{
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
+               pFile, pFile->pMapRegion));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winSync1", pFile->zPath);
+    }
+  }
+#endif
   rc = osFlushFileBuffers(pFile->h);
   SimulateIOError( rc=FALSE );
   if( rc ){
-    OSTRACE(("SYNC file=%p, rc=SQLITE_OK\n", pFile->h));
+    OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_OK;
   }else{
     pFile->lastErrno = osGetLastError();
-    OSTRACE(("SYNC file=%p, rc=SQLITE_IOERR_FSYNC\n", pFile->h));
+    OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
-                       "winSync", pFile->zPath);
+                       "winSync2", pFile->zPath);
   }
 #endif
 }
@@ -35855,6 +41445,12 @@ static int winLock(sqlite3_file *id, int locktype){
     return SQLITE_OK;
   }
 
+  /* Do not allow any kind of write-lock on a read-only database
+  */
+  if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
+    return SQLITE_IOERR_LOCK;
+  }
+
   /* Make sure the locking sequence is correct
   */
   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
@@ -35866,9 +41462,8 @@ static int winLock(sqlite3_file *id, int locktype){
   ** the PENDING_LOCK byte is temporary.
   */
   newLocktype = pFile->locktype;
-  if(   (pFile->locktype==NO_LOCK)
-     || (   (locktype==EXCLUSIVE_LOCK)
-         && (pFile->locktype==RESERVED_LOCK))
+  if( pFile->locktype==NO_LOCK
+   || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)
   ){
     int cnt = 3;
     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
@@ -35984,7 +41579,7 @@ static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
     res = 1;
     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
   }else{
-    res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE, 0, 1, 0);
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
     if( res ){
       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
     }
@@ -36041,6 +41636,44 @@ static int winUnlock(sqlite3_file *id, int locktype){
   return rc;
 }
 
+/******************************************************************************
+****************************** No-op Locking **********************************
+**
+** Of the various locking implementations available, this is by far the
+** simplest:  locking is ignored.  No attempt is made to lock the database
+** file for reading or writing.
+**
+** This locking mode is appropriate for use on read-only databases
+** (ex: databases that are burned into CD-ROM, for example.)  It can
+** also be used if the application employs some external mechanism to
+** prevent simultaneous access of the same database by two or more
+** database connections.  But there is a serious risk of database
+** corruption if this locking mode is used in situations where multiple
+** database connections are accessing the same database file at the same
+** time and one or more of those connections are writing.
+*/
+
+static int winNolockLock(sqlite3_file *id, int locktype){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(locktype);
+  return SQLITE_OK;
+}
+
+static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(pResOut);
+  return SQLITE_OK;
+}
+
+static int winNolockUnlock(sqlite3_file *id, int locktype){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(locktype);
+  return SQLITE_OK;
+}
+
+/******************* End of the no-op lock implementation *********************
+******************************************************************************/
+
 /*
 ** If *pArg is initially negative then this is a query.  Set *pArg to
 ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
@@ -36074,7 +41707,7 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
-    case SQLITE_LAST_ERRNO: {
+    case SQLITE_FCNTL_LAST_ERRNO: {
       *(int*)pArg = (int)pFile->lastErrno;
       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
@@ -36132,6 +41765,12 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
+    case SQLITE_FCNTL_WIN32_GET_HANDLE: {
+      LPHANDLE phFile = (LPHANDLE)pArg;
+      *phFile = pFile->h;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
+      return SQLITE_OK;
+    }
 #ifdef SQLITE_TEST
     case SQLITE_FCNTL_WIN32_SET_HANDLE: {
       LPHANDLE phFile = (LPHANDLE)pArg;
@@ -36224,14 +41863,14 @@ static SYSTEM_INFO winSysInfo;
 **   winShmLeaveMutex()
 */
 static void winShmEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 static void winShmLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #ifndef NDEBUG
 static int winShmMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #endif
 
@@ -36274,7 +41913,7 @@ struct winShmNode {
   int nRef;                  /* Number of winShm objects pointing to this */
   winShm *pFirst;            /* All winShm objects pointing to this */
   winShmNode *pNext;         /* Next in list of all winShmNode objects */
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   u8 nextShmId;              /* Next available winShm.id value */
 #endif
 };
@@ -36305,7 +41944,7 @@ struct winShm {
   u8 hasMutex;               /* True if holding the winShmNode mutex */
   u16 sharedMask;            /* Mask of shared locks held */
   u16 exclMask;              /* Mask of exclusive locks held */
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   u8 id;                     /* Id of this connection with its winShmNode */
 #endif
 };
@@ -36319,12 +41958,12 @@ struct winShm {
 /*
 ** Apply advisory locks for all n bytes beginning at ofst.
 */
-#define _SHM_UNLCK  1
-#define _SHM_RDLCK  2
-#define _SHM_WRLCK  3
+#define WINSHM_UNLCK  1
+#define WINSHM_RDLCK  2
+#define WINSHM_WRLCK  3
 static int winShmSystemLock(
   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
-  int lockType,         /* _SHM_UNLCK, _SHM_RDLCK, or _SHM_WRLCK */
+  int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
   int ofst,             /* Offset to first byte to be locked/unlocked */
   int nByte             /* Number of bytes to lock or unlock */
 ){
@@ -36337,12 +41976,12 @@ static int winShmSystemLock(
            pFile->hFile.h, lockType, ofst, nByte));
 
   /* Release/Acquire the system-level lock */
-  if( lockType==_SHM_UNLCK ){
+  if( lockType==WINSHM_UNLCK ){
     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
   }else{
     /* Initialize the locking parameters */
     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
-    if( lockType == _SHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
+    if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
   }
 
@@ -36354,7 +41993,7 @@ static int winShmSystemLock(
   }
 
   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
-           pFile->hFile.h, (lockType == _SHM_UNLCK) ? "winUnlockFile" :
+           pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :
            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
 
   return rc;
@@ -36432,12 +42071,12 @@ static int winOpenSharedMemory(winFile *pDbFd){
   ** allocate space for a new winShmNode and filename.
   */
   p = sqlite3MallocZero( sizeof(*p) );
-  if( p==0 ) return SQLITE_IOERR_NOMEM;
+  if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;
   nName = sqlite3Strlen30(pDbFd->zPath);
   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
   if( pNew==0 ){
     sqlite3_free(p);
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
   pNew->zFilename = (char*)&pNew[1];
   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
@@ -36462,10 +42101,12 @@ static int winOpenSharedMemory(winFile *pDbFd){
     pShmNode->pNext = winShmNodeList;
     winShmNodeList = pShmNode;
 
-    pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-    if( pShmNode->mutex==0 ){
-      rc = SQLITE_IOERR_NOMEM;
-      goto shm_open_err;
+    if( sqlite3GlobalConfig.bCoreMutex ){
+      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+      if( pShmNode->mutex==0 ){
+        rc = SQLITE_IOERR_NOMEM_BKPT;
+        goto shm_open_err;
+      }
     }
 
     rc = winOpen(pDbFd->pVfs,
@@ -36480,7 +42121,7 @@ static int winOpenSharedMemory(winFile *pDbFd){
     /* Check to see if another process is holding the dead-man switch.
     ** If not, truncate the file to zero length.
     */
-    if( winShmSystemLock(pShmNode, _SHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
+    if( winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, 0);
       if( rc!=SQLITE_OK ){
         rc = winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
@@ -36488,15 +42129,15 @@ static int winOpenSharedMemory(winFile *pDbFd){
       }
     }
     if( rc==SQLITE_OK ){
-      winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
-      rc = winShmSystemLock(pShmNode, _SHM_RDLCK, WIN_SHM_DMS, 1);
+      winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
+      rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
     }
     if( rc ) goto shm_open_err;
   }
 
   /* Make the new connection a child of the winShmNode */
   p->pShmNode = pShmNode;
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   p->id = pShmNode->nextShmId++;
 #endif
   pShmNode->nRef++;
@@ -36518,7 +42159,7 @@ static int winOpenSharedMemory(winFile *pDbFd){
 
   /* Jump here on any error */
 shm_open_err:
-  winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
+  winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
   sqlite3_free(p);
   sqlite3_free(pNew);
@@ -36607,7 +42248,7 @@ static int winShmLock(
 
     /* Unlock the system-level locks */
     if( (mask & allMask)==0 ){
-      rc = winShmSystemLock(pShmNode, _SHM_UNLCK, ofst+WIN_SHM_BASE, n);
+      rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);
     }else{
       rc = SQLITE_OK;
     }
@@ -36635,7 +42276,7 @@ static int winShmLock(
     /* Get shared locks at the system level, if necessary */
     if( rc==SQLITE_OK ){
       if( (allShared & mask)==0 ){
-        rc = winShmSystemLock(pShmNode, _SHM_RDLCK, ofst+WIN_SHM_BASE, n);
+        rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);
       }else{
         rc = SQLITE_OK;
       }
@@ -36660,7 +42301,7 @@ static int winShmLock(
     ** also mark the local connection as being locked.
     */
     if( rc==SQLITE_OK ){
-      rc = winShmSystemLock(pShmNode, _SHM_WRLCK, ofst+WIN_SHM_BASE, n);
+      rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);
       if( rc==SQLITE_OK ){
         assert( (p->sharedMask & mask)==0 );
         p->exclMask |= mask;
@@ -36684,8 +42325,8 @@ static void winShmBarrier(
   sqlite3_file *fd          /* Database holding the shared memory */
 ){
   UNUSED_PARAMETER(fd);
-  /* MemoryBarrier(); // does not work -- do not know why not */
-  winShmEnterMutex();
+  sqlite3MemoryBarrier();   /* compiler-defined memory barrier */
+  winShmEnterMutex();       /* Also mutex, for redundancy */
   winShmLeaveMutex();
 }
 
@@ -36716,16 +42357,16 @@ static int winShmMap(
   void volatile **pp              /* OUT: Mapped memory */
 ){
   winFile *pDbFd = (winFile*)fd;
-  winShm *p = pDbFd->pShm;
+  winShm *pShm = pDbFd->pShm;
   winShmNode *pShmNode;
   int rc = SQLITE_OK;
 
-  if( !p ){
+  if( !pShm ){
     rc = winOpenSharedMemory(pDbFd);
     if( rc!=SQLITE_OK ) return rc;
-    p = pDbFd->pShm;
+    pShm = pDbFd->pShm;
   }
-  pShmNode = p->pShmNode;
+  pShmNode = pShm->pShmNode;
 
   sqlite3_mutex_enter(pShmNode->mutex);
   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
@@ -36765,11 +42406,11 @@ static int winShmMap(
     }
 
     /* Map the requested memory region into this processes address space. */
-    apNew = (struct ShmRegion *)sqlite3_realloc(
+    apNew = (struct ShmRegion *)sqlite3_realloc64(
         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
     );
     if( !apNew ){
-      rc = SQLITE_IOERR_NOMEM;
+      rc = SQLITE_IOERR_NOMEM_BKPT;
       goto shmpage_out;
     }
     pShmNode->aRegion = apNew;
@@ -36786,7 +42427,7 @@ static int winShmMap(
       hMap = osCreateFileMappingW(pShmNode->hFile.h,
           NULL, PAGE_READWRITE, 0, nByte, NULL
       );
-#elif defined(SQLITE_WIN32_HAS_ANSI)
+#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
       hMap = osCreateFileMappingA(pShmNode->hFile.h,
           NULL, PAGE_READWRITE, 0, nByte, NULL
       );
@@ -36930,17 +42571,19 @@ static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
     DWORD flags = FILE_MAP_READ;
 
     winUnmapfile(pFd);
+#ifdef SQLITE_MMAP_READWRITE
     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
       protect = PAGE_READWRITE;
       flags |= FILE_MAP_WRITE;
     }
+#endif
 #if SQLITE_OS_WINRT
     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
 #elif defined(SQLITE_WIN32_HAS_WIDE)
     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
                                 (DWORD)((nMap>>32) & 0xffffffff),
                                 (DWORD)(nMap & 0xffffffff), NULL);
-#elif defined(SQLITE_WIN32_HAS_ANSI)
+#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
                                 (DWORD)((nMap>>32) & 0xffffffff),
                                 (DWORD)(nMap & 0xffffffff), NULL);
@@ -37101,6 +42744,44 @@ static const sqlite3_io_methods winIoMethod = {
   winUnfetch                      /* xUnfetch */
 };
 
+/*
+** This vector defines all the methods that can operate on an
+** sqlite3_file for win32 without performing any locking.
+*/
+static const sqlite3_io_methods winIoNolockMethod = {
+  3,                              /* iVersion */
+  winClose,                       /* xClose */
+  winRead,                        /* xRead */
+  winWrite,                       /* xWrite */
+  winTruncate,                    /* xTruncate */
+  winSync,                        /* xSync */
+  winFileSize,                    /* xFileSize */
+  winNolockLock,                  /* xLock */
+  winNolockUnlock,                /* xUnlock */
+  winNolockCheckReservedLock,     /* xCheckReservedLock */
+  winFileControl,                 /* xFileControl */
+  winSectorSize,                  /* xSectorSize */
+  winDeviceCharacteristics,       /* xDeviceCharacteristics */
+  winShmMap,                      /* xShmMap */
+  winShmLock,                     /* xShmLock */
+  winShmBarrier,                  /* xShmBarrier */
+  winShmUnmap,                    /* xShmUnmap */
+  winFetch,                       /* xFetch */
+  winUnfetch                      /* xUnfetch */
+};
+
+static winVfsAppData winAppData = {
+  &winIoMethod,       /* pMethod */
+  0,                  /* pAppData */
+  0                   /* bNoLock */
+};
+
+static winVfsAppData winNolockAppData = {
+  &winIoNolockMethod, /* pMethod */
+  0,                  /* pAppData */
+  1                   /* bNoLock */
+};
+
 /****************************************************************************
 **************************** sqlite3_vfs methods ****************************
 **
@@ -37121,7 +42802,7 @@ static char *winConvertToUtf8Filename(const void *zFilename){
   }
 #ifdef SQLITE_WIN32_HAS_ANSI
   else{
-    zConverted = sqlite3_win32_mbcs_to_utf8(zFilename);
+    zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());
   }
 #endif
   /* caller will handle out of memory */
@@ -37142,7 +42823,7 @@ static void *winConvertFromUtf8Filename(const char *zFilename){
   }
 #ifdef SQLITE_WIN32_HAS_ANSI
   else{
-    zConverted = sqlite3_win32_utf8_to_mbcs(zFilename);
+    zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());
   }
 #endif
   /* caller will handle out of memory */
@@ -37197,7 +42878,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
   zBuf = sqlite3MallocZero( nBuf );
   if( !zBuf ){
     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
 
   /* Figure out the effective temporary directory.  First, check if one
@@ -37255,7 +42936,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
         if( !zConverted ){
           sqlite3_free(zBuf);
           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-          return SQLITE_IOERR_NOMEM;
+          return SQLITE_IOERR_NOMEM_BKPT;
         }
         if( winIsDir(zConverted) ){
           sqlite3_snprintf(nMax, zBuf, "%s", zDir);
@@ -37268,7 +42949,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
         if( !zConverted ){
           sqlite3_free(zBuf);
           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-          return SQLITE_IOERR_NOMEM;
+          return SQLITE_IOERR_NOMEM_BKPT;
         }
         if( cygwin_conv_path(
                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
@@ -37289,7 +42970,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
             sqlite3_free(zConverted);
             sqlite3_free(zBuf);
             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-            return SQLITE_IOERR_NOMEM;
+            return SQLITE_IOERR_NOMEM_BKPT;
           }
           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
           sqlite3_free(zUtf8);
@@ -37307,7 +42988,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
     if( !zWidePath ){
       sqlite3_free(zBuf);
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     if( osGetTempPathW(nMax, zWidePath)==0 ){
       sqlite3_free(zWidePath);
@@ -37325,7 +43006,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
       sqlite3_free(zWidePath);
       sqlite3_free(zBuf);
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
   }
 #ifdef SQLITE_WIN32_HAS_ANSI
@@ -37335,7 +43016,7 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
     if( !zMbcsPath ){
       sqlite3_free(zBuf);
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     if( osGetTempPathA(nMax, zMbcsPath)==0 ){
       sqlite3_free(zBuf);
@@ -37343,14 +43024,14 @@ static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
                          "winGetTempname3", 0);
     }
-    zUtf8 = sqlite3_win32_mbcs_to_utf8(zMbcsPath);
+    zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());
     if( zUtf8 ){
       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
       sqlite3_free(zUtf8);
     }else{
       sqlite3_free(zBuf);
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
   }
 #endif /* SQLITE_WIN32_HAS_ANSI */
@@ -37433,7 +43114,7 @@ static int winIsDir(const void *zConverted){
 ** Open a file.
 */
 static int winOpen(
-  sqlite3_vfs *pVfs,        /* Used to get maximum path name length */
+  sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */
   const char *zName,        /* Name of the file (UTF-8) */
   sqlite3_file *id,         /* Write the SQLite file handle here */
   int flags,                /* Open mode flags */
@@ -37448,6 +43129,7 @@ static int winOpen(
 #if SQLITE_OS_WINCE
   int isTemp = 0;
 #endif
+  winVfsAppData *pAppData;
   winFile *pFile = (winFile*)id;
   void *zConverted;              /* Filename in OS encoding */
   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
@@ -37542,7 +43224,7 @@ static int winOpen(
   if( zConverted==0 ){
     sqlite3_free(zTmpname);
     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
 
   if( winIsDir(zConverted) ){
@@ -37637,7 +43319,7 @@ static int winOpen(
     }
   }
 #endif
-  winLogIoerr(cnt);
+  winLogIoerr(cnt, __LINE__);
 
   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
@@ -37669,15 +43351,20 @@ static int winOpen(
            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
 
+  pAppData = (winVfsAppData*)pVfs->pAppData;
+
 #if SQLITE_OS_WINCE
-  if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
-       && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
-  ){
-    osCloseHandle(h);
-    sqlite3_free(zConverted);
-    sqlite3_free(zTmpname);
-    OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
-    return rc;
+  {
+    if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
+         && ((pAppData==NULL) || !pAppData->bNoLock)
+         && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
+    ){
+      osCloseHandle(h);
+      sqlite3_free(zConverted);
+      sqlite3_free(zTmpname);
+      OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
+      return rc;
+    }
   }
   if( isTemp ){
     pFile->zDeleteOnClose = zConverted;
@@ -37688,7 +43375,7 @@ static int winOpen(
   }
 
   sqlite3_free(zTmpname);
-  pFile->pMethod = &winIoMethod;
+  pFile->pMethod = pAppData ? pAppData->pMethod : &winIoMethod;
   pFile->pVfs = pVfs;
   pFile->h = h;
   if( isReadonly ){
@@ -37742,7 +43429,7 @@ static int winDelete(
   zConverted = winConvertFromUtf8Filename(zFilename);
   if( zConverted==0 ){
     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
   if( osIsNT() ){
     do {
@@ -37821,7 +43508,7 @@ static int winDelete(
   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
   }else{
-    winLogIoerr(cnt);
+    winLogIoerr(cnt, __LINE__);
   }
   sqlite3_free(zConverted);
   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
@@ -37850,7 +43537,7 @@ static int winAccess(
   zConverted = winConvertFromUtf8Filename(zFilename);
   if( zConverted==0 ){
     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
   if( osIsNT() ){
     int cnt = 0;
@@ -37871,7 +43558,7 @@ static int winAccess(
         attr = sAttrData.dwFileAttributes;
       }
     }else{
-      winLogIoerr(cnt);
+      winLogIoerr(cnt, __LINE__);
       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
         sqlite3_free(zConverted);
         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
@@ -37963,6 +43650,18 @@ static int winFullPathname(
   int nFull,                    /* Size of output buffer in bytes */
   char *zFull                   /* Output buffer */
 ){
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
+  DWORD nByte;
+  void *zConverted;
+  char *zOut;
+#endif
+
+  /* If this path name begins with "/X:", where "X" is any alphabetic
+  ** character, discard the initial "/" from the pathname.
+  */
+  if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){
+    zRelative++;
+  }
 
 #if defined(__CYGWIN__)
   SimulateIOError( return SQLITE_ERROR );
@@ -37977,7 +43676,7 @@ static int winFullPathname(
     */
     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
     if( !zOut ){
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     if( cygwin_conv_path(
             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
@@ -37989,7 +43688,7 @@ static int winFullPathname(
       char *zUtf8 = winConvertToUtf8Filename(zOut);
       if( !zUtf8 ){
         sqlite3_free(zOut);
-        return SQLITE_IOERR_NOMEM;
+        return SQLITE_IOERR_NOMEM_BKPT;
       }
       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
                        sqlite3_data_directory, winGetDirSep(), zUtf8);
@@ -37999,7 +43698,7 @@ static int winFullPathname(
   }else{
     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
     if( !zOut ){
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     if( cygwin_conv_path(
             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
@@ -38011,7 +43710,7 @@ static int winFullPathname(
       char *zUtf8 = winConvertToUtf8Filename(zOut);
       if( !zUtf8 ){
         sqlite3_free(zOut);
-        return SQLITE_IOERR_NOMEM;
+        return SQLITE_IOERR_NOMEM_BKPT;
       }
       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
       sqlite3_free(zUtf8);
@@ -38041,17 +43740,6 @@ static int winFullPathname(
 #endif
 
 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
-  DWORD nByte;
-  void *zConverted;
-  char *zOut;
-
-  /* If this path name begins with "/X:", where "X" is any alphabetic
-  ** character, discard the initial "/" from the pathname.
-  */
-  if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){
-    zRelative++;
-  }
-
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
   ** function failing. This function could fail if, for example, the
@@ -38071,7 +43759,7 @@ static int winFullPathname(
   }
   zConverted = winConvertFromUtf8Filename(zRelative);
   if( zConverted==0 ){
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
   if( osIsNT() ){
     LPWSTR zTemp;
@@ -38085,7 +43773,7 @@ static int winFullPathname(
     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
     if( zTemp==0 ){
       sqlite3_free(zConverted);
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
     if( nByte==0 ){
@@ -38111,7 +43799,7 @@ static int winFullPathname(
     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
     if( zTemp==0 ){
       sqlite3_free(zConverted);
-      return SQLITE_IOERR_NOMEM;
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
     nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
     if( nByte==0 ){
@@ -38121,7 +43809,7 @@ static int winFullPathname(
                          "winFullPathname4", zRelative);
     }
     sqlite3_free(zConverted);
-    zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
+    zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
     sqlite3_free(zTemp);
   }
 #endif
@@ -38130,7 +43818,7 @@ static int winFullPathname(
     sqlite3_free(zOut);
     return SQLITE_OK;
   }else{
-    return SQLITE_IOERR_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
 #endif
 }
@@ -38205,49 +43893,85 @@ static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
   #define winDlClose 0
 #endif
 
+/* State information for the randomness gatherer. */
+typedef struct EntropyGatherer EntropyGatherer;
+struct EntropyGatherer {
+  unsigned char *a;   /* Gather entropy into this buffer */
+  int na;             /* Size of a[] in bytes */
+  int i;              /* XOR next input into a[i] */
+  int nXor;           /* Number of XOR operations done */
+};
+
+#if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
+/* Mix sz bytes of entropy into p. */
+static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){
+  int j, k;
+  for(j=0, k=p->i; ja[k++] ^= x[j];
+    if( k>=p->na ) k = 0;
+  }
+  p->i = k;
+  p->nXor += sz;
+}
+#endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */
 
 /*
 ** Write up to nBuf bytes of randomness into zBuf.
 */
 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
-  int n = 0;
+#if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
   UNUSED_PARAMETER(pVfs);
-#if defined(SQLITE_TEST)
-  n = nBuf;
   memset(zBuf, 0, nBuf);
+  return nBuf;
 #else
-  if( sizeof(SYSTEMTIME)<=nBuf-n ){
+  EntropyGatherer e;
+  UNUSED_PARAMETER(pVfs);
+  memset(zBuf, 0, nBuf);
+#if defined(_MSC_VER) && _MSC_VER>=1400 && !SQLITE_OS_WINCE
+  rand_s((unsigned int*)zBuf); /* rand_s() is not available with MinGW */
+#endif /* defined(_MSC_VER) && _MSC_VER>=1400 */
+  e.a = (unsigned char*)zBuf;
+  e.na = nBuf;
+  e.nXor = 0;
+  e.i = 0;
+  {
     SYSTEMTIME x;
     osGetSystemTime(&x);
-    memcpy(&zBuf[n], &x, sizeof(x));
-    n += sizeof(x);
+    xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));
   }
-  if( sizeof(DWORD)<=nBuf-n ){
+  {
     DWORD pid = osGetCurrentProcessId();
-    memcpy(&zBuf[n], &pid, sizeof(pid));
-    n += sizeof(pid);
+    xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));
   }
 #if SQLITE_OS_WINRT
-  if( sizeof(ULONGLONG)<=nBuf-n ){
+  {
     ULONGLONG cnt = osGetTickCount64();
-    memcpy(&zBuf[n], &cnt, sizeof(cnt));
-    n += sizeof(cnt);
+    xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));
   }
 #else
-  if( sizeof(DWORD)<=nBuf-n ){
+  {
     DWORD cnt = osGetTickCount();
-    memcpy(&zBuf[n], &cnt, sizeof(cnt));
-    n += sizeof(cnt);
+    xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));
   }
-#endif
-  if( sizeof(LARGE_INTEGER)<=nBuf-n ){
+#endif /* SQLITE_OS_WINRT */
+  {
     LARGE_INTEGER i;
     osQueryPerformanceCounter(&i);
-    memcpy(&zBuf[n], &i, sizeof(i));
-    n += sizeof(i);
+    xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));
   }
-#endif
-  return n;
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  {
+    UUID id;
+    memset(&id, 0, sizeof(UUID));
+    osUuidCreate(&id);
+    xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
+    memset(&id, 0, sizeof(UUID));
+    osUuidCreateSequential(&id);
+    xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
+  }
+#endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */
+  return e.nXor>nBuf ? nBuf : e.nXor;
+#endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */
 }
 
 
@@ -38363,8 +44087,10 @@ static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
 */
 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  DWORD e = osGetLastError();
   UNUSED_PARAMETER(pVfs);
-  return winGetLastErrorMsg(osGetLastError(), nBuf, zBuf);
+  if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);
+  return e;
 }
 
 /*
@@ -38372,59 +44098,109 @@ static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
 */
 SQLITE_API int sqlite3_os_init(void){
   static sqlite3_vfs winVfs = {
-    3,                   /* iVersion */
-    sizeof(winFile),     /* szOsFile */
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
-    0,                   /* pNext */
-    "win32",             /* zName */
-    0,                   /* pAppData */
-    winOpen,             /* xOpen */
-    winDelete,           /* xDelete */
-    winAccess,           /* xAccess */
-    winFullPathname,     /* xFullPathname */
-    winDlOpen,           /* xDlOpen */
-    winDlError,          /* xDlError */
-    winDlSym,            /* xDlSym */
-    winDlClose,          /* xDlClose */
-    winRandomness,       /* xRandomness */
-    winSleep,            /* xSleep */
-    winCurrentTime,      /* xCurrentTime */
-    winGetLastError,     /* xGetLastError */
-    winCurrentTimeInt64, /* xCurrentTimeInt64 */
-    winSetSystemCall,    /* xSetSystemCall */
-    winGetSystemCall,    /* xGetSystemCall */
-    winNextSystemCall,   /* xNextSystemCall */
+    0,                     /* pNext */
+    "win32",               /* zName */
+    &winAppData,           /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
   };
 #if defined(SQLITE_WIN32_HAS_WIDE)
   static sqlite3_vfs winLongPathVfs = {
-    3,                   /* iVersion */
-    sizeof(winFile),     /* szOsFile */
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
-    0,                   /* pNext */
-    "win32-longpath",    /* zName */
-    0,                   /* pAppData */
-    winOpen,             /* xOpen */
-    winDelete,           /* xDelete */
-    winAccess,           /* xAccess */
-    winFullPathname,     /* xFullPathname */
-    winDlOpen,           /* xDlOpen */
-    winDlError,          /* xDlError */
-    winDlSym,            /* xDlSym */
-    winDlClose,          /* xDlClose */
-    winRandomness,       /* xRandomness */
-    winSleep,            /* xSleep */
-    winCurrentTime,      /* xCurrentTime */
-    winGetLastError,     /* xGetLastError */
-    winCurrentTimeInt64, /* xCurrentTimeInt64 */
-    winSetSystemCall,    /* xSetSystemCall */
-    winGetSystemCall,    /* xGetSystemCall */
-    winNextSystemCall,   /* xNextSystemCall */
+    0,                     /* pNext */
+    "win32-longpath",      /* zName */
+    &winAppData,           /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
+  };
+#endif
+  static sqlite3_vfs winNolockVfs = {
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32-none",          /* zName */
+    &winNolockAppData,     /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
+  };
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  static sqlite3_vfs winLongPathNolockVfs = {
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32-longpath-none", /* zName */
+    &winNolockAppData,     /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
   };
 #endif
 
   /* Double-check that the aSyscall[] array has been constructed
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
-  assert( ArraySize(aSyscall)==77 );
+  assert( ArraySize(aSyscall)==80 );
 
   /* get memory map allocation granularity */
   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
@@ -38442,6 +44218,12 @@ SQLITE_API int sqlite3_os_init(void){
   sqlite3_vfs_register(&winLongPathVfs, 0);
 #endif
 
+  sqlite3_vfs_register(&winNolockVfs, 0);
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  sqlite3_vfs_register(&winLongPathNolockVfs, 0);
+#endif
+
   return SQLITE_OK;
 }
 
@@ -38495,13 +44277,15 @@ SQLITE_API int sqlite3_os_end(void){
 ** start of a transaction, and is thus usually less than a few thousand,
 ** but can be as large as 2 billion for a really big database.
 */
+/* #include "sqliteInt.h" */
 
 /* Size of the Bitvec structure in bytes. */
 #define BITVEC_SZ        512
 
 /* Round the union size down to the nearest pointer boundary, since that's how 
 ** it will be aligned within the Bitvec struct. */
-#define BITVEC_USIZE     (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))
+#define BITVEC_USIZE \
+    (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))
 
 /* Type of the array "element" for the bitmap representation. 
 ** Should be a power of 2, and ideally, evenly divide into BITVEC_USIZE. 
@@ -38586,10 +44370,10 @@ SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32 iSize){
 ** If p is NULL (if the bitmap has not been created) or if
 ** i is out of range, then return false.
 */
-SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
-  if( p==0 ) return 0;
-  if( i>p->iSize || i==0 ) return 0;
+SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec *p, u32 i){
+  assert( p!=0 );
   i--;
+  if( i>=p->iSize ) return 0;
   while( p->iDivisor ){
     u32 bin = i/p->iDivisor;
     i = i%p->iDivisor;
@@ -38609,6 +44393,9 @@ SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
     return 0;
   }
 }
+SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
+  return p!=0 && sqlite3BitvecTestNotNull(p,i);
+}
 
 /*
 ** Set the i-th bit.  Return 0 on success and an error code if
@@ -38633,7 +44420,7 @@ SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec *p, u32 i){
     i = i%p->iDivisor;
     if( p->u.apSub[bin]==0 ){
       p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
-      if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
+      if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM_BKPT;
     }
     p = p->u.apSub[bin];
   }
@@ -38668,7 +44455,7 @@ bitvec_set_rehash:
     int rc;
     u32 *aiValues = sqlite3StackAllocRaw(0, sizeof(p->u.aHash));
     if( aiValues==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }else{
       memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));
       memset(p->u.apSub, 0, sizeof(p->u.apSub));
@@ -38749,7 +44536,7 @@ SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec *p){
   return p->iSize;
 }
 
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifndef SQLITE_UNTESTABLE
 /*
 ** Let V[] be an array of unsigned characters sufficient to hold
 ** up to N bits.  Let I be an integer between 0 and N.  0<=IpDirtyNext.
+**   PCache.pDirty points to the first (newest) element in the list and
+**   pDirtyTail to the last (oldest).
+**
+**   The PCache.pSynced variable is used to optimize searching for a dirty
+**   page to eject from the cache mid-transaction. It is better to eject
+**   a page that does not require a journal sync than one that does. 
+**   Therefore, pSynced is maintained to that it *almost* always points
+**   to either the oldest page in the pDirty/pDirtyTail list that has a
+**   clear PGHDR_NEED_SYNC flag or to a page that is older than this one
+**   (so that the right page to eject can be found by following pDirtyPrev
+**   pointers).
 */
 struct PCache {
   PgHdr *pDirty, *pDirtyTail;         /* List of dirty pages in LRU order */
   PgHdr *pSynced;                     /* Last synced page in dirty page list */
-  int nRef;                           /* Number of referenced pages */
+  int nRefSum;                        /* Sum of ref counts over all pages */
   int szCache;                        /* Configured cache size */
+  int szSpill;                        /* Size before spilling occurs */
   int szPage;                         /* Size of every page in this cache */
   int szExtra;                        /* Size of extra space for each page */
   u8 bPurgeable;                      /* True if pages are on backing store */
@@ -38897,9 +44708,97 @@ struct PCache {
   int (*xStress)(void*,PgHdr*);       /* Call to try make a page clean */
   void *pStress;                      /* Argument to xStress */
   sqlite3_pcache *pCache;             /* Pluggable cache module */
-  PgHdr *pPage1;                      /* Reference to page 1 */
 };
 
+/********************************** Test and Debug Logic **********************/
+/*
+** Debug tracing macros.  Enable by by changing the "0" to "1" and
+** recompiling.
+**
+** When sqlite3PcacheTrace is 1, single line trace messages are issued.
+** When sqlite3PcacheTrace is 2, a dump of the pcache showing all cache entries
+** is displayed for many operations, resulting in a lot of output.
+*/
+#if defined(SQLITE_DEBUG) && 0
+  int sqlite3PcacheTrace = 2;       /* 0: off  1: simple  2: cache dumps */
+  int sqlite3PcacheMxDump = 9999;   /* Max cache entries for pcacheDump() */
+# define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;}
+  void pcacheDump(PCache *pCache){
+    int N;
+    int i, j;
+    sqlite3_pcache_page *pLower;
+    PgHdr *pPg;
+    unsigned char *a;
+  
+    if( sqlite3PcacheTrace<2 ) return;
+    if( pCache->pCache==0 ) return;
+    N = sqlite3PcachePagecount(pCache);
+    if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump;
+    for(i=1; i<=N; i++){
+       pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0);
+       if( pLower==0 ) continue;
+       pPg = (PgHdr*)pLower->pExtra;
+       printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
+       a = (unsigned char *)pLower->pBuf;
+       for(j=0; j<12; j++) printf("%02x", a[j]);
+       printf("\n");
+       if( pPg->pPage==0 ){
+         sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0);
+       }
+    }
+  }
+  #else
+# define pcacheTrace(X)
+# define pcacheDump(X)
+#endif
+
+/*
+** Check invariants on a PgHdr entry.  Return true if everything is OK.
+** Return false if any invariant is violated.
+**
+** This routine is for use inside of assert() statements only.  For
+** example:
+**
+**          assert( sqlite3PcachePageSanity(pPg) );
+*/
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr *pPg){
+  PCache *pCache;
+  assert( pPg!=0 );
+  assert( pPg->pgno>0 || pPg->pPager==0 );    /* Page number is 1 or more */
+  pCache = pPg->pCache;
+  assert( pCache!=0 );      /* Every page has an associated PCache */
+  if( pPg->flags & PGHDR_CLEAN ){
+    assert( (pPg->flags & PGHDR_DIRTY)==0 );/* Cannot be both CLEAN and DIRTY */
+    assert( pCache->pDirty!=pPg );          /* CLEAN pages not on dirty list */
+    assert( pCache->pDirtyTail!=pPg );
+  }
+  /* WRITEABLE pages must also be DIRTY */
+  if( pPg->flags & PGHDR_WRITEABLE ){
+    assert( pPg->flags & PGHDR_DIRTY );     /* WRITEABLE implies DIRTY */
+  }
+  /* NEED_SYNC can be set independently of WRITEABLE.  This can happen,
+  ** for example, when using the sqlite3PagerDontWrite() optimization:
+  **    (1)  Page X is journalled, and gets WRITEABLE and NEED_SEEK.
+  **    (2)  Page X moved to freelist, WRITEABLE is cleared
+  **    (3)  Page X reused, WRITEABLE is set again
+  ** If NEED_SYNC had been cleared in step 2, then it would not be reset
+  ** in step 3, and page might be written into the database without first
+  ** syncing the rollback journal, which might cause corruption on a power
+  ** loss.
+  **
+  ** Another example is when the database page size is smaller than the
+  ** disk sector size.  When any page of a sector is journalled, all pages
+  ** in that sector are marked NEED_SYNC even if they are still CLEAN, just
+  ** in case they are later modified, since all pages in the same sector
+  ** must be journalled and synced before any of those pages can be safely
+  ** written.
+  */
+  return 1;
+}
+#endif /* SQLITE_DEBUG */
+
+
 /********************************** Linked List Management ********************/
 
 /* Allowed values for second argument to pcacheManageDirtyList() */
@@ -38916,17 +44815,16 @@ struct PCache {
 static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
   PCache *p = pPage->pCache;
 
+  pcacheTrace(("%p.DIRTYLIST.%s %d\n", p,
+                addRemove==1 ? "REMOVE" : addRemove==2 ? "ADD" : "FRONT",
+                pPage->pgno));
   if( addRemove & PCACHE_DIRTYLIST_REMOVE ){
     assert( pPage->pDirtyNext || pPage==p->pDirtyTail );
     assert( pPage->pDirtyPrev || pPage==p->pDirty );
   
     /* Update the PCache1.pSynced variable if necessary. */
     if( p->pSynced==pPage ){
-      PgHdr *pSynced = pPage->pDirtyPrev;
-      while( pSynced && (pSynced->flags&PGHDR_NEED_SYNC) ){
-        pSynced = pSynced->pDirtyPrev;
-      }
-      p->pSynced = pSynced;
+      p->pSynced = pPage->pDirtyPrev;
     }
   
     if( pPage->pDirtyNext ){
@@ -38938,10 +44836,15 @@ static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
     if( pPage->pDirtyPrev ){
       pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;
     }else{
+      /* If there are now no dirty pages in the cache, set eCreate to 2. 
+      ** This is an optimization that allows sqlite3PcacheFetch() to skip
+      ** searching for a dirty page to eject from the cache when it might
+      ** otherwise have to.  */
       assert( pPage==p->pDirty );
       p->pDirty = pPage->pDirtyNext;
-      if( p->pDirty==0 && p->bPurgeable ){
-        assert( p->eCreate==1 );
+      assert( p->bPurgeable || p->eCreate==2 );
+      if( p->pDirty==0 ){         /*OPTIMIZATION-IF-TRUE*/
+        assert( p->bPurgeable==0 || p->eCreate==1 );
         p->eCreate = 2;
       }
     }
@@ -38963,10 +44866,19 @@ static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
       }
     }
     p->pDirty = pPage;
-    if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
+
+    /* If pSynced is NULL and this page has a clear NEED_SYNC flag, set
+    ** pSynced to point to it. Checking the NEED_SYNC flag is an 
+    ** optimization, as if pSynced points to a page with the NEED_SYNC
+    ** flag set sqlite3PcacheFetchStress() searches through all newer 
+    ** entries of the dirty-list for a page with NEED_SYNC clear anyway.  */
+    if( !p->pSynced 
+     && 0==(pPage->flags&PGHDR_NEED_SYNC)   /*OPTIMIZATION-IF-FALSE*/
+    ){
       p->pSynced = pPage;
     }
   }
+  pcacheDump(p);
 }
 
 /*
@@ -38975,20 +44887,25 @@ static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
 */
 static void pcacheUnpin(PgHdr *p){
   if( p->pCache->bPurgeable ){
-    if( p->pgno==1 ){
-      p->pCache->pPage1 = 0;
-    }
+    pcacheTrace(("%p.UNPIN %d\n", p->pCache, p->pgno));
     sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 0);
+    pcacheDump(p->pCache);
   }
 }
 
 /*
-** Compute the number of pages of cache requested.
+** Compute the number of pages of cache requested.   p->szCache is the
+** cache size requested by the "PRAGMA cache_size" statement.
 */
 static int numberOfCachePages(PCache *p){
   if( p->szCache>=0 ){
+    /* IMPLEMENTATION-OF: R-42059-47211 If the argument N is positive then the
+    ** suggested cache size is set to N. */
     return p->szCache;
   }else{
+    /* IMPLEMENTATION-OF: R-61436-13639 If the argument N is negative, then
+    ** the number of cache pages is adjusted to use approximately abs(N*1024)
+    ** bytes of memory. */
     return (int)((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));
   }
 }
@@ -39024,6 +44941,12 @@ SQLITE_PRIVATE int sqlite3PcacheSize(void){ return sizeof(PCache); }
 ** has already been allocated and is passed in as the p pointer. 
 ** The caller discovers how much space needs to be allocated by 
 ** calling sqlite3PcacheSize().
+**
+** szExtra is some extra space allocated for each page.  The first
+** 8 bytes of the extra space will be zeroed as the page is allocated,
+** but remaining content will be uninitialized.  Though it is opaque
+** to this module, the extra space really ends up being the MemPage
+** structure in the pager.
 */
 SQLITE_PRIVATE int sqlite3PcacheOpen(
   int szPage,                  /* Size of every page */
@@ -39036,11 +44959,14 @@ SQLITE_PRIVATE int sqlite3PcacheOpen(
   memset(p, 0, sizeof(PCache));
   p->szPage = 1;
   p->szExtra = szExtra;
+  assert( szExtra>=8 );  /* First 8 bytes will be zeroed */
   p->bPurgeable = bPurgeable;
   p->eCreate = 2;
   p->xStress = xStress;
   p->pStress = pStress;
   p->szCache = 100;
+  p->szSpill = 1;
+  pcacheTrace(("%p.OPEN szPage %d bPurgeable %d\n",p,szPage,bPurgeable));
   return sqlite3PcacheSetPageSize(p, szPage);
 }
 
@@ -39049,21 +44975,21 @@ SQLITE_PRIVATE int sqlite3PcacheOpen(
 ** are no outstanding page references when this function is called.
 */
 SQLITE_PRIVATE int sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
-  assert( pCache->nRef==0 && pCache->pDirty==0 );
+  assert( pCache->nRefSum==0 && pCache->pDirty==0 );
   if( pCache->szPage ){
     sqlite3_pcache *pNew;
     pNew = sqlite3GlobalConfig.pcache2.xCreate(
                 szPage, pCache->szExtra + ROUND8(sizeof(PgHdr)),
                 pCache->bPurgeable
     );
-    if( pNew==0 ) return SQLITE_NOMEM;
+    if( pNew==0 ) return SQLITE_NOMEM_BKPT;
     sqlite3GlobalConfig.pcache2.xCachesize(pNew, numberOfCachePages(pCache));
     if( pCache->pCache ){
       sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
     }
     pCache->pCache = pNew;
-    pCache->pPage1 = 0;
     pCache->szPage = szPage;
+    pcacheTrace(("%p.PAGESIZE %d\n",pCache,szPage));
   }
   return SQLITE_OK;
 }
@@ -39098,11 +45024,12 @@ SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(
   int createFlag        /* If true, create page if it does not exist already */
 ){
   int eCreate;
+  sqlite3_pcache_page *pRes;
 
   assert( pCache!=0 );
   assert( pCache->pCache!=0 );
   assert( createFlag==3 || createFlag==0 );
-  assert( pgno>0 );
+  assert( pCache->eCreate==((pCache->bPurgeable && pCache->pDirty) ? 1 : 2) );
 
   /* eCreate defines what to do if the page does not exist.
   **    0     Do not allocate a new page.  (createFlag==0)
@@ -39115,12 +45042,15 @@ SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(
   assert( eCreate==0 || eCreate==1 || eCreate==2 );
   assert( createFlag==0 || pCache->eCreate==eCreate );
   assert( createFlag==0 || eCreate==1+(!pCache->bPurgeable||!pCache->pDirty) );
-  return sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);
+  pRes = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);
+  pcacheTrace(("%p.FETCH %d%s (result: %p)\n",pCache,pgno,
+               createFlag?" create":"",pRes));
+  return pRes;
 }
 
 /*
 ** If the sqlite3PcacheFetch() routine is unable to allocate a new
-** page because new clean pages are available for reuse and the cache
+** page because no clean pages are available for reuse and the cache
 ** size limit has been reached, then this routine can be invoked to 
 ** try harder to allocate a page.  This routine might invoke the stress
 ** callback to spill dirty pages to the journal.  It will then try to
@@ -39137,36 +45067,43 @@ SQLITE_PRIVATE int sqlite3PcacheFetchStress(
   PgHdr *pPg;
   if( pCache->eCreate==2 ) return 0;
 
-
-  /* Find a dirty page to write-out and recycle. First try to find a 
-  ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
-  ** cleared), but if that is not possible settle for any other 
-  ** unreferenced dirty page.
-  */
-  for(pPg=pCache->pSynced; 
-      pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
-      pPg=pPg->pDirtyPrev
-  );
-  pCache->pSynced = pPg;
-  if( !pPg ){
-    for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);
-  }
-  if( pPg ){
-    int rc;
+  if( sqlite3PcachePagecount(pCache)>pCache->szSpill ){
+    /* Find a dirty page to write-out and recycle. First try to find a 
+    ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
+    ** cleared), but if that is not possible settle for any other 
+    ** unreferenced dirty page.
+    **
+    ** If the LRU page in the dirty list that has a clear PGHDR_NEED_SYNC
+    ** flag is currently referenced, then the following may leave pSynced
+    ** set incorrectly (pointing to other than the LRU page with NEED_SYNC
+    ** cleared). This is Ok, as pSynced is just an optimization.  */
+    for(pPg=pCache->pSynced; 
+        pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
+        pPg=pPg->pDirtyPrev
+    );
+    pCache->pSynced = pPg;
+    if( !pPg ){
+      for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);
+    }
+    if( pPg ){
+      int rc;
 #ifdef SQLITE_LOG_CACHE_SPILL
-    sqlite3_log(SQLITE_FULL, 
-                "spill page %d making room for %d - cache used: %d/%d",
-                pPg->pgno, pgno,
-                sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
+      sqlite3_log(SQLITE_FULL, 
+                  "spill page %d making room for %d - cache used: %d/%d",
+                  pPg->pgno, pgno,
+                  sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
                 numberOfCachePages(pCache));
 #endif
-    rc = pCache->xStress(pCache->pStress, pPg);
-    if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
-      return rc;
+      pcacheTrace(("%p.SPILL %d\n",pCache,pPg->pgno));
+      rc = pCache->xStress(pCache->pStress, pPg);
+      pcacheDump(pCache);
+      if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
+        return rc;
+      }
     }
   }
   *ppPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2);
-  return *ppPage==0 ? SQLITE_NOMEM : SQLITE_OK;
+  return *ppPage==0 ? SQLITE_NOMEM_BKPT : SQLITE_OK;
 }
 
 /*
@@ -39187,13 +45124,14 @@ static SQLITE_NOINLINE PgHdr *pcacheFetchFinishWithInit(
   assert( pPage!=0 );
   pPgHdr = (PgHdr*)pPage->pExtra;
   assert( pPgHdr->pPage==0 );
- memset(pPgHdr, 0, sizeof(PgHdr));
+  memset(&pPgHdr->pDirty, 0, sizeof(PgHdr) - offsetof(PgHdr,pDirty));
   pPgHdr->pPage = pPage;
   pPgHdr->pData = pPage->pBuf;
   pPgHdr->pExtra = (void *)&pPgHdr[1];
-  memset(pPgHdr->pExtra, 0, pCache->szExtra);
+  memset(pPgHdr->pExtra, 0, 8);
   pPgHdr->pCache = pCache;
   pPgHdr->pgno = pgno;
+  pPgHdr->flags = PGHDR_CLEAN;
   return sqlite3PcacheFetchFinish(pCache,pgno,pPage);
 }
 
@@ -39210,19 +45148,15 @@ SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(
 ){
   PgHdr *pPgHdr;
 
-  if( pPage==0 ) return 0;
+  assert( pPage!=0 );
   pPgHdr = (PgHdr *)pPage->pExtra;
 
   if( !pPgHdr->pPage ){
     return pcacheFetchFinishWithInit(pCache, pgno, pPage);
   }
-  if( 0==pPgHdr->nRef ){
-    pCache->nRef++;
-  }
+  pCache->nRefSum++;
   pPgHdr->nRef++;
-  if( pgno==1 ){
-    pCache->pPage1 = pPgHdr;
-  }
+  assert( sqlite3PcachePageSanity(pPgHdr) );
   return pPgHdr;
 }
 
@@ -39232,13 +45166,15 @@ SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(
 */
 SQLITE_PRIVATE void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
   assert( p->nRef>0 );
-  p->nRef--;
-  if( p->nRef==0 ){
-    p->pCache->nRef--;
-    if( (p->flags&PGHDR_DIRTY)==0 ){
+  p->pCache->nRefSum--;
+  if( (--p->nRef)==0 ){
+    if( p->flags&PGHDR_CLEAN ){
       pcacheUnpin(p);
-    }else if( p->pDirtyPrev!=0 ){
-      /* Move the page to the head of the dirty list. */
+    }else if( p->pDirtyPrev!=0 ){ /*OPTIMIZATION-IF-FALSE*/
+      /* Move the page to the head of the dirty list. If p->pDirtyPrev==0,
+      ** then page p is already at the head of the dirty list and the
+      ** following call would be a no-op. Hence the OPTIMIZATION-IF-FALSE
+      ** tag above.  */
       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
     }
   }
@@ -39249,7 +45185,9 @@ SQLITE_PRIVATE void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
 */
 SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr *p){
   assert(p->nRef>0);
+  assert( sqlite3PcachePageSanity(p) );
   p->nRef++;
+  p->pCache->nRefSum++;
 }
 
 /*
@@ -39259,13 +45197,11 @@ SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr *p){
 */
 SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr *p){
   assert( p->nRef==1 );
+  assert( sqlite3PcachePageSanity(p) );
   if( p->flags&PGHDR_DIRTY ){
     pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
   }
-  p->pCache->nRef--;
-  if( p->pgno==1 ){
-    p->pCache->pPage1 = 0;
-  }
+  p->pCache->nRefSum--;
   sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1);
 }
 
@@ -39274,11 +45210,17 @@ SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr *p){
 ** make it so.
 */
 SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr *p){
-  p->flags &= ~PGHDR_DONT_WRITE;
   assert( p->nRef>0 );
-  if( 0==(p->flags & PGHDR_DIRTY) ){
-    p->flags |= PGHDR_DIRTY;
-    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);
+  assert( sqlite3PcachePageSanity(p) );
+  if( p->flags & (PGHDR_CLEAN|PGHDR_DONT_WRITE) ){    /*OPTIMIZATION-IF-FALSE*/
+    p->flags &= ~PGHDR_DONT_WRITE;
+    if( p->flags & PGHDR_CLEAN ){
+      p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN);
+      pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno));
+      assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY );
+      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);
+    }
+    assert( sqlite3PcachePageSanity(p) );
   }
 }
 
@@ -39287,9 +45229,14 @@ SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr *p){
 ** make it so.
 */
 SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr *p){
-  if( (p->flags & PGHDR_DIRTY) ){
+  assert( sqlite3PcachePageSanity(p) );
+  if( ALWAYS((p->flags & PGHDR_DIRTY)!=0) ){
+    assert( (p->flags & PGHDR_CLEAN)==0 );
     pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
-    p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC);
+    p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
+    p->flags |= PGHDR_CLEAN;
+    pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno));
+    assert( sqlite3PcachePageSanity(p) );
     if( p->nRef==0 ){
       pcacheUnpin(p);
     }
@@ -39301,11 +45248,24 @@ SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr *p){
 */
 SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache *pCache){
   PgHdr *p;
+  pcacheTrace(("%p.CLEAN-ALL\n",pCache));
   while( (p = pCache->pDirty)!=0 ){
     sqlite3PcacheMakeClean(p);
   }
 }
 
+/*
+** Clear the PGHDR_NEED_SYNC and PGHDR_WRITEABLE flag from all dirty pages.
+*/
+SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache *pCache){
+  PgHdr *p;
+  pcacheTrace(("%p.CLEAR-WRITEABLE\n",pCache));
+  for(p=pCache->pDirty; p; p=p->pDirtyNext){
+    p->flags &= ~(PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
+  }
+  pCache->pSynced = pCache->pDirtyTail;
+}
+
 /*
 ** Clear the PGHDR_NEED_SYNC flag from all dirty pages.
 */
@@ -39324,6 +45284,8 @@ SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
   PCache *pCache = p->pCache;
   assert( p->nRef>0 );
   assert( newPgno>0 );
+  assert( sqlite3PcachePageSanity(p) );
+  pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno));
   sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);
   p->pgno = newPgno;
   if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){
@@ -39344,6 +45306,7 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
   if( pCache->pCache ){
     PgHdr *p;
     PgHdr *pNext;
+    pcacheTrace(("%p.TRUNCATE %d\n",pCache,pgno));
     for(p=pCache->pDirty; p; p=pNext){
       pNext = p->pDirtyNext;
       /* This routine never gets call with a positive pgno except right
@@ -39351,14 +45314,19 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
       ** it must be that pgno==0.
       */
       assert( p->pgno>0 );
-      if( ALWAYS(p->pgno>pgno) ){
+      if( p->pgno>pgno ){
         assert( p->flags&PGHDR_DIRTY );
         sqlite3PcacheMakeClean(p);
       }
     }
-    if( pgno==0 && pCache->pPage1 ){
-      memset(pCache->pPage1->pData, 0, pCache->szPage);
-      pgno = 1;
+    if( pgno==0 && pCache->nRefSum ){
+      sqlite3_pcache_page *pPage1;
+      pPage1 = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache,1,0);
+      if( ALWAYS(pPage1) ){  /* Page 1 is always available in cache, because
+                             ** pCache->nRefSum>0 */
+        memset(pPage1->pBuf, 0, pCache->szPage);
+        pgno = 1;
+      }
     }
     sqlite3GlobalConfig.pcache2.xTruncate(pCache->pCache, pgno+1);
   }
@@ -39369,6 +45337,7 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
 */
 SQLITE_PRIVATE void sqlite3PcacheClose(PCache *pCache){
   assert( pCache->pCache!=0 );
+  pcacheTrace(("%p.CLOSE\n",pCache));
   sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
 }
 
@@ -39381,29 +45350,31 @@ SQLITE_PRIVATE void sqlite3PcacheClear(PCache *pCache){
 
 /*
 ** Merge two lists of pages connected by pDirty and in pgno order.
-** Do not both fixing the pDirtyPrev pointers.
+** Do not bother fixing the pDirtyPrev pointers.
 */
 static PgHdr *pcacheMergeDirtyList(PgHdr *pA, PgHdr *pB){
   PgHdr result, *pTail;
   pTail = &result;
-  while( pA && pB ){
+  assert( pA!=0 && pB!=0 );
+  for(;;){
     if( pA->pgnopgno ){
       pTail->pDirty = pA;
       pTail = pA;
       pA = pA->pDirty;
+      if( pA==0 ){
+        pTail->pDirty = pB;
+        break;
+      }
     }else{
       pTail->pDirty = pB;
       pTail = pB;
       pB = pB->pDirty;
+      if( pB==0 ){
+        pTail->pDirty = pA;
+        break;
+      }
     }
   }
-  if( pA ){
-    pTail->pDirty = pA;
-  }else if( pB ){
-    pTail->pDirty = pB;
-  }else{
-    pTail->pDirty = 0;
-  }
   return result.pDirty;
 }
 
@@ -39444,7 +45415,8 @@ static PgHdr *pcacheSortDirtyList(PgHdr *pIn){
   }
   p = a[0];
   for(i=1; inRef;
+  return pCache->nRefSum;
 }
 
 /*
@@ -39501,6 +45476,25 @@ SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *pCache, int mxPage){
                                          numberOfCachePages(pCache));
 }
 
+/*
+** Set the suggested cache-spill value.  Make no changes if if the
+** argument is zero.  Return the effective cache-spill size, which will
+** be the larger of the szSpill and szCache.
+*/
+SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *p, int mxPage){
+  int res;
+  assert( p->pCache!=0 );
+  if( mxPage ){
+    if( mxPage<0 ){
+      mxPage = (int)((-1024*(i64)mxPage)/(p->szPage+p->szExtra));
+    }
+    p->szSpill = mxPage;
+  }
+  res = numberOfCachePages(p);
+  if( resszSpill ) res = p->szSpill; 
+  return res;
+}
+
 /*
 ** Free up as much memory as possible from the page cache.
 */
@@ -39515,6 +45509,17 @@ SQLITE_PRIVATE void sqlite3PcacheShrink(PCache *pCache){
 */
 SQLITE_PRIVATE int sqlite3HeaderSizePcache(void){ return ROUND8(sizeof(PgHdr)); }
 
+/*
+** Return the number of dirty pages currently in the cache, as a percentage
+** of the configured cache size.
+*/
+SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache *pCache){
+  PgHdr *pDirty;
+  int nDirty = 0;
+  int nCache = numberOfCachePages(pCache);
+  for(pDirty=pCache->pDirty; pDirty; pDirty=pDirty->pDirtyNext) nDirty++;
+  return nCache ? (int)(((i64)nDirty * 100) / nCache) : 0;
+}
 
 #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
 /*
@@ -39549,14 +45554,96 @@ SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHd
 ** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.
 ** If the default page cache implementation is overridden, then neither of
 ** these two features are available.
+**
+** A Page cache line looks like this:
+**
+**  -------------------------------------------------------------
+**  |  database page content   |  PgHdr1  |  MemPage  |  PgHdr  |
+**  -------------------------------------------------------------
+**
+** The database page content is up front (so that buffer overreads tend to
+** flow harmlessly into the PgHdr1, MemPage, and PgHdr extensions).   MemPage
+** is the extension added by the btree.c module containing information such
+** as the database page number and how that database page is used.  PgHdr
+** is added by the pcache.c layer and contains information used to keep track
+** of which pages are "dirty".  PgHdr1 is an extension added by this
+** module (pcache1.c).  The PgHdr1 header is a subclass of sqlite3_pcache_page.
+** PgHdr1 contains information needed to look up a page by its page number.
+** The superclass sqlite3_pcache_page.pBuf points to the start of the
+** database page content and sqlite3_pcache_page.pExtra points to PgHdr.
+**
+** The size of the extension (MemPage+PgHdr+PgHdr1) can be determined at
+** runtime using sqlite3_config(SQLITE_CONFIG_PCACHE_HDRSZ, &size).  The
+** sizes of the extensions sum to 272 bytes on x64 for 3.8.10, but this
+** size can vary according to architecture, compile-time options, and
+** SQLite library version number.
+**
+** If SQLITE_PCACHE_SEPARATE_HEADER is defined, then the extension is obtained
+** using a separate memory allocation from the database page content.  This
+** seeks to overcome the "clownshoe" problem (also called "internal
+** fragmentation" in academic literature) of allocating a few bytes more
+** than a power of two with the memory allocator rounding up to the next
+** power of two, and leaving the rounded-up space unused.
+**
+** This module tracks pointers to PgHdr1 objects.  Only pcache.c communicates
+** with this module.  Information is passed back and forth as PgHdr1 pointers.
+**
+** The pcache.c and pager.c modules deal pointers to PgHdr objects.
+** The btree.c module deals with pointers to MemPage objects.
+**
+** SOURCE OF PAGE CACHE MEMORY:
+**
+** Memory for a page might come from any of three sources:
+**
+**    (1)  The general-purpose memory allocator - sqlite3Malloc()
+**    (2)  Global page-cache memory provided using sqlite3_config() with
+**         SQLITE_CONFIG_PAGECACHE.
+**    (3)  PCache-local bulk allocation.
+**
+** The third case is a chunk of heap memory (defaulting to 100 pages worth)
+** that is allocated when the page cache is created.  The size of the local
+** bulk allocation can be adjusted using 
+**
+**     sqlite3_config(SQLITE_CONFIG_PAGECACHE, (void*)0, 0, N).
+**
+** If N is positive, then N pages worth of memory are allocated using a single
+** sqlite3Malloc() call and that memory is used for the first N pages allocated.
+** Or if N is negative, then -1024*N bytes of memory are allocated and used
+** for as many pages as can be accomodated.
+**
+** Only one of (2) or (3) can be used.  Once the memory available to (2) or
+** (3) is exhausted, subsequent allocations fail over to the general-purpose
+** memory allocator (1).
+**
+** Earlier versions of SQLite used only methods (1) and (2).  But experiments
+** show that method (3) with N==100 provides about a 5% performance boost for
+** common workloads.
 */
-
+/* #include "sqliteInt.h" */
 
 typedef struct PCache1 PCache1;
 typedef struct PgHdr1 PgHdr1;
 typedef struct PgFreeslot PgFreeslot;
 typedef struct PGroup PGroup;
 
+/*
+** Each cache entry is represented by an instance of the following 
+** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
+** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
+** in memory.
+*/
+struct PgHdr1 {
+  sqlite3_pcache_page page;      /* Base class. Must be first. pBuf & pExtra */
+  unsigned int iKey;             /* Key value (page number) */
+  u8 isPinned;                   /* Page in use, not on the LRU list */
+  u8 isBulkLocal;                /* This page from bulk local storage */
+  u8 isAnchor;                   /* This is the PGroup.lru element */
+  PgHdr1 *pNext;                 /* Next in hash table chain */
+  PCache1 *pCache;               /* Cache that currently owns this page */
+  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
+  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
+};
+
 /* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
 ** of one or more PCaches that are able to recycle each other's unpinned
 ** pages when they are under memory pressure.  A PGroup is an instance of
@@ -39585,7 +45672,7 @@ struct PGroup {
   unsigned int nMinPage;         /* Sum of nMin for purgeable caches */
   unsigned int mxPinned;         /* nMaxpage + 10 - nMinPage */
   unsigned int nCurrentPage;     /* Number of purgeable pages allocated */
-  PgHdr1 *pLruHead, *pLruTail;   /* LRU list of unpinned pages */
+  PgHdr1 lru;                    /* The beginning and end of the LRU list */
 };
 
 /* Each page cache is an instance of the following object.  Every
@@ -39603,8 +45690,9 @@ struct PCache1 {
   ** The PGroup mutex must be held when accessing nMax.
   */
   PGroup *pGroup;                     /* PGroup this cache belongs to */
-  int szPage;                         /* Size of allocated pages in bytes */
-  int szExtra;                        /* Size of extra space in bytes */
+  int szPage;                         /* Size of database content section */
+  int szExtra;                        /* sizeof(MemPage)+sizeof(PgHdr) */
+  int szAlloc;                        /* Total size of one pcache line */
   int bPurgeable;                     /* True if cache is purgeable */
   unsigned int nMin;                  /* Minimum number of pages reserved */
   unsigned int nMax;                  /* Configured "cache_size" value */
@@ -39618,27 +45706,13 @@ struct PCache1 {
   unsigned int nPage;                 /* Total number of pages in apHash */
   unsigned int nHash;                 /* Number of slots in apHash[] */
   PgHdr1 **apHash;                    /* Hash table for fast lookup by key */
+  PgHdr1 *pFree;                      /* List of unused pcache-local pages */
+  void *pBulk;                        /* Bulk memory used by pcache-local */
 };
 
 /*
-** Each cache entry is represented by an instance of the following 
-** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
-** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
-** in memory.
-*/
-struct PgHdr1 {
-  sqlite3_pcache_page page;
-  unsigned int iKey;             /* Key value (page number) */
-  u8 isPinned;                   /* Page in use, not on the LRU list */
-  PgHdr1 *pNext;                 /* Next in hash table chain */
-  PCache1 *pCache;               /* Cache that currently owns this page */
-  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
-  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
-};
-
-/*
-** Free slots in the allocator used to divide up the buffer provided using
-** the SQLITE_CONFIG_PAGECACHE mechanism.
+** Free slots in the allocator used to divide up the global page cache
+** buffer provided using the SQLITE_CONFIG_PAGECACHE mechanism.
 */
 struct PgFreeslot {
   PgFreeslot *pNext;  /* Next free slot */
@@ -39656,10 +45730,12 @@ static SQLITE_WSD struct PCacheGlobal {
   ** The nFreeSlot and pFree values do require mutex protection.
   */
   int isInit;                    /* True if initialized */
+  int separateCache;             /* Use a new PGroup for each PCache */
+  int nInitPage;                 /* Initial bulk allocation size */   
   int szSlot;                    /* Size of each free slot */
   int nSlot;                     /* The number of pcache slots */
   int nReserve;                  /* Try to keep nFreeSlot above this */
-  void *pStart, *pEnd;           /* Bounds of pagecache malloc range */
+  void *pStart, *pEnd;           /* Bounds of global page cache memory */
   /* Above requires no mutex.  Use mutex below for variable that follow. */
   sqlite3_mutex *mutex;          /* Mutex for accessing the following: */
   PgFreeslot *pFree;             /* Free page blocks */
@@ -39681,12 +45757,20 @@ static SQLITE_WSD struct PCacheGlobal {
 /*
 ** Macros to enter and leave the PCache LRU mutex.
 */
-#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
-#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+#if !defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
+# define pcache1EnterMutex(X)  assert((X)->mutex==0)
+# define pcache1LeaveMutex(X)  assert((X)->mutex==0)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 0
+#else
+# define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
+# define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 1
+#endif
 
 /******************************************************************************/
 /******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/
 
+
 /*
 ** This function is called during initialization if a static buffer is 
 ** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE
@@ -39699,6 +45783,7 @@ static SQLITE_WSD struct PCacheGlobal {
 SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
   if( pcache1.isInit ){
     PgFreeslot *p;
+    if( pBuf==0 ) sz = n = 0;
     sz = ROUNDDOWN8(sz);
     pcache1.szSlot = sz;
     pcache1.nSlot = pcache1.nFreeSlot = n;
@@ -39716,6 +45801,43 @@ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
   }
 }
 
+/*
+** Try to initialize the pCache->pFree and pCache->pBulk fields.  Return
+** true if pCache->pFree ends up containing one or more free pages.
+*/
+static int pcache1InitBulk(PCache1 *pCache){
+  i64 szBulk;
+  char *zBulk;
+  if( pcache1.nInitPage==0 ) return 0;
+  /* Do not bother with a bulk allocation if the cache size very small */
+  if( pCache->nMax<3 ) return 0;
+  sqlite3BeginBenignMalloc();
+  if( pcache1.nInitPage>0 ){
+    szBulk = pCache->szAlloc * (i64)pcache1.nInitPage;
+  }else{
+    szBulk = -1024 * (i64)pcache1.nInitPage;
+  }
+  if( szBulk > pCache->szAlloc*(i64)pCache->nMax ){
+    szBulk = pCache->szAlloc*(i64)pCache->nMax;
+  }
+  zBulk = pCache->pBulk = sqlite3Malloc( szBulk );
+  sqlite3EndBenignMalloc();
+  if( zBulk ){
+    int nBulk = sqlite3MallocSize(zBulk)/pCache->szAlloc;
+    do{
+      PgHdr1 *pX = (PgHdr1*)&zBulk[pCache->szPage];
+      pX->page.pBuf = zBulk;
+      pX->page.pExtra = &pX[1];
+      pX->isBulkLocal = 1;
+      pX->isAnchor = 0;
+      pX->pNext = pCache->pFree;
+      pCache->pFree = pX;
+      zBulk += pCache->szAlloc;
+    }while( --nBulk );
+  }
+  return pCache->pFree!=0;
+}
+
 /*
 ** Malloc function used within this file to allocate space from the buffer
 ** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 
@@ -39728,7 +45850,6 @@ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
 static void *pcache1Alloc(int nByte){
   void *p = 0;
   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
-  sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
   if( nByte<=pcache1.szSlot ){
     sqlite3_mutex_enter(pcache1.mutex);
     p = (PgHdr1 *)pcache1.pFree;
@@ -39737,7 +45858,8 @@ static void *pcache1Alloc(int nByte){
       pcache1.nFreeSlot--;
       pcache1.bUnderPressure = pcache1.nFreeSlot=0 );
-      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
+      sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
+      sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_USED, 1);
     }
     sqlite3_mutex_leave(pcache1.mutex);
   }
@@ -39750,7 +45872,8 @@ static void *pcache1Alloc(int nByte){
     if( p ){
       int sz = sqlite3MallocSize(p);
       sqlite3_mutex_enter(pcache1.mutex);
-      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
+      sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
+      sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
       sqlite3_mutex_leave(pcache1.mutex);
     }
 #endif
@@ -39762,13 +45885,12 @@ static void *pcache1Alloc(int nByte){
 /*
 ** Free an allocated buffer obtained from pcache1Alloc().
 */
-static int pcache1Free(void *p){
-  int nFreed = 0;
-  if( p==0 ) return 0;
-  if( p>=pcache1.pStart && ppNext = pcache1.pFree;
     pcache1.pFree = pSlot;
@@ -39779,15 +45901,17 @@ static int pcache1Free(void *p){
   }else{
     assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
     sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
-    nFreed = sqlite3MallocSize(p);
 #ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS
-    sqlite3_mutex_enter(pcache1.mutex);
-    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -nFreed);
-    sqlite3_mutex_leave(pcache1.mutex);
+    {
+      int nFreed = 0;
+      nFreed = sqlite3MallocSize(p);
+      sqlite3_mutex_enter(pcache1.mutex);
+      sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);
+      sqlite3_mutex_leave(pcache1.mutex);
+    }
 #endif
     sqlite3_free(p);
   }
-  return nFreed;
 }
 
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
@@ -39811,58 +45935,72 @@ static int pcache1MemSize(void *p){
 /*
 ** Allocate a new page object initially associated with cache pCache.
 */
-static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
+static PgHdr1 *pcache1AllocPage(PCache1 *pCache, int benignMalloc){
   PgHdr1 *p = 0;
   void *pPg;
 
-  /* The group mutex must be released before pcache1Alloc() is called. This
-  ** is because it may call sqlite3_release_memory(), which assumes that 
-  ** this mutex is not held. */
   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
-  pcache1LeaveMutex(pCache->pGroup);
+  if( pCache->pFree || (pCache->nPage==0 && pcache1InitBulk(pCache)) ){
+    p = pCache->pFree;
+    pCache->pFree = p->pNext;
+    p->pNext = 0;
+  }else{
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+    /* The group mutex must be released before pcache1Alloc() is called. This
+    ** is because it might call sqlite3_release_memory(), which assumes that 
+    ** this mutex is not held. */
+    assert( pcache1.separateCache==0 );
+    assert( pCache->pGroup==&pcache1.grp );
+    pcache1LeaveMutex(pCache->pGroup);
+#endif
+    if( benignMalloc ){ sqlite3BeginBenignMalloc(); }
 #ifdef SQLITE_PCACHE_SEPARATE_HEADER
-  pPg = pcache1Alloc(pCache->szPage);
-  p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);
-  if( !pPg || !p ){
-    pcache1Free(pPg);
-    sqlite3_free(p);
-    pPg = 0;
-  }
+    pPg = pcache1Alloc(pCache->szPage);
+    p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);
+    if( !pPg || !p ){
+      pcache1Free(pPg);
+      sqlite3_free(p);
+      pPg = 0;
+    }
 #else
-  pPg = pcache1Alloc(ROUND8(sizeof(PgHdr1)) + pCache->szPage + pCache->szExtra);
-  p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];
+    pPg = pcache1Alloc(pCache->szAlloc);
+    p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];
 #endif
-  pcache1EnterMutex(pCache->pGroup);
-
-  if( pPg ){
+    if( benignMalloc ){ sqlite3EndBenignMalloc(); }
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+    pcache1EnterMutex(pCache->pGroup);
+#endif
+    if( pPg==0 ) return 0;
     p->page.pBuf = pPg;
     p->page.pExtra = &p[1];
-    if( pCache->bPurgeable ){
-      pCache->pGroup->nCurrentPage++;
-    }
-    return p;
+    p->isBulkLocal = 0;
+    p->isAnchor = 0;
   }
-  return 0;
+  if( pCache->bPurgeable ){
+    pCache->pGroup->nCurrentPage++;
+  }
+  return p;
 }
 
 /*
 ** Free a page object allocated by pcache1AllocPage().
-**
-** The pointer is allowed to be NULL, which is prudent.  But it turns out
-** that the current implementation happens to never call this routine
-** with a NULL pointer, so we mark the NULL test with ALWAYS().
 */
 static void pcache1FreePage(PgHdr1 *p){
-  if( ALWAYS(p) ){
-    PCache1 *pCache = p->pCache;
-    assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
+  PCache1 *pCache;
+  assert( p!=0 );
+  pCache = p->pCache;
+  assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
+  if( p->isBulkLocal ){
+    p->pNext = pCache->pFree;
+    pCache->pFree = p;
+  }else{
     pcache1Free(p->page.pBuf);
 #ifdef SQLITE_PCACHE_SEPARATE_HEADER
     sqlite3_free(p);
 #endif
-    if( pCache->bPurgeable ){
-      pCache->pGroup->nCurrentPage--;
-    }
+  }
+  if( pCache->bPurgeable ){
+    pCache->pGroup->nCurrentPage--;
   }
 }
 
@@ -39957,41 +46095,35 @@ static void pcache1ResizeHash(PCache1 *p){
 **
 ** The PGroup mutex must be held when this function is called.
 */
-static void pcache1PinPage(PgHdr1 *pPage){
+static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){
   PCache1 *pCache;
-  PGroup *pGroup;
 
   assert( pPage!=0 );
   assert( pPage->isPinned==0 );
   pCache = pPage->pCache;
-  pGroup = pCache->pGroup;
-  assert( pPage->pLruNext || pPage==pGroup->pLruTail );
-  assert( pPage->pLruPrev || pPage==pGroup->pLruHead );
-  assert( sqlite3_mutex_held(pGroup->mutex) );
-  if( pPage->pLruPrev ){
-    pPage->pLruPrev->pLruNext = pPage->pLruNext;
-  }else{
-    pGroup->pLruHead = pPage->pLruNext;
-  }
-  if( pPage->pLruNext ){
-    pPage->pLruNext->pLruPrev = pPage->pLruPrev;
-  }else{
-    pGroup->pLruTail = pPage->pLruPrev;
-  }
+  assert( pPage->pLruNext );
+  assert( pPage->pLruPrev );
+  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
+  pPage->pLruPrev->pLruNext = pPage->pLruNext;
+  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
   pPage->pLruNext = 0;
   pPage->pLruPrev = 0;
   pPage->isPinned = 1;
+  assert( pPage->isAnchor==0 );
+  assert( pCache->pGroup->lru.isAnchor==1 );
   pCache->nRecyclable--;
+  return pPage;
 }
 
 
 /*
 ** Remove the page supplied as an argument from the hash table 
 ** (PCache1.apHash structure) that it is currently stored in.
+** Also free the page if freePage is true.
 **
 ** The PGroup mutex must be held when this function is called.
 */
-static void pcache1RemoveFromHash(PgHdr1 *pPage){
+static void pcache1RemoveFromHash(PgHdr1 *pPage, int freeFlag){
   unsigned int h;
   PCache1 *pCache = pPage->pCache;
   PgHdr1 **pp;
@@ -40002,21 +46134,28 @@ static void pcache1RemoveFromHash(PgHdr1 *pPage){
   *pp = (*pp)->pNext;
 
   pCache->nPage--;
+  if( freeFlag ) pcache1FreePage(pPage);
 }
 
 /*
 ** If there are currently more than nMaxPage pages allocated, try
 ** to recycle pages to reduce the number allocated to nMaxPage.
 */
-static void pcache1EnforceMaxPage(PGroup *pGroup){
+static void pcache1EnforceMaxPage(PCache1 *pCache){
+  PGroup *pGroup = pCache->pGroup;
+  PgHdr1 *p;
   assert( sqlite3_mutex_held(pGroup->mutex) );
-  while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){
-    PgHdr1 *p = pGroup->pLruTail;
+  while( pGroup->nCurrentPage>pGroup->nMaxPage
+      && (p=pGroup->lru.pLruPrev)->isAnchor==0
+  ){
     assert( p->pCache->pGroup==pGroup );
     assert( p->isPinned==0 );
     pcache1PinPage(p);
-    pcache1RemoveFromHash(p);
-    pcache1FreePage(p);
+    pcache1RemoveFromHash(p, 1);
+  }
+  if( pCache->nPage==0 && pCache->pBulk ){
+    sqlite3_free(pCache->pBulk);
+    pCache->pBulk = pCache->pFree = 0;
   }
 }
 
@@ -40031,12 +46170,30 @@ static void pcache1TruncateUnsafe(
   PCache1 *pCache,             /* The cache to truncate */
   unsigned int iLimit          /* Drop pages with this pgno or larger */
 ){
-  TESTONLY( unsigned int nPage = 0; )  /* To assert pCache->nPage is correct */
-  unsigned int h;
+  TESTONLY( int nPage = 0; )  /* To assert pCache->nPage is correct */
+  unsigned int h, iStop;
   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
-  for(h=0; hnHash; h++){
-    PgHdr1 **pp = &pCache->apHash[h]; 
+  assert( pCache->iMaxKey >= iLimit );
+  assert( pCache->nHash > 0 );
+  if( pCache->iMaxKey - iLimit < pCache->nHash ){
+    /* If we are just shaving the last few pages off the end of the
+    ** cache, then there is no point in scanning the entire hash table.
+    ** Only scan those hash slots that might contain pages that need to
+    ** be removed. */
+    h = iLimit % pCache->nHash;
+    iStop = pCache->iMaxKey % pCache->nHash;
+    TESTONLY( nPage = -10; )  /* Disable the pCache->nPage validity check */
+  }else{
+    /* This is the general case where many pages are being removed.
+    ** It is necessary to scan the entire hash table */
+    h = pCache->nHash/2;
+    iStop = h - 1;
+  }
+  for(;;){
+    PgHdr1 **pp;
     PgHdr1 *pPage;
+    assert( hnHash );
+    pp = &pCache->apHash[h]; 
     while( (pPage = *pp)!=0 ){
       if( pPage->iKey>=iLimit ){
         pCache->nPage--;
@@ -40045,11 +46202,13 @@ static void pcache1TruncateUnsafe(
         pcache1FreePage(pPage);
       }else{
         pp = &pPage->pNext;
-        TESTONLY( nPage++; )
+        TESTONLY( if( nPage>=0 ) nPage++; )
       }
     }
+    if( h==iStop ) break;
+    h = (h+1) % pCache->nHash;
   }
-  assert( pCache->nPage==nPage );
+  assert( nPage<0 || pCache->nPage==(unsigned)nPage );
 }
 
 /******************************************************************************/
@@ -40062,9 +46221,44 @@ static int pcache1Init(void *NotUsed){
   UNUSED_PARAMETER(NotUsed);
   assert( pcache1.isInit==0 );
   memset(&pcache1, 0, sizeof(pcache1));
+
+
+  /*
+  ** The pcache1.separateCache variable is true if each PCache has its own
+  ** private PGroup (mode-1).  pcache1.separateCache is false if the single
+  ** PGroup in pcache1.grp is used for all page caches (mode-2).
+  **
+  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
+  **
+  **   *  Use a unified cache in single-threaded applications that have
+  **      configured a start-time buffer for use as page-cache memory using
+  **      sqlite3_config(SQLITE_CONFIG_PAGECACHE, pBuf, sz, N) with non-NULL 
+  **      pBuf argument.
+  **
+  **   *  Otherwise use separate caches (mode-1)
+  */
+#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
+  pcache1.separateCache = 0;
+#elif SQLITE_THREADSAFE
+  pcache1.separateCache = sqlite3GlobalConfig.pPage==0
+                          || sqlite3GlobalConfig.bCoreMutex>0;
+#else
+  pcache1.separateCache = sqlite3GlobalConfig.pPage==0;
+#endif
+
+#if SQLITE_THREADSAFE
   if( sqlite3GlobalConfig.bCoreMutex ){
-    pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
-    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM);
+    pcache1.grp.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU);
+    pcache1.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PMEM);
+  }
+#endif
+  if( pcache1.separateCache
+   && sqlite3GlobalConfig.nPage!=0
+   && sqlite3GlobalConfig.pPage==0
+  ){
+    pcache1.nInitPage = sqlite3GlobalConfig.nPage;
+  }else{
+    pcache1.nInitPage = 0;
   }
   pcache1.grp.mxPinned = 10;
   pcache1.isInit = 1;
@@ -40095,39 +46289,26 @@ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
   PGroup *pGroup;       /* The group the new page cache will belong to */
   int sz;               /* Bytes of memory required to allocate the new cache */
 
-  /*
-  ** The separateCache variable is true if each PCache has its own private
-  ** PGroup.  In other words, separateCache is true for mode (1) where no
-  ** mutexing is required.
-  **
-  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
-  **
-  **   *  Always use a unified cache in single-threaded applications
-  **
-  **   *  Otherwise (if multi-threaded and ENABLE_MEMORY_MANAGEMENT is off)
-  **      use separate caches (mode-1)
-  */
-#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
-  const int separateCache = 0;
-#else
-  int separateCache = sqlite3GlobalConfig.bCoreMutex>0;
-#endif
-
   assert( (szPage & (szPage-1))==0 && szPage>=512 && szPage<=65536 );
   assert( szExtra < 300 );
 
-  sz = sizeof(PCache1) + sizeof(PGroup)*separateCache;
+  sz = sizeof(PCache1) + sizeof(PGroup)*pcache1.separateCache;
   pCache = (PCache1 *)sqlite3MallocZero(sz);
   if( pCache ){
-    if( separateCache ){
+    if( pcache1.separateCache ){
       pGroup = (PGroup*)&pCache[1];
       pGroup->mxPinned = 10;
     }else{
       pGroup = &pcache1.grp;
     }
+    if( pGroup->lru.isAnchor==0 ){
+      pGroup->lru.isAnchor = 1;
+      pGroup->lru.pLruPrev = pGroup->lru.pLruNext = &pGroup->lru;
+    }
     pCache->pGroup = pGroup;
     pCache->szPage = szPage;
     pCache->szExtra = szExtra;
+    pCache->szAlloc = szPage + szExtra + ROUND8(sizeof(PgHdr1));
     pCache->bPurgeable = (bPurgeable ? 1 : 0);
     pcache1EnterMutex(pGroup);
     pcache1ResizeHash(pCache);
@@ -40159,7 +46340,7 @@ static void pcache1Cachesize(sqlite3_pcache *p, int nMax){
     pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
     pCache->nMax = nMax;
     pCache->n90pct = pCache->nMax*9/10;
-    pcache1EnforceMaxPage(pGroup);
+    pcache1EnforceMaxPage(pCache);
     pcache1LeaveMutex(pGroup);
   }
 }
@@ -40177,7 +46358,7 @@ static void pcache1Shrink(sqlite3_pcache *p){
     pcache1EnterMutex(pGroup);
     savedMaxPage = pGroup->nMaxPage;
     pGroup->nMaxPage = 0;
-    pcache1EnforceMaxPage(pGroup);
+    pcache1EnforceMaxPage(pCache);
     pGroup->nMaxPage = savedMaxPage;
     pcache1LeaveMutex(pGroup);
   }
@@ -40230,26 +46411,17 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
   assert( pCache->nHash>0 && pCache->apHash );
 
   /* Step 4. Try to recycle a page. */
-  if( pCache->bPurgeable && pGroup->pLruTail && (
-         (pCache->nPage+1>=pCache->nMax)
-      || pGroup->nCurrentPage>=pGroup->nMaxPage
-      || pcache1UnderMemoryPressure(pCache)
-  )){
+  if( pCache->bPurgeable
+   && !pGroup->lru.pLruPrev->isAnchor
+   && ((pCache->nPage+1>=pCache->nMax) || pcache1UnderMemoryPressure(pCache))
+  ){
     PCache1 *pOther;
-    pPage = pGroup->pLruTail;
+    pPage = pGroup->lru.pLruPrev;
     assert( pPage->isPinned==0 );
-    pcache1RemoveFromHash(pPage);
+    pcache1RemoveFromHash(pPage, 0);
     pcache1PinPage(pPage);
     pOther = pPage->pCache;
-
-    /* We want to verify that szPage and szExtra are the same for pOther
-    ** and pCache.  Assert that we can verify this by comparing sums. */
-    assert( (pCache->szPage & (pCache->szPage-1))==0 && pCache->szPage>=512 );
-    assert( pCache->szExtra<512 );
-    assert( (pOther->szPage & (pOther->szPage-1))==0 && pOther->szPage>=512 );
-    assert( pOther->szExtra<512 );
-
-    if( pOther->szPage+pOther->szExtra != pCache->szPage+pCache->szExtra ){
+    if( pOther->szAlloc != pCache->szAlloc ){
       pcache1FreePage(pPage);
       pPage = 0;
     }else{
@@ -40261,9 +46433,7 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
   ** attempt to allocate a new one. 
   */
   if( !pPage ){
-    if( createFlag==1 ) sqlite3BeginBenignMalloc();
-    pPage = pcache1AllocPage(pCache);
-    if( createFlag==1 ) sqlite3EndBenignMalloc();
+    pPage = pcache1AllocPage(pCache, createFlag==1);
   }
 
   if( pPage ){
@@ -40337,8 +46507,13 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
 **      proceed to step 5. 
 **
 **   5. Otherwise, allocate and return a new page buffer.
+**
+** There are two versions of this routine.  pcache1FetchWithMutex() is
+** the general case.  pcache1FetchNoMutex() is a faster implementation for
+** the common case where pGroup->mutex is NULL.  The pcache1Fetch() wrapper
+** invokes the appropriate routine.
 */
-static sqlite3_pcache_page *pcache1Fetch(
+static PgHdr1 *pcache1FetchNoMutex(
   sqlite3_pcache *p, 
   unsigned int iKey, 
   int createFlag
@@ -40346,28 +46521,66 @@ static sqlite3_pcache_page *pcache1Fetch(
   PCache1 *pCache = (PCache1 *)p;
   PgHdr1 *pPage = 0;
 
-  assert( offsetof(PgHdr1,page)==0 );
-  assert( pCache->bPurgeable || createFlag!=1 );
-  assert( pCache->bPurgeable || pCache->nMin==0 );
-  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
-  assert( pCache->nMin==0 || pCache->bPurgeable );
-  assert( pCache->nHash>0 );
-  pcache1EnterMutex(pCache->pGroup);
-
   /* Step 1: Search the hash table for an existing entry. */
   pPage = pCache->apHash[iKey % pCache->nHash];
   while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; }
 
-  /* Step 2: Abort if no existing page is found and createFlag is 0 */
+  /* Step 2: If the page was found in the hash table, then return it.
+  ** If the page was not in the hash table and createFlag is 0, abort.
+  ** Otherwise (page not in hash and createFlag!=0) continue with
+  ** subsequent steps to try to create the page. */
   if( pPage ){
-    if( !pPage->isPinned ) pcache1PinPage(pPage);
+    if( !pPage->isPinned ){
+      return pcache1PinPage(pPage);
+    }else{
+      return pPage;
+    }
   }else if( createFlag ){
     /* Steps 3, 4, and 5 implemented by this subroutine */
-    pPage = pcache1FetchStage2(pCache, iKey, createFlag);
+    return pcache1FetchStage2(pCache, iKey, createFlag);
+  }else{
+    return 0;
   }
+}
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+static PgHdr1 *pcache1FetchWithMutex(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+  PCache1 *pCache = (PCache1 *)p;
+  PgHdr1 *pPage;
+
+  pcache1EnterMutex(pCache->pGroup);
+  pPage = pcache1FetchNoMutex(p, iKey, createFlag);
   assert( pPage==0 || pCache->iMaxKey>=iKey );
   pcache1LeaveMutex(pCache->pGroup);
-  return (sqlite3_pcache_page*)pPage;
+  return pPage;
+}
+#endif
+static sqlite3_pcache_page *pcache1Fetch(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX || defined(SQLITE_DEBUG)
+  PCache1 *pCache = (PCache1 *)p;
+#endif
+
+  assert( offsetof(PgHdr1,page)==0 );
+  assert( pCache->bPurgeable || createFlag!=1 );
+  assert( pCache->bPurgeable || pCache->nMin==0 );
+  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
+  assert( pCache->nMin==0 || pCache->bPurgeable );
+  assert( pCache->nHash>0 );
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+  if( pCache->pGroup->mutex ){
+    return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag);
+  }else
+#endif
+  {
+    return (sqlite3_pcache_page*)pcache1FetchNoMutex(p, iKey, createFlag);
+  }
 }
 
 
@@ -40392,22 +46605,16 @@ static void pcache1Unpin(
   ** part of the PGroup LRU list.
   */
   assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
-  assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage );
   assert( pPage->isPinned==1 );
 
   if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
-    pcache1RemoveFromHash(pPage);
-    pcache1FreePage(pPage);
+    pcache1RemoveFromHash(pPage, 1);
   }else{
     /* Add the page to the PGroup LRU list. */
-    if( pGroup->pLruHead ){
-      pGroup->pLruHead->pLruPrev = pPage;
-      pPage->pLruNext = pGroup->pLruHead;
-      pGroup->pLruHead = pPage;
-    }else{
-      pGroup->pLruTail = pPage;
-      pGroup->pLruHead = pPage;
-    }
+    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;
+    pPage->pLruPrev = &pGroup->lru;
+    (pPage->pLruNext = *ppFirst)->pLruPrev = pPage;
+    *ppFirst = pPage;
     pCache->nRecyclable++;
     pPage->isPinned = 0;
   }
@@ -40478,14 +46685,15 @@ static void pcache1Destroy(sqlite3_pcache *p){
   PGroup *pGroup = pCache->pGroup;
   assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) );
   pcache1EnterMutex(pGroup);
-  pcache1TruncateUnsafe(pCache, 0);
+  if( pCache->nPage ) pcache1TruncateUnsafe(pCache, 0);
   assert( pGroup->nMaxPage >= pCache->nMax );
   pGroup->nMaxPage -= pCache->nMax;
   assert( pGroup->nMinPage >= pCache->nMin );
   pGroup->nMinPage -= pCache->nMin;
   pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
-  pcache1EnforceMaxPage(pGroup);
+  pcache1EnforceMaxPage(pCache);
   pcache1LeaveMutex(pGroup);
+  sqlite3_free(pCache->pBulk);
   sqlite3_free(pCache->apHash);
   sqlite3_free(pCache);
 }
@@ -40519,6 +46727,14 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void){
 */
 SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void){ return ROUND8(sizeof(PgHdr1)); }
 
+/*
+** Return the global mutex used by this PCACHE implementation.  The
+** sqlite3_status() routine needs access to this mutex.
+*/
+SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void){
+  return pcache1.mutex;
+}
+
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
 /*
 ** This function is called to free superfluous dynamically allocated memory
@@ -40533,18 +46749,20 @@ SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int nReq){
   int nFree = 0;
   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
   assert( sqlite3_mutex_notheld(pcache1.mutex) );
-  if( pcache1.pStart==0 ){
+  if( sqlite3GlobalConfig.pPage==0 ){
     PgHdr1 *p;
     pcache1EnterMutex(&pcache1.grp);
-    while( (nReq<0 || nFreeisAnchor==0
+    ){
       nFree += pcache1MemSize(p->page.pBuf);
 #ifdef SQLITE_PCACHE_SEPARATE_HEADER
       nFree += sqlite3MemSize(p);
 #endif
       assert( p->isPinned==0 );
       pcache1PinPage(p);
-      pcache1RemoveFromHash(p);
-      pcache1FreePage(p);
+      pcache1RemoveFromHash(p, 1);
     }
     pcache1LeaveMutex(&pcache1.grp);
   }
@@ -40565,7 +46783,7 @@ SQLITE_PRIVATE void sqlite3PcacheStats(
 ){
   PgHdr1 *p;
   int nRecyclable = 0;
-  for(p=pcache1.grp.pLruHead; p; p=p->pLruNext){
+  for(p=pcache1.grp.lru.pLruNext; p && !p->isAnchor; p=p->pLruNext){
     assert( p->isPinned==0 );
     nRecyclable++;
   }
@@ -40637,9 +46855,11 @@ SQLITE_PRIVATE void sqlite3PcacheStats(
 ** of the first SMALLEST is O(NlogN).  Second and subsequent SMALLEST
 ** primitives are constant time.  The cost of DESTROY is O(N).
 **
-** There is an added cost of O(N) when switching between TEST and
-** SMALLEST primitives.
+** TEST and SMALLEST may not be used by the same RowSet.  This used to
+** be possible, but the feature was not used, so it was removed in order
+** to simplify the code.
 */
+/* #include "sqliteInt.h" */
 
 
 /*
@@ -40758,9 +46978,11 @@ SQLITE_PRIVATE void sqlite3RowSetClear(RowSet *p){
 */
 static struct RowSetEntry *rowSetEntryAlloc(RowSet *p){
   assert( p!=0 );
-  if( p->nFresh==0 ){
+  if( p->nFresh==0 ){  /*OPTIMIZATION-IF-FALSE*/
+    /* We could allocate a fresh RowSetEntry each time one is needed, but it
+    ** is more efficient to pull a preallocated entry from the pool */
     struct RowSetChunk *pNew;
-    pNew = sqlite3DbMallocRaw(p->db, sizeof(*pNew));
+    pNew = sqlite3DbMallocRawNN(p->db, sizeof(*pNew));
     if( pNew==0 ){
       return 0;
     }
@@ -40792,7 +47014,9 @@ SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet *p, i64 rowid){
   pEntry->pRight = 0;
   pLast = p->pLast;
   if( pLast ){
-    if( (p->rsFlags & ROWSET_SORTED)!=0 && rowid<=pLast->v ){
+    if( rowid<=pLast->v ){  /*OPTIMIZATION-IF-FALSE*/
+      /* Avoid unnecessary sorts by preserving the ROWSET_SORTED flags
+      ** where possible */
       p->rsFlags &= ~ROWSET_SORTED;
     }
     pLast->pRight = pEntry;
@@ -40816,28 +47040,26 @@ static struct RowSetEntry *rowSetEntryMerge(
   struct RowSetEntry *pTail;
 
   pTail = &head;
-  while( pA && pB ){
+  assert( pA!=0 && pB!=0 );
+  for(;;){
     assert( pA->pRight==0 || pA->v<=pA->pRight->v );
     assert( pB->pRight==0 || pB->v<=pB->pRight->v );
-    if( pA->vv ){
-      pTail->pRight = pA;
+    if( pA->v<=pB->v ){
+      if( pA->vv ) pTail = pTail->pRight = pA;
       pA = pA->pRight;
-      pTail = pTail->pRight;
-    }else if( pB->vv ){
-      pTail->pRight = pB;
-      pB = pB->pRight;
-      pTail = pTail->pRight;
+      if( pA==0 ){
+        pTail->pRight = pB;
+        break;
+      }
     }else{
-      pA = pA->pRight;
+      pTail = pTail->pRight = pB;
+      pB = pB->pRight;
+      if( pB==0 ){
+        pTail->pRight = pA;
+        break;
+      }
     }
   }
-  if( pA ){
-    assert( pA->pRight==0 || pA->v<=pA->pRight->v );
-    pTail->pRight = pA;
-  }else{
-    assert( pB==0 || pB->pRight==0 || pB->v<=pB->pRight->v );
-    pTail->pRight = pB;
-  }
   return head.pRight;
 }
 
@@ -40860,9 +47082,10 @@ static struct RowSetEntry *rowSetEntrySort(struct RowSetEntry *pIn){
     aBucket[i] = pIn;
     pIn = pNext;
   }
-  pIn = 0;
-  for(i=0; i1 ){   /*OPTIMIZATION-IF-TRUE*/
+    /* This branch causes a *balanced* tree to be generated.  A valid tree
+    ** is still generated without this branch, but the tree is wildly
+    ** unbalanced and inefficient. */
+    pLeft = rowSetNDeepTree(ppList, iDepth-1);
+    p = *ppList;
+    if( p==0 ){     /*OPTIMIZATION-IF-FALSE*/
+      /* It is safe to always return here, but the resulting tree
+      ** would be unbalanced */
+      return pLeft;
+    }
+    p->pLeft = pLeft;
+    *ppList = p->pRight;
+    p->pRight = rowSetNDeepTree(ppList, iDepth-1);
+  }else{
     p = *ppList;
     *ppList = p->pRight;
     p->pLeft = p->pRight = 0;
-    return p;
   }
-  pLeft = rowSetNDeepTree(ppList, iDepth-1);
-  p = *ppList;
-  if( p==0 ){
-    return pLeft;
-  }
-  p->pLeft = pLeft;
-  *ppList = p->pRight;
-  p->pRight = rowSetNDeepTree(ppList, iDepth-1);
   return p;
 }
 
@@ -40957,59 +47186,37 @@ static struct RowSetEntry *rowSetListToTree(struct RowSetEntry *pList){
   return p;
 }
 
-/*
-** Take all the entries on p->pEntry and on the trees in p->pForest and
-** sort them all together into one big ordered list on p->pEntry.
-**
-** This routine should only be called once in the life of a RowSet.
-*/
-static void rowSetToList(RowSet *p){
-
-  /* This routine is called only once */
-  assert( p!=0 && (p->rsFlags & ROWSET_NEXT)==0 );
-
-  if( (p->rsFlags & ROWSET_SORTED)==0 ){
-    p->pEntry = rowSetEntrySort(p->pEntry);
-  }
-
-  /* While this module could theoretically support it, sqlite3RowSetNext()
-  ** is never called after sqlite3RowSetText() for the same RowSet.  So
-  ** there is never a forest to deal with.  Should this change, simply
-  ** remove the assert() and the #if 0. */
-  assert( p->pForest==0 );
-#if 0
-  while( p->pForest ){
-    struct RowSetEntry *pTree = p->pForest->pLeft;
-    if( pTree ){
-      struct RowSetEntry *pHead, *pTail;
-      rowSetTreeToList(pTree, &pHead, &pTail);
-      p->pEntry = rowSetEntryMerge(p->pEntry, pHead);
-    }
-    p->pForest = p->pForest->pRight;
-  }
-#endif
-  p->rsFlags |= ROWSET_NEXT;  /* Verify this routine is never called again */
-}
-
 /*
 ** Extract the smallest element from the RowSet.
 ** Write the element into *pRowid.  Return 1 on success.  Return
 ** 0 if the RowSet is already empty.
 **
 ** After this routine has been called, the sqlite3RowSetInsert()
-** routine may not be called again.  
+** routine may not be called again.
+**
+** This routine may not be called after sqlite3RowSetTest() has
+** been used.  Older versions of RowSet allowed that, but as the
+** capability was not used by the code generator, it was removed
+** for code economy.
 */
 SQLITE_PRIVATE int sqlite3RowSetNext(RowSet *p, i64 *pRowid){
   assert( p!=0 );
+  assert( p->pForest==0 );  /* Cannot be used with sqlite3RowSetText() */
 
   /* Merge the forest into a single sorted list on first call */
-  if( (p->rsFlags & ROWSET_NEXT)==0 ) rowSetToList(p);
+  if( (p->rsFlags & ROWSET_NEXT)==0 ){  /*OPTIMIZATION-IF-FALSE*/
+    if( (p->rsFlags & ROWSET_SORTED)==0 ){  /*OPTIMIZATION-IF-FALSE*/
+      p->pEntry = rowSetEntrySort(p->pEntry);
+    }
+    p->rsFlags |= ROWSET_SORTED|ROWSET_NEXT;
+  }
 
   /* Return the next entry on the list */
   if( p->pEntry ){
     *pRowid = p->pEntry->v;
     p->pEntry = p->pEntry->pRight;
-    if( p->pEntry==0 ){
+    if( p->pEntry==0 ){ /*OPTIMIZATION-IF-TRUE*/
+      /* Free memory immediately, rather than waiting on sqlite3_finalize() */
       sqlite3RowSetClear(p);
     }
     return 1;
@@ -41032,13 +47239,15 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64
   /* This routine is never called after sqlite3RowSetNext() */
   assert( pRowSet!=0 && (pRowSet->rsFlags & ROWSET_NEXT)==0 );
 
-  /* Sort entries into the forest on the first test of a new batch 
+  /* Sort entries into the forest on the first test of a new batch.
+  ** To save unnecessary work, only do this when the batch number changes.
   */
-  if( iBatch!=pRowSet->iBatch ){
+  if( iBatch!=pRowSet->iBatch ){  /*OPTIMIZATION-IF-FALSE*/
     p = pRowSet->pEntry;
     if( p ){
       struct RowSetEntry **ppPrevTree = &pRowSet->pForest;
-      if( (pRowSet->rsFlags & ROWSET_SORTED)==0 ){
+      if( (pRowSet->rsFlags & ROWSET_SORTED)==0 ){ /*OPTIMIZATION-IF-FALSE*/
+        /* Only sort the current set of entiries if they need it */
         p = rowSetEntrySort(p);
       }
       for(pTree = pRowSet->pForest; pTree; pTree=pTree->pRight){
@@ -41109,6 +47318,7 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64
 ** another is writing.
 */
 #ifndef SQLITE_OMIT_DISKIO
+/* #include "sqliteInt.h" */
 /************** Include wal.h in the middle of pager.c ***********************/
 /************** Begin file wal.h *********************************************/
 /*
@@ -41127,9 +47337,10 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64
 ** the implementation of each function in log.c for further details.
 */
 
-#ifndef _WAL_H_
-#define _WAL_H_
+#ifndef SQLITE_WAL_H
+#define SQLITE_WAL_H
 
+/* #include "sqliteInt.h" */
 
 /* Additional values that can be added to the sync_flags argument of
 ** sqlite3WalFrames():
@@ -41140,7 +47351,7 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64
 #ifdef SQLITE_OMIT_WAL
 # define sqlite3WalOpen(x,y,z)                   0
 # define sqlite3WalLimit(x,y)
-# define sqlite3WalClose(w,x,y,z)                0
+# define sqlite3WalClose(v,w,x,y,z)              0
 # define sqlite3WalBeginReadTransaction(y,z)     0
 # define sqlite3WalEndReadTransaction(z)
 # define sqlite3WalDbsize(y)                     0
@@ -41150,12 +47361,13 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64
 # define sqlite3WalSavepoint(y,z)
 # define sqlite3WalSavepointUndo(y,z)            0
 # define sqlite3WalFrames(u,v,w,x,y,z)           0
-# define sqlite3WalCheckpoint(r,s,t,u,v,w,x,y,z) 0
+# define sqlite3WalCheckpoint(q,r,s,t,u,v,w,x,y,z) 0
 # define sqlite3WalCallback(z)                   0
 # define sqlite3WalExclusiveMode(y,z)            0
 # define sqlite3WalHeapMemory(z)                 0
 # define sqlite3WalFramesize(z)                  0
 # define sqlite3WalFindFrame(x,y,z)              0
+# define sqlite3WalFile(x)                       0
 #else
 
 #define WAL_SAVEPOINT_NDATA 4
@@ -41167,7 +47379,7 @@ typedef struct Wal Wal;
 
 /* Open and close a connection to a write-ahead log. */
 SQLITE_PRIVATE int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *, int, i64, Wal**);
-SQLITE_PRIVATE int sqlite3WalClose(Wal *pWal, int sync_flags, int, u8 *);
+SQLITE_PRIVATE int sqlite3WalClose(Wal *pWal, sqlite3*, int sync_flags, int, u8 *);
 
 /* Set the limiting size of a WAL file. */
 SQLITE_PRIVATE void sqlite3WalLimit(Wal*, i64);
@@ -41210,6 +47422,7 @@ SQLITE_PRIVATE int sqlite3WalFrames(Wal *pWal, int, PgHdr *, Pgno, int, int);
 /* Copy pages from the log to the database file */ 
 SQLITE_PRIVATE int sqlite3WalCheckpoint(
   Wal *pWal,                      /* Write-ahead log connection */
+  sqlite3 *db,                    /* Check this handle's interrupt flag */
   int eMode,                      /* One of PASSIVE, FULL and RESTART */
   int (*xBusy)(void*),            /* Function to call when busy */
   void *pBusyArg,                 /* Context argument for xBusyHandler */
@@ -41238,6 +47451,12 @@ SQLITE_PRIVATE int sqlite3WalExclusiveMode(Wal *pWal, int op);
 */
 SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal);
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot);
+SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot);
+SQLITE_PRIVATE int sqlite3WalSnapshotRecover(Wal *pWal);
+#endif
+
 #ifdef SQLITE_ENABLE_ZIPVFS
 /* If the WAL file is not empty, return the number of bytes of content
 ** stored in each frame (i.e. the db page-size when the WAL was created).
@@ -41245,8 +47464,11 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal);
 SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal);
 #endif
 
+/* Return the sqlite3_file object for the WAL file */
+SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal);
+
 #endif /* ifndef SQLITE_OMIT_WAL */
-#endif /* _WAL_H_ */
+#endif /* SQLITE_WAL_H */
 
 /************** End of wal.h *************************************************/
 /************** Continuing where we left off in pager.c **********************/
@@ -41657,6 +47879,7 @@ int sqlite3PagerTrace=1;  /* True to enable tracing */
 */
 #define MAX_SECTOR_SIZE 0x10000
 
+
 /*
 ** An instance of the following structure is allocated for each active
 ** savepoint and statement transaction in the system. All such structures
@@ -41685,9 +47908,9 @@ struct PagerSavepoint {
 /*
 ** Bits of the Pager.doNotSpill flag.  See further description below.
 */
-#define SPILLFLAG_OFF         0x01      /* Never spill cache.  Set via pragma */
-#define SPILLFLAG_ROLLBACK    0x02      /* Current rolling back, so do not spill */
-#define SPILLFLAG_NOSYNC      0x04      /* Spill is ok, but do not sync */
+#define SPILLFLAG_OFF         0x01 /* Never spill cache.  Set via pragma */
+#define SPILLFLAG_ROLLBACK    0x02 /* Current rolling back, so do not spill */
+#define SPILLFLAG_NOSYNC      0x04 /* Spill is ok, but do not sync */
 
 /*
 ** An open page cache is an instance of struct Pager. A description of
@@ -41769,11 +47992,11 @@ struct PagerSavepoint {
 **   while it is being traversed by code in pager_playback().  The SPILLFLAG_OFF
 **   case is a user preference.
 ** 
-**   If the SPILLFLAG_NOSYNC bit is set, writing to the database from pagerStress()
-**   is permitted, but syncing the journal file is not. This flag is set
-**   by sqlite3PagerWrite() when the file-system sector-size is larger than
-**   the database page-size in order to prevent a journal sync from happening 
-**   in between the journalling of two pages on the same sector. 
+**   If the SPILLFLAG_NOSYNC bit is set, writing to the database from
+**   pagerStress() is permitted, but syncing the journal file is not.
+**   This flag is set by sqlite3PagerWrite() when the file-system sector-size
+**   is larger than the database page-size in order to prevent a journal sync
+**   from happening in between the journalling of two pages on the same sector. 
 **
 ** subjInMemory
 **
@@ -41852,6 +48075,7 @@ struct Pager {
   u8 useJournal;              /* Use a rollback journal on this file */
   u8 noSync;                  /* Do not sync the journal if true */
   u8 fullSync;                /* Do extra syncs of the journal for robustness */
+  u8 extraSync;               /* sync directory after journal delete */
   u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
   u8 walSyncFlags;            /* SYNC_NORMAL or SYNC_FULL for wal writes */
   u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
@@ -41876,7 +48100,7 @@ struct Pager {
   u8 doNotSpill;              /* Do not spill the cache when non-zero */
   u8 subjInMemory;            /* True to use in-memory sub-journals */
   u8 bUseFetch;               /* True to use xFetch() */
-  u8 hasBeenUsed;             /* True if any content previously read from this pager*/
+  u8 hasHeldSharedLock;       /* True if a shared lock has ever been held */
   Pgno dbSize;                /* Number of pages in the database */
   Pgno dbOrigSize;            /* dbSize before the current transaction */
   Pgno dbFileSize;            /* Number of pages in the database file */
@@ -41920,6 +48144,7 @@ struct Pager {
   int nRead;                  /* Database pages read */
 #endif
   void (*xReiniter)(DbPage*); /* Call this routine when reloading pages */
+  int (*xGet)(Pager*,Pgno,DbPage**,int); /* Routine to fetch a patch */
 #ifdef SQLITE_HAS_CODEC
   void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
   void (*xCodecSizeChng)(void*,int,int); /* Notify of page size changes */
@@ -42037,16 +48262,23 @@ static const unsigned char aJournalMagic[] = {
 **
 **   if( pPager->jfd->pMethods ){ ...
 */
-#define isOpen(pFd) ((pFd)->pMethods)
+#define isOpen(pFd) ((pFd)->pMethods!=0)
 
 /*
-** Return true if this pager uses a write-ahead log instead of the usual
-** rollback journal. Otherwise false.
+** Return true if this pager uses a write-ahead log to read page pgno.
+** Return false if the pager reads pgno directly from the database.
 */
-#ifndef SQLITE_OMIT_WAL
-static int pagerUseWal(Pager *pPager){
-  return (pPager->pWal!=0);
+#if !defined(SQLITE_OMIT_WAL) && defined(SQLITE_DIRECT_OVERFLOW_READ)
+SQLITE_PRIVATE int sqlite3PagerUseWal(Pager *pPager, Pgno pgno){
+  u32 iRead = 0;
+  int rc;
+  if( pPager->pWal==0 ) return 0;
+  rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iRead);
+  return rc || iRead;
 }
+#endif
+#ifndef SQLITE_OMIT_WAL
+# define pagerUseWal(x) ((x)->pWal!=0)
 #else
 # define pagerUseWal(x) 0
 # define pagerRollbackWal(x) 0
@@ -42099,6 +48331,7 @@ static int assert_pager_state(Pager *p){
   ** state.
   */
   if( MEMDB ){
+    assert( !isOpen(p->fd) );
     assert( p->noSync );
     assert( p->journalMode==PAGER_JOURNALMODE_OFF 
          || p->journalMode==PAGER_JOURNALMODE_MEMORY 
@@ -42185,7 +48418,7 @@ static int assert_pager_state(Pager *p){
       ** back to OPEN state.
       */
       assert( pPager->errCode!=SQLITE_OK );
-      assert( sqlite3PcacheRefCount(pPager->pPCache)>0 );
+      assert( sqlite3PcacheRefCount(pPager->pPCache)>0 || pPager->tempFile );
       break;
   }
 
@@ -42244,6 +48477,33 @@ static char *print_pager_state(Pager *p){
 }
 #endif
 
+/* Forward references to the various page getters */
+static int getPageNormal(Pager*,Pgno,DbPage**,int);
+static int getPageError(Pager*,Pgno,DbPage**,int);
+#if SQLITE_MAX_MMAP_SIZE>0
+static int getPageMMap(Pager*,Pgno,DbPage**,int);
+#endif
+
+/*
+** Set the Pager.xGet method for the appropriate routine used to fetch
+** content from the pager.
+*/
+static void setGetterMethod(Pager *pPager){
+  if( pPager->errCode ){
+    pPager->xGet = getPageError;
+#if SQLITE_MAX_MMAP_SIZE>0
+  }else if( USEFETCH(pPager)
+#ifdef SQLITE_HAS_CODEC
+   && pPager->xCodec==0
+#endif
+  ){
+    pPager->xGet = getPageMMap;
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+  }else{
+    pPager->xGet = getPageNormal;
+  }
+}
+
 /*
 ** Return true if it is necessary to write page *pPg into the sub-journal.
 ** A page needs to be written into the sub-journal if there exists one
@@ -42260,19 +48520,21 @@ static int subjRequiresPage(PgHdr *pPg){
   int i;
   for(i=0; inSavepoint; i++){
     p = &pPager->aSavepoint[i];
-    if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
+    if( p->nOrig>=pgno && 0==sqlite3BitvecTestNotNull(p->pInSavepoint, pgno) ){
       return 1;
     }
   }
   return 0;
 }
 
+#ifdef SQLITE_DEBUG
 /*
 ** Return true if the page is already in the journal file.
 */
 static int pageInJournal(Pager *pPager, PgHdr *pPg){
   return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);
 }
+#endif
 
 /*
 ** Read a 32-bit integer from the given file descriptor.  Store the integer
@@ -42395,6 +48657,8 @@ static int jrnlBufferSize(Pager *pPager){
 
   return JOURNAL_HDR_SZ(pPager) + JOURNAL_PG_SZ(pPager);
 }
+#else
+# define jrnlBufferSize(x) 0
 #endif
 
 /*
@@ -42555,6 +48819,7 @@ static i64 journalHdrOffset(Pager *pPager){
 static int zeroJournalHdr(Pager *pPager, int doTruncate){
   int rc = SQLITE_OK;                               /* Return code */
   assert( isOpen(pPager->jfd) );
+  assert( !sqlite3JournalIsInMemory(pPager->jfd) );
   if( pPager->journalOff ){
     const i64 iLimit = pPager->journalSizeLimit;    /* Local cache of jsl */
 
@@ -42884,7 +49149,8 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){
    || (0 != (rc = sqlite3OsWrite(pPager->jfd, zMaster, nMaster, iHdrOff+4)))
    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster, nMaster)))
    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster+4, cksum)))
-   || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8, iHdrOff+4+nMaster+8)))
+   || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8,
+                                 iHdrOff+4+nMaster+8)))
   ){
     return rc;
   }
@@ -42935,7 +49201,7 @@ static void releaseAllSavepoints(Pager *pPager){
   for(ii=0; iinSavepoint; ii++){
     sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);
   }
-  if( !pPager->exclusiveMode || sqlite3IsMemJournal(pPager->sjfd) ){
+  if( !pPager->exclusiveMode || sqlite3JournalIsInMemory(pPager->sjfd) ){
     sqlite3OsClose(pPager->sjfd);
   }
   sqlite3_free(pPager->aSavepoint);
@@ -43041,13 +49307,18 @@ static void pager_unlock(Pager *pPager){
   ** it can safely move back to PAGER_OPEN state. This happens in both
   ** normal and exclusive-locking mode.
   */
+  assert( pPager->errCode==SQLITE_OK || !MEMDB );
   if( pPager->errCode ){
-    assert( !MEMDB );
-    pager_reset(pPager);
-    pPager->changeCountDone = pPager->tempFile;
-    pPager->eState = PAGER_OPEN;
-    pPager->errCode = SQLITE_OK;
+    if( pPager->tempFile==0 ){
+      pager_reset(pPager);
+      pPager->changeCountDone = 0;
+      pPager->eState = PAGER_OPEN;
+    }else{
+      pPager->eState = (isOpen(pPager->jfd) ? PAGER_OPEN : PAGER_READER);
+    }
     if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
+    pPager->errCode = SQLITE_OK;
+    setGetterMethod(pPager);
   }
 
   pPager->journalOff = 0;
@@ -43085,12 +49356,36 @@ static int pager_error(Pager *pPager, int rc){
   if( rc2==SQLITE_FULL || rc2==SQLITE_IOERR ){
     pPager->errCode = rc;
     pPager->eState = PAGER_ERROR;
+    setGetterMethod(pPager);
   }
   return rc;
 }
 
 static int pager_truncate(Pager *pPager, Pgno nPage);
 
+/*
+** The write transaction open on pPager is being committed (bCommit==1)
+** or rolled back (bCommit==0).
+**
+** Return TRUE if and only if all dirty pages should be flushed to disk.
+**
+** Rules:
+**
+**   *  For non-TEMP databases, always sync to disk.  This is necessary
+**      for transactions to be durable.
+**
+**   *  Sync TEMP database only on a COMMIT (not a ROLLBACK) when the backing
+**      file has been created already (via a spill on pagerStress()) and
+**      when the number of dirty pages in memory exceeds 25% of the total
+**      cache size.
+*/
+static int pagerFlushOnCommit(Pager *pPager, int bCommit){
+  if( pPager->tempFile==0 ) return 1;
+  if( !bCommit ) return 0;
+  if( !isOpen(pPager->fd) ) return 0;
+  return (sqlite3PCachePercentDirty(pPager->pPCache)>=25);
+}
+
 /*
 ** This routine ends a transaction. A transaction is usually ended by 
 ** either a COMMIT or a ROLLBACK operation. This routine may be called 
@@ -43173,8 +49468,8 @@ static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
     assert( !pagerUseWal(pPager) );
 
     /* Finalize the journal file. */
-    if( sqlite3IsMemJournal(pPager->jfd) ){
-      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
+    if( sqlite3JournalIsInMemory(pPager->jfd) ){
+      /* assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ); */
       sqlite3OsClose(pPager->jfd);
     }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
       if( pPager->journalOff==0 ){
@@ -43194,22 +49489,23 @@ static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
     }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
       || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
     ){
-      rc = zeroJournalHdr(pPager, hasMaster);
+      rc = zeroJournalHdr(pPager, hasMaster||pPager->tempFile);
       pPager->journalOff = 0;
     }else{
       /* This branch may be executed with Pager.journalMode==MEMORY if
       ** a hot-journal was just rolled back. In this case the journal
       ** file should be closed and deleted. If this connection writes to
-      ** the database file, it will do so using an in-memory journal. 
+      ** the database file, it will do so using an in-memory journal.
       */
-      int bDelete = (!pPager->tempFile && sqlite3JournalExists(pPager->jfd));
+      int bDelete = !pPager->tempFile;
+      assert( sqlite3JournalIsInMemory(pPager->jfd)==0 );
       assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
            || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
            || pPager->journalMode==PAGER_JOURNALMODE_WAL 
       );
       sqlite3OsClose(pPager->jfd);
       if( bDelete ){
-        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
+        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, pPager->extraSync);
       }
     }
   }
@@ -43228,8 +49524,14 @@ static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
   sqlite3BitvecDestroy(pPager->pInJournal);
   pPager->pInJournal = 0;
   pPager->nRec = 0;
-  sqlite3PcacheCleanAll(pPager->pPCache);
-  sqlite3PcacheTruncate(pPager->pPCache, pPager->dbSize);
+  if( rc==SQLITE_OK ){
+    if( MEMDB || pagerFlushOnCommit(pPager, bCommit) ){
+      sqlite3PcacheCleanAll(pPager->pPCache);
+    }else{
+      sqlite3PcacheClearWritable(pPager->pPCache);
+    }
+    sqlite3PcacheTruncate(pPager->pPCache, pPager->dbSize);
+  }
 
   if( pagerUseWal(pPager) ){
     /* Drop the WAL write-lock, if any. Also, if the connection was in 
@@ -43342,6 +49644,20 @@ static void pagerReportSize(Pager *pPager){
 # define pagerReportSize(X)     /* No-op if we do not support a codec */
 #endif
 
+#ifdef SQLITE_HAS_CODEC
+/*
+** Make sure the number of reserved bits is the same in the destination
+** pager as it is in the source.  This comes up when a VACUUM changes the
+** number of reserved bits to the "optimal" amount.
+*/
+SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager *pDest, Pager *pSrc){
+  if( pDest->nReserve!=pSrc->nReserve ){
+    pDest->nReserve = pSrc->nReserve;
+    pagerReportSize(pDest);
+  }
+}
+#endif
+
 /*
 ** Read a single page from either the journal file (if isMainJrnl==1) or
 ** from the sub-journal (if isMainJrnl==0) and playback that page.
@@ -43393,6 +49709,11 @@ static int pager_playback_one_page(
   char *aData;                  /* Temporary storage for the page */
   sqlite3_file *jfd;            /* The file descriptor for the journal file */
   int isSynced;                 /* True if journal page is synced */
+#ifdef SQLITE_HAS_CODEC
+  /* The jrnlEnc flag is true if Journal pages should be passed through
+  ** the codec.  It is false for pure in-memory journals. */
+  const int jrnlEnc = (isMainJrnl || pPager->subjInMemory==0);
+#endif
 
   assert( (isMainJrnl&~1)==0 );      /* isMainJrnl is 0 or 1 */
   assert( (isSavepnt&~1)==0 );       /* isSavepnt is 0 or 1 */
@@ -43444,7 +49765,7 @@ static int pager_playback_one_page(
     }
   }
 
-  /* If this page has already been played by before during the current
+  /* If this page has already been played back before during the current
   ** rollback, then don't bother to play it back again.
   */
   if( pDone && (rc = sqlite3BitvecSet(pDone, pgno))!=SQLITE_OK ){
@@ -43499,7 +49820,7 @@ static int pager_playback_one_page(
     pPg = sqlite3PagerLookup(pPager, pgno);
   }
   assert( pPg || !MEMDB );
-  assert( pPager->eState!=PAGER_OPEN || pPg==0 );
+  assert( pPager->eState!=PAGER_OPEN || pPg==0 || pPager->tempFile );
   PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n",
            PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData),
            (isMainJrnl?"main-journal":"sub-journal")
@@ -43516,14 +49837,34 @@ static int pager_playback_one_page(
     i64 ofst = (pgno-1)*(i64)pPager->pageSize;
     testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
     assert( !pagerUseWal(pPager) );
+
+    /* Write the data read from the journal back into the database file.
+    ** This is usually safe even for an encrypted database - as the data
+    ** was encrypted before it was written to the journal file. The exception
+    ** is if the data was just read from an in-memory sub-journal. In that
+    ** case it must be encrypted here before it is copied into the database
+    ** file.  */
+#ifdef SQLITE_HAS_CODEC
+    if( !jrnlEnc ){
+      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT, aData);
+      rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
+      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
+    }else
+#endif
     rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
+
     if( pgno>pPager->dbFileSize ){
       pPager->dbFileSize = pgno;
     }
     if( pPager->pBackup ){
-      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM);
+#ifdef SQLITE_HAS_CODEC
+      if( jrnlEnc ){
+        CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
+        sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
+        CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT,aData);
+      }else
+#endif
       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
-      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM, aData);
     }
   }else if( !isMainJrnl && pPg==0 ){
     /* If this is a rollback of a savepoint and data was not written to
@@ -43545,11 +49886,10 @@ static int pager_playback_one_page(
     assert( isSavepnt );
     assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 );
     pPager->doNotSpill |= SPILLFLAG_ROLLBACK;
-    rc = sqlite3PagerAcquire(pPager, pgno, &pPg, 1);
+    rc = sqlite3PagerGet(pPager, pgno, &pPg, 1);
     assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 );
     pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK;
     if( rc!=SQLITE_OK ) return rc;
-    pPg->flags &= ~PGHDR_NEED_READ;
     sqlite3PcacheMakeDirty(pPg);
   }
   if( pPg ){
@@ -43563,29 +49903,10 @@ static int pager_playback_one_page(
     pData = pPg->pData;
     memcpy(pData, (u8*)aData, pPager->pageSize);
     pPager->xReiniter(pPg);
-    if( isMainJrnl && (!isSavepnt || *pOffset<=pPager->journalHdr) ){
-      /* If the contents of this page were just restored from the main 
-      ** journal file, then its content must be as they were when the 
-      ** transaction was first opened. In this case we can mark the page
-      ** as clean, since there will be no need to write it out to the
-      ** database.
-      **
-      ** There is one exception to this rule. If the page is being rolled
-      ** back as part of a savepoint (or statement) rollback from an 
-      ** unsynced portion of the main journal file, then it is not safe
-      ** to mark the page as clean. This is because marking the page as
-      ** clean will clear the PGHDR_NEED_SYNC flag. Since the page is
-      ** already in the journal file (recorded in Pager.pInJournal) and
-      ** the PGHDR_NEED_SYNC flag is cleared, if the page is written to
-      ** again within this transaction, it will be marked as dirty but
-      ** the PGHDR_NEED_SYNC flag will not be set. It could then potentially
-      ** be written out into the database file before its journal file
-      ** segment is synced. If a crash occurs during or following this,
-      ** database corruption may ensue.
-      */
-      assert( !pagerUseWal(pPager) );
-      sqlite3PcacheMakeClean(pPg);
-    }
+    /* It used to be that sqlite3PcacheMakeClean(pPg) was called here.  But
+    ** that call was dangerous and had no detectable benefit since the cache
+    ** is normally cleaned by sqlite3PcacheCleanAll() after rollback and so
+    ** has been removed. */
     pager_set_pagehash(pPg);
 
     /* If this was page 1, then restore the value of Pager.dbFileVers.
@@ -43595,7 +49916,9 @@ static int pager_playback_one_page(
     }
 
     /* Decode the page just read from disk */
-    CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM);
+#if SQLITE_HAS_CODEC
+    if( jrnlEnc ){ CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM_BKPT); }
+#endif
     sqlite3PcacheRelease(pPg);
   }
   return rc;
@@ -43661,7 +49984,7 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   pMaster = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
   pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
   if( !pMaster ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }else{
     const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
     rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);
@@ -43678,7 +50001,7 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   nMasterPtr = pVfs->mxPathname+1;
   zMasterJournal = sqlite3Malloc(nMasterJournal + nMasterPtr + 1);
   if( !zMasterJournal ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto delmaster_out;
   }
   zMasterPtr = &zMasterJournal[nMasterJournal+1];
@@ -43926,7 +50249,7 @@ static int pager_playback(Pager *pPager, int isHot){
   ** TODO: Technically the following is an error because it assumes that
   ** buffer Pager.pTmpSpace is (mxPathname+1) bytes or larger. i.e. that
   ** (pPager->pageSize >= pPager->pVfs->mxPathname+1). Using os_unix.c,
-  **  mxPathname is 512, which is the same as the minimum allowable value
+  ** mxPathname is 512, which is the same as the minimum allowable value
   ** for pageSize.
   */
   zMaster = pPager->pTmpSpace;
@@ -44148,7 +50471,7 @@ static int readDbPage(PgHdr *pPg, u32 iFrame){
       memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
     }
   }
-  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM);
+  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM_BKPT);
 
   PAGER_INCR(sqlite3_pager_readdb_count);
   PAGER_INCR(pPager->nRead);
@@ -44273,9 +50596,7 @@ static int pagerWalFrames(
 ){
   int rc;                         /* Return code */
   int nList;                      /* Number of pages in pList */
-#if defined(SQLITE_DEBUG) || defined(SQLITE_CHECK_PAGES)
   PgHdr *p;                       /* For looping over pages */
-#endif
 
   assert( pPager->pWal );
   assert( pList );
@@ -44292,7 +50613,6 @@ static int pagerWalFrames(
     ** any pages with page numbers greater than nTruncate into the WAL file.
     ** They will never be read by any client. So remove them from the pDirty
     ** list here. */
-    PgHdr *p;
     PgHdr **ppNext = &pList;
     nList = 0;
     for(p=pList; (*ppNext = p)!=0; p=p->pDirty){
@@ -44312,7 +50632,6 @@ static int pagerWalFrames(
       pPager->pageSize, pList, nTruncate, isCommit, pPager->walSyncFlags
   );
   if( rc==SQLITE_OK && pPager->pBackup ){
-    PgHdr *p;
     for(p=pList; p; p=p->pDirty){
       sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
     }
@@ -44380,22 +50699,20 @@ static int pagerPagecount(Pager *pPager, Pgno *pnPage){
   */
   assert( pPager->eState==PAGER_OPEN );
   assert( pPager->eLock>=SHARED_LOCK );
+  assert( isOpen(pPager->fd) );
+  assert( pPager->tempFile==0 );
   nPage = sqlite3WalDbsize(pPager->pWal);
 
-  /* If the database size was not available from the WAL sub-system,
-  ** determine it based on the size of the database file. If the size
-  ** of the database file is not an integer multiple of the page-size,
-  ** round down to the nearest page. Except, any file larger than 0
-  ** bytes in size is considered to contain at least one page.
+  /* If the number of pages in the database is not available from the
+  ** WAL sub-system, determine the page count based on the size of
+  ** the database file.  If the size of the database file is not an
+  ** integer multiple of the page-size, round up the result.
   */
-  if( nPage==0 ){
+  if( nPage==0 && ALWAYS(isOpen(pPager->fd)) ){
     i64 n = 0;                    /* Size of db file in bytes */
-    assert( isOpen(pPager->fd) || pPager->tempFile );
-    if( isOpen(pPager->fd) ){
-      int rc = sqlite3OsFileSize(pPager->fd, &n);
-      if( rc!=SQLITE_OK ){
-        return rc;
-      }
+    int rc = sqlite3OsFileSize(pPager->fd, &n);
+    if( rc!=SQLITE_OK ){
+      return rc;
     }
     nPage = (Pgno)((n+pPager->pageSize-1) / pPager->pageSize);
   }
@@ -44438,23 +50755,21 @@ static int pagerOpenWalIfPresent(Pager *pPager){
 
   if( !pPager->tempFile ){
     int isWal;                    /* True if WAL file exists */
-    Pgno nPage;                   /* Size of the database file */
-
-    rc = pagerPagecount(pPager, &nPage);
-    if( rc ) return rc;
-    if( nPage==0 ){
-      rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0);
-      if( rc==SQLITE_IOERR_DELETE_NOENT ) rc = SQLITE_OK;
-      isWal = 0;
-    }else{
-      rc = sqlite3OsAccess(
-          pPager->pVfs, pPager->zWal, SQLITE_ACCESS_EXISTS, &isWal
-      );
-    }
+    rc = sqlite3OsAccess(
+        pPager->pVfs, pPager->zWal, SQLITE_ACCESS_EXISTS, &isWal
+    );
     if( rc==SQLITE_OK ){
       if( isWal ){
-        testcase( sqlite3PcachePagecount(pPager->pPCache)==0 );
-        rc = sqlite3PagerOpenWal(pPager, 0);
+        Pgno nPage;                   /* Size of the database file */
+
+        rc = pagerPagecount(pPager, &nPage);
+        if( rc ) return rc;
+        if( nPage==0 ){
+          rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0);
+        }else{
+          testcase( sqlite3PcachePagecount(pPager->pPCache)==0 );
+          rc = sqlite3PagerOpenWal(pPager, 0);
+        }
       }else if( pPager->journalMode==PAGER_JOURNALMODE_WAL ){
         pPager->journalMode = PAGER_JOURNALMODE_DELETE;
       }
@@ -44513,7 +50828,7 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
   if( pSavepoint ){
     pDone = sqlite3BitvecCreate(pSavepoint->nOrig);
     if( !pDone ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   }
 
@@ -44609,12 +50924,21 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
 }
 
 /*
-** Change the maximum number of in-memory pages that are allowed.
+** Change the maximum number of in-memory pages that are allowed
+** before attempting to recycle clean and unused pages.
 */
 SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
   sqlite3PcacheSetCachesize(pPager->pPCache, mxPage);
 }
 
+/*
+** Change the maximum number of in-memory pages that are allowed
+** before attempting to spill pages to journal.
+*/
+SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager *pPager, int mxPage){
+  return sqlite3PcacheSetSpillsize(pPager->pPCache, mxPage);
+}
+
 /*
 ** Invoke SQLITE_FCNTL_MMAP_SIZE based on the current value of szMmap.
 */
@@ -44625,6 +50949,7 @@ static void pagerFixMaplimit(Pager *pPager){
     sqlite3_int64 sz;
     sz = pPager->szMmap;
     pPager->bUseFetch = (sz>0);
+    setGetterMethod(pPager);
     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);
   }
 #endif
@@ -44651,7 +50976,7 @@ SQLITE_PRIVATE void sqlite3PagerShrink(Pager *pPager){
 ** The "level" in pgFlags & PAGER_SYNCHRONOUS_MASK sets the robustness
 ** of the database to damage due to OS crashes or power failures by
 ** changing the number of syncs()s when writing the journals.
-** There are three levels:
+** There are four levels:
 **
 **    OFF       sqlite3OsSync() is never called.  This is the default
 **              for temporary and transient files.
@@ -44671,6 +50996,10 @@ SQLITE_PRIVATE void sqlite3PagerShrink(Pager *pPager){
 **              assurance that the journal will not be corrupted to the
 **              point of causing damage to the database during rollback.
 **
+**    EXTRA     This is like FULL except that is also syncs the directory
+**              that contains the rollback journal after the rollback
+**              journal is unlinked.
+**
 ** The above is for a rollback-journal mode.  For WAL mode, OFF continues
 ** to mean that no syncs ever occur.  NORMAL means that the WAL is synced
 ** prior to the start of checkpoint and that the database file is synced
@@ -44678,7 +51007,8 @@ SQLITE_PRIVATE void sqlite3PagerShrink(Pager *pPager){
 ** was written back into the database.  But no sync operations occur for
 ** an ordinary commit in NORMAL mode with WAL.  FULL means that the WAL
 ** file is synced following each commit operation, in addition to the
-** syncs associated with NORMAL.
+** syncs associated with NORMAL.  There is no difference between FULL
+** and EXTRA for WAL mode.
 **
 ** Do not confuse synchronous=FULL with SQLITE_SYNC_FULL.  The
 ** SQLITE_SYNC_FULL macro means to use the MacOSX-style full-fsync
@@ -44697,9 +51027,15 @@ SQLITE_PRIVATE void sqlite3PagerSetFlags(
   unsigned pgFlags      /* Various flags */
 ){
   unsigned level = pgFlags & PAGER_SYNCHRONOUS_MASK;
-  assert( level>=1 && level<=3 );
-  pPager->noSync =  (level==1 || pPager->tempFile) ?1:0;
-  pPager->fullSync = (level==3 && !pPager->tempFile) ?1:0;
+  if( pPager->tempFile ){
+    pPager->noSync = 1;
+    pPager->fullSync = 0;
+    pPager->extraSync = 0;
+  }else{
+    pPager->noSync =  level==PAGER_SYNCHRONOUS_OFF ?1:0;
+    pPager->fullSync = level>=PAGER_SYNCHRONOUS_FULL ?1:0;
+    pPager->extraSync = level==PAGER_SYNCHRONOUS_EXTRA ?1:0;
+  }
   if( pPager->noSync ){
     pPager->syncFlags = 0;
     pPager->ckptSyncFlags = 0;
@@ -44861,7 +51197,7 @@ SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nR
     }
     if( rc==SQLITE_OK ){
       pNew = (char *)sqlite3PageMalloc(pageSize);
-      if( !pNew ) rc = SQLITE_NOMEM;
+      if( !pNew ) rc = SQLITE_NOMEM_BKPT;
     }
 
     if( rc==SQLITE_OK ){
@@ -45110,6 +51446,7 @@ static int pagerSyncHotJournal(Pager *pPager){
   return rc;
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
 /*
 ** Obtain a reference to a memory mapped page object for page number pgno. 
 ** The new object will use the pointer pData, obtained from xFetch().
@@ -45132,12 +51469,13 @@ static int pagerAcquireMapPage(
     *ppPage = p = pPager->pMmapFreelist;
     pPager->pMmapFreelist = p->pDirty;
     p->pDirty = 0;
-    memset(p->pExtra, 0, pPager->nExtra);
+    assert( pPager->nExtra>=8 );
+    memset(p->pExtra, 0, 8);
   }else{
     *ppPage = p = (PgHdr *)sqlite3MallocZero(sizeof(PgHdr) + pPager->nExtra);
     if( p==0 ){
       sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1) * pPager->pageSize, pData);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     p->pExtra = (void *)&p[1];
     p->flags = PGHDR_MMAP;
@@ -45157,6 +51495,7 @@ static int pagerAcquireMapPage(
 
   return SQLITE_OK;
 }
+#endif
 
 /*
 ** Release a reference to page pPg. pPg must have been returned by an 
@@ -45199,9 +51538,10 @@ static void pagerFreeMapHdrs(Pager *pPager){
 ** a hot journal may be left in the filesystem but no error is returned
 ** to the caller.
 */
-SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){
+SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager, sqlite3 *db){
   u8 *pTmp = (u8 *)pPager->pTmpSpace;
 
+  assert( db || pagerUseWal(pPager)==0 );
   assert( assert_pager_state(pPager) );
   disable_simulated_io_errors();
   sqlite3BeginBenignMalloc();
@@ -45209,7 +51549,10 @@ SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){
   /* pPager->errCode = 0; */
   pPager->exclusiveMode = 0;
 #ifndef SQLITE_OMIT_WAL
-  sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags, pPager->pageSize, pTmp);
+  assert( db || pPager->pWal==0 );
+  sqlite3WalClose(pPager->pWal, db, pPager->ckptSyncFlags, pPager->pageSize,
+      (db && (db->flags & SQLITE_NoCkptOnClose) ? 0 : pTmp)
+  );
   pPager->pWal = 0;
 #endif
   pager_reset(pPager);
@@ -45451,8 +51794,9 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
 
   /* This function is only called for rollback pagers in WRITER_DBMOD state. */
   assert( !pagerUseWal(pPager) );
-  assert( pPager->eState==PAGER_WRITER_DBMOD );
+  assert( pPager->tempFile || pPager->eState==PAGER_WRITER_DBMOD );
   assert( pPager->eLock==EXCLUSIVE_LOCK );
+  assert( isOpen(pPager->fd) || pList->pDirty==0 );
 
   /* If the file is a temp-file has not yet been opened, open it now. It
   ** is not possible for rc to be other than SQLITE_OK if this branch
@@ -45495,7 +51839,7 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
       if( pList->pgno==1 ) pager_write_changecounter(pList);
 
       /* Encode the database */
-      CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM, pData);
+      CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM_BKPT, pData);
 
       /* Write out the page data. */
       rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);
@@ -45540,19 +51884,20 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
 static int openSubJournal(Pager *pPager){
   int rc = SQLITE_OK;
   if( !isOpen(pPager->sjfd) ){
+    const int flags =  SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_READWRITE 
+      | SQLITE_OPEN_CREATE | SQLITE_OPEN_EXCLUSIVE 
+      | SQLITE_OPEN_DELETEONCLOSE;
+    int nStmtSpill = sqlite3Config.nStmtSpill;
     if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
-      sqlite3MemJournalOpen(pPager->sjfd);
-    }else{
-      rc = pagerOpentemp(pPager, pPager->sjfd, SQLITE_OPEN_SUBJOURNAL);
+      nStmtSpill = -1;
     }
+    rc = sqlite3JournalOpen(pPager->pVfs, 0, pPager->sjfd, flags, nStmtSpill);
   }
   return rc;
 }
 
 /*
 ** Append a record of the current state of page pPg to the sub-journal. 
-** It is the callers responsibility to use subjRequiresPage() to check 
-** that it is really required before calling this function.
 **
 ** If successful, set the bit corresponding to pPg->pgno in the bitvecs
 ** for all open savepoints before returning.
@@ -45583,8 +51928,13 @@ static int subjournalPage(PgHdr *pPg){
       void *pData = pPg->pData;
       i64 offset = (i64)pPager->nSubRec*(4+pPager->pageSize);
       char *pData2;
-  
-      CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
+
+#if SQLITE_HAS_CODEC   
+      if( !pPager->subjInMemory ){
+        CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
+      }else
+#endif
+      pData2 = pData;
       PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
       rc = write32bits(pPager->sjfd, offset, pPg->pgno);
       if( rc==SQLITE_OK ){
@@ -45599,6 +51949,13 @@ static int subjournalPage(PgHdr *pPg){
   }
   return rc;
 }
+static int subjournalPageIfRequired(PgHdr *pPg){
+  if( subjRequiresPage(pPg) ){
+    return subjournalPage(pPg);
+  }else{
+    return SQLITE_OK;
+  }
+}
 
 /*
 ** This function is called by the pcache layer when it has reached some
@@ -45656,9 +52013,7 @@ static int pagerStress(void *p, PgHdr *pPg){
   pPg->pDirty = 0;
   if( pagerUseWal(pPager) ){
     /* Write a single frame for this page to the log. */
-    if( subjRequiresPage(pPg) ){ 
-      rc = subjournalPage(pPg); 
-    }
+    rc = subjournalPageIfRequired(pPg); 
     if( rc==SQLITE_OK ){
       rc = pagerWalFrames(pPager, pPg, 0, 0);
     }
@@ -45671,39 +52026,6 @@ static int pagerStress(void *p, PgHdr *pPg){
       rc = syncJournal(pPager, 1);
     }
   
-    /* If the page number of this page is larger than the current size of
-    ** the database image, it may need to be written to the sub-journal.
-    ** This is because the call to pager_write_pagelist() below will not
-    ** actually write data to the file in this case.
-    **
-    ** Consider the following sequence of events:
-    **
-    **   BEGIN;
-    **     
-    **     
-    **     SAVEPOINT sp;
-    **       
-    **       pagerStress(page X)
-    **     ROLLBACK TO sp;
-    **
-    ** If (X>Y), then when pagerStress is called page X will not be written
-    ** out to the database file, but will be dropped from the cache. Then,
-    ** following the "ROLLBACK TO sp" statement, reading page X will read
-    ** data from the database file. This will be the copy of page X as it
-    ** was when the transaction started, not as it was when "SAVEPOINT sp"
-    ** was executed.
-    **
-    ** The solution is to write the current data for page X into the 
-    ** sub-journal file now (if it is not already there), so that it will
-    ** be restored to its current value when the "ROLLBACK TO sp" is 
-    ** executed.
-    */
-    if( NEVER(
-        rc==SQLITE_OK && pPg->pgno>pPager->dbSize && subjRequiresPage(pPg)
-    ) ){
-      rc = subjournalPage(pPg);
-    }
-  
     /* Write the contents of the page out to the database file. */
     if( rc==SQLITE_OK ){
       assert( (pPg->flags&PGHDR_NEED_SYNC)==0 );
@@ -45720,6 +52042,25 @@ static int pagerStress(void *p, PgHdr *pPg){
   return pager_error(pPager, rc); 
 }
 
+/*
+** Flush all unreferenced dirty pages to disk.
+*/
+SQLITE_PRIVATE int sqlite3PagerFlush(Pager *pPager){
+  int rc = pPager->errCode;
+  if( !MEMDB ){
+    PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
+    assert( assert_pager_state(pPager) );
+    while( rc==SQLITE_OK && pList ){
+      PgHdr *pNext = pList->pDirty;
+      if( pList->nRef==0 ){
+        rc = pagerStress((void*)pPager, pList);
+      }
+      pList = pNext;
+    }
+  }
+
+  return rc;
+}
 
 /*
 ** Allocate and initialize a new Pager object and put a pointer to it
@@ -45735,7 +52076,9 @@ static int pagerStress(void *p, PgHdr *pPg){
 **
 ** The nExtra parameter specifies the number of bytes of space allocated
 ** along with each page reference. This space is available to the user
-** via the sqlite3PagerGetExtra() API.
+** via the sqlite3PagerGetExtra() API.  When a new page is allocated, the
+** first 8 bytes of this space are zeroed but the remainder is uninitialized.
+** (The extra space is used by btree as the MemPage object.)
 **
 ** The flags argument is used to specify properties that affect the
 ** operation of the pager. It should be passed some bitwise combination
@@ -45776,18 +52119,8 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   int nUri = 0;            /* Number of bytes of URI args at *zUri */
 
   /* Figure out how much space is required for each journal file-handle
-  ** (there are two of them, the main journal and the sub-journal). This
-  ** is the maximum space required for an in-memory journal file handle 
-  ** and a regular journal file-handle. Note that a "regular journal-handle"
-  ** may be a wrapper capable of caching the first portion of the journal
-  ** file in memory to implement the atomic-write optimization (see 
-  ** source file journal.c).
-  */
-  if( sqlite3JournalSize(pVfs)>sqlite3MemJournalSize() ){
-    journalFileSize = ROUND8(sqlite3JournalSize(pVfs));
-  }else{
-    journalFileSize = ROUND8(sqlite3MemJournalSize());
-  }
+  ** (there are two of them, the main journal and the sub-journal).  */
+  journalFileSize = ROUND8(sqlite3JournalSize(pVfs));
 
   /* Set the output variable to NULL in case an error occurs. */
   *ppPager = 0;
@@ -45797,7 +52130,7 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     memDb = 1;
     if( zFilename && zFilename[0] ){
       zPathname = sqlite3DbStrDup(0, zFilename);
-      if( zPathname==0  ) return SQLITE_NOMEM;
+      if( zPathname==0  ) return SQLITE_NOMEM_BKPT;
       nPathname = sqlite3Strlen30(zPathname);
       zFilename = 0;
     }
@@ -45813,7 +52146,7 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     nPathname = pVfs->mxPathname+1;
     zPathname = sqlite3DbMallocRaw(0, nPathname*2);
     if( zPathname==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     zPathname[0] = 0; /* Make sure initialized even if FullPathname() fails */
     rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);
@@ -45866,7 +52199,7 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) );
   if( !pPtr ){
     sqlite3DbFree(0, zPathname);
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pPager =              (Pager*)(pPtr);
   pPager->pPCache =    (PCache*)(pPtr += ROUND8(sizeof(*pPager)));
@@ -45959,7 +52292,7 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
 act_like_temp_file:
     tempFile = 1;
     pPager->eState = PAGER_READER;     /* Pretend we already have a lock */
-    pPager->eLock = EXCLUSIVE_LOCK;    /* Pretend we are in EXCLUSIVE locking mode */
+    pPager->eLock = EXCLUSIVE_LOCK;    /* Pretend we are in EXCLUSIVE mode */
     pPager->noLock = 1;                /* Do no locking */
     readOnly = (vfsFlags&SQLITE_OPEN_READONLY);
   }
@@ -45975,10 +52308,10 @@ act_like_temp_file:
 
   /* Initialize the PCache object. */
   if( rc==SQLITE_OK ){
-    assert( nExtra<1000 );
     nExtra = ROUND8(nExtra);
+    assert( nExtra>=8 && nExtra<1000 );
     rc = sqlite3PcacheOpen(szPageDflt, nExtra, !memDb,
-                           !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);
+                       !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);
   }
 
   /* If an error occurred above, free the  Pager structure and close the file.
@@ -46015,11 +52348,13 @@ act_like_temp_file:
   pPager->noSync = pPager->tempFile;
   if( pPager->noSync ){
     assert( pPager->fullSync==0 );
+    assert( pPager->extraSync==0 );
     assert( pPager->syncFlags==0 );
     assert( pPager->walSyncFlags==0 );
     assert( pPager->ckptSyncFlags==0 );
   }else{
     pPager->fullSync = 1;
+    pPager->extraSync = 0;
     pPager->syncFlags = SQLITE_SYNC_NORMAL;
     pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
     pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
@@ -46039,6 +52374,7 @@ act_like_temp_file:
   /* pPager->xBusyHandler = 0; */
   /* pPager->pBusyHandlerArg = 0; */
   pPager->xReiniter = xReinit;
+  setGetterMethod(pPager);
   /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
   /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */
 
@@ -46136,6 +52472,7 @@ static int hasHotJournal(Pager *pPager, int *pExists){
     if( rc==SQLITE_OK && !locked ){
       Pgno nPage;                 /* Number of pages in database file */
 
+      assert( pPager->tempFile==0 );
       rc = pagerPagecount(pPager, &nPage);
       if( rc==SQLITE_OK ){
         /* If the database is zero pages in size, that means that either (1) the
@@ -46197,7 +52534,7 @@ static int hasHotJournal(Pager *pPager, int *pExists){
 
 /*
 ** This function is called to obtain a shared lock on the database file.
-** It is illegal to call sqlite3PagerAcquire() until after this function
+** It is illegal to call sqlite3PagerGet() until after this function
 ** has been successfully called. If a shared-lock is already held when
 ** this function is called, it is a no-op.
 **
@@ -46228,17 +52565,17 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
   /* This routine is only called from b-tree and only when there are no
   ** outstanding pages. This implies that the pager state should either
   ** be OPEN or READER. READER is only possible if the pager is or was in 
-  ** exclusive access mode.
-  */
+  ** exclusive access mode.  */
   assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
   assert( assert_pager_state(pPager) );
   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );
-  if( NEVER(MEMDB && pPager->errCode) ){ return pPager->errCode; }
+  assert( pPager->errCode==SQLITE_OK );
 
   if( !pagerUseWal(pPager) && pPager->eState==PAGER_OPEN ){
     int bHotJournal = 1;          /* True if there exists a hot journal-file */
 
     assert( !MEMDB );
+    assert( pPager->tempFile==0 || pPager->eLock==EXCLUSIVE_LOCK );
 
     rc = pager_wait_on_lock(pPager, SHARED_LOCK);
     if( rc!=SQLITE_OK ){
@@ -46324,7 +52661,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
         assert( rc==SQLITE_OK );
         rc = pagerSyncHotJournal(pPager);
         if( rc==SQLITE_OK ){
-          rc = pager_playback(pPager, 1);
+          rc = pager_playback(pPager, !pPager->tempFile);
           pPager->eState = PAGER_OPEN;
         }
       }else if( !pPager->exclusiveMode ){
@@ -46358,14 +52695,14 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
       );
     }
 
-    if( !pPager->tempFile && pPager->hasBeenUsed ){
+    if( !pPager->tempFile && pPager->hasHeldSharedLock ){
       /* The shared-lock has just been acquired then check to
       ** see if the database has been modified.  If the database has changed,
-      ** flush the cache.  The pPager->hasBeenUsed flag prevents this from
+      ** flush the cache.  The hasHeldSharedLock flag prevents this from
       ** occurring on the very first access to a file, in order to save a
       ** single unnecessary sqlite3OsRead() call at the start-up.
       **
-      ** Database changes is detected by looking at 15 bytes beginning
+      ** Database changes are detected by looking at 15 bytes beginning
       ** at offset 24 into the file.  The first 4 of these 16 bytes are
       ** a 32-bit counter that is incremented with each change.  The
       ** other bytes change randomly with each file change when
@@ -46375,19 +52712,14 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
       ** detected.  The chance of an undetected change is so small that
       ** it can be neglected.
       */
-      Pgno nPage = 0;
       char dbFileVers[sizeof(pPager->dbFileVers)];
 
-      rc = pagerPagecount(pPager, &nPage);
-      if( rc ) goto failed;
-
-      if( nPage>0 ){
-        IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
-        rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
-        if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){
+      IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
+      rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
+      if( rc!=SQLITE_OK ){
+        if( rc!=SQLITE_IOERR_SHORT_READ ){
           goto failed;
         }
-      }else{
         memset(dbFileVers, 0, sizeof(dbFileVers));
       }
 
@@ -46420,7 +52752,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
     rc = pagerBeginReadTransaction(pPager);
   }
 
-  if( pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){
+  if( pPager->tempFile==0 && pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){
     rc = pagerPagecount(pPager, &pPager->dbSize);
   }
 
@@ -46431,6 +52763,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
     assert( pPager->eState==PAGER_OPEN );
   }else{
     pPager->eState = PAGER_READER;
+    pPager->hasHeldSharedLock = 1;
   }
   return rc;
 }
@@ -46450,10 +52783,17 @@ static void pagerUnlockIfUnused(Pager *pPager){
 }
 
 /*
-** Acquire a reference to page number pgno in pager pPager (a page
-** reference has type DbPage*). If the requested reference is 
+** The page getter methods each try to acquire a reference to a
+** page with page number pgno. If the requested reference is 
 ** successfully obtained, it is copied to *ppPage and SQLITE_OK returned.
 **
+** There are different implementations of the getter method depending
+** on the current state of the pager.
+**
+**     getPageNormal()         --  The normal getter
+**     getPageError()          --  Used if the pager is in an error state
+**     getPageMmap()           --  Used if memory-mapped I/O is enabled
+**
 ** If the requested page is already in the cache, it is returned. 
 ** Otherwise, a new page object is allocated and populated with data
 ** read from the database file. In some cases, the pcache module may
@@ -46465,14 +52805,14 @@ static void pagerUnlockIfUnused(Pager *pPager){
 ** already in the cache when this function is called, then the extra
 ** data is left as it was when the page object was last used.
 **
-** If the database image is smaller than the requested page or if a 
-** non-zero value is passed as the noContent parameter and the 
+** If the database image is smaller than the requested page or if 
+** the flags parameter contains the PAGER_GET_NOCONTENT bit and the 
 ** requested page is not already stored in the cache, then no 
 ** actual disk read occurs. In this case the memory image of the 
 ** page is initialized to all zeros. 
 **
-** If noContent is true, it means that we do not care about the contents
-** of the page. This occurs in two scenarios:
+** If PAGER_GET_NOCONTENT is true, it means that we do not care about
+** the contents of the page. This occurs in two scenarios:
 **
 **   a) When reading a free-list leaf page from the database, and
 **
@@ -46480,8 +52820,8 @@ static void pagerUnlockIfUnused(Pager *pPager){
 **      a new page into the cache to be filled with the data read
 **      from the savepoint journal.
 **
-** If noContent is true, then the data returned is zeroed instead of
-** being read from the database. Additionally, the bits corresponding
+** If PAGER_GET_NOCONTENT is true, then the data returned is zeroed instead
+** of being read from the database. Additionally, the bits corresponding
 ** to pgno in Pager.pInJournal (bitvec of pages already written to the
 ** journal file) and the PagerSavepoint.pInSavepoint bitvecs of any open
 ** savepoints are set. This means if the page is made writable at any
@@ -46499,97 +52839,40 @@ static void pagerUnlockIfUnused(Pager *pPager){
 ** Since Lookup() never goes to disk, it never has to deal with locks
 ** or journal files.
 */
-SQLITE_PRIVATE int sqlite3PagerAcquire(
+static int getPageNormal(
   Pager *pPager,      /* The pager open on the database file */
   Pgno pgno,          /* Page number to fetch */
   DbPage **ppPage,    /* Write a pointer to the page here */
   int flags           /* PAGER_GET_XXX flags */
 ){
   int rc = SQLITE_OK;
-  PgHdr *pPg = 0;
-  u32 iFrame = 0;                 /* Frame to read from WAL file */
-  const int noContent = (flags & PAGER_GET_NOCONTENT);
-
-  /* It is acceptable to use a read-only (mmap) page for any page except
-  ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY
-  ** flag was specified by the caller. And so long as the db is not a 
-  ** temporary or in-memory database.  */
-  const int bMmapOk = (pgno!=1 && USEFETCH(pPager)
-   && (pPager->eState==PAGER_READER || (flags & PAGER_GET_READONLY))
-#ifdef SQLITE_HAS_CODEC
-   && pPager->xCodec==0
-#endif
-  );
+  PgHdr *pPg;
+  u8 noContent;                   /* True if PAGER_GET_NOCONTENT is set */
+  sqlite3_pcache_page *pBase;
 
+  assert( pPager->errCode==SQLITE_OK );
   assert( pPager->eState>=PAGER_READER );
   assert( assert_pager_state(pPager) );
-  assert( noContent==0 || bMmapOk==0 );
-
-  if( pgno==0 ){
-    return SQLITE_CORRUPT_BKPT;
-  }
-  pPager->hasBeenUsed = 1;
-
-  /* If the pager is in the error state, return an error immediately. 
-  ** Otherwise, request the page from the PCache layer. */
-  if( pPager->errCode!=SQLITE_OK ){
-    rc = pPager->errCode;
-  }else{
-    if( bMmapOk && pagerUseWal(pPager) ){
-      rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
-      if( rc!=SQLITE_OK ) goto pager_acquire_err;
-    }
-
-    if( bMmapOk && iFrame==0 ){
-      void *pData = 0;
-
-      rc = sqlite3OsFetch(pPager->fd, 
-          (i64)(pgno-1) * pPager->pageSize, pPager->pageSize, &pData
-      );
+  assert( pPager->hasHeldSharedLock==1 );
 
-      if( rc==SQLITE_OK && pData ){
-        if( pPager->eState>PAGER_READER ){
-          pPg = sqlite3PagerLookup(pPager, pgno);
-        }
-        if( pPg==0 ){
-          rc = pagerAcquireMapPage(pPager, pgno, pData, &pPg);
-        }else{
-          sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1)*pPager->pageSize, pData);
-        }
-        if( pPg ){
-          assert( rc==SQLITE_OK );
-          *ppPage = pPg;
-          return SQLITE_OK;
-        }
-      }
-      if( rc!=SQLITE_OK ){
-        goto pager_acquire_err;
-      }
-    }
-
-    {
-      sqlite3_pcache_page *pBase;
-      pBase = sqlite3PcacheFetch(pPager->pPCache, pgno, 3);
-      if( pBase==0 ){
-        rc = sqlite3PcacheFetchStress(pPager->pPCache, pgno, &pBase);
-        if( rc!=SQLITE_OK ) goto pager_acquire_err;
-      }
-      pPg = *ppPage = sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pBase);
-      if( pPg==0 ) rc = SQLITE_NOMEM;
-    }
-  }
-
-  if( rc!=SQLITE_OK ){
-    /* Either the call to sqlite3PcacheFetch() returned an error or the
-    ** pager was already in the error-state when this function was called.
-    ** Set pPg to 0 and jump to the exception handler.  */
+  if( pgno==0 ) return SQLITE_CORRUPT_BKPT;
+  pBase = sqlite3PcacheFetch(pPager->pPCache, pgno, 3);
+  if( pBase==0 ){
     pPg = 0;
-    goto pager_acquire_err;
+    rc = sqlite3PcacheFetchStress(pPager->pPCache, pgno, &pBase);
+    if( rc!=SQLITE_OK ) goto pager_acquire_err;
+    if( pBase==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+      goto pager_acquire_err;
+    }
   }
-  assert( (*ppPage)->pgno==pgno );
-  assert( (*ppPage)->pPager==pPager || (*ppPage)->pPager==0 );
+  pPg = *ppPage = sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pBase);
+  assert( pPg==(*ppPage) );
+  assert( pPg->pgno==pgno );
+  assert( pPg->pPager==pPager || pPg->pPager==0 );
 
-  if( (*ppPage)->pPager && !noContent ){
+  noContent = (flags & PAGER_GET_NOCONTENT)!=0;
+  if( pPg->pPager && !noContent ){
     /* In this case the pcache already contains an initialized copy of
     ** the page. Return without further ado.  */
     assert( pgno<=PAGER_MAX_PGNO && pgno!=PAGER_MJ_PGNO(pPager) );
@@ -46598,19 +52881,20 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
 
   }else{
     /* The pager cache has created a new page. Its content needs to 
-    ** be initialized.  */
-
-    pPg = *ppPage;
-    pPg->pPager = pPager;
-
-    /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
-    ** number greater than this, or the unused locking-page, is requested. */
+    ** be initialized. But first some error checks:
+    **
+    ** (1) The maximum page number is 2^31
+    ** (2) Never try to fetch the locking page
+    */
     if( pgno>PAGER_MAX_PGNO || pgno==PAGER_MJ_PGNO(pPager) ){
       rc = SQLITE_CORRUPT_BKPT;
       goto pager_acquire_err;
     }
 
-    if( MEMDB || pPager->dbSizefd) ){
+    pPg->pPager = pPager;
+
+    assert( !isOpen(pPager->fd) || !MEMDB );
+    if( !isOpen(pPager->fd) || pPager->dbSizepPager->mxPgno ){
         rc = SQLITE_FULL;
         goto pager_acquire_err;
@@ -46634,7 +52918,8 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
       memset(pPg->pData, 0, pPager->pageSize);
       IOTRACE(("ZERO %p %d\n", pPager, pgno));
     }else{
-      if( pagerUseWal(pPager) && bMmapOk==0 ){
+      u32 iFrame = 0;                 /* Frame to read from WAL file */
+      if( pagerUseWal(pPager) ){
         rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
         if( rc!=SQLITE_OK ) goto pager_acquire_err;
       }
@@ -46647,7 +52932,6 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
     }
     pager_set_pagehash(pPg);
   }
-
   return SQLITE_OK;
 
 pager_acquire_err:
@@ -46656,11 +52940,109 @@ pager_acquire_err:
     sqlite3PcacheDrop(pPg);
   }
   pagerUnlockIfUnused(pPager);
-
   *ppPage = 0;
   return rc;
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* The page getter for when memory-mapped I/O is enabled */
+static int getPageMMap(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int flags           /* PAGER_GET_XXX flags */
+){
+  int rc = SQLITE_OK;
+  PgHdr *pPg = 0;
+  u32 iFrame = 0;                 /* Frame to read from WAL file */
+
+  /* It is acceptable to use a read-only (mmap) page for any page except
+  ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY
+  ** flag was specified by the caller. And so long as the db is not a 
+  ** temporary or in-memory database.  */
+  const int bMmapOk = (pgno>1
+   && (pPager->eState==PAGER_READER || (flags & PAGER_GET_READONLY))
+  );
+
+  assert( USEFETCH(pPager) );
+#ifdef SQLITE_HAS_CODEC
+  assert( pPager->xCodec==0 );
+#endif
+
+  /* Optimization note:  Adding the "pgno<=1" term before "pgno==0" here
+  ** allows the compiler optimizer to reuse the results of the "pgno>1"
+  ** test in the previous statement, and avoid testing pgno==0 in the
+  ** common case where pgno is large. */
+  if( pgno<=1 && pgno==0 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+  assert( pPager->eState>=PAGER_READER );
+  assert( assert_pager_state(pPager) );
+  assert( pPager->hasHeldSharedLock==1 );
+  assert( pPager->errCode==SQLITE_OK );
+
+  if( bMmapOk && pagerUseWal(pPager) ){
+    rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+    if( rc!=SQLITE_OK ){
+      *ppPage = 0;
+      return rc;
+    }
+  }
+  if( bMmapOk && iFrame==0 ){
+    void *pData = 0;
+    rc = sqlite3OsFetch(pPager->fd, 
+        (i64)(pgno-1) * pPager->pageSize, pPager->pageSize, &pData
+    );
+    if( rc==SQLITE_OK && pData ){
+      if( pPager->eState>PAGER_READER || pPager->tempFile ){
+        pPg = sqlite3PagerLookup(pPager, pgno);
+      }
+      if( pPg==0 ){
+        rc = pagerAcquireMapPage(pPager, pgno, pData, &pPg);
+     }else{
+        sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1)*pPager->pageSize, pData);
+      }
+      if( pPg ){
+        assert( rc==SQLITE_OK );
+        *ppPage = pPg;
+        return SQLITE_OK;
+      }
+    }
+    if( rc!=SQLITE_OK ){
+      *ppPage = 0;
+      return rc;
+    }
+  }
+  return getPageNormal(pPager, pgno, ppPage, flags);
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+/* The page getter method for when the pager is an error state */
+static int getPageError(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int flags           /* PAGER_GET_XXX flags */
+){
+  UNUSED_PARAMETER(pgno);
+  UNUSED_PARAMETER(flags);
+  assert( pPager->errCode!=SQLITE_OK );
+  *ppPage = 0;
+  return pPager->errCode;
+}
+
+
+/* Dispatch all page fetch requests to the appropriate getter method.
+*/
+SQLITE_PRIVATE int sqlite3PagerGet(
+  Pager *pPager,      /* The pager open on the database file */
+  Pgno pgno,          /* Page number to fetch */
+  DbPage **ppPage,    /* Write a pointer to the page here */
+  int flags           /* PAGER_GET_XXX flags */
+){
+  return pPager->xGet(pPager, pgno, ppPage, flags);
+}
+
 /*
 ** Acquire a page if it is already in the in-memory cache.  Do
 ** not read the page from disk.  Return a pointer to the page,
@@ -46678,7 +53060,8 @@ SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
   assert( pgno!=0 );
   assert( pPager->pPCache!=0 );
   pPage = sqlite3PcacheFetch(pPager->pPCache, pgno, 0);
-  assert( pPage==0 || pPager->hasBeenUsed );
+  assert( pPage==0 || pPager->hasHeldSharedLock );
+  if( pPage==0 ) return 0;
   return sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pPage);
 }
 
@@ -46743,7 +53126,7 @@ static int pager_open_journal(Pager *pPager){
   if( !pagerUseWal(pPager) && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
     pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);
     if( pPager->pInJournal==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   
     /* Open the journal file if it is not already open. */
@@ -46751,24 +53134,24 @@ static int pager_open_journal(Pager *pPager){
       if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
         sqlite3MemJournalOpen(pPager->jfd);
       }else{
-        const int flags =                   /* VFS flags to open journal file */
-          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
-          (pPager->tempFile ? 
-            (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL):
-            (SQLITE_OPEN_MAIN_JOURNAL)
-          );
+        int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
+        int nSpill;
 
+        if( pPager->tempFile ){
+          flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);
+          nSpill = sqlite3Config.nStmtSpill;
+        }else{
+          flags |= SQLITE_OPEN_MAIN_JOURNAL;
+          nSpill = jrnlBufferSize(pPager);
+        }
+          
         /* Verify that the database still has the same name as it did when
         ** it was originally opened. */
         rc = databaseIsUnmoved(pPager);
         if( rc==SQLITE_OK ){
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
-          rc = sqlite3JournalOpen(
-              pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
+          rc = sqlite3JournalOpen (
+              pVfs, pPager->zJournal, pPager->jfd, flags, nSpill
           );
-#else
-          rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
-#endif
         }
       }
       assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
@@ -46835,7 +53218,7 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
         if( rc!=SQLITE_OK ){
           return rc;
         }
-        sqlite3WalExclusiveMode(pPager->pWal, 1);
+        (void)sqlite3WalExclusiveMode(pPager->pWal, 1);
       }
 
       /* Grab the write lock on the log file. If successful, upgrade to
@@ -46882,6 +53265,59 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
   return rc;
 }
 
+/*
+** Write page pPg onto the end of the rollback journal.
+*/
+static SQLITE_NOINLINE int pagerAddPageToRollbackJournal(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  int rc;
+  u32 cksum;
+  char *pData2;
+  i64 iOff = pPager->journalOff;
+
+  /* We should never write to the journal file the page that
+  ** contains the database locks.  The following assert verifies
+  ** that we do not. */
+  assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
+
+  assert( pPager->journalHdr<=pPager->journalOff );
+  CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
+  cksum = pager_cksum(pPager, (u8*)pData2);
+
+  /* Even if an IO or diskfull error occurs while journalling the
+  ** page in the block above, set the need-sync flag for the page.
+  ** Otherwise, when the transaction is rolled back, the logic in
+  ** playback_one_page() will think that the page needs to be restored
+  ** in the database file. And if an IO error occurs while doing so,
+  ** then corruption may follow.
+  */
+  pPg->flags |= PGHDR_NEED_SYNC;
+
+  rc = write32bits(pPager->jfd, iOff, pPg->pgno);
+  if( rc!=SQLITE_OK ) return rc;
+  rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
+  if( rc!=SQLITE_OK ) return rc;
+  rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
+  if( rc!=SQLITE_OK ) return rc;
+
+  IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
+           pPager->journalOff, pPager->pageSize));
+  PAGER_INCR(sqlite3_pager_writej_count);
+  PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
+       PAGERID(pPager), pPg->pgno, 
+       ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
+
+  pPager->journalOff += 8 + pPager->pageSize;
+  pPager->nRec++;
+  assert( pPager->pInJournal!=0 );
+  rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
+  testcase( rc==SQLITE_NOMEM );
+  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+  rc |= addToSavepointBitvecs(pPager, pPg->pgno);
+  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+  return rc;
+}
+
 /*
 ** Mark a single data page as writeable. The page is written into the 
 ** main journal or sub-journal as required. If the page is written into
@@ -46892,7 +53328,6 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
 static int pager_write(PgHdr *pPg){
   Pager *pPager = pPg->pPager;
   int rc = SQLITE_OK;
-  int inJournal;
 
   /* This routine is not called unless a write-transaction has already 
   ** been started. The journal file may or may not be open at this point.
@@ -46905,7 +53340,6 @@ static int pager_write(PgHdr *pPg){
   assert( assert_pager_state(pPager) );
   assert( pPager->errCode==0 );
   assert( pPager->readOnly==0 );
-
   CHECK_PAGE(pPg);
 
   /* The journal file needs to be opened. Higher level routines have already
@@ -46924,91 +53358,48 @@ static int pager_write(PgHdr *pPg){
   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );
   assert( assert_pager_state(pPager) );
 
-  /* Mark the page as dirty.  If the page has already been written
-  ** to the journal then we can return right away.
-  */
+  /* Mark the page that is about to be modified as dirty. */
   sqlite3PcacheMakeDirty(pPg);
-  inJournal = pageInJournal(pPager, pPg);
-  if( inJournal && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){
-    assert( !pagerUseWal(pPager) );
-  }else{
-  
-    /* The transaction journal now exists and we have a RESERVED or an
-    ** EXCLUSIVE lock on the main database file.  Write the current page to
-    ** the transaction journal if it is not there already.
-    */
-    if( !inJournal && !pagerUseWal(pPager) ){
-      assert( pagerUseWal(pPager)==0 );
-      if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){
-        u32 cksum;
-        char *pData2;
-        i64 iOff = pPager->journalOff;
-
-        /* We should never write to the journal file the page that
-        ** contains the database locks.  The following assert verifies
-        ** that we do not. */
-        assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
-
-        assert( pPager->journalHdr<=pPager->journalOff );
-        CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
-        cksum = pager_cksum(pPager, (u8*)pData2);
-
-        /* Even if an IO or diskfull error occurs while journalling the
-        ** page in the block above, set the need-sync flag for the page.
-        ** Otherwise, when the transaction is rolled back, the logic in
-        ** playback_one_page() will think that the page needs to be restored
-        ** in the database file. And if an IO error occurs while doing so,
-        ** then corruption may follow.
-        */
-        pPg->flags |= PGHDR_NEED_SYNC;
 
-        rc = write32bits(pPager->jfd, iOff, pPg->pgno);
-        if( rc!=SQLITE_OK ) return rc;
-        rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
-        if( rc!=SQLITE_OK ) return rc;
-        rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
-        if( rc!=SQLITE_OK ) return rc;
-
-        IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
-                 pPager->journalOff, pPager->pageSize));
-        PAGER_INCR(sqlite3_pager_writej_count);
-        PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
-             PAGERID(pPager), pPg->pgno, 
-             ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
-
-        pPager->journalOff += 8 + pPager->pageSize;
-        pPager->nRec++;
-        assert( pPager->pInJournal!=0 );
-        rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
-        testcase( rc==SQLITE_NOMEM );
-        assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
-        rc |= addToSavepointBitvecs(pPager, pPg->pgno);
-        if( rc!=SQLITE_OK ){
-          assert( rc==SQLITE_NOMEM );
-          return rc;
-        }
-      }else{
-        if( pPager->eState!=PAGER_WRITER_DBMOD ){
-          pPg->flags |= PGHDR_NEED_SYNC;
-        }
-        PAGERTRACE(("APPEND %d page %d needSync=%d\n",
-                PAGERID(pPager), pPg->pgno,
-               ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
+  /* If a rollback journal is in use, them make sure the page that is about
+  ** to change is in the rollback journal, or if the page is a new page off
+  ** then end of the file, make sure it is marked as PGHDR_NEED_SYNC.
+  */
+  assert( (pPager->pInJournal!=0) == isOpen(pPager->jfd) );
+  if( pPager->pInJournal!=0
+   && sqlite3BitvecTestNotNull(pPager->pInJournal, pPg->pgno)==0
+  ){
+    assert( pagerUseWal(pPager)==0 );
+    if( pPg->pgno<=pPager->dbOrigSize ){
+      rc = pagerAddPageToRollbackJournal(pPg);
+      if( rc!=SQLITE_OK ){
+        return rc;
       }
-    }
-  
-    /* If the statement journal is open and the page is not in it,
-    ** then write the current page to the statement journal.  Note that
-    ** the statement journal format differs from the standard journal format
-    ** in that it omits the checksums and the header.
-    */
-    if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){
-      rc = subjournalPage(pPg);
+    }else{
+      if( pPager->eState!=PAGER_WRITER_DBMOD ){
+        pPg->flags |= PGHDR_NEED_SYNC;
+      }
+      PAGERTRACE(("APPEND %d page %d needSync=%d\n",
+              PAGERID(pPager), pPg->pgno,
+             ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
     }
   }
 
-  /* Update the database size and return.
+  /* The PGHDR_DIRTY bit is set above when the page was added to the dirty-list
+  ** and before writing the page into the rollback journal.  Wait until now,
+  ** after the page has been successfully journalled, before setting the
+  ** PGHDR_WRITEABLE bit that indicates that the page can be safely modified.
   */
+  pPg->flags |= PGHDR_WRITEABLE;
+  
+  /* If the statement journal is open and the page is not in it,
+  ** then write the page into the statement journal.
+  */
+  if( pPager->nSavepoint>0 ){
+    rc = subjournalPageIfRequired(pPg);
+  }
+
+  /* Update the database size and return. */
   if( pPager->dbSizepgno ){
     pPager->dbSize = pPg->pgno;
   }
@@ -47023,17 +53414,17 @@ static int pager_write(PgHdr *pPg){
 ** a write.
 **
 ** Usually, the sector size is less than or equal to the page size, in which
-** case pages can be individually written.  This routine only runs in the exceptional
-** case where the page size is smaller than the sector size.
+** case pages can be individually written.  This routine only runs in the
+** exceptional case where the page size is smaller than the sector size.
 */
 static SQLITE_NOINLINE int pagerWriteLargeSector(PgHdr *pPg){
-  int rc = SQLITE_OK;            /* Return code */
-  Pgno nPageCount;               /* Total number of pages in database file */
-  Pgno pg1;                      /* First page of the sector pPg is located on. */
-  int nPage = 0;                 /* Number of pages starting at pg1 to journal */
-  int ii;                        /* Loop counter */
-  int needSync = 0;              /* True if any page has PGHDR_NEED_SYNC */
-  Pager *pPager = pPg->pPager;   /* The pager that owns pPg */
+  int rc = SQLITE_OK;          /* Return code */
+  Pgno nPageCount;             /* Total number of pages in database file */
+  Pgno pg1;                    /* First page of the sector pPg is located on. */
+  int nPage = 0;               /* Number of pages starting at pg1 to journal */
+  int ii;                      /* Loop counter */
+  int needSync = 0;            /* True if any page has PGHDR_NEED_SYNC */
+  Pager *pPager = pPg->pPager; /* The pager that owns pPg */
   Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
 
   /* Set the doNotSpill NOSYNC bit to 1. This is because we cannot allow
@@ -47067,7 +53458,7 @@ static SQLITE_NOINLINE int pagerWriteLargeSector(PgHdr *pPg){
     PgHdr *pPage;
     if( pg==pPg->pgno || !sqlite3BitvecTest(pPager->pInJournal, pg) ){
       if( pg!=PAGER_MJ_PGNO(pPager) ){
-        rc = sqlite3PagerGet(pPager, pg, &pPage);
+        rc = sqlite3PagerGet(pPager, pg, &pPage, 0);
         if( rc==SQLITE_OK ){
           rc = pager_write(pPage);
           if( pPage->flags&PGHDR_NEED_SYNC ){
@@ -47121,11 +53512,17 @@ static SQLITE_NOINLINE int pagerWriteLargeSector(PgHdr *pPg){
 ** as appropriate. Otherwise, SQLITE_OK.
 */
 SQLITE_PRIVATE int sqlite3PagerWrite(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
   assert( (pPg->flags & PGHDR_MMAP)==0 );
-  assert( pPg->pPager->eState>=PAGER_WRITER_LOCKED );
-  assert( pPg->pPager->eState!=PAGER_ERROR );
-  assert( assert_pager_state(pPg->pPager) );
-  if( pPg->pPager->sectorSize > (u32)pPg->pPager->pageSize ){
+  assert( pPager->eState>=PAGER_WRITER_LOCKED );
+  assert( assert_pager_state(pPager) );
+  if( (pPg->flags & PGHDR_WRITEABLE)!=0 && pPager->dbSize>=pPg->pgno ){
+    if( pPager->nSavepoint ) return subjournalPageIfRequired(pPg);
+    return SQLITE_OK;
+  }else if( pPager->errCode ){
+    return pPager->errCode;
+  }else if( pPager->sectorSize > (u32)pPager->pageSize ){
+    assert( pPager->tempFile==0 );
     return pagerWriteLargeSector(pPg);
   }else{
     return pager_write(pPg);
@@ -47139,7 +53536,7 @@ SQLITE_PRIVATE int sqlite3PagerWrite(PgHdr *pPg){
 */
 #ifndef NDEBUG
 SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage *pPg){
-  return pPg->flags&PGHDR_DIRTY;
+  return pPg->flags & PGHDR_WRITEABLE;
 }
 #endif
 
@@ -47156,13 +53553,21 @@ SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage *pPg){
 **
 ** Tests show that this optimization can quadruple the speed of large 
 ** DELETE operations.
+**
+** This optimization cannot be used with a temp-file, as the page may
+** have been dirty at the start of the transaction. In that case, if
+** memory pressure forces page pPg out of the cache, the data does need 
+** to be written out to disk so that it may be read back in if the 
+** current transaction is rolled back.
 */
 SQLITE_PRIVATE void sqlite3PagerDontWrite(PgHdr *pPg){
   Pager *pPager = pPg->pPager;
-  if( (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){
+  if( !pPager->tempFile && (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){
     PAGERTRACE(("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager)));
     IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno))
     pPg->flags |= PGHDR_DONT_WRITE;
+    pPg->flags &= ~PGHDR_WRITEABLE;
+    testcase( pPg->flags & PGHDR_NEED_SYNC );
     pager_set_pagehash(pPg);
   }
 }
@@ -47221,7 +53626,7 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
     assert( !pPager->tempFile && isOpen(pPager->fd) );
 
     /* Open page 1 of the file for writing. */
-    rc = sqlite3PagerGet(pPager, 1, &pPgHdr);
+    rc = sqlite3PagerGet(pPager, 1, &pPgHdr, 0);
     assert( pPgHdr==0 || rc==SQLITE_OK );
 
     /* If page one was fetched successfully, and this function is not
@@ -47241,7 +53646,7 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
       if( DIRECT_MODE ){
         const void *zBuf;
         assert( pPager->dbFileSize>0 );
-        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM, zBuf);
+        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM_BKPT, zBuf);
         if( rc==SQLITE_OK ){
           rc = sqlite3OsWrite(pPager->fd, zBuf, pPager->pageSize, 0);
           pPager->aStat[PAGER_STAT_WRITE]++;
@@ -47299,14 +53704,17 @@ SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zMaster){
 ** returned.
 */
 SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager *pPager){
-  int rc = SQLITE_OK;
-  assert( pPager->eState==PAGER_WRITER_CACHEMOD 
-       || pPager->eState==PAGER_WRITER_DBMOD 
-       || pPager->eState==PAGER_WRITER_LOCKED 
-  );
+  int rc = pPager->errCode;
   assert( assert_pager_state(pPager) );
-  if( 0==pagerUseWal(pPager) ){
-    rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+  if( rc==SQLITE_OK ){
+    assert( pPager->eState==PAGER_WRITER_CACHEMOD 
+         || pPager->eState==PAGER_WRITER_DBMOD 
+         || pPager->eState==PAGER_WRITER_LOCKED 
+    );
+    assert( assert_pager_state(pPager) );
+    if( 0==pagerUseWal(pPager) ){
+      rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+    }
   }
   return rc;
 }
@@ -47354,17 +53762,21 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
   /* If a prior error occurred, report that error again. */
   if( NEVER(pPager->errCode) ) return pPager->errCode;
 
+  /* Provide the ability to easily simulate an I/O error during testing */
+  if( sqlite3FaultSim(400) ) return SQLITE_IOERR;
+
   PAGERTRACE(("DATABASE SYNC: File=%s zMaster=%s nSize=%d\n", 
       pPager->zFilename, zMaster, pPager->dbSize));
 
   /* If no database changes have been made, return early. */
   if( pPager->eStatetempFile );
+  assert( isOpen(pPager->fd) || pPager->tempFile );
+  if( 0==pagerFlushOnCommit(pPager, 1) ){
     /* If this is an in-memory db, or no pages have been written to, or this
     ** function has already been called, it is mostly a no-op.  However, any
-    ** backup in progress needs to be restarted.
-    */
+    ** backup in progress needs to be restarted.  */
     sqlite3BackupRestart(pPager->pBackup);
   }else{
     if( pagerUseWal(pPager) ){
@@ -47373,7 +53785,7 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
       if( pList==0 ){
         /* Must have at least one page for the WAL commit flag.
         ** Ticket [2d1a5c67dfc2363e44f29d9bbd57f] 2011-05-18 */
-        rc = sqlite3PagerGet(pPager, 1, &pPageOne);
+        rc = sqlite3PagerGet(pPager, 1, &pPageOne, 0);
         pList = pPageOne;
         pList->pDirty = 0;
       }
@@ -47603,6 +54015,7 @@ SQLITE_PRIVATE int sqlite3PagerRollback(Pager *pPager){
       */
       pPager->errCode = SQLITE_ABORT;
       pPager->eState = PAGER_ERROR;
+      setGetterMethod(pPager);
       return rc;
     }
   }else{
@@ -47629,12 +54042,14 @@ SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager *pPager){
   return pPager->readOnly;
 }
 
+#ifdef SQLITE_DEBUG
 /*
-** Return the number of references to the pager.
+** Return the sum of the reference counts for all pages held by pPager.
 */
 SQLITE_PRIVATE int sqlite3PagerRefcount(Pager *pPager){
   return sqlite3PcacheRefCount(pPager->pPCache);
 }
+#endif
 
 /*
 ** Return the approximate number of bytes of memory currently
@@ -47701,10 +54116,10 @@ SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *pPager, int eStat, int reset, i
 }
 
 /*
-** Return true if this is an in-memory pager.
+** Return true if this is an in-memory or temp-file backed pager.
 */
 SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){
-  return MEMDB;
+  return pPager->tempFile;
 }
 
 /*
@@ -47717,54 +54132,62 @@ SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){
 ** occurs while opening the sub-journal file, then an IO error code is
 ** returned. Otherwise, SQLITE_OK.
 */
-SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
+static SQLITE_NOINLINE int pagerOpenSavepoint(Pager *pPager, int nSavepoint){
   int rc = SQLITE_OK;                       /* Return code */
   int nCurrent = pPager->nSavepoint;        /* Current number of savepoints */
+  int ii;                                   /* Iterator variable */
+  PagerSavepoint *aNew;                     /* New Pager.aSavepoint array */
 
   assert( pPager->eState>=PAGER_WRITER_LOCKED );
   assert( assert_pager_state(pPager) );
+  assert( nSavepoint>nCurrent && pPager->useJournal );
 
-  if( nSavepoint>nCurrent && pPager->useJournal ){
-    int ii;                                 /* Iterator variable */
-    PagerSavepoint *aNew;                   /* New Pager.aSavepoint array */
+  /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM
+  ** if the allocation fails. Otherwise, zero the new portion in case a 
+  ** malloc failure occurs while populating it in the for(...) loop below.
+  */
+  aNew = (PagerSavepoint *)sqlite3Realloc(
+      pPager->aSavepoint, sizeof(PagerSavepoint)*nSavepoint
+  );
+  if( !aNew ){
+    return SQLITE_NOMEM_BKPT;
+  }
+  memset(&aNew[nCurrent], 0, (nSavepoint-nCurrent) * sizeof(PagerSavepoint));
+  pPager->aSavepoint = aNew;
 
-    /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM
-    ** if the allocation fails. Otherwise, zero the new portion in case a 
-    ** malloc failure occurs while populating it in the for(...) loop below.
-    */
-    aNew = (PagerSavepoint *)sqlite3Realloc(
-        pPager->aSavepoint, sizeof(PagerSavepoint)*nSavepoint
-    );
-    if( !aNew ){
-      return SQLITE_NOMEM;
+  /* Populate the PagerSavepoint structures just allocated. */
+  for(ii=nCurrent; iidbSize;
+    if( isOpen(pPager->jfd) && pPager->journalOff>0 ){
+      aNew[ii].iOffset = pPager->journalOff;
+    }else{
+      aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
     }
-    memset(&aNew[nCurrent], 0, (nSavepoint-nCurrent) * sizeof(PagerSavepoint));
-    pPager->aSavepoint = aNew;
-
-    /* Populate the PagerSavepoint structures just allocated. */
-    for(ii=nCurrent; iidbSize;
-      if( isOpen(pPager->jfd) && pPager->journalOff>0 ){
-        aNew[ii].iOffset = pPager->journalOff;
-      }else{
-        aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
-      }
-      aNew[ii].iSubRec = pPager->nSubRec;
-      aNew[ii].pInSavepoint = sqlite3BitvecCreate(pPager->dbSize);
-      if( !aNew[ii].pInSavepoint ){
-        return SQLITE_NOMEM;
-      }
-      if( pagerUseWal(pPager) ){
-        sqlite3WalSavepoint(pPager->pWal, aNew[ii].aWalData);
-      }
-      pPager->nSavepoint = ii+1;
+    aNew[ii].iSubRec = pPager->nSubRec;
+    aNew[ii].pInSavepoint = sqlite3BitvecCreate(pPager->dbSize);
+    if( !aNew[ii].pInSavepoint ){
+      return SQLITE_NOMEM_BKPT;
     }
-    assert( pPager->nSavepoint==nSavepoint );
-    assertTruncateConstraint(pPager);
+    if( pagerUseWal(pPager) ){
+      sqlite3WalSavepoint(pPager->pWal, aNew[ii].aWalData);
+    }
+    pPager->nSavepoint = ii+1;
   }
-
+  assert( pPager->nSavepoint==nSavepoint );
+  assertTruncateConstraint(pPager);
   return rc;
 }
+SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
+  assert( pPager->eState>=PAGER_WRITER_LOCKED );
+  assert( assert_pager_state(pPager) );
+
+  if( nSavepoint>pPager->nSavepoint && pPager->useJournal ){
+    return pagerOpenSavepoint(pPager, nSavepoint);
+  }else{
+    return SQLITE_OK;
+  }
+}
+
 
 /*
 ** This function is called to rollback or release (commit) a savepoint.
@@ -47797,7 +54220,11 @@ SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
 ** savepoint. If no errors occur, SQLITE_OK is returned.
 */ 
 SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
-  int rc = pPager->errCode;       /* Return code */
+  int rc = pPager->errCode;
+  
+#ifdef SQLITE_ENABLE_ZIPVFS
+  if( op==SAVEPOINT_RELEASE ) rc = SQLITE_OK;
+#endif
 
   assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );
   assert( iSavepoint>=0 || op==SAVEPOINT_ROLLBACK );
@@ -47821,7 +54248,7 @@ SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
     if( op==SAVEPOINT_RELEASE ){
       if( nNew==0 && isOpen(pPager->sjfd) ){
         /* Only truncate if it is an in-memory sub-journal. */
-        if( sqlite3IsMemJournal(pPager->sjfd) ){
+        if( sqlite3JournalIsInMemory(pPager->sjfd) ){
           rc = sqlite3OsTruncate(pPager->sjfd, 0);
           assert( rc==SQLITE_OK );
         }
@@ -47838,6 +54265,21 @@ SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
       rc = pagerPlaybackSavepoint(pPager, pSavepoint);
       assert(rc!=SQLITE_DONE);
     }
+    
+#ifdef SQLITE_ENABLE_ZIPVFS
+    /* If the cache has been modified but the savepoint cannot be rolled 
+    ** back journal_mode=off, put the pager in the error state. This way,
+    ** if the VFS used by this pager includes ZipVFS, the entire transaction
+    ** can be rolled back at the ZipVFS level.  */
+    else if( 
+        pPager->journalMode==PAGER_JOURNALMODE_OFF 
+     && pPager->eState>=PAGER_WRITER_CACHEMOD
+    ){
+      pPager->errCode = SQLITE_ABORT;
+      pPager->eState = PAGER_ERROR;
+      setGetterMethod(pPager);
+    }
+#endif
   }
 
   return rc;
@@ -47860,7 +54302,7 @@ SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager *pPager, int nullIfMemDb){
 /*
 ** Return the VFS structure for the pager.
 */
-SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
+SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
   return pPager->pVfs;
 }
 
@@ -47874,18 +54316,22 @@ SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager *pPager){
 }
 
 /*
-** Return the full pathname of the journal file.
+** Return the file handle for the journal file (if it exists).
+** This will be either the rollback journal or the WAL file.
 */
-SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager *pPager){
-  return pPager->zJournal;
+SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager *pPager){
+#if SQLITE_OMIT_WAL
+  return pPager->jfd;
+#else
+  return pPager->pWal ? sqlite3WalFile(pPager->pWal) : pPager->jfd;
+#endif
 }
 
 /*
-** Return true if fsync() calls are disabled for this pager.  Return FALSE
-** if fsync()s are executed normally.
+** Return the full pathname of the journal file.
 */
-SQLITE_PRIVATE int sqlite3PagerNosync(Pager *pPager){
-  return pPager->noSync;
+SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager *pPager){
+  return pPager->zJournal;
 }
 
 #ifdef SQLITE_HAS_CODEC
@@ -47904,6 +54350,7 @@ SQLITE_PRIVATE void sqlite3PagerSetCodec(
   pPager->xCodecSizeChng = xCodecSizeChng;
   pPager->xCodecFree = xCodecFree;
   pPager->pCodec = pCodec;
+  setGetterMethod(pPager);
   pagerReportSize(pPager);
 }
 SQLITE_PRIVATE void *sqlite3PagerGetCodec(Pager *pPager){
@@ -47972,7 +54419,8 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   /* In order to be able to rollback, an in-memory database must journal
   ** the page we are moving from.
   */
-  if( MEMDB ){
+  assert( pPager->tempFile || !MEMDB );
+  if( pPager->tempFile ){
     rc = sqlite3PagerWrite(pPg);
     if( rc ) return rc;
   }
@@ -47995,9 +54443,8 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   ** one or more savepoint bitvecs. This is the reason this function
   ** may return SQLITE_NOMEM.
   */
-  if( pPg->flags&PGHDR_DIRTY
-   && subjRequiresPage(pPg)
-   && SQLITE_OK!=(rc = subjournalPage(pPg))
+  if( (pPg->flags & PGHDR_DIRTY)!=0
+   && SQLITE_OK!=(rc = subjournalPageIfRequired(pPg))
   ){
     return rc;
   }
@@ -48030,7 +54477,7 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   assert( !pPgOld || pPgOld->nRef==1 );
   if( pPgOld ){
     pPg->flags |= (pPgOld->flags&PGHDR_NEED_SYNC);
-    if( MEMDB ){
+    if( pPager->tempFile ){
       /* Do not discard pages from an in-memory database since we might
       ** need to rollback later.  Just move the page out of the way. */
       sqlite3PcacheMove(pPgOld, pPager->dbSize+1);
@@ -48047,8 +54494,7 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   ** to exist, in case the transaction needs to roll back.  Use pPgOld
   ** as the original page since it has already been allocated.
   */
-  if( MEMDB ){
-    assert( pPgOld );
+  if( pPager->tempFile && pPgOld ){
     sqlite3PcacheMove(pPgOld, origPgno);
     sqlite3PagerUnrefNotNull(pPgOld);
   }
@@ -48069,7 +54515,7 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
     ** the journal file twice, but that is not a problem.
     */
     PgHdr *pPgHdr;
-    rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr);
+    rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr, 0);
     if( rc!=SQLITE_OK ){
       if( needSyncPgno<=pPager->dbOrigSize ){
         assert( pPager->pTmpSpace!=0 );
@@ -48243,6 +54689,8 @@ SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){
         }
         assert( state==pPager->eState );
       }
+    }else if( eMode==PAGER_JOURNALMODE_OFF ){
+      sqlite3OsClose(pPager->jfd);
     }
   }
 
@@ -48298,10 +54746,12 @@ SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
 ** Unless this is an in-memory or temporary database, clear the pager cache.
 */
 SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){
-  if( !MEMDB && pPager->tempFile==0 ) pager_reset(pPager);
+  assert( MEMDB==0 || pPager->tempFile );
+  if( pPager->tempFile==0 ) pager_reset(pPager);
 }
 #endif
 
+
 #ifndef SQLITE_OMIT_WAL
 /*
 ** This function is called when the user invokes "PRAGMA wal_checkpoint",
@@ -48310,10 +54760,16 @@ SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){
 **
 ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
 */
-SQLITE_PRIVATE int sqlite3PagerCheckpoint(Pager *pPager, int eMode, int *pnLog, int *pnCkpt){
+SQLITE_PRIVATE int sqlite3PagerCheckpoint(
+  Pager *pPager,                  /* Checkpoint on this pager */
+  sqlite3 *db,                    /* Db handle used to check for interrupts */
+  int eMode,                      /* Type of checkpoint */
+  int *pnLog,                     /* OUT: Final number of frames in log */
+  int *pnCkpt                     /* OUT: Final number of checkpointed frames */
+){
   int rc = SQLITE_OK;
   if( pPager->pWal ){
-    rc = sqlite3WalCheckpoint(pPager->pWal, eMode,
+    rc = sqlite3WalCheckpoint(pPager->pWal, db, eMode,
         (eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),
         pPager->pBusyHandlerArg,
         pPager->ckptSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
@@ -48333,6 +54789,7 @@ SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager){
 */
 SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager){
   const sqlite3_io_methods *pMethods = pPager->fd->pMethods;
+  if( pPager->noLock ) return 0;
   return pPager->exclusiveMode || (pMethods->iVersion>=2 && pMethods->xShmMap);
 }
 
@@ -48444,7 +54901,7 @@ SQLITE_PRIVATE int sqlite3PagerOpenWal(
 ** error (SQLITE_BUSY) is returned and the log connection is not closed.
 ** If successful, the EXCLUSIVE lock is not released before returning.
 */
-SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager){
+SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager, sqlite3 *db){
   int rc = SQLITE_OK;
 
   assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );
@@ -48472,15 +54929,58 @@ SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager){
   if( rc==SQLITE_OK && pPager->pWal ){
     rc = pagerExclusiveLock(pPager);
     if( rc==SQLITE_OK ){
-      rc = sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags,
+      rc = sqlite3WalClose(pPager->pWal, db, pPager->ckptSyncFlags,
                            pPager->pageSize, (u8*)pPager->pTmpSpace);
       pPager->pWal = 0;
       pagerFixMaplimit(pPager);
+      if( rc && !pPager->exclusiveMode ) pagerUnlockDb(pPager, SHARED_LOCK);
     }
   }
   return rc;
 }
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/*
+** If this is a WAL database, obtain a snapshot handle for the snapshot
+** currently open. Otherwise, return an error.
+*/
+SQLITE_PRIVATE int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot){
+  int rc = SQLITE_ERROR;
+  if( pPager->pWal ){
+    rc = sqlite3WalSnapshotGet(pPager->pWal, ppSnapshot);
+  }
+  return rc;
+}
+
+/*
+** If this is a WAL database, store a pointer to pSnapshot. Next time a
+** read transaction is opened, attempt to read from the snapshot it 
+** identifies. If this is not a WAL database, return an error.
+*/
+SQLITE_PRIVATE int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot){
+  int rc = SQLITE_OK;
+  if( pPager->pWal ){
+    sqlite3WalSnapshotOpen(pPager->pWal, pSnapshot);
+  }else{
+    rc = SQLITE_ERROR;
+  }
+  return rc;
+}
+
+/*
+** If this is a WAL database, call sqlite3WalSnapshotRecover(). If this 
+** is not a WAL database, return an error.
+*/
+SQLITE_PRIVATE int sqlite3PagerSnapshotRecover(Pager *pPager){
+  int rc;
+  if( pPager->pWal ){
+    rc = sqlite3WalSnapshotRecover(pPager->pWal);
+  }else{
+    rc = SQLITE_ERROR;
+  }
+  return rc;
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
 #endif /* !SQLITE_OMIT_WAL */
 
 #ifdef SQLITE_ENABLE_ZIPVFS
@@ -48497,7 +54997,6 @@ SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager){
 }
 #endif
 
-
 #endif /* SQLITE_OMIT_DISKIO */
 
 /************** End of pager.c ***********************************************/
@@ -48746,6 +55245,7 @@ SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager){
 */
 #ifndef SQLITE_OMIT_WAL
 
+/* #include "wal.h" */
 
 /*
 ** Trace output macros
@@ -48775,7 +55275,8 @@ SQLITE_PRIVATE int sqlite3WalTrace = 0;
 
 /*
 ** Indices of various locking bytes.   WAL_NREADER is the number
-** of available reader locks and should be at least 3.
+** of available reader locks and should be at least 3.  The default
+** is SQLITE_SHM_NLOCK==8 and  WAL_NREADER==5.
 */
 #define WAL_WRITE_LOCK         0
 #define WAL_ALL_BUT_WRITE      1
@@ -48795,7 +55296,10 @@ typedef struct WalCkptInfo WalCkptInfo;
 ** The following object holds a copy of the wal-index header content.
 **
 ** The actual header in the wal-index consists of two copies of this
-** object.
+** object followed by one instance of the WalCkptInfo object.
+** For all versions of SQLite through 3.10.0 and probably beyond,
+** the locking bytes (WalCkptInfo.aLock) start at offset 120 and
+** the total header size is 136 bytes.
 **
 ** The szPage value can be any power of 2 between 512 and 32768, inclusive.
 ** Or it can be 1 to represent a 65536-byte page.  The latter case was
@@ -48828,6 +55332,16 @@ struct WalIndexHdr {
 ** However, a WAL_WRITE_LOCK thread can move the value of nBackfill from
 ** mxFrame back to zero when the WAL is reset.
 **
+** nBackfillAttempted is the largest value of nBackfill that a checkpoint
+** has attempted to achieve.  Normally nBackfill==nBackfillAtempted, however
+** the nBackfillAttempted is set before any backfilling is done and the
+** nBackfill is only set after all backfilling completes.  So if a checkpoint
+** crashes, nBackfillAttempted might be larger than nBackfill.  The
+** WalIndexHdr.mxFrame must never be less than nBackfillAttempted.
+**
+** The aLock[] field is a set of bytes used for locking.  These bytes should
+** never be read or written.
+**
 ** There is one entry in aReadMark[] for each reader lock.  If a reader
 ** holds read-lock K, then the value in aReadMark[K] is no greater than
 ** the mxFrame for that reader.  The value READMARK_NOT_USED (0xffffffff)
@@ -48867,6 +55381,9 @@ struct WalIndexHdr {
 struct WalCkptInfo {
   u32 nBackfill;                  /* Number of WAL frames backfilled into DB */
   u32 aReadMark[WAL_NREADER];     /* Reader marks */
+  u8 aLock[SQLITE_SHM_NLOCK];     /* Reserved space for locks */
+  u32 nBackfillAttempted;         /* WAL frames perhaps written, or maybe not */
+  u32 notUsed0;                   /* Available for future enhancements */
 };
 #define READMARK_NOT_USED  0xffffffff
 
@@ -48876,9 +55393,8 @@ struct WalCkptInfo {
 ** only support mandatory file-locks, we do not read or write data
 ** from the region of the file on which locks are applied.
 */
-#define WALINDEX_LOCK_OFFSET   (sizeof(WalIndexHdr)*2 + sizeof(WalCkptInfo))
-#define WALINDEX_LOCK_RESERVED 16
-#define WALINDEX_HDR_SIZE      (WALINDEX_LOCK_OFFSET+WALINDEX_LOCK_RESERVED)
+#define WALINDEX_LOCK_OFFSET (sizeof(WalIndexHdr)*2+offsetof(WalCkptInfo,aLock))
+#define WALINDEX_HDR_SIZE    (sizeof(WalIndexHdr)*2+sizeof(WalCkptInfo))
 
 /* Size of header before each frame in wal */
 #define WAL_FRAME_HDRSIZE 24
@@ -48931,11 +55447,16 @@ struct Wal {
   u8 syncHeader;             /* Fsync the WAL header if true */
   u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
   WalIndexHdr hdr;           /* Wal-index header for current transaction */
+  u32 minFrame;              /* Ignore wal frames before this one */
+  u32 iReCksum;              /* On commit, recalculate checksums from here */
   const char *zWalName;      /* Name of WAL file */
   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
 #ifdef SQLITE_DEBUG
   u8 lockError;              /* True if a locking error has occurred */
 #endif
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  WalIndexHdr *pSnapshot;    /* Start transaction here if not NULL */
+#endif
 };
 
 /*
@@ -49025,10 +55546,10 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
   if( pWal->nWiData<=iPage ){
     int nByte = sizeof(u32*)*(iPage+1);
     volatile u32 **apNew;
-    apNew = (volatile u32 **)sqlite3_realloc((void *)pWal->apWiData, nByte);
+    apNew = (volatile u32 **)sqlite3_realloc64((void *)pWal->apWiData, nByte);
     if( !apNew ){
       *ppPage = 0;
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset((void*)&apNew[pWal->nWiData], 0,
            sizeof(u32*)*(iPage+1-pWal->nWiData));
@@ -49040,7 +55561,7 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
   if( pWal->apWiData[iPage]==0 ){
     if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
       pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
-      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM;
+      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;
     }else{
       rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
           pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
@@ -49151,9 +55672,9 @@ static void walIndexWriteHdr(Wal *pWal){
   pWal->hdr.isInit = 1;
   pWal->hdr.iVersion = WALINDEX_MAX_VERSION;
   walChecksumBytes(1, (u8*)&pWal->hdr, nCksum, 0, pWal->hdr.aCksum);
-  memcpy((void *)&aHdr[1], (void *)&pWal->hdr, sizeof(WalIndexHdr));
+  memcpy((void*)&aHdr[1], (const void*)&pWal->hdr, sizeof(WalIndexHdr));
   walShmBarrier(pWal);
-  memcpy((void *)&aHdr[0], (void *)&pWal->hdr, sizeof(WalIndexHdr));
+  memcpy((void*)&aHdr[0], (const void*)&pWal->hdr, sizeof(WalIndexHdr));
 }
 
 /*
@@ -49181,14 +55702,18 @@ static void walEncodeFrame(
   assert( WAL_FRAME_HDRSIZE==24 );
   sqlite3Put4byte(&aFrame[0], iPage);
   sqlite3Put4byte(&aFrame[4], nTruncate);
-  memcpy(&aFrame[8], pWal->hdr.aSalt, 8);
+  if( pWal->iReCksum==0 ){
+    memcpy(&aFrame[8], pWal->hdr.aSalt, 8);
 
-  nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
-  walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
-  walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);
+    nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
+    walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
+    walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);
 
-  sqlite3Put4byte(&aFrame[16], aCksum[0]);
-  sqlite3Put4byte(&aFrame[20], aCksum[1]);
+    sqlite3Put4byte(&aFrame[16], aCksum[0]);
+    sqlite3Put4byte(&aFrame[20], aCksum[1]);
+  }else{
+    memset(&aFrame[8], 0, 16);
+  }
 }
 
 /*
@@ -49454,13 +55979,13 @@ static void walCleanupHash(Wal *pWal){
   ** via the hash table even after the cleanup.
   */
   if( iLimit ){
-    int i;           /* Loop counter */
+    int j;           /* Loop counter */
     int iKey;        /* Hash key */
-    for(i=1; i<=iLimit; i++){
-      for(iKey=walHash(aPgno[i]); aHash[iKey]; iKey=walNextHash(iKey)){
-        if( aHash[iKey]==i ) break;
+    for(j=1; j<=iLimit; j++){
+      for(iKey=walHash(aPgno[j]); aHash[iKey]; iKey=walNextHash(iKey)){
+        if( aHash[iKey]==j ) break;
       }
-      assert( aHash[iKey]==i );
+      assert( aHash[iKey]==j );
     }
   }
 #endif /* SQLITE_ENABLE_EXPENSIVE_ASSERT */
@@ -49649,9 +56174,9 @@ static int walIndexRecover(Wal *pWal){
 
     /* Malloc a buffer to read frames into. */
     szFrame = szPage + WAL_FRAME_HDRSIZE;
-    aFrame = (u8 *)sqlite3_malloc(szFrame);
+    aFrame = (u8 *)sqlite3_malloc64(szFrame);
     if( !aFrame ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto recovery_error;
     }
     aData = &aFrame[WAL_FRAME_HDRSIZE];
@@ -49700,6 +56225,7 @@ finished:
     */
     pInfo = walCkptInfo(pWal);
     pInfo->nBackfill = 0;
+    pInfo->nBackfillAttempted = pWal->hdr.mxFrame;
     pInfo->aReadMark[0] = 0;
     for(i=1; iaReadMark[i] = READMARK_NOT_USED;
     if( pWal->hdr.mxFrame ) pInfo->aReadMark[1] = pWal->hdr.mxFrame;
@@ -49771,7 +56297,11 @@ SQLITE_PRIVATE int sqlite3WalOpen(
   /* In the amalgamation, the os_unix.c and os_win.c source files come before
   ** this source file.  Verify that the #defines of the locking byte offsets
   ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value.
+  ** For that matter, if the lock offset ever changes from its initial design
+  ** value of 120, we need to know that so there is an assert() to check it.
   */
+  assert( 120==WALINDEX_LOCK_OFFSET );
+  assert( 136==WALINDEX_HDR_SIZE );
 #ifdef WIN_SHM_BASE
   assert( WIN_SHM_BASE==WALINDEX_LOCK_OFFSET );
 #endif
@@ -49784,7 +56314,7 @@ SQLITE_PRIVATE int sqlite3WalOpen(
   *ppWal = 0;
   pRet = (Wal*)sqlite3MallocZero(sizeof(Wal) + pVfs->szOsFile);
   if( !pRet ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   pRet->pVfs = pVfs;
@@ -49962,7 +56492,7 @@ static void walMergesort(
   int nMerge = 0;                 /* Number of elements in list aMerge */
   ht_slot *aMerge = 0;            /* List to be merged */
   int iList;                      /* Index into input list */
-  int iSub = 0;                   /* Index into aSub array */
+  u32 iSub = 0;                   /* Index into aSub array */
   struct Sublist aSub[13];        /* Array of sub-lists */
 
   memset(aSub, 0, sizeof(aSub));
@@ -49973,7 +56503,9 @@ static void walMergesort(
     nMerge = 1;
     aMerge = &aList[iList];
     for(iSub=0; iList & (1<aList && p->nList<=(1<aList==&aList[iList&~((2<aList, p->nList, &aMerge, &nMerge, aBuffer);
@@ -49984,7 +56516,9 @@ static void walMergesort(
 
   for(iSub++; iSubnList<=(1<aList==&aList[nList&~((2<aList, p->nList, &aMerge, &nMerge, aBuffer);
@@ -50042,9 +56576,9 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
   nByte = sizeof(WalIterator) 
         + (nSegment-1)*sizeof(struct WalSegment)
         + iLast*sizeof(ht_slot);
-  p = (WalIterator *)sqlite3_malloc(nByte);
+  p = (WalIterator *)sqlite3_malloc64(nByte);
   if( !p ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memset(p, 0, nByte);
   p->nSegment = nSegment;
@@ -50052,11 +56586,11 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
   /* Allocate temporary space used by the merge-sort routine. This block
   ** of memory will be freed before this function returns.
   */
-  aTmp = (ht_slot *)sqlite3_malloc(
+  aTmp = (ht_slot *)sqlite3_malloc64(
       sizeof(ht_slot) * (iLast>HASHTABLE_NPAGE?HASHTABLE_NPAGE:iLast)
   );
   if( !aTmp ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
 
   for(i=0; rc==SQLITE_OK && ihdr.aSalt[1], &salt1, 4);
   walIndexWriteHdr(pWal);
   pInfo->nBackfill = 0;
+  pInfo->nBackfillAttempted = 0;
   pInfo->aReadMark[1] = 0;
   for(i=2; iaReadMark[i] = READMARK_NOT_USED;
   assert( pInfo->aReadMark[0]==0 );
@@ -50191,13 +56726,14 @@ static void walRestartHdr(Wal *pWal, u32 salt1){
 */
 static int walCheckpoint(
   Wal *pWal,                      /* Wal connection */
+  sqlite3 *db,                    /* Check for interrupts on this handle */
   int eMode,                      /* One of PASSIVE, FULL or RESTART */
   int (*xBusy)(void*),            /* Function to call when busy */
   void *pBusyArg,                 /* Context argument for xBusyHandler */
   int sync_flags,                 /* Flags for OsSync() (or 0) */
   u8 *zBuf                        /* Temporary buffer to use */
 ){
-  int rc;                         /* Return code */
+  int rc = SQLITE_OK;             /* Return code */
   int szPage;                     /* Database page-size */
   WalIterator *pIter = 0;         /* Wal iterator context */
   u32 iDbpage = 0;                /* Next database page to write */
@@ -50211,104 +56747,121 @@ static int walCheckpoint(
   testcase( szPage<=32768 );
   testcase( szPage>=65536 );
   pInfo = walCkptInfo(pWal);
-  if( pInfo->nBackfill>=pWal->hdr.mxFrame ) return SQLITE_OK;
+  if( pInfo->nBackfillhdr.mxFrame ){
 
-  /* Allocate the iterator */
-  rc = walIteratorInit(pWal, &pIter);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-  assert( pIter );
+    /* Allocate the iterator */
+    rc = walIteratorInit(pWal, &pIter);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    assert( pIter );
 
-  /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
-  ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
-  assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );
+    /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
+    ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
+    assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );
 
-  /* Compute in mxSafeFrame the index of the last frame of the WAL that is
-  ** safe to write into the database.  Frames beyond mxSafeFrame might
-  ** overwrite database pages that are in use by active readers and thus
-  ** cannot be backfilled from the WAL.
-  */
-  mxSafeFrame = pWal->hdr.mxFrame;
-  mxPage = pWal->hdr.nPage;
-  for(i=1; iaReadMark[i];
-    if( mxSafeFrame>y ){
-      assert( y<=pWal->hdr.mxFrame );
-      rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(i), 1);
-      if( rc==SQLITE_OK ){
-        pInfo->aReadMark[i] = (i==1 ? mxSafeFrame : READMARK_NOT_USED);
-        walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
-      }else if( rc==SQLITE_BUSY ){
-        mxSafeFrame = y;
-        xBusy = 0;
-      }else{
-        goto walcheckpoint_out;
+    /* Compute in mxSafeFrame the index of the last frame of the WAL that is
+    ** safe to write into the database.  Frames beyond mxSafeFrame might
+    ** overwrite database pages that are in use by active readers and thus
+    ** cannot be backfilled from the WAL.
+    */
+    mxSafeFrame = pWal->hdr.mxFrame;
+    mxPage = pWal->hdr.nPage;
+    for(i=1; iaReadMark[i];
+      if( mxSafeFrame>y ){
+        assert( y<=pWal->hdr.mxFrame );
+        rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(i), 1);
+        if( rc==SQLITE_OK ){
+          pInfo->aReadMark[i] = (i==1 ? mxSafeFrame : READMARK_NOT_USED);
+          walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
+        }else if( rc==SQLITE_BUSY ){
+          mxSafeFrame = y;
+          xBusy = 0;
+        }else{
+          goto walcheckpoint_out;
+        }
       }
     }
-  }
 
-  if( pInfo->nBackfillnBackfill;
+    if( pInfo->nBackfillnBackfill;
 
-    /* Sync the WAL to disk */
-    if( sync_flags ){
-      rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
-    }
+      pInfo->nBackfillAttempted = mxSafeFrame;
 
-    /* If the database may grow as a result of this checkpoint, hint
-    ** about the eventual size of the db file to the VFS layer.
-    */
-    if( rc==SQLITE_OK ){
-      i64 nReq = ((i64)mxPage * szPage);
-      rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);
-      if( rc==SQLITE_OK && nSizepDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);
+      /* Sync the WAL to disk */
+      if( sync_flags ){
+        rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
       }
-    }
 
+      /* If the database may grow as a result of this checkpoint, hint
+      ** about the eventual size of the db file to the VFS layer.
+      */
+      if( rc==SQLITE_OK ){
+        i64 nReq = ((i64)mxPage * szPage);
+        rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);
+        if( rc==SQLITE_OK && nSizepDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);
+        }
+      }
 
-    /* Iterate through the contents of the WAL, copying data to the db file. */
-    while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
-      i64 iOffset;
-      assert( walFramePgno(pWal, iFrame)==iDbpage );
-      if( iFrame<=nBackfill || iFrame>mxSafeFrame || iDbpage>mxPage ) continue;
-      iOffset = walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE;
-      /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL file */
-      rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);
-      if( rc!=SQLITE_OK ) break;
-      iOffset = (iDbpage-1)*(i64)szPage;
-      testcase( IS_BIG_INT(iOffset) );
-      rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);
-      if( rc!=SQLITE_OK ) break;
-    }
 
-    /* If work was actually accomplished... */
-    if( rc==SQLITE_OK ){
-      if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){
-        i64 szDb = pWal->hdr.nPage*(i64)szPage;
-        testcase( IS_BIG_INT(szDb) );
-        rc = sqlite3OsTruncate(pWal->pDbFd, szDb);
-        if( rc==SQLITE_OK && sync_flags ){
-          rc = sqlite3OsSync(pWal->pDbFd, sync_flags);
+      /* Iterate through the contents of the WAL, copying data to the db file */
+      while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
+        i64 iOffset;
+        assert( walFramePgno(pWal, iFrame)==iDbpage );
+        if( db->u1.isInterrupted ){
+          rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;
+          break;
+        }
+        if( iFrame<=nBackfill || iFrame>mxSafeFrame || iDbpage>mxPage ){
+          continue;
         }
+        iOffset = walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE;
+        /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL file */
+        rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);
+        if( rc!=SQLITE_OK ) break;
+        iOffset = (iDbpage-1)*(i64)szPage;
+        testcase( IS_BIG_INT(iOffset) );
+        rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);
+        if( rc!=SQLITE_OK ) break;
       }
+
+      /* If work was actually accomplished... */
       if( rc==SQLITE_OK ){
-        pInfo->nBackfill = mxSafeFrame;
+        if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){
+          i64 szDb = pWal->hdr.nPage*(i64)szPage;
+          testcase( IS_BIG_INT(szDb) );
+          rc = sqlite3OsTruncate(pWal->pDbFd, szDb);
+          if( rc==SQLITE_OK && sync_flags ){
+            rc = sqlite3OsSync(pWal->pDbFd, sync_flags);
+          }
+        }
+        if( rc==SQLITE_OK ){
+          pInfo->nBackfill = mxSafeFrame;
+        }
       }
-    }
 
-    /* Release the reader lock held while backfilling */
-    walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);
-  }
+      /* Release the reader lock held while backfilling */
+      walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);
+    }
 
-  if( rc==SQLITE_BUSY ){
-    /* Reset the return code so as not to report a checkpoint failure
-    ** just because there are active readers.  */
-    rc = SQLITE_OK;
+    if( rc==SQLITE_BUSY ){
+      /* Reset the return code so as not to report a checkpoint failure
+      ** just because there are active readers.  */
+      rc = SQLITE_OK;
+    }
   }
 
   /* If this is an SQLITE_CHECKPOINT_RESTART or TRUNCATE operation, and the
@@ -50323,7 +56876,7 @@ static int walCheckpoint(
     }else if( eMode>=SQLITE_CHECKPOINT_RESTART ){
       u32 salt1;
       sqlite3_randomness(4, &salt1);
-      assert( mxSafeFrame==pWal->hdr.mxFrame );
+      assert( pInfo->nBackfill==pWal->hdr.mxFrame );
       rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(1), WAL_NREADER-1);
       if( rc==SQLITE_OK ){
         if( eMode==SQLITE_CHECKPOINT_TRUNCATE ){
@@ -50376,6 +56929,7 @@ static void walLimitSize(Wal *pWal, i64 nMax){
 */
 SQLITE_PRIVATE int sqlite3WalClose(
   Wal *pWal,                      /* Wal to close */
+  sqlite3 *db,                    /* For interrupt flag */
   int sync_flags,                 /* Flags to pass to OsSync() (or 0) */
   int nBuf,
   u8 *zBuf                        /* Buffer of at least nBuf bytes */
@@ -50392,13 +56946,14 @@ SQLITE_PRIVATE int sqlite3WalClose(
     **
     ** The EXCLUSIVE lock is not released before returning.
     */
-    rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE);
-    if( rc==SQLITE_OK ){
+    if( zBuf!=0
+     && SQLITE_OK==(rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE))
+    ){
       if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
         pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
       }
-      rc = sqlite3WalCheckpoint(
-          pWal, SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
+      rc = sqlite3WalCheckpoint(pWal, db, 
+          SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
       );
       if( rc==SQLITE_OK ){
         int bPersist = -1;
@@ -50634,6 +57189,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   int mxI;                        /* Index of largest aReadMark[] value */
   int i;                          /* Loop counter */
   int rc = SQLITE_OK;             /* Return code  */
+  u32 mxFrame;                    /* Wal frame to lock to */
 
   assert( pWal->readLock<0 );     /* Not currently locked */
 
@@ -50697,7 +57253,12 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   }
 
   pInfo = walCkptInfo(pWal);
-  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame ){
+  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0
+     || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr)))
+#endif
+  ){
     /* The WAL has been completely backfilled (or it is empty).
     ** and can be safely ignored.
     */
@@ -50735,73 +57296,169 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   */
   mxReadMark = 0;
   mxI = 0;
+  mxFrame = pWal->hdr.mxFrame;
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  if( pWal->pSnapshot && pWal->pSnapshot->mxFramepSnapshot->mxFrame;
+  }
+#endif
   for(i=1; iaReadMark[i];
-    if( mxReadMark<=thisMark && thisMark<=pWal->hdr.mxFrame ){
+    if( mxReadMark<=thisMark && thisMark<=mxFrame ){
       assert( thisMark!=READMARK_NOT_USED );
       mxReadMark = thisMark;
       mxI = i;
     }
   }
-  /* There was once an "if" here. The extra "{" is to preserve indentation. */
-  {
-    if( (pWal->readOnly & WAL_SHM_RDONLY)==0
-     && (mxReadMarkhdr.mxFrame || mxI==0)
-    ){
-      for(i=1; iaReadMark[i] = pWal->hdr.mxFrame;
-          mxI = i;
-          walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
-          break;
-        }else if( rc!=SQLITE_BUSY ){
-          return rc;
-        }
+  if( (pWal->readOnly & WAL_SHM_RDONLY)==0
+   && (mxReadMarkaReadMark[i] = mxFrame;
+        mxI = i;
+        walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
+        break;
+      }else if( rc!=SQLITE_BUSY ){
+        return rc;
       }
     }
-    if( mxI==0 ){
-      assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
-      return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
-    }
+  }
+  if( mxI==0 ){
+    assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
+    return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
+  }
 
-    rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
-    if( rc ){
-      return rc==SQLITE_BUSY ? WAL_RETRY : rc;
-    }
-    /* Now that the read-lock has been obtained, check that neither the
-    ** value in the aReadMark[] array or the contents of the wal-index
-    ** header have changed.
-    **
-    ** It is necessary to check that the wal-index header did not change
-    ** between the time it was read and when the shared-lock was obtained
-    ** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
-    ** that the log file may have been wrapped by a writer, or that frames
-    ** that occur later in the log than pWal->hdr.mxFrame may have been
-    ** copied into the database by a checkpointer. If either of these things
-    ** happened, then reading the database with the current value of
-    ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
-    ** instead.
-    **
-    ** This does not guarantee that the copy of the wal-index header is up to
-    ** date before proceeding. That would not be possible without somehow
-    ** blocking writers. It only guarantees that a dangerous checkpoint or 
-    ** log-wrap (either of which would require an exclusive lock on
-    ** WAL_READ_LOCK(mxI)) has not occurred since the snapshot was valid.
-    */
-    walShmBarrier(pWal);
-    if( pInfo->aReadMark[mxI]!=mxReadMark
-     || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
-    ){
-      walUnlockShared(pWal, WAL_READ_LOCK(mxI));
-      return WAL_RETRY;
-    }else{
-      assert( mxReadMark<=pWal->hdr.mxFrame );
-      pWal->readLock = (i16)mxI;
+  rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
+  if( rc ){
+    return rc==SQLITE_BUSY ? WAL_RETRY : rc;
+  }
+  /* Now that the read-lock has been obtained, check that neither the
+  ** value in the aReadMark[] array or the contents of the wal-index
+  ** header have changed.
+  **
+  ** It is necessary to check that the wal-index header did not change
+  ** between the time it was read and when the shared-lock was obtained
+  ** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
+  ** that the log file may have been wrapped by a writer, or that frames
+  ** that occur later in the log than pWal->hdr.mxFrame may have been
+  ** copied into the database by a checkpointer. If either of these things
+  ** happened, then reading the database with the current value of
+  ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
+  ** instead.
+  **
+  ** Before checking that the live wal-index header has not changed
+  ** since it was read, set Wal.minFrame to the first frame in the wal
+  ** file that has not yet been checkpointed. This client will not need
+  ** to read any frames earlier than minFrame from the wal file - they
+  ** can be safely read directly from the database file.
+  **
+  ** Because a ShmBarrier() call is made between taking the copy of 
+  ** nBackfill and checking that the wal-header in shared-memory still
+  ** matches the one cached in pWal->hdr, it is guaranteed that the 
+  ** checkpointer that set nBackfill was not working with a wal-index
+  ** header newer than that cached in pWal->hdr. If it were, that could
+  ** cause a problem. The checkpointer could omit to checkpoint
+  ** a version of page X that lies before pWal->minFrame (call that version
+  ** A) on the basis that there is a newer version (version B) of the same
+  ** page later in the wal file. But if version B happens to like past
+  ** frame pWal->hdr.mxFrame - then the client would incorrectly assume
+  ** that it can read version A from the database file. However, since
+  ** we can guarantee that the checkpointer that set nBackfill could not
+  ** see any pages past pWal->hdr.mxFrame, this problem does not come up.
+  */
+  pWal->minFrame = pInfo->nBackfill+1;
+  walShmBarrier(pWal);
+  if( pInfo->aReadMark[mxI]!=mxReadMark
+   || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
+  ){
+    walUnlockShared(pWal, WAL_READ_LOCK(mxI));
+    return WAL_RETRY;
+  }else{
+    assert( mxReadMark<=pWal->hdr.mxFrame );
+    pWal->readLock = (i16)mxI;
+  }
+  return rc;
+}
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/*
+** Attempt to reduce the value of the WalCkptInfo.nBackfillAttempted 
+** variable so that older snapshots can be accessed. To do this, loop
+** through all wal frames from nBackfillAttempted to (nBackfill+1), 
+** comparing their content to the corresponding page with the database
+** file, if any. Set nBackfillAttempted to the frame number of the
+** first frame for which the wal file content matches the db file.
+**
+** This is only really safe if the file-system is such that any page 
+** writes made by earlier checkpointers were atomic operations, which 
+** is not always true. It is also possible that nBackfillAttempted
+** may be left set to a value larger than expected, if a wal frame
+** contains content that duplicate of an earlier version of the same
+** page.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code if an
+** error occurs. It is not an error if nBackfillAttempted cannot be
+** decreased at all.
+*/
+SQLITE_PRIVATE int sqlite3WalSnapshotRecover(Wal *pWal){
+  int rc;
+
+  assert( pWal->readLock>=0 );
+  rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
+  if( rc==SQLITE_OK ){
+    volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
+    int szPage = (int)pWal->szPage;
+    i64 szDb;                   /* Size of db file in bytes */
+
+    rc = sqlite3OsFileSize(pWal->pDbFd, &szDb);
+    if( rc==SQLITE_OK ){
+      void *pBuf1 = sqlite3_malloc(szPage);
+      void *pBuf2 = sqlite3_malloc(szPage);
+      if( pBuf1==0 || pBuf2==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        u32 i = pInfo->nBackfillAttempted;
+        for(i=pInfo->nBackfillAttempted; i>pInfo->nBackfill; i--){
+          volatile ht_slot *dummy;
+          volatile u32 *aPgno;      /* Array of page numbers */
+          u32 iZero;                /* Frame corresponding to aPgno[0] */
+          u32 pgno;                 /* Page number in db file */
+          i64 iDbOff;               /* Offset of db file entry */
+          i64 iWalOff;              /* Offset of wal file entry */
+
+          rc = walHashGet(pWal, walFramePage(i), &dummy, &aPgno, &iZero);
+          if( rc!=SQLITE_OK ) break;
+          pgno = aPgno[i-iZero];
+          iDbOff = (i64)(pgno-1) * szPage;
+
+          if( iDbOff+szPage<=szDb ){
+            iWalOff = walFrameOffset(i, szPage) + WAL_FRAME_HDRSIZE;
+            rc = sqlite3OsRead(pWal->pWalFd, pBuf1, szPage, iWalOff);
+
+            if( rc==SQLITE_OK ){
+              rc = sqlite3OsRead(pWal->pDbFd, pBuf2, szPage, iDbOff);
+            }
+
+            if( rc!=SQLITE_OK || 0==memcmp(pBuf1, pBuf2, szPage) ){
+              break;
+            }
+          }
+
+          pInfo->nBackfillAttempted = i-1;
+        }
+      }
+
+      sqlite3_free(pBuf1);
+      sqlite3_free(pBuf2);
     }
+    walUnlockExclusive(pWal, WAL_CKPT_LOCK, 1);
   }
+
   return rc;
 }
+#endif /* SQLITE_ENABLE_SNAPSHOT */
 
 /*
 ** Begin a read transaction on the database.
@@ -50821,6 +57478,14 @@ SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
   int rc;                         /* Return code */
   int cnt = 0;                    /* Number of TryBeginRead attempts */
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  int bChanged = 0;
+  WalIndexHdr *pSnapshot = pWal->pSnapshot;
+  if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){
+    bChanged = 1;
+  }
+#endif
+
   do{
     rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);
   }while( rc==WAL_RETRY );
@@ -50828,6 +57493,70 @@ SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
   testcase( (rc&0xff)==SQLITE_IOERR );
   testcase( rc==SQLITE_PROTOCOL );
   testcase( rc==SQLITE_OK );
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  if( rc==SQLITE_OK ){
+    if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){
+      /* At this point the client has a lock on an aReadMark[] slot holding
+      ** a value equal to or smaller than pSnapshot->mxFrame, but pWal->hdr
+      ** is populated with the wal-index header corresponding to the head
+      ** of the wal file. Verify that pSnapshot is still valid before
+      ** continuing.  Reasons why pSnapshot might no longer be valid:
+      **
+      **    (1)  The WAL file has been reset since the snapshot was taken.
+      **         In this case, the salt will have changed.
+      **
+      **    (2)  A checkpoint as been attempted that wrote frames past
+      **         pSnapshot->mxFrame into the database file.  Note that the
+      **         checkpoint need not have completed for this to cause problems.
+      */
+      volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
+
+      assert( pWal->readLock>0 || pWal->hdr.mxFrame==0 );
+      assert( pInfo->aReadMark[pWal->readLock]<=pSnapshot->mxFrame );
+
+      /* It is possible that there is a checkpointer thread running 
+      ** concurrent with this code. If this is the case, it may be that the
+      ** checkpointer has already determined that it will checkpoint 
+      ** snapshot X, where X is later in the wal file than pSnapshot, but 
+      ** has not yet set the pInfo->nBackfillAttempted variable to indicate 
+      ** its intent. To avoid the race condition this leads to, ensure that
+      ** there is no checkpointer process by taking a shared CKPT lock 
+      ** before checking pInfo->nBackfillAttempted.  
+      **
+      ** TODO: Does the aReadMark[] lock prevent a checkpointer from doing
+      **       this already?
+      */
+      rc = walLockShared(pWal, WAL_CKPT_LOCK);
+
+      if( rc==SQLITE_OK ){
+        /* Check that the wal file has not been wrapped. Assuming that it has
+        ** not, also check that no checkpointer has attempted to checkpoint any
+        ** frames beyond pSnapshot->mxFrame. If either of these conditions are
+        ** true, return SQLITE_BUSY_SNAPSHOT. Otherwise, overwrite pWal->hdr
+        ** with *pSnapshot and set *pChanged as appropriate for opening the
+        ** snapshot.  */
+        if( !memcmp(pSnapshot->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))
+         && pSnapshot->mxFrame>=pInfo->nBackfillAttempted
+        ){
+          assert( pWal->readLock>0 );
+          memcpy(&pWal->hdr, pSnapshot, sizeof(WalIndexHdr));
+          *pChanged = bChanged;
+        }else{
+          rc = SQLITE_BUSY_SNAPSHOT;
+        }
+
+        /* Release the shared CKPT lock obtained above. */
+        walUnlockShared(pWal, WAL_CKPT_LOCK);
+      }
+
+
+      if( rc!=SQLITE_OK ){
+        sqlite3WalEndReadTransaction(pWal);
+      }
+    }
+  }
+#endif
   return rc;
 }
 
@@ -50859,6 +57588,7 @@ SQLITE_PRIVATE int sqlite3WalFindFrame(
   u32 iRead = 0;                  /* If !=0, WAL frame to return data from */
   u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */
   int iHash;                      /* Used to loop through N hash tables */
+  int iMinHash;
 
   /* This routine is only be called from within a read transaction. */
   assert( pWal->readLock>=0 || pWal->lockError );
@@ -50899,7 +57629,8 @@ SQLITE_PRIVATE int sqlite3WalFindFrame(
   **     This condition filters out entries that were added to the hash
   **     table after the current read-transaction had started.
   */
-  for(iHash=walFramePage(iLast); iHash>=0 && iRead==0; iHash--){
+  iMinHash = walFramePage(pWal->minFrame);
+  for(iHash=walFramePage(iLast); iHash>=iMinHash && iRead==0; iHash--){
     volatile ht_slot *aHash;      /* Pointer to hash table */
     volatile u32 *aPgno;          /* Pointer to array of page numbers */
     u32 iZero;                    /* Frame number corresponding to aPgno[0] */
@@ -50914,7 +57645,7 @@ SQLITE_PRIVATE int sqlite3WalFindFrame(
     nCollide = HASHTABLE_NSLOT;
     for(iKey=walHash(pgno); aHash[iKey]; iKey=walNextHash(iKey)){
       u32 iFrame = aHash[iKey] + iZero;
-      if( iFrame<=iLast && aPgno[aHash[iKey]]==pgno ){
+      if( iFrame<=iLast && iFrame>=pWal->minFrame && aPgno[aHash[iKey]]==pgno ){
         assert( iFrame>iRead || CORRUPT_DB );
         iRead = iFrame;
       }
@@ -50931,7 +57662,8 @@ SQLITE_PRIVATE int sqlite3WalFindFrame(
   {
     u32 iRead2 = 0;
     u32 iTest;
-    for(iTest=iLast; iTest>0; iTest--){
+    assert( pWal->minFrame>0 );
+    for(iTest=iLast; iTest>=pWal->minFrame; iTest--){
       if( walFramePgno(pWal, iTest)==pgno ){
         iRead2 = iTest;
         break;
@@ -50997,6 +57729,7 @@ SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal){
   /* Cannot start a write transaction without first holding a read
   ** transaction. */
   assert( pWal->readLock>=0 );
+  assert( pWal->writeLock==0 && pWal->iReCksum==0 );
 
   if( pWal->readOnly ){
     return SQLITE_READONLY;
@@ -51032,6 +57765,7 @@ SQLITE_PRIVATE int sqlite3WalEndWriteTransaction(Wal *pWal){
   if( pWal->writeLock ){
     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
     pWal->writeLock = 0;
+    pWal->iReCksum = 0;
     pWal->truncateOnCommit = 0;
   }
   return SQLITE_OK;
@@ -51238,7 +57972,7 @@ static int walWriteOneFrame(
   void *pData;                    /* Data actually written */
   u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
 #if defined(SQLITE_HAS_CODEC)
-  if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM;
+  if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM_BKPT;
 #else
   pData = pPage->pData;
 #endif
@@ -51250,6 +57984,59 @@ static int walWriteOneFrame(
   return rc;
 }
 
+/*
+** This function is called as part of committing a transaction within which
+** one or more frames have been overwritten. It updates the checksums for
+** all frames written to the wal file by the current transaction starting
+** with the earliest to have been overwritten.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+static int walRewriteChecksums(Wal *pWal, u32 iLast){
+  const int szPage = pWal->szPage;/* Database page size */
+  int rc = SQLITE_OK;             /* Return code */
+  u8 *aBuf;                       /* Buffer to load data from wal file into */
+  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-headers in */
+  u32 iRead;                      /* Next frame to read from wal file */
+  i64 iCksumOff;
+
+  aBuf = sqlite3_malloc(szPage + WAL_FRAME_HDRSIZE);
+  if( aBuf==0 ) return SQLITE_NOMEM_BKPT;
+
+  /* Find the checksum values to use as input for the recalculating the
+  ** first checksum. If the first frame is frame 1 (implying that the current
+  ** transaction restarted the wal file), these values must be read from the
+  ** wal-file header. Otherwise, read them from the frame header of the
+  ** previous frame.  */
+  assert( pWal->iReCksum>0 );
+  if( pWal->iReCksum==1 ){
+    iCksumOff = 24;
+  }else{
+    iCksumOff = walFrameOffset(pWal->iReCksum-1, szPage) + 16;
+  }
+  rc = sqlite3OsRead(pWal->pWalFd, aBuf, sizeof(u32)*2, iCksumOff);
+  pWal->hdr.aFrameCksum[0] = sqlite3Get4byte(aBuf);
+  pWal->hdr.aFrameCksum[1] = sqlite3Get4byte(&aBuf[sizeof(u32)]);
+
+  iRead = pWal->iReCksum;
+  pWal->iReCksum = 0;
+  for(; rc==SQLITE_OK && iRead<=iLast; iRead++){
+    i64 iOff = walFrameOffset(iRead, szPage);
+    rc = sqlite3OsRead(pWal->pWalFd, aBuf, szPage+WAL_FRAME_HDRSIZE, iOff);
+    if( rc==SQLITE_OK ){
+      u32 iPgno, nDbSize;
+      iPgno = sqlite3Get4byte(aBuf);
+      nDbSize = sqlite3Get4byte(&aBuf[4]);
+
+      walEncodeFrame(pWal, iPgno, nDbSize, &aBuf[WAL_FRAME_HDRSIZE], aFrame);
+      rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOff);
+    }
+  }
+
+  sqlite3_free(aBuf);
+  return rc;
+}
+
 /* 
 ** Write a set of frames to the log. The caller must hold the write-lock
 ** on the log file (obtained using sqlite3WalBeginWriteTransaction()).
@@ -51270,6 +58057,8 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   int szFrame;                    /* The size of a single frame */
   i64 iOffset;                    /* Next byte to write in WAL file */
   WalWriter w;                    /* The writer */
+  u32 iFirst = 0;                 /* First frame that may be overwritten */
+  WalIndexHdr *pLive;             /* Pointer to shared header */
 
   assert( pList );
   assert( pWal->writeLock );
@@ -51285,6 +58074,11 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   }
 #endif
 
+  pLive = (WalIndexHdr*)walIndexHdr(pWal);
+  if( memcmp(&pWal->hdr, (void *)pLive, sizeof(WalIndexHdr))!=0 ){
+    iFirst = pLive->mxFrame+1;
+  }
+
   /* See if it is possible to write these frames into the start of the
   ** log file, instead of appending to it at pWal->hdr.mxFrame.
   */
@@ -51349,6 +58143,33 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   /* Write all frames into the log file exactly once */
   for(p=pList; p; p=p->pDirty){
     int nDbSize;   /* 0 normally.  Positive == commit flag */
+
+    /* Check if this page has already been written into the wal file by
+    ** the current transaction. If so, overwrite the existing frame and
+    ** set Wal.writeLock to WAL_WRITELOCK_RECKSUM - indicating that 
+    ** checksums must be recomputed when the transaction is committed.  */
+    if( iFirst && (p->pDirty || isCommit==0) ){
+      u32 iWrite = 0;
+      VVA_ONLY(rc =) sqlite3WalFindFrame(pWal, p->pgno, &iWrite);
+      assert( rc==SQLITE_OK || iWrite==0 );
+      if( iWrite>=iFirst ){
+        i64 iOff = walFrameOffset(iWrite, szPage) + WAL_FRAME_HDRSIZE;
+        void *pData;
+        if( pWal->iReCksum==0 || iWriteiReCksum ){
+          pWal->iReCksum = iWrite;
+        }
+#if defined(SQLITE_HAS_CODEC)
+        if( (pData = sqlite3PagerCodec(p))==0 ) return SQLITE_NOMEM;
+#else
+        pData = p->pData;
+#endif
+        rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOff);
+        if( rc ) return rc;
+        p->flags &= ~PGHDR_WAL_APPEND;
+        continue;
+      }
+    }
+
     iFrame++;
     assert( iOffset==walFrameOffset(iFrame, szPage) );
     nDbSize = (isCommit && p->pDirty==0) ? nTruncate : 0;
@@ -51356,6 +58177,13 @@ SQLITE_PRIVATE int sqlite3WalFrames(
     if( rc ) return rc;
     pLast = p;
     iOffset += szFrame;
+    p->flags |= PGHDR_WAL_APPEND;
+  }
+
+  /* Recalculate checksums within the wal file if required. */
+  if( isCommit && pWal->iReCksum ){
+    rc = walRewriteChecksums(pWal, iFrame);
+    if( rc ) return rc;
   }
 
   /* If this is the end of a transaction, then we might need to pad
@@ -51373,16 +58201,21 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   ** past the sector boundary is written after the sync.
   */
   if( isCommit && (sync_flags & WAL_SYNC_TRANSACTIONS)!=0 ){
+    int bSync = 1;
     if( pWal->padToSectorBoundary ){
       int sectorSize = sqlite3SectorSize(pWal->pWalFd);
       w.iSyncPoint = ((iOffset+sectorSize-1)/sectorSize)*sectorSize;
+      bSync = (w.iSyncPoint==iOffset);
+      testcase( bSync );
       while( iOffsethdr.mxFrame;
   for(p=pList; p && rc==SQLITE_OK; p=p->pDirty){
+    if( (p->flags & PGHDR_WAL_APPEND)==0 ) continue;
     iFrame++;
     rc = walIndexAppend(pWal, iFrame, p->pgno);
   }
@@ -51449,6 +58283,7 @@ SQLITE_PRIVATE int sqlite3WalFrames(
 */
 SQLITE_PRIVATE int sqlite3WalCheckpoint(
   Wal *pWal,                      /* Wal connection */
+  sqlite3 *db,                    /* Check this handle's interrupt flag */
   int eMode,                      /* PASSIVE, FULL, RESTART, or TRUNCATE */
   int (*xBusy)(void*),            /* Function to call when busy */
   void *pBusyArg,                 /* Context argument for xBusyHandler */
@@ -51519,10 +58354,11 @@ SQLITE_PRIVATE int sqlite3WalCheckpoint(
 
   /* Copy data from the log to the database file. */
   if( rc==SQLITE_OK ){
+
     if( pWal->hdr.mxFrame && walPagesize(pWal)!=nBuf ){
       rc = SQLITE_CORRUPT_BKPT;
     }else{
-      rc = walCheckpoint(pWal, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);
+      rc = walCheckpoint(pWal, db, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);
     }
 
     /* If no error occurred, set the output variables. */
@@ -51634,6 +58470,57 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
   return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );
 }
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/* Create a snapshot object.  The content of a snapshot is opaque to
+** every other subsystem, so the WAL module can put whatever it needs
+** in the object.
+*/
+SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot){
+  int rc = SQLITE_OK;
+  WalIndexHdr *pRet;
+  static const u32 aZero[4] = { 0, 0, 0, 0 };
+
+  assert( pWal->readLock>=0 && pWal->writeLock==0 );
+
+  if( memcmp(&pWal->hdr.aFrameCksum[0],aZero,16)==0 ){
+    *ppSnapshot = 0;
+    return SQLITE_ERROR;
+  }
+  pRet = (WalIndexHdr*)sqlite3_malloc(sizeof(WalIndexHdr));
+  if( pRet==0 ){
+    rc = SQLITE_NOMEM_BKPT;
+  }else{
+    memcpy(pRet, &pWal->hdr, sizeof(WalIndexHdr));
+    *ppSnapshot = (sqlite3_snapshot*)pRet;
+  }
+
+  return rc;
+}
+
+/* Try to open on pSnapshot when the next read-transaction starts
+*/
+SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot){
+  pWal->pSnapshot = (WalIndexHdr*)pSnapshot;
+}
+
+/* 
+** Return a +ve value if snapshot p1 is newer than p2. A -ve value if
+** p1 is older than p2 and zero if p1 and p2 are the same snapshot.
+*/
+SQLITE_API int sqlite3_snapshot_cmp(sqlite3_snapshot *p1, sqlite3_snapshot *p2){
+  WalIndexHdr *pHdr1 = (WalIndexHdr*)p1;
+  WalIndexHdr *pHdr2 = (WalIndexHdr*)p2;
+
+  /* aSalt[0] is a copy of the value stored in the wal file header. It
+  ** is incremented each time the wal file is restarted.  */
+  if( pHdr1->aSalt[0]aSalt[0] ) return -1;
+  if( pHdr1->aSalt[0]>pHdr2->aSalt[0] ) return +1;
+  if( pHdr1->mxFramemxFrame ) return -1;
+  if( pHdr1->mxFrame>pHdr2->mxFrame ) return +1;
+  return 0;
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
+
 #ifdef SQLITE_ENABLE_ZIPVFS
 /*
 ** If the argument is not NULL, it points to a Wal object that holds a
@@ -51646,6 +58533,12 @@ SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal){
 }
 #endif
 
+/* Return the sqlite3_file object for the WAL file
+*/
+SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal){
+  return pWal->pWalFd;
+}
+
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
 /************** End of wal.c *************************************************/
@@ -51884,6 +58777,7 @@ SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal){
 **      4     Number of leaf pointers on this page
 **      *     zero or more pages numbers of leaves
 */
+/* #include "sqliteInt.h" */
 
 
 /* The following value is the maximum cell size assuming a maximum page
@@ -51901,6 +58795,7 @@ SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal){
 /* Forward declarations */
 typedef struct MemPage MemPage;
 typedef struct BtLock BtLock;
+typedef struct CellInfo CellInfo;
 
 /*
 ** This is a magic string that appears at the beginning of every
@@ -51928,52 +58823,49 @@ typedef struct BtLock BtLock;
 #define PTF_LEAF      0x08
 
 /*
-** As each page of the file is loaded into memory, an instance of the following
-** structure is appended and initialized to zero.  This structure stores
-** information about the page that is decoded from the raw file page.
+** An instance of this object stores information about each a single database
+** page that has been loaded into memory.  The information in this object
+** is derived from the raw on-disk page content.
 **
-** The pParent field points back to the parent page.  This allows us to
-** walk up the BTree from any leaf to the root.  Care must be taken to
-** unref() the parent page pointer when this page is no longer referenced.
-** The pageDestructor() routine handles that chore.
+** As each database page is loaded into memory, the pager allocats an
+** instance of this object and zeros the first 8 bytes.  (This is the
+** "extra" information associated with each page of the pager.)
 **
 ** Access to all fields of this structure is controlled by the mutex
 ** stored in MemPage.pBt->mutex.
 */
 struct MemPage {
   u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
-  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
+  u8 bBusy;            /* Prevent endless loops on corrupt database files */
   u8 intKey;           /* True if table b-trees.  False for index b-trees */
   u8 intKeyLeaf;       /* True if the leaf of an intKey table */
-  u8 noPayload;        /* True if internal intKey page (thus w/o data) */
+  Pgno pgno;           /* Page number for this page */
+  /* Only the first 8 bytes (above) are zeroed by pager.c when a new page
+  ** is allocated. All fields that follow must be initialized before use */
   u8 leaf;             /* True if a leaf page */
   u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
   u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
   u8 max1bytePayload;  /* min(maxLocal,127) */
+  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
   u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
   u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
   u16 cellOffset;      /* Index in aData of first cell pointer */
   u16 nFree;           /* Number of free bytes on the page */
   u16 nCell;           /* Number of cells on this page, local and ovfl */
   u16 maskPage;        /* Mask for page offset */
-  u16 aiOvfl[5];       /* Insert the i-th overflow cell before the aiOvfl-th
+  u16 aiOvfl[4];       /* Insert the i-th overflow cell before the aiOvfl-th
                        ** non-overflow cell */
-  u8 *apOvfl[5];       /* Pointers to the body of overflow cells */
+  u8 *apOvfl[4];       /* Pointers to the body of overflow cells */
   BtShared *pBt;       /* Pointer to BtShared that this page is part of */
   u8 *aData;           /* Pointer to disk image of the page data */
   u8 *aDataEnd;        /* One byte past the end of usable data */
   u8 *aCellIdx;        /* The cell index area */
+  u8 *aDataOfst;       /* Same as aData for leaves.  aData+4 for interior */
   DbPage *pDbPage;     /* Pager page handle */
-  Pgno pgno;           /* Page number for this page */
+  u16 (*xCellSize)(MemPage*,u8*);             /* cellSizePtr method */
+  void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */
 };
 
-/*
-** The in-memory image of a disk page has the auxiliary information appended
-** to the end.  EXTRA_SIZE is the number of bytes of space needed to hold
-** that extra information.
-*/
-#define EXTRA_SIZE sizeof(MemPage)
-
 /*
 ** A linked list of the following structures is stored at BtShared.pLock.
 ** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor 
@@ -52019,6 +58911,7 @@ struct Btree {
   u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
   u8 sharable;       /* True if we can share pBt with another db */
   u8 locked;         /* True if db currently has pBt locked */
+  u8 hasIncrblobCur; /* True if there are one or more Incrblob cursors */
   int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
   int nBackup;       /* Number of backup operations reading this btree */
   u32 iDataVersion;  /* Combines with pBt->pPager->iDataVersion */
@@ -52088,6 +58981,9 @@ struct BtShared {
 #endif
   u8 inTransaction;     /* Transaction state */
   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
+#ifdef SQLITE_HAS_CODEC
+  u8 optimalReserve;    /* Desired amount of reserved space per page */
+#endif
   u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
@@ -52116,23 +59012,23 @@ struct BtShared {
 #define BTS_READ_ONLY        0x0001   /* Underlying file is readonly */
 #define BTS_PAGESIZE_FIXED   0x0002   /* Page size can no longer be changed */
 #define BTS_SECURE_DELETE    0x0004   /* PRAGMA secure_delete is enabled */
-#define BTS_INITIALLY_EMPTY  0x0008   /* Database was empty at trans start */
-#define BTS_NO_WAL           0x0010   /* Do not open write-ahead-log files */
-#define BTS_EXCLUSIVE        0x0020   /* pWriter has an exclusive lock */
-#define BTS_PENDING          0x0040   /* Waiting for read-locks to clear */
+#define BTS_OVERWRITE        0x0008   /* Overwrite deleted content with zeros */
+#define BTS_FAST_SECURE      0x000c   /* Combination of the previous two */
+#define BTS_INITIALLY_EMPTY  0x0010   /* Database was empty at trans start */
+#define BTS_NO_WAL           0x0020   /* Do not open write-ahead-log files */
+#define BTS_EXCLUSIVE        0x0040   /* pWriter has an exclusive lock */
+#define BTS_PENDING          0x0080   /* Waiting for read-locks to clear */
 
 /*
 ** An instance of the following structure is used to hold information
 ** about a cell.  The parseCellPtr() function fills in this structure
 ** based on information extract from the raw disk page.
 */
-typedef struct CellInfo CellInfo;
 struct CellInfo {
   i64 nKey;      /* The key for INTKEY tables, or nPayload otherwise */
   u8 *pPayload;  /* Pointer to the start of payload */
   u32 nPayload;  /* Bytes of payload */
   u16 nLocal;    /* Amount of payload held locally, not on overflow */
-  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
   u16 nSize;     /* Size of the cell content on the main b-tree page */
 };
 
@@ -52169,8 +59065,7 @@ struct CellInfo {
 struct BtCursor {
   Btree *pBtree;            /* The Btree to which this cursor belongs */
   BtShared *pBt;            /* The BtShared this cursor points to */
-  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
-  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
+  BtCursor *pNext;          /* Forms a linked list of all cursors */
   Pgno *aOverflow;          /* Cache of overflow page locations */
   CellInfo info;            /* A parse of the cell we are pointing at */
   i64 nKey;                 /* Size of pKey, or last integer key */
@@ -52180,11 +59075,18 @@ struct BtCursor {
   int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.
                    ** Error code if eState==CURSOR_FAULT */
   u8 curFlags;              /* zero or more BTCF_* flags defined below */
+  u8 curPagerFlags;         /* Flags to send to sqlite3PagerGet() */
   u8 eState;                /* One of the CURSOR_XXX constants (see below) */
-  u8 hints;                             /* As configured by CursorSetHints() */
-  i16 iPage;                            /* Index of current page in apPage */
-  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
-  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
+  u8 hints;                 /* As configured by CursorSetHints() */
+  /* All fields above are zeroed when the cursor is allocated.  See
+  ** sqlite3BtreeCursorZero().  Fields that follow must be manually
+  ** initialized. */
+  i8 iPage;                 /* Index of current page in apPage */
+  u8 curIntKey;             /* Value of apPage[0]->intKey */
+  u16 ix;                   /* Current index for apPage[iPage] */
+  u16 aiIdx[BTCURSOR_MAX_DEPTH-1];     /* Current index in apPage[i] */
+  struct KeyInfo *pKeyInfo;            /* Arg passed to comparison function */
+  MemPage *apPage[BTCURSOR_MAX_DEPTH]; /* Pages from root to current page */
 };
 
 /*
@@ -52195,6 +59097,7 @@ struct BtCursor {
 #define BTCF_ValidOvfl    0x04   /* True if aOverflow is valid */
 #define BTCF_AtLast       0x08   /* Cursor is pointing ot the last entry */
 #define BTCF_Incrblob     0x10   /* True if an incremental I/O handle */
+#define BTCF_Multiple     0x20   /* Maybe another cursor on the same btree */
 
 /*
 ** Potential values for BtCursor.eState.
@@ -52337,6 +59240,7 @@ struct IntegrityCk {
   const char *zPfx; /* Error message prefix */
   int v1, v2;       /* Values for up to two %d fields in zPfx */
   StrAccum errMsg;  /* Accumulate the error message text here */
+  u32 *heap;        /* Min-heap used for analyzing cell coverage */
 };
 
 /*
@@ -52347,6 +59251,21 @@ struct IntegrityCk {
 #define get4byte sqlite3Get4byte
 #define put4byte sqlite3Put4byte
 
+/*
+** get2byteAligned(), unlike get2byte(), requires that its argument point to a
+** two-byte aligned address.  get2bytea() is only used for accessing the
+** cell addresses in a btree header.
+*/
+#if SQLITE_BYTEORDER==4321
+# define get2byteAligned(x)  (*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4008000
+# define get2byteAligned(x)  __builtin_bswap16(*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+# define get2byteAligned(x)  _byteswap_ushort(*(u16*)(x))
+#else
+# define get2byteAligned(x)  ((x)[0]<<8 | (x)[1])
+#endif
+
 /************** End of btreeInt.h ********************************************/
 /************** Continuing where we left off in btmutex.c ********************/
 #ifndef SQLITE_OMIT_SHARED_CACHE
@@ -52474,6 +59393,7 @@ static void SQLITE_NOINLINE btreeLockCarefully(Btree *p){
 ** Exit the recursive mutex on a Btree.
 */
 SQLITE_PRIVATE void sqlite3BtreeLeave(Btree *p){
+  assert( sqlite3_mutex_held(p->db->mutex) );
   if( p->sharable ){
     assert( p->wantToLock>0 );
     p->wantToLock--;
@@ -52501,21 +59421,6 @@ SQLITE_PRIVATE int sqlite3BtreeHoldsMutex(Btree *p){
 #endif
 
 
-#ifndef SQLITE_OMIT_INCRBLOB
-/*
-** Enter and leave a mutex on a Btree given a cursor owned by that
-** Btree.  These entry points are used by incremental I/O and can be
-** omitted if that module is not used.
-*/
-SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
-  sqlite3BtreeEnter(pCur->pBtree);
-}
-SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
-  sqlite3BtreeLeave(pCur->pBtree);
-}
-#endif /* SQLITE_OMIT_INCRBLOB */
-
-
 /*
 ** Enter the mutex on every Btree associated with a database
 ** connection.  This is needed (for example) prior to parsing
@@ -52530,16 +59435,24 @@ SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
 ** two or more btrees in common both try to lock all their btrees
 ** at the same instant.
 */
-SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
+static void SQLITE_NOINLINE btreeEnterAll(sqlite3 *db){
   int i;
+  int skipOk = 1;
   Btree *p;
   assert( sqlite3_mutex_held(db->mutex) );
   for(i=0; inDb; i++){
     p = db->aDb[i].pBt;
-    if( p ) sqlite3BtreeEnter(p);
+    if( p && p->sharable ){
+      sqlite3BtreeEnter(p);
+      skipOk = 0;
+    }
   }
+  db->skipBtreeMutex = skipOk;
 }
-SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){
+SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
+  if( db->skipBtreeMutex==0 ) btreeEnterAll(db);
+}
+static void SQLITE_NOINLINE btreeLeaveAll(sqlite3 *db){
   int i;
   Btree *p;
   assert( sqlite3_mutex_held(db->mutex) );
@@ -52548,13 +59461,8 @@ SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){
     if( p ) sqlite3BtreeLeave(p);
   }
 }
-
-/*
-** Return true if a particular Btree requires a lock.  Return FALSE if
-** no lock is ever required since it is not sharable.
-*/
-SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
-  return p->sharable;
+SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){
+  if( db->skipBtreeMutex==0 ) btreeLeaveAll(db);
 }
 
 #ifndef NDEBUG
@@ -52630,6 +59538,25 @@ SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
   }
 }
 #endif /* if SQLITE_THREADSAFE */
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Enter a mutex on a Btree given a cursor owned by that Btree. 
+**
+** These entry points are used by incremental I/O only. Enter() is required 
+** any time OMIT_SHARED_CACHE is not defined, regardless of whether or not 
+** the build is threadsafe. Leave() is only required by threadsafe builds.
+*/
+SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
+  sqlite3BtreeEnter(pCur->pBtree);
+}
+# if SQLITE_THREADSAFE
+SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
+  sqlite3BtreeLeave(pCur->pBtree);
+}
+# endif
+#endif /* ifndef SQLITE_OMIT_INCRBLOB */
+
 #endif /* ifndef SQLITE_OMIT_SHARED_CACHE */
 
 /************** End of btmutex.c *********************************************/
@@ -52649,6 +59576,7 @@ SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
 ** See the header comment on "btreeInt.h" for additional information.
 ** Including a description of file format and an overview of operation.
 */
+/* #include "btreeInt.h" */
 
 /*
 ** The header string that appears at the beginning of every
@@ -52787,7 +59715,7 @@ static int hasSharedCacheTableLock(
   ** Return true immediately.
   */
   if( (pBtree->sharable==0)
-   || (eLockType==READ_LOCK && (pBtree->db->flags & SQLITE_ReadUncommitted))
+   || (eLockType==READ_LOCK && (pBtree->db->flags & SQLITE_ReadUncommit))
   ){
     return 1;
   }
@@ -52810,6 +59738,12 @@ static int hasSharedCacheTableLock(
     for(p=sqliteHashFirst(&pSchema->idxHash); p; p=sqliteHashNext(p)){
       Index *pIdx = (Index *)sqliteHashData(p);
       if( pIdx->tnum==(int)iRoot ){
+        if( iTab ){
+          /* Two or more indexes share the same root page.  There must
+          ** be imposter tables.  So just return true.  The assert is not
+          ** useful in that case. */
+          return 1;
+        }
         iTab = pIdx->pTable->tnum;
       }
     }
@@ -52858,7 +59792,7 @@ static int hasReadConflicts(Btree *pBtree, Pgno iRoot){
   for(p=pBtree->pBt->pCursor; p; p=p->pNext){
     if( p->pgnoRoot==iRoot 
      && p->pBtree!=pBtree
-     && 0==(p->pBtree->db->flags & SQLITE_ReadUncommitted)
+     && 0==(p->pBtree->db->flags & SQLITE_ReadUncommit)
     ){
       return 1;
     }
@@ -52880,7 +59814,7 @@ static int querySharedCacheTableLock(Btree *p, Pgno iTab, u8 eLock){
   assert( sqlite3BtreeHoldsMutex(p) );
   assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
   assert( p->db!=0 );
-  assert( !(p->db->flags&SQLITE_ReadUncommitted)||eLock==WRITE_LOCK||iTab==1 );
+  assert( !(p->db->flags&SQLITE_ReadUncommit)||eLock==WRITE_LOCK||iTab==1 );
   
   /* If requesting a write-lock, then the Btree must have an open write
   ** transaction on this file. And, obviously, for this to be so there 
@@ -52958,7 +59892,7 @@ static int setSharedCacheTableLock(Btree *p, Pgno iTable, u8 eLock){
   ** obtain a read-lock using this function. The only read-lock obtained
   ** by a connection in read-uncommitted mode is on the sqlite_master 
   ** table, and that lock is obtained in BtreeBeginTrans().  */
-  assert( 0==(p->db->flags&SQLITE_ReadUncommitted) || eLock==WRITE_LOCK );
+  assert( 0==(p->db->flags&SQLITE_ReadUncommit) || eLock==WRITE_LOCK );
 
   /* This function should only be called on a sharable b-tree after it 
   ** has been determined that no other b-tree holds a conflicting lock.  */
@@ -52979,7 +59913,7 @@ static int setSharedCacheTableLock(Btree *p, Pgno iTable, u8 eLock){
   if( !pLock ){
     pLock = (BtLock *)sqlite3MallocZero(sizeof(BtLock));
     if( !pLock ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pLock->iTable = iTable;
     pLock->pBtree = p;
@@ -53079,6 +60013,19 @@ static void releasePage(MemPage *pPage);  /* Forward reference */
 static int cursorHoldsMutex(BtCursor *p){
   return sqlite3_mutex_held(p->pBt->mutex);
 }
+
+/* Verify that the cursor and the BtShared agree about what is the current
+** database connetion. This is important in shared-cache mode. If the database 
+** connection pointers get out-of-sync, it is possible for routines like
+** btreeInitPage() to reference an stale connection pointer that references a
+** a connection that has already closed.  This routine is used inside assert()
+** statements only and for the purpose of double-checking that the btree code
+** does keep the database connection pointers up-to-date.
+*/
+static int cursorOwnsBtShared(BtCursor *p){
+  assert( cursorHoldsMutex(p) );
+  return (p->pBtree->db==p->pBt->db);
+}
 #endif
 
 /*
@@ -53115,24 +60062,27 @@ static void invalidateAllOverflowCache(BtShared *pBt){
 */
 static void invalidateIncrblobCursors(
   Btree *pBtree,          /* The database file to check */
+  Pgno pgnoRoot,          /* The table that might be changing */
   i64 iRow,               /* The rowid that might be changing */
   int isClearTable        /* True if all rows are being deleted */
 ){
   BtCursor *p;
-  BtShared *pBt = pBtree->pBt;
+  if( pBtree->hasIncrblobCur==0 ) return;
   assert( sqlite3BtreeHoldsMutex(pBtree) );
-  for(p=pBt->pCursor; p; p=p->pNext){
-    if( (p->curFlags & BTCF_Incrblob)!=0
-     && (isClearTable || p->info.nKey==iRow)
-    ){
-      p->eState = CURSOR_INVALID;
+  pBtree->hasIncrblobCur = 0;
+  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
+    if( (p->curFlags & BTCF_Incrblob)!=0 ){
+      pBtree->hasIncrblobCur = 1;
+      if( p->pgnoRoot==pgnoRoot && (isClearTable || p->info.nKey==iRow) ){
+        p->eState = CURSOR_INVALID;
+      }
     }
   }
 }
 
 #else
   /* Stub function when INCRBLOB is omitted */
-  #define invalidateIncrblobCursors(x,y,z)
+  #define invalidateIncrblobCursors(w,x,y,z)
 #endif /* SQLITE_OMIT_INCRBLOB */
 
 /*
@@ -53176,7 +60126,7 @@ static int btreeSetHasContent(BtShared *pBt, Pgno pgno){
     assert( pgno<=pBt->nPage );
     pBt->pHasContent = sqlite3BitvecCreate(pBt->nPage);
     if( !pBt->pHasContent ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
   if( rc==SQLITE_OK && pgno<=sqlite3BitvecSize(pBt->pHasContent) ){
@@ -53218,51 +60168,75 @@ static void btreeReleaseAllCursorPages(BtCursor *pCur){
   pCur->iPage = -1;
 }
 
-
 /*
-** Save the current cursor position in the variables BtCursor.nKey 
-** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+** The cursor passed as the only argument must point to a valid entry
+** when this function is called (i.e. have eState==CURSOR_VALID). This
+** function saves the current cursor key in variables pCur->nKey and
+** pCur->pKey. SQLITE_OK is returned if successful or an SQLite error 
+** code otherwise.
 **
-** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
-** prior to calling this routine.  
+** If the cursor is open on an intkey table, then the integer key
+** (the rowid) is stored in pCur->nKey and pCur->pKey is left set to
+** NULL. If the cursor is open on a non-intkey table, then pCur->pKey is 
+** set to point to a malloced buffer pCur->nKey bytes in size containing 
+** the key.
 */
-static int saveCursorPosition(BtCursor *pCur){
-  int rc;
-
+static int saveCursorKey(BtCursor *pCur){
+  int rc = SQLITE_OK;
   assert( CURSOR_VALID==pCur->eState );
   assert( 0==pCur->pKey );
   assert( cursorHoldsMutex(pCur) );
 
-  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
-  assert( rc==SQLITE_OK );  /* KeySize() cannot fail */
-
-  /* If this is an intKey table, then the above call to BtreeKeySize()
-  ** stores the integer key in pCur->nKey. In this case this value is
-  ** all that is required. Otherwise, if pCur is not open on an intKey
-  ** table, then malloc space for and store the pCur->nKey bytes of key 
-  ** data.
-  */
-  if( 0==pCur->apPage[0]->intKey ){
-    void *pKey = sqlite3Malloc( pCur->nKey );
+  if( pCur->curIntKey ){
+    /* Only the rowid is required for a table btree */
+    pCur->nKey = sqlite3BtreeIntegerKey(pCur);
+  }else{
+    /* For an index btree, save the complete key content */
+    void *pKey;
+    pCur->nKey = sqlite3BtreePayloadSize(pCur);
+    pKey = sqlite3Malloc( pCur->nKey );
     if( pKey ){
-      rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
+      rc = sqlite3BtreePayload(pCur, 0, (int)pCur->nKey, pKey);
       if( rc==SQLITE_OK ){
         pCur->pKey = pKey;
       }else{
         sqlite3_free(pKey);
       }
     }else{
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
-  assert( !pCur->apPage[0]->intKey || !pCur->pKey );
+  assert( !pCur->curIntKey || !pCur->pKey );
+  return rc;
+}
 
+/*
+** Save the current cursor position in the variables BtCursor.nKey 
+** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+**
+** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
+** prior to calling this routine.  
+*/
+static int saveCursorPosition(BtCursor *pCur){
+  int rc;
+
+  assert( CURSOR_VALID==pCur->eState || CURSOR_SKIPNEXT==pCur->eState );
+  assert( 0==pCur->pKey );
+  assert( cursorHoldsMutex(pCur) );
+
+  if( pCur->eState==CURSOR_SKIPNEXT ){
+    pCur->eState = CURSOR_VALID;
+  }else{
+    pCur->skipNext = 0;
+  }
+
+  rc = saveCursorKey(pCur);
   if( rc==SQLITE_OK ){
     btreeReleaseAllCursorPages(pCur);
     pCur->eState = CURSOR_REQUIRESEEK;
   }
 
-  invalidateOverflowCache(pCur);
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl|BTCF_AtLast);
   return rc;
 }
 
@@ -53277,6 +60251,15 @@ static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);
 ** routine is called just before cursor pExcept is used to modify the
 ** table, for example in BtreeDelete() or BtreeInsert().
 **
+** If there are two or more cursors on the same btree, then all such 
+** cursors should have their BTCF_Multiple flag set.  The btreeCursor()
+** routine enforces that rule.  This routine only needs to be called in
+** the uncommon case when pExpect has the BTCF_Multiple flag set.
+**
+** If pExpect!=NULL and if no other cursors are found on the same root-page,
+** then the BTCF_Multiple flag on pExpect is cleared, to avoid another
+** pointless call to this routine.
+**
 ** Implementation note:  This routine merely checks to see if any cursors
 ** need to be saved.  It calls out to saveCursorsOnList() in the (unusual)
 ** event that cursors are in need to being saved.
@@ -53288,7 +60271,9 @@ static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
   for(p=pBt->pCursor; p; p=p->pNext){
     if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ) break;
   }
-  return p ? saveCursorsOnList(p, iRoot, pExcept) : SQLITE_OK;
+  if( p ) return saveCursorsOnList(p, iRoot, pExcept);
+  if( pExcept ) pExcept->curFlags &= ~BTCF_Multiple;
+  return SQLITE_OK;
 }
 
 /* This helper routine to saveAllCursors does the actual work of saving
@@ -53303,7 +60288,7 @@ static int SQLITE_NOINLINE saveCursorsOnList(
 ){
   do{
     if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
-      if( p->eState==CURSOR_VALID ){
+      if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
         int rc = saveCursorPosition(p);
         if( SQLITE_OK!=rc ){
           return rc;
@@ -53342,26 +60327,23 @@ static int btreeMoveto(
 ){
   int rc;                    /* Status code */
   UnpackedRecord *pIdxKey;   /* Unpacked index key */
-  char aSpace[200];          /* Temp space for pIdxKey - to avoid a malloc */
-  char *pFree = 0;
 
   if( pKey ){
     assert( nKey==(i64)(int)nKey );
-    pIdxKey = sqlite3VdbeAllocUnpackedRecord(
-        pCur->pKeyInfo, aSpace, sizeof(aSpace), &pFree
-    );
-    if( pIdxKey==0 ) return SQLITE_NOMEM;
+    pIdxKey = sqlite3VdbeAllocUnpackedRecord(pCur->pKeyInfo);
+    if( pIdxKey==0 ) return SQLITE_NOMEM_BKPT;
     sqlite3VdbeRecordUnpack(pCur->pKeyInfo, (int)nKey, pKey, pIdxKey);
     if( pIdxKey->nField==0 ){
-      sqlite3DbFree(pCur->pKeyInfo->db, pFree);
-      return SQLITE_CORRUPT_BKPT;
+      rc = SQLITE_CORRUPT_PGNO(pCur->apPage[pCur->iPage]->pgno);
+      goto moveto_done;
     }
   }else{
     pIdxKey = 0;
   }
   rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
-  if( pFree ){
-    sqlite3DbFree(pCur->pKeyInfo->db, pFree);
+moveto_done:
+  if( pIdxKey ){
+    sqlite3DbFree(pCur->pKeyInfo->db, pIdxKey);
   }
   return rc;
 }
@@ -53375,17 +60357,19 @@ static int btreeMoveto(
 */
 static int btreeRestoreCursorPosition(BtCursor *pCur){
   int rc;
-  assert( cursorHoldsMutex(pCur) );
+  int skipNext;
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState>=CURSOR_REQUIRESEEK );
   if( pCur->eState==CURSOR_FAULT ){
     return pCur->skipNext;
   }
   pCur->eState = CURSOR_INVALID;
-  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
+  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);
   if( rc==SQLITE_OK ){
     sqlite3_free(pCur->pKey);
     pCur->pKey = 0;
     assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
+    pCur->skipNext |= skipNext;
     if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
       pCur->eState = CURSOR_SKIPNEXT;
     }
@@ -53437,14 +60421,35 @@ SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor *pCur, int *pDifferentRow)
     *pDifferentRow = 1;
     return rc;
   }
-  if( pCur->eState!=CURSOR_VALID || NEVER(pCur->skipNext!=0) ){
+  if( pCur->eState!=CURSOR_VALID ){
     *pDifferentRow = 1;
   }else{
+    assert( pCur->skipNext==0 );
     *pDifferentRow = 0;
   }
   return SQLITE_OK;
 }
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Provide hints to the cursor.  The particular hint given (and the type
+** and number of the varargs parameters) is determined by the eHintType
+** parameter.  See the definitions of the BTREE_HINT_* macros for details.
+*/
+SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor *pCur, int eHintType, ...){
+  /* Used only by system that substitute their own storage engine */
+}
+#endif
+
+/*
+** Provide flag hints to the cursor.
+*/
+SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor *pCur, unsigned x){
+  assert( x==BTREE_SEEK_EQ || x==BTREE_BULKLOAD || x==0 );
+  pCur->hints = x;
+}
+
+
 #ifndef SQLITE_OMIT_AUTOVACUUM
 /*
 ** Given a page number of a regular database page, return the page
@@ -53498,7 +60503,7 @@ static void ptrmapPut(BtShared *pBt, Pgno key, u8 eType, Pgno parent, int *pRC){
     return;
   }
   iPtrmap = PTRMAP_PAGENO(pBt, key);
-  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
   if( rc!=SQLITE_OK ){
     *pRC = rc;
     return;
@@ -53541,7 +60546,7 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
   assert( sqlite3_mutex_held(pBt->mutex) );
 
   iPtrmap = PTRMAP_PAGENO(pBt, key);
-  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
   if( rc!=0 ){
     return rc;
   }
@@ -53558,7 +60563,7 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
   if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);
 
   sqlite3PagerUnref(pDbPage);
-  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_BKPT;
+  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_PGNO(iPtrmap);
   return SQLITE_OK;
 }
 
@@ -53573,39 +60578,85 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
 ** the page, 1 means the second cell, and so forth) return a pointer
 ** to the cell content.
 **
+** findCellPastPtr() does the same except it skips past the initial
+** 4-byte child pointer found on interior pages, if there is one.
+**
 ** This routine works only for pages that do not contain overflow cells.
 */
 #define findCell(P,I) \
-  ((P)->aData + ((P)->maskPage & get2byte(&(P)->aCellIdx[2*(I)])))
-#define findCellv2(D,M,O,I) (D+(M&get2byte(D+(O+2*(I)))))
+  ((P)->aData + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
+#define findCellPastPtr(P,I) \
+  ((P)->aDataOfst + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
 
 
 /*
-** This a more complex version of findCell() that works for
-** pages that do contain overflow cells.
+** This is common tail processing for btreeParseCellPtr() and
+** btreeParseCellPtrIndex() for the case when the cell does not fit entirely
+** on a single B-tree page.  Make necessary adjustments to the CellInfo
+** structure.
 */
-static u8 *findOverflowCell(MemPage *pPage, int iCell){
-  int i;
-  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  for(i=pPage->nOverflow-1; i>=0; i--){
-    int k;
-    k = pPage->aiOvfl[i];
-    if( k<=iCell ){
-      if( k==iCell ){
-        return pPage->apOvfl[i];
-      }
-      iCell--;
-    }
+static SQLITE_NOINLINE void btreeParseCellAdjustSizeForOverflow(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  /* If the payload will not fit completely on the local page, we have
+  ** to decide how much to store locally and how much to spill onto
+  ** overflow pages.  The strategy is to minimize the amount of unused
+  ** space on overflow pages while keeping the amount of local storage
+  ** in between minLocal and maxLocal.
+  **
+  ** Warning:  changing the way overflow payload is distributed in any
+  ** way will result in an incompatible file format.
+  */
+  int minLocal;  /* Minimum amount of payload held locally */
+  int maxLocal;  /* Maximum amount of payload held locally */
+  int surplus;   /* Overflow payload available for local storage */
+
+  minLocal = pPage->minLocal;
+  maxLocal = pPage->maxLocal;
+  surplus = minLocal + (pInfo->nPayload - minLocal)%(pPage->pBt->usableSize-4);
+  testcase( surplus==maxLocal );
+  testcase( surplus==maxLocal+1 );
+  if( surplus <= maxLocal ){
+    pInfo->nLocal = (u16)surplus;
+  }else{
+    pInfo->nLocal = (u16)minLocal;
   }
-  return findCell(pPage, iCell);
+  pInfo->nSize = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell) + 4;
 }
 
 /*
-** Parse a cell content block and fill in the CellInfo structure.  There
-** are two versions of this function.  btreeParseCell() takes a 
-** cell index as the second argument and btreeParseCellPtr() 
-** takes a pointer to the body of the cell as its second argument.
+** The following routines are implementations of the MemPage.xParseCell()
+** method.
+**
+** Parse a cell content block and fill in the CellInfo structure.
+**
+** btreeParseCellPtr()        =>   table btree leaf nodes
+** btreeParseCellNoPayload()  =>   table btree internal nodes
+** btreeParseCellPtrIndex()   =>   index btree nodes
+**
+** There is also a wrapper function btreeParseCell() that works for
+** all MemPage types and that references the cell by index rather than
+** by pointer.
 */
+static void btreeParseCellPtrNoPayload(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( pPage->leaf==0 );
+  assert( pPage->childPtrSize==4 );
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER(pPage);
+#endif
+  pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
+  pInfo->nPayload = 0;
+  pInfo->nLocal = 0;
+  pInfo->pPayload = 0;
+  return;
+}
 static void btreeParseCellPtr(
   MemPage *pPage,         /* Page containing the cell */
   u8 *pCell,              /* Pointer to the cell text. */
@@ -53613,26 +60664,52 @@ static void btreeParseCellPtr(
 ){
   u8 *pIter;              /* For scanning through pCell */
   u32 nPayload;           /* Number of bytes of cell payload */
+  u64 iKey;               /* Extracted Key value */
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   assert( pPage->leaf==0 || pPage->leaf==1 );
-  if( pPage->intKeyLeaf ){
-    assert( pPage->childPtrSize==0 );
-    pIter = pCell + getVarint32(pCell, nPayload);
-    pIter += getVarint(pIter, (u64*)&pInfo->nKey);
-  }else if( pPage->noPayload ){
-    assert( pPage->childPtrSize==4 );
-    pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
-    pInfo->nPayload = 0;
-    pInfo->nLocal = 0;
-    pInfo->iOverflow = 0;
-    pInfo->pPayload = 0;
-    return;
-  }else{
-    pIter = pCell + pPage->childPtrSize;
-    pIter += getVarint32(pIter, nPayload);
-    pInfo->nKey = nPayload;
+  assert( pPage->intKeyLeaf );
+  assert( pPage->childPtrSize==0 );
+  pIter = pCell;
+
+  /* The next block of code is equivalent to:
+  **
+  **     pIter += getVarint32(pIter, nPayload);
+  **
+  ** The code is inlined to avoid a function call.
+  */
+  nPayload = *pIter;
+  if( nPayload>=0x80 ){
+    u8 *pEnd = &pIter[8];
+    nPayload &= 0x7f;
+    do{
+      nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+    }while( (*pIter)>=0x80 && pIternKey);
+  **
+  ** The code is inlined to avoid a function call.
+  */
+  iKey = *pIter;
+  if( iKey>=0x80 ){
+    u8 *pEnd = &pIter[7];
+    iKey &= 0x7f;
+    while(1){
+      iKey = (iKey<<7) | (*++pIter & 0x7f);
+      if( (*pIter)<0x80 ) break;
+      if( pIter>=pEnd ){
+        iKey = (iKey<<8) | *++pIter;
+        break;
+      }
+    }
+  }
+  pIter++;
+
+  pInfo->nKey = *(i64*)&iKey;
   pInfo->nPayload = nPayload;
   pInfo->pPayload = pIter;
   testcase( nPayload==pPage->maxLocal );
@@ -53644,33 +60721,45 @@ static void btreeParseCellPtr(
     pInfo->nSize = nPayload + (u16)(pIter - pCell);
     if( pInfo->nSize<4 ) pInfo->nSize = 4;
     pInfo->nLocal = (u16)nPayload;
-    pInfo->iOverflow = 0;
   }else{
-    /* If the payload will not fit completely on the local page, we have
-    ** to decide how much to store locally and how much to spill onto
-    ** overflow pages.  The strategy is to minimize the amount of unused
-    ** space on overflow pages while keeping the amount of local storage
-    ** in between minLocal and maxLocal.
-    **
-    ** Warning:  changing the way overflow payload is distributed in any
-    ** way will result in an incompatible file format.
-    */
-    int minLocal;  /* Minimum amount of payload held locally */
-    int maxLocal;  /* Maximum amount of payload held locally */
-    int surplus;   /* Overflow payload available for local storage */
+    btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
+  }
+}
+static void btreeParseCellPtrIndex(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  u8 *pIter;              /* For scanning through pCell */
+  u32 nPayload;           /* Number of bytes of cell payload */
 
-    minLocal = pPage->minLocal;
-    maxLocal = pPage->maxLocal;
-    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
-    testcase( surplus==maxLocal );
-    testcase( surplus==maxLocal+1 );
-    if( surplus <= maxLocal ){
-      pInfo->nLocal = (u16)surplus;
-    }else{
-      pInfo->nLocal = (u16)minLocal;
-    }
-    pInfo->iOverflow = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell);
-    pInfo->nSize = pInfo->iOverflow + 4;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( pPage->leaf==0 || pPage->leaf==1 );
+  assert( pPage->intKeyLeaf==0 );
+  pIter = pCell + pPage->childPtrSize;
+  nPayload = *pIter;
+  if( nPayload>=0x80 ){
+    u8 *pEnd = &pIter[8];
+    nPayload &= 0x7f;
+    do{
+      nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+    }while( *(pIter)>=0x80 && pIternKey = nPayload;
+  pInfo->nPayload = nPayload;
+  pInfo->pPayload = pIter;
+  testcase( nPayload==pPage->maxLocal );
+  testcase( nPayload==pPage->maxLocal+1 );
+  if( nPayload<=pPage->maxLocal ){
+    /* This is the (easy) common case where the entire payload fits
+    ** on the local page.  No overflow is required.
+    */
+    pInfo->nSize = nPayload + (u16)(pIter - pCell);
+    if( pInfo->nSize<4 ) pInfo->nSize = 4;
+    pInfo->nLocal = (u16)nPayload;
+  }else{
+    btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
   }
 }
 static void btreeParseCell(
@@ -53678,14 +60767,20 @@ static void btreeParseCell(
   int iCell,              /* The cell index.  First cell is 0 */
   CellInfo *pInfo         /* Fill in this structure */
 ){
-  btreeParseCellPtr(pPage, findCell(pPage, iCell), pInfo);
+  pPage->xParseCell(pPage, findCell(pPage, iCell), pInfo);
 }
 
 /*
+** The following routines are implementations of the MemPage.xCellSize
+** method.
+**
 ** Compute the total number of bytes that a Cell needs in the cell
 ** data area of the btree-page.  The return number includes the cell
 ** data header and the local payload, but not any overflow page or
 ** the space used by the cell pointer.
+**
+** cellSizePtrNoPayload()    =>   table internal nodes
+** cellSizePtr()             =>   all index nodes & table leaf nodes
 */
 static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
   u8 *pIter = pCell + pPage->childPtrSize; /* For looping over bytes of pCell */
@@ -53698,18 +60793,12 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
   ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
   ** this function verifies that this invariant is not violated. */
   CellInfo debuginfo;
-  btreeParseCellPtr(pPage, pCell, &debuginfo);
+  pPage->xParseCell(pPage, pCell, &debuginfo);
 #endif
 
-  if( pPage->noPayload ){
-    pEnd = &pIter[9];
-    while( (*pIter++)&0x80 && pIterchildPtrSize==4 );
-    return (u16)(pIter - pCell);
-  }
   nSize = *pIter;
   if( nSize>=0x80 ){
-    pEnd = &pIter[9];
+    pEnd = &pIter[8];
     nSize &= 0x7f;
     do{
       nSize = (nSize<<7) | (*++pIter & 0x7f);
@@ -53741,12 +60830,34 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
   assert( nSize==debuginfo.nSize || CORRUPT_DB );
   return (u16)nSize;
 }
+static u16 cellSizePtrNoPayload(MemPage *pPage, u8 *pCell){
+  u8 *pIter = pCell + 4; /* For looping over bytes of pCell */
+  u8 *pEnd;              /* End mark for a varint */
+
+#ifdef SQLITE_DEBUG
+  /* The value returned by this function should always be the same as
+  ** the (CellInfo.nSize) value found by doing a full parse of the
+  ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
+  ** this function verifies that this invariant is not violated. */
+  CellInfo debuginfo;
+  pPage->xParseCell(pPage, pCell, &debuginfo);
+#else
+  UNUSED_PARAMETER(pPage);
+#endif
+
+  assert( pPage->childPtrSize==4 );
+  pEnd = pIter + 9;
+  while( (*pIter++)&0x80 && pIterxCellSize(pPage, findCell(pPage, iCell));
 }
 #endif
 
@@ -53760,9 +60871,9 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
   CellInfo info;
   if( *pRC ) return;
   assert( pCell!=0 );
-  btreeParseCellPtr(pPage, pCell, &info);
-  if( info.iOverflow ){
-    Pgno ovfl = get4byte(&pCell[info.iOverflow]);
+  pPage->xParseCell(pPage, pCell, &info);
+  if( info.nLocalpBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);
   }
 }
@@ -53770,17 +60881,18 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
 
 
 /*
-** Defragment the page given.  All Cells are moved to the
-** end of the page and all free space is collected into one
-** big FreeBlk that occurs in between the header and cell
-** pointer array and the cell content area.
+** Defragment the page given. This routine reorganizes cells within the
+** page so that there are no free-blocks on the free-block list.
+**
+** Parameter nMaxFrag is the maximum amount of fragmented space that may be
+** present in the page after this routine returns.
 **
 ** EVIDENCE-OF: R-44582-60138 SQLite may from time to time reorganize a
 ** b-tree page so that there are no freeblocks or fragment bytes, all
 ** unused bytes are contained in the unallocated space region, and all
 ** cells are packed tightly at the end of the page.
 */
-static int defragmentPage(MemPage *pPage){
+static int defragmentPage(MemPage *pPage, int nMaxFrag){
   int i;                     /* Loop counter */
   int pc;                    /* Address of the i-th cell */
   int hdr;                   /* Offset to the page header */
@@ -53795,7 +60907,6 @@ static int defragmentPage(MemPage *pPage){
   int iCellFirst;            /* First allowable cell index */
   int iCellLast;             /* Last possible cell index */
 
-
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( pPage->pBt!=0 );
   assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
@@ -53807,9 +60918,56 @@ static int defragmentPage(MemPage *pPage){
   cellOffset = pPage->cellOffset;
   nCell = pPage->nCell;
   assert( nCell==get2byte(&data[hdr+3]) );
+  iCellFirst = cellOffset + 2*nCell;
   usableSize = pPage->pBt->usableSize;
+
+  /* This block handles pages with two or fewer free blocks and nMaxFrag
+  ** or fewer fragmented bytes. In this case it is faster to move the
+  ** two (or one) blocks of cells using memmove() and add the required
+  ** offsets to each pointer in the cell-pointer array than it is to 
+  ** reconstruct the entire page.  */
+  if( (int)data[hdr+7]<=nMaxFrag ){
+    int iFree = get2byte(&data[hdr+1]);
+    if( iFree ){
+      int iFree2 = get2byte(&data[iFree]);
+
+      /* pageFindSlot() has already verified that free blocks are sorted
+      ** in order of offset within the page, and that no block extends
+      ** past the end of the page. Provided the two free slots do not 
+      ** overlap, this guarantees that the memmove() calls below will not
+      ** overwrite the usableSize byte buffer, even if the database page
+      ** is corrupt.  */
+      assert( iFree2==0 || iFree2>iFree );
+      assert( iFree+get2byte(&data[iFree+2]) <= usableSize );
+      assert( iFree2==0 || iFree2+get2byte(&data[iFree2+2]) <= usableSize );
+
+      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
+        u8 *pEnd = &data[cellOffset + nCell*2];
+        u8 *pAddr;
+        int sz2 = 0;
+        int sz = get2byte(&data[iFree+2]);
+        int top = get2byte(&data[hdr+5]);
+        if( iFree2 ){
+          if( iFree+sz>iFree2 ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
+          sz2 = get2byte(&data[iFree2+2]);
+          assert( iFree+sz+sz2+iFree2-(iFree+sz) <= usableSize );
+          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));
+          sz += sz2;
+        }
+        cbrk = top+sz;
+        assert( cbrk+(iFree-top) <= usableSize );
+        memmove(&data[cbrk], &data[top], iFree-top);
+        for(pAddr=&data[cellOffset]; pAddriCellLast ){
-      return SQLITE_CORRUPT_BKPT;
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
     }
-#endif
     assert( pc>=iCellFirst && pc<=iCellLast );
-    size = cellSizePtr(pPage, &src[pc]);
+    size = pPage->xCellSize(pPage, &src[pc]);
     cbrk -= size;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
-    if( cbrkusableSize ){
-      return SQLITE_CORRUPT_BKPT;
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
     }
-#endif
     assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
     testcase( cbrk+size==usableSize );
     testcase( pc+size==usableSize );
@@ -53851,16 +61001,18 @@ static int defragmentPage(MemPage *pPage){
     }
     memcpy(&data[cbrk], &src[pc], size);
   }
+  data[hdr+7] = 0;
+
+ defragment_out:
+  if( data[hdr+7]+cbrk-iCellFirst!=pPage->nFree ){
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
+  }
   assert( cbrk>=iCellFirst );
   put2byte(&data[hdr+5], cbrk);
   data[hdr+1] = 0;
   data[hdr+2] = 0;
-  data[hdr+7] = 0;
   memset(&data[iCellFirst], 0, cbrk-iCellFirst);
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
-  if( cbrk-iCellFirst!=pPage->nFree ){
-    return SQLITE_CORRUPT_BKPT;
-  }
   return SQLITE_OK;
 }
 
@@ -53874,47 +61026,46 @@ static int defragmentPage(MemPage *pPage){
 ** This function may detect corruption within pPg.  If corruption is
 ** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.
 **
-** If a slot of at least nByte bytes is found but cannot be used because 
-** there are already at least 60 fragmented bytes on the page, return NULL.
-** In this case, if pbDefrag parameter is not NULL, set *pbDefrag to true.
+** Slots on the free list that are between 1 and 3 bytes larger than nByte
+** will be ignored if adding the extra space to the fragmentation count
+** causes the fragmentation count to exceed 60.
 */
-static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc, int *pbDefrag){
+static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc){
   const int hdr = pPg->hdrOffset;
   u8 * const aData = pPg->aData;
-  int iAddr;
-  int pc;
+  int iAddr = hdr + 1;
+  int pc = get2byte(&aData[iAddr]);
+  int x;
   int usableSize = pPg->pBt->usableSize;
 
-  for(iAddr=hdr+1; (pc = get2byte(&aData[iAddr]))>0; iAddr=pc){
+  assert( pc>0 );
+  do{
     int size;            /* Size of the free slot */
     /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
     ** increasing offset. */
     if( pc>usableSize-4 || pcpgno);
       return 0;
     }
     /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each
     ** freeblock form a big-endian integer which is the size of the freeblock
     ** in bytes, including the 4-byte header. */
     size = get2byte(&aData[pc+2]);
-    if( size>=nByte ){
-      int x = size - nByte;
+    if( (x = size - nByte)>=0 ){
       testcase( x==4 );
       testcase( x==3 );
-      if( x<4 ){
+      if( pc < pPg->cellOffset+2*pPg->nCell || size+pc > usableSize ){
+        *pRc = SQLITE_CORRUPT_PGNO(pPg->pgno);
+        return 0;
+      }else if( x<4 ){
         /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
         ** number of bytes in fragments may not exceed 60. */
-        if( aData[hdr+7]>=60 ){
-          if( pbDefrag ) *pbDefrag = 1;
-          return 0;
-        }
+        if( aData[hdr+7]>57 ) return 0;
+
         /* Remove the slot from the free-list. Update the number of
         ** fragmented bytes within the page. */
         memcpy(&aData[iAddr], &aData[pc], 2);
         aData[hdr+7] += (u8)x;
-      }else if( size+pc > usableSize ){
-        *pRc = SQLITE_CORRUPT_BKPT;
-        return 0;
       }else{
         /* The slot remains on the free-list. Reduce its size to account
          ** for the portion used by the new allocation. */
@@ -53922,7 +61073,9 @@ static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc, int *pbDefrag){
       }
       return &aData[pc + x];
     }
-  }
+    iAddr = pc;
+    pc = get2byte(&aData[pc]);
+  }while( pc );
 
   return 0;
 }
@@ -53963,8 +61116,15 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   ** then the cell content offset of an empty page wants to be 65536.
   ** However, that integer is too large to be stored in a 2-byte unsigned
   ** integer, so a value of 0 is used in its place. */
-  top = get2byteNotZero(&data[hdr+5]);
-  if( gap>top ) return SQLITE_CORRUPT_BKPT;
+  top = get2byte(&data[hdr+5]);
+  assert( top<=(int)pPage->pBt->usableSize ); /* Prevent by getAndInitPage() */
+  if( gap>top ){
+    if( top==0 && pPage->pBt->usableSize==65536 ){
+      top = 65536;
+    }else{
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
+    }
+  }
 
   /* If there is enough space between gap and top for one more cell pointer
   ** array entry offset, and if the freelist is not empty, then search the
@@ -53973,15 +61133,14 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   testcase( gap+2==top );
   testcase( gap+1==top );
   testcase( gap==top );
-  if( gap+2<=top && (data[hdr+1] || data[hdr+2]) ){
-    int bDefrag = 0;
-    u8 *pSpace = pageFindSlot(pPage, nByte, &rc, &bDefrag);
-    if( rc ) return rc;
-    if( bDefrag ) goto defragment_page;
+  if( (data[hdr+2] || data[hdr+1]) && gap+2<=top ){
+    u8 *pSpace = pageFindSlot(pPage, nByte, &rc);
     if( pSpace ){
       assert( pSpace>=data && (pSpace - data)<65536 );
       *pIdx = (int)(pSpace - data);
       return SQLITE_OK;
+    }else if( rc ){
+      return rc;
     }
   }
 
@@ -53990,12 +61149,11 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   */
   testcase( gap+2+nByte==top );
   if( gap+2+nByte>top ){
- defragment_page:
     assert( pPage->nCell>0 || CORRUPT_DB );
-    rc = defragmentPage(pPage);
+    rc = defragmentPage(pPage, MIN(4, pPage->nFree - (2+nByte)));
     if( rc ) return rc;
     top = get2byteNotZero(&data[hdr+5]);
-    assert( gap+nByte<=top );
+    assert( gap+2+nByte<=top );
   }
 
 
@@ -54037,7 +61195,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
 
   assert( pPage->pBt!=0 );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
-  assert( iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
+  assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
   assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   assert( iSize>=4 );   /* Minimum cell size is 4 */
@@ -54045,7 +61203,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
 
   /* Overwrite deleted information with zeros when the secure_delete
   ** option is enabled */
-  if( pPage->pBt->btsFlags & BTS_SECURE_DELETE ){
+  if( pPage->pBt->btsFlags & BTS_FAST_SECURE ){
     memset(&data[iStart], 0, iSize);
   }
 
@@ -54057,23 +61215,29 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
   if( data[iPtr+1]==0 && data[iPtr]==0 ){
     iFreeBlk = 0;  /* Shortcut for the case when the freelist is empty */
   }else{
-    while( (iFreeBlk = get2byte(&data[iPtr]))>0 && iFreeBlkpgno);
+      }
       iPtr = iFreeBlk;
     }
-    if( iFreeBlk>iLast ) return SQLITE_CORRUPT_BKPT;
+    if( iFreeBlk>iLast ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
     assert( iFreeBlk>iPtr || iFreeBlk==0 );
   
     /* At this point:
     **    iFreeBlk:   First freeblock after iStart, or zero if none
-    **    iPtr:       The address of a pointer iFreeBlk
+    **    iPtr:       The address of a pointer to iFreeBlk
     **
     ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
     */
     if( iFreeBlk && iEnd+3>=iFreeBlk ){
       nFrag = iFreeBlk - iEnd;
-      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_BKPT;
+      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
       iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
+      if( iEnd > pPage->pBt->usableSize ){
+        return SQLITE_CORRUPT_PGNO(pPage->pgno);
+      }
       iSize = iEnd - iStart;
       iFreeBlk = get2byte(&data[iFreeBlk]);
     }
@@ -54085,20 +61249,20 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
     if( iPtr>hdr+1 ){
       int iPtrEnd = iPtr + get2byte(&data[iPtr+2]);
       if( iPtrEnd+3>=iStart ){
-        if( iPtrEnd>iStart ) return SQLITE_CORRUPT_BKPT;
+        if( iPtrEnd>iStart ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
         nFrag += iStart - iPtrEnd;
         iSize = iEnd - iPtr;
         iStart = iPtr;
       }
     }
-    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_BKPT;
+    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
     data[hdr+7] -= nFrag;
   }
   if( iStart==get2byte(&data[hdr+5]) ){
     /* The new freeblock is at the beginning of the cell content area,
     ** so just extend the cell content area rather than create another
     ** freelist entry */
-    if( iPtr!=hdr+1 ) return SQLITE_CORRUPT_BKPT;
+    if( iPtr!=hdr+1 ) return SQLITE_CORRUPT_PGNO(pPage->pgno);
     put2byte(&data[hdr+1], iFreeBlk);
     put2byte(&data[hdr+5], iEnd);
   }else{
@@ -54131,35 +61295,42 @@ static int decodeFlags(MemPage *pPage, int flagByte){
   pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
   flagByte &= ~PTF_LEAF;
   pPage->childPtrSize = 4-4*pPage->leaf;
+  pPage->xCellSize = cellSizePtr;
   pBt = pPage->pBt;
   if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
-    /* EVIDENCE-OF: R-03640-13415 A value of 5 means the page is an interior
-    ** table b-tree page. */
+    /* EVIDENCE-OF: R-07291-35328 A value of 5 (0x05) means the page is an
+    ** interior table b-tree page. */
     assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
-    /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf
-    ** table b-tree page. */
+    /* EVIDENCE-OF: R-26900-09176 A value of 13 (0x0d) means the page is a
+    ** leaf table b-tree page. */
     assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
     pPage->intKey = 1;
-    pPage->intKeyLeaf = pPage->leaf;
-    pPage->noPayload = !pPage->leaf;
+    if( pPage->leaf ){
+      pPage->intKeyLeaf = 1;
+      pPage->xParseCell = btreeParseCellPtr;
+    }else{
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtrNoPayload;
+      pPage->xParseCell = btreeParseCellPtrNoPayload;
+    }
     pPage->maxLocal = pBt->maxLeaf;
     pPage->minLocal = pBt->minLeaf;
   }else if( flagByte==PTF_ZERODATA ){
-    /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior
-    ** index b-tree page. */
+    /* EVIDENCE-OF: R-43316-37308 A value of 2 (0x02) means the page is an
+    ** interior index b-tree page. */
     assert( (PTF_ZERODATA)==2 );
-    /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf
-    ** index b-tree page. */
+    /* EVIDENCE-OF: R-59615-42828 A value of 10 (0x0a) means the page is a
+    ** leaf index b-tree page. */
     assert( (PTF_ZERODATA|PTF_LEAF)==10 );
     pPage->intKey = 0;
     pPage->intKeyLeaf = 0;
-    pPage->noPayload = 0;
+    pPage->xParseCell = btreeParseCellPtrIndex;
     pPage->maxLocal = pBt->maxLocal;
     pPage->minLocal = pBt->minLocal;
   }else{
     /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
     ** an error. */
-    return SQLITE_CORRUPT_BKPT;
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
   }
   pPage->max1bytePayload = pBt->max1bytePayload;
   return SQLITE_OK;
@@ -54175,129 +61346,136 @@ static int decodeFlags(MemPage *pPage, int flagByte){
 ** we failed to detect any corruption.
 */
 static int btreeInitPage(MemPage *pPage){
+  int pc;            /* Address of a freeblock within pPage->aData[] */
+  u8 hdr;            /* Offset to beginning of page header */
+  u8 *data;          /* Equal to pPage->aData */
+  BtShared *pBt;        /* The main btree structure */
+  int usableSize;    /* Amount of usable space on each page */
+  u16 cellOffset;    /* Offset from start of page to first cell pointer */
+  int nFree;         /* Number of unused bytes on the page */
+  int top;           /* First byte of the cell content area */
+  int iCellFirst;    /* First allowable cell or freeblock offset */
+  int iCellLast;     /* Last possible cell or freeblock offset */
 
   assert( pPage->pBt!=0 );
+  assert( pPage->pBt->db!=0 );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
   assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
   assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );
+  assert( pPage->isInit==0 );
 
-  if( !pPage->isInit ){
-    u16 pc;            /* Address of a freeblock within pPage->aData[] */
-    u8 hdr;            /* Offset to beginning of page header */
-    u8 *data;          /* Equal to pPage->aData */
-    BtShared *pBt;        /* The main btree structure */
-    int usableSize;    /* Amount of usable space on each page */
-    u16 cellOffset;    /* Offset from start of page to first cell pointer */
-    int nFree;         /* Number of unused bytes on the page */
-    int top;           /* First byte of the cell content area */
-    int iCellFirst;    /* First allowable cell or freeblock offset */
-    int iCellLast;     /* Last possible cell or freeblock offset */
-
-    pBt = pPage->pBt;
-
-    hdr = pPage->hdrOffset;
-    data = pPage->aData;
-    /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
-    ** the b-tree page type. */
-    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
-    assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
-    pPage->maskPage = (u16)(pBt->pageSize - 1);
-    pPage->nOverflow = 0;
-    usableSize = pBt->usableSize;
-    pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
-    pPage->aDataEnd = &data[usableSize];
-    pPage->aCellIdx = &data[cellOffset];
-    /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
-    ** the start of the cell content area. A zero value for this integer is
-    ** interpreted as 65536. */
-    top = get2byteNotZero(&data[hdr+5]);
-    /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
-    ** number of cells on the page. */
-    pPage->nCell = get2byte(&data[hdr+3]);
-    if( pPage->nCell>MX_CELL(pBt) ){
-      /* To many cells for a single page.  The page must be corrupt */
-      return SQLITE_CORRUPT_BKPT;
-    }
-    testcase( pPage->nCell==MX_CELL(pBt) );
-    /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
-    ** possible for a root page of a table that contains no rows) then the
-    ** offset to the cell content area will equal the page size minus the
-    ** bytes of reserved space. */
-    assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );
-
-    /* A malformed database page might cause us to read past the end
-    ** of page when parsing a cell.  
-    **
-    ** The following block of code checks early to see if a cell extends
-    ** past the end of a page boundary and causes SQLITE_CORRUPT to be 
-    ** returned if it does.
-    */
-    iCellFirst = cellOffset + 2*pPage->nCell;
-    iCellLast = usableSize - 4;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
-    {
-      int i;            /* Index into the cell pointer array */
-      int sz;           /* Size of a cell */
-
-      if( !pPage->leaf ) iCellLast--;
-      for(i=0; inCell; i++){
-        pc = get2byte(&data[cellOffset+i*2]);
-        testcase( pc==iCellFirst );
-        testcase( pc==iCellLast );
-        if( pciCellLast ){
-          return SQLITE_CORRUPT_BKPT;
-        }
-        sz = cellSizePtr(pPage, &data[pc]);
-        testcase( pc+sz==usableSize );
-        if( pc+sz>usableSize ){
-          return SQLITE_CORRUPT_BKPT;
-        }
+  pBt = pPage->pBt;
+  hdr = pPage->hdrOffset;
+  data = pPage->aData;
+  /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
+  ** the b-tree page type. */
+  if( decodeFlags(pPage, data[hdr]) ){
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
+  }
+  assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
+  pPage->maskPage = (u16)(pBt->pageSize - 1);
+  pPage->nOverflow = 0;
+  usableSize = pBt->usableSize;
+  pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
+  pPage->aDataEnd = &data[usableSize];
+  pPage->aCellIdx = &data[cellOffset];
+  pPage->aDataOfst = &data[pPage->childPtrSize];
+  /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
+  ** the start of the cell content area. A zero value for this integer is
+  ** interpreted as 65536. */
+  top = get2byteNotZero(&data[hdr+5]);
+  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+  ** number of cells on the page. */
+  pPage->nCell = get2byte(&data[hdr+3]);
+  if( pPage->nCell>MX_CELL(pBt) ){
+    /* To many cells for a single page.  The page must be corrupt */
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
+  }
+  testcase( pPage->nCell==MX_CELL(pBt) );
+  /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
+  ** possible for a root page of a table that contains no rows) then the
+  ** offset to the cell content area will equal the page size minus the
+  ** bytes of reserved space. */
+  assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );
+
+  /* A malformed database page might cause us to read past the end
+  ** of page when parsing a cell.  
+  **
+  ** The following block of code checks early to see if a cell extends
+  ** past the end of a page boundary and causes SQLITE_CORRUPT to be 
+  ** returned if it does.
+  */
+  iCellFirst = cellOffset + 2*pPage->nCell;
+  iCellLast = usableSize - 4;
+  if( pBt->db->flags & SQLITE_CellSizeCk ){
+    int i;            /* Index into the cell pointer array */
+    int sz;           /* Size of a cell */
+
+    if( !pPage->leaf ) iCellLast--;
+    for(i=0; inCell; i++){
+      pc = get2byteAligned(&data[cellOffset+i*2]);
+      testcase( pc==iCellFirst );
+      testcase( pc==iCellLast );
+      if( pciCellLast ){
+        return SQLITE_CORRUPT_PGNO(pPage->pgno);
       }
-      if( !pPage->leaf ) iCellLast++;
-    }  
-#endif
+      sz = pPage->xCellSize(pPage, &data[pc]);
+      testcase( pc+sz==usableSize );
+      if( pc+sz>usableSize ){
+        return SQLITE_CORRUPT_PGNO(pPage->pgno);
+      }
+    }
+    if( !pPage->leaf ) iCellLast++;
+  }  
 
-    /* Compute the total free space on the page
-    ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
-    ** start of the first freeblock on the page, or is zero if there are no
-    ** freeblocks. */
-    pc = get2byte(&data[hdr+1]);
-    nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
-    while( pc>0 ){
-      u16 next, size;
-      if( pciCellLast ){
-        /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
-        ** always be at least one cell before the first freeblock.
-        **
-        ** Or, the freeblock is off the end of the page
-        */
-        return SQLITE_CORRUPT_BKPT; 
+  /* Compute the total free space on the page
+  ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
+  ** start of the first freeblock on the page, or is zero if there are no
+  ** freeblocks. */
+  pc = get2byte(&data[hdr+1]);
+  nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
+  if( pc>0 ){
+    u32 next, size;
+    if( pcpgno); 
+    }
+    while( 1 ){
+      if( pc>iCellLast ){
+        /* Freeblock off the end of the page */
+        return SQLITE_CORRUPT_PGNO(pPage->pgno);
       }
       next = get2byte(&data[pc]);
       size = get2byte(&data[pc+2]);
-      if( (next>0 && next<=pc+size+3) || pc+size>usableSize ){
-        /* Free blocks must be in ascending order. And the last byte of
-        ** the free-block must lie on the database page.  */
-        return SQLITE_CORRUPT_BKPT; 
-      }
       nFree = nFree + size;
+      if( next<=pc+size+3 ) break;
       pc = next;
     }
-
-    /* At this point, nFree contains the sum of the offset to the start
-    ** of the cell-content area plus the number of free bytes within
-    ** the cell-content area. If this is greater than the usable-size
-    ** of the page, then the page must be corrupted. This check also
-    ** serves to verify that the offset to the start of the cell-content
-    ** area, according to the page header, lies within the page.
-    */
-    if( nFree>usableSize ){
-      return SQLITE_CORRUPT_BKPT; 
+    if( next>0 ){
+      /* Freeblock not in ascending order */
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
+    }
+    if( pc+size>(unsigned int)usableSize ){
+      /* Last freeblock extends past page end */
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
     }
-    pPage->nFree = (u16)(nFree - iCellFirst);
-    pPage->isInit = 1;
   }
+
+  /* At this point, nFree contains the sum of the offset to the start
+  ** of the cell-content area plus the number of free bytes within
+  ** the cell-content area. If this is greater than the usable-size
+  ** of the page, then the page must be corrupted. This check also
+  ** serves to verify that the offset to the start of the cell-content
+  ** area, according to the page header, lies within the page.
+  */
+  if( nFree>usableSize ){
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
+  }
+  pPage->nFree = (u16)(nFree - iCellFirst);
+  pPage->isInit = 1;
   return SQLITE_OK;
 }
 
@@ -54316,7 +61494,7 @@ static void zeroPage(MemPage *pPage, int flags){
   assert( sqlite3PagerGetData(pPage->pDbPage) == data );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( sqlite3_mutex_held(pBt->mutex) );
-  if( pBt->btsFlags & BTS_SECURE_DELETE ){
+  if( pBt->btsFlags & BTS_FAST_SECURE ){
     memset(&data[hdr], 0, pBt->usableSize - hdr);
   }
   data[hdr] = (char)flags;
@@ -54329,6 +61507,7 @@ static void zeroPage(MemPage *pPage, int flags){
   pPage->cellOffset = first;
   pPage->aDataEnd = &data[pBt->usableSize];
   pPage->aCellIdx = &data[first];
+  pPage->aDataOfst = &data[pPage->childPtrSize];
   pPage->nOverflow = 0;
   assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
   pPage->maskPage = (u16)(pBt->pageSize - 1);
@@ -54343,20 +61522,23 @@ static void zeroPage(MemPage *pPage, int flags){
 */
 static MemPage *btreePageFromDbPage(DbPage *pDbPage, Pgno pgno, BtShared *pBt){
   MemPage *pPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
-  pPage->aData = sqlite3PagerGetData(pDbPage);
-  pPage->pDbPage = pDbPage;
-  pPage->pBt = pBt;
-  pPage->pgno = pgno;
-  pPage->hdrOffset = pPage->pgno==1 ? 100 : 0;
+  if( pgno!=pPage->pgno ){
+    pPage->aData = sqlite3PagerGetData(pDbPage);
+    pPage->pDbPage = pDbPage;
+    pPage->pBt = pBt;
+    pPage->pgno = pgno;
+    pPage->hdrOffset = pgno==1 ? 100 : 0;
+  }
+  assert( pPage->aData==sqlite3PagerGetData(pDbPage) );
   return pPage; 
 }
 
 /*
 ** Get a page from the pager.  Initialize the MemPage.pBt and
-** MemPage.aData elements if needed.
+** MemPage.aData elements if needed.  See also: btreeGetUnusedPage().
 **
-** If the noContent flag is set, it means that we do not care about
-** the content of the page at this time.  So do not go to the disk
+** If the PAGER_GET_NOCONTENT flag is set, it means that we do not care
+** about the content of the page at this time.  So do not go to the disk
 ** to fetch the content.  Just fill in the content with zeros for now.
 ** If in the future we call sqlite3PagerWrite() on this page, that
 ** means we have started to be concerned about content and the disk
@@ -54373,7 +61555,7 @@ static int btreeGetPage(
 
   assert( flags==0 || flags==PAGER_GET_NOCONTENT || flags==PAGER_GET_READONLY );
   assert( sqlite3_mutex_held(pBt->mutex) );
-  rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
+  rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
   if( rc ) return rc;
   *ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
   return SQLITE_OK;
@@ -54408,35 +61590,63 @@ SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree *p){
 }
 
 /*
-** Get a page from the pager and initialize it.  This routine is just a
-** convenience wrapper around separate calls to btreeGetPage() and 
-** btreeInitPage().
+** Get a page from the pager and initialize it.
 **
-** If an error occurs, then the value *ppPage is set to is undefined. It
+** If pCur!=0 then the page is being fetched as part of a moveToChild()
+** call.  Do additional sanity checking on the page in this case.
+** And if the fetch fails, this routine must decrement pCur->iPage.
+**
+** The page is fetched as read-write unless pCur is not NULL and is
+** a read-only cursor.
+**
+** If an error occurs, then *ppPage is undefined. It
 ** may remain unchanged, or it may be set to an invalid value.
 */
 static int getAndInitPage(
   BtShared *pBt,                  /* The database file */
   Pgno pgno,                      /* Number of the page to get */
   MemPage **ppPage,               /* Write the page pointer here */
-  int bReadonly                   /* PAGER_GET_READONLY or 0 */
+  BtCursor *pCur,                 /* Cursor to receive the page, or NULL */
+  int bReadOnly                   /* True for a read-only page */
 ){
   int rc;
+  DbPage *pDbPage;
   assert( sqlite3_mutex_held(pBt->mutex) );
-  assert( bReadonly==PAGER_GET_READONLY || bReadonly==0 );
+  assert( pCur==0 || ppPage==&pCur->apPage[pCur->iPage] );
+  assert( pCur==0 || bReadOnly==pCur->curPagerFlags );
+  assert( pCur==0 || pCur->iPage>0 );
 
   if( pgno>btreePagecount(pBt) ){
     rc = SQLITE_CORRUPT_BKPT;
-  }else{
-    rc = btreeGetPage(pBt, pgno, ppPage, bReadonly);
-    if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
-      rc = btreeInitPage(*ppPage);
-      if( rc!=SQLITE_OK ){
-        releasePage(*ppPage);
-      }
+    goto getAndInitPage_error;
+  }
+  rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, bReadOnly);
+  if( rc ){
+    goto getAndInitPage_error;
+  }
+  *ppPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
+  if( (*ppPage)->isInit==0 ){
+    btreePageFromDbPage(pDbPage, pgno, pBt);
+    rc = btreeInitPage(*ppPage);
+    if( rc!=SQLITE_OK ){
+      releasePage(*ppPage);
+      goto getAndInitPage_error;
     }
   }
+  assert( (*ppPage)->pgno==pgno );
+  assert( (*ppPage)->aData==sqlite3PagerGetData(pDbPage) );
+
+  /* If obtaining a child page for a cursor, we must verify that the page is
+  ** compatible with the root page. */
+  if( pCur && ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->curIntKey) ){
+    rc = SQLITE_CORRUPT_PGNO(pgno);
+    releasePage(*ppPage);
+    goto getAndInitPage_error;
+  }
+  return SQLITE_OK;
 
+getAndInitPage_error:
+  if( pCur ) pCur->iPage--;
   testcase( pgno==0 );
   assert( pgno!=0 || rc==SQLITE_CORRUPT );
   return rc;
@@ -54446,18 +61656,49 @@ static int getAndInitPage(
 ** Release a MemPage.  This should be called once for each prior
 ** call to btreeGetPage.
 */
+static void releasePageNotNull(MemPage *pPage){
+  assert( pPage->aData );
+  assert( pPage->pBt );
+  assert( pPage->pDbPage!=0 );
+  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+  assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  sqlite3PagerUnrefNotNull(pPage->pDbPage);
+}
 static void releasePage(MemPage *pPage){
-  if( pPage ){
-    assert( pPage->aData );
-    assert( pPage->pBt );
-    assert( pPage->pDbPage!=0 );
-    assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
-    assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
-    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-    sqlite3PagerUnrefNotNull(pPage->pDbPage);
+  if( pPage ) releasePageNotNull(pPage);
+}
+
+/*
+** Get an unused page.
+**
+** This works just like btreeGetPage() with the addition:
+**
+**   *  If the page is already in use for some other purpose, immediately
+**      release it and return an SQLITE_CURRUPT error.
+**   *  Make sure the isInit flag is clear
+*/
+static int btreeGetUnusedPage(
+  BtShared *pBt,       /* The btree */
+  Pgno pgno,           /* Number of the page to fetch */
+  MemPage **ppPage,    /* Return the page in this parameter */
+  int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */
+){
+  int rc = btreeGetPage(pBt, pgno, ppPage, flags);
+  if( rc==SQLITE_OK ){
+    if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
+      releasePage(*ppPage);
+      *ppPage = 0;
+      return SQLITE_CORRUPT_BKPT;
+    }
+    (*ppPage)->isInit = 0;
+  }else{
+    *ppPage = 0;
   }
+  return rc;
 }
 
+
 /*
 ** During a rollback, when the pager reloads information into the cache
 ** so that the cache is restored to its original state at the start of
@@ -54564,7 +61805,7 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   }
   p = sqlite3MallocZero(sizeof(Btree));
   if( !p ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   p->inTrans = TRANS_NONE;
   p->db = db;
@@ -54580,16 +61821,18 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   */
   if( isTempDb==0 && (isMemdb==0 || (vfsFlags&SQLITE_OPEN_URI)!=0) ){
     if( vfsFlags & SQLITE_OPEN_SHAREDCACHE ){
+      int nFilename = sqlite3Strlen30(zFilename)+1;
       int nFullPathname = pVfs->mxPathname+1;
-      char *zFullPathname = sqlite3Malloc(nFullPathname);
+      char *zFullPathname = sqlite3Malloc(MAX(nFullPathname,nFilename));
       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
+
       p->sharable = 1;
       if( !zFullPathname ){
         sqlite3_free(p);
-        return SQLITE_NOMEM;
+        return SQLITE_NOMEM_BKPT;
       }
       if( isMemdb ){
-        memcpy(zFullPathname, zFilename, sqlite3Strlen30(zFilename)+1);
+        memcpy(zFullPathname, zFilename, nFilename);
       }else{
         rc = sqlite3OsFullPathname(pVfs, zFilename,
                                    nFullPathname, zFullPathname);
@@ -54646,19 +61889,19 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
     ** the right size.  This is to guard against size changes that result
     ** when compiling on a different architecture.
     */
-    assert( sizeof(i64)==8 || sizeof(i64)==4 );
-    assert( sizeof(u64)==8 || sizeof(u64)==4 );
+    assert( sizeof(i64)==8 );
+    assert( sizeof(u64)==8 );
     assert( sizeof(u32)==4 );
     assert( sizeof(u16)==2 );
     assert( sizeof(Pgno)==4 );
   
     pBt = sqlite3MallocZero( sizeof(*pBt) );
     if( pBt==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto btree_open_out;
     }
     rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
-                          EXTRA_SIZE, flags, vfsFlags, pageReinit);
+                          sizeof(MemPage), flags, vfsFlags, pageReinit);
     if( rc==SQLITE_OK ){
       sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);
       rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
@@ -54674,8 +61917,10 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
     pBt->pCursor = 0;
     pBt->pPage1 = 0;
     if( sqlite3PagerIsreadonly(pBt->pPager) ) pBt->btsFlags |= BTS_READ_ONLY;
-#ifdef SQLITE_SECURE_DELETE
+#if defined(SQLITE_SECURE_DELETE)
     pBt->btsFlags |= BTS_SECURE_DELETE;
+#elif defined(SQLITE_FAST_SECURE_DELETE)
+    pBt->btsFlags |= BTS_OVERWRITE;
 #endif
     /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
     ** determined by the 2-byte integer located at an offset of 16 bytes from
@@ -54716,15 +61961,14 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
     /* Add the new BtShared object to the linked list sharable BtShareds.
     */
+    pBt->nRef = 1;
     if( p->sharable ){
       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
-      pBt->nRef = 1;
       MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);)
       if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
         pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
         if( pBt->mutex==0 ){
-          rc = SQLITE_NOMEM;
-          db->mallocFailed = 0;
+          rc = SQLITE_NOMEM_BKPT;
           goto btree_open_out;
         }
       }
@@ -54747,12 +61991,12 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
     for(i=0; inDb; i++){
       if( (pSib = db->aDb[i].pBt)!=0 && pSib->sharable ){
         while( pSib->pPrev ){ pSib = pSib->pPrev; }
-        if( p->pBtpBt ){
+        if( (uptr)p->pBt<(uptr)pSib->pBt ){
           p->pNext = pSib;
           p->pPrev = 0;
           pSib->pPrev = p;
         }else{
-          while( pSib->pNext && pSib->pNext->pBtpBt ){
+          while( pSib->pNext && (uptr)pSib->pNext->pBt<(uptr)p->pBt ){
             pSib = pSib->pNext;
           }
           p->pNext = pSib->pNext;
@@ -54772,12 +62016,14 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 btree_open_out:
   if( rc!=SQLITE_OK ){
     if( pBt && pBt->pPager ){
-      sqlite3PagerClose(pBt->pPager);
+      sqlite3PagerClose(pBt->pPager, 0);
     }
     sqlite3_free(pBt);
     sqlite3_free(p);
     *ppBtree = 0;
   }else{
+    sqlite3_file *pFile;
+
     /* If the B-Tree was successfully opened, set the pager-cache size to the
     ** default value. Except, when opening on an existing shared pager-cache,
     ** do not change the pager-cache size.
@@ -54785,11 +62031,17 @@ btree_open_out:
     if( sqlite3BtreeSchema(p, 0, 0)==0 ){
       sqlite3PagerSetCachesize(p->pBt->pPager, SQLITE_DEFAULT_CACHE_SIZE);
     }
+
+    pFile = sqlite3PagerFile(pBt->pPager);
+    if( pFile->pMethods ){
+      sqlite3OsFileControlHint(pFile, SQLITE_FCNTL_PDB, (void*)&pBt->db);
+    }
   }
   if( mutexOpen ){
     assert( sqlite3_mutex_held(mutexOpen) );
     sqlite3_mutex_leave(mutexOpen);
   }
+  assert( rc!=SQLITE_OK || sqlite3BtreeConnectionCount(*ppBtree)>0 );
   return rc;
 }
 
@@ -54913,7 +62165,7 @@ SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){
     ** Clean out and delete the BtShared object.
     */
     assert( !pBt->pCursor );
-    sqlite3PagerClose(pBt->pPager);
+    sqlite3PagerClose(pBt->pPager, p->db);
     if( pBt->xFreeSchema && pBt->pSchema ){
       pBt->xFreeSchema(pBt->pSchema);
     }
@@ -54934,19 +62186,11 @@ SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){
 }
 
 /*
-** Change the limit on the number of pages allowed in the cache.
-**
-** The maximum number of cache pages is set to the absolute
-** value of mxPage.  If mxPage is negative, the pager will
-** operate asynchronously - it will not stop to do fsync()s
-** to insure data is written to the disk surface before
-** continuing.  Transactions still work if synchronous is off,
-** and the database cannot be corrupted if this program
-** crashes.  But if the operating system crashes or there is
-** an abrupt power failure when synchronous is off, the database
-** could be left in an inconsistent and unrecoverable state.
-** Synchronous is on by default so database corruption is not
-** normally a worry.
+** Change the "soft" limit on the number of pages in the cache.
+** Unused and unmodified pages will be recycled when the number of
+** pages in the cache exceeds this soft limit.  But the size of the
+** cache is allowed to grow larger than this limit if it contains
+** dirty pages or pages still in active use.
 */
 SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
   BtShared *pBt = p->pBt;
@@ -54957,6 +62201,26 @@ SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
   return SQLITE_OK;
 }
 
+/*
+** Change the "spill" limit on the number of pages in the cache.
+** If the number of pages exceeds this limit during a write transaction,
+** the pager might attempt to "spill" pages to the journal early in
+** order to free up memory.
+**
+** The value returned is the current spill size.  If zero is passed
+** as an argument, no changes are made to the spill size setting, so
+** using mxPage of 0 is a way to query the current spill size.
+*/
+SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree *p, int mxPage){
+  BtShared *pBt = p->pBt;
+  int res;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  res = sqlite3PagerSetSpillsize(pBt->pPager, mxPage);
+  sqlite3BtreeLeave(p);
+  return res;
+}
+
 #if SQLITE_MAX_MMAP_SIZE>0
 /*
 ** Change the limit on the amount of the database file that may be
@@ -54994,21 +62258,6 @@ SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(
 }
 #endif
 
-/*
-** Return TRUE if the given btree is set to safety level 1.  In other
-** words, return TRUE if no sync() occurs on the disk files.
-*/
-SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree *p){
-  BtShared *pBt = p->pBt;
-  int rc;
-  assert( sqlite3_mutex_held(p->db->mutex) );  
-  sqlite3BtreeEnter(p);
-  assert( pBt && pBt->pPager );
-  rc = sqlite3PagerNosync(pBt->pPager);
-  sqlite3BtreeLeave(p);
-  return rc;
-}
-
 /*
 ** Change the default pages size and the number of reserved bytes per page.
 ** Or, if the page size has already been fixed, return SQLITE_READONLY 
@@ -55034,6 +62283,9 @@ SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve,
   BtShared *pBt = p->pBt;
   assert( nReserve>=-1 && nReserve<=255 );
   sqlite3BtreeEnter(p);
+#if SQLITE_HAS_CODEC
+  if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;
+#endif
   if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
     sqlite3BtreeLeave(p);
     return SQLITE_READONLY;
@@ -55045,7 +62297,7 @@ SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve,
   if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
         ((pageSize-1)&pageSize)==0 ){
     assert( (pageSize & 7)==0 );
-    assert( !pBt->pPage1 && !pBt->pCursor );
+    assert( !pBt->pCursor );
     pBt->pageSize = (u32)pageSize;
     freeTempSpace(pBt);
   }
@@ -55063,7 +62315,6 @@ SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree *p){
   return p->pBt->pageSize;
 }
 
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
 /*
 ** This function is similar to sqlite3BtreeGetReserve(), except that it
 ** may only be called if it is guaranteed that the b-tree mutex is already
@@ -55076,25 +62327,33 @@ SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree *p){
 ** database handle that owns *p, causing undefined behavior.
 */
 SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p){
+  int n;
   assert( sqlite3_mutex_held(p->pBt->mutex) );
-  return p->pBt->pageSize - p->pBt->usableSize;
+  n = p->pBt->pageSize - p->pBt->usableSize;
+  return n;
 }
-#endif /* SQLITE_HAS_CODEC || SQLITE_DEBUG */
 
-#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
 /*
 ** Return the number of bytes of space at the end of every page that
 ** are intentually left unused.  This is the "reserved" space that is
 ** sometimes used by extensions.
+**
+** If SQLITE_HAS_MUTEX is defined then the number returned is the
+** greater of the current reserved space and the maximum requested
+** reserve space.
 */
-SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree *p){
+SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree *p){
   int n;
   sqlite3BtreeEnter(p);
-  n = p->pBt->pageSize - p->pBt->usableSize;
+  n = sqlite3BtreeGetReserveNoMutex(p);
+#ifdef SQLITE_HAS_CODEC
+  if( npBt->optimalReserve ) n = p->pBt->optimalReserve;
+#endif
   sqlite3BtreeLeave(p);
   return n;
 }
 
+
 /*
 ** Set the maximum page count for a database if mxPage is positive.
 ** No changes are made if mxPage is 0 or negative.
@@ -55109,23 +62368,37 @@ SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){
 }
 
 /*
-** Set the BTS_SECURE_DELETE flag if newFlag is 0 or 1.  If newFlag is -1,
-** then make no changes.  Always return the value of the BTS_SECURE_DELETE
-** setting after the change.
+** Change the values for the BTS_SECURE_DELETE and BTS_OVERWRITE flags:
+**
+**    newFlag==0       Both BTS_SECURE_DELETE and BTS_OVERWRITE are cleared
+**    newFlag==1       BTS_SECURE_DELETE set and BTS_OVERWRITE is cleared
+**    newFlag==2       BTS_SECURE_DELETE cleared and BTS_OVERWRITE is set
+**    newFlag==(-1)    No changes
+**
+** This routine acts as a query if newFlag is less than zero
+**
+** With BTS_OVERWRITE set, deleted content is overwritten by zeros, but
+** freelist leaf pages are not written back to the database.  Thus in-page
+** deleted content is cleared, but freelist deleted content is not.
+**
+** With BTS_SECURE_DELETE, operation is like BTS_OVERWRITE with the addition
+** that freelist leaf pages are written back into the database, increasing
+** the amount of disk I/O.
 */
 SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
   int b;
   if( p==0 ) return 0;
   sqlite3BtreeEnter(p);
+  assert( BTS_OVERWRITE==BTS_SECURE_DELETE*2 );
+  assert( BTS_FAST_SECURE==(BTS_OVERWRITE|BTS_SECURE_DELETE) );
   if( newFlag>=0 ){
-    p->pBt->btsFlags &= ~BTS_SECURE_DELETE;
-    if( newFlag ) p->pBt->btsFlags |= BTS_SECURE_DELETE;
-  } 
-  b = (p->pBt->btsFlags & BTS_SECURE_DELETE)!=0;
+    p->pBt->btsFlags &= ~BTS_FAST_SECURE;
+    p->pBt->btsFlags |= BTS_SECURE_DELETE*newFlag;
+  }
+  b = (p->pBt->btsFlags & BTS_FAST_SECURE)/BTS_SECURE_DELETE;
   sqlite3BtreeLeave(p);
   return b;
 }
-#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
 
 /*
 ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
@@ -55173,6 +62446,31 @@ SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *p){
 #endif
 }
 
+/*
+** If the user has not set the safety-level for this database connection
+** using "PRAGMA synchronous", and if the safety-level is not already
+** set to the value passed to this function as the second parameter,
+** set it so.
+*/
+#if SQLITE_DEFAULT_SYNCHRONOUS!=SQLITE_DEFAULT_WAL_SYNCHRONOUS
+static void setDefaultSyncFlag(BtShared *pBt, u8 safety_level){
+  sqlite3 *db;
+  Db *pDb;
+  if( (db=pBt->db)!=0 && (pDb=db->aDb)!=0 ){
+    while( pDb->pBt==0 || pDb->pBt->pBt!=pBt ){ pDb++; }
+    if( pDb->bSyncSet==0 
+     && pDb->safety_level!=safety_level 
+     && pDb!=&db->aDb[1] 
+    ){
+      pDb->safety_level = safety_level;
+      sqlite3PagerSetFlags(pBt->pPager,
+          pDb->safety_level | (db->flags & PAGER_FLAGS_MASK));
+    }
+  }
+}
+#else
+# define setDefaultSyncFlag(pBt,safety_level)
+#endif
 
 /*
 ** Get a reference to pPage1 of the database file.  This will
@@ -55245,11 +62543,16 @@ static int lockBtree(BtShared *pBt){
       rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
       if( rc!=SQLITE_OK ){
         goto page1_init_failed;
-      }else if( isOpen==0 ){
-        releasePage(pPage1);
-        return SQLITE_OK;
+      }else{
+        setDefaultSyncFlag(pBt, SQLITE_DEFAULT_WAL_SYNCHRONOUS+1);
+        if( isOpen==0 ){
+          releasePage(pPage1);
+          return SQLITE_OK;
+        }
       }
       rc = SQLITE_NOTADB;
+    }else{
+      setDefaultSyncFlag(pBt, SQLITE_DEFAULT_SYNCHRONOUS+1);
     }
 #endif
 
@@ -55298,7 +62601,7 @@ static int lockBtree(BtShared *pBt){
                                    pageSize-usableSize);
       return rc;
     }
-    if( (pBt->db->flags & SQLITE_RecoveryMode)==0 && nPage>nPageFile ){
+    if( (pBt->db->flags & SQLITE_WriteSchema)==0 && nPage>nPageFile ){
       rc = SQLITE_CORRUPT_BKPT;
       goto page1_init_failed;
     }
@@ -55389,7 +62692,7 @@ static void unlockBtreeIfUnused(BtShared *pBt){
     assert( pPage1->aData );
     assert( sqlite3PagerRefcount(pBt->pPager)==1 );
     pBt->pPage1 = 0;
-    releasePage(pPage1);
+    releasePageNotNull(pPage1);
   }
 }
 
@@ -55487,7 +62790,6 @@ SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p){
 ** proceed.
 */
 SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
-  sqlite3 *pBlock = 0;
   BtShared *pBt = p->pBt;
   int rc = SQLITE_OK;
 
@@ -55510,27 +62812,30 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
   }
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
-  /* If another database handle has already opened a write transaction 
-  ** on this shared-btree structure and a second write transaction is
-  ** requested, return SQLITE_LOCKED.
-  */
-  if( (wrflag && pBt->inTransaction==TRANS_WRITE)
-   || (pBt->btsFlags & BTS_PENDING)!=0
-  ){
-    pBlock = pBt->pWriter->db;
-  }else if( wrflag>1 ){
-    BtLock *pIter;
-    for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
-      if( pIter->pBtree!=p ){
-        pBlock = pIter->pBtree->db;
-        break;
+  {
+    sqlite3 *pBlock = 0;
+    /* If another database handle has already opened a write transaction 
+    ** on this shared-btree structure and a second write transaction is
+    ** requested, return SQLITE_LOCKED.
+    */
+    if( (wrflag && pBt->inTransaction==TRANS_WRITE)
+     || (pBt->btsFlags & BTS_PENDING)!=0
+    ){
+      pBlock = pBt->pWriter->db;
+    }else if( wrflag>1 ){
+      BtLock *pIter;
+      for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
+        if( pIter->pBtree!=p ){
+          pBlock = pIter->pBtree->db;
+          break;
+        }
       }
     }
-  }
-  if( pBlock ){
-    sqlite3ConnectionBlocked(p->db, pBlock);
-    rc = SQLITE_LOCKED_SHAREDCACHE;
-    goto trans_begun;
+    if( pBlock ){
+      sqlite3ConnectionBlocked(p->db, pBlock);
+      rc = SQLITE_LOCKED_SHAREDCACHE;
+      goto trans_begun;
+    }
   }
 #endif
 
@@ -55636,14 +62941,11 @@ static int setChildPtrmaps(MemPage *pPage){
   int nCell;                         /* Number of cells in page pPage */
   int rc;                            /* Return code */
   BtShared *pBt = pPage->pBt;
-  u8 isInitOrig = pPage->isInit;
   Pgno pgno = pPage->pgno;
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  rc = btreeInitPage(pPage);
-  if( rc!=SQLITE_OK ){
-    goto set_child_ptrmaps_out;
-  }
+  rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);
+  if( rc!=SQLITE_OK ) return rc;
   nCell = pPage->nCell;
 
   for(i=0; iisInit = isInitOrig;
   return rc;
 }
 
@@ -55687,28 +62987,31 @@ static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
   if( eType==PTRMAP_OVERFLOW2 ){
     /* The pointer is always the first 4 bytes of the page in this case.  */
     if( get4byte(pPage->aData)!=iFrom ){
-      return SQLITE_CORRUPT_BKPT;
+      return SQLITE_CORRUPT_PGNO(pPage->pgno);
     }
     put4byte(pPage->aData, iTo);
   }else{
-    u8 isInitOrig = pPage->isInit;
     int i;
     int nCell;
+    int rc;
 
-    btreeInitPage(pPage);
+    rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);
+    if( rc ) return rc;
     nCell = pPage->nCell;
 
     for(i=0; iaData+pPage->maskPage
-         && iFrom==get4byte(&pCell[info.iOverflow])
-        ){
-          put4byte(&pCell[info.iOverflow], iTo);
-          break;
+        pPage->xParseCell(pPage, pCell, &info);
+        if( info.nLocal pPage->aData+pPage->pBt->usableSize ){
+            return SQLITE_CORRUPT_PGNO(pPage->pgno);
+          }
+          if( iFrom==get4byte(pCell+info.nSize-4) ){
+            put4byte(pCell+info.nSize-4, iTo);
+            break;
+          }
         }
       }else{
         if( get4byte(pCell)==iFrom ){
@@ -55721,12 +63024,10 @@ static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
     if( i==nCell ){
       if( eType!=PTRMAP_BTREE || 
           get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){
-        return SQLITE_CORRUPT_BKPT;
+        return SQLITE_CORRUPT_PGNO(pPage->pgno);
       }
       put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);
     }
-
-    pPage->isInit = isInitOrig;
   }
   return SQLITE_OK;
 }
@@ -56001,7 +63302,7 @@ SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *p){
 static int autoVacuumCommit(BtShared *pBt){
   int rc = SQLITE_OK;
   Pager *pPager = pBt->pPager;
-  VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager) );
+  VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager); )
 
   assert( sqlite3_mutex_held(pBt->mutex) );
   invalidateAllOverflowCache(pBt);
@@ -56245,7 +63546,7 @@ SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int wr
     for(p=pBtree->pBt->pCursor; p; p=p->pNext){
       int i;
       if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){
-        if( p->eState==CURSOR_VALID ){
+        if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
           rc = saveCursorPosition(p);
           if( rc!=SQLITE_OK ){
             (void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);
@@ -56385,7 +63686,12 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
     assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );
     assert( iSavepoint>=0 || (iSavepoint==-1 && op==SAVEPOINT_ROLLBACK) );
     sqlite3BtreeEnter(p);
-    rc = sqlite3PagerSavepoint(pBt->pPager, op, iSavepoint);
+    if( op==SAVEPOINT_ROLLBACK ){
+      rc = saveAllCursors(pBt, 0, 0);
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3PagerSavepoint(pBt->pPager, op, iSavepoint);
+    }
     if( rc==SQLITE_OK ){
       if( iSavepoint<0 && (pBt->btsFlags & BTS_INITIALLY_EMPTY)!=0 ){
         pBt->nPage = 0;
@@ -56410,13 +63716,13 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
 ** on the database already. If a write-cursor is requested, then
 ** the caller is assumed to have an open write transaction.
 **
-** If wrFlag==0, then the cursor can only be used for reading.
-** If wrFlag==1, then the cursor can be used for reading or for
-** writing if other conditions for writing are also met.  These
-** are the conditions that must be met in order for writing to
-** be allowed:
+** If the BTREE_WRCSR bit of wrFlag is clear, then the cursor can only
+** be used for reading.  If the BTREE_WRCSR bit is set, then the cursor
+** can be used for reading or for writing if other conditions for writing
+** are also met.  These are the conditions that must be met in order
+** for writing to be allowed:
 **
-** 1:  The cursor must have been opened with wrFlag==1
+** 1:  The cursor must have been opened with wrFlag containing BTREE_WRCSR
 **
 ** 2:  Other database connections that share the same pager cache
 **     but which are not in the READ_UNCOMMITTED state may not have
@@ -56428,6 +63734,16 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
 **
 ** 4:  There must be an active transaction.
 **
+** The BTREE_FORDELETE bit of wrFlag may optionally be set if BTREE_WRCSR
+** is set.  If FORDELETE is set, that is a hint to the implementation that
+** this cursor will only be used to seek to and delete entries of an index
+** as part of a larger DELETE statement.  The FORDELETE hint is not used by
+** this implementation.  But in a hypothetical alternative storage engine 
+** in which index entries are automatically deleted when corresponding table
+** rows are deleted, the FORDELETE flag is a hint that all SEEK and DELETE
+** operations on this cursor can be no-ops and all READ operations can 
+** return a null row (2-bytes: 0x01 0x00).
+**
 ** No checking is done to make sure that page iTable really is the
 ** root page of a b-tree.  If it is not, then the cursor acquired
 ** will not work correctly.
@@ -56443,28 +63759,30 @@ static int btreeCursor(
   BtCursor *pCur                         /* Space for new cursor */
 ){
   BtShared *pBt = p->pBt;                /* Shared b-tree handle */
+  BtCursor *pX;                          /* Looping over other all cursors */
 
   assert( sqlite3BtreeHoldsMutex(p) );
-  assert( wrFlag==0 || wrFlag==1 );
+  assert( wrFlag==0 
+       || wrFlag==BTREE_WRCSR 
+       || wrFlag==(BTREE_WRCSR|BTREE_FORDELETE) 
+  );
 
   /* The following assert statements verify that if this is a sharable 
   ** b-tree database, the connection is holding the required table locks, 
   ** and that no other connection has any open cursor that conflicts with 
   ** this lock.  */
-  assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, wrFlag+1) );
+  assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, (wrFlag?2:1)) );
   assert( wrFlag==0 || !hasReadConflicts(p, iTable) );
 
   /* Assert that the caller has opened the required transaction. */
   assert( p->inTrans>TRANS_NONE );
   assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
   assert( pBt->pPage1 && pBt->pPage1->aData );
+  assert( wrFlag==0 || (pBt->btsFlags & BTS_READ_ONLY)==0 );
 
-  if( NEVER(wrFlag && (pBt->btsFlags & BTS_READ_ONLY)!=0) ){
-    return SQLITE_READONLY;
-  }
   if( wrFlag ){
     allocateTempSpace(pBt);
-    if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM;
+    if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM_BKPT;
   }
   if( iTable==1 && btreePagecount(pBt)==0 ){
     assert( wrFlag==0 );
@@ -56478,12 +63796,17 @@ static int btreeCursor(
   pCur->pKeyInfo = pKeyInfo;
   pCur->pBtree = p;
   pCur->pBt = pBt;
-  assert( wrFlag==0 || wrFlag==BTCF_WriteFlag );
-  pCur->curFlags = wrFlag;
-  pCur->pNext = pBt->pCursor;
-  if( pCur->pNext ){
-    pCur->pNext->pPrev = pCur;
+  pCur->curFlags = wrFlag ? BTCF_WriteFlag : 0;
+  pCur->curPagerFlags = wrFlag ? 0 : PAGER_GET_READONLY;
+  /* If there are two or more cursors on the same btree, then all such
+  ** cursors *must* have the BTCF_Multiple flag set. */
+  for(pX=pBt->pCursor; pX; pX=pX->pNext){
+    if( pX->pgnoRoot==(Pgno)iTable ){
+      pX->curFlags |= BTCF_Multiple;
+      pCur->curFlags |= BTCF_Multiple;
+    }
   }
+  pCur->pNext = pBt->pCursor;
   pBt->pCursor = pCur;
   pCur->eState = CURSOR_INVALID;
   return SQLITE_OK;
@@ -56496,9 +63819,13 @@ SQLITE_PRIVATE int sqlite3BtreeCursor(
   BtCursor *pCur                              /* Write new cursor here */
 ){
   int rc;
-  sqlite3BtreeEnter(p);
-  rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
-  sqlite3BtreeLeave(p);
+  if( iTable<1 ){
+    rc = SQLITE_CORRUPT_BKPT;
+  }else{
+    sqlite3BtreeEnter(p);
+    rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
+    sqlite3BtreeLeave(p);
+  }
   return rc;
 }
 
@@ -56537,13 +63864,18 @@ SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
     BtShared *pBt = pCur->pBt;
     sqlite3BtreeEnter(pBtree);
     sqlite3BtreeClearCursor(pCur);
-    if( pCur->pPrev ){
-      pCur->pPrev->pNext = pCur->pNext;
-    }else{
+    assert( pBt->pCursor!=0 );
+    if( pBt->pCursor==pCur ){
       pBt->pCursor = pCur->pNext;
-    }
-    if( pCur->pNext ){
-      pCur->pNext->pPrev = pCur->pPrev;
+    }else{
+      BtCursor *pPrev = pBt->pCursor;
+      do{
+        if( pPrev->pNext==pCur ){
+          pPrev->pNext = pCur->pNext;
+          break;
+        }
+        pPrev = pPrev->pNext;
+      }while( ALWAYS(pPrev) );
     }
     for(i=0; i<=pCur->iPage; i++){
       releasePage(pCur->apPage[i]);
@@ -56563,47 +63895,27 @@ SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
 **
 ** BtCursor.info is a cache of the information in the current cell.
 ** Using this cache reduces the number of calls to btreeParseCell().
-**
-** 2007-06-25:  There is a bug in some versions of MSVC that cause the
-** compiler to crash when getCellInfo() is implemented as a macro.
-** But there is a measureable speed advantage to using the macro on gcc
-** (when less compiler optimizations like -Os or -O0 are used and the
-** compiler is not doing aggressive inlining.)  So we use a real function
-** for MSVC and a macro for everything else.  Ticket #2457.
 */
 #ifndef NDEBUG
   static void assertCellInfo(BtCursor *pCur){
     CellInfo info;
     int iPage = pCur->iPage;
     memset(&info, 0, sizeof(info));
-    btreeParseCell(pCur->apPage[iPage], pCur->aiIdx[iPage], &info);
+    btreeParseCell(pCur->apPage[iPage], pCur->ix, &info);
     assert( CORRUPT_DB || memcmp(&info, &pCur->info, sizeof(info))==0 );
   }
 #else
   #define assertCellInfo(x)
 #endif
-#ifdef _MSC_VER
-  /* Use a real function in MSVC to work around bugs in that compiler. */
-  static void getCellInfo(BtCursor *pCur){
-    if( pCur->info.nSize==0 ){
-      int iPage = pCur->iPage;
-      btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
-      pCur->curFlags |= BTCF_ValidNKey;
-    }else{
-      assertCellInfo(pCur);
-    }
-  }
-#else /* if not _MSC_VER */
-  /* Use a macro in all other compilers so that the function is inlined */
-#define getCellInfo(pCur)                                                      \
-  if( pCur->info.nSize==0 ){                                                   \
-    int iPage = pCur->iPage;                                                   \
-    btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);        \
-    pCur->curFlags |= BTCF_ValidNKey;                                          \
-  }else{                                                                       \
-    assertCellInfo(pCur);                                                      \
+static SQLITE_NOINLINE void getCellInfo(BtCursor *pCur){
+  if( pCur->info.nSize==0 ){
+    int iPage = pCur->iPage;
+    pCur->curFlags |= BTCF_ValidNKey;
+    btreeParseCell(pCur->apPage[iPage],pCur->ix,&pCur->info);
+  }else{
+    assertCellInfo(pCur);
   }
-#endif /* _MSC_VER */
+}
 
 #ifndef NDEBUG  /* The next routine used only within assert() statements */
 /*
@@ -56615,46 +63927,39 @@ SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor *pCur){
   return pCur && pCur->eState==CURSOR_VALID;
 }
 #endif /* NDEBUG */
+SQLITE_PRIVATE int sqlite3BtreeCursorIsValidNN(BtCursor *pCur){
+  assert( pCur!=0 );
+  return pCur->eState==CURSOR_VALID;
+}
 
 /*
-** Set *pSize to the size of the buffer needed to hold the value of
-** the key for the current entry.  If the cursor is not pointing
-** to a valid entry, *pSize is set to 0. 
-**
-** For a table with the INTKEY flag set, this routine returns the key
-** itself, not the number of bytes in the key.
-**
-** The caller must position the cursor prior to invoking this routine.
-** 
-** This routine cannot fail.  It always returns SQLITE_OK.  
+** Return the value of the integer key or "rowid" for a table btree.
+** This routine is only valid for a cursor that is pointing into a
+** ordinary table btree.  If the cursor points to an index btree or
+** is invalid, the result of this routine is undefined.
 */
-SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
+SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor *pCur){
   assert( cursorHoldsMutex(pCur) );
   assert( pCur->eState==CURSOR_VALID );
+  assert( pCur->curIntKey );
   getCellInfo(pCur);
-  *pSize = pCur->info.nKey;
-  return SQLITE_OK;
+  return pCur->info.nKey;
 }
 
 /*
-** Set *pSize to the number of bytes of data in the entry the
-** cursor currently points to.
+** Return the number of bytes of payload for the entry that pCur is
+** currently pointing to.  For table btrees, this will be the amount
+** of data.  For index btrees, this will be the size of the key.
 **
 ** The caller must guarantee that the cursor is pointing to a non-NULL
 ** valid entry.  In other words, the calling procedure must guarantee
 ** that the cursor has Cursor.eState==CURSOR_VALID.
-**
-** Failure is not possible.  This function always returns SQLITE_OK.
-** It might just as well be a procedure (returning void) but we continue
-** to return an integer result code for historical reasons.
 */
-SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
+SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor *pCur){
   assert( cursorHoldsMutex(pCur) );
   assert( pCur->eState==CURSOR_VALID );
-  assert( pCur->apPage[pCur->iPage]->intKeyLeaf==1 );
   getCellInfo(pCur);
-  *pSize = pCur->info.nPayload;
-  return SQLITE_OK;
+  return pCur->info.nPayload;
 }
 
 /*
@@ -56772,7 +64077,6 @@ static int copyPayload(
 **
 **   0: The operation is a read. Populate the overflow cache.
 **   1: The operation is a write. Populate the overflow cache.
-**   2: The operation is a read. Do not populate the overflow cache.
 **
 ** A total of "amt" bytes are read or written beginning at "offset".
 ** Data is read to or from the buffer pBuf.
@@ -56780,13 +64084,13 @@ static int copyPayload(
 ** The content being read or written might appear on the main page
 ** or be scattered out on multiple overflow pages.
 **
-** If the current cursor entry uses one or more overflow pages and the
-** eOp argument is not 2, this function may allocate space for and lazily 
-** populates the overflow page-list cache array (BtCursor.aOverflow). 
+** If the current cursor entry uses one or more overflow pages
+** this function may allocate space for and lazily populate
+** the overflow page-list cache array (BtCursor.aOverflow). 
 ** Subsequent calls use this cache to make seeking to the supplied offset 
 ** more efficient.
 **
-** Once an overflow page-list cache has been allocated, it may be
+** Once an overflow page-list cache has been allocated, it must be
 ** invalidated if some other cursor writes to the same table, or if
 ** the cursor is moved to a different row. Additionally, in auto-vacuum
 ** mode, the following events may invalidate an overflow page-list cache.
@@ -56808,26 +64112,27 @@ static int accessPayload(
   MemPage *pPage = pCur->apPage[pCur->iPage]; /* Btree page of current entry */
   BtShared *pBt = pCur->pBt;                  /* Btree this cursor belongs to */
 #ifdef SQLITE_DIRECT_OVERFLOW_READ
-  unsigned char * const pBufStart = pBuf;
-  int bEnd;                                 /* True if reading to end of data */
+  unsigned char * const pBufStart = pBuf;     /* Start of original out buffer */
 #endif
 
   assert( pPage );
+  assert( eOp==0 || eOp==1 );
   assert( pCur->eState==CURSOR_VALID );
-  assert( pCur->aiIdx[pCur->iPage]nCell );
+  assert( pCur->ixnCell );
   assert( cursorHoldsMutex(pCur) );
-  assert( eOp!=2 || offset==0 );    /* Always start from beginning for eOp==2 */
 
   getCellInfo(pCur);
   aPayload = pCur->info.pPayload;
-#ifdef SQLITE_DIRECT_OVERFLOW_READ
-  bEnd = offset+amt==pCur->info.nPayload;
-#endif
   assert( offset+amt <= pCur->info.nPayload );
 
-  if( &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize] ){
-    /* Trying to read or write past the end of the data is an error */
-    return SQLITE_CORRUPT_BKPT;
+  assert( aPayload > pPage->aData );
+  if( (uptr)(aPayload - pPage->aData) > (pBt->usableSize - pCur->info.nLocal) ){
+    /* Trying to read or write past the end of the data is an error.  The
+    ** conditional above is really:
+    **    &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
+    ** but is recast into its current form to avoid integer overflow problems
+    */
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
   }
 
   /* Check if data must be read/written to/from the btree page itself. */
@@ -56836,7 +64141,7 @@ static int accessPayload(
     if( a+offset>pCur->info.nLocal ){
       a = pCur->info.nLocal - offset;
     }
-    rc = copyPayload(&aPayload[offset], pBuf, a, (eOp & 0x01), pPage->pDbPage);
+    rc = copyPayload(&aPayload[offset], pBuf, a, eOp, pPage->pDbPage);
     offset = 0;
     pBuf += a;
     amt -= a;
@@ -56852,51 +64157,46 @@ static int accessPayload(
     nextPage = get4byte(&aPayload[pCur->info.nLocal]);
 
     /* If the BtCursor.aOverflow[] has not been allocated, allocate it now.
-    ** Except, do not allocate aOverflow[] for eOp==2.
     **
     ** The aOverflow[] array is sized at one entry for each overflow page
     ** in the overflow chain. The page number of the first overflow page is
     ** stored in aOverflow[0], etc. A value of 0 in the aOverflow[] array
     ** means "not yet known" (the cache is lazily populated).
     */
-    if( eOp!=2 && (pCur->curFlags & BTCF_ValidOvfl)==0 ){
+    if( (pCur->curFlags & BTCF_ValidOvfl)==0 ){
       int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
       if( nOvfl>pCur->nOvflAlloc ){
         Pgno *aNew = (Pgno*)sqlite3Realloc(
             pCur->aOverflow, nOvfl*2*sizeof(Pgno)
         );
         if( aNew==0 ){
-          rc = SQLITE_NOMEM;
+          return SQLITE_NOMEM_BKPT;
         }else{
           pCur->nOvflAlloc = nOvfl*2;
           pCur->aOverflow = aNew;
         }
       }
-      if( rc==SQLITE_OK ){
-        memset(pCur->aOverflow, 0, nOvfl*sizeof(Pgno));
-        pCur->curFlags |= BTCF_ValidOvfl;
+      memset(pCur->aOverflow, 0, nOvfl*sizeof(Pgno));
+      pCur->curFlags |= BTCF_ValidOvfl;
+    }else{
+      /* If the overflow page-list cache has been allocated and the
+      ** entry for the first required overflow page is valid, skip
+      ** directly to it.
+      */
+      if( pCur->aOverflow[offset/ovflSize] ){
+        iIdx = (offset/ovflSize);
+        nextPage = pCur->aOverflow[iIdx];
+        offset = (offset%ovflSize);
       }
     }
 
-    /* If the overflow page-list cache has been allocated and the
-    ** entry for the first required overflow page is valid, skip
-    ** directly to it.
-    */
-    if( (pCur->curFlags & BTCF_ValidOvfl)!=0
-     && pCur->aOverflow[offset/ovflSize]
-    ){
-      iIdx = (offset/ovflSize);
-      nextPage = pCur->aOverflow[iIdx];
-      offset = (offset%ovflSize);
-    }
-
-    for( ; rc==SQLITE_OK && amt>0 && nextPage; iIdx++){
-
+    assert( rc==SQLITE_OK && amt>0 );
+    while( nextPage ){
       /* If required, populate the overflow page-list cache. */
-      if( (pCur->curFlags & BTCF_ValidOvfl)!=0 ){
-        assert(!pCur->aOverflow[iIdx] || pCur->aOverflow[iIdx]==nextPage);
-        pCur->aOverflow[iIdx] = nextPage;
-      }
+      assert( pCur->aOverflow[iIdx]==0
+              || pCur->aOverflow[iIdx]==nextPage
+              || CORRUPT_DB );
+      pCur->aOverflow[iIdx] = nextPage;
 
       if( offset>=ovflSize ){
         /* The only reason to read this page is to obtain the page
@@ -56904,11 +64204,7 @@ static int accessPayload(
         ** data is not required. So first try to lookup the overflow
         ** page-list cache, if any, then fall back to the getOverflowPage()
         ** function.
-        **
-        ** Note that the aOverflow[] array must be allocated because eOp!=2
-        ** here.  If eOp==2, then offset==0 and this branch is never taken.
         */
-        assert( eOp!=2 );
         assert( pCur->curFlags & BTCF_ValidOvfl );
         assert( pCur->pBtree->db==pBt->db );
         if( pCur->aOverflow[iIdx+1] ){
@@ -56922,7 +64218,7 @@ static int accessPayload(
         ** range of data that is being read (eOp==0) or written (eOp!=0).
         */
 #ifdef SQLITE_DIRECT_OVERFLOW_READ
-        sqlite3_file *fd;
+        sqlite3_file *fd;      /* File from which to do direct overflow read */
 #endif
         int a = amt;
         if( a + offset > ovflSize ){
@@ -56934,27 +64230,25 @@ static int accessPayload(
         **
         **   1) this is a read operation, and 
         **   2) data is required from the start of this overflow page, and
-        **   3) the database is file-backed, and
-        **   4) there is no open write-transaction, and
-        **   5) the database is not a WAL database,
-        **   6) all data from the page is being read.
-        **   7) at least 4 bytes have already been read into the output buffer 
+        **   3) there is no open write-transaction, and
+        **   4) the database is file-backed, and
+        **   5) the page is not in the WAL file
+        **   6) at least 4 bytes have already been read into the output buffer 
         **
         ** then data can be read directly from the database file into the
         ** output buffer, bypassing the page-cache altogether. This speeds
         ** up loading large records that span many overflow pages.
         */
-        if( (eOp&0x01)==0                                      /* (1) */
+        if( eOp==0                                             /* (1) */
          && offset==0                                          /* (2) */
-         && (bEnd || a==ovflSize)                              /* (6) */
-         && pBt->inTransaction==TRANS_READ                     /* (4) */
-         && (fd = sqlite3PagerFile(pBt->pPager))->pMethods     /* (3) */
-         && pBt->pPage1->aData[19]==0x01                       /* (5) */
-         && &pBuf[-4]>=pBufStart                               /* (7) */
+         && pBt->inTransaction==TRANS_READ                     /* (3) */
+         && (fd = sqlite3PagerFile(pBt->pPager))->pMethods     /* (4) */
+         && 0==sqlite3PagerUseWal(pBt->pPager, nextPage)       /* (5) */
+         && &pBuf[-4]>=pBufStart                               /* (6) */
         ){
           u8 aSave[4];
           u8 *aWrite = &pBuf[-4];
-          assert( aWrite>=pBufStart );                         /* hence (7) */
+          assert( aWrite>=pBufStart );                         /* due to (6) */
           memcpy(aSave, aWrite, 4);
           rc = sqlite3OsRead(fd, aWrite, a+4, (i64)pBt->pageSize*(nextPage-1));
           nextPage = get4byte(aWrite);
@@ -56964,77 +64258,87 @@ static int accessPayload(
 
         {
           DbPage *pDbPage;
-          rc = sqlite3PagerAcquire(pBt->pPager, nextPage, &pDbPage,
-              ((eOp&0x01)==0 ? PAGER_GET_READONLY : 0)
+          rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage,
+              (eOp==0 ? PAGER_GET_READONLY : 0)
           );
           if( rc==SQLITE_OK ){
             aPayload = sqlite3PagerGetData(pDbPage);
             nextPage = get4byte(aPayload);
-            rc = copyPayload(&aPayload[offset+4], pBuf, a, (eOp&0x01), pDbPage);
+            rc = copyPayload(&aPayload[offset+4], pBuf, a, eOp, pDbPage);
             sqlite3PagerUnref(pDbPage);
             offset = 0;
           }
         }
         amt -= a;
+        if( amt==0 ) return rc;
         pBuf += a;
       }
+      if( rc ) break;
+      iIdx++;
     }
   }
 
   if( rc==SQLITE_OK && amt>0 ){
-    return SQLITE_CORRUPT_BKPT;
+    /* Overflow chain ends prematurely */
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
   }
   return rc;
 }
 
 /*
-** Read part of the key associated with cursor pCur.  Exactly
-** "amt" bytes will be transferred into pBuf[].  The transfer
+** Read part of the payload for the row at which that cursor pCur is currently
+** pointing.  "amt" bytes will be transferred into pBuf[].  The transfer
 ** begins at "offset".
 **
-** The caller must ensure that pCur is pointing to a valid row
-** in the table.
+** pCur can be pointing to either a table or an index b-tree.
+** If pointing to a table btree, then the content section is read.  If
+** pCur is pointing to an index b-tree then the key section is read.
+**
+** For sqlite3BtreePayload(), the caller must ensure that pCur is pointing
+** to a valid row in the table.  For sqlite3BtreePayloadChecked(), the
+** cursor might be invalid or might need to be restored before being read.
 **
 ** Return SQLITE_OK on success or an error code if anything goes
 ** wrong.  An error is returned if "offset+amt" is larger than
 ** the available payload.
 */
-SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+SQLITE_PRIVATE int sqlite3BtreePayload(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
   assert( cursorHoldsMutex(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
-  assert( pCur->aiIdx[pCur->iPage]apPage[pCur->iPage]->nCell );
+  assert( pCur->ixapPage[pCur->iPage]->nCell );
   return accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0);
 }
 
 /*
-** Read part of the data associated with cursor pCur.  Exactly
-** "amt" bytes will be transfered into pBuf[].  The transfer
-** begins at "offset".
-**
-** Return SQLITE_OK on success or an error code if anything goes
-** wrong.  An error is returned if "offset+amt" is larger than
-** the available payload.
+** This variant of sqlite3BtreePayload() works even if the cursor has not
+** in the CURSOR_VALID state.  It is only used by the sqlite3_blob_read()
+** interface.
 */
-SQLITE_PRIVATE int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
-  int rc;
-
 #ifndef SQLITE_OMIT_INCRBLOB
+static SQLITE_NOINLINE int accessPayloadChecked(
+  BtCursor *pCur,
+  u32 offset,
+  u32 amt,
+  void *pBuf
+){
+  int rc;
   if ( pCur->eState==CURSOR_INVALID ){
     return SQLITE_ABORT;
   }
-#endif
-
-  assert( cursorHoldsMutex(pCur) );
-  rc = restoreCursorPosition(pCur);
-  if( rc==SQLITE_OK ){
-    assert( pCur->eState==CURSOR_VALID );
-    assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
-    assert( pCur->aiIdx[pCur->iPage]apPage[pCur->iPage]->nCell );
-    rc = accessPayload(pCur, offset, amt, pBuf, 0);
+  assert( cursorOwnsBtShared(pCur) );
+  rc = btreeRestoreCursorPosition(pCur);
+  return rc ? rc : accessPayload(pCur, offset, amt, pBuf, 0);
+}
+SQLITE_PRIVATE int sqlite3BtreePayloadChecked(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+  if( pCur->eState==CURSOR_VALID ){
+    assert( cursorOwnsBtShared(pCur) );
+    return accessPayload(pCur, offset, amt, pBuf, 0);
+  }else{
+    return accessPayloadChecked(pCur, offset, amt, pBuf);
   }
-  return rc;
 }
+#endif /* SQLITE_OMIT_INCRBLOB */
 
 /*
 ** Return a pointer to payload information from the entry that the 
@@ -57059,13 +64363,18 @@ static const void *fetchPayload(
   BtCursor *pCur,      /* Cursor pointing to entry to read from */
   u32 *pAmt            /* Write the number of available bytes here */
 ){
+  u32 amt;
   assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
   assert( pCur->eState==CURSOR_VALID );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  assert( cursorHoldsMutex(pCur) );
-  assert( pCur->aiIdx[pCur->iPage]apPage[pCur->iPage]->nCell );
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pCur->ixapPage[pCur->iPage]->nCell );
   assert( pCur->info.nSize>0 );
-  *pAmt = pCur->info.nLocal;
+  assert( pCur->info.pPayload>pCur->apPage[pCur->iPage]->aData || CORRUPT_DB );
+  assert( pCur->info.pPayloadapPage[pCur->iPage]->aDataEnd ||CORRUPT_DB);
+  amt = (int)(pCur->apPage[pCur->iPage]->aDataEnd - pCur->info.pPayload);
+  if( pCur->info.nLocalinfo.nLocal;
+  *pAmt = amt;
   return (void*)pCur->info.pPayload;
 }
 
@@ -57084,10 +64393,7 @@ static const void *fetchPayload(
 ** These routines is used to get quick access to key and data
 ** in the common case where no overflow pages are used.
 */
-SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor *pCur, u32 *pAmt){
-  return fetchPayload(pCur, pAmt);
-}
-SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor *pCur, u32 *pAmt){
+SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor *pCur, u32 *pAmt){
   return fetchPayload(pCur, pAmt);
 }
 
@@ -57102,34 +64408,24 @@ SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor *pCur, u32 *pAmt){
 ** vice-versa).
 */
 static int moveToChild(BtCursor *pCur, u32 newPgno){
-  int rc;
-  int i = pCur->iPage;
-  MemPage *pNewPage;
   BtShared *pBt = pCur->pBt;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPageiPage>=0 );
   if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
     return SQLITE_CORRUPT_BKPT;
   }
-  rc = getAndInitPage(pBt, newPgno, &pNewPage,
-               (pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
-  if( rc ) return rc;
-  pCur->apPage[i+1] = pNewPage;
-  pCur->aiIdx[i+1] = 0;
-  pCur->iPage++;
-
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
-  if( pNewPage->nCell<1 || pNewPage->intKey!=pCur->apPage[i]->intKey ){
-    return SQLITE_CORRUPT_BKPT;
-  }
-  return SQLITE_OK;
+  pCur->aiIdx[pCur->iPage++] = pCur->ix;
+  pCur->ix = 0;
+  return getAndInitPage(pBt, newPgno, &pCur->apPage[pCur->iPage],
+                        pCur, pCur->curPagerFlags);
 }
 
-#if 0
+#ifdef SQLITE_DEBUG
 /*
 ** Page pParent is an internal (non-leaf) tree page. This function 
 ** asserts that page number iChild is the left-child if the iIdx'th
@@ -57138,6 +64434,8 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
 ** the page.
 */
 static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
+  if( CORRUPT_DB ) return;  /* The conditions tested below might not be true
+                            ** in a corrupt database */
   assert( iIdx<=pParent->nCell );
   if( iIdx==pParent->nCell ){
     assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );
@@ -57158,29 +64456,20 @@ static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
 ** the largest cell index.
 */
 static void moveToParent(BtCursor *pCur){
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPage>0 );
   assert( pCur->apPage[pCur->iPage] );
-
-  /* UPDATE: It is actually possible for the condition tested by the assert
-  ** below to be untrue if the database file is corrupt. This can occur if
-  ** one cursor has modified page pParent while a reference to it is held 
-  ** by a second cursor. Which can only happen if a single page is linked
-  ** into more than one b-tree structure in a corrupt database.  */
-#if 0
   assertParentIndex(
     pCur->apPage[pCur->iPage-1], 
     pCur->aiIdx[pCur->iPage-1], 
     pCur->apPage[pCur->iPage]->pgno
   );
-#endif
   testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
-
-  releasePage(pCur->apPage[pCur->iPage]);
-  pCur->iPage--;
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+  pCur->ix = pCur->aiIdx[pCur->iPage-1];
+  releasePageNotNull(pCur->apPage[pCur->iPage--]);
 }
 
 /*
@@ -57208,7 +64497,7 @@ static int moveToRoot(BtCursor *pCur){
   MemPage *pRoot;
   int rc = SQLITE_OK;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
   assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
   assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
@@ -57221,18 +64510,26 @@ static int moveToRoot(BtCursor *pCur){
   }
 
   if( pCur->iPage>=0 ){
-    while( pCur->iPage ) releasePage(pCur->apPage[pCur->iPage--]);
+    if( pCur->iPage ){
+      do{
+        assert( pCur->apPage[pCur->iPage]!=0 );
+        releasePageNotNull(pCur->apPage[pCur->iPage--]);
+      }while( pCur->iPage);
+      goto skip_init;
+    }
   }else if( pCur->pgnoRoot==0 ){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;
   }else{
+    assert( pCur->iPage==(-1) );
     rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
-                 (pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
+                        0, pCur->curPagerFlags);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
-      return rc;
+       return rc;
     }
     pCur->iPage = 0;
+    pCur->curIntKey = pCur->apPage[0]->intKey;
   }
   pRoot = pCur->apPage[0];
   assert( pRoot->pgno==pCur->pgnoRoot );
@@ -57249,13 +64546,15 @@ static int moveToRoot(BtCursor *pCur){
   ** (or the freelist).  */
   assert( pRoot->intKey==1 || pRoot->intKey==0 );
   if( pRoot->isInit==0 || (pCur->pKeyInfo==0)!=pRoot->intKey ){
-    return SQLITE_CORRUPT_BKPT;
+    return SQLITE_CORRUPT_PGNO(pCur->apPage[pCur->iPage]->pgno);
   }
 
-  pCur->aiIdx[0] = 0;
+skip_init:  
+  pCur->ix = 0;
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);
 
+  pRoot = pCur->apPage[0];
   if( pRoot->nCell>0 ){
     pCur->eState = CURSOR_VALID;
   }else if( !pRoot->leaf ){
@@ -57282,11 +64581,11 @@ static int moveToLeftmost(BtCursor *pCur){
   int rc = SQLITE_OK;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
-    assert( pCur->aiIdx[pCur->iPage]nCell );
-    pgno = get4byte(findCell(pPage, pCur->aiIdx[pCur->iPage]));
+    assert( pCur->ixnCell );
+    pgno = get4byte(findCell(pPage, pCur->ix));
     rc = moveToChild(pCur, pgno);
   }
   return rc;
@@ -57307,15 +64606,15 @@ static int moveToRightmost(BtCursor *pCur){
   int rc = SQLITE_OK;
   MemPage *pPage = 0;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   while( !(pPage = pCur->apPage[pCur->iPage])->leaf ){
     pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
-    pCur->aiIdx[pCur->iPage] = pPage->nCell;
+    pCur->ix = pPage->nCell;
     rc = moveToChild(pCur, pgno);
     if( rc ) return rc;
   }
-  pCur->aiIdx[pCur->iPage] = pPage->nCell-1;
+  pCur->ix = pPage->nCell-1;
   assert( pCur->info.nSize==0 );
   assert( (pCur->curFlags & BTCF_ValidNKey)==0 );
   return SQLITE_OK;
@@ -57328,7 +64627,7 @@ static int moveToRightmost(BtCursor *pCur){
 SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
   int rc;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
   rc = moveToRoot(pCur);
   if( rc==SQLITE_OK ){
@@ -57351,7 +64650,7 @@ SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
 SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
   int rc;
  
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
 
   /* If the cursor already points to the last entry, this is a no-op. */
@@ -57363,7 +64662,7 @@ SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
     for(ii=0; iiiPage; ii++){
       assert( pCur->aiIdx[ii]==pCur->apPage[ii]->nCell );
     }
-    assert( pCur->aiIdx[pCur->iPage]==pCur->apPage[pCur->iPage]->nCell-1 );
+    assert( pCur->ix==pCur->apPage[pCur->iPage]->nCell-1 );
     assert( pCur->apPage[pCur->iPage]->leaf );
 #endif
     return SQLITE_OK;
@@ -57416,6 +64715,8 @@ SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
 **     *pRes>0      The cursor is left pointing at an entry that
 **                  is larger than intKey/pIdxKey.
 **
+** For index tables, the pIdxKey->eqSeen field is set to 1 if there
+** exists an entry in the table that exactly matches pIdxKey.  
 */
 SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
   BtCursor *pCur,          /* The cursor to be moved */
@@ -57427,23 +64728,44 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
   int rc;
   RecordCompare xRecordCompare;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
   assert( pRes );
   assert( (pIdxKey==0)==(pCur->pKeyInfo==0) );
+  assert( pCur->eState!=CURSOR_VALID || (pIdxKey==0)==(pCur->curIntKey!=0) );
 
   /* If the cursor is already positioned at the point we are trying
   ** to move to, then just return without doing any work */
-  if( pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
-   && pCur->apPage[0]->intKey 
+  if( pIdxKey==0
+   && pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
   ){
     if( pCur->info.nKey==intKey ){
       *pRes = 0;
       return SQLITE_OK;
     }
-    if( (pCur->curFlags & BTCF_AtLast)!=0 && pCur->info.nKeyinfo.nKeycurFlags & BTCF_AtLast)!=0 ){
+        *pRes = -1;
+        return SQLITE_OK;
+      }
+      /* If the requested key is one more than the previous key, then
+      ** try to get there using sqlite3BtreeNext() rather than a full
+      ** binary search.  This is an optimization only.  The correct answer
+      ** is still obtained without this case, only a little more slowely */
+      if( pCur->info.nKey+1==intKey && !pCur->skipNext ){
+        *pRes = 0;
+        rc = sqlite3BtreeNext(pCur, 0);
+        if( rc==SQLITE_OK ){
+          getCellInfo(pCur);
+          if( pCur->info.nKey==intKey ){
+            return SQLITE_OK;
+          }
+        }else if( rc==SQLITE_DONE ){
+          rc = SQLITE_OK;
+        }else{
+          return rc;
+        }
+      }
     }
   }
 
@@ -57470,7 +64792,8 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
     assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
     return SQLITE_OK;
   }
-  assert( pCur->apPage[0]->intKey || pIdxKey );
+  assert( pCur->apPage[0]->intKey==pCur->curIntKey );
+  assert( pCur->curIntKey || pIdxKey );
   for(;;){
     int lwr, upr, idx, c;
     Pgno chldPg;
@@ -57489,14 +64812,16 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
     upr = pPage->nCell-1;
     assert( biasRight==0 || biasRight==1 );
     idx = upr>>(1-biasRight); /* idx = biasRight ? upr : (lwr+upr)/2; */
-    pCur->aiIdx[pCur->iPage] = (u16)idx;
+    pCur->ix = (u16)idx;
     if( xRecordCompare==0 ){
       for(;;){
         i64 nCellKey;
-        pCell = findCell(pPage, idx) + pPage->childPtrSize;
+        pCell = findCellPastPtr(pPage, idx);
         if( pPage->intKeyLeaf ){
           while( 0x80 <= *(pCell++) ){
-            if( pCell>=pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;
+            if( pCell>=pPage->aDataEnd ){
+              return SQLITE_CORRUPT_PGNO(pPage->pgno);
+            }
           }
         }
         getVarint(pCell, (u64*)&nCellKey);
@@ -57508,16 +64833,16 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
           if( lwr>upr ){ c = +1; break; }
         }else{
           assert( nCellKey==intKey );
-          pCur->curFlags |= BTCF_ValidNKey;
-          pCur->info.nKey = nCellKey;
-          pCur->aiIdx[pCur->iPage] = (u16)idx;
+          pCur->ix = (u16)idx;
           if( !pPage->leaf ){
             lwr = idx;
             goto moveto_next_layer;
           }else{
+            pCur->curFlags |= BTCF_ValidNKey;
+            pCur->info.nKey = nCellKey;
+            pCur->info.nSize = 0;
             *pRes = 0;
-            rc = SQLITE_OK;
-            goto moveto_finish;
+            return SQLITE_OK;
           }
         }
         assert( lwr+upr>=0 );
@@ -57525,8 +64850,8 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
       }
     }else{
       for(;;){
-        int nCell;
-        pCell = findCell(pPage, idx) + pPage->childPtrSize;
+        int nCell;  /* Size of the pCell cell in bytes */
+        pCell = findCellPastPtr(pPage, idx);
 
         /* The maximum supported page-size is 65536 bytes. This means that
         ** the maximum number of record bytes stored on an index B-Tree
@@ -57554,18 +64879,32 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
           /* The record flows over onto one or more overflow pages. In
           ** this case the whole cell needs to be parsed, a buffer allocated
           ** and accessPayload() used to retrieve the record into the
-          ** buffer before VdbeRecordCompare() can be called. */
+          ** buffer before VdbeRecordCompare() can be called. 
+          **
+          ** If the record is corrupt, the xRecordCompare routine may read
+          ** up to two varints past the end of the buffer. An extra 18 
+          ** bytes of padding is allocated at the end of the buffer in
+          ** case this happens.  */
           void *pCellKey;
           u8 * const pCellBody = pCell - pPage->childPtrSize;
-          btreeParseCellPtr(pPage, pCellBody, &pCur->info);
+          pPage->xParseCell(pPage, pCellBody, &pCur->info);
           nCell = (int)pCur->info.nKey;
-          pCellKey = sqlite3Malloc( nCell );
+          testcase( nCell<0 );   /* True if key size is 2^32 or more */
+          testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */
+          testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */
+          testcase( nCell==2 );  /* Minimum legal index key size */
+          if( nCell<2 ){
+            rc = SQLITE_CORRUPT_PGNO(pPage->pgno);
+            goto moveto_finish;
+          }
+          pCellKey = sqlite3Malloc( nCell+18 );
           if( pCellKey==0 ){
-            rc = SQLITE_NOMEM;
+            rc = SQLITE_NOMEM_BKPT;
             goto moveto_finish;
           }
-          pCur->aiIdx[pCur->iPage] = (u16)idx;
-          rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 2);
+          pCur->ix = (u16)idx;
+          rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 0);
+          pCur->curFlags &= ~BTCF_ValidOvfl;
           if( rc ){
             sqlite3_free(pCellKey);
             goto moveto_finish;
@@ -57585,7 +64924,7 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
           assert( c==0 );
           *pRes = 0;
           rc = SQLITE_OK;
-          pCur->aiIdx[pCur->iPage] = (u16)idx;
+          pCur->ix = (u16)idx;
           if( pIdxKey->errCode ) rc = SQLITE_CORRUPT;
           goto moveto_finish;
         }
@@ -57597,8 +64936,8 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
     assert( lwr==upr+1 || (pPage->intKey && !pPage->leaf) );
     assert( pPage->isInit );
     if( pPage->leaf ){
-      assert( pCur->aiIdx[pCur->iPage]apPage[pCur->iPage]->nCell );
-      pCur->aiIdx[pCur->iPage] = (u16)idx;
+      assert( pCur->ixapPage[pCur->iPage]->nCell );
+      pCur->ix = (u16)idx;
       *pRes = c;
       rc = SQLITE_OK;
       goto moveto_finish;
@@ -57609,13 +64948,13 @@ moveto_next_layer:
     }else{
       chldPg = get4byte(findCell(pPage, lwr));
     }
-    pCur->aiIdx[pCur->iPage] = (u16)lwr;
+    pCur->ix = (u16)lwr;
     rc = moveToChild(pCur, chldPg);
     if( rc ) break;
   }
 moveto_finish:
   pCur->info.nSize = 0;
-  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+  assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
   return rc;
 }
 
@@ -57636,10 +64975,36 @@ SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor *pCur){
 }
 
 /*
-** Advance the cursor to the next entry in the database.  If
-** successful then set *pRes=0.  If the cursor
-** was already pointing to the last entry in the database before
-** this routine was called, then set *pRes=1.
+** Return an estimate for the number of rows in the table that pCur is
+** pointing to.  Return a negative number if no estimate is currently 
+** available.
+*/
+SQLITE_PRIVATE i64 sqlite3BtreeRowCountEst(BtCursor *pCur){
+  i64 n;
+  u8 i;
+
+  assert( cursorOwnsBtShared(pCur) );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+
+  /* Currently this interface is only called by the OP_IfSmaller
+  ** opcode, and it that case the cursor will always be valid and
+  ** will always point to a leaf node. */
+  if( NEVER(pCur->eState!=CURSOR_VALID) ) return -1;
+  if( NEVER(pCur->apPage[pCur->iPage]->leaf==0) ) return -1;
+
+  for(n=1, i=0; i<=pCur->iPage; i++){
+    n *= pCur->apPage[i]->nCell;
+  }
+  return n;
+}
+
+/*
+** Advance the cursor to the next entry in the database. 
+** Return value:
+**
+**    SQLITE_OK        success
+**    SQLITE_DONE      cursor is already pointing at the last element
+**    otherwise        some kind of error occurred
 **
 ** The main entry point is sqlite3BtreeNext().  That routine is optimized
 ** for the common case of merely incrementing the cell counter BtCursor.aiIdx
@@ -57647,23 +65012,19 @@ SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor *pCur){
 ** routine is called when it is necessary to move to a different page or
 ** to restore the cursor.
 **
-** The calling function will set *pRes to 0 or 1.  The initial *pRes value
-** will be 1 if the cursor being stepped corresponds to an SQL index and
-** if this routine could have been skipped if that SQL index had been
-** a unique index.  Otherwise the caller will have set *pRes to zero.
-** Zero is the common case. The btree implementation is free to use the
-** initial *pRes value as a hint to improve performance, but the current
-** SQLite btree implementation does not. (Note that the comdb2 btree
-** implementation does use this hint, however.)
+** If bit 0x01 of the F argument in sqlite3BtreeNext(C,F) is 1, then the
+** cursor corresponds to an SQL index and this routine could have been
+** skipped if the SQL index had been a unique index.  The F argument
+** is a hint to the implement.  SQLite btree implementation does not use
+** this hint, but COMDB2 does.
 */
-static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
+static SQLITE_NOINLINE int btreeNext(BtCursor *pCur){
   int rc;
   int idx;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
-  assert( *pRes==0 );
   if( pCur->eState!=CURSOR_VALID ){
     assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
     rc = restoreCursorPosition(pCur);
@@ -57671,8 +65032,7 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
       return rc;
     }
     if( CURSOR_INVALID==pCur->eState ){
-      *pRes = 1;
-      return SQLITE_OK;
+      return SQLITE_DONE;
     }
     if( pCur->skipNext ){
       assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
@@ -57686,7 +65046,7 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
   }
 
   pPage = pCur->apPage[pCur->iPage];
-  idx = ++pCur->aiIdx[pCur->iPage];
+  idx = ++pCur->ix;
   assert( pPage->isInit );
 
   /* If the database file is corrupt, it is possible for the value of idx 
@@ -57704,15 +65064,14 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
     }
     do{
       if( pCur->iPage==0 ){
-        *pRes = 1;
         pCur->eState = CURSOR_INVALID;
-        return SQLITE_OK;
+        return SQLITE_DONE;
       }
       moveToParent(pCur);
       pPage = pCur->apPage[pCur->iPage];
-    }while( pCur->aiIdx[pCur->iPage]>=pPage->nCell );
+    }while( pCur->ix>=pPage->nCell );
     if( pPage->intKey ){
-      return sqlite3BtreeNext(pCur, pRes);
+      return sqlite3BtreeNext(pCur, 0);
     }else{
       return SQLITE_OK;
     }
@@ -57723,20 +65082,19 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
     return moveToLeftmost(pCur);
   }
 }
-SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
+SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int flags){
   MemPage *pPage;
-  assert( cursorHoldsMutex(pCur) );
-  assert( pRes!=0 );
-  assert( *pRes==0 || *pRes==1 );
+  UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */
+  assert( cursorOwnsBtShared(pCur) );
+  assert( flags==0 || flags==1 );
   assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
-  *pRes = 0;
-  if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur, pRes);
+  if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur);
   pPage = pCur->apPage[pCur->iPage];
-  if( (++pCur->aiIdx[pCur->iPage])>=pPage->nCell ){
-    pCur->aiIdx[pCur->iPage]--;
-    return btreeNext(pCur, pRes);
+  if( (++pCur->ix)>=pPage->nCell ){
+    pCur->ix--;
+    return btreeNext(pCur);
   }
   if( pPage->leaf ){
     return SQLITE_OK;
@@ -57746,10 +65104,12 @@ SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
 }
 
 /*
-** Step the cursor to the back to the previous entry in the database.  If
-** successful then set *pRes=0.  If the cursor
-** was already pointing to the first entry in the database before
-** this routine was called, then set *pRes=1.
+** Step the cursor to the back to the previous entry in the database.
+** Return values:
+**
+**     SQLITE_OK     success
+**     SQLITE_DONE   the cursor is already on the first element of the table
+**     otherwise     some kind of error occurred
 **
 ** The main entry point is sqlite3BtreePrevious().  That routine is optimized
 ** for the common case of merely decrementing the cell counter BtCursor.aiIdx
@@ -57757,22 +65117,17 @@ SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
 ** helper routine is called when it is necessary to move to a different page
 ** or to restore the cursor.
 **
-** The calling function will set *pRes to 0 or 1.  The initial *pRes value
-** will be 1 if the cursor being stepped corresponds to an SQL index and
-** if this routine could have been skipped if that SQL index had been
-** a unique index.  Otherwise the caller will have set *pRes to zero.
-** Zero is the common case. The btree implementation is free to use the
-** initial *pRes value as a hint to improve performance, but the current
-** SQLite btree implementation does not. (Note that the comdb2 btree
-** implementation does use this hint, however.)
+** If bit 0x01 of the F argument to sqlite3BtreePrevious(C,F) is 1, then
+** the cursor corresponds to an SQL index and this routine could have been
+** skipped if the SQL index had been a unique index.  The F argument is a
+** hint to the implement.  The native SQLite btree implementation does not
+** use this hint, but COMDB2 does.
 */
-static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
+static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur){
   int rc;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
-  assert( pRes!=0 );
-  assert( *pRes==0 );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
   assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );
   assert( pCur->info.nSize==0 );
@@ -57782,8 +65137,7 @@ static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
       return rc;
     }
     if( CURSOR_INVALID==pCur->eState ){
-      *pRes = 1;
-      return SQLITE_OK;
+      return SQLITE_DONE;
     }
     if( pCur->skipNext ){
       assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
@@ -57799,47 +65153,45 @@ static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
   pPage = pCur->apPage[pCur->iPage];
   assert( pPage->isInit );
   if( !pPage->leaf ){
-    int idx = pCur->aiIdx[pCur->iPage];
+    int idx = pCur->ix;
     rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
     if( rc ) return rc;
     rc = moveToRightmost(pCur);
   }else{
-    while( pCur->aiIdx[pCur->iPage]==0 ){
+    while( pCur->ix==0 ){
       if( pCur->iPage==0 ){
         pCur->eState = CURSOR_INVALID;
-        *pRes = 1;
-        return SQLITE_OK;
+        return SQLITE_DONE;
       }
       moveToParent(pCur);
     }
     assert( pCur->info.nSize==0 );
-    assert( (pCur->curFlags & (BTCF_ValidNKey|BTCF_ValidOvfl))==0 );
+    assert( (pCur->curFlags & (BTCF_ValidOvfl))==0 );
 
-    pCur->aiIdx[pCur->iPage]--;
+    pCur->ix--;
     pPage = pCur->apPage[pCur->iPage];
     if( pPage->intKey && !pPage->leaf ){
-      rc = sqlite3BtreePrevious(pCur, pRes);
+      rc = sqlite3BtreePrevious(pCur, 0);
     }else{
       rc = SQLITE_OK;
     }
   }
   return rc;
 }
-SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
-  assert( cursorHoldsMutex(pCur) );
-  assert( pRes!=0 );
-  assert( *pRes==0 || *pRes==1 );
+SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int flags){
+  assert( cursorOwnsBtShared(pCur) );
+  assert( flags==0 || flags==1 );
   assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
-  *pRes = 0;
+  UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */
   pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);
   pCur->info.nSize = 0;
   if( pCur->eState!=CURSOR_VALID
-   || pCur->aiIdx[pCur->iPage]==0
+   || pCur->ix==0
    || pCur->apPage[pCur->iPage]->leaf==0
   ){
-    return btreePrevious(pCur, pRes);
+    return btreePrevious(pCur);
   }
-  pCur->aiIdx[pCur->iPage]--;
+  pCur->ix--;
   return SQLITE_OK;
 }
 
@@ -57852,8 +65204,7 @@ SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
 ** sqlite3PagerUnref() on the new page when it is done.
 **
 ** SQLITE_OK is returned on success.  Any other return value indicates
-** an error.  *ppPage and *pPgno are undefined in the event of an error.
-** Do not invoke sqlite3PagerUnref() on *ppPage if an error is returned.
+** an error.  *ppPage is set to NULL in the event of an error.
 **
 ** If the "nearby" parameter is not 0, then an effort is made to 
 ** locate a page close to the page number "nearby".  This can be used in an
@@ -57896,6 +65247,7 @@ static int allocateBtreePage(
     /* There are pages on the freelist.  Reuse one of those pages. */
     Pgno iTrunk;
     u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
+    u32 nSearch = 0;   /* Count of the number of search attempts */
     
     /* If eMode==BTALLOC_EXACT and a query of the pointer-map
     ** shows that the page 'nearby' is somewhere on the free-list, then
@@ -57944,10 +65296,10 @@ static int allocateBtreePage(
         iTrunk = get4byte(&pPage1->aData[32]);
       }
       testcase( iTrunk==mxPage );
-      if( iTrunk>mxPage ){
-        rc = SQLITE_CORRUPT_BKPT;
+      if( iTrunk>mxPage || nSearch++ > n ){
+        rc = SQLITE_CORRUPT_PGNO(pPrevTrunk ? pPrevTrunk->pgno : 1);
       }else{
-        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+        rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);
       }
       if( rc ){
         pTrunk = 0;
@@ -57974,7 +65326,7 @@ static int allocateBtreePage(
         TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
       }else if( k>(u32)(pBt->usableSize/4 - 2) ){
         /* Value of k is out of range.  Database corruption */
-        rc = SQLITE_CORRUPT_BKPT;
+        rc = SQLITE_CORRUPT_PGNO(iTrunk);
         goto end_allocate_page;
 #ifndef SQLITE_OMIT_AUTOVACUUM
       }else if( searchList 
@@ -58008,11 +65360,11 @@ static int allocateBtreePage(
           MemPage *pNewTrunk;
           Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);
           if( iNewTrunk>mxPage ){ 
-            rc = SQLITE_CORRUPT_BKPT;
+            rc = SQLITE_CORRUPT_PGNO(iTrunk);
             goto end_allocate_page;
           }
           testcase( iNewTrunk==mxPage );
-          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+          rc = btreeGetUnusedPage(pBt, iNewTrunk, &pNewTrunk, 0);
           if( rc!=SQLITE_OK ){
             goto end_allocate_page;
           }
@@ -58073,7 +65425,7 @@ static int allocateBtreePage(
         iPage = get4byte(&aData[8+closest*4]);
         testcase( iPage==mxPage );
         if( iPage>mxPage ){
-          rc = SQLITE_CORRUPT_BKPT;
+          rc = SQLITE_CORRUPT_PGNO(iTrunk);
           goto end_allocate_page;
         }
         testcase( iPage==mxPage );
@@ -58092,11 +65444,12 @@ static int allocateBtreePage(
           }
           put4byte(&aData[4], k-1);
           noContent = !btreeGetHasContent(pBt, *pPgno)? PAGER_GET_NOCONTENT : 0;
-          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
+          rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, noContent);
           if( rc==SQLITE_OK ){
             rc = sqlite3PagerWrite((*ppPage)->pDbPage);
             if( rc!=SQLITE_OK ){
               releasePage(*ppPage);
+              *ppPage = 0;
             }
           }
           searchList = 0;
@@ -58140,7 +65493,7 @@ static int allocateBtreePage(
       MemPage *pPg = 0;
       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));
       assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
-      rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent);
+      rc = btreeGetUnusedPage(pBt, pBt->nPage, &pPg, bNoContent);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pPg->pDbPage);
         releasePage(pPg);
@@ -58154,11 +65507,12 @@ static int allocateBtreePage(
     *pPgno = pBt->nPage;
 
     assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
-    rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent);
+    rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, bNoContent);
     if( rc ) return rc;
     rc = sqlite3PagerWrite((*ppPage)->pDbPage);
     if( rc!=SQLITE_OK ){
       releasePage(*ppPage);
+      *ppPage = 0;
     }
     TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
   }
@@ -58168,17 +65522,8 @@ static int allocateBtreePage(
 end_allocate_page:
   releasePage(pTrunk);
   releasePage(pPrevTrunk);
-  if( rc==SQLITE_OK ){
-    if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
-      releasePage(*ppPage);
-      *ppPage = 0;
-      return SQLITE_CORRUPT_BKPT;
-    }
-    (*ppPage)->isInit = 0;
-  }else{
-    *ppPage = 0;
-  }
-  assert( rc!=SQLITE_OK || sqlite3PagerIswriteable((*ppPage)->pDbPage) );
+  assert( rc!=SQLITE_OK || sqlite3PagerPageRefcount((*ppPage)->pDbPage)<=1 );
+  assert( rc!=SQLITE_OK || (*ppPage)->isInit==0 );
   return rc;
 }
 
@@ -58203,9 +65548,10 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
   int nFree;                          /* Initial number of pages on free-list */
 
   assert( sqlite3_mutex_held(pBt->mutex) );
-  assert( iPage>1 );
+  assert( CORRUPT_DB || iPage>1 );
   assert( !pMemPage || pMemPage->pgno==iPage );
 
+  if( iPage<2 ) return SQLITE_CORRUPT_BKPT;
   if( pMemPage ){
     pPage = pMemPage;
     sqlite3PagerRef(pPage->pDbPage);
@@ -58335,29 +65681,30 @@ static void freePage(MemPage *pPage, int *pRC){
 static int clearCell(
   MemPage *pPage,          /* The page that contains the Cell */
   unsigned char *pCell,    /* First byte of the Cell */
-  u16 *pnSize              /* Write the size of the Cell here */
+  CellInfo *pInfo          /* Size information about the cell */
 ){
   BtShared *pBt = pPage->pBt;
-  CellInfo info;
   Pgno ovflPgno;
   int rc;
   int nOvfl;
   u32 ovflPageSize;
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  btreeParseCellPtr(pPage, pCell, &info);
-  *pnSize = info.nSize;
-  if( info.iOverflow==0 ){
+  pPage->xParseCell(pPage, pCell, pInfo);
+  if( pInfo->nLocal==pInfo->nPayload ){
     return SQLITE_OK;  /* No overflow pages. Return without doing anything */
   }
-  if( pCell+info.iOverflow+3 > pPage->aData+pPage->maskPage ){
-    return SQLITE_CORRUPT_BKPT;  /* Cell extends past end of page */
+  if( pCell+pInfo->nSize-1 > pPage->aData+pPage->maskPage ){
+    /* Cell extends past end of page */
+    return SQLITE_CORRUPT_PGNO(pPage->pgno);
   }
-  ovflPgno = get4byte(&pCell[info.iOverflow]);
+  ovflPgno = get4byte(pCell + pInfo->nSize - 4);
   assert( pBt->usableSize > 4 );
   ovflPageSize = pBt->usableSize - 4;
-  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
-  assert( ovflPgno==0 || nOvfl>0 );
+  nOvfl = (pInfo->nPayload - pInfo->nLocal + ovflPageSize - 1)/ovflPageSize;
+  assert( nOvfl>0 || 
+    (CORRUPT_DB && (pInfo->nPayload + ovflPageSize)childPtrSize;
-  nPayload = nData + nZero;
-  if( pPage->intKeyLeaf ){
+  if( pPage->intKey ){
+    nPayload = pX->nData + pX->nZero;
+    pSrc = pX->pData;
+    nSrc = pX->nData;
+    assert( pPage->intKeyLeaf ); /* fillInCell() only called for leaves */
     nHeader += putVarint32(&pCell[nHeader], nPayload);
+    nHeader += putVarint(&pCell[nHeader], *(u64*)&pX->nKey);
   }else{
-    assert( nData==0 );
-    assert( nZero==0 );
+    assert( pX->nKey<=0x7fffffff && pX->pKey!=0 );
+    nSrc = nPayload = (int)pX->nKey;
+    pSrc = pX->pKey;
+    nHeader += putVarint32(&pCell[nHeader], nPayload);
   }
-  nHeader += putVarint(&pCell[nHeader], *(u64*)&nKey);
   
-  /* Fill in the payload size */
-  if( pPage->intKey ){
-    pSrc = pData;
-    nSrc = nData;
-    nData = 0;
-  }else{ 
-    if( NEVER(nKey>0x7fffffff || pKey==0) ){
-      return SQLITE_CORRUPT_BKPT;
-    }
-    nPayload = (int)nKey;
-    pSrc = pKey;
-    nSrc = (int)nKey;
-  }
+  /* Fill in the payload */
   if( nPayload<=pPage->maxLocal ){
     n = nHeader + nPayload;
     testcase( n==3 );
@@ -58494,15 +65832,14 @@ static int fillInCell(
   ** Use a call to btreeParseCellPtr() to verify that the values above
   ** were computed correctly.
   */
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
   {
     CellInfo info;
-    btreeParseCellPtr(pPage, pCell, &info);
-    assert( nHeader=(int)(info.pPayload - pCell) );
-    assert( info.nKey==nKey );
+    pPage->xParseCell(pPage, pCell, &info);
+    assert( nHeader==(int)(info.pPayload - pCell) );
+    assert( info.nKey==pX->nKey );
     assert( *pnSize == info.nSize );
     assert( spaceLeft == info.nLocal );
-    assert( pPrior == &pCell[info.iOverflow] );
   }
 #endif
 
@@ -58585,10 +65922,6 @@ static int fillInCell(
     pSrc += n;
     nSrc -= n;
     spaceLeft -= n;
-    if( nSrc==0 ){
-      nSrc = nData;
-      pSrc = pData;
-    }
   }
   releasePage(pToRelease);
   return SQLITE_OK;
@@ -58610,9 +65943,8 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
   int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */
 
   if( *pRC ) return;
-
   assert( idx>=0 && idxnCell );
-  assert( sz==cellSize(pPage, idx) );
+  assert( CORRUPT_DB || sz==cellSize(pPage, idx) );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   data = pPage->aData;
@@ -58655,6 +65987,8 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
 ** in pTemp or the original pCell) and also record its index. 
 ** Allocating a new entry in pPage->aCell[] implies that 
 ** pPage->nOverflow is incremented.
+**
+** *pRC must be SQLITE_OK when this routine is called.
 */
 static void insertCell(
   MemPage *pPage,   /* Page into which we are copying */
@@ -58667,13 +66001,10 @@ static void insertCell(
 ){
   int idx = 0;      /* Where to write new cell content in data[] */
   int j;            /* Loop counter */
-  int end;          /* First byte past the last cell pointer in data[] */
-  int ins;          /* Index in data[] where new cell pointer is inserted */
-  int cellOffset;   /* Address of first cell pointer in data[] */
   u8 *data;         /* The content of the whole page */
+  u8 *pIns;         /* The point in pPage->aCellIdx[] where no cell inserted */
 
-  if( *pRC ) return;
-
+  assert( *pRC==SQLITE_OK );
   assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
   assert( MX_CELL(pPage->pBt)<=10921 );
   assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );
@@ -58685,7 +66016,7 @@ static void insertCell(
   ** wanted to be less than 4 but got rounded up to 4 on the leaf, then size
   ** might be less than 8 (leaf-size + pointer) on the interior node.  Hence
   ** the term after the || in the following assert(). */
-  assert( sz==cellSizePtr(pPage, pCell) || (sz==8 && iChild>0) );
+  assert( sz==pPage->xCellSize(pPage, pCell) || (sz==8 && iChild>0) );
   if( pPage->nOverflow || sz+2>pPage->nFree ){
     if( pTemp ){
       memcpy(pTemp, pCell, sz);
@@ -58695,9 +66026,20 @@ static void insertCell(
       put4byte(pCell, iChild);
     }
     j = pPage->nOverflow++;
-    assert( j<(int)(sizeof(pPage->apOvfl)/sizeof(pPage->apOvfl[0])) );
+    /* Comparison against ArraySize-1 since we hold back one extra slot
+    ** as a contingency.  In other words, never need more than 3 overflow
+    ** slots but 4 are allocated, just to be safe. */
+    assert( j < ArraySize(pPage->apOvfl)-1 );
     pPage->apOvfl[j] = pCell;
     pPage->aiOvfl[j] = (u16)i;
+
+    /* When multiple overflows occur, they are always sequential and in
+    ** sorted order.  This invariants arise because multiple overflows can
+    ** only occur when inserting divider cells into the parent page during
+    ** balancing, and the dividers are adjacent and sorted.
+    */
+    assert( j==0 || pPage->aiOvfl[j-1]<(u16)i ); /* Overflows in sorted order */
+    assert( j==0 || i==pPage->aiOvfl[j-1]+1 );   /* Overflows are sequential */
   }else{
     int rc = sqlite3PagerWrite(pPage->pDbPage);
     if( rc!=SQLITE_OK ){
@@ -58706,24 +66048,26 @@ static void insertCell(
     }
     assert( sqlite3PagerIswriteable(pPage->pDbPage) );
     data = pPage->aData;
-    cellOffset = pPage->cellOffset;
-    end = cellOffset + 2*pPage->nCell;
-    ins = cellOffset + 2*i;
+    assert( &data[pPage->cellOffset]==pPage->aCellIdx );
     rc = allocateSpace(pPage, sz, &idx);
     if( rc ){ *pRC = rc; return; }
-    /* The allocateSpace() routine guarantees the following two properties
-    ** if it returns success */
-    assert( idx >= end+2 );
+    /* The allocateSpace() routine guarantees the following properties
+    ** if it returns successfully */
+    assert( idx >= 0 );
+    assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );
     assert( idx+sz <= (int)pPage->pBt->usableSize );
-    pPage->nCell++;
     pPage->nFree -= (u16)(2 + sz);
     memcpy(&data[idx], pCell, sz);
     if( iChild ){
       put4byte(&data[idx], iChild);
     }
-    memmove(&data[ins+2], &data[ins], end-ins);
-    put2byte(&data[ins], idx);
-    put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
+    pIns = pPage->aCellIdx + i*2;
+    memmove(pIns+2, pIns, 2*(pPage->nCell - i));
+    put2byte(pIns, idx);
+    pPage->nCell++;
+    /* increment the cell count */
+    if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;
+    assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell );
 #ifndef SQLITE_OMIT_AUTOVACUUM
     if( pPage->pBt->autoVacuum ){
       /* The cell may contain a pointer to an overflow page. If so, write
@@ -58735,6 +66079,52 @@ static void insertCell(
   }
 }
 
+/*
+** A CellArray object contains a cache of pointers and sizes for a
+** consecutive sequence of cells that might be held on multiple pages.
+*/
+typedef struct CellArray CellArray;
+struct CellArray {
+  int nCell;              /* Number of cells in apCell[] */
+  MemPage *pRef;          /* Reference page */
+  u8 **apCell;            /* All cells begin balanced */
+  u16 *szCell;            /* Local size of all cells in apCell[] */
+};
+
+/*
+** Make sure the cell sizes at idx, idx+1, ..., idx+N-1 have been
+** computed.
+*/
+static void populateCellCache(CellArray *p, int idx, int N){
+  assert( idx>=0 && idx+N<=p->nCell );
+  while( N>0 ){
+    assert( p->apCell[idx]!=0 );
+    if( p->szCell[idx]==0 ){
+      p->szCell[idx] = p->pRef->xCellSize(p->pRef, p->apCell[idx]);
+    }else{
+      assert( CORRUPT_DB ||
+              p->szCell[idx]==p->pRef->xCellSize(p->pRef, p->apCell[idx]) );
+    }
+    idx++;
+    N--;
+  }
+}
+
+/*
+** Return the size of the Nth element of the cell array
+*/
+static SQLITE_NOINLINE u16 computeCellSize(CellArray *p, int N){
+  assert( N>=0 && NnCell );
+  assert( p->szCell[N]==0 );
+  p->szCell[N] = p->pRef->xCellSize(p->pRef, p->apCell[N]);
+  return p->szCell[N];
+}
+static u16 cachedCellSize(CellArray *p, int N){
+  assert( N>=0 && NnCell );
+  if( p->szCell[N] ) return p->szCell[N];
+  return computeCellSize(p, N);
+}
+
 /*
 ** Array apCell[] contains pointers to nCell b-tree page cells. The 
 ** szCell[] array contains the size in bytes of each cell. This function
@@ -58748,7 +66138,7 @@ static void insertCell(
 ** The MemPage.nFree field is invalidated by this function. It is the 
 ** responsibility of the caller to set it correctly.
 */
-static void rebuildPage(
+static int rebuildPage(
   MemPage *pPg,                   /* Edit this page */
   int nCell,                      /* Final number of cells on page */
   u8 **apCell,                    /* Array of cells */
@@ -58769,14 +66159,16 @@ static void rebuildPage(
   pData = pEnd;
   for(i=0; iaData && pCellxCellSize(pPg, pCell) || CORRUPT_DB );
+    testcase( szCell[i]!=pPg->xCellSize(pPg,pCell) );
   }
 
   /* The pPg->nFree field is now set incorrectly. The caller will fix it. */
@@ -58787,6 +66179,7 @@ static void rebuildPage(
   put2byte(&aData[hdr+3], pPg->nCell);
   put2byte(&aData[hdr+5], pData - aData);
   aData[hdr+7] = 0x00;
+  return SQLITE_OK;
 }
 
 /*
@@ -58819,25 +66212,31 @@ static int pageInsertArray(
   u8 *pBegin,                     /* End of cell-pointer array */
   u8 **ppData,                    /* IN/OUT: Page content -area pointer */
   u8 *pCellptr,                   /* Pointer to cell-pointer area */
+  int iFirst,                     /* Index of first cell to add */
   int nCell,                      /* Number of cells to add to pPg */
-  u8 **apCell,                    /* Array of cells */
-  u16 *szCell                     /* Array of cell sizes */
+  CellArray *pCArray              /* Array of cells */
 ){
   int i;
   u8 *aData = pPg->aData;
   u8 *pData = *ppData;
-  const int bFreelist = aData[1] || aData[2];
+  int iEnd = iFirst + nCell;
   assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */
-  for(i=0; iapCell[i] will never overlap on a well-formed
+    ** database.  But they might for a corrupt database.  Hence use memmove()
+    ** since memcpy() sends SIGABORT with overlapping buffers on OpenBSD */
+    assert( (pSlot+sz)<=pCArray->apCell[i]
+         || pSlot>=(pCArray->apCell[i]+sz)
+         || CORRUPT_DB );
+    memmove(pSlot, pCArray->apCell[i], sz);
     put2byte(pCellptr, (pSlot - aData));
     pCellptr += 2;
   }
@@ -58856,22 +66255,27 @@ static int pageInsertArray(
 */
 static int pageFreeArray(
   MemPage *pPg,                   /* Page to edit */
+  int iFirst,                     /* First cell to delete */
   int nCell,                      /* Cells to delete */
-  u8 **apCell,                    /* Array of cells */
-  u16 *szCell                     /* Array of cell sizes */
+  CellArray *pCArray              /* Array of cells */
 ){
   u8 * const aData = pPg->aData;
   u8 * const pEnd = &aData[pPg->pBt->usableSize];
   u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];
   int nRet = 0;
   int i;
+  int iEnd = iFirst + nCell;
   u8 *pFree = 0;
   int szFree = 0;
 
-  for(i=0; i=pStart && pCellapCell[i];
+    if( SQLITE_WITHIN(pCell, pStart, pEnd) ){
+      int sz;
+      /* No need to use cachedCellSize() here.  The sizes of all cells that
+      ** are to be freed have already been computing while deciding which
+      ** cells need freeing */
+      sz = pCArray->szCell[i];  assert( sz>0 );
       if( pFree!=(pCell + sz) ){
         if( pFree ){
           assert( pFree>aData && (pFree - aData)<65536 );
@@ -58906,13 +66310,12 @@ static int pageFreeArray(
 ** The pPg->nFree field is invalid when this function returns. It is the
 ** responsibility of the caller to set it correctly.
 */
-static void editPage(
+static int editPage(
   MemPage *pPg,                   /* Edit this page */
   int iOld,                       /* Index of first cell currently on page */
   int iNew,                       /* Index of new first cell on page */
   int nNew,                       /* Final number of cells on page */
-  u8 **apCell,                    /* Array of cells */
-  u16 *szCell                     /* Array of cell sizes */
+  CellArray *pCArray              /* Array of cells and sizes */
 ){
   u8 * const aData = pPg->aData;
   const int hdr = pPg->hdrOffset;
@@ -58931,16 +66334,12 @@ static void editPage(
 
   /* Remove cells from the start and end of the page */
   if( iOldaCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
     nCell -= nShift;
   }
   if( iNewEnd < iOldEnd ){
-    nCell -= pageFreeArray(
-        pPg, iOldEnd-iNewEnd, &apCell[iNewEnd], &szCell[iNewEnd]
-    );
+    nCell -= pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
   }
 
   pData = &aData[get2byteNotZero(&aData[hdr+5])];
@@ -58954,7 +66353,7 @@ static void editPage(
     memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
     if( pageInsertArray(
           pPg, pBegin, &pData, pCellptr,
-          nAdd, &apCell[iNew], &szCell[iNew]
+          iNew, nAdd, pCArray
     ) ) goto editpage_fail;
     nCell += nAdd;
   }
@@ -58968,7 +66367,7 @@ static void editPage(
       nCell++;
       if( pageInsertArray(
             pPg, pBegin, &pData, pCellptr,
-            1, &apCell[iCell + iNew], &szCell[iCell + iNew]
+            iCell+iNew, 1, pCArray
       ) ) goto editpage_fail;
     }
   }
@@ -58977,7 +66376,7 @@ static void editPage(
   pCellptr = &pPg->aCellIdx[nCell*2];
   if( pageInsertArray(
         pPg, pBegin, &pData, pCellptr,
-        nNew-nCell, &apCell[iNew+nCell], &szCell[iNew+nCell]
+        iNew+nCell, nNew-nCell, pCArray
   ) ) goto editpage_fail;
 
   pPg->nCell = nNew;
@@ -58988,19 +66387,21 @@ static void editPage(
 
 #ifdef SQLITE_DEBUG
   for(i=0; iaCellIdx[i*2]);
-    if( pCell>=aData && pCell<&aData[pPg->pBt->usableSize] ){
+    u8 *pCell = pCArray->apCell[i+iNew];
+    int iOff = get2byteAligned(&pPg->aCellIdx[i*2]);
+    if( SQLITE_WITHIN(pCell, aData, &aData[pPg->pBt->usableSize]) ){
       pCell = &pTmp[pCell - aData];
     }
-    assert( 0==memcmp(pCell, &aData[iOff], szCell[i+iNew]) );
+    assert( 0==memcmp(pCell, &aData[iOff],
+            pCArray->pRef->xCellSize(pCArray->pRef, pCArray->apCell[i+iNew])) );
   }
 #endif
 
-  return;
+  return SQLITE_OK;
  editpage_fail:
   /* Unable to edit this page. Rebuild it from scratch instead. */
-  rebuildPage(pPg, nNew, &apCell[iNew], &szCell[iNew]);
+  populateCellCache(pCArray, iNew, nNew);
+  return rebuildPage(pPg, nNew, &pCArray->apCell[iNew], &pCArray->szCell[iNew]);
 }
 
 /*
@@ -59066,13 +66467,14 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
 
     u8 *pOut = &pSpace[4];
     u8 *pCell = pPage->apOvfl[0];
-    u16 szCell = cellSizePtr(pPage, pCell);
+    u16 szCell = pPage->xCellSize(pPage, pCell);
     u8 *pStop;
 
     assert( sqlite3PagerIswriteable(pNew->pDbPage) );
     assert( pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
     zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
-    rebuildPage(pNew, 1, &pCell, &szCell);
+    rc = rebuildPage(pNew, 1, &pCell, &szCell);
+    if( NEVER(rc) ) return rc;
     pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;
 
     /* If this is an auto-vacuum database, update the pointer map
@@ -59111,8 +66513,10 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
     while( ((*(pOut++) = *(pCell++))&0x80) && pCellnCell, pSpace, (int)(pOut-pSpace),
-               0, pPage->pgno, &rc);
+    if( rc==SQLITE_OK ){
+      insertCell(pParent, pParent->nCell, pSpace, (int)(pOut-pSpace),
+                   0, pPage->pgno, &rc);
+    }
 
     /* Set the right-child pointer of pParent to point to the new page. */
     put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);
@@ -59145,9 +66549,9 @@ static int ptrmapCheckPages(MemPage **apPage, int nPage){
       u8 *z;
      
       z = findCell(pPage, j);
-      btreeParseCellPtr(pPage, z, &info);
-      if( info.iOverflow ){
-        Pgno ovfl = get4byte(&z[info.iOverflow]);
+      pPage->xParseCell(pPage, z, &info);
+      if( info.nLocalpgno && e==PTRMAP_OVERFLOW1 );
       }
@@ -59265,9 +66669,6 @@ static void copyNodeContent(MemPage *pFrom, MemPage *pTo, int *pRC){
 ** If aOvflSpace is set to a null pointer, this function returns 
 ** SQLITE_NOMEM.
 */
-#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_M_ARM)
-#pragma optimize("", off)
-#endif
 static int balance_nonroot(
   MemPage *pParent,               /* Parent page of siblings being balanced */
   int iParentIdx,                 /* Index of "the page" in pParent */
@@ -59276,7 +66677,6 @@ static int balance_nonroot(
   int bBulk                       /* True if this call is part of a bulk load */
 ){
   BtShared *pBt;               /* The whole database */
-  int nCell = 0;               /* Number of cells in apCell[] */
   int nMaxCells = 0;           /* Allocated size of apCell, szCell, aFrom. */
   int nNew = 0;                /* Number of pages in apNew[] */
   int nOld;                    /* Number of pages in apOld[] */
@@ -59287,7 +66687,6 @@ static int balance_nonroot(
   int leafData;                /* True if pPage is a leaf of a LEAFDATA tree */
   int usableSpace;             /* Bytes in pPage beyond the header */
   int pageFlags;               /* Value of pPage->aData[0] */
-  int subtotal;                /* Subtotal of bytes in cells on one page */
   int iSpace1 = 0;             /* First unused byte of aSpace1[] */
   int iOvflSpace = 0;          /* First unused byte of aOvflSpace[] */
   int szScratch;               /* Size of scratch memory requested */
@@ -59295,19 +66694,20 @@ static int balance_nonroot(
   MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
   u8 *pRight;                  /* Location in parent of right-sibling pointer */
   u8 *apDiv[NB-1];             /* Divider cells in pParent */
-  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */
-  int cntOld[NB+2];            /* Old index in aCell[] after i-th page */
+  int cntNew[NB+2];            /* Index in b.paCell[] of cell after i-th page */
+  int cntOld[NB+2];            /* Old index in b.apCell[] */
   int szNew[NB+2];             /* Combined size of cells placed on i-th page */
-  u8 **apCell = 0;             /* All cells begin balanced */
-  u16 *szCell;                 /* Local size of all cells in apCell[] */
   u8 *aSpace1;                 /* Space for copies of dividers cells */
   Pgno pgno;                   /* Temp var to store a page number in */
   u8 abDone[NB+2];             /* True after i'th new page is populated */
   Pgno aPgno[NB+2];            /* Page numbers of new pages before shuffling */
   Pgno aPgOrder[NB+2];         /* Copy of aPgno[] used for sorting pages */
   u16 aPgFlags[NB+2];          /* flags field of new pages before shuffling */
+  CellArray b;                  /* Parsed information on cells being balanced */
 
   memset(abDone, 0, sizeof(abDone));
+  b.nCell = 0;
+  b.apCell = 0;
   pBt = pParent->pBt;
   assert( sqlite3_mutex_held(pBt->mutex) );
   assert( sqlite3PagerIswriteable(pParent->pDbPage) );
@@ -59325,7 +66725,7 @@ static int balance_nonroot(
   assert( pParent->nOverflow==0 || pParent->aiOvfl[0]==iParentIdx );
 
   if( !aOvflSpace ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   /* Find the sibling pages to balance. Also locate the cells in pParent 
@@ -59349,7 +66749,6 @@ static int balance_nonroot(
     }else if( iParentIdx==i ){
       nxDiv = i-2+bBulk;
     }else{
-      assert( bBulk==0 );
       nxDiv = iParentIdx-1;
     }
     i = 2-bBulk;
@@ -59362,7 +66761,7 @@ static int balance_nonroot(
   }
   pgno = get4byte(pRight);
   while( 1 ){
-    rc = getAndInitPage(pBt, pgno, &apOld[i], 0);
+    rc = getAndInitPage(pBt, pgno, &apOld[i], 0, 0);
     if( rc ){
       memset(apOld, 0, (i+1)*sizeof(MemPage*));
       goto balance_cleanup;
@@ -59370,15 +66769,15 @@ static int balance_nonroot(
     nMaxCells += 1+apOld[i]->nCell+apOld[i]->nOverflow;
     if( (i--)==0 ) break;
 
-    if( i+nxDiv==pParent->aiOvfl[0] && pParent->nOverflow ){
+    if( pParent->nOverflow && i+nxDiv==pParent->aiOvfl[0] ){
       apDiv[i] = pParent->apOvfl[0];
       pgno = get4byte(apDiv[i]);
-      szNew[i] = cellSizePtr(pParent, apDiv[i]);
+      szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
       pParent->nOverflow = 0;
     }else{
       apDiv[i] = findCell(pParent, i+nxDiv-pParent->nOverflow);
       pgno = get4byte(apDiv[i]);
-      szNew[i] = cellSizePtr(pParent, apDiv[i]);
+      szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
 
       /* Drop the cell from the parent page. apDiv[i] still points to
       ** the cell within the parent, even though it has been dropped.
@@ -59392,7 +66791,7 @@ static int balance_nonroot(
       ** In this case, temporarily copy the cell into the aOvflSpace[]
       ** buffer. It will be copied out again as soon as the aSpace[] buffer
       ** is allocated.  */
-      if( pBt->btsFlags & BTS_SECURE_DELETE ){
+      if( pBt->btsFlags & BTS_FAST_SECURE ){
         int iOff;
 
         iOff = SQLITE_PTR_TO_INT(apDiv[i]) - SQLITE_PTR_TO_INT(pParent->aData);
@@ -59417,130 +66816,199 @@ static int balance_nonroot(
   ** Allocate space for memory structures
   */
   szScratch =
-       nMaxCells*sizeof(u8*)                       /* apCell */
-     + nMaxCells*sizeof(u16)                       /* szCell */
+       nMaxCells*sizeof(u8*)                       /* b.apCell */
+     + nMaxCells*sizeof(u16)                       /* b.szCell */
      + pBt->pageSize;                              /* aSpace1 */
 
   /* EVIDENCE-OF: R-28375-38319 SQLite will never request a scratch buffer
   ** that is more than 6 times the database page size. */
   assert( szScratch<=6*(int)pBt->pageSize );
-  apCell = sqlite3ScratchMalloc( szScratch ); 
-  if( apCell==0 ){
-    rc = SQLITE_NOMEM;
+  b.apCell = sqlite3ScratchMalloc( szScratch ); 
+  if( b.apCell==0 ){
+    rc = SQLITE_NOMEM_BKPT;
     goto balance_cleanup;
   }
-  szCell = (u16*)&apCell[nMaxCells];
-  aSpace1 = (u8*)&szCell[nMaxCells];
+  b.szCell = (u16*)&b.apCell[nMaxCells];
+  aSpace1 = (u8*)&b.szCell[nMaxCells];
   assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );
 
   /*
   ** Load pointers to all cells on sibling pages and the divider cells
-  ** into the local apCell[] array.  Make copies of the divider cells
+  ** into the local b.apCell[] array.  Make copies of the divider cells
   ** into space obtained from aSpace1[]. The divider cells have already
   ** been removed from pParent.
   **
   ** If the siblings are on leaf pages, then the child pointers of the
   ** divider cells are stripped from the cells before they are copied
-  ** into aSpace1[].  In this way, all cells in apCell[] are without
+  ** into aSpace1[].  In this way, all cells in b.apCell[] are without
   ** child pointers.  If siblings are not leaves, then all cell in
-  ** apCell[] include child pointers.  Either way, all cells in apCell[]
+  ** b.apCell[] include child pointers.  Either way, all cells in b.apCell[]
   ** are alike.
   **
   ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
   **       leafData:  1 if pPage holds key+data and pParent holds only keys.
   */
-  leafCorrection = apOld[0]->leaf*4;
-  leafData = apOld[0]->intKeyLeaf;
+  b.pRef = apOld[0];
+  leafCorrection = b.pRef->leaf*4;
+  leafData = b.pRef->intKeyLeaf;
   for(i=0; inCell;
+    u8 *aData = pOld->aData;
+    u16 maskPage = pOld->maskPage;
+    u8 *piCell = aData + pOld->cellOffset;
+    u8 *piEnd;
+
+    /* Verify that all sibling pages are of the same "type" (table-leaf,
+    ** table-interior, index-leaf, or index-interior).
+    */
+    if( pOld->aData[0]!=apOld[0]->aData[0] ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
 
-    limit = pOld->nCell+pOld->nOverflow;
+    /* Load b.apCell[] with pointers to all cells in pOld.  If pOld
+    ** constains overflow cells, include them in the b.apCell[] array
+    ** in the correct spot.
+    **
+    ** Note that when there are multiple overflow cells, it is always the
+    ** case that they are sequential and adjacent.  This invariant arises
+    ** because multiple overflows can only occurs when inserting divider
+    ** cells into a parent on a prior balance, and divider cells are always
+    ** adjacent and are inserted in order.  There is an assert() tagged
+    ** with "NOTE 1" in the overflow cell insertion loop to prove this
+    ** invariant.
+    **
+    ** This must be done in advance.  Once the balance starts, the cell
+    ** offset section of the btree page will be overwritten and we will no
+    ** long be able to find the cells if a pointer to each cell is not saved
+    ** first.
+    */
+    memset(&b.szCell[b.nCell], 0, sizeof(b.szCell[0])*(limit+pOld->nOverflow));
     if( pOld->nOverflow>0 ){
+      limit = pOld->aiOvfl[0];
       for(j=0; jaData;
-      u16 maskPage = pOld->maskPage;
-      u16 cellOffset = pOld->cellOffset;
-      for(j=0; jnOverflow; k++){
+        assert( k==0 || pOld->aiOvfl[k-1]+1==pOld->aiOvfl[k] );/* NOTE 1 */
+        b.apCell[b.nCell] = pOld->apOvfl[k];
+        b.nCell++;
       }
-    }       
-    cntOld[i] = nCell;
+    }
+    piEnd = aData + pOld->cellOffset + 2*pOld->nCell;
+    while( piCellmaxLocal+23 );
       assert( iSpace1 <= (int)pBt->pageSize );
       memcpy(pTemp, apDiv[i], sz);
-      apCell[nCell] = pTemp+leafCorrection;
+      b.apCell[b.nCell] = pTemp+leafCorrection;
       assert( leafCorrection==0 || leafCorrection==4 );
-      szCell[nCell] = szCell[nCell] - leafCorrection;
+      b.szCell[b.nCell] = b.szCell[b.nCell] - leafCorrection;
       if( !pOld->leaf ){
         assert( leafCorrection==0 );
         assert( pOld->hdrOffset==0 );
         /* The right pointer of the child page pOld becomes the left
         ** pointer of the divider cell */
-        memcpy(apCell[nCell], &pOld->aData[8], 4);
+        memcpy(b.apCell[b.nCell], &pOld->aData[8], 4);
       }else{
         assert( leafCorrection==4 );
-        if( szCell[nCell]<4 ){
+        while( b.szCell[b.nCell]<4 ){
           /* Do not allow any cells smaller than 4 bytes. If a smaller cell
           ** does exist, pad it with 0x00 bytes. */
-          assert( szCell[nCell]==3 );
-          assert( apCell[nCell]==&aSpace1[iSpace1-3] );
+          assert( b.szCell[b.nCell]==3 || CORRUPT_DB );
+          assert( b.apCell[b.nCell]==&aSpace1[iSpace1-3] || CORRUPT_DB );
           aSpace1[iSpace1++] = 0x00;
-          szCell[nCell] = 4;
+          b.szCell[b.nCell]++;
         }
       }
-      nCell++;
+      b.nCell++;
     }
   }
 
   /*
-  ** Figure out the number of pages needed to hold all nCell cells.
+  ** Figure out the number of pages needed to hold all b.nCell cells.
   ** Store this number in "k".  Also compute szNew[] which is the total
   ** size of all cells on the i-th page and cntNew[] which is the index
-  ** in apCell[] of the cell that divides page i from page i+1.  
-  ** cntNew[k] should equal nCell.
+  ** in b.apCell[] of the cell that divides page i from page i+1.  
+  ** cntNew[k] should equal b.nCell.
   **
   ** Values computed by this block:
   **
   **           k: The total number of sibling pages
   **    szNew[i]: Spaced used on the i-th sibling page.
-  **   cntNew[i]: Index in apCell[] and szCell[] for the first cell to
+  **   cntNew[i]: Index in b.apCell[] and b.szCell[] for the first cell to
   **              the right of the i-th sibling page.
   ** usableSpace: Number of bytes of space available on each sibling.
   ** 
   */
   usableSpace = pBt->usableSize - 12 + leafCorrection;
-  for(subtotal=k=i=0; i usableSpace ){
-      szNew[k] = subtotal - szCell[i] - 2;
-      cntNew[k] = i;
-      if( leafData ){ i--; }
-      subtotal = 0;
-      k++;
-      if( k>NB+1 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
-    }
-  }
-  szNew[k] = subtotal;
-  cntNew[k] = nCell;
-  k++;
+  for(i=0; inFree;
+    for(j=0; jnOverflow; j++){
+      szNew[i] += 2 + p->xCellSize(p, p->apOvfl[j]);
+    }
+    cntNew[i] = cntOld[i];
+  }
+  k = nOld;
+  for(i=0; iusableSpace ){
+      if( i+1>=k ){
+        k = i+2;
+        if( k>NB+2 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
+        szNew[k-1] = 0;
+        cntNew[k-1] = b.nCell;
+      }
+      sz = 2 + cachedCellSize(&b, cntNew[i]-1);
+      szNew[i] -= sz;
+      if( !leafData ){
+        if( cntNew[i]usableSpace ) break;
+      szNew[i] += sz;
+      cntNew[i]++;
+      if( !leafData ){
+        if( cntNew[i]=b.nCell ){
+      k = i+1;
+    }else if( cntNew[i] <= (i>0 ? cntNew[i-1] : 0) ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
+  }
 
   /*
   ** The packing computed by the previous block is biased toward the siblings
@@ -59561,19 +67029,27 @@ static int balance_nonroot(
 
     r = cntNew[i-1] - 1;
     d = r + 1 - leafData;
-    assert( d szLeft-(b.szCell[r]+(i==k-1?0:2)))){
+        break;
+      }
+      szRight += b.szCell[d] + 2;
+      szLeft -= b.szCell[r] + 2;
+      cntNew[i-1] = r;
+      r--;
+      d--;
+    }while( r>=0 );
     szNew[i] = szRight;
     szNew[i-1] = szLeft;
+    if( cntNew[i-1] <= (i>1 ? cntNew[i-2] : 0) ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
   }
 
   /* Sanity check:  For a non-corrupt database file one of the follwing
@@ -59593,10 +67069,6 @@ static int balance_nonroot(
   /*
   ** Allocate k new pages.  Reuse old pages where possible.
   */
-  if( apOld[0]->pgno<=1 ){
-    rc = SQLITE_CORRUPT_BKPT;
-    goto balance_cleanup;
-  }
   pageFlags = apOld[0]->aData[0];
   for(i=0; inCell + pOld->nOverflow + !leafData;
@@ -59738,15 +67210,15 @@ static int balance_nonroot(
       ** overflow cell), we can skip updating the pointer map entries.  */
       if( iOld>=nNew
        || pNew->pgno!=aPgno[iOld]
-       || pCell=&aOld[usableSize]
+       || !SQLITE_WITHIN(pCell,aOld,&aOld[usableSize])
       ){
         if( !leafCorrection ){
           ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
         }
-        if( szCell[i]>pNew->minLocal ){
+        if( cachedCellSize(&b,i)>pNew->minLocal ){
           ptrmapPutOvflPtr(pNew, pCell, &rc);
         }
+        if( rc ) goto balance_cleanup;
       }
     }
   }
@@ -59760,20 +67232,21 @@ static int balance_nonroot(
     j = cntNew[i];
 
     assert( jleaf ){
       memcpy(&pNew->aData[8], pCell, 4);
     }else if( leafData ){
       /* If the tree is a leaf-data tree, and the siblings are leaves, 
-      ** then there is no divider cell in apCell[]. Instead, the divider 
+      ** then there is no divider cell in b.apCell[]. Instead, the divider 
       ** cell consists of the integer key for the right-most cell of 
       ** the sibling-page assembled above only.
       */
       CellInfo info;
       j--;
-      btreeParseCellPtr(pNew, apCell[j], &info);
+      pNew->xParseCell(pNew, b.apCell[j], &info);
       pCell = pTemp;
       sz = 4 + putVarint(&pCell[4], info.nKey);
       pTemp = 0;
@@ -59786,13 +67259,13 @@ static int balance_nonroot(
       ** any cell). But it is important to pass the correct size to 
       ** insertCell(), so reparse the cell now.
       **
-      ** Note that this can never happen in an SQLite data file, as all
-      ** cells are at least 4 bytes. It only happens in b-trees used
-      ** to evaluate "IN (SELECT ...)" and similar clauses.
+      ** This can only happen for b-trees used to evaluate "IN (SELECT ...)"
+      ** and WITHOUT ROWID tables with exactly one column which is the
+      ** primary key.
       */
-      if( szCell[j]==4 ){
+      if( b.szCell[j]==4 ){
         assert(leafCorrection==4);
-        sz = cellSizePtr(pParent, pCell);
+        sz = pParent->xCellSize(pParent, pCell);
       }
     }
     iOvflSpace += sz;
@@ -59848,12 +67321,13 @@ static int balance_nonroot(
         iNew = iOld = 0;
         nNewCell = cntNew[0];
       }else{
-        iOld = iPgnFree = usableSpace-szNew[iPg];
       assert( apNew[iPg]->nOverflow==0 );
@@ -59883,8 +67357,8 @@ static int balance_nonroot(
     ** by smaller than the child due to the database header, and so all the
     ** free space needs to be up front.
     */
-    assert( nNew==1 );
-    rc = defragmentPage(apNew[0]);
+    assert( nNew==1 || CORRUPT_DB );
+    rc = defragmentPage(apNew[0], -1);
     testcase( rc!=SQLITE_OK );
     assert( apNew[0]->nFree == 
         (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
@@ -59904,7 +67378,7 @@ static int balance_nonroot(
 
   assert( pParent->isInit );
   TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
-          nOld, nNew, nCell));
+          nOld, nNew, b.nCell));
 
   /* Free any old pages that were not reused as new pages.
   */
@@ -59927,7 +67401,7 @@ static int balance_nonroot(
   ** Cleanup before returning.
   */
 balance_cleanup:
-  sqlite3ScratchFree(apCell);
+  sqlite3ScratchFree(b.apCell);
   for(i=0; i= 1700 && defined(_M_ARM)
-#pragma optimize("", on)
-#endif
 
 
 /*
@@ -60024,8 +67495,8 @@ static int balance(BtCursor *pCur){
   u8 aBalanceQuickSpace[13];
   u8 *pFree = 0;
 
-  TESTONLY( int balance_quick_called = 0 );
-  TESTONLY( int balance_deeper_called = 0 );
+  VVA_ONLY( int balance_quick_called = 0 );
+  VVA_ONLY( int balance_deeper_called = 0 );
 
   do {
     int iPage = pCur->iPage;
@@ -60038,12 +67509,13 @@ static int balance(BtCursor *pCur){
         ** and copy the current contents of the root-page to it. The
         ** next iteration of the do-loop will balance the child page.
         */ 
-        assert( (balance_deeper_called++)==0 );
+        assert( balance_deeper_called==0 );
+        VVA_ONLY( balance_deeper_called++ );
         rc = balance_deeper(pPage, &pCur->apPage[1]);
         if( rc==SQLITE_OK ){
           pCur->iPage = 1;
+          pCur->ix = 0;
           pCur->aiIdx[0] = 0;
-          pCur->aiIdx[1] = 0;
           assert( pCur->apPage[1]->nOverflow );
         }
       }else{
@@ -60077,7 +67549,8 @@ static int balance(BtCursor *pCur){
           ** function. If this were not verified, a subtle bug involving reuse
           ** of the aBalanceQuickSpace[] might sneak in.
           */
-          assert( (balance_quick_called++)==0 );
+          assert( balance_quick_called==0 ); 
+          VVA_ONLY( balance_quick_called++ );
           rc = balance_quick(pParent, pPage, aBalanceQuickSpace);
         }else
 #endif
@@ -60100,7 +67573,8 @@ static int balance(BtCursor *pCur){
           ** pSpace buffer passed to the latter call to balance_nonroot().
           */
           u8 *pSpace = sqlite3PageMalloc(pCur->pBt->pageSize);
-          rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1, pCur->hints);
+          rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1,
+                               pCur->hints&BTREE_BULKLOAD);
           if( pFree ){
             /* If pFree is not NULL, it points to the pSpace buffer used 
             ** by a previous call to balance_nonroot(). Its contents are
@@ -60121,6 +67595,7 @@ static int balance(BtCursor *pCur){
       /* The next iteration of the do-loop balances the parent page. */
       releasePage(pPage);
       pCur->iPage--;
+      assert( pCur->iPage>=0 );
     }
   }while( rc==SQLITE_OK );
 
@@ -60132,33 +67607,39 @@ static int balance(BtCursor *pCur){
 
 
 /*
-** Insert a new record into the BTree.  The key is given by (pKey,nKey)
-** and the data is given by (pData,nData).  The cursor is used only to
-** define what table the record should be inserted into.  The cursor
-** is left pointing at a random location.
+** Insert a new record into the BTree.  The content of the new record
+** is described by the pX object.  The pCur cursor is used only to
+** define what table the record should be inserted into, and is left
+** pointing at a random location.
+**
+** For a table btree (used for rowid tables), only the pX.nKey value of
+** the key is used. The pX.pKey value must be NULL.  The pX.nKey is the
+** rowid or INTEGER PRIMARY KEY of the row.  The pX.nData,pData,nZero fields
+** hold the content of the row.
 **
-** For an INTKEY table, only the nKey value of the key is used.  pKey is
-** ignored.  For a ZERODATA table, the pData and nData are both ignored.
+** For an index btree (used for indexes and WITHOUT ROWID tables), the
+** key is an arbitrary byte sequence stored in pX.pKey,nKey.  The 
+** pX.pData,nData,nZero fields must be zero.
 **
 ** If the seekResult parameter is non-zero, then a successful call to
-** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
-** been performed. seekResult is the search result returned (a negative
-** number if pCur points at an entry that is smaller than (pKey, nKey), or
-** a positive value if pCur points at an entry that is larger than 
-** (pKey, nKey)). 
-**
-** If the seekResult parameter is non-zero, then the caller guarantees that
-** cursor pCur is pointing at the existing copy of a row that is to be
-** overwritten.  If the seekResult parameter is 0, then cursor pCur may
-** point to any entry or to no entry at all and so this function has to seek
-** the cursor before the new key can be inserted.
+** MovetoUnpacked() to seek cursor pCur to (pKey,nKey) has already
+** been performed.  In other words, if seekResult!=0 then the cursor
+** is currently pointing to a cell that will be adjacent to the cell
+** to be inserted.  If seekResult<0 then pCur points to a cell that is
+** smaller then (pKey,nKey).  If seekResult>0 then pCur points to a cell
+** that is larger than (pKey,nKey).
+**
+** If seekResult==0, that means pCur is pointing at some unknown location.
+** In that case, this routine must seek the cursor to the correct insertion
+** point for (pKey,nKey) before doing the insertion.  For index btrees,
+** if pX->nMem is non-zero, then pX->aMem contains pointers to the unpacked
+** key values and pX->aMem can be used instead of pX->pKey to avoid having
+** to decode the key.
 */
 SQLITE_PRIVATE int sqlite3BtreeInsert(
   BtCursor *pCur,                /* Insert data into the table of this cursor */
-  const void *pKey, i64 nKey,    /* The key of the new record */
-  const void *pData, int nData,  /* The data of the new record */
-  int nZero,                     /* Number of extra 0 bytes to append to data */
-  int appendBias,                /* True if this is likely an append */
+  const BtreePayload *pX,        /* Content of the row to be inserted */
+  int flags,                     /* True if this is likely an append */
   int seekResult                 /* Result of prior MovetoUnpacked() call */
 ){
   int rc;
@@ -60171,12 +67652,14 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   unsigned char *oldCell;
   unsigned char *newCell = 0;
 
+  assert( (flags & (BTREE_SAVEPOSITION|BTREE_APPEND))==flags );
+
   if( pCur->eState==CURSOR_FAULT ){
     assert( pCur->skipNext!=SQLITE_OK );
     return pCur->skipNext;
   }
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( (pCur->curFlags & BTCF_WriteFlag)!=0
               && pBt->inTransaction==TRANS_WRITE
               && (pBt->btsFlags & BTS_READ_ONLY)==0 );
@@ -60187,7 +67670,7 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** keys with no associated data. If the cursor was opened expecting an
   ** intkey table, the caller should be inserting integer keys with a
   ** blob of associated data.  */
-  assert( (pKey==0)==(pCur->pKeyInfo==0) );
+  assert( (pX->pKey==0)==(pCur->pKeyInfo==0) );
 
   /* Save the positions of any other cursors open on this table.
   **
@@ -60200,46 +67683,67 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** doing any work. To avoid thwarting these optimizations, it is important
   ** not to clear the cursor here.
   */
-  rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
-  if( rc ) return rc;
+  if( pCur->curFlags & BTCF_Multiple ){
+    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+    if( rc ) return rc;
+  }
 
   if( pCur->pKeyInfo==0 ){
+    assert( pX->pKey==0 );
     /* If this is an insert into a table b-tree, invalidate any incrblob 
     ** cursors open on the row being replaced */
-    invalidateIncrblobCursors(p, nKey, 0);
+    invalidateIncrblobCursors(p, pCur->pgnoRoot, pX->nKey, 0);
+
+    /* If BTREE_SAVEPOSITION is set, the cursor must already be pointing 
+    ** to a row with the same key as the new entry being inserted.  */
+    assert( (flags & BTREE_SAVEPOSITION)==0 || 
+            ((pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey==pCur->info.nKey) );
 
     /* If the cursor is currently on the last row and we are appending a
-    ** new row onto the end, set the "loc" to avoid an unnecessary btreeMoveto()
-    ** call */
-    if( (pCur->curFlags&BTCF_ValidNKey)!=0 && nKey>0
-      && pCur->info.nKey==nKey-1 ){
-      loc = -1;
+    ** new row onto the end, set the "loc" to avoid an unnecessary
+    ** btreeMoveto() call */
+    if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey==pCur->info.nKey ){
+      loc = 0;
+    }else if( loc==0 ){
+      rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, flags!=0, &loc);
+      if( rc ) return rc;
+    }
+  }else if( loc==0 && (flags & BTREE_SAVEPOSITION)==0 ){
+    if( pX->nMem ){
+      UnpackedRecord r;
+      r.pKeyInfo = pCur->pKeyInfo;
+      r.aMem = pX->aMem;
+      r.nField = pX->nMem;
+      r.default_rc = 0;
+      r.errCode = 0;
+      r.r1 = 0;
+      r.r2 = 0;
+      r.eqSeen = 0;
+      rc = sqlite3BtreeMovetoUnpacked(pCur, &r, 0, flags!=0, &loc);
+    }else{
+      rc = btreeMoveto(pCur, pX->pKey, pX->nKey, flags!=0, &loc);
     }
-  }
-
-  if( !loc ){
-    rc = btreeMoveto(pCur, pKey, nKey, appendBias, &loc);
     if( rc ) return rc;
   }
   assert( pCur->eState==CURSOR_VALID || (pCur->eState==CURSOR_INVALID && loc) );
 
   pPage = pCur->apPage[pCur->iPage];
-  assert( pPage->intKey || nKey>=0 );
+  assert( pPage->intKey || pX->nKey>=0 );
   assert( pPage->leaf || !pPage->intKey );
 
   TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
-          pCur->pgnoRoot, nKey, nData, pPage->pgno,
+          pCur->pgnoRoot, pX->nKey, pX->nData, pPage->pgno,
           loc==0 ? "overwrite" : "new entry"));
   assert( pPage->isInit );
   newCell = pBt->pTmpSpace;
   assert( newCell!=0 );
-  rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, &szNew);
+  rc = fillInCell(pPage, newCell, pX, &szNew);
   if( rc ) goto end_insert;
-  assert( szNew==cellSizePtr(pPage, newCell) );
+  assert( szNew==pPage->xCellSize(pPage, newCell) );
   assert( szNew <= MX_CELL_SIZE(pBt) );
-  idx = pCur->aiIdx[pCur->iPage];
+  idx = pCur->ix;
   if( loc==0 ){
-    u16 szOld;
+    CellInfo info;
     assert( idxnCell );
     rc = sqlite3PagerWrite(pPage->pDbPage);
     if( rc ){
@@ -60249,16 +67753,35 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
     if( !pPage->leaf ){
       memcpy(newCell, oldCell, 4);
     }
-    rc = clearCell(pPage, oldCell, &szOld);
-    dropCell(pPage, idx, szOld, &rc);
+    rc = clearCell(pPage, oldCell, &info);
+    if( info.nSize==szNew && info.nLocal==info.nPayload 
+     && (!ISAUTOVACUUM || szNewminLocal)
+    ){
+      /* Overwrite the old cell with the new if they are the same size.
+      ** We could also try to do this if the old cell is smaller, then add
+      ** the leftover space to the free list.  But experiments show that
+      ** doing that is no faster then skipping this optimization and just
+      ** calling dropCell() and insertCell(). 
+      **
+      ** This optimization cannot be used on an autovacuum database if the
+      ** new entry uses overflow pages, as the insertCell() call below is
+      ** necessary to add the PTRMAP_OVERFLOW1 pointer-map entry.  */
+      assert( rc==SQLITE_OK ); /* clearCell never fails when nLocal==nPayload */
+      if( oldCell+szNew > pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;
+      memcpy(oldCell, newCell, szNew);
+      return SQLITE_OK;
+    }
+    dropCell(pPage, idx, info.nSize, &rc);
     if( rc ) goto end_insert;
   }else if( loc<0 && pPage->nCell>0 ){
     assert( pPage->leaf );
-    idx = ++pCur->aiIdx[pCur->iPage];
+    idx = ++pCur->ix;
+    pCur->curFlags &= ~BTCF_ValidNKey;
   }else{
     assert( pPage->leaf );
   }
   insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);
+  assert( pPage->nOverflow==0 || rc==SQLITE_OK );
   assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );
 
   /* If no error has occurred and pPage has an overflow cell, call balance() 
@@ -60282,7 +67805,8 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** row without seeking the cursor. This can be a big performance boost.
   */
   pCur->info.nSize = 0;
-  if( rc==SQLITE_OK && pPage->nOverflow ){
+  if( pPage->nOverflow ){
+    assert( rc==SQLITE_OK );
     pCur->curFlags &= ~(BTCF_ValidNKey);
     rc = balance(pCur);
 
@@ -60292,6 +67816,20 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
     ** from trying to save the current position of the cursor.  */
     pCur->apPage[pCur->iPage]->nOverflow = 0;
     pCur->eState = CURSOR_INVALID;
+    if( (flags & BTREE_SAVEPOSITION) && rc==SQLITE_OK ){
+      rc = moveToRoot(pCur);
+      if( pCur->pKeyInfo ){
+        assert( pCur->pKey==0 );
+        pCur->pKey = sqlite3Malloc( pX->nKey );
+        if( pCur->pKey==0 ){
+          rc = SQLITE_NOMEM;
+        }else{
+          memcpy(pCur->pKey, pX->pKey, pX->nKey);
+        }
+      }
+      pCur->eState = CURSOR_REQUIRESEEK;
+      pCur->nKey = pX->nKey;
+    }
   }
   assert( pCur->apPage[pCur->iPage]->nOverflow==0 );
 
@@ -60300,10 +67838,23 @@ end_insert:
 }
 
 /*
-** Delete the entry that the cursor is pointing to.  The cursor
-** is left pointing at an arbitrary location.
+** Delete the entry that the cursor is pointing to. 
+**
+** If the BTREE_SAVEPOSITION bit of the flags parameter is zero, then
+** the cursor is left pointing at an arbitrary location after the delete.
+** But if that bit is set, then the cursor is left in a state such that
+** the next call to BtreeNext() or BtreePrev() moves it to the same row
+** as it would have been on if the call to BtreeDelete() had been omitted.
+**
+** The BTREE_AUXDELETE bit of flags indicates that is one of several deletes
+** associated with a single table entry and its indexes.  Only one of those
+** deletes is considered the "primary" delete.  The primary delete occurs
+** on a cursor that is not a BTREE_FORDELETE cursor.  All but one delete
+** operation on non-FORDELETE cursors is tagged with the AUXDELETE flag.
+** The BTREE_AUXDELETE bit is a hint that is not used by this implementation,
+** but which might be used by alternative storage engines.
 */
-SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
+SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
   Btree *p = pCur->pBtree;
   BtShared *pBt = p->pBt;              
   int rc;                              /* Return code */
@@ -60311,26 +67862,47 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   unsigned char *pCell;                /* Pointer to cell to delete */
   int iCellIdx;                        /* Index of cell to delete */
   int iCellDepth;                      /* Depth of node containing pCell */ 
-  u16 szCell;                          /* Size of the cell being deleted */
+  CellInfo info;                       /* Size of the cell being deleted */
+  int bSkipnext = 0;                   /* Leaf cursor in SKIPNEXT state */
+  u8 bPreserve = flags & BTREE_SAVEPOSITION;  /* Keep cursor valid */
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pBt->inTransaction==TRANS_WRITE );
   assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
   assert( pCur->curFlags & BTCF_WriteFlag );
   assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
   assert( !hasReadConflicts(p, pCur->pgnoRoot) );
-
-  if( NEVER(pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell) 
-   || NEVER(pCur->eState!=CURSOR_VALID)
-  ){
-    return SQLITE_ERROR;  /* Something has gone awry. */
-  }
+  assert( pCur->ixapPage[pCur->iPage]->nCell );
+  assert( pCur->eState==CURSOR_VALID );
+  assert( (flags & ~(BTREE_SAVEPOSITION | BTREE_AUXDELETE))==0 );
 
   iCellDepth = pCur->iPage;
-  iCellIdx = pCur->aiIdx[iCellDepth];
+  iCellIdx = pCur->ix;
   pPage = pCur->apPage[iCellDepth];
   pCell = findCell(pPage, iCellIdx);
 
+  /* If the bPreserve flag is set to true, then the cursor position must
+  ** be preserved following this delete operation. If the current delete
+  ** will cause a b-tree rebalance, then this is done by saving the cursor
+  ** key and leaving the cursor in CURSOR_REQUIRESEEK state before 
+  ** returning. 
+  **
+  ** Or, if the current delete will not cause a rebalance, then the cursor
+  ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately
+  ** before or after the deleted entry. In this case set bSkipnext to true.  */
+  if( bPreserve ){
+    if( !pPage->leaf 
+     || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
+    ){
+      /* A b-tree rebalance will be required after deleting this entry.
+      ** Save the cursor key.  */
+      rc = saveCursorKey(pCur);
+      if( rc ) return rc;
+    }else{
+      bSkipnext = 1;
+    }
+  }
+
   /* If the page containing the entry to delete is not a leaf page, move
   ** the cursor to the largest entry in the tree that is smaller than
   ** the entry being deleted. This cell will replace the cell being deleted
@@ -60339,29 +67911,31 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   ** sub-tree headed by the child page of the cell being deleted. This makes
   ** balancing the tree following the delete operation easier.  */
   if( !pPage->leaf ){
-    int notUsed = 0;
-    rc = sqlite3BtreePrevious(pCur, ¬Used);
+    rc = sqlite3BtreePrevious(pCur, 0);
+    assert( rc!=SQLITE_DONE );
     if( rc ) return rc;
   }
 
   /* Save the positions of any other cursors open on this table before
-  ** making any modifications. Make the page containing the entry to be 
-  ** deleted writable. Then free any overflow pages associated with the 
-  ** entry and finally remove the cell itself from within the page.  
-  */
-  rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
-  if( rc ) return rc;
+  ** making any modifications.  */
+  if( pCur->curFlags & BTCF_Multiple ){
+    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+    if( rc ) return rc;
+  }
 
   /* If this is a delete operation to remove a row from a table b-tree,
   ** invalidate any incrblob cursors open on the row being deleted.  */
   if( pCur->pKeyInfo==0 ){
-    invalidateIncrblobCursors(p, pCur->info.nKey, 0);
+    invalidateIncrblobCursors(p, pCur->pgnoRoot, pCur->info.nKey, 0);
   }
 
+  /* Make the page containing the entry to be deleted writable. Then free any
+  ** overflow pages associated with the entry and finally remove the cell
+  ** itself from within the page.  */
   rc = sqlite3PagerWrite(pPage->pDbPage);
   if( rc ) return rc;
-  rc = clearCell(pPage, pCell, &szCell);
-  dropCell(pPage, iCellIdx, szCell, &rc);
+  rc = clearCell(pPage, pCell, &info);
+  dropCell(pPage, iCellIdx, info.nSize, &rc);
   if( rc ) return rc;
 
   /* If the cell deleted was not located on a leaf page, then the cursor
@@ -60376,12 +67950,15 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
     unsigned char *pTmp;
 
     pCell = findCell(pLeaf, pLeaf->nCell-1);
-    nCell = cellSizePtr(pLeaf, pCell);
+    if( pCell<&pLeaf->aData[4] ) return SQLITE_CORRUPT_BKPT;
+    nCell = pLeaf->xCellSize(pLeaf, pCell);
     assert( MX_CELL_SIZE(pBt) >= nCell );
     pTmp = pBt->pTmpSpace;
     assert( pTmp!=0 );
     rc = sqlite3PagerWrite(pLeaf->pDbPage);
-    insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
+    if( rc==SQLITE_OK ){
+      insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
+    }
     dropCell(pLeaf, pLeaf->nCell-1, nCell, &rc);
     if( rc ) return rc;
   }
@@ -60410,7 +67987,23 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   }
 
   if( rc==SQLITE_OK ){
-    moveToRoot(pCur);
+    if( bSkipnext ){
+      assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );
+      assert( pPage==pCur->apPage[pCur->iPage] || CORRUPT_DB );
+      assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );
+      pCur->eState = CURSOR_SKIPNEXT;
+      if( iCellIdx>=pPage->nCell ){
+        pCur->skipNext = -1;
+        pCur->ix = pPage->nCell-1;
+      }else{
+        pCur->skipNext = 1;
+      }
+    }else{
+      rc = moveToRoot(pCur);
+      if( bPreserve ){
+        pCur->eState = CURSOR_REQUIRESEEK;
+      }
+    }
   }
   return rc;
 }
@@ -60468,7 +68061,8 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
         pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
       pgnoRoot++;
     }
-    assert( pgnoRoot>=3 );
+    assert( pgnoRoot>=3 || CORRUPT_DB );
+    testcase( pgnoRoot<3 );
 
     /* Allocate a page. The page that currently resides at pgnoRoot will
     ** be moved to the allocated page (unless the allocated page happens
@@ -60591,15 +68185,19 @@ static int clearDatabasePage(
   unsigned char *pCell;
   int i;
   int hdr;
-  u16 szCell;
+  CellInfo info;
 
   assert( sqlite3_mutex_held(pBt->mutex) );
   if( pgno>btreePagecount(pBt) ){
     return SQLITE_CORRUPT_BKPT;
   }
-
-  rc = getAndInitPage(pBt, pgno, &pPage, 0);
+  rc = getAndInitPage(pBt, pgno, &pPage, 0, 0);
   if( rc ) return rc;
+  if( pPage->bBusy ){
+    rc = SQLITE_CORRUPT_BKPT;
+    goto cleardatabasepage_out;
+  }
+  pPage->bBusy = 1;
   hdr = pPage->hdrOffset;
   for(i=0; inCell; i++){
     pCell = findCell(pPage, i);
@@ -60607,14 +68205,15 @@ static int clearDatabasePage(
       rc = clearDatabasePage(pBt, get4byte(pCell), 1, pnChange);
       if( rc ) goto cleardatabasepage_out;
     }
-    rc = clearCell(pPage, pCell, &szCell);
+    rc = clearCell(pPage, pCell, &info);
     if( rc ) goto cleardatabasepage_out;
   }
   if( !pPage->leaf ){
     rc = clearDatabasePage(pBt, get4byte(&pPage->aData[hdr+8]), 1, pnChange);
     if( rc ) goto cleardatabasepage_out;
   }else if( pnChange ){
-    assert( pPage->intKey );
+    assert( pPage->intKey || CORRUPT_DB );
+    testcase( !pPage->intKey );
     *pnChange += pPage->nCell;
   }
   if( freePageFlag ){
@@ -60624,6 +68223,7 @@ static int clearDatabasePage(
   }
 
 cleardatabasepage_out:
+  pPage->bBusy = 0;
   releasePage(pPage);
   return rc;
 }
@@ -60653,7 +68253,7 @@ SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree *p, int iTable, int *pnChange){
     /* Invalidate all incrblob cursors open on table iTable (assuming iTable
     ** is the root of a table b-tree - if it is not, the following call is
     ** a no-op).  */
-    invalidateIncrblobCursors(p, 0, 1);
+    invalidateIncrblobCursors(p, (Pgno)iTable, 0, 1);
     rc = clearDatabasePage(pBt, (Pgno)iTable, 0, pnChange);
   }
   sqlite3BtreeLeave(p);
@@ -60696,19 +68296,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
 
   assert( sqlite3BtreeHoldsMutex(p) );
   assert( p->inTrans==TRANS_WRITE );
-
-  /* It is illegal to drop a table if any cursors are open on the
-  ** database. This is because in auto-vacuum mode the backend may
-  ** need to move another root-page to fill a gap left by the deleted
-  ** root page. If an open cursor was using this page a problem would 
-  ** occur.
-  **
-  ** This error is caught long before control reaches this point.
-  */
-  if( NEVER(pBt->pCursor) ){
-    sqlite3ConnectionBlocked(p->db, pBt->pCursor->pBtree->db);
-    return SQLITE_LOCKED_SHAREDCACHE;
-  }
+  assert( iTable>=2 );
 
   rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
   if( rc ) return rc;
@@ -60720,76 +68308,67 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
 
   *piMoved = 0;
 
-  if( iTable>1 ){
 #ifdef SQLITE_OMIT_AUTOVACUUM
-    freePage(pPage, &rc);
-    releasePage(pPage);
+  freePage(pPage, &rc);
+  releasePage(pPage);
 #else
-    if( pBt->autoVacuum ){
-      Pgno maxRootPgno;
-      sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);
-
-      if( iTable==maxRootPgno ){
-        /* If the table being dropped is the table with the largest root-page
-        ** number in the database, put the root page on the free list. 
-        */
-        freePage(pPage, &rc);
-        releasePage(pPage);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-      }else{
-        /* The table being dropped does not have the largest root-page
-        ** number in the database. So move the page that does into the 
-        ** gap left by the deleted root-page.
-        */
-        MemPage *pMove;
-        releasePage(pPage);
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
-        releasePage(pMove);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        pMove = 0;
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
-        freePage(pMove, &rc);
-        releasePage(pMove);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        *piMoved = maxRootPgno;
-      }
+  if( pBt->autoVacuum ){
+    Pgno maxRootPgno;
+    sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);
 
-      /* Set the new 'max-root-page' value in the database header. This
-      ** is the old value less one, less one more if that happens to
-      ** be a root-page number, less one again if that is the
-      ** PENDING_BYTE_PAGE.
+    if( iTable==maxRootPgno ){
+      /* If the table being dropped is the table with the largest root-page
+      ** number in the database, put the root page on the free list. 
       */
-      maxRootPgno--;
-      while( maxRootPgno==PENDING_BYTE_PAGE(pBt)
-             || PTRMAP_ISPAGE(pBt, maxRootPgno) ){
-        maxRootPgno--;
+      freePage(pPage, &rc);
+      releasePage(pPage);
+      if( rc!=SQLITE_OK ){
+        return rc;
       }
-      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
-
-      rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
     }else{
-      freePage(pPage, &rc);
+      /* The table being dropped does not have the largest root-page
+      ** number in the database. So move the page that does into the 
+      ** gap left by the deleted root-page.
+      */
+      MemPage *pMove;
       releasePage(pPage);
+      rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
+      releasePage(pMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      pMove = 0;
+      rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+      freePage(pMove, &rc);
+      releasePage(pMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      *piMoved = maxRootPgno;
     }
-#endif
-  }else{
-    /* If sqlite3BtreeDropTable was called on page 1.
-    ** This really never should happen except in a corrupt
-    ** database. 
+
+    /* Set the new 'max-root-page' value in the database header. This
+    ** is the old value less one, less one more if that happens to
+    ** be a root-page number, less one again if that is the
+    ** PENDING_BYTE_PAGE.
     */
-    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
+    maxRootPgno--;
+    while( maxRootPgno==PENDING_BYTE_PAGE(pBt)
+           || PTRMAP_ISPAGE(pBt, maxRootPgno) ){
+      maxRootPgno--;
+    }
+    assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
+
+    rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
+  }else{
+    freePage(pPage, &rc);
     releasePage(pPage);
   }
+#endif
   return rc;  
 }
 SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
@@ -60928,16 +68507,16 @@ SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
           return moveToRoot(pCur);
         }
         moveToParent(pCur);
-      }while ( pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell );
+      }while ( pCur->ix>=pCur->apPage[pCur->iPage]->nCell );
 
-      pCur->aiIdx[pCur->iPage]++;
+      pCur->ix++;
       pPage = pCur->apPage[pCur->iPage];
     }
 
     /* Descend to the child node of the cell that the cursor currently 
     ** points at. This is the right-child if (iIdx==pPage->nCell).
     */
-    iIdx = pCur->aiIdx[pCur->iPage];
+    iIdx = pCur->ix;
     if( iIdx==pPage->nCell ){
       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
     }else{
@@ -60968,7 +68547,6 @@ static void checkAppendMsg(
   ...
 ){
   va_list ap;
-  char zBuf[200];
   if( !pCheck->mxErr ) return;
   pCheck->mxErr--;
   pCheck->nErr++;
@@ -60977,10 +68555,9 @@ static void checkAppendMsg(
     sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
   }
   if( pCheck->zPfx ){
-    sqlite3_snprintf(sizeof(zBuf), zBuf, pCheck->zPfx, pCheck->v1, pCheck->v2);
-    sqlite3StrAccumAppendAll(&pCheck->errMsg, zBuf);
+    sqlite3XPrintf(&pCheck->errMsg, pCheck->zPfx, pCheck->v1, pCheck->v2);
   }
-  sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
+  sqlite3VXPrintf(&pCheck->errMsg, zFormat, ap);
   va_end(ap);
   if( pCheck->errMsg.accError==STRACCUM_NOMEM ){
     pCheck->mallocFailed = 1;
@@ -61084,7 +68661,7 @@ static void checkList(
       break;
     }
     if( checkRef(pCheck, iPage) ) break;
-    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage) ){
+    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
       checkAppendMsg(pCheck, "failed to get page %d", iPage);
       break;
     }
@@ -61127,10 +68704,65 @@ static void checkList(
 #endif
     iPage = get4byte(pOvflData);
     sqlite3PagerUnref(pOvflPage);
+
+    if( isFreeList && N<(iPage!=0) ){
+      checkAppendMsg(pCheck, "free-page count in header is too small");
+    }
   }
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
+/*
+** An implementation of a min-heap.
+**
+** aHeap[0] is the number of elements on the heap.  aHeap[1] is the
+** root element.  The daughter nodes of aHeap[N] are aHeap[N*2]
+** and aHeap[N*2+1].
+**
+** The heap property is this:  Every node is less than or equal to both
+** of its daughter nodes.  A consequence of the heap property is that the
+** root node aHeap[1] is always the minimum value currently in the heap.
+**
+** The btreeHeapInsert() routine inserts an unsigned 32-bit number onto
+** the heap, preserving the heap property.  The btreeHeapPull() routine
+** removes the root element from the heap (the minimum value in the heap)
+** and then moves other nodes around as necessary to preserve the heap
+** property.
+**
+** This heap is used for cell overlap and coverage testing.  Each u32
+** entry represents the span of a cell or freeblock on a btree page.  
+** The upper 16 bits are the index of the first byte of a range and the
+** lower 16 bits are the index of the last byte of that range.
+*/
+static void btreeHeapInsert(u32 *aHeap, u32 x){
+  u32 j, i = ++aHeap[0];
+  aHeap[i] = x;
+  while( (j = i/2)>0 && aHeap[j]>aHeap[i] ){
+    x = aHeap[j];
+    aHeap[j] = aHeap[i];
+    aHeap[i] = x;
+    i = j;
+  }
+}
+static int btreeHeapPull(u32 *aHeap, u32 *pOut){
+  u32 j, i, x;
+  if( (x = aHeap[0])==0 ) return 0;
+  *pOut = aHeap[1];
+  aHeap[1] = aHeap[x];
+  aHeap[x] = 0xffffffff;
+  aHeap[0]--;
+  i = 1;
+  while( (j = i*2)<=aHeap[0] ){
+    if( aHeap[j]>aHeap[j+1] ) j++;
+    if( aHeap[i]zPfx;
   int saved_v1 = pCheck->v1;
   int saved_v2 = pCheck->v2;
+  u8 savedIsInit = 0;
 
   /* Check that the page exists
   */
@@ -61181,54 +68821,96 @@ static int checkTreePage(
   if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
     checkAppendMsg(pCheck,
        "unable to get the page. error code=%d", rc);
-    depth = -1;
     goto end_of_check;
   }
 
   /* Clear MemPage.isInit to make sure the corruption detection code in
   ** btreeInitPage() is executed.  */
+  savedIsInit = pPage->isInit;
   pPage->isInit = 0;
   if( (rc = btreeInitPage(pPage))!=0 ){
     assert( rc==SQLITE_CORRUPT );  /* The only possible error from InitPage */
     checkAppendMsg(pCheck,
                    "btreeInitPage() returns error code %d", rc);
-    releasePage(pPage);
-    depth = -1;
     goto end_of_check;
   }
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
 
-  /* Check out all the cells.
-  */
-  depth = 0;
-  for(i=0; inCell && pCheck->mxErr; i++){
-    u8 *pCell;
-    u32 sz;
+  /* Set up for cell analysis */
+  pCheck->zPfx = "On tree page %d cell %d: ";
+  contentOffset = get2byteNotZero(&data[hdr+5]);
+  assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
+
+  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+  ** number of cells on the page. */
+  nCell = get2byte(&data[hdr+3]);
+  assert( pPage->nCell==nCell );
+
+  /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
+  ** immediately follows the b-tree page header. */
+  cellStart = hdr + 12 - 4*pPage->leaf;
+  assert( pPage->aCellIdx==&data[cellStart] );
+  pCellIdx = &data[cellStart + 2*(nCell-1)];
+
+  if( !pPage->leaf ){
+    /* Analyze the right-child page of internal pages */
+    pgno = get4byte(&data[hdr+8]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->autoVacuum ){
+      pCheck->zPfx = "On page %d at right child: ";
+      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
+    }
+#endif
+    depth = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+    keyCanBeEqual = 0;
+  }else{
+    /* For leaf pages, the coverage check will occur in the same loop
+    ** as the other cell checks, so initialize the heap.  */
+    heap = pCheck->heap;
+    heap[0] = 0;
+  }
+
+  /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte
+  ** integer offsets to the cell contents. */
+  for(i=nCell-1; i>=0 && pCheck->mxErr; i--){
     CellInfo info;
 
-    /* Check payload overflow pages
-    */
-    pCheck->zPfx = "On tree page %d cell %d: ";
-    pCheck->v1 = iPage;
+    /* Check cell size */
     pCheck->v2 = i;
-    pCell = findCell(pPage,i);
-    btreeParseCellPtr(pPage, pCell, &info);
-    sz = info.nPayload;
-    /* For intKey pages, check that the keys are in order.
-    */
+    assert( pCellIdx==&data[cellStart + i*2] );
+    pc = get2byteAligned(pCellIdx);
+    pCellIdx -= 2;
+    if( pcusableSize-4 ){
+      checkAppendMsg(pCheck, "Offset %d out of range %d..%d",
+                             pc, contentOffset, usableSize-4);
+      doCoverageCheck = 0;
+      continue;
+    }
+    pCell = &data[pc];
+    pPage->xParseCell(pPage, pCell, &info);
+    if( pc+info.nSize>usableSize ){
+      checkAppendMsg(pCheck, "Extends off end of page");
+      doCoverageCheck = 0;
+      continue;
+    }
+
+    /* Check for integer primary key out of range */
     if( pPage->intKey ){
-      if( i==0 ){
-        nMinKey = nMaxKey = info.nKey;
-      }else if( info.nKey <= nMaxKey ){
-        checkAppendMsg(pCheck,
-           "Rowid %lld out of order (previous was %lld)", info.nKey, nMaxKey);
+      if( keyCanBeEqual ? (info.nKey > maxKey) : (info.nKey >= maxKey) ){
+        checkAppendMsg(pCheck, "Rowid %lld out of order", info.nKey);
       }
-      nMaxKey = info.nKey;
+      maxKey = info.nKey;
+      keyCanBeEqual = 0;     /* Only the first key on the page may ==maxKey */
     }
-    if( (sz>info.nLocal) 
-     && (&pCell[info.iOverflow]<=&pPage->aData[pBt->usableSize])
-    ){
-      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
-      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
+
+    /* Check the content overflow list */
+    if( info.nPayload>info.nLocal ){
+      int nPage;       /* Number of pages on the overflow chain */
+      Pgno pgnoOvfl;   /* First page of the overflow chain */
+      assert( pc + info.nSize - 4 <= usableSize );
+      nPage = (info.nPayload - info.nLocal + usableSize - 5)/(usableSize - 4);
+      pgnoOvfl = get4byte(&pCell[info.nSize - 4]);
 #ifndef SQLITE_OMIT_AUTOVACUUM
       if( pBt->autoVacuum ){
         checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage);
@@ -61237,119 +68919,57 @@ static int checkTreePage(
       checkList(pCheck, 0, pgnoOvfl, nPage);
     }
 
-    /* Check sanity of left child page.
-    */
     if( !pPage->leaf ){
+      /* Check sanity of left child page for internal pages */
       pgno = get4byte(pCell);
 #ifndef SQLITE_OMIT_AUTOVACUUM
       if( pBt->autoVacuum ){
         checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
       }
 #endif
-      d2 = checkTreePage(pCheck, pgno, &nMinKey, i==0?NULL:&nMaxKey);
-      if( i>0 && d2!=depth ){
+      d2 = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+      keyCanBeEqual = 0;
+      if( d2!=depth ){
         checkAppendMsg(pCheck, "Child page depth differs");
+        depth = d2;
       }
-      depth = d2;
-    }
-  }
-
-  if( !pPage->leaf ){
-    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
-    pCheck->zPfx = "On page %d at right child: ";
-    pCheck->v1 = iPage;
-#ifndef SQLITE_OMIT_AUTOVACUUM
-    if( pBt->autoVacuum ){
-      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
-    }
-#endif
-    checkTreePage(pCheck, pgno, NULL, !pPage->nCell?NULL:&nMaxKey);
-  }
- 
-  /* For intKey leaf pages, check that the min/max keys are in order
-  ** with any left/parent/right pages.
-  */
-  pCheck->zPfx = "Page %d: ";
-  pCheck->v1 = iPage;
-  if( pPage->leaf && pPage->intKey ){
-    /* if we are a left child page */
-    if( pnParentMinKey ){
-      /* if we are the left most child page */
-      if( !pnParentMaxKey ){
-        if( nMaxKey > *pnParentMinKey ){
-          checkAppendMsg(pCheck,
-              "Rowid %lld out of order (max larger than parent min of %lld)",
-              nMaxKey, *pnParentMinKey);
-        }
-      }else{
-        if( nMinKey <= *pnParentMinKey ){
-          checkAppendMsg(pCheck,
-              "Rowid %lld out of order (min less than parent min of %lld)",
-              nMinKey, *pnParentMinKey);
-        }
-        if( nMaxKey > *pnParentMaxKey ){
-          checkAppendMsg(pCheck,
-              "Rowid %lld out of order (max larger than parent max of %lld)",
-              nMaxKey, *pnParentMaxKey);
-        }
-        *pnParentMinKey = nMaxKey;
-      }
-    /* else if we're a right child page */
-    } else if( pnParentMaxKey ){
-      if( nMinKey <= *pnParentMaxKey ){
-        checkAppendMsg(pCheck,
-            "Rowid %lld out of order (min less than parent max of %lld)",
-            nMinKey, *pnParentMaxKey);
-      }
+    }else{
+      /* Populate the coverage-checking heap for leaf pages */
+      btreeHeapInsert(heap, (pc<<16)|(pc+info.nSize-1));
     }
   }
+  *piMinKey = maxKey;
 
   /* Check for complete coverage of the page
   */
-  data = pPage->aData;
-  hdr = pPage->hdrOffset;
-  hit = sqlite3PageMalloc( pBt->pageSize );
   pCheck->zPfx = 0;
-  if( hit==0 ){
-    pCheck->mallocFailed = 1;
-  }else{
-    int contentOffset = get2byteNotZero(&data[hdr+5]);
-    assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
-    memset(hit+contentOffset, 0, usableSize-contentOffset);
-    memset(hit, 1, contentOffset);
-    /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
-    ** number of cells on the page. */
-    nCell = get2byte(&data[hdr+3]);
-    /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
-    ** immediately follows the b-tree page header. */
-    cellStart = hdr + 12 - 4*pPage->leaf;
-    /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte
-    ** integer offsets to the cell contents. */
-    for(i=0; i=usableSize ){
-        pCheck->zPfx = 0;
-        checkAppendMsg(pCheck,
-            "Corruption detected in cell %d on page %d",i,iPage);
-      }else{
-        for(j=pc+size-1; j>=pc; j--) hit[j]++;
+  if( doCoverageCheck && pCheck->mxErr>0 ){
+    /* For leaf pages, the min-heap has already been initialized and the
+    ** cells have already been inserted.  But for internal pages, that has
+    ** not yet been done, so do it now */
+    if( !pPage->leaf ){
+      heap = pCheck->heap;
+      heap[0] = 0;
+      for(i=nCell-1; i>=0; i--){
+        u32 size;
+        pc = get2byteAligned(&data[cellStart+i*2]);
+        size = pPage->xCellSize(pPage, &data[pc]);
+        btreeHeapInsert(heap, (pc<<16)|(pc+size-1));
       }
     }
-    /* EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header
+    /* Add the freeblocks to the min-heap
+    **
+    ** EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header
     ** is the offset of the first freeblock, or zero if there are no
-    ** freeblocks on the page. */
+    ** freeblocks on the page. 
+    */
     i = get2byte(&data[hdr+1]);
     while( i>0 ){
       int size, j;
-      assert( i<=usableSize-4 );     /* Enforced by btreeInitPage() */
+      assert( (u32)i<=usableSize-4 );     /* Enforced by btreeInitPage() */
       size = get2byte(&data[i+2]);
-      assert( i+size<=usableSize );  /* Enforced by btreeInitPage() */
-      for(j=i+size-1; j>=i; j--) hit[j]++;
+      assert( (u32)(i+size)<=usableSize );  /* Enforced by btreeInitPage() */
+      btreeHeapInsert(heap, (((u32)i)<<16)|(i+size-1));
       /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a
       ** big-endian integer which is the offset in the b-tree page of the next
       ** freeblock in the chain, or zero if the freeblock is the last on the
@@ -61358,33 +68978,50 @@ static int checkTreePage(
       /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
       ** increasing offset. */
       assert( j==0 || j>i+size );  /* Enforced by btreeInitPage() */
-      assert( j<=usableSize-4 );   /* Enforced by btreeInitPage() */
+      assert( (u32)j<=usableSize-4 );   /* Enforced by btreeInitPage() */
       i = j;
     }
-    for(i=cnt=0; i1 ){
+    /* Analyze the min-heap looking for overlap between cells and/or 
+    ** freeblocks, and counting the number of untracked bytes in nFrag.
+    ** 
+    ** Each min-heap entry is of the form:    (start_address<<16)|end_address.
+    ** There is an implied first entry the covers the page header, the cell
+    ** pointer index, and the gap between the cell pointer index and the start
+    ** of cell content.  
+    **
+    ** The loop below pulls entries from the min-heap in order and compares
+    ** the start_address against the previous end_address.  If there is an
+    ** overlap, that means bytes are used multiple times.  If there is a gap,
+    ** that gap is added to the fragmentation count.
+    */
+    nFrag = 0;
+    prev = contentOffset - 1;   /* Implied first min-heap entry */
+    while( btreeHeapPull(heap,&x) ){
+      if( (prev&0xffff)>=(x>>16) ){
         checkAppendMsg(pCheck,
-          "Multiple uses for byte %d of page %d", i, iPage);
+          "Multiple uses for byte %u of page %d", x>>16, iPage);
         break;
+      }else{
+        nFrag += (x>>16) - (prev&0xffff) - 1;
+        prev = x;
       }
     }
+    nFrag += usableSize - (prev&0xffff) - 1;
     /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments
     ** is stored in the fifth field of the b-tree page header.
     ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the
     ** number of fragmented free bytes within the cell content area.
     */
-    if( cnt!=data[hdr+7] ){
+    if( heap[0]==0 && nFrag!=data[hdr+7] ){
       checkAppendMsg(pCheck,
           "Fragmentation of %d bytes reported as %d on page %d",
-          cnt, data[hdr+7], iPage);
+          nFrag, data[hdr+7], iPage);
     }
   }
-  sqlite3PageFree(hit);
-  releasePage(pPage);
 
 end_of_check:
+  if( !doCoverageCheck ) pPage->isInit = savedIsInit;
+  releasePage(pPage);
   pCheck->zPfx = saved_zPfx;
   pCheck->v1 = saved_v1;
   pCheck->v2 = saved_v2;
@@ -61414,14 +69051,16 @@ SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(
   int *pnErr    /* Write number of errors seen to this variable */
 ){
   Pgno i;
-  int nRef;
   IntegrityCk sCheck;
   BtShared *pBt = p->pBt;
+  int savedDbFlags = pBt->db->flags;
   char zErr[100];
+  VVA_ONLY( int nRef );
 
   sqlite3BtreeEnter(p);
   assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );
-  nRef = sqlite3PagerRefcount(pBt->pPager);
+  VVA_ONLY( nRef = sqlite3PagerRefcount(pBt->pPager) );
+  assert( nRef>=0 );
   sCheck.pBt = pBt;
   sCheck.pPager = pBt->pPager;
   sCheck.nPage = btreePagecount(sCheck.pBt);
@@ -61431,22 +69070,27 @@ SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(
   sCheck.zPfx = 0;
   sCheck.v1 = 0;
   sCheck.v2 = 0;
-  *pnErr = 0;
+  sCheck.aPgRef = 0;
+  sCheck.heap = 0;
+  sqlite3StrAccumInit(&sCheck.errMsg, 0, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
+  sCheck.errMsg.printfFlags = SQLITE_PRINTF_INTERNAL;
   if( sCheck.nPage==0 ){
-    sqlite3BtreeLeave(p);
-    return 0;
+    goto integrity_ck_cleanup;
   }
 
   sCheck.aPgRef = sqlite3MallocZero((sCheck.nPage / 8)+ 1);
   if( !sCheck.aPgRef ){
-    *pnErr = 1;
-    sqlite3BtreeLeave(p);
-    return 0;
+    sCheck.mallocFailed = 1;
+    goto integrity_ck_cleanup;
   }
+  sCheck.heap = (u32*)sqlite3PageMalloc( pBt->pageSize );
+  if( sCheck.heap==0 ){
+    sCheck.mallocFailed = 1;
+    goto integrity_ck_cleanup;
+  }
+
   i = PENDING_BYTE_PAGE(pBt);
   if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);
-  sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
-  sCheck.errMsg.useMalloc = 2;
 
   /* Check the integrity of the freelist
   */
@@ -61457,17 +69101,19 @@ SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(
 
   /* Check all the tables.
   */
+  testcase( pBt->db->flags & SQLITE_CellSizeCk );
+  pBt->db->flags &= ~SQLITE_CellSizeCk;
   for(i=0; (int)iautoVacuum && aRoot[i]>1 ){
       checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0);
     }
 #endif
-    sCheck.zPfx = "List of tree roots: ";
-    checkTreePage(&sCheck, aRoot[i], NULL, NULL);
-    sCheck.zPfx = 0;
+    checkTreePage(&sCheck, aRoot[i], ¬Used, LARGEST_INT64);
   }
+  pBt->db->flags = savedDbFlags;
 
   /* Make sure every page in the file is referenced
   */
@@ -61491,28 +69137,20 @@ SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(
 #endif
   }
 
-  /* Make sure this analysis did not leave any unref() pages.
-  ** This is an internal consistency check; an integrity check
-  ** of the integrity check.
-  */
-  if( NEVER(nRef != sqlite3PagerRefcount(pBt->pPager)) ){
-    checkAppendMsg(&sCheck,
-      "Outstanding page count goes from %d to %d during this analysis",
-      nRef, sqlite3PagerRefcount(pBt->pPager)
-    );
-  }
-
   /* Clean  up and report errors.
   */
-  sqlite3BtreeLeave(p);
+integrity_ck_cleanup:
+  sqlite3PageFree(sCheck.heap);
   sqlite3_free(sCheck.aPgRef);
   if( sCheck.mallocFailed ){
     sqlite3StrAccumReset(&sCheck.errMsg);
-    *pnErr = sCheck.nErr+1;
-    return 0;
+    sCheck.nErr++;
   }
   *pnErr = sCheck.nErr;
   if( sCheck.nErr==0 ) sqlite3StrAccumReset(&sCheck.errMsg);
+  /* Make sure this analysis did not leave any unref() pages. */
+  assert( nRef==sqlite3PagerRefcount(pBt->pPager) );
+  sqlite3BtreeLeave(p);
   return sqlite3StrAccumFinish(&sCheck.errMsg);
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
@@ -61567,7 +69205,7 @@ SQLITE_PRIVATE int sqlite3BtreeCheckpoint(Btree *p, int eMode, int *pnLog, int *
     if( pBt->inTransaction!=TRANS_NONE ){
       rc = SQLITE_LOCKED;
     }else{
-      rc = sqlite3PagerCheckpoint(pBt->pPager, eMode, pnLog, pnCkpt);
+      rc = sqlite3PagerCheckpoint(pBt->pPager, p->db, eMode, pnLog, pnCkpt);
     }
     sqlite3BtreeLeave(p);
   }
@@ -61675,7 +69313,7 @@ SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *p, int iTab, u8 isWriteLock){
 */
 SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
   int rc;
-  assert( cursorHoldsMutex(pCsr) );
+  assert( cursorOwnsBtShared(pCsr) );
   assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
   assert( pCsr->curFlags & BTCF_Incrblob );
 
@@ -61723,6 +69361,7 @@ SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void
 */
 SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *pCur){
   pCur->curFlags |= BTCF_Incrblob;
+  pCur->pBtree->hasIncrblobCur = 1;
 }
 #endif
 
@@ -61763,12 +69402,11 @@ SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
 }
 
 /*
-** set the mask of hint flags for cursor pCsr. Currently the only valid
-** values are 0 and BTREE_BULKLOAD.
+** Return true if the cursor has a hint specified.  This routine is
+** only used from within assert() statements
 */
-SQLITE_PRIVATE void sqlite3BtreeCursorHints(BtCursor *pCsr, unsigned int mask){
-  assert( mask==BTREE_BULKLOAD || mask==0 );
-  pCsr->hints = mask;
+SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor *pCsr, unsigned int mask){
+  return (pCsr->hints & mask)!=0;
 }
 
 /*
@@ -61783,6 +69421,25 @@ SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *p){
 */
 SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
 
+#if !defined(SQLITE_OMIT_SHARED_CACHE)
+/*
+** Return true if the Btree passed as the only argument is sharable.
+*/
+SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
+  return p->sharable;
+}
+
+/*
+** Return the number of connections to the BtShared object accessed by
+** the Btree handle passed as the only argument. For private caches 
+** this is always 1. For shared caches it may be 1 or greater.
+*/
+SQLITE_PRIVATE int sqlite3BtreeConnectionCount(Btree *p){
+  testcase( p->sharable );
+  return p->pBt->nRef;
+}
+#endif
+
 /************** End of btree.c ***********************************************/
 /************** Begin file backup.c ******************************************/
 /*
@@ -61799,6 +69456,8 @@ SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage));
 ** This file contains the implementation of the sqlite3_backup_XXX() 
 ** API functions and the related features.
 */
+/* #include "sqliteInt.h" */
+/* #include "btreeInt.h" */
 
 /*
 ** Structure allocated for each backup operation.
@@ -61868,22 +69527,16 @@ static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
   int i = sqlite3FindDbName(pDb, zDb);
 
   if( i==1 ){
-    Parse *pParse;
+    Parse sParse;
     int rc = 0;
-    pParse = sqlite3StackAllocZero(pErrorDb, sizeof(*pParse));
-    if( pParse==0 ){
-      sqlite3ErrorWithMsg(pErrorDb, SQLITE_NOMEM, "out of memory");
-      rc = SQLITE_NOMEM;
-    }else{
-      pParse->db = pDb;
-      if( sqlite3OpenTempDatabase(pParse) ){
-        sqlite3ErrorWithMsg(pErrorDb, pParse->rc, "%s", pParse->zErrMsg);
-        rc = SQLITE_ERROR;
-      }
-      sqlite3DbFree(pErrorDb, pParse->zErrMsg);
-      sqlite3ParserReset(pParse);
-      sqlite3StackFree(pErrorDb, pParse);
+    memset(&sParse, 0, sizeof(sParse));
+    sParse.db = pDb;
+    if( sqlite3OpenTempDatabase(&sParse) ){
+      sqlite3ErrorWithMsg(pErrorDb, sParse.rc, "%s", sParse.zErrMsg);
+      rc = SQLITE_ERROR;
     }
+    sqlite3DbFree(pErrorDb, sParse.zErrMsg);
+    sqlite3ParserReset(&sParse);
     if( rc ){
       return 0;
     }
@@ -61967,7 +69620,7 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
     ** sqlite3_backup_finish(). */
     p = (sqlite3_backup *)sqlite3MallocZero(sizeof(sqlite3_backup));
     if( !p ){
-      sqlite3Error(pDestDb, SQLITE_NOMEM);
+      sqlite3Error(pDestDb, SQLITE_NOMEM_BKPT);
     }
   }
 
@@ -61981,7 +69634,6 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
     p->isAttached = 0;
 
     if( 0==p->pSrc || 0==p->pDest 
-     || setDestPgsz(p)==SQLITE_NOMEM 
      || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 
      ){
       /* One (or both) of the named databases did not exist or an OOM
@@ -62032,7 +69684,7 @@ static int backupOnePage(
   ** guaranteed that the shared-mutex is held by this thread, handle
   ** p->pSrc may not actually be the owner.  */
   int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);
-  int nDestReserve = sqlite3BtreeGetReserve(p->pDest);
+  int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);
 #endif
   int rc = SQLITE_OK;
   i64 iOff;
@@ -62078,7 +69730,7 @@ static int backupOnePage(
     DbPage *pDestPg = 0;
     Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;
     if( iDest==PENDING_BYTE_PAGE(p->pDest->pBt) ) continue;
-    if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg))
+    if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg, 0))
      && SQLITE_OK==(rc = sqlite3PagerWrite(pDestPg))
     ){
       const u8 *zIn = &zSrcData[iOff%nSrcPgsz];
@@ -62169,14 +69821,6 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       rc = SQLITE_OK;
     }
 
-    /* Lock the destination database, if it is not locked already. */
-    if( SQLITE_OK==rc && p->bDestLocked==0
-     && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2)) 
-    ){
-      p->bDestLocked = 1;
-      sqlite3BtreeGetMeta(p->pDest, BTREE_SCHEMA_VERSION, &p->iDestSchema);
-    }
-
     /* If there is no open read-transaction on the source database, open
     ** one now. If a transaction is opened here, then it will be closed
     ** before this function exits.
@@ -62186,6 +69830,24 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       bCloseTrans = 1;
     }
 
+    /* If the destination database has not yet been locked (i.e. if this
+    ** is the first call to backup_step() for the current backup operation),
+    ** try to set its page size to the same as the source database. This
+    ** is especially important on ZipVFS systems, as in that case it is
+    ** not possible to create a database file that uses one page size by
+    ** writing to it with another.  */
+    if( p->bDestLocked==0 && rc==SQLITE_OK && setDestPgsz(p)==SQLITE_NOMEM ){
+      rc = SQLITE_NOMEM;
+    }
+
+    /* Lock the destination database, if it is not locked already. */
+    if( SQLITE_OK==rc && p->bDestLocked==0
+     && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2)) 
+    ){
+      p->bDestLocked = 1;
+      sqlite3BtreeGetMeta(p->pDest, BTREE_SCHEMA_VERSION, &p->iDestSchema);
+    }
+
     /* Do not allow backup if the destination database is in WAL mode
     ** and the page sizes are different between source and destination */
     pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);
@@ -62204,8 +69866,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       const Pgno iSrcPg = p->iNext;                 /* Source page number */
       if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){
         DbPage *pSrcPg;                             /* Source page object */
-        rc = sqlite3PagerAcquire(pSrcPager, iSrcPg, &pSrcPg,
-                                 PAGER_GET_READONLY);
+        rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg,PAGER_GET_READONLY);
         if( rc==SQLITE_OK ){
           rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);
           sqlite3PagerUnref(pSrcPg);
@@ -62305,7 +69966,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){
             if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){
               DbPage *pPg;
-              rc = sqlite3PagerGet(pDestPager, iPg, &pPg);
+              rc = sqlite3PagerGet(pDestPager, iPg, &pPg, 0);
               if( rc==SQLITE_OK ){
                 rc = sqlite3PagerWrite(pPg);
                 sqlite3PagerUnref(pPg);
@@ -62325,7 +69986,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           ){
             PgHdr *pSrcPg = 0;
             const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
-            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
+            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg, 0);
             if( rc==SQLITE_OK ){
               u8 *zData = sqlite3PagerGetData(pSrcPg);
               rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
@@ -62367,7 +70028,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     }
   
     if( rc==SQLITE_IOERR_NOMEM ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
     p->rc = rc;
   }
@@ -62470,9 +70131,13 @@ SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p){
 ** corresponding to the source database is held when this function is
 ** called.
 */
-SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
-  sqlite3_backup *p;                   /* Iterator variable */
-  for(p=pBackup; p; p=p->pNext){
+static SQLITE_NOINLINE void backupUpdate(
+  sqlite3_backup *p,
+  Pgno iPage,
+  const u8 *aData
+){
+  assert( p!=0 );
+  do{
     assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );
     if( !isFatalError(p->rc) && iPageiNext ){
       /* The backup process p has already copied page iPage. But now it
@@ -62489,7 +70154,10 @@ SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, con
         p->rc = rc;
       }
     }
-  }
+  }while( (p = p->pNext)!=0 );
+}
+SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
+  if( pBackup ) backupUpdate(pBackup, iPage, aData);
 }
 
 /*
@@ -62547,15 +70215,19 @@ SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
   b.pDest = pTo;
   b.iNext = 1;
 
+#ifdef SQLITE_HAS_CODEC
+  sqlite3PagerAlignReserve(sqlite3BtreePager(pTo), sqlite3BtreePager(pFrom));
+#endif
+
   /* 0x7FFFFFFF is the hard limit for the number of pages in a database
   ** file. By passing this as the number of pages to copy to
   ** sqlite3_backup_step(), we can guarantee that the copy finishes 
   ** within a single call (unless an error occurs). The assert() statement
   ** checks this assumption - (p->rc) should be set to either SQLITE_DONE 
-  ** or an error code.
-  */
+  ** or an error code.  */
   sqlite3_backup_step(&b, 0x7FFFFFFF);
   assert( b.rc!=SQLITE_OK );
+
   rc = sqlite3_backup_finish(&b);
   if( rc==SQLITE_OK ){
     pTo->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;
@@ -62590,6 +70262,8 @@ copy_finished:
 ** only within the VDBE.  Interface routines refer to a Mem using the
 ** name sqlite_value
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifdef SQLITE_DEBUG
 /*
@@ -62600,7 +70274,7 @@ copy_finished:
 */
 SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem *p){
   /* If MEM_Dyn is set then Mem.xDel!=0.  
-  ** Mem.xDel is might not be initialized if MEM_Dyn is clear.
+  ** Mem.xDel might not be initialized if MEM_Dyn is clear.
   */
   assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );
 
@@ -62613,6 +70287,35 @@ SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem *p){
   /* Cannot be both MEM_Int and MEM_Real at the same time */
   assert( (p->flags & (MEM_Int|MEM_Real))!=(MEM_Int|MEM_Real) );
 
+  if( p->flags & MEM_Null ){
+    /* Cannot be both MEM_Null and some other type */
+    assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob
+                         |MEM_RowSet|MEM_Frame|MEM_Agg|MEM_Zero))==0 );
+
+    /* If MEM_Null is set, then either the value is a pure NULL (the usual
+    ** case) or it is a pointer set using sqlite3_bind_pointer() or
+    ** sqlite3_result_pointer().  If a pointer, then MEM_Term must also be
+    ** set.
+    */
+    if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){
+      /* This is a pointer type.  There may be a flag to indicate what to
+      ** do with the pointer. */
+      assert( ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
+              ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +
+              ((p->flags&MEM_Static)!=0 ? 1 : 0) <= 1 );
+
+      /* No other bits set */
+      assert( (p->flags & ~(MEM_Null|MEM_Term|MEM_Subtype
+                           |MEM_Dyn|MEM_Ephem|MEM_Static))==0 );
+    }else{
+      /* A pure NULL might have other flags, such as MEM_Static, MEM_Dyn,
+      ** MEM_Ephem, MEM_Cleared, or MEM_Subtype */
+    }
+  }else{
+    /* The MEM_Cleared bit is only allowed on NULLs */
+    assert( (p->flags & MEM_Cleared)==0 );
+  }
+
   /* The szMalloc field holds the correct memory allocation size */
   assert( p->szMalloc==0
        || p->szMalloc==sqlite3DbMallocSize(p->db,p->zMalloc) );
@@ -62689,6 +70392,7 @@ SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
   assert( sqlite3VdbeCheckMemInvariants(pMem) );
   assert( (pMem->flags&MEM_RowSet)==0 );
+  testcase( pMem->db==0 );
 
   /* If the bPreserve flag is set to true, then the memory cell must already
   ** contain a valid string or blob value.  */
@@ -62697,26 +70401,24 @@ SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPre
 
   assert( pMem->szMalloc==0
        || pMem->szMalloc==sqlite3DbMallocSize(pMem->db, pMem->zMalloc) );
-  if( pMem->szMallocszMalloc>0 && pMem->z==pMem->zMalloc ){
-      pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
-      bPreserve = 0;
-    }else{
-      if( pMem->szMalloc>0 ) sqlite3DbFree(pMem->db, pMem->zMalloc);
-      pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
-    }
-    if( pMem->zMalloc==0 ){
-      sqlite3VdbeMemSetNull(pMem);
-      pMem->z = 0;
-      pMem->szMalloc = 0;
-      return SQLITE_NOMEM;
-    }else{
-      pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
-    }
+  if( n<32 ) n = 32;
+  if( bPreserve && pMem->szMalloc>0 && pMem->z==pMem->zMalloc ){
+    pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
+    bPreserve = 0;
+  }else{
+    if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
+    pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
+  }
+  if( pMem->zMalloc==0 ){
+    sqlite3VdbeMemSetNull(pMem);
+    pMem->z = 0;
+    pMem->szMalloc = 0;
+    return SQLITE_NOMEM_BKPT;
+  }else{
+    pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
   }
 
-  if( bPreserve && pMem->z && pMem->z!=pMem->zMalloc ){
+  if( bPreserve && pMem->z && ALWAYS(pMem->z!=pMem->zMalloc) ){
     memcpy(pMem->zMalloc, pMem->z, pMem->n);
   }
   if( (pMem->flags&MEM_Dyn)!=0 ){
@@ -62761,22 +70463,23 @@ SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){
 ** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
 */
 SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem *pMem){
-  int f;
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( (pMem->flags&MEM_RowSet)==0 );
-  ExpandBlob(pMem);
-  f = pMem->flags;
-  if( (f&(MEM_Str|MEM_Blob)) && (pMem->szMalloc==0 || pMem->z!=pMem->zMalloc) ){
-    if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
-      return SQLITE_NOMEM;
+  if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){
+    if( ExpandBlob(pMem) ) return SQLITE_NOMEM;
+    if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){
+      if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
+        return SQLITE_NOMEM_BKPT;
+      }
+      pMem->z[pMem->n] = 0;
+      pMem->z[pMem->n+1] = 0;
+      pMem->flags |= MEM_Term;
     }
-    pMem->z[pMem->n] = 0;
-    pMem->z[pMem->n+1] = 0;
-    pMem->flags |= MEM_Term;
+  }
+  pMem->flags &= ~MEM_Ephem;
 #ifdef SQLITE_DEBUG
-    pMem->pScopyFrom = 0;
+  pMem->pScopyFrom = 0;
 #endif
-  }
 
   return SQLITE_OK;
 }
@@ -62787,25 +70490,24 @@ SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem *pMem){
 */
 #ifndef SQLITE_OMIT_INCRBLOB
 SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){
-  if( pMem->flags & MEM_Zero ){
-    int nByte;
-    assert( pMem->flags&MEM_Blob );
-    assert( (pMem->flags&MEM_RowSet)==0 );
-    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
-
-    /* Set nByte to the number of bytes required to store the expanded blob. */
-    nByte = pMem->n + pMem->u.nZero;
-    if( nByte<=0 ){
-      nByte = 1;
-    }
-    if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
-      return SQLITE_NOMEM;
-    }
+  int nByte;
+  assert( pMem->flags & MEM_Zero );
+  assert( pMem->flags&MEM_Blob );
+  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
 
-    memset(&pMem->z[pMem->n], 0, pMem->u.nZero);
-    pMem->n += pMem->u.nZero;
-    pMem->flags &= ~(MEM_Zero|MEM_Term);
+  /* Set nByte to the number of bytes required to store the expanded blob. */
+  nByte = pMem->n + pMem->u.nZero;
+  if( nByte<=0 ){
+    nByte = 1;
+  }
+  if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
+    return SQLITE_NOMEM_BKPT;
   }
+
+  memset(&pMem->z[pMem->n], 0, pMem->u.nZero);
+  pMem->n += pMem->u.nZero;
+  pMem->flags &= ~(MEM_Zero|MEM_Term);
   return SQLITE_OK;
 }
 #endif
@@ -62816,7 +70518,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){
 */
 static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){
   if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pMem->z[pMem->n] = 0;
   pMem->z[pMem->n+1] = 0;
@@ -62865,7 +70567,8 @@ SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){
 
 
   if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
-    return SQLITE_NOMEM;
+    pMem->enc = 0;
+    return SQLITE_NOMEM_BKPT;
   }
 
   /* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
@@ -62912,7 +70615,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
     ctx.pFunc = pFunc;
     pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
     assert( (pMem->flags & MEM_Dyn)==0 );
-    if( pMem->szMalloc>0 ) sqlite3DbFree(pMem->db, pMem->zMalloc);
+    if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
     memcpy(pMem, &t, sizeof(t));
     rc = ctx.isError;
   }
@@ -62963,7 +70666,7 @@ static SQLITE_NOINLINE void vdbeMemClear(Mem *p){
     vdbeMemClearExternAndSetNull(p);
   }
   if( p->szMalloc ){
-    sqlite3DbFree(p->db, p->zMalloc);
+    sqlite3DbFreeNN(p->db, p->zMalloc);
     p->szMalloc = 0;
   }
   p->z = 0;
@@ -62991,7 +70694,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){
 ** If the double is out of range of a 64-bit signed integer then
 ** return the closest available 64-bit signed integer.
 */
-static i64 doubleToInt64(double r){
+static SQLITE_NOINLINE i64 doubleToInt64(double r){
 #ifdef SQLITE_OMIT_FLOATING_POINT
   /* When floating-point is omitted, double and int64 are the same thing */
   return r;
@@ -63027,6 +70730,11 @@ static i64 doubleToInt64(double r){
 **
 ** If pMem represents a string value, its encoding might be changed.
 */
+static SQLITE_NOINLINE i64 memIntValue(Mem *pMem){
+  i64 value = 0;
+  sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);
+  return value;
+}
 SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem *pMem){
   int flags;
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
@@ -63037,10 +70745,8 @@ SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem *pMem){
   }else if( flags & MEM_Real ){
     return doubleToInt64(pMem->u.r);
   }else if( flags & (MEM_Str|MEM_Blob) ){
-    i64 value = 0;
     assert( pMem->z || pMem->n==0 );
-    sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);
-    return value;
+    return memIntValue(pMem);
   }else{
     return 0;
   }
@@ -63052,6 +70758,12 @@ SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem *pMem){
 ** value.  If it is a string or blob, try to convert it to a double.
 ** If it is a NULL, return 0.0.
 */
+static SQLITE_NOINLINE double memRealValue(Mem *pMem){
+  /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
+  double val = (double)0;
+  sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc);
+  return val;
+}
 SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
@@ -63060,10 +70772,7 @@ SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem *pMem){
   }else if( pMem->flags & MEM_Int ){
     return (double)pMem->u.i;
   }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
-    /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
-    double val = (double)0;
-    sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc);
-    return val;
+    return memRealValue(pMem);
   }else{
     /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
     return (double)0;
@@ -63146,7 +70855,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem *pMem){
     }
   }
   assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))!=0 );
-  pMem->flags &= ~(MEM_Str|MEM_Blob);
+  pMem->flags &= ~(MEM_Str|MEM_Blob|MEM_Zero);
   return SQLITE_OK;
 }
 
@@ -63160,11 +70869,11 @@ SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem *pMem){
 SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem *pMem, u8 aff, u8 encoding){
   if( pMem->flags & MEM_Null ) return;
   switch( aff ){
-    case SQLITE_AFF_NONE: {   /* Really a cast to BLOB */
+    case SQLITE_AFF_BLOB: {   /* Really a cast to BLOB */
       if( (pMem->flags & MEM_Blob)==0 ){
         sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);
         assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );
-        MemSetTypeFlag(pMem, MEM_Blob);
+        if( pMem->flags & MEM_Str ) MemSetTypeFlag(pMem, MEM_Blob);
       }else{
         pMem->flags &= ~(MEM_TypeMask&~MEM_Blob);
       }
@@ -63268,6 +70977,27 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
   }
 }
 
+/* A no-op destructor */
+static void sqlite3NoopDestructor(void *p){ UNUSED_PARAMETER(p); }
+
+/*
+** Set the value stored in *pMem should already be a NULL.
+** Also store a pointer to go with it.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMemSetPointer(
+  Mem *pMem,
+  void *pPtr,
+  const char *zPType,
+  void (*xDestructor)(void*)
+){
+  assert( pMem->flags==MEM_Null );
+  pMem->u.zPType = zPType ? zPType : "";
+  pMem->z = pPtr;
+  pMem->flags = MEM_Null|MEM_Dyn|MEM_Subtype|MEM_Term;
+  pMem->eSubtype = 'p';
+  pMem->xDel = xDestructor ? xDestructor : sqlite3NoopDestructor;
+}
+
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Delete any previous value and set the value stored in *pMem to val,
@@ -63291,7 +71021,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetRowSet(Mem *pMem){
   assert( db!=0 );
   assert( (pMem->flags & MEM_RowSet)==0 );
   sqlite3VdbeMemRelease(pMem);
-  pMem->zMalloc = sqlite3DbMallocRaw(db, 64);
+  pMem->zMalloc = sqlite3DbMallocRawNN(db, 64);
   if( db->mallocFailed ){
     pMem->flags = MEM_Null;
     pMem->szMalloc = 0;
@@ -63332,7 +71062,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem *p){
 SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
   int i;
   Mem *pX;
-  for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){
+  for(i=0, pX=pVdbe->aMem; inMem; i++, pX++){
     if( pX->pScopyFrom==pMem ){
       pX->flags |= MEM_Undefined;
       pX->pScopyFrom = 0;
@@ -63342,10 +71072,6 @@ SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
 }
 #endif /* SQLITE_DEBUG */
 
-/*
-** Size of struct Mem not including the Mem.zMalloc member.
-*/
-#define MEMCELLSIZE offsetof(Mem,zMalloc)
 
 /*
 ** Make an shallow copy of pFrom into pTo.  Prior contents of
@@ -63353,10 +71079,15 @@ SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
 ** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
 ** and flags gets srcType (either MEM_Ephem or MEM_Static).
 */
+static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
+  vdbeMemClearExternAndSetNull(pTo);
+  assert( !VdbeMemDynamic(pTo) );
+  sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
+}
 SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
   assert( (pFrom->flags & MEM_RowSet)==0 );
   assert( pTo->db==pFrom->db );
-  if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
+  if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
   memcpy(pTo, pFrom, MEMCELLSIZE);
   if( (pFrom->flags&MEM_Static)==0 ){
     pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
@@ -63372,7 +71103,6 @@ SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int sr
 SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
 
-  assert( pTo->db==pFrom->db );
   assert( (pFrom->flags & MEM_RowSet)==0 );
   if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);
@@ -63472,7 +71202,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
     testcase( nAlloc==31 );
     testcase( nAlloc==32 );
     if( sqlite3VdbeMemClearAndResize(pMem, MAX(nAlloc,32)) ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memcpy(pMem->z, z, nAlloc);
   }else if( xDel==SQLITE_DYNAMIC ){
@@ -63492,7 +71222,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
 
 #ifndef SQLITE_OMIT_UTF16
   if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 #endif
 
@@ -63505,10 +71235,9 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
 
 /*
 ** Move data out of a btree key or data field and into a Mem structure.
-** The data or key is taken from the entry that pCur is currently pointing
+** The data is payload from the entry that pCur is currently pointing
 ** to.  offset and amt determine what portion of the data or key to retrieve.
-** key is true to get the key or false to get data.  The result is written
-** into the pMem element.
+** The result is written into the pMem element.
 **
 ** The pMem object must have been initialized.  This routine will use
 ** pMem->zMalloc to hold the content from the btree, if possible.  New
@@ -63519,11 +71248,31 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
 ** If this routine fails for any reason (malloc returns NULL or unable
 ** to read from the disk) then the pMem is left in an inconsistent state.
 */
+static SQLITE_NOINLINE int vdbeMemFromBtreeResize(
+  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
+  u32 offset,       /* Offset from the start of data to return bytes from. */
+  u32 amt,          /* Number of bytes to return. */
+  Mem *pMem         /* OUT: Return data in this Mem structure. */
+){
+  int rc;
+  pMem->flags = MEM_Null;
+  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
+    rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
+    if( rc==SQLITE_OK ){
+      pMem->z[amt] = 0;
+      pMem->z[amt+1] = 0;
+      pMem->flags = MEM_Blob|MEM_Term;
+      pMem->n = (int)amt;
+    }else{
+      sqlite3VdbeMemRelease(pMem);
+    }
+  }
+  return rc;
+}
 SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(
   BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
   u32 offset,       /* Offset from the start of data to return bytes from. */
   u32 amt,          /* Number of bytes to return. */
-  int key,          /* If true, retrieve from the btree key, not data. */
   Mem *pMem         /* OUT: Return data in this Mem structure. */
 ){
   char *zData;        /* Data from the btree layer */
@@ -63536,11 +71285,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(
   /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() 
   ** that both the BtShared and database handle mutexes are held. */
   assert( (pMem->flags & MEM_RowSet)==0 );
-  if( key ){
-    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
-  }else{
-    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
-  }
+  zData = (char *)sqlite3BtreePayloadFetch(pCur, &available);
   assert( zData!=0 );
 
   if( offset+amt<=available ){
@@ -63548,22 +71293,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(
     pMem->flags = MEM_Blob|MEM_Ephem;
     pMem->n = (int)amt;
   }else{
-    pMem->flags = MEM_Null;
-    if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
-      if( key ){
-        rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
-      }else{
-        rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
-      }
-      if( rc==SQLITE_OK ){
-        pMem->z[amt] = 0;
-        pMem->z[amt+1] = 0;
-        pMem->flags = MEM_Blob|MEM_Term;
-        pMem->n = (int)amt;
-      }else{
-        sqlite3VdbeMemRelease(pMem);
-      }
-    }
+    rc = vdbeMemFromBtreeResize(pCur, offset, amt, pMem);
   }
 
   return rc;
@@ -63581,10 +71311,8 @@ static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
   assert( (pVal->flags & MEM_RowSet)==0 );
   assert( (pVal->flags & (MEM_Null))==0 );
   if( pVal->flags & (MEM_Blob|MEM_Str) ){
+    if( ExpandBlob(pVal) ) return 0;
     pVal->flags |= MEM_Str;
-    if( pVal->flags & MEM_Zero ){
-      sqlite3VdbeMemExpandBlob(pVal);
-    }
     if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){
       sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
     }
@@ -63663,7 +71391,7 @@ struct ValueNewStat4Ctx {
 ** Otherwise, if the second argument is non-zero, then this function is 
 ** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
 ** already been allocated, allocate the UnpackedRecord structure that 
-** that function will return to its caller here. Then return a pointer 
+** that function will return to its caller here. Then return a pointer to
 ** an sqlite3_value within the UnpackedRecord.a[] array.
 */
 static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
@@ -63690,7 +71418,7 @@ static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
             pRec->aMem[i].db = db;
           }
         }else{
-          sqlite3DbFree(db, pRec);
+          sqlite3DbFreeNN(db, pRec);
           pRec = 0;
         }
       }
@@ -63707,6 +71435,111 @@ static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
   return sqlite3ValueNew(db);
 }
 
+/*
+** The expression object indicated by the second argument is guaranteed
+** to be a scalar SQL function. If
+**
+**   * all function arguments are SQL literals,
+**   * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and
+**   * the SQLITE_FUNC_NEEDCOLL function flag is not set,
+**
+** then this routine attempts to invoke the SQL function. Assuming no
+** error occurs, output parameter (*ppVal) is set to point to a value 
+** object containing the result before returning SQLITE_OK.
+**
+** Affinity aff is applied to the result of the function before returning.
+** If the result is a text value, the sqlite3_value object uses encoding 
+** enc.
+**
+** If the conditions above are not met, this function returns SQLITE_OK
+** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to
+** NULL and an SQLite error code returned.
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static int valueFromFunction(
+  sqlite3 *db,                    /* The database connection */
+  Expr *p,                        /* The expression to evaluate */
+  u8 enc,                         /* Encoding to use */
+  u8 aff,                         /* Affinity to use */
+  sqlite3_value **ppVal,          /* Write the new value here */
+  struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */
+){
+  sqlite3_context ctx;            /* Context object for function invocation */
+  sqlite3_value **apVal = 0;      /* Function arguments */
+  int nVal = 0;                   /* Size of apVal[] array */
+  FuncDef *pFunc = 0;             /* Function definition */
+  sqlite3_value *pVal = 0;        /* New value */
+  int rc = SQLITE_OK;             /* Return code */
+  ExprList *pList = 0;            /* Function arguments */
+  int i;                          /* Iterator variable */
+
+  assert( pCtx!=0 );
+  assert( (p->flags & EP_TokenOnly)==0 );
+  pList = p->x.pList;
+  if( pList ) nVal = pList->nExpr;
+  pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);
+  assert( pFunc );
+  if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0 
+   || (pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)
+  ){
+    return SQLITE_OK;
+  }
+
+  if( pList ){
+    apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal);
+    if( apVal==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+      goto value_from_function_out;
+    }
+    for(i=0; ia[i].pExpr, enc, aff, &apVal[i]);
+      if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out;
+    }
+  }
+
+  pVal = valueNew(db, pCtx);
+  if( pVal==0 ){
+    rc = SQLITE_NOMEM_BKPT;
+    goto value_from_function_out;
+  }
+
+  assert( pCtx->pParse->rc==SQLITE_OK );
+  memset(&ctx, 0, sizeof(ctx));
+  ctx.pOut = pVal;
+  ctx.pFunc = pFunc;
+  pFunc->xSFunc(&ctx, nVal, apVal);
+  if( ctx.isError ){
+    rc = ctx.isError;
+    sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
+  }else{
+    sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
+    assert( rc==SQLITE_OK );
+    rc = sqlite3VdbeChangeEncoding(pVal, enc);
+    if( rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal) ){
+      rc = SQLITE_TOOBIG;
+      pCtx->pParse->nErr++;
+    }
+  }
+  pCtx->pParse->rc = rc;
+
+ value_from_function_out:
+  if( rc!=SQLITE_OK ){
+    pVal = 0;
+  }
+  if( apVal ){
+    for(i=0; iop)==TK_UPLUS ) pExpr = pExpr->pLeft;
+  assert( pExpr!=0 );
+  while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;
   if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
 
+  /* Compressed expressions only appear when parsing the DEFAULT clause
+  ** on a table column definition, and hence only when pCtx==0.  This
+  ** check ensures that an EP_TokenOnly expression is never passed down
+  ** into valueFromFunction(). */
+  assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );
+
   if( op==TK_CAST ){
     u8 aff = sqlite3AffinityType(pExpr->u.zToken,0);
     rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);
@@ -63771,7 +71607,7 @@ static int valueFromExpr(
       if( zVal==0 ) goto no_mem;
       sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
     }
-    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
+    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_BLOB ){
       sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
     }else{
       sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
@@ -63782,7 +71618,7 @@ static int valueFromExpr(
     }
   }else if( op==TK_UMINUS ) {
     /* This branch happens for multiple negative signs.  Ex: -(-5) */
-    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) 
+    if( SQLITE_OK==valueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal,pCtx) 
      && pVal!=0
     ){
       sqlite3VdbeMemNumerify(pVal);
@@ -63799,6 +71635,7 @@ static int valueFromExpr(
   }else if( op==TK_NULL ){
     pVal = valueNew(db, pCtx);
     if( pVal==0 ) goto no_mem;
+    sqlite3VdbeMemNumerify(pVal);
   }
 #ifndef SQLITE_OMIT_BLOB_LITERAL
   else if( op==TK_BLOB ){
@@ -63815,11 +71652,17 @@ static int valueFromExpr(
   }
 #endif
 
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  else if( op==TK_FUNCTION && pCtx!=0 ){
+    rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);
+  }
+#endif
+
   *ppVal = pVal;
   return rc;
 
 no_mem:
-  db->mallocFailed = 1;
+  sqlite3OomFault(db);
   sqlite3DbFree(db, zVal);
   assert( *ppVal==0 );
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
@@ -63827,7 +71670,7 @@ no_mem:
 #else
   assert( pCtx==0 ); sqlite3ValueFree(pVal);
 #endif
-  return SQLITE_NOMEM;
+  return SQLITE_NOMEM_BKPT;
 }
 
 /*
@@ -63847,7 +71690,7 @@ SQLITE_PRIVATE int sqlite3ValueFromExpr(
   u8 affinity,              /* Affinity to use */
   sqlite3_value **ppVal     /* Write the new value here */
 ){
-  return valueFromExpr(db, pExpr, enc, affinity, ppVal, 0);
+  return pExpr ? valueFromExpr(db, pExpr, enc, affinity, ppVal, 0) : 0;
 }
 
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
@@ -63865,21 +71708,20 @@ static void recordFunc(
   sqlite3_value **argv
 ){
   const int file_format = 1;
-  int iSerial;                    /* Serial type */
+  u32 iSerial;                    /* Serial type */
   int nSerial;                    /* Bytes of space for iSerial as varint */
-  int nVal;                       /* Bytes of space required for argv[0] */
+  u32 nVal;                       /* Bytes of space required for argv[0] */
   int nRet;
   sqlite3 *db;
   u8 *aRet;
 
   UNUSED_PARAMETER( argc );
-  iSerial = sqlite3VdbeSerialType(argv[0], file_format);
+  iSerial = sqlite3VdbeSerialType(argv[0], file_format, &nVal);
   nSerial = sqlite3VarintLen(iSerial);
-  nVal = sqlite3VdbeSerialTypeLen(iSerial);
   db = sqlite3_context_db_handle(context);
 
   nRet = 1 + nSerial + nVal;
-  aRet = sqlite3DbMallocRaw(db, nRet);
+  aRet = sqlite3DbMallocRawNN(db, nRet);
   if( aRet==0 ){
     sqlite3_result_error_nomem(context);
   }else{
@@ -63887,7 +71729,7 @@ static void recordFunc(
     putVarint32(&aRet[1], iSerial);
     sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
     sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
-    sqlite3DbFree(db, aRet);
+    sqlite3DbFreeNN(db, aRet);
   }
 }
 
@@ -63895,15 +71737,10 @@ static void recordFunc(
 ** Register built-in functions used to help read ANALYZE data.
 */
 SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void){
-  static SQLITE_WSD FuncDef aAnalyzeTableFuncs[] = {
+  static FuncDef aAnalyzeTableFuncs[] = {
     FUNCTION(sqlite_record,   1, 0, 0, recordFunc),
   };
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAnalyzeTableFuncs);
-  for(i=0; iop!=TK_REGISTER || pExpr->op2!=TK_VARIABLE );
   if( !pExpr ){
     pVal = valueNew(db, pAlloc);
     if( pVal ){
       sqlite3VdbeMemSetNull((Mem*)pVal);
     }
-  }else if( pExpr->op==TK_VARIABLE
-        || NEVER(pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
-  ){
+  }else if( pExpr->op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){
     Vdbe *v;
     int iBindVar = pExpr->iColumn;
     sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
@@ -63953,9 +71789,7 @@ static int stat4ValueFromExpr(
       pVal = valueNew(db, pAlloc);
       if( pVal ){
         rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
-        if( rc==SQLITE_OK ){
-          sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
-        }
+        sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
         pVal->db = pParse->db;
       }
     }
@@ -63973,9 +71807,9 @@ static int stat4ValueFromExpr(
 ** structures intended to be compared against sample index keys stored 
 ** in the sqlite_stat4 table.
 **
-** A single call to this function attempts to populates field iVal (leftmost 
-** is 0 etc.) of the unpacked record with a value extracted from expression
-** pExpr. Extraction of values is possible if:
+** A single call to this function populates zero or more fields of the
+** record starting with field iVal (fields are numbered from left to
+** right starting with 0). A single field is populated if:
 **
 **  * (pExpr==0). In this case the value is assumed to be an SQL NULL,
 **
@@ -63984,10 +71818,14 @@ static int stat4ValueFromExpr(
 **  * The sqlite3ValueFromExpr() function is able to extract a value 
 **    from the expression (i.e. the expression is a literal value).
 **
-** If a value can be extracted, the affinity passed as the 5th argument
-** is applied to it before it is copied into the UnpackedRecord. Output
-** parameter *pbOk is set to true if a value is extracted, or false 
-** otherwise.
+** Or, if pExpr is a TK_VECTOR, one field is populated for each of the
+** vector components that match either of the two latter criteria listed
+** above.
+**
+** Before any value is appended to the record, the affinity of the 
+** corresponding column within index pIdx is applied to it. Before
+** this function returns, output parameter *pnExtract is set to the
+** number of values appended to the record.
 **
 ** When this function is called, *ppRec must either point to an object
 ** allocated by an earlier call to this function, or must be NULL. If it
@@ -64003,22 +71841,33 @@ SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
   Index *pIdx,                    /* Index being probed */
   UnpackedRecord **ppRec,         /* IN/OUT: Probe record */
   Expr *pExpr,                    /* The expression to extract a value from */
-  u8 affinity,                    /* Affinity to use */
+  int nElem,                      /* Maximum number of values to append */
   int iVal,                       /* Array element to populate */
-  int *pbOk                       /* OUT: True if value was extracted */
+  int *pnExtract                  /* OUT: Values appended to the record */
 ){
-  int rc;
-  sqlite3_value *pVal = 0;
-  struct ValueNewStat4Ctx alloc;
+  int rc = SQLITE_OK;
+  int nExtract = 0;
+
+  if( pExpr==0 || pExpr->op!=TK_SELECT ){
+    int i;
+    struct ValueNewStat4Ctx alloc;
 
-  alloc.pParse = pParse;
-  alloc.pIdx = pIdx;
-  alloc.ppRec = ppRec;
-  alloc.iVal = iVal;
+    alloc.pParse = pParse;
+    alloc.pIdx = pIdx;
+    alloc.ppRec = ppRec;
 
-  rc = stat4ValueFromExpr(pParse, pExpr, affinity, &alloc, &pVal);
-  assert( pVal==0 || pVal->db==pParse->db );
-  *pbOk = (pVal!=0);
+    for(i=0; idb, pIdx, iVal+i);
+      alloc.iVal = iVal+i;
+      rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal);
+      if( !pVal ) break;
+      nExtract++;
+    }
+  }
+
+  *pnExtract = nExtract;
   return rc;
 }
 
@@ -64082,7 +71931,7 @@ SQLITE_PRIVATE int sqlite3Stat4Column(
   if( iField>nRec ) return SQLITE_CORRUPT_BKPT;
   if( pMem==0 ){
     pMem = *ppVal = sqlite3ValueNew(db);
-    if( pMem==0 ) return SQLITE_NOMEM;
+    if( pMem==0 ) return SQLITE_NOMEM_BKPT;
   }
   sqlite3VdbeSerialGet(&a[iField-szField], t, pMem);
   pMem->enc = ENC(db);
@@ -64101,10 +71950,10 @@ SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
     Mem *aMem = pRec->aMem;
     sqlite3 *db = aMem[0].db;
     for(i=0; ipKeyInfo);
-    sqlite3DbFree(db, pRec);
+    sqlite3DbFreeNN(db, pRec);
   }
 }
 #endif /* ifdef SQLITE_ENABLE_STAT4 */
@@ -64128,23 +71977,32 @@ SQLITE_PRIVATE void sqlite3ValueSetStr(
 SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value *v){
   if( !v ) return;
   sqlite3VdbeMemRelease((Mem *)v);
-  sqlite3DbFree(((Mem*)v)->db, v);
+  sqlite3DbFreeNN(((Mem*)v)->db, v);
 }
 
 /*
-** Return the number of bytes in the sqlite3_value object assuming
-** that it uses the encoding "enc"
+** The sqlite3ValueBytes() routine returns the number of bytes in the
+** sqlite3_value object assuming that it uses the encoding "enc".
+** The valueBytes() routine is a helper function.
 */
+static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){
+  return valueToText(pVal, enc)!=0 ? pVal->n : 0;
+}
 SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
   Mem *p = (Mem*)pVal;
-  if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(pVal, enc) ){
+  assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 );
+  if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){
+    return p->n;
+  }
+  if( (p->flags & MEM_Blob)!=0 ){
     if( p->flags & MEM_Zero ){
       return p->n + p->u.nZero;
     }else{
       return p->n;
     }
   }
-  return 0;
+  if( p->flags & MEM_Null ) return 0;
+  return valueBytes(pVal, enc);
 }
 
 /************** End of vdbemem.c *********************************************/
@@ -64163,6 +72021,8 @@ SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
 ** This file contains code used for creating, destroying, and populating
 ** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.) 
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 /*
 ** Create a new virtual database engine.
@@ -64170,8 +72030,9 @@ SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
 SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse *pParse){
   sqlite3 *db = pParse->db;
   Vdbe *p;
-  p = sqlite3DbMallocZero(db, sizeof(Vdbe) );
+  p = sqlite3DbMallocRawNN(db, sizeof(Vdbe) );
   if( p==0 ) return 0;
+  memset(&p->aOp, 0, sizeof(Vdbe)-offsetof(Vdbe,aOp));
   p->db = db;
   if( db->pVdbe ){
     db->pVdbe->pPrev = p;
@@ -64184,29 +72045,32 @@ SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse *pParse){
   assert( pParse->aLabel==0 );
   assert( pParse->nLabel==0 );
   assert( pParse->nOpAlloc==0 );
+  assert( pParse->szOpAlloc==0 );
   return p;
 }
 
 /*
-** Remember the SQL string for a prepared statement.
+** Change the error string stored in Vdbe.zErrMsg
 */
-SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepareV2){
-  assert( isPrepareV2==1 || isPrepareV2==0 );
-  if( p==0 ) return;
-#if defined(SQLITE_OMIT_TRACE) && !defined(SQLITE_ENABLE_SQLLOG)
-  if( !isPrepareV2 ) return;
-#endif
-  assert( p->zSql==0 );
-  p->zSql = sqlite3DbStrNDup(p->db, z, n);
-  p->isPrepareV2 = (u8)isPrepareV2;
+SQLITE_PRIVATE void sqlite3VdbeError(Vdbe *p, const char *zFormat, ...){
+  va_list ap;
+  sqlite3DbFree(p->db, p->zErrMsg);
+  va_start(ap, zFormat);
+  p->zErrMsg = sqlite3VMPrintf(p->db, zFormat, ap);
+  va_end(ap);
 }
 
 /*
-** Return the SQL associated with a prepared statement
+** Remember the SQL string for a prepared statement.
 */
-SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt){
-  Vdbe *p = (Vdbe *)pStmt;
-  return (p && p->isPrepareV2) ? p->zSql : 0;
+SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, u8 prepFlags){
+  if( p==0 ) return;
+  p->prepFlags = prepFlags;
+  if( (prepFlags & SQLITE_PREPARE_SAVESQL)==0 ){
+    p->expmask = 0;
+  }
+  assert( p->zSql==0 );
+  p->zSql = sqlite3DbStrNDup(p->db, z, n);
 }
 
 /*
@@ -64215,6 +72079,7 @@ SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt){
 SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
   Vdbe tmp, *pTmp;
   char *zTmp;
+  assert( pA->db==pB->db );
   tmp = *pA;
   *pA = *pB;
   *pB = tmp;
@@ -64227,7 +72092,10 @@ SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
   zTmp = pA->zSql;
   pA->zSql = pB->zSql;
   pB->zSql = zTmp;
-  pB->isPrepareV2 = pA->isPrepareV2;
+  pB->expmask = pA->expmask;
+  pB->prepFlags = pA->prepFlags;
+  memcpy(pB->aCounter, pA->aCounter, sizeof(pB->aCounter));
+  pB->aCounter[SQLITE_STMTSTATUS_REPREPARE]++;
 }
 
 /*
@@ -64258,14 +72126,21 @@ static int growOpArray(Vdbe *v, int nOp){
   UNUSED_PARAMETER(nOp);
 #endif
 
+  /* Ensure that the size of a VDBE does not grow too large */
+  if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
+    sqlite3OomFault(p->db);
+    return SQLITE_NOMEM;
+  }
+
   assert( nOp<=(1024/sizeof(Op)) );
   assert( nNew>=(p->nOpAlloc+nOp) );
   pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
   if( pNew ){
-    p->nOpAlloc = sqlite3DbMallocSize(p->db, pNew)/sizeof(Op);
+    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
+    p->nOpAlloc = p->szOpAlloc/sizeof(Op);
     v->aOp = pNew;
   }
-  return (pNew ? SQLITE_OK : SQLITE_NOMEM);
+  return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
 }
 
 #ifdef SQLITE_DEBUG
@@ -64295,17 +72170,21 @@ static void test_addop_breakpoint(void){
 ** the sqlite3VdbeChangeP4() function to change the value of the P4
 ** operand.
 */
+static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
+  assert( p->pParse->nOpAlloc<=p->nOp );
+  if( growOpArray(p, 1) ) return 1;
+  assert( p->pParse->nOpAlloc>p->nOp );
+  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
+}
 SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   int i;
   VdbeOp *pOp;
 
   i = p->nOp;
   assert( p->magic==VDBE_MAGIC_INIT );
-  assert( op>0 && op<0xff );
+  assert( op>=0 && op<0xff );
   if( p->pParse->nOpAlloc<=i ){
-    if( growOpArray(p, 1) ){
-      return 1;
-    }
+    return growOp3(p, op, p1, p2, p3);
   }
   p->nOp++;
   pOp = &p->aOp[i];
@@ -64323,9 +72202,8 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   if( p->db->flags & SQLITE_VdbeAddopTrace ){
     int jj, kk;
     Parse *pParse = p->pParse;
-    for(jj=kk=0; jjnColCache; jj++){
       struct yColCache *x = pParse->aColCache + jj;
-      if( x->iLevel>pParse->iCacheLevel || x->iReg==0 ) continue;
       printf(" r[%d]={%d:%d}", x->iReg, x->iTable, x->iColumn);
       kk++;
     }
@@ -64353,6 +72231,49 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
   return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
 }
 
+/* Generate code for an unconditional jump to instruction iDest
+*/
+SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe *p, int iDest){
+  return sqlite3VdbeAddOp3(p, OP_Goto, 0, iDest, 0);
+}
+
+/* Generate code to cause the string zStr to be loaded into
+** register iDest
+*/
+SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe *p, int iDest, const char *zStr){
+  return sqlite3VdbeAddOp4(p, OP_String8, 0, iDest, 0, zStr, 0);
+}
+
+/*
+** Generate code that initializes multiple registers to string or integer
+** constants.  The registers begin with iDest and increase consecutively.
+** One register is initialized for each characgter in zTypes[].  For each
+** "s" character in zTypes[], the register is a string if the argument is
+** not NULL, or OP_Null if the value is a null pointer.  For each "i" character
+** in zTypes[], the register is initialized to an integer.
+**
+** If the input string does not end with "X" then an OP_ResultRow instruction
+** is generated for the values inserted.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){
+  va_list ap;
+  int i;
+  char c;
+  va_start(ap, zTypes);
+  for(i=0; (c = zTypes[i])!=0; i++){
+    if( c=='s' ){
+      const char *z = va_arg(ap, const char*);
+      sqlite3VdbeAddOp4(p, z==0 ? OP_Null : OP_String8, 0, iDest+i, 0, z, 0);
+    }else if( c=='i' ){
+      sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest+i);
+    }else{
+      goto skip_op_resultrow;
+    }
+  }
+  sqlite3VdbeAddOp2(p, OP_ResultRow, iDest, i);
+skip_op_resultrow:
+  va_end(ap);
+}
 
 /*
 ** Add an opcode that includes the p4 value as a pointer.
@@ -64371,6 +72292,24 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4(
   return addr;
 }
 
+/*
+** Add an opcode that includes the p4 value with a P4_INT64 or
+** P4_REAL type.
+*/
+SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(
+  Vdbe *p,            /* Add the opcode to this VM */
+  int op,             /* The new opcode */
+  int p1,             /* The P1 operand */
+  int p2,             /* The P2 operand */
+  int p3,             /* The P3 operand */
+  const u8 *zP4,      /* The P4 operand */
+  int p4type          /* P4 operand type */
+){
+  char *p4copy = sqlite3DbMallocRawNN(sqlite3VdbeDb(p), 8);
+  if( p4copy ) memcpy(p4copy, zP4, 8);
+  return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
+}
+
 /*
 ** Add an OP_ParseSchema opcode.  This routine is broken out from
 ** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
@@ -64381,8 +72320,7 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4(
 */
 SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
   int j;
-  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
-  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
+  sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
   for(j=0; jdb->nDb; j++) sqlite3VdbeUsesBtree(p, j);
 }
 
@@ -64398,10 +72336,29 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(
   int p4              /* The P4 operand as an integer */
 ){
   int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
-  sqlite3VdbeChangeP4(p, addr, SQLITE_INT_TO_PTR(p4), P4_INT32);
+  if( p->db->mallocFailed==0 ){
+    VdbeOp *pOp = &p->aOp[addr];
+    pOp->p4type = P4_INT32;
+    pOp->p4.i = p4;
+  }
   return addr;
 }
 
+/* Insert the end of a co-routine
+*/
+SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe *v, int regYield){
+  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
+
+  /* Clear the temporary register cache, thereby ensuring that each
+  ** co-routine has its own independent set of registers, because co-routines
+  ** might expect their registers to be preserved across an OP_Yield, and
+  ** that could cause problems if two or more co-routines are using the same
+  ** temporary register.
+  */
+  v->pParse->nTempReg = 0;
+  v->pParse->nRangeReg = 0;
+}
+
 /*
 ** Create a new symbolic label for an instruction that has yet to be
 ** coded.  The symbolic label is really just a negative number.  The
@@ -64427,7 +72384,7 @@ SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe *v){
   if( p->aLabel ){
     p->aLabel[i] = -1;
   }
-  return -1-i;
+  return ADDR(i);
 }
 
 /*
@@ -64437,13 +72394,13 @@ SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe *v){
 */
 SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe *v, int x){
   Parse *p = v->pParse;
-  int j = -1-x;
+  int j = ADDR(x);
   assert( v->magic==VDBE_MAGIC_INIT );
   assert( jnLabel );
-  if( ALWAYS(j>=0) && p->aLabel ){
+  assert( j>=0 );
+  if( p->aLabel ){
     p->aLabel[j] = v->nOp;
   }
-  p->iFixedOp = v->nOp - 1;
 }
 
 /*
@@ -64453,6 +72410,13 @@ SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe *p){
   p->runOnlyOnce = 1;
 }
 
+/*
+** Mark the VDBE as one that can only be run multiple times.
+*/
+SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe *p){
+  p->runOnlyOnce = 0;
+}
+
 #ifdef SQLITE_DEBUG /* sqlite3AssertMayAbort() logic */
 
 /*
@@ -64535,6 +72499,7 @@ static Op *opIterNext(VdbeOpIter *p){
 **   *  OP_VUpdate
 **   *  OP_VRename
 **   *  OP_FkCounter with P2==0 (immediate foreign key constraint)
+**   *  OP_CreateTable and OP_InitCoroutine (for CREATE TABLE AS SELECT ...)
 **
 ** Then check that the value of Parse.mayAbort is true if an
 ** ABORT may be thrown, or false otherwise. Return true if it does
@@ -64546,6 +72511,8 @@ static Op *opIterNext(VdbeOpIter *p){
 SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   int hasAbort = 0;
   int hasFkCounter = 0;
+  int hasCreateTable = 0;
+  int hasInitCoroutine = 0;
   Op *pOp;
   VdbeOpIter sIter;
   memset(&sIter, 0, sizeof(sIter));
@@ -64560,6 +72527,8 @@ SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
       hasAbort = 1;
       break;
     }
+    if( opcode==OP_CreateTable ) hasCreateTable = 1;
+    if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
 #ifndef SQLITE_OMIT_FOREIGN_KEY
     if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
       hasFkCounter = 1;
@@ -64573,94 +72542,105 @@ SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   ** through all opcodes and hasAbort may be set incorrectly. Return
   ** true for this case to prevent the assert() in the callers frame
   ** from failing.  */
-  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter );
+  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter
+              || (hasCreateTable && hasInitCoroutine) );
 }
 #endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */
 
 /*
-** Loop through the program looking for P2 values that are negative
-** on jump instructions.  Each such value is a label.  Resolve the
-** label by setting the P2 value to its correct non-zero value.
+** This routine is called after all opcodes have been inserted.  It loops
+** through all the opcodes and fixes up some details.
+**
+** (1) For each jump instruction with a negative P2 value (a label)
+**     resolve the P2 value to an actual address.
+**
+** (2) Compute the maximum number of arguments used by any SQL function
+**     and store that value in *pMaxFuncArgs.
+**
+** (3) Update the Vdbe.readOnly and Vdbe.bIsReader flags to accurately
+**     indicate what the prepared statement actually does.
 **
-** This routine is called once after all opcodes have been inserted.
+** (4) Initialize the p4.xAdvance pointer on opcodes that use it.
 **
-** Variable *pMaxFuncArgs is set to the maximum value of any P2 argument 
-** to an OP_Function, OP_AggStep or OP_VFilter opcode. This is used by 
-** sqlite3VdbeMakeReady() to size the Vdbe.apArg[] array.
+** (5) Reclaim the memory allocated for storing labels.
 **
-** The Op.opflags field is set on all opcodes.
+** This routine will only function correctly if the mkopcodeh.tcl generator
+** script numbers the opcodes correctly.  Changes to this routine must be
+** coordinated with changes to mkopcodeh.tcl.
 */
 static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
-  int i;
   int nMaxArgs = *pMaxFuncArgs;
   Op *pOp;
   Parse *pParse = p->pParse;
   int *aLabel = pParse->aLabel;
   p->readOnly = 1;
   p->bIsReader = 0;
-  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
-    u8 opcode = pOp->opcode;
-
-    /* NOTE: Be sure to update mkopcodeh.awk when adding or removing
-    ** cases from this switch! */
-    switch( opcode ){
-      case OP_Function:
-      case OP_AggStep: {
-        if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
-        break;
-      }
-      case OP_Transaction: {
-        if( pOp->p2!=0 ) p->readOnly = 0;
-        /* fall thru */
-      }
-      case OP_AutoCommit:
-      case OP_Savepoint: {
-        p->bIsReader = 1;
-        break;
-      }
+  pOp = &p->aOp[p->nOp-1];
+  while(1){
+
+    /* Only JUMP opcodes and the short list of special opcodes in the switch
+    ** below need to be considered.  The mkopcodeh.tcl generator script groups
+    ** all these opcodes together near the front of the opcode list.  Skip
+    ** any opcode that does not need processing by virtual of the fact that
+    ** it is larger than SQLITE_MX_JUMP_OPCODE, as a performance optimization.
+    */
+    if( pOp->opcode<=SQLITE_MX_JUMP_OPCODE ){
+      /* NOTE: Be sure to update mkopcodeh.tcl when adding or removing
+      ** cases from this switch! */
+      switch( pOp->opcode ){
+        case OP_Transaction: {
+          if( pOp->p2!=0 ) p->readOnly = 0;
+          /* fall thru */
+        }
+        case OP_AutoCommit:
+        case OP_Savepoint: {
+          p->bIsReader = 1;
+          break;
+        }
 #ifndef SQLITE_OMIT_WAL
-      case OP_Checkpoint:
+        case OP_Checkpoint:
 #endif
-      case OP_Vacuum:
-      case OP_JournalMode: {
-        p->readOnly = 0;
-        p->bIsReader = 1;
-        break;
-      }
+        case OP_Vacuum:
+        case OP_JournalMode: {
+          p->readOnly = 0;
+          p->bIsReader = 1;
+          break;
+        }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-      case OP_VUpdate: {
-        if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
-        break;
-      }
-      case OP_VFilter: {
-        int n;
-        assert( p->nOp - i >= 3 );
-        assert( pOp[-1].opcode==OP_Integer );
-        n = pOp[-1].p1;
-        if( n>nMaxArgs ) nMaxArgs = n;
-        break;
-      }
+        case OP_VUpdate: {
+          if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
+          break;
+        }
+        case OP_VFilter: {
+          int n;
+          assert( (pOp - p->aOp) >= 3 );
+          assert( pOp[-1].opcode==OP_Integer );
+          n = pOp[-1].p1;
+          if( n>nMaxArgs ) nMaxArgs = n;
+          break;
+        }
 #endif
-      case OP_Next:
-      case OP_NextIfOpen:
-      case OP_SorterNext: {
-        pOp->p4.xAdvance = sqlite3BtreeNext;
-        pOp->p4type = P4_ADVANCE;
-        break;
+        case OP_Next:
+        case OP_NextIfOpen:
+        case OP_SorterNext: {
+          pOp->p4.xAdvance = sqlite3BtreeNext;
+          pOp->p4type = P4_ADVANCE;
+          break;
+        }
+        case OP_Prev:
+        case OP_PrevIfOpen: {
+          pOp->p4.xAdvance = sqlite3BtreePrevious;
+          pOp->p4type = P4_ADVANCE;
+          break;
+        }
       }
-      case OP_Prev:
-      case OP_PrevIfOpen: {
-        pOp->p4.xAdvance = sqlite3BtreePrevious;
-        pOp->p4type = P4_ADVANCE;
-        break;
+      if( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 && pOp->p2<0 ){
+        assert( ADDR(pOp->p2)nLabel );
+        pOp->p2 = aLabel[ADDR(pOp->p2)];
       }
     }
-
-    pOp->opflags = sqlite3OpcodeProperty[opcode];
-    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
-      assert( -1-pOp->p2nLabel );
-      pOp->p2 = aLabel[-1-pOp->p2];
-    }
+    if( pOp==p->aOp ) break;
+    pOp--;
   }
   sqlite3DbFree(p->db, pParse->aLabel);
   pParse->aLabel = 0;
@@ -64677,6 +72657,36 @@ SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe *p){
   return p->nOp;
 }
 
+/*
+** Verify that at least N opcode slots are available in p without
+** having to malloc for more space (except when compiled using
+** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing
+** to verify that certain calls to sqlite3VdbeAddOpList() can never
+** fail due to a OOM fault and hence that the return value from
+** sqlite3VdbeAddOpList() will always be non-NULL.
+*/
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
+SQLITE_PRIVATE void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
+  assert( p->nOp + N <= p->pParse->nOpAlloc );
+}
+#endif
+
+/*
+** Verify that the VM passed as the only argument does not contain
+** an OP_ResultRow opcode. Fail an assert() if it does. This is used
+** by code in pragma.c to ensure that the implementation of certain
+** pragmas comports with the flags specified in the mkpragmatab.tcl
+** script.
+*/
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
+SQLITE_PRIVATE void sqlite3VdbeVerifyNoResultRow(Vdbe *p){
+  int i;
+  for(i=0; inOp; i++){
+    assert( p->aOp[i].opcode!=OP_ResultRow );
+  }
+}
+#endif
+
 /*
 ** This function returns a pointer to the array of opcodes associated with
 ** the Vdbe passed as the first argument. It is the callers responsibility
@@ -64702,51 +72712,54 @@ SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg)
 }
 
 /*
-** Add a whole list of operations to the operation stack.  Return the
-** address of the first operation added.
+** Add a whole list of operations to the operation stack.  Return a
+** pointer to the first operation inserted.
+**
+** Non-zero P2 arguments to jump instructions are automatically adjusted
+** so that the jump target is relative to the first operation inserted.
 */
-SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp, int iLineno){
-  int addr;
+SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(
+  Vdbe *p,                     /* Add opcodes to the prepared statement */
+  int nOp,                     /* Number of opcodes to add */
+  VdbeOpList const *aOp,       /* The opcodes to be added */
+  int iLineno                  /* Source-file line number of first opcode */
+){
+  int i;
+  VdbeOp *pOut, *pFirst;
+  assert( nOp>0 );
   assert( p->magic==VDBE_MAGIC_INIT );
   if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
     return 0;
   }
-  addr = p->nOp;
-  if( ALWAYS(nOp>0) ){
-    int i;
-    VdbeOpList const *pIn = aOp;
-    for(i=0; ip2;
-      VdbeOp *pOut = &p->aOp[i+addr];
-      pOut->opcode = pIn->opcode;
-      pOut->p1 = pIn->p1;
-      if( p2<0 ){
-        assert( sqlite3OpcodeProperty[pOut->opcode] & OPFLG_JUMP );
-        pOut->p2 = addr + ADDR(p2);
-      }else{
-        pOut->p2 = p2;
-      }
-      pOut->p3 = pIn->p3;
-      pOut->p4type = P4_NOTUSED;
-      pOut->p4.p = 0;
-      pOut->p5 = 0;
+  pFirst = pOut = &p->aOp[p->nOp];
+  for(i=0; iopcode = aOp->opcode;
+    pOut->p1 = aOp->p1;
+    pOut->p2 = aOp->p2;
+    assert( aOp->p2>=0 );
+    if( (sqlite3OpcodeProperty[aOp->opcode] & OPFLG_JUMP)!=0 && aOp->p2>0 ){
+      pOut->p2 += p->nOp;
+    }
+    pOut->p3 = aOp->p3;
+    pOut->p4type = P4_NOTUSED;
+    pOut->p4.p = 0;
+    pOut->p5 = 0;
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-      pOut->zComment = 0;
+    pOut->zComment = 0;
 #endif
 #ifdef SQLITE_VDBE_COVERAGE
-      pOut->iSrcLine = iLineno+i;
+    pOut->iSrcLine = iLineno+i;
 #else
-      (void)iLineno;
+    (void)iLineno;
 #endif
 #ifdef SQLITE_DEBUG
-      if( p->db->flags & SQLITE_VdbeAddopTrace ){
-        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
-      }
-#endif
+    if( p->db->flags & SQLITE_VdbeAddopTrace ){
+      sqlite3VdbePrintOp(0, i+p->nOp, &p->aOp[i+p->nOp]);
     }
-    p->nOp += nOp;
+#endif
   }
-  return addr;
+  p->nOp += nOp;
+  return pFirst;
 }
 
 #if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
@@ -64778,49 +72791,24 @@ SQLITE_PRIVATE void sqlite3VdbeScanStatus(
 
 
 /*
-** Change the value of the P1 operand for a specific instruction.
-** This routine is useful when a large program is loaded from a
-** static array using sqlite3VdbeAddOpList but we want to make a
-** few minor changes to the program.
+** Change the value of the opcode, or P1, P2, P3, or P5 operands
+** for a specific instruction.
 */
+SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe *p, u32 addr, u8 iNewOpcode){
+  sqlite3VdbeGetOp(p,addr)->opcode = iNewOpcode;
+}
 SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p1 = val;
-  }
+  sqlite3VdbeGetOp(p,addr)->p1 = val;
 }
-
-/*
-** Change the value of the P2 operand for a specific instruction.
-** This routine is useful for setting a jump destination.
-*/
 SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p2 = val;
-  }
+  sqlite3VdbeGetOp(p,addr)->p2 = val;
 }
-
-/*
-** Change the value of the P3 operand for a specific instruction.
-*/
 SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p3 = val;
-  }
+  sqlite3VdbeGetOp(p,addr)->p3 = val;
 }
-
-/*
-** Change the value of the P5 operand for the most recently
-** added operation.
-*/
-SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
-  assert( p!=0 );
-  if( p->aOp ){
-    assert( p->nOp>0 );
-    p->aOp[p->nOp-1].p5 = val;
-  }
+SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u16 p5){
+  assert( p->nOp>0 || p->db->mallocFailed );
+  if( p->nOp>0 ) p->aOp[p->nOp-1].p5 = p5;
 }
 
 /*
@@ -64829,7 +72817,6 @@ SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
 */
 SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
   sqlite3VdbeChangeP2(p, addr, p->nOp);
-  p->pParse->iFixedOp = p->nOp - 1;
 }
 
 
@@ -64838,8 +72825,8 @@ SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
 ** the FuncDef is not ephermal, then do nothing.
 */
 static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
-  if( ALWAYS(pDef) && (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
-    sqlite3DbFree(db, pDef);
+  if( (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
+    sqlite3DbFreeNN(db, pDef);
   }
 }
 
@@ -64848,43 +72835,53 @@ static void vdbeFreeOpArray(sqlite3 *, Op *, int);
 /*
 ** Delete a P4 value if necessary.
 */
+static SQLITE_NOINLINE void freeP4Mem(sqlite3 *db, Mem *p){
+  if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
+  sqlite3DbFreeNN(db, p);
+}
+static SQLITE_NOINLINE void freeP4FuncCtx(sqlite3 *db, sqlite3_context *p){
+  freeEphemeralFunction(db, p->pFunc);
+ sqlite3DbFreeNN(db, p);
+}
 static void freeP4(sqlite3 *db, int p4type, void *p4){
-  if( p4 ){
-    assert( db );
-    switch( p4type ){
-      case P4_REAL:
-      case P4_INT64:
-      case P4_DYNAMIC:
-      case P4_INTARRAY: {
-        sqlite3DbFree(db, p4);
-        break;
-      }
-      case P4_KEYINFO: {
-        if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);
-        break;
-      }
-      case P4_MPRINTF: {
-        if( db->pnBytesFreed==0 ) sqlite3_free(p4);
-        break;
-      }
-      case P4_FUNCDEF: {
-        freeEphemeralFunction(db, (FuncDef*)p4);
-        break;
-      }
-      case P4_MEM: {
-        if( db->pnBytesFreed==0 ){
-          sqlite3ValueFree((sqlite3_value*)p4);
-        }else{
-          Mem *p = (Mem*)p4;
-          if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
-          sqlite3DbFree(db, p);
-        }
-        break;
-      }
-      case P4_VTAB : {
-        if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
-        break;
+  assert( db );
+  switch( p4type ){
+    case P4_FUNCCTX: {
+      freeP4FuncCtx(db, (sqlite3_context*)p4);
+      break;
+    }
+    case P4_REAL:
+    case P4_INT64:
+    case P4_DYNAMIC:
+    case P4_INTARRAY: {
+      sqlite3DbFree(db, p4);
+      break;
+    }
+    case P4_KEYINFO: {
+      if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);
+      break;
+    }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+    case P4_EXPR: {
+      sqlite3ExprDelete(db, (Expr*)p4);
+      break;
+    }
+#endif
+    case P4_FUNCDEF: {
+      freeEphemeralFunction(db, (FuncDef*)p4);
+      break;
+    }
+    case P4_MEM: {
+      if( db->pnBytesFreed==0 ){
+        sqlite3ValueFree((sqlite3_value*)p4);
+      }else{
+        freeP4Mem(db, (Mem*)p4);
       }
+      break;
+    }
+    case P4_VTAB : {
+      if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
+      break;
     }
   }
 }
@@ -64897,14 +72894,14 @@ static void freeP4(sqlite3 *db, int p4type, void *p4){
 static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
   if( aOp ){
     Op *pOp;
-    for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
-      freeP4(db, pOp->p4type, pOp->p4.p);
+    for(pOp=&aOp[nOp-1]; pOp>=aOp; pOp--){
+      if( pOp->p4type <= P4_FREE_IF_LE ) freeP4(db, pOp->p4type, pOp->p4.p);
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
       sqlite3DbFree(db, pOp->zComment);
 #endif     
     }
+    sqlite3DbFreeNN(db, aOp);
   }
-  sqlite3DbFree(db, aOp);
 }
 
 /*
@@ -64920,15 +72917,16 @@ SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){
 /*
 ** Change the opcode at addr into OP_Noop
 */
-SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
-  if( addrnOp ){
-    VdbeOp *pOp = &p->aOp[addr];
-    sqlite3 *db = p->db;
-    freeP4(db, pOp->p4type, pOp->p4.p);
-    memset(pOp, 0, sizeof(pOp[0]));
-    pOp->opcode = OP_Noop;
-    if( addr==p->nOp-1 ) p->nOp--;
-  }
+SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
+  VdbeOp *pOp;
+  if( p->db->mallocFailed ) return 0;
+  assert( addr>=0 && addrnOp );
+  pOp = &p->aOp[addr];
+  freeP4(p->db, pOp->p4type, pOp->p4.p);
+  pOp->p4type = P4_NOTUSED;
+  pOp->p4.z = 0;
+  pOp->opcode = OP_Noop;
+  return 1;
 }
 
 /*
@@ -64936,9 +72934,8 @@ SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
 ** then remove it.  Return true if and only if an opcode was removed.
 */
 SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
-  if( (p->nOp-1)>(p->pParse->iFixedOp) && p->aOp[p->nOp-1].opcode==op ){
-    sqlite3VdbeChangeToNoop(p, p->nOp-1);
-    return 1;
+  if( p->nOp>0 && p->aOp[p->nOp-1].opcode==op ){
+    return sqlite3VdbeChangeToNoop(p, p->nOp-1);
   }else{
     return 0;
   }
@@ -64961,16 +72958,34 @@ SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
 **
 ** If addr<0 then change P4 on the most recently inserted instruction.
 */
+static void SQLITE_NOINLINE vdbeChangeP4Full(
+  Vdbe *p,
+  Op *pOp,
+  const char *zP4,
+  int n
+){
+  if( pOp->p4type ){
+    freeP4(p->db, pOp->p4type, pOp->p4.p);
+    pOp->p4type = 0;
+    pOp->p4.p = 0;
+  }
+  if( n<0 ){
+    sqlite3VdbeChangeP4(p, (int)(pOp - p->aOp), zP4, n);
+  }else{
+    if( n==0 ) n = sqlite3Strlen30(zP4);
+    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
+    pOp->p4type = P4_DYNAMIC;
+  }
+}
 SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
   Op *pOp;
   sqlite3 *db;
   assert( p!=0 );
   db = p->db;
   assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->aOp==0 || db->mallocFailed ){
-    if( n!=P4_VTAB ){
-      freeP4(db, n, (void*)*(char**)&zP4);
-    }
+  assert( p->aOp!=0 || db->mallocFailed );
+  if( db->mallocFailed ){
+    if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);
     return;
   }
   assert( p->nOp>0 );
@@ -64979,34 +72994,45 @@ SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int
     addr = p->nOp - 1;
   }
   pOp = &p->aOp[addr];
-  assert( pOp->p4type==P4_NOTUSED
-       || pOp->p4type==P4_INT32
-       || pOp->p4type==P4_KEYINFO );
-  freeP4(db, pOp->p4type, pOp->p4.p);
-  pOp->p4.p = 0;
+  if( n>=0 || pOp->p4type ){
+    vdbeChangeP4Full(p, pOp, zP4, n);
+    return;
+  }
   if( n==P4_INT32 ){
     /* Note: this cast is safe, because the origin data point was an int
     ** that was cast to a (const char *). */
     pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
     pOp->p4type = P4_INT32;
-  }else if( zP4==0 ){
-    pOp->p4.p = 0;
-    pOp->p4type = P4_NOTUSED;
-  }else if( n==P4_KEYINFO ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_KEYINFO;
-  }else if( n==P4_VTAB ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_VTAB;
-    sqlite3VtabLock((VTable *)zP4);
-    assert( ((VTable *)zP4)->db==p->db );
-  }else if( n<0 ){
+  }else if( zP4!=0 ){
+    assert( n<0 );
     pOp->p4.p = (void*)zP4;
     pOp->p4type = (signed char)n;
+    if( n==P4_VTAB ) sqlite3VtabLock((VTable*)zP4);
+  }
+}
+
+/*
+** Change the P4 operand of the most recently coded instruction 
+** to the value defined by the arguments.  This is a high-speed
+** version of sqlite3VdbeChangeP4().
+**
+** The P4 operand must not have been previously defined.  And the new
+** P4 must not be P4_INT32.  Use sqlite3VdbeChangeP4() in either of
+** those cases.
+*/
+SQLITE_PRIVATE void sqlite3VdbeAppendP4(Vdbe *p, void *pP4, int n){
+  VdbeOp *pOp;
+  assert( n!=P4_INT32 && n!=P4_VTAB );
+  assert( n<=0 );
+  if( p->db->mallocFailed ){
+    freeP4(p->db, n, pP4);
   }else{
-    if( n==0 ) n = sqlite3Strlen30(zP4);
-    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
-    pOp->p4type = P4_DYNAMIC;
+    assert( pP4!=0 );
+    assert( p->nOp>0 );
+    pOp = &p->aOp[p->nOp-1];
+    assert( pOp->p4type==P4_NOTUSED );
+    pOp->p4type = n;
+    pOp->p4.p = pP4;
   }
 }
 
@@ -65016,10 +73042,11 @@ SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int
 */
 SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse *pParse, Index *pIdx){
   Vdbe *v = pParse->pVdbe;
+  KeyInfo *pKeyInfo;
   assert( v!=0 );
   assert( pIdx!=0 );
-  sqlite3VdbeChangeP4(v, -1, (char*)sqlite3KeyInfoOfIndex(pParse, pIdx),
-                      P4_KEYINFO);
+  pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pIdx);
+  if( pKeyInfo ) sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
 }
 
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
@@ -65131,12 +73158,21 @@ static int displayComment(
   const char *zSynopsis;
   int nOpName;
   int ii, jj;
+  char zAlt[50];
   zOpName = sqlite3OpcodeName(pOp->opcode);
   nOpName = sqlite3Strlen30(zOpName);
   if( zOpName[nOpName+1] ){
     int seenCom = 0;
     char c;
     zSynopsis = zOpName += nOpName + 1;
+    if( strncmp(zSynopsis,"IF ",3)==0 ){
+      if( pOp->p5 & SQLITE_STOREP2 ){
+        sqlite3_snprintf(sizeof(zAlt), zAlt, "r[P2] = (%s)", zSynopsis+3);
+      }else{
+        sqlite3_snprintf(sizeof(zAlt), zAlt, "if %s goto P2", zSynopsis+3);
+      }
+      zSynopsis = zAlt;
+    }
     for(ii=jj=0; jjop ){
+    case TK_STRING:
+      sqlite3XPrintf(p, "%Q", pExpr->u.zToken);
+      break;
+    case TK_INTEGER:
+      sqlite3XPrintf(p, "%d", pExpr->u.iValue);
+      break;
+    case TK_NULL:
+      sqlite3XPrintf(p, "NULL");
+      break;
+    case TK_REGISTER: {
+      sqlite3XPrintf(p, "r[%d]", pExpr->iTable);
+      break;
+    }
+    case TK_COLUMN: {
+      if( pExpr->iColumn<0 ){
+        sqlite3XPrintf(p, "rowid");
+      }else{
+        sqlite3XPrintf(p, "c%d", (int)pExpr->iColumn);
+      }
+      break;
+    }
+    case TK_LT:      zOp = "LT";      break;
+    case TK_LE:      zOp = "LE";      break;
+    case TK_GT:      zOp = "GT";      break;
+    case TK_GE:      zOp = "GE";      break;
+    case TK_NE:      zOp = "NE";      break;
+    case TK_EQ:      zOp = "EQ";      break;
+    case TK_IS:      zOp = "IS";      break;
+    case TK_ISNOT:   zOp = "ISNOT";   break;
+    case TK_AND:     zOp = "AND";     break;
+    case TK_OR:      zOp = "OR";      break;
+    case TK_PLUS:    zOp = "ADD";     break;
+    case TK_STAR:    zOp = "MUL";     break;
+    case TK_MINUS:   zOp = "SUB";     break;
+    case TK_REM:     zOp = "REM";     break;
+    case TK_BITAND:  zOp = "BITAND";  break;
+    case TK_BITOR:   zOp = "BITOR";   break;
+    case TK_SLASH:   zOp = "DIV";     break;
+    case TK_LSHIFT:  zOp = "LSHIFT";  break;
+    case TK_RSHIFT:  zOp = "RSHIFT";  break;
+    case TK_CONCAT:  zOp = "CONCAT";  break;
+    case TK_UMINUS:  zOp = "MINUS";   break;
+    case TK_UPLUS:   zOp = "PLUS";    break;
+    case TK_BITNOT:  zOp = "BITNOT";  break;
+    case TK_NOT:     zOp = "NOT";     break;
+    case TK_ISNULL:  zOp = "ISNULL";  break;
+    case TK_NOTNULL: zOp = "NOTNULL"; break;
 
-#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
-     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+    default:
+      sqlite3XPrintf(p, "%s", "expr");
+      break;
+  }
+
+  if( zOp ){
+    sqlite3XPrintf(p, "%s(", zOp);
+    displayP4Expr(p, pExpr->pLeft);
+    if( pExpr->pRight ){
+      sqlite3StrAccumAppend(p, ",", 1);
+      displayP4Expr(p, pExpr->pRight);
+    }
+    sqlite3StrAccumAppend(p, ")", 1);
+  }
+}
+#endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */
+
+
+#if VDBE_DISPLAY_P4
 /*
 ** Compute a string that describes the P4 parameter for an opcode.
 ** Use zTemp for any required temporary buffer space.
 */
 static char *displayP4(Op *pOp, char *zTemp, int nTemp){
   char *zP4 = zTemp;
+  StrAccum x;
   assert( nTemp>=20 );
+  sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
   switch( pOp->p4type ){
     case P4_KEYINFO: {
-      int i, j;
+      int j;
       KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
       assert( pKeyInfo->aSortOrder!=0 );
-      sqlite3_snprintf(nTemp, zTemp, "k(%d", pKeyInfo->nField);
-      i = sqlite3Strlen30(zTemp);
+      sqlite3XPrintf(&x, "k(%d", pKeyInfo->nField);
       for(j=0; jnField; j++){
         CollSeq *pColl = pKeyInfo->aColl[j];
-        const char *zColl = pColl ? pColl->zName : "nil";
-        int n = sqlite3Strlen30(zColl);
-        if( n==6 && memcmp(zColl,"BINARY",6)==0 ){
-          zColl = "B";
-          n = 1;
-        }
-        if( i+n>nTemp-6 ){
-          memcpy(&zTemp[i],",...",4);
-          break;
-        }
-        zTemp[i++] = ',';
-        if( pKeyInfo->aSortOrder[j] ){
-          zTemp[i++] = '-';
-        }
-        memcpy(&zTemp[i], zColl, n+1);
-        i += n;
+        const char *zColl = pColl ? pColl->zName : "";
+        if( strcmp(zColl, "BINARY")==0 ) zColl = "B";
+        sqlite3XPrintf(&x, ",%s%s", pKeyInfo->aSortOrder[j] ? "-" : "", zColl);
       }
-      zTemp[i++] = ')';
-      zTemp[i] = 0;
-      assert( ip4.pExpr);
       break;
     }
+#endif
     case P4_COLLSEQ: {
       CollSeq *pColl = pOp->p4.pColl;
-      sqlite3_snprintf(nTemp, zTemp, "(%.20s)", pColl->zName);
+      sqlite3XPrintf(&x, "(%.20s)", pColl->zName);
       break;
     }
     case P4_FUNCDEF: {
       FuncDef *pDef = pOp->p4.pFunc;
-      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
+      sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
+      break;
+    }
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+    case P4_FUNCCTX: {
+      FuncDef *pDef = pOp->p4.pCtx->pFunc;
+      sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
       break;
     }
+#endif
     case P4_INT64: {
-      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
+      sqlite3XPrintf(&x, "%lld", *pOp->p4.pI64);
       break;
     }
     case P4_INT32: {
-      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
+      sqlite3XPrintf(&x, "%d", pOp->p4.i);
       break;
     }
     case P4_REAL: {
-      sqlite3_snprintf(nTemp, zTemp, "%.16g", *pOp->p4.pReal);
+      sqlite3XPrintf(&x, "%.16g", *pOp->p4.pReal);
       break;
     }
     case P4_MEM: {
@@ -65253,11 +73360,11 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
       if( pMem->flags & MEM_Str ){
         zP4 = pMem->z;
       }else if( pMem->flags & MEM_Int ){
-        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
+        sqlite3XPrintf(&x, "%lld", pMem->u.i);
       }else if( pMem->flags & MEM_Real ){
-        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->u.r);
+        sqlite3XPrintf(&x, "%.16g", pMem->u.r);
       }else if( pMem->flags & MEM_Null ){
-        sqlite3_snprintf(nTemp, zTemp, "NULL");
+        zP4 = "NULL";
       }else{
         assert( pMem->flags & MEM_Blob );
         zP4 = "(blob)";
@@ -65267,22 +73374,34 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     case P4_VTAB: {
       sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;
-      sqlite3_snprintf(nTemp, zTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
+      sqlite3XPrintf(&x, "vtab:%p", pVtab);
       break;
     }
 #endif
     case P4_INTARRAY: {
-      sqlite3_snprintf(nTemp, zTemp, "intarray");
+      int i;
+      int *ai = pOp->p4.ai;
+      int n = ai[0];   /* The first element of an INTARRAY is always the
+                       ** count of the number of elements to follow */
+      for(i=1; ip4.pTab->zName);
+      break;
+    }
     default: {
       zP4 = pOp->p4.z;
       if( zP4==0 ){
@@ -65291,10 +73410,11 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
       }
     }
   }
+  sqlite3StrAccumFinish(&x);
   assert( zP4!=0 );
   return zP4;
 }
-#endif
+#endif /* VDBE_DISPLAY_P4 */
 
 /*
 ** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
@@ -65313,7 +73433,7 @@ SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe *p, int i){
   }
 }
 
-#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
+#if !defined(SQLITE_OMIT_SHARED_CACHE)
 /*
 ** If SQLite is compiled to support shared-cache mode and to be threadsafe,
 ** this routine obtains the mutex associated with each BtShared structure
@@ -65356,12 +73476,11 @@ SQLITE_PRIVATE void sqlite3VdbeEnter(Vdbe *p){
 /*
 ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().
 */
-SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
+static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){
   int i;
   sqlite3 *db;
   Db *aDb;
   int nDb;
-  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
   db = p->db;
   aDb = db->aDb;
   nDb = db->nDb;
@@ -65371,6 +73490,10 @@ SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
     }
   }
 }
+SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
+  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
+  vdbeLeave(p);
+}
 #endif
 
 #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
@@ -65400,6 +73523,21 @@ SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
 }
 #endif
 
+/*
+** Initialize an array of N Mem element.
+*/
+static void initMemArray(Mem *p, int N, sqlite3 *db, u16 flags){
+  while( (N--)>0 ){
+    p->db = db;
+    p->flags = flags;
+    p->szMalloc = 0;
+#ifdef SQLITE_DEBUG
+    p->pScopyFrom = 0;
+#endif
+    p++;
+  }
+}
+
 /*
 ** Release an array of N Mem elements
 */
@@ -65407,7 +73545,6 @@ static void releaseMemArray(Mem *p, int N){
   if( p && N ){
     Mem *pEnd = &p[N];
     sqlite3 *db = p->db;
-    u8 malloc_failed = db->mallocFailed;
     if( db->pnBytesFreed ){
       do{
         if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
@@ -65437,13 +73574,12 @@ static void releaseMemArray(Mem *p, int N){
       if( p->flags&(MEM_Agg|MEM_Dyn|MEM_Frame|MEM_RowSet) ){
         sqlite3VdbeMemRelease(p);
       }else if( p->szMalloc ){
-        sqlite3DbFree(db, p->zMalloc);
+        sqlite3DbFreeNN(db, p->zMalloc);
         p->szMalloc = 0;
       }
 
       p->flags = MEM_Undefined;
     }while( (++p)mallocFailed = malloc_failed;
   }
 }
 
@@ -65459,6 +73595,7 @@ SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame *p){
     sqlite3VdbeFreeCursor(p->v, apCsr[i]);
   }
   releaseMemArray(aMem, p->nChildMem);
+  sqlite3VdbeDeleteAuxData(p->v->db, &p->pAuxData, -1, 0);
   sqlite3DbFree(p->v->db, p);
 }
 
@@ -65501,10 +73638,10 @@ SQLITE_PRIVATE int sqlite3VdbeList(
   releaseMemArray(pMem, 8);
   p->pResultSet = 0;
 
-  if( p->rc==SQLITE_NOMEM ){
+  if( p->rc==SQLITE_NOMEM_BKPT ){
     /* This happens if a malloc() inside a call to sqlite3_column_text() or
     ** sqlite3_column_text16() failed.  */
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     return SQLITE_ERROR;
   }
 
@@ -65543,7 +73680,7 @@ SQLITE_PRIVATE int sqlite3VdbeList(
   }else if( db->u1.isInterrupted ){
     p->rc = SQLITE_INTERRUPT;
     rc = SQLITE_ERROR;
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(p->rc));
+    sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
   }else{
     char *zP4;
     Op *pOp;
@@ -65605,13 +73742,14 @@ SQLITE_PRIVATE int sqlite3VdbeList(
     pMem->u.i = pOp->p3;                          /* P3 */
     pMem++;
 
-    if( sqlite3VdbeMemClearAndResize(pMem, 32) ){ /* P4 */
+    if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
       assert( p->db->mallocFailed );
       return SQLITE_ERROR;
     }
     pMem->flags = MEM_Str|MEM_Term;
-    zP4 = displayP4(pOp, pMem->z, 32);
+    zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
     if( zP4!=pMem->z ){
+      pMem->n = 0;
       sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
     }else{
       assert( pMem->z!=0 );
@@ -65702,43 +73840,46 @@ SQLITE_PRIVATE void sqlite3VdbeIOTraceSql(Vdbe *p){
 }
 #endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */
 
-/*
-** Allocate space from a fixed size buffer and return a pointer to
-** that space.  If insufficient space is available, return NULL.
-**
-** The pBuf parameter is the initial value of a pointer which will
-** receive the new memory.  pBuf is normally NULL.  If pBuf is not
-** NULL, it means that memory space has already been allocated and that
-** this routine should not allocate any new memory.  When pBuf is not
-** NULL simply return pBuf.  Only allocate new memory space when pBuf
-** is NULL.
-**
-** nByte is the number of bytes of space needed.
+/* An instance of this object describes bulk memory available for use
+** by subcomponents of a prepared statement.  Space is allocated out
+** of a ReusableSpace object by the allocSpace() routine below.
+*/
+struct ReusableSpace {
+  u8 *pSpace;          /* Available memory */
+  int nFree;           /* Bytes of available memory */
+  int nNeeded;         /* Total bytes that could not be allocated */
+};
+
+/* Try to allocate nByte bytes of 8-byte aligned bulk memory for pBuf
+** from the ReusableSpace object.  Return a pointer to the allocated
+** memory on success.  If insufficient memory is available in the
+** ReusableSpace object, increase the ReusableSpace.nNeeded
+** value by the amount needed and return NULL.
 **
-** *ppFrom points to available space and pEnd points to the end of the
-** available space.  When space is allocated, *ppFrom is advanced past
-** the end of the allocated space.
+** If pBuf is not initially NULL, that means that the memory has already
+** been allocated by a prior call to this routine, so just return a copy
+** of pBuf and leave ReusableSpace unchanged.
 **
-** *pnByte is a counter of the number of bytes of space that have failed
-** to allocate.  If there is insufficient space in *ppFrom to satisfy the
-** request, then increment *pnByte by the amount of the request.
+** This allocator is employed to repurpose unused slots at the end of the
+** opcode array of prepared state for other memory needs of the prepared
+** statement.
 */
 static void *allocSpace(
-  void *pBuf,          /* Where return pointer will be stored */
-  int nByte,           /* Number of bytes to allocate */
-  u8 **ppFrom,         /* IN/OUT: Allocate from *ppFrom */
-  u8 *pEnd,            /* Pointer to 1 byte past the end of *ppFrom buffer */
-  int *pnByte          /* If allocation cannot be made, increment *pnByte */
-){
-  assert( EIGHT_BYTE_ALIGNMENT(*ppFrom) );
-  if( pBuf ) return pBuf;
-  nByte = ROUND8(nByte);
-  if( &(*ppFrom)[nByte] <= pEnd ){
-    pBuf = (void*)*ppFrom;
-    *ppFrom += nByte;
-  }else{
-    *pnByte += nByte;
+  struct ReusableSpace *p,  /* Bulk memory available for allocation */
+  void *pBuf,               /* Pointer to a prior allocation */
+  int nByte                 /* Bytes of memory needed */
+){
+  assert( EIGHT_BYTE_ALIGNMENT(p->pSpace) );
+  if( pBuf==0 ){
+    nByte = ROUND8(nByte);
+    if( nByte <= p->nFree ){
+      p->nFree -= nByte;
+      pBuf = &p->pSpace[p->nFree];
+    }else{
+      p->nNeeded += nByte;
+    }
   }
+  assert( EIGHT_BYTE_ALIGNMENT(pBuf) );
   return pBuf;
 }
 
@@ -65751,7 +73892,7 @@ SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe *p){
   int i;
 #endif
   assert( p!=0 );
-  assert( p->magic==VDBE_MAGIC_INIT );
+  assert( p->magic==VDBE_MAGIC_INIT || p->magic==VDBE_MAGIC_RESET );
 
   /* There should be at least one opcode.
   */
@@ -65761,14 +73902,13 @@ SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe *p){
   p->magic = VDBE_MAGIC_RUN;
 
 #ifdef SQLITE_DEBUG
-  for(i=1; inMem; i++){
+  for(i=0; inMem; i++){
     assert( p->aMem[i].db==p->db );
   }
 #endif
   p->pc = -1;
   p->rc = SQLITE_OK;
   p->errorAction = OE_Abort;
-  p->magic = VDBE_MAGIC_RUN;
   p->nChange = 0;
   p->cacheCtr = 1;
   p->minWriteFileFormat = 255;
@@ -65809,11 +73949,8 @@ SQLITE_PRIVATE void sqlite3VdbeMakeReady(
   int nMem;                      /* Number of VM memory registers */
   int nCursor;                   /* Number of cursors required */
   int nArg;                      /* Number of arguments in subprograms */
-  int nOnce;                     /* Number of OP_Once instructions */
   int n;                         /* Loop counter */
-  u8 *zCsr;                      /* Memory available for allocation */
-  u8 *zEnd;                      /* First byte past allocated memory */
-  int nByte;                     /* How much extra memory is needed */
+  struct ReusableSpace x;        /* Reusable bulk memory */
 
   assert( p!=0 );
   assert( p->nOp>0 );
@@ -65826,88 +73963,75 @@ SQLITE_PRIVATE void sqlite3VdbeMakeReady(
   nMem = pParse->nMem;
   nCursor = pParse->nTab;
   nArg = pParse->nMaxArg;
-  nOnce = pParse->nOnce;
-  if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
   
-  /* For each cursor required, also allocate a memory cell. Memory
-  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
-  ** the vdbe program. Instead they are used to allocate space for
-  ** VdbeCursor/BtCursor structures. The blob of memory associated with 
-  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
-  ** stores the blob of memory associated with cursor 1, etc.
-  **
+  /* Each cursor uses a memory cell.  The first cursor (cursor 0) can
+  ** use aMem[0] which is not otherwise used by the VDBE program.  Allocate
+  ** space at the end of aMem[] for cursors 1 and greater.
   ** See also: allocateCursor().
   */
   nMem += nCursor;
+  if( nCursor==0 && nMem>0 ) nMem++;  /* Space for aMem[0] even if not used */
 
-  /* Allocate space for memory registers, SQL variables, VDBE cursors and 
-  ** an array to marshal SQL function arguments in.
+  /* Figure out how much reusable memory is available at the end of the
+  ** opcode array.  This extra memory will be reallocated for other elements
+  ** of the prepared statement.
   */
-  zCsr = (u8*)&p->aOp[p->nOp];            /* Memory avaliable for allocation */
-  zEnd = (u8*)&p->aOp[pParse->nOpAlloc];  /* First byte past end of zCsr[] */
+  n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode memory used */
+  x.pSpace = &((u8*)p->aOp)[n];               /* Unused opcode memory */
+  assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );
+  x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n);  /* Bytes of unused memory */
+  assert( x.nFree>=0 );
+  assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );
 
   resolveP2Values(p, &nArg);
   p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
   if( pParse->explain && nMem<10 ){
     nMem = 10;
   }
-  memset(zCsr, 0, zEnd-zCsr);
-  zCsr += (zCsr - (u8*)0)&7;
-  assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
   p->expired = 0;
 
-  /* Memory for registers, parameters, cursor, etc, is allocated in two
-  ** passes.  On the first pass, we try to reuse unused space at the 
+  /* Memory for registers, parameters, cursor, etc, is allocated in one or two
+  ** passes.  On the first pass, we try to reuse unused memory at the 
   ** end of the opcode array.  If we are unable to satisfy all memory
   ** requirements by reusing the opcode array tail, then the second
-  ** pass will fill in the rest using a fresh allocation.  
+  ** pass will fill in the remainder using a fresh memory allocation.  
   **
   ** This two-pass approach that reuses as much memory as possible from
-  ** the leftover space at the end of the opcode array can significantly
+  ** the leftover memory at the end of the opcode array.  This can significantly
   ** reduce the amount of memory held by a prepared statement.
   */
   do {
-    nByte = 0;
-    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
-    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
-    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
-    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
-    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
-                          &zCsr, zEnd, &nByte);
-    p->aOnceFlag = allocSpace(p->aOnceFlag, nOnce, &zCsr, zEnd, &nByte);
+    x.nNeeded = 0;
+    p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
+    p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
+    p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
+    p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-    p->anExec = allocSpace(p->anExec, p->nOp*sizeof(i64), &zCsr, zEnd, &nByte);
+    p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
 #endif
-    if( nByte ){
-      p->pFree = sqlite3DbMallocZero(db, nByte);
-    }
-    zCsr = p->pFree;
-    zEnd = &zCsr[nByte];
-  }while( nByte && !db->mallocFailed );
+    if( x.nNeeded==0 ) break;
+    x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
+    x.nFree = x.nNeeded;
+  }while( !db->mallocFailed );
 
-  p->nCursor = nCursor;
-  p->nOnceFlag = nOnce;
-  if( p->aVar ){
+  p->pVList = pParse->pVList;
+  pParse->pVList =  0;
+  p->explain = pParse->explain;
+  if( db->mallocFailed ){
+    p->nVar = 0;
+    p->nCursor = 0;
+    p->nMem = 0;
+  }else{
+    p->nCursor = nCursor;
     p->nVar = (ynVar)nVar;
-    for(n=0; naVar[n].flags = MEM_Null;
-      p->aVar[n].db = db;
-    }
-  }
-  if( p->azVar && pParse->nzVar>0 ){
-    p->nzVar = pParse->nzVar;
-    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
-    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
-  }
-  if( p->aMem ){
-    p->aMem--;                      /* aMem[] goes from 1..nMem */
-    p->nMem = nMem;                 /*       not from 0..nMem-1 */
-    for(n=1; n<=nMem; n++){
-      p->aMem[n].flags = MEM_Undefined;
-      p->aMem[n].db = db;
-    }
+    initMemArray(p->aVar, nVar, db, MEM_Null);
+    p->nMem = nMem;
+    initMemArray(p->aMem, nMem, db, MEM_Undefined);
+    memset(p->apCsr, 0, nCursor*sizeof(VdbeCursor*));
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+    memset(p->anExec, 0, p->nOp*sizeof(i64));
+#endif
   }
-  p->explain = pParse->explain;
   sqlite3VdbeRewind(p);
 }
 
@@ -65919,23 +74043,50 @@ SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
   if( pCx==0 ){
     return;
   }
-  sqlite3VdbeSorterClose(p->db, pCx);
-  if( pCx->pBt ){
-    sqlite3BtreeClose(pCx->pBt);
-    /* The pCx->pCursor will be close automatically, if it exists, by
-    ** the call above. */
-  }else if( pCx->pCursor ){
-    sqlite3BtreeCloseCursor(pCx->pCursor);
-  }
+  assert( pCx->pBtx==0 || pCx->eCurType==CURTYPE_BTREE );
+  switch( pCx->eCurType ){
+    case CURTYPE_SORTER: {
+      sqlite3VdbeSorterClose(p->db, pCx);
+      break;
+    }
+    case CURTYPE_BTREE: {
+      if( pCx->isEphemeral ){
+        if( pCx->pBtx ) sqlite3BtreeClose(pCx->pBtx);
+        /* The pCx->pCursor will be close automatically, if it exists, by
+        ** the call above. */
+      }else{
+        assert( pCx->uc.pCursor!=0 );
+        sqlite3BtreeCloseCursor(pCx->uc.pCursor);
+      }
+      break;
+    }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  else if( pCx->pVtabCursor ){
-    sqlite3_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
-    const sqlite3_module *pModule = pVtabCursor->pVtab->pModule;
-    p->inVtabMethod = 1;
-    pModule->xClose(pVtabCursor);
-    p->inVtabMethod = 0;
-  }
+    case CURTYPE_VTAB: {
+      sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;
+      const sqlite3_module *pModule = pVCur->pVtab->pModule;
+      assert( pVCur->pVtab->nRef>0 );
+      pVCur->pVtab->nRef--;
+      pModule->xClose(pVCur);
+      break;
+    }
 #endif
+  }
+}
+
+/*
+** Close all cursors in the current frame.
+*/
+static void closeCursorsInFrame(Vdbe *p){
+  if( p->apCsr ){
+    int i;
+    for(i=0; inCursor; i++){
+      VdbeCursor *pC = p->apCsr[i];
+      if( pC ){
+        sqlite3VdbeFreeCursor(p, pC);
+        p->apCsr[i] = 0;
+      }
+    }
+  }
 }
 
 /*
@@ -65945,11 +74096,10 @@ SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
 */
 SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
   Vdbe *v = pFrame->v;
+  closeCursorsInFrame(v);
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
   v->anExec = pFrame->anExec;
 #endif
-  v->aOnceFlag = pFrame->aOnceFlag;
-  v->nOnceFlag = pFrame->nOnceFlag;
   v->aOp = pFrame->aOp;
   v->nOp = pFrame->nOp;
   v->aMem = pFrame->aMem;
@@ -65959,6 +74109,9 @@ SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
   v->db->lastRowid = pFrame->lastRowid;
   v->nChange = pFrame->nChange;
   v->db->nChange = pFrame->nDbChange;
+  sqlite3VdbeDeleteAuxData(v->db, &v->pAuxData, -1, 0);
+  v->pAuxData = pFrame->pAuxData;
+  pFrame->pAuxData = 0;
   return pFrame->pc;
 }
 
@@ -65979,19 +74132,9 @@ static void closeAllCursors(Vdbe *p){
     p->nFrame = 0;
   }
   assert( p->nFrame==0 );
-
-  if( p->apCsr ){
-    int i;
-    for(i=0; inCursor; i++){
-      VdbeCursor *pC = p->apCsr[i];
-      if( pC ){
-        sqlite3VdbeFreeCursor(p, pC);
-        p->apCsr[i] = 0;
-      }
-    }
-  }
+  closeCursorsInFrame(p);
   if( p->aMem ){
-    releaseMemArray(&p->aMem[1], p->nMem);
+    releaseMemArray(p->aMem, p->nMem);
   }
   while( p->pDelFrame ){
     VdbeFrame *pDel = p->pDelFrame;
@@ -66000,7 +74143,7 @@ static void closeAllCursors(Vdbe *p){
   }
 
   /* Delete any auxdata allocations made by the VM */
-  if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p, -1, 0);
+  if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p->db, &p->pAuxData, -1, 0);
   assert( p->pAuxData==0 );
 }
 
@@ -66016,7 +74159,7 @@ static void Cleanup(Vdbe *p){
   int i;
   if( p->apCsr ) for(i=0; inCursor; i++) assert( p->apCsr[i]==0 );
   if( p->aMem ){
-    for(i=1; i<=p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
+    for(i=0; inMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
   }
 #endif
 
@@ -66032,21 +74175,18 @@ static void Cleanup(Vdbe *p){
 ** be called on an SQL statement before sqlite3_step().
 */
 SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){
-  Mem *pColName;
   int n;
   sqlite3 *db = p->db;
 
-  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
-  sqlite3DbFree(db, p->aColName);
+  if( p->nResColumn ){
+    releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+    sqlite3DbFree(db, p->aColName);
+  }
   n = nResColumn*COLNAME_N;
   p->nResColumn = (u16)nResColumn;
-  p->aColName = pColName = (Mem*)sqlite3DbMallocZero(db, sizeof(Mem)*n );
+  p->aColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
   if( p->aColName==0 ) return;
-  while( n-- > 0 ){
-    pColName->flags = MEM_Null;
-    pColName->db = p->db;
-    pColName++;
-  }
+  initMemArray(p->aColName, n, db, MEM_Null);
 }
 
 /*
@@ -66072,7 +74212,7 @@ SQLITE_PRIVATE int sqlite3VdbeSetColName(
   assert( vardb->mallocFailed ){
     assert( !zName || xDel!=SQLITE_DYNAMIC );
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   assert( p->aColName!=0 );
   pColName = &(p->aColName[idx+var*p->nResColumn]);
@@ -66089,7 +74229,9 @@ SQLITE_PRIVATE int sqlite3VdbeSetColName(
 */
 static int vdbeCommit(sqlite3 *db, Vdbe *p){
   int i;
-  int nTrans = 0;  /* Number of databases with an active write-transaction */
+  int nTrans = 0;  /* Number of databases with an active write-transaction
+                   ** that are candidates for a two-phase commit using a
+                   ** master-journal */
   int rc = SQLITE_OK;
   int needXcommit = 0;
 
@@ -66117,10 +74259,28 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   for(i=0; rc==SQLITE_OK && inDb; i++){ 
     Btree *pBt = db->aDb[i].pBt;
     if( sqlite3BtreeIsInTrans(pBt) ){
+      /* Whether or not a database might need a master journal depends upon
+      ** its journal mode (among other things).  This matrix determines which
+      ** journal modes use a master journal and which do not */
+      static const u8 aMJNeeded[] = {
+        /* DELETE   */  1,
+        /* PERSIST   */ 1,
+        /* OFF       */ 0,
+        /* TRUNCATE  */ 1,
+        /* MEMORY    */ 0,
+        /* WAL       */ 0
+      };
+      Pager *pPager;   /* Pager associated with pBt */
       needXcommit = 1;
-      if( i!=1 ) nTrans++;
       sqlite3BtreeEnter(pBt);
-      rc = sqlite3PagerExclusiveLock(sqlite3BtreePager(pBt));
+      pPager = sqlite3BtreePager(pBt);
+      if( db->aDb[i].safety_level!=PAGER_SYNCHRONOUS_OFF
+       && aMJNeeded[sqlite3PagerGetJournalMode(pPager)]
+      ){ 
+        assert( i!=1 );
+        nTrans++;
+      }
+      rc = sqlite3PagerExclusiveLock(pPager);
       sqlite3BtreeLeave(pBt);
     }
   }
@@ -66178,7 +74338,6 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
 #ifndef SQLITE_OMIT_DISKIO
   else{
     sqlite3_vfs *pVfs = db->pVfs;
-    int needSync = 0;
     char *zMaster = 0;   /* File-name for the master journal */
     char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
     sqlite3_file *pMaster = 0;
@@ -66190,7 +74349,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
     /* Select a master journal file name */
     nMainFile = sqlite3Strlen30(zMainFile);
     zMaster = sqlite3MPrintf(db, "%s-mjXXXXXX9XXz", zMainFile);
-    if( zMaster==0 ) return SQLITE_NOMEM;
+    if( zMaster==0 ) return SQLITE_NOMEM_BKPT;
     do {
       u32 iRandom;
       if( retryCount ){
@@ -66238,9 +74397,6 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
           continue;  /* Ignore TEMP and :memory: databases */
         }
         assert( zFile[0]!=0 );
-        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
-          needSync = 1;
-        }
         rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
         offset += sqlite3Strlen30(zFile)+1;
         if( rc!=SQLITE_OK ){
@@ -66255,8 +74411,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
     /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
     ** flag is set this is not required.
     */
-    if( needSync 
-     && 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
+    if( 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
      && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))
     ){
       sqlite3OsCloseFree(pMaster);
@@ -66366,60 +74521,59 @@ static void checkActiveVdbeCnt(sqlite3 *db){
 ** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
 ** Otherwise SQLITE_OK.
 */
-SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
+static SQLITE_NOINLINE int vdbeCloseStatement(Vdbe *p, int eOp){
   sqlite3 *const db = p->db;
   int rc = SQLITE_OK;
+  int i;
+  const int iSavepoint = p->iStatement-1;
 
-  /* If p->iStatement is greater than zero, then this Vdbe opened a 
-  ** statement transaction that should be closed here. The only exception
-  ** is that an IO error may have occurred, causing an emergency rollback.
-  ** In this case (db->nStatement==0), and there is nothing to do.
-  */
-  if( db->nStatement && p->iStatement ){
-    int i;
-    const int iSavepoint = p->iStatement-1;
-
-    assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);
-    assert( db->nStatement>0 );
-    assert( p->iStatement==(db->nStatement+db->nSavepoint) );
-
-    for(i=0; inDb; i++){ 
-      int rc2 = SQLITE_OK;
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        if( eOp==SAVEPOINT_ROLLBACK ){
-          rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_ROLLBACK, iSavepoint);
-        }
-        if( rc2==SQLITE_OK ){
-          rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_RELEASE, iSavepoint);
-        }
-        if( rc==SQLITE_OK ){
-          rc = rc2;
-        }
-      }
-    }
-    db->nStatement--;
-    p->iStatement = 0;
+  assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);
+  assert( db->nStatement>0 );
+  assert( p->iStatement==(db->nStatement+db->nSavepoint) );
 
-    if( rc==SQLITE_OK ){
+  for(i=0; inDb; i++){ 
+    int rc2 = SQLITE_OK;
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
       if( eOp==SAVEPOINT_ROLLBACK ){
-        rc = sqlite3VtabSavepoint(db, SAVEPOINT_ROLLBACK, iSavepoint);
+        rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_ROLLBACK, iSavepoint);
+      }
+      if( rc2==SQLITE_OK ){
+        rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_RELEASE, iSavepoint);
       }
       if( rc==SQLITE_OK ){
-        rc = sqlite3VtabSavepoint(db, SAVEPOINT_RELEASE, iSavepoint);
+        rc = rc2;
       }
     }
+  }
+  db->nStatement--;
+  p->iStatement = 0;
 
-    /* If the statement transaction is being rolled back, also restore the 
-    ** database handles deferred constraint counter to the value it had when 
-    ** the statement transaction was opened.  */
+  if( rc==SQLITE_OK ){
     if( eOp==SAVEPOINT_ROLLBACK ){
-      db->nDeferredCons = p->nStmtDefCons;
-      db->nDeferredImmCons = p->nStmtDefImmCons;
+      rc = sqlite3VtabSavepoint(db, SAVEPOINT_ROLLBACK, iSavepoint);
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3VtabSavepoint(db, SAVEPOINT_RELEASE, iSavepoint);
     }
   }
+
+  /* If the statement transaction is being rolled back, also restore the 
+  ** database handles deferred constraint counter to the value it had when 
+  ** the statement transaction was opened.  */
+  if( eOp==SAVEPOINT_ROLLBACK ){
+    db->nDeferredCons = p->nStmtDefCons;
+    db->nDeferredImmCons = p->nStmtDefImmCons;
+  }
   return rc;
 }
+SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
+  if( p->db->nStatement && p->iStatement ){
+    return vdbeCloseStatement(p, eOp);
+  }
+  return SQLITE_OK;
+}
+
 
 /*
 ** This function is called when a transaction opened by the database 
@@ -66439,7 +74593,7 @@ SQLITE_PRIVATE int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
   ){
     p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
     p->errorAction = OE_Abort;
-    sqlite3SetString(&p->zErrMsg, db, "FOREIGN KEY constraint failed");
+    sqlite3VdbeError(p, "FOREIGN KEY constraint failed");
     return SQLITE_ERROR;
   }
   return SQLITE_OK;
@@ -66479,14 +74633,13 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
   ** one, or the complete transaction if there is no statement transaction.
   */
 
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
-  }
-  if( p->aOnceFlag ) memset(p->aOnceFlag, 0, p->nOnceFlag);
-  closeAllCursors(p);
   if( p->magic!=VDBE_MAGIC_RUN ){
     return SQLITE_OK;
   }
+  if( db->mallocFailed ){
+    p->rc = SQLITE_NOMEM_BKPT;
+  }
+  closeAllCursors(p);
   checkActiveVdbeCnt(db);
 
   /* No commit or rollback needed if the program never started or if the
@@ -66640,8 +74793,8 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
   }
   p->magic = VDBE_MAGIC_HALT;
   checkActiveVdbeCnt(db);
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
+  if( db->mallocFailed ){
+    p->rc = SQLITE_NOMEM_BKPT;
   }
 
   /* If the auto-commit flag is set to true, then any locks that were held
@@ -66677,16 +74830,16 @@ SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p){
   sqlite3 *db = p->db;
   int rc = p->rc;
   if( p->zErrMsg ){
-    u8 mallocFailed = db->mallocFailed;
+    db->bBenignMalloc++;
     sqlite3BeginBenignMalloc();
     if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
     sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
     sqlite3EndBenignMalloc();
-    db->mallocFailed = mallocFailed;
-    db->errCode = rc;
-  }else{
-    sqlite3Error(db, rc);
+    db->bBenignMalloc--;
+  }else if( db->pErr ){
+    sqlite3ValueSetNull(db->pErr);
   }
+  db->errCode = rc;
   return rc;
 }
 
@@ -66793,8 +74946,7 @@ SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe *p){
     }
   }
 #endif
-  p->iCurrentTime = 0;
-  p->magic = VDBE_MAGIC_INIT;
+  p->magic = VDBE_MAGIC_RESET;
   return p->rc & db->errMask;
 }
  
@@ -66828,21 +74980,22 @@ SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe *p){
 **    * the corresponding bit in argument mask is clear (where the first
 **      function parameter corresponds to bit 0 etc.).
 */
-SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(Vdbe *pVdbe, int iOp, int mask){
-  AuxData **pp = &pVdbe->pAuxData;
+SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3 *db, AuxData **pp, int iOp, int mask){
   while( *pp ){
     AuxData *pAux = *pp;
     if( (iOp<0)
-     || (pAux->iOp==iOp && (pAux->iArg>31 || !(mask & MASKBIT32(pAux->iArg))))
+     || (pAux->iAuxOp==iOp
+          && pAux->iAuxArg>=0
+          && (pAux->iAuxArg>31 || !(mask & MASKBIT32(pAux->iAuxArg))))
     ){
-      testcase( pAux->iArg==31 );
-      if( pAux->xDelete ){
-        pAux->xDelete(pAux->pAux);
+      testcase( pAux->iAuxArg==31 );
+      if( pAux->xDeleteAux ){
+        pAux->xDeleteAux(pAux->pAux);
       }
-      *pp = pAux->pNext;
-      sqlite3DbFree(pVdbe->db, pAux);
+      *pp = pAux->pNextAux;
+      sqlite3DbFree(db, pAux);
     }else{
-      pp= &pAux->pNext;
+      pp= &pAux->pNextAux;
     }
   }
 }
@@ -66857,25 +75010,29 @@ SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(Vdbe *pVdbe, int iOp, int mask){
 */
 SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
   SubProgram *pSub, *pNext;
-  int i;
   assert( p->db==0 || p->db==db );
-  releaseMemArray(p->aVar, p->nVar);
   releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
   for(pSub=p->pProgram; pSub; pSub=pNext){
     pNext = pSub->pNext;
     vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
     sqlite3DbFree(db, pSub);
   }
-  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
+  if( p->magic!=VDBE_MAGIC_INIT ){
+    releaseMemArray(p->aVar, p->nVar);
+    sqlite3DbFree(db, p->pVList);
+    sqlite3DbFree(db, p->pFree);
+  }
   vdbeFreeOpArray(db, p->aOp, p->nOp);
   sqlite3DbFree(db, p->aColName);
   sqlite3DbFree(db, p->zSql);
-  sqlite3DbFree(db, p->pFree);
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-  for(i=0; inScan; i++){
-    sqlite3DbFree(db, p->aScan[i].zName);
+  {
+    int i;
+    for(i=0; inScan; i++){
+      sqlite3DbFree(db, p->aScan[i].zName);
+    }
+    sqlite3DbFree(db, p->aScan);
   }
-  sqlite3DbFree(db, p->aScan);
 #endif
 }
 
@@ -66900,7 +75057,7 @@ SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe *p){
   }
   p->magic = VDBE_MAGIC_DEAD;
   p->db = 0;
-  sqlite3DbFree(db, p);
+  sqlite3DbFreeNN(db, p);
 }
 
 /*
@@ -66915,7 +75072,8 @@ static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
 #endif
   assert( p->deferredMoveto );
   assert( p->isTable );
-  rc = sqlite3BtreeMovetoUnpacked(p->pCursor, 0, p->movetoTarget, 0, &res);
+  assert( p->eCurType==CURTYPE_BTREE );
+  rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);
   if( rc ) return rc;
   if( res!=0 ) return SQLITE_CORRUPT_BKPT;
 #ifdef SQLITE_TEST
@@ -66935,9 +75093,10 @@ static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
 */
 static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
   int isDifferentRow, rc;
-  assert( p->pCursor!=0 );
-  assert( sqlite3BtreeCursorHasMoved(p->pCursor) );
-  rc = sqlite3BtreeCursorRestore(p->pCursor, &isDifferentRow);
+  assert( p->eCurType==CURTYPE_BTREE );
+  assert( p->uc.pCursor!=0 );
+  assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );
+  rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);
   p->cacheStatus = CACHE_STALE;
   if( isDifferentRow ) p->nullRow = 1;
   return rc;
@@ -66948,7 +75107,8 @@ static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
 ** if need be.  Return any I/O error from the restore operation.
 */
 SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor *p){
-  if( sqlite3BtreeCursorHasMoved(p->pCursor) ){
+  assert( p->eCurType==CURTYPE_BTREE );
+  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
     return handleMovedCursor(p);
   }
   return SQLITE_OK;
@@ -66967,12 +75127,21 @@ SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor *p){
 ** If the cursor is already pointing to the correct row and that row has
 ** not been deleted out from under the cursor, then this routine is a no-op.
 */
-SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
-  if( p->deferredMoveto ){
-    return handleDeferredMoveto(p);
-  }
-  if( p->pCursor && sqlite3BtreeCursorHasMoved(p->pCursor) ){
-    return handleMovedCursor(p);
+SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
+  VdbeCursor *p = *pp;
+  if( p->eCurType==CURTYPE_BTREE ){
+    if( p->deferredMoveto ){
+      int iMap;
+      if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){
+        *pp = p->pAltCursor;
+        *piCol = iMap - 1;
+        return SQLITE_OK;
+      }
+      return handleDeferredMoveto(p);
+    }
+    if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
+      return handleMovedCursor(p);
+    }
   }
   return SQLITE_OK;
 }
@@ -67022,11 +75191,13 @@ SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
 /*
 ** Return the serial-type for the value stored in pMem.
 */
-SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
+SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
   int flags = pMem->flags;
   u32 n;
 
+  assert( pLen!=0 );
   if( flags&MEM_Null ){
+    *pLen = 0;
     return 0;
   }
   if( flags&MEM_Int ){
@@ -67040,15 +75211,23 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
       u = i;
     }
     if( u<=127 ){
-      return ((i&1)==i && file_format>=4) ? 8+(u32)u : 1;
+      if( (i&1)==i && file_format>=4 ){
+        *pLen = 0;
+        return 8+(u32)u;
+      }else{
+        *pLen = 1;
+        return 1;
+      }
     }
-    if( u<=32767 ) return 2;
-    if( u<=8388607 ) return 3;
-    if( u<=2147483647 ) return 4;
-    if( u<=MAX_6BYTE ) return 5;
+    if( u<=32767 ){ *pLen = 2; return 2; }
+    if( u<=8388607 ){ *pLen = 3; return 3; }
+    if( u<=2147483647 ){ *pLen = 4; return 4; }
+    if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }
+    *pLen = 8;
     return 6;
   }
   if( flags&MEM_Real ){
+    *pLen = 8;
     return 7;
   }
   assert( pMem->db->mallocFailed || flags&(MEM_Str|MEM_Blob) );
@@ -67057,20 +75236,46 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
   if( flags & MEM_Zero ){
     n += pMem->u.nZero;
   }
+  *pLen = n;
   return ((n*2) + 12 + ((flags&MEM_Str)!=0));
 }
 
+/*
+** The sizes for serial types less than 128
+*/
+static const u8 sqlite3SmallTypeSizes[] = {
+        /*  0   1   2   3   4   5   6   7   8   9 */   
+/*   0 */   0,  1,  2,  3,  4,  6,  8,  8,  0,  0,
+/*  10 */   0,  0,  0,  0,  1,  1,  2,  2,  3,  3,
+/*  20 */   4,  4,  5,  5,  6,  6,  7,  7,  8,  8,
+/*  30 */   9,  9, 10, 10, 11, 11, 12, 12, 13, 13,
+/*  40 */  14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
+/*  50 */  19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
+/*  60 */  24, 24, 25, 25, 26, 26, 27, 27, 28, 28,
+/*  70 */  29, 29, 30, 30, 31, 31, 32, 32, 33, 33,
+/*  80 */  34, 34, 35, 35, 36, 36, 37, 37, 38, 38,
+/*  90 */  39, 39, 40, 40, 41, 41, 42, 42, 43, 43,
+/* 100 */  44, 44, 45, 45, 46, 46, 47, 47, 48, 48,
+/* 110 */  49, 49, 50, 50, 51, 51, 52, 52, 53, 53,
+/* 120 */  54, 54, 55, 55, 56, 56, 57, 57
+};
+
 /*
 ** Return the length of the data corresponding to the supplied serial-type.
 */
 SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
-  if( serial_type>=12 ){
+  if( serial_type>=128 ){
     return (serial_type-12)/2;
   }else{
-    static const u8 aSize[] = { 0, 1, 2, 3, 4, 6, 8, 8, 0, 0, 0, 0 };
-    return aSize[serial_type];
+    assert( serial_type<12 
+            || sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );
+    return sqlite3SmallTypeSizes[serial_type];
   }
 }
+SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){
+  assert( serial_type<128 );
+  return sqlite3SmallTypeSizes[serial_type];  
+}
 
 /*
 ** If we are on an architecture with mixed-endian floating 
@@ -67152,7 +75357,7 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
     }else{
       v = pMem->u.i;
     }
-    len = i = sqlite3VdbeSerialTypeLen(serial_type);
+    len = i = sqlite3SmallTypeSizes[serial_type];
     assert( i>0 );
     do{
       buf[--i] = (u8)(v&0xFF);
@@ -67166,7 +75371,7 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
     assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
              == (int)sqlite3VdbeSerialTypeLen(serial_type) );
     len = pMem->n;
-    memcpy(buf, pMem->z, len);
+    if( len>0 ) memcpy(buf, pMem->z, len);
     return len;
   }
 
@@ -67269,6 +75474,10 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(
       /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit
       ** twos-complement integer. */
       pMem->u.i = FOUR_BYTE_INT(buf);
+#ifdef __HP_cc 
+      /* Work around a sign-extension bug in the HP compiler for HP/UX */
+      if( buf[0]&0x80 ) pMem->u.i |= 0xffffffff80000000LL;
+#endif
       pMem->flags = MEM_Int;
       testcase( pMem->u.i<0 );
       return 4;
@@ -67324,30 +75533,13 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(
 ** If an OOM error occurs, NULL is returned.
 */
 SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(
-  KeyInfo *pKeyInfo,              /* Description of the record */
-  char *pSpace,                   /* Unaligned space available */
-  int szSpace,                    /* Size of pSpace[] in bytes */
-  char **ppFree                   /* OUT: Caller should free this pointer */
+  KeyInfo *pKeyInfo               /* Description of the record */
 ){
   UnpackedRecord *p;              /* Unpacked record to return */
-  int nOff;                       /* Increment pSpace by nOff to align it */
   int nByte;                      /* Number of bytes required for *p */
-
-  /* We want to shift the pointer pSpace up such that it is 8-byte aligned.
-  ** Thus, we need to calculate a value, nOff, between 0 and 7, to shift 
-  ** it by.  If pSpace is already 8-byte aligned, nOff should be zero.
-  */
-  nOff = (8 - (SQLITE_PTR_TO_INT(pSpace) & 7)) & 7;
   nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
-  if( nByte>szSpace+nOff ){
-    p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
-    *ppFree = (char *)p;
-    if( !p ) return 0;
-  }else{
-    p = (UnpackedRecord*)&pSpace[nOff];
-    *ppFree = 0;
-  }
-
+  p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
+  if( !p ) return 0;
   p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
   assert( pKeyInfo->aSortOrder!=0 );
   p->pKeyInfo = pKeyInfo;
@@ -67386,6 +75578,7 @@ SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(
     pMem->db = pKeyInfo->db;
     /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
     pMem->szMalloc = 0;
+    pMem->z = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
     if( (++u)>=p->nField ) break;
@@ -67394,7 +75587,7 @@ SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(
   p->nField = u;
 }
 
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
 /*
 ** This function compares two index or table record keys in the same way
 ** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),
@@ -67437,6 +75630,7 @@ static int vdbeRecordCompareDebug(
   /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */
   
   idx1 = getVarint32(aKey1, szHdr1);
+  if( szHdr1>98307 ) return SQLITE_CORRUPT;
   d1 = szHdr1;
   assert( pKeyInfo->nField+pKeyInfo->nXField>=pPKey2->nField || CORRUPT_DB );
   assert( pKeyInfo->aSortOrder!=0 );
@@ -67498,7 +75692,7 @@ debugCompareEnd:
 }
 #endif
 
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
 /*
 ** Count the number of fields (a.k.a. columns) in the record given by
 ** pKey,nKey.  The verify that this count is less than or equal to the
@@ -67522,7 +75716,8 @@ static void vdbeAssertFieldCountWithinLimits(
 
   if( CORRUPT_DB ) return;
   idx = getVarint32(aKey, szHdr);
-  assert( szHdr<=nKey );
+  assert( nKey>=0 );
+  assert( szHdr<=(u32)nKey );
   while( idxdb, MEM_Null);
@@ -67560,28 +75754,92 @@ static int vdbeCompareMemString(
     sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
     sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
     v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
-    n1 = v1==0 ? 0 : c1.n;
     v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
-    n2 = v2==0 ? 0 : c2.n;
-    rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
+    if( (v1==0 || v2==0) ){
+      if( prcErr ) *prcErr = SQLITE_NOMEM_BKPT;
+      rc = 0;
+    }else{
+      rc = pColl->xCmp(pColl->pUser, c1.n, v1, c2.n, v2);
+    }
     sqlite3VdbeMemRelease(&c1);
     sqlite3VdbeMemRelease(&c2);
-    if( (v1==0 || v2==0) && prcErr ) *prcErr = SQLITE_NOMEM;
     return rc;
   }
 }
 
+/*
+** The input pBlob is guaranteed to be a Blob that is not marked
+** with MEM_Zero.  Return true if it could be a zero-blob.
+*/
+static int isAllZero(const char *z, int n){
+  int i;
+  for(i=0; iz, pB2->z, pB1->n>pB2->n ? pB2->n : pB1->n);
+  int c;
+  int n1 = pB1->n;
+  int n2 = pB2->n;
+
+  /* It is possible to have a Blob value that has some non-zero content
+  ** followed by zero content.  But that only comes up for Blobs formed
+  ** by the OP_MakeRecord opcode, and such Blobs never get passed into
+  ** sqlite3MemCompare(). */
+  assert( (pB1->flags & MEM_Zero)==0 || n1==0 );
+  assert( (pB2->flags & MEM_Zero)==0 || n2==0 );
+
+  if( (pB1->flags|pB2->flags) & MEM_Zero ){
+    if( pB1->flags & pB2->flags & MEM_Zero ){
+      return pB1->u.nZero - pB2->u.nZero;
+    }else if( pB1->flags & MEM_Zero ){
+      if( !isAllZero(pB2->z, pB2->n) ) return -1;
+      return pB1->u.nZero - n2;
+    }else{
+      if( !isAllZero(pB1->z, pB1->n) ) return +1;
+      return n1 - pB2->u.nZero;
+    }
+  }
+  c = memcmp(pB1->z, pB2->z, n1>n2 ? n2 : n1);
   if( c ) return c;
-  return pB1->n - pB2->n;
+  return n1 - n2;
 }
 
+/*
+** Do a comparison between a 64-bit signed integer and a 64-bit floating-point
+** number.  Return negative, zero, or positive if the first (i64) is less than,
+** equal to, or greater than the second (double).
+*/
+static int sqlite3IntFloatCompare(i64 i, double r){
+  if( sizeof(LONGDOUBLE_TYPE)>8 ){
+    LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
+    if( xr ) return +1;
+    return 0;
+  }else{
+    i64 y;
+    double s;
+    if( r<-9223372036854775808.0 ) return +1;
+    if( r>9223372036854775807.0 ) return -1;
+    y = (i64)r;
+    if( iy ){
+      if( y==SMALLEST_INT64 && r>0.0 ) return -1;
+      return +1;
+    }
+    s = (double)i;
+    if( sr ) return +1;
+    return 0;
+  }
+}
 
 /*
 ** Compare the values contained by the two memory cells, returning
@@ -67608,34 +75866,34 @@ SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const C
     return (f2&MEM_Null) - (f1&MEM_Null);
   }
 
-  /* If one value is a number and the other is not, the number is less.
-  ** If both are numbers, compare as reals if one is a real, or as integers
-  ** if both values are integers.
+  /* At least one of the two values is a number
   */
   if( combined_flags&(MEM_Int|MEM_Real) ){
-    double r1, r2;
     if( (f1 & f2 & MEM_Int)!=0 ){
       if( pMem1->u.i < pMem2->u.i ) return -1;
-      if( pMem1->u.i > pMem2->u.i ) return 1;
+      if( pMem1->u.i > pMem2->u.i ) return +1;
       return 0;
     }
-    if( (f1&MEM_Real)!=0 ){
-      r1 = pMem1->u.r;
-    }else if( (f1&MEM_Int)!=0 ){
-      r1 = (double)pMem1->u.i;
-    }else{
-      return 1;
+    if( (f1 & f2 & MEM_Real)!=0 ){
+      if( pMem1->u.r < pMem2->u.r ) return -1;
+      if( pMem1->u.r > pMem2->u.r ) return +1;
+      return 0;
     }
-    if( (f2&MEM_Real)!=0 ){
-      r2 = pMem2->u.r;
-    }else if( (f2&MEM_Int)!=0 ){
-      r2 = (double)pMem2->u.i;
-    }else{
-      return -1;
+    if( (f1&MEM_Int)!=0 ){
+      if( (f2&MEM_Real)!=0 ){
+        return sqlite3IntFloatCompare(pMem1->u.i, pMem2->u.r);
+      }else{
+        return -1;
+      }
     }
-    if( r1r2 ) return 1;
-    return 0;
+    if( (f1&MEM_Real)!=0 ){
+      if( (f2&MEM_Int)!=0 ){
+        return -sqlite3IntFloatCompare(pMem2->u.i, pMem1->u.r);
+      }else{
+        return -1;
+      }
+    }
+    return +1;
   }
 
   /* If one value is a string and the other is a blob, the string is less.
@@ -67649,7 +75907,7 @@ SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const C
       return -1;
     }
 
-    assert( pMem1->enc==pMem2->enc );
+    assert( pMem1->enc==pMem2->enc || pMem1->db->mallocFailed );
     assert( pMem1->enc==SQLITE_UTF8 || 
             pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
 
@@ -67733,7 +75991,7 @@ static i64 vdbeRecordDecodeInt(u32 serial_type, const u8 *aKey){
 ** pPKey2->errCode is set to SQLITE_NOMEM and, if it is not NULL, the
 ** malloc-failed flag set on database handle (pPKey2->pKeyInfo->db).
 */
-static int vdbeRecordCompareWithSkip(
+SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(
   int nKey1, const void *pKey1,   /* Left key */
   UnpackedRecord *pPKey2,         /* Right key */
   int bSkip                       /* If true, skip the first field */
@@ -67781,18 +76039,13 @@ static int vdbeRecordCompareWithSkip(
     if( pRhs->flags & MEM_Int ){
       serial_type = aKey1[idx1];
       testcase( serial_type==12 );
-      if( serial_type>=12 ){
+      if( serial_type>=10 ){
         rc = +1;
       }else if( serial_type==0 ){
         rc = -1;
       }else if( serial_type==7 ){
-        double rhs = (double)pRhs->u.i;
         sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
-        if( mem1.u.rrhs ){
-          rc = +1;
-        }
+        rc = -sqlite3IntFloatCompare(pRhs->u.i, mem1.u.r);
       }else{
         i64 lhs = vdbeRecordDecodeInt(serial_type, &aKey1[d1]);
         i64 rhs = pRhs->u.i;
@@ -67807,23 +76060,24 @@ static int vdbeRecordCompareWithSkip(
     /* RHS is real */
     else if( pRhs->flags & MEM_Real ){
       serial_type = aKey1[idx1];
-      if( serial_type>=12 ){
+      if( serial_type>=10 ){
+        /* Serial types 12 or greater are strings and blobs (greater than
+        ** numbers). Types 10 and 11 are currently "reserved for future 
+        ** use", so it doesn't really matter what the results of comparing
+        ** them to numberic values are.  */
         rc = +1;
       }else if( serial_type==0 ){
         rc = -1;
       }else{
-        double rhs = pRhs->u.r;
-        double lhs;
         sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
         if( serial_type==7 ){
-          lhs = mem1.u.r;
+          if( mem1.u.ru.r ){
+            rc = -1;
+          }else if( mem1.u.r>pRhs->u.r ){
+            rc = +1;
+          }
         }else{
-          lhs = (double)mem1.u.i;
-        }
-        if( lhsrhs ){
-          rc = +1;
+          rc = sqlite3IntFloatCompare(mem1.u.i, pRhs->u.r);
         }
       }
     }
@@ -67861,6 +76115,7 @@ static int vdbeRecordCompareWithSkip(
 
     /* RHS is a blob */
     else if( pRhs->flags & MEM_Blob ){
+      assert( (pRhs->flags & MEM_Zero)==0 || pRhs->n==0 );
       getVarint32(&aKey1[idx1], serial_type);
       testcase( serial_type==12 );
       if( serial_type<12 || (serial_type & 0x01) ){
@@ -67872,6 +76127,12 @@ static int vdbeRecordCompareWithSkip(
         if( (d1+nStr) > (unsigned)nKey1 ){
           pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
           return 0;                /* Corruption */
+        }else if( pRhs->flags & MEM_Zero ){
+          if( !isAllZero((const char*)&aKey1[d1],nStr) ){
+            rc = 1;
+          }else{
+            rc = nStr - pRhs->u.nZero;
+          }
         }else{
           int nCmp = MIN(nStr, pRhs->n);
           rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
@@ -67913,13 +76174,14 @@ static int vdbeRecordCompareWithSkip(
        || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc) 
        || pKeyInfo->db->mallocFailed
   );
+  pPKey2->eqSeen = 1;
   return pPKey2->default_rc;
 }
 SQLITE_PRIVATE int sqlite3VdbeRecordCompare(
   int nKey1, const void *pKey1,   /* Left key */
   UnpackedRecord *pPKey2          /* Right key */
 ){
-  return vdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);
+  return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);
 }
 
 
@@ -67941,7 +76203,7 @@ static int vdbeRecordCompareInt(
   int res;
   u32 y;
   u64 x;
-  i64 v = pPKey2->aMem[0].u.i;
+  i64 v;
   i64 lhs;
 
   vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
@@ -68000,6 +76262,7 @@ static int vdbeRecordCompareInt(
       return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
   }
 
+  v = pPKey2->aMem[0].u.i;
   if( v>lhs ){
     res = pPKey2->r1;
   }else if( vnField>1 ){
     /* The first fields of the two keys are equal. Compare the trailing 
     ** fields.  */
-    res = vdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
+    res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
   }else{
     /* The first fields of the two keys are equal and there are no trailing
     ** fields. Return pPKey2->default_rc in this case. */
     res = pPKey2->default_rc;
+    pPKey2->eqSeen = 1;
   }
 
   assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res) );
@@ -68032,6 +76296,7 @@ static int vdbeRecordCompareString(
   int serial_type;
   int res;
 
+  assert( pPKey2->aMem[0].flags & MEM_Str );
   vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
   getVarint32(&aKey1[1], serial_type);
   if( serial_type<12 ){
@@ -68055,9 +76320,10 @@ static int vdbeRecordCompareString(
       res = nStr - pPKey2->aMem[0].n;
       if( res==0 ){
         if( pPKey2->nField>1 ){
-          res = vdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
+          res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
         }else{
           res = pPKey2->default_rc;
+          pPKey2->eqSeen = 1;
         }
       }else if( res>0 ){
         res = pPKey2->r2;
@@ -68143,13 +76409,12 @@ SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
   ** this code can safely assume that nCellKey is 32-bits  
   */
   assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );     /* pCur is always valid so KeySize cannot fail */
+  nCellKey = sqlite3BtreePayloadSize(pCur);
   assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );
 
   /* Read in the complete content of the index entry */
   sqlite3VdbeMemInit(&m, db, 0);
-  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
+  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);
   if( rc ){
     return rc;
   }
@@ -68176,7 +76441,7 @@ SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
   if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){
     goto idx_rowid_corruption;
   }
-  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
+  lenRowid = sqlite3SmallTypeSizes[typeRowid];
   testcase( (u32)m.n==szHdr+lenRowid );
   if( unlikely((u32)m.npCursor;
+  BtCursor *pCur;
   Mem m;
 
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCur = pC->uc.pCursor;
   assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
+  nCellKey = sqlite3BtreePayloadSize(pCur);
   /* nCellKey will always be between 0 and 0xffffffff because of the way
   ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
   if( nCellKey<=0 || nCellKey>0x7fffffff ){
@@ -68228,7 +76494,7 @@ SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(
     return SQLITE_CORRUPT_BKPT;
   }
   sqlite3VdbeMemInit(&m, db, 0);
-  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (u32)nCellKey, 1, &m);
+  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);
   if( rc ){
     return rc;
   }
@@ -68279,6 +76545,13 @@ SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe *v){
   return v->db;
 }
 
+/*
+** Return the SQLITE_PREPARE flags for a Vdbe.
+*/
+SQLITE_PRIVATE u8 sqlite3VdbePrepareFlags(Vdbe *v){
+  return v->prepFlags;
+}
+
 /*
 ** Return a pointer to an sqlite3_value structure containing the value bound
 ** parameter iVar of VM v. Except, if the value is an SQL NULL, return 
@@ -68291,6 +76564,7 @@ SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff
   assert( iVar>0 );
   if( v ){
     Mem *pMem = &v->aVar[iVar-1];
+    assert( (v->db->flags & SQLITE_EnableQPSG)==0 );
     if( 0==(pMem->flags & MEM_Null) ){
       sqlite3_value *pRet = sqlite3ValueNew(v->db);
       if( pRet ){
@@ -68310,13 +76584,36 @@ SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff
 */
 SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
   assert( iVar>0 );
-  if( iVar>32 ){
-    v->expmask = 0xffffffff;
+  assert( (v->db->flags & SQLITE_EnableQPSG)==0 );
+  if( iVar>=32 ){
+    v->expmask |= 0x80000000;
   }else{
     v->expmask |= ((u32)1 << (iVar-1));
   }
 }
 
+/*
+** Cause a function to throw an error if it was call from OP_PureFunc
+** rather than OP_Function.
+**
+** OP_PureFunc means that the function must be deterministic, and should
+** throw an error if it is given inputs that would make it non-deterministic.
+** This routine is invoked by date/time functions that use non-deterministic
+** features such as 'now'.
+*/
+SQLITE_PRIVATE int sqlite3NotPureFunc(sqlite3_context *pCtx){
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pCtx->pVdbe==0 ) return 1;
+#endif
+  if( pCtx->pVdbe->aOp[pCtx->iOp].opcode==OP_PureFunc ){
+    sqlite3_result_error(pCtx, 
+       "non-deterministic function in index expression or CHECK constraint",
+       -1);
+    return 0;
+  }
+  return 1;
+}
+
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
 ** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
@@ -68324,14 +76621,105 @@ SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
 ** in memory obtained from sqlite3DbMalloc).
 */
 SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
-  sqlite3 *db = p->db;
-  sqlite3DbFree(db, p->zErrMsg);
-  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-  sqlite3_free(pVtab->zErrMsg);
-  pVtab->zErrMsg = 0;
+  if( pVtab->zErrMsg ){
+    sqlite3 *db = p->db;
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
+    sqlite3_free(pVtab->zErrMsg);
+    pVtab->zErrMsg = 0;
+  }
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+
+/*
+** If the second argument is not NULL, release any allocations associated 
+** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord
+** structure itself, using sqlite3DbFree().
+**
+** This function is used to free UnpackedRecord structures allocated by
+** the vdbeUnpackRecord() function found in vdbeapi.c.
+*/
+static void vdbeFreeUnpacked(sqlite3 *db, int nField, UnpackedRecord *p){
+  if( p ){
+    int i;
+    for(i=0; iaMem[i];
+      if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);
+    }
+    sqlite3DbFreeNN(db, p);
+  }
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Invoke the pre-update hook. If this is an UPDATE or DELETE pre-update call,
+** then cursor passed as the second argument should point to the row about
+** to be update or deleted. If the application calls sqlite3_preupdate_old(),
+** the required value will be read from the row the cursor points to.
+*/
+SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(
+  Vdbe *v,                        /* Vdbe pre-update hook is invoked by */
+  VdbeCursor *pCsr,               /* Cursor to grab old.* values from */
+  int op,                         /* SQLITE_INSERT, UPDATE or DELETE */
+  const char *zDb,                /* Database name */
+  Table *pTab,                    /* Modified table */
+  i64 iKey1,                      /* Initial key value */
+  int iReg                        /* Register for new.* record */
+){
+  sqlite3 *db = v->db;
+  i64 iKey2;
+  PreUpdate preupdate;
+  const char *zTbl = pTab->zName;
+  static const u8 fakeSortOrder = 0;
+
+  assert( db->pPreUpdate==0 );
+  memset(&preupdate, 0, sizeof(PreUpdate));
+  if( HasRowid(pTab)==0 ){
+    iKey1 = iKey2 = 0;
+    preupdate.pPk = sqlite3PrimaryKeyIndex(pTab);
+  }else{
+    if( op==SQLITE_UPDATE ){
+      iKey2 = v->aMem[iReg].u.i;
+    }else{
+      iKey2 = iKey1;
+    }
+  }
+
+  assert( pCsr->nField==pTab->nCol 
+       || (pCsr->nField==pTab->nCol+1 && op==SQLITE_DELETE && iReg==-1)
+  );
+
+  preupdate.v = v;
+  preupdate.pCsr = pCsr;
+  preupdate.op = op;
+  preupdate.iNewReg = iReg;
+  preupdate.keyinfo.db = db;
+  preupdate.keyinfo.enc = ENC(db);
+  preupdate.keyinfo.nField = pTab->nCol;
+  preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
+  preupdate.iKey1 = iKey1;
+  preupdate.iKey2 = iKey2;
+  preupdate.pTab = pTab;
+
+  db->pPreUpdate = &preupdate;
+  db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
+  db->pPreUpdate = 0;
+  sqlite3DbFree(db, preupdate.aRecord);
+  vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pUnpacked);
+  vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pNewUnpacked);
+  if( preupdate.aNew ){
+    int i;
+    for(i=0; inField; i++){
+      sqlite3VdbeMemRelease(&preupdate.aNew[i]);
+    }
+    sqlite3DbFreeNN(db, preupdate.aNew);
+  }
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 /************** End of vdbeaux.c *********************************************/
 /************** Begin file vdbeapi.c *****************************************/
 /*
@@ -68349,6 +76737,8 @@ SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
 ** This file contains code use to implement APIs that are part of the
 ** VDBE.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
@@ -68387,6 +76777,38 @@ static int vdbeSafetyNotNull(Vdbe *p){
   }
 }
 
+#ifndef SQLITE_OMIT_TRACE
+/*
+** Invoke the profile callback.  This routine is only called if we already
+** know that the profile callback is defined and needs to be invoked.
+*/
+static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
+  sqlite3_int64 iNow;
+  sqlite3_int64 iElapse;
+  assert( p->startTime>0 );
+  assert( db->xProfile!=0 || (db->mTrace & SQLITE_TRACE_PROFILE)!=0 );
+  assert( db->init.busy==0 );
+  assert( p->zSql!=0 );
+  sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
+  iElapse = (iNow - p->startTime)*1000000;
+  if( db->xProfile ){
+    db->xProfile(db->pProfileArg, p->zSql, iElapse);
+  }
+  if( db->mTrace & SQLITE_TRACE_PROFILE ){
+    db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
+  }
+  p->startTime = 0;
+}
+/*
+** The checkProfileCallback(DB,P) macro checks to see if a profile callback
+** is needed, and it invokes the callback if it is needed.
+*/
+# define checkProfileCallback(DB,P) \
+   if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }
+#else
+# define checkProfileCallback(DB,P)  /*no-op*/
+#endif
+
 /*
 ** The following routine destroys a virtual machine that is created by
 ** the sqlite3_compile() routine. The integer returned is an SQLITE_
@@ -68407,6 +76829,7 @@ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt){
     sqlite3 *db = v->db;
     if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;
     sqlite3_mutex_enter(db->mutex);
+    checkProfileCallback(db, v);
     rc = sqlite3VdbeFinalize(v);
     rc = sqlite3ApiExit(db, rc);
     sqlite3LeaveMutexAndCloseZombie(db);
@@ -68428,12 +76851,14 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt){
     rc = SQLITE_OK;
   }else{
     Vdbe *v = (Vdbe*)pStmt;
-    sqlite3_mutex_enter(v->db->mutex);
+    sqlite3 *db = v->db;
+    sqlite3_mutex_enter(db->mutex);
+    checkProfileCallback(db, v);
     rc = sqlite3VdbeReset(v);
     sqlite3VdbeRewind(v);
-    assert( (rc & (v->db->errMask))==rc );
-    rc = sqlite3ApiExit(v->db, rc);
-    sqlite3_mutex_leave(v->db->mutex);
+    assert( (rc & (db->errMask))==rc );
+    rc = sqlite3ApiExit(db, rc);
+    sqlite3_mutex_leave(db->mutex);
   }
   return rc;
 }
@@ -68453,7 +76878,8 @@ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
     sqlite3VdbeMemRelease(&p->aVar[i]);
     p->aVar[i].flags = MEM_Null;
   }
-  if( p->isPrepareV2 && p->expmask ){
+  assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
+  if( p->expmask ){
     p->expired = 1;
   }
   sqlite3_mutex_leave(mutex);
@@ -68468,7 +76894,10 @@ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
 SQLITE_API const void *sqlite3_value_blob(sqlite3_value *pVal){
   Mem *p = (Mem*)pVal;
   if( p->flags & (MEM_Blob|MEM_Str) ){
-    sqlite3VdbeMemExpandBlob(p);
+    if( ExpandBlob(p)!=SQLITE_OK ){
+      assert( p->flags==MEM_Null && p->z==0 );
+      return 0;
+    }
     p->flags |= MEM_Blob;
     return p->n ? p->z : 0;
   }else{
@@ -68490,6 +76919,23 @@ SQLITE_API int sqlite3_value_int(sqlite3_value *pVal){
 SQLITE_API sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
   return sqlite3VdbeIntValue((Mem*)pVal);
 }
+SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
+  Mem *pMem = (Mem*)pVal;
+  return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
+}
+SQLITE_API void *sqlite3_value_pointer(sqlite3_value *pVal, const char *zPType){
+  Mem *p = (Mem*)pVal;
+  if( (p->flags&(MEM_TypeMask|MEM_Term|MEM_Subtype)) ==
+                 (MEM_Null|MEM_Term|MEM_Subtype)
+   && zPType!=0
+   && p->eSubtype=='p'
+   && strcmp(p->u.zPType, zPType)==0
+  ){
+    return (void*)p->z;
+  }else{
+    return 0;
+  }
+}
 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
 }
@@ -68504,6 +76950,10 @@ SQLITE_API const void *sqlite3_value_text16le(sqlite3_value *pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16LE);
 }
 #endif /* SQLITE_OMIT_UTF16 */
+/* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five
+** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating
+** point number string BLOB NULL
+*/
 SQLITE_API int sqlite3_value_type(sqlite3_value* pVal){
   static const u8 aType[] = {
      SQLITE_BLOB,     /* 0x00 */
@@ -68542,6 +76992,36 @@ SQLITE_API int sqlite3_value_type(sqlite3_value* pVal){
   return aType[pVal->flags&MEM_AffMask];
 }
 
+/* Make a copy of an sqlite3_value object
+*/
+SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){
+  sqlite3_value *pNew;
+  if( pOrig==0 ) return 0;
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return 0;
+  memset(pNew, 0, sizeof(*pNew));
+  memcpy(pNew, pOrig, MEMCELLSIZE);
+  pNew->flags &= ~MEM_Dyn;
+  pNew->db = 0;
+  if( pNew->flags&(MEM_Str|MEM_Blob) ){
+    pNew->flags &= ~(MEM_Static|MEM_Dyn);
+    pNew->flags |= MEM_Ephem;
+    if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){
+      sqlite3ValueFree(pNew);
+      pNew = 0;
+    }
+  }
+  return pNew;
+}
+
+/* Destroy an sqlite3_value object previously obtained from
+** sqlite3_value_dup().
+*/
+SQLITE_API void sqlite3_value_free(sqlite3_value *pOld){
+  sqlite3ValueFree(pOld);
+}
+  
+
 /**************************** sqlite3_result_  *******************************
 ** The following routines are used by user-defined functions to specify
 ** the function result.
@@ -68634,6 +77114,24 @@ SQLITE_API void sqlite3_result_null(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetNull(pCtx->pOut);
 }
+SQLITE_API void sqlite3_result_pointer(
+  sqlite3_context *pCtx,
+  void *pPtr,
+  const char *zPType,
+  void (*xDestructor)(void*)
+){
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  sqlite3VdbeMemRelease(pOut);
+  pOut->flags = MEM_Null;
+  sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);
+}
+SQLITE_API void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  pOut->eSubtype = eSubtype & 0xff;
+  pOut->flags |= MEM_Subtype;
+}
 SQLITE_API void sqlite3_result_text(
   sqlite3_context *pCtx, 
   const char *z, 
@@ -68696,9 +77194,21 @@ SQLITE_API void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, n);
 }
+SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    return SQLITE_TOOBIG;
+  }
+  sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
+  return SQLITE_OK;
+}
 SQLITE_API void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
   pCtx->isError = errCode;
   pCtx->fErrorOrAux = 1;
+#ifdef SQLITE_DEBUG
+  if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
+#endif
   if( pCtx->pOut->flags & MEM_Null ){
     sqlite3VdbeMemSetStr(pCtx->pOut, sqlite3ErrStr(errCode), -1, 
                          SQLITE_UTF8, SQLITE_STATIC);
@@ -68718,9 +77228,9 @@ SQLITE_API void sqlite3_result_error_toobig(sqlite3_context *pCtx){
 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   sqlite3VdbeMemSetNull(pCtx->pOut);
-  pCtx->isError = SQLITE_NOMEM;
+  pCtx->isError = SQLITE_NOMEM_BKPT;
   pCtx->fErrorOrAux = 1;
-  pCtx->pOut->db->mallocFailed = 1;
+  sqlite3OomFault(pCtx->pOut->db);
 }
 
 /*
@@ -68739,7 +77249,7 @@ static int doWalCallbacks(sqlite3 *db){
       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
       sqlite3BtreeLeave(pBt);
       if( db->xWalCallback && nEntry>0 && rc==SQLITE_OK ){
-        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zName, nEntry);
+        rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
       }
     }
   }
@@ -68747,6 +77257,7 @@ static int doWalCallbacks(sqlite3 *db){
   return rc;
 }
 
+
 /*
 ** Execute the statement pStmt, either until a row of data is ready, the
 ** statement is completely executed or an error occurs.
@@ -68779,7 +77290,7 @@ static int sqlite3Step(Vdbe *p){
     ** or SQLITE_BUSY error.
     */
 #ifdef SQLITE_OMIT_AUTORESET
-    if( p->rc==SQLITE_BUSY || p->rc==SQLITE_LOCKED ){
+    if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
       sqlite3_reset((sqlite3_stmt*)p);
     }else{
       return SQLITE_MISUSE_BKPT;
@@ -68793,7 +77304,7 @@ static int sqlite3Step(Vdbe *p){
   db = p->db;
   if( db->mallocFailed ){
     p->rc = SQLITE_NOMEM;
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   if( p->pc<=0 && p->expired ){
@@ -68815,8 +77326,11 @@ static int sqlite3Step(Vdbe *p){
     );
 
 #ifndef SQLITE_OMIT_TRACE
-    if( db->xProfile && !db->init.busy ){
+    if( (db->xProfile || (db->mTrace & SQLITE_TRACE_PROFILE)!=0)
+        && !db->init.busy && p->zSql ){
       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
+    }else{
+      assert( p->startTime==0 );
     }
 #endif
 
@@ -68825,6 +77339,9 @@ static int sqlite3Step(Vdbe *p){
     if( p->bIsReader ) db->nVdbeRead++;
     p->pc = 0;
   }
+#ifdef SQLITE_DEBUG
+  p->rcApp = SQLITE_OK;
+#endif
 #ifndef SQLITE_OMIT_EXPLAIN
   if( p->explain ){
     rc = sqlite3VdbeList(p);
@@ -68837,13 +77354,8 @@ static int sqlite3Step(Vdbe *p){
   }
 
 #ifndef SQLITE_OMIT_TRACE
-  /* Invoke the profile callback if there is one
-  */
-  if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy && p->zSql ){
-    sqlite3_int64 iNow;
-    sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
-    db->xProfile(db->pProfileArg, p->zSql, (iNow - p->startTime)*1000000);
-  }
+  /* If the statement completed successfully, invoke the profile callback */
+  if( rc!=SQLITE_ROW ) checkProfileCallback(db, p);
 #endif
 
   if( rc==SQLITE_DONE ){
@@ -68856,7 +77368,7 @@ static int sqlite3Step(Vdbe *p){
 
   db->errCode = rc;
   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
-    p->rc = SQLITE_NOMEM;
+    p->rc = SQLITE_NOMEM_BKPT;
   }
 end_of_step:
   /* At this point local variable rc holds the value that should be 
@@ -68867,11 +77379,14 @@ end_of_step:
   ** were called on statement p.
   */
   assert( rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR 
-       || rc==SQLITE_BUSY || rc==SQLITE_MISUSE
+       || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
   );
-  assert( p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE );
-  if( p->isPrepareV2 && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
-    /* If this statement was prepared using sqlite3_prepare_v2(), and an
+  assert( (p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE) || p->rc==p->rcApp );
+  if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 
+   && rc!=SQLITE_ROW 
+   && rc!=SQLITE_DONE 
+  ){
+    /* If this statement was prepared using saved SQL and an 
     ** error has occurred, then return the error code in p->rc to the
     ** caller. Set the error code in the database handle to the same value.
     */ 
@@ -68923,7 +77438,7 @@ SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){
       v->rc = rc2;
     } else {
       v->zErrMsg = 0;
-      v->rc = rc = SQLITE_NOMEM;
+      v->rc = rc = SQLITE_NOMEM_BKPT;
     }
   }
   rc = sqlite3ApiExit(db, rc);
@@ -68952,21 +77467,31 @@ SQLITE_API void *sqlite3_user_data(sqlite3_context *p){
 ** application defined function.
 */
 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
-  assert( p && p->pFunc );
+  assert( p && p->pOut );
   return p->pOut->db;
 }
 
 /*
-** Return the current time for a statement
+** Return the current time for a statement.  If the current time
+** is requested more than once within the same run of a single prepared
+** statement, the exact same time is returned for each invocation regardless
+** of the amount of time that elapses between invocations.  In other words,
+** the time returned is always the time of the first call.
 */
 SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
-  Vdbe *v = p->pVdbe;
   int rc;
-  if( v->iCurrentTime==0 ){
-    rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, &v->iCurrentTime);
-    if( rc ) v->iCurrentTime = 0;
+#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
+  sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
+  assert( p->pVdbe!=0 );
+#else
+  sqlite3_int64 iTime = 0;
+  sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
+#endif
+  if( *piTime==0 ){
+    rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
+    if( rc ) *piTime = 0;
   }
-  return v->iCurrentTime;
+  return *piTime;
 }
 
 /*
@@ -69018,7 +77543,7 @@ static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
 ** same context that was returned on prior calls.
 */
 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
-  assert( p && p->pFunc && p->pFunc->xStep );
+  assert( p && p->pFunc && p->pFunc->xFinalize );
   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
   testcase( nByte<0 );
   if( (p->pMem->flags & MEM_Agg)==0 ){
@@ -69031,22 +77556,40 @@ SQLITE_API void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
 /*
 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
 ** the user-function defined by pCtx.
+**
+** The left-most argument is 0.
+**
+** Undocumented behavior:  If iArg is negative then access a cache of
+** auxiliary data pointers that is available to all functions within a
+** single prepared statement.  The iArg values must match.
 */
 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
   AuxData *pAuxData;
 
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
-  for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
-    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
+#if SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pCtx->pVdbe==0 ) return 0;
+#else
+  assert( pCtx->pVdbe!=0 );
+#endif
+  for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
+    if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
+      return pAuxData->pAux;
+    }
   }
-
-  return (pAuxData ? pAuxData->pAux : 0);
+  return 0;
 }
 
 /*
 ** Set the auxiliary data pointer and delete function, for the iArg'th
 ** argument to the user-function defined by pCtx. Any previous value is
 ** deleted by calling the delete function specified when it was set.
+**
+** The left-most argument is 0.
+**
+** Undocumented behavior:  If iArg is negative then make the data available
+** to all functions within the current prepared statement using iArg as an
+** access code.
 */
 SQLITE_API void sqlite3_set_auxdata(
   sqlite3_context *pCtx, 
@@ -69058,28 +77601,34 @@ SQLITE_API void sqlite3_set_auxdata(
   Vdbe *pVdbe = pCtx->pVdbe;
 
   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
-  if( iArg<0 ) goto failed;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pVdbe==0 ) goto failed;
+#else
+  assert( pVdbe!=0 );
+#endif
 
-  for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
-    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
+  for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
+    if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
+      break;
+    }
   }
   if( pAuxData==0 ){
     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
     if( !pAuxData ) goto failed;
-    pAuxData->iOp = pCtx->iOp;
-    pAuxData->iArg = iArg;
-    pAuxData->pNext = pVdbe->pAuxData;
+    pAuxData->iAuxOp = pCtx->iOp;
+    pAuxData->iAuxArg = iArg;
+    pAuxData->pNextAux = pVdbe->pAuxData;
     pVdbe->pAuxData = pAuxData;
     if( pCtx->fErrorOrAux==0 ){
       pCtx->isError = 0;
       pCtx->fErrorOrAux = 1;
     }
-  }else if( pAuxData->xDelete ){
-    pAuxData->xDelete(pAuxData->pAux);
+  }else if( pAuxData->xDeleteAux ){
+    pAuxData->xDeleteAux(pAuxData->pAux);
   }
 
   pAuxData->pAux = pAux;
-  pAuxData->xDelete = xDelete;
+  pAuxData->xDeleteAux = xDelete;
   return;
 
 failed:
@@ -69099,7 +77648,7 @@ failed:
 ** context.
 */
 SQLITE_API int sqlite3_aggregate_count(sqlite3_context *p){
-  assert( p && p->pMem && p->pFunc && p->pFunc->xStep );
+  assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
   return p->pMem->n;
 }
 #endif
@@ -69141,18 +77690,19 @@ static const Mem *columnNullValue(void){
 #endif
     = {
         /* .u          = */ {0},
-        /* .flags      = */ MEM_Null,
-        /* .enc        = */ 0,
-        /* .n          = */ 0,
-        /* .z          = */ 0,
-        /* .zMalloc    = */ 0,
-        /* .szMalloc   = */ 0,
-        /* .iPadding1  = */ 0,
-        /* .db         = */ 0,
-        /* .xDel       = */ 0,
+        /* .flags      = */ (u16)MEM_Null,
+        /* .enc        = */ (u8)0,
+        /* .eSubtype   = */ (u8)0,
+        /* .n          = */ (int)0,
+        /* .z          = */ (char*)0,
+        /* .zMalloc    = */ (char*)0,
+        /* .szMalloc   = */ (int)0,
+        /* .uTemp      = */ (u32)0,
+        /* .db         = */ (sqlite3*)0,
+        /* .xDel       = */ (void(*)(void*))0,
 #ifdef SQLITE_DEBUG
-        /* .pScopyFrom = */ 0,
-        /* .pFiller    = */ 0,
+        /* .pScopyFrom = */ (Mem*)0,
+        /* .pFiller    = */ (void*)0,
 #endif
       };
   return &nullMem;
@@ -69169,14 +77719,13 @@ static Mem *columnMem(sqlite3_stmt *pStmt, int i){
   Mem *pOut;
 
   pVm = (Vdbe *)pStmt;
-  if( pVm && pVm->pResultSet!=0 && inResColumn && i>=0 ){
-    sqlite3_mutex_enter(pVm->db->mutex);
+  if( pVm==0 ) return (Mem*)columnNullValue();
+  assert( pVm->db );
+  sqlite3_mutex_enter(pVm->db->mutex);
+  if( pVm->pResultSet!=0 && inResColumn && i>=0 ){
     pOut = &pVm->pResultSet[i];
   }else{
-    if( pVm && ALWAYS(pVm->db) ){
-      sqlite3_mutex_enter(pVm->db->mutex);
-      sqlite3Error(pVm->db, SQLITE_RANGE);
-    }
+    sqlite3Error(pVm->db, SQLITE_RANGE);
     pOut = (Mem*)columnNullValue();
   }
   return pOut;
@@ -69209,6 +77758,8 @@ static void columnMallocFailure(sqlite3_stmt *pStmt)
   */
   Vdbe *p = (Vdbe *)pStmt;
   if( p ){
+    assert( p->db!=0 );
+    assert( sqlite3_mutex_held(p->db->mutex) );
     p->rc = sqlite3ApiExit(p->db, p->rc);
     sqlite3_mutex_leave(p->db->mutex);
   }
@@ -69326,7 +77877,7 @@ static const void *columnName(
     ** is the case, clear the mallocFailed flag and return NULL.
     */
     if( db->mallocFailed ){
-      db->mallocFailed = 0;
+      sqlite3OomClear(db);
       ret = 0;
     }
     sqlite3_mutex_leave(db->mutex);
@@ -69474,9 +78025,8 @@ static int vdbeUnbind(Vdbe *p, int i){
   ** as if there had been a schema change, on the first sqlite3_step() call
   ** following any change to the bindings of that parameter.
   */
-  if( p->isPrepareV2 &&
-     ((i<32 && p->expmask & ((u32)1 << i)) || p->expmask==0xffffffff)
-  ){
+  assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
+  if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<expired = 1;
   }
   return SQLITE_OK;
@@ -69505,8 +78055,10 @@ static int bindText(
       if( rc==SQLITE_OK && encoding!=0 ){
         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
       }
-      sqlite3Error(p->db, rc);
-      rc = sqlite3ApiExit(p->db, rc);
+      if( rc ){
+        sqlite3Error(p->db, rc);
+        rc = sqlite3ApiExit(p->db, rc);
+      }
     }
     sqlite3_mutex_leave(p->db->mutex);
   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){
@@ -69526,6 +78078,9 @@ SQLITE_API int sqlite3_bind_blob(
   int nData, 
   void (*xDel)(void*)
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( nData<0 ) return SQLITE_MISUSE_BKPT;
+#endif
   return bindText(pStmt, i, zData, nData, xDel, 0);
 }
 SQLITE_API int sqlite3_bind_blob64(
@@ -69574,6 +78129,24 @@ SQLITE_API int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
   }
   return rc;
 }
+SQLITE_API int sqlite3_bind_pointer(
+  sqlite3_stmt *pStmt,
+  int i,
+  void *pPtr,
+  const char *zPTtype,
+  void (*xDestructor)(void*)
+){
+  int rc;
+  Vdbe *p = (Vdbe*)pStmt;
+  rc = vdbeUnbind(p, i);
+  if( rc==SQLITE_OK ){
+    sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);
+    sqlite3_mutex_leave(p->db->mutex);
+  }else if( xDestructor ){
+    xDestructor(pPtr);
+  }
+  return rc;
+}
 SQLITE_API int sqlite3_bind_text( 
   sqlite3_stmt *pStmt, 
   int i, 
@@ -69651,6 +78224,20 @@ SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
   }
   return rc;
 }
+SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    rc = SQLITE_TOOBIG;
+  }else{
+    assert( (n & 0x7FFFFFFF)==n );
+    rc = sqlite3_bind_zeroblob(pStmt, i, n);
+  }
+  rc = sqlite3ApiExit(p->db, rc);
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
 
 /*
 ** Return the number of wildcards that can be potentially bound to.
@@ -69669,10 +78256,8 @@ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
 */
 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
   Vdbe *p = (Vdbe*)pStmt;
-  if( p==0 || i<1 || i>p->nzVar ){
-    return 0;
-  }
-  return p->azVar[i-1];
+  if( p==0 ) return 0;
+  return sqlite3VListNumToName(p->pVList, i);
 }
 
 /*
@@ -69681,19 +78266,8 @@ SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
 ** return 0.
 */
 SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
-  int i;
-  if( p==0 ){
-    return 0;
-  }
-  if( zName ){
-    for(i=0; inzVar; i++){
-      const char *z = p->azVar[i];
-      if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
-        return i+1;
-      }
-    }
-  }
-  return 0;
+  if( p==0 || zName==0 ) return 0;
+  return sqlite3VListNameToNum(p->pVList, zName, nName);
 }
 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
@@ -69735,10 +78309,12 @@ SQLITE_API int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *
   if( pFrom->nVar!=pTo->nVar ){
     return SQLITE_ERROR;
   }
-  if( pTo->isPrepareV2 && pTo->expmask ){
+  assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );
+  if( pTo->expmask ){
     pTo->expired = 1;
   }
-  if( pFrom->isPrepareV2 && pFrom->expmask ){
+  assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );
+  if( pFrom->expmask ){
     pFrom->expired = 1;
   }
   return sqlite3TransferBindings(pFromStmt, pToStmt);
@@ -69768,7 +78344,7 @@ SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
 */
 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
   Vdbe *v = (Vdbe*)pStmt;
-  return v!=0 && v->pc>=0 && v->magic==VDBE_MAGIC_RUN;
+  return v!=0 && v->magic==VDBE_MAGIC_RUN && v->pc>=0;
 }
 
 /*
@@ -69807,11 +78383,241 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
     return 0;
   }
 #endif
-  v = pVdbe->aCounter[op];
-  if( resetFlag ) pVdbe->aCounter[op] = 0;
+  if( op==SQLITE_STMTSTATUS_MEMUSED ){
+    sqlite3 *db = pVdbe->db;
+    sqlite3_mutex_enter(db->mutex);
+    v = 0;
+    db->pnBytesFreed = (int*)&v;
+    sqlite3VdbeClearObject(db, pVdbe);
+    sqlite3DbFree(db, pVdbe);
+    db->pnBytesFreed = 0;
+    sqlite3_mutex_leave(db->mutex);
+  }else{
+    v = pVdbe->aCounter[op];
+    if( resetFlag ) pVdbe->aCounter[op] = 0;
+  }
   return (int)v;
 }
 
+/*
+** Return the SQL associated with a prepared statement
+*/
+SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe *)pStmt;
+  return p ? p->zSql : 0;
+}
+
+/*
+** Return the SQL associated with a prepared statement with
+** bound parameters expanded.  Space to hold the returned string is
+** obtained from sqlite3_malloc().  The caller is responsible for
+** freeing the returned string by passing it to sqlite3_free().
+**
+** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
+** expanded bound parameters.
+*/
+SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
+#ifdef SQLITE_OMIT_TRACE
+  return 0;
+#else
+  char *z = 0;
+  const char *zSql = sqlite3_sql(pStmt);
+  if( zSql ){
+    Vdbe *p = (Vdbe *)pStmt;
+    sqlite3_mutex_enter(p->db->mutex);
+    z = sqlite3VdbeExpandSql(p, zSql);
+    sqlite3_mutex_leave(p->db->mutex);
+  }
+  return z;
+#endif
+}
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Allocate and populate an UnpackedRecord structure based on the serialized
+** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
+** if successful, or a NULL pointer if an OOM error is encountered.
+*/
+static UnpackedRecord *vdbeUnpackRecord(
+  KeyInfo *pKeyInfo, 
+  int nKey, 
+  const void *pKey
+){
+  UnpackedRecord *pRet;           /* Return value */
+
+  pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
+  if( pRet ){
+    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1));
+    sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
+  }
+  return pRet;
+}
+
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or deleted.
+*/
+SQLITE_API int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  Mem *pMem;
+  int rc = SQLITE_OK;
+
+  /* Test that this call is being made from within an SQLITE_DELETE or
+  ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
+  if( !p || p->op==SQLITE_INSERT ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_old_out;
+  }
+  if( p->pPk ){
+    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_old_out;
+  }
+
+  /* If the old.* record has not yet been loaded into memory, do so now. */
+  if( p->pUnpacked==0 ){
+    u32 nRec;
+    u8 *aRec;
+
+    nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
+    aRec = sqlite3DbMallocRaw(db, nRec);
+    if( !aRec ) goto preupdate_old_out;
+    rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
+    if( rc==SQLITE_OK ){
+      p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
+      if( !p->pUnpacked ) rc = SQLITE_NOMEM;
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, aRec);
+      goto preupdate_old_out;
+    }
+    p->aRecord = aRec;
+  }
+
+  pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
+  if( iIdx==p->pTab->iPKey ){
+    sqlite3VdbeMemSetInt64(pMem, p->iKey1);
+  }else if( iIdx>=p->pUnpacked->nField ){
+    *ppValue = (sqlite3_value *)columnNullValue();
+  }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
+    if( pMem->flags & MEM_Int ){
+      sqlite3VdbeMemRealify(pMem);
+    }
+  }
+
+ preupdate_old_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** the number of columns in the row being updated, deleted or inserted.
+*/
+SQLITE_API int sqlite3_preupdate_count(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->keyinfo.nField : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is designed to be called from within a pre-update callback
+** only. It returns zero if the change that caused the callback was made
+** immediately by a user SQL statement. Or, if the change was made by a
+** trigger program, it returns the number of trigger programs currently
+** on the stack (1 for a top-level trigger, 2 for a trigger fired by a 
+** top-level trigger etc.).
+**
+** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
+** or SET DEFAULT action is considered a trigger.
+*/
+SQLITE_API int sqlite3_preupdate_depth(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->v->nFrame : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or inserted.
+*/
+SQLITE_API int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+  Mem *pMem;
+
+  if( !p || p->op==SQLITE_DELETE ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_new_out;
+  }
+  if( p->pPk && p->op!=SQLITE_UPDATE ){
+    iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_new_out;
+  }
+
+  if( p->op==SQLITE_INSERT ){
+    /* For an INSERT, memory cell p->iNewReg contains the serialized record
+    ** that is being inserted. Deserialize it. */
+    UnpackedRecord *pUnpack = p->pNewUnpacked;
+    if( !pUnpack ){
+      Mem *pData = &p->v->aMem[p->iNewReg];
+      rc = ExpandBlob(pData);
+      if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
+      if( !pUnpack ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+      p->pNewUnpacked = pUnpack;
+    }
+    pMem = &pUnpack->aMem[iIdx];
+    if( iIdx==p->pTab->iPKey ){
+      sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+    }else if( iIdx>=pUnpack->nField ){
+      pMem = (sqlite3_value *)columnNullValue();
+    }
+  }else{
+    /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
+    ** value. Make a copy of the cell contents and return a pointer to it.
+    ** It is not safe to return a pointer to the memory cell itself as the
+    ** caller may modify the value text encoding.
+    */
+    assert( p->op==SQLITE_UPDATE );
+    if( !p->aNew ){
+      p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
+      if( !p->aNew ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+    }
+    assert( iIdx>=0 && iIdxpCsr->nField );
+    pMem = &p->aNew[iIdx];
+    if( pMem->flags==0 ){
+      if( iIdx==p->pTab->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }else{
+        rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
+        if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      }
+    }
+  }
+  *ppValue = pMem;
+
+ preupdate_new_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 /*
 ** Return status data for a single loop within query pStmt.
@@ -69900,6 +78706,8 @@ SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
 **
 ** The Vdbe parse-tree explainer is also found here.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_TRACE
 
@@ -69964,12 +78772,14 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
   int i;                   /* Loop counter */
   Mem *pVar;               /* Value of a host parameter */
   StrAccum out;            /* Accumulate the output here */
+#ifndef SQLITE_OMIT_UTF16
+  Mem utf8;                /* Used to convert UTF16 parameters into UTF8 for display */
+#endif
   char zBase[100];         /* Initial working space */
 
   db = p->db;
-  sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
+  sqlite3StrAccumInit(&out, 0, zBase, sizeof(zBase), 
                       db->aLimit[SQLITE_LIMIT_LENGTH]);
-  out.db = db;
   if( db->nVdbeExec>1 ){
     while( *zRawSql ){
       const char *zStart = zRawSql;
@@ -69978,6 +78788,8 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
       assert( (zRawSql - zStart) > 0 );
       sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart));
     }
+  }else if( p->nVar==0 ){
+    sqlite3StrAccumAppend(&out, zRawSql, sqlite3Strlen30(zRawSql));
   }else{
     while( zRawSql[0] ){
       n = findNextHostParameter(zRawSql, &nToken);
@@ -69994,10 +78806,12 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
           idx = nextIndex;
         }
       }else{
-        assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' );
+        assert( zRawSql[0]==':' || zRawSql[0]=='$' ||
+                zRawSql[0]=='@' || zRawSql[0]=='#' );
         testcase( zRawSql[0]==':' );
         testcase( zRawSql[0]=='$' );
         testcase( zRawSql[0]=='@' );
+        testcase( zRawSql[0]=='#' );
         idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken);
         assert( idx>0 );
       }
@@ -70008,19 +78822,21 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
       if( pVar->flags & MEM_Null ){
         sqlite3StrAccumAppend(&out, "NULL", 4);
       }else if( pVar->flags & MEM_Int ){
-        sqlite3XPrintf(&out, 0, "%lld", pVar->u.i);
+        sqlite3XPrintf(&out, "%lld", pVar->u.i);
       }else if( pVar->flags & MEM_Real ){
-        sqlite3XPrintf(&out, 0, "%!.15g", pVar->u.r);
+        sqlite3XPrintf(&out, "%!.15g", pVar->u.r);
       }else if( pVar->flags & MEM_Str ){
         int nOut;  /* Number of bytes of the string text to include in output */
 #ifndef SQLITE_OMIT_UTF16
         u8 enc = ENC(db);
-        Mem utf8;
         if( enc!=SQLITE_UTF8 ){
           memset(&utf8, 0, sizeof(utf8));
           utf8.db = db;
           sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
-          sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
+          if( SQLITE_NOMEM==sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8) ){
+            out.accError = STRACCUM_NOMEM;
+            out.nAlloc = 0;
+          }
           pVar = &utf8;
         }
 #endif
@@ -70031,17 +78847,17 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
           while( nOutn && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; }
         }
 #endif    
-        sqlite3XPrintf(&out, 0, "'%.*q'", nOut, pVar->z);
+        sqlite3XPrintf(&out, "'%.*q'", nOut, pVar->z);
 #ifdef SQLITE_TRACE_SIZE_LIMIT
         if( nOutn ){
-          sqlite3XPrintf(&out, 0, "/*+%d bytes*/", pVar->n-nOut);
+          sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
         }
 #endif
 #ifndef SQLITE_OMIT_UTF16
         if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8);
 #endif
       }else if( pVar->flags & MEM_Zero ){
-        sqlite3XPrintf(&out, 0, "zeroblob(%d)", pVar->u.nZero);
+        sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero);
       }else{
         int nOut;  /* Number of bytes of the blob to include in output */
         assert( pVar->flags & MEM_Blob );
@@ -70051,17 +78867,18 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
         if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT;
 #endif
         for(i=0; iz[i]&0xff);
+          sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff);
         }
         sqlite3StrAccumAppend(&out, "'", 1);
 #ifdef SQLITE_TRACE_SIZE_LIMIT
         if( nOutn ){
-          sqlite3XPrintf(&out, 0, "/*+%d bytes*/", pVar->n-nOut);
+          sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
         }
 #endif
       }
     }
   }
+  if( out.accError ) sqlite3StrAccumReset(&out);
   return sqlite3StrAccumFinish(&out);
 }
 
@@ -70089,6 +78906,8 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 /*
 ** Invoke this macro on memory cells just prior to changing the
@@ -70155,6 +78974,16 @@ static void updateMaxBlobsize(Mem *p){
 }
 #endif
 
+/*
+** This macro evaluates to true if either the update hook or the preupdate
+** hook are enabled for database connect DB.
+*/
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+# define HAS_UPDATE_HOOK(DB) ((DB)->xPreUpdateCallback||(DB)->xUpdateCallback)
+#else
+# define HAS_UPDATE_HOOK(DB) ((DB)->xUpdateCallback)
+#endif
+
 /*
 ** The next global variable is incremented each time the OP_Found opcode
 ** is executed. This is used to test whether or not the foreign key
@@ -70170,7 +78999,7 @@ SQLITE_API int sqlite3_found_count = 0;
 ** Test a register to see if it exceeds the current maximum blob size.
 ** If it does, record the new maximum blob size.
 */
-#if defined(SQLITE_TEST) && !defined(SQLITE_OMIT_BUILTIN_TEST)
+#if defined(SQLITE_TEST) && !defined(SQLITE_UNTESTABLE)
 # define UPDATE_MAX_BLOBSIZE(P)  updateMaxBlobsize(P)
 #else
 # define UPDATE_MAX_BLOBSIZE(P)
@@ -70234,7 +79063,7 @@ SQLITE_API int sqlite3_found_count = 0;
        && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
 
 /* Return true if the cursor was opened using the OP_OpenSorter opcode. */
-#define isSorter(x) ((x)->pSorter!=0)
+#define isSorter(x) ((x)->eCurType==CURTYPE_SORTER)
 
 /*
 ** Allocate VdbeCursor number iCur.  Return a pointer to it.  Return NULL
@@ -70245,7 +79074,7 @@ static VdbeCursor *allocateCursor(
   int iCur,             /* Index of the new VdbeCursor */
   int nField,           /* Number of fields in the table or index */
   int iDb,              /* Database the cursor belongs to, or -1 */
-  int isBtreeCursor     /* True for B-Tree.  False for pseudo-table or vtab */
+  u8 eCurType           /* Type of the new cursor */
 ){
   /* Find the memory cell that will be used to store the blob of memory
   ** required for this VdbeCursor structure. It is convenient to use a 
@@ -70261,33 +79090,34 @@ static VdbeCursor *allocateCursor(
   **     be freed lazily via the sqlite3_release_memory() API. This
   **     minimizes the number of malloc calls made by the system.
   **
-  ** Memory cells for cursors are allocated at the top of the address
-  ** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
-  ** cursor 1 is managed by memory cell (p->nMem-1), etc.
+  ** The memory cell for cursor 0 is aMem[0]. The rest are allocated from
+  ** the top of the register space.  Cursor 1 is at Mem[p->nMem-1].
+  ** Cursor 2 is at Mem[p->nMem-2]. And so forth.
   */
-  Mem *pMem = &p->aMem[p->nMem-iCur];
+  Mem *pMem = iCur>0 ? &p->aMem[p->nMem-iCur] : p->aMem;
 
   int nByte;
   VdbeCursor *pCx = 0;
   nByte = 
       ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
-      (isBtreeCursor?sqlite3BtreeCursorSize():0);
+      (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);
 
-  assert( iCurnCursor );
-  if( p->apCsr[iCur] ){
+  assert( iCur>=0 && iCurnCursor );
+  if( p->apCsr[iCur] ){ /*OPTIMIZATION-IF-FALSE*/
     sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
     p->apCsr[iCur] = 0;
   }
   if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){
     p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
-    memset(pCx, 0, sizeof(VdbeCursor));
+    memset(pCx, 0, offsetof(VdbeCursor,pAltCursor));
+    pCx->eCurType = eCurType;
     pCx->iDb = iDb;
     pCx->nField = nField;
     pCx->aOffset = &pCx->aType[nField];
-    if( isBtreeCursor ){
-      pCx->pCursor = (BtCursor*)
+    if( eCurType==CURTYPE_BTREE ){
+      pCx->uc.pCursor = (BtCursor*)
           &pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];
-      sqlite3BtreeCursorZero(pCx->pCursor);
+      sqlite3BtreeCursorZero(pCx->uc.pCursor);
     }
   }
   return pCx;
@@ -70339,7 +79169,7 @@ static void applyNumericAffinity(Mem *pRec, int bTryForInt){
 ** SQLITE_AFF_TEXT:
 **    Convert pRec to a text representation.
 **
-** SQLITE_AFF_NONE:
+** SQLITE_AFF_BLOB:
 **    No-op.  pRec is unchanged.
 */
 static void applyAffinity(
@@ -70350,7 +79180,7 @@ static void applyAffinity(
   if( affinity>=SQLITE_AFF_NUMERIC ){
     assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
              || affinity==SQLITE_AFF_NUMERIC );
-    if( (pRec->flags & MEM_Int)==0 ){
+    if( (pRec->flags & MEM_Int)==0 ){ /*OPTIMIZATION-IF-FALSE*/
       if( (pRec->flags & MEM_Real)==0 ){
         if( pRec->flags & MEM_Str ) applyNumericAffinity(pRec,1);
       }else{
@@ -70360,11 +79190,15 @@ static void applyAffinity(
   }else if( affinity==SQLITE_AFF_TEXT ){
     /* Only attempt the conversion to TEXT if there is an integer or real
     ** representation (blob and NULL do not get converted) but no string
-    ** representation.
-    */
-    if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
-      sqlite3VdbeMemStringify(pRec, enc, 1);
+    ** representation.  It would be harmless to repeat the conversion if 
+    ** there is already a string rep, but it is pointless to waste those
+    ** CPU cycles. */
+    if( 0==(pRec->flags&MEM_Str) ){ /*OPTIMIZATION-IF-FALSE*/
+      if( (pRec->flags&(MEM_Real|MEM_Int)) ){
+        sqlite3VdbeMemStringify(pRec, enc, 1);
+      }
     }
+    pRec->flags &= ~(MEM_Real|MEM_Int);
   }
 }
 
@@ -70457,9 +79291,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
     }else{
       c = 's';
     }
-
-    sqlite3_snprintf(100, zCsr, "%c", c);
-    zCsr += sqlite3Strlen30(zCsr);
+    *(zCsr++) = c;
     sqlite3_snprintf(100, zCsr, "%d[", pMem->n);
     zCsr += sqlite3Strlen30(zCsr);
     for(i=0; i<16 && in; i++){
@@ -70471,9 +79303,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
       if( z<32 || z>126 ) *zCsr++ = '.';
       else *zCsr++ = z;
     }
-
-    sqlite3_snprintf(100, zCsr, "]%s", encnames[pMem->enc]);
-    zCsr += sqlite3Strlen30(zCsr);
+    *(zCsr++) = ']';
     if( f & MEM_Zero ){
       sqlite3_snprintf(100, zCsr,"+%dz",pMem->u.nZero);
       zCsr += sqlite3Strlen30(zCsr);
@@ -70538,11 +79368,13 @@ static void memTracePrint(Mem *p){
     sqlite3VdbeMemPrettyPrint(p, zBuf);
     printf(" %s", zBuf);
   }
+  if( p->flags & MEM_Subtype ) printf(" subtype=0x%02x", p->eSubtype);
 }
 static void registerTrace(int iReg, Mem *p){
   printf("REG[%d] = ", iReg);
   memTracePrint(p);
   printf("\n");
+  sqlite3VdbeCheckMemInvariants(p);
 }
 #endif
 
@@ -70576,8 +79408,8 @@ static void registerTrace(int iReg, Mem *p){
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -70645,7 +79477,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in vdbe.c ***********************/
@@ -70672,6 +79504,29 @@ static int checkSavepointCount(sqlite3 *db){
 }
 #endif
 
+/*
+** Return the register of pOp->p2 after first preparing it to be
+** overwritten with an integer value.
+*/
+static SQLITE_NOINLINE Mem *out2PrereleaseWithClear(Mem *pOut){
+  sqlite3VdbeMemSetNull(pOut);
+  pOut->flags = MEM_Int;
+  return pOut;
+}
+static Mem *out2Prerelease(Vdbe *p, VdbeOp *pOp){
+  Mem *pOut;
+  assert( pOp->p2>0 );
+  assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+  pOut = &p->aMem[pOp->p2];
+  memAboutToChange(p, pOut);
+  if( VdbeMemDynamic(pOut) ){ /*OPTIMIZATION-IF-FALSE*/
+    return out2PrereleaseWithClear(pOut);
+  }else{
+    pOut->flags = MEM_Int;
+    return pOut;
+  }
+}
+
 
 /*
 ** Execute as much of a VDBE program as we can.
@@ -70680,25 +79535,28 @@ static int checkSavepointCount(sqlite3 *db){
 SQLITE_PRIVATE int sqlite3VdbeExec(
   Vdbe *p                    /* The VDBE */
 ){
-  int pc=0;                  /* The program counter */
   Op *aOp = p->aOp;          /* Copy of p->aOp */
-  Op *pOp;                   /* Current operation */
+  Op *pOp = aOp;             /* Current operation */
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+  Op *pOrigOp;               /* Value of pOp at the top of the loop */
+#endif
+#ifdef SQLITE_DEBUG
+  int nExtraDelete = 0;      /* Verifies FORDELETE and AUXDELETE flags */
+#endif
   int rc = SQLITE_OK;        /* Value to return */
   sqlite3 *db = p->db;       /* The database */
   u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */
   u8 encoding = ENC(db);     /* The database encoding */
-  int iCompare = 0;          /* Result of last OP_Compare operation */
+  int iCompare = 0;          /* Result of last comparison */
   unsigned nVmStep = 0;      /* Number of virtual machine steps */
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-  unsigned nProgressLimit = 0;/* Invoke xProgress() when nVmStep reaches this */
+  unsigned nProgressLimit;   /* Invoke xProgress() when nVmStep reaches this */
 #endif
   Mem *aMem = p->aMem;       /* Copy of p->aMem */
   Mem *pIn1 = 0;             /* 1st input operand */
   Mem *pIn2 = 0;             /* 2nd input operand */
   Mem *pIn3 = 0;             /* 3rd input operand */
   Mem *pOut = 0;             /* Output operand */
-  int *aPermute = 0;         /* Permutation of columns for OP_Compare */
-  i64 lastRowid = db->lastRowid;  /* Saved value of the last insert ROWID */
 #ifdef VDBE_PROFILE
   u64 start;                 /* CPU clock count at start of opcode */
 #endif
@@ -70711,9 +79569,8 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
     ** sqlite3_column_text16() failed.  */
     goto no_mem;
   }
-  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+  assert( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_BUSY );
   assert( p->bIsReader || p->readOnly!=0 );
-  p->rc = SQLITE_OK;
   p->iCurrentTime = 0;
   assert( p->explain==0 );
   p->pResultSet = 0;
@@ -70722,13 +79579,11 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
   sqlite3VdbeIOTraceSql(p);
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   if( db->xProgress ){
+    u32 iPrior = p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
     assert( 0 < db->nProgressOps );
-    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
-    if( nProgressLimit==0 ){
-      nProgressLimit = db->nProgressOps;
-    }else{
-      nProgressLimit %= (unsigned)db->nProgressOps;
-    }
+    nProgressLimit = db->nProgressOps - (iPrior % db->nProgressOps);
+  }else{
+    nProgressLimit = 0xffffffff;
   }
 #endif
 #ifdef SQLITE_DEBUG
@@ -70758,23 +79613,25 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
   }
   sqlite3EndBenignMalloc();
 #endif
-  for(pc=p->pc; rc==SQLITE_OK; pc++){
-    assert( pc>=0 && pcnOp );
-    if( db->mallocFailed ) goto no_mem;
+  for(pOp=&aOp[p->pc]; 1; pOp++){
+    /* Errors are detected by individual opcodes, with an immediate
+    ** jumps to abort_due_to_error. */
+    assert( rc==SQLITE_OK );
+
+    assert( pOp>=aOp && pOp<&aOp[p->nOp]);
 #ifdef VDBE_PROFILE
     start = sqlite3Hwtime();
 #endif
     nVmStep++;
-    pOp = &aOp[pc];
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-    if( p->anExec ) p->anExec[pc]++;
+    if( p->anExec ) p->anExec[(int)(pOp-aOp)]++;
 #endif
 
     /* Only allow tracing if SQLITE_DEBUG is defined.
     */
 #ifdef SQLITE_DEBUG
     if( db->flags & SQLITE_VdbeTrace ){
-      sqlite3VdbePrintOp(stdout, pc, pOp);
+      sqlite3VdbePrintOp(stdout, (int)(pOp - aOp), pOp);
     }
 #endif
       
@@ -70791,55 +79648,46 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
     }
 #endif
 
-    /* On any opcode with the "out2-prerelease" tag, free any
-    ** external allocations out of mem[p2] and set mem[p2] to be
-    ** an undefined integer.  Opcodes will either fill in the integer
-    ** value or convert mem[p2] to a different type.
-    */
-    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
-    if( pOp->opflags & OPFLG_OUT2_PRERELEASE ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=(p->nMem-p->nCursor) );
-      pOut = &aMem[pOp->p2];
-      memAboutToChange(p, pOut);
-      if( VdbeMemDynamic(pOut) ) sqlite3VdbeMemSetNull(pOut);
-      pOut->flags = MEM_Int;
-    }
-
     /* Sanity checking on other operands */
 #ifdef SQLITE_DEBUG
-    if( (pOp->opflags & OPFLG_IN1)!=0 ){
-      assert( pOp->p1>0 );
-      assert( pOp->p1<=(p->nMem-p->nCursor) );
-      assert( memIsValid(&aMem[pOp->p1]) );
-      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p1]) );
-      REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
-    }
-    if( (pOp->opflags & OPFLG_IN2)!=0 ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=(p->nMem-p->nCursor) );
-      assert( memIsValid(&aMem[pOp->p2]) );
-      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p2]) );
-      REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
-    }
-    if( (pOp->opflags & OPFLG_IN3)!=0 ){
-      assert( pOp->p3>0 );
-      assert( pOp->p3<=(p->nMem-p->nCursor) );
-      assert( memIsValid(&aMem[pOp->p3]) );
-      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p3]) );
-      REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
-    }
-    if( (pOp->opflags & OPFLG_OUT2)!=0 ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=(p->nMem-p->nCursor) );
-      memAboutToChange(p, &aMem[pOp->p2]);
-    }
-    if( (pOp->opflags & OPFLG_OUT3)!=0 ){
-      assert( pOp->p3>0 );
-      assert( pOp->p3<=(p->nMem-p->nCursor) );
-      memAboutToChange(p, &aMem[pOp->p3]);
+    {
+      u8 opProperty = sqlite3OpcodeProperty[pOp->opcode];
+      if( (opProperty & OPFLG_IN1)!=0 ){
+        assert( pOp->p1>0 );
+        assert( pOp->p1<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p1]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p1]) );
+        REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
+      }
+      if( (opProperty & OPFLG_IN2)!=0 ){
+        assert( pOp->p2>0 );
+        assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p2]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p2]) );
+        REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
+      }
+      if( (opProperty & OPFLG_IN3)!=0 ){
+        assert( pOp->p3>0 );
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p3]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p3]) );
+        REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
+      }
+      if( (opProperty & OPFLG_OUT2)!=0 ){
+        assert( pOp->p2>0 );
+        assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+        memAboutToChange(p, &aMem[pOp->p2]);
+      }
+      if( (opProperty & OPFLG_OUT3)!=0 ){
+        assert( pOp->p3>0 );
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+        memAboutToChange(p, &aMem[pOp->p3]);
+      }
     }
 #endif
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+    pOrigOp = pOp;
+#endif
   
     switch( pOp->opcode ){
 
@@ -70863,7 +79711,7 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
 **
 ** Other keywords in the comment that follows each case are used to
 ** construct the OPFLG_INITIALIZER value that initializes opcodeProperty[].
-** Keywords include: in1, in2, in3, out2_prerelease, out2, out3.  See
+** Keywords include: in1, in2, in3, out2, out3.  See
 ** the mkopcodeh.awk script for additional information.
 **
 ** Documentation about VDBE opcodes is generated by scanning this file
@@ -70891,10 +79739,11 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
 ** to the current line should be indented for EXPLAIN output.
 */
 case OP_Goto: {             /* jump */
-  pc = pOp->p2 - 1;
+jump_to_p2_and_check_for_interrupt:
+  pOp = &aOp[pOp->p2 - 1];
 
   /* Opcodes that are used as the bottom of a loop (OP_Next, OP_Prev,
-  ** OP_VNext, OP_RowSetNext, or OP_SorterNext) all jump here upon
+  ** OP_VNext, or OP_SorterNext) all jump here upon
   ** completion.  Check to see if sqlite3_interrupt() has been called
   ** or if the progress callback needs to be invoked. 
   **
@@ -70912,12 +79761,12 @@ check_for_interrupt:
   ** If the progress callback returns non-zero, exit the virtual machine with
   ** a return code SQLITE_ABORT.
   */
-  if( db->xProgress!=0 && nVmStep>=nProgressLimit ){
+  if( nVmStep>=nProgressLimit && db->xProgress!=0 ){
     assert( db->nProgressOps!=0 );
     nProgressLimit = nVmStep + db->nProgressOps - (nVmStep%db->nProgressOps);
     if( db->xProgress(db->pProgressArg) ){
       rc = SQLITE_INTERRUPT;
-      goto vdbe_error_halt;
+      goto abort_due_to_error;
     }
   }
 #endif
@@ -70931,14 +79780,18 @@ check_for_interrupt:
 ** and then jump to address P2.
 */
 case OP_Gosub: {            /* jump */
-  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
   pIn1 = &aMem[pOp->p1];
   assert( VdbeMemDynamic(pIn1)==0 );
   memAboutToChange(p, pIn1);
   pIn1->flags = MEM_Int;
-  pIn1->u.i = pc;
+  pIn1->u.i = (int)(pOp-aOp);
   REGISTER_TRACE(pOp->p1, pIn1);
-  pc = pOp->p2 - 1;
+
+  /* Most jump operations do a goto to this spot in order to update
+  ** the pOp pointer. */
+jump_to_p2:
+  pOp = &aOp[pOp->p2 - 1];
   break;
 }
 
@@ -70950,7 +79803,7 @@ case OP_Gosub: {            /* jump */
 case OP_Return: {           /* in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags==MEM_Int );
-  pc = (int)pIn1->u.i;
+  pOp = &aOp[pIn1->u.i];
   pIn1->flags = MEM_Undefined;
   break;
 }
@@ -70967,14 +79820,14 @@ case OP_Return: {           /* in1 */
 ** See also: EndCoroutine
 */
 case OP_InitCoroutine: {     /* jump */
-  assert( pOp->p1>0 &&  pOp->p1<=(p->nMem-p->nCursor) );
+  assert( pOp->p1>0 &&  pOp->p1<=(p->nMem+1 - p->nCursor) );
   assert( pOp->p2>=0 && pOp->p2nOp );
   assert( pOp->p3>=0 && pOp->p3nOp );
   pOut = &aMem[pOp->p1];
   assert( !VdbeMemDynamic(pOut) );
   pOut->u.i = pOp->p3 - 1;
   pOut->flags = MEM_Int;
-  if( pOp->p2 ) pc = pOp->p2 - 1;
+  if( pOp->p2 ) goto jump_to_p2;
   break;
 }
 
@@ -70994,7 +79847,7 @@ case OP_EndCoroutine: {           /* in1 */
   pCaller = &aOp[pIn1->u.i];
   assert( pCaller->opcode==OP_Yield );
   assert( pCaller->p2>=0 && pCaller->p2nOp );
-  pc = pCaller->p2 - 1;
+  pOp = &aOp[pCaller->p2 - 1];
   pIn1->flags = MEM_Undefined;
   break;
 }
@@ -71018,14 +79871,14 @@ case OP_Yield: {            /* in1, jump */
   assert( VdbeMemDynamic(pIn1)==0 );
   pIn1->flags = MEM_Int;
   pcDest = (int)pIn1->u.i;
-  pIn1->u.i = pc;
+  pIn1->u.i = (int)(pOp - aOp);
   REGISTER_TRACE(pOp->p1, pIn1);
-  pc = pcDest;
+  pOp = &aOp[pcDest];
   break;
 }
 
 /* Opcode:  HaltIfNull  P1 P2 P3 P4 P5
-** Synopsis:  if r[P3]=null halt
+** Synopsis: if r[P3]=null halt
 **
 ** Check the value in register P3.  If it is NULL then Halt using
 ** parameter P1, P2, and P4 as if this were a Halt instruction.  If the
@@ -71069,61 +79922,55 @@ case OP_HaltIfNull: {      /* in3 */
 ** is the same as executing Halt.
 */
 case OP_Halt: {
-  const char *zType;
-  const char *zLogFmt;
+  VdbeFrame *pFrame;
+  int pcx;
 
+  pcx = (int)(pOp - aOp);
   if( pOp->p1==SQLITE_OK && p->pFrame ){
     /* Halt the sub-program. Return control to the parent frame. */
-    VdbeFrame *pFrame = p->pFrame;
+    pFrame = p->pFrame;
     p->pFrame = pFrame->pParent;
     p->nFrame--;
     sqlite3VdbeSetChanges(db, p->nChange);
-    pc = sqlite3VdbeFrameRestore(pFrame);
-    lastRowid = db->lastRowid;
+    pcx = sqlite3VdbeFrameRestore(pFrame);
     if( pOp->p2==OE_Ignore ){
-      /* Instruction pc is the OP_Program that invoked the sub-program 
+      /* Instruction pcx is the OP_Program that invoked the sub-program 
       ** currently being halted. If the p2 instruction of this OP_Halt
       ** instruction is set to OE_Ignore, then the sub-program is throwing
       ** an IGNORE exception. In this case jump to the address specified
       ** as the p2 of the calling OP_Program.  */
-      pc = p->aOp[pc].p2-1;
+      pcx = p->aOp[pcx].p2-1;
     }
     aOp = p->aOp;
     aMem = p->aMem;
+    pOp = &aOp[pcx];
     break;
   }
   p->rc = pOp->p1;
   p->errorAction = (u8)pOp->p2;
-  p->pc = pc;
+  p->pc = pcx;
+  assert( pOp->p5<=4 );
   if( p->rc ){
     if( pOp->p5 ){
       static const char * const azType[] = { "NOT NULL", "UNIQUE", "CHECK",
                                              "FOREIGN KEY" };
-      assert( pOp->p5>=1 && pOp->p5<=4 );
       testcase( pOp->p5==1 );
       testcase( pOp->p5==2 );
       testcase( pOp->p5==3 );
       testcase( pOp->p5==4 );
-      zType = azType[pOp->p5-1];
-    }else{
-      zType = 0;
-    }
-    assert( zType!=0 || pOp->p4.z!=0 );
-    zLogFmt = "abort at %d in [%s]: %s";
-    if( zType && pOp->p4.z ){
-      sqlite3SetString(&p->zErrMsg, db, "%s constraint failed: %s", 
-                       zType, pOp->p4.z);
-    }else if( pOp->p4.z ){
-      sqlite3SetString(&p->zErrMsg, db, "%s", pOp->p4.z);
+      sqlite3VdbeError(p, "%s constraint failed", azType[pOp->p5-1]);
+      if( pOp->p4.z ){
+        p->zErrMsg = sqlite3MPrintf(db, "%z: %s", p->zErrMsg, pOp->p4.z);
+      }
     }else{
-      sqlite3SetString(&p->zErrMsg, db, "%s constraint failed", zType);
+      sqlite3VdbeError(p, "%s", pOp->p4.z);
     }
-    sqlite3_log(pOp->p1, zLogFmt, pc, p->zSql, p->zErrMsg);
+    sqlite3_log(pOp->p1, "abort at %d in [%s]: %s", pcx, p->zSql, p->zErrMsg);
   }
   rc = sqlite3VdbeHalt(p);
   assert( rc==SQLITE_BUSY || rc==SQLITE_OK || rc==SQLITE_ERROR );
   if( rc==SQLITE_BUSY ){
-    p->rc = rc = SQLITE_BUSY;
+    p->rc = SQLITE_BUSY;
   }else{
     assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );
     assert( rc==SQLITE_OK || db->nDeferredCons>0 || db->nDeferredImmCons>0 );
@@ -71137,7 +79984,8 @@ case OP_Halt: {
 **
 ** The 32-bit integer value P1 is written into register P2.
 */
-case OP_Integer: {         /* out2-prerelease */
+case OP_Integer: {         /* out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = pOp->p1;
   break;
 }
@@ -71148,7 +79996,8 @@ case OP_Integer: {         /* out2-prerelease */
 ** P4 is a pointer to a 64-bit integer value.
 ** Write that value into register P2.
 */
-case OP_Int64: {           /* out2-prerelease */
+case OP_Int64: {           /* out2 */
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p4.pI64!=0 );
   pOut->u.i = *pOp->p4.pI64;
   break;
@@ -71161,7 +80010,8 @@ case OP_Int64: {           /* out2-prerelease */
 ** P4 is a pointer to a 64-bit floating point value.
 ** Write that value into register P2.
 */
-case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
+case OP_Real: {            /* same as TK_FLOAT, out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Real;
   assert( !sqlite3IsNaN(*pOp->p4.pReal) );
   pOut->u.r = *pOp->p4.pReal;
@@ -71173,19 +80023,20 @@ case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
 ** Synopsis: r[P2]='P4'
 **
 ** P4 points to a nul terminated UTF-8 string. This opcode is transformed 
-** into a String before it is executed for the first time.  During
+** into a String opcode before it is executed for the first time.  During
 ** this transformation, the length of string P4 is computed and stored
 ** as the P1 parameter.
 */
-case OP_String8: {         /* same as TK_STRING, out2-prerelease */
+case OP_String8: {         /* same as TK_STRING, out2 */
   assert( pOp->p4.z!=0 );
+  pOut = out2Prerelease(p, pOp);
   pOp->opcode = OP_String;
   pOp->p1 = sqlite3Strlen30(pOp->p4.z);
 
 #ifndef SQLITE_OMIT_UTF16
   if( encoding!=SQLITE_UTF8 ){
     rc = sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
-    if( rc==SQLITE_TOOBIG ) goto too_big;
+    assert( rc==SQLITE_OK || rc==SQLITE_TOOBIG );
     if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
     assert( pOut->szMalloc>0 && pOut->zMalloc==pOut->z );
     assert( VdbeMemDynamic(pOut)==0 );
@@ -71198,30 +80049,48 @@ case OP_String8: {         /* same as TK_STRING, out2-prerelease */
     pOp->p4.z = pOut->z;
     pOp->p1 = pOut->n;
   }
+  testcase( rc==SQLITE_TOOBIG );
 #endif
   if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
+  assert( rc==SQLITE_OK );
   /* Fall through to the next case, OP_String */
 }
   
-/* Opcode: String P1 P2 * P4 *
+/* Opcode: String P1 P2 P3 P4 P5
 ** Synopsis: r[P2]='P4' (len=P1)
 **
 ** The string value P4 of length P1 (bytes) is stored in register P2.
+**
+** If P3 is not zero and the content of register P3 is equal to P5, then
+** the datatype of the register P2 is converted to BLOB.  The content is
+** the same sequence of bytes, it is merely interpreted as a BLOB instead
+** of a string, as if it had been CAST.  In other words:
+**
+** if( P3!=0 and reg[P3]==P5 ) reg[P2] := CAST(reg[P2] as BLOB)
 */
-case OP_String: {          /* out2-prerelease */
+case OP_String: {          /* out2 */
   assert( pOp->p4.z!=0 );
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Str|MEM_Static|MEM_Term;
   pOut->z = pOp->p4.z;
   pOut->n = pOp->p1;
   pOut->enc = encoding;
   UPDATE_MAX_BLOBSIZE(pOut);
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  if( pOp->p3>0 ){
+    assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+    pIn3 = &aMem[pOp->p3];
+    assert( pIn3->flags & MEM_Int );
+    if( pIn3->u.i==pOp->p5 ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
+  }
+#endif
   break;
 }
 
 /* Opcode: Null P1 P2 P3 * *
-** Synopsis:  r[P2..P3]=NULL
+** Synopsis: r[P2..P3]=NULL
 **
 ** Write a NULL into registers P2.  If P3 greater than P2, then also write
 ** NULL into register P3 and every register in between P2 and P3.  If P3
@@ -71232,24 +80101,27 @@ case OP_String: {          /* out2-prerelease */
 ** NULL values will not compare equal even if SQLITE_NULLEQ is set on
 ** OP_Ne or OP_Eq.
 */
-case OP_Null: {           /* out2-prerelease */
+case OP_Null: {           /* out2 */
   int cnt;
   u16 nullFlag;
+  pOut = out2Prerelease(p, pOp);
   cnt = pOp->p3-pOp->p2;
-  assert( pOp->p3<=(p->nMem-p->nCursor) );
+  assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
   pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
+  pOut->n = 0;
   while( cnt>0 ){
     pOut++;
     memAboutToChange(p, pOut);
     sqlite3VdbeMemSetNull(pOut);
     pOut->flags = nullFlag;
+    pOut->n = 0;
     cnt--;
   }
   break;
 }
 
 /* Opcode: SoftNull P1 * * * *
-** Synopsis:  r[P1]=NULL
+** Synopsis: r[P1]=NULL
 **
 ** Set register P1 to have the value NULL as seen by the OP_MakeRecord
 ** instruction, but do not free any string or blob memory associated with
@@ -71257,9 +80129,9 @@ case OP_Null: {           /* out2-prerelease */
 ** previously copied using OP_SCopy, the copies will continue to be valid.
 */
 case OP_SoftNull: {
-  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
   pOut = &aMem[pOp->p1];
-  pOut->flags = (pOut->flags|MEM_Null)&~MEM_Undefined;
+  pOut->flags = (pOut->flags&~(MEM_Undefined|MEM_AffMask))|MEM_Null;
   break;
 }
 
@@ -71269,8 +80141,9 @@ case OP_SoftNull: {
 ** P4 points to a blob of data P1 bytes long.  Store this
 ** blob in register P2.
 */
-case OP_Blob: {                /* out2-prerelease */
+case OP_Blob: {                /* out2 */
   assert( pOp->p1 <= SQLITE_MAX_LENGTH );
+  pOut = out2Prerelease(p, pOp);
   sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
   pOut->enc = encoding;
   UPDATE_MAX_BLOBSIZE(pOut);
@@ -71285,22 +80158,23 @@ case OP_Blob: {                /* out2-prerelease */
 ** If the parameter is named, then its name appears in P4.
 ** The P4 value is used by sqlite3_bind_parameter_name().
 */
-case OP_Variable: {            /* out2-prerelease */
+case OP_Variable: {            /* out2 */
   Mem *pVar;       /* Value being transferred */
 
   assert( pOp->p1>0 && pOp->p1<=p->nVar );
-  assert( pOp->p4.z==0 || pOp->p4.z==p->azVar[pOp->p1-1] );
+  assert( pOp->p4.z==0 || pOp->p4.z==sqlite3VListNumToName(p->pVList,pOp->p1) );
   pVar = &p->aVar[pOp->p1 - 1];
   if( sqlite3VdbeMemTooBig(pVar) ){
     goto too_big;
   }
+  pOut = &aMem[pOp->p2];
   sqlite3VdbeMemShallowCopy(pOut, pVar, MEM_Static);
   UPDATE_MAX_BLOBSIZE(pOut);
   break;
 }
 
 /* Opcode: Move P1 P2 P3 * *
-** Synopsis:  r[P2@P3]=r[P1@P3]
+** Synopsis: r[P2@P3]=r[P1@P3]
 **
 ** Move the P3 values in register P1..P1+P3-1 over into
 ** registers P2..P2+P3-1.  Registers P1..P1+P3-1 are
@@ -71322,16 +80196,17 @@ case OP_Move: {
   pIn1 = &aMem[p1];
   pOut = &aMem[p2];
   do{
-    assert( pOut<=&aMem[(p->nMem-p->nCursor)] );
-    assert( pIn1<=&aMem[(p->nMem-p->nCursor)] );
+    assert( pOut<=&aMem[(p->nMem+1 - p->nCursor)] );
+    assert( pIn1<=&aMem[(p->nMem+1 - p->nCursor)] );
     assert( memIsValid(pIn1) );
     memAboutToChange(p, pOut);
     sqlite3VdbeMemMove(pOut, pIn1);
 #ifdef SQLITE_DEBUG
-    if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<&aMem[p1+pOp->p3] ){
-      pOut->pScopyFrom += p1 - pOp->p2;
+    if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrompScopyFrom += pOp->p2 - p1;
     }
 #endif
+    Deephemeralize(pOut);
     REGISTER_TRACE(p2++, pOut);
     pIn1++;
     pOut++;
@@ -71392,8 +80267,24 @@ case OP_SCopy: {            /* out2 */
   break;
 }
 
+/* Opcode: IntCopy P1 P2 * * *
+** Synopsis: r[P2]=r[P1]
+**
+** Transfer the integer value held in register P1 into register P2.
+**
+** This is an optimized version of SCopy that works only for integer
+** values.
+*/
+case OP_IntCopy: {            /* out2 */
+  pIn1 = &aMem[pOp->p1];
+  assert( (pIn1->flags & MEM_Int)!=0 );
+  pOut = &aMem[pOp->p2];
+  sqlite3VdbeMemSetInt64(pOut, pIn1->u.i);
+  break;
+}
+
 /* Opcode: ResultRow P1 P2 * * *
-** Synopsis:  output=r[P1@P2]
+** Synopsis: output=r[P1@P2]
 **
 ** The registers P1 through P1+P2-1 contain a single row of
 ** results. This opcode causes the sqlite3_step() call to terminate
@@ -71406,17 +80297,17 @@ case OP_ResultRow: {
   int i;
   assert( p->nResColumn==pOp->p2 );
   assert( pOp->p1>0 );
-  assert( pOp->p1+pOp->p2<=(p->nMem-p->nCursor)+1 );
+  assert( pOp->p1+pOp->p2<=(p->nMem+1 - p->nCursor)+1 );
 
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   /* Run the progress counter just before returning.
   */
   if( db->xProgress!=0
-   && nVmStep>=nProgressLimit
+   && nVmStep>=nProgressLimit 
    && db->xProgress(db->pProgressArg)!=0
   ){
     rc = SQLITE_INTERRUPT;
-    goto vdbe_error_halt;
+    goto abort_due_to_error;
   }
 #endif
 
@@ -71426,7 +80317,7 @@ case OP_ResultRow: {
   if( SQLITE_OK!=(rc = sqlite3VdbeCheckFk(p, 0)) ){
     assert( db->flags&SQLITE_CountRows );
     assert( p->usesStmtJournal );
-    break;
+    goto abort_due_to_error;
   }
 
   /* If the SQLITE_CountRows flag is set in sqlite3.flags mask, then 
@@ -71446,9 +80337,7 @@ case OP_ResultRow: {
   */
   assert( p->iStatement==0 || db->flags&SQLITE_CountRows );
   rc = sqlite3VdbeCloseStatement(p, SAVEPOINT_RELEASE);
-  if( NEVER(rc!=SQLITE_OK) ){
-    break;
-  }
+  assert( rc==SQLITE_OK );
 
   /* Invalidate all ephemeral cursor row caches */
   p->cacheCtr = (p->cacheCtr + 2)|1;
@@ -71468,9 +80357,13 @@ case OP_ResultRow: {
   }
   if( db->mallocFailed ) goto no_mem;
 
+  if( db->mTrace & SQLITE_TRACE_ROW ){
+    db->xTrace(SQLITE_TRACE_ROW, db->pTraceArg, p, 0);
+  }
+
   /* Return SQLITE_ROW
   */
-  p->pc = pc + 1;
+  p->pc = (int)(pOp - aOp) + 1;
   rc = SQLITE_ROW;
   goto vdbe_return;
 }
@@ -71524,14 +80417,14 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
 }
 
 /* Opcode: Add P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P1]+r[P2]
+** Synopsis: r[P3]=r[P1]+r[P2]
 **
 ** Add the value in register P1 to the value in register P2
 ** and store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Multiply P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P1]*r[P2]
+** Synopsis: r[P3]=r[P1]*r[P2]
 **
 **
 ** Multiply the value in register P1 by the value in register P2
@@ -71539,14 +80432,14 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Subtract P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P2]-r[P1]
+** Synopsis: r[P3]=r[P2]-r[P1]
 **
 ** Subtract the value in register P1 from the value in register P2
 ** and store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Divide P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P2]/r[P1]
+** Synopsis: r[P3]=r[P2]/r[P1]
 **
 ** Divide the value in register P1 by the value in register P2
 ** and store the result in register P3 (P3=P2/P1). If the value in 
@@ -71554,7 +80447,7 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
 ** NULL, the result is NULL.
 */
 /* Opcode: Remainder P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P2]%r[P1]
+** Synopsis: r[P3]=r[P2]%r[P1]
 **
 ** Compute the remainder after integer register P2 is divided by 
 ** register P1 and store the result in register P3. 
@@ -71581,7 +80474,6 @@ case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
   type2 = numericType(pIn2);
   pOut = &aMem[pOp->p3];
   flags = pIn1->flags | pIn2->flags;
-  if( (flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
   if( (type1 & type2 & MEM_Int)!=0 ){
     iA = pIn1->u.i;
     iB = pIn2->u.i;
@@ -71605,6 +80497,8 @@ case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
     }
     pOut->u.i = iB;
     MemSetTypeFlag(pOut, MEM_Int);
+  }else if( (flags & MEM_Null)!=0 ){
+    goto arithmetic_result_is_null;
   }else{
     bIntint = 0;
 fp_math:
@@ -71652,7 +80546,7 @@ arithmetic_result_is_null:
 
 /* Opcode: CollSeq P1 * * P4
 **
-** P4 is a pointer to a CollSeq struct. If the next call to a user function
+** P4 is a pointer to a CollSeq object. If the next call to a user function
 ** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
 ** be returned. This is used by the built-in min(), max() and nullif()
 ** functions.
@@ -71663,7 +80557,7 @@ arithmetic_result_is_null:
 **
 ** The interface used by the implementation of the aforementioned functions
 ** to retrieve the collation sequence set by this opcode is not available
-** publicly, only to user functions defined in func.c.
+** publicly.  Only built-in functions have access to this feature.
 */
 case OP_CollSeq: {
   assert( pOp->p4type==P4_COLLSEQ );
@@ -71673,93 +80567,22 @@ case OP_CollSeq: {
   break;
 }
 
-/* Opcode: Function P1 P2 P3 P4 P5
-** Synopsis: r[P3]=func(r[P2@P5])
-**
-** Invoke a user function (P4 is a pointer to a Function structure that
-** defines the function) with P5 arguments taken from register P2 and
-** successors.  The result of the function is stored in register P3.
-** Register P3 must not be one of the function inputs.
-**
-** P1 is a 32-bit bitmask indicating whether or not each argument to the 
-** function was determined to be constant at compile time. If the first
-** argument was constant then bit 0 of P1 is set. This is used to determine
-** whether meta data associated with a user function argument using the
-** sqlite3_set_auxdata() API may be safely retained until the next
-** invocation of this opcode.
-**
-** See also: AggStep and AggFinal
-*/
-case OP_Function: {
-  int i;
-  Mem *pArg;
-  sqlite3_context ctx;
-  sqlite3_value **apVal;
-  int n;
-
-  n = pOp->p5;
-  apVal = p->apArg;
-  assert( apVal || n==0 );
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
-  ctx.pOut = &aMem[pOp->p3];
-  memAboutToChange(p, ctx.pOut);
-
-  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem-p->nCursor)+1) );
-  assert( pOp->p3p2 || pOp->p3>=pOp->p2+n );
-  pArg = &aMem[pOp->p2];
-  for(i=0; ip2+i, pArg);
-  }
-
-  assert( pOp->p4type==P4_FUNCDEF );
-  ctx.pFunc = pOp->p4.pFunc;
-  ctx.iOp = pc;
-  ctx.pVdbe = p;
-  MemSetTypeFlag(ctx.pOut, MEM_Null);
-  ctx.fErrorOrAux = 0;
-  db->lastRowid = lastRowid;
-  (*ctx.pFunc->xFunc)(&ctx, n, apVal); /* IMP: R-24505-23230 */
-  lastRowid = db->lastRowid;  /* Remember rowid changes made by xFunc */
-
-  /* If the function returned an error, throw an exception */
-  if( ctx.fErrorOrAux ){
-    if( ctx.isError ){
-      sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(ctx.pOut));
-      rc = ctx.isError;
-    }
-    sqlite3VdbeDeleteAuxData(p, pc, pOp->p1);
-  }
-
-  /* Copy the result of the function into register P3 */
-  sqlite3VdbeChangeEncoding(ctx.pOut, encoding);
-  if( sqlite3VdbeMemTooBig(ctx.pOut) ){
-    goto too_big;
-  }
-
-  REGISTER_TRACE(pOp->p3, ctx.pOut);
-  UPDATE_MAX_BLOBSIZE(ctx.pOut);
-  break;
-}
-
 /* Opcode: BitAnd P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P1]&r[P2]
+** Synopsis: r[P3]=r[P1]&r[P2]
 **
 ** Take the bit-wise AND of the values in register P1 and P2 and
 ** store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: BitOr P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P1]|r[P2]
+** Synopsis: r[P3]=r[P1]|r[P2]
 **
 ** Take the bit-wise OR of the values in register P1 and P2 and
 ** store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: ShiftLeft P1 P2 P3 * *
-** Synopsis:  r[P3]=r[P2]<>r[P1]
+** Synopsis: r[P3]=r[P2]>>r[P1]
 **
 ** Shift the integer value in register P2 to the right by the
 ** number of bits specified by the integer in register P1.
@@ -71827,7 +80650,7 @@ case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */
 }
 
 /* Opcode: AddImm  P1 P2 * * *
-** Synopsis:  r[P1]=r[P1]+P2
+** Synopsis: r[P1]=r[P1]+P2
 ** 
 ** Add the constant P2 to the value in register P1.
 ** The result is always an integer.
@@ -71859,8 +80682,7 @@ case OP_MustBeInt: {            /* jump, in1 */
         rc = SQLITE_MISMATCH;
         goto abort_due_to_error;
       }else{
-        pc = pOp->p2 - 1;
-        break;
+        goto jump_to_p2;
       }
     }
   }
@@ -71894,19 +80716,19 @@ case OP_RealAffinity: {                  /* in1 */
 ** Force the value in register P1 to be the type defined by P2.
 ** 
 ** 
      
-** 
    •  TEXT
-** 
    •  BLOB
-** 
    •  NUMERIC
-** 
    •  INTEGER
-** 
    •  REAL
+** 
    •  P2=='A' → BLOB
+** 
    •  P2=='B' → TEXT
+** 
    •  P2=='C' → NUMERIC
+** 
    •  P2=='D' → INTEGER
+** 
    •  P2=='E' → REAL
 ** 
    
 **
 ** A NULL value is not changed by this routine.  It remains NULL.
 */
 case OP_Cast: {                  /* in1 */
-  assert( pOp->p2>=SQLITE_AFF_NONE && pOp->p2<=SQLITE_AFF_REAL );
+  assert( pOp->p2>=SQLITE_AFF_BLOB && pOp->p2<=SQLITE_AFF_REAL );
   testcase( pOp->p2==SQLITE_AFF_TEXT );
-  testcase( pOp->p2==SQLITE_AFF_NONE );
+  testcase( pOp->p2==SQLITE_AFF_BLOB );
   testcase( pOp->p2==SQLITE_AFF_NUMERIC );
   testcase( pOp->p2==SQLITE_AFF_INTEGER );
   testcase( pOp->p2==SQLITE_AFF_REAL );
@@ -71915,19 +80737,17 @@ case OP_Cast: {                  /* in1 */
   rc = ExpandBlob(pIn1);
   sqlite3VdbeMemCast(pIn1, pOp->p2, encoding);
   UPDATE_MAX_BLOBSIZE(pIn1);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_CAST */
 
-/* Opcode: Lt P1 P2 P3 P4 P5
-** Synopsis: if r[P1]r[P3] goto P2
+** Synopsis: IF r[P3]>r[P1]
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the content of register P3 is greater than the content of
 ** register P1.  See the Lt opcode for additional information.
 */
 /* Opcode: Ge P1 P2 P3 P4 P5
-** Synopsis: if r[P1]>=r[P3] goto P2
+** Synopsis: IF r[P3]>=r[P1]
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the content of register P3 is greater than or equal to the content of
@@ -72007,7 +80844,7 @@ case OP_Lt:               /* same as TK_LT, jump, in1, in3 */
 case OP_Le:               /* same as TK_LE, jump, in1, in3 */
 case OP_Gt:               /* same as TK_GT, jump, in1, in3 */
 case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
-  int res;            /* Result of the comparison of pIn1 against pIn3 */
+  int res, res2;      /* Result of the comparison of pIn1 against pIn3 */
   char affinity;      /* Affinity to use for comparison */
   u16 flags1;         /* Copy of initial value of pIn1->flags */
   u16 flags3;         /* Copy of initial value of pIn3->flags */
@@ -72026,13 +80863,12 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       assert( pOp->opcode==OP_Eq || pOp->opcode==OP_Ne );
       assert( (flags1 & MEM_Cleared)==0 );
       assert( (pOp->p5 & SQLITE_JUMPIFNULL)==0 );
-      if( (flags1&MEM_Null)!=0
-       && (flags3&MEM_Null)!=0
+      if( (flags1&flags3&MEM_Null)!=0
        && (flags3&MEM_Cleared)==0
       ){
-        res = 0;  /* Results are equal */
+        res = 0;  /* Operands are equal */
       }else{
-        res = 1;  /* Results are not equal */
+        res = 1;  /* Operands are not equal */
       }
     }else{
       /* SQLITE_NULLEQ is clear and at least one operand is NULL,
@@ -72041,12 +80877,14 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       */
       if( pOp->p5 & SQLITE_STOREP2 ){
         pOut = &aMem[pOp->p2];
+        iCompare = 1;    /* Operands are not equal */
+        memAboutToChange(p, pOut);
         MemSetTypeFlag(pOut, MEM_Null);
         REGISTER_TRACE(pOp->p2, pOut);
       }else{
         VdbeBranchTaken(2,3);
         if( pOp->p5 & SQLITE_JUMPIFNULL ){
-          pc = pOp->p2-1;
+          goto jump_to_p2;
         }
       }
       break;
@@ -72055,76 +80893,128 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
     /* Neither operand is NULL.  Do a comparison. */
     affinity = pOp->p5 & SQLITE_AFF_MASK;
     if( affinity>=SQLITE_AFF_NUMERIC ){
-      if( (pIn1->flags & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
-        applyNumericAffinity(pIn1,0);
+      if( (flags1 | flags3)&MEM_Str ){
+        if( (flags1 & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
+          applyNumericAffinity(pIn1,0);
+          testcase( flags3!=pIn3->flags ); /* Possible if pIn1==pIn3 */
+          flags3 = pIn3->flags;
+        }
+        if( (flags3 & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
+          applyNumericAffinity(pIn3,0);
+        }
       }
-      if( (pIn3->flags & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
-        applyNumericAffinity(pIn3,0);
+      /* Handle the common case of integer comparison here, as an
+      ** optimization, to avoid a call to sqlite3MemCompare() */
+      if( (pIn1->flags & pIn3->flags & MEM_Int)!=0 ){
+        if( pIn3->u.i > pIn1->u.i ){ res = +1; goto compare_op; }
+        if( pIn3->u.i < pIn1->u.i ){ res = -1; goto compare_op; }
+        res = 0;
+        goto compare_op;
       }
     }else if( affinity==SQLITE_AFF_TEXT ){
-      if( (pIn1->flags & MEM_Str)==0 && (pIn1->flags & (MEM_Int|MEM_Real))!=0 ){
+      if( (flags1 & MEM_Str)==0 && (flags1 & (MEM_Int|MEM_Real))!=0 ){
         testcase( pIn1->flags & MEM_Int );
         testcase( pIn1->flags & MEM_Real );
         sqlite3VdbeMemStringify(pIn1, encoding, 1);
+        testcase( (flags1&MEM_Dyn) != (pIn1->flags&MEM_Dyn) );
+        flags1 = (pIn1->flags & ~MEM_TypeMask) | (flags1 & MEM_TypeMask);
+        assert( pIn1!=pIn3 );
       }
-      if( (pIn3->flags & MEM_Str)==0 && (pIn3->flags & (MEM_Int|MEM_Real))!=0 ){
+      if( (flags3 & MEM_Str)==0 && (flags3 & (MEM_Int|MEM_Real))!=0 ){
         testcase( pIn3->flags & MEM_Int );
         testcase( pIn3->flags & MEM_Real );
         sqlite3VdbeMemStringify(pIn3, encoding, 1);
+        testcase( (flags3&MEM_Dyn) != (pIn3->flags&MEM_Dyn) );
+        flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask);
       }
     }
     assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
-    if( pIn1->flags & MEM_Zero ){
-      sqlite3VdbeMemExpandBlob(pIn1);
-      flags1 &= ~MEM_Zero;
-    }
-    if( pIn3->flags & MEM_Zero ){
-      sqlite3VdbeMemExpandBlob(pIn3);
-      flags3 &= ~MEM_Zero;
-    }
-    if( db->mallocFailed ) goto no_mem;
     res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
   }
+compare_op:
   switch( pOp->opcode ){
-    case OP_Eq:    res = res==0;     break;
-    case OP_Ne:    res = res!=0;     break;
-    case OP_Lt:    res = res<0;      break;
-    case OP_Le:    res = res<=0;     break;
-    case OP_Gt:    res = res>0;      break;
-    default:       res = res>=0;     break;
+    case OP_Eq:    res2 = res==0;     break;
+    case OP_Ne:    res2 = res;        break;
+    case OP_Lt:    res2 = res<0;      break;
+    case OP_Le:    res2 = res<=0;     break;
+    case OP_Gt:    res2 = res>0;      break;
+    default:       res2 = res>=0;     break;
   }
 
+  /* Undo any changes made by applyAffinity() to the input registers. */
+  assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );
+  pIn1->flags = flags1;
+  assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );
+  pIn3->flags = flags3;
+
   if( pOp->p5 & SQLITE_STOREP2 ){
     pOut = &aMem[pOp->p2];
+    iCompare = res;
+    res2 = res2!=0;  /* For this path res2 must be exactly 0 or 1 */
+    if( (pOp->p5 & SQLITE_KEEPNULL)!=0 ){
+      /* The KEEPNULL flag prevents OP_Eq from overwriting a NULL with 1
+      ** and prevents OP_Ne from overwriting NULL with 0.  This flag
+      ** is only used in contexts where either:
+      **   (1) op==OP_Eq && (r[P2]==NULL || r[P2]==0)
+      **   (2) op==OP_Ne && (r[P2]==NULL || r[P2]==1)
+      ** Therefore it is not necessary to check the content of r[P2] for
+      ** NULL. */
+      assert( pOp->opcode==OP_Ne || pOp->opcode==OP_Eq );
+      assert( res2==0 || res2==1 );
+      testcase( res2==0 && pOp->opcode==OP_Eq );
+      testcase( res2==1 && pOp->opcode==OP_Eq );
+      testcase( res2==0 && pOp->opcode==OP_Ne );
+      testcase( res2==1 && pOp->opcode==OP_Ne );
+      if( (pOp->opcode==OP_Eq)==res2 ) break;
+    }
     memAboutToChange(p, pOut);
     MemSetTypeFlag(pOut, MEM_Int);
-    pOut->u.i = res;
+    pOut->u.i = res2;
     REGISTER_TRACE(pOp->p2, pOut);
   }else{
     VdbeBranchTaken(res!=0, (pOp->p5 & SQLITE_NULLEQ)?2:3);
-    if( res ){
-      pc = pOp->p2-1;
+    if( res2 ){
+      goto jump_to_p2;
     }
   }
-  /* Undo any changes made by applyAffinity() to the input registers. */
-  pIn1->flags = flags1;
-  pIn3->flags = flags3;
   break;
 }
 
+/* Opcode: ElseNotEq * P2 * * *
+**
+** This opcode must immediately follow an OP_Lt or OP_Gt comparison operator.
+** If result of an OP_Eq comparison on the same two operands
+** would have be NULL or false (0), then then jump to P2. 
+** If the result of an OP_Eq comparison on the two previous operands
+** would have been true (1), then fall through.
+*/
+case OP_ElseNotEq: {       /* same as TK_ESCAPE, jump */
+  assert( pOp>aOp );
+  assert( pOp[-1].opcode==OP_Lt || pOp[-1].opcode==OP_Gt );
+  assert( pOp[-1].p5 & SQLITE_STOREP2 );
+  VdbeBranchTaken(iCompare!=0, 2);
+  if( iCompare!=0 ) goto jump_to_p2;
+  break;
+}
+
+
 /* Opcode: Permutation * * * P4 *
 **
-** Set the permutation used by the OP_Compare operator to be the array
-** of integers in P4.
+** Set the permutation used by the OP_Compare operator in the next
+** instruction.  The permutation is stored in the P4 operand.
 **
 ** The permutation is only valid until the next OP_Compare that has
 ** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 
 ** occur immediately prior to the OP_Compare.
+**
+** The first integer in the P4 integer array is the length of the array
+** and does not become part of the permutation.
 */
 case OP_Permutation: {
   assert( pOp->p4type==P4_INTARRAY );
   assert( pOp->p4.ai );
-  aPermute = pOp->p4.ai;
+  assert( pOp[1].opcode==OP_Compare );
+  assert( pOp[1].p5 & OPFLAG_PERMUTE );
   break;
 }
 
@@ -72157,23 +81047,32 @@ case OP_Compare: {
   int idx;
   CollSeq *pColl;    /* Collating sequence to use on this term */
   int bRev;          /* True for DESCENDING sort order */
+  int *aPermute;     /* The permutation */
 
-  if( (pOp->p5 & OPFLAG_PERMUTE)==0 ) aPermute = 0;
+  if( (pOp->p5 & OPFLAG_PERMUTE)==0 ){
+    aPermute = 0;
+  }else{
+    assert( pOp>aOp );
+    assert( pOp[-1].opcode==OP_Permutation );
+    assert( pOp[-1].p4type==P4_INTARRAY );
+    aPermute = pOp[-1].p4.ai + 1;
+    assert( aPermute!=0 );
+  }
   n = pOp->p3;
   pKeyInfo = pOp->p4.pKeyInfo;
   assert( n>0 );
   assert( pKeyInfo!=0 );
   p1 = pOp->p1;
   p2 = pOp->p2;
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
   if( aPermute ){
     int k, mx = 0;
     for(k=0; kmx ) mx = aPermute[k];
-    assert( p1>0 && p1+mx<=(p->nMem-p->nCursor)+1 );
-    assert( p2>0 && p2+mx<=(p->nMem-p->nCursor)+1 );
+    assert( p1>0 && p1+mx<=(p->nMem+1 - p->nCursor)+1 );
+    assert( p2>0 && p2+mx<=(p->nMem+1 - p->nCursor)+1 );
   }else{
-    assert( p1>0 && p1+n<=(p->nMem-p->nCursor)+1 );
-    assert( p2>0 && p2+n<=(p->nMem-p->nCursor)+1 );
+    assert( p1>0 && p1+n<=(p->nMem+1 - p->nCursor)+1 );
+    assert( p2>0 && p2+n<=(p->nMem+1 - p->nCursor)+1 );
   }
 #endif /* SQLITE_DEBUG */
   for(i=0; ip1 - 1;  VdbeBranchTaken(0,3);
+    VdbeBranchTaken(0,3); pOp = &aOp[pOp->p1 - 1];
   }else if( iCompare==0 ){
-    pc = pOp->p2 - 1;  VdbeBranchTaken(1,3);
+    VdbeBranchTaken(1,3); pOp = &aOp[pOp->p2 - 1];
   }else{
-    pc = pOp->p3 - 1;  VdbeBranchTaken(2,3);
+    VdbeBranchTaken(2,3); pOp = &aOp[pOp->p3 - 1];
   }
   break;
 }
@@ -72304,23 +81202,39 @@ case OP_BitNot: {             /* same as TK_BITNOT, in1, out2 */
 
 /* Opcode: Once P1 P2 * * *
 **
-** Check the "once" flag number P1. If it is set, jump to instruction P2. 
-** Otherwise, set the flag and fall through to the next instruction.
-** In other words, this opcode causes all following opcodes up through P2
-** (but not including P2) to run just once and to be skipped on subsequent
-** times through the loop.
+** Fall through to the next instruction the first time this opcode is
+** encountered on each invocation of the byte-code program.  Jump to P2
+** on the second and all subsequent encounters during the same invocation.
+**
+** Top-level programs determine first invocation by comparing the P1
+** operand against the P1 operand on the OP_Init opcode at the beginning
+** of the program.  If the P1 values differ, then fall through and make
+** the P1 of this opcode equal to the P1 of OP_Init.  If P1 values are
+** the same then take the jump.
 **
-** All "once" flags are initially cleared whenever a prepared statement
-** first begins to run.
+** For subprograms, there is a bitmask in the VdbeFrame that determines
+** whether or not the jump should be taken.  The bitmask is necessary
+** because the self-altering code trick does not work for recursive
+** triggers.
 */
 case OP_Once: {             /* jump */
-  assert( pOp->p1nOnceFlag );
-  VdbeBranchTaken(p->aOnceFlag[pOp->p1]!=0, 2);
-  if( p->aOnceFlag[pOp->p1] ){
-    pc = pOp->p2-1;
+  u32 iAddr;                /* Address of this instruction */
+  assert( p->aOp[0].opcode==OP_Init );
+  if( p->pFrame ){
+    iAddr = (int)(pOp - p->aOp);
+    if( (p->pFrame->aOnce[iAddr/8] & (1<<(iAddr & 7)))!=0 ){
+      VdbeBranchTaken(1, 2);
+      goto jump_to_p2;
+    }
+    p->pFrame->aOnce[iAddr/8] |= 1<<(iAddr & 7);
   }else{
-    p->aOnceFlag[pOp->p1] = 1;
+    if( p->aOp[0].p1==pOp->p1 ){
+      VdbeBranchTaken(1, 2);
+      goto jump_to_p2;
+    }
   }
+  VdbeBranchTaken(0, 2);
+  pOp->p1 = p->aOp[0].p1;
   break;
 }
 
@@ -72352,13 +81266,13 @@ case OP_IfNot: {            /* jump, in1 */
   }
   VdbeBranchTaken(c!=0, 2);
   if( c ){
-    pc = pOp->p2-1;
+    goto jump_to_p2;
   }
   break;
 }
 
 /* Opcode: IsNull P1 P2 * * *
-** Synopsis:  if r[P1]==NULL goto P2
+** Synopsis: if r[P1]==NULL goto P2
 **
 ** Jump to P2 if the value in register P1 is NULL.
 */
@@ -72366,7 +81280,7 @@ case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */
   pIn1 = &aMem[pOp->p1];
   VdbeBranchTaken( (pIn1->flags & MEM_Null)!=0, 2);
   if( (pIn1->flags & MEM_Null)!=0 ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
   }
   break;
 }
@@ -72380,13 +81294,31 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
   pIn1 = &aMem[pOp->p1];
   VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);
   if( (pIn1->flags & MEM_Null)==0 ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
+  }
+  break;
+}
+
+/* Opcode: IfNullRow P1 P2 P3 * *
+** Synopsis: if P1.nullRow then r[P3]=NULL, goto P2
+**
+** Check the cursor P1 to see if it is currently pointing at a NULL row.
+** If it is, then set register P3 to NULL and jump immediately to P2.
+** If P1 is not on a NULL row, then fall through without making any
+** changes.
+*/
+case OP_IfNullRow: {         /* jump */
+  assert( pOp->p1>=0 && pOp->p1nCursor );
+  assert( p->apCsr[pOp->p1]!=0 );
+  if( p->apCsr[pOp->p1]->nullRow ){
+    sqlite3VdbeMemSetNull(aMem + pOp->p3);
+    goto jump_to_p2;
   }
   break;
 }
 
 /* Opcode: Column P1 P2 P3 P4 P5
-** Synopsis:  r[P3]=PX
+** Synopsis: r[P3]=PX
 **
 ** Interpret the data that cursor P1 points to as a structure built using
 ** the MakeRecord instruction.  (See the MakeRecord opcode for additional
@@ -72396,7 +81328,7 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
 **
 ** The value extracted is stored in register P3.
 **
-** If the column contains fewer than P2 fields, then extract a NULL.  Or,
+** If the record contains fewer than P2 fields, then extract a NULL.  Or,
 ** if the P4 argument is a P4_MEM use the value of the P4 argument as
 ** the result.
 **
@@ -72405,13 +81337,12 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
 ** The first OP_Column against a pseudo-table after the value of the content
 ** register has changed should have this bit set.
 **
-** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 when
+** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 then
 ** the result is guaranteed to only be used as the argument of a length()
 ** or typeof() function, respectively.  The loading of large blobs can be
 ** skipped for length() and all content loading can be skipped for typeof().
 */
 case OP_Column: {
-  i64 payloadSize64; /* Number of bytes in the record */
   int p2;            /* column number to retrieve */
   VdbeCursor *pC;    /* The VDBE cursor */
   BtCursor *pCrsr;   /* The BTree cursor */
@@ -72424,36 +81355,36 @@ case OP_Column: {
   const u8 *zHdr;    /* Next unparsed byte of the header */
   const u8 *zEndHdr; /* Pointer to first byte after the header */
   u32 offset;        /* Offset into the data */
-  u32 szField;       /* Number of bytes in the content of a field */
+  u64 offset64;      /* 64-bit offset */
   u32 avail;         /* Number of bytes of available data */
   u32 t;             /* A type code from the record header */
-  u16 fx;            /* pDest->flags value */
   Mem *pReg;         /* PseudoTable input register */
 
+  pC = p->apCsr[pOp->p1];
   p2 = pOp->p2;
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
+
+  /* If the cursor cache is stale (meaning it is not currently point at
+  ** the correct row) then bring it up-to-date by doing the necessary 
+  ** B-Tree seek. */
+  rc = sqlite3VdbeCursorMoveto(&pC, &p2);
+  if( rc ) goto abort_due_to_error;
+
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pDest = &aMem[pOp->p3];
   memAboutToChange(p, pDest);
   assert( pOp->p1>=0 && pOp->p1nCursor );
-  pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
   assert( p2nField );
   aOffset = pC->aOffset;
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  assert( pC->pVtabCursor==0 ); /* OP_Column never called on virtual table */
-#endif
-  pCrsr = pC->pCursor;
-  assert( pCrsr!=0 || pC->pseudoTableReg>0 ); /* pCrsr NULL on PseudoTables */
-  assert( pCrsr!=0 || pC->nullRow );          /* pC->nullRow on PseudoTables */
+  assert( pC->eCurType!=CURTYPE_VTAB );
+  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
+  assert( pC->eCurType!=CURTYPE_SORTER );
 
-  /* If the cursor cache is stale, bring it up-to-date */
-  rc = sqlite3VdbeCursorMoveto(pC);
-  if( rc ) goto abort_due_to_error;
-  if( pC->cacheStatus!=p->cacheCtr ){
+  if( pC->cacheStatus!=p->cacheCtr ){                /*OPTIMIZATION-IF-FALSE*/
     if( pC->nullRow ){
-      if( pCrsr==0 ){
-        assert( pC->pseudoTableReg>0 );
-        pReg = &aMem[pC->pseudoTableReg];
+      if( pC->eCurType==CURTYPE_PSEUDO ){
+        assert( pC->uc.pseudoTableReg>0 );
+        pReg = &aMem[pC->uc.pseudoTableReg];
         assert( pReg->flags & MEM_Blob );
         assert( memIsValid(pReg) );
         pC->payloadSize = pC->szRow = avail = pReg->n;
@@ -72463,67 +81394,57 @@ case OP_Column: {
         goto op_column_out;
       }
     }else{
+      pCrsr = pC->uc.pCursor;
+      assert( pC->eCurType==CURTYPE_BTREE );
       assert( pCrsr );
-      if( pC->isTable==0 ){
-        assert( sqlite3BtreeCursorIsValid(pCrsr) );
-        VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
-        assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
-        /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
-        ** payload size, so it is impossible for payloadSize64 to be
-        ** larger than 32 bits. */
-        assert( (payloadSize64 & SQLITE_MAX_U32)==(u64)payloadSize64 );
-        pC->aRow = sqlite3BtreeKeyFetch(pCrsr, &avail);
-        pC->payloadSize = (u32)payloadSize64;
-      }else{
-        assert( sqlite3BtreeCursorIsValid(pCrsr) );
-        VVA_ONLY(rc =) sqlite3BtreeDataSize(pCrsr, &pC->payloadSize);
-        assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
-        pC->aRow = sqlite3BtreeDataFetch(pCrsr, &avail);
-      }
+      assert( sqlite3BtreeCursorIsValid(pCrsr) );
+      pC->payloadSize = sqlite3BtreePayloadSize(pCrsr);
+      pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &avail);
       assert( avail<=65536 );  /* Maximum page size is 64KiB */
       if( pC->payloadSize <= (u32)avail ){
         pC->szRow = pC->payloadSize;
+      }else if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+        goto too_big;
       }else{
         pC->szRow = avail;
       }
-      if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-        goto too_big;
-      }
     }
     pC->cacheStatus = p->cacheCtr;
     pC->iHdrOffset = getVarint32(pC->aRow, offset);
     pC->nHdrParsed = 0;
     aOffset[0] = offset;
 
-    /* Make sure a corrupt database has not given us an oversize header.
-    ** Do this now to avoid an oversize memory allocation.
-    **
-    ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte
-    ** types use so much data space that there can only be 4096 and 32 of
-    ** them, respectively.  So the maximum header length results from a
-    ** 3-byte type for each of the maximum of 32768 columns plus three
-    ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
-    */
-    if( offset > 98307 || offset > pC->payloadSize ){
-      rc = SQLITE_CORRUPT_BKPT;
-      goto op_column_error;
-    }
 
-    if( availaRow does not have to hold the entire row, but it does at least
       ** need to cover the header of the record.  If pC->aRow does not contain
       ** the complete header, then set it to zero, forcing the header to be
       ** dynamically allocated. */
       pC->aRow = 0;
       pC->szRow = 0;
-    }
 
-    /* The following goto is an optimization.  It can be omitted and
-    ** everything will still work.  But OP_Column is measurably faster
-    ** by skipping the subsequent conditional, which is always true.
-    */
-    assert( pC->nHdrParsed<=p2 );         /* Conditional skipped */
-    goto op_column_read_header;
+      /* Make sure a corrupt database has not given us an oversize header.
+      ** Do this now to avoid an oversize memory allocation.
+      **
+      ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte
+      ** types use so much data space that there can only be 4096 and 32 of
+      ** them, respectively.  So the maximum header length results from a
+      ** 3-byte type for each of the maximum of 32768 columns plus three
+      ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
+      */
+      if( offset > 98307 || offset > pC->payloadSize ){
+        rc = SQLITE_CORRUPT_BKPT;
+        goto abort_due_to_error;
+      }
+    }else if( offset>0 ){ /*OPTIMIZATION-IF-TRUE*/
+      /* The following goto is an optimization.  It can be omitted and
+      ** everything will still work.  But OP_Column is measurably faster
+      ** by skipping the subsequent conditional, which is always true.
+      */
+      zData = pC->aRow;
+      assert( pC->nHdrParsed<=p2 );         /* Conditional skipped */
+      goto op_column_read_header;
+    }
   }
 
   /* Make sure at least the first p2+1 entries of the header have been
@@ -72533,68 +81454,56 @@ case OP_Column: {
     /* If there is more header available for parsing in the record, try
     ** to extract additional fields up through the p2+1-th field 
     */
-    op_column_read_header:
     if( pC->iHdrOffsetaRow==0 ){
         memset(&sMem, 0, sizeof(sMem));
-        rc = sqlite3VdbeMemFromBtree(pCrsr, 0, aOffset[0], 
-                                     !pC->isTable, &sMem);
-        if( rc!=SQLITE_OK ){
-          goto op_column_error;
-        }
+        rc = sqlite3VdbeMemFromBtree(pC->uc.pCursor, 0, aOffset[0], &sMem);
+        if( rc!=SQLITE_OK ) goto abort_due_to_error;
         zData = (u8*)sMem.z;
       }else{
         zData = pC->aRow;
       }
   
       /* Fill in pC->aType[i] and aOffset[i] values through the p2-th field. */
+    op_column_read_header:
       i = pC->nHdrParsed;
-      offset = aOffset[i];
+      offset64 = aOffset[i];
       zHdr = zData + pC->iHdrOffset;
       zEndHdr = zData + aOffset[0];
-      assert( i<=p2 && zHdraType[i] = t;
-        szField = sqlite3VdbeSerialTypeLen(t);
-        offset += szField;
-        if( offsetaType[i++] = t;
+        aOffset[i] = (u32)(offset64 & 0xffffffff);
       }while( i<=p2 && zHdrnHdrParsed = i;
-      pC->iHdrOffset = (u32)(zHdr - zData);
-      if( pC->aRow==0 ){
-        sqlite3VdbeMemRelease(&sMem);
-        sMem.flags = MEM_Null;
-      }
-  
+
       /* The record is corrupt if any of the following are true:
       ** (1) the bytes of the header extend past the declared header size
-      **          (zHdr>zEndHdr)
       ** (2) the entire header was used but not all data was used
-      **          (zHdr==zEndHdr && offset!=pC->payloadSize)
       ** (3) the end of the data extends beyond the end of the record.
-      **          (offset > pC->payloadSize)
       */
-      if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset!=pC->payloadSize))
-       || (offset > pC->payloadSize)
+      if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset64!=pC->payloadSize))
+       || (offset64 > pC->payloadSize)
       ){
+        if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
         rc = SQLITE_CORRUPT_BKPT;
-        goto op_column_error;
+        goto abort_due_to_error;
       }
+
+      pC->nHdrParsed = i;
+      pC->iHdrOffset = (u32)(zHdr - zData);
+      if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
+    }else{
+      t = 0;
     }
 
-    /* If after trying to extra new entries from the header, nHdrParsed is
+    /* If after trying to extract new entries from the header, nHdrParsed is
     ** still not up to p2, that means that the record has fewer than p2
     ** columns.  So the result will be either the default value or a NULL.
     */
@@ -72606,6 +81515,8 @@ case OP_Column: {
       }
       goto op_column_out;
     }
+  }else{
+    t = pC->aType[p2];
   }
 
   /* Extract the content for the p2+1-th column.  Control can only
@@ -72615,13 +81526,37 @@ case OP_Column: {
   assert( p2nHdrParsed );
   assert( rc==SQLITE_OK );
   assert( sqlite3VdbeCheckMemInvariants(pDest) );
-  if( VdbeMemDynamic(pDest) ) sqlite3VdbeMemSetNull(pDest);
-  t = pC->aType[p2];
+  if( VdbeMemDynamic(pDest) ){
+    sqlite3VdbeMemSetNull(pDest);
+  }
+  assert( t==pC->aType[p2] );
   if( pC->szRow>=aOffset[p2+1] ){
     /* This is the common case where the desired content fits on the original
     ** page - where the content is not on an overflow page */
-    sqlite3VdbeSerialGet(pC->aRow+aOffset[p2], t, pDest);
+    zData = pC->aRow + aOffset[p2];
+    if( t<12 ){
+      sqlite3VdbeSerialGet(zData, t, pDest);
+    }else{
+      /* If the column value is a string, we need a persistent value, not
+      ** a MEM_Ephem value.  This branch is a fast short-cut that is equivalent
+      ** to calling sqlite3VdbeSerialGet() and sqlite3VdbeDeephemeralize().
+      */
+      static const u16 aFlag[] = { MEM_Blob, MEM_Str|MEM_Term };
+      pDest->n = len = (t-12)/2;
+      pDest->enc = encoding;
+      if( pDest->szMalloc < len+2 ){
+        pDest->flags = MEM_Null;
+        if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;
+      }else{
+        pDest->z = pDest->zMalloc;
+      }
+      memcpy(pDest->z, zData, len);
+      pDest->z[len] = 0;
+      pDest->z[len+1] = 0;
+      pDest->flags = aFlag[t&1];
+    }
   }else{
+    pDest->enc = encoding;
     /* This branch happens only when content is on overflow pages */
     if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
           && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))
@@ -72632,39 +81567,23 @@ case OP_Column: {
       **    2. the length(X) function if X is a blob, and
       **    3. if the content length is zero.
       ** So we might as well use bogus content rather than reading
-      ** content from disk.  NULL will work for the value for strings
-      ** and blobs and whatever is in the payloadSize64 variable
-      ** will work for everything else. */
-      sqlite3VdbeSerialGet(t<=13 ? (u8*)&payloadSize64 : 0, t, pDest);
+      ** content from disk. 
+      **
+      ** Although sqlite3VdbeSerialGet() may read at most 8 bytes from the
+      ** buffer passed to it, debugging function VdbeMemPrettyPrint() may
+      ** read up to 16. So 16 bytes of bogus content is supplied.
+      */
+      static u8 aZero[16];  /* This is the bogus content */
+      sqlite3VdbeSerialGet(aZero, t, pDest);
     }else{
-      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, !pC->isTable,
-                                   pDest);
-      if( rc!=SQLITE_OK ){
-        goto op_column_error;
-      }
+      rc = sqlite3VdbeMemFromBtree(pC->uc.pCursor, aOffset[p2], len, pDest);
+      if( rc!=SQLITE_OK ) goto abort_due_to_error;
       sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
       pDest->flags &= ~MEM_Ephem;
     }
   }
-  pDest->enc = encoding;
 
 op_column_out:
-  /* If the column value is an ephemeral string, go ahead and persist
-  ** that string in case the cursor moves before the column value is
-  ** used.  The following code does the equivalent of Deephemeralize()
-  ** but does it faster. */
-  if( (pDest->flags & MEM_Ephem)!=0 && pDest->z ){
-    fx = pDest->flags & (MEM_Str|MEM_Blob);
-    assert( fx!=0 );
-    zData = (const u8*)pDest->z;
-    len = pDest->n;
-    if( sqlite3VdbeMemClearAndResize(pDest, len+2) ) goto no_mem;
-    memcpy(pDest->z, zData, len);
-    pDest->z[len] = 0;
-    pDest->z[len+1] = 0;
-    pDest->flags = fx|MEM_Term;
-  }
-op_column_error:
   UPDATE_MAX_BLOBSIZE(pDest);
   REGISTER_TRACE(pOp->p3, pDest);
   break;
@@ -72675,24 +81594,24 @@ op_column_error:
 **
 ** Apply affinities to a range of P2 registers starting with P1.
 **
-** P4 is a string that is P2 characters long. The nth character of the
-** string indicates the column affinity that should be used for the nth
+** P4 is a string that is P2 characters long. The N-th character of the
+** string indicates the column affinity that should be used for the N-th
 ** memory cell in the range.
 */
 case OP_Affinity: {
   const char *zAffinity;   /* The affinity to be applied */
-  char cAff;               /* A single character of affinity */
 
   zAffinity = pOp->p4.z;
   assert( zAffinity!=0 );
+  assert( pOp->p2>0 );
   assert( zAffinity[pOp->p2]==0 );
   pIn1 = &aMem[pOp->p1];
-  while( (cAff = *(zAffinity++))!=0 ){
-    assert( pIn1 <= &p->aMem[(p->nMem-p->nCursor)] );
+  do{
+    assert( pIn1 <= &p->aMem[(p->nMem+1 - p->nCursor)] );
     assert( memIsValid(pIn1) );
-    applyAffinity(pIn1, cAff, encoding);
+    applyAffinity(pIn1, *(zAffinity++), encoding);
     pIn1++;
-  }
+  }while( zAffinity[0] );
   break;
 }
 
@@ -72703,14 +81622,14 @@ case OP_Affinity: {
 ** use as a data record in a database table or as a key
 ** in an index.  The OP_Column opcode can decode the record later.
 **
-** P4 may be a string that is P2 characters long.  The nth character of the
-** string indicates the column affinity that should be used for the nth
+** P4 may be a string that is P2 characters long.  The N-th character of the
+** string indicates the column affinity that should be used for the N-th
 ** field of the index key.
 **
 ** The mapping from character to affinity is given by the SQLITE_AFF_
 ** macros defined in sqliteInt.h.
 **
-** If P4 is NULL then all index fields have the affinity NONE.
+** If P4 is NULL then all index fields have the affinity BLOB.
 */
 case OP_MakeRecord: {
   u8 *zNewRecord;        /* A buffer to hold the data for the new record */
@@ -72718,7 +81637,7 @@ case OP_MakeRecord: {
   u64 nData;             /* Number of bytes of data space */
   int nHdr;              /* Number of bytes of header space */
   i64 nByte;             /* Data space required for this record */
-  int nZero;             /* Number of zero bytes at the end of the record */
+  i64 nZero;             /* Number of zero bytes at the end of the record */
   int nVarint;           /* Number of bytes in a varint */
   u32 serial_type;       /* Type field */
   Mem *pData0;           /* First field to be combined into the record */
@@ -72728,7 +81647,7 @@ case OP_MakeRecord: {
   int file_format;       /* File format to use for encoding */
   int i;                 /* Space used in zNewRecord[] header */
   int j;                 /* Space used in zNewRecord[] content */
-  int len;               /* Length of a field */
+  u32 len;               /* Length of a field */
 
   /* Assuming the record contains N fields, the record format looks
   ** like this:
@@ -72750,7 +81669,7 @@ case OP_MakeRecord: {
   nZero = 0;         /* Number of zero bytes at the end of the record */
   nField = pOp->p1;
   zAffinity = pOp->p4.z;
-  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem-p->nCursor)+1 );
+  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem+1 - p->nCursor)+1 );
   pData0 = &aMem[nField];
   nField = pOp->p2;
   pLast = &pData0[nField-1];
@@ -72772,17 +81691,30 @@ case OP_MakeRecord: {
     }while( zAffinity[0] );
   }
 
+#ifdef SQLITE_ENABLE_NULL_TRIM
+  /* NULLs can be safely trimmed from the end of the record, as long as
+  ** as the schema format is 2 or more and none of the omitted columns
+  ** have a non-NULL default value.  Also, the record must be left with
+  ** at least one field.  If P5>0 then it will be one more than the
+  ** index of the right-most column with a non-NULL default value */
+  if( pOp->p5 ){
+    while( (pLast->flags & MEM_Null)!=0 && nField>pOp->p5 ){
+      pLast--;
+      nField--;
+    }
+  }
+#endif
+
   /* Loop through the elements that will make up the record to figure
   ** out how much space is required for the new record.
   */
   pRec = pLast;
   do{
     assert( memIsValid(pRec) );
-    pRec->uTemp = serial_type = sqlite3VdbeSerialType(pRec, file_format);
-    len = sqlite3VdbeSerialTypeLen(serial_type);
+    pRec->uTemp = serial_type = sqlite3VdbeSerialType(pRec, file_format, &len);
     if( pRec->flags & MEM_Zero ){
       if( nData ){
-        sqlite3VdbeMemExpandBlob(pRec);
+        if( sqlite3VdbeMemExpandBlob(pRec) ) goto no_mem;
       }else{
         nZero += pRec->u.nZero;
         len -= pRec->u.nZero;
@@ -72792,7 +81724,9 @@ case OP_MakeRecord: {
     testcase( serial_type==127 );
     testcase( serial_type==128 );
     nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
-  }while( (--pRec)>=pData0 );
+    if( pRec==pData0 ) break;
+    pRec--;
+  }while(1);
 
   /* EVIDENCE-OF: R-22564-11647 The header begins with a single varint
   ** which determines the total number of bytes in the header. The varint
@@ -72810,7 +81744,7 @@ case OP_MakeRecord: {
     if( nVarintdb->aLimit[SQLITE_LIMIT_LENGTH] ){
+  if( nByte+nZero>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
 
@@ -72841,14 +81775,13 @@ case OP_MakeRecord: {
   assert( i==nHdr );
   assert( j==nByte );
 
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pOut->n = (int)nByte;
   pOut->flags = MEM_Blob;
   if( nZero ){
     pOut->u.nZero = nZero;
     pOut->flags |= MEM_Zero;
   }
-  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
   REGISTER_TRACE(pOp->p3, pOut);
   UPDATE_MAX_BLOBSIZE(pOut);
   break;
@@ -72861,14 +81794,17 @@ case OP_MakeRecord: {
 ** opened by cursor P1 in register P2
 */
 #ifndef SQLITE_OMIT_BTREECOUNT
-case OP_Count: {         /* out2-prerelease */
+case OP_Count: {         /* out2 */
   i64 nEntry;
   BtCursor *pCrsr;
 
-  pCrsr = p->apCsr[pOp->p1]->pCursor;
+  assert( p->apCsr[pOp->p1]->eCurType==CURTYPE_BTREE );
+  pCrsr = p->apCsr[pOp->p1]->uc.pCursor;
   assert( pCrsr );
   nEntry = 0;  /* Not needed.  Only used to silence a warning. */
   rc = sqlite3BtreeCount(pCrsr, &nEntry);
+  if( rc ) goto abort_due_to_error;
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = nEntry;
   break;
 }
@@ -72907,8 +81843,7 @@ case OP_Savepoint: {
       /* A new savepoint cannot be created if there are active write 
       ** statements (i.e. open read/write incremental blob handles).
       */
-      sqlite3SetString(&p->zErrMsg, db, "cannot open savepoint - "
-        "SQL statements in progress");
+      sqlite3VdbeError(p, "cannot open savepoint - SQL statements in progress");
       rc = SQLITE_BUSY;
     }else{
       nName = sqlite3Strlen30(zName);
@@ -72925,7 +81860,7 @@ case OP_Savepoint: {
 #endif
 
       /* Create a new savepoint structure. */
-      pNew = sqlite3DbMallocRaw(db, sizeof(Savepoint)+nName+1);
+      pNew = sqlite3DbMallocRawNN(db, sizeof(Savepoint)+nName+1);
       if( pNew ){
         pNew->zName = (char *)&pNew[1];
         memcpy(pNew->zName, zName, nName+1);
@@ -72938,7 +81873,7 @@ case OP_Savepoint: {
         }else{
           db->nSavepoint++;
         }
-    
+
         /* Link the new savepoint into the database handle's list. */
         pNew->pNext = db->pSavepoint;
         db->pSavepoint = pNew;
@@ -72959,15 +81894,14 @@ case OP_Savepoint: {
       iSavepoint++;
     }
     if( !pSavepoint ){
-      sqlite3SetString(&p->zErrMsg, db, "no such savepoint: %s", zName);
+      sqlite3VdbeError(p, "no such savepoint: %s", zName);
       rc = SQLITE_ERROR;
     }else if( db->nVdbeWrite>0 && p1==SAVEPOINT_RELEASE ){
       /* It is not possible to release (commit) a savepoint if there are 
       ** active write statements.
       */
-      sqlite3SetString(&p->zErrMsg, db, 
-        "cannot release savepoint - SQL statements in progress"
-      );
+      sqlite3VdbeError(p, "cannot release savepoint - "
+                          "SQL statements in progress");
       rc = SQLITE_BUSY;
     }else{
 
@@ -72982,7 +81916,7 @@ case OP_Savepoint: {
         }
         db->autoCommit = 1;
         if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
-          p->pc = pc;
+          p->pc = (int)(pOp - aOp);
           db->autoCommit = 0;
           p->rc = rc = SQLITE_BUSY;
           goto vdbe_return;
@@ -73041,12 +81975,13 @@ case OP_Savepoint: {
         db->nDeferredImmCons = pSavepoint->nDeferredImmCons;
       }
 
-      if( !isTransaction ){
+      if( !isTransaction || p1==SAVEPOINT_ROLLBACK ){
         rc = sqlite3VtabSavepoint(db, p1, iSavepoint);
         if( rc!=SQLITE_OK ) goto abort_due_to_error;
       }
     }
   }
+  if( rc ) goto abort_due_to_error;
 
   break;
 }
@@ -73063,49 +81998,37 @@ case OP_Savepoint: {
 case OP_AutoCommit: {
   int desiredAutoCommit;
   int iRollback;
-  int turnOnAC;
 
   desiredAutoCommit = pOp->p1;
   iRollback = pOp->p2;
-  turnOnAC = desiredAutoCommit && !db->autoCommit;
   assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
   assert( desiredAutoCommit==1 || iRollback==0 );
   assert( db->nVdbeActive>0 );  /* At least this one VM is active */
   assert( p->bIsReader );
 
-#if 0
-  if( turnOnAC && iRollback && db->nVdbeActive>1 ){
-    /* If this instruction implements a ROLLBACK and other VMs are
-    ** still running, and a transaction is active, return an error indicating
-    ** that the other VMs must complete first. 
-    */
-    sqlite3SetString(&p->zErrMsg, db, "cannot rollback transaction - "
-        "SQL statements in progress");
-    rc = SQLITE_BUSY;
-  }else
-#endif
-  if( turnOnAC && !iRollback && db->nVdbeWrite>0 ){
-    /* If this instruction implements a COMMIT and other VMs are writing
-    ** return an error indicating that the other VMs must complete first. 
-    */
-    sqlite3SetString(&p->zErrMsg, db, "cannot commit transaction - "
-        "SQL statements in progress");
-    rc = SQLITE_BUSY;
-  }else if( desiredAutoCommit!=db->autoCommit ){
+  if( desiredAutoCommit!=db->autoCommit ){
     if( iRollback ){
       assert( desiredAutoCommit==1 );
       sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
       db->autoCommit = 1;
+    }else if( desiredAutoCommit && db->nVdbeWrite>0 ){
+      /* If this instruction implements a COMMIT and other VMs are writing
+      ** return an error indicating that the other VMs must complete first. 
+      */
+      sqlite3VdbeError(p, "cannot commit transaction - "
+                          "SQL statements in progress");
+      rc = SQLITE_BUSY;
+      goto abort_due_to_error;
     }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
       goto vdbe_return;
     }else{
       db->autoCommit = (u8)desiredAutoCommit;
-      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
-        p->pc = pc;
-        db->autoCommit = (u8)(1-desiredAutoCommit);
-        p->rc = rc = SQLITE_BUSY;
-        goto vdbe_return;
-      }
+    }
+    if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
+      p->pc = (int)(pOp - aOp);
+      db->autoCommit = (u8)(1-desiredAutoCommit);
+      p->rc = rc = SQLITE_BUSY;
+      goto vdbe_return;
     }
     assert( db->nStatement==0 );
     sqlite3CloseSavepoints(db);
@@ -73116,12 +82039,13 @@ case OP_AutoCommit: {
     }
     goto vdbe_return;
   }else{
-    sqlite3SetString(&p->zErrMsg, db,
+    sqlite3VdbeError(p,
         (!desiredAutoCommit)?"cannot start a transaction within a transaction":(
         (iRollback)?"cannot rollback - no transaction is active":
                    "cannot commit - no transaction is active"));
          
     rc = SQLITE_ERROR;
+    goto abort_due_to_error;
   }
   break;
 }
@@ -73177,12 +82101,14 @@ case OP_Transaction: {
 
   if( pBt ){
     rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
-    if( rc==SQLITE_BUSY ){
-      p->pc = pc;
-      p->rc = rc = SQLITE_BUSY;
-      goto vdbe_return;
-    }
+    testcase( rc==SQLITE_BUSY_SNAPSHOT );
+    testcase( rc==SQLITE_BUSY_RECOVERY );
     if( rc!=SQLITE_OK ){
+      if( (rc&0xff)==SQLITE_BUSY ){
+        p->pc = (int)(pOp - aOp);
+        p->rc = rc;
+        goto vdbe_return;
+      }
       goto abort_due_to_error;
     }
 
@@ -73208,7 +82134,11 @@ case OP_Transaction: {
       p->nStmtDefImmCons = db->nDeferredImmCons;
     }
 
-    /* Gather the schema version number for checking */
+    /* Gather the schema version number for checking:
+    ** IMPLEMENTATION-OF: R-03189-51135 As each SQL statement runs, the schema
+    ** version is checked to ensure that the schema has not changed since the
+    ** SQL statement was prepared.
+    */
     sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
     iGen = db->aDb[pOp->p1].pSchema->iGeneration;
   }else{
@@ -73237,6 +82167,7 @@ case OP_Transaction: {
     p->expired = 1;
     rc = SQLITE_SCHEMA;
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -73252,7 +82183,7 @@ case OP_Transaction: {
 ** must be started or there must be an open cursor) before
 ** executing this instruction.
 */
-case OP_ReadCookie: {               /* out2-prerelease */
+case OP_ReadCookie: {               /* out2 */
   int iMeta;
   int iDb;
   int iCookie;
@@ -73266,21 +82197,22 @@ case OP_ReadCookie: {               /* out2-prerelease */
   assert( DbMaskTest(p->btreeMask, iDb) );
 
   sqlite3BtreeGetMeta(db->aDb[iDb].pBt, iCookie, (u32 *)&iMeta);
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = iMeta;
   break;
 }
 
 /* Opcode: SetCookie P1 P2 P3 * *
 **
-** Write the content of register P3 (interpreted as an integer)
-** into cookie number P2 of database P1.  P2==1 is the schema version.  
-** P2==2 is the database format. P2==3 is the recommended pager cache 
+** Write the integer value P3 into cookie number P2 of database P1.
+** P2==1 is the schema version.  P2==2 is the database format.
+** P2==3 is the recommended pager cache 
 ** size, and so forth.  P1==0 is the main database file and P1==1 is the 
 ** database file used to store temporary tables.
 **
 ** A transaction must be started before executing this opcode.
 */
-case OP_SetCookie: {       /* in3 */
+case OP_SetCookie: {
   Db *pDb;
   assert( pOp->p2p1>=0 && pOp->p1nDb );
@@ -73289,17 +82221,15 @@ case OP_SetCookie: {       /* in3 */
   pDb = &db->aDb[pOp->p1];
   assert( pDb->pBt!=0 );
   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
-  pIn3 = &aMem[pOp->p3];
-  sqlite3VdbeMemIntegerify(pIn3);
   /* See note about index shifting on OP_ReadCookie */
-  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, (int)pIn3->u.i);
+  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, pOp->p3);
   if( pOp->p2==BTREE_SCHEMA_VERSION ){
     /* When the schema cookie changes, record the new cookie internally */
-    pDb->pSchema->schema_cookie = (int)pIn3->u.i;
+    pDb->pSchema->schema_cookie = pOp->p3;
     db->flags |= SQLITE_InternChanges;
   }else if( pOp->p2==BTREE_FILE_FORMAT ){
     /* Record changes in the file format */
-    pDb->pSchema->file_format = (u8)pIn3->u.i;
+    pDb->pSchema->file_format = pOp->p3;
   }
   if( pOp->p1==1 ){
     /* Invalidate all prepared statements whenever the TEMP database
@@ -73307,6 +82237,7 @@ case OP_SetCookie: {       /* in3 */
     sqlite3ExpirePreparedStatements(db);
     p->expired = 0;
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -73376,38 +82307,35 @@ case OP_SetCookie: {       /* in3 */
 ** See also OpenRead.
 */
 case OP_ReopenIdx: {
+  int nField;
+  KeyInfo *pKeyInfo;
+  int p2;
+  int iDb;
+  int wrFlag;
+  Btree *pX;
   VdbeCursor *pCur;
+  Db *pDb;
 
-  assert( pOp->p5==0 );
+  assert( pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
   assert( pOp->p4type==P4_KEYINFO );
   pCur = p->apCsr[pOp->p1];
   if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){
     assert( pCur->iDb==pOp->p3 );      /* Guaranteed by the code generator */
-    break;
+    goto open_cursor_set_hints;
   }
   /* If the cursor is not currently open or is open on a different
   ** index, then fall through into OP_OpenRead to force a reopen */
-}
 case OP_OpenRead:
-case OP_OpenWrite: {
-  int nField;
-  KeyInfo *pKeyInfo;
-  int p2;
-  int iDb;
-  int wrFlag;
-  Btree *pX;
-  VdbeCursor *pCur;
-  Db *pDb;
+case OP_OpenWrite:
 
-  assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR))==pOp->p5 );
-  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 );
+  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
   assert( p->bIsReader );
   assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx
           || p->readOnly==0 );
 
   if( p->expired ){
     rc = SQLITE_ABORT_ROLLBACK;
-    break;
+    goto abort_due_to_error;
   }
 
   nField = 0;
@@ -73420,7 +82348,8 @@ case OP_OpenWrite: {
   pX = pDb->pBt;
   assert( pX!=0 );
   if( pOp->opcode==OP_OpenWrite ){
-    wrFlag = 1;
+    assert( OPFLAG_FORDELETE==BTREE_FORDELETE );
+    wrFlag = BTREE_WRCSR | (pOp->p5 & OPFLAG_FORDELETE);
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     if( pDb->pSchema->file_format < p->minWriteFileFormat ){
       p->minWriteFileFormat = pDb->pSchema->file_format;
@@ -73430,7 +82359,7 @@ case OP_OpenWrite: {
   }
   if( pOp->p5 & OPFLAG_P2ISREG ){
     assert( p2>0 );
-    assert( p2<=(p->nMem-p->nCursor) );
+    assert( p2<=(p->nMem+1 - p->nCursor) );
     pIn2 = &aMem[p2];
     assert( memIsValid(pIn2) );
     assert( (pIn2->flags & MEM_Int)!=0 );
@@ -73440,10 +82369,7 @@ case OP_OpenWrite: {
     ** that opcode will always set the p2 value to 2 or more or else fail.
     ** If there were a failure, the prepared statement would have halted
     ** before reaching this instruction. */
-    if( NEVER(p2<2) ) {
-      rc = SQLITE_CORRUPT_BKPT;
-      goto abort_due_to_error;
-    }
+    assert( p2>=2 );
   }
   if( pOp->p4type==P4_KEYINFO ){
     pKeyInfo = pOp->p4.pKeyInfo;
@@ -73456,24 +82382,66 @@ case OP_OpenWrite: {
   assert( pOp->p1>=0 );
   assert( nField>=0 );
   testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
-  pCur = allocateCursor(p, pOp->p1, nField, iDb, 1);
+  pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);
   if( pCur==0 ) goto no_mem;
   pCur->nullRow = 1;
   pCur->isOrdered = 1;
   pCur->pgnoRoot = p2;
-  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->pCursor);
+#ifdef SQLITE_DEBUG
+  pCur->wrFlag = wrFlag;
+#endif
+  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->uc.pCursor);
   pCur->pKeyInfo = pKeyInfo;
-  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
-  sqlite3BtreeCursorHints(pCur->pCursor, (pOp->p5 & OPFLAG_BULKCSR));
-
   /* Set the VdbeCursor.isTable variable. Previous versions of
   ** SQLite used to check if the root-page flags were sane at this point
   ** and report database corruption if they were not, but this check has
   ** since moved into the btree layer.  */  
   pCur->isTable = pOp->p4type!=P4_KEYINFO;
+
+open_cursor_set_hints:
+  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
+  assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );
+  testcase( pOp->p5 & OPFLAG_BULKCSR );
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+  testcase( pOp->p2 & OPFLAG_SEEKEQ );
+#endif
+  sqlite3BtreeCursorHintFlags(pCur->uc.pCursor,
+                               (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
+/* Opcode: OpenDup P1 P2 * * *
+**
+** Open a new cursor P1 that points to the same ephemeral table as
+** cursor P2.  The P2 cursor must have been opened by a prior OP_OpenEphemeral
+** opcode.  Only ephemeral cursors may be duplicated.
+**
+** Duplicate ephemeral cursors are used for self-joins of materialized views.
+*/
+case OP_OpenDup: {
+  VdbeCursor *pOrig;    /* The original cursor to be duplicated */
+  VdbeCursor *pCx;      /* The new cursor */
+
+  pOrig = p->apCsr[pOp->p2];
+  assert( pOrig->pBtx!=0 );  /* Only ephemeral cursors can be duplicated */
+
+  pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);
+  if( pCx==0 ) goto no_mem;
+  pCx->nullRow = 1;
+  pCx->isEphemeral = 1;
+  pCx->pKeyInfo = pOrig->pKeyInfo;
+  pCx->isTable = pOrig->isTable;
+  rc = sqlite3BtreeCursor(pOrig->pBtx, MASTER_ROOT, BTREE_WRCSR,
+                          pCx->pKeyInfo, pCx->uc.pCursor);
+  /* The sqlite3BtreeCursor() routine can only fail for the first cursor
+  ** opened for a database.  Since there is already an open cursor when this
+  ** opcode is run, the sqlite3BtreeCursor() cannot fail */
+  assert( rc==SQLITE_OK );
+  break;
+}
+
+
 /* Opcode: OpenEphemeral P1 P2 * P4 P5
 ** Synopsis: nColumn=P2
 **
@@ -73513,14 +82481,14 @@ case OP_OpenEphemeral: {
       SQLITE_OPEN_TRANSIENT_DB;
   assert( pOp->p1>=0 );
   assert( pOp->p2>=0 );
-  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
+  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_BTREE);
   if( pCx==0 ) goto no_mem;
   pCx->nullRow = 1;
   pCx->isEphemeral = 1;
-  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
+  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBtx, 
                         BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
   if( rc==SQLITE_OK ){
-    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
+    rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1);
   }
   if( rc==SQLITE_OK ){
     /* If a transient index is required, create it by calling
@@ -73528,23 +82496,25 @@ case OP_OpenEphemeral: {
     ** opening it. If a transient table is required, just use the
     ** automatically created table with root-page 1 (an BLOB_INTKEY table).
     */
-    if( (pKeyInfo = pOp->p4.pKeyInfo)!=0 ){
+    if( (pCx->pKeyInfo = pKeyInfo = pOp->p4.pKeyInfo)!=0 ){
       int pgno;
       assert( pOp->p4type==P4_KEYINFO );
-      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_BLOBKEY | pOp->p5); 
+      rc = sqlite3BtreeCreateTable(pCx->pBtx, &pgno, BTREE_BLOBKEY | pOp->p5); 
       if( rc==SQLITE_OK ){
         assert( pgno==MASTER_ROOT+1 );
         assert( pKeyInfo->db==db );
         assert( pKeyInfo->enc==ENC(db) );
-        pCx->pKeyInfo = pKeyInfo;
-        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, pKeyInfo, pCx->pCursor);
+        rc = sqlite3BtreeCursor(pCx->pBtx, pgno, BTREE_WRCSR,
+                                pKeyInfo, pCx->uc.pCursor);
       }
       pCx->isTable = 0;
     }else{
-      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
+      rc = sqlite3BtreeCursor(pCx->pBtx, MASTER_ROOT, BTREE_WRCSR,
+                              0, pCx->uc.pCursor);
       pCx->isTable = 1;
     }
   }
+  if( rc ) goto abort_due_to_error;
   pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
   break;
 }
@@ -73564,12 +82534,13 @@ case OP_SorterOpen: {
 
   assert( pOp->p1>=0 );
   assert( pOp->p2>=0 );
-  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
+  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_SORTER);
   if( pCx==0 ) goto no_mem;
   pCx->pKeyInfo = pOp->p4.pKeyInfo;
   assert( pCx->pKeyInfo->db==db );
   assert( pCx->pKeyInfo->enc==ENC(db) );
   rc = sqlite3VdbeSorterInit(db, pOp->p3, pCx);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -73584,9 +82555,9 @@ case OP_SequenceTest: {
   VdbeCursor *pC;
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
-  assert( pC->pSorter );
+  assert( isSorter(pC) );
   if( (pC->seqCount++)==0 ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
   }
   break;
 }
@@ -73612,10 +82583,10 @@ case OP_OpenPseudo: {
 
   assert( pOp->p1>=0 );
   assert( pOp->p3>=0 );
-  pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
+  pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, CURTYPE_PSEUDO);
   if( pCx==0 ) goto no_mem;
   pCx->nullRow = 1;
-  pCx->pseudoTableReg = pOp->p2;
+  pCx->uc.pseudoTableReg = pOp->p2;
   pCx->isTable = 1;
   assert( pOp->p5==0 );
   break;
@@ -73633,6 +82604,26 @@ case OP_Close: {
   break;
 }
 
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+/* Opcode: ColumnsUsed P1 * * P4 *
+**
+** This opcode (which only exists if SQLite was compiled with
+** SQLITE_ENABLE_COLUMN_USED_MASK) identifies which columns of the
+** table or index for cursor P1 are used.  P4 is a 64-bit integer
+** (P4_INT64) in which the first 63 bits are one for each of the
+** first 63 columns of the table or index that are actually used
+** by the cursor.  The high-order bit is set if any column after
+** the 64th is used.
+*/
+case OP_ColumnsUsed: {
+  VdbeCursor *pC;
+  pC = p->apCsr[pOp->p1];
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pC->maskUsed = *(u64*)pOp->p4.pI64;
+  break;
+}
+#endif
+
 /* Opcode: SeekGE P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
@@ -73645,6 +82636,13 @@ case OP_Close: {
 ** is greater than or equal to the key value. If there are no records 
 ** greater than or equal to the key and P2 is not zero, then jump to P2.
 **
+** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
+** opcode will always land on a record that equally equals the key, or
+** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this
+** opcode must be followed by an IdxLE opcode with the same arguments.
+** The IdxLE opcode will be skipped if this opcode succeeds, but the
+** IdxLE opcode will be used on subsequent loop iterations.
+**
 ** This opcode leaves the cursor configured to move in forward order,
 ** from the beginning toward the end.  In other words, the cursor is
 ** configured to use Next, not Prev.
@@ -73703,35 +82701,49 @@ case OP_Close: {
 ** from the end toward the beginning.  In other words, the cursor is
 ** configured to use Prev, not Next.
 **
+** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
+** opcode will always land on a record that equally equals the key, or
+** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this
+** opcode must be followed by an IdxGE opcode with the same arguments.
+** The IdxGE opcode will be skipped if this opcode succeeds, but the
+** IdxGE opcode will be used on subsequent loop iterations.
+**
 ** See also: Found, NotFound, SeekGt, SeekGe, SeekLt
 */
 case OP_SeekLT:         /* jump, in3 */
 case OP_SeekLE:         /* jump, in3 */
 case OP_SeekGE:         /* jump, in3 */
 case OP_SeekGT: {       /* jump, in3 */
-  int res;
-  int oc;
-  VdbeCursor *pC;
-  UnpackedRecord r;
-  int nField;
-  i64 iKey;      /* The rowid we are to seek to */
+  int res;           /* Comparison result */
+  int oc;            /* Opcode */
+  VdbeCursor *pC;    /* The cursor to seek */
+  UnpackedRecord r;  /* The key to seek for */
+  int nField;        /* Number of columns or fields in the key */
+  i64 iKey;          /* The rowid we are to seek to */
+  int eqOnly;        /* Only interested in == results */
 
   assert( pOp->p1>=0 && pOp->p1nCursor );
   assert( pOp->p2!=0 );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->pseudoTableReg==0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
   assert( OP_SeekLE == OP_SeekLT+1 );
   assert( OP_SeekGE == OP_SeekLT+2 );
   assert( OP_SeekGT == OP_SeekLT+3 );
   assert( pC->isOrdered );
-  assert( pC->pCursor!=0 );
+  assert( pC->uc.pCursor!=0 );
   oc = pOp->opcode;
+  eqOnly = 0;
   pC->nullRow = 0;
 #ifdef SQLITE_DEBUG
   pC->seekOp = pOp->opcode;
 #endif
+
   if( pC->isTable ){
+    /* The BTREE_SEEK_EQ flag is only set on index cursors */
+    assert( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ)==0
+              || CORRUPT_DB );
+
     /* The input value in P3 might be of any type: integer, real, string,
     ** blob, or NULL.  But it needs to be an integer before we can do
     ** the seek, so convert it. */
@@ -73747,7 +82759,7 @@ case OP_SeekGT: {       /* jump, in3 */
       if( (pIn3->flags & MEM_Real)==0 ){
         /* If the P3 value cannot be converted into any kind of a number,
         ** then the seek is not possible, so jump to P2 */
-        pc = pOp->p2 - 1;  VdbeBranchTaken(1,2);
+        VdbeBranchTaken(1,2); goto jump_to_p2;
         break;
       }
 
@@ -73774,12 +82786,26 @@ case OP_SeekGT: {       /* jump, in3 */
         if( (oc & 0x0001)==(OP_SeekLT & 0x0001) ) oc++;
       }
     } 
-    rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, 0, (u64)iKey, 0, &res);
+    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)iKey, 0, &res);
     pC->movetoTarget = iKey;  /* Used by OP_Delete */
     if( rc!=SQLITE_OK ){
       goto abort_due_to_error;
     }
   }else{
+    /* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and
+    ** OP_SeekLE opcodes are allowed, and these must be immediately followed
+    ** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.
+    */
+    if( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ) ){
+      eqOnly = 1;
+      assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );
+      assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
+      assert( pOp[1].p1==pOp[0].p1 );
+      assert( pOp[1].p2==pOp[0].p2 );
+      assert( pOp[1].p3==pOp[0].p3 );
+      assert( pOp[1].p4.i==pOp[0].p4.i );
+    }
+
     nField = pOp->p4.i;
     assert( pOp->p4type==P4_INT32 );
     assert( nField>0 );
@@ -73803,11 +82829,15 @@ case OP_SeekGT: {       /* jump, in3 */
 #ifdef SQLITE_DEBUG
     { int i; for(i=0; ipCursor, &r, 0, 0, &res);
+    r.eqSeen = 0;
+    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, &r, 0, 0, &res);
     if( rc!=SQLITE_OK ){
       goto abort_due_to_error;
     }
+    if( eqOnly && r.eqSeen==0 ){
+      assert( res!=0 );
+      goto seek_not_found;
+    }
   }
   pC->deferredMoveto = 0;
   pC->cacheStatus = CACHE_STALE;
@@ -73817,8 +82847,15 @@ case OP_SeekGT: {       /* jump, in3 */
   if( oc>=OP_SeekGE ){  assert( oc==OP_SeekGE || oc==OP_SeekGT );
     if( res<0 || (res==0 && oc==OP_SeekGT) ){
       res = 0;
-      rc = sqlite3BtreeNext(pC->pCursor, &res);
-      if( rc!=SQLITE_OK ) goto abort_due_to_error;
+      rc = sqlite3BtreeNext(pC->uc.pCursor, 0);
+      if( rc!=SQLITE_OK ){
+        if( rc==SQLITE_DONE ){
+          rc = SQLITE_OK;
+          res = 1;
+        }else{
+          goto abort_due_to_error;
+        }
+      }
     }else{
       res = 0;
     }
@@ -73826,49 +82863,34 @@ case OP_SeekGT: {       /* jump, in3 */
     assert( oc==OP_SeekLT || oc==OP_SeekLE );
     if( res>0 || (res==0 && oc==OP_SeekLT) ){
       res = 0;
-      rc = sqlite3BtreePrevious(pC->pCursor, &res);
-      if( rc!=SQLITE_OK ) goto abort_due_to_error;
+      rc = sqlite3BtreePrevious(pC->uc.pCursor, 0);
+      if( rc!=SQLITE_OK ){
+        if( rc==SQLITE_DONE ){
+          rc = SQLITE_OK;
+          res = 1;
+        }else{
+          goto abort_due_to_error;
+        }
+      }
     }else{
       /* res might be negative because the table is empty.  Check to
       ** see if this is the case.
       */
-      res = sqlite3BtreeEof(pC->pCursor);
+      res = sqlite3BtreeEof(pC->uc.pCursor);
     }
   }
+seek_not_found:
   assert( pOp->p2>0 );
   VdbeBranchTaken(res!=0,2);
   if( res ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
+  }else if( eqOnly ){
+    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
+    pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */
   }
   break;
 }
 
-/* Opcode: Seek P1 P2 * * *
-** Synopsis:  intkey=r[P2]
-**
-** P1 is an open table cursor and P2 is a rowid integer.  Arrange
-** for P1 to move so that it points to the rowid given by P2.
-**
-** This is actually a deferred seek.  Nothing actually happens until
-** the cursor is used to read a record.  That way, if no reads
-** occur, no unnecessary I/O happens.
-*/
-case OP_Seek: {    /* in2 */
-  VdbeCursor *pC;
-
-  assert( pOp->p1>=0 && pOp->p1nCursor );
-  pC = p->apCsr[pOp->p1];
-  assert( pC!=0 );
-  assert( pC->pCursor!=0 );
-  assert( pC->isTable );
-  pC->nullRow = 0;
-  pIn2 = &aMem[pOp->p2];
-  pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
-  pC->deferredMoveto = 1;
-  break;
-}
-  
-
 /* Opcode: Found P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
@@ -73932,13 +82954,13 @@ case OP_NoConflict:     /* jump, in3 */
 case OP_NotFound:       /* jump, in3 */
 case OP_Found: {        /* jump, in3 */
   int alreadyExists;
+  int takeJump;
   int ii;
   VdbeCursor *pC;
   int res;
-  char *pFree;
+  UnpackedRecord *pFree;
   UnpackedRecord *pIdxKey;
   UnpackedRecord r;
-  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*4 + 7];
 
 #ifdef SQLITE_TEST
   if( pOp->opcode!=OP_NoConflict ) sqlite3_found_count++;
@@ -73952,48 +82974,48 @@ case OP_Found: {        /* jump, in3 */
   pC->seekOp = pOp->opcode;
 #endif
   pIn3 = &aMem[pOp->p3];
-  assert( pC->pCursor!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
   assert( pC->isTable==0 );
-  pFree = 0;  /* Not needed.  Only used to suppress a compiler warning. */
   if( pOp->p4.i>0 ){
     r.pKeyInfo = pC->pKeyInfo;
     r.nField = (u16)pOp->p4.i;
     r.aMem = pIn3;
+#ifdef SQLITE_DEBUG
     for(ii=0; iip3+ii, &r.aMem[ii]);
-#endif
     }
+#endif
     pIdxKey = &r;
+    pFree = 0;
   }else{
-    pIdxKey = sqlite3VdbeAllocUnpackedRecord(
-        pC->pKeyInfo, aTempRec, sizeof(aTempRec), &pFree
-    );
-    if( pIdxKey==0 ) goto no_mem;
     assert( pIn3->flags & MEM_Blob );
-    ExpandBlob(pIn3);
+    rc = ExpandBlob(pIn3);
+    assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+    if( rc ) goto no_mem;
+    pFree = pIdxKey = sqlite3VdbeAllocUnpackedRecord(pC->pKeyInfo);
+    if( pIdxKey==0 ) goto no_mem;
     sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z, pIdxKey);
   }
   pIdxKey->default_rc = 0;
+  takeJump = 0;
   if( pOp->opcode==OP_NoConflict ){
     /* For the OP_NoConflict opcode, take the jump if any of the
     ** input fields are NULL, since any key with a NULL will not
     ** conflict */
     for(ii=0; iinField; ii++){
       if( pIdxKey->aMem[ii].flags & MEM_Null ){
-        pc = pOp->p2 - 1; VdbeBranchTaken(1,2);
+        takeJump = 1;
         break;
       }
     }
   }
-  rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, pIdxKey, 0, 0, &res);
-  if( pOp->p4.i==0 ){
-    sqlite3DbFree(db, pFree);
-  }
+  rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, pIdxKey, 0, 0, &res);
+  if( pFree ) sqlite3DbFreeNN(db, pFree);
   if( rc!=SQLITE_OK ){
-    break;
+    goto abort_due_to_error;
   }
   pC->seekResult = res;
   alreadyExists = (res==0);
@@ -74002,22 +83024,51 @@ case OP_Found: {        /* jump, in3 */
   pC->cacheStatus = CACHE_STALE;
   if( pOp->opcode==OP_Found ){
     VdbeBranchTaken(alreadyExists!=0,2);
-    if( alreadyExists ) pc = pOp->p2 - 1;
+    if( alreadyExists ) goto jump_to_p2;
   }else{
-    VdbeBranchTaken(alreadyExists==0,2);
-    if( !alreadyExists ) pc = pOp->p2 - 1;
+    VdbeBranchTaken(takeJump||alreadyExists==0,2);
+    if( takeJump || !alreadyExists ) goto jump_to_p2;
   }
   break;
 }
 
+/* Opcode: SeekRowid P1 P2 P3 * *
+** Synopsis: intkey=r[P3]
+**
+** P1 is the index of a cursor open on an SQL table btree (with integer
+** keys).  If register P3 does not contain an integer or if P1 does not
+** contain a record with rowid P3 then jump immediately to P2.  
+** Or, if P2 is 0, raise an SQLITE_CORRUPT error. If P1 does contain
+** a record with rowid P3 then 
+** leave the cursor pointing at that record and fall through to the next
+** instruction.
+**
+** The OP_NotExists opcode performs the same operation, but with OP_NotExists
+** the P3 register must be guaranteed to contain an integer value.  With this
+** opcode, register P3 might not contain an integer.
+**
+** The OP_NotFound opcode performs the same operation on index btrees
+** (with arbitrary multi-value keys).
+**
+** This opcode leaves the cursor in a state where it cannot be advanced
+** in either direction.  In other words, the Next and Prev opcodes will
+** not work following this opcode.
+**
+** See also: Found, NotFound, NoConflict, SeekRowid
+*/
 /* Opcode: NotExists P1 P2 P3 * *
 ** Synopsis: intkey=r[P3]
 **
 ** P1 is the index of a cursor open on an SQL table btree (with integer
 ** keys).  P3 is an integer rowid.  If P1 does not contain a record with
-** rowid P3 then jump immediately to P2.  If P1 does contain a record
-** with rowid P3 then leave the cursor pointing at that record and fall
-** through to the next instruction.
+** rowid P3 then jump immediately to P2.  Or, if P2 is 0, raise an
+** SQLITE_CORRUPT error. If P1 does contain a record with rowid P3 then 
+** leave the cursor pointing at that record and fall through to the next
+** instruction.
+**
+** The OP_SeekRowid opcode performs the same operation but also allows the
+** P3 register to contain a non-integer value, in which case the jump is
+** always taken.  This opcode requires that P3 always contain an integer.
 **
 ** The OP_NotFound opcode performs the same operation on index btrees
 ** (with arbitrary multi-value keys).
@@ -74026,14 +83077,21 @@ case OP_Found: {        /* jump, in3 */
 ** in either direction.  In other words, the Next and Prev opcodes will
 ** not work following this opcode.
 **
-** See also: Found, NotFound, NoConflict
+** See also: Found, NotFound, NoConflict, SeekRowid
 */
-case OP_NotExists: {        /* jump, in3 */
+case OP_SeekRowid: {        /* jump, in3 */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
   u64 iKey;
 
+  pIn3 = &aMem[pOp->p3];
+  if( (pIn3->flags & MEM_Int)==0 ){
+    applyAffinity(pIn3, SQLITE_AFF_NUMERIC, encoding);
+    if( (pIn3->flags & MEM_Int)==0 ) goto jump_to_p2;
+  }
+  /* Fall through into OP_NotExists */
+case OP_NotExists:          /* jump, in3 */
   pIn3 = &aMem[pOp->p3];
   assert( pIn3->flags & MEM_Int );
   assert( pOp->p1>=0 && pOp->p1nCursor );
@@ -74043,21 +83101,28 @@ case OP_NotExists: {        /* jump, in3 */
   pC->seekOp = 0;
 #endif
   assert( pC->isTable );
-  assert( pC->pseudoTableReg==0 );
-  pCrsr = pC->pCursor;
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
   assert( pCrsr!=0 );
   res = 0;
   iKey = pIn3->u.i;
   rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);
+  assert( rc==SQLITE_OK || res==0 );
   pC->movetoTarget = iKey;  /* Used by OP_Delete */
   pC->nullRow = 0;
   pC->cacheStatus = CACHE_STALE;
   pC->deferredMoveto = 0;
   VdbeBranchTaken(res!=0,2);
+  pC->seekResult = res;
   if( res!=0 ){
-    pc = pOp->p2 - 1;
+    assert( rc==SQLITE_OK );
+    if( pOp->p2==0 ){
+      rc = SQLITE_CORRUPT_BKPT;
+    }else{
+      goto jump_to_p2;
+    }
   }
-  pC->seekResult = res;
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -74069,9 +83134,11 @@ case OP_NotExists: {        /* jump, in3 */
 ** The sequence number on the cursor is incremented after this
 ** instruction.  
 */
-case OP_Sequence: {           /* out2-prerelease */
+case OP_Sequence: {           /* out2 */
   assert( pOp->p1>=0 && pOp->p1nCursor );
   assert( p->apCsr[pOp->p1]!=0 );
+  assert( p->apCsr[pOp->p1]->eCurType!=CURTYPE_VTAB );
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = p->apCsr[pOp->p1]->seqCount++;
   break;
 }
@@ -74092,7 +83159,7 @@ case OP_Sequence: {           /* out2-prerelease */
 ** generated record number. This P3 mechanism is used to help implement the
 ** AUTOINCREMENT feature.
 */
-case OP_NewRowid: {           /* out2-prerelease */
+case OP_NewRowid: {           /* out2 */
   i64 v;                 /* The new rowid */
   VdbeCursor *pC;        /* Cursor of table to get the new rowid */
   int res;               /* Result of an sqlite3BtreeLast() */
@@ -74102,12 +83169,13 @@ case OP_NewRowid: {           /* out2-prerelease */
 
   v = 0;
   res = 0;
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  if( NEVER(pC->pCursor==0) ){
-    /* The zero initialization above is all that is needed */
-  }else{
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  {
     /* The next rowid or record number (different terms for the same
     ** thing) is obtained in a two-step algorithm.
     **
@@ -74134,16 +83202,15 @@ case OP_NewRowid: {           /* out2-prerelease */
 #endif
 
     if( !pC->useRandomRowid ){
-      rc = sqlite3BtreeLast(pC->pCursor, &res);
+      rc = sqlite3BtreeLast(pC->uc.pCursor, &res);
       if( rc!=SQLITE_OK ){
         goto abort_due_to_error;
       }
       if( res ){
         v = 1;   /* IMP: R-61914-48074 */
       }else{
-        assert( sqlite3BtreeCursorIsValid(pC->pCursor) );
-        rc = sqlite3BtreeKeySize(pC->pCursor, &v);
-        assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
+        assert( sqlite3BtreeCursorIsValid(pC->uc.pCursor) );
+        v = sqlite3BtreeIntegerKey(pC->uc.pCursor);
         if( v>=MAX_ROWID ){
           pC->useRandomRowid = 1;
         }else{
@@ -74163,7 +83230,7 @@ case OP_NewRowid: {           /* out2-prerelease */
         pMem = &pFrame->aMem[pOp->p3];
       }else{
         /* Assert that P3 is a valid memory cell. */
-        assert( pOp->p3<=(p->nMem-p->nCursor) );
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
         pMem = &aMem[pOp->p3];
         memAboutToChange(p, pMem);
       }
@@ -74173,7 +83240,7 @@ case OP_NewRowid: {           /* out2-prerelease */
       sqlite3VdbeMemIntegerify(pMem);
       assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
       if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
-        rc = SQLITE_FULL;   /* IMP: R-12275-61338 */
+        rc = SQLITE_FULL;   /* IMP: R-17817-00630 */
         goto abort_due_to_error;
       }
       if( vu.i+1 ){
@@ -74193,11 +83260,12 @@ case OP_NewRowid: {           /* out2-prerelease */
       do{
         sqlite3_randomness(sizeof(v), &v);
         v &= (MAX_ROWID>>1); v++;  /* Ensure that v is greater than zero */
-      }while(  ((rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, 0, (u64)v,
+      }while(  ((rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)v,
                                                  0, &res))==SQLITE_OK)
             && (res==0)
             && (++cnt<100));
-      if( rc==SQLITE_OK && res==0 ){
+      if( rc ) goto abort_due_to_error;
+      if( res==0 ){
         rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
         goto abort_due_to_error;
       }
@@ -74224,22 +83292,19 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** then rowid is stored for subsequent return by the
 ** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
 **
-** If the OPFLAG_USESEEKRESULT flag of P5 is set and if the result of
-** the last seek operation (OP_NotExists) was a success, then this
-** operation will not attempt to find the appropriate row before doing
-** the insert but will instead overwrite the row that the cursor is
-** currently pointing to.  Presumably, the prior OP_NotExists opcode
-** has already positioned the cursor correctly.  This is an optimization
-** that boosts performance by avoiding redundant seeks.
+** If the OPFLAG_USESEEKRESULT flag of P5 is set, the implementation might
+** run faster by avoiding an unnecessary seek on cursor P1.  However,
+** the OPFLAG_USESEEKRESULT flag must only be set if there have been no prior
+** seeks on the cursor or if the most recent seek used a key equal to P3.
 **
 ** If the OPFLAG_ISUPDATE flag is set, then this opcode is part of an
 ** UPDATE operation.  Otherwise (if the flag is clear) then this opcode
 ** is part of an INSERT operation.  The difference is only important to
 ** the update hook.
 **
-** Parameter P4 may point to a string containing the table-name, or
-** may be NULL. If it is not NULL, then the update-hook 
-** (sqlite3.xUpdateCallback) is invoked following a successful insert.
+** Parameter P4 may point to a Table structure, or may be NULL. If it is 
+** not NULL, then the update-hook (sqlite3.xUpdateCallback) is invoked 
+** following a successful insert.
 **
 ** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
 ** allocated, then ownership of P2 is transferred to the pseudo-cursor
@@ -74251,7 +83316,7 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** for indices is OP_IdxInsert.
 */
 /* Opcode: InsertInt P1 P2 P3 P4 P5
-** Synopsis:  intkey=P3 data=r[P2]
+** Synopsis: intkey=P3 data=r[P2]
 **
 ** This works exactly like OP_Insert except that the key is the
 ** integer value P3, not the value of the integer stored in register P3.
@@ -74260,22 +83325,23 @@ case OP_Insert:
 case OP_InsertInt: {
   Mem *pData;       /* MEM cell holding data for the record to be inserted */
   Mem *pKey;        /* MEM cell holding key  for the record */
-  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
   VdbeCursor *pC;   /* Cursor to table into which insert is written */
-  int nZero;        /* Number of zero-bytes to append */
   int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
   const char *zDb;  /* database name - used by the update hook */
-  const char *zTbl; /* Table name - used by the opdate hook */
+  Table *pTab;      /* Table structure - used by update and pre-update hooks */
   int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
+  BtreePayload x;   /* Payload to be inserted */
 
+  op = 0;
   pData = &aMem[pOp->p2];
   assert( pOp->p1>=0 && pOp->p1nCursor );
   assert( memIsValid(pData) );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->pCursor!=0 );
-  assert( pC->pseudoTableReg==0 );
-  assert( pC->isTable );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  assert( (pOp->p5 & OPFLAG_ISNOOP) || pC->isTable );
+  assert( pOp->p4type==P4_TABLE || pOp->p4type>=P4_STATIC );
   REGISTER_TRACE(pOp->p2, pData);
 
   if( pOp->opcode==OP_Insert ){
@@ -74283,95 +83349,192 @@ case OP_InsertInt: {
     assert( pKey->flags & MEM_Int );
     assert( memIsValid(pKey) );
     REGISTER_TRACE(pOp->p3, pKey);
-    iKey = pKey->u.i;
+    x.nKey = pKey->u.i;
   }else{
     assert( pOp->opcode==OP_InsertInt );
-    iKey = pOp->p3;
+    x.nKey = pOp->p3;
   }
 
+  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
+    assert( pC->iDb>=0 );
+    zDb = db->aDb[pC->iDb].zDbSName;
+    pTab = pOp->p4.pTab;
+    assert( (pOp->p5 & OPFLAG_ISNOOP) || HasRowid(pTab) );
+    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
+  }else{
+    pTab = 0; /* Not needed.  Silence a compiler warning. */
+    zDb = 0;  /* Not needed.  Silence a compiler warning. */
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update hook, if any */
+  if( db->xPreUpdateCallback 
+   && pOp->p4type==P4_TABLE
+   && !(pOp->p5 & OPFLAG_ISUPDATE)
+  ){
+    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey, pOp->p2);
+  }
+  if( pOp->p5 & OPFLAG_ISNOOP ) break;
+#endif
+
   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
-  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = iKey;
+  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = x.nKey;
   if( pData->flags & MEM_Null ){
-    pData->z = 0;
-    pData->n = 0;
+    x.pData = 0;
+    x.nData = 0;
   }else{
     assert( pData->flags & (MEM_Blob|MEM_Str) );
+    x.pData = pData->z;
+    x.nData = pData->n;
   }
   seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
   if( pData->flags & MEM_Zero ){
-    nZero = pData->u.nZero;
+    x.nZero = pData->u.nZero;
   }else{
-    nZero = 0;
+    x.nZero = 0;
   }
-  rc = sqlite3BtreeInsert(pC->pCursor, 0, iKey,
-                          pData->z, pData->n, nZero,
-                          (pOp->p5 & OPFLAG_APPEND)!=0, seekResult
+  x.pKey = 0;
+  rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,
+      (pOp->p5 & (OPFLAG_APPEND|OPFLAG_SAVEPOSITION)), seekResult
   );
   pC->deferredMoveto = 0;
   pC->cacheStatus = CACHE_STALE;
 
   /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
-    zDb = db->aDb[pC->iDb].zName;
-    zTbl = pOp->p4.z;
-    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
-    assert( pC->isTable );
-    db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
-    assert( pC->iDb>=0 );
+  if( rc ) goto abort_due_to_error;
+  if( db->xUpdateCallback && op ){
+    db->xUpdateCallback(db->pUpdateArg, op, zDb, pTab->zName, x.nKey);
   }
   break;
 }
 
-/* Opcode: Delete P1 P2 * P4 *
+/* Opcode: Delete P1 P2 P3 P4 P5
 **
 ** Delete the record at which the P1 cursor is currently pointing.
 **
-** The cursor will be left pointing at either the next or the previous
+** If the OPFLAG_SAVEPOSITION bit of the P5 parameter is set, then
+** the cursor will be left pointing at  either the next or the previous
 ** record in the table. If it is left pointing at the next record, then
-** the next Next instruction will be a no-op.  Hence it is OK to delete
-** a record from within a Next loop.
+** the next Next instruction will be a no-op. As a result, in this case
+** it is ok to delete a record from within a Next loop. If 
+** OPFLAG_SAVEPOSITION bit of P5 is clear, then the cursor will be
+** left in an undefined state.
+**
+** If the OPFLAG_AUXDELETE bit is set on P5, that indicates that this
+** delete one of several associated with deleting a table row and all its
+** associated index entries.  Exactly one of those deletes is the "primary"
+** delete.  The others are all on OPFLAG_FORDELETE cursors or else are
+** marked with the AUXDELETE flag.
 **
-** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
-** incremented (otherwise not).
+** If the OPFLAG_NCHANGE flag of P2 (NB: P2 not P5) is set, then the row
+** change count is incremented (otherwise not).
 **
 ** P1 must not be pseudo-table.  It has to be a real table with
 ** multiple rows.
 **
-** If P4 is not NULL, then it is the name of the table that P1 is
-** pointing to.  The update hook will be invoked, if it exists.
-** If P4 is not NULL then the P1 cursor must have been positioned
-** using OP_NotFound prior to invoking this opcode.
+** If P4 is not NULL then it points to a Table object. In this case either 
+** the update or pre-update hook, or both, may be invoked. The P1 cursor must
+** have been positioned using OP_NotFound prior to invoking this opcode in 
+** this case. Specifically, if one is configured, the pre-update hook is 
+** invoked if P4 is not NULL. The update-hook is invoked if one is configured, 
+** P4 is not NULL, and the OPFLAG_NCHANGE flag is set in P2.
+**
+** If the OPFLAG_ISUPDATE flag is set in P2, then P3 contains the address
+** of the memory cell that contains the value that the rowid of the row will
+** be set to by the update.
 */
 case OP_Delete: {
   VdbeCursor *pC;
+  const char *zDb;
+  Table *pTab;
+  int opflags;
 
+  opflags = pOp->p2;
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
   assert( pC->deferredMoveto==0 );
 
 #ifdef SQLITE_DEBUG
-  /* The seek operation that positioned the cursor prior to OP_Delete will
-  ** have also set the pC->movetoTarget field to the rowid of the row that
-  ** is being deleted */
-  if( pOp->p4.z && pC->isTable ){
-    i64 iKey = 0;
-    sqlite3BtreeKeySize(pC->pCursor, &iKey);
-    assert( pC->movetoTarget==iKey ); 
+  if( pOp->p4type==P4_TABLE && HasRowid(pOp->p4.pTab) && pOp->p5==0 ){
+    /* If p5 is zero, the seek operation that positioned the cursor prior to
+    ** OP_Delete will have also set the pC->movetoTarget field to the rowid of
+    ** the row that is being deleted */
+    i64 iKey = sqlite3BtreeIntegerKey(pC->uc.pCursor);
+    assert( pC->movetoTarget==iKey );
+  }
+#endif
+
+  /* If the update-hook or pre-update-hook will be invoked, set zDb to
+  ** the name of the db to pass as to it. Also set local pTab to a copy
+  ** of p4.pTab. Finally, if p5 is true, indicating that this cursor was
+  ** last moved with OP_Next or OP_Prev, not Seek or NotFound, set 
+  ** VdbeCursor.movetoTarget to the current rowid.  */
+  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
+    assert( pC->iDb>=0 );
+    assert( pOp->p4.pTab!=0 );
+    zDb = db->aDb[pC->iDb].zDbSName;
+    pTab = pOp->p4.pTab;
+    if( (pOp->p5 & OPFLAG_SAVEPOSITION)!=0 && pC->isTable ){
+      pC->movetoTarget = sqlite3BtreeIntegerKey(pC->uc.pCursor);
+    }
+  }else{
+    zDb = 0;   /* Not needed.  Silence a compiler warning. */
+    pTab = 0;  /* Not needed.  Silence a compiler warning. */
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update-hook if required. */
+  if( db->xPreUpdateCallback && pOp->p4.pTab ){
+    assert( !(opflags & OPFLAG_ISUPDATE) 
+         || HasRowid(pTab)==0 
+         || (aMem[pOp->p3].flags & MEM_Int) 
+    );
+    sqlite3VdbePreUpdateHook(p, pC,
+        (opflags & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_DELETE, 
+        zDb, pTab, pC->movetoTarget,
+        pOp->p3
+    );
   }
+  if( opflags & OPFLAG_ISNOOP ) break;
 #endif
  
-  rc = sqlite3BtreeDelete(pC->pCursor);
+  /* Only flags that can be set are SAVEPOISTION and AUXDELETE */ 
+  assert( (pOp->p5 & ~(OPFLAG_SAVEPOSITION|OPFLAG_AUXDELETE))==0 );
+  assert( OPFLAG_SAVEPOSITION==BTREE_SAVEPOSITION );
+  assert( OPFLAG_AUXDELETE==BTREE_AUXDELETE );
+
+#ifdef SQLITE_DEBUG
+  if( p->pFrame==0 ){
+    if( pC->isEphemeral==0
+        && (pOp->p5 & OPFLAG_AUXDELETE)==0
+        && (pC->wrFlag & OPFLAG_FORDELETE)==0
+      ){
+      nExtraDelete++;
+    }
+    if( pOp->p2 & OPFLAG_NCHANGE ){
+      nExtraDelete--;
+    }
+  }
+#endif
+
+  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
   pC->cacheStatus = CACHE_STALE;
+  pC->seekResult = 0;
+  if( rc ) goto abort_due_to_error;
 
   /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z && pC->isTable ){
-    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
-                        db->aDb[pC->iDb].zName, pOp->p4.z, pC->movetoTarget);
-    assert( pC->iDb>=0 );
+  if( opflags & OPFLAG_NCHANGE ){
+    p->nChange++;
+    if( db->xUpdateCallback && HasRowid(pTab) ){
+      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,
+          pC->movetoTarget);
+      assert( pC->iDb>=0 );
+    }
   }
-  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
+
   break;
 }
 /* Opcode: ResetCount * * * * *
@@ -74388,7 +83551,7 @@ case OP_ResetCount: {
 }
 
 /* Opcode: SorterCompare P1 P2 P3 P4
-** Synopsis:  if key(P1)!=trim(r[P3],P4) goto P2
+** Synopsis: if key(P1)!=trim(r[P3],P4) goto P2
 **
 ** P1 is a sorter cursor. This instruction compares a prefix of the
 ** record blob in register P3 against a prefix of the entry that 
@@ -74415,9 +83578,8 @@ case OP_SorterCompare: {
   res = 0;
   rc = sqlite3VdbeSorterCompare(pC, pIn3, nKeyCol, &res);
   VdbeBranchTaken(res!=0,2);
-  if( res ){
-    pc = pOp->p2-1;
-  }
+  if( rc ) goto abort_due_to_error;
+  if( res ) goto jump_to_p2;
   break;
 };
 
@@ -74442,57 +83604,59 @@ case OP_SorterData: {
   rc = sqlite3VdbeSorterRowkey(pC, pOut);
   assert( rc!=SQLITE_OK || (pOut->flags & MEM_Blob) );
   assert( pOp->p1>=0 && pOp->p1nCursor );
+  if( rc ) goto abort_due_to_error;
   p->apCsr[pOp->p3]->cacheStatus = CACHE_STALE;
   break;
 }
 
-/* Opcode: RowData P1 P2 * * *
+/* Opcode: RowData P1 P2 P3 * *
 ** Synopsis: r[P2]=data
 **
-** Write into register P2 the complete row data for cursor P1.
+** Write into register P2 the complete row content for the row at 
+** which cursor P1 is currently pointing.
 ** There is no interpretation of the data.  
 ** It is just copied onto the P2 register exactly as 
 ** it is found in the database file.
 **
+** If cursor P1 is an index, then the content is the key of the row.
+** If cursor P2 is a table, then the content extracted is the data.
+**
 ** If the P1 cursor must be pointing to a valid row (not a NULL row)
 ** of a real table, not a pseudo-table.
-*/
-/* Opcode: RowKey P1 P2 * * *
-** Synopsis: r[P2]=key
 **
-** Write into register P2 the complete row key for cursor P1.
-** There is no interpretation of the data.  
-** The key is copied onto the P2 register exactly as 
-** it is found in the database file.
+** If P3!=0 then this opcode is allowed to make an ephermeral pointer
+** into the database page.  That means that the content of the output
+** register will be invalidated as soon as the cursor moves - including
+** moves caused by other cursors that "save" the the current cursors
+** position in order that they can write to the same table.  If P3==0
+** then a copy of the data is made into memory.  P3!=0 is faster, but
+** P3==0 is safer.
 **
-** If the P1 cursor must be pointing to a valid row (not a NULL row)
-** of a real table, not a pseudo-table.
+** If P3!=0 then the content of the P2 register is unsuitable for use
+** in OP_Result and any OP_Result will invalidate the P2 register content.
+** The P2 register content is invalidated by opcodes like OP_Function or
+** by any use of another cursor pointing to the same table.
 */
-case OP_RowKey:
 case OP_RowData: {
   VdbeCursor *pC;
   BtCursor *pCrsr;
   u32 n;
-  i64 n64;
 
-  pOut = &aMem[pOp->p2];
-  memAboutToChange(p, pOut);
+  pOut = out2Prerelease(p, pOp);
 
-  /* Note that RowKey and RowData are really exactly the same instruction */
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
-  assert( isSorter(pC)==0 );
-  assert( pC->isTable || pOp->opcode!=OP_RowData );
-  assert( pC->isTable==0 || pOp->opcode==OP_RowData );
   assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( isSorter(pC)==0 );
   assert( pC->nullRow==0 );
-  assert( pC->pseudoTableReg==0 );
-  assert( pC->pCursor!=0 );
-  pCrsr = pC->pCursor;
+  assert( pC->uc.pCursor!=0 );
+  pCrsr = pC->uc.pCursor;
 
-  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
-  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
-  ** the cursor.  If this where not the case, on of the following assert()s
+  /* The OP_RowData opcodes always follow OP_NotExists or
+  ** OP_SeekRowid or OP_Rewind/Op_Next with no intervening instructions
+  ** that might invalidate the cursor.
+  ** If this where not the case, on of the following assert()s
   ** would fail.  Should this ever change (because of changes in the code
   ** generator) then the fix would be to insert a call to
   ** sqlite3VdbeCursorMoveto().
@@ -74504,33 +83668,14 @@ case OP_RowData: {
   if( rc!=SQLITE_OK ) goto abort_due_to_error;
 #endif
 
-  if( pC->isTable==0 ){
-    assert( !pC->isTable );
-    VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &n64);
-    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
-    if( n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
-      goto too_big;
-    }
-    n = (u32)n64;
-  }else{
-    VVA_ONLY(rc =) sqlite3BtreeDataSize(pCrsr, &n);
-    assert( rc==SQLITE_OK );    /* DataSize() cannot fail */
-    if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-      goto too_big;
-    }
+  n = sqlite3BtreePayloadSize(pCrsr);
+  if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
   }
   testcase( n==0 );
-  if( sqlite3VdbeMemClearAndResize(pOut, MAX(n,32)) ){
-    goto no_mem;
-  }
-  pOut->n = n;
-  MemSetTypeFlag(pOut, MEM_Blob);
-  if( pC->isTable==0 ){
-    rc = sqlite3BtreeKey(pCrsr, 0, n, pOut->z);
-  }else{
-    rc = sqlite3BtreeData(pCrsr, 0, n, pOut->z);
-  }
-  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
+  rc = sqlite3VdbeMemFromBtree(pCrsr, 0, n, pOut);
+  if( rc ) goto abort_due_to_error;
+  if( !pOp->p3 ) Deephemeralize(pOut);
   UPDATE_MAX_BLOBSIZE(pOut);
   REGISTER_TRACE(pOp->p2, pOut);
   break;
@@ -74546,39 +83691,42 @@ case OP_RowData: {
 ** be a separate OP_VRowid opcode for use with virtual tables, but this
 ** one opcode now works for both table types.
 */
-case OP_Rowid: {                 /* out2-prerelease */
+case OP_Rowid: {                 /* out2 */
   VdbeCursor *pC;
   i64 v;
   sqlite3_vtab *pVtab;
   const sqlite3_module *pModule;
 
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->pseudoTableReg==0 || pC->nullRow );
+  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
   if( pC->nullRow ){
     pOut->flags = MEM_Null;
     break;
   }else if( pC->deferredMoveto ){
     v = pC->movetoTarget;
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  }else if( pC->pVtabCursor ){
-    pVtab = pC->pVtabCursor->pVtab;
+  }else if( pC->eCurType==CURTYPE_VTAB ){
+    assert( pC->uc.pVCur!=0 );
+    pVtab = pC->uc.pVCur->pVtab;
     pModule = pVtab->pModule;
     assert( pModule->xRowid );
-    rc = pModule->xRowid(pC->pVtabCursor, &v);
+    rc = pModule->xRowid(pC->uc.pVCur, &v);
     sqlite3VtabImportErrmsg(p, pVtab);
+    if( rc ) goto abort_due_to_error;
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
   }else{
-    assert( pC->pCursor!=0 );
+    assert( pC->eCurType==CURTYPE_BTREE );
+    assert( pC->uc.pCursor!=0 );
     rc = sqlite3VdbeCursorRestore(pC);
     if( rc ) goto abort_due_to_error;
     if( pC->nullRow ){
       pOut->flags = MEM_Null;
       break;
     }
-    rc = sqlite3BtreeKeySize(pC->pCursor, &v);
-    assert( rc==SQLITE_OK );  /* Always so because of CursorRestore() above */
+    v = sqlite3BtreeIntegerKey(pC->uc.pCursor);
   }
   pOut->u.i = v;
   break;
@@ -74598,13 +83746,14 @@ case OP_NullRow: {
   assert( pC!=0 );
   pC->nullRow = 1;
   pC->cacheStatus = CACHE_STALE;
-  if( pC->pCursor ){
-    sqlite3BtreeClearCursor(pC->pCursor);
+  if( pC->eCurType==CURTYPE_BTREE ){
+    assert( pC->uc.pCursor!=0 );
+    sqlite3BtreeClearCursor(pC->uc.pCursor);
   }
   break;
 }
 
-/* Opcode: Last P1 P2 * * *
+/* Opcode: Last P1 P2 P3 * *
 **
 ** The next use of the Rowid or Column or Prev instruction for P1 
 ** will refer to the last entry in the database table or index.
@@ -74615,6 +83764,13 @@ case OP_NullRow: {
 ** This opcode leaves the cursor configured to move in reverse order,
 ** from the end toward the beginning.  In other words, the cursor is
 ** configured to use Prev, not Next.
+**
+** If P3 is -1, then the cursor is positioned at the end of the btree
+** for the purpose of appending a new entry onto the btree.  In that
+** case P2 must be 0.  It is assumed that the cursor is used only for
+** appending and so if the cursor is valid, then the cursor must already
+** be pointing at the end of the btree and so no changes are made to
+** the cursor.
 */
 case OP_Last: {        /* jump */
   VdbeCursor *pC;
@@ -74624,24 +83780,67 @@ case OP_Last: {        /* jump */
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  pCrsr = pC->pCursor;
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
   res = 0;
   assert( pCrsr!=0 );
-  rc = sqlite3BtreeLast(pCrsr, &res);
-  pC->nullRow = (u8)res;
-  pC->deferredMoveto = 0;
-  pC->cacheStatus = CACHE_STALE;
+  pC->seekResult = pOp->p3;
 #ifdef SQLITE_DEBUG
   pC->seekOp = OP_Last;
 #endif
-  if( pOp->p2>0 ){
-    VdbeBranchTaken(res!=0,2);
-    if( res ) pc = pOp->p2 - 1;
+  if( pOp->p3==0 || !sqlite3BtreeCursorIsValidNN(pCrsr) ){
+    rc = sqlite3BtreeLast(pCrsr, &res);
+    pC->nullRow = (u8)res;
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+    if( rc ) goto abort_due_to_error;
+    if( pOp->p2>0 ){
+      VdbeBranchTaken(res!=0,2);
+      if( res ) goto jump_to_p2;
+    }
+  }else{
+    assert( pOp->p2==0 );
+  }
+  break;
+}
+
+/* Opcode: IfSmaller P1 P2 P3 * *
+**
+** Estimate the number of rows in the table P1.  Jump to P2 if that
+** estimate is less than approximately 2**(0.1*P3).
+*/
+case OP_IfSmaller: {        /* jump */
+  VdbeCursor *pC;
+  BtCursor *pCrsr;
+  int res;
+  i64 sz;
+
+  assert( pOp->p1>=0 && pOp->p1nCursor );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  pCrsr = pC->uc.pCursor;
+  assert( pCrsr );
+  rc = sqlite3BtreeFirst(pCrsr, &res);
+  if( rc ) goto abort_due_to_error;
+  if( res==0 ){
+    sz = sqlite3BtreeRowCountEst(pCrsr);
+    if( ALWAYS(sz>=0) && sqlite3LogEst((u64)sz)p3 ) res = 1;
   }
+  VdbeBranchTaken(res!=0,2);
+  if( res ) goto jump_to_p2;
   break;
 }
 
 
+/* Opcode: SorterSort P1 P2 * * *
+**
+** After all records have been inserted into the Sorter object
+** identified by P1, invoke this opcode to actually do the sorting.
+** Jump to P2 if there are no records to be sorted.
+**
+** This opcode is an alias for OP_Sort and OP_Rewind that is used
+** for Sorter objects.
+*/
 /* Opcode: Sort P1 P2 * * *
 **
 ** This opcode does exactly the same thing as OP_Rewind except that
@@ -74691,18 +83890,18 @@ case OP_Rewind: {        /* jump */
   if( isSorter(pC) ){
     rc = sqlite3VdbeSorterRewind(pC, &res);
   }else{
-    pCrsr = pC->pCursor;
+    assert( pC->eCurType==CURTYPE_BTREE );
+    pCrsr = pC->uc.pCursor;
     assert( pCrsr );
     rc = sqlite3BtreeFirst(pCrsr, &res);
     pC->deferredMoveto = 0;
     pC->cacheStatus = CACHE_STALE;
   }
+  if( rc ) goto abort_due_to_error;
   pC->nullRow = (u8)res;
   assert( pOp->p2>0 && pOp->p2nOp );
   VdbeBranchTaken(res!=0,2);
-  if( res ){
-    pc = pOp->p2 - 1;
-  }
+  if( res ) goto jump_to_p2;
   break;
 }
 
@@ -74769,14 +83968,19 @@ case OP_Rewind: {        /* jump */
 ** This opcode works just like Prev except that if cursor P1 is not
 ** open it behaves a no-op.
 */
+/* Opcode: SorterNext P1 P2 * * P5
+**
+** This opcode works just like OP_Next except that P1 must be a
+** sorter object for which the OP_SorterSort opcode has been
+** invoked.  This opcode advances the cursor to the next sorted
+** record, or jumps to P2 if there are no more sorted records.
+*/
 case OP_SorterNext: {  /* jump */
   VdbeCursor *pC;
-  int res;
 
   pC = p->apCsr[pOp->p1];
   assert( isSorter(pC) );
-  res = 0;
-  rc = sqlite3VdbeSorterNext(db, pC, &res);
+  rc = sqlite3VdbeSorterNext(db, pC);
   goto next_tail;
 case OP_PrevIfOpen:    /* jump */
 case OP_NextIfOpen:    /* jump */
@@ -74787,12 +83991,9 @@ case OP_Next:          /* jump */
   assert( pOp->p1>=0 && pOp->p1nCursor );
   assert( pOp->p5aCounter) );
   pC = p->apCsr[pOp->p1];
-  res = pOp->p3;
   assert( pC!=0 );
   assert( pC->deferredMoveto==0 );
-  assert( pC->pCursor );
-  assert( res==0 || (res==1 && pC->isTable==0) );
-  testcase( res==1 );
+  assert( pC->eCurType==CURTYPE_BTREE );
   assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
   assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
   assert( pOp->opcode!=OP_NextIfOpen || pOp->p4.xAdvance==sqlite3BtreeNext );
@@ -74807,50 +84008,63 @@ case OP_Next:          /* jump */
        || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
        || pC->seekOp==OP_Last );
 
-  rc = pOp->p4.xAdvance(pC->pCursor, &res);
+  rc = pOp->p4.xAdvance(pC->uc.pCursor, pOp->p3);
 next_tail:
   pC->cacheStatus = CACHE_STALE;
-  VdbeBranchTaken(res==0,2);
-  if( res==0 ){
+  VdbeBranchTaken(rc==SQLITE_OK,2);
+  if( rc==SQLITE_OK ){
     pC->nullRow = 0;
-    pc = pOp->p2 - 1;
     p->aCounter[pOp->p5]++;
 #ifdef SQLITE_TEST
     sqlite3_search_count++;
 #endif
-  }else{
-    pC->nullRow = 1;
+    goto jump_to_p2_and_check_for_interrupt;
   }
+  if( rc!=SQLITE_DONE ) goto abort_due_to_error;
+  rc = SQLITE_OK;
+  pC->nullRow = 1;
   goto check_for_interrupt;
 }
 
-/* Opcode: IdxInsert P1 P2 P3 * P5
+/* Opcode: IdxInsert P1 P2 P3 P4 P5
 ** Synopsis: key=r[P2]
 **
 ** Register P2 holds an SQL index key made using the
 ** MakeRecord instructions.  This opcode writes that key
 ** into the index P1.  Data for the entry is nil.
 **
-** P3 is a flag that provides a hint to the b-tree layer that this
-** insert is likely to be an append.
+** If P4 is not zero, then it is the number of values in the unpacked
+** key of reg(P2).  In that case, P3 is the index of the first register
+** for the unpacked key.  The availability of the unpacked key can sometimes
+** be an optimization.
+**
+** If P5 has the OPFLAG_APPEND bit set, that is a hint to the b-tree layer
+** that this insert is likely to be an append.
 **
 ** If P5 has the OPFLAG_NCHANGE bit set, then the change counter is
 ** incremented by this instruction.  If the OPFLAG_NCHANGE bit is clear,
 ** then the change counter is unchanged.
 **
-** If P5 has the OPFLAG_USESEEKRESULT bit set, then the cursor must have
-** just done a seek to the spot where the new entry is to be inserted.
-** This flag avoids doing an extra seek.
+** If the OPFLAG_USESEEKRESULT flag of P5 is set, the implementation might
+** run faster by avoiding an unnecessary seek on cursor P1.  However,
+** the OPFLAG_USESEEKRESULT flag must only be set if there have been no prior
+** seeks on the cursor or if the most recent seek used a key equivalent
+** to P2. 
 **
 ** This instruction only works for indices.  The equivalent instruction
 ** for tables is OP_Insert.
 */
+/* Opcode: SorterInsert P1 P2 * * *
+** Synopsis: key=r[P2]
+**
+** Register P2 holds an SQL index key made using the
+** MakeRecord instructions.  This opcode writes that key
+** into the sorter P1.  Data for the entry is nil.
+*/
 case OP_SorterInsert:       /* in2 */
 case OP_IdxInsert: {        /* in2 */
   VdbeCursor *pC;
-  BtCursor *pCrsr;
-  int nKey;
-  const char *zKey;
+  BtreePayload x;
 
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
@@ -74858,24 +84072,26 @@ case OP_IdxInsert: {        /* in2 */
   assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );
   pIn2 = &aMem[pOp->p2];
   assert( pIn2->flags & MEM_Blob );
-  pCrsr = pC->pCursor;
   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
-  assert( pCrsr!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE || pOp->opcode==OP_SorterInsert );
   assert( pC->isTable==0 );
   rc = ExpandBlob(pIn2);
-  if( rc==SQLITE_OK ){
-    if( isSorter(pC) ){
-      rc = sqlite3VdbeSorterWrite(pC, pIn2);
-    }else{
-      nKey = pIn2->n;
-      zKey = pIn2->z;
-      rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p3, 
-          ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
-          );
-      assert( pC->deferredMoveto==0 );
-      pC->cacheStatus = CACHE_STALE;
-    }
+  if( rc ) goto abort_due_to_error;
+  if( pOp->opcode==OP_SorterInsert ){
+    rc = sqlite3VdbeSorterWrite(pC, pIn2);
+  }else{
+    x.nKey = pIn2->n;
+    x.pKey = pIn2->z;
+    x.aMem = aMem + pOp->p3;
+    x.nMem = (u16)pOp->p4.i;
+    rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,
+         (pOp->p5 & (OPFLAG_APPEND|OPFLAG_SAVEPOSITION)), 
+        ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
+        );
+    assert( pC->deferredMoveto==0 );
+    pC->cacheStatus = CACHE_STALE;
   }
+  if( rc) goto abort_due_to_error;
   break;
 }
 
@@ -74893,29 +84109,49 @@ case OP_IdxDelete: {
   UnpackedRecord r;
 
   assert( pOp->p3>0 );
-  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem-p->nCursor)+1 );
+  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem+1 - p->nCursor)+1 );
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  pCrsr = pC->pCursor;
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
   assert( pCrsr!=0 );
   assert( pOp->p5==0 );
   r.pKeyInfo = pC->pKeyInfo;
   r.nField = (u16)pOp->p3;
   r.default_rc = 0;
   r.aMem = &aMem[pOp->p2];
-#ifdef SQLITE_DEBUG
-  { int i; for(i=0; ideferredMoveto==0 );
   pC->cacheStatus = CACHE_STALE;
+  pC->seekResult = 0;
   break;
 }
 
+/* Opcode: DeferredSeek P1 * P3 P4 *
+** Synopsis: Move P3 to P1.rowid if needed
+**
+** P1 is an open index cursor and P3 is a cursor on the corresponding
+** table.  This opcode does a deferred seek of the P3 table cursor
+** to the row that corresponds to the current row of P1.
+**
+** This is a deferred seek.  Nothing actually happens until
+** the cursor is used to read a record.  That way, if no reads
+** occur, no unnecessary I/O happens.
+**
+** P4 may be an array of integers (type P4_INTARRAY) containing
+** one entry for each column in the P3 table.  If array entry a(i)
+** is non-zero, then reading column a(i)-1 from cursor P3 is 
+** equivalent to performing the deferred seek and then reading column i 
+** from P1.  This information is stored in P3 and used to redirect
+** reads against P3 over to P1, thus possibly avoiding the need to
+** seek and read cursor P3.
+*/
 /* Opcode: IdxRowid P1 P2 * * *
 ** Synopsis: r[P2]=rowid
 **
@@ -74925,35 +84161,56 @@ case OP_IdxDelete: {
 **
 ** See also: Rowid, MakeRecord.
 */
-case OP_IdxRowid: {              /* out2-prerelease */
-  BtCursor *pCrsr;
-  VdbeCursor *pC;
-  i64 rowid;
+case OP_DeferredSeek:
+case OP_IdxRowid: {           /* out2 */
+  VdbeCursor *pC;             /* The P1 index cursor */
+  VdbeCursor *pTabCur;        /* The P2 table cursor (OP_DeferredSeek only) */
+  i64 rowid;                  /* Rowid that P1 current points to */
 
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  pCrsr = pC->pCursor;
-  assert( pCrsr!=0 );
-  pOut->flags = MEM_Null;
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
   assert( pC->isTable==0 );
   assert( pC->deferredMoveto==0 );
+  assert( !pC->nullRow || pOp->opcode==OP_IdxRowid );
 
-  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
-  ** out from under the cursor.  That will never happend for an IdxRowid
-  ** opcode, hence the NEVER() arround the check of the return value.
-  */
+  /* The IdxRowid and Seek opcodes are combined because of the commonality
+  ** of sqlite3VdbeCursorRestore() and sqlite3VdbeIdxRowid(). */
   rc = sqlite3VdbeCursorRestore(pC);
+
+  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
+  ** out from under the cursor.  That will never happens for an IdxRowid
+  ** or Seek opcode */
   if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
 
   if( !pC->nullRow ){
     rowid = 0;  /* Not needed.  Only used to silence a warning. */
-    rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid);
+    rc = sqlite3VdbeIdxRowid(db, pC->uc.pCursor, &rowid);
     if( rc!=SQLITE_OK ){
       goto abort_due_to_error;
     }
-    pOut->u.i = rowid;
-    pOut->flags = MEM_Int;
+    if( pOp->opcode==OP_DeferredSeek ){
+      assert( pOp->p3>=0 && pOp->p3nCursor );
+      pTabCur = p->apCsr[pOp->p3];
+      assert( pTabCur!=0 );
+      assert( pTabCur->eCurType==CURTYPE_BTREE );
+      assert( pTabCur->uc.pCursor!=0 );
+      assert( pTabCur->isTable );
+      pTabCur->nullRow = 0;
+      pTabCur->movetoTarget = rowid;
+      pTabCur->deferredMoveto = 1;
+      assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );
+      pTabCur->aAltMap = pOp->p4.ai;
+      pTabCur->pAltCursor = pC;
+    }else{
+      pOut = out2Prerelease(p, pOp);
+      pOut->u.i = rowid;
+    }
+  }else{
+    assert( pOp->opcode==OP_IdxRowid );
+    sqlite3VdbeMemSetNull(&aMem[pOp->p2]);
   }
   break;
 }
@@ -75014,7 +84271,8 @@ case OP_IdxGE:  {       /* jump */
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
   assert( pC->isOrdered );
-  assert( pC->pCursor!=0);
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0);
   assert( pC->deferredMoveto==0 );
   assert( pOp->p5==0 || pOp->p5==1 );
   assert( pOp->p4type==P4_INT32 );
@@ -75042,9 +84300,8 @@ case OP_IdxGE:  {       /* jump */
     res++;
   }
   VdbeBranchTaken(res>0,2);
-  if( res>0 ){
-    pc = pOp->p2 - 1 ;
-  }
+  if( rc ) goto abort_due_to_error;
+  if( res>0 ) goto jump_to_p2;
   break;
 }
 
@@ -75061,46 +84318,42 @@ case OP_IdxGE:  {       /* jump */
 ** might be moved into the newly deleted root page in order to keep all
 ** root pages contiguous at the beginning of the database.  The former
 ** value of the root page that moved - its value before the move occurred -
-** is stored in register P2.  If no page 
-** movement was required (because the table being dropped was already 
-** the last one in the database) then a zero is stored in register P2.
-** If AUTOVACUUM is disabled then a zero is stored in register P2.
+** is stored in register P2. If no page movement was required (because the
+** table being dropped was already the last one in the database) then a 
+** zero is stored in register P2.  If AUTOVACUUM is disabled then a zero 
+** is stored in register P2.
+**
+** This opcode throws an error if there are any active reader VMs when
+** it is invoked. This is done to avoid the difficulty associated with 
+** updating existing cursors when a root page is moved in an AUTOVACUUM 
+** database. This error is thrown even if the database is not an AUTOVACUUM 
+** db in order to avoid introducing an incompatibility between autovacuum 
+** and non-autovacuum modes.
 **
 ** See also: Clear
 */
-case OP_Destroy: {     /* out2-prerelease */
+case OP_Destroy: {     /* out2 */
   int iMoved;
-  int iCnt;
-  Vdbe *pVdbe;
   int iDb;
 
   assert( p->readOnly==0 );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  iCnt = 0;
-  for(pVdbe=db->pVdbe; pVdbe; pVdbe = pVdbe->pNext){
-    if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->bIsReader 
-     && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 
-    ){
-      iCnt++;
-    }
-  }
-#else
-  iCnt = db->nVdbeRead;
-#endif
+  assert( pOp->p1>1 );
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Null;
-  if( iCnt>1 ){
+  if( db->nVdbeRead > db->nVDestroy+1 ){
     rc = SQLITE_LOCKED;
     p->errorAction = OE_Abort;
+    goto abort_due_to_error;
   }else{
     iDb = pOp->p3;
-    assert( iCnt==1 );
     assert( DbMaskTest(p->btreeMask, iDb) );
     iMoved = 0;  /* Not needed.  Only to silence a warning. */
     rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
     pOut->flags = MEM_Int;
     pOut->u.i = iMoved;
+    if( rc ) goto abort_due_to_error;
 #ifndef SQLITE_OMIT_AUTOVACUUM
-    if( rc==SQLITE_OK && iMoved!=0 ){
+    if( iMoved!=0 ){
       sqlite3RootPageMoved(db, iDb, iMoved, pOp->p1);
       /* All OP_Destroy operations occur on the same btree */
       assert( resetSchemaOnFault==0 || resetSchemaOnFault==iDb+1 );
@@ -75146,6 +84399,7 @@ case OP_Clear: {
       aMem[pOp->p3].u.i += nChange;
     }
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -75163,11 +84417,13 @@ case OP_ResetSorter: {
   assert( pOp->p1>=0 && pOp->p1nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  if( pC->pSorter ){
-    sqlite3VdbeSorterReset(db, pC->pSorter);
+  if( isSorter(pC) ){
+    sqlite3VdbeSorterReset(db, pC->uc.pSorter);
   }else{
+    assert( pC->eCurType==CURTYPE_BTREE );
     assert( pC->isEphemeral );
-    rc = sqlite3BtreeClearTableOfCursor(pC->pCursor);
+    rc = sqlite3BtreeClearTableOfCursor(pC->uc.pCursor);
+    if( rc ) goto abort_due_to_error;
   }
   break;
 }
@@ -75196,12 +84452,13 @@ case OP_ResetSorter: {
 **
 ** See documentation on OP_CreateTable for additional information.
 */
-case OP_CreateIndex:            /* out2-prerelease */
-case OP_CreateTable: {          /* out2-prerelease */
+case OP_CreateIndex:            /* out2 */
+case OP_CreateTable: {          /* out2 */
   int pgno;
   int flags;
   Db *pDb;
 
+  pOut = out2Prerelease(p, pOp);
   pgno = 0;
   assert( pOp->p1>=0 && pOp->p1nDb );
   assert( DbMaskTest(p->btreeMask, pOp->p1) );
@@ -75215,10 +84472,23 @@ case OP_CreateTable: {          /* out2-prerelease */
     flags = BTREE_BLOBKEY;
   }
   rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
+  if( rc ) goto abort_due_to_error;
   pOut->u.i = pgno;
   break;
 }
 
+/* Opcode: SqlExec * * * P4 *
+**
+** Run the SQL statement or statements specified in the P4 string.
+*/
+case OP_SqlExec: {
+  db->nSqlExec++;
+  rc = sqlite3_exec(db, pOp->p4.z, 0, 0, 0);
+  db->nSqlExec--;
+  if( rc ) goto abort_due_to_error;
+  break;
+}
+
 /* Opcode: ParseSchema P1 * * P4 *
 **
 ** Read and parse all entries from the SQLITE_MASTER table of database P1
@@ -75247,15 +84517,15 @@ case OP_ParseSchema: {
   assert( iDb>=0 && iDbnDb );
   assert( DbHasProperty(db, iDb, DB_SchemaLoaded) );
   /* Used to be a conditional */ {
-    zMaster = SCHEMA_TABLE(iDb);
+    zMaster = MASTER_NAME;
     initData.db = db;
     initData.iDb = pOp->p1;
     initData.pzErrMsg = &p->zErrMsg;
     zSql = sqlite3MPrintf(db,
        "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
-       db->aDb[iDb].zName, zMaster, pOp->p4.z);
+       db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);
     if( zSql==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       assert( db->init.busy==0 );
       db->init.busy = 1;
@@ -75263,13 +84533,16 @@ case OP_ParseSchema: {
       assert( !db->mallocFailed );
       rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
       if( rc==SQLITE_OK ) rc = initData.rc;
-      sqlite3DbFree(db, zSql);
+      sqlite3DbFreeNN(db, zSql);
       db->init.busy = 0;
     }
   }
-  if( rc ) sqlite3ResetAllSchemasOfConnection(db);
-  if( rc==SQLITE_NOMEM ){
-    goto no_mem;
+  if( rc ){
+    sqlite3ResetAllSchemasOfConnection(db);
+    if( rc==SQLITE_NOMEM ){
+      goto no_mem;
+    }
+    goto abort_due_to_error;
   }
   break;  
 }
@@ -75284,6 +84557,7 @@ case OP_ParseSchema: {
 case OP_LoadAnalysis: {
   assert( pOp->p1>=0 && pOp->p1nDb );
   rc = sqlite3AnalysisLoad(db, pOp->p1);
+  if( rc ) goto abort_due_to_error;
   break;  
 }
 #endif /* !defined(SQLITE_OMIT_ANALYZE) */
@@ -75329,20 +84603,19 @@ case OP_DropTrigger: {
 
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
-/* Opcode: IntegrityCk P1 P2 P3 * P5
+/* Opcode: IntegrityCk P1 P2 P3 P4 P5
 **
 ** Do an analysis of the currently open database.  Store in
 ** register P1 the text of an error message describing any problems.
 ** If no problems are found, store a NULL in register P1.
 **
-** The register P3 contains the maximum number of allowed errors.
+** The register P3 contains one less than the maximum number of allowed errors.
 ** At most reg(P3) errors will be reported.
 ** In other words, the analysis stops as soon as reg(P1) errors are 
 ** seen.  Reg(P1) is updated with the number of errors remaining.
 **
-** The root page numbers of all tables in the database are integer
-** stored in reg(P1), reg(P1+1), reg(P1+2), ....  There are P2 tables
-** total.
+** The root page numbers of all tables in the database are integers
+** stored in P4_INTARRAY argument.
 **
 ** If P5 is not zero, the check is done on the auxiliary database
 ** file, not the main database file.
@@ -75352,37 +84625,31 @@ case OP_DropTrigger: {
 case OP_IntegrityCk: {
   int nRoot;      /* Number of tables to check.  (Number of root pages.) */
   int *aRoot;     /* Array of rootpage numbers for tables to be checked */
-  int j;          /* Loop counter */
   int nErr;       /* Number of errors reported */
   char *z;        /* Text of the error report */
   Mem *pnErr;     /* Register keeping track of errors remaining */
 
   assert( p->bIsReader );
   nRoot = pOp->p2;
+  aRoot = pOp->p4.ai;
   assert( nRoot>0 );
-  aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
-  if( aRoot==0 ) goto no_mem;
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
+  assert( aRoot[nRoot]==0 );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pnErr = &aMem[pOp->p3];
   assert( (pnErr->flags & MEM_Int)!=0 );
   assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
   pIn1 = &aMem[pOp->p1];
-  for(j=0; jp5nDb );
   assert( DbMaskTest(p->btreeMask, pOp->p5) );
   z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,
-                                 (int)pnErr->u.i, &nErr);
-  sqlite3DbFree(db, aRoot);
-  pnErr->u.i -= nErr;
+                                 (int)pnErr->u.i+1, &nErr);
   sqlite3VdbeMemSetNull(pIn1);
   if( nErr==0 ){
     assert( z==0 );
   }else if( z==0 ){
     goto no_mem;
   }else{
+    pnErr->u.i -= nErr-1;
     sqlite3VdbeMemSetStr(pIn1, z, -1, SQLITE_UTF8, sqlite3_free);
   }
   UPDATE_MAX_BLOBSIZE(pIn1);
@@ -75392,9 +84659,9 @@ case OP_IntegrityCk: {
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
 /* Opcode: RowSetAdd P1 P2 * * *
-** Synopsis:  rowset(P1)=r[P2]
+** Synopsis: rowset(P1)=r[P2]
 **
-** Insert the integer value held by register P2 into a boolean index
+** Insert the integer value held by register P2 into a RowSet object
 ** held in register P1.
 **
 ** An assertion fails if P2 is not an integer.
@@ -75412,10 +84679,11 @@ case OP_RowSetAdd: {       /* in1, in2 */
 }
 
 /* Opcode: RowSetRead P1 P2 P3 * *
-** Synopsis:  r[P3]=rowset(P1)
+** Synopsis: r[P3]=rowset(P1)
 **
-** Extract the smallest value from boolean index P1 and put that value into
-** register P3.  Or, if boolean index P1 is initially empty, leave P3
+** Extract the smallest value from the RowSet object in P1
+** and put that value into register P3.
+** Or, if RowSet object P1 is initially empty, leave P3
 ** unchanged and jump to instruction P2.
 */
 case OP_RowSetRead: {       /* jump, in1, out3 */
@@ -75427,12 +84695,12 @@ case OP_RowSetRead: {       /* jump, in1, out3 */
   ){
     /* The boolean index is empty */
     sqlite3VdbeMemSetNull(pIn1);
-    pc = pOp->p2 - 1;
     VdbeBranchTaken(1,2);
+    goto jump_to_p2_and_check_for_interrupt;
   }else{
     /* A value was pulled from the index */
-    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], val);
     VdbeBranchTaken(0,2);
+    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], val);
   }
   goto check_for_interrupt;
 }
@@ -75446,15 +84714,14 @@ case OP_RowSetRead: {       /* jump, in1, out3 */
 ** integer in P3 into the RowSet and continue on to the
 ** next opcode.
 **
-** The RowSet object is optimized for the case where successive sets
-** of integers, where each set contains no duplicates. Each set
-** of values is identified by a unique P4 value. The first set
-** must have P4==0, the final set P4=-1.  P4 must be either -1 or
-** non-negative.  For non-negative values of P4 only the lower 4
-** bits are significant.
+** The RowSet object is optimized for the case where sets of integers
+** are inserted in distinct phases, which each set contains no duplicates.
+** Each set is identified by a unique P4 value. The first set
+** must have P4==0, the final set must have P4==-1, and for all other sets
+** must have P4>0.
 **
 ** This allows optimizations: (a) when P4==0 there is no need to test
-** the rowset object for P3, as it is guaranteed not to contain it,
+** the RowSet object for P3, as it is guaranteed not to contain it,
 ** (b) when P4==-1 there is no need to insert the value, as it will
 ** never be tested for, and (c) when a value that is part of set X is
 ** inserted, there is no need to search to see if the same value was
@@ -75483,10 +84750,7 @@ case OP_RowSetTest: {                     /* jump, in1, in3 */
   if( iSet ){
     exists = sqlite3RowSetTest(pIn1->u.pRowSet, iSet, pIn3->u.i);
     VdbeBranchTaken(exists!=0,2);
-    if( exists ){
-      pc = pOp->p2 - 1;
-      break;
-    }
+    if( exists ) goto jump_to_p2;
   }
   if( iSet>=0 ){
     sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
@@ -75545,8 +84809,8 @@ case OP_Program: {        /* jump */
 
   if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
     rc = SQLITE_ERROR;
-    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
-    break;
+    sqlite3VdbeError(p, "too many levels of trigger recursion");
+    goto abort_due_to_error;
   }
 
   /* Register pRt is used to store the memory required to save the state
@@ -75560,10 +84824,12 @@ case OP_Program: {        /* jump */
     ** variable nMem (and later, VdbeFrame.nChildMem) to this value.
     */
     nMem = pProgram->nMem + pProgram->nCsr;
+    assert( nMem>0 );
+    if( pProgram->nCsr==0 ) nMem++;
     nByte = ROUND8(sizeof(VdbeFrame))
               + nMem * sizeof(Mem)
-              + pProgram->nCsr * sizeof(VdbeCursor *)
-              + pProgram->nOnce * sizeof(u8);
+              + pProgram->nCsr * sizeof(VdbeCursor*)
+              + (pProgram->nOp + 7)/8;
     pFrame = sqlite3DbMallocZero(db, nByte);
     if( !pFrame ){
       goto no_mem;
@@ -75575,7 +84841,7 @@ case OP_Program: {        /* jump */
     pFrame->v = p;
     pFrame->nChildMem = nMem;
     pFrame->nChildCsr = pProgram->nCsr;
-    pFrame->pc = pc;
+    pFrame->pc = (int)(pOp - aOp);
     pFrame->aMem = p->aMem;
     pFrame->nMem = p->nMem;
     pFrame->apCsr = p->apCsr;
@@ -75583,8 +84849,6 @@ case OP_Program: {        /* jump */
     pFrame->aOp = p->aOp;
     pFrame->nOp = p->nOp;
     pFrame->token = pProgram->token;
-    pFrame->aOnceFlag = p->aOnceFlag;
-    pFrame->nOnceFlag = p->nOnceFlag;
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
     pFrame->anExec = p->anExec;
 #endif
@@ -75596,31 +84860,34 @@ case OP_Program: {        /* jump */
     }
   }else{
     pFrame = pRt->u.pFrame;
-    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem );
+    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem 
+        || (pProgram->nCsr==0 && pProgram->nMem+1==pFrame->nChildMem) );
     assert( pProgram->nCsr==pFrame->nChildCsr );
-    assert( pc==pFrame->pc );
+    assert( (int)(pOp - aOp)==pFrame->pc );
   }
 
   p->nFrame++;
   pFrame->pParent = p->pFrame;
-  pFrame->lastRowid = lastRowid;
+  pFrame->lastRowid = db->lastRowid;
   pFrame->nChange = p->nChange;
   pFrame->nDbChange = p->db->nChange;
+  assert( pFrame->pAuxData==0 );
+  pFrame->pAuxData = p->pAuxData;
+  p->pAuxData = 0;
   p->nChange = 0;
   p->pFrame = pFrame;
-  p->aMem = aMem = &VdbeFrameMem(pFrame)[-1];
+  p->aMem = aMem = VdbeFrameMem(pFrame);
   p->nMem = pFrame->nChildMem;
   p->nCursor = (u16)pFrame->nChildCsr;
-  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
+  p->apCsr = (VdbeCursor **)&aMem[p->nMem];
+  pFrame->aOnce = (u8*)&p->apCsr[pProgram->nCsr];
+  memset(pFrame->aOnce, 0, (pProgram->nOp + 7)/8);
   p->aOp = aOp = pProgram->aOp;
   p->nOp = pProgram->nOp;
-  p->aOnceFlag = (u8 *)&p->apCsr[p->nCursor];
-  p->nOnceFlag = pProgram->nOnce;
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
   p->anExec = 0;
 #endif
-  pc = -1;
-  memset(p->aOnceFlag, 0, p->nOnceFlag);
+  pOp = &aOp[-1];
 
   break;
 }
@@ -75637,9 +84904,10 @@ case OP_Program: {        /* jump */
 ** the value of the P1 argument to the value of the P1 argument to the
 ** calling OP_Program instruction.
 */
-case OP_Param: {           /* out2-prerelease */
+case OP_Param: {           /* out2 */
   VdbeFrame *pFrame;
   Mem *pIn;
+  pOut = out2Prerelease(p, pOp);
   pFrame = p->pFrame;
   pIn = &pFrame->aMem[pOp->p1 + pFrame->aOp[pFrame->pc].p1];   
   sqlite3VdbeMemShallowCopy(pOut, pIn, MEM_Ephem);
@@ -75683,10 +84951,10 @@ case OP_FkCounter: {
 case OP_FkIfZero: {         /* jump */
   if( pOp->p1 ){
     VdbeBranchTaken(db->nDeferredCons==0 && db->nDeferredImmCons==0, 2);
-    if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
+    if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;
   }else{
     VdbeBranchTaken(p->nFkConstraint==0 && db->nDeferredImmCons==0, 2);
-    if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
+    if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;
   }
   break;
 }
@@ -75723,109 +84991,199 @@ case OP_MemMax: {        /* in2 */
 }
 #endif /* SQLITE_OMIT_AUTOINCREMENT */
 
-/* Opcode: IfPos P1 P2 * * *
-** Synopsis: if r[P1]>0 goto P2
+/* Opcode: IfPos P1 P2 P3 * *
+** Synopsis: if r[P1]>0 then r[P1]-=P3, goto P2
 **
-** If the value of register P1 is 1 or greater, jump to P2.
+** Register P1 must contain an integer.
+** If the value of register P1 is 1 or greater, subtract P3 from the
+** value in P1 and jump to P2.
 **
-** It is illegal to use this instruction on a register that does
-** not contain an integer.  An assertion fault will result if you try.
+** If the initial value of register P1 is less than 1, then the
+** value is unchanged and control passes through to the next instruction.
 */
 case OP_IfPos: {        /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
   VdbeBranchTaken( pIn1->u.i>0, 2);
   if( pIn1->u.i>0 ){
-     pc = pOp->p2 - 1;
+    pIn1->u.i -= pOp->p3;
+    goto jump_to_p2;
   }
   break;
 }
 
-/* Opcode: IfNeg P1 P2 P3 * *
-** Synopsis: r[P1]+=P3, if r[P1]<0 goto P2
+/* Opcode: OffsetLimit P1 P2 P3 * *
+** Synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)
 **
-** Register P1 must contain an integer.  Add literal P3 to the value in
-** register P1 then if the value of register P1 is less than zero, jump to P2. 
+** This opcode performs a commonly used computation associated with
+** LIMIT and OFFSET process.  r[P1] holds the limit counter.  r[P3]
+** holds the offset counter.  The opcode computes the combined value
+** of the LIMIT and OFFSET and stores that value in r[P2].  The r[P2]
+** value computed is the total number of rows that will need to be
+** visited in order to complete the query.
+**
+** If r[P3] is zero or negative, that means there is no OFFSET
+** and r[P2] is set to be the value of the LIMIT, r[P1].
+**
+** if r[P1] is zero or negative, that means there is no LIMIT
+** and r[P2] is set to -1. 
+**
+** Otherwise, r[P2] is set to the sum of r[P1] and r[P3].
+*/
+case OP_OffsetLimit: {    /* in1, out2, in3 */
+  i64 x;
+  pIn1 = &aMem[pOp->p1];
+  pIn3 = &aMem[pOp->p3];
+  pOut = out2Prerelease(p, pOp);
+  assert( pIn1->flags & MEM_Int );
+  assert( pIn3->flags & MEM_Int );
+  x = pIn1->u.i;
+  if( x<=0 || sqlite3AddInt64(&x, pIn3->u.i>0?pIn3->u.i:0) ){
+    /* If the LIMIT is less than or equal to zero, loop forever.  This
+    ** is documented.  But also, if the LIMIT+OFFSET exceeds 2^63 then
+    ** also loop forever.  This is undocumented.  In fact, one could argue
+    ** that the loop should terminate.  But assuming 1 billion iterations
+    ** per second (far exceeding the capabilities of any current hardware)
+    ** it would take nearly 300 years to actually reach the limit.  So
+    ** looping forever is a reasonable approximation. */
+    pOut->u.i = -1;
+  }else{
+    pOut->u.i = x;
+  }
+  break;
+}
+
+/* Opcode: IfNotZero P1 P2 * * *
+** Synopsis: if r[P1]!=0 then r[P1]--, goto P2
+**
+** Register P1 must contain an integer.  If the content of register P1 is
+** initially greater than zero, then decrement the value in register P1.
+** If it is non-zero (negative or positive) and then also jump to P2.  
+** If register P1 is initially zero, leave it unchanged and fall through.
 */
-case OP_IfNeg: {        /* jump, in1 */
+case OP_IfNotZero: {        /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
-  pIn1->u.i += pOp->p3;
   VdbeBranchTaken(pIn1->u.i<0, 2);
-  if( pIn1->u.i<0 ){
-     pc = pOp->p2 - 1;
+  if( pIn1->u.i ){
+     if( pIn1->u.i>0 ) pIn1->u.i--;
+     goto jump_to_p2;
   }
   break;
 }
 
-/* Opcode: IfZero P1 P2 P3 * *
-** Synopsis: r[P1]+=P3, if r[P1]==0 goto P2
+/* Opcode: DecrJumpZero P1 P2 * * *
+** Synopsis: if (--r[P1])==0 goto P2
 **
-** The register P1 must contain an integer.  Add literal P3 to the
-** value in register P1.  If the result is exactly 0, jump to P2. 
+** Register P1 must hold an integer.  Decrement the value in P1
+** and jump to P2 if the new value is exactly zero.
 */
-case OP_IfZero: {        /* jump, in1 */
+case OP_DecrJumpZero: {      /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
-  pIn1->u.i += pOp->p3;
+  if( pIn1->u.i>SMALLEST_INT64 ) pIn1->u.i--;
   VdbeBranchTaken(pIn1->u.i==0, 2);
-  if( pIn1->u.i==0 ){
-     pc = pOp->p2 - 1;
-  }
+  if( pIn1->u.i==0 ) goto jump_to_p2;
   break;
 }
 
-/* Opcode: AggStep * P2 P3 P4 P5
+
+/* Opcode: AggStep0 * P2 P3 P4 P5
 ** Synopsis: accum=r[P3] step(r[P2@P5])
 **
 ** Execute the step function for an aggregate.  The
 ** function has P5 arguments.   P4 is a pointer to the FuncDef
-** structure that specifies the function.  Use register
-** P3 as the accumulator.
+** structure that specifies the function.  Register P3 is the
+** accumulator.
 **
 ** The P5 arguments are taken from register P2 and its
 ** successors.
 */
-case OP_AggStep: {
+/* Opcode: AggStep * P2 P3 P4 P5
+** Synopsis: accum=r[P3] step(r[P2@P5])
+**
+** Execute the step function for an aggregate.  The
+** function has P5 arguments.   P4 is a pointer to an sqlite3_context
+** object that is used to run the function.  Register P3 is
+** as the accumulator.
+**
+** The P5 arguments are taken from register P2 and its
+** successors.
+**
+** This opcode is initially coded as OP_AggStep0.  On first evaluation,
+** the FuncDef stored in P4 is converted into an sqlite3_context and
+** the opcode is changed.  In this way, the initialization of the
+** sqlite3_context only happens once, instead of on each call to the
+** step function.
+*/
+case OP_AggStep0: {
   int n;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCDEF );
+  n = pOp->p5;
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
+  assert( pOp->p3p2 || pOp->p3>=pOp->p2+n );
+  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
+  if( pCtx==0 ) goto no_mem;
+  pCtx->pMem = 0;
+  pCtx->pFunc = pOp->p4.pFunc;
+  pCtx->iOp = (int)(pOp - aOp);
+  pCtx->pVdbe = p;
+  pCtx->argc = n;
+  pOp->p4type = P4_FUNCCTX;
+  pOp->p4.pCtx = pCtx;
+  pOp->opcode = OP_AggStep;
+  /* Fall through into OP_AggStep */
+}
+case OP_AggStep: {
   int i;
+  sqlite3_context *pCtx;
   Mem *pMem;
-  Mem *pRec;
   Mem t;
-  sqlite3_context ctx;
-  sqlite3_value **apVal;
 
-  n = pOp->p5;
-  assert( n>=0 );
-  pRec = &aMem[pOp->p2];
-  apVal = p->apArg;
-  assert( apVal || n==0 );
-  for(i=0; ip4type==P4_FUNCCTX );
+  pCtx = pOp->p4.pCtx;
+  pMem = &aMem[pOp->p3];
+
+  /* If this function is inside of a trigger, the register array in aMem[]
+  ** might change from one evaluation to the next.  The next block of code
+  ** checks to see if the register array has changed, and if so it
+  ** reinitializes the relavant parts of the sqlite3_context object */
+  if( pCtx->pMem != pMem ){
+    pCtx->pMem = pMem;
+    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
+  }
+
+#ifdef SQLITE_DEBUG
+  for(i=0; iargc; i++){
+    assert( memIsValid(pCtx->argv[i]) );
+    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
   }
-  ctx.pFunc = pOp->p4.pFunc;
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
-  ctx.pMem = pMem = &aMem[pOp->p3];
+#endif
+
   pMem->n++;
   sqlite3VdbeMemInit(&t, db, MEM_Null);
-  ctx.pOut = &t;
-  ctx.isError = 0;
-  ctx.pVdbe = p;
-  ctx.iOp = pc;
-  ctx.skipFlag = 0;
-  (ctx.pFunc->xStep)(&ctx, n, apVal); /* IMP: R-24505-23230 */
-  if( ctx.isError ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&t));
-    rc = ctx.isError;
+  pCtx->pOut = &t;
+  pCtx->fErrorOrAux = 0;
+  pCtx->skipFlag = 0;
+  (pCtx->pFunc->xSFunc)(pCtx,pCtx->argc,pCtx->argv); /* IMP: R-24505-23230 */
+  if( pCtx->fErrorOrAux ){
+    if( pCtx->isError ){
+      sqlite3VdbeError(p, "%s", sqlite3_value_text(&t));
+      rc = pCtx->isError;
+    }
+    sqlite3VdbeMemRelease(&t);
+    if( rc ) goto abort_due_to_error;
+  }else{
+    assert( t.flags==MEM_Null );
   }
-  if( ctx.skipFlag ){
+  if( pCtx->skipFlag ){
     assert( pOp[-1].opcode==OP_CollSeq );
     i = pOp[-1].p1;
     if( i ) sqlite3VdbeMemSetInt64(&aMem[i], 1);
   }
-  sqlite3VdbeMemRelease(&t);
   break;
 }
 
@@ -75844,12 +85202,13 @@ case OP_AggStep: {
 */
 case OP_AggFinal: {
   Mem *pMem;
-  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
   pMem = &aMem[pOp->p1];
   assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
   rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
   if( rc ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(pMem));
+    sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));
+    goto abort_due_to_error;
   }
   sqlite3VdbeChangeEncoding(pMem, encoding);
   UPDATE_MAX_BLOBSIZE(pMem);
@@ -75885,7 +85244,8 @@ case OP_Checkpoint: {
        || pOp->p2==SQLITE_CHECKPOINT_TRUNCATE
   );
   rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &aRes[1], &aRes[2]);
-  if( rc==SQLITE_BUSY ){
+  if( rc ){
+    if( rc!=SQLITE_BUSY ) goto abort_due_to_error;
     rc = SQLITE_OK;
     aRes[0] = 1;
   }
@@ -75908,7 +85268,7 @@ case OP_Checkpoint: {
 **
 ** Write a string containing the final journal-mode to register P2.
 */
-case OP_JournalMode: {    /* out2-prerelease */
+case OP_JournalMode: {    /* out2 */
   Btree *pBt;                     /* Btree to change journal mode of */
   Pager *pPager;                  /* Pager associated with pBt */
   int eNew;                       /* New journal mode */
@@ -75917,6 +85277,7 @@ case OP_JournalMode: {    /* out2-prerelease */
   const char *zFilename;          /* Name of database file for pPager */
 #endif
 
+  pOut = out2Prerelease(p, pOp);
   eNew = pOp->p3;
   assert( eNew==PAGER_JOURNALMODE_DELETE 
        || eNew==PAGER_JOURNALMODE_TRUNCATE 
@@ -75953,11 +85314,11 @@ case OP_JournalMode: {    /* out2-prerelease */
   ){
     if( !db->autoCommit || db->nVdbeRead>1 ){
       rc = SQLITE_ERROR;
-      sqlite3SetString(&p->zErrMsg, db, 
+      sqlite3VdbeError(p,
           "cannot change %s wal mode from within a transaction",
           (eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
       );
-      break;
+      goto abort_due_to_error;
     }else{
  
       if( eOld==PAGER_JOURNALMODE_WAL ){
@@ -75966,7 +85327,7 @@ case OP_JournalMode: {    /* out2-prerelease */
         ** file. An EXCLUSIVE lock may still be held on the database file 
         ** after a successful return. 
         */
-        rc = sqlite3PagerCloseWal(pPager);
+        rc = sqlite3PagerCloseWal(pPager, db);
         if( rc==SQLITE_OK ){
           sqlite3PagerSetJournalMode(pPager, eNew);
         }
@@ -75987,31 +85348,29 @@ case OP_JournalMode: {    /* out2-prerelease */
   }
 #endif /* ifndef SQLITE_OMIT_WAL */
 
-  if( rc ){
-    eNew = eOld;
-  }
+  if( rc ) eNew = eOld;
   eNew = sqlite3PagerSetJournalMode(pPager, eNew);
 
-  pOut = &aMem[pOp->p2];
   pOut->flags = MEM_Str|MEM_Static|MEM_Term;
   pOut->z = (char *)sqlite3JournalModename(eNew);
   pOut->n = sqlite3Strlen30(pOut->z);
   pOut->enc = SQLITE_UTF8;
   sqlite3VdbeChangeEncoding(pOut, encoding);
+  if( rc ) goto abort_due_to_error;
   break;
 };
 #endif /* SQLITE_OMIT_PRAGMA */
 
 #if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
-/* Opcode: Vacuum * * * * *
+/* Opcode: Vacuum P1 * * * *
 **
-** Vacuum the entire database.  This opcode will cause other virtual
-** machines to be created and run.  It may not be called from within
-** a transaction.
+** Vacuum the entire database P1.  P1 is 0 for "main", and 2 or more
+** for an attached database.  The "temp" database may not be vacuumed.
 */
 case OP_Vacuum: {
   assert( p->readOnly==0 );
-  rc = sqlite3RunVacuum(&p->zErrMsg, db);
+  rc = sqlite3RunVacuum(&p->zErrMsg, db, pOp->p1);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif
@@ -76032,9 +85391,10 @@ case OP_IncrVacuum: {        /* jump */
   pBt = db->aDb[pOp->p1].pBt;
   rc = sqlite3BtreeIncrVacuum(pBt);
   VdbeBranchTaken(rc==SQLITE_DONE,2);
-  if( rc==SQLITE_DONE ){
-    pc = pOp->p2 - 1;
+  if( rc ){
+    if( rc!=SQLITE_DONE ) goto abort_due_to_error;
     rc = SQLITE_OK;
+    goto jump_to_p2;
   }
   break;
 }
@@ -76077,15 +85437,18 @@ case OP_Expire: {
 */
 case OP_TableLock: {
   u8 isWriteLock = (u8)pOp->p3;
-  if( isWriteLock || 0==(db->flags&SQLITE_ReadUncommitted) ){
+  if( isWriteLock || 0==(db->flags&SQLITE_ReadUncommit) ){
     int p1 = pOp->p1; 
     assert( p1>=0 && p1nDb );
     assert( DbMaskTest(p->btreeMask, p1) );
     assert( isWriteLock==0 || isWriteLock==1 );
     rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
-    if( (rc&0xFF)==SQLITE_LOCKED ){
-      const char *z = pOp->p4.z;
-      sqlite3SetString(&p->zErrMsg, db, "database table is locked: %s", z);
+    if( rc ){
+      if( (rc&0xFF)==SQLITE_LOCKED ){
+        const char *z = pOp->p4.z;
+        sqlite3VdbeError(p, "database table is locked: %s", z);
+      }
+      goto abort_due_to_error;
     }
   }
   break;
@@ -76107,18 +85470,36 @@ case OP_VBegin: {
   pVTab = pOp->p4.pVtab;
   rc = sqlite3VtabBegin(db, pVTab);
   if( pVTab ) sqlite3VtabImportErrmsg(p, pVTab->pVtab);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-/* Opcode: VCreate P1 * * P4 *
+/* Opcode: VCreate P1 P2 * * *
 **
-** P4 is the name of a virtual table in database P1. Call the xCreate method
-** for that table.
+** P2 is a register that holds the name of a virtual table in database 
+** P1. Call the xCreate method for that table.
 */
 case OP_VCreate: {
-  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.z, &p->zErrMsg);
+  Mem sMem;          /* For storing the record being decoded */
+  const char *zTab;  /* Name of the virtual table */
+
+  memset(&sMem, 0, sizeof(sMem));
+  sMem.db = db;
+  /* Because P2 is always a static string, it is impossible for the
+  ** sqlite3VdbeMemCopy() to fail */
+  assert( (aMem[pOp->p2].flags & MEM_Str)!=0 );
+  assert( (aMem[pOp->p2].flags & MEM_Static)!=0 );
+  rc = sqlite3VdbeMemCopy(&sMem, &aMem[pOp->p2]);
+  assert( rc==SQLITE_OK );
+  zTab = (const char*)sqlite3_value_text(&sMem);
+  assert( zTab || db->mallocFailed );
+  if( zTab ){
+    rc = sqlite3VtabCallCreate(db, pOp->p1, zTab, &p->zErrMsg);
+  }
+  sqlite3VdbeMemRelease(&sMem);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -76130,9 +85511,10 @@ case OP_VCreate: {
 ** of that table.
 */
 case OP_VDestroy: {
-  p->inVtabMethod = 2;
+  db->nVDestroy++;
   rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
-  p->inVtabMethod = 0;
+  db->nVDestroy--;
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -76146,30 +85528,35 @@ case OP_VDestroy: {
 */
 case OP_VOpen: {
   VdbeCursor *pCur;
-  sqlite3_vtab_cursor *pVtabCursor;
+  sqlite3_vtab_cursor *pVCur;
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
+  const sqlite3_module *pModule;
 
   assert( p->bIsReader );
   pCur = 0;
-  pVtabCursor = 0;
+  pVCur = 0;
   pVtab = pOp->p4.pVtab->pVtab;
-  pModule = (sqlite3_module *)pVtab->pModule;
-  assert(pVtab && pModule);
-  rc = pModule->xOpen(pVtab, &pVtabCursor);
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    goto abort_due_to_error;
+  }
+  pModule = pVtab->pModule;
+  rc = pModule->xOpen(pVtab, &pVCur);
   sqlite3VtabImportErrmsg(p, pVtab);
-  if( SQLITE_OK==rc ){
-    /* Initialize sqlite3_vtab_cursor base class */
-    pVtabCursor->pVtab = pVtab;
+  if( rc ) goto abort_due_to_error;
 
-    /* Initialize vdbe cursor object */
-    pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
-    if( pCur ){
-      pCur->pVtabCursor = pVtabCursor;
-    }else{
-      db->mallocFailed = 1;
-      pModule->xClose(pVtabCursor);
-    }
+  /* Initialize sqlite3_vtab_cursor base class */
+  pVCur->pVtab = pVtab;
+
+  /* Initialize vdbe cursor object */
+  pCur = allocateCursor(p, pOp->p1, 0, -1, CURTYPE_VTAB);
+  if( pCur ){
+    pCur->uc.pVCur = pVCur;
+    pVtab->nRef++;
+  }else{
+    assert( db->mallocFailed );
+    pModule->xClose(pVCur);
+    goto no_mem;
   }
   break;
 }
@@ -76201,7 +85588,7 @@ case OP_VFilter: {   /* jump */
   const sqlite3_module *pModule;
   Mem *pQuery;
   Mem *pArgc;
-  sqlite3_vtab_cursor *pVtabCursor;
+  sqlite3_vtab_cursor *pVCur;
   sqlite3_vtab *pVtab;
   VdbeCursor *pCur;
   int res;
@@ -76213,9 +85600,9 @@ case OP_VFilter: {   /* jump */
   pCur = p->apCsr[pOp->p1];
   assert( memIsValid(pQuery) );
   REGISTER_TRACE(pOp->p3, pQuery);
-  assert( pCur->pVtabCursor );
-  pVtabCursor = pCur->pVtabCursor;
-  pVtab = pVtabCursor->pVtab;
+  assert( pCur->eCurType==CURTYPE_VTAB );
+  pVCur = pCur->uc.pVCur;
+  pVtab = pVCur->pVtab;
   pModule = pVtab->pModule;
 
   /* Grab the index number and argc parameters */
@@ -76224,27 +85611,18 @@ case OP_VFilter: {   /* jump */
   iQuery = (int)pQuery->u.i;
 
   /* Invoke the xFilter method */
-  {
-    res = 0;
-    apArg = p->apArg;
-    for(i = 0; iinVtabMethod = 1;
-    rc = pModule->xFilter(pVtabCursor, iQuery, pOp->p4.z, nArg, apArg);
-    p->inVtabMethod = 0;
-    sqlite3VtabImportErrmsg(p, pVtab);
-    if( rc==SQLITE_OK ){
-      res = pModule->xEof(pVtabCursor);
-    }
-    VdbeBranchTaken(res!=0,2);
-    if( res ){
-      pc = pOp->p2 - 1;
-    }
+  res = 0;
+  apArg = p->apArg;
+  for(i = 0; ixFilter(pVCur, iQuery, pOp->p4.z, nArg, apArg);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  if( rc ) goto abort_due_to_error;
+  res = pModule->xEof(pVCur);
   pCur->nullRow = 0;
-
+  VdbeBranchTaken(res!=0,2);
+  if( res ) goto jump_to_p2;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -76264,21 +85642,21 @@ case OP_VColumn: {
   sqlite3_context sContext;
 
   VdbeCursor *pCur = p->apCsr[pOp->p1];
-  assert( pCur->pVtabCursor );
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
+  assert( pCur->eCurType==CURTYPE_VTAB );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pDest = &aMem[pOp->p3];
   memAboutToChange(p, pDest);
   if( pCur->nullRow ){
     sqlite3VdbeMemSetNull(pDest);
     break;
   }
-  pVtab = pCur->pVtabCursor->pVtab;
+  pVtab = pCur->uc.pVCur->pVtab;
   pModule = pVtab->pModule;
   assert( pModule->xColumn );
   memset(&sContext, 0, sizeof(sContext));
   sContext.pOut = pDest;
   MemSetTypeFlag(pDest, MEM_Null);
-  rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);
+  rc = pModule->xColumn(pCur->uc.pVCur, &sContext, pOp->p2);
   sqlite3VtabImportErrmsg(p, pVtab);
   if( sContext.isError ){
     rc = sContext.isError;
@@ -76290,6 +85668,7 @@ case OP_VColumn: {
   if( sqlite3VdbeMemTooBig(pDest) ){
     goto too_big;
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -76309,11 +85688,11 @@ case OP_VNext: {   /* jump */
 
   res = 0;
   pCur = p->apCsr[pOp->p1];
-  assert( pCur->pVtabCursor );
+  assert( pCur->eCurType==CURTYPE_VTAB );
   if( pCur->nullRow ){
     break;
   }
-  pVtab = pCur->pVtabCursor->pVtab;
+  pVtab = pCur->uc.pVCur->pVtab;
   pModule = pVtab->pModule;
   assert( pModule->xNext );
 
@@ -76323,17 +85702,14 @@ case OP_VNext: {   /* jump */
   ** data is available) and the error code returned when xColumn or
   ** some other method is next invoked on the save virtual table cursor.
   */
-  p->inVtabMethod = 1;
-  rc = pModule->xNext(pCur->pVtabCursor);
-  p->inVtabMethod = 0;
+  rc = pModule->xNext(pCur->uc.pVCur);
   sqlite3VtabImportErrmsg(p, pVtab);
-  if( rc==SQLITE_OK ){
-    res = pModule->xEof(pCur->pVtabCursor);
-  }
+  if( rc ) goto abort_due_to_error;
+  res = pModule->xEof(pCur->uc.pVCur);
   VdbeBranchTaken(!res,2);
   if( !res ){
     /* If there is data, jump to P2 */
-    pc = pOp->p2 - 1;
+    goto jump_to_p2_and_check_for_interrupt;
   }
   goto check_for_interrupt;
 }
@@ -76361,11 +85737,11 @@ case OP_VRename: {
   testcase( pName->enc==SQLITE_UTF16BE );
   testcase( pName->enc==SQLITE_UTF16LE );
   rc = sqlite3VdbeChangeEncoding(pName, SQLITE_UTF8);
-  if( rc==SQLITE_OK ){
-    rc = pVtab->pModule->xRename(pVtab, pName->z);
-    sqlite3VtabImportErrmsg(p, pVtab);
-    p->expired = 0;
-  }
+  if( rc ) goto abort_due_to_error;
+  rc = pVtab->pModule->xRename(pVtab, pName->z);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  p->expired = 0;
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif
@@ -76400,7 +85776,7 @@ case OP_VRename: {
 */
 case OP_VUpdate: {
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
+  const sqlite3_module *pModule;
   int nArg;
   int i;
   sqlite_int64 rowid;
@@ -76412,7 +85788,11 @@ case OP_VUpdate: {
   );
   assert( p->readOnly==0 );
   pVtab = pOp->p4.pVtab->pVtab;
-  pModule = (sqlite3_module *)pVtab->pModule;
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    goto abort_due_to_error;
+  }
+  pModule = pVtab->pModule;
   nArg = pOp->p2;
   assert( pOp->p4type==P4_VTAB );
   if( ALWAYS(pModule->xUpdate) ){
@@ -76431,7 +85811,7 @@ case OP_VUpdate: {
     sqlite3VtabImportErrmsg(p, pVtab);
     if( rc==SQLITE_OK && pOp->p1 ){
       assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
-      db->lastRowid = lastRowid = rowid;
+      db->lastRowid = rowid;
     }
     if( (rc&0xff)==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
       if( pOp->p5==OE_Ignore ){
@@ -76442,6 +85822,7 @@ case OP_VUpdate: {
     }else{
       p->nChange++;
     }
+    if( rc ) goto abort_due_to_error;
   }
   break;
 }
@@ -76452,7 +85833,8 @@ case OP_VUpdate: {
 **
 ** Write the current number of pages in database P1 to memory cell P2.
 */
-case OP_Pagecount: {            /* out2-prerelease */
+case OP_Pagecount: {            /* out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = sqlite3BtreeLastPage(db->aDb[pOp->p1].pBt);
   break;
 }
@@ -76468,10 +85850,11 @@ case OP_Pagecount: {            /* out2-prerelease */
 **
 ** Store the maximum page count after the change in register P2.
 */
-case OP_MaxPgcnt: {            /* out2-prerelease */
+case OP_MaxPgcnt: {            /* out2 */
   unsigned int newMax;
   Btree *pBt;
 
+  pOut = out2Prerelease(p, pOp);
   pBt = db->aDb[pOp->p1].pBt;
   newMax = 0;
   if( pOp->p3 ){
@@ -76483,9 +85866,124 @@ case OP_MaxPgcnt: {            /* out2-prerelease */
 }
 #endif
 
+/* Opcode: Function0 P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
+**
+** Invoke a user function (P4 is a pointer to a FuncDef object that
+** defines the function) with P5 arguments taken from register P2 and
+** successors.  The result of the function is stored in register P3.
+** Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** See also: Function, AggStep, AggFinal
+*/
+/* Opcode: Function P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
+**
+** Invoke a user function (P4 is a pointer to an sqlite3_context object that
+** contains a pointer to the function to be run) with P5 arguments taken
+** from register P2 and successors.  The result of the function is stored
+** in register P3.  Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** SQL functions are initially coded as OP_Function0 with P4 pointing
+** to a FuncDef object.  But on first evaluation, the P4 operand is
+** automatically converted into an sqlite3_context object and the operation
+** changed to this OP_Function opcode.  In this way, the initialization of
+** the sqlite3_context object occurs only once, rather than once for each
+** evaluation of the function.
+**
+** See also: Function0, AggStep, AggFinal
+*/
+case OP_PureFunc0:
+case OP_Function0: {
+  int n;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCDEF );
+  n = pOp->p5;
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
+  assert( pOp->p3p2 || pOp->p3>=pOp->p2+n );
+  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
+  if( pCtx==0 ) goto no_mem;
+  pCtx->pOut = 0;
+  pCtx->pFunc = pOp->p4.pFunc;
+  pCtx->iOp = (int)(pOp - aOp);
+  pCtx->pVdbe = p;
+  pCtx->argc = n;
+  pOp->p4type = P4_FUNCCTX;
+  pOp->p4.pCtx = pCtx;
+  assert( OP_PureFunc == OP_PureFunc0+2 );
+  assert( OP_Function == OP_Function0+2 );
+  pOp->opcode += 2;
+  /* Fall through into OP_Function */
+}
+case OP_PureFunc:
+case OP_Function: {
+  int i;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCCTX );
+  pCtx = pOp->p4.pCtx;
+
+  /* If this function is inside of a trigger, the register array in aMem[]
+  ** might change from one evaluation to the next.  The next block of code
+  ** checks to see if the register array has changed, and if so it
+  ** reinitializes the relavant parts of the sqlite3_context object */
+  pOut = &aMem[pOp->p3];
+  if( pCtx->pOut != pOut ){
+    pCtx->pOut = pOut;
+    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
+  }
+
+  memAboutToChange(p, pOut);
+#ifdef SQLITE_DEBUG
+  for(i=0; iargc; i++){
+    assert( memIsValid(pCtx->argv[i]) );
+    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
+  }
+#endif
+  MemSetTypeFlag(pOut, MEM_Null);
+  pCtx->fErrorOrAux = 0;
+  (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */
+
+  /* If the function returned an error, throw an exception */
+  if( pCtx->fErrorOrAux ){
+    if( pCtx->isError ){
+      sqlite3VdbeError(p, "%s", sqlite3_value_text(pOut));
+      rc = pCtx->isError;
+    }
+    sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);
+    if( rc ) goto abort_due_to_error;
+  }
 
-/* Opcode: Init * P2 * P4 *
-** Synopsis:  Start at P2
+  /* Copy the result of the function into register P3 */
+  if( pOut->flags & (MEM_Str|MEM_Blob) ){
+    sqlite3VdbeChangeEncoding(pOut, encoding);
+    if( sqlite3VdbeMemTooBig(pOut) ) goto too_big;
+  }
+
+  REGISTER_TRACE(pOp->p3, pOut);
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+
+
+/* Opcode: Init P1 P2 * P4 *
+** Synopsis: Start at P2
 **
 ** Programs contain a single instance of this opcode as the very first
 ** opcode.
@@ -76495,30 +85993,54 @@ case OP_MaxPgcnt: {            /* out2-prerelease */
 ** Or if P4 is blank, use the string returned by sqlite3_sql().
 **
 ** If P2 is not zero, jump to instruction P2.
+**
+** Increment the value of P1 so that OP_Once opcodes will jump the
+** first time they are evaluated for this run.
 */
 case OP_Init: {          /* jump */
   char *zTrace;
-  char *z;
+  int i;
+
+  /* If the P4 argument is not NULL, then it must be an SQL comment string.
+  ** The "--" string is broken up to prevent false-positives with srcck1.c.
+  **
+  ** This assert() provides evidence for:
+  ** EVIDENCE-OF: R-50676-09860 The callback can compute the same text that
+  ** would have been returned by the legacy sqlite3_trace() interface by
+  ** using the X argument when X begins with "--" and invoking
+  ** sqlite3_expanded_sql(P) otherwise.
+  */
+  assert( pOp->p4.z==0 || strncmp(pOp->p4.z, "-" "- ", 3)==0 );
+  assert( pOp==p->aOp );  /* Always instruction 0 */
 
-  if( pOp->p2 ){
-    pc = pOp->p2 - 1;
-  }
 #ifndef SQLITE_OMIT_TRACE
-  if( db->xTrace
+  if( (db->mTrace & (SQLITE_TRACE_STMT|SQLITE_TRACE_LEGACY))!=0
    && !p->doingRerun
    && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
   ){
-    z = sqlite3VdbeExpandSql(p, zTrace);
-    db->xTrace(db->pTraceArg, z);
-    sqlite3DbFree(db, z);
+#ifndef SQLITE_OMIT_DEPRECATED
+    if( db->mTrace & SQLITE_TRACE_LEGACY ){
+      void (*x)(void*,const char*) = (void(*)(void*,const char*))db->xTrace;
+      char *z = sqlite3VdbeExpandSql(p, zTrace);
+      x(db->pTraceArg, z);
+      sqlite3_free(z);
+    }else
+#endif
+    if( db->nVdbeExec>1 ){
+      char *z = sqlite3MPrintf(db, "-- %s", zTrace);
+      (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, z);
+      sqlite3DbFree(db, z);
+    }else{
+      (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, zTrace);
+    }
   }
 #ifdef SQLITE_USE_FCNTL_TRACE
   zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
   if( zTrace ){
-    int i;
-    for(i=0; inDb; i++){
-      if( DbMaskTest(p->btreeMask, i)==0 ) continue;
-      sqlite3_file_control(db, db->aDb[i].zName, SQLITE_FCNTL_TRACE, zTrace);
+    int j;
+    for(j=0; jnDb; j++){
+      if( DbMaskTest(p->btreeMask, j)==0 ) continue;
+      sqlite3_file_control(db, db->aDb[j].zDbSName, SQLITE_FCNTL_TRACE, zTrace);
     }
   }
 #endif /* SQLITE_USE_FCNTL_TRACE */
@@ -76530,9 +86052,40 @@ case OP_Init: {          /* jump */
   }
 #endif /* SQLITE_DEBUG */
 #endif /* SQLITE_OMIT_TRACE */
-  break;
+  assert( pOp->p2>0 );
+  if( pOp->p1>=sqlite3GlobalConfig.iOnceResetThreshold ){
+    for(i=1; inOp; i++){
+      if( p->aOp[i].opcode==OP_Once ) p->aOp[i].p1 = 0;
+    }
+    pOp->p1 = 0;
+  }
+  pOp->p1++;
+  p->aCounter[SQLITE_STMTSTATUS_RUN]++;
+  goto jump_to_p2;
 }
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/* Opcode: CursorHint P1 * * P4 *
+**
+** Provide a hint to cursor P1 that it only needs to return rows that
+** satisfy the Expr in P4.  TK_REGISTER terms in the P4 expression refer
+** to values currently held in registers.  TK_COLUMN terms in the P4
+** expression refer to columns in the b-tree to which cursor P1 is pointing.
+*/
+case OP_CursorHint: {
+  VdbeCursor *pC;
+
+  assert( pOp->p1>=0 && pOp->p1nCursor );
+  assert( pOp->p4type==P4_EXPR );
+  pC = p->apCsr[pOp->p1];
+  if( pC ){
+    assert( pC->eCurType==CURTYPE_BTREE );
+    sqlite3BtreeCursorHint(pC->uc.pCursor, BTREE_HINT_RANGE,
+                           pOp->p4.pExpr, aMem);
+  }
+  break;
+}
+#endif /* SQLITE_ENABLE_CURSOR_HINTS */
 
 /* Opcode: Noop * * * * *
 **
@@ -76561,8 +86114,8 @@ default: {          /* This is really OP_Noop and OP_Explain */
 #ifdef VDBE_PROFILE
     {
       u64 endTime = sqlite3Hwtime();
-      if( endTime>start ) pOp->cycles += endTime - start;
-      pOp->cnt++;
+      if( endTime>start ) pOrigOp->cycles += endTime - start;
+      pOrigOp->cnt++;
     }
 #endif
 
@@ -76572,16 +86125,17 @@ default: {          /* This is really OP_Noop and OP_Explain */
     ** the evaluator loop.  So we can leave it out when NDEBUG is defined.
     */
 #ifndef NDEBUG
-    assert( pc>=-1 && pcnOp );
+    assert( pOp>=&aOp[-1] && pOp<&aOp[p->nOp-1] );
 
 #ifdef SQLITE_DEBUG
     if( db->flags & SQLITE_VdbeTrace ){
+      u8 opProperty = sqlite3OpcodeProperty[pOrigOp->opcode];
       if( rc!=0 ) printf("rc=%d\n",rc);
-      if( pOp->opflags & (OPFLG_OUT2_PRERELEASE|OPFLG_OUT2) ){
-        registerTrace(pOp->p2, &aMem[pOp->p2]);
+      if( opProperty & (OPFLG_OUT2) ){
+        registerTrace(pOrigOp->p2, &aMem[pOrigOp->p2]);
       }
-      if( pOp->opflags & OPFLG_OUT3 ){
-        registerTrace(pOp->p3, &aMem[pOp->p3]);
+      if( opProperty & OPFLG_OUT3 ){
+        registerTrace(pOrigOp->p3, &aMem[pOrigOp->p3]);
       }
     }
 #endif  /* SQLITE_DEBUG */
@@ -76591,14 +86145,19 @@ default: {          /* This is really OP_Noop and OP_Explain */
   /* If we reach this point, it means that execution is finished with
   ** an error of some kind.
   */
-vdbe_error_halt:
+abort_due_to_error:
+  if( db->mallocFailed ) rc = SQLITE_NOMEM_BKPT;
   assert( rc );
+  if( p->zErrMsg==0 && rc!=SQLITE_IOERR_NOMEM ){
+    sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
+  }
   p->rc = rc;
+  sqlite3SystemError(db, rc);
   testcase( sqlite3GlobalConfig.xLog!=0 );
   sqlite3_log(rc, "statement aborts at %d: [%s] %s", 
-                   pc, p->zSql, p->zErrMsg);
+                   (int)(pOp - aOp), p->zSql, p->zErrMsg);
   sqlite3VdbeHalt(p);
-  if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
+  if( rc==SQLITE_IOERR_NOMEM ) sqlite3OomFault(db);
   rc = SQLITE_ERROR;
   if( resetSchemaOnFault>0 ){
     sqlite3ResetOneSchema(db, resetSchemaOnFault-1);
@@ -76608,48 +86167,39 @@ vdbe_error_halt:
   ** release the mutexes on btrees that were acquired at the
   ** top. */
 vdbe_return:
-  db->lastRowid = lastRowid;
   testcase( nVmStep>0 );
   p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
   sqlite3VdbeLeave(p);
+  assert( rc!=SQLITE_OK || nExtraDelete==0 
+       || sqlite3_strlike("DELETE%",p->zSql,0)!=0 
+  );
   return rc;
 
   /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
   ** is encountered.
   */
 too_big:
-  sqlite3SetString(&p->zErrMsg, db, "string or blob too big");
+  sqlite3VdbeError(p, "string or blob too big");
   rc = SQLITE_TOOBIG;
-  goto vdbe_error_halt;
+  goto abort_due_to_error;
 
   /* Jump to here if a malloc() fails.
   */
 no_mem:
-  db->mallocFailed = 1;
-  sqlite3SetString(&p->zErrMsg, db, "out of memory");
-  rc = SQLITE_NOMEM;
-  goto vdbe_error_halt;
-
-  /* Jump to here for any other kind of fatal error.  The "rc" variable
-  ** should hold the error number.
-  */
-abort_due_to_error:
-  assert( p->zErrMsg==0 );
-  if( db->mallocFailed ) rc = SQLITE_NOMEM;
-  if( rc!=SQLITE_IOERR_NOMEM ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
-  }
-  goto vdbe_error_halt;
+  sqlite3OomFault(db);
+  sqlite3VdbeError(p, "out of memory");
+  rc = SQLITE_NOMEM_BKPT;
+  goto abort_due_to_error;
 
   /* Jump to here if the sqlite3_interrupt() API sets the interrupt
   ** flag.
   */
 abort_due_to_interrupt:
   assert( db->u1.isInterrupted );
-  rc = SQLITE_INTERRUPT;
+  rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;
   p->rc = rc;
-  sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
-  goto vdbe_error_halt;
+  sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
+  goto abort_due_to_error;
 }
 
 
@@ -76670,6 +86220,8 @@ abort_due_to_interrupt:
 ** This file contains code used to implement incremental BLOB I/O.
 */
 
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_INCRBLOB
 
@@ -76678,13 +86230,14 @@ abort_due_to_interrupt:
 */
 typedef struct Incrblob Incrblob;
 struct Incrblob {
-  int flags;              /* Copy of "flags" passed to sqlite3_blob_open() */
   int nByte;              /* Size of open blob, in bytes */
   int iOffset;            /* Byte offset of blob in cursor data */
-  int iCol;               /* Table column this handle is open on */
+  u16 iCol;               /* Table column this handle is open on */
   BtCursor *pCsr;         /* Cursor pointing at blob row */
   sqlite3_stmt *pStmt;    /* Statement holding cursor open */
   sqlite3 *db;            /* The associated database */
+  char *zDb;              /* Database name */
+  Table *pTab;            /* Table object */
 };
 
 
@@ -76710,17 +86263,27 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
   char *zErr = 0;                 /* Error message */
   Vdbe *v = (Vdbe *)p->pStmt;
 
-  /* Set the value of the SQL statements only variable to integer iRow. 
-  ** This is done directly instead of using sqlite3_bind_int64() to avoid 
-  ** triggering asserts related to mutexes.
+  /* Set the value of register r[1] in the SQL statement to integer iRow. 
+  ** This is done directly as a performance optimization
   */
-  assert( v->aVar[0].flags&MEM_Int );
-  v->aVar[0].u.i = iRow;
+  v->aMem[1].flags = MEM_Int;
+  v->aMem[1].u.i = iRow;
 
-  rc = sqlite3_step(p->pStmt);
+  /* If the statement has been run before (and is paused at the OP_ResultRow)
+  ** then back it up to the point where it does the OP_SeekRowid.  This could
+  ** have been down with an extra OP_Goto, but simply setting the program
+  ** counter is faster. */
+  if( v->pc>3 ){
+    v->pc = 3;
+    rc = sqlite3VdbeExec(v);
+  }else{
+    rc = sqlite3_step(p->pStmt);
+  }
   if( rc==SQLITE_ROW ){
     VdbeCursor *pC = v->apCsr[0];
-    u32 type = pC->aType[p->iCol];
+    u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;
+    testcase( pC->nHdrParsed==p->iCol );
+    testcase( pC->nHdrParsed==p->iCol+1 );
     if( type<12 ){
       zErr = sqlite3MPrintf(p->db, "cannot open value of type %s",
           type==0?"null": type==7?"real": "integer"
@@ -76731,7 +86294,7 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
     }else{
       p->iOffset = pC->aType[p->iCol + pC->nField];
       p->nByte = sqlite3VdbeSerialTypeLen(type);
-      p->pCsr =  pC->pCursor;
+      p->pCsr =  pC->uc.pCursor;
       sqlite3BtreeIncrblobCursor(p->pCsr);
     }
   }
@@ -76765,43 +86328,11 @@ SQLITE_API int sqlite3_blob_open(
   const char *zTable,     /* The table containing the blob */
   const char *zColumn,    /* The column containing the blob */
   sqlite_int64 iRow,      /* The row containing the glob */
-  int flags,              /* True -> read/write access, false -> read-only */
+  int wrFlag,             /* True -> read/write access, false -> read-only */
   sqlite3_blob **ppBlob   /* Handle for accessing the blob returned here */
 ){
   int nAttempt = 0;
   int iCol;               /* Index of zColumn in row-record */
-
-  /* This VDBE program seeks a btree cursor to the identified 
-  ** db/table/row entry. The reason for using a vdbe program instead
-  ** of writing code to use the b-tree layer directly is that the
-  ** vdbe program will take advantage of the various transaction,
-  ** locking and error handling infrastructure built into the vdbe.
-  **
-  ** After seeking the cursor, the vdbe executes an OP_ResultRow.
-  ** Code external to the Vdbe then "borrows" the b-tree cursor and
-  ** uses it to implement the blob_read(), blob_write() and 
-  ** blob_bytes() functions.
-  **
-  ** The sqlite3_blob_close() function finalizes the vdbe program,
-  ** which closes the b-tree cursor and (possibly) commits the 
-  ** transaction.
-  */
-  static const int iLn = VDBE_OFFSET_LINENO(4);
-  static const VdbeOpList openBlob[] = {
-    /* {OP_Transaction, 0, 0, 0},  // 0: Inserted separately */
-    {OP_TableLock, 0, 0, 0},       /* 1: Acquire a read or write lock */
-    /* One of the following two instructions is replaced by an OP_Noop. */
-    {OP_OpenRead, 0, 0, 0},        /* 2: Open cursor 0 for reading */
-    {OP_OpenWrite, 0, 0, 0},       /* 3: Open cursor 0 for read/write */
-    {OP_Variable, 1, 1, 1},        /* 4: Push the rowid to the stack */
-    {OP_NotExists, 0, 10, 1},      /* 5: Seek the cursor */
-    {OP_Column, 0, 0, 1},          /* 6  */
-    {OP_ResultRow, 1, 0, 0},       /* 7  */
-    {OP_Goto, 0, 4, 0},            /* 8  */
-    {OP_Close, 0, 0, 0},           /* 9  */
-    {OP_Halt, 0, 0, 0},            /* 10 */
-  };
-
   int rc = SQLITE_OK;
   char *zErr = 0;
   Table *pTab;
@@ -76809,12 +86340,17 @@ SQLITE_API int sqlite3_blob_open(
   Incrblob *pBlob = 0;
 
 #ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) || ppBlob==0 || zTable==0 ){
+  if( ppBlob==0 ){
     return SQLITE_MISUSE_BKPT;
   }
 #endif
-  flags = !!flags;                /* flags = (flags ? 1 : 0); */
   *ppBlob = 0;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zTable==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  wrFlag = !!wrFlag;                /* wrFlag = (wrFlag ? 1 : 0); */
 
   sqlite3_mutex_enter(db->mutex);
 
@@ -76855,6 +86391,8 @@ SQLITE_API int sqlite3_blob_open(
       sqlite3BtreeLeaveAll(db);
       goto blob_open_out;
     }
+    pBlob->pTab = pTab;
+    pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zDbSName;
 
     /* Now search pTab for the exact column. */
     for(iCol=0; iColnCol; iCol++) {
@@ -76872,9 +86410,8 @@ SQLITE_API int sqlite3_blob_open(
 
     /* If the value is being opened for writing, check that the
     ** column is not indexed, and that it is not part of a foreign key. 
-    ** It is against the rules to open a column to which either of these
-    ** descriptions applies for writing.  */
-    if( flags ){
+    */
+    if( wrFlag ){
       const char *zFault = 0;
       Index *pIdx;
 #ifndef SQLITE_OMIT_FOREIGN_KEY
@@ -76897,7 +86434,8 @@ SQLITE_API int sqlite3_blob_open(
       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
         int j;
         for(j=0; jnKeyCol; j++){
-          if( pIdx->aiColumn[j]==iCol ){
+          /* FIXME: Be smarter about indexes that use expressions */
+          if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==XN_EXPR ){
             zFault = "indexed";
           }
         }
@@ -76914,60 +86452,89 @@ SQLITE_API int sqlite3_blob_open(
     pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(pParse);
     assert( pBlob->pStmt || db->mallocFailed );
     if( pBlob->pStmt ){
+      
+      /* This VDBE program seeks a btree cursor to the identified 
+      ** db/table/row entry. The reason for using a vdbe program instead
+      ** of writing code to use the b-tree layer directly is that the
+      ** vdbe program will take advantage of the various transaction,
+      ** locking and error handling infrastructure built into the vdbe.
+      **
+      ** After seeking the cursor, the vdbe executes an OP_ResultRow.
+      ** Code external to the Vdbe then "borrows" the b-tree cursor and
+      ** uses it to implement the blob_read(), blob_write() and 
+      ** blob_bytes() functions.
+      **
+      ** The sqlite3_blob_close() function finalizes the vdbe program,
+      ** which closes the b-tree cursor and (possibly) commits the 
+      ** transaction.
+      */
+      static const int iLn = VDBE_OFFSET_LINENO(2);
+      static const VdbeOpList openBlob[] = {
+        {OP_TableLock,      0, 0, 0},  /* 0: Acquire a read or write lock */
+        {OP_OpenRead,       0, 0, 0},  /* 1: Open a cursor */
+        /* blobSeekToRow() will initialize r[1] to the desired rowid */
+        {OP_NotExists,      0, 5, 1},  /* 2: Seek the cursor to rowid=r[1] */
+        {OP_Column,         0, 0, 1},  /* 3  */
+        {OP_ResultRow,      1, 0, 0},  /* 4  */
+        {OP_Halt,           0, 0, 0},  /* 5  */
+      };
       Vdbe *v = (Vdbe *)pBlob->pStmt;
       int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+      VdbeOp *aOp;
 
-
-      sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags, 
+      sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, wrFlag, 
                            pTab->pSchema->schema_cookie,
                            pTab->pSchema->iGeneration);
       sqlite3VdbeChangeP5(v, 1);     
-      sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);
 
       /* Make sure a mutex is held on the table to be accessed */
       sqlite3VdbeUsesBtree(v, iDb); 
 
-      /* Configure the OP_TableLock instruction */
+      if( db->mallocFailed==0 ){
+        assert( aOp!=0 );
+        /* Configure the OP_TableLock instruction */
 #ifdef SQLITE_OMIT_SHARED_CACHE
-      sqlite3VdbeChangeToNoop(v, 1);
+        aOp[0].opcode = OP_Noop;
 #else
-      sqlite3VdbeChangeP1(v, 1, iDb);
-      sqlite3VdbeChangeP2(v, 1, pTab->tnum);
-      sqlite3VdbeChangeP3(v, 1, flags);
-      sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
-#endif
-
-      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
-      ** parameter of the other to pTab->tnum.  */
-      sqlite3VdbeChangeToNoop(v, 3 - flags);
-      sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum);
-      sqlite3VdbeChangeP3(v, 2 + flags, iDb);
-
-      /* Configure the number of columns. Configure the cursor to
-      ** think that the table has one more column than it really
-      ** does. An OP_Column to retrieve this imaginary column will
-      ** always return an SQL NULL. This is useful because it means
-      ** we can invoke OP_Column to fill in the vdbe cursors type 
-      ** and offset cache without causing any IO.
-      */
-      sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
-      sqlite3VdbeChangeP2(v, 6, pTab->nCol);
-      if( !db->mallocFailed ){
-        pParse->nVar = 1;
+        aOp[0].p1 = iDb;
+        aOp[0].p2 = pTab->tnum;
+        aOp[0].p3 = wrFlag;
+        sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
+      }
+      if( db->mallocFailed==0 ){
+#endif
+
+        /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
+        ** parameter of the other to pTab->tnum.  */
+        if( wrFlag ) aOp[1].opcode = OP_OpenWrite;
+        aOp[1].p2 = pTab->tnum;
+        aOp[1].p3 = iDb;   
+
+        /* Configure the number of columns. Configure the cursor to
+        ** think that the table has one more column than it really
+        ** does. An OP_Column to retrieve this imaginary column will
+        ** always return an SQL NULL. This is useful because it means
+        ** we can invoke OP_Column to fill in the vdbe cursors type 
+        ** and offset cache without causing any IO.
+        */
+        aOp[1].p4type = P4_INT32;
+        aOp[1].p4.i = pTab->nCol+1;
+        aOp[3].p2 = pTab->nCol;
+
+        pParse->nVar = 0;
         pParse->nMem = 1;
         pParse->nTab = 1;
         sqlite3VdbeMakeReady(v, pParse);
       }
     }
    
-    pBlob->flags = flags;
     pBlob->iCol = iCol;
     pBlob->db = db;
     sqlite3BtreeLeaveAll(db);
     if( db->mallocFailed ){
       goto blob_open_out;
     }
-    sqlite3_bind_int64(pBlob->pStmt, 1, iRow);
     rc = blobSeekToRow(pBlob, iRow, &zErr);
   } while( (++nAttempt)mutex);
   v = (Vdbe*)p->pStmt;
 
-  if( n<0 || iOffset<0 || (iOffset+n)>p->nByte ){
+  if( n<0 || iOffset<0 || ((sqlite3_int64)iOffset+n)>p->nByte ){
     /* Request is out of range. Return a transient error. */
     rc = SQLITE_ERROR;
   }else if( v==0 ){
@@ -77042,6 +86609,30 @@ static int blobReadWrite(
     */
     assert( db == v->db );
     sqlite3BtreeEnterCursor(p->pCsr);
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+    if( xCall==sqlite3BtreePutData && db->xPreUpdateCallback ){
+      /* If a pre-update hook is registered and this is a write cursor, 
+      ** invoke it here. 
+      ** 
+      ** TODO: The preupdate-hook is passed SQLITE_DELETE, even though this
+      ** operation should really be an SQLITE_UPDATE. This is probably
+      ** incorrect, but is convenient because at this point the new.* values 
+      ** are not easily obtainable. And for the sessions module, an 
+      ** SQLITE_UPDATE where the PK columns do not change is handled in the 
+      ** same way as an SQLITE_DELETE (the SQLITE_DELETE code is actually
+      ** slightly more efficient). Since you cannot write to a PK column
+      ** using the incremental-blob API, this works. For the sessions module
+      ** anyhow.
+      */
+      sqlite3_int64 iKey;
+      iKey = sqlite3BtreeIntegerKey(p->pCsr);
+      sqlite3VdbePreUpdateHook(
+          v, v->apCsr[0], SQLITE_DELETE, p->zDb, p->pTab, iKey, -1
+      );
+    }
+#endif
+
     rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
     sqlite3BtreeLeaveCursor(p->pCsr);
     if( rc==SQLITE_ABORT ){
@@ -77061,7 +86652,7 @@ static int blobReadWrite(
 ** Read data from a blob handle.
 */
 SQLITE_API int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
-  return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreeData);
+  return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreePayloadChecked);
 }
 
 /*
@@ -77263,6 +86854,8 @@ SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
 ** thread to merge the output of each of the others to a single PMA for
 ** the main thread to read from.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 /* 
 ** If SQLITE_DEBUG_SORTER_THREADS is defined, this module outputs various
@@ -77417,6 +87010,7 @@ struct MergeEngine {
 ** after the thread has finished are not dire. So we don't worry about
 ** memory barriers and such here.
 */
+typedef int (*SorterCompare)(SortSubtask*,int*,const void*,int,const void*,int);
 struct SortSubtask {
   SQLiteThread *pThread;          /* Background thread, if any */
   int bDone;                      /* Set if thread is finished but not joined */
@@ -77424,10 +87018,12 @@ struct SortSubtask {
   UnpackedRecord *pUnpacked;      /* Space to unpack a record */
   SorterList list;                /* List for thread to write to a PMA */
   int nPMA;                       /* Number of PMAs currently in file */
+  SorterCompare xCompare;         /* Compare function to use */
   SorterFile file;                /* Temp file for level-0 PMAs */
   SorterFile file2;               /* Space for other PMAs */
 };
 
+
 /*
 ** Main sorter structure. A single instance of this is allocated for each 
 ** sorter cursor created by the VDBE.
@@ -77454,9 +87050,13 @@ struct VdbeSorter {
   u8 bUseThreads;                 /* True to use background threads */
   u8 iPrev;                       /* Previous thread used to flush PMA */
   u8 nTask;                       /* Size of aTask[] array */
+  u8 typeMask;
   SortSubtask aTask[1];           /* One or more subtasks */
 };
 
+#define SORTER_TYPE_INTEGER 0x01
+#define SORTER_TYPE_TEXT    0x02
+
 /*
 ** An instance of the following object is used to read records out of a
 ** PMA, in sorted order.  The next key to be read is cached in nKey/aKey.
@@ -77659,7 +87259,7 @@ static int vdbePmaReadBlob(
       int nNew = MAX(128, p->nAlloc*2);
       while( nByte>nNew ) nNew = nNew*2;
       aNew = sqlite3Realloc(p->aAlloc, nNew);
-      if( !aNew ) return SQLITE_NOMEM;
+      if( !aNew ) return SQLITE_NOMEM_BKPT;
       p->nAlloc = nNew;
       p->aAlloc = aNew;
     }
@@ -77771,7 +87371,7 @@ static int vdbePmaReaderSeek(
     int iBuf = pReadr->iReadOff % pgsz;
     if( pReadr->aBuffer==0 ){
       pReadr->aBuffer = (u8*)sqlite3Malloc(pgsz);
-      if( pReadr->aBuffer==0 ) rc = SQLITE_NOMEM;
+      if( pReadr->aBuffer==0 ) rc = SQLITE_NOMEM_BKPT;
       pReadr->nBuffer = pgsz;
     }
     if( rc==SQLITE_OK && iBuf ){
@@ -77856,7 +87456,7 @@ static int vdbePmaReaderInit(
 
   rc = vdbePmaReaderSeek(pTask, pReadr, pFile, iStart);
   if( rc==SQLITE_OK ){
-    u64 nByte;                    /* Size of PMA in bytes */
+    u64 nByte = 0;                 /* Size of PMA in bytes */
     rc = vdbePmaReadVarint(pReadr, &nByte);
     pReadr->iEof = pReadr->iReadOff + nByte;
     *pnByte += nByte;
@@ -77868,32 +87468,161 @@ static int vdbePmaReaderInit(
   return rc;
 }
 
+/*
+** A version of vdbeSorterCompare() that assumes that it has already been
+** determined that the first field of key1 is equal to the first field of 
+** key2.
+*/
+static int vdbeSorterCompareTail(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  UnpackedRecord *r2 = pTask->pUnpacked;
+  if( *pbKey2Cached==0 ){
+    sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);
+    *pbKey2Cached = 1;
+  }
+  return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, r2, 1);
+}
 
 /*
 ** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, 
 ** size nKey2 bytes). Use (pTask->pKeyInfo) for the collation sequences
 ** used by the comparison. Return the result of the comparison.
 **
-** Before returning, object (pTask->pUnpacked) is populated with the
-** unpacked version of key2. Or, if pKey2 is passed a NULL pointer, then it 
-** is assumed that the (pTask->pUnpacked) structure already contains the 
-** unpacked key to use as key2.
+** If IN/OUT parameter *pbKey2Cached is true when this function is called,
+** it is assumed that (pTask->pUnpacked) contains the unpacked version
+** of key2. If it is false, (pTask->pUnpacked) is populated with the unpacked
+** version of key2 and *pbKey2Cached set to true before returning.
 **
 ** If an OOM error is encountered, (pTask->pUnpacked->error_rc) is set
 ** to SQLITE_NOMEM.
 */
 static int vdbeSorterCompare(
   SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
   const void *pKey1, int nKey1,   /* Left side of comparison */
   const void *pKey2, int nKey2    /* Right side of comparison */
 ){
   UnpackedRecord *r2 = pTask->pUnpacked;
-  if( pKey2 ){
+  if( !*pbKey2Cached ){
     sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);
+    *pbKey2Cached = 1;
   }
   return sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
 }
 
+/*
+** A specially optimized version of vdbeSorterCompare() that assumes that
+** the first field of each key is a TEXT value and that the collation
+** sequence to compare them with is BINARY.
+*/
+static int vdbeSorterCompareText(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  const u8 * const p1 = (const u8 * const)pKey1;
+  const u8 * const p2 = (const u8 * const)pKey2;
+  const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */
+  const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */
+
+  int n1;
+  int n2;
+  int res;
+
+  getVarint32(&p1[1], n1);
+  getVarint32(&p2[1], n2);
+  res = memcmp(v1, v2, (MIN(n1, n2) - 13)/2);
+  if( res==0 ){
+    res = n1 - n2;
+  }
+
+  if( res==0 ){
+    if( pTask->pSorter->pKeyInfo->nField>1 ){
+      res = vdbeSorterCompareTail(
+          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
+      );
+    }
+  }else{
+    if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
+      res = res * -1;
+    }
+  }
+
+  return res;
+}
+
+/*
+** A specially optimized version of vdbeSorterCompare() that assumes that
+** the first field of each key is an INTEGER value.
+*/
+static int vdbeSorterCompareInt(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  const u8 * const p1 = (const u8 * const)pKey1;
+  const u8 * const p2 = (const u8 * const)pKey2;
+  const int s1 = p1[1];                 /* Left hand serial type */
+  const int s2 = p2[1];                 /* Right hand serial type */
+  const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */
+  const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */
+  int res;                              /* Return value */
+
+  assert( (s1>0 && s1<7) || s1==8 || s1==9 );
+  assert( (s2>0 && s2<7) || s2==8 || s2==9 );
+
+  if( s1==s2 ){
+    /* The two values have the same sign. Compare using memcmp(). */
+    static const u8 aLen[] = {0, 1, 2, 3, 4, 6, 8, 0, 0, 0 };
+    const u8 n = aLen[s1];
+    int i;
+    res = 0;
+    for(i=0; i7 && s2>7 ){
+    res = s1 - s2;
+  }else{
+    if( s2>7 ){
+      res = +1;
+    }else if( s1>7 ){
+      res = -1;
+    }else{
+      res = s1 - s2;
+    }
+    assert( res!=0 );
+
+    if( res>0 ){
+      if( *v1 & 0x80 ) res = -1;
+    }else{
+      if( *v2 & 0x80 ) res = +1;
+    }
+  }
+
+  if( res==0 ){
+    if( pTask->pSorter->pKeyInfo->nField>1 ){
+      res = vdbeSorterCompareTail(
+          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
+      );
+    }
+  }else if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
+    res = res * -1;
+  }
+
+  return res;
+}
+
 /*
 ** Initialize the temporary index cursor just opened as a sorter cursor.
 **
@@ -77920,7 +87649,6 @@ SQLITE_PRIVATE int sqlite3VdbeSorterInit(
 ){
   int pgsz;                       /* Page size of main database */
   int i;                          /* Used to iterate through aTask[] */
-  int mxCache;                    /* Cache size */
   VdbeSorter *pSorter;            /* The new sorter */
   KeyInfo *pKeyInfo;              /* Copy of pCsr->pKeyInfo with db==0 */
   int szKeyInfo;                  /* Size of pCsr->pKeyInfo in bytes */
@@ -77949,21 +87677,26 @@ SQLITE_PRIVATE int sqlite3VdbeSorterInit(
   }
 #endif
 
-  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
+  assert( pCsr->pKeyInfo && pCsr->pBtx==0 );
+  assert( pCsr->eCurType==CURTYPE_SORTER );
   szKeyInfo = sizeof(KeyInfo) + (pCsr->pKeyInfo->nField-1)*sizeof(CollSeq*);
   sz = sizeof(VdbeSorter) + nWorker * sizeof(SortSubtask);
 
   pSorter = (VdbeSorter*)sqlite3DbMallocZero(db, sz + szKeyInfo);
-  pCsr->pSorter = pSorter;
+  pCsr->uc.pSorter = pSorter;
   if( pSorter==0 ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }else{
     pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);
     memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);
     pKeyInfo->db = 0;
-    if( nField && nWorker==0 ) pKeyInfo->nField = nField;
+    if( nField && nWorker==0 ){
+      pKeyInfo->nXField += (pKeyInfo->nField - nField);
+      pKeyInfo->nField = nField;
+    }
     pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
     pSorter->nTask = nWorker + 1;
+    pSorter->iPrev = (u8)(nWorker - 1);
     pSorter->bUseThreads = (pSorter->nTask>1);
     pSorter->db = db;
     for(i=0; inTask; i++){
@@ -77972,11 +87705,20 @@ SQLITE_PRIVATE int sqlite3VdbeSorterInit(
     }
 
     if( !sqlite3TempInMemory(db) ){
+      i64 mxCache;                /* Cache size in bytes*/
       u32 szPma = sqlite3GlobalConfig.szPma;
       pSorter->mnPmaSize = szPma * pgsz;
+
       mxCache = db->aDb[0].pSchema->cache_size;
-      if( mxCache<(int)szPma ) mxCache = (int)szPma;
-      pSorter->mxPmaSize = MIN((i64)mxCache*pgsz, SQLITE_MAX_PMASZ);
+      if( mxCache<0 ){
+        /* A negative cache-size value C indicates that the cache is abs(C)
+        ** KiB in size.  */
+        mxCache = mxCache * -1024;
+      }else{
+        mxCache = mxCache * pgsz;
+      }
+      mxCache = MIN(mxCache, SQLITE_MAX_PMASZ);
+      pSorter->mxPmaSize = MAX(pSorter->mnPmaSize, (int)mxCache);
 
       /* EVIDENCE-OF: R-26747-61719 When the application provides any amount of
       ** scratch memory using SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary
@@ -77986,9 +87728,15 @@ SQLITE_PRIVATE int sqlite3VdbeSorterInit(
         assert( pSorter->iMemory==0 );
         pSorter->nMemory = pgsz;
         pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);
-        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM;
+        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM_BKPT;
       }
     }
+
+    if( (pKeyInfo->nField+pKeyInfo->nXField)<13 
+     && (pKeyInfo->aColl[0]==0 || pKeyInfo->aColl[0]==db->pDfltColl)
+    ){
+      pSorter->typeMask = SORTER_TYPE_INTEGER | SORTER_TYPE_TEXT;
+    }
   }
 
   return rc;
@@ -78013,30 +87761,24 @@ static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
 */
 static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){
   sqlite3DbFree(db, pTask->pUnpacked);
-  pTask->pUnpacked = 0;
 #if SQLITE_MAX_WORKER_THREADS>0
   /* pTask->list.aMemory can only be non-zero if it was handed memory
   ** from the main thread.  That only occurs SQLITE_MAX_WORKER_THREADS>0 */
   if( pTask->list.aMemory ){
     sqlite3_free(pTask->list.aMemory);
-    pTask->list.aMemory = 0;
   }else
 #endif
   {
     assert( pTask->list.aMemory==0 );
     vdbeSorterRecordFree(0, pTask->list.pList);
   }
-  pTask->list.pList = 0;
   if( pTask->file.pFd ){
     sqlite3OsCloseFree(pTask->file.pFd);
-    pTask->file.pFd = 0;
-    pTask->file.iEof = 0;
   }
   if( pTask->file2.pFd ){
     sqlite3OsCloseFree(pTask->file2.pFd);
-    pTask->file2.pFd = 0;
-    pTask->file2.iEof = 0;
   }
+  memset(pTask, 0, sizeof(SortSubtask));
 }
 
 #ifdef SQLITE_DEBUG_SORTER_THREADS
@@ -78216,6 +87958,7 @@ SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
   for(i=0; inTask; i++){
     SortSubtask *pTask = &pSorter->aTask[i];
     vdbeSortSubtaskCleanup(db, pTask);
+    pTask->pSorter = pSorter;
   }
   if( pSorter->list.aMemory==0 ){
     vdbeSorterRecordFree(0, pSorter->list.pList);
@@ -78233,12 +87976,14 @@ SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
 ** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
 */
 SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
   if( pSorter ){
     sqlite3VdbeSorterReset(db, pSorter);
     sqlite3_free(pSorter->list.aMemory);
     sqlite3DbFree(db, pSorter);
-    pCsr->pSorter = 0;
+    pCsr->uc.pSorter = 0;
   }
 }
 
@@ -78277,6 +88022,7 @@ static int vdbeSorterOpenTempFile(
   sqlite3_file **ppFd
 ){
   int rc;
+  if( sqlite3FaultSim(202) ) return SQLITE_IOERR_ACCESS;
   rc = sqlite3OsOpenMalloc(db->pVfs, 0, ppFd,
       SQLITE_OPEN_TEMP_JOURNAL |
       SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
@@ -78299,12 +88045,8 @@ static int vdbeSorterOpenTempFile(
 */
 static int vdbeSortAllocUnpacked(SortSubtask *pTask){
   if( pTask->pUnpacked==0 ){
-    char *pFree;
-    pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord(
-        pTask->pSorter->pKeyInfo, 0, 0, &pFree
-    );
-    assert( pTask->pUnpacked==(UnpackedRecord*)pFree );
-    if( pFree==0 ) return SQLITE_NOMEM;
+    pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pTask->pSorter->pKeyInfo);
+    if( pTask->pUnpacked==0 ) return SQLITE_NOMEM_BKPT;
     pTask->pUnpacked->nField = pTask->pSorter->pKeyInfo->nField;
     pTask->pUnpacked->errCode = 0;
   }
@@ -78314,36 +88056,56 @@ static int vdbeSortAllocUnpacked(SortSubtask *pTask){
 
 /*
 ** Merge the two sorted lists p1 and p2 into a single list.
-** Set *ppOut to the head of the new list.
 */
-static void vdbeSorterMerge(
+static SorterRecord *vdbeSorterMerge(
   SortSubtask *pTask,             /* Calling thread context */
   SorterRecord *p1,               /* First list to merge */
-  SorterRecord *p2,               /* Second list to merge */
-  SorterRecord **ppOut            /* OUT: Head of merged list */
+  SorterRecord *p2                /* Second list to merge */
 ){
   SorterRecord *pFinal = 0;
   SorterRecord **pp = &pFinal;
-  void *pVal2 = p2 ? SRVAL(p2) : 0;
+  int bCached = 0;
 
-  while( p1 && p2 ){
+  assert( p1!=0 && p2!=0 );
+  for(;;){
     int res;
-    res = vdbeSorterCompare(pTask, SRVAL(p1), p1->nVal, pVal2, p2->nVal);
+    res = pTask->xCompare(
+        pTask, &bCached, SRVAL(p1), p1->nVal, SRVAL(p2), p2->nVal
+    );
+
     if( res<=0 ){
       *pp = p1;
       pp = &p1->u.pNext;
       p1 = p1->u.pNext;
-      pVal2 = 0;
+      if( p1==0 ){
+        *pp = p2;
+        break;
+      }
     }else{
       *pp = p2;
-       pp = &p2->u.pNext;
+      pp = &p2->u.pNext;
       p2 = p2->u.pNext;
-      if( p2==0 ) break;
-      pVal2 = SRVAL(p2);
+      bCached = 0;
+      if( p2==0 ){
+        *pp = p1;
+        break;
+      }
     }
   }
-  *pp = p1 ? p1 : p2;
-  *ppOut = pFinal;
+  return pFinal;
+}
+
+/*
+** Return the SorterCompare function to compare values collected by the
+** sorter object passed as the only argument.
+*/
+static SorterCompare vdbeSorterGetCompare(VdbeSorter *p){
+  if( p->typeMask==SORTER_TYPE_INTEGER ){
+    return vdbeSorterCompareInt;
+  }else if( p->typeMask==SORTER_TYPE_TEXT ){
+    return vdbeSorterCompareText; 
+  }
+  return vdbeSorterCompare;
 }
 
 /*
@@ -78360,12 +88122,14 @@ static int vdbeSorterSort(SortSubtask *pTask, SorterList *pList){
   rc = vdbeSortAllocUnpacked(pTask);
   if( rc!=SQLITE_OK ) return rc;
 
+  p = pList->pList;
+  pTask->xCompare = vdbeSorterGetCompare(pTask->pSorter);
+
   aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));
   if( !aSlot ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
-  p = pList->pList;
   while( p ){
     SorterRecord *pNext;
     if( pList->aMemory ){
@@ -78381,7 +88145,7 @@ static int vdbeSorterSort(SortSubtask *pTask, SorterList *pList){
 
     p->u.pNext = 0;
     for(i=0; aSlot[i]; i++){
-      vdbeSorterMerge(pTask, p, aSlot[i], &p);
+      p = vdbeSorterMerge(pTask, p, aSlot[i]);
       aSlot[i] = 0;
     }
     aSlot[i] = p;
@@ -78390,7 +88154,8 @@ static int vdbeSorterSort(SortSubtask *pTask, SorterList *pList){
 
   p = 0;
   for(i=0; i<64; i++){
-    vdbeSorterMerge(pTask, p, aSlot[i], &p);
+    if( aSlot[i]==0 ) continue;
+    p = p ? vdbeSorterMerge(pTask, p, aSlot[i]) : aSlot[i];
   }
   pList->pList = p;
 
@@ -78413,7 +88178,7 @@ static void vdbePmaWriterInit(
   memset(p, 0, sizeof(PmaWriter));
   p->aBuffer = (u8*)sqlite3Malloc(nBuf);
   if( !p->aBuffer ){
-    p->eFWErr = SQLITE_NOMEM;
+    p->eFWErr = SQLITE_NOMEM_BKPT;
   }else{
     p->iBufEnd = p->iBufStart = (iStart % nBuf);
     p->iWriteOff = iStart - p->iBufStart;
@@ -78579,13 +88344,12 @@ static int vdbeMergeEngineStep(
     int i;                      /* Index of aTree[] to recalculate */
     PmaReader *pReadr1;         /* First PmaReader to compare */
     PmaReader *pReadr2;         /* Second PmaReader to compare */
-    u8 *pKey2;                  /* To pReadr2->aKey, or 0 if record cached */
+    int bCached = 0;
 
     /* Find the first two PmaReaders to compare. The one that was just
     ** advanced (iPrev) and the one next to it in the array.  */
     pReadr1 = &pMerger->aReadr[(iPrev & 0xFFFE)];
     pReadr2 = &pMerger->aReadr[(iPrev | 0x0001)];
-    pKey2 = pReadr2->aKey;
 
     for(i=(pMerger->nTree+iPrev)/2; i>0; i=i/2){
       /* Compare pReadr1 and pReadr2. Store the result in variable iRes. */
@@ -78595,8 +88359,8 @@ static int vdbeMergeEngineStep(
       }else if( pReadr2->pFd==0 ){
         iRes = -1;
       }else{
-        iRes = vdbeSorterCompare(pTask, 
-            pReadr1->aKey, pReadr1->nKey, pKey2, pReadr2->nKey
+        iRes = pTask->xCompare(pTask, &bCached,
+            pReadr1->aKey, pReadr1->nKey, pReadr2->aKey, pReadr2->nKey
         );
       }
 
@@ -78618,9 +88382,9 @@ static int vdbeMergeEngineStep(
       if( iRes<0 || (iRes==0 && pReadr1aTree[i] = (int)(pReadr1 - pMerger->aReadr);
         pReadr2 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];
-        pKey2 = pReadr2->aKey;
+        bCached = 0;
       }else{
-        if( pReadr1->pFd ) pKey2 = 0;
+        if( pReadr1->pFd ) bCached = 0;
         pMerger->aTree[i] = (int)(pReadr2 - pMerger->aReadr);
         pReadr1 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];
       }
@@ -78702,7 +88466,7 @@ static int vdbeSorterFlushPMA(VdbeSorter *pSorter){
         pSorter->nMemory = sqlite3MallocSize(aMem);
       }else if( pSorter->list.aMemory ){
         pSorter->list.aMemory = sqlite3Malloc(pSorter->nMemory);
-        if( !pSorter->list.aMemory ) return SQLITE_NOMEM;
+        if( !pSorter->list.aMemory ) return SQLITE_NOMEM_BKPT;
       }
 
       rc = vdbeSorterCreateThread(pTask, vdbeSorterFlushThread, pCtx);
@@ -78720,13 +88484,24 @@ SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
   const VdbeCursor *pCsr,         /* Sorter cursor */
   Mem *pVal                       /* Memory cell containing record */
 ){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
   int rc = SQLITE_OK;             /* Return Code */
   SorterRecord *pNew;             /* New list element */
-
   int bFlush;                     /* True to flush contents of memory to PMA */
   int nReq;                       /* Bytes of memory required */
   int nPMA;                       /* Bytes of PMA space required */
+  int t;                          /* serial type of first record field */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  getVarint32((const u8*)&pVal->z[1], t);
+  if( t>0 && t<10 && t!=7 ){
+    pSorter->typeMask &= SORTER_TYPE_INTEGER;
+  }else if( t>10 && (t & 0x01) ){
+    pSorter->typeMask &= SORTER_TYPE_TEXT;
+  }else{
+    pSorter->typeMask = 0;
+  }
 
   assert( pSorter );
 
@@ -78775,27 +88550,28 @@ SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
 
     if( nMin>pSorter->nMemory ){
       u8 *aNew;
+      int iListOff = (u8*)pSorter->list.pList - pSorter->list.aMemory;
       int nNew = pSorter->nMemory * 2;
       while( nNew < nMin ) nNew = nNew*2;
       if( nNew > pSorter->mxPmaSize ) nNew = pSorter->mxPmaSize;
       if( nNew < nMin ) nNew = nMin;
 
       aNew = sqlite3Realloc(pSorter->list.aMemory, nNew);
-      if( !aNew ) return SQLITE_NOMEM;
-      pSorter->list.pList = (SorterRecord*)(
-          aNew + ((u8*)pSorter->list.pList - pSorter->list.aMemory)
-      );
+      if( !aNew ) return SQLITE_NOMEM_BKPT;
+      pSorter->list.pList = (SorterRecord*)&aNew[iListOff];
       pSorter->list.aMemory = aNew;
       pSorter->nMemory = nNew;
     }
 
     pNew = (SorterRecord*)&pSorter->list.aMemory[pSorter->iMemory];
     pSorter->iMemory += ROUND8(nReq);
-    pNew->u.iNext = (int)((u8*)(pSorter->list.pList) - pSorter->list.aMemory);
+    if( pSorter->list.pList ){
+      pNew->u.iNext = (int)((u8*)(pSorter->list.pList) - pSorter->list.aMemory);
+    }
   }else{
     pNew = (SorterRecord *)sqlite3Malloc(nReq);
     if( pNew==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pNew->u.pNext = pSorter->list.pList;
   }
@@ -78942,7 +88718,7 @@ static int vdbeIncrMergerNew(
     pTask->file2.iEof += pIncr->mxSz;
   }else{
     vdbeMergeEngineFree(pMerger);
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
   return rc;
 }
@@ -78992,10 +88768,12 @@ static void vdbeMergeEngineCompare(
   }else if( p2->pFd==0 ){
     iRes = i1;
   }else{
+    SortSubtask *pTask = pMerger->pTask;
+    int bCached = 0;
     int res;
-    assert( pMerger->pTask->pUnpacked!=0 );  /* from vdbeSortSubtaskMain() */
-    res = vdbeSorterCompare(
-        pMerger->pTask, p1->aKey, p1->nKey, p2->aKey, p2->nKey
+    assert( pTask->pUnpacked!=0 );  /* from vdbeSortSubtaskMain() */
+    res = pTask->xCompare(
+        pTask, &bCached, p1->aKey, p1->nKey, p2->aKey, p2->nKey
     );
     if( res<=0 ){
       iRes = i1;
@@ -79019,11 +88797,12 @@ static void vdbeMergeEngineCompare(
 #define INCRINIT_TASK   1
 #define INCRINIT_ROOT   2
 
-/* Forward reference.
-** The vdbeIncrMergeInit() and vdbePmaReaderIncrMergeInit() routines call each
-** other (when building a merge tree).
+/* 
+** Forward reference required as the vdbeIncrMergeInit() and
+** vdbePmaReaderIncrInit() routines are called mutually recursively when
+** building a merge tree.
 */
-static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode);
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode);
 
 /*
 ** Initialize the MergeEngine object passed as the second argument. Once this
@@ -79070,7 +88849,7 @@ static int vdbeMergeEngineInit(
       ** better advantage of multi-processor hardware. */
       rc = vdbePmaReaderNext(&pMerger->aReadr[nTree-i-1]);
     }else{
-      rc = vdbePmaReaderIncrMergeInit(&pMerger->aReadr[i], INCRINIT_NORMAL);
+      rc = vdbePmaReaderIncrInit(&pMerger->aReadr[i], INCRINIT_NORMAL);
     }
     if( rc!=SQLITE_OK ) return rc;
   }
@@ -79082,17 +88861,15 @@ static int vdbeMergeEngineInit(
 }
 
 /*
-** Initialize the IncrMerge field of a PmaReader.
-**
-** If the PmaReader passed as the first argument is not an incremental-reader
-** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it serves
-** to open and/or initialize the temp file related fields of the IncrMerge
+** The PmaReader passed as the first argument is guaranteed to be an
+** incremental-reader (pReadr->pIncr!=0). This function serves to open
+** and/or initialize the temp file related fields of the IncrMerge
 ** object at (pReadr->pIncr).
 **
 ** If argument eMode is set to INCRINIT_NORMAL, then all PmaReaders
-** in the sub-tree headed by pReadr are also initialized. Data is then loaded
-** into the buffers belonging to pReadr and it is set to
-** point to the first key in its range.
+** in the sub-tree headed by pReadr are also initialized. Data is then 
+** loaded into the buffers belonging to pReadr and it is set to point to 
+** the first key in its range.
 **
 ** If argument eMode is set to INCRINIT_TASK, then pReadr is guaranteed
 ** to be a multi-threaded PmaReader and this function is being called in a
@@ -79119,59 +88896,62 @@ static int vdbeMergeEngineInit(
 static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){
   int rc = SQLITE_OK;
   IncrMerger *pIncr = pReadr->pIncr;
+  SortSubtask *pTask = pIncr->pTask;
+  sqlite3 *db = pTask->pSorter->db;
 
   /* eMode is always INCRINIT_NORMAL in single-threaded mode */
   assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );
 
-  if( pIncr ){
-    SortSubtask *pTask = pIncr->pTask;
-    sqlite3 *db = pTask->pSorter->db;
-
-    rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);
+  rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);
 
-    /* Set up the required files for pIncr. A multi-theaded IncrMerge object
-    ** requires two temp files to itself, whereas a single-threaded object
-    ** only requires a region of pTask->file2. */
-    if( rc==SQLITE_OK ){
-      int mxSz = pIncr->mxSz;
+  /* Set up the required files for pIncr. A multi-theaded IncrMerge object
+  ** requires two temp files to itself, whereas a single-threaded object
+  ** only requires a region of pTask->file2. */
+  if( rc==SQLITE_OK ){
+    int mxSz = pIncr->mxSz;
 #if SQLITE_MAX_WORKER_THREADS>0
-      if( pIncr->bUseThread ){
-        rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);
-        if( rc==SQLITE_OK ){
-          rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);
-        }
-      }else
+    if( pIncr->bUseThread ){
+      rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);
+      if( rc==SQLITE_OK ){
+        rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);
+      }
+    }else
 #endif
-      /*if( !pIncr->bUseThread )*/{
-        if( pTask->file2.pFd==0 ){
-          assert( pTask->file2.iEof>0 );
-          rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);
-          pTask->file2.iEof = 0;
-        }
-        if( rc==SQLITE_OK ){
-          pIncr->aFile[1].pFd = pTask->file2.pFd;
-          pIncr->iStartOff = pTask->file2.iEof;
-          pTask->file2.iEof += mxSz;
-        }
+    /*if( !pIncr->bUseThread )*/{
+      if( pTask->file2.pFd==0 ){
+        assert( pTask->file2.iEof>0 );
+        rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);
+        pTask->file2.iEof = 0;
+      }
+      if( rc==SQLITE_OK ){
+        pIncr->aFile[1].pFd = pTask->file2.pFd;
+        pIncr->iStartOff = pTask->file2.iEof;
+        pTask->file2.iEof += mxSz;
       }
     }
+  }
 
 #if SQLITE_MAX_WORKER_THREADS>0
-    if( rc==SQLITE_OK && pIncr->bUseThread ){
-      /* Use the current thread to populate aFile[1], even though this
-      ** PmaReader is multi-threaded. The reason being that this function
-      ** is already running in background thread pIncr->pTask->thread. */
-      assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );
-      rc = vdbeIncrPopulate(pIncr);
-    }
+  if( rc==SQLITE_OK && pIncr->bUseThread ){
+    /* Use the current thread to populate aFile[1], even though this
+    ** PmaReader is multi-threaded. If this is an INCRINIT_TASK object,
+    ** then this function is already running in background thread 
+    ** pIncr->pTask->thread. 
+    **
+    ** If this is the INCRINIT_ROOT object, then it is running in the 
+    ** main VDBE thread. But that is Ok, as that thread cannot return
+    ** control to the VDBE or proceed with anything useful until the 
+    ** first results are ready from this merger object anyway.
+    */
+    assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );
+    rc = vdbeIncrPopulate(pIncr);
+  }
 #endif
 
-    if( rc==SQLITE_OK
-     && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK)
-    ){
-      rc = vdbePmaReaderNext(pReadr);
-    }
+  if( rc==SQLITE_OK && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK) ){
+    rc = vdbePmaReaderNext(pReadr);
   }
+
   return rc;
 }
 
@@ -79180,7 +88960,7 @@ static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){
 ** The main routine for vdbePmaReaderIncrMergeInit() operations run in 
 ** background threads.
 */
-static void *vdbePmaReaderBgInit(void *pCtx){
+static void *vdbePmaReaderBgIncrInit(void *pCtx){
   PmaReader *pReader = (PmaReader*)pCtx;
   void *pRet = SQLITE_INT_TO_PTR(
                   vdbePmaReaderIncrMergeInit(pReader,INCRINIT_TASK)
@@ -79188,20 +88968,36 @@ static void *vdbePmaReaderBgInit(void *pCtx){
   pReader->pIncr->pTask->bDone = 1;
   return pRet;
 }
+#endif
 
 /*
-** Use a background thread to invoke vdbePmaReaderIncrMergeInit(INCRINIT_TASK) 
-** on the PmaReader object passed as the first argument.
-**
-** This call will initialize the various fields of the pReadr->pIncr 
-** structure and, if it is a multi-threaded IncrMerger, launch a 
-** background thread to populate aFile[1].
+** If the PmaReader passed as the first argument is not an incremental-reader
+** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it invokes
+** the vdbePmaReaderIncrMergeInit() function with the parameters passed to
+** this routine to initialize the incremental merge.
+** 
+** If the IncrMerger object is multi-threaded (IncrMerger.bUseThread==1), 
+** then a background thread is launched to call vdbePmaReaderIncrMergeInit().
+** Or, if the IncrMerger is single threaded, the same function is called
+** using the current thread.
 */
-static int vdbePmaReaderBgIncrInit(PmaReader *pReadr){
-  void *pCtx = (void*)pReadr;
-  return vdbeSorterCreateThread(pReadr->pIncr->pTask, vdbePmaReaderBgInit, pCtx);
-}
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode){
+  IncrMerger *pIncr = pReadr->pIncr;   /* Incremental merger */
+  int rc = SQLITE_OK;                  /* Return code */
+  if( pIncr ){
+#if SQLITE_MAX_WORKER_THREADS>0
+    assert( pIncr->bUseThread==0 || eMode==INCRINIT_TASK );
+    if( pIncr->bUseThread ){
+      void *pCtx = (void*)pReadr;
+      rc = vdbeSorterCreateThread(pIncr->pTask, vdbePmaReaderBgIncrInit, pCtx);
+    }else
 #endif
+    {
+      rc = vdbePmaReaderIncrMergeInit(pReadr, eMode);
+    }
+  }
+  return rc;
+}
 
 /*
 ** Allocate a new MergeEngine object to merge the contents of nPMA level-0
@@ -79227,10 +89023,10 @@ static int vdbeMergeEngineLevel0(
   int rc = SQLITE_OK;
 
   *ppOut = pNew = vdbeMergeEngineNew(nPMA);
-  if( pNew==0 ) rc = SQLITE_NOMEM;
+  if( pNew==0 ) rc = SQLITE_NOMEM_BKPT;
 
   for(i=0; iaReadr[i];
     rc = vdbePmaReaderInit(pTask, &pTask->file, iOff, pReadr, &nDummy);
     iOff = pReadr->iEof;
@@ -79298,7 +89094,7 @@ static int vdbeSorterAddToTree(
     if( pReadr->pIncr==0 ){
       MergeEngine *pNew = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);
       if( pNew==0 ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
       }else{
         rc = vdbeIncrMergerNew(pTask, pNew, &pReadr->pIncr);
       }
@@ -79343,7 +89139,7 @@ static int vdbeSorterMergeTreeBuild(
   assert( pSorter->bUseThreads || pSorter->nTask==1 );
   if( pSorter->nTask>1 ){
     pMain = vdbeMergeEngineNew(pSorter->nTask);
-    if( pMain==0 ) rc = SQLITE_NOMEM;
+    if( pMain==0 ) rc = SQLITE_NOMEM_BKPT;
   }
 #endif
 
@@ -79361,7 +89157,7 @@ static int vdbeSorterMergeTreeBuild(
         int i;
         int iSeq = 0;
         pRoot = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);
-        if( pRoot==0 ) rc = SQLITE_NOMEM;
+        if( pRoot==0 ) rc = SQLITE_NOMEM_BKPT;
         for(i=0; inPMA && rc==SQLITE_OK; i += SORTER_MAX_MERGE_COUNT){
           MergeEngine *pMerger = 0; /* New level-0 PMA merger */
           int nReader;              /* Number of level-0 PMAs to merge */
@@ -79413,6 +89209,11 @@ static int vdbeSorterSetupMerge(VdbeSorter *pSorter){
   MergeEngine *pMain = 0;
 #if SQLITE_MAX_WORKER_THREADS
   sqlite3 *db = pTask0->pSorter->db;
+  int i;
+  SorterCompare xCompare = vdbeSorterGetCompare(pSorter);
+  for(i=0; inTask; i++){
+    pSorter->aTask[i].xCompare = xCompare;
+  }
 #endif
 
   rc = vdbeSorterMergeTreeBuild(pSorter, &pMain);
@@ -79427,7 +89228,7 @@ static int vdbeSorterSetupMerge(VdbeSorter *pSorter){
       if( rc==SQLITE_OK ){
         pReadr = (PmaReader*)sqlite3DbMallocZero(db, sizeof(PmaReader));
         pSorter->pReader = pReadr;
-        if( pReadr==0 ) rc = SQLITE_NOMEM;
+        if( pReadr==0 ) rc = SQLITE_NOMEM_BKPT;
       }
       if( rc==SQLITE_OK ){
         rc = vdbeIncrMergerNew(pLast, pMain, &pReadr->pIncr);
@@ -79441,15 +89242,21 @@ static int vdbeSorterSetupMerge(VdbeSorter *pSorter){
             }
           }
           for(iTask=0; rc==SQLITE_OK && iTasknTask; iTask++){
+            /* Check that:
+            **   
+            **   a) The incremental merge object is configured to use the
+            **      right task, and
+            **   b) If it is using task (nTask-1), it is configured to run
+            **      in single-threaded mode. This is important, as the
+            **      root merge (INCRINIT_ROOT) will be using the same task
+            **      object.
+            */
             PmaReader *p = &pMain->aReadr[iTask];
-            assert( p->pIncr==0 || p->pIncr->pTask==&pSorter->aTask[iTask] );
-            if( p->pIncr ){ 
-              if( iTask==pSorter->nTask-1 ){
-                rc = vdbePmaReaderIncrMergeInit(p, INCRINIT_TASK);
-              }else{
-                rc = vdbePmaReaderBgIncrInit(p);
-              }
-            }
+            assert( p->pIncr==0 || (
+                (p->pIncr->pTask==&pSorter->aTask[iTask])             /* a */
+             && (iTask!=pSorter->nTask-1 || p->pIncr->bUseThread==0)  /* b */
+            ));
+            rc = vdbePmaReaderIncrInit(p, INCRINIT_TASK);
           }
         }
         pMain = 0;
@@ -79479,9 +89286,11 @@ static int vdbeSorterSetupMerge(VdbeSorter *pSorter){
 ** in sorted order.
 */
 SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *pCsr, int *pbEof){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
   int rc = SQLITE_OK;             /* Return code */
 
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
   assert( pSorter );
 
   /* If no data has been written to disk, then do not do so now. Instead,
@@ -79522,12 +89331,18 @@ SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *pCsr, int *pbEof){
 }
 
 /*
-** Advance to the next element in the sorter.
+** Advance to the next element in the sorter.  Return value:
+**
+**    SQLITE_OK     success
+**    SQLITE_DONE   end of data
+**    otherwise     some kind of error.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){
-  VdbeSorter *pSorter = pCsr->pSorter;
+SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr){
+  VdbeSorter *pSorter;
   int rc;                         /* Return code */
 
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
   assert( pSorter->bUsePMA || (pSorter->pReader==0 && pSorter->pMerger==0) );
   if( pSorter->bUsePMA ){
     assert( pSorter->pReader==0 || pSorter->pMerger==0 );
@@ -79536,21 +89351,22 @@ SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, in
 #if SQLITE_MAX_WORKER_THREADS>0
     if( pSorter->bUseThreads ){
       rc = vdbePmaReaderNext(pSorter->pReader);
-      *pbEof = (pSorter->pReader->pFd==0);
+      if( rc==SQLITE_OK && pSorter->pReader->pFd==0 ) rc = SQLITE_DONE;
     }else
 #endif
     /*if( !pSorter->bUseThreads )*/ {
+      int res = 0;
       assert( pSorter->pMerger!=0 );
       assert( pSorter->pMerger->pTask==(&pSorter->aTask[0]) );
-      rc = vdbeMergeEngineStep(pSorter->pMerger, pbEof);
+      rc = vdbeMergeEngineStep(pSorter->pMerger, &res);
+      if( rc==SQLITE_OK && res ) rc = SQLITE_DONE;
     }
   }else{
     SorterRecord *pFree = pSorter->list.pList;
     pSorter->list.pList = pFree->u.pNext;
     pFree->u.pNext = 0;
     if( pSorter->list.aMemory==0 ) vdbeSorterRecordFree(db, pFree);
-    *pbEof = !pSorter->list.pList;
-    rc = SQLITE_OK;
+    rc = pSorter->list.pList ? SQLITE_OK : SQLITE_DONE;
   }
   return rc;
 }
@@ -79587,12 +89403,14 @@ static void *vdbeSorterRowkey(
 ** Copy the current sorter key into the memory cell pOut.
 */
 SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *pCsr, Mem *pOut){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
   void *pKey; int nKey;           /* Sorter key to copy into pOut */
 
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
   pKey = vdbeSorterRowkey(pSorter, &nKey);
   if( sqlite3VdbeMemClearAndResize(pOut, nKey) ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pOut->n = nKey;
   MemSetTypeFlag(pOut, MEM_Blob);
@@ -79623,17 +89441,19 @@ SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
   int nKeyCol,                    /* Compare this many columns */
   int *pRes                       /* OUT: Result of comparison */
 ){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  UnpackedRecord *r2 = pSorter->pUnpacked;
-  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
+  VdbeSorter *pSorter;
+  UnpackedRecord *r2;
+  KeyInfo *pKeyInfo;
   int i;
   void *pKey; int nKey;           /* Sorter key to compare pVal with */
 
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  r2 = pSorter->pUnpacked;
+  pKeyInfo = pCsr->pKeyInfo;
   if( r2==0 ){
-    char *p;
-    r2 = pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pKeyInfo,0,0,&p);
-    assert( pSorter->pUnpacked==(UnpackedRecord*)p );
-    if( r2==0 ) return SQLITE_NOMEM;
+    r2 = pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
+    if( r2==0 ) return SQLITE_NOMEM_BKPT;
     r2->nField = nKeyCol;
   }
   assert( r2->nField==nKeyCol );
@@ -79652,264 +89472,6 @@ SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
 }
 
 /************** End of vdbesort.c ********************************************/
-/************** Begin file journal.c *****************************************/
-/*
-** 2007 August 22
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-**
-** This file implements a special kind of sqlite3_file object used
-** by SQLite to create journal files if the atomic-write optimization
-** is enabled.
-**
-** The distinctive characteristic of this sqlite3_file is that the
-** actual on disk file is created lazily. When the file is created,
-** the caller specifies a buffer size for an in-memory buffer to
-** be used to service read() and write() requests. The actual file
-** on disk is not created or populated until either:
-**
-**   1) The in-memory representation grows too large for the allocated 
-**      buffer, or
-**   2) The sqlite3JournalCreate() function is called.
-*/
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
-
-
-/*
-** A JournalFile object is a subclass of sqlite3_file used by
-** as an open file handle for journal files.
-*/
-struct JournalFile {
-  sqlite3_io_methods *pMethod;    /* I/O methods on journal files */
-  int nBuf;                       /* Size of zBuf[] in bytes */
-  char *zBuf;                     /* Space to buffer journal writes */
-  int iSize;                      /* Amount of zBuf[] currently used */
-  int flags;                      /* xOpen flags */
-  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
-  sqlite3_file *pReal;            /* The "real" underlying file descriptor */
-  const char *zJournal;           /* Name of the journal file */
-};
-typedef struct JournalFile JournalFile;
-
-/*
-** If it does not already exists, create and populate the on-disk file 
-** for JournalFile p.
-*/
-static int createFile(JournalFile *p){
-  int rc = SQLITE_OK;
-  if( !p->pReal ){
-    sqlite3_file *pReal = (sqlite3_file *)&p[1];
-    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
-    if( rc==SQLITE_OK ){
-      p->pReal = pReal;
-      if( p->iSize>0 ){
-        assert(p->iSize<=p->nBuf);
-        rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
-      }
-      if( rc!=SQLITE_OK ){
-        /* If an error occurred while writing to the file, close it before
-        ** returning. This way, SQLite uses the in-memory journal data to 
-        ** roll back changes made to the internal page-cache before this
-        ** function was called.  */
-        sqlite3OsClose(pReal);
-        p->pReal = 0;
-      }
-    }
-  }
-  return rc;
-}
-
-/*
-** Close the file.
-*/
-static int jrnlClose(sqlite3_file *pJfd){
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    sqlite3OsClose(p->pReal);
-  }
-  sqlite3_free(p->zBuf);
-  return SQLITE_OK;
-}
-
-/*
-** Read data from the file.
-*/
-static int jrnlRead(
-  sqlite3_file *pJfd,    /* The journal file from which to read */
-  void *zBuf,            /* Put the results here */
-  int iAmt,              /* Number of bytes to read */
-  sqlite_int64 iOfst     /* Begin reading at this offset */
-){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
-  }else if( (iAmt+iOfst)>p->iSize ){
-    rc = SQLITE_IOERR_SHORT_READ;
-  }else{
-    memcpy(zBuf, &p->zBuf[iOfst], iAmt);
-  }
-  return rc;
-}
-
-/*
-** Write data to the file.
-*/
-static int jrnlWrite(
-  sqlite3_file *pJfd,    /* The journal file into which to write */
-  const void *zBuf,      /* Take data to be written from here */
-  int iAmt,              /* Number of bytes to write */
-  sqlite_int64 iOfst     /* Begin writing at this offset into the file */
-){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( !p->pReal && (iOfst+iAmt)>p->nBuf ){
-    rc = createFile(p);
-  }
-  if( rc==SQLITE_OK ){
-    if( p->pReal ){
-      rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
-    }else{
-      memcpy(&p->zBuf[iOfst], zBuf, iAmt);
-      if( p->iSize<(iOfst+iAmt) ){
-        p->iSize = (iOfst+iAmt);
-      }
-    }
-  }
-  return rc;
-}
-
-/*
-** Truncate the file.
-*/
-static int jrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsTruncate(p->pReal, size);
-  }else if( sizeiSize ){
-    p->iSize = size;
-  }
-  return rc;
-}
-
-/*
-** Sync the file.
-*/
-static int jrnlSync(sqlite3_file *pJfd, int flags){
-  int rc;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsSync(p->pReal, flags);
-  }else{
-    rc = SQLITE_OK;
-  }
-  return rc;
-}
-
-/*
-** Query the size of the file in bytes.
-*/
-static int jrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsFileSize(p->pReal, pSize);
-  }else{
-    *pSize = (sqlite_int64) p->iSize;
-  }
-  return rc;
-}
-
-/*
-** Table of methods for JournalFile sqlite3_file object.
-*/
-static struct sqlite3_io_methods JournalFileMethods = {
-  1,             /* iVersion */
-  jrnlClose,     /* xClose */
-  jrnlRead,      /* xRead */
-  jrnlWrite,     /* xWrite */
-  jrnlTruncate,  /* xTruncate */
-  jrnlSync,      /* xSync */
-  jrnlFileSize,  /* xFileSize */
-  0,             /* xLock */
-  0,             /* xUnlock */
-  0,             /* xCheckReservedLock */
-  0,             /* xFileControl */
-  0,             /* xSectorSize */
-  0,             /* xDeviceCharacteristics */
-  0,             /* xShmMap */
-  0,             /* xShmLock */
-  0,             /* xShmBarrier */
-  0              /* xShmUnmap */
-};
-
-/* 
-** Open a journal file.
-*/
-SQLITE_PRIVATE int sqlite3JournalOpen(
-  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
-  const char *zName,         /* Name of the journal file */
-  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
-  int flags,                 /* Opening flags */
-  int nBuf                   /* Bytes buffered before opening the file */
-){
-  JournalFile *p = (JournalFile *)pJfd;
-  memset(p, 0, sqlite3JournalSize(pVfs));
-  if( nBuf>0 ){
-    p->zBuf = sqlite3MallocZero(nBuf);
-    if( !p->zBuf ){
-      return SQLITE_NOMEM;
-    }
-  }else{
-    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
-  }
-  p->pMethod = &JournalFileMethods;
-  p->nBuf = nBuf;
-  p->flags = flags;
-  p->zJournal = zName;
-  p->pVfs = pVfs;
-  return SQLITE_OK;
-}
-
-/*
-** If the argument p points to a JournalFile structure, and the underlying
-** file has not yet been created, create it now.
-*/
-SQLITE_PRIVATE int sqlite3JournalCreate(sqlite3_file *p){
-  if( p->pMethods!=&JournalFileMethods ){
-    return SQLITE_OK;
-  }
-  return createFile((JournalFile *)p);
-}
-
-/*
-** The file-handle passed as the only argument is guaranteed to be an open
-** file. It may or may not be of class JournalFile. If the file is a
-** JournalFile, and the underlying file on disk has not yet been opened,
-** return 0. Otherwise, return 1.
-*/
-SQLITE_PRIVATE int sqlite3JournalExists(sqlite3_file *p){
-  return (p->pMethods!=&JournalFileMethods || ((JournalFile *)p)->pReal!=0);
-}
-
-/* 
-** Return the number of bytes required to store a JournalFile that uses vfs
-** pVfs to create the underlying on-disk files.
-*/
-SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
-  return (pVfs->szOsFile+sizeof(JournalFile));
-}
-#endif
-
-/************** End of journal.c *********************************************/
 /************** Begin file memjournal.c **************************************/
 /*
 ** 2008 October 7
@@ -79926,31 +89488,45 @@ SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
 ** This file contains code use to implement an in-memory rollback journal.
 ** The in-memory rollback journal is used to journal transactions for
 ** ":memory:" databases and when the journal_mode=MEMORY pragma is used.
+**
+** Update:  The in-memory journal is also used to temporarily cache
+** smaller journals that are not critical for power-loss recovery.
+** For example, statement journals that are not too big will be held
+** entirely in memory, thus reducing the number of file I/O calls, and
+** more importantly, reducing temporary file creation events.  If these
+** journals become too large for memory, they are spilled to disk.  But
+** in the common case, they are usually small and no file I/O needs to
+** occur.
 */
+/* #include "sqliteInt.h" */
 
 /* Forward references to internal structures */
 typedef struct MemJournal MemJournal;
 typedef struct FilePoint FilePoint;
 typedef struct FileChunk FileChunk;
 
-/* Space to hold the rollback journal is allocated in increments of
-** this many bytes.
-**
-** The size chosen is a little less than a power of two.  That way,
-** the FileChunk object will have a size that almost exactly fills
-** a power-of-two allocation.  This minimizes wasted space in power-of-two
-** memory allocators.
-*/
-#define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))
-
 /*
 ** The rollback journal is composed of a linked list of these structures.
+**
+** The zChunk array is always at least 8 bytes in size - usually much more.
+** Its actual size is stored in the MemJournal.nChunkSize variable.
 */
 struct FileChunk {
   FileChunk *pNext;               /* Next chunk in the journal */
-  u8 zChunk[JOURNAL_CHUNKSIZE];   /* Content of this chunk */
+  u8 zChunk[8];                   /* Content of this chunk */
 };
 
+/*
+** By default, allocate this many bytes of memory for each FileChunk object.
+*/
+#define MEMJOURNAL_DFLT_FILECHUNKSIZE 1024
+
+/*
+** For chunk size nChunkSize, return the number of bytes that should
+** be allocated for each FileChunk structure.
+*/
+#define fileChunkSize(nChunkSize) (sizeof(FileChunk) + ((nChunkSize)-8))
+
 /*
 ** An instance of this object serves as a cursor into the rollback journal.
 ** The cursor can be either for reading or writing.
@@ -79961,14 +89537,22 @@ struct FilePoint {
 };
 
 /*
-** This subclass is a subclass of sqlite3_file.  Each open memory-journal
+** This structure is a subclass of sqlite3_file. Each open memory-journal
 ** is an instance of this class.
 */
 struct MemJournal {
-  sqlite3_io_methods *pMethod;    /* Parent class. MUST BE FIRST */
+  const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
+  int nChunkSize;                 /* In-memory chunk-size */
+
+  int nSpill;                     /* Bytes of data before flushing */
+  int nSize;                      /* Bytes of data currently in memory */
   FileChunk *pFirst;              /* Head of in-memory chunk-list */
   FilePoint endpoint;             /* Pointer to the end of the file */
   FilePoint readpoint;            /* Pointer to the end of the last xRead() */
+
+  int flags;                      /* xOpen flags */
+  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
+  const char *zJournal;           /* Name of the journal file */
 };
 
 /*
@@ -79987,36 +89571,94 @@ static int memjrnlRead(
   int iChunkOffset;
   FileChunk *pChunk;
 
-  /* SQLite never tries to read past the end of a rollback journal file */
-  assert( iOfst+iAmt<=p->endpoint.iOffset );
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+  if( (iAmt+iOfst)>p->endpoint.iOffset ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+#endif
 
+  assert( (iAmt+iOfst)<=p->endpoint.iOffset );
+  assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 );
   if( p->readpoint.iOffset!=iOfst || iOfst==0 ){
     sqlite3_int64 iOff = 0;
     for(pChunk=p->pFirst; 
-        ALWAYS(pChunk) && (iOff+JOURNAL_CHUNKSIZE)<=iOfst;
+        ALWAYS(pChunk) && (iOff+p->nChunkSize)<=iOfst;
         pChunk=pChunk->pNext
     ){
-      iOff += JOURNAL_CHUNKSIZE;
+      iOff += p->nChunkSize;
     }
   }else{
     pChunk = p->readpoint.pChunk;
+    assert( pChunk!=0 );
   }
 
-  iChunkOffset = (int)(iOfst%JOURNAL_CHUNKSIZE);
+  iChunkOffset = (int)(iOfst%p->nChunkSize);
   do {
-    int iSpace = JOURNAL_CHUNKSIZE - iChunkOffset;
-    int nCopy = MIN(nRead, (JOURNAL_CHUNKSIZE - iChunkOffset));
-    memcpy(zOut, &pChunk->zChunk[iChunkOffset], nCopy);
+    int iSpace = p->nChunkSize - iChunkOffset;
+    int nCopy = MIN(nRead, (p->nChunkSize - iChunkOffset));
+    memcpy(zOut, (u8*)pChunk->zChunk + iChunkOffset, nCopy);
     zOut += nCopy;
     nRead -= iSpace;
     iChunkOffset = 0;
   } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 );
-  p->readpoint.iOffset = iOfst+iAmt;
+  p->readpoint.iOffset = pChunk ? iOfst+iAmt : 0;
   p->readpoint.pChunk = pChunk;
 
   return SQLITE_OK;
 }
 
+/*
+** Free the list of FileChunk structures headed at MemJournal.pFirst.
+*/
+static void memjrnlFreeChunks(MemJournal *p){
+  FileChunk *pIter;
+  FileChunk *pNext;
+  for(pIter=p->pFirst; pIter; pIter=pNext){
+    pNext = pIter->pNext;
+    sqlite3_free(pIter);
+  } 
+  p->pFirst = 0;
+}
+
+/*
+** Flush the contents of memory to a real file on disk.
+*/
+static int memjrnlCreateFile(MemJournal *p){
+  int rc;
+  sqlite3_file *pReal = (sqlite3_file*)p;
+  MemJournal copy = *p;
+
+  memset(p, 0, sizeof(MemJournal));
+  rc = sqlite3OsOpen(copy.pVfs, copy.zJournal, pReal, copy.flags, 0);
+  if( rc==SQLITE_OK ){
+    int nChunk = copy.nChunkSize;
+    i64 iOff = 0;
+    FileChunk *pIter;
+    for(pIter=copy.pFirst; pIter; pIter=pIter->pNext){
+      if( iOff + nChunk > copy.endpoint.iOffset ){
+        nChunk = copy.endpoint.iOffset - iOff;
+      }
+      rc = sqlite3OsWrite(pReal, (u8*)pIter->zChunk, nChunk, iOff);
+      if( rc ) break;
+      iOff += nChunk;
+    }
+    if( rc==SQLITE_OK ){
+      /* No error has occurred. Free the in-memory buffers. */
+      memjrnlFreeChunks(©);
+    }
+  }
+  if( rc!=SQLITE_OK ){
+    /* If an error occurred while creating or writing to the file, restore
+    ** the original before returning. This way, SQLite uses the in-memory
+    ** journal data to roll back changes made to the internal page-cache
+    ** before this function was called.  */
+    sqlite3OsClose(pReal);
+    *p = copy;
+  }
+  return rc;
+}
+
+
 /*
 ** Write data to the file.
 */
@@ -80030,38 +89672,62 @@ static int memjrnlWrite(
   int nWrite = iAmt;
   u8 *zWrite = (u8 *)zBuf;
 
-  /* An in-memory journal file should only ever be appended to. Random
-  ** access writes are not required by sqlite.
-  */
-  assert( iOfst==p->endpoint.iOffset );
-  UNUSED_PARAMETER(iOfst);
+  /* If the file should be created now, create it and write the new data
+  ** into the file on disk. */
+  if( p->nSpill>0 && (iAmt+iOfst)>p->nSpill ){
+    int rc = memjrnlCreateFile(p);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3OsWrite(pJfd, zBuf, iAmt, iOfst);
+    }
+    return rc;
+  }
 
-  while( nWrite>0 ){
-    FileChunk *pChunk = p->endpoint.pChunk;
-    int iChunkOffset = (int)(p->endpoint.iOffset%JOURNAL_CHUNKSIZE);
-    int iSpace = MIN(nWrite, JOURNAL_CHUNKSIZE - iChunkOffset);
+  /* If the contents of this write should be stored in memory */
+  else{
+    /* An in-memory journal file should only ever be appended to. Random
+    ** access writes are not required. The only exception to this is when
+    ** the in-memory journal is being used by a connection using the
+    ** atomic-write optimization. In this case the first 28 bytes of the
+    ** journal file may be written as part of committing the transaction. */ 
+    assert( iOfst==p->endpoint.iOffset || iOfst==0 );
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+    if( iOfst==0 && p->pFirst ){
+      assert( p->nChunkSize>iAmt );
+      memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt);
+    }else
+#else
+    assert( iOfst>0 || p->pFirst==0 );
+#endif
+    {
+      while( nWrite>0 ){
+        FileChunk *pChunk = p->endpoint.pChunk;
+        int iChunkOffset = (int)(p->endpoint.iOffset%p->nChunkSize);
+        int iSpace = MIN(nWrite, p->nChunkSize - iChunkOffset);
+
+        if( iChunkOffset==0 ){
+          /* New chunk is required to extend the file. */
+          FileChunk *pNew = sqlite3_malloc(fileChunkSize(p->nChunkSize));
+          if( !pNew ){
+            return SQLITE_IOERR_NOMEM_BKPT;
+          }
+          pNew->pNext = 0;
+          if( pChunk ){
+            assert( p->pFirst );
+            pChunk->pNext = pNew;
+          }else{
+            assert( !p->pFirst );
+            p->pFirst = pNew;
+          }
+          p->endpoint.pChunk = pNew;
+        }
 
-    if( iChunkOffset==0 ){
-      /* New chunk is required to extend the file. */
-      FileChunk *pNew = sqlite3_malloc(sizeof(FileChunk));
-      if( !pNew ){
-        return SQLITE_IOERR_NOMEM;
-      }
-      pNew->pNext = 0;
-      if( pChunk ){
-        assert( p->pFirst );
-        pChunk->pNext = pNew;
-      }else{
-        assert( !p->pFirst );
-        p->pFirst = pNew;
+        memcpy((u8*)p->endpoint.pChunk->zChunk + iChunkOffset, zWrite, iSpace);
+        zWrite += iSpace;
+        nWrite -= iSpace;
+        p->endpoint.iOffset += iSpace;
       }
-      p->endpoint.pChunk = pNew;
+      p->nSize = iAmt + iOfst;
     }
-
-    memcpy(&p->endpoint.pChunk->zChunk[iChunkOffset], zWrite, iSpace);
-    zWrite += iSpace;
-    nWrite -= iSpace;
-    p->endpoint.iOffset += iSpace;
   }
 
   return SQLITE_OK;
@@ -80069,19 +89735,21 @@ static int memjrnlWrite(
 
 /*
 ** Truncate the file.
+**
+** If the journal file is already on disk, truncate it there. Or, if it
+** is still in main memory but is being truncated to zero bytes in size,
+** ignore 
 */
 static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
   MemJournal *p = (MemJournal *)pJfd;
-  FileChunk *pChunk;
-  assert(size==0);
-  UNUSED_PARAMETER(size);
-  pChunk = p->pFirst;
-  while( pChunk ){
-    FileChunk *pTmp = pChunk;
-    pChunk = pChunk->pNext;
-    sqlite3_free(pTmp);
-  }
-  sqlite3MemJournalOpen(pJfd);
+  if( ALWAYS(size==0) ){
+    memjrnlFreeChunks(p);
+    p->nSize = 0;
+    p->endpoint.pChunk = 0;
+    p->endpoint.iOffset = 0;
+    p->readpoint.pChunk = 0;
+    p->readpoint.iOffset = 0;
+  }
   return SQLITE_OK;
 }
 
@@ -80089,21 +89757,19 @@ static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
 ** Close the file.
 */
 static int memjrnlClose(sqlite3_file *pJfd){
-  memjrnlTruncate(pJfd, 0);
+  MemJournal *p = (MemJournal *)pJfd;
+  memjrnlFreeChunks(p);
   return SQLITE_OK;
 }
 
-
 /*
 ** Sync the file.
 **
-** Syncing an in-memory journal is a no-op.  And, in fact, this routine
-** is never called in a working implementation.  This implementation
-** exists purely as a contingency, in case some malfunction in some other
-** part of SQLite causes Sync to be called by mistake.
+** If the real file has been created, call its xSync method. Otherwise, 
+** syncing an in-memory journal is a no-op. 
 */
-static int memjrnlSync(sqlite3_file *NotUsed, int NotUsed2){
-  UNUSED_PARAMETER2(NotUsed, NotUsed2);
+static int memjrnlSync(sqlite3_file *pJfd, int flags){
+  UNUSED_PARAMETER2(pJfd, flags);
   return SQLITE_OK;
 }
 
@@ -80142,28 +89808,88 @@ static const struct sqlite3_io_methods MemJournalMethods = {
 };
 
 /* 
-** Open a journal file.
+** Open a journal file. 
+**
+** The behaviour of the journal file depends on the value of parameter 
+** nSpill. If nSpill is 0, then the journal file is always create and 
+** accessed using the underlying VFS. If nSpill is less than zero, then
+** all content is always stored in main-memory. Finally, if nSpill is a
+** positive value, then the journal file is initially created in-memory
+** but may be flushed to disk later on. In this case the journal file is
+** flushed to disk either when it grows larger than nSpill bytes in size,
+** or when sqlite3JournalCreate() is called.
+*/
+SQLITE_PRIVATE int sqlite3JournalOpen(
+  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
+  const char *zName,         /* Name of the journal file */
+  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
+  int flags,                 /* Opening flags */
+  int nSpill                 /* Bytes buffered before opening the file */
+){
+  MemJournal *p = (MemJournal*)pJfd;
+
+  /* Zero the file-handle object. If nSpill was passed zero, initialize
+  ** it using the sqlite3OsOpen() function of the underlying VFS. In this
+  ** case none of the code in this module is executed as a result of calls
+  ** made on the journal file-handle.  */
+  memset(p, 0, sizeof(MemJournal));
+  if( nSpill==0 ){
+    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
+  }
+
+  if( nSpill>0 ){
+    p->nChunkSize = nSpill;
+  }else{
+    p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk);
+    assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );
+  }
+
+  p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;
+  p->nSpill = nSpill;
+  p->flags = flags;
+  p->zJournal = zName;
+  p->pVfs = pVfs;
+  return SQLITE_OK;
+}
+
+/*
+** Open an in-memory journal file.
 */
 SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *pJfd){
-  MemJournal *p = (MemJournal *)pJfd;
-  assert( EIGHT_BYTE_ALIGNMENT(p) );
-  memset(p, 0, sqlite3MemJournalSize());
-  p->pMethod = (sqlite3_io_methods*)&MemJournalMethods;
+  sqlite3JournalOpen(0, 0, pJfd, 0, -1);
 }
 
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
 /*
-** Return true if the file-handle passed as an argument is 
-** an in-memory journal 
+** If the argument p points to a MemJournal structure that is not an 
+** in-memory-only journal file (i.e. is one that was opened with a +ve
+** nSpill parameter), and the underlying file has not yet been created, 
+** create it now.
 */
-SQLITE_PRIVATE int sqlite3IsMemJournal(sqlite3_file *pJfd){
-  return pJfd->pMethods==&MemJournalMethods;
+SQLITE_PRIVATE int sqlite3JournalCreate(sqlite3_file *p){
+  int rc = SQLITE_OK;
+  if( p->pMethods==&MemJournalMethods && ((MemJournal*)p)->nSpill>0 ){
+    rc = memjrnlCreateFile((MemJournal*)p);
+  }
+  return rc;
+}
+#endif
+
+/*
+** The file-handle passed as the only argument is open on a journal file.
+** Return true if this "journal file" is currently stored in heap memory,
+** or false otherwise.
+*/
+SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p){
+  return p->pMethods==&MemJournalMethods;
 }
 
 /* 
-** Return the number of bytes required to store a MemJournal file descriptor.
+** Return the number of bytes required to store a JournalFile that uses vfs
+** pVfs to create the underlying on-disk files.
 */
-SQLITE_PRIVATE int sqlite3MemJournalSize(void){
-  return sizeof(MemJournal);
+SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
+  return MAX(pVfs->szOsFile, (int)sizeof(MemJournal));
 }
 
 /************** End of memjournal.c ******************************************/
@@ -80182,6 +89908,7 @@ SQLITE_PRIVATE int sqlite3MemJournalSize(void){
 ** This file contains routines used for walking the parser tree for
 ** an SQL statement.
 */
+/* #include "sqliteInt.h" */
 /* #include  */
 /* #include  */
 
@@ -80196,32 +89923,36 @@ SQLITE_PRIVATE int sqlite3MemJournalSize(void){
 **
 **    WRC_Continue      Continue descending down the tree.
 **
-**    WRC_Prune         Do not descend into child nodes.  But allow
+**    WRC_Prune         Do not descend into child nodes, but allow
 **                      the walk to continue with sibling nodes.
 **
 **    WRC_Abort         Do no more callbacks.  Unwind the stack and
-**                      return the top-level walk call.
+**                      return from the top-level walk call.
 **
 ** The return value from this routine is WRC_Abort to abandon the tree walk
 ** and WRC_Continue to continue.
 */
-SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){
   int rc;
-  if( pExpr==0 ) return WRC_Continue;
   testcase( ExprHasProperty(pExpr, EP_TokenOnly) );
   testcase( ExprHasProperty(pExpr, EP_Reduced) );
   rc = pWalker->xExprCallback(pWalker, pExpr);
-  if( rc==WRC_Continue
-              && !ExprHasProperty(pExpr,EP_TokenOnly) ){
-    if( sqlite3WalkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
-    if( sqlite3WalkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
-    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+  if( rc ) return rc & WRC_Abort;
+  if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){
+    if( pExpr->pLeft && walkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
+    assert( pExpr->x.pList==0 || pExpr->pRight==0 );
+    if( pExpr->pRight ){
+      if( walkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
+    }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
       if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
-    }else{
+    }else if( pExpr->x.pList ){
       if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
     }
   }
-  return rc & WRC_Abort;
+  return WRC_Continue;
+}
+SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+  return pExpr ? walkExpr(pWalker,pExpr) : WRC_Continue;
 }
 
 /*
@@ -80271,7 +90002,12 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
   pSrc = p->pSrc;
   if( ALWAYS(pSrc) ){
     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
-      if( sqlite3WalkSelect(pWalker, pItem->pSelect) ){
+      if( pItem->pSelect && sqlite3WalkSelect(pWalker, pItem->pSelect) ){
+        return WRC_Abort;
+      }
+      if( pItem->fg.isTabFunc
+       && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)
+      ){
         return WRC_Abort;
       }
     }
@@ -80286,8 +90022,9 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
 **
 ** If it is not NULL, the xSelectCallback() callback is invoked before
 ** the walk of the expressions and FROM clause. The xSelectCallback2()
-** method, if it is not NULL, is invoked following the walk of the 
-** expressions and FROM clause.
+** method is invoked following the walk of the expressions and FROM clause,
+** but only if both xSelectCallback and xSelectCallback2 are both non-NULL
+** and if the expressions and FROM clause both return WRC_Continue;
 **
 ** Return WRC_Continue under normal conditions.  Return WRC_Abort if
 ** there is an abort request.
@@ -80297,29 +90034,22 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
 */
 SQLITE_PRIVATE int sqlite3WalkSelect(Walker *pWalker, Select *p){
   int rc;
-  if( p==0 || (pWalker->xSelectCallback==0 && pWalker->xSelectCallback2==0) ){
-    return WRC_Continue;
-  }
-  rc = WRC_Continue;
-  pWalker->walkerDepth++;
-  while( p ){
-    if( pWalker->xSelectCallback ){
-       rc = pWalker->xSelectCallback(pWalker, p);
-       if( rc ) break;
-    }
+  if( p==0 ) return WRC_Continue;
+  if( pWalker->xSelectCallback==0 ) return WRC_Continue;
+  do{
+    rc = pWalker->xSelectCallback(pWalker, p);
+    if( rc ) return rc & WRC_Abort;
     if( sqlite3WalkSelectExpr(pWalker, p)
      || sqlite3WalkSelectFrom(pWalker, p)
     ){
-      pWalker->walkerDepth--;
       return WRC_Abort;
     }
     if( pWalker->xSelectCallback2 ){
       pWalker->xSelectCallback2(pWalker, p);
     }
     p = p->pPrior;
-  }
-  pWalker->walkerDepth--;
-  return rc & WRC_Abort;
+  }while( p!=0 );
+  return WRC_Continue;
 }
 
 /************** End of walker.c **********************************************/
@@ -80340,8 +90070,7 @@ SQLITE_PRIVATE int sqlite3WalkSelect(Walker *pWalker, Select *p){
 ** resolve all identifiers by associating them with a particular
 ** table and column.
 */
-/* #include  */
-/* #include  */
+/* #include "sqliteInt.h" */
 
 /*
 ** Walk the expression tree pExpr and increase the aggregate function
@@ -80370,30 +90099,6 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
 ** Turn the pExpr expression into an alias for the iCol-th column of the
 ** result set in pEList.
 **
-** If the result set column is a simple column reference, then this routine
-** makes an exact copy.  But for any other kind of expression, this
-** routine make a copy of the result set column as the argument to the
-** TK_AS operator.  The TK_AS operator causes the expression to be
-** evaluated just once and then reused for each alias.
-**
-** The reason for suppressing the TK_AS term when the expression is a simple
-** column reference is so that the column reference will be recognized as
-** usable by indices within the WHERE clause processing logic. 
-**
-** The TK_AS operator is inhibited if zType[0]=='G'.  This means
-** that in a GROUP BY clause, the expression is evaluated twice.  Hence:
-**
-**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
-**
-** Is equivalent to:
-**
-**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
-**
-** The result of random()%5 in the GROUP BY clause is probably different
-** from the result in the result-set.  On the other hand Standard SQL does
-** not allow the GROUP BY clause to contain references to result-set columns.
-** So this should never come up in well-formed queries.
-**
 ** If the reference is followed by a COLLATE operator, then make sure
 ** the COLLATE operator is preserved.  For example:
 **
@@ -80404,7 +90109,7 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
 **     SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;
 **
 ** The nSubquery parameter specifies how many levels of subquery the
-** alias is removed from the original expression.  The usually value is
+** alias is removed from the original expression.  The usual value is
 ** zero but it might be more if the alias is contained within a subquery
 ** of the original expression.  The Expr.op2 field of TK_AGG_FUNCTION
 ** structures must be increased by the nSubquery amount.
@@ -80424,23 +90129,14 @@ static void resolveAlias(
   assert( iCol>=0 && iColnExpr );
   pOrig = pEList->a[iCol].pExpr;
   assert( pOrig!=0 );
-  assert( pOrig->flags & EP_Resolved );
   db = pParse->db;
   pDup = sqlite3ExprDup(db, pOrig, 0);
   if( pDup==0 ) return;
-  if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
-    incrAggFunctionDepth(pDup, nSubquery);
-    pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
-    if( pDup==0 ) return;
-    ExprSetProperty(pDup, EP_Skip);
-    if( pEList->a[iCol].u.x.iAlias==0 ){
-      pEList->a[iCol].u.x.iAlias = (u16)(++pParse->nAlias);
-    }
-    pDup->iTable = pEList->a[iCol].u.x.iAlias;
-  }
+  if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery);
   if( pExpr->op==TK_COLLATE ){
     pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
   }
+  ExprSetProperty(pDup, EP_Alias);
 
   /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
   ** prevents ExprDelete() from deleting the Expr structure itself,
@@ -80572,14 +90268,15 @@ static int lookupName(
     testcase( pNC->ncFlags & NC_PartIdx );
     testcase( pNC->ncFlags & NC_IsCheck );
     if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
-      /* Silently ignore database qualifiers inside CHECK constraints and partial
-      ** indices.  Do not raise errors because that might break legacy and
-      ** because it does not hurt anything to just ignore the database name. */
+      /* Silently ignore database qualifiers inside CHECK constraints and
+      ** partial indices.  Do not raise errors because that might break
+      ** legacy and because it does not hurt anything to just ignore the
+      ** database name. */
       zDb = 0;
     }else{
       for(i=0; inDb; i++){
-        assert( db->aDb[i].zName );
-        if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+        assert( db->aDb[i].zDbSName );
+        if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){
           pSchema = db->aDb[i].pSchema;
           break;
         }
@@ -80588,7 +90285,8 @@ static int lookupName(
   }
 
   /* Start at the inner-most context and move outward until a match is found */
-  while( pNC && cnt==0 ){
+  assert( pNC && cnt==0 );
+  do{
     ExprList *pEList;
     SrcList *pSrcList = pNC->pSrcList;
 
@@ -80631,7 +90329,7 @@ static int lookupName(
             ** USING clause, then skip this match.
             */
             if( cnt==1 ){
-              if( pItem->jointype & JT_NATURAL ) continue;
+              if( pItem->fg.jointype & JT_NATURAL ) continue;
               if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
             }
             cnt++;
@@ -80645,8 +90343,9 @@ static int lookupName(
       if( pMatch ){
         pExpr->iTable = pMatch->iCursor;
         pExpr->pTab = pMatch->pTab;
-        assert( (pMatch->jointype & JT_RIGHT)==0 ); /* RIGHT JOIN not (yet) supported */
-        if( (pMatch->jointype & JT_LEFT)!=0 ){
+        /* RIGHT JOIN not (yet) supported */
+        assert( (pMatch->fg.jointype & JT_RIGHT)==0 );
+        if( (pMatch->fg.jointype & JT_LEFT)!=0 ){
           ExprSetProperty(pExpr, EP_CanBeNull);
         }
         pSchema = pExpr->pTab->pSchema;
@@ -80682,9 +90381,8 @@ static int lookupName(
             break;
           }
         }
-        if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && HasRowid(pTab) ){
+        if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){
           /* IMP: R-51414-32910 */
-          /* IMP: R-44911-55124 */
           iCol = -1;
         }
         if( iColnCol ){
@@ -80711,10 +90409,15 @@ static int lookupName(
     /*
     ** Perhaps the name is a reference to the ROWID
     */
-    if( cnt==0 && cntTab==1 && pMatch && sqlite3IsRowid(zCol)
-     && HasRowid(pMatch->pTab) ){
+    if( cnt==0
+     && cntTab==1
+     && pMatch
+     && (pNC->ncFlags & NC_IdxExpr)==0
+     && sqlite3IsRowid(zCol)
+     && VisibleRowid(pMatch->pTab)
+    ){
       cnt = 1;
-      pExpr->iColumn = -1;     /* IMP: R-44911-55124 */
+      pExpr->iColumn = -1;
       pExpr->affinity = SQLITE_AFF_INTEGER;
     }
 
@@ -80731,9 +90434,9 @@ static int lookupName(
     ** resolved by the time the WHERE clause is resolved.
     **
     ** The ability to use an output result-set column in the WHERE, GROUP BY,
-    ** or HAVING clauses, or as part of a larger expression in the ORDRE BY
+    ** or HAVING clauses, or as part of a larger expression in the ORDER BY
     ** clause is not standard SQL.  This is a (goofy) SQLite extension, that
-    ** is supported for backwards compatibility only.  TO DO: Issue a warning
+    ** is supported for backwards compatibility only. Hence, we issue a warning
     ** on sqlite3_log() whenever the capability is used.
     */
     if( (pEList = pNC->pEList)!=0
@@ -80752,6 +90455,10 @@ static int lookupName(
             sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
             return WRC_Abort;
           }
+          if( sqlite3ExprVectorSize(pOrig)!=1 ){
+            sqlite3ErrorMsg(pParse, "row value misused");
+            return WRC_Abort;
+          }
           resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);
           cnt = 1;
           pMatch = 0;
@@ -80764,11 +90471,11 @@ static int lookupName(
     /* Advance to the next name context.  The loop will exit when either
     ** we have a match (cnt>0) or when we run out of name contexts.
     */
-    if( cnt==0 ){
-      pNC = pNC->pNext;
-      nSubquery++;
-    }
-  }
+    if( cnt ) break;
+    pNC = pNC->pNext;
+    nSubquery++;
+  }while( pNC );
+
 
   /*
   ** If X and Y are NULL (in other words if only the column name Z is
@@ -80827,10 +90534,11 @@ static int lookupName(
   sqlite3ExprDelete(db, pExpr->pRight);
   pExpr->pRight = 0;
   pExpr->op = (isTrigger ? TK_TRIGGER : TK_COLUMN);
+  ExprSetProperty(pExpr, EP_Leaf);
 lookupname_end:
   if( cnt==1 ){
     assert( pNC!=0 );
-    if( pExpr->op!=TK_AS ){
+    if( !ExprHasProperty(pExpr, EP_Alias) ){
       sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
     }
     /* Increment the nRef value on all name contexts from TopNC up to
@@ -80865,42 +90573,30 @@ SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSr
       testcase( iCol==BMS-1 );
       pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
     }
-    ExprSetProperty(p, EP_Resolved);
   }
   return p;
 }
 
 /*
-** Report an error that an expression is not valid for a partial index WHERE
-** clause.
+** Report an error that an expression is not valid for some set of
+** pNC->ncFlags values determined by validMask.
 */
-static void notValidPartIdxWhere(
+static void notValid(
   Parse *pParse,       /* Leave error message here */
   NameContext *pNC,    /* The name context */
-  const char *zMsg     /* Type of error */
+  const char *zMsg,    /* Type of error */
+  int validMask        /* Set of contexts for which prohibited */
 ){
-  if( (pNC->ncFlags & NC_PartIdx)!=0 ){
-    sqlite3ErrorMsg(pParse, "%s prohibited in partial index WHERE clauses",
-                    zMsg);
-  }
-}
-
+  assert( (validMask&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr))==0 );
+  if( (pNC->ncFlags & validMask)!=0 ){
+    const char *zIn = "partial index WHERE clauses";
+    if( pNC->ncFlags & NC_IdxExpr )      zIn = "index expressions";
 #ifndef SQLITE_OMIT_CHECK
-/*
-** Report an error that an expression is not valid for a CHECK constraint.
-*/
-static void notValidCheckConstraint(
-  Parse *pParse,       /* Leave error message here */
-  NameContext *pNC,    /* The name context */
-  const char *zMsg     /* Type of error */
-){
-  if( (pNC->ncFlags & NC_IsCheck)!=0 ){
-    sqlite3ErrorMsg(pParse,"%s prohibited in CHECK constraints", zMsg);
+    else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints";
+#endif
+    sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn);
   }
 }
-#else
-# define notValidCheckConstraint(P,N,M)
-#endif
 
 /*
 ** Expression p should encode a floating point value between 1.0 and 0.0.
@@ -80936,8 +90632,6 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
   pParse = pNC->pParse;
   assert( pParse==pWalker->pParse );
 
-  if( ExprHasProperty(pExpr, EP_Resolved) ) return WRC_Prune;
-  ExprSetProperty(pExpr, EP_Resolved);
 #ifndef NDEBUG
   if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
     SrcList *pSrcList = pNC->pSrcList;
@@ -80966,34 +90660,41 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       pExpr->affinity = SQLITE_AFF_INTEGER;
       break;
     }
-#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
+#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
+          && !defined(SQLITE_OMIT_SUBQUERY) */
 
-    /* A lone identifier is the name of a column.
-    */
-    case TK_ID: {
-      return lookupName(pParse, 0, 0, pExpr->u.zToken, pNC, pExpr);
-    }
-  
-    /* A table name and column name:     ID.ID
+    /* A column name:                    ID
+    ** Or table name and column name:    ID.ID
     ** Or a database, table and column:  ID.ID.ID
+    **
+    ** The TK_ID and TK_OUT cases are combined so that there will only
+    ** be one call to lookupName().  Then the compiler will in-line 
+    ** lookupName() for a size reduction and performance increase.
     */
+    case TK_ID:
     case TK_DOT: {
       const char *zColumn;
       const char *zTable;
       const char *zDb;
       Expr *pRight;
 
-      /* if( pSrcList==0 ) break; */
-      pRight = pExpr->pRight;
-      if( pRight->op==TK_ID ){
+      if( pExpr->op==TK_ID ){
         zDb = 0;
-        zTable = pExpr->pLeft->u.zToken;
-        zColumn = pRight->u.zToken;
+        zTable = 0;
+        zColumn = pExpr->u.zToken;
       }else{
-        assert( pRight->op==TK_DOT );
-        zDb = pExpr->pLeft->u.zToken;
-        zTable = pRight->pLeft->u.zToken;
-        zColumn = pRight->pRight->u.zToken;
+        notValid(pParse, pNC, "the \".\" operator", NC_IdxExpr);
+        pRight = pExpr->pRight;
+        if( pRight->op==TK_ID ){
+          zDb = 0;
+          zTable = pExpr->pLeft->u.zToken;
+          zColumn = pRight->u.zToken;
+        }else{
+          assert( pRight->op==TK_DOT );
+          zDb = pExpr->pLeft->u.zToken;
+          zTable = pRight->pLeft->u.zToken;
+          zColumn = pRight->pRight->u.zToken;
+        }
       }
       return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr);
     }
@@ -81006,67 +90707,84 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       int no_such_func = 0;       /* True if no such function exists */
       int wrong_num_args = 0;     /* True if wrong number of arguments */
       int is_agg = 0;             /* True if is an aggregate function */
-      int auth;                   /* Authorization to use the function */
       int nId;                    /* Number of characters in function name */
       const char *zId;            /* The function name. */
       FuncDef *pDef;              /* Information about the function */
       u8 enc = ENC(pParse->db);   /* The database encoding */
 
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-      notValidPartIdxWhere(pParse, pNC, "functions");
       zId = pExpr->u.zToken;
       nId = sqlite3Strlen30(zId);
-      pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
+      pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0);
       if( pDef==0 ){
-        pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
+        pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0);
         if( pDef==0 ){
           no_such_func = 1;
         }else{
           wrong_num_args = 1;
         }
       }else{
-        is_agg = pDef->xFunc==0;
+        is_agg = pDef->xFinalize!=0;
         if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
           ExprSetProperty(pExpr, EP_Unlikely|EP_Skip);
           if( n==2 ){
             pExpr->iTable = exprProbability(pList->a[1].pExpr);
             if( pExpr->iTable<0 ){
-              sqlite3ErrorMsg(pParse, "second argument to likelihood() must be a "
-                                      "constant between 0.0 and 1.0");
+              sqlite3ErrorMsg(pParse,
+                "second argument to likelihood() must be a "
+                "constant between 0.0 and 1.0");
               pNC->nErr++;
             }
           }else{
-            /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is equivalent to
-            ** likelihood(X, 0.0625).
-            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is short-hand for
-            ** likelihood(X,0.0625).
-            ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand for
-            ** likelihood(X,0.9375).
-            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent to
-            ** likelihood(X,0.9375). */
+            /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is
+            ** equivalent to likelihood(X, 0.0625).
+            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is
+            ** short-hand for likelihood(X,0.0625).
+            ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand
+            ** for likelihood(X,0.9375).
+            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent
+            ** to likelihood(X,0.9375). */
             /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */
             pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120;
           }             
         }
 #ifndef SQLITE_OMIT_AUTHORIZATION
-        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
-        if( auth!=SQLITE_OK ){
-          if( auth==SQLITE_DENY ){
-            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
-                                    pDef->zName);
-            pNC->nErr++;
+        {
+          int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0);
+          if( auth!=SQLITE_OK ){
+            if( auth==SQLITE_DENY ){
+              sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
+                                      pDef->zName);
+              pNC->nErr++;
+            }
+            pExpr->op = TK_NULL;
+            return WRC_Prune;
           }
-          pExpr->op = TK_NULL;
-          return WRC_Prune;
         }
 #endif
-        if( pDef->funcFlags & SQLITE_FUNC_CONSTANT ) ExprSetProperty(pExpr,EP_Constant);
+        if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){
+          /* For the purposes of the EP_ConstFunc flag, date and time
+          ** functions and other functions that change slowly are considered
+          ** constant because they are constant for the duration of one query */
+          ExprSetProperty(pExpr,EP_ConstFunc);
+        }
+        if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){
+          /* Date/time functions that use 'now', and other functions like
+          ** sqlite_version() that might change over time cannot be used
+          ** in an index. */
+          notValid(pParse, pNC, "non-deterministic functions",
+                   NC_IdxExpr|NC_PartIdx);
+        }
       }
       if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
         pNC->nErr++;
         is_agg = 0;
-      }else if( no_such_func && pParse->db->init.busy==0 ){
+      }else if( no_such_func && pParse->db->init.busy==0
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+                && pParse->explain==0
+#endif
+      ){
         sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
         pNC->nErr++;
       }else if( wrong_num_args ){
@@ -81106,21 +90824,56 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_IN );
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         int nRef = pNC->nRef;
-        notValidCheckConstraint(pParse, pNC, "subqueries");
-        notValidPartIdxWhere(pParse, pNC, "subqueries");
+        notValid(pParse, pNC, "subqueries", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
         sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
         assert( pNC->nRef>=nRef );
         if( nRef!=pNC->nRef ){
           ExprSetProperty(pExpr, EP_VarSelect);
+          pNC->ncFlags |= NC_VarSelect;
         }
       }
       break;
     }
     case TK_VARIABLE: {
-      notValidCheckConstraint(pParse, pNC, "parameters");
-      notValidPartIdxWhere(pParse, pNC, "parameters");
+      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
       break;
     }
+    case TK_BETWEEN:
+    case TK_EQ:
+    case TK_NE:
+    case TK_LT:
+    case TK_LE:
+    case TK_GT:
+    case TK_GE:
+    case TK_IS:
+    case TK_ISNOT: {
+      int nLeft, nRight;
+      if( pParse->db->mallocFailed ) break;
+      assert( pExpr->pLeft!=0 );
+      nLeft = sqlite3ExprVectorSize(pExpr->pLeft);
+      if( pExpr->op==TK_BETWEEN ){
+        nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr);
+        if( nRight==nLeft ){
+          nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr);
+        }
+      }else{
+        assert( pExpr->pRight!=0 );
+        nRight = sqlite3ExprVectorSize(pExpr->pRight);
+      }
+      if( nLeft!=nRight ){
+        testcase( pExpr->op==TK_EQ );
+        testcase( pExpr->op==TK_NE );
+        testcase( pExpr->op==TK_LT );
+        testcase( pExpr->op==TK_LE );
+        testcase( pExpr->op==TK_GT );
+        testcase( pExpr->op==TK_GE );
+        testcase( pExpr->op==TK_IS );
+        testcase( pExpr->op==TK_ISNOT );
+        testcase( pExpr->op==TK_BETWEEN );
+        sqlite3ErrorMsg(pParse, "row value misused");
+      }
+      break; 
+    }
   }
   return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
 }
@@ -81211,7 +90964,7 @@ static int resolveOrderByTermToExprList(
   ** result-set entry.
   */
   for(i=0; inExpr; i++){
-    if( sqlite3ExprCompare(pEList->a[i].pExpr, pE, -1)<2 ){
+    if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){
       return i+1;
     }
   }
@@ -81312,9 +91065,11 @@ static int resolveCompoundOrderBy(
         if( pItem->pExpr==pE ){
           pItem->pExpr = pNew;
         }else{
-          assert( pItem->pExpr->op==TK_COLLATE );
-          assert( pItem->pExpr->pLeft==pE );
-          pItem->pExpr->pLeft = pNew;
+          Expr *pParent = pItem->pExpr;
+          assert( pParent->op==TK_COLLATE );
+          while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft;
+          assert( pParent->pLeft==pE );
+          pParent->pLeft = pNew;
         }
         sqlite3ExprDelete(db, pE);
         pItem->u.x.iOrderByCol = (u16)iCol;
@@ -81371,7 +91126,8 @@ SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(
         resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
         return 1;
       }
-      resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr, zType,0);
+      resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,
+                   zType,0);
     }
   }
   return 0;
@@ -81442,7 +91198,7 @@ static int resolveOrderGroupBy(
       return 1;
     }
     for(j=0; jpEList->nExpr; j++){
-      if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
+      if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
         pItem->u.x.iOrderByCol = j+1;
       }
     }
@@ -81459,7 +91215,6 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
   int isCompound;         /* True if p is a compound select */
   int nCompound;          /* Number of compound terms processed so far */
   Parse *pParse;          /* Parsing context */
-  ExprList *pEList;       /* Result set expression list */
   int i;                  /* Loop counter */
   ExprList *pGroupBy;     /* The GROUP BY clause */
   Select *pLeftmost;      /* Left-most of SELECT of a compound */
@@ -81504,6 +91259,20 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         sqlite3ResolveExprNames(&sNC, p->pOffset) ){
       return WRC_Abort;
     }
+
+    /* If the SF_Converted flags is set, then this Select object was
+    ** was created by the convertCompoundSelectToSubquery() function.
+    ** In this case the ORDER BY clause (p->pOrderBy) should be resolved
+    ** as if it were part of the sub-query, not the parent. This block
+    ** moves the pOrderBy down to the sub-query. It will be moved back
+    ** after the names have been resolved.  */
+    if( p->selFlags & SF_Converted ){
+      Select *pSub = p->pSrc->a[0].pSelect;
+      assert( p->pSrc->nSrc==1 && p->pOrderBy );
+      assert( pSub->pPrior && pSub->pOrderBy==0 );
+      pSub->pOrderBy = p->pOrderBy;
+      p->pOrderBy = 0;
+    }
   
     /* Recursively resolve names in all subqueries
     */
@@ -81518,7 +91287,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         ** parent contexts. After resolving references to expressions in
         ** pItem->pSelect, check if this value has changed. If so, then
         ** SELECT statement pItem->pSelect must be correlated. Set the
-        ** pItem->isCorrelated flag if this is the case. */
+        ** pItem->fg.isCorrelated flag if this is the case. */
         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;
 
         if( pItem->zName ) pParse->zAuthContext = pItem->zName;
@@ -81527,8 +91296,8 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         if( pParse->nErr || db->mallocFailed ) return WRC_Abort;
 
         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
-        assert( pItem->isCorrelated==0 && nRef<=0 );
-        pItem->isCorrelated = (nRef!=0);
+        assert( pItem->fg.isCorrelated==0 && nRef<=0 );
+        pItem->fg.isCorrelated = (nRef!=0);
       }
     }
   
@@ -81540,14 +91309,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     sNC.pNext = pOuterNC;
   
     /* Resolve names in the result set. */
-    pEList = p->pEList;
-    assert( pEList!=0 );
-    for(i=0; inExpr; i++){
-      Expr *pX = pEList->a[i].pExpr;
-      if( sqlite3ResolveExprNames(&sNC, pX) ){
-        return WRC_Abort;
-      }
-    }
+    if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort;
   
     /* If there are no aggregate functions in the result-set, and no GROUP BY 
     ** expression, do not allow aggregates in any of the other expressions.
@@ -81580,18 +91342,46 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
     if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
 
+    /* Resolve names in table-valued-function arguments */
+    for(i=0; ipSrc->nSrc; i++){
+      struct SrcList_item *pItem = &p->pSrc->a[i];
+      if( pItem->fg.isTabFunc
+       && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 
+      ){
+        return WRC_Abort;
+      }
+    }
+
     /* The ORDER BY and GROUP BY clauses may not refer to terms in
     ** outer queries 
     */
     sNC.pNext = 0;
     sNC.ncFlags |= NC_AllowAgg;
 
+    /* If this is a converted compound query, move the ORDER BY clause from 
+    ** the sub-query back to the parent query. At this point each term
+    ** within the ORDER BY clause has been transformed to an integer value.
+    ** These integers will be replaced by copies of the corresponding result
+    ** set expressions by the call to resolveOrderGroupBy() below.  */
+    if( p->selFlags & SF_Converted ){
+      Select *pSub = p->pSrc->a[0].pSelect;
+      p->pOrderBy = pSub->pOrderBy;
+      pSub->pOrderBy = 0;
+    }
+
     /* Process the ORDER BY clause for singleton SELECT statements.
     ** The ORDER BY clause for compounds SELECT statements is handled
     ** below, after all of the result-sets for all of the elements of
     ** the compound have been resolved.
+    **
+    ** If there is an ORDER BY clause on a term of a compound-select other
+    ** than the right-most term, then that is a syntax error.  But the error
+    ** is not detected until much later, and so we need to go ahead and
+    ** resolve those symbols on the incorrect ORDER BY for consistency.
     */
-    if( !isCompound && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") ){
+    if( isCompound<=nCompound  /* Defer right-most ORDER BY of a compound */
+     && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER")
+    ){
       return WRC_Abort;
     }
     if( db->mallocFailed ){
@@ -81616,6 +91406,13 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       }
     }
 
+    /* If this is part of a compound SELECT, check that it has the right
+    ** number of expressions in the select list. */
+    if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){
+      sqlite3SelectWrongNumTermsError(pParse, p->pNext);
+      return WRC_Abort;
+    }
+
     /* Advance to the next term of the compound
     */
     p = p->pPrior;
@@ -81687,37 +91484,48 @@ SQLITE_PRIVATE int sqlite3ResolveExprNames(
   u16 savedHasAgg;
   Walker w;
 
-  if( pExpr==0 ) return 0;
-#if SQLITE_MAX_EXPR_DEPTH>0
-  {
-    Parse *pParse = pNC->pParse;
-    if( sqlite3ExprCheckHeight(pParse, pExpr->nHeight+pNC->pParse->nHeight) ){
-      return 1;
-    }
-    pParse->nHeight += pExpr->nHeight;
-  }
-#endif
+  if( pExpr==0 ) return SQLITE_OK;
   savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
   pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
-  memset(&w, 0, sizeof(w));
+  w.pParse = pNC->pParse;
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
-  w.pParse = pNC->pParse;
+  w.xSelectCallback2 = 0;
   w.u.pNC = pNC;
+#if SQLITE_MAX_EXPR_DEPTH>0
+  w.pParse->nHeight += pExpr->nHeight;
+  if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){
+    return SQLITE_ERROR;
+  }
+#endif
   sqlite3WalkExpr(&w, pExpr);
 #if SQLITE_MAX_EXPR_DEPTH>0
-  pNC->pParse->nHeight -= pExpr->nHeight;
+  w.pParse->nHeight -= pExpr->nHeight;
 #endif
-  if( pNC->nErr>0 || w.pParse->nErr>0 ){
-    ExprSetProperty(pExpr, EP_Error);
-  }
   if( pNC->ncFlags & NC_HasAgg ){
     ExprSetProperty(pExpr, EP_Agg);
   }
   pNC->ncFlags |= savedHasAgg;
-  return ExprHasProperty(pExpr, EP_Error);
+  return pNC->nErr>0 || w.pParse->nErr>0;
 }
 
+/*
+** Resolve all names for all expression in an expression list.  This is
+** just like sqlite3ResolveExprNames() except that it works for an expression
+** list rather than a single expression.
+*/
+SQLITE_PRIVATE int sqlite3ResolveExprListNames( 
+  NameContext *pNC,       /* Namespace to resolve expressions in. */
+  ExprList *pList         /* The expression list to be analyzed. */
+){
+  int i;
+  if( pList ){
+    for(i=0; inExpr; i++){
+      if( sqlite3ResolveExprNames(pNC, pList->a[i].pExpr) ) return WRC_Abort;
+    }
+  }
+  return WRC_Continue;
+}
 
 /*
 ** Resolve all names in all expressions of a SELECT and in all
@@ -81739,9 +91547,9 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
   Walker w;
 
   assert( p!=0 );
-  memset(&w, 0, sizeof(w));
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
+  w.xSelectCallback2 = 0;
   w.pParse = pParse;
   w.u.pNC = pOuterNC;
   sqlite3WalkSelect(&w, p);
@@ -81761,15 +91569,14 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
 SQLITE_PRIVATE void sqlite3ResolveSelfReference(
   Parse *pParse,      /* Parsing context */
   Table *pTab,        /* The table being referenced */
-  int type,           /* NC_IsCheck or NC_PartIdx */
+  int type,           /* NC_IsCheck or NC_PartIdx or NC_IdxExpr */
   Expr *pExpr,        /* Expression to resolve.  May be NULL. */
   ExprList *pList     /* Expression list to resolve.  May be NUL. */
 ){
   SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
   NameContext sNC;                /* Name context for pParse->pNewTable */
-  int i;                          /* Loop counter */
 
-  assert( type==NC_IsCheck || type==NC_PartIdx );
+  assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr );
   memset(&sNC, 0, sizeof(sNC));
   memset(&sSrc, 0, sizeof(sSrc));
   sSrc.nSrc = 1;
@@ -81780,13 +91587,7 @@ SQLITE_PRIVATE void sqlite3ResolveSelfReference(
   sNC.pSrcList = &sSrc;
   sNC.ncFlags = type;
   if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
-  if( pList ){
-    for(i=0; inExpr; i++){
-      if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
-        return;
-      }
-    }
-  }
+  if( pList ) sqlite3ResolveExprListNames(&sNC, pList);
 }
 
 /************** End of resolve.c *********************************************/
@@ -81805,6 +91606,19 @@ SQLITE_PRIVATE void sqlite3ResolveSelfReference(
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 */
+/* #include "sqliteInt.h" */
+
+/* Forward declarations */
+static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
+static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);
+
+/*
+** Return the affinity character for a single column of a table.
+*/
+SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table *pTab, int iCol){
+  assert( iColnCol );
+  return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
+}
 
 /*
 ** Return the 'affinity' of the expression pExpr if any.
@@ -81831,21 +91645,21 @@ SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){
     assert( pExpr->flags&EP_xIsSelect );
     return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
   }
+  if( op==TK_REGISTER ) op = pExpr->op2;
 #ifndef SQLITE_OMIT_CAST
   if( op==TK_CAST ){
     assert( !ExprHasProperty(pExpr, EP_IntValue) );
     return sqlite3AffinityType(pExpr->u.zToken, 0);
   }
 #endif
-  if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER) 
-   && pExpr->pTab!=0
-  ){
-    /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
-    ** a TK_COLUMN but was previously evaluated and cached in a register */
-    int j = pExpr->iColumn;
-    if( j<0 ) return SQLITE_AFF_INTEGER;
-    assert( pExpr->pTab && jpTab->nCol );
-    return pExpr->pTab->aCol[j].affinity;
+  if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->pTab ){
+    return sqlite3TableColumnAffinity(pExpr->pTab, pExpr->iColumn);
+  }
+  if( op==TK_SELECT_COLUMN ){
+    assert( pExpr->pLeft->flags&EP_xIsSelect );
+    return sqlite3ExprAffinity(
+        pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
+    );
   }
   return pExpr->affinity;
 }
@@ -81861,10 +91675,11 @@ SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){
 SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(
   Parse *pParse,           /* Parsing context */
   Expr *pExpr,             /* Add the "COLLATE" clause to this expression */
-  const Token *pCollName   /* Name of collating sequence */
+  const Token *pCollName,  /* Name of collating sequence */
+  int dequote              /* True to dequote pCollName */
 ){
   if( pCollName->n>0 ){
-    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, 1);
+    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
     if( pNew ){
       pNew->pLeft = pExpr;
       pNew->flags |= EP_Collate|EP_Skip;
@@ -81876,13 +91691,12 @@ SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(
 SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
   Token s;
   assert( zC!=0 );
-  s.z = zC;
-  s.n = sqlite3Strlen30(s.z);
-  return sqlite3ExprAddCollateToken(pParse, pExpr, &s);
+  sqlite3TokenInit(&s, (char*)zC);
+  return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
 }
 
 /*
-** Skip over any TK_COLLATE or TK_AS operators and any unlikely()
+** Skip over any TK_COLLATE operators and any unlikely()
 ** or likelihood() function at the root of an expression.
 */
 SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr *pExpr){
@@ -81893,7 +91707,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr *pExpr){
       assert( pExpr->op==TK_FUNCTION );
       pExpr = pExpr->x.pList->a[0].pExpr;
     }else{
-      assert( pExpr->op==TK_COLLATE || pExpr->op==TK_AS );
+      assert( pExpr->op==TK_COLLATE );
       pExpr = pExpr->pLeft;
     }
   }   
@@ -81924,9 +91738,9 @@ SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
       pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
       break;
     }
-    if( p->pTab!=0
-     && (op==TK_AGG_COLUMN || op==TK_COLUMN
+    if( (op==TK_AGG_COLUMN || op==TK_COLUMN
           || op==TK_REGISTER || op==TK_TRIGGER)
+     && p->pTab!=0
     ){
       /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
       ** a TK_COLUMN but was previously evaluated and cached in a register */
@@ -81938,10 +91752,25 @@ SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
       break;
     }
     if( p->flags & EP_Collate ){
-      if( ALWAYS(p->pLeft) && (p->pLeft->flags & EP_Collate)!=0 ){
+      if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
         p = p->pLeft;
       }else{
-        p = p->pRight;
+        Expr *pNext  = p->pRight;
+        /* The Expr.x union is never used at the same time as Expr.pRight */
+        assert( p->x.pList==0 || p->pRight==0 );
+        /* p->flags holds EP_Collate and p->pLeft->flags does not.  And
+        ** p->x.pSelect cannot.  So if p->x.pLeft exists, it must hold at
+        ** least one EP_Collate. Thus the following two ALWAYS. */
+        if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){
+          int i;
+          for(i=0; ALWAYS(ix.pList->nExpr); i++){
+            if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
+              pNext = p->x.pList->a[i].pExpr;
+              break;
+            }
+          }
+        }
+        p = pNext;
       }
     }else{
       break;
@@ -81967,13 +91796,13 @@ SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2){
     if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
       return SQLITE_AFF_NUMERIC;
     }else{
-      return SQLITE_AFF_NONE;
+      return SQLITE_AFF_BLOB;
     }
   }else if( !aff1 && !aff2 ){
     /* Neither side of the comparison is a column.  Compare the
     ** results directly.
     */
-    return SQLITE_AFF_NONE;
+    return SQLITE_AFF_BLOB;
   }else{
     /* One side is a column, the other is not. Use the columns affinity. */
     assert( aff1==0 || aff2==0 );
@@ -81996,8 +91825,8 @@ static char comparisonAffinity(Expr *pExpr){
     aff = sqlite3CompareAffinity(pExpr->pRight, aff);
   }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
     aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
-  }else if( !aff ){
-    aff = SQLITE_AFF_NONE;
+  }else if( aff==0 ){
+    aff = SQLITE_AFF_BLOB;
   }
   return aff;
 }
@@ -82011,7 +91840,7 @@ static char comparisonAffinity(Expr *pExpr){
 SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
   char aff = comparisonAffinity(pExpr);
   switch( aff ){
-    case SQLITE_AFF_NONE:
+    case SQLITE_AFF_BLOB:
       return 1;
     case SQLITE_AFF_TEXT:
       return idx_affinity==SQLITE_AFF_TEXT;
@@ -82086,6 +91915,270 @@ static int codeCompare(
   return addr;
 }
 
+/*
+** Return true if expression pExpr is a vector, or false otherwise.
+**
+** A vector is defined as any expression that results in two or more
+** columns of result.  Every TK_VECTOR node is an vector because the
+** parser will not generate a TK_VECTOR with fewer than two entries.
+** But a TK_SELECT might be either a vector or a scalar. It is only
+** considered a vector if it has two or more result columns.
+*/
+SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr){
+  return sqlite3ExprVectorSize(pExpr)>1;
+}
+
+/*
+** If the expression passed as the only argument is of type TK_VECTOR 
+** return the number of expressions in the vector. Or, if the expression
+** is a sub-select, return the number of columns in the sub-select. For
+** any other type of expression, return 1.
+*/
+SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr){
+  u8 op = pExpr->op;
+  if( op==TK_REGISTER ) op = pExpr->op2;
+  if( op==TK_VECTOR ){
+    return pExpr->x.pList->nExpr;
+  }else if( op==TK_SELECT ){
+    return pExpr->x.pSelect->pEList->nExpr;
+  }else{
+    return 1;
+  }
+}
+
+/*
+** Return a pointer to a subexpression of pVector that is the i-th
+** column of the vector (numbered starting with 0).  The caller must
+** ensure that i is within range.
+**
+** If pVector is really a scalar (and "scalar" here includes subqueries
+** that return a single column!) then return pVector unmodified.
+**
+** pVector retains ownership of the returned subexpression.
+**
+** If the vector is a (SELECT ...) then the expression returned is
+** just the expression for the i-th term of the result set, and may
+** not be ready for evaluation because the table cursor has not yet
+** been positioned.
+*/
+SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
+  assert( iop2==0 || pVector->op==TK_REGISTER );
+    if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
+      return pVector->x.pSelect->pEList->a[i].pExpr;
+    }else{
+      return pVector->x.pList->a[i].pExpr;
+    }
+  }
+  return pVector;
+}
+
+/*
+** Compute and return a new Expr object which when passed to
+** sqlite3ExprCode() will generate all necessary code to compute
+** the iField-th column of the vector expression pVector.
+**
+** It is ok for pVector to be a scalar (as long as iField==0).  
+** In that case, this routine works like sqlite3ExprDup().
+**
+** The caller owns the returned Expr object and is responsible for
+** ensuring that the returned value eventually gets freed.
+**
+** The caller retains ownership of pVector.  If pVector is a TK_SELECT,
+** then the returned object will reference pVector and so pVector must remain
+** valid for the life of the returned object.  If pVector is a TK_VECTOR
+** or a scalar expression, then it can be deleted as soon as this routine
+** returns.
+**
+** A trick to cause a TK_SELECT pVector to be deleted together with
+** the returned Expr object is to attach the pVector to the pRight field
+** of the returned TK_SELECT_COLUMN Expr object.
+*/
+SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(
+  Parse *pParse,       /* Parsing context */
+  Expr *pVector,       /* The vector.  List of expressions or a sub-SELECT */
+  int iField           /* Which column of the vector to return */
+){
+  Expr *pRet;
+  if( pVector->op==TK_SELECT ){
+    assert( pVector->flags & EP_xIsSelect );
+    /* The TK_SELECT_COLUMN Expr node:
+    **
+    ** pLeft:           pVector containing TK_SELECT.  Not deleted.
+    ** pRight:          not used.  But recursively deleted.
+    ** iColumn:         Index of a column in pVector
+    ** iTable:          0 or the number of columns on the LHS of an assignment
+    ** pLeft->iTable:   First in an array of register holding result, or 0
+    **                  if the result is not yet computed.
+    **
+    ** sqlite3ExprDelete() specifically skips the recursive delete of
+    ** pLeft on TK_SELECT_COLUMN nodes.  But pRight is followed, so pVector
+    ** can be attached to pRight to cause this node to take ownership of
+    ** pVector.  Typically there will be multiple TK_SELECT_COLUMN nodes
+    ** with the same pLeft pointer to the pVector, but only one of them
+    ** will own the pVector.
+    */
+    pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);
+    if( pRet ){
+      pRet->iColumn = iField;
+      pRet->pLeft = pVector;
+    }
+    assert( pRet==0 || pRet->iTable==0 );
+  }else{
+    if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
+    pRet = sqlite3ExprDup(pParse->db, pVector, 0);
+  }
+  return pRet;
+}
+
+/*
+** If expression pExpr is of type TK_SELECT, generate code to evaluate
+** it. Return the register in which the result is stored (or, if the 
+** sub-select returns more than one column, the first in an array
+** of registers in which the result is stored).
+**
+** If pExpr is not a TK_SELECT expression, return 0.
+*/
+static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
+  int reg = 0;
+#ifndef SQLITE_OMIT_SUBQUERY
+  if( pExpr->op==TK_SELECT ){
+    reg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
+  }
+#endif
+  return reg;
+}
+
+/*
+** Argument pVector points to a vector expression - either a TK_VECTOR
+** or TK_SELECT that returns more than one column. This function returns
+** the register number of a register that contains the value of
+** element iField of the vector.
+**
+** If pVector is a TK_SELECT expression, then code for it must have 
+** already been generated using the exprCodeSubselect() routine. In this
+** case parameter regSelect should be the first in an array of registers
+** containing the results of the sub-select. 
+**
+** If pVector is of type TK_VECTOR, then code for the requested field
+** is generated. In this case (*pRegFree) may be set to the number of
+** a temporary register to be freed by the caller before returning.
+**
+** Before returning, output parameter (*ppExpr) is set to point to the
+** Expr object corresponding to element iElem of the vector.
+*/
+static int exprVectorRegister(
+  Parse *pParse,                  /* Parse context */
+  Expr *pVector,                  /* Vector to extract element from */
+  int iField,                     /* Field to extract from pVector */
+  int regSelect,                  /* First in array of registers */
+  Expr **ppExpr,                  /* OUT: Expression element */
+  int *pRegFree                   /* OUT: Temp register to free */
+){
+  u8 op = pVector->op;
+  assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );
+  if( op==TK_REGISTER ){
+    *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
+    return pVector->iTable+iField;
+  }
+  if( op==TK_SELECT ){
+    *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
+     return regSelect+iField;
+  }
+  *ppExpr = pVector->x.pList->a[iField].pExpr;
+  return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
+}
+
+/*
+** Expression pExpr is a comparison between two vector values. Compute
+** the result of the comparison (1, 0, or NULL) and write that
+** result into register dest.
+**
+** The caller must satisfy the following preconditions:
+**
+**    if pExpr->op==TK_IS:      op==TK_EQ and p5==SQLITE_NULLEQ
+**    if pExpr->op==TK_ISNOT:   op==TK_NE and p5==SQLITE_NULLEQ
+**    otherwise:                op==pExpr->op and p5==0
+*/
+static void codeVectorCompare(
+  Parse *pParse,        /* Code generator context */
+  Expr *pExpr,          /* The comparison operation */
+  int dest,             /* Write results into this register */
+  u8 op,                /* Comparison operator */
+  u8 p5                 /* SQLITE_NULLEQ or zero */
+){
+  Vdbe *v = pParse->pVdbe;
+  Expr *pLeft = pExpr->pLeft;
+  Expr *pRight = pExpr->pRight;
+  int nLeft = sqlite3ExprVectorSize(pLeft);
+  int i;
+  int regLeft = 0;
+  int regRight = 0;
+  u8 opx = op;
+  int addrDone = sqlite3VdbeMakeLabel(v);
+
+  if( nLeft!=sqlite3ExprVectorSize(pRight) ){
+    sqlite3ErrorMsg(pParse, "row value misused");
+    return;
+  }
+  assert( pExpr->op==TK_EQ || pExpr->op==TK_NE 
+       || pExpr->op==TK_IS || pExpr->op==TK_ISNOT 
+       || pExpr->op==TK_LT || pExpr->op==TK_GT 
+       || pExpr->op==TK_LE || pExpr->op==TK_GE 
+  );
+  assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
+            || (pExpr->op==TK_ISNOT && op==TK_NE) );
+  assert( p5==0 || pExpr->op!=op );
+  assert( p5==SQLITE_NULLEQ || pExpr->op==op );
+
+  p5 |= SQLITE_STOREP2;
+  if( opx==TK_LE ) opx = TK_LT;
+  if( opx==TK_GE ) opx = TK_GT;
+
+  regLeft = exprCodeSubselect(pParse, pLeft);
+  regRight = exprCodeSubselect(pParse, pRight);
+
+  for(i=0; 1 /*Loop exits by "break"*/; i++){
+    int regFree1 = 0, regFree2 = 0;
+    Expr *pL, *pR; 
+    int r1, r2;
+    assert( i>=0 && i0 ) sqlite3ExprCachePush(pParse);
+    r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1);
+    r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2);
+    codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5);
+    testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
+    testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
+    testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
+    testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
+    testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
+    testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
+    sqlite3ReleaseTempReg(pParse, regFree1);
+    sqlite3ReleaseTempReg(pParse, regFree2);
+    if( i>0 ) sqlite3ExprCachePop(pParse);
+    if( i==nLeft-1 ){
+      break;
+    }
+    if( opx==TK_EQ ){
+      sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);
+      p5 |= SQLITE_KEEPNULL;
+    }else if( opx==TK_NE ){
+      sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);
+      p5 |= SQLITE_KEEPNULL;
+    }else{
+      assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
+      sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);
+      VdbeCoverageIf(v, op==TK_LT);
+      VdbeCoverageIf(v, op==TK_GT);
+      VdbeCoverageIf(v, op==TK_LE);
+      VdbeCoverageIf(v, op==TK_GE);
+      if( i==nLeft-2 ) opx = op;
+    }
+  }
+  sqlite3VdbeResolveLabel(v, addrDone);
+}
+
 #if SQLITE_MAX_EXPR_DEPTH>0
 /*
 ** Check that argument nHeight is less than or equal to the maximum
@@ -82147,6 +92240,9 @@ static void heightOfSelect(Select *p, int *pnHeight){
 ** Expr.pSelect member has a height of 1. Any other expression
 ** has a height equal to the maximum height of any other 
 ** referenced Expr plus one.
+**
+** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
+** if appropriate.
 */
 static void exprSetHeight(Expr *p){
   int nHeight = 0;
@@ -82154,8 +92250,9 @@ static void exprSetHeight(Expr *p){
   heightOfExpr(p->pRight, &nHeight);
   if( ExprHasProperty(p, EP_xIsSelect) ){
     heightOfSelect(p->x.pSelect, &nHeight);
-  }else{
+  }else if( p->x.pList ){
     heightOfExprList(p->x.pList, &nHeight);
+    p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
   }
   p->nHeight = nHeight + 1;
 }
@@ -82164,8 +92261,12 @@ static void exprSetHeight(Expr *p){
 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
 ** the height is greater than the maximum allowed expression depth,
 ** leave an error in pParse.
+**
+** Also propagate all EP_Propagate flags from the Expr.x.pList into
+** Expr.flags. 
 */
-SQLITE_PRIVATE void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
+  if( pParse->nErr ) return;
   exprSetHeight(p);
   sqlite3ExprCheckHeight(pParse, p->nHeight);
 }
@@ -82179,8 +92280,17 @@ SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){
   heightOfSelect(p, &nHeight);
   return nHeight;
 }
-#else
-  #define exprSetHeight(y)
+#else /* ABOVE:  Height enforcement enabled.  BELOW: Height enforcement off */
+/*
+** Propagate all EP_Propagate flags from the Expr.x.pList into
+** Expr.flags. 
+*/
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
+  if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
+    p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
+  }
+}
+#define exprSetHeight(y)
 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
 
 /*
@@ -82192,7 +92302,7 @@ SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){
 ** is responsible for making sure the node eventually gets freed.
 **
 ** If dequote is true, then the token (if it exists) is dequoted.
-** If dequote is false, no dequoting is performance.  The deQuote
+** If dequote is false, no dequoting is performed.  The deQuote
 ** parameter is ignored if pToken is NULL or if the token does not
 ** appear to be quoted.  If the quotes were of the form "..." (double-quotes)
 ** then the EP_DblQuoted flag is set on the expression node.
@@ -82204,7 +92314,7 @@ SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){
 ** is allocated to hold the integer text and the dequote flag is ignored.
 */
 SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
-  sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */
+  sqlite3 *db,            /* Handle for sqlite3DbMallocRawNN() */
   int op,                 /* Expression opcode */
   const Token *pToken,    /* Token argument.  Might be NULL */
   int dequote             /* True to dequote */
@@ -82213,6 +92323,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
   int nExtra = 0;
   int iValue = 0;
 
+  assert( db!=0 );
   if( pToken ){
     if( op!=TK_INTEGER || pToken->z==0
           || sqlite3GetInt32(pToken->z, &iValue)==0 ){
@@ -82220,24 +92331,23 @@ SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
       assert( iValue>=0 );
     }
   }
-  pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
+  pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
   if( pNew ){
+    memset(pNew, 0, sizeof(Expr));
     pNew->op = (u8)op;
     pNew->iAgg = -1;
     if( pToken ){
       if( nExtra==0 ){
-        pNew->flags |= EP_IntValue;
+        pNew->flags |= EP_IntValue|EP_Leaf;
         pNew->u.iValue = iValue;
       }else{
-        int c;
         pNew->u.zToken = (char*)&pNew[1];
         assert( pToken->z!=0 || pToken->n==0 );
         if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
         pNew->u.zToken[pToken->n] = 0;
-        if( dequote && nExtra>=3 
-             && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){
+        if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
+          if( pNew->u.zToken[0]=='"' ) pNew->flags |= EP_DblQuoted;
           sqlite3Dequote(pNew->u.zToken);
-          if( c=='"' ) pNew->flags |= EP_DblQuoted;
         }
       }
     }
@@ -82282,11 +92392,11 @@ SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(
   }else{
     if( pRight ){
       pRoot->pRight = pRight;
-      pRoot->flags |= EP_Collate & pRight->flags;
+      pRoot->flags |= EP_Propagate & pRight->flags;
     }
     if( pLeft ){
       pRoot->pLeft = pLeft;
-      pRoot->flags |= EP_Collate & pLeft->flags;
+      pRoot->flags |= EP_Propagate & pLeft->flags;
     }
     exprSetHeight(pRoot);
   }
@@ -82303,15 +92413,19 @@ SQLITE_PRIVATE Expr *sqlite3PExpr(
   Parse *pParse,          /* Parsing context */
   int op,                 /* Expression opcode */
   Expr *pLeft,            /* Left operand */
-  Expr *pRight,           /* Right operand */
-  const Token *pToken     /* Argument token */
+  Expr *pRight            /* Right operand */
 ){
   Expr *p;
-  if( op==TK_AND && pLeft && pRight && pParse->nErr==0 ){
+  if( op==TK_AND && pParse->nErr==0 ){
     /* Take advantage of short-circuit false optimization for AND */
     p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
   }else{
-    p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
+    p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
+    if( p ){
+      memset(p, 0, sizeof(Expr));
+      p->op = op & TKFLG_MASK;
+      p->iAgg = -1;
+    }
     sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
   }
   if( p ) {
@@ -82320,6 +92434,22 @@ SQLITE_PRIVATE Expr *sqlite3PExpr(
   return p;
 }
 
+/*
+** Add pSelect to the Expr.x.pSelect field.  Or, if pExpr is NULL (due
+** do a memory allocation failure) then delete the pSelect object.
+*/
+SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
+  if( pExpr ){
+    pExpr->x.pSelect = pSelect;
+    ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
+    sqlite3ExprSetHeightAndFlags(pParse, pExpr);
+  }else{
+    assert( pParse->db->mallocFailed );
+    sqlite3SelectDelete(pParse->db, pSelect);
+  }
+}
+
+
 /*
 ** If the expression is always either TRUE or FALSE (respectively),
 ** then return 1.  If one cannot determine the truth value of the
@@ -82386,7 +92516,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *
   }
   pNew->x.pList = pList;
   assert( !ExprHasProperty(pNew, EP_xIsSelect) );
-  sqlite3ExprSetHeight(pParse, pNew);
+  sqlite3ExprSetHeightAndFlags(pParse, pNew);
   return pNew;
 }
 
@@ -82398,7 +92528,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *
 ** variable number.
 **
 ** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
-** sure "nnn" is not too be to avoid a denial of service attack when
+** sure "nnn" is not too big to avoid a denial of service attack when
 ** the SQL statement comes from an external source.
 **
 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
@@ -82406,28 +92536,34 @@ SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *
 ** instance of the wildcard, the next sequential variable number is
 ** assigned.
 */
-SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
+SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
   sqlite3 *db = pParse->db;
   const char *z;
+  ynVar x;
 
   if( pExpr==0 ) return;
   assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
   z = pExpr->u.zToken;
   assert( z!=0 );
   assert( z[0]!=0 );
+  assert( n==(u32)sqlite3Strlen30(z) );
   if( z[1]==0 ){
     /* Wildcard of the form "?".  Assign the next variable number */
     assert( z[0]=='?' );
-    pExpr->iColumn = (ynVar)(++pParse->nVar);
+    x = (ynVar)(++pParse->nVar);
   }else{
-    ynVar x = 0;
-    u32 n = sqlite3Strlen30(z);
+    int doAdd = 0;
     if( z[0]=='?' ){
       /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
       ** use it as the variable number */
       i64 i;
-      int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
-      pExpr->iColumn = x = (ynVar)i;
+      int bOk;
+      if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/
+        i = z[1]-'0';  /* The common case of ?N for a single digit N */
+        bOk = 1;
+      }else{
+        bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
+      }
       testcase( i==0 );
       testcase( i==1 );
       testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
@@ -82435,41 +92571,32 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
       if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
         sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
             db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
-        x = 0;
+        return;
       }
-      if( i>pParse->nVar ){
-        pParse->nVar = (int)i;
+      x = (ynVar)i;
+      if( x>pParse->nVar ){
+        pParse->nVar = (int)x;
+        doAdd = 1;
+      }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){
+        doAdd = 1;
       }
     }else{
       /* Wildcards like ":aaa", "$aaa" or "@aaa".  Reuse the same variable
       ** number as the prior appearance of the same name, or if the name
       ** has never appeared before, reuse the same variable number
       */
-      ynVar i;
-      for(i=0; inzVar; i++){
-        if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
-          pExpr->iColumn = x = (ynVar)i+1;
-          break;
-        }
+      x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
+      if( x==0 ){
+        x = (ynVar)(++pParse->nVar);
+        doAdd = 1;
       }
-      if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
     }
-    if( x>0 ){
-      if( x>pParse->nzVar ){
-        char **a;
-        a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
-        if( a==0 ) return;  /* Error reported through db->mallocFailed */
-        pParse->azVar = a;
-        memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
-        pParse->nzVar = x;
-      }
-      if( z[0]!='?' || pParse->azVar[x-1]==0 ){
-        sqlite3DbFree(db, pParse->azVar[x-1]);
-        pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
-      }
+    if( doAdd ){
+      pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
     }
-  } 
-  if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
+  }
+  pExpr->iColumn = x;
+  if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
     sqlite3ErrorMsg(pParse, "too many SQL variables");
   }
 }
@@ -82477,26 +92604,37 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
 /*
 ** Recursively delete an expression tree.
 */
-SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){
-  if( p==0 ) return;
+static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
+  assert( p!=0 );
   /* Sanity check: Assert that the IntValue is non-negative if it exists */
   assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
-  if( !ExprHasProperty(p, EP_TokenOnly) ){
+#ifdef SQLITE_DEBUG
+  if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){
+    assert( p->pLeft==0 );
+    assert( p->pRight==0 );
+    assert( p->x.pSelect==0 );
+  }
+#endif
+  if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
     /* The Expr.x union is never used at the same time as Expr.pRight */
     assert( p->x.pList==0 || p->pRight==0 );
-    sqlite3ExprDelete(db, p->pLeft);
-    sqlite3ExprDelete(db, p->pRight);
-    if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
-    if( ExprHasProperty(p, EP_xIsSelect) ){
+    if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
+    if( p->pRight ){
+      sqlite3ExprDeleteNN(db, p->pRight);
+    }else if( ExprHasProperty(p, EP_xIsSelect) ){
       sqlite3SelectDelete(db, p->x.pSelect);
     }else{
       sqlite3ExprListDelete(db, p->x.pList);
     }
   }
+  if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
   if( !ExprHasProperty(p, EP_Static) ){
-    sqlite3DbFree(db, p);
+    sqlite3DbFreeNN(db, p);
   }
 }
+SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){
+  if( p ) sqlite3ExprDeleteNN(db, p);
+}
 
 /*
 ** Return the number of bytes allocated for the expression structure 
@@ -82548,7 +92686,7 @@ static int dupedExprStructSize(Expr *p, int flags){
   assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
   assert( EXPR_FULLSIZE<=0xfff );
   assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
-  if( 0==(flags&EXPRDUP_REDUCE) ){
+  if( 0==flags || p->op==TK_SELECT_COLUMN ){
     nSize = EXPR_FULLSIZE;
   }else{
     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
@@ -82610,84 +92748,94 @@ static int dupedExprSize(Expr *p, int flags){
 ** if any. Before returning, *pzBuffer is set to the first byte past the
 ** portion of the buffer copied into by this function.
 */
-static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
-  Expr *pNew = 0;                      /* Value to return */
-  if( p ){
-    const int isReduced = (flags&EXPRDUP_REDUCE);
-    u8 *zAlloc;
-    u32 staticFlag = 0;
+static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
+  Expr *pNew;           /* Value to return */
+  u8 *zAlloc;           /* Memory space from which to build Expr object */
+  u32 staticFlag;       /* EP_Static if space not obtained from malloc */
+
+  assert( db!=0 );
+  assert( p );
+  assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
+  assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
 
-    assert( pzBuffer==0 || isReduced );
+  /* Figure out where to write the new Expr structure. */
+  if( pzBuffer ){
+    zAlloc = *pzBuffer;
+    staticFlag = EP_Static;
+  }else{
+    zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
+    staticFlag = 0;
+  }
+  pNew = (Expr *)zAlloc;
 
-    /* Figure out where to write the new Expr structure. */
-    if( pzBuffer ){
-      zAlloc = *pzBuffer;
-      staticFlag = EP_Static;
+  if( pNew ){
+    /* Set nNewSize to the size allocated for the structure pointed to
+    ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
+    ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
+    ** by the copy of the p->u.zToken string (if any).
+    */
+    const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
+    const int nNewSize = nStructSize & 0xfff;
+    int nToken;
+    if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
+      nToken = sqlite3Strlen30(p->u.zToken) + 1;
     }else{
-      zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
+      nToken = 0;
     }
-    pNew = (Expr *)zAlloc;
-
-    if( pNew ){
-      /* Set nNewSize to the size allocated for the structure pointed to
-      ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
-      ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
-      ** by the copy of the p->u.zToken string (if any).
-      */
-      const unsigned nStructSize = dupedExprStructSize(p, flags);
-      const int nNewSize = nStructSize & 0xfff;
-      int nToken;
-      if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
-        nToken = sqlite3Strlen30(p->u.zToken) + 1;
-      }else{
-        nToken = 0;
-      }
-      if( isReduced ){
-        assert( ExprHasProperty(p, EP_Reduced)==0 );
-        memcpy(zAlloc, p, nNewSize);
-      }else{
-        int nSize = exprStructSize(p);
-        memcpy(zAlloc, p, nSize);
+    if( dupFlags ){
+      assert( ExprHasProperty(p, EP_Reduced)==0 );
+      memcpy(zAlloc, p, nNewSize);
+    }else{
+      u32 nSize = (u32)exprStructSize(p);
+      memcpy(zAlloc, p, nSize);
+      if( nSizeflags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
-      pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
-      pNew->flags |= staticFlag;
+    /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
+    pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
+    pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
+    pNew->flags |= staticFlag;
 
-      /* Copy the p->u.zToken string, if any. */
-      if( nToken ){
-        char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
-        memcpy(zToken, p->u.zToken, nToken);
-      }
+    /* Copy the p->u.zToken string, if any. */
+    if( nToken ){
+      char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
+      memcpy(zToken, p->u.zToken, nToken);
+    }
 
-      if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
-        /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
-        if( ExprHasProperty(p, EP_xIsSelect) ){
-          pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
-        }else{
-          pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
-        }
+    if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
+      /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
+      if( ExprHasProperty(p, EP_xIsSelect) ){
+        pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
+      }else{
+        pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
       }
+    }
 
-      /* Fill in pNew->pLeft and pNew->pRight. */
-      if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
-        zAlloc += dupedExprNodeSize(p, flags);
-        if( ExprHasProperty(pNew, EP_Reduced) ){
-          pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
-          pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
-        }
-        if( pzBuffer ){
-          *pzBuffer = zAlloc;
-        }
-      }else{
-        if( !ExprHasProperty(p, EP_TokenOnly) ){
+    /* Fill in pNew->pLeft and pNew->pRight. */
+    if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
+      zAlloc += dupedExprNodeSize(p, dupFlags);
+      if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){
+        pNew->pLeft = p->pLeft ?
+                      exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
+        pNew->pRight = p->pRight ?
+                       exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
+      }
+      if( pzBuffer ){
+        *pzBuffer = zAlloc;
+      }
+    }else{
+      if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
+        if( pNew->op==TK_SELECT_COLUMN ){
+          pNew->pLeft = p->pLeft;
+          assert( p->iColumn==0 || p->pRight==0 );
+          assert( p->pRight==0  || p->pRight==p->pLeft );
+        }else{
           pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
-          pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
         }
+        pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
       }
-
     }
   }
   return pNew;
@@ -82738,26 +92886,42 @@ static With *withDup(sqlite3 *db, With *p){
 ** part of the in-memory representation of the database schema.
 */
 SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
-  return exprDup(db, p, flags, 0);
+  assert( flags==0 || flags==EXPRDUP_REDUCE );
+  return p ? exprDup(db, p, flags, 0) : 0;
 }
 SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
   ExprList *pNew;
   struct ExprList_item *pItem, *pOldItem;
   int i;
+  Expr *pPriorSelectCol = 0;
+  assert( db!=0 );
   if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  pNew = sqlite3DbMallocRawNN(db, 
+             sizeof(*pNew)+sizeof(pNew->a[0])*(p->nExpr-1) );
   if( pNew==0 ) return 0;
-  pNew->nExpr = i = p->nExpr;
-  if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; inExpr; i+=i){}
-  pNew->a = pItem = sqlite3DbMallocRaw(db,  i*sizeof(p->a[0]) );
-  if( pItem==0 ){
-    sqlite3DbFree(db, pNew);
-    return 0;
-  } 
+  pNew->nAlloc = pNew->nExpr = p->nExpr;
+  pItem = pNew->a;
   pOldItem = p->a;
   for(i=0; inExpr; i++, pItem++, pOldItem++){
     Expr *pOldExpr = pOldItem->pExpr;
+    Expr *pNewExpr;
     pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
+    if( pOldExpr 
+     && pOldExpr->op==TK_SELECT_COLUMN
+     && (pNewExpr = pItem->pExpr)!=0 
+    ){
+      assert( pNewExpr->iColumn==0 || i>0 );
+      if( pNewExpr->iColumn==0 ){
+        assert( pOldExpr->pLeft==pOldExpr->pRight );
+        pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;
+      }else{
+        assert( i>0 );
+        assert( pItem[-1].pExpr!=0 );
+        assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
+        assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
+        pNewExpr->pLeft = pPriorSelectCol;
+      }
+    }
     pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
     pItem->sortOrder = pOldItem->sortOrder;
@@ -82780,9 +92944,10 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
   SrcList *pNew;
   int i;
   int nByte;
+  assert( db!=0 );
   if( p==0 ) return 0;
   nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
-  pNew = sqlite3DbMallocRaw(db, nByte );
+  pNew = sqlite3DbMallocRawNN(db, nByte );
   if( pNew==0 ) return 0;
   pNew->nSrc = pNew->nAlloc = p->nSrc;
   for(i=0; inSrc; i++){
@@ -82793,19 +92958,21 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
     pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
     pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
-    pNewItem->jointype = pOldItem->jointype;
+    pNewItem->fg = pOldItem->fg;
     pNewItem->iCursor = pOldItem->iCursor;
     pNewItem->addrFillSub = pOldItem->addrFillSub;
     pNewItem->regReturn = pOldItem->regReturn;
-    pNewItem->isCorrelated = pOldItem->isCorrelated;
-    pNewItem->viaCoroutine = pOldItem->viaCoroutine;
-    pNewItem->isRecursive = pOldItem->isRecursive;
-    pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
-    pNewItem->notIndexed = pOldItem->notIndexed;
-    pNewItem->pIndex = pOldItem->pIndex;
+    if( pNewItem->fg.isIndexedBy ){
+      pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
+    }
+    pNewItem->pIBIndex = pOldItem->pIBIndex;
+    if( pNewItem->fg.isTabFunc ){
+      pNewItem->u1.pFuncArg = 
+          sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
+    }
     pTab = pNewItem->pTab = pOldItem->pTab;
     if( pTab ){
-      pTab->nRef++;
+      pTab->nTabRef++;
     }
     pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
     pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
@@ -82817,13 +92984,14 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
 SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
   IdList *pNew;
   int i;
+  assert( db!=0 );
   if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
   if( pNew==0 ) return 0;
   pNew->nId = p->nId;
-  pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
+  pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );
   if( pNew->a==0 ){
-    sqlite3DbFree(db, pNew);
+    sqlite3DbFreeNN(db, pNew);
     return 0;
   }
   /* Note that because the size of the allocation for p->a[] is not
@@ -82837,32 +93005,41 @@ SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
   }
   return pNew;
 }
-SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
-  Select *pNew, *pPrior;
-  if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
-  if( pNew==0 ) return 0;
-  pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
-  pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
-  pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
-  pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
-  pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
-  pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
-  pNew->op = p->op;
-  pNew->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags);
-  if( pPrior ) pPrior->pNext = pNew;
-  pNew->pNext = 0;
-  pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
-  pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
-  pNew->iLimit = 0;
-  pNew->iOffset = 0;
-  pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
-  pNew->addrOpenEphm[0] = -1;
-  pNew->addrOpenEphm[1] = -1;
-  pNew->nSelectRow = p->nSelectRow;
-  pNew->pWith = withDup(db, p->pWith);
-  sqlite3SelectSetName(pNew, p->zSelName);
-  return pNew;
+SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
+  Select *pRet = 0;
+  Select *pNext = 0;
+  Select **pp = &pRet;
+  Select *p;
+
+  assert( db!=0 );
+  for(p=pDup; p; p=p->pPrior){
+    Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
+    if( pNew==0 ) break;
+    pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
+    pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
+    pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
+    pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
+    pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
+    pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
+    pNew->op = p->op;
+    pNew->pNext = pNext;
+    pNew->pPrior = 0;
+    pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
+    pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
+    pNew->iLimit = 0;
+    pNew->iOffset = 0;
+    pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
+    pNew->addrOpenEphm[0] = -1;
+    pNew->addrOpenEphm[1] = -1;
+    pNew->nSelectRow = p->nSelectRow;
+    pNew->pWith = withDup(db, p->pWith);
+    sqlite3SelectSetName(pNew, p->zSelName);
+    *pp = pNew;
+    pp = &pNew->pPrior;
+    pNext = pNew;
+  }
+
+  return pRet;
 }
 #else
 SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
@@ -82885,29 +93062,31 @@ SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(
   ExprList *pList,        /* List to which to append. Might be NULL */
   Expr *pExpr             /* Expression to be appended. Might be NULL */
 ){
+  struct ExprList_item *pItem;
   sqlite3 *db = pParse->db;
+  assert( db!=0 );
   if( pList==0 ){
-    pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
+    pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );
     if( pList==0 ){
       goto no_mem;
     }
-    pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0]));
-    if( pList->a==0 ) goto no_mem;
-  }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
-    struct ExprList_item *a;
-    assert( pList->nExpr>0 );
-    a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
-    if( a==0 ){
+    pList->nExpr = 0;
+    pList->nAlloc = 1;
+  }else if( pList->nExpr==pList->nAlloc ){
+    ExprList *pNew;
+    pNew = sqlite3DbRealloc(db, pList, 
+             sizeof(*pList)+(2*pList->nAlloc - 1)*sizeof(pList->a[0]));
+    if( pNew==0 ){
       goto no_mem;
     }
-    pList->a = a;
-  }
-  assert( pList->a!=0 );
-  if( 1 ){
-    struct ExprList_item *pItem = &pList->a[pList->nExpr++];
-    memset(pItem, 0, sizeof(*pItem));
-    pItem->pExpr = pExpr;
+    pList = pNew;
+    pList->nAlloc *= 2;
   }
+  pItem = &pList->a[pList->nExpr++];
+  assert( offsetof(struct ExprList_item,zName)==sizeof(pItem->pExpr) );
+  assert( offsetof(struct ExprList_item,pExpr)==0 );
+  memset(&pItem->zName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zName));
+  pItem->pExpr = pExpr;
   return pList;
 
 no_mem:     
@@ -82917,6 +93096,88 @@ no_mem:
   return 0;
 }
 
+/*
+** pColumns and pExpr form a vector assignment which is part of the SET
+** clause of an UPDATE statement.  Like this:
+**
+**        (a,b,c) = (expr1,expr2,expr3)
+** Or:    (a,b,c) = (SELECT x,y,z FROM ....)
+**
+** For each term of the vector assignment, append new entries to the
+** expression list pList.  In the case of a subquery on the RHS, append
+** TK_SELECT_COLUMN expressions.
+*/
+SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(
+  Parse *pParse,         /* Parsing context */
+  ExprList *pList,       /* List to which to append. Might be NULL */
+  IdList *pColumns,      /* List of names of LHS of the assignment */
+  Expr *pExpr            /* Vector expression to be appended. Might be NULL */
+){
+  sqlite3 *db = pParse->db;
+  int n;
+  int i;
+  int iFirst = pList ? pList->nExpr : 0;
+  /* pColumns can only be NULL due to an OOM but an OOM will cause an
+  ** exit prior to this routine being invoked */
+  if( NEVER(pColumns==0) ) goto vector_append_error;
+  if( pExpr==0 ) goto vector_append_error;
+
+  /* If the RHS is a vector, then we can immediately check to see that 
+  ** the size of the RHS and LHS match.  But if the RHS is a SELECT, 
+  ** wildcards ("*") in the result set of the SELECT must be expanded before
+  ** we can do the size check, so defer the size check until code generation.
+  */
+  if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){
+    sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
+                    pColumns->nId, n);
+    goto vector_append_error;
+  }
+
+  for(i=0; inId; i++){
+    Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);
+    pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
+    if( pList ){
+      assert( pList->nExpr==iFirst+i+1 );
+      pList->a[pList->nExpr-1].zName = pColumns->a[i].zName;
+      pColumns->a[i].zName = 0;
+    }
+  }
+
+  if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){
+    Expr *pFirst = pList->a[iFirst].pExpr;
+    assert( pFirst!=0 );
+    assert( pFirst->op==TK_SELECT_COLUMN );
+     
+    /* Store the SELECT statement in pRight so it will be deleted when
+    ** sqlite3ExprListDelete() is called */
+    pFirst->pRight = pExpr;
+    pExpr = 0;
+
+    /* Remember the size of the LHS in iTable so that we can check that
+    ** the RHS and LHS sizes match during code generation. */
+    pFirst->iTable = pColumns->nId;
+  }
+
+vector_append_error:
+  sqlite3ExprDelete(db, pExpr);
+  sqlite3IdListDelete(db, pColumns);
+  return pList;
+}
+
+/*
+** Set the sort order for the last element on the given ExprList.
+*/
+SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
+  if( p==0 ) return;
+  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );
+  assert( p->nExpr>0 );
+  if( iSortOrder<0 ){
+    assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC );
+    return;
+  }
+  p->a[p->nExpr-1].sortOrder = (u8)iSortOrder;
+}
+
 /*
 ** Set the ExprList.a[].zName element of the most recently added item
 ** on the expression list.
@@ -82938,7 +93199,7 @@ SQLITE_PRIVATE void sqlite3ExprListSetName(
     pItem = &pList->a[pList->nExpr-1];
     assert( pItem->zName==0 );
     pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
-    if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName);
+    if( dequote ) sqlite3Dequote(pItem->zName);
   }
 }
 
@@ -82987,18 +93248,37 @@ SQLITE_PRIVATE void sqlite3ExprListCheckLength(
 /*
 ** Delete an entire expression list.
 */
-SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
-  int i;
-  struct ExprList_item *pItem;
-  if( pList==0 ) return;
-  assert( pList->a!=0 || pList->nExpr==0 );
-  for(pItem=pList->a, i=0; inExpr; i++, pItem++){
+static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
+  int i = pList->nExpr;
+  struct ExprList_item *pItem =  pList->a;
+  assert( pList->nExpr>0 );
+  do{
     sqlite3ExprDelete(db, pItem->pExpr);
     sqlite3DbFree(db, pItem->zName);
     sqlite3DbFree(db, pItem->zSpan);
+    pItem++;
+  }while( --i>0 );
+  sqlite3DbFreeNN(db, pList);
+}
+SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
+  if( pList ) exprListDeleteNN(db, pList);
+}
+
+/*
+** Return the bitwise-OR of all Expr.flags fields in the given
+** ExprList.
+*/
+SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList *pList){
+  int i;
+  u32 m = 0;
+  if( pList ){
+    for(i=0; inExpr; i++){
+       Expr *pExpr = pList->a[i].pExpr;
+       assert( pExpr!=0 );
+       m |= pExpr->flags;
+    }
   }
-  sqlite3DbFree(db, pList->a);
-  sqlite3DbFree(db, pList);
+  return m;
 }
 
 /*
@@ -83011,7 +93291,7 @@ SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
 **
 **     sqlite3ExprIsConstant()                  pWalker->eCode==1
 **     sqlite3ExprIsConstantNotJoin()           pWalker->eCode==2
-**     sqlite3ExprRefOneTableOnly()             pWalker->eCode==3
+**     sqlite3ExprIsTableConstant()             pWalker->eCode==3
 **     sqlite3ExprIsConstantOrFunction()        pWalker->eCode==4 or 5
 **
 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
@@ -83041,7 +93321,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
     ** and either pWalker->eCode==4 or 5 or the function has the
     ** SQLITE_FUNC_CONST flag. */
     case TK_FUNCTION:
-      if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_Constant) ){
+      if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc) ){
         return WRC_Continue;
       }else{
         pWalker->eCode = 0;
@@ -83057,10 +93337,12 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_AGG_COLUMN );
       if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
         return WRC_Continue;
-      }else{
-        pWalker->eCode = 0;
-        return WRC_Abort;
       }
+      /* Fall through */
+    case TK_IF_NULL_ROW:
+      testcase( pExpr->op==TK_IF_NULL_ROW );
+      pWalker->eCode = 0;
+      return WRC_Abort;
     case TK_VARIABLE:
       if( pWalker->eCode==5 ){
         /* Silently convert bound parameters that appear inside of CREATE
@@ -83087,10 +93369,12 @@ static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
 }
 static int exprIsConst(Expr *p, int initFlag, int iCur){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.eCode = initFlag;
   w.xExprCallback = exprNodeIsConstant;
   w.xSelectCallback = selectNodeIsConstant;
+#ifdef SQLITE_DEBUG
+  w.xSelectCallback2 = sqlite3SelectWalkAssert2;
+#endif
   w.u.iCur = iCur;
   sqlite3WalkExpr(&w, p);
   return w.eCode;
@@ -83119,7 +93403,7 @@ SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr *p){
 }
 
 /*
-** Walk an expression tree.  Return non-zero if the expression constant
+** Walk an expression tree.  Return non-zero if the expression is constant
 ** for any single row of the table with cursor iCur.  In other words, the
 ** expression must not refer to any non-deterministic function nor any
 ** table other than iCur.
@@ -83128,6 +93412,65 @@ SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr *p, int iCur){
   return exprIsConst(p, 3, iCur);
 }
 
+
+/*
+** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
+*/
+static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
+  ExprList *pGroupBy = pWalker->u.pGroupBy;
+  int i;
+
+  /* Check if pExpr is identical to any GROUP BY term. If so, consider
+  ** it constant.  */
+  for(i=0; inExpr; i++){
+    Expr *p = pGroupBy->a[i].pExpr;
+    if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
+      CollSeq *pColl = sqlite3ExprCollSeq(pWalker->pParse, p);
+      if( pColl==0 || sqlite3_stricmp("BINARY", pColl->zName)==0 ){
+        return WRC_Prune;
+      }
+    }
+  }
+
+  /* Check if pExpr is a sub-select. If so, consider it variable. */
+  if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+    pWalker->eCode = 0;
+    return WRC_Abort;
+  }
+
+  return exprNodeIsConstant(pWalker, pExpr);
+}
+
+/*
+** Walk the expression tree passed as the first argument. Return non-zero
+** if the expression consists entirely of constants or copies of terms 
+** in pGroupBy that sort with the BINARY collation sequence.
+**
+** This routine is used to determine if a term of the HAVING clause can
+** be promoted into the WHERE clause.  In order for such a promotion to work,
+** the value of the HAVING clause term must be the same for all members of
+** a "group".  The requirement that the GROUP BY term must be BINARY
+** assumes that no other collating sequence will have a finer-grained
+** grouping than binary.  In other words (A=B COLLATE binary) implies
+** A=B in every other collating sequence.  The requirement that the
+** GROUP BY be BINARY is stricter than necessary.  It would also work
+** to promote HAVING clauses that use the same alternative collating
+** sequence as the GROUP BY term, but that is much harder to check,
+** alternative collating sequences are uncommon, and this is only an
+** optimization, so we take the easy way out and simply require the
+** GROUP BY to use the BINARY collating sequence.
+*/
+SQLITE_PRIVATE int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
+  Walker w;
+  w.eCode = 1;
+  w.xExprCallback = exprNodeIsConstantOrGroupBy;
+  w.xSelectCallback = 0;
+  w.u.pGroupBy = pGroupBy;
+  w.pParse = pParse;
+  sqlite3WalkExpr(&w, p);
+  return w.eCode;
+}
+
 /*
 ** Walk an expression tree.  Return non-zero if the expression is constant
 ** or a function call with constant arguments.  Return and 0 if there
@@ -83142,6 +93485,24 @@ SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
   return exprIsConst(p, 4+isInit, 0);
 }
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Walk an expression tree.  Return 1 if the expression contains a
+** subquery of some kind.  Return 0 if there are no subqueries.
+*/
+SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr *p){
+  Walker w;
+  w.eCode = 1;
+  w.xExprCallback = sqlite3ExprWalkNoop;
+  w.xSelectCallback = selectNodeIsConstant;
+#ifdef SQLITE_DEBUG
+  w.xSelectCallback2 = sqlite3SelectWalkAssert2;
+#endif
+  sqlite3WalkExpr(&w, p);
+  return w.eCode==0;
+}
+#endif
+
 /*
 ** If the expression p codes a constant integer that is small enough
 ** to fit in a 32-bit integer, return 1 and put the value of the integer
@@ -83150,6 +93511,7 @@ SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
 */
 SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr *p, int *pValue){
   int rc = 0;
+  if( p==0 ) return 0;  /* Can only happen following on OOM */
 
   /* If an expression is an integer literal that fits in a signed 32-bit
   ** integer, then the EP_IntValue flag will have already been set */
@@ -83225,7 +93587,7 @@ SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr *p){
 */
 SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
   u8 op;
-  if( aff==SQLITE_AFF_NONE ) return 1;
+  if( aff==SQLITE_AFF_BLOB ) return 1;
   while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
   op = p->op;
   if( op==TK_REGISTER ) op = p->op2;
@@ -83264,23 +93626,22 @@ SQLITE_PRIVATE int sqlite3IsRowid(const char *z){
 }
 
 /*
-** Return true if we are able to the IN operator optimization on a
-** query of the form
-**
-**       x IN (SELECT ...)
-**
-** Where the SELECT... clause is as specified by the parameter to this
-** routine.
-**
-** The Select object passed in has already been preprocessed and no
-** errors have been found.
+** pX is the RHS of an IN operator.  If pX is a SELECT statement 
+** that can be simplified to a direct table access, then return
+** a pointer to the SELECT statement.  If pX is not a SELECT statement,
+** or if the SELECT statement needs to be manifested into a transient
+** table, then return NULL.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
-static int isCandidateForInOpt(Select *p){
+static Select *isCandidateForInOpt(Expr *pX){
+  Select *p;
   SrcList *pSrc;
   ExprList *pEList;
   Table *pTab;
-  if( p==0 ) return 0;                   /* right-hand side of IN is SELECT */
+  int i;
+  if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0;  /* Not a subquery */
+  if( ExprHasProperty(pX, EP_VarSelect)  ) return 0;  /* Correlated subq */
+  p = pX->x.pSelect;
   if( p->pPrior ) return 0;              /* Not a compound SELECT */
   if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
     testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
@@ -83296,25 +93657,22 @@ static int isCandidateForInOpt(Select *p){
   if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
   if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
   pTab = pSrc->a[0].pTab;
-  if( NEVER(pTab==0) ) return 0;
+  assert( pTab!=0 );
   assert( pTab->pSelect==0 );            /* FROM clause is not a view */
   if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
   pEList = p->pEList;
-  if( pEList->nExpr!=1 ) return 0;       /* One column in the result set */
-  if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
-  return 1;
+  assert( pEList!=0 );
+  /* All SELECT results must be columns. */
+  for(i=0; inExpr; i++){
+    Expr *pRes = pEList->a[i].pExpr;
+    if( pRes->op!=TK_COLUMN ) return 0;
+    assert( pRes->iTable==pSrc->a[0].iCursor );  /* Not a correlated subquery */
+  }
+  return p;
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
-/*
-** Code an OP_Once instruction and allocate space for its flag. Return the 
-** address of the new instruction.
-*/
-SQLITE_PRIVATE int sqlite3CodeOnce(Parse *pParse){
-  Vdbe *v = sqlite3GetVdbe(pParse);      /* Virtual machine being coded */
-  return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
-}
-
+#ifndef SQLITE_OMIT_SUBQUERY
 /*
 ** Generate code that checks the left-most column of index table iCur to see if
 ** it contains any NULL entries.  Cause the register at regHasNull to be set
@@ -83322,14 +93680,15 @@ SQLITE_PRIVATE int sqlite3CodeOnce(Parse *pParse){
 ** to be set to NULL if iCur contains one or more NULL values.
 */
 static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
-  int j1;
+  int addr1;
   sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
-  j1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
+  addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
   sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
   sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
   VdbeComment((v, "first_entry_in(%d)", iCur));
-  sqlite3VdbeJumpHere(v, j1);
+  sqlite3VdbeJumpHere(v, addr1);
 }
+#endif
 
 
 #ifndef SQLITE_OMIT_SUBQUERY
@@ -83374,7 +93733,7 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
 ** An existing b-tree might be used if the RHS expression pX is a simple
 ** subquery such as:
 **
-**     SELECT  FROM 
+**     SELECT , ... FROM 
    
 **
 ** If the RHS of the IN operator is a list or a more complex subquery, then
 ** an ephemeral table might need to be generated from the RHS and then
@@ -83390,14 +93749,14 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
 **
 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
 ** through the set members) then the b-tree must not contain duplicates.
-** An epheremal table must be used unless the selected  is guaranteed
-** to be unique - either because it is an INTEGER PRIMARY KEY or it
-** has a UNIQUE constraint or UNIQUE index.
+** An epheremal table must be used unless the selected columns are guaranteed
+** to be unique - either because it is an INTEGER PRIMARY KEY or due to
+** a UNIQUE constraint or index.
 **
 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used 
 ** for fast set membership tests) then an epheremal table must 
-** be used unless  is an INTEGER PRIMARY KEY or an index can 
-** be found with  as its left-most column.
+** be used unless  is a single INTEGER PRIMARY KEY column or an 
+** index can be found with the specified  as its left-most.
 **
 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
 ** if the RHS of the IN operator is a list (not a subquery) then this
@@ -83418,9 +93777,26 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
 ** the value in that register will be NULL if the b-tree contains one or more
 ** NULL values, and it will be some non-NULL value if the b-tree contains no
 ** NULL values.
+**
+** If the aiMap parameter is not NULL, it must point to an array containing
+** one element for each column returned by the SELECT statement on the RHS
+** of the IN(...) operator. The i'th entry of the array is populated with the
+** offset of the index column that matches the i'th column returned by the
+** SELECT. For example, if the expression and selected index are:
+**
+**   (?,?,?) IN (SELECT a, b, c FROM t1)
+**   CREATE INDEX i1 ON t1(b, c, a);
+**
+** then aiMap[] is populated with {2, 0, 1}.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
-SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
+SQLITE_PRIVATE int sqlite3FindInIndex(
+  Parse *pParse,             /* Parsing context */
+  Expr *pX,                  /* The right-hand side (RHS) of the IN operator */
+  u32 inFlags,               /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
+  int *prRhsHasNull,         /* Register holding NULL status.  See notes */
+  int *aiMap                 /* Mapping from Index fields to RHS fields */
+){
   Select *p;                            /* SELECT to the right of IN operator */
   int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
   int iTab = pParse->nTab++;            /* Cursor of the RHS table */
@@ -83430,38 +93806,46 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int
   assert( pX->op==TK_IN );
   mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
 
+  /* If the RHS of this IN(...) operator is a SELECT, and if it matters 
+  ** whether or not the SELECT result contains NULL values, check whether
+  ** or not NULL is actually possible (it may not be, for example, due 
+  ** to NOT NULL constraints in the schema). If no NULL values are possible,
+  ** set prRhsHasNull to 0 before continuing.  */
+  if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){
+    int i;
+    ExprList *pEList = pX->x.pSelect->pEList;
+    for(i=0; inExpr; i++){
+      if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
+    }
+    if( i==pEList->nExpr ){
+      prRhsHasNull = 0;
+    }
+  }
+
   /* Check to see if an existing table or index can be used to
   ** satisfy the query.  This is preferable to generating a new 
-  ** ephemeral table.
-  */
-  p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
-  if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
+  ** ephemeral table.  */
+  if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
     sqlite3 *db = pParse->db;              /* Database connection */
     Table *pTab;                           /* Table 
    . */
-    Expr *pExpr;                           /* Expression  */
-    i16 iCol;                              /* Index of column  */
     i16 iDb;                               /* Database idx for pTab */
+    ExprList *pEList = p->pEList;
+    int nExpr = pEList->nExpr;
 
-    assert( p );                        /* Because of isCandidateForInOpt(p) */
     assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
     assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
     assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
     pTab = p->pSrc->a[0].pTab;
-    pExpr = p->pEList->a[0].pExpr;
-    iCol = (i16)pExpr->iColumn;
-   
+
     /* Code an OP_Transaction and OP_TableLock for 
    . */
     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
     sqlite3CodeVerifySchema(pParse, iDb);
     sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
 
-    /* This function is only called from two places. In both cases the vdbe
-    ** has already been allocated. So assume sqlite3GetVdbe() is always
-    ** successful here.
-    */
-    assert(v);
-    if( iCol<0 ){
-      int iAddr = sqlite3CodeOnce(pParse);
+    assert(v);  /* sqlite3GetVdbe() has always been previously called */
+    if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
+      /* The "x IN (SELECT rowid FROM table)" case */
+      int iAddr = sqlite3VdbeAddOp0(v, OP_Once);
       VdbeCoverage(v);
 
       sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
@@ -83470,44 +93854,114 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int
       sqlite3VdbeJumpHere(v, iAddr);
     }else{
       Index *pIdx;                         /* Iterator variable */
+      int affinity_ok = 1;
+      int i;
 
-      /* The collation sequence used by the comparison. If an index is to
-      ** be used in place of a temp-table, it must be ordered according
-      ** to this collation sequence.  */
-      CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
-
-      /* Check that the affinity that will be used to perform the 
-      ** comparison is the same as the affinity of the column. If
-      ** it is not, it is not possible to use any index.
-      */
-      int affinity_ok = sqlite3IndexAffinityOk(pX, pTab->aCol[iCol].affinity);
-
-      for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
-        if( (pIdx->aiColumn[0]==iCol)
-         && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq
-         && (!mustBeUnique || (pIdx->nKeyCol==1 && IsUniqueIndex(pIdx)))
-        ){
-          int iAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
-          sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
-          sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
-          VdbeComment((v, "%s", pIdx->zName));
-          assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
-          eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
-
-          if( prRhsHasNull && !pTab->aCol[iCol].notNull ){
-            *prRhsHasNull = ++pParse->nMem;
-            sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
+      /* Check that the affinity that will be used to perform each 
+      ** comparison is the same as the affinity of each column in table
+      ** on the RHS of the IN operator.  If it not, it is not possible to
+      ** use any index of the RHS table.  */
+      for(i=0; ipLeft, i);
+        int iCol = pEList->a[i].pExpr->iColumn;
+        char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
+        char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
+        testcase( cmpaff==SQLITE_AFF_BLOB );
+        testcase( cmpaff==SQLITE_AFF_TEXT );
+        switch( cmpaff ){
+          case SQLITE_AFF_BLOB:
+            break;
+          case SQLITE_AFF_TEXT:
+            /* sqlite3CompareAffinity() only returns TEXT if one side or the
+            ** other has no affinity and the other side is TEXT.  Hence,
+            ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
+            ** and for the term on the LHS of the IN to have no affinity. */
+            assert( idxaff==SQLITE_AFF_TEXT );
+            break;
+          default:
+            affinity_ok = sqlite3IsNumericAffinity(idxaff);
+        }
+      }
+
+      if( affinity_ok ){
+        /* Search for an existing index that will work for this IN operator */
+        for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
+          Bitmask colUsed;      /* Columns of the index used */
+          Bitmask mCol;         /* Mask for the current column */
+          if( pIdx->nColumnnColumn==BMS-2 );
+          testcase( pIdx->nColumn==BMS-1 );
+          if( pIdx->nColumn>=BMS-1 ) continue;
+          if( mustBeUnique ){
+            if( pIdx->nKeyCol>nExpr
+             ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
+            ){
+              continue;  /* This index is not unique over the IN RHS columns */
+            }
           }
-          sqlite3VdbeJumpHere(v, iAddr);
-        }
-      }
-    }
-  }
+  
+          colUsed = 0;   /* Columns of index used so far */
+          for(i=0; ipLeft, i);
+            Expr *pRhs = pEList->a[i].pExpr;
+            CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
+            int j;
+  
+            assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
+            for(j=0; jaiColumn[j]!=pRhs->iColumn ) continue;
+              assert( pIdx->azColl[j] );
+              if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
+                continue;
+              }
+              break;
+            }
+            if( j==nExpr ) break;
+            mCol = MASKBIT(j);
+            if( mCol & colUsed ) break; /* Each column used only once */
+            colUsed |= mCol;
+            if( aiMap ) aiMap[i] = j;
+          }
+  
+          assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
+          if( colUsed==(MASKBIT(nExpr)-1) ){
+            /* If we reach this point, that means the index pIdx is usable */
+            int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+#ifndef SQLITE_OMIT_EXPLAIN
+            sqlite3VdbeAddOp4(v, OP_Explain, 0, 0, 0,
+              sqlite3MPrintf(db, "USING INDEX %s FOR IN-OPERATOR",pIdx->zName),
+              P4_DYNAMIC);
+#endif
+            sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
+            sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+            VdbeComment((v, "%s", pIdx->zName));
+            assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
+            eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
+  
+            if( prRhsHasNull ){
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+              i64 mask = (1<nMem;
+              if( nExpr==1 ){
+                sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
+              }
+            }
+            sqlite3VdbeJumpHere(v, iAddr);
+          }
+        } /* End loop over indexes */
+      } /* End if( affinity_ok ) */
+    } /* End if not an rowid index */
+  } /* End attempt to optimize using an index */
 
   /* If no preexisting index is available for the IN clause
   ** and IN_INDEX_NOOP is an allowed reply
   ** and the RHS of the IN operator is a list, not a subquery
-  ** and the RHS is not contant or has two or fewer terms,
+  ** and the RHS is not constant or has two or fewer terms,
   ** then it is not worth creating an ephemeral table to evaluate
   ** the IN operator so return IN_INDEX_NOOP.
   */
@@ -83518,7 +93972,6 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int
   ){
     eType = IN_INDEX_NOOP;
   }
-     
 
   if( eType==0 ){
     /* Could not find an existing table or index to use as the RHS b-tree.
@@ -83540,10 +93993,85 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int
   }else{
     pX->iTable = iTab;
   }
+
+  if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
+    int i, n;
+    n = sqlite3ExprVectorSize(pX->pLeft);
+    for(i=0; ipLeft;
+  int nVal = sqlite3ExprVectorSize(pLeft);
+  Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;
+  char *zRet;
+
+  assert( pExpr->op==TK_IN );
+  zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
+  if( zRet ){
+    int i;
+    for(i=0; ipEList->a[i].pExpr, a);
+      }else{
+        zRet[i] = a;
+      }
+    }
+    zRet[nVal] = '\0';
+  }
+  return zRet;
+}
+#endif
+
+#ifndef SQLITE_OMIT_SUBQUERY
+/*
+** Load the Parse object passed as the first argument with an error 
+** message of the form:
+**
+**   "sub-select returns N columns - expected M"
+*/   
+SQLITE_PRIVATE void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
+  const char *zFmt = "sub-select returns %d columns - expected %d";
+  sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
+}
+#endif
+
+/*
+** Expression pExpr is a vector that has been used in a context where
+** it is not permitted. If pExpr is a sub-select vector, this routine 
+** loads the Parse object with a message of the form:
+**
+**   "sub-select returns N columns - expected 1"
+**
+** Or, if it is a regular scalar vector:
+**
+**   "row value misused"
+*/   
+SQLITE_PRIVATE void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){
+#ifndef SQLITE_OMIT_SUBQUERY
+  if( pExpr->flags & EP_xIsSelect ){
+    sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);
+  }else
+#endif
+  {
+    sqlite3ErrorMsg(pParse, "row value misused");
+  }
+}
+
 /*
 ** Generate code for scalar subqueries used as a subquery expression, EXISTS,
 ** or IN operators.  Examples:
@@ -83569,7 +94097,9 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int
 ** value to non-NULL if the RHS is NULL-free.
 **
 ** For a SELECT or EXISTS operator, return the register that holds the
-** result.  For IN operators or if an error occurs, the return value is 0.
+** result.  For a multi-column SELECT, the result is stored in a contiguous
+** array of registers and the return value is the register of the left-most
+** result column.  Return 0 for IN operators or if an error occurs.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
 SQLITE_PRIVATE int sqlite3CodeSubselect(
@@ -83584,8 +94114,8 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
   if( NEVER(v==0) ) return 0;
   sqlite3ExprCachePush(pParse);
 
-  /* This code must be run in its entirety every time it is encountered
-  ** if any of the following is true:
+  /* The evaluation of the IN/EXISTS/SELECT must be repeated every time it
+  ** is encountered if any of the following is true:
   **
   **    *  The right-hand side is a correlated subquery
   **    *  The right-hand side is an expression list containing variables
@@ -83595,14 +94125,15 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
   ** save the results, and reuse the same result on subsequent invocations.
   */
   if( !ExprHasProperty(pExpr, EP_VarSelect) ){
-    jmpIfDynamic = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+    jmpIfDynamic = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
   }
 
 #ifndef SQLITE_OMIT_EXPLAIN
   if( pParse->explain==2 ){
-    char *zMsg = sqlite3MPrintf(
-        pParse->db, "EXECUTE %s%s SUBQUERY %d", jmpIfDynamic>=0?"":"CORRELATED ",
-        pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId
+    char *zMsg = sqlite3MPrintf(pParse->db, "EXECUTE %s%s SUBQUERY %d",
+        jmpIfDynamic>=0?"":"CORRELATED ",
+        pExpr->op==TK_IN?"LIST":"SCALAR",
+        pParse->iNextSelectId
     );
     sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
   }
@@ -83610,17 +94141,18 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
 
   switch( pExpr->op ){
     case TK_IN: {
-      char affinity;              /* Affinity of the LHS of the IN */
       int addr;                   /* Address of OP_OpenEphemeral instruction */
       Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
       KeyInfo *pKeyInfo = 0;      /* Key information */
-
-      affinity = sqlite3ExprAffinity(pLeft);
+      int nVal;                   /* Size of vector pLeft */
+      
+      nVal = sqlite3ExprVectorSize(pLeft);
+      assert( !isRowid || nVal==1 );
 
       /* Whether this is an 'x IN(SELECT...)' or an 'x IN()'
       ** expression it is handled the same way.  An ephemeral table is 
-      ** filled with single-field index keys representing the results
-      ** from the SELECT or the .
+      ** filled with index keys representing the results from the 
+      ** SELECT or the .
       **
       ** If the 'x' expression is a column value, or the SELECT...
       ** statement returns a column value, then the affinity of that
@@ -83631,8 +94163,9 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
       ** is used.
       */
       pExpr->iTable = pParse->nTab++;
-      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
-      pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, 1, 1);
+      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, 
+          pExpr->iTable, (isRowid?0:nVal));
+      pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, nVal, 1);
 
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         /* Case 1:     expr IN (SELECT ...)
@@ -83641,27 +94174,36 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         ** table allocated and opened above.
         */
         Select *pSelect = pExpr->x.pSelect;
-        SelectDest dest;
-        ExprList *pEList;
+        ExprList *pEList = pSelect->pEList;
 
         assert( !isRowid );
-        sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
-        dest.affSdst = (u8)affinity;
-        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
-        pSelect->iLimit = 0;
-        testcase( pSelect->selFlags & SF_Distinct );
-        testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
-        if( sqlite3Select(pParse, pSelect, &dest) ){
-          sqlite3KeyInfoUnref(pKeyInfo);
-          return 0;
+        /* If the LHS and RHS of the IN operator do not match, that
+        ** error will have been caught long before we reach this point. */
+        if( ALWAYS(pEList->nExpr==nVal) ){
+          SelectDest dest;
+          int i;
+          sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
+          dest.zAffSdst = exprINAffinity(pParse, pExpr);
+          pSelect->iLimit = 0;
+          testcase( pSelect->selFlags & SF_Distinct );
+          testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
+          if( sqlite3Select(pParse, pSelect, &dest) ){
+            sqlite3DbFree(pParse->db, dest.zAffSdst);
+            sqlite3KeyInfoUnref(pKeyInfo);
+            return 0;
+          }
+          sqlite3DbFree(pParse->db, dest.zAffSdst);
+          assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
+          assert( pEList!=0 );
+          assert( pEList->nExpr>0 );
+          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
+          for(i=0; iaColl[i] = sqlite3BinaryCompareCollSeq(
+                pParse, p, pEList->a[i].pExpr
+            );
+          }
         }
-        pEList = pSelect->pEList;
-        assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
-        assert( pEList!=0 );
-        assert( pEList->nExpr>0 );
-        assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
-        pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
-                                                         pEList->a[0].pExpr);
       }else if( ALWAYS(pExpr->x.pList!=0) ){
         /* Case 2:     expr IN (exprlist)
         **
@@ -83670,13 +94212,15 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         ** that columns affinity when building index keys. If  is not
         ** a column, use numeric affinity.
         */
+        char affinity;            /* Affinity of the LHS of the IN */
         int i;
         ExprList *pList = pExpr->x.pList;
         struct ExprList_item *pItem;
         int r1, r2, r3;
 
+        affinity = sqlite3ExprAffinity(pLeft);
         if( !affinity ){
-          affinity = SQLITE_AFF_NONE;
+          affinity = SQLITE_AFF_BLOB;
         }
         if( pKeyInfo ){
           assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
@@ -83714,7 +94258,7 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
             }else{
               sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
               sqlite3ExprCacheAffinityChange(pParse, r3, 1);
-              sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
+              sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pExpr->iTable, r2, r3, 1);
             }
           }
         }
@@ -83730,26 +94274,37 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
     case TK_EXISTS:
     case TK_SELECT:
     default: {
-      /* If this has to be a scalar SELECT.  Generate code to put the
-      ** value of this select in a memory cell and record the number
-      ** of the memory cell in iColumn.  If this is an EXISTS, write
-      ** an integer 0 (not exists) or 1 (exists) into a memory cell
-      ** and record that memory cell in iColumn.
+      /* Case 3:    (SELECT ... FROM ...)
+      **     or:    EXISTS(SELECT ... FROM ...)
+      **
+      ** For a SELECT, generate code to put the values for all columns of
+      ** the first row into an array of registers and return the index of
+      ** the first register.
+      **
+      ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
+      ** into a register and return that register number.
+      **
+      ** In both cases, the query is augmented with "LIMIT 1".  Any 
+      ** preexisting limit is discarded in place of the new LIMIT 1.
       */
       Select *pSel;                         /* SELECT statement to encode */
-      SelectDest dest;                      /* How to deal with SELECt result */
+      SelectDest dest;                      /* How to deal with SELECT result */
+      int nReg;                             /* Registers to allocate */
 
       testcase( pExpr->op==TK_EXISTS );
       testcase( pExpr->op==TK_SELECT );
       assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
-
       assert( ExprHasProperty(pExpr, EP_xIsSelect) );
+
       pSel = pExpr->x.pSelect;
-      sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
+      nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
+      sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
+      pParse->nMem += nReg;
       if( pExpr->op==TK_SELECT ){
         dest.eDest = SRT_Mem;
         dest.iSdst = dest.iSDParm;
-        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iSDParm);
+        dest.nSdst = nReg;
+        sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
         VdbeComment((v, "Init subquery result"));
       }else{
         dest.eDest = SRT_Exists;
@@ -83757,9 +94312,10 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         VdbeComment((v, "Init EXISTS result"));
       }
       sqlite3ExprDelete(pParse->db, pSel->pLimit);
-      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
-                                  &sqlite3IntTokens[1]);
+      pSel->pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,
+                                  &sqlite3IntTokens[1], 0);
       pSel->iLimit = 0;
+      pSel->selFlags &= ~SF_MultiValue;
       if( sqlite3Select(pParse, pSel, &dest) ){
         return 0;
       }
@@ -83782,6 +94338,28 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
+#ifndef SQLITE_OMIT_SUBQUERY
+/*
+** Expr pIn is an IN(...) expression. This function checks that the 
+** sub-select on the RHS of the IN() operator has the same number of 
+** columns as the vector on the LHS. Or, if the RHS of the IN() is not 
+** a sub-query, that the LHS is a vector of size 1.
+*/
+SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
+  int nVector = sqlite3ExprVectorSize(pIn->pLeft);
+  if( (pIn->flags & EP_xIsSelect) ){
+    if( nVector!=pIn->x.pSelect->pEList->nExpr ){
+      sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
+      return 1;
+    }
+  }else if( nVector!=1 ){
+    sqlite3VectorErrorMsg(pParse, pIn->pLeft);
+    return 1;
+  }
+  return 0;
+}
+#endif
+
 #ifndef SQLITE_OMIT_SUBQUERY
 /*
 ** Generate code for an IN expression.
@@ -83789,16 +94367,24 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
 **      x IN (SELECT ...)
 **      x IN (value, value, ...)
 **
-** The left-hand side (LHS) is a scalar expression.  The right-hand side (RHS)
-** is an array of zero or more values.  The expression is true if the LHS is
-** contained within the RHS.  The value of the expression is unknown (NULL)
-** if the LHS is NULL or if the LHS is not contained within the RHS and the
-** RHS contains one or more NULL values.
+** The left-hand side (LHS) is a scalar or vector expression.  The 
+** right-hand side (RHS) is an array of zero or more scalar values, or a
+** subquery.  If the RHS is a subquery, the number of result columns must
+** match the number of columns in the vector on the LHS.  If the RHS is
+** a list of values, the LHS must be a scalar. 
+**
+** The IN operator is true if the LHS value is contained within the RHS.
+** The result is false if the LHS is definitely not in the RHS.  The 
+** result is NULL if the presence of the LHS in the RHS cannot be 
+** determined due to NULLs.
 **
 ** This routine generates code that jumps to destIfFalse if the LHS is not 
 ** contained within the RHS.  If due to NULLs we cannot determine if the LHS
 ** is contained in the RHS then jump to destIfNull.  If the LHS is contained
 ** within the RHS then fall through.
+**
+** See the separate in-operator.md documentation file in the canonical
+** SQLite source tree for additional information.
 */
 static void sqlite3ExprCodeIN(
   Parse *pParse,        /* Parsing and code generating context */
@@ -83807,36 +94393,83 @@ static void sqlite3ExprCodeIN(
   int destIfNull        /* Jump here if the results are unknown due to NULLs */
 ){
   int rRhsHasNull = 0;  /* Register that is true if RHS contains NULL values */
-  char affinity;        /* Comparison affinity to use */
   int eType;            /* Type of the RHS */
-  int r1;               /* Temporary use register */
+  int rLhs;             /* Register(s) holding the LHS values */
+  int rLhsOrig;         /* LHS values prior to reordering by aiMap[] */
   Vdbe *v;              /* Statement under construction */
+  int *aiMap = 0;       /* Map from vector field to index column */
+  char *zAff = 0;       /* Affinity string for comparisons */
+  int nVector;          /* Size of vectors for this IN operator */
+  int iDummy;           /* Dummy parameter to exprCodeVector() */
+  Expr *pLeft;          /* The LHS of the IN operator */
+  int i;                /* loop counter */
+  int destStep2;        /* Where to jump when NULLs seen in step 2 */
+  int destStep6 = 0;    /* Start of code for Step 6 */
+  int addrTruthOp;      /* Address of opcode that determines the IN is true */
+  int destNotNull;      /* Jump here if a comparison is not true in step 6 */
+  int addrTop;          /* Top of the step-6 loop */ 
+
+  pLeft = pExpr->pLeft;
+  if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
+  zAff = exprINAffinity(pParse, pExpr);
+  nVector = sqlite3ExprVectorSize(pExpr->pLeft);
+  aiMap = (int*)sqlite3DbMallocZero(
+      pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
+  );
+  if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;
 
-  /* Compute the RHS.   After this step, the table with cursor
-  ** pExpr->iTable will contains the values that make up the RHS.
-  */
+  /* Attempt to compute the RHS. After this step, if anything other than
+  ** IN_INDEX_NOOP is returned, the table opened ith cursor pExpr->iTable 
+  ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
+  ** the RHS has not yet been coded.  */
   v = pParse->pVdbe;
   assert( v!=0 );       /* OOM detected prior to this routine */
   VdbeNoopComment((v, "begin IN expr"));
   eType = sqlite3FindInIndex(pParse, pExpr,
                              IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
-                             destIfFalse==destIfNull ? 0 : &rRhsHasNull);
+                             destIfFalse==destIfNull ? 0 : &rRhsHasNull, aiMap);
 
-  /* Figure out the affinity to use to create a key from the results
-  ** of the expression. affinityStr stores a static string suitable for
-  ** P4 of OP_MakeRecord.
-  */
-  affinity = comparisonAffinity(pExpr);
+  assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
+       || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC 
+  );
+#ifdef SQLITE_DEBUG
+  /* Confirm that aiMap[] contains nVector integer values between 0 and
+  ** nVector-1. */
+  for(i=0; i from " IN (...)".
+  /* Code the LHS, the  from " IN (...)". If the LHS is a 
+  ** vector, then it is stored in an array of nVector registers starting 
+  ** at r1.
+  **
+  ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
+  ** so that the fields are in the same order as an existing index.   The
+  ** aiMap[] array contains a mapping from the original LHS field order to
+  ** the field order that matches the RHS index.
   */
   sqlite3ExprCachePush(pParse);
-  r1 = sqlite3GetTempReg(pParse);
-  sqlite3ExprCode(pParse, pExpr->pLeft, r1);
+  rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
+  for(i=0; ix.pList;
@@ -83848,7 +94481,7 @@ static void sqlite3ExprCodeIN(
     assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
     if( destIfNull!=destIfFalse ){
       regCkNull = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp3(v, OP_BitAnd, r1, r1, regCkNull);
+      sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
     }
     for(ii=0; iinExpr; ii++){
       r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, ®ToFree);
@@ -83856,111 +94489,135 @@ static void sqlite3ExprCodeIN(
         sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
       }
       if( iinExpr-1 || destIfNull!=destIfFalse ){
-        sqlite3VdbeAddOp4(v, OP_Eq, r1, labelOk, r2,
+        sqlite3VdbeAddOp4(v, OP_Eq, rLhs, labelOk, r2,
                           (void*)pColl, P4_COLLSEQ);
         VdbeCoverageIf(v, iinExpr-1);
         VdbeCoverageIf(v, ii==pList->nExpr-1);
-        sqlite3VdbeChangeP5(v, affinity);
+        sqlite3VdbeChangeP5(v, zAff[0]);
       }else{
         assert( destIfNull==destIfFalse );
-        sqlite3VdbeAddOp4(v, OP_Ne, r1, destIfFalse, r2,
+        sqlite3VdbeAddOp4(v, OP_Ne, rLhs, destIfFalse, r2,
                           (void*)pColl, P4_COLLSEQ); VdbeCoverage(v);
-        sqlite3VdbeChangeP5(v, affinity | SQLITE_JUMPIFNULL);
+        sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
       }
       sqlite3ReleaseTempReg(pParse, regToFree);
     }
     if( regCkNull ){
       sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
+      sqlite3VdbeGoto(v, destIfFalse);
     }
     sqlite3VdbeResolveLabel(v, labelOk);
     sqlite3ReleaseTempReg(pParse, regCkNull);
+    goto sqlite3ExprCodeIN_finished;
+  }
+
+  /* Step 2: Check to see if the LHS contains any NULL columns.  If the
+  ** LHS does contain NULLs then the result must be either FALSE or NULL.
+  ** We will then skip the binary search of the RHS.
+  */
+  if( destIfNull==destIfFalse ){
+    destStep2 = destIfFalse;
   }else{
-  
-    /* If the LHS is NULL, then the result is either false or NULL depending
-    ** on whether the RHS is empty or not, respectively.
-    */
-    if( sqlite3ExprCanBeNull(pExpr->pLeft) ){
-      if( destIfNull==destIfFalse ){
-        /* Shortcut for the common case where the false and NULL outcomes are
-        ** the same. */
-        sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); VdbeCoverage(v);
-      }else{
-        int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
-        VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
-        sqlite3VdbeJumpHere(v, addr1);
-      }
-    }
-  
-    if( eType==IN_INDEX_ROWID ){
-      /* In this case, the RHS is the ROWID of table b-tree
-      */
-      sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse); VdbeCoverage(v);
-      sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
+    destStep2 = destStep6 = sqlite3VdbeMakeLabel(v);
+  }
+  for(i=0; ipLeft, i);
+    if( sqlite3ExprCanBeNull(p) ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
       VdbeCoverage(v);
-    }else{
-      /* In this case, the RHS is an index b-tree.
-      */
-      sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
-  
-      /* If the set membership test fails, then the result of the 
-      ** "x IN (...)" expression must be either 0 or NULL. If the set
-      ** contains no NULL values, then the result is 0. If the set 
-      ** contains one or more NULL values, then the result of the
-      ** expression is also NULL.
-      */
-      assert( destIfFalse!=destIfNull || rRhsHasNull==0 );
-      if( rRhsHasNull==0 ){
-        /* This branch runs if it is known at compile time that the RHS
-        ** cannot contain NULL values. This happens as the result
-        ** of a "NOT NULL" constraint in the database schema.
-        **
-        ** Also run this branch if NULL is equivalent to FALSE
-        ** for this particular IN operator.
-        */
-        sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
-        VdbeCoverage(v);
-      }else{
-        /* In this branch, the RHS of the IN might contain a NULL and
-        ** the presence of a NULL on the RHS makes a difference in the
-        ** outcome.
-        */
-        int j1;
-  
-        /* First check to see if the LHS is contained in the RHS.  If so,
-        ** then the answer is TRUE the presence of NULLs in the RHS does
-        ** not matter.  If the LHS is not contained in the RHS, then the
-        ** answer is NULL if the RHS contains NULLs and the answer is
-        ** FALSE if the RHS is NULL-free.
-        */
-        j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
-        VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_IsNull, rRhsHasNull, destIfNull);
-        VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
-        sqlite3VdbeJumpHere(v, j1);
-      }
     }
   }
-  sqlite3ReleaseTempReg(pParse, r1);
+
+  /* Step 3.  The LHS is now known to be non-NULL.  Do the binary search
+  ** of the RHS using the LHS as a probe.  If found, the result is
+  ** true.
+  */
+  if( eType==IN_INDEX_ROWID ){
+    /* In this case, the RHS is the ROWID of table b-tree and so we also
+    ** know that the RHS is non-NULL.  Hence, we combine steps 3 and 4
+    ** into a single opcode. */
+    sqlite3VdbeAddOp3(v, OP_SeekRowid, pExpr->iTable, destIfFalse, rLhs);
+    VdbeCoverage(v);
+    addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto);  /* Return True */
+  }else{
+    sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
+    if( destIfFalse==destIfNull ){
+      /* Combine Step 3 and Step 5 into a single opcode */
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse,
+                           rLhs, nVector); VdbeCoverage(v);
+      goto sqlite3ExprCodeIN_finished;
+    }
+    /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
+    addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0,
+                                      rLhs, nVector); VdbeCoverage(v);
+  }
+
+  /* Step 4.  If the RHS is known to be non-NULL and we did not find
+  ** an match on the search above, then the result must be FALSE.
+  */
+  if( rRhsHasNull && nVector==1 ){
+    sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
+    VdbeCoverage(v);
+  }
+
+  /* Step 5.  If we do not care about the difference between NULL and
+  ** FALSE, then just return false. 
+  */
+  if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);
+
+  /* Step 6: Loop through rows of the RHS.  Compare each row to the LHS.
+  ** If any comparison is NULL, then the result is NULL.  If all
+  ** comparisons are FALSE then the final result is FALSE.
+  **
+  ** For a scalar LHS, it is sufficient to check just the first row
+  ** of the RHS.
+  */
+  if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
+  addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
+  VdbeCoverage(v);
+  if( nVector>1 ){
+    destNotNull = sqlite3VdbeMakeLabel(v);
+  }else{
+    /* For nVector==1, combine steps 6 and 7 by immediately returning
+    ** FALSE if the first comparison is not NULL */
+    destNotNull = destIfFalse;
+  }
+  for(i=0; iiTable, i, r3);
+    sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
+                      (void*)pColl, P4_COLLSEQ);
+    VdbeCoverage(v);
+    sqlite3ReleaseTempReg(pParse, r3);
+  }
+  sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
+  if( nVector>1 ){
+    sqlite3VdbeResolveLabel(v, destNotNull);
+    sqlite3VdbeAddOp2(v, OP_Next, pExpr->iTable, addrTop+1);
+    VdbeCoverage(v);
+
+    /* Step 7:  If we reach this point, we know that the result must
+    ** be false. */
+    sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
+  }
+
+  /* Jumps here in order to return true. */
+  sqlite3VdbeJumpHere(v, addrTruthOp);
+
+sqlite3ExprCodeIN_finished:
+  if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
   sqlite3ExprCachePop(pParse);
   VdbeComment((v, "end IN expr"));
+sqlite3ExprCodeIN_oom_error:
+  sqlite3DbFree(pParse->db, aiMap);
+  sqlite3DbFree(pParse->db, zAff);
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
-/*
-** Duplicate an 8-byte value
-*/
-static char *dup8bytes(Vdbe *v, const char *in){
-  char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
-  if( out ){
-    memcpy(out, in, 8);
-  }
-  return out;
-}
-
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Generate an instruction that will put the floating point
@@ -83973,12 +94630,10 @@ static char *dup8bytes(Vdbe *v, const char *in){
 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
   if( ALWAYS(z!=0) ){
     double value;
-    char *zV;
     sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
     assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
     if( negateFlag ) value = -value;
-    zV = dup8bytes(v, (char*)&value);
-    sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
+    sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
   }
 }
 #endif
@@ -84003,37 +94658,38 @@ static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
     const char *z = pExpr->u.zToken;
     assert( z!=0 );
     c = sqlite3DecOrHexToI64(z, &value);
-    if( c==0 || (c==2 && negFlag) ){
-      char *zV;
-      if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
-      zV = dup8bytes(v, (char*)&value);
-      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
-    }else{
+    if( c==1 || (c==2 && !negFlag) || (negFlag && value==SMALLEST_INT64)){
 #ifdef SQLITE_OMIT_FLOATING_POINT
       sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
 #else
 #ifndef SQLITE_OMIT_HEX_INTEGER
       if( sqlite3_strnicmp(z,"0x",2)==0 ){
-        sqlite3ErrorMsg(pParse, "hex literal too big: %s", z);
+        sqlite3ErrorMsg(pParse, "hex literal too big: %s%s", negFlag?"-":"",z);
       }else
 #endif
       {
         codeReal(v, z, negFlag, iMem);
       }
 #endif
+    }else{
+      if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
+      sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
     }
   }
 }
 
 /*
-** Clear a cache entry.
+** Erase column-cache entry number i
 */
-static void cacheEntryClear(Parse *pParse, struct yColCache *p){
-  if( p->tempReg ){
+static void cacheEntryClear(Parse *pParse, int i){
+  if( pParse->aColCache[i].tempReg ){
     if( pParse->nTempRegaTempReg) ){
-      pParse->aTempReg[pParse->nTempReg++] = p->iReg;
+      pParse->aTempReg[pParse->nTempReg++] = pParse->aColCache[i].iReg;
     }
-    p->tempReg = 0;
+  }
+  pParse->nColCache--;
+  if( inColCache ){
+    pParse->aColCache[i] = pParse->aColCache[pParse->nColCache];
   }
 }
 
@@ -84048,7 +94704,8 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
   int idxLru;
   struct yColCache *p;
 
-  assert( iReg>0 );  /* Register numbers are always positive */
+  /* Unless an error has occurred, register numbers are always positive. */
+  assert( iReg>0 || pParse->nErr || pParse->db->mallocFailed );
   assert( iCol>=-1 && iCol<32768 );  /* Finite column numbers */
 
   /* The SQLITE_ColumnCache flag disables the column cache.  This is used
@@ -84063,43 +94720,33 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
   ** that the object will never already be in cache.  Verify this guarantee.
   */
 #ifndef NDEBUG
-  for(i=0, p=pParse->aColCache; iiReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
+  for(i=0, p=pParse->aColCache; inColCache; i++, p++){
+    assert( p->iTable!=iTab || p->iColumn!=iCol );
   }
 #endif
 
-  /* Find an empty slot and replace it */
-  for(i=0, p=pParse->aColCache; iiReg==0 ){
-      p->iLevel = pParse->iCacheLevel;
-      p->iTable = iTab;
-      p->iColumn = iCol;
-      p->iReg = iReg;
-      p->tempReg = 0;
-      p->lru = pParse->iCacheCnt++;
-      return;
-    }
-  }
-
-  /* Replace the last recently used */
-  minLru = 0x7fffffff;
-  idxLru = -1;
-  for(i=0, p=pParse->aColCache; ilrulru;
+  /* If the cache is already full, delete the least recently used entry */
+  if( pParse->nColCache>=SQLITE_N_COLCACHE ){
+    minLru = 0x7fffffff;
+    idxLru = -1;
+    for(i=0, p=pParse->aColCache; ilrulru;
+      }
     }
-  }
-  if( ALWAYS(idxLru>=0) ){
     p = &pParse->aColCache[idxLru];
-    p->iLevel = pParse->iCacheLevel;
-    p->iTable = iTab;
-    p->iColumn = iCol;
-    p->iReg = iReg;
-    p->tempReg = 0;
-    p->lru = pParse->iCacheCnt++;
-    return;
+  }else{
+    p = &pParse->aColCache[pParse->nColCache++];
   }
+
+  /* Add the new entry to the end of the cache */
+  p->iLevel = pParse->iCacheLevel;
+  p->iTable = iTab;
+  p->iColumn = iCol;
+  p->iReg = iReg;
+  p->tempReg = 0;
+  p->lru = pParse->iCacheCnt++;
 }
 
 /*
@@ -84107,14 +94754,13 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
 ** Purge the range of registers from the column cache.
 */
 SQLITE_PRIVATE void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
-  int i;
-  int iLast = iReg + nReg - 1;
-  struct yColCache *p;
-  for(i=0, p=pParse->aColCache; iiReg;
-    if( r>=iReg && r<=iLast ){
-      cacheEntryClear(pParse, p);
-      p->iReg = 0;
+  int i = 0;
+  while( inColCache ){
+    struct yColCache *p = &pParse->aColCache[i];
+    if( p->iReg >= iReg && p->iReg < iReg+nReg ){
+      cacheEntryClear(pParse, i);
+    }else{
+      i++;
     }
   }
 }
@@ -84139,8 +94785,7 @@ SQLITE_PRIVATE void sqlite3ExprCachePush(Parse *pParse){
 ** the cache to the state it was in prior the most recent Push.
 */
 SQLITE_PRIVATE void sqlite3ExprCachePop(Parse *pParse){
-  int i;
-  struct yColCache *p;
+  int i = 0;
   assert( pParse->iCacheLevel>=1 );
   pParse->iCacheLevel--;
 #ifdef SQLITE_DEBUG
@@ -84148,10 +94793,11 @@ SQLITE_PRIVATE void sqlite3ExprCachePop(Parse *pParse){
     printf("POP  to %d\n", pParse->iCacheLevel);
   }
 #endif
-  for(i=0, p=pParse->aColCache; iiReg && p->iLevel>pParse->iCacheLevel ){
-      cacheEntryClear(pParse, p);
-      p->iReg = 0;
+  while( inColCache ){
+    if( pParse->aColCache[i].iLevel>pParse->iCacheLevel ){
+      cacheEntryClear(pParse, i);
+    }else{
+      i++;
     }
   }
 }
@@ -84165,13 +94811,36 @@ SQLITE_PRIVATE void sqlite3ExprCachePop(Parse *pParse){
 static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
   int i;
   struct yColCache *p;
-  for(i=0, p=pParse->aColCache; iaColCache; inColCache; i++, p++){
     if( p->iReg==iReg ){
       p->tempReg = 0;
     }
   }
 }
 
+/* Generate code that will load into register regOut a value that is
+** appropriate for the iIdxCol-th column of index pIdx.
+*/
+SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(
+  Parse *pParse,  /* The parsing context */
+  Index *pIdx,    /* The index whose column is to be loaded */
+  int iTabCur,    /* Cursor pointing to a table row */
+  int iIdxCol,    /* The column of the index to be loaded */
+  int regOut      /* Store the index column value in this register */
+){
+  i16 iTabCol = pIdx->aiColumn[iIdxCol];
+  if( iTabCol==XN_EXPR ){
+    assert( pIdx->aColExpr );
+    assert( pIdx->aColExpr->nExpr>iIdxCol );
+    pParse->iSelfTab = iTabCur + 1;
+    sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
+    pParse->iSelfTab = 0;
+  }else{
+    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
+                                    iTabCol, regOut);
+  }
+}
+
 /*
 ** Generate code to extract the value of the iCol-th column of a table.
 */
@@ -84182,12 +94851,16 @@ SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
   int iCol,       /* Index of the column to extract */
   int regOut      /* Extract the value into this register */
 ){
+  if( pTab==0 ){
+    sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut);
+    return;
+  }
   if( iCol<0 || iCol==pTab->iPKey ){
     sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
   }else{
     int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
     int x = iCol;
-    if( !HasRowid(pTab) ){
+    if( !HasRowid(pTab) && !IsVirtual(pTab) ){
       x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
     }
     sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
@@ -84199,9 +94872,12 @@ SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
 
 /*
 ** Generate code that will extract the iColumn-th column from
-** table pTab and store the column value in a register.  An effort
-** is made to store the column value in register iReg, but this is
-** not guaranteed.  The location of the column value is returned.
+** table pTab and store the column value in a register. 
+**
+** An effort is made to store the column value in register iReg.  This
+** is not garanteeed for GetColumn() - the result can be stored in
+** any register.  But the result is guaranteed to land in register iReg
+** for GetColumnToReg().
 **
 ** There must be an open cursor to pTab in iTable when this routine
 ** is called.  If iColumn<0 then code is generated that extracts the rowid.
@@ -84212,14 +94888,14 @@ SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(
   int iColumn,     /* Index of the table column */
   int iTable,      /* The cursor pointing to the table */
   int iReg,        /* Store results here */
-  u8 p5            /* P5 value for OP_Column */
+  u8 p5            /* P5 value for OP_Column + FLAGS */
 ){
   Vdbe *v = pParse->pVdbe;
   int i;
   struct yColCache *p;
 
-  for(i=0, p=pParse->aColCache; iiReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
+  for(i=0, p=pParse->aColCache; inColCache; i++, p++){
+    if( p->iTable==iTable && p->iColumn==iColumn ){
       p->lru = pParse->iCacheCnt++;
       sqlite3ExprCachePinRegister(pParse, p->iReg);
       return p->iReg;
@@ -84234,25 +94910,37 @@ SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(
   }
   return iReg;
 }
+SQLITE_PRIVATE void sqlite3ExprCodeGetColumnToReg(
+  Parse *pParse,   /* Parsing and code generating context */
+  Table *pTab,     /* Description of the table we are reading from */
+  int iColumn,     /* Index of the table column */
+  int iTable,      /* The cursor pointing to the table */
+  int iReg         /* Store results here */
+){
+  int r1 = sqlite3ExprCodeGetColumn(pParse, pTab, iColumn, iTable, iReg, 0);
+  if( r1!=iReg ) sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, r1, iReg);
+}
+
 
 /*
 ** Clear all column cache entries.
 */
 SQLITE_PRIVATE void sqlite3ExprCacheClear(Parse *pParse){
   int i;
-  struct yColCache *p;
 
-#if SQLITE_DEBUG
+#ifdef SQLITE_DEBUG
   if( pParse->db->flags & SQLITE_VdbeAddopTrace ){
     printf("CLEAR\n");
   }
 #endif
-  for(i=0, p=pParse->aColCache; iiReg ){
-      cacheEntryClear(pParse, p);
-      p->iReg = 0;
+  for(i=0; inColCache; i++){
+    if( pParse->aColCache[i].tempReg
+     && pParse->nTempRegaTempReg)
+    ){
+       pParse->aTempReg[pParse->nTempReg++] = pParse->aColCache[i].iReg;
     }
   }
+  pParse->nColCache = 0;
 }
 
 /*
@@ -84284,7 +94972,7 @@ SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int n
 static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
   int i;
   struct yColCache *p;
-  for(i=0, p=pParse->aColCache; iaColCache; inColCache; i++, p++){
     int r = p->iReg;
     if( r>=iFrom && r<=iTo ) return 1;    /*NO_TEST*/
   }
@@ -84292,8 +94980,11 @@ static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
 }
 #endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
 
+
 /*
-** Convert an expression node to a TK_REGISTER
+** Convert a scalar expression node to a TK_REGISTER referencing
+** register iReg.  The caller must ensure that iReg already contains
+** the correct value for the expression.
 */
 static void exprToRegister(Expr *p, int iReg){
   p->op2 = p->op;
@@ -84302,6 +94993,42 @@ static void exprToRegister(Expr *p, int iReg){
   ExprClearProperty(p, EP_Skip);
 }
 
+/*
+** Evaluate an expression (either a vector or a scalar expression) and store
+** the result in continguous temporary registers.  Return the index of
+** the first register used to store the result.
+**
+** If the returned result register is a temporary scalar, then also write
+** that register number into *piFreeable.  If the returned result register
+** is not a temporary or if the expression is a vector set *piFreeable
+** to 0.
+*/
+static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
+  int iResult;
+  int nResult = sqlite3ExprVectorSize(p);
+  if( nResult==1 ){
+    iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
+  }else{
+    *piFreeable = 0;
+    if( p->op==TK_SELECT ){
+#if SQLITE_OMIT_SUBQUERY
+      iResult = 0;
+#else
+      iResult = sqlite3CodeSubselect(pParse, p, 0, 0);
+#endif
+    }else{
+      int i;
+      iResult = pParse->nMem+1;
+      pParse->nMem += nResult;
+      for(i=0; ix.pList->a[i].pExpr, i+iResult);
+      }
+    }
+  }
+  return iResult;
+}
+
+
 /*
 ** Generate code into the current Vdbe to evaluate the given
 ** expression.  Attempt to store the results in register "target".
@@ -84319,9 +95046,9 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
   int inReg = target;       /* Results stored in register inReg */
   int regFree1 = 0;         /* If non-zero free this temporary register */
   int regFree2 = 0;         /* If non-zero free this temporary register */
-  int r1, r2, r3, r4;       /* Various register numbers */
-  sqlite3 *db = pParse->db; /* The database connection */
+  int r1, r2;               /* Various register numbers */
   Expr tempX;               /* Temporary expression node */
+  int p5 = 0;
 
   assert( target>0 && target<=pParse->nMem );
   if( v==0 ){
@@ -84340,51 +95067,49 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
       if( !pAggInfo->directMode ){
         assert( pCol->iMem>0 );
-        inReg = pCol->iMem;
-        break;
+        return pCol->iMem;
       }else if( pAggInfo->useSortingIdx ){
         sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                               pCol->iSorterColumn, target);
-        break;
+        return target;
       }
       /* Otherwise, fall thru into the TK_COLUMN case */
     }
     case TK_COLUMN: {
       int iTab = pExpr->iTable;
       if( iTab<0 ){
-        if( pParse->ckBase>0 ){
+        if( pParse->iSelfTab<0 ){
           /* Generating CHECK constraints or inserting into partial index */
-          inReg = pExpr->iColumn + pParse->ckBase;
-          break;
+          return pExpr->iColumn - pParse->iSelfTab;
         }else{
-          /* Deleting from a partial index */
-          iTab = pParse->iPartIdxTab;
+          /* Coding an expression that is part of an index where column names
+          ** in the index refer to the table to which the index belongs */
+          iTab = pParse->iSelfTab - 1;
         }
       }
-      inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
+      return sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
                                pExpr->iColumn, iTab, target,
                                pExpr->op2);
-      break;
     }
     case TK_INTEGER: {
       codeInteger(pParse, pExpr, 0, target);
-      break;
+      return target;
     }
 #ifndef SQLITE_OMIT_FLOATING_POINT
     case TK_FLOAT: {
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
       codeReal(v, pExpr->u.zToken, 0, target);
-      break;
+      return target;
     }
 #endif
     case TK_STRING: {
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
-      sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0);
-      break;
+      sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
+      return target;
     }
     case TK_NULL: {
       sqlite3VdbeAddOp2(v, OP_Null, 0, target);
-      break;
+      return target;
     }
 #ifndef SQLITE_OMIT_BLOB_LITERAL
     case TK_BLOB: {
@@ -84399,7 +95124,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       assert( z[n]=='\'' );
       zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
       sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
-      break;
+      return target;
     }
 #endif
     case TK_VARIABLE: {
@@ -84408,19 +95133,15 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       assert( pExpr->u.zToken[0]!=0 );
       sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
       if( pExpr->u.zToken[1]!=0 ){
-        assert( pExpr->u.zToken[0]=='?' 
-             || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
-        sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
+        const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
+        assert( pExpr->u.zToken[0]=='?' || strcmp(pExpr->u.zToken, z)==0 );
+        pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */
+        sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
       }
-      break;
+      return target;
     }
     case TK_REGISTER: {
-      inReg = pExpr->iTable;
-      break;
-    }
-    case TK_AS: {
-      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
-      break;
+      return pExpr->iTable;
     }
 #ifndef SQLITE_OMIT_CAST
     case TK_CAST: {
@@ -84434,42 +95155,37 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
                         sqlite3AffinityType(pExpr->u.zToken, 0));
       testcase( usedAsColumnCache(pParse, inReg, inReg) );
       sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
-      break;
+      return inReg;
     }
 #endif /* SQLITE_OMIT_CAST */
+    case TK_IS:
+    case TK_ISNOT:
+      op = (op==TK_IS) ? TK_EQ : TK_NE;
+      p5 = SQLITE_NULLEQ;
+      /* fall-through */
     case TK_LT:
     case TK_LE:
     case TK_GT:
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, inReg, SQLITE_STOREP2);
-      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
-      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
-      assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
-      assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
-      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
-      assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      break;
-    }
-    case TK_IS:
-    case TK_ISNOT: {
-      testcase( op==TK_IS );
-      testcase( op==TK_ISNOT );
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
-      op = (op==TK_IS) ? TK_EQ : TK_NE;
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
-      VdbeCoverageIf(v, op==TK_EQ);
-      VdbeCoverageIf(v, op==TK_NE);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
+      Expr *pLeft = pExpr->pLeft;
+      if( sqlite3ExprIsVector(pLeft) ){
+        codeVectorCompare(pParse, pExpr, target, op, p5);
+      }else{
+        r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
+        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
+        codeCompare(pParse, pLeft, pExpr->pRight, op,
+            r1, r2, inReg, SQLITE_STOREP2 | p5);
+        assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
+        assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
+        assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
+        assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
+        assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
+        assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
+        testcase( regFree1==0 );
+        testcase( regFree2==0 );
+      }
       break;
     }
     case TK_AND:
@@ -84507,10 +95223,12 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       assert( pLeft );
       if( pLeft->op==TK_INTEGER ){
         codeInteger(pParse, pLeft, 1, target);
+        return target;
 #ifndef SQLITE_OMIT_FLOATING_POINT
       }else if( pLeft->op==TK_FLOAT ){
         assert( !ExprHasProperty(pExpr, EP_IntValue) );
         codeReal(v, pLeft->u.zToken, 1, target);
+        return target;
 #endif
       }else{
         tempX.op = TK_INTEGER;
@@ -84521,7 +95239,6 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
         testcase( regFree2==0 );
       }
-      inReg = target;
       break;
     }
     case TK_BITNOT:
@@ -84530,7 +95247,6 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       assert( TK_NOT==OP_Not );         testcase( op==TK_NOT );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
       testcase( regFree1==0 );
-      inReg = target;
       sqlite3VdbeAddOp2(v, op, r1, inReg);
       break;
     }
@@ -84555,7 +95271,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         assert( !ExprHasProperty(pExpr, EP_IntValue) );
         sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
       }else{
-        inReg = pInfo->aFunc[pExpr->iAgg].iMem;
+        return pInfo->aFunc[pExpr->iAgg].iMem;
       }
       break;
     }
@@ -84563,13 +95279,18 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       ExprList *pFarg;       /* List of function arguments */
       int nFarg;             /* Number of function arguments */
       FuncDef *pDef;         /* The function definition object */
-      int nId;               /* Length of the function name in bytes */
       const char *zId;       /* The function name */
       u32 constMask = 0;     /* Mask of function arguments that are constant */
       int i;                 /* Loop counter */
+      sqlite3 *db = pParse->db;  /* The database connection */
       u8 enc = ENC(db);      /* The text encoding used by this database */
       CollSeq *pColl = 0;    /* A collating sequence */
 
+      if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
+        /* SQL functions can be expensive. So try to move constant functions
+        ** out of the inner loop, even if that means an extra OP_Copy. */
+        return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
+      }
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
       if( ExprHasProperty(pExpr, EP_TokenOnly) ){
         pFarg = 0;
@@ -84579,10 +95300,14 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       nFarg = pFarg ? pFarg->nExpr : 0;
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
       zId = pExpr->u.zToken;
-      nId = sqlite3Strlen30(zId);
-      pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
-      if( pDef==0 || pDef->xFunc==0 ){
-        sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
+      pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+      if( pDef==0 && pParse->explain ){
+        pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
+      }
+#endif
+      if( pDef==0 || pDef->xFinalize!=0 ){
+        sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);
         break;
       }
 
@@ -84611,9 +95336,24 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       */
       if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
         assert( nFarg>=1 );
-        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
-        break;
+        return sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
+      }
+
+#ifdef SQLITE_DEBUG
+      /* The AFFINITY() function evaluates to a string that describes
+      ** the type affinity of the argument.  This is used for testing of
+      ** the SQLite type logic.
+      */
+      if( pDef->funcFlags & SQLITE_FUNC_AFFINITY ){
+        const char *azAff[] = { "blob", "text", "numeric", "integer", "real" };
+        char aff;
+        assert( nFarg==1 );
+        aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);
+        sqlite3VdbeLoadString(v, target, 
+                              aff ? azAff[aff-SQLITE_AFF_BLOB] : "none");
+        return target;
       }
+#endif
 
       for(i=0; ia[i].pExpr) ){
@@ -84652,7 +95392,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         }
 
         sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
-        sqlite3ExprCodeExprList(pParse, pFarg, r1,
+        sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
                                 SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
         sqlite3ExprCachePop(pParse);      /* Ticket 2ea2425d34be */
       }else{
@@ -84681,22 +95421,41 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         if( !pColl ) pColl = db->pDfltColl; 
         sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
       }
-      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
-                        (char*)pDef, P4_FUNCDEF);
+      sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
+                        constMask, r1, target, (char*)pDef, P4_FUNCDEF);
       sqlite3VdbeChangeP5(v, (u8)nFarg);
       if( nFarg && constMask==0 ){
         sqlite3ReleaseTempRange(pParse, r1, nFarg);
       }
-      break;
+      return target;
     }
 #ifndef SQLITE_OMIT_SUBQUERY
     case TK_EXISTS:
     case TK_SELECT: {
+      int nCol;
       testcase( op==TK_EXISTS );
       testcase( op==TK_SELECT );
-      inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
+      if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
+        sqlite3SubselectError(pParse, nCol, 1);
+      }else{
+        return sqlite3CodeSubselect(pParse, pExpr, 0, 0);
+      }
       break;
     }
+    case TK_SELECT_COLUMN: {
+      int n;
+      if( pExpr->pLeft->iTable==0 ){
+        pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft, 0, 0);
+      }
+      assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );
+      if( pExpr->iTable
+       && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft)) 
+      ){
+        sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
+                                pExpr->iTable, n);
+      }
+      return pExpr->pLeft->iTable + pExpr->iColumn;
+    }
     case TK_IN: {
       int destIfFalse = sqlite3VdbeMakeLabel(v);
       int destIfNull = sqlite3VdbeMakeLabel(v);
@@ -84706,7 +95465,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       sqlite3VdbeResolveLabel(v, destIfFalse);
       sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
       sqlite3VdbeResolveLabel(v, destIfNull);
-      break;
+      return target;
     }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
@@ -84723,34 +95482,13 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     ** Z is stored in pExpr->pList->a[1].pExpr.
     */
     case TK_BETWEEN: {
-      Expr *pLeft = pExpr->pLeft;
-      struct ExprList_item *pLItem = pExpr->x.pList->a;
-      Expr *pRight = pLItem->pExpr;
-
-      r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
-      r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      r3 = sqlite3GetTempReg(pParse);
-      r4 = sqlite3GetTempReg(pParse);
-      codeCompare(pParse, pLeft, pRight, OP_Ge,
-                  r1, r2, r3, SQLITE_STOREP2);  VdbeCoverage(v);
-      pLItem++;
-      pRight = pLItem->pExpr;
-      sqlite3ReleaseTempReg(pParse, regFree2);
-      r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2);
-      testcase( regFree2==0 );
-      codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
-      VdbeCoverage(v);
-      sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
-      sqlite3ReleaseTempReg(pParse, r3);
-      sqlite3ReleaseTempReg(pParse, r4);
-      break;
+      exprCodeBetween(pParse, pExpr, target, 0, 0);
+      return target;
     }
+    case TK_SPAN:
     case TK_COLLATE: 
     case TK_UPLUS: {
-      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
-      break;
+      return sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
     }
 
     case TK_TRIGGER: {
@@ -84809,6 +95547,21 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       break;
     }
 
+    case TK_VECTOR: {
+      sqlite3ErrorMsg(pParse, "row value misused");
+      break;
+    }
+
+    case TK_IF_NULL_ROW: {
+      int addrINR;
+      addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
+      sqlite3ExprCachePush(pParse);
+      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+      sqlite3ExprCachePop(pParse);
+      sqlite3VdbeJumpHere(v, addrINR);
+      sqlite3VdbeChangeP3(v, addrINR, inReg);
+      break;
+    }
 
     /*
     ** Form A:
@@ -84852,8 +95605,9 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       if( (pX = pExpr->pLeft)!=0 ){
         tempX = *pX;
         testcase( pX->op==TK_COLUMN );
-        exprToRegister(&tempX, sqlite3ExprCodeTemp(pParse, pX, ®Free1));
+        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, ®Free1));
         testcase( regFree1==0 );
+        memset(&opCompare, 0, sizeof(opCompare));
         opCompare.op = TK_EQ;
         opCompare.pLeft = &tempX;
         pTest = &opCompare;
@@ -84876,7 +95630,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
         testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
         sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
+        sqlite3VdbeGoto(v, endLabel);
         sqlite3ExprCachePop(pParse);
         sqlite3VdbeResolveLabel(v, nextCase);
       }
@@ -84887,7 +95641,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, target);
       }
-      assert( db->mallocFailed || pParse->nErr>0 
+      assert( pParse->db->mallocFailed || pParse->nErr>0 
            || pParse->iCacheLevel==iCacheLevel );
       sqlite3VdbeResolveLabel(v, endLabel);
       break;
@@ -84928,24 +95682,40 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
 
 /*
 ** Factor out the code of the given expression to initialization time.
+**
+** If regDest>=0 then the result is always stored in that register and the
+** result is not reusable.  If regDest<0 then this routine is free to 
+** store the value whereever it wants.  The register where the expression 
+** is stored is returned.  When regDest<0, two identical expressions will
+** code to the same register.
 */
-SQLITE_PRIVATE void sqlite3ExprCodeAtInit(
+SQLITE_PRIVATE int sqlite3ExprCodeAtInit(
   Parse *pParse,    /* Parsing context */
   Expr *pExpr,      /* The expression to code when the VDBE initializes */
-  int regDest,      /* Store the value in this register */
-  u8 reusable       /* True if this expression is reusable */
+  int regDest       /* Store the value in this register */
 ){
   ExprList *p;
   assert( ConstFactorOk(pParse) );
   p = pParse->pConstExpr;
+  if( regDest<0 && p ){
+    struct ExprList_item *pItem;
+    int i;
+    for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
+      if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){
+        return pItem->u.iConstExprReg;
+      }
+    }
+  }
   pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
   p = sqlite3ExprListAppend(pParse, p, pExpr);
   if( p ){
      struct ExprList_item *pItem = &p->a[p->nExpr-1];
+     pItem->reusable = regDest<0;
+     if( regDest<0 ) regDest = ++pParse->nMem;
      pItem->u.iConstExprReg = regDest;
-     pItem->reusable = reusable;
   }
   pParse->pConstExpr = p;
+  return regDest;
 }
 
 /*
@@ -84968,19 +95738,8 @@ SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
    && pExpr->op!=TK_REGISTER
    && sqlite3ExprIsConstantNotJoin(pExpr)
   ){
-    ExprList *p = pParse->pConstExpr;
-    int i;
     *pReg  = 0;
-    if( p ){
-      struct ExprList_item *pItem;
-      for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
-        if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
-          return pItem->u.iConstExprReg;
-        }
-      }
-    }
-    r2 = ++pParse->nMem;
-    sqlite3ExprCodeAtInit(pParse, pExpr, r2, 1);
+    r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);
   }else{
     int r1 = sqlite3GetTempReg(pParse);
     r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
@@ -85007,13 +95766,25 @@ SQLITE_PRIVATE void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
     sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
   }else{
     inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
-    assert( pParse->pVdbe || pParse->db->mallocFailed );
+    assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
     if( inReg!=target && pParse->pVdbe ){
       sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
     }
   }
 }
 
+/*
+** Make a transient copy of expression pExpr and then code it using
+** sqlite3ExprCode().  This routine works just like sqlite3ExprCode()
+** except that the input expression is guaranteed to be unchanged.
+*/
+SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
+  sqlite3 *db = pParse->db;
+  pExpr = sqlite3ExprDup(db, pExpr, 0);
+  if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
+  sqlite3ExprDelete(db, pExpr);
+}
+
 /*
 ** Generate code that will evaluate expression pExpr and store the
 ** results in register target.  The results are guaranteed to appear
@@ -85022,7 +95793,7 @@ SQLITE_PRIVATE void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
 */
 SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
   if( pParse->okConstFactor && sqlite3ExprIsConstant(pExpr) ){
-    sqlite3ExprCodeAtInit(pParse, pExpr, target, 0);
+    sqlite3ExprCodeAtInit(pParse, pExpr, target);
   }else{
     sqlite3ExprCode(pParse, pExpr, target);
   }
@@ -85052,268 +95823,6 @@ SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int targ
   exprToRegister(pExpr, iMem);
 }
 
-#ifdef SQLITE_DEBUG
-/*
-** Generate a human-readable explanation of an expression tree.
-*/
-SQLITE_PRIVATE void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){
-  const char *zBinOp = 0;   /* Binary operator */
-  const char *zUniOp = 0;   /* Unary operator */
-  pView = sqlite3TreeViewPush(pView, moreToFollow);
-  if( pExpr==0 ){
-    sqlite3TreeViewLine(pView, "nil");
-    sqlite3TreeViewPop(pView);
-    return;
-  }
-  switch( pExpr->op ){
-    case TK_AGG_COLUMN: {
-      sqlite3TreeViewLine(pView, "AGG{%d:%d}",
-            pExpr->iTable, pExpr->iColumn);
-      break;
-    }
-    case TK_COLUMN: {
-      if( pExpr->iTable<0 ){
-        /* This only happens when coding check constraints */
-        sqlite3TreeViewLine(pView, "COLUMN(%d)", pExpr->iColumn);
-      }else{
-        sqlite3TreeViewLine(pView, "{%d:%d}",
-                             pExpr->iTable, pExpr->iColumn);
-      }
-      break;
-    }
-    case TK_INTEGER: {
-      if( pExpr->flags & EP_IntValue ){
-        sqlite3TreeViewLine(pView, "%d", pExpr->u.iValue);
-      }else{
-        sqlite3TreeViewLine(pView, "%s", pExpr->u.zToken);
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_FLOATING_POINT
-    case TK_FLOAT: {
-      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
-      break;
-    }
-#endif
-    case TK_STRING: {
-      sqlite3TreeViewLine(pView,"%Q", pExpr->u.zToken);
-      break;
-    }
-    case TK_NULL: {
-      sqlite3TreeViewLine(pView,"NULL");
-      break;
-    }
-#ifndef SQLITE_OMIT_BLOB_LITERAL
-    case TK_BLOB: {
-      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
-      break;
-    }
-#endif
-    case TK_VARIABLE: {
-      sqlite3TreeViewLine(pView,"VARIABLE(%s,%d)",
-                          pExpr->u.zToken, pExpr->iColumn);
-      break;
-    }
-    case TK_REGISTER: {
-      sqlite3TreeViewLine(pView,"REGISTER(%d)", pExpr->iTable);
-      break;
-    }
-    case TK_AS: {
-      sqlite3TreeViewLine(pView,"AS %Q", pExpr->u.zToken);
-      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
-      break;
-    }
-    case TK_ID: {
-      sqlite3TreeViewLine(pView,"ID %Q", pExpr->u.zToken);
-      break;
-    }
-#ifndef SQLITE_OMIT_CAST
-    case TK_CAST: {
-      /* Expressions of the form:   CAST(pLeft AS token) */
-      sqlite3TreeViewLine(pView,"CAST %Q", pExpr->u.zToken);
-      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
-      break;
-    }
-#endif /* SQLITE_OMIT_CAST */
-    case TK_LT:      zBinOp = "LT";     break;
-    case TK_LE:      zBinOp = "LE";     break;
-    case TK_GT:      zBinOp = "GT";     break;
-    case TK_GE:      zBinOp = "GE";     break;
-    case TK_NE:      zBinOp = "NE";     break;
-    case TK_EQ:      zBinOp = "EQ";     break;
-    case TK_IS:      zBinOp = "IS";     break;
-    case TK_ISNOT:   zBinOp = "ISNOT";  break;
-    case TK_AND:     zBinOp = "AND";    break;
-    case TK_OR:      zBinOp = "OR";     break;
-    case TK_PLUS:    zBinOp = "ADD";    break;
-    case TK_STAR:    zBinOp = "MUL";    break;
-    case TK_MINUS:   zBinOp = "SUB";    break;
-    case TK_REM:     zBinOp = "REM";    break;
-    case TK_BITAND:  zBinOp = "BITAND"; break;
-    case TK_BITOR:   zBinOp = "BITOR";  break;
-    case TK_SLASH:   zBinOp = "DIV";    break;
-    case TK_LSHIFT:  zBinOp = "LSHIFT"; break;
-    case TK_RSHIFT:  zBinOp = "RSHIFT"; break;
-    case TK_CONCAT:  zBinOp = "CONCAT"; break;
-    case TK_DOT:     zBinOp = "DOT";    break;
-
-    case TK_UMINUS:  zUniOp = "UMINUS"; break;
-    case TK_UPLUS:   zUniOp = "UPLUS";  break;
-    case TK_BITNOT:  zUniOp = "BITNOT"; break;
-    case TK_NOT:     zUniOp = "NOT";    break;
-    case TK_ISNULL:  zUniOp = "ISNULL"; break;
-    case TK_NOTNULL: zUniOp = "NOTNULL"; break;
-
-    case TK_COLLATE: {
-      sqlite3TreeViewLine(pView, "COLLATE %Q", pExpr->u.zToken);
-      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
-      break;
-    }
-
-    case TK_AGG_FUNCTION:
-    case TK_FUNCTION: {
-      ExprList *pFarg;       /* List of function arguments */
-      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
-        pFarg = 0;
-      }else{
-        pFarg = pExpr->x.pList;
-      }
-      if( pExpr->op==TK_AGG_FUNCTION ){
-        sqlite3TreeViewLine(pView, "AGG_FUNCTION%d %Q",
-                             pExpr->op2, pExpr->u.zToken);
-      }else{
-        sqlite3TreeViewLine(pView, "FUNCTION %Q", pExpr->u.zToken);
-      }
-      if( pFarg ){
-        sqlite3TreeViewExprList(pView, pFarg, 0, 0);
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_SUBQUERY
-    case TK_EXISTS: {
-      sqlite3TreeViewLine(pView, "EXISTS-expr");
-      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
-      break;
-    }
-    case TK_SELECT: {
-      sqlite3TreeViewLine(pView, "SELECT-expr");
-      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
-      break;
-    }
-    case TK_IN: {
-      sqlite3TreeViewLine(pView, "IN");
-      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
-      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-        sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
-      }else{
-        sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
-      }
-      break;
-    }
-#endif /* SQLITE_OMIT_SUBQUERY */
-
-    /*
-    **    x BETWEEN y AND z
-    **
-    ** This is equivalent to
-    **
-    **    x>=y AND x<=z
-    **
-    ** X is stored in pExpr->pLeft.
-    ** Y is stored in pExpr->pList->a[0].pExpr.
-    ** Z is stored in pExpr->pList->a[1].pExpr.
-    */
-    case TK_BETWEEN: {
-      Expr *pX = pExpr->pLeft;
-      Expr *pY = pExpr->x.pList->a[0].pExpr;
-      Expr *pZ = pExpr->x.pList->a[1].pExpr;
-      sqlite3TreeViewLine(pView, "BETWEEN");
-      sqlite3TreeViewExpr(pView, pX, 1);
-      sqlite3TreeViewExpr(pView, pY, 1);
-      sqlite3TreeViewExpr(pView, pZ, 0);
-      break;
-    }
-    case TK_TRIGGER: {
-      /* If the opcode is TK_TRIGGER, then the expression is a reference
-      ** to a column in the new.* or old.* pseudo-tables available to
-      ** trigger programs. In this case Expr.iTable is set to 1 for the
-      ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
-      ** is set to the column of the pseudo-table to read, or to -1 to
-      ** read the rowid field.
-      */
-      sqlite3TreeViewLine(pView, "%s(%d)", 
-          pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
-      break;
-    }
-    case TK_CASE: {
-      sqlite3TreeViewLine(pView, "CASE");
-      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
-      sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
-      break;
-    }
-#ifndef SQLITE_OMIT_TRIGGER
-    case TK_RAISE: {
-      const char *zType = "unk";
-      switch( pExpr->affinity ){
-        case OE_Rollback:   zType = "rollback";  break;
-        case OE_Abort:      zType = "abort";     break;
-        case OE_Fail:       zType = "fail";      break;
-        case OE_Ignore:     zType = "ignore";    break;
-      }
-      sqlite3TreeViewLine(pView, "RAISE %s(%Q)", zType, pExpr->u.zToken);
-      break;
-    }
-#endif
-    default: {
-      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
-      break;
-    }
-  }
-  if( zBinOp ){
-    sqlite3TreeViewLine(pView, "%s", zBinOp);
-    sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
-    sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
-  }else if( zUniOp ){
-    sqlite3TreeViewLine(pView, "%s", zUniOp);
-    sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
-  }
-  sqlite3TreeViewPop(pView);
-}
-#endif /* SQLITE_DEBUG */
-
-#ifdef SQLITE_DEBUG
-/*
-** Generate a human-readable explanation of an expression list.
-*/
-SQLITE_PRIVATE void sqlite3TreeViewExprList(
-  TreeView *pView,
-  const ExprList *pList,
-  u8 moreToFollow,
-  const char *zLabel
-){
-  int i;
-  pView = sqlite3TreeViewPush(pView, moreToFollow);
-  if( zLabel==0 || zLabel[0]==0 ) zLabel = "LIST";
-  if( pList==0 ){
-    sqlite3TreeViewLine(pView, "%s (empty)", zLabel);
-  }else{
-    sqlite3TreeViewLine(pView, "%s", zLabel);
-    for(i=0; inExpr; i++){
-      sqlite3TreeViewExpr(pView, pList->a[i].pExpr, inExpr-1);
-#if 0
-     if( pList->a[i].zName ){
-        sqlite3ExplainPrintf(pOut, " AS %s", pList->a[i].zName);
-      }
-      if( pList->a[i].bSpanIsTab ){
-        sqlite3ExplainPrintf(pOut, " (%s)", pList->a[i].zSpan);
-      }
-#endif
-    }
-  }
-  sqlite3TreeViewPop(pView);
-}
-#endif /* SQLITE_DEBUG */
-
 /*
 ** Generate code that pushes the value of every element of the given
 ** expression list into a sequence of registers beginning at target.
@@ -85325,16 +95834,22 @@ SQLITE_PRIVATE void sqlite3TreeViewExprList(
 **
 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
 ** factored out into initialization code.
+**
+** The SQLITE_ECEL_REF flag means that expressions in the list with
+** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
+** in registers at srcReg, and so the value can be copied from there.
 */
 SQLITE_PRIVATE int sqlite3ExprCodeExprList(
   Parse *pParse,     /* Parsing context */
   ExprList *pList,   /* The expression list to be coded */
   int target,        /* Where to write results */
+  int srcReg,        /* Source registers if SQLITE_ECEL_REF */
   u8 flags           /* SQLITE_ECEL_* flags */
 ){
   struct ExprList_item *pItem;
-  int i, n;
+  int i, j, n;
   u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
+  Vdbe *v = pParse->pVdbe;
   assert( pList!=0 );
   assert( target>0 );
   assert( pParse->pVdbe!=0 );  /* Never gets this far otherwise */
@@ -85342,13 +95857,19 @@ SQLITE_PRIVATE int sqlite3ExprCodeExprList(
   if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
   for(pItem=pList->a, i=0; ipExpr;
-    if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
-      sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
+    if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
+      if( flags & SQLITE_ECEL_OMITREF ){
+        i--;
+        n--;
+      }else{
+        sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
+      }
+    }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
+      sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
     }else{
       int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
       if( inReg!=target+i ){
         VdbeOp *pOp;
-        Vdbe *v = pParse->pVdbe;
         if( copyOp==OP_Copy
          && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
          && pOp->p1+pOp->p3+1==inReg
@@ -85375,20 +95896,33 @@ SQLITE_PRIVATE int sqlite3ExprCodeExprList(
 **
 ** Code it as such, taking care to do the common subexpression
 ** elimination of x.
+**
+** The xJumpIf parameter determines details:
+**
+**    NULL:                   Store the boolean result in reg[dest]
+**    sqlite3ExprIfTrue:      Jump to dest if true
+**    sqlite3ExprIfFalse:     Jump to dest if false
+**
+** The jumpIfNull parameter is ignored if xJumpIf is NULL.
 */
 static void exprCodeBetween(
   Parse *pParse,    /* Parsing and code generating context */
   Expr *pExpr,      /* The BETWEEN expression */
-  int dest,         /* Jump here if the jump is taken */
-  int jumpIfTrue,   /* Take the jump if the BETWEEN is true */
+  int dest,         /* Jump destination or storage location */
+  void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
   int jumpIfNull    /* Take the jump if the BETWEEN is NULL */
 ){
-  Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
+ Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
   Expr compLeft;    /* The  x>=y  term */
   Expr compRight;   /* The  x<=z  term */
   Expr exprX;       /* The  x  subexpression */
   int regFree1 = 0; /* Temporary use register */
 
+
+  memset(&compLeft, 0, sizeof(Expr));
+  memset(&compRight, 0, sizeof(Expr));
+  memset(&exprAnd, 0, sizeof(Expr));
+
   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
   exprX = *pExpr->pLeft;
   exprAnd.op = TK_AND;
@@ -85400,23 +95934,30 @@ static void exprCodeBetween(
   compRight.op = TK_LE;
   compRight.pLeft = &exprX;
   compRight.pRight = pExpr->x.pList->a[1].pExpr;
-  exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, ®Free1));
-  if( jumpIfTrue ){
-    sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
-  }else{
-    sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
+  exprToRegister(&exprX, exprCodeVector(pParse, &exprX, ®Free1));
+  if( xJump ){
+    xJump(pParse, &exprAnd, dest, jumpIfNull);
+  }else{
+    /* Mark the expression is being from the ON or USING clause of a join
+    ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
+    ** it into the Parse.pConstExpr list.  We should use a new bit for this,
+    ** for clarity, but we are out of bits in the Expr.flags field so we
+    ** have to reuse the EP_FromJoin bit.  Bummer. */
+    exprX.flags |= EP_FromJoin;
+    sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
   }
   sqlite3ReleaseTempReg(pParse, regFree1);
 
   /* Ensure adequate test coverage */
-  testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 );
-  testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 );
-  testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 );
-  testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 );
-  testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 );
-  testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 );
-  testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 );
-  testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=0 );
+  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1==0 );
+  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1!=0 );
+  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1==0 );
+  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1!=0 );
+  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
+  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
+  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
+  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
+  testcase( xJump==0 );
 }
 
 /*
@@ -85468,12 +96009,20 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
       break;
     }
+    case TK_IS:
+    case TK_ISNOT:
+      testcase( op==TK_IS );
+      testcase( op==TK_ISNOT );
+      op = (op==TK_IS) ? TK_EQ : TK_NE;
+      jumpIfNull = SQLITE_NULLEQ;
+      /* Fall thru */
     case TK_LT:
     case TK_LE:
     case TK_GT:
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
+      if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
       testcase( jumpIfNull==0 );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
@@ -85483,23 +96032,12 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
       assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
-      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
-      assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      break;
-    }
-    case TK_IS:
-    case TK_ISNOT: {
-      testcase( op==TK_IS );
-      testcase( op==TK_ISNOT );
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
-      op = (op==TK_IS) ? TK_EQ : TK_NE;
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, SQLITE_NULLEQ);
-      VdbeCoverageIf(v, op==TK_EQ);
-      VdbeCoverageIf(v, op==TK_NE);
+      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
+      assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
@@ -85517,7 +96055,7 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
     }
     case TK_BETWEEN: {
       testcase( jumpIfNull==0 );
-      exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
+      exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
       break;
     }
 #ifndef SQLITE_OMIT_SUBQUERY
@@ -85525,14 +96063,15 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
       int destIfFalse = sqlite3VdbeMakeLabel(v);
       int destIfNull = jumpIfNull ? dest : destIfFalse;
       sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
+      sqlite3VdbeGoto(v, dest);
       sqlite3VdbeResolveLabel(v, destIfFalse);
       break;
     }
 #endif
     default: {
+    default_expr:
       if( exprAlwaysTrue(pExpr) ){
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
+        sqlite3VdbeGoto(v, dest);
       }else if( exprAlwaysFalse(pExpr) ){
         /* No-op */
       }else{
@@ -85624,12 +96163,20 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
       break;
     }
+    case TK_IS:
+    case TK_ISNOT:
+      testcase( pExpr->op==TK_IS );
+      testcase( pExpr->op==TK_ISNOT );
+      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
+      jumpIfNull = SQLITE_NULLEQ;
+      /* Fall thru */
     case TK_LT:
     case TK_LE:
     case TK_GT:
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
+      if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
       testcase( jumpIfNull==0 );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
@@ -85639,23 +96186,12 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
       assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
-      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
-      assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      break;
-    }
-    case TK_IS:
-    case TK_ISNOT: {
-      testcase( pExpr->op==TK_IS );
-      testcase( pExpr->op==TK_ISNOT );
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
-      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, SQLITE_NULLEQ);
-      VdbeCoverageIf(v, op==TK_EQ);
-      VdbeCoverageIf(v, op==TK_NE);
+      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
+      assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
@@ -85671,7 +96207,7 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
     }
     case TK_BETWEEN: {
       testcase( jumpIfNull==0 );
-      exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
+      exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
       break;
     }
 #ifndef SQLITE_OMIT_SUBQUERY
@@ -85687,8 +96223,9 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
     }
 #endif
     default: {
+    default_expr: 
       if( exprAlwaysFalse(pExpr) ){
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
+        sqlite3VdbeGoto(v, dest);
       }else if( exprAlwaysTrue(pExpr) ){
         /* no-op */
       }else{
@@ -85705,6 +96242,56 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
   sqlite3ReleaseTempReg(pParse, regFree2);
 }
 
+/*
+** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
+** code generation, and that copy is deleted after code generation. This
+** ensures that the original pExpr is unchanged.
+*/
+SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
+  sqlite3 *db = pParse->db;
+  Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
+  if( db->mallocFailed==0 ){
+    sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
+  }
+  sqlite3ExprDelete(db, pCopy);
+}
+
+/*
+** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
+** type of expression.
+**
+** If pExpr is a simple SQL value - an integer, real, string, blob
+** or NULL value - then the VDBE currently being prepared is configured
+** to re-prepare each time a new value is bound to variable pVar.
+**
+** Additionally, if pExpr is a simple SQL value and the value is the
+** same as that currently bound to variable pVar, non-zero is returned.
+** Otherwise, if the values are not the same or if pExpr is not a simple
+** SQL value, zero is returned.
+*/
+static int exprCompareVariable(Parse *pParse, Expr *pVar, Expr *pExpr){
+  int res = 0;
+  int iVar;
+  sqlite3_value *pL, *pR = 0;
+  
+  sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);
+  if( pR ){
+    iVar = pVar->iColumn;
+    sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
+    pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);
+    if( pL ){
+      if( sqlite3_value_type(pL)==SQLITE_TEXT ){
+        sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */
+      }
+      res =  0==sqlite3MemCompare(pL, pR, 0);
+    }
+    sqlite3ValueFree(pR);
+    sqlite3ValueFree(pL);
+  }
+
+  return res;
+}
+
 /*
 ** Do a deep comparison of two expression trees.  Return 0 if the two
 ** expressions are completely identical.  Return 1 if they differ only
@@ -85726,12 +96313,22 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
 ** this routine is used, it does not hurt to get an extra 2 - that
 ** just might result in some slightly slower code.  But returning
 ** an incorrect 0 or 1 could lead to a malfunction.
+**
+** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
+** pParse->pReprepare can be matched against literals in pB.  The 
+** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
+** If pParse is NULL (the normal case) then any TK_VARIABLE term in 
+** Argument pParse should normally be NULL. If it is not NULL and pA or
+** pB causes a return value of 2.
 */
-SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
+SQLITE_PRIVATE int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){
   u32 combinedFlags;
   if( pA==0 || pB==0 ){
     return pB==pA ? 0 : 2;
   }
+  if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){
+    return 0;
+  }
   combinedFlags = pA->flags | pB->flags;
   if( combinedFlags & EP_IntValue ){
     if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
@@ -85740,26 +96337,28 @@ SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
     return 2;
   }
   if( pA->op!=pB->op ){
-    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
+    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
       return 1;
     }
-    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
+    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
       return 1;
     }
     return 2;
   }
-  if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken ){
-    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
+  if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
+    if( pA->op==TK_FUNCTION ){
+      if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
+    }else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
       return pA->op==TK_COLLATE ? 1 : 2;
     }
   }
   if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
   if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
     if( combinedFlags & EP_xIsSelect ) return 2;
-    if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
-    if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
+    if( sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
+    if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
     if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
-    if( ALWAYS((combinedFlags & EP_Reduced)==0) ){
+    if( ALWAYS((combinedFlags & EP_Reduced)==0) && pA->op!=TK_STRING ){
       if( pA->iColumn!=pB->iColumn ) return 2;
       if( pA->iTable!=pB->iTable 
        && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
@@ -85792,11 +96391,22 @@ SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
     Expr *pExprA = pA->a[i].pExpr;
     Expr *pExprB = pB->a[i].pExpr;
     if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
-    if( sqlite3ExprCompare(pExprA, pExprB, iTab) ) return 1;
+    if( sqlite3ExprCompare(0, pExprA, pExprB, iTab) ) return 1;
   }
   return 0;
 }
 
+/*
+** Like sqlite3ExprCompare() except COLLATE operators at the top-level
+** are ignored.
+*/
+SQLITE_PRIVATE int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){
+  return sqlite3ExprCompare(0,
+             sqlite3ExprSkipCollate(pA),
+             sqlite3ExprSkipCollate(pB),
+             iTab);
+}
+
 /*
 ** Return true if we can prove the pE2 will always be true if pE1 is
 ** true.  Return false if we cannot complete the proof or if pE2 might
@@ -85813,29 +96423,88 @@ SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
 ** Expr.iTable<0 then assume a table number given by iTab.
 **
+** If pParse is not NULL, then the values of bound variables in pE1 are 
+** compared against literal values in pE2 and pParse->pVdbe->expmask is
+** modified to record which bound variables are referenced.  If pParse 
+** is NULL, then false will be returned if pE1 contains any bound variables.
+**
 ** When in doubt, return false.  Returning true might give a performance
 ** improvement.  Returning false might cause a performance reduction, but
 ** it will always give the correct answer and is hence always safe.
 */
-SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Expr *pE1, Expr *pE2, int iTab){
-  if( sqlite3ExprCompare(pE1, pE2, iTab)==0 ){
+SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){
+  if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){
     return 1;
   }
   if( pE2->op==TK_OR
-   && (sqlite3ExprImpliesExpr(pE1, pE2->pLeft, iTab)
-             || sqlite3ExprImpliesExpr(pE1, pE2->pRight, iTab) )
+   && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)
+             || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )
   ){
     return 1;
   }
-  if( pE2->op==TK_NOTNULL
-   && sqlite3ExprCompare(pE1->pLeft, pE2->pLeft, iTab)==0
-   && (pE1->op!=TK_ISNULL && pE1->op!=TK_IS)
-  ){
-    return 1;
+  if( pE2->op==TK_NOTNULL && pE1->op!=TK_ISNULL && pE1->op!=TK_IS ){
+    Expr *pX = sqlite3ExprSkipCollate(pE1->pLeft);
+    testcase( pX!=pE1->pLeft );
+    if( sqlite3ExprCompare(pParse, pX, pE2->pLeft, iTab)==0 ) return 1;
   }
   return 0;
 }
 
+/*
+** An instance of the following structure is used by the tree walker
+** to determine if an expression can be evaluated by reference to the
+** index only, without having to do a search for the corresponding
+** table entry.  The IdxCover.pIdx field is the index.  IdxCover.iCur
+** is the cursor for the table.
+*/
+struct IdxCover {
+  Index *pIdx;     /* The index to be tested for coverage */
+  int iCur;        /* Cursor number for the table corresponding to the index */
+};
+
+/*
+** Check to see if there are references to columns in table 
+** pWalker->u.pIdxCover->iCur can be satisfied using the index
+** pWalker->u.pIdxCover->pIdx.
+*/
+static int exprIdxCover(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN
+   && pExpr->iTable==pWalker->u.pIdxCover->iCur
+   && sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
+  ){
+    pWalker->eCode = 1;
+    return WRC_Abort;
+  }
+  return WRC_Continue;
+}
+
+/*
+** Determine if an index pIdx on table with cursor iCur contains will
+** the expression pExpr.  Return true if the index does cover the
+** expression and false if the pExpr expression references table columns
+** that are not found in the index pIdx.
+**
+** An index covering an expression means that the expression can be
+** evaluated using only the index and without having to lookup the
+** corresponding table entry.
+*/
+SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(
+  Expr *pExpr,        /* The index to be tested */
+  int iCur,           /* The cursor number for the corresponding table */
+  Index *pIdx         /* The index that might be used for coverage */
+){
+  Walker w;
+  struct IdxCover xcov;
+  memset(&w, 0, sizeof(w));
+  xcov.iCur = iCur;
+  xcov.pIdx = pIdx;
+  w.xExprCallback = exprIdxCover;
+  w.u.pIdxCover = &xcov;
+  sqlite3WalkExpr(&w, pExpr);
+  return !w.eCode;
+}
+
+
 /*
 ** An instance of the following structure is used by the tree walker
 ** to count references to table columns in the arguments of an 
@@ -85884,8 +96553,8 @@ SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
   Walker w;
   struct SrcCount cnt;
   assert( pExpr->op==TK_AGG_FUNCTION );
-  memset(&w, 0, sizeof(w));
   w.xExprCallback = exprSrcCount;
+  w.xSelectCallback = 0;
   w.u.pSrcCount = &cnt;
   cnt.pSrc = pSrcList;
   cnt.nThis = 0;
@@ -86017,7 +96686,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
         */
         struct AggInfo_func *pItem = pAggInfo->aFunc;
         for(i=0; inFunc; i++, pItem++){
-          if( sqlite3ExprCompare(pItem->pExpr, pExpr, -1)==0 ){
+          if( sqlite3ExprCompare(0, pItem->pExpr, pExpr, -1)==0 ){
             break;
           }
         }
@@ -86033,7 +96702,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
             pItem->iMem = ++pParse->nMem;
             assert( !ExprHasProperty(pExpr, EP_IntValue) );
             pItem->pFunc = sqlite3FindFunction(pParse->db,
-                   pExpr->u.zToken, sqlite3Strlen30(pExpr->u.zToken),
+                   pExpr->u.zToken, 
                    pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
             if( pExpr->flags & EP_Distinct ){
               pItem->iDistinct = pParse->nTab++;
@@ -86057,10 +96726,14 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
   return WRC_Continue;
 }
 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
-  UNUSED_PARAMETER(pWalker);
   UNUSED_PARAMETER(pSelect);
+  pWalker->walkerDepth++;
   return WRC_Continue;
 }
+static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){
+  UNUSED_PARAMETER(pSelect);
+  pWalker->walkerDepth--;
+}
 
 /*
 ** Analyze the pExpr expression looking for aggregate functions and
@@ -86073,9 +96746,10 @@ static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
 */
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.xExprCallback = analyzeAggregate;
   w.xSelectCallback = analyzeAggregatesInSelect;
+  w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
+  w.walkerDepth = 0;
   w.u.pNC = pNC;
   assert( pNC->pSrcList!=0 );
   sqlite3WalkExpr(&w, pExpr);
@@ -86119,7 +96793,7 @@ SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
   if( iReg && pParse->nTempRegaTempReg) ){
     int i;
     struct yColCache *p;
-    for(i=0, p=pParse->aColCache; iaColCache; inColCache; i++, p++){
       if( p->iReg==iReg ){
         p->tempReg = 1;
         return;
@@ -86130,10 +96804,11 @@ SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
 }
 
 /*
-** Allocate or deallocate a block of nReg consecutive registers
+** Allocate or deallocate a block of nReg consecutive registers.
 */
 SQLITE_PRIVATE int sqlite3GetTempRange(Parse *pParse, int nReg){
   int i, n;
+  if( nReg==1 ) return sqlite3GetTempReg(pParse);
   i = pParse->iRangeReg;
   n = pParse->nRangeReg;
   if( nReg<=n ){
@@ -86147,6 +96822,10 @@ SQLITE_PRIVATE int sqlite3GetTempRange(Parse *pParse, int nReg){
   return i;
 }
 SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
+  if( nReg==1 ){
+    sqlite3ReleaseTempReg(pParse, iReg);
+    return;
+  }
   sqlite3ExprCacheRemove(pParse, iReg, nReg);
   if( nReg>pParse->nRangeReg ){
     pParse->nRangeReg = nReg;
@@ -86162,6 +96841,29 @@ SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse *pParse){
   pParse->nRangeReg = 0;
 }
 
+/*
+** Validate that no temporary register falls within the range of
+** iFirst..iLast, inclusive.  This routine is only call from within assert()
+** statements.
+*/
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
+  int i;
+  if( pParse->nRangeReg>0
+   && pParse->iRangeReg+pParse->nRangeReg > iFirst
+   && pParse->iRangeReg <= iLast
+  ){
+     return 0;
+  }
+  for(i=0; inTempReg; i++){
+    if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
+      return 0;
+    }
+  }
+  return 1;
+}
+#endif /* SQLITE_DEBUG */
+
 /************** End of expr.c ************************************************/
 /************** Begin file alter.c *******************************************/
 /*
@@ -86178,6 +96880,7 @@ SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse *pParse){
 ** This file contains C code routines that used to generate VDBE code
 ** that implements the ALTER TABLE command.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** The code in this file only exists if we are not omitting the
@@ -86291,6 +96994,7 @@ static void renameParentFunc(
         n = sqlite3GetToken(z, &token);
       }while( token==TK_SPACE );
 
+      if( token==TK_ILLEGAL ) break;
       zParent = sqlite3DbStrNDup(db, (const char *)z, n);
       if( zParent==0 ) break;
       sqlite3Dequote(zParent);
@@ -86393,7 +97097,7 @@ static void renameTriggerFunc(
 ** Register built-in functions used to help implement ALTER TABLE
 */
 SQLITE_PRIVATE void sqlite3AlterFunctions(void){
-  static SQLITE_WSD FuncDef aAlterTableFuncs[] = {
+  static FuncDef aAlterTableFuncs[] = {
     FUNCTION(sqlite_rename_table,   2, 0, 0, renameTableFunc),
 #ifndef SQLITE_OMIT_TRIGGER
     FUNCTION(sqlite_rename_trigger, 2, 0, 0, renameTriggerFunc),
@@ -86402,13 +97106,7 @@ SQLITE_PRIVATE void sqlite3AlterFunctions(void){
     FUNCTION(sqlite_rename_parent,  3, 0, 0, renameParentFunc),
 #endif
   };
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAlterTableFuncs);
-
-  for(i=0; i6 && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
+  if( 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
     sqlite3ErrorMsg(pParse, "table %s may not be altered", zName);
     return 1;
   }
@@ -86583,7 +97281,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
   pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
   if( !pTab ) goto exit_rename_table;
   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
-  zDb = db->aDb[iDb].zName;
+  zDb = db->aDb[iDb].zDbSName;
   db->flags |= SQLITE_PreferBuiltin;
 
   /* Get a NULL terminated version of the new table name. */
@@ -86655,7 +97353,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   if( pVTab ){
     int i = ++pParse->nMem;
-    sqlite3VdbeAddOp4(v, OP_String8, 0, i, 0, zName, 0);
+    sqlite3VdbeLoadString(v, i, zName);
     sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
     sqlite3MayAbort(pParse);
   }
@@ -86674,7 +97372,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
       sqlite3NestedParse(pParse, 
           "UPDATE \"%w\".%s SET "
               "sql = sqlite_rename_parent(sql, %Q, %Q) "
-              "WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere);
+              "WHERE %s;", zDb, MASTER_NAME, zTabName, zName, zWhere);
       sqlite3DbFree(db, zWhere);
     }
   }
@@ -86698,7 +97396,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
             "ELSE name END "
       "WHERE tbl_name=%Q COLLATE nocase AND "
           "(type='table' OR type='index' OR type='trigger');", 
-      zDb, SCHEMA_TABLE(iDb), zName, zName, zName, 
+      zDb, MASTER_NAME, zName, zName, zName, 
 #ifndef SQLITE_OMIT_TRIGGER
       zName,
 #endif
@@ -86752,33 +97450,6 @@ exit_rename_table:
   db->flags = savedDbFlags;
 }
 
-
-/*
-** Generate code to make sure the file format number is at least minFormat.
-** The generated code will increase the file format number if necessary.
-*/
-SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
-  Vdbe *v;
-  v = sqlite3GetVdbe(pParse);
-  /* The VDBE should have been allocated before this routine is called.
-  ** If that allocation failed, we would have quit before reaching this
-  ** point */
-  if( ALWAYS(v) ){
-    int r1 = sqlite3GetTempReg(pParse);
-    int r2 = sqlite3GetTempReg(pParse);
-    int j1;
-    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
-    sqlite3VdbeUsesBtree(v, iDb);
-    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
-    j1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
-    sqlite3VdbeChangeP5(v, SQLITE_NOTNULL); VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2);
-    sqlite3VdbeJumpHere(v, j1);
-    sqlite3ReleaseTempReg(pParse, r1);
-    sqlite3ReleaseTempReg(pParse, r2);
-  }
-}
-
 /*
 ** This function is called after an "ALTER TABLE ... ADD" statement
 ** has been parsed. Argument pColDef contains the text of the new
@@ -86797,15 +97468,18 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   Column *pCol;             /* The new column */
   Expr *pDflt;              /* Default value for the new column */
   sqlite3 *db;              /* The database connection; */
+  Vdbe *v = pParse->pVdbe;  /* The prepared statement under construction */
+  int r1;                   /* Temporary registers */
 
   db = pParse->db;
   if( pParse->nErr || db->mallocFailed ) return;
+  assert( v!=0 );
   pNew = pParse->pNewTable;
   assert( pNew );
 
   assert( sqlite3BtreeHoldsAllMutexes(db) );
   iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
-  zDb = db->aDb[iDb].zName;
+  zDb = db->aDb[iDb].zDbSName;
   zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */
   pCol = &pNew->aCol[pNew->nCol-1];
   pDflt = pCol->pDflt;
@@ -86823,7 +97497,8 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   ** literal NULL, then set pDflt to 0. This simplifies checking
   ** for an SQL NULL default below.
   */
-  if( pDflt && pDflt->op==TK_NULL ){
+  assert( pDflt==0 || pDflt->op==TK_SPAN );
+  if( pDflt && pDflt->pLeft->op==TK_NULL ){
     pDflt = 0;
   }
 
@@ -86855,8 +97530,11 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   */
   if( pDflt ){
     sqlite3_value *pVal = 0;
-    if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
-      db->mallocFailed = 1;
+    int rc;
+    rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
+    assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+    if( rc!=SQLITE_OK ){
+      assert( db->mallocFailed == 1 );
       return;
     }
     if( !pVal ){
@@ -86879,18 +97557,25 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
         "UPDATE \"%w\".%s SET "
           "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
         "WHERE type = 'table' AND name = %Q", 
-      zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
+      zDb, MASTER_NAME, pNew->addColOffset, zCol, pNew->addColOffset+1,
       zTab
     );
     sqlite3DbFree(db, zCol);
     db->flags = savedDbFlags;
   }
 
-  /* If the default value of the new column is NULL, then set the file
-  ** format to 2. If the default value of the new column is not NULL,
-  ** the file format becomes 3.
+  /* Make sure the schema version is at least 3.  But do not upgrade
+  ** from less than 3 to 4, as that will corrupt any preexisting DESC
+  ** index.
   */
-  sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
+  r1 = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
+  sqlite3VdbeUsesBtree(v, iDb);
+  sqlite3VdbeAddOp2(v, OP_AddImm, r1, -2);
+  sqlite3VdbeAddOp2(v, OP_IfPos, r1, sqlite3VdbeCurrentAddr(v)+2);
+  VdbeCoverage(v);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, 3);
+  sqlite3ReleaseTempReg(pParse, r1);
 
   /* Reload the schema of the modified table. */
   reloadTableSchema(pParse, pTab, pTab->zName);
@@ -86956,7 +97641,7 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
   if( !pNew ) goto exit_begin_add_column;
   pParse->pNewTable = pNew;
-  pNew->nRef = 1;
+  pNew->nTabRef = 1;
   pNew->nCol = pTab->nCol;
   assert( pNew->nCol>0 );
   nAlloc = (((pNew->nCol-1)/8)*8)+8;
@@ -86964,7 +97649,7 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
   pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
   if( !pNew->aCol || !pNew->zName ){
-    db->mallocFailed = 1;
+    assert( db->mallocFailed );
     goto exit_begin_add_column;
   }
   memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
@@ -86972,13 +97657,11 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
     Column *pCol = &pNew->aCol[i];
     pCol->zName = sqlite3DbStrDup(db, pCol->zName);
     pCol->zColl = 0;
-    pCol->zType = 0;
     pCol->pDflt = 0;
-    pCol->zDflt = 0;
   }
   pNew->pSchema = db->aDb[iDb].pSchema;
   pNew->addColOffset = pTab->addColOffset;
-  pNew->nRef = 1;
+  pNew->nTabRef = 1;
 
   /* Begin a transaction and increment the schema cookie.  */
   sqlite3BeginWriteOperation(pParse, 0, iDb);
@@ -87136,6 +97819,7 @@ exit_begin_add_column:
 ** integer in the equivalent columns in sqlite_stat4.
 */
 #ifndef SQLITE_OMIT_ANALYZE
+/* #include "sqliteInt.h" */
 
 #if defined(SQLITE_ENABLE_STAT4)
 # define IsStat4     1
@@ -87205,14 +97889,14 @@ static void openStatTable(
   for(i=0; izName))==0 ){
+    if( (pStat = sqlite3FindTable(db, zTab, pDb->zDbSName))==0 ){
       if( aTable[i].zCols ){
         /* The sqlite_statN table does not exist. Create it. Note that a 
         ** side-effect of the CREATE TABLE statement is to leave the rootpage 
         ** of the new table in register pParse->regRoot. This is important 
         ** because the OpenWrite opcode below will be needing it. */
         sqlite3NestedParse(pParse,
-            "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols
+            "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
         );
         aRoot[i] = pParse->regRoot;
         aCreateTbl[i] = OPFLAG_P2ISREG;
@@ -87227,7 +97911,7 @@ static void openStatTable(
       if( zWhere ){
         sqlite3NestedParse(pParse,
            "DELETE FROM %Q.%s WHERE %s=%Q",
-           pDb->zName, zTab, zWhereType, zWhere
+           pDb->zDbSName, zTab, zWhereType, zWhere
         );
       }else{
         /* The sqlite_stat[134] table already exists.  Delete all rows. */
@@ -87285,6 +97969,7 @@ struct Stat4Accum {
   Stat4Sample *aBest;       /* Array of nCol best samples */
   int iMin;                 /* Index in a[] of entry with minimum score */
   int nSample;              /* Current number of samples */
+  int nMaxEqZero;           /* Max leading 0 in anEq[] for any a[] entry */
   int iGet;                 /* Index of current sample accessed by stat_get() */
   Stat4Sample *a;           /* Array of mxSample Stat4Sample objects */
   sqlite3 *db;              /* Database connection, for malloc() */
@@ -87308,7 +97993,7 @@ static void sampleClear(sqlite3 *db, Stat4Sample *p){
 static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){
   assert( db!=0 );
   if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
-  p->u.aRowid = sqlite3DbMallocRaw(db, n);
+  p->u.aRowid = sqlite3DbMallocRawNN(db, n);
   if( p->u.aRowid ){
     p->nRowid = n;
     memcpy(p->u.aRowid, pData, n);
@@ -87473,12 +98158,10 @@ static const FuncDef statInitFuncdef = {
   SQLITE_UTF8,     /* funcFlags */
   0,               /* pUserData */
   0,               /* pNext */
-  statInit,        /* xFunc */
-  0,               /* xStep */
+  statInit,        /* xSFunc */
   0,               /* xFinalize */
   "stat_init",     /* zName */
-  0,               /* pHash */
-  0                /* pDestructor */
+  {0}
 };
 
 #ifdef SQLITE_ENABLE_STAT4
@@ -87551,6 +98234,13 @@ static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){
   assert( IsStat4 || nEqZero==0 );
 
 #ifdef SQLITE_ENABLE_STAT4
+  /* Stat4Accum.nMaxEqZero is set to the maximum number of leading 0
+  ** values in the anEq[] array of any sample in Stat4Accum.a[]. In
+  ** other words, if nMaxEqZero is n, then it is guaranteed that there
+  ** are no samples with Stat4Sample.anEq[m]==0 for (m>=n). */
+  if( nEqZero>p->nMaxEqZero ){
+    p->nMaxEqZero = nEqZero;
+  }
   if( pNew->isPSample==0 ){
     Stat4Sample *pUpgrade = 0;
     assert( pNew->anEq[pNew->iCol]>0 );
@@ -87648,12 +98338,22 @@ static void samplePushPrevious(Stat4Accum *p, int iChng){
     }
   }
 
-  /* Update the anEq[] fields of any samples already collected. */
+  /* Check that no sample contains an anEq[] entry with an index of
+  ** p->nMaxEqZero or greater set to zero. */
   for(i=p->nSample-1; i>=0; i--){
     int j;
-    for(j=iChng; jnCol; j++){
-      if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];
+    for(j=p->nMaxEqZero; jnCol; j++) assert( p->a[i].anEq[j]>0 );
+  }
+
+  /* Update the anEq[] fields of any samples already collected. */
+  if( iChngnMaxEqZero ){
+    for(i=p->nSample-1; i>=0; i--){
+      int j;
+      for(j=iChng; jnCol; j++){
+        if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];
+      }
     }
+    p->nMaxEqZero = iChng;
   }
 #endif
 
@@ -87774,12 +98474,10 @@ static const FuncDef statPushFuncdef = {
   SQLITE_UTF8,     /* funcFlags */
   0,               /* pUserData */
   0,               /* pNext */
-  statPush,        /* xFunc */
-  0,               /* xStep */
+  statPush,        /* xSFunc */
   0,               /* xFinalize */
   "stat_push",     /* zName */
-  0,               /* pHash */
-  0                /* pDestructor */
+  {0}
 };
 
 #define STAT_GET_STAT1 0          /* "stat" column of stat1 table */
@@ -87796,6 +98494,12 @@ static const FuncDef statPushFuncdef = {
 ** The content to returned is determined by the parameter J
 ** which is one of the STAT_GET_xxxx values defined above.
 **
+** The stat_get(P,J) function is not available to generic SQL.  It is
+** inserted as part of a manually constructed bytecode program.  (See
+** the callStatGet() routine below.)  It is guaranteed that the P
+** parameter will always be a poiner to a Stat4Accum object, never a
+** NULL.
+**
 ** If neither STAT3 nor STAT4 are enabled, then J is always
 ** STAT_GET_STAT1 and is hence omitted and this routine becomes
 ** a one-parameter function, stat_get(P), that always returns the
@@ -87921,12 +98625,10 @@ static const FuncDef statGetFuncdef = {
   SQLITE_UTF8,     /* funcFlags */
   0,               /* pUserData */
   0,               /* pNext */
-  statGet,         /* xFunc */
-  0,               /* xStep */
+  statGet,         /* xSFunc */
   0,               /* xFinalize */
   "stat_get",      /* zName */
-  0,               /* pHash */
-  0                /* pDestructor */
+  {0}
 };
 
 static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){
@@ -87938,8 +98640,8 @@ static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){
 #else
   UNUSED_PARAMETER( iParam );
 #endif
-  sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4, regOut);
-  sqlite3VdbeChangeP4(v, -1, (char*)&statGetFuncdef, P4_FUNCDEF);
+  sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4, regOut,
+                    (char*)&statGetFuncdef, P4_FUNCDEF);
   sqlite3VdbeChangeP5(v, 1 + IsStat34);
 }
 
@@ -87985,7 +98687,7 @@ static void analyzeOneTable(
     /* Do not gather statistics on views or virtual tables */
     return;
   }
-  if( sqlite3_strnicmp(pTab->zName, "sqlite_", 7)==0 ){
+  if( sqlite3_strlike("sqlite_%", pTab->zName, 0)==0 ){
     /* Do not gather statistics on system tables */
     return;
   }
@@ -87995,7 +98697,7 @@ static void analyzeOneTable(
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
 #ifndef SQLITE_OMIT_AUTHORIZATION
   if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
-      db->aDb[iDb].zName ) ){
+      db->aDb[iDb].zDbSName ) ){
     return;
   }
 #endif
@@ -88009,7 +98711,7 @@ static void analyzeOneTable(
   iIdxCur = iTab++;
   pParse->nTab = MAX(pParse->nTab, iTab);
   sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
-  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
+  sqlite3VdbeLoadString(v, regTabname, pTab->zName);
 
   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
     int nCol;                     /* Number of columns in pIdx. "N" */
@@ -88031,7 +98733,7 @@ static void analyzeOneTable(
     }
 
     /* Populate the register containing the index name. */
-    sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, zIdxName, 0);
+    sqlite3VdbeLoadString(v, regIdxname, zIdxName);
     VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName));
 
     /*
@@ -88093,8 +98795,8 @@ static void analyzeOneTable(
 #endif
     sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1);
     sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2);
-    sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4+1, regStat4);
-    sqlite3VdbeChangeP4(v, -1, (char*)&statInitFuncdef, P4_FUNCDEF);
+    sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4+1, regStat4,
+                     (char*)&statInitFuncdef, P4_FUNCDEF);
     sqlite3VdbeChangeP5(v, 2+IsStat34);
 
     /* Implementation of the following:
@@ -88113,7 +98815,7 @@ static void analyzeOneTable(
     if( nColTest>0 ){
       int endDistinctTest = sqlite3VdbeMakeLabel(v);
       int *aGotoChng;               /* Array of jump instruction addresses */
-      aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*nColTest);
+      aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);
       if( aGotoChng==0 ) continue;
 
       /*
@@ -88145,7 +98847,7 @@ static void analyzeOneTable(
         VdbeCoverage(v);
       }
       sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, endDistinctTest);
+      sqlite3VdbeGoto(v, endDistinctTest);
   
   
       /*
@@ -88181,6 +98883,7 @@ static void analyzeOneTable(
       regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
       for(j=0; jnKeyCol; j++){
         k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        assert( k>=0 && knColumn );
         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
         VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));
       }
@@ -88189,8 +98892,8 @@ static void analyzeOneTable(
     }
 #endif
     assert( regChng==(regStat4+1) );
-    sqlite3VdbeAddOp3(v, OP_Function, 1, regStat4, regTemp);
-    sqlite3VdbeChangeP4(v, -1, (char*)&statPushFuncdef, P4_FUNCDEF);
+    sqlite3VdbeAddOp4(v, OP_Function0, 1, regStat4, regTemp,
+                     (char*)&statPushFuncdef, P4_FUNCDEF);
     sqlite3VdbeChangeP5(v, 2+IsStat34);
     sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
 
@@ -88230,12 +98933,10 @@ static void analyzeOneTable(
       ** be taken */
       VdbeCoverageNeverTaken(v);
 #ifdef SQLITE_ENABLE_STAT3
-      sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, 
-                                      pIdx->aiColumn[0], regSample);
+      sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, 0, regSample);
 #else
       for(i=0; iaiColumn[i];
-        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, iCol, regCol+i);
+        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);
       }
       sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);
 #endif
@@ -88366,27 +99067,14 @@ SQLITE_PRIVATE void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
       if( i==1 ) continue;  /* Do not analyze the TEMP database */
       analyzeDatabase(pParse, i);
     }
-  }else if( pName2->n==0 ){
-    /* Form 2:  Analyze the database or table named */
-    iDb = sqlite3FindDb(db, pName1);
-    if( iDb>=0 ){
-      analyzeDatabase(pParse, iDb);
-    }else{
-      z = sqlite3NameFromToken(db, pName1);
-      if( z ){
-        if( (pIdx = sqlite3FindIndex(db, z, 0))!=0 ){
-          analyzeTable(pParse, pIdx->pTable, pIdx);
-        }else if( (pTab = sqlite3LocateTable(pParse, 0, z, 0))!=0 ){
-          analyzeTable(pParse, pTab, 0);
-        }
-        sqlite3DbFree(db, z);
-      }
-    }
+  }else if( pName2->n==0 && (iDb = sqlite3FindDb(db, pName1))>=0 ){
+    /* Analyze the schema named as the argument */
+    analyzeDatabase(pParse, iDb);
   }else{
-    /* Form 3: Analyze the fully qualified table name */
+    /* Form 3: Analyze the table or index named as an argument */
     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);
     if( iDb>=0 ){
-      zDb = db->aDb[iDb].zName;
+      zDb = pName2->n ? db->aDb[iDb].zDbSName : 0;
       z = sqlite3NameFromToken(db, pTableName);
       if( z ){
         if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){
@@ -88396,10 +99084,11 @@ SQLITE_PRIVATE void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
         }
         sqlite3DbFree(db, z);
       }
-    }   
+    }
+  }
+  if( db->nSqlExec==0 && (v = sqlite3GetVdbe(pParse))!=0 ){
+    sqlite3VdbeAddOp0(v, OP_Expire);
   }
-  v = sqlite3GetVdbe(pParse);
-  if( v ) sqlite3VdbeAddOp0(v, OP_Expire);
 }
 
 /*
@@ -88514,18 +99203,25 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
   z = argv[2];
 
   if( pIndex ){
+    tRowcnt *aiRowEst = 0;
     int nCol = pIndex->nKeyCol+1;
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-    tRowcnt * const aiRowEst = pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(
-        sizeof(tRowcnt) * nCol
-    );
-    if( aiRowEst==0 ) pInfo->db->mallocFailed = 1;
-#else
-    tRowcnt * const aiRowEst = 0;
+    /* Index.aiRowEst may already be set here if there are duplicate 
+    ** sqlite_stat1 entries for this index. In that case just clobber
+    ** the old data with the new instead of allocating a new array.  */
+    if( pIndex->aiRowEst==0 ){
+      pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol);
+      if( pIndex->aiRowEst==0 ) sqlite3OomFault(pInfo->db);
+    }
+    aiRowEst = pIndex->aiRowEst;
 #endif
     pIndex->bUnordered = 0;
     decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex);
-    if( pIndex->pPartIdxWhere==0 ) pTable->nRowLogEst = pIndex->aiRowLogEst[0];
+    pIndex->hasStat1 = 1;
+    if( pIndex->pPartIdxWhere==0 ){
+      pTable->nRowLogEst = pIndex->aiRowLogEst[0];
+      pTable->tabFlags |= TF_HasStat1;
+    }
   }else{
     Index fakeIdx;
     fakeIdx.szIdxRow = pTable->szTabRow;
@@ -88534,6 +99230,7 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
 #endif
     decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx);
     pTable->szTabRow = fakeIdx.szIdxRow;
+    pTable->tabFlags |= TF_HasStat1;
   }
 
   return 0;
@@ -88614,7 +99311,7 @@ static void initAvgEq(Index *pIdx){
         }
       }
 
-      if( nDist100>nSum100 ){
+      if( nDist100>nSum100 && sumEqaSample[] */
 
-  assert( db->lookaside.bEnabled==0 );
+  assert( db->lookaside.bDisable );
   zSql = sqlite3MPrintf(db, zSql1, zDb);
   if( !zSql ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
   sqlite3DbFree(db, zSql);
@@ -88709,7 +99406,7 @@ static int loadStatTbl(
     pIdx->aSample = sqlite3DbMallocZero(db, nByte);
     if( pIdx->aSample==0 ){
       sqlite3_finalize(pStmt);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pSpace = (tRowcnt*)&pIdx->aSample[nSample];
     pIdx->aAvgEq = pSpace; pSpace += nIdxCol;
@@ -88725,7 +99422,7 @@ static int loadStatTbl(
 
   zSql = sqlite3MPrintf(db, zSql2, zDb);
   if( !zSql ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
   sqlite3DbFree(db, zSql);
@@ -88763,9 +99460,11 @@ static int loadStatTbl(
     pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);
     if( pSample->p==0 ){
       sqlite3_finalize(pStmt);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
+    }
+    if( pSample->n ){
+      memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);
     }
-    memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);
     pIdx->nSample++;
   }
   rc = sqlite3_finalize(pStmt);
@@ -88780,7 +99479,7 @@ static int loadStatTbl(
 static int loadStat4(sqlite3 *db, const char *zDb){
   int rc = SQLITE_OK;             /* Result codes from subroutines */
 
-  assert( db->lookaside.bEnabled==0 );
+  assert( db->lookaside.bDisable );
   if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
     rc = loadStatTbl(db, 0,
       "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 
@@ -88825,49 +99524,56 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
   analysisInfo sInfo;
   HashElem *i;
   char *zSql;
-  int rc;
+  int rc = SQLITE_OK;
+  Schema *pSchema = db->aDb[iDb].pSchema;
 
   assert( iDb>=0 && iDbnDb );
   assert( db->aDb[iDb].pBt!=0 );
 
   /* Clear any prior statistics */
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
+  for(i=sqliteHashFirst(&pSchema->tblHash); i; i=sqliteHashNext(i)){
+    Table *pTab = sqliteHashData(i);
+    pTab->tabFlags &= ~TF_HasStat1;
+  }
+  for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
     Index *pIdx = sqliteHashData(i);
-    sqlite3DefaultRowEst(pIdx);
+    pIdx->hasStat1 = 0;
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
     sqlite3DeleteIndexSamples(db, pIdx);
     pIdx->aSample = 0;
 #endif
   }
 
-  /* Check to make sure the sqlite_stat1 table exists */
+  /* Load new statistics out of the sqlite_stat1 table */
   sInfo.db = db;
-  sInfo.zDatabase = db->aDb[iDb].zName;
-  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){
-    return SQLITE_ERROR;
+  sInfo.zDatabase = db->aDb[iDb].zDbSName;
+  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){
+    zSql = sqlite3MPrintf(db, 
+        "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+    }else{
+      rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
+      sqlite3DbFree(db, zSql);
+    }
   }
 
-  /* Load new statistics out of the sqlite_stat1 table */
-  zSql = sqlite3MPrintf(db, 
-      "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
-  if( zSql==0 ){
-    rc = SQLITE_NOMEM;
-  }else{
-    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
-    sqlite3DbFree(db, zSql);
+  /* Set appropriate defaults on all indexes not in the sqlite_stat1 table */
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
+    Index *pIdx = sqliteHashData(i);
+    if( !pIdx->hasStat1 ) sqlite3DefaultRowEst(pIdx);
   }
 
-
   /* Load the statistics from the sqlite_stat4 table. */
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   if( rc==SQLITE_OK && OptimizationEnabled(db, SQLITE_Stat34) ){
-    int lookasideEnabled = db->lookaside.bEnabled;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.bDisable++;
     rc = loadStat4(db, sInfo.zDatabase);
-    db->lookaside.bEnabled = lookasideEnabled;
+    db->lookaside.bDisable--;
   }
-  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
+  for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
     Index *pIdx = sqliteHashData(i);
     sqlite3_free(pIdx->aiRowEst);
     pIdx->aiRowEst = 0;
@@ -88875,7 +99581,7 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
 #endif
 
   if( rc==SQLITE_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return rc;
 }
@@ -88898,6 +99604,7 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
 *************************************************************************
 ** This file contains code used to implement the ATTACH and DETACH commands.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_ATTACH
 /*
@@ -88955,7 +99662,8 @@ static void attachFunc(
   char *zPath = 0;
   char *zErr = 0;
   unsigned int flags;
-  Db *aNew;
+  Db *aNew;                 /* New array of Db pointers */
+  Db *pNew;                 /* Db object for the newly attached database */
   char *zErrDyn = 0;
   sqlite3_vfs *pVfs;
 
@@ -88983,7 +99691,7 @@ static void attachFunc(
     goto attach_error;
   }
   for(i=0; inDb; i++){
-    char *z = db->aDb[i].zName;
+    char *z = db->aDb[i].zDbSName;
     assert( z && zName );
     if( sqlite3StrICmp(z, zName)==0 ){
       zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
@@ -88995,7 +99703,7 @@ static void attachFunc(
   ** hash tables.
   */
   if( db->aDb==db->aDbStatic ){
-    aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
+    aNew = sqlite3DbMallocRawNN(db, sizeof(db->aDb[0])*3 );
     if( aNew==0 ) return;
     memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
   }else{
@@ -89003,8 +99711,8 @@ static void attachFunc(
     if( aNew==0 ) return;
   }
   db->aDb = aNew;
-  aNew = &db->aDb[db->nDb];
-  memset(aNew, 0, sizeof(*aNew));
+  pNew = &db->aDb[db->nDb];
+  memset(pNew, 0, sizeof(*pNew));
 
   /* Open the database file. If the btree is successfully opened, use
   ** it to obtain the database schema. At this point the schema may
@@ -89013,43 +99721,45 @@ static void attachFunc(
   flags = db->openFlags;
   rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
   if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
     sqlite3_result_error(context, zErr, -1);
     sqlite3_free(zErr);
     return;
   }
   assert( pVfs );
   flags |= SQLITE_OPEN_MAIN_DB;
-  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags);
+  rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags);
   sqlite3_free( zPath );
   db->nDb++;
+  db->skipBtreeMutex = 0;
   if( rc==SQLITE_CONSTRAINT ){
     rc = SQLITE_ERROR;
     zErrDyn = sqlite3MPrintf(db, "database is already attached");
   }else if( rc==SQLITE_OK ){
     Pager *pPager;
-    aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt);
-    if( !aNew->pSchema ){
-      rc = SQLITE_NOMEM;
-    }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
+    pNew->pSchema = sqlite3SchemaGet(db, pNew->pBt);
+    if( !pNew->pSchema ){
+      rc = SQLITE_NOMEM_BKPT;
+    }else if( pNew->pSchema->file_format && pNew->pSchema->enc!=ENC(db) ){
       zErrDyn = sqlite3MPrintf(db, 
         "attached databases must use the same text encoding as main database");
       rc = SQLITE_ERROR;
     }
-    sqlite3BtreeEnter(aNew->pBt);
-    pPager = sqlite3BtreePager(aNew->pBt);
+    sqlite3BtreeEnter(pNew->pBt);
+    pPager = sqlite3BtreePager(pNew->pBt);
     sqlite3PagerLockingMode(pPager, db->dfltLockMode);
-    sqlite3BtreeSecureDelete(aNew->pBt,
+    sqlite3BtreeSecureDelete(pNew->pBt,
                              sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
-    sqlite3BtreeSetPagerFlags(aNew->pBt, 3 | (db->flags & PAGER_FLAGS_MASK));
+    sqlite3BtreeSetPagerFlags(pNew->pBt,
+                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
 #endif
-    sqlite3BtreeLeave(aNew->pBt);
+    sqlite3BtreeLeave(pNew->pBt);
   }
-  aNew->safety_level = 3;
-  aNew->zName = sqlite3DbStrDup(db, zName);
-  if( rc==SQLITE_OK && aNew->zName==0 ){
-    rc = SQLITE_NOMEM;
+  pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
+  pNew->zDbSName = sqlite3DbStrDup(db, zName);
+  if( rc==SQLITE_OK && pNew->zDbSName==0 ){
+    rc = SQLITE_NOMEM_BKPT;
   }
 
 
@@ -89077,7 +99787,7 @@ static void attachFunc(
       case SQLITE_NULL:
         /* No key specified.  Use the key from the main database */
         sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
-        if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){
+        if( nKey || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
           rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
         }
         break;
@@ -89115,7 +99825,7 @@ static void attachFunc(
     sqlite3ResetAllSchemasOfConnection(db);
     db->nDb = iDb;
     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       sqlite3DbFree(db, zErrDyn);
       zErrDyn = sqlite3MPrintf(db, "out of memory");
     }else if( zErrDyn==0 ){
@@ -89160,7 +99870,7 @@ static void detachFunc(
   for(i=0; inDb; i++){
     pDb = &db->aDb[i];
     if( pDb->pBt==0 ) continue;
-    if( sqlite3StrICmp(pDb->zName, zName)==0 ) break;
+    if( sqlite3StrICmp(pDb->zDbSName, zName)==0 ) break;
   }
 
   if( i>=db->nDb ){
@@ -89184,7 +99894,7 @@ static void detachFunc(
   sqlite3BtreeClose(pDb->pBt);
   pDb->pBt = 0;
   pDb->pSchema = 0;
-  sqlite3ResetAllSchemasOfConnection(db);
+  sqlite3CollapseDatabaseArray(db);
   return;
 
 detach_error:
@@ -89210,6 +99920,7 @@ static void codeAttach(
   sqlite3* db = pParse->db;
   int regArgs;
 
+  if( pParse->nErr ) goto attach_end;
   memset(&sName, 0, sizeof(NameContext));
   sName.pParse = pParse;
 
@@ -89218,7 +99929,6 @@ static void codeAttach(
       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
   ){
-    pParse->nErr++;
     goto attach_end;
   }
 
@@ -89246,11 +99956,11 @@ static void codeAttach(
 
   assert( v || db->mallocFailed );
   if( v ){
-    sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3);
+    sqlite3VdbeAddOp4(v, OP_Function0, 0, regArgs+3-pFunc->nArg, regArgs+3,
+                      (char *)pFunc, P4_FUNCDEF);
     assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
     sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
-    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);
-
+ 
     /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
     ** statement only). For DETACH, set it to false (expire all existing
     ** statements).
@@ -89275,12 +99985,10 @@ SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){
     SQLITE_UTF8,      /* funcFlags */
     0,                /* pUserData */
     0,                /* pNext */
-    detachFunc,       /* xFunc */
-    0,                /* xStep */
+    detachFunc,       /* xSFunc */
     0,                /* xFinalize */
     "sqlite_detach",  /* zName */
-    0,                /* pHash */
-    0                 /* pDestructor */
+    {0}
   };
   codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
 }
@@ -89296,12 +100004,10 @@ SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *p
     SQLITE_UTF8,      /* funcFlags */
     0,                /* pUserData */
     0,                /* pNext */
-    attachFunc,       /* xFunc */
-    0,                /* xStep */
+    attachFunc,       /* xSFunc */
     0,                /* xFinalize */
     "sqlite_attach",  /* zName */
-    0,                /* pHash */
-    0                 /* pDestructor */
+    {0}
   };
   codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
 }
@@ -89323,7 +100029,7 @@ SQLITE_PRIVATE void sqlite3FixInit(
   db = pParse->db;
   assert( db->nDb>iDb );
   pFix->pParse = pParse;
-  pFix->zDb = db->aDb[iDb].zName;
+  pFix->zDb = db->aDb[iDb].zDbSName;
   pFix->pSchema = db->aDb[iDb].pSchema;
   pFix->zType = zType;
   pFix->pName = pName;
@@ -89420,7 +100126,7 @@ SQLITE_PRIVATE int sqlite3FixExpr(
         return 1;
       }
     }
-    if( ExprHasProperty(pExpr, EP_TokenOnly) ) break;
+    if( ExprHasProperty(pExpr, EP_TokenOnly|EP_Leaf) ) break;
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
       if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;
     }else{
@@ -89488,6 +100194,7 @@ SQLITE_PRIVATE int sqlite3FixTriggerStep(
 ** systems that do not need this facility may omit it by recompiling
 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** All of the code in this file may be omitted by defining a single
@@ -89580,10 +100287,11 @@ SQLITE_PRIVATE int sqlite3AuthReadCol(
   const char *zCol,               /* Column name */
   int iDb                         /* Index of containing database. */
 ){
-  sqlite3 *db = pParse->db;       /* Database handle */
-  char *zDb = db->aDb[iDb].zName; /* Name of attached database */
-  int rc;                         /* Auth callback return code */
+  sqlite3 *db = pParse->db;          /* Database handle */
+  char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */
+  int rc;                            /* Auth callback return code */
 
+  if( db->init.busy ) return SQLITE_OK;
   rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext
 #ifdef SQLITE_USER_AUTHENTICATION
                  ,db->auth.zAuthUser
@@ -89688,6 +100396,18 @@ SQLITE_PRIVATE int sqlite3AuthCheck(
   if( db->xAuth==0 ){
     return SQLITE_OK;
   }
+
+  /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the
+  ** callback are either NULL pointers or zero-terminated strings that
+  ** contain additional details about the action to be authorized.
+  **
+  ** The following testcase() macros show that any of the 3rd through 6th
+  ** parameters can be either NULL or a string. */
+  testcase( zArg1==0 );
+  testcase( zArg2==0 );
+  testcase( zArg3==0 );
+  testcase( pParse->zAuthContext==0 );
+
   rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext
 #ifdef SQLITE_USER_AUTHENTICATION
                  ,db->auth.zAuthUser
@@ -89758,15 +100478,7 @@ SQLITE_PRIVATE void sqlite3AuthContextPop(AuthContext *pContext){
 **     COMMIT
 **     ROLLBACK
 */
-
-/*
-** This routine is called when a new SQL statement is beginning to
-** be parsed.  Initialize the pParse structure as needed.
-*/
-SQLITE_PRIVATE void sqlite3BeginParse(Parse *pParse, int explainFlag){
-  pParse->explain = (u8)explainFlag;
-  pParse->nVar = 0;
-}
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
 /*
@@ -89774,10 +100486,10 @@ SQLITE_PRIVATE void sqlite3BeginParse(Parse *pParse, int explainFlag){
 ** codeTableLocks() functions.
 */
 struct TableLock {
-  int iDb;             /* The database containing the table to be locked */
-  int iTab;            /* The root page of the table to be locked */
-  u8 isWriteLock;      /* True for write lock.  False for a read lock */
-  const char *zName;   /* Name of the table */
+  int iDb;               /* The database containing the table to be locked */
+  int iTab;              /* The root page of the table to be locked */
+  u8 isWriteLock;        /* True for write lock.  False for a read lock */
+  const char *zLockName; /* Name of the table */
 };
 
 /*
@@ -89803,6 +100515,8 @@ SQLITE_PRIVATE void sqlite3TableLock(
   TableLock *p;
   assert( iDb>=0 );
 
+  if( iDb==1 ) return;
+  if( !sqlite3BtreeSharable(pParse->db->aDb[iDb].pBt) ) return;
   for(i=0; inTableLock; i++){
     p = &pToplevel->aTableLock[i];
     if( p->iDb==iDb && p->iTab==iTab ){
@@ -89819,10 +100533,10 @@ SQLITE_PRIVATE void sqlite3TableLock(
     p->iDb = iDb;
     p->iTab = iTab;
     p->isWriteLock = isWriteLock;
-    p->zName = zName;
+    p->zLockName = zName;
   }else{
     pToplevel->nTableLock = 0;
-    pToplevel->db->mallocFailed = 1;
+    sqlite3OomFault(pToplevel->db);
   }
 }
 
@@ -89841,7 +100555,7 @@ static void codeTableLocks(Parse *pParse){
     TableLock *p = &pParse->aTableLock[i];
     int p1 = p->iDb;
     sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, p->isWriteLock,
-                      p->zName, P4_STATIC);
+                      p->zLockName, P4_STATIC);
   }
 }
 #else
@@ -89877,9 +100591,11 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
 
   assert( pParse->pToplevel==0 );
   db = pParse->db;
-  if( db->mallocFailed ) return;
   if( pParse->nested ) return;
-  if( pParse->nErr ) return;
+  if( db->mallocFailed || pParse->nErr ){
+    if( pParse->rc==SQLITE_OK ) pParse->rc = SQLITE_ERROR;
+    return;
+  }
 
   /* Begin by generating some termination code at the end of the
   ** vdbe program
@@ -89888,15 +100604,14 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
   assert( !pParse->isMultiWrite 
        || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
   if( v ){
-    while( sqlite3VdbeDeletePriorOpcode(v, OP_Close) ){}
     sqlite3VdbeAddOp0(v, OP_Halt);
 
 #if SQLITE_USER_AUTHENTICATION
     if( pParse->nTableLock>0 && db->init.busy==0 ){
       sqlite3UserAuthInit(db);
       if( db->auth.authLevelrc = SQLITE_AUTH_USER;
         sqlite3ErrorMsg(pParse, "user not authenticated");
+        pParse->rc = SQLITE_AUTH_USER;
         return;
       }
     }
@@ -89915,16 +100630,20 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
       assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );
       sqlite3VdbeJumpHere(v, 0);
       for(iDb=0; iDbnDb; iDb++){
+        Schema *pSchema;
         if( DbMaskTest(pParse->cookieMask, iDb)==0 ) continue;
         sqlite3VdbeUsesBtree(v, iDb);
+        pSchema = db->aDb[iDb].pSchema;
         sqlite3VdbeAddOp4Int(v,
           OP_Transaction,                    /* Opcode */
           iDb,                               /* P1 */
           DbMaskTest(pParse->writeMask,iDb), /* P2 */
-          pParse->cookieValue[iDb],          /* P3 */
-          db->aDb[iDb].pSchema->iGeneration  /* P4 */
+          pSchema->schema_cookie,            /* P3 */
+          pSchema->iGeneration               /* P4 */
         );
         if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
+        VdbeComment((v,
+              "usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));
       }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
       for(i=0; inVtabLock; i++){
@@ -89954,29 +100673,23 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
       }
 
       /* Finally, jump back to the beginning of the executable code. */
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, 1);
+      sqlite3VdbeGoto(v, 1);
     }
   }
 
 
   /* Get the VDBE program ready for execution
   */
-  if( v && ALWAYS(pParse->nErr==0) && !db->mallocFailed ){
+  if( v && pParse->nErr==0 && !db->mallocFailed ){
     assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
     /* A minimum of one cursor is required if autoincrement is used
     *  See ticket [a696379c1f08866] */
     if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
     sqlite3VdbeMakeReady(v, pParse);
     pParse->rc = SQLITE_DONE;
-    pParse->colNamesSet = 0;
   }else{
     pParse->rc = SQLITE_ERROR;
   }
-  pParse->nTab = 0;
-  pParse->nMem = 0;
-  pParse->nSet = 0;
-  pParse->nVar = 0;
-  DbMaskZero(pParse->cookieMask);
 }
 
 /*
@@ -89996,8 +100709,7 @@ SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
   char *zSql;
   char *zErrMsg = 0;
   sqlite3 *db = pParse->db;
-# define SAVE_SZ  (sizeof(Parse) - offsetof(Parse,nVar))
-  char saveBuf[SAVE_SZ];
+  char saveBuf[PARSE_TAIL_SZ];
 
   if( pParse->nErr ) return;
   assert( pParse->nested<10 );  /* Nesting should only be of limited depth */
@@ -90008,12 +100720,12 @@ SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
     return;   /* A malloc must have failed */
   }
   pParse->nested++;
-  memcpy(saveBuf, &pParse->nVar, SAVE_SZ);
-  memset(&pParse->nVar, 0, SAVE_SZ);
+  memcpy(saveBuf, PARSE_TAIL(pParse), PARSE_TAIL_SZ);
+  memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);
   sqlite3RunParser(pParse, zSql, &zErrMsg);
   sqlite3DbFree(db, zErrMsg);
   sqlite3DbFree(db, zSql);
-  memcpy(&pParse->nVar, saveBuf, SAVE_SZ);
+  memcpy(PARSE_TAIL(pParse), saveBuf, PARSE_TAIL_SZ);
   pParse->nested--;
 }
 
@@ -90043,10 +100755,6 @@ SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const cha
   Table *p = 0;
   int i;
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return 0;
-#endif
-
   /* All mutexes are required for schema access.  Make sure we hold them. */
   assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
 #if SQLITE_USER_AUTHENTICATION
@@ -90056,14 +100764,22 @@ SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const cha
     return 0;
   }
 #endif
-  for(i=OMIT_TEMPDB; inDb; i++){
-    int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
-    if( zDatabase!=0 && sqlite3StrICmp(zDatabase, db->aDb[j].zName) ) continue;
-    assert( sqlite3SchemaMutexHeld(db, j, 0) );
-    p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
-    if( p ) break;
+  while(1){
+    for(i=OMIT_TEMPDB; inDb; i++){
+      int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
+      if( zDatabase==0 || sqlite3StrICmp(zDatabase, db->aDb[j].zDbSName)==0 ){
+        assert( sqlite3SchemaMutexHeld(db, j, 0) );
+        p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
+        if( p ) return p;
+      }
+    }
+    /* Not found.  If the name we were looking for was temp.sqlite_master
+    ** then change the name to sqlite_temp_master and try again. */
+    if( sqlite3StrICmp(zName, MASTER_NAME)!=0 ) break;
+    if( sqlite3_stricmp(zDatabase, db->aDb[1].zDbSName)!=0 ) break;
+    zName = TEMP_MASTER_NAME;
   }
-  return p;
+  return 0;
 }
 
 /*
@@ -90078,7 +100794,7 @@ SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const cha
 */
 SQLITE_PRIVATE Table *sqlite3LocateTable(
   Parse *pParse,         /* context in which to report errors */
-  int isView,            /* True if looking for a VIEW rather than a TABLE */
+  u32 flags,             /* LOCATE_VIEW or LOCATE_NOERR */
   const char *zName,     /* Name of the table we are looking for */
   const char *zDbase     /* Name of the database.  Might be NULL */
 ){
@@ -90092,20 +100808,31 @@ SQLITE_PRIVATE Table *sqlite3LocateTable(
 
   p = sqlite3FindTable(pParse->db, zName, zDbase);
   if( p==0 ){
-    const char *zMsg = isView ? "no such view" : "no such table";
-    if( zDbase ){
-      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
-    }else{
-      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
+    const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( sqlite3FindDbName(pParse->db, zDbase)<1 ){
+      /* If zName is the not the name of a table in the schema created using
+      ** CREATE, then check to see if it is the name of an virtual table that
+      ** can be an eponymous virtual table. */
+      Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
+      if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
+        pMod = sqlite3PragmaVtabRegister(pParse->db, zName);
+      }
+      if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
+        return pMod->pEpoTab;
+      }
     }
-    pParse->checkSchema = 1;
-  }
-#if SQLITE_USER_AUTHENICATION
-  else if( pParse->db->auth.authLevelcheckSchema = 1;
+    }
+  }
+
   return p;
 }
 
@@ -90120,18 +100847,18 @@ SQLITE_PRIVATE Table *sqlite3LocateTable(
 */
 SQLITE_PRIVATE Table *sqlite3LocateTableItem(
   Parse *pParse, 
-  int isView, 
+  u32 flags,
   struct SrcList_item *p
 ){
   const char *zDb;
   assert( p->pSchema==0 || p->zDatabase==0 );
   if( p->pSchema ){
     int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);
-    zDb = pParse->db->aDb[iDb].zName;
+    zDb = pParse->db->aDb[iDb].zDbSName;
   }else{
     zDb = p->zDatabase;
   }
-  return sqlite3LocateTable(pParse, isView, p->zName, zDb);
+  return sqlite3LocateTable(pParse, flags, p->zName, zDb);
 }
 
 /*
@@ -90155,7 +100882,7 @@ SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const cha
     int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
     Schema *pSchema = db->aDb[j].pSchema;
     assert( pSchema );
-    if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zName) ) continue;
+    if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zDbSName) ) continue;
     assert( sqlite3SchemaMutexHeld(db, j, 0) );
     p = sqlite3HashFind(&pSchema->idxHash, zName);
     if( p ) break;
@@ -90171,8 +100898,9 @@ static void freeIndex(sqlite3 *db, Index *p){
   sqlite3DeleteIndexSamples(db, p);
 #endif
   sqlite3ExprDelete(db, p->pPartIdxWhere);
+  sqlite3ExprListDelete(db, p->aColExpr);
   sqlite3DbFree(db, p->zColAff);
-  if( p->isResized ) sqlite3DbFree(db, p->azColl);
+  if( p->isResized ) sqlite3DbFree(db, (void *)p->azColl);
 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   sqlite3_free(p->aiRowEst);
 #endif
@@ -90223,8 +100951,8 @@ SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3 *db){
   for(i=j=2; inDb; i++){
     struct Db *pDb = &db->aDb[i];
     if( pDb->pBt==0 ){
-      sqlite3DbFree(db, pDb->zName);
-      pDb->zName = 0;
+      sqlite3DbFree(db, pDb->zDbSName);
+      pDb->zDbSName = 0;
       continue;
     }
     if( jaDb[j], 0, (db->nDb-j)*sizeof(db->aDb[j]));
   db->nDb = j;
   if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
     memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
@@ -90297,7 +101024,7 @@ SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3 *db){
 ** Delete memory allocated for the column names of a table or view (the
 ** Table.aCol[] array).
 */
-static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
+SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){
   int i;
   Column *pCol;
   assert( pTable!=0 );
@@ -90305,8 +101032,6 @@ static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
     for(i=0; inCol; i++, pCol++){
       sqlite3DbFree(db, pCol->zName);
       sqlite3ExprDelete(db, pCol->pDflt);
-      sqlite3DbFree(db, pCol->zDflt);
-      sqlite3DbFree(db, pCol->zType);
       sqlite3DbFree(db, pCol->zColl);
     }
     sqlite3DbFree(db, pTable->aCol);
@@ -90328,16 +101053,10 @@ static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
 ** db parameter can be used with db->pnBytesFreed to measure the memory
 ** used by the Table object.
 */
-SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
+static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){
   Index *pIndex, *pNext;
   TESTONLY( int nLookaside; ) /* Used to verify lookaside not used for schema */
 
-  assert( !pTable || pTable->nRef>0 );
-
-  /* Do not delete the table until the reference count reaches zero. */
-  if( !pTable ) return;
-  if( ((!db || db->pnBytesFreed==0) && (--pTable->nRef)>0) ) return;
-
   /* Record the number of outstanding lookaside allocations in schema Tables
   ** prior to doing any free() operations.  Since schema Tables do not use
   ** lookaside, this number should not change. */
@@ -90347,8 +101066,9 @@ SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
   /* Delete all indices associated with this table. */
   for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
     pNext = pIndex->pNext;
-    assert( pIndex->pSchema==pTable->pSchema );
-    if( !db || db->pnBytesFreed==0 ){
+    assert( pIndex->pSchema==pTable->pSchema
+         || (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) );
+    if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){
       char *zName = pIndex->zName; 
       TESTONLY ( Index *pOld = ) sqlite3HashInsert(
          &pIndex->pSchema->idxHash, zName, 0
@@ -90364,13 +101084,11 @@ SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
 
   /* Delete the Table structure itself.
   */
-  sqliteDeleteColumnNames(db, pTable);
+  sqlite3DeleteColumnNames(db, pTable);
   sqlite3DbFree(db, pTable->zName);
   sqlite3DbFree(db, pTable->zColAff);
   sqlite3SelectDelete(db, pTable->pSelect);
-#ifndef SQLITE_OMIT_CHECK
   sqlite3ExprListDelete(db, pTable->pCheck);
-#endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   sqlite3VtabClear(db, pTable);
 #endif
@@ -90379,6 +101097,13 @@ SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
   /* Verify that no lookaside memory was used by schema tables */
   assert( nLookaside==0 || nLookaside==db->lookaside.nOut );
 }
+SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
+  /* Do not delete the table until the reference count reaches zero. */
+  if( !pTable ) return;
+  if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return;
+  deleteTable(db, pTable);
+}
+
 
 /*
 ** Unlink the given table from the hash tables and the delete the
@@ -90429,7 +101154,7 @@ SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3 *db, Token *pName){
 */
 SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *p, int iDb){
   Vdbe *v = sqlite3GetVdbe(p);
-  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
+  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, MASTER_NAME);
   sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, MASTER_ROOT, iDb, 5);
   if( p->nTab==0 ){
     p->nTab = 1;
@@ -90446,12 +101171,11 @@ SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *db, const char *zName){
   int i = -1;         /* Database number */
   if( zName ){
     Db *pDb;
-    int n = sqlite3Strlen30(zName);
     for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
-      if( (!OMIT_TEMPDB || i!=1 ) && n==sqlite3Strlen30(pDb->zName) && 
-          0==sqlite3StrICmp(pDb->zName, zName) ){
-        break;
-      }
+      if( 0==sqlite3_stricmp(pDb->zDbSName, zName) ) break;
+      /* "main" is always an acceptable alias for the primary database
+      ** even if it has been renamed using SQLITE_DBCONFIG_MAINDBNAME. */
+      if( i==0 && 0==sqlite3_stricmp("main", zName) ) break;
     }
   }
   return i;
@@ -90497,21 +101221,20 @@ SQLITE_PRIVATE int sqlite3TwoPartName(
   int iDb;                    /* Database holding the object */
   sqlite3 *db = pParse->db;
 
-  if( ALWAYS(pName2!=0) && pName2->n>0 ){
+  assert( pName2!=0 );
+  if( pName2->n>0 ){
     if( db->init.busy ) {
       sqlite3ErrorMsg(pParse, "corrupt database");
-      pParse->nErr++;
       return -1;
     }
     *pUnqual = pName2;
     iDb = sqlite3FindDb(db, pName1);
     if( iDb<0 ){
       sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
-      pParse->nErr++;
       return -1;
     }
   }else{
-    assert( db->init.iDb==0 || db->init.busy );
+    assert( db->init.iDb==0 || db->init.busy || (db->flags & SQLITE_Vacuum)!=0);
     iDb = db->init.iDb;
     *pUnqual = pName1;
   }
@@ -90588,62 +101311,46 @@ SQLITE_PRIVATE void sqlite3StartTable(
   int iDb;         /* Database number to create the table in */
   Token *pName;    /* Unqualified name of the table to create */
 
-  /* The table or view name to create is passed to this routine via tokens
-  ** pName1 and pName2. If the table name was fully qualified, for example:
-  **
-  ** CREATE TABLE xxx.yyy (...);
-  ** 
-  ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
-  ** the table name is not fully qualified, i.e.:
-  **
-  ** CREATE TABLE yyy(...);
-  **
-  ** Then pName1 is set to "yyy" and pName2 is "".
-  **
-  ** The call below sets the pName pointer to point at the token (pName1 or
-  ** pName2) that stores the unqualified table name. The variable iDb is
-  ** set to the index of the database that the table or view is to be
-  ** created in.
-  */
-  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
-  if( iDb<0 ) return;
-  if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
-    /* If creating a temp table, the name may not be qualified. Unless 
-    ** the database name is "temp" anyway.  */
-    sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
-    return;
+  if( db->init.busy && db->init.newTnum==1 ){
+    /* Special case:  Parsing the sqlite_master or sqlite_temp_master schema */
+    iDb = db->init.iDb;
+    zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));
+    pName = pName1;
+  }else{
+    /* The common case */
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+    if( iDb<0 ) return;
+    if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
+      /* If creating a temp table, the name may not be qualified. Unless 
+      ** the database name is "temp" anyway.  */
+      sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
+      return;
+    }
+    if( !OMIT_TEMPDB && isTemp ) iDb = 1;
+    zName = sqlite3NameFromToken(db, pName);
   }
-  if( !OMIT_TEMPDB && isTemp ) iDb = 1;
-
   pParse->sNameToken = *pName;
-  zName = sqlite3NameFromToken(db, pName);
   if( zName==0 ) return;
   if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
     goto begin_table_error;
   }
   if( db->init.iDb==1 ) isTemp = 1;
 #ifndef SQLITE_OMIT_AUTHORIZATION
-  assert( (isTemp & 1)==isTemp );
+  assert( isTemp==0 || isTemp==1 );
+  assert( isView==0 || isView==1 );
   {
-    int code;
-    char *zDb = db->aDb[iDb].zName;
+    static const u8 aCode[] = {
+       SQLITE_CREATE_TABLE,
+       SQLITE_CREATE_TEMP_TABLE,
+       SQLITE_CREATE_VIEW,
+       SQLITE_CREATE_TEMP_VIEW
+    };
+    char *zDb = db->aDb[iDb].zDbSName;
     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
       goto begin_table_error;
     }
-    if( isView ){
-      if( !OMIT_TEMPDB && isTemp ){
-        code = SQLITE_CREATE_TEMP_VIEW;
-      }else{
-        code = SQLITE_CREATE_VIEW;
-      }
-    }else{
-      if( !OMIT_TEMPDB && isTemp ){
-        code = SQLITE_CREATE_TEMP_TABLE;
-      }else{
-        code = SQLITE_CREATE_TABLE;
-      }
-    }
-    if( !isVirtual && sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
+    if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],
+                                       zName, 0, zDb) ){
       goto begin_table_error;
     }
   }
@@ -90657,7 +101364,7 @@ SQLITE_PRIVATE void sqlite3StartTable(
   ** collisions.
   */
   if( !IN_DECLARE_VTAB ){
-    char *zDb = db->aDb[iDb].zName;
+    char *zDb = db->aDb[iDb].zDbSName;
     if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
       goto begin_table_error;
     }
@@ -90666,7 +101373,7 @@ SQLITE_PRIVATE void sqlite3StartTable(
       if( !noErr ){
         sqlite3ErrorMsg(pParse, "table %T already exists", pName);
       }else{
-        assert( !db->init.busy );
+        assert( !db->init.busy || CORRUPT_DB );
         sqlite3CodeVerifySchema(pParse, iDb);
       }
       goto begin_table_error;
@@ -90679,16 +101386,20 @@ SQLITE_PRIVATE void sqlite3StartTable(
 
   pTable = sqlite3DbMallocZero(db, sizeof(Table));
   if( pTable==0 ){
-    db->mallocFailed = 1;
-    pParse->rc = SQLITE_NOMEM;
+    assert( db->mallocFailed );
+    pParse->rc = SQLITE_NOMEM_BKPT;
     pParse->nErr++;
     goto begin_table_error;
   }
   pTable->zName = zName;
   pTable->iPKey = -1;
   pTable->pSchema = db->aDb[iDb].pSchema;
-  pTable->nRef = 1;
+  pTable->nTabRef = 1;
+#ifdef SQLITE_DEFAULT_ROWEST
+  pTable->nRowLogEst = sqlite3LogEst(SQLITE_DEFAULT_ROWEST);
+#else
   pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
+#endif
   assert( pParse->pNewTable==0 );
   pParse->pNewTable = pTable;
 
@@ -90712,10 +101423,12 @@ SQLITE_PRIVATE void sqlite3StartTable(
   ** now.
   */
   if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
-    int j1;
+    int addr1;
     int fileFormat;
     int reg1, reg2, reg3;
-    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    /* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */
+    static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     if( isVirtual ){
@@ -90731,14 +101444,12 @@ SQLITE_PRIVATE void sqlite3StartTable(
     reg3 = ++pParse->nMem;
     sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
     sqlite3VdbeUsesBtree(v, iDb);
-    j1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
+    addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
     fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                   1 : SQLITE_MAX_FILE_FORMAT;
-    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, reg3);
-    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, reg3);
-    sqlite3VdbeJumpHere(v, j1);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
+    sqlite3VdbeJumpHere(v, addr1);
 
     /* This just creates a place-holder record in the sqlite_master table.
     ** The record created does not contain anything yet.  It will be replaced
@@ -90759,7 +101470,7 @@ SQLITE_PRIVATE void sqlite3StartTable(
     }
     sqlite3OpenMasterTable(pParse, iDb);
     sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
-    sqlite3VdbeAddOp2(v, OP_Null, 0, reg3);
+    sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
     sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
     sqlite3VdbeAddOp0(v, OP_Close);
@@ -90774,18 +101485,19 @@ begin_table_error:
   return;
 }
 
-/*
-** This macro is used to compare two strings in a case-insensitive manner.
-** It is slightly faster than calling sqlite3StrICmp() directly, but
-** produces larger code.
-**
-** WARNING: This macro is not compatible with the strcmp() family. It
-** returns true if the two strings are equal, otherwise false.
+/* Set properties of a table column based on the (magical)
+** name of the column.
 */
-#define STRICMP(x, y) (\
-sqlite3UpperToLower[*(unsigned char *)(x)]==   \
-sqlite3UpperToLower[*(unsigned char *)(y)]     \
-&& sqlite3StrICmp((x)+1,(y)+1)==0 )
+#if SQLITE_ENABLE_HIDDEN_COLUMNS
+SQLITE_PRIVATE void sqlite3ColumnPropertiesFromName(Table *pTab, Column *pCol){
+  if( sqlite3_strnicmp(pCol->zName, "__hidden__", 10)==0 ){
+    pCol->colFlags |= COLFLAG_HIDDEN;
+  }else if( pTab && pCol!=pTab->aCol && (pCol[-1].colFlags & COLFLAG_HIDDEN) ){
+    pTab->tabFlags |= TF_OOOHidden;
+  }
+}
+#endif
+
 
 /*
 ** Add a new column to the table currently being constructed.
@@ -90795,10 +101507,11 @@ sqlite3UpperToLower[*(unsigned char *)(y)]     \
 ** first to get things going.  Then this routine is called for each
 ** column.
 */
-SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
+SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){
   Table *p;
   int i;
   char *z;
+  char *zType;
   Column *pCol;
   sqlite3 *db = pParse->db;
   if( (p = pParse->pNewTable)==0 ) return;
@@ -90808,10 +101521,13 @@ SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
     return;
   }
 #endif
-  z = sqlite3NameFromToken(db, pName);
+  z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
   if( z==0 ) return;
+  memcpy(z, pName->z, pName->n);
+  z[pName->n] = 0;
+  sqlite3Dequote(z);
   for(i=0; inCol; i++){
-    if( STRICMP(z, p->aCol[i].zName) ){
+    if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
       sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
       sqlite3DbFree(db, z);
       return;
@@ -90829,14 +101545,23 @@ SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
   pCol = &p->aCol[p->nCol];
   memset(pCol, 0, sizeof(p->aCol[0]));
   pCol->zName = z;
+  sqlite3ColumnPropertiesFromName(p, pCol);
  
-  /* If there is no type specified, columns have the default affinity
-  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
-  ** be called next to set pCol->affinity correctly.
-  */
-  pCol->affinity = SQLITE_AFF_NONE;
-  pCol->szEst = 1;
+  if( pType->n==0 ){
+    /* If there is no type specified, columns have the default affinity
+    ** 'BLOB'. */
+    pCol->affinity = SQLITE_AFF_BLOB;
+    pCol->szEst = 1;
+  }else{
+    zType = z + sqlite3Strlen30(z) + 1;
+    memcpy(zType, pType->z, pType->n);
+    zType[pType->n] = 0;
+    sqlite3Dequote(zType);
+    pCol->affinity = sqlite3AffinityType(zType, &pCol->szEst);
+    pCol->colFlags |= COLFLAG_HASTYPE;
+  }
   p->nCol++;
+  pParse->constraintName.n = 0;
 }
 
 /*
@@ -90850,6 +101575,7 @@ SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){
   p = pParse->pNewTable;
   if( p==0 || NEVER(p->nCol<1) ) return;
   p->aCol[p->nCol-1].notNull = (u8)onError;
+  p->tabFlags |= TF_HasNotNull;
 }
 
 /*
@@ -90869,7 +101595,7 @@ SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){
 ** 'CHAR'        | SQLITE_AFF_TEXT
 ** 'CLOB'        | SQLITE_AFF_TEXT
 ** 'TEXT'        | SQLITE_AFF_TEXT
-** 'BLOB'        | SQLITE_AFF_NONE
+** 'BLOB'        | SQLITE_AFF_BLOB
 ** 'REAL'        | SQLITE_AFF_REAL
 ** 'FLOA'        | SQLITE_AFF_REAL
 ** 'DOUB'        | SQLITE_AFF_REAL
@@ -90882,7 +101608,7 @@ SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, u8 *pszEst){
   char aff = SQLITE_AFF_NUMERIC;
   const char *zChar = 0;
 
-  if( zIn==0 ) return aff;
+  assert( zIn!=0 );
   while( zIn[0] ){
     h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];
     zIn++;
@@ -90895,7 +101621,7 @@ SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, u8 *pszEst){
       aff = SQLITE_AFF_TEXT;
     }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
         && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
-      aff = SQLITE_AFF_NONE;
+      aff = SQLITE_AFF_BLOB;
       if( zIn[0]=='(' ) zChar = zIn;
 #ifndef SQLITE_OMIT_FLOATING_POINT
     }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
@@ -90939,27 +101665,6 @@ SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, u8 *pszEst){
   return aff;
 }
 
-/*
-** This routine is called by the parser while in the middle of
-** parsing a CREATE TABLE statement.  The pFirst token is the first
-** token in the sequence of tokens that describe the type of the
-** column currently under construction.   pLast is the last token
-** in the sequence.  Use this information to construct a string
-** that contains the typename of the column and store that string
-** in zType.
-*/ 
-SQLITE_PRIVATE void sqlite3AddColumnType(Parse *pParse, Token *pType){
-  Table *p;
-  Column *pCol;
-
-  p = pParse->pNewTable;
-  if( p==0 || NEVER(p->nCol<1) ) return;
-  pCol = &p->aCol[p->nCol-1];
-  assert( pCol->zType==0 );
-  pCol->zType = sqlite3NameFromToken(pParse->db, pType);
-  pCol->affinity = sqlite3AffinityType(pCol->zType, &pCol->szEst);
-}
-
 /*
 ** The expression is the default value for the most recently added column
 ** of the table currently under construction.
@@ -90985,16 +101690,45 @@ SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse *pParse, ExprSpan *pSpan){
       ** tokens that point to volatile memory. The 'span' of the expression
       ** is required by pragma table_info.
       */
+      Expr x;
       sqlite3ExprDelete(db, pCol->pDflt);
-      pCol->pDflt = sqlite3ExprDup(db, pSpan->pExpr, EXPRDUP_REDUCE);
-      sqlite3DbFree(db, pCol->zDflt);
-      pCol->zDflt = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
-                                     (int)(pSpan->zEnd - pSpan->zStart));
+      memset(&x, 0, sizeof(x));
+      x.op = TK_SPAN;
+      x.u.zToken = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
+                                    (int)(pSpan->zEnd - pSpan->zStart));
+      x.pLeft = pSpan->pExpr;
+      x.flags = EP_Skip;
+      pCol->pDflt = sqlite3ExprDup(db, &x, EXPRDUP_REDUCE);
+      sqlite3DbFree(db, x.u.zToken);
     }
   }
   sqlite3ExprDelete(db, pSpan->pExpr);
 }
 
+/*
+** Backwards Compatibility Hack:
+** 
+** Historical versions of SQLite accepted strings as column names in
+** indexes and PRIMARY KEY constraints and in UNIQUE constraints.  Example:
+**
+**     CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)
+**     CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);
+**
+** This is goofy.  But to preserve backwards compatibility we continue to
+** accept it.  This routine does the necessary conversion.  It converts
+** the expression given in its argument from a TK_STRING into a TK_ID
+** if the expression is just a TK_STRING with an optional COLLATE clause.
+** If the epxression is anything other than TK_STRING, the expression is
+** unchanged.
+*/
+static void sqlite3StringToId(Expr *p){
+  if( p->op==TK_STRING ){
+    p->op = TK_ID;
+  }else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){
+    p->pLeft->op = TK_ID;
+  }
+}
+
 /*
 ** Designate the PRIMARY KEY for the table.  pList is a list of names 
 ** of columns that form the primary key.  If pList is NULL, then the
@@ -91021,10 +101755,10 @@ SQLITE_PRIVATE void sqlite3AddPrimaryKey(
   int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */
 ){
   Table *pTab = pParse->pNewTable;
-  char *zType = 0;
+  Column *pCol = 0;
   int iCol = -1, i;
   int nTerm;
-  if( pTab==0 || IN_DECLARE_VTAB ) goto primary_key_exit;
+  if( pTab==0 ) goto primary_key_exit;
   if( pTab->tabFlags & TF_HasPrimaryKey ){
     sqlite3ErrorMsg(pParse, 
       "table \"%s\" has more than one primary key", pTab->zName);
@@ -91033,24 +101767,31 @@ SQLITE_PRIVATE void sqlite3AddPrimaryKey(
   pTab->tabFlags |= TF_HasPrimaryKey;
   if( pList==0 ){
     iCol = pTab->nCol - 1;
-    pTab->aCol[iCol].colFlags |= COLFLAG_PRIMKEY;
-    zType = pTab->aCol[iCol].zType;
+    pCol = &pTab->aCol[iCol];
+    pCol->colFlags |= COLFLAG_PRIMKEY;
     nTerm = 1;
   }else{
     nTerm = pList->nExpr;
     for(i=0; inCol; iCol++){
-        if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
-          pTab->aCol[iCol].colFlags |= COLFLAG_PRIMKEY;
-          zType = pTab->aCol[iCol].zType;
-          break;
+      Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);
+      assert( pCExpr!=0 );
+      sqlite3StringToId(pCExpr);
+      if( pCExpr->op==TK_ID ){
+        const char *zCName = pCExpr->u.zToken;
+        for(iCol=0; iColnCol; iCol++){
+          if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){
+            pCol = &pTab->aCol[iCol];
+            pCol->colFlags |= COLFLAG_PRIMKEY;
+            break;
+          }
         }
       }
     }
   }
   if( nTerm==1
-   && zType && sqlite3StrICmp(zType, "INTEGER")==0
-   && sortOrder==SQLITE_SO_ASC
+   && pCol
+   && sqlite3StrICmp(sqlite3ColumnType(pCol,""), "INTEGER")==0
+   && sortOrder!=SQLITE_SO_DESC
   ){
     pTab->iPKey = iCol;
     pTab->keyConf = (u8)onError;
@@ -91063,15 +101804,8 @@ SQLITE_PRIVATE void sqlite3AddPrimaryKey(
        "INTEGER PRIMARY KEY");
 #endif
   }else{
-    Vdbe *v = pParse->pVdbe;
-    Index *p;
-    if( v ) pParse->addrSkipPK = sqlite3VdbeAddOp0(v, OP_Noop);
-    p = sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
-                           0, sortOrder, 0);
-    if( p ){
-      p->idxType = SQLITE_IDXTYPE_PRIMARYKEY;
-      if( v ) sqlite3VdbeJumpHere(v, pParse->addrSkipPK);
-    }
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
+                           0, sortOrder, 0, SQLITE_IDXTYPE_PRIMARYKEY);
     pList = 0;
   }
 
@@ -91190,15 +101924,16 @@ SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){
 ** set back to prior value.  But schema changes are infrequent
 ** and the probability of hitting the same cookie value is only
 ** 1 chance in 2^32.  So we're safe enough.
+**
+** IMPLEMENTATION-OF: R-34230-56049 SQLite automatically increments
+** the schema-version whenever the schema changes.
 */
 SQLITE_PRIVATE void sqlite3ChangeCookie(Parse *pParse, int iDb){
-  int r1 = sqlite3GetTempReg(pParse);
   sqlite3 *db = pParse->db;
   Vdbe *v = pParse->pVdbe;
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, r1);
-  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, r1);
-  sqlite3ReleaseTempReg(pParse, r1);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, 
+                    db->aDb[iDb].pSchema->schema_cookie+1);
 }
 
 /*
@@ -91280,7 +102015,7 @@ static char *createTableStmt(sqlite3 *db, Table *p){
   n += 35 + 6*p->nCol;
   zStmt = sqlite3DbMallocRaw(0, n);
   if( zStmt==0 ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     return 0;
   }
   sqlite3_snprintf(n, zStmt, "CREATE TABLE ");
@@ -91289,7 +102024,7 @@ static char *createTableStmt(sqlite3 *db, Table *p){
   zStmt[k++] = '(';
   for(pCol=p->aCol, i=0; inCol; i++, pCol++){
     static const char * const azType[] = {
-        /* SQLITE_AFF_NONE    */ "",
+        /* SQLITE_AFF_BLOB    */ "",
         /* SQLITE_AFF_TEXT    */ " TEXT",
         /* SQLITE_AFF_NUMERIC */ " NUM",
         /* SQLITE_AFF_INTEGER */ " INT",
@@ -91302,17 +102037,17 @@ static char *createTableStmt(sqlite3 *db, Table *p){
     k += sqlite3Strlen30(&zStmt[k]);
     zSep = zSep2;
     identPut(zStmt, &k, pCol->zName);
-    assert( pCol->affinity-SQLITE_AFF_NONE >= 0 );
-    assert( pCol->affinity-SQLITE_AFF_NONE < ArraySize(azType) );
-    testcase( pCol->affinity==SQLITE_AFF_NONE );
+    assert( pCol->affinity-SQLITE_AFF_BLOB >= 0 );
+    assert( pCol->affinity-SQLITE_AFF_BLOB < ArraySize(azType) );
+    testcase( pCol->affinity==SQLITE_AFF_BLOB );
     testcase( pCol->affinity==SQLITE_AFF_TEXT );
     testcase( pCol->affinity==SQLITE_AFF_NUMERIC );
     testcase( pCol->affinity==SQLITE_AFF_INTEGER );
     testcase( pCol->affinity==SQLITE_AFF_REAL );
     
-    zType = azType[pCol->affinity - SQLITE_AFF_NONE];
+    zType = azType[pCol->affinity - SQLITE_AFF_BLOB];
     len = sqlite3Strlen30(zType);
-    assert( pCol->affinity==SQLITE_AFF_NONE 
+    assert( pCol->affinity==SQLITE_AFF_BLOB 
             || pCol->affinity==sqlite3AffinityType(zType, 0) );
     memcpy(&zStmt[k], zType, len);
     k += len;
@@ -91333,9 +102068,9 @@ static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){
   assert( pIdx->isResized==0 );
   nByte = (sizeof(char*) + sizeof(i16) + 1)*N;
   zExtra = sqlite3DbMallocZero(db, nByte);
-  if( zExtra==0 ) return SQLITE_NOMEM;
+  if( zExtra==0 ) return SQLITE_NOMEM_BKPT;
   memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);
-  pIdx->azColl = (char**)zExtra;
+  pIdx->azColl = (const char**)zExtra;
   zExtra += sizeof(char*)*N;
   memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);
   pIdx->aiColumn = (i16*)zExtra;
@@ -91390,21 +102125,23 @@ static int hasColumn(const i16 *aiCol, int nCol, int x){
 ** are appropriate for a WITHOUT ROWID table instead of a rowid table.
 ** Changes include:
 **
-**     (1)  Convert the OP_CreateTable into an OP_CreateIndex.  There is
+**     (1)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
+**     (2)  Convert the OP_CreateTable into an OP_CreateIndex.  There is
 **          no rowid btree for a WITHOUT ROWID.  Instead, the canonical
 **          data storage is a covering index btree.
-**     (2)  Bypass the creation of the sqlite_master table entry
+**     (3)  Bypass the creation of the sqlite_master table entry
 **          for the PRIMARY KEY as the primary key index is now
 **          identified by the sqlite_master table entry of the table itself.
-**     (3)  Set the Index.tnum of the PRIMARY KEY Index object in the
+**     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the
 **          schema to the rootpage from the main table.
-**     (4)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
 **     (5)  Add all table columns to the PRIMARY KEY Index object
 **          so that the PRIMARY KEY is a covering index.  The surplus
 **          columns are part of KeyInfo.nXField and are not used for
 **          sorting or lookup or uniqueness checks.
 **     (6)  Replace the rowid tail on all automatically generated UNIQUE
 **          indices with the PRIMARY KEY columns.
+**
+** For virtual tables, only (1) is performed.
 */
 static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
   Index *pIdx;
@@ -91414,21 +102151,27 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
   sqlite3 *db = pParse->db;
   Vdbe *v = pParse->pVdbe;
 
+  /* Mark every PRIMARY KEY column as NOT NULL (except for imposter tables)
+  */
+  if( !db->init.imposterTable ){
+    for(i=0; inCol; i++){
+      if( (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){
+        pTab->aCol[i].notNull = OE_Abort;
+      }
+    }
+  }
+
+  /* The remaining transformations only apply to b-tree tables, not to
+  ** virtual tables */
+  if( IN_DECLARE_VTAB ) return;
+
   /* Convert the OP_CreateTable opcode that would normally create the
   ** root-page for the table into an OP_CreateIndex opcode.  The index
   ** created will become the PRIMARY KEY index.
   */
   if( pParse->addrCrTab ){
     assert( v );
-    sqlite3VdbeGetOp(v, pParse->addrCrTab)->opcode = OP_CreateIndex;
-  }
-
-  /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master
-  ** table entry.
-  */
-  if( pParse->addrSkipPK ){
-    assert( v );
-    sqlite3VdbeGetOp(v, pParse->addrSkipPK)->opcode = OP_Goto;
+    sqlite3VdbeChangeOpcode(v, pParse->addrCrTab, OP_CreateIndex);
   }
 
   /* Locate the PRIMARY KEY index.  Or, if this table was originally
@@ -91436,18 +102179,21 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
   */
   if( pTab->iPKey>=0 ){
     ExprList *pList;
-    pList = sqlite3ExprListAppend(pParse, 0, 0);
+    Token ipkToken;
+    sqlite3TokenInit(&ipkToken, pTab->aCol[pTab->iPKey].zName);
+    pList = sqlite3ExprListAppend(pParse, 0, 
+                  sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));
     if( pList==0 ) return;
-    pList->a[0].zName = sqlite3DbStrDup(pParse->db,
-                                        pTab->aCol[pTab->iPKey].zName);
     pList->a[0].sortOrder = pParse->iPkSortOrder;
     assert( pParse->pNewTable==pTab );
-    pPk = sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0);
-    if( pPk==0 ) return;
-    pPk->idxType = SQLITE_IDXTYPE_PRIMARYKEY;
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0,
+                       SQLITE_IDXTYPE_PRIMARYKEY);
+    if( db->mallocFailed ) return;
+    pPk = sqlite3PrimaryKeyIndex(pTab);
     pTab->iPKey = -1;
   }else{
     pPk = sqlite3PrimaryKeyIndex(pTab);
+
     /*
     ** Remove all redundant columns from the PRIMARY KEY.  For example, change
     ** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)".  Later
@@ -91462,15 +102208,19 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
     }
     pPk->nKeyCol = j;
   }
-  pPk->isCovering = 1;
   assert( pPk!=0 );
+  pPk->isCovering = 1;
+  if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
   nPk = pPk->nKeyCol;
 
-  /* Make sure every column of the PRIMARY KEY is NOT NULL */
-  for(i=0; iaCol[pPk->aiColumn[i]].notNull = 1;
+  /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master
+  ** table entry. This is only required if currently generating VDBE
+  ** code for a CREATE TABLE (not when parsing one as part of reading
+  ** a database schema).  */
+  if( v && pPk->tnum>0 ){
+    assert( db->init.busy==0 );
+    sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);
   }
-  pPk->uniqNotNull = 1;
 
   /* The root page of the PRIMARY KEY is the table root page */
   pPk->tnum = pTab->tnum;
@@ -91509,7 +102259,7 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
       if( !hasColumn(pPk->aiColumn, j, i) ){
         assert( jnColumn );
         pPk->aiColumn[j] = i;
-        pPk->azColl[j] = "BINARY";
+        pPk->azColl[j] = sqlite3StrBINARY;
         j++;
       }
     }
@@ -91552,9 +102302,10 @@ SQLITE_PRIVATE void sqlite3EndTable(
   int iDb;                  /* Database in which the table lives */
   Index *pIdx;              /* An implied index of the table */
 
-  if( (pEnd==0 && pSelect==0) || db->mallocFailed ){
+  if( pEnd==0 && pSelect==0 ){
     return;
   }
+  assert( !db->mallocFailed );
   p = pParse->pNewTable;
   if( p==0 ) return;
 
@@ -91565,9 +102316,13 @@ SQLITE_PRIVATE void sqlite3EndTable(
   ** So do not write to the disk again.  Extract the root page number
   ** for the table from the db->init.newTnum field.  (The page number
   ** should have been put there by the sqliteOpenCb routine.)
+  **
+  ** If the root page number is 1, that means this is the sqlite_master
+  ** table itself.  So mark it read-only.
   */
   if( db->init.busy ){
     p->tnum = db->init.newTnum;
+    if( p->tnum==1 ) p->tabFlags |= TF_Readonly;
   }
 
   /* Special processing for WITHOUT ROWID Tables */
@@ -91580,7 +102335,7 @@ SQLITE_PRIVATE void sqlite3EndTable(
     if( (p->tabFlags & TF_HasPrimaryKey)==0 ){
       sqlite3ErrorMsg(pParse, "PRIMARY KEY missing on table %s", p->zName);
     }else{
-      p->tabFlags |= TF_WithoutRowid;
+      p->tabFlags |= TF_WithoutRowid | TF_NoVisibleRowid;
       convertToWithoutRowidTable(pParse, p);
     }
   }
@@ -91648,26 +102403,46 @@ SQLITE_PRIVATE void sqlite3EndTable(
     ** be redundant.
     */
     if( pSelect ){
-      SelectDest dest;
-      Table *pSelTab;
-
+      SelectDest dest;    /* Where the SELECT should store results */
+      int regYield;       /* Register holding co-routine entry-point */
+      int addrTop;        /* Top of the co-routine */
+      int regRec;         /* A record to be insert into the new table */
+      int regRowid;       /* Rowid of the next row to insert */
+      int addrInsLoop;    /* Top of the loop for inserting rows */
+      Table *pSelTab;     /* A table that describes the SELECT results */
+
+      regYield = ++pParse->nMem;
+      regRec = ++pParse->nMem;
+      regRowid = ++pParse->nMem;
       assert(pParse->nTab==1);
+      sqlite3MayAbort(pParse);
       sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
       sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
       pParse->nTab = 2;
-      sqlite3SelectDestInit(&dest, SRT_Table, 1);
+      addrTop = sqlite3VdbeCurrentAddr(v) + 1;
+      sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
+      sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
       sqlite3Select(pParse, pSelect, &dest);
+      sqlite3VdbeEndCoroutine(v, regYield);
+      sqlite3VdbeJumpHere(v, addrTop - 1);
+      if( pParse->nErr ) return;
+      pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
+      if( pSelTab==0 ) return;
+      assert( p->aCol==0 );
+      p->nCol = pSelTab->nCol;
+      p->aCol = pSelTab->aCol;
+      pSelTab->nCol = 0;
+      pSelTab->aCol = 0;
+      sqlite3DeleteTable(db, pSelTab);
+      addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
+      VdbeCoverage(v);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);
+      sqlite3TableAffinity(v, p, 0);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);
+      sqlite3VdbeGoto(v, addrInsLoop);
+      sqlite3VdbeJumpHere(v, addrInsLoop);
       sqlite3VdbeAddOp1(v, OP_Close, 1);
-      if( pParse->nErr==0 ){
-        pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
-        if( pSelTab==0 ) return;
-        assert( p->aCol==0 );
-        p->nCol = pSelTab->nCol;
-        p->aCol = pSelTab->aCol;
-        pSelTab->nCol = 0;
-        pSelTab->aCol = 0;
-        sqlite3DeleteTable(db, pSelTab);
-      }
     }
 
     /* Compute the complete text of the CREATE statement */
@@ -91690,7 +102465,7 @@ SQLITE_PRIVATE void sqlite3EndTable(
       "UPDATE %Q.%s "
          "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "
        "WHERE rowid=#%d",
-      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+      db->aDb[iDb].zDbSName, MASTER_NAME,
       zType,
       p->zName,
       p->zName,
@@ -91705,13 +102480,13 @@ SQLITE_PRIVATE void sqlite3EndTable(
     /* Check to see if we need to create an sqlite_sequence table for
     ** keeping track of autoincrement keys.
     */
-    if( p->tabFlags & TF_Autoincrement ){
+    if( (p->tabFlags & TF_Autoincrement)!=0 ){
       Db *pDb = &db->aDb[iDb];
       assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
       if( pDb->pSchema->pSeqTab==0 ){
         sqlite3NestedParse(pParse,
           "CREATE TABLE %Q.sqlite_sequence(name,seq)",
-          pDb->zName
+          pDb->zDbSName
         );
       }
     }
@@ -91732,7 +102507,7 @@ SQLITE_PRIVATE void sqlite3EndTable(
     pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);
     if( pOld ){
       assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return;
     }
     pParse->pNewTable = 0;
@@ -91762,6 +102537,7 @@ SQLITE_PRIVATE void sqlite3CreateView(
   Token *pBegin,     /* The CREATE token that begins the statement */
   Token *pName1,     /* The token that holds the name of the view */
   Token *pName2,     /* The token that holds the name of the view */
+  ExprList *pCNames, /* Optional list of view column names */
   Select *pSelect,   /* A SELECT statement that will become the new view */
   int isTemp,        /* TRUE for a TEMPORARY view */
   int noErr          /* Suppress error messages if VIEW already exists */
@@ -91777,22 +102553,15 @@ SQLITE_PRIVATE void sqlite3CreateView(
 
   if( pParse->nVar>0 ){
     sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
-    sqlite3SelectDelete(db, pSelect);
-    return;
+    goto create_view_fail;
   }
   sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
   p = pParse->pNewTable;
-  if( p==0 || pParse->nErr ){
-    sqlite3SelectDelete(db, pSelect);
-    return;
-  }
+  if( p==0 || pParse->nErr ) goto create_view_fail;
   sqlite3TwoPartName(pParse, pName1, pName2, &pName);
   iDb = sqlite3SchemaToIndex(db, p->pSchema);
   sqlite3FixInit(&sFix, pParse, iDb, "view", pName);
-  if( sqlite3FixSelect(&sFix, pSelect) ){
-    sqlite3SelectDelete(db, pSelect);
-    return;
-  }
+  if( sqlite3FixSelect(&sFix, pSelect) ) goto create_view_fail;
 
   /* Make a copy of the entire SELECT statement that defines the view.
   ** This will force all the Expr.token.z values to be dynamically
@@ -91800,30 +102569,31 @@ SQLITE_PRIVATE void sqlite3CreateView(
   ** they will persist after the current sqlite3_exec() call returns.
   */
   p->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
-  sqlite3SelectDelete(db, pSelect);
-  if( db->mallocFailed ){
-    return;
-  }
-  if( !db->init.busy ){
-    sqlite3ViewGetColumnNames(pParse, p);
-  }
+  p->pCheck = sqlite3ExprListDup(db, pCNames, EXPRDUP_REDUCE);
+  if( db->mallocFailed ) goto create_view_fail;
 
   /* Locate the end of the CREATE VIEW statement.  Make sEnd point to
   ** the end.
   */
   sEnd = pParse->sLastToken;
-  if( ALWAYS(sEnd.z[0]!=0) && sEnd.z[0]!=';' ){
+  assert( sEnd.z[0]!=0 );
+  if( sEnd.z[0]!=';' ){
     sEnd.z += sEnd.n;
   }
   sEnd.n = 0;
   n = (int)(sEnd.z - pBegin->z);
+  assert( n>0 );
   z = pBegin->z;
-  while( ALWAYS(n>0) && sqlite3Isspace(z[n-1]) ){ n--; }
+  while( sqlite3Isspace(z[n-1]) ){ n--; }
   sEnd.z = &z[n-1];
   sEnd.n = 1;
 
   /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */
   sqlite3EndTable(pParse, 0, &sEnd, 0, 0);
+
+create_view_fail:
+  sqlite3SelectDelete(db, pSelect);
+  sqlite3ExprListDelete(db, pCNames);
   return;
 }
 #endif /* SQLITE_OMIT_VIEW */
@@ -91840,7 +102610,9 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
   int nErr = 0;     /* Number of errors encountered */
   int n;            /* Temporarily holds the number of cursors assigned */
   sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
+#ifndef SQLITE_OMIT_AUTHORIZATION
   sqlite3_xauth xAuth;       /* Saved xAuth pointer */
+#endif
 
   assert( pTable );
 
@@ -91888,11 +102660,10 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
   assert( pTable->pSelect );
   pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
   if( pSel ){
-    u8 enableLookaside = db->lookaside.bEnabled;
     n = pParse->nTab;
     sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
     pTable->nCol = -1;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.bDisable++;
 #ifndef SQLITE_OMIT_AUTHORIZATION
     xAuth = db->xAuth;
     db->xAuth = 0;
@@ -91901,25 +102672,43 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
 #else
     pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
 #endif
-    db->lookaside.bEnabled = enableLookaside;
     pParse->nTab = n;
-    if( pSelTab ){
+    if( pTable->pCheck ){
+      /* CREATE VIEW name(arglist) AS ...
+      ** The names of the columns in the table are taken from
+      ** arglist which is stored in pTable->pCheck.  The pCheck field
+      ** normally holds CHECK constraints on an ordinary table, but for
+      ** a VIEW it holds the list of column names.
+      */
+      sqlite3ColumnsFromExprList(pParse, pTable->pCheck, 
+                                 &pTable->nCol, &pTable->aCol);
+      if( db->mallocFailed==0 
+       && pParse->nErr==0
+       && pTable->nCol==pSel->pEList->nExpr
+      ){
+        sqlite3SelectAddColumnTypeAndCollation(pParse, pTable, pSel);
+      }
+    }else if( pSelTab ){
+      /* CREATE VIEW name AS...  without an argument list.  Construct
+      ** the column names from the SELECT statement that defines the view.
+      */
       assert( pTable->aCol==0 );
       pTable->nCol = pSelTab->nCol;
       pTable->aCol = pSelTab->aCol;
       pSelTab->nCol = 0;
       pSelTab->aCol = 0;
-      sqlite3DeleteTable(db, pSelTab);
       assert( sqlite3SchemaMutexHeld(db, 0, pTable->pSchema) );
-      pTable->pSchema->schemaFlags |= DB_UnresetViews;
     }else{
       pTable->nCol = 0;
       nErr++;
     }
+    sqlite3DeleteTable(db, pSelTab);
     sqlite3SelectDelete(db, pSel);
+    db->lookaside.bDisable--;
   } else {
     nErr++;
   }
+  pTable->pSchema->schemaFlags |= DB_UnresetViews;
 #endif /* SQLITE_OMIT_VIEW */
   return nErr;  
 }
@@ -91936,7 +102725,7 @@ static void sqliteViewResetAll(sqlite3 *db, int idx){
   for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){
     Table *pTab = sqliteHashData(i);
     if( pTab->pSelect ){
-      sqliteDeleteColumnNames(db, pTab);
+      sqlite3DeleteColumnNames(db, pTab);
       pTab->aCol = 0;
       pTab->nCol = 0;
     }
@@ -91998,6 +102787,7 @@ SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3 *db, int iDb, int iFrom, int iT
 static void destroyRootPage(Parse *pParse, int iTable, int iDb){
   Vdbe *v = sqlite3GetVdbe(pParse);
   int r1 = sqlite3GetTempReg(pParse);
+  assert( iTable>1 );
   sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
   sqlite3MayAbort(pParse);
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -92012,7 +102802,7 @@ static void destroyRootPage(Parse *pParse, int iTable, int iDb){
   */
   sqlite3NestedParse(pParse, 
      "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",
-     pParse->db->aDb[iDb].zName, SCHEMA_TABLE(iDb), iTable, r1, r1);
+     pParse->db->aDb[iDb].zDbSName, MASTER_NAME, iTable, r1, r1);
 #endif
   sqlite3ReleaseTempReg(pParse, r1);
 }
@@ -92088,7 +102878,7 @@ static void sqlite3ClearStatTables(
   const char *zName      /* Name of index or table */
 ){
   int i;
-  const char *zDbName = pParse->db->aDb[iDb].zName;
+  const char *zDbName = pParse->db->aDb[iDb].zDbSName;
   for(i=1; i<=4; i++){
     char zTab[24];
     sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
@@ -92141,7 +102931,7 @@ SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, in
   if( pTab->tabFlags & TF_Autoincrement ){
     sqlite3NestedParse(pParse,
       "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
-      pDb->zName, pTab->zName
+      pDb->zDbSName, pTab->zName
     );
   }
 #endif
@@ -92155,7 +102945,7 @@ SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, in
   */
   sqlite3NestedParse(pParse, 
       "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
-      pDb->zName, SCHEMA_TABLE(iDb), pTab->zName);
+      pDb->zDbSName, MASTER_NAME, pTab->zName);
   if( !isView && !IsVirtual(pTab) ){
     destroyTable(pParse, pTab);
   }
@@ -92186,7 +102976,9 @@ SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView,
   }
   assert( pParse->nErr==0 );
   assert( pName->nSrc==1 );
+  if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
   if( noErr ) db->suppressErr++;
+  assert( isView==0 || isView==LOCATE_VIEW );
   pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
   if( noErr ) db->suppressErr--;
 
@@ -92207,7 +102999,7 @@ SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView,
   {
     int code;
     const char *zTab = SCHEMA_TABLE(iDb);
-    const char *zDb = db->aDb[iDb].zName;
+    const char *zDb = db->aDb[iDb].zDbSName;
     const char *zArg2 = 0;
     if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
       goto exit_drop_table;
@@ -92382,7 +103174,7 @@ SQLITE_PRIVATE void sqlite3CreateForeignKey(
       pFKey->zTo, (void *)pFKey
   );
   if( pNextTo==pFKey ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     goto fk_end;
   }
   if( pNextTo ){
@@ -92448,7 +103240,7 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
 
 #ifndef SQLITE_OMIT_AUTHORIZATION
   if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
-      db->aDb[iDb].zName ) ){
+      db->aDb[iDb].zDbSName ) ){
     return;
   }
 #endif
@@ -92464,6 +103256,7 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     tnum = pIndex->tnum;
   }
   pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);
+  assert( pKey!=0 || db->mallocFailed || pParse->nErr );
 
   /* Open the sorter cursor if we are to use one. */
   iSorter = pParse->nTab++;
@@ -92487,10 +103280,9 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));
 
   addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0); VdbeCoverage(v);
-  assert( pKey!=0 || db->mallocFailed || pParse->nErr );
-  if( IsUniqueIndex(pIndex) && pKey!=0 ){
+  if( IsUniqueIndex(pIndex) ){
     int j2 = sqlite3VdbeCurrentAddr(v) + 3;
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
+    sqlite3VdbeGoto(v, j2);
     addr2 = sqlite3VdbeCurrentAddr(v);
     sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,
                          pIndex->nKeyCol); VdbeCoverage(v);
@@ -92499,7 +103291,8 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     addr2 = sqlite3VdbeCurrentAddr(v);
   }
   sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);
-  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 1);
+  sqlite3VdbeAddOp3(v, OP_Last, iIdx, 0, -1);
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
   sqlite3ReleaseTempReg(pParse, regRecord);
   sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);
@@ -92534,7 +103327,7 @@ SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(
   p = sqlite3DbMallocZero(db, nByte + nExtra);
   if( p ){
     char *pExtra = ((char*)p)+ROUND8(sizeof(Index));
-    p->azColl = (char**)pExtra;       pExtra += ROUND8(sizeof(char*)*nCol);
+    p->azColl = (const char**)pExtra; pExtra += ROUND8(sizeof(char*)*nCol);
     p->aiRowLogEst = (LogEst*)pExtra; pExtra += sizeof(LogEst)*(nCol+1);
     p->aiColumn = (i16*)pExtra;       pExtra += sizeof(i16)*nCol;
     p->aSortOrder = (u8*)pExtra;
@@ -92556,12 +103349,8 @@ SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(
 ** pList is a list of columns to be indexed.  pList will be NULL if this
 ** is a primary key or unique-constraint on the most recent column added
 ** to the table currently under construction.  
-**
-** If the index is created successfully, return a pointer to the new Index
-** structure. This is used by sqlite3AddPrimaryKey() to mark the index
-** as the tables primary key (Index.idxType==SQLITE_IDXTYPE_PRIMARYKEY)
 */
-SQLITE_PRIVATE Index *sqlite3CreateIndex(
+SQLITE_PRIVATE void sqlite3CreateIndex(
   Parse *pParse,     /* All information about this parse */
   Token *pName1,     /* First part of index name. May be NULL */
   Token *pName2,     /* Second part of index name. May be NULL */
@@ -92571,9 +103360,9 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   Token *pStart,     /* The CREATE token that begins this statement */
   Expr *pPIWhere,    /* WHERE clause for partial indices */
   int sortOrder,     /* Sort order of primary key when pList==NULL */
-  int ifNotExist     /* Omit error if index already exists */
+  int ifNotExist,    /* Omit error if index already exists */
+  u8 idxType         /* The index type */
 ){
-  Index *pRet = 0;     /* Pointer to return */
   Table *pTab = 0;     /* Table to be indexed */
   Index *pIndex = 0;   /* The index to be created */
   char *zName = 0;     /* Name of the index */
@@ -92586,14 +103375,15 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   int iDb;             /* Index of the database that is being written */
   Token *pName = 0;    /* Unqualified name of the index to create */
   struct ExprList_item *pListItem; /* For looping over pList */
-  const Column *pTabCol;           /* A column in the table */
   int nExtra = 0;                  /* Space allocated for zExtra[] */
   int nExtraCol;                   /* Number of extra columns needed */
   char *zExtra = 0;                /* Extra space after the Index object */
   Index *pPk = 0;      /* PRIMARY KEY index for WITHOUT ROWID tables */
 
-  assert( pParse->nErr==0 );      /* Never called with prior errors */
-  if( db->mallocFailed || IN_DECLARE_VTAB ){
+  if( db->mallocFailed || pParse->nErr>0 ){
+    goto exit_create_index;
+  }
+  if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){
     goto exit_create_index;
   }
   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
@@ -92702,7 +103492,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
         goto exit_create_index;
       }
     }
-    if( sqlite3FindIndex(db, zName, pDb->zName)!=0 ){
+    if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){
       if( !ifNotExist ){
         sqlite3ErrorMsg(pParse, "index %s already exists", zName);
       }else{
@@ -92719,13 +103509,20 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     if( zName==0 ){
       goto exit_create_index;
     }
+
+    /* Automatic index names generated from within sqlite3_declare_vtab()
+    ** must have names that are distinct from normal automatic index names.
+    ** The following statement converts "sqlite3_autoindex..." into
+    ** "sqlite3_butoindex..." in order to make the names distinct.
+    ** The "vtab_err.test" test demonstrates the need of this statement. */
+    if( IN_DECLARE_VTAB ) zName[7]++;
   }
 
   /* Check for authorization to create an index.
   */
 #ifndef SQLITE_OMIT_AUTHORIZATION
   {
-    const char *zDb = pDb->zName;
+    const char *zDb = pDb->zDbSName;
     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){
       goto exit_create_index;
     }
@@ -92742,11 +103539,15 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   ** So create a fake list to simulate this.
   */
   if( pList==0 ){
-    pList = sqlite3ExprListAppend(pParse, 0, 0);
+    Token prevCol;
+    sqlite3TokenInit(&prevCol, pTab->aCol[pTab->nCol-1].zName);
+    pList = sqlite3ExprListAppend(pParse, 0,
+              sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
     if( pList==0 ) goto exit_create_index;
-    pList->a[0].zName = sqlite3DbStrDup(pParse->db,
-                                        pTab->aCol[pTab->nCol-1].zName);
-    pList->a[0].sortOrder = (u8)sortOrder;
+    assert( pList->nExpr==1 );
+    sqlite3ExprListSetSortOrder(pList, sortOrder);
+  }else{
+    sqlite3ExprListCheckLength(pParse, pList, "index");
   }
 
   /* Figure out how many bytes of space are required to store explicitly
@@ -92754,8 +103555,8 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   */
   for(i=0; inExpr; i++){
     Expr *pExpr = pList->a[i].pExpr;
-    if( pExpr ){
-      assert( pExpr->op==TK_COLLATE );
+    assert( pExpr!=0 );
+    if( pExpr->op==TK_COLLATE ){
       nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
     }
   }
@@ -92778,7 +103579,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   pIndex->pTable = pTab;
   pIndex->onError = (u8)onError;
   pIndex->uniqNotNull = onError!=OE_None;
-  pIndex->idxType = pName ? SQLITE_IDXTYPE_APPDEF : SQLITE_IDXTYPE_UNIQUE;
+  pIndex->idxType = idxType;
   pIndex->pSchema = db->aDb[iDb].pSchema;
   pIndex->nKeyCol = pList->nExpr;
   if( pPIWhere ){
@@ -92796,35 +103597,54 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     sortOrderMask = 0;    /* Ignore DESC */
   }
 
-  /* Scan the names of the columns of the table to be indexed and
-  ** load the column indices into the Index structure.  Report an error
-  ** if any column is not found.
+  /* Analyze the list of expressions that form the terms of the index and
+  ** report any errors.  In the common case where the expression is exactly
+  ** a table column, store that column in aiColumn[].  For general expressions,
+  ** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].
   **
-  ** TODO:  Add a test to make sure that the same column is not named
-  ** more than once within the same index.  Only the first instance of
-  ** the column will ever be used by the optimizer.  Note that using the
-  ** same column more than once cannot be an error because that would 
-  ** break backwards compatibility - it needs to be a warning.
+  ** TODO: Issue a warning if two or more columns of the index are identical.
+  ** TODO: Issue a warning if the table primary key is used as part of the
+  ** index key.
   */
   for(i=0, pListItem=pList->a; inExpr; i++, pListItem++){
-    const char *zColName = pListItem->zName;
-    int requestedSortOrder;
-    char *zColl;                   /* Collation sequence name */
-
-    for(j=0, pTabCol=pTab->aCol; jnCol; j++, pTabCol++){
-      if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
-    }
-    if( j>=pTab->nCol ){
-      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
-        pTab->zName, zColName);
-      pParse->checkSchema = 1;
-      goto exit_create_index;
+    Expr *pCExpr;                  /* The i-th index expression */
+    int requestedSortOrder;        /* ASC or DESC on the i-th expression */
+    const char *zColl;             /* Collation sequence name */
+
+    sqlite3StringToId(pListItem->pExpr);
+    sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);
+    if( pParse->nErr ) goto exit_create_index;
+    pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
+    if( pCExpr->op!=TK_COLUMN ){
+      if( pTab==pParse->pNewTable ){
+        sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "
+                                "UNIQUE constraints");
+        goto exit_create_index;
+      }
+      if( pIndex->aColExpr==0 ){
+        ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
+        pIndex->aColExpr = pCopy;
+        if( !db->mallocFailed ){
+          assert( pCopy!=0 );
+          pListItem = &pCopy->a[i];
+        }
+      }
+      j = XN_EXPR;
+      pIndex->aiColumn[i] = XN_EXPR;
+      pIndex->uniqNotNull = 0;
+    }else{
+      j = pCExpr->iColumn;
+      assert( j<=0x7fff );
+      if( j<0 ){
+        j = pTab->iPKey;
+      }else if( pTab->aCol[j].notNull==0 ){
+        pIndex->uniqNotNull = 0;
+      }
+      pIndex->aiColumn[i] = (i16)j;
     }
-    assert( j<=0x7fff );
-    pIndex->aiColumn[i] = (i16)j;
-    if( pListItem->pExpr ){
+    zColl = 0;
+    if( pListItem->pExpr->op==TK_COLLATE ){
       int nColl;
-      assert( pListItem->pExpr->op==TK_COLLATE );
       zColl = pListItem->pExpr->u.zToken;
       nColl = sqlite3Strlen30(zColl) + 1;
       assert( nExtra>=nColl );
@@ -92832,21 +103652,26 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       zColl = zExtra;
       zExtra += nColl;
       nExtra -= nColl;
-    }else{
+    }else if( j>=0 ){
       zColl = pTab->aCol[j].zColl;
-      if( !zColl ) zColl = "BINARY";
     }
+    if( !zColl ) zColl = sqlite3StrBINARY;
     if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
       goto exit_create_index;
     }
     pIndex->azColl[i] = zColl;
     requestedSortOrder = pListItem->sortOrder & sortOrderMask;
     pIndex->aSortOrder[i] = (u8)requestedSortOrder;
-    if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0;
   }
+
+  /* Append the table key to the end of the index.  For WITHOUT ROWID
+  ** tables (when pPk!=0) this will be the declared PRIMARY KEY.  For
+  ** normal tables (when pPk==0) this will be the rowid.
+  */
   if( pPk ){
     for(j=0; jnKeyCol; j++){
       int x = pPk->aiColumn[j];
+      assert( x>=0 );
       if( hasColumn(pIndex->aiColumn, pIndex->nKeyCol, x) ){
         pIndex->nColumn--; 
       }else{
@@ -92858,12 +103683,26 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     }
     assert( i==pIndex->nColumn );
   }else{
-    pIndex->aiColumn[i] = -1;
-    pIndex->azColl[i] = "BINARY";
+    pIndex->aiColumn[i] = XN_ROWID;
+    pIndex->azColl[i] = sqlite3StrBINARY;
   }
   sqlite3DefaultRowEst(pIndex);
   if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);
 
+  /* If this index contains every column of its table, then mark
+  ** it as a covering index */
+  assert( HasRowid(pTab) 
+      || pTab->iPKey<0 || sqlite3ColumnOfIndex(pIndex, pTab->iPKey)>=0 );
+  if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
+    pIndex->isCovering = 1;
+    for(j=0; jnCol; j++){
+      if( j==pTab->iPKey ) continue;
+      if( sqlite3ColumnOfIndex(pIndex,j)>=0 ) continue;
+      pIndex->isCovering = 0;
+      break;
+    }
+  }
+
   if( pTab==pParse->pNewTable ){
     /* This routine has been called to create an automatic index as a
     ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
@@ -92897,10 +103736,11 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       for(k=0; knKeyCol; k++){
         const char *z1;
         const char *z2;
+        assert( pIdx->aiColumn[k]>=0 );
         if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
         z1 = pIdx->azColl[k];
         z2 = pIndex->azColl[k];
-        if( z1!=z2 && sqlite3StrICmp(z1, z2) ) break;
+        if( sqlite3StrICmp(z1, z2) ) break;
       }
       if( k==pIdx->nKeyCol ){
         if( pIdx->onError!=pIndex->onError ){
@@ -92919,6 +103759,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
             pIdx->onError = pIndex->onError;
           }
         }
+        if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;
         goto exit_create_index;
       }
     }
@@ -92927,14 +103768,16 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   /* Link the new Index structure to its table and to the other
   ** in-memory database structures. 
   */
+  assert( pParse->nErr==0 );
   if( db->init.busy ){
     Index *p;
+    assert( !IN_DECLARE_VTAB );
     assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
     p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
                           pIndex->zName, pIndex);
     if( p ){
       assert( p==pIndex );  /* Malloc must have failed */
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       goto exit_create_index;
     }
     db->flags |= SQLITE_InternChanges;
@@ -92956,7 +103799,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   ** has just been created, it contains no data and the index initialization
   ** step can be skipped.
   */
-  else if( pParse->nErr==0 && (HasRowid(pTab) || pTblName!=0) ){
+  else if( HasRowid(pTab) || pTblName!=0 ){
     Vdbe *v;
     char *zStmt;
     int iMem = ++pParse->nMem;
@@ -92964,10 +103807,15 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     v = sqlite3GetVdbe(pParse);
     if( v==0 ) goto exit_create_index;
 
-
-    /* Create the rootpage for the index
-    */
     sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+    /* Create the rootpage for the index using CreateIndex. But before
+    ** doing so, code a Noop instruction and store its address in 
+    ** Index.tnum. This is required in case this index is actually a 
+    ** PRIMARY KEY and the table is actually a WITHOUT ROWID table. In 
+    ** that case the convertToWithoutRowidTable() routine will replace
+    ** the Noop with a Goto to jump over the VDBE code generated below. */
+    pIndex->tnum = sqlite3VdbeAddOp0(v, OP_Noop);
     sqlite3VdbeAddOp2(v, OP_CreateIndex, iDb, iMem);
 
     /* Gather the complete text of the CREATE INDEX statement into
@@ -92989,7 +103837,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     */
     sqlite3NestedParse(pParse, 
         "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",
-        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+        db->aDb[iDb].zDbSName, MASTER_NAME,
         pIndex->zName,
         pTab->zName,
         iMem,
@@ -93005,8 +103853,10 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       sqlite3ChangeCookie(pParse, iDb);
       sqlite3VdbeAddParseSchemaOp(v, iDb,
          sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
-      sqlite3VdbeAddOp1(v, OP_Expire, 0);
+      sqlite3VdbeAddOp0(v, OP_Expire);
     }
+
+    sqlite3VdbeJumpHere(v, pIndex->tnum);
   }
 
   /* When adding an index to the list of indices for a table, make
@@ -93028,7 +103878,6 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       pIndex->pNext = pOther->pNext;
       pOther->pNext = pIndex;
     }
-    pRet = pIndex;
     pIndex = 0;
   }
 
@@ -93039,7 +103888,6 @@ exit_create_index:
   sqlite3ExprListDelete(db, pList);
   sqlite3SrcListDelete(db, pTblName);
   sqlite3DbFree(db, zName);
-  return pRet;
 }
 
 /*
@@ -93067,11 +103915,15 @@ SQLITE_PRIVATE void sqlite3DefaultRowEst(Index *pIdx){
   int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);
   int i;
 
+  /* Indexes with default row estimates should not have stat1 data */
+  assert( !pIdx->hasStat1 );
+
   /* Set the first entry (number of rows in the index) to the estimated 
-  ** number of rows in the table. Or 10, if the estimated number of rows 
-  ** in the table is less than that.  */
+  ** number of rows in the table, or half the number of rows in the table
+  ** for a partial index.   But do not let the estimate drop below 10. */
   a[0] = pIdx->pTable->nRowLogEst;
-  if( a[0]<33 ) a[0] = 33;        assert( 33==sqlite3LogEst(10) );
+  if( pIdx->pPartIdxWhere!=0 ) a[0] -= 10;  assert( 10==sqlite3LogEst(2) );
+  if( a[0]<33 ) a[0] = 33;                  assert( 33==sqlite3LogEst(10) );
 
   /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is
   ** 6 and each subsequent value (if any) is 5.  */
@@ -93122,7 +103974,7 @@ SQLITE_PRIVATE void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists
   {
     int code = SQLITE_DROP_INDEX;
     Table *pTab = pIndex->pTable;
-    const char *zDb = db->aDb[iDb].zName;
+    const char *zDb = db->aDb[iDb].zDbSName;
     const char *zTab = SCHEMA_TABLE(iDb);
     if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
       goto exit_drop_index;
@@ -93140,7 +103992,7 @@ SQLITE_PRIVATE void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists
     sqlite3BeginWriteOperation(pParse, 1, iDb);
     sqlite3NestedParse(pParse,
        "DELETE FROM %Q.%s WHERE name=%Q AND type='index'",
-       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pIndex->zName
+       db->aDb[iDb].zDbSName, MASTER_NAME, pIndex->zName
     );
     sqlite3ClearStatTables(pParse, iDb, "idx", pIndex->zName);
     sqlite3ChangeCookie(pParse, iDb);
@@ -93231,7 +104083,7 @@ SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3 *db, IdList *pList){
     sqlite3DbFree(db, pList->a[i].zName);
   }
   sqlite3DbFree(db, pList->a);
-  sqlite3DbFree(db, pList);
+  sqlite3DbFreeNN(db, pList);
 }
 
 /*
@@ -93283,7 +104135,7 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(
   /* Allocate additional space if needed */
   if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){
     SrcList *pNew;
-    int nAlloc = pSrc->nSrc+nExtra;
+    int nAlloc = pSrc->nSrc*2+nExtra;
     int nGot;
     pNew = sqlite3DbRealloc(db, pSrc,
                sizeof(*pSrc) + (nAlloc-1)*sizeof(pSrc->a[0]) );
@@ -93356,12 +104208,17 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(
 ){
   struct SrcList_item *pItem;
   assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */
+  assert( db!=0 );
   if( pList==0 ){
-    pList = sqlite3DbMallocZero(db, sizeof(SrcList) );
+    pList = sqlite3DbMallocRawNN(db, sizeof(SrcList) );
     if( pList==0 ) return 0;
     pList->nAlloc = 1;
+    pList->nSrc = 1;
+    memset(&pList->a[0], 0, sizeof(pList->a[0]));
+    pList->a[0].iCursor = -1;
+  }else{
+    pList = sqlite3SrcListEnlarge(db, pList, 1, pList->nSrc);
   }
-  pList = sqlite3SrcListEnlarge(db, pList, 1, pList->nSrc);
   if( db->mallocFailed ){
     sqlite3SrcListDelete(db, pList);
     return 0;
@@ -93371,12 +104228,12 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(
     pDatabase = 0;
   }
   if( pDatabase ){
-    Token *pTemp = pDatabase;
-    pDatabase = pTable;
-    pTable = pTemp;
+    pItem->zName = sqlite3NameFromToken(db, pDatabase);
+    pItem->zDatabase = sqlite3NameFromToken(db, pTable);
+  }else{
+    pItem->zName = sqlite3NameFromToken(db, pTable);
+    pItem->zDatabase = 0;
   }
-  pItem->zName = sqlite3NameFromToken(db, pTable);
-  pItem->zDatabase = sqlite3NameFromToken(db, pDatabase);
   return pList;
 }
 
@@ -93409,13 +104266,14 @@ SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
     sqlite3DbFree(db, pItem->zDatabase);
     sqlite3DbFree(db, pItem->zName);
     sqlite3DbFree(db, pItem->zAlias);
-    sqlite3DbFree(db, pItem->zIndex);
+    if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
+    if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
     sqlite3DeleteTable(db, pItem->pTab);
     sqlite3SelectDelete(db, pItem->pSelect);
     sqlite3ExprDelete(db, pItem->pOn);
     sqlite3IdListDelete(db, pItem->pUsing);
   }
-  sqlite3DbFree(db, pList);
+  sqlite3DbFreeNN(db, pList);
 }
 
 /*
@@ -93482,17 +104340,37 @@ SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pI
   assert( pIndexedBy!=0 );
   if( p && ALWAYS(p->nSrc>0) ){
     struct SrcList_item *pItem = &p->a[p->nSrc-1];
-    assert( pItem->notIndexed==0 && pItem->zIndex==0 );
+    assert( pItem->fg.notIndexed==0 );
+    assert( pItem->fg.isIndexedBy==0 );
+    assert( pItem->fg.isTabFunc==0 );
     if( pIndexedBy->n==1 && !pIndexedBy->z ){
       /* A "NOT INDEXED" clause was supplied. See parse.y 
       ** construct "indexed_opt" for details. */
-      pItem->notIndexed = 1;
+      pItem->fg.notIndexed = 1;
     }else{
-      pItem->zIndex = sqlite3NameFromToken(pParse->db, pIndexedBy);
+      pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
+      pItem->fg.isIndexedBy = (pItem->u1.zIndexedBy!=0);
     }
   }
 }
 
+/*
+** Add the list of function arguments to the SrcList entry for a
+** table-valued-function.
+*/
+SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){
+  if( p ){
+    struct SrcList_item *pItem = &p->a[p->nSrc-1];
+    assert( pItem->fg.notIndexed==0 );
+    assert( pItem->fg.isIndexedBy==0 );
+    assert( pItem->fg.isTabFunc==0 );
+    pItem->u1.pFuncArg = pList;
+    pItem->fg.isTabFunc = 1;
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  }
+}
+
 /*
 ** When building up a FROM clause in the parser, the join operator
 ** is initially attached to the left operand.  But the code generator
@@ -93511,16 +104389,15 @@ SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pI
 SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList *p){
   if( p ){
     int i;
-    assert( p->a || p->nSrc==0 );
     for(i=p->nSrc-1; i>0; i--){
-      p->a[i].jointype = p->a[i-1].jointype;
+      p->a[i].fg.jointype = p->a[i-1].fg.jointype;
     }
-    p->a[0].jointype = 0;
+    p->a[0].fg.jointype = 0;
   }
 }
 
 /*
-** Begin a transaction
+** Generate VDBE code for a BEGIN statement.
 */
 SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
   sqlite3 *db;
@@ -93530,7 +104407,6 @@ SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
   assert( pParse!=0 );
   db = pParse->db;
   assert( db!=0 );
-/*  if( db->aDb[0].pBt==0 ) return; */
   if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){
     return;
   }
@@ -93542,40 +104418,29 @@ SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
       sqlite3VdbeUsesBtree(v, i);
     }
   }
-  sqlite3VdbeAddOp2(v, OP_AutoCommit, 0, 0);
-}
-
-/*
-** Commit a transaction
-*/
-SQLITE_PRIVATE void sqlite3CommitTransaction(Parse *pParse){
-  Vdbe *v;
-
-  assert( pParse!=0 );
-  assert( pParse->db!=0 );
-  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ){
-    return;
-  }
-  v = sqlite3GetVdbe(pParse);
-  if( v ){
-    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 0);
-  }
+  sqlite3VdbeAddOp0(v, OP_AutoCommit);
 }
 
 /*
-** Rollback a transaction
+** Generate VDBE code for a COMMIT or ROLLBACK statement.
+** Code for ROLLBACK is generated if eType==TK_ROLLBACK.  Otherwise
+** code is generated for a COMMIT.
 */
-SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse *pParse){
+SQLITE_PRIVATE void sqlite3EndTransaction(Parse *pParse, int eType){
   Vdbe *v;
+  int isRollback;
 
   assert( pParse!=0 );
   assert( pParse->db!=0 );
-  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ){
+  assert( eType==TK_COMMIT || eType==TK_END || eType==TK_ROLLBACK );
+  isRollback = eType==TK_ROLLBACK;
+  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, 
+       isRollback ? "ROLLBACK" : "COMMIT", 0, 0) ){
     return;
   }
   v = sqlite3GetVdbe(pParse);
   if( v ){
-    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 1);
+    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, isRollback);
   }
 }
 
@@ -93625,7 +104490,7 @@ SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){
     db->aDb[1].pBt = pBt;
     assert( db->aDb[1].pSchema );
     if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return 1;
     }
   }
@@ -93640,15 +104505,13 @@ SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){
 */
 SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
   Parse *pToplevel = sqlite3ParseToplevel(pParse);
-  sqlite3 *db = pToplevel->db;
 
-  assert( iDb>=0 && iDbnDb );
-  assert( db->aDb[iDb].pBt!=0 || iDb==1 );
+  assert( iDb>=0 && iDbdb->nDb );
+  assert( pParse->db->aDb[iDb].pBt!=0 || iDb==1 );
   assert( iDbdb, iDb, 0) );
   if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){
     DbMaskSet(pToplevel->cookieMask, iDb);
-    pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
     if( !OMIT_TEMPDB && iDb==1 ){
       sqlite3OpenTempDatabase(pToplevel);
     }
@@ -93664,7 +104527,7 @@ SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb)
   int i;
   for(i=0; inDb; i++){
     Db *pDb = &db->aDb[i];
-    if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zName)) ){
+    if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zDbSName)) ){
       sqlite3CodeVerifySchema(pParse, i);
     }
   }
@@ -93742,7 +104605,7 @@ SQLITE_PRIVATE void sqlite3HaltConstraint(
     sqlite3MayAbort(pParse);
   }
   sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
-  if( p5Errmsg ) sqlite3VdbeChangeP5(v, p5Errmsg);
+  sqlite3VdbeChangeP5(v, p5Errmsg);
 }
 
 /*
@@ -93758,14 +104621,19 @@ SQLITE_PRIVATE void sqlite3UniqueConstraint(
   StrAccum errMsg;
   Table *pTab = pIdx->pTable;
 
-  sqlite3StrAccumInit(&errMsg, 0, 0, 200);
-  errMsg.db = pParse->db;
-  for(j=0; jnKeyCol; j++){
-    char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
-    if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
-    sqlite3StrAccumAppendAll(&errMsg, pTab->zName);
-    sqlite3StrAccumAppend(&errMsg, ".", 1);
-    sqlite3StrAccumAppendAll(&errMsg, zCol);
+  sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 200);
+  if( pIdx->aColExpr ){
+    sqlite3XPrintf(&errMsg, "index '%q'", pIdx->zName);
+  }else{
+    for(j=0; jnKeyCol; j++){
+      char *zCol;
+      assert( pIdx->aiColumn[j]>=0 );
+      zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
+      if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
+      sqlite3StrAccumAppendAll(&errMsg, pTab->zName);
+      sqlite3StrAccumAppend(&errMsg, ".", 1);
+      sqlite3StrAccumAppendAll(&errMsg, zCol);
+    }
   }
   zErr = sqlite3StrAccumFinish(&errMsg);
   sqlite3HaltConstraint(pParse, 
@@ -93908,7 +104776,7 @@ SQLITE_PRIVATE void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
   if( iDb<0 ) return;
   z = sqlite3NameFromToken(db, pObjName);
   if( z==0 ) return;
-  zDb = db->aDb[iDb].zName;
+  zDb = db->aDb[iDb].zDbSName;
   pTab = sqlite3FindTable(db, z, zDb);
   if( pTab ){
     reindexTable(pParse, pTab, 0);
@@ -93929,10 +104797,6 @@ SQLITE_PRIVATE void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
 /*
 ** Return a KeyInfo structure that is appropriate for the given Index.
 **
-** The KeyInfo structure for an index is cached in the Index object.
-** So there might be multiple references to the returned pointer.  The
-** caller should not try to modify the KeyInfo object.
-**
 ** The caller should invoke sqlite3KeyInfoUnref() on the returned object
 ** when it has finished using it.
 */
@@ -93950,9 +104814,8 @@ SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
   if( pKey ){
     assert( sqlite3KeyInfoIsWriteable(pKey) );
     for(i=0; iazColl[i];
-      assert( zColl!=0 );
-      pKey->aColl[i] = strcmp(zColl,"BINARY")==0 ? 0 :
+      const char *zColl = pIdx->azColl[i];
+      pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
                         sqlite3LocateCollSeq(pParse, zColl);
       pKey->aSortOrder[i] = pIdx->aSortOrder[i];
     }
@@ -93998,10 +104861,9 @@ SQLITE_PRIVATE With *sqlite3WithAdd(
   }else{
     pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
   }
-  assert( zName!=0 || pNew==0 );
-  assert( db->mallocFailed==0 || pNew==0 );
+  assert( (pNew!=0 && zName!=0) || db->mallocFailed );
 
-  if( pNew==0 ){
+  if( db->mallocFailed ){
     sqlite3ExprListDelete(db, pArglist);
     sqlite3SelectDelete(db, pQuery);
     sqlite3DbFree(db, zName);
@@ -94010,7 +104872,7 @@ SQLITE_PRIVATE With *sqlite3WithAdd(
     pNew->a[pNew->nCte].pSelect = pQuery;
     pNew->a[pNew->nCte].pCols = pArglist;
     pNew->a[pNew->nCte].zName = zName;
-    pNew->a[pNew->nCte].zErr = 0;
+    pNew->a[pNew->nCte].zCteErr = 0;
     pNew->nCte++;
   }
 
@@ -94052,6 +104914,7 @@ SQLITE_PRIVATE void sqlite3WithDelete(sqlite3 *db, With *pWith){
 ** of user defined functions and collation sequences.
 */
 
+/* #include "sqliteInt.h" */
 
 /*
 ** Invoke the 'collation needed' callback to request a collation sequence
@@ -94158,7 +105021,7 @@ SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(
 ** from the main database is substituted, if one is available.
 */
 SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
-  if( pColl ){
+  if( pColl && pColl->xCmp==0 ){
     const char *zName = pColl->zName;
     sqlite3 *db = pParse->db;
     CollSeq *p = sqlite3GetCollSeq(pParse, ENC(db), pColl, zName);
@@ -94194,8 +105057,8 @@ static CollSeq *findCollSeqEntry(
   pColl = sqlite3HashFind(&db->aCollSeq, zName);
 
   if( 0==pColl && create ){
-    int nName = sqlite3Strlen30(zName);
-    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1);
+    int nName = sqlite3Strlen30(zName) + 1;
+    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName);
     if( pColl ){
       CollSeq *pDel = 0;
       pColl[0].zName = (char*)&pColl[3];
@@ -94205,7 +105068,6 @@ static CollSeq *findCollSeqEntry(
       pColl[2].zName = (char*)&pColl[3];
       pColl[2].enc = SQLITE_UTF16BE;
       memcpy(pColl[0].zName, zName, nName);
-      pColl[0].zName[nName] = 0;
       pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, pColl);
 
       /* If a malloc() failure occurred in sqlite3HashInsert(), it will 
@@ -94214,7 +105076,7 @@ static CollSeq *findCollSeqEntry(
       */
       assert( pDel==0 || pDel==pColl );
       if( pDel!=0 ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
         sqlite3DbFree(db, pDel);
         pColl = 0;
       }
@@ -94280,8 +105142,8 @@ SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(
 ** 5: UTF16 byte order conversion required - argument count matches exactly
 ** 6: Perfect match:  encoding and argument count match exactly.
 **
-** If nArg==(-2) then any function with a non-null xStep or xFunc is
-** a perfect match and any function with both xStep and xFunc NULL is
+** If nArg==(-2) then any function with a non-null xSFunc is
+** a perfect match and any function with xSFunc NULL is
 ** a non-match.
 */
 #define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */
@@ -94293,7 +105155,7 @@ static int matchQuality(
   int match;
 
   /* nArg of -2 is a special case */
-  if( nArg==(-2) ) return (p->xFunc==0 && p->xStep==0) ? 0 : FUNC_PERFECT_MATCH;
+  if( nArg==(-2) ) return (p->xSFunc==0) ? 0 : FUNC_PERFECT_MATCH;
 
   /* Wrong number of arguments means "no match" */
   if( p->nArg!=nArg && p->nArg>=0 ) return 0;
@@ -94321,14 +105183,12 @@ static int matchQuality(
 ** a pointer to the matching FuncDef if found, or 0 if there is no match.
 */
 static FuncDef *functionSearch(
-  FuncDefHash *pHash,  /* Hash table to search */
   int h,               /* Hash of the name */
-  const char *zFunc,   /* Name of function */
-  int nFunc            /* Number of bytes in zFunc */
+  const char *zFunc    /* Name of function */
 ){
   FuncDef *p;
-  for(p=pHash->a[h]; p; p=p->pHash){
-    if( sqlite3StrNICmp(p->zName, zFunc, nFunc)==0 && p->zName[nFunc]==0 ){
+  for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
+    if( sqlite3StrICmp(p->zName, zFunc)==0 ){
       return p;
     }
   }
@@ -94338,23 +105198,27 @@ static FuncDef *functionSearch(
 /*
 ** Insert a new FuncDef into a FuncDefHash hash table.
 */
-SQLITE_PRIVATE void sqlite3FuncDefInsert(
-  FuncDefHash *pHash,  /* The hash table into which to insert */
-  FuncDef *pDef        /* The function definition to insert */
+SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(
+  FuncDef *aDef,      /* List of global functions to be inserted */
+  int nDef            /* Length of the apDef[] list */
 ){
-  FuncDef *pOther;
-  int nName = sqlite3Strlen30(pDef->zName);
-  u8 c1 = (u8)pDef->zName[0];
-  int h = (sqlite3UpperToLower[c1] + nName) % ArraySize(pHash->a);
-  pOther = functionSearch(pHash, h, pDef->zName, nName);
-  if( pOther ){
-    assert( pOther!=pDef && pOther->pNext!=pDef );
-    pDef->pNext = pOther->pNext;
-    pOther->pNext = pDef;
-  }else{
-    pDef->pNext = 0;
-    pDef->pHash = pHash->a[h];
-    pHash->a[h] = pDef;
+  int i;
+  for(i=0; i='a' && zName[0]<='z' );
+    pOther = functionSearch(h, zName);
+    if( pOther ){
+      assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );
+      aDef[i].pNext = pOther->pNext;
+      pOther->pNext = &aDef[i];
+    }else{
+      aDef[i].pNext = 0;
+      aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];
+      sqlite3BuiltinFunctions.a[h] = &aDef[i];
+    }
   }
 }
   
@@ -94371,7 +105235,7 @@ SQLITE_PRIVATE void sqlite3FuncDefInsert(
 ** no matching function previously existed.
 **
 ** If nArg is -2, then the first valid function found is returned.  A
-** function is valid if either xFunc or xStep is non-zero.  The nArg==(-2)
+** function is valid if xSFunc is non-zero.  The nArg==(-2)
 ** case is used to see if zName is a valid function name for some number
 ** of arguments.  If nArg is -2, then createFlag must be 0.
 **
@@ -94381,8 +105245,7 @@ SQLITE_PRIVATE void sqlite3FuncDefInsert(
 */
 SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   sqlite3 *db,       /* An open database */
-  const char *zName, /* Name of the function.  Not null-terminated */
-  int nName,         /* Number of characters in the name */
+  const char *zName, /* Name of the function.  zero-terminated */
   int nArg,          /* Number of arguments.  -1 means any number */
   u8 enc,            /* Preferred text encoding */
   u8 createFlag      /* Create new entry if true and does not otherwise exist */
@@ -94391,14 +105254,15 @@ SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   FuncDef *pBest = 0; /* Best match found so far */
   int bestScore = 0;  /* Score of best match */
   int h;              /* Hash value */
+  int nName;          /* Length of the name */
 
   assert( nArg>=(-2) );
   assert( nArg>=(-1) || createFlag==0 );
-  h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % ArraySize(db->aFunc.a);
+  nName = sqlite3Strlen30(zName);
 
   /* First search for a match amongst the application-defined functions.
   */
-  p = functionSearch(&db->aFunc, h, zName, nName);
+  p = (FuncDef*)sqlite3HashFind(&db->aFunc, zName);
   while( p ){
     int score = matchQuality(p, nArg, enc);
     if( score>bestScore ){
@@ -94421,9 +105285,9 @@ SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   ** So we must not search for built-ins when creating a new function.
   */ 
   if( !createFlag && (pBest==0 || (db->flags & SQLITE_PreferBuiltin)!=0) ){
-    FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
     bestScore = 0;
-    p = functionSearch(pHash, h, zName, nName);
+    h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % SQLITE_FUNC_HASH_SZ;
+    p = functionSearch(h, zName);
     while( p ){
       int score = matchQuality(p, nArg, enc);
       if( score>bestScore ){
@@ -94440,15 +105304,22 @@ SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   */
   if( createFlag && bestScorezName = (char *)&pBest[1];
+    FuncDef *pOther;
+    pBest->zName = (const char*)&pBest[1];
     pBest->nArg = (u16)nArg;
     pBest->funcFlags = enc;
-    memcpy(pBest->zName, zName, nName);
-    pBest->zName[nName] = 0;
-    sqlite3FuncDefInsert(&db->aFunc, pBest);
+    memcpy((char*)&pBest[1], zName, nName+1);
+    pOther = (FuncDef*)sqlite3HashInsert(&db->aFunc, pBest->zName, pBest);
+    if( pOther==pBest ){
+      sqlite3DbFree(db, pBest);
+      sqlite3OomFault(db);
+      return 0;
+    }else{
+      pBest->pNext = pOther;
+    }
   }
 
-  if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
+  if( pBest && (pBest->xSFunc || createFlag) ){
     return pBest;
   }
   return 0;
@@ -94502,7 +105373,7 @@ SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
     p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
   }
   if( !p ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }else if ( 0==p->file_format ){
     sqlite3HashInit(&p->tblHash);
     sqlite3HashInit(&p->idxHash);
@@ -94529,6 +105400,7 @@ SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
 ** This file contains C code routines that are called by the parser
 ** in order to generate code for DELETE FROM statements.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** While a SrcList can in general represent multiple tables and subqueries
@@ -94552,7 +105424,7 @@ SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
   sqlite3DeleteTable(pParse->db, pItem->pTab);
   pItem->pTab = pTab;
   if( pTab ){
-    pTab->nRef++;
+    pTab->nTabRef++;
   }
   if( sqlite3IndexedByLookup(pParse, pItem) ){
     pTab = 0;
@@ -94618,11 +105490,12 @@ SQLITE_PRIVATE void sqlite3MaterializeView(
   if( pFrom ){
     assert( pFrom->nSrc==1 );
     pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
-    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
+    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
     assert( pFrom->a[0].pOn==0 );
     assert( pFrom->a[0].pUsing==0 );
   }
-  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
+  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 
+                          SF_IncludeHidden, 0, 0);
   sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
   sqlite3Select(pParse, pSel, &dest);
   sqlite3SelectDelete(db, pSel);
@@ -94658,7 +105531,7 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   */
   if( pOrderBy && (pLimit == 0) ) {
     sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
-    goto limit_where_cleanup_2;
+    goto limit_where_cleanup;
   }
 
   /* We only need to generate a select expression if there
@@ -94679,17 +105552,17 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   **   );
   */
 
-  pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
-  if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
+  pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0);
+  if( pSelectRowid == 0 ) goto limit_where_cleanup;
   pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
-  if( pEList == 0 ) goto limit_where_cleanup_2;
+  if( pEList == 0 ) goto limit_where_cleanup;
 
   /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
   ** and the SELECT subtree. */
   pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
   if( pSelectSrc == 0 ) {
     sqlite3ExprListDelete(pParse->db, pEList);
-    goto limit_where_cleanup_2;
+    goto limit_where_cleanup;
   }
 
   /* generate the SELECT expression tree. */
@@ -94698,22 +105571,12 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   if( pSelect == 0 ) return 0;
 
   /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
-  pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
-  if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
-  pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
-  if( pInClause == 0 ) goto limit_where_cleanup_1;
-
-  pInClause->x.pSelect = pSelect;
-  pInClause->flags |= EP_xIsSelect;
-  sqlite3ExprSetHeight(pParse, pInClause);
+  pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0);
+  pInClause = pWhereRowid ? sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0) : 0;
+  sqlite3PExprAddSelect(pParse, pInClause, pSelect);
   return pInClause;
 
-  /* something went wrong. clean up anything allocated. */
-limit_where_cleanup_1:
-  sqlite3SelectDelete(pParse->db, pSelect);
-  return 0;
-
-limit_where_cleanup_2:
+limit_where_cleanup:
   sqlite3ExprDelete(pParse->db, pWhere);
   sqlite3ExprListDelete(pParse->db, pOrderBy);
   sqlite3ExprDelete(pParse->db, pLimit);
@@ -94737,7 +105600,6 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
 ){
   Vdbe *v;               /* The virtual database engine */
   Table *pTab;           /* The table from which records will be deleted */
-  const char *zDb;       /* Name of database holding pTab */
   int i;                 /* Loop counter */
   WhereInfo *pWInfo;     /* Information about the WHERE clause */
   Index *pIdx;           /* For looping over indices of the table */
@@ -94751,7 +105613,7 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   int iDb;               /* Database number */
   int memCnt = -1;       /* Memory cell used for change counting */
   int rcauth;            /* Value returned by authorization callback */
-  int okOnePass;         /* True for one-pass algorithm without the FIFO */
+  int eOnePass;          /* ONEPASS_OFF or _SINGLE or _MULTI */
   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
   u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
   Index *pPk;            /* The PRIMARY KEY index on the table */
@@ -94763,8 +105625,9 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   int iRowSet = 0;       /* Register for rowset of rows to delete */
   int addrBypass = 0;    /* Address of jump over the delete logic */
   int addrLoop = 0;      /* Top of the delete loop */
-  int addrDelete = 0;    /* Jump directly to the delete logic */
   int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
+  int bComplex;          /* True if there are triggers or FKs or
+                         ** subqueries in the WHERE clause */
  
 #ifndef SQLITE_OMIT_TRIGGER
   int isView;                  /* True if attempting to delete from a view */
@@ -94792,6 +105655,7 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
 #ifndef SQLITE_OMIT_TRIGGER
   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
   isView = pTab->pSelect!=0;
+  bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
 #else
 # define pTrigger 0
 # define isView 0
@@ -94812,8 +105676,8 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   }
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
   assert( iDbnDb );
-  zDb = db->aDb[iDb].zName;
-  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb);
+  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, 
+                            db->aDb[iDb].zDbSName);
   assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
   if( rcauth==SQLITE_DENY ){
     goto delete_from_cleanup;
@@ -94874,9 +105738,21 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   /* Special case: A DELETE without a WHERE clause deletes everything.
   ** It is easier just to erase the whole table. Prior to version 3.6.5,
   ** this optimization caused the row change count (the value returned by 
-  ** API function sqlite3_count_changes) to be set incorrectly.  */
-  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) 
-   && 0==sqlite3FkRequired(pParse, pTab, 0, 0)
+  ** API function sqlite3_count_changes) to be set incorrectly.
+  **
+  ** The "rcauth==SQLITE_OK" terms is the
+  ** IMPLEMENTATION-OF: R-17228-37124 If the action code is SQLITE_DELETE and
+  ** the callback returns SQLITE_IGNORE then the DELETE operation proceeds but
+  ** the truncate optimization is disabled and all rows are deleted
+  ** individually.
+  */
+  if( rcauth==SQLITE_OK
+   && pWhere==0
+   && !bComplex
+   && !IsVirtual(pTab)
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+   && db->xPreUpdateCallback==0
+#endif
   ){
     assert( !isView );
     sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
@@ -94891,6 +105767,9 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   }else
 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
   {
+    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK|WHERE_SEEK_TABLE;
+    if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
+    wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
     if( HasRowid(pTab) ){
       /* For a rowid table, initialize the RowSet to an empty set */
       pPk = 0;
@@ -94911,13 +105790,18 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
     }
   
     /* Construct a query to find the rowid or primary key for every row
-    ** to be deleted, based on the WHERE clause.
+    ** to be deleted, based on the WHERE clause. Set variable eOnePass
+    ** to indicate the strategy used to implement this delete:
+    **
+    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
+    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
+    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
     */
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
-                               WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK,
-                               iTabCur+1);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);
     if( pWInfo==0 ) goto delete_from_cleanup;
-    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
+    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
   
     /* Keep track of the number of rows to be deleted */
     if( db->flags & SQLITE_CountRows ){
@@ -94927,6 +105811,7 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
     /* Extract the rowid or primary key for the current row */
     if( pPk ){
       for(i=0; iaiColumn[i]>=0 );
         sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
                                         pPk->aiColumn[i], iPk+i);
       }
@@ -94937,13 +105822,12 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
       if( iKey>pParse->nMem ) pParse->nMem = iKey;
     }
   
-    if( okOnePass ){
-      /* For ONEPASS, no need to store the rowid/primary-key.  There is only
+    if( eOnePass!=ONEPASS_OFF ){
+      /* For ONEPASS, no need to store the rowid/primary-key. There is only
       ** one, so just keep it in its register(s) and fall through to the
-      ** delete code.
-      */
+      ** delete code.  */
       nKey = nPk; /* OP_Found will use an unpacked key */
-      aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
+      aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);
       if( aToOpen==0 ){
         sqlite3WhereEnd(pWInfo);
         goto delete_from_cleanup;
@@ -94953,27 +105837,27 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
       if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
       if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
       if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
-      addrDelete = sqlite3VdbeAddOp0(v, OP_Goto); /* Jump to DELETE logic */
-    }else if( pPk ){
-      /* Construct a composite key for the row to be deleted and remember it */
-      iKey = ++pParse->nMem;
-      nKey = 0;   /* Zero tells OP_Found to use a composite key */
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
-                        sqlite3IndexAffinityStr(v, pPk), nPk);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey);
     }else{
-      /* Get the rowid of the row to be deleted and remember it in the RowSet */
-      nKey = 1;  /* OP_Seek always uses a single rowid */
-      sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
+      if( pPk ){
+        /* Add the PK key for this row to the temporary table */
+        iKey = ++pParse->nMem;
+        nKey = 0;   /* Zero tells OP_Found to use a composite key */
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
+            sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
+        sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEphCur, iKey, iPk, nPk);
+      }else{
+        /* Add the rowid of the row to be deleted to the RowSet */
+        nKey = 1;  /* OP_DeferredSeek always uses a single rowid */
+        sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
+      }
     }
   
-    /* End of the WHERE loop */
-    sqlite3WhereEnd(pWInfo);
-    if( okOnePass ){
-      /* Bypass the delete logic below if the WHERE loop found zero rows */
+    /* If this DELETE cannot use the ONEPASS strategy, this is the 
+    ** end of the WHERE loop */
+    if( eOnePass!=ONEPASS_OFF ){
       addrBypass = sqlite3VdbeMakeLabel(v);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBypass);
-      sqlite3VdbeJumpHere(v, addrDelete);
+    }else{
+      sqlite3WhereEnd(pWInfo);
     }
   
     /* Unless this is a view, open cursors for the table we are 
@@ -94982,28 +105866,31 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
     ** triggers.
     */
     if( !isView ){
+      int iAddrOnce = 0;
+      if( eOnePass==ONEPASS_MULTI ){
+        iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+      }
       testcase( IsVirtual(pTab) );
-      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
-                                 &iDataCur, &iIdxCur);
+      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
+                                 iTabCur, aToOpen, &iDataCur, &iIdxCur);
       assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
       assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
+      if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
     }
   
     /* Set up a loop over the rowids/primary-keys that were found in the
     ** where-clause loop above.
     */
-    if( okOnePass ){
-      /* Just one row.  Hence the top-of-loop is a no-op */
+    if( eOnePass!=ONEPASS_OFF ){
       assert( nKey==nPk );  /* OP_Found will use an unpacked key */
-      assert( !IsVirtual(pTab) );
-      if( aToOpen[iDataCur-iTabCur] ){
+      if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
         assert( pPk!=0 || pTab->pSelect!=0 );
         sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
         VdbeCoverage(v);
       }
     }else if( pPk ){
       addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
+      sqlite3VdbeAddOp2(v, OP_RowData, iEphCur, iKey);
       assert( nKey==0 );  /* OP_Found will use a composite key */
     }else{
       addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
@@ -95018,33 +105905,30 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
       sqlite3VtabMakeWritable(pParse, pTab);
       sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
       sqlite3VdbeChangeP5(v, OE_Abort);
+      assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
       sqlite3MayAbort(pParse);
+      if( eOnePass==ONEPASS_SINGLE && sqlite3IsToplevel(pParse) ){
+        pParse->isMultiWrite = 0;
+      }
     }else
 #endif
     {
       int count = (pParse->nested==0);    /* True to count changes */
       sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
-                               iKey, nKey, count, OE_Default, okOnePass);
+          iKey, nKey, count, OE_Default, eOnePass, aiCurOnePass[1]);
     }
   
     /* End of the loop over all rowids/primary-keys. */
-    if( okOnePass ){
+    if( eOnePass!=ONEPASS_OFF ){
       sqlite3VdbeResolveLabel(v, addrBypass);
+      sqlite3WhereEnd(pWInfo);
     }else if( pPk ){
       sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
       sqlite3VdbeJumpHere(v, addrLoop);
     }else{
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrLoop);
+      sqlite3VdbeGoto(v, addrLoop);
       sqlite3VdbeJumpHere(v, addrLoop);
     }     
-  
-    /* Close the cursors open on the table and its indexes. */
-    if( !isView && !IsVirtual(pTab) ){
-      if( !pPk ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
-      for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
-        sqlite3VdbeAddOp1(v, OP_Close, iIdxCur + i);
-      }
-    }
   } /* End non-truncate path */
 
   /* Update the sqlite_sequence table by storing the content of the
@@ -95101,6 +105985,27 @@ delete_from_cleanup:
 **       sequence of nPk memory cells starting at iPk.  If nPk==0 that means
 **       that a search record formed from OP_MakeRecord is contained in the
 **       single memory location iPk.
+**
+** eMode:
+**   Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
+**   ONEPASS_MULTI.  If eMode is not ONEPASS_OFF, then the cursor
+**   iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
+**   then this function must seek iDataCur to the entry identified by iPk
+**   and nPk before reading from it.
+**
+**   If eMode is ONEPASS_MULTI, then this call is being made as part
+**   of a ONEPASS delete that affects multiple rows. In this case, if 
+**   iIdxNoSeek is a valid cursor number (>=0) and is not the same as
+**   iDataCur, then its position should be preserved following the delete
+**   operation. Or, if iIdxNoSeek is not a valid cursor number, the
+**   position of iDataCur should be preserved instead.
+**
+** iIdxNoSeek:
+**   If iIdxNoSeek is a valid cursor number (>=0) not equal to iDataCur,
+**   then it identifies an index cursor (from within array of cursors
+**   starting at iIdxCur) that already points to the index entry to be deleted.
+**   Except, this optimization is disabled if there are BEFORE triggers since
+**   the trigger body might have moved the cursor.
 */
 SQLITE_PRIVATE void sqlite3GenerateRowDelete(
   Parse *pParse,     /* Parsing context */
@@ -95112,7 +106017,8 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
   i16 nPk,           /* Number of PRIMARY KEY memory cells */
   u8 count,          /* If non-zero, increment the row change counter */
   u8 onconf,         /* Default ON CONFLICT policy for triggers */
-  u8 bNoSeek         /* iDataCur is already pointing to the row to delete */
+  u8 eMode,          /* ONEPASS_OFF, _SINGLE, or _MULTI.  See above */
+  int iIdxNoSeek     /* Cursor number of cursor that does not need seeking */
 ){
   Vdbe *v = pParse->pVdbe;        /* Vdbe */
   int iOld = 0;                   /* First register in OLD.* array */
@@ -95129,7 +106035,7 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
   ** not attempt to delete it or fire any DELETE triggers.  */
   iLabel = sqlite3VdbeMakeLabel(v);
   opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
-  if( !bNoSeek ){
+  if( eMode==ONEPASS_OFF ){
     sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
     VdbeCoverageIf(v, opSeek==OP_NotExists);
     VdbeCoverageIf(v, opSeek==OP_NotFound);
@@ -95170,13 +106076,18 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
 
     /* If any BEFORE triggers were coded, then seek the cursor to the 
     ** row to be deleted again. It may be that the BEFORE triggers moved
-    ** the cursor or of already deleted the row that the cursor was
+    ** the cursor or already deleted the row that the cursor was
     ** pointing to.
+    **
+    ** Also disable the iIdxNoSeek optimization since the BEFORE trigger
+    ** may have moved that cursor.
     */
     if( addrStart=0 );
+      iIdxNoSeek = -1;
     }
 
     /* Do FK processing. This call checks that any FK constraints that
@@ -95187,13 +106098,29 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
 
   /* Delete the index and table entries. Skip this step if pTab is really
   ** a view (in which case the only effect of the DELETE statement is to
-  ** fire the INSTEAD OF triggers).  */ 
+  ** fire the INSTEAD OF triggers).  
+  **
+  ** If variable 'count' is non-zero, then this OP_Delete instruction should
+  ** invoke the update-hook. The pre-update-hook, on the other hand should
+  ** be invoked unless table pTab is a system table. The difference is that
+  ** the update-hook is not invoked for rows removed by REPLACE, but the 
+  ** pre-update-hook is.
+  */ 
   if( pTab->pSelect==0 ){
-    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
+    u8 p5 = 0;
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
     sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
-    if( count ){
-      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
+    if( pParse->nested==0 ){
+      sqlite3VdbeAppendP4(v, (char*)pTab, P4_TABLE);
     }
+    if( eMode!=ONEPASS_OFF ){
+      sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);
+    }
+    if( iIdxNoSeek>=0 && iIdxNoSeek!=iDataCur ){
+      sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
+    }
+    if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;
+    sqlite3VdbeChangeP5(v, p5);
   }
 
   /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
@@ -95236,7 +106163,8 @@ SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(
   Table *pTab,       /* Table containing the row to be deleted */
   int iDataCur,      /* Cursor of table holding data. */
   int iIdxCur,       /* First index cursor */
-  int *aRegIdx       /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
+  int *aRegIdx,      /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
+  int iIdxNoSeek     /* Do not delete from this cursor */
 ){
   int i;             /* Index loop counter */
   int r1 = -1;       /* Register holding an index key */
@@ -95252,11 +106180,12 @@ SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(
     assert( iIdxCur+i!=iDataCur || pPk==pIdx );
     if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
     if( pIdx==pPk ) continue;
+    if( iIdxCur+i==iIdxNoSeek ) continue;
     VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
     r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
-                                 &iPartIdxLabel, pPrior, r1);
+        &iPartIdxLabel, pPrior, r1);
     sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
-                      pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
+        pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
     sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
     pPrior = pIdx;
   }
@@ -95305,17 +106234,17 @@ SQLITE_PRIVATE int sqlite3GenerateIndexKey(
 ){
   Vdbe *v = pParse->pVdbe;
   int j;
-  Table *pTab = pIdx->pTable;
   int regBase;
   int nCol;
 
   if( piPartIdxLabel ){
     if( pIdx->pPartIdxWhere ){
       *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
-      pParse->iPartIdxTab = iDataCur;
+      pParse->iSelfTab = iDataCur + 1;
       sqlite3ExprCachePush(pParse);
-      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
-                         SQLITE_JUMPIFNULL);
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
+                            SQLITE_JUMPIFNULL);
+      pParse->iSelfTab = 0;
     }else{
       *piPartIdxLabel = 0;
     }
@@ -95324,9 +106253,14 @@ SQLITE_PRIVATE int sqlite3GenerateIndexKey(
   regBase = sqlite3GetTempRange(pParse, nCol);
   if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
   for(j=0; jaiColumn[j]==pIdx->aiColumn[j] ) continue;
-    sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pIdx->aiColumn[j],
-                                    regBase+j);
+    if( pPrior
+     && pPrior->aiColumn[j]==pIdx->aiColumn[j]
+     && pPrior->aiColumn[j]!=XN_EXPR
+    ){
+      /* This column was already computed by the previous index */
+      continue;
+    }
+    sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
     /* If the column affinity is REAL but the number is an integer, then it
     ** might be stored in the table as an integer (using a compact
     ** representation) then converted to REAL by an OP_RealAffinity opcode.
@@ -95337,6 +106271,10 @@ SQLITE_PRIVATE int sqlite3GenerateIndexKey(
   }
   if( regOut ){
     sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
+    if( pIdx->pTable->pSelect ){
+      const char *zAff = sqlite3IndexAffinityStr(pParse->db, pIdx);
+      sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT);
+    }
   }
   sqlite3ReleaseTempRange(pParse, regBase, nCol);
   return regBase;
@@ -95371,14 +106309,18 @@ SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){
 ** functions of SQLite.  (Some function, and in particular the date and
 ** time functions, are implemented separately.)
 */
+/* #include "sqliteInt.h" */
 /* #include  */
 /* #include  */
+/* #include "vdbeInt.h" */
 
 /*
 ** Return the collating function associated with a function.
 */
 static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
-  VdbeOp *pOp = &context->pVdbe->aOp[context->iOp-1];
+  VdbeOp *pOp;
+  assert( context->pVdbe!=0 );
+  pOp = &context->pVdbe->aOp[context->iOp-1];
   assert( pOp->opcode==OP_CollSeq );
   assert( pOp->p4type==P4_COLLSEQ );
   return pOp->p4.pColl;
@@ -95430,16 +106372,20 @@ static void typeofFunc(
   int NotUsed,
   sqlite3_value **argv
 ){
-  const char *z = 0;
+  static const char *azType[] = { "integer", "real", "text", "blob", "null" };
+  int i = sqlite3_value_type(argv[0]) - 1;
   UNUSED_PARAMETER(NotUsed);
-  switch( sqlite3_value_type(argv[0]) ){
-    case SQLITE_INTEGER: z = "integer"; break;
-    case SQLITE_TEXT:    z = "text";    break;
-    case SQLITE_FLOAT:   z = "real";    break;
-    case SQLITE_BLOB:    z = "blob";    break;
-    default:             z = "null";    break;
-  }
-  sqlite3_result_text(context, z, -1, SQLITE_STATIC);
+  assert( i>=0 && i0 ){
+    if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
+      zHaystack = sqlite3_value_blob(argv[0]);
+      zNeedle = sqlite3_value_blob(argv[1]);
+      isText = 0;
+    }else{
+      zHaystack = sqlite3_value_text(argv[0]);
+      zNeedle = sqlite3_value_text(argv[1]);
+      isText = 1;
+    }
+    if( zNeedle==0 || (nHaystack && zHaystack==0) ) return;
+    while( nNeedle<=nHaystack && memcmp(zHaystack, zNeedle, nNeedle)!=0 ){
+      N++;
+      do{
+        nHaystack--;
+        zHaystack++;
+      }while( isText && (zHaystack[0]&0xc0)==0x80 );
+    }
+    if( nNeedle>nHaystack ) N = 0;
   }
-  if( nNeedle>nHaystack ) N = 0;
   sqlite3_result_int(context, N);
 }
 
@@ -95586,14 +106535,15 @@ static void printfFunc(
   StrAccum str;
   const char *zFormat;
   int n;
+  sqlite3 *db = sqlite3_context_db_handle(context);
 
   if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){
     x.nArg = argc-1;
     x.nUsed = 0;
     x.apArg = argv+1;
-    sqlite3StrAccumInit(&str, 0, 0, SQLITE_MAX_LENGTH);
-    str.db = sqlite3_context_db_handle(context);
-    sqlite3XPrintf(&str, SQLITE_PRINTF_SQLFUNC, zFormat, &x);
+    sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
+    str.printfFlags = SQLITE_PRINTF_SQLFUNC;
+    sqlite3XPrintf(&str, zFormat, &x);
     n = str.nChar;
     sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
                         SQLITE_DYNAMIC);
@@ -95647,6 +106597,14 @@ static void substrFunc(
       }
     }
   }
+#ifdef SQLITE_SUBSTR_COMPATIBILITY
+  /* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as
+  ** as substr(X,1,N) - it returns the first N characters of X.  This
+  ** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]
+  ** from 2009-02-02 for compatibility of applications that exploited the
+  ** old buggy behavior. */
+  if( p1==0 ) p1 = 1; /*  */
+#endif
   if( argc==3 ){
     p2 = sqlite3_value_int(argv[2]);
     if( p2<0 ){
@@ -95734,7 +106692,7 @@ static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 #endif
 
 /*
-** Allocate nByte bytes of space using sqlite3_malloc(). If the
+** Allocate nByte bytes of space using sqlite3Malloc(). If the
 ** allocation fails, call sqlite3_result_error_nomem() to notify
 ** the database handle that malloc() has failed and return NULL.
 ** If nByte is larger than the maximum string or blob length, then
@@ -95913,25 +106871,23 @@ static void total_changes(
 ** A structure defining how to do GLOB-style comparisons.
 */
 struct compareInfo {
-  u8 matchAll;
-  u8 matchOne;
-  u8 matchSet;
-  u8 noCase;
+  u8 matchAll;          /* "*" or "%" */
+  u8 matchOne;          /* "?" or "_" */
+  u8 matchSet;          /* "[" or 0 */
+  u8 noCase;            /* true to ignore case differences */
 };
 
 /*
 ** For LIKE and GLOB matching on EBCDIC machines, assume that every
-** character is exactly one byte in size.  Also, all characters are
-** able to participate in upper-case-to-lower-case mappings in EBCDIC
-** whereas only characters less than 0x80 do in ASCII.
+** character is exactly one byte in size.  Also, provde the Utf8Read()
+** macro for fast reading of the next character in the common case where
+** the next character is ASCII.
 */
 #if defined(SQLITE_EBCDIC)
 # define sqlite3Utf8Read(A)        (*((*A)++))
-# define GlobUpperToLower(A)       A = sqlite3UpperToLower[A]
-# define GlobUpperToLowerAscii(A)  A = sqlite3UpperToLower[A]
+# define Utf8Read(A)               (*(A++))
 #else
-# define GlobUpperToLower(A)       if( A<=0x7f ){ A = sqlite3UpperToLower[A]; }
-# define GlobUpperToLowerAscii(A)  A = sqlite3UpperToLower[A]
+# define Utf8Read(A)               (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))
 #endif
 
 static const struct compareInfo globInfo = { '*', '?', '[', 0 };
@@ -95943,9 +106899,19 @@ static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
 static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
 
 /*
-** Compare two UTF-8 strings for equality where the first string can
-** potentially be a "glob" or "like" expression.  Return true (1) if they
-** are the same and false (0) if they are different.
+** Possible error returns from patternMatch()
+*/
+#define SQLITE_MATCH             0
+#define SQLITE_NOMATCH           1
+#define SQLITE_NOWILDCARDMATCH   2
+
+/*
+** Compare two UTF-8 strings for equality where the first string is
+** a GLOB or LIKE expression.  Return values:
+**
+**    SQLITE_MATCH:            Match
+**    SQLITE_NOMATCH:          No match
+**    SQLITE_NOWILDCARDMATCH:  No match in spite of having * or % wildcards.
 **
 ** Globbing rules:
 **
@@ -95973,7 +106939,7 @@ static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
 **      Ec        Where E is the "esc" character and c is any other
 **                character, including '%', '_', and esc, match exactly c.
 **
-** The comments through this routine usually assume glob matching.
+** The comments within this routine usually assume glob matching.
 **
 ** This routine is usually quick, but can be N**2 in the worst case.
 */
@@ -95981,54 +106947,46 @@ static int patternCompare(
   const u8 *zPattern,              /* The glob pattern */
   const u8 *zString,               /* The string to compare against the glob */
   const struct compareInfo *pInfo, /* Information about how to do the compare */
-  u32 esc                          /* The escape character */
+  u32 matchOther                   /* The escape char (LIKE) or '[' (GLOB) */
 ){
   u32 c, c2;                       /* Next pattern and input string chars */
   u32 matchOne = pInfo->matchOne;  /* "?" or "_" */
   u32 matchAll = pInfo->matchAll;  /* "*" or "%" */
-  u32 matchOther;                  /* "[" or the escape character */
   u8 noCase = pInfo->noCase;       /* True if uppercase==lowercase */
   const u8 *zEscaped = 0;          /* One past the last escaped input char */
   
-  /* The GLOB operator does not have an ESCAPE clause.  And LIKE does not
-  ** have the matchSet operator.  So we either have to look for one or
-  ** the other, never both.  Hence the single variable matchOther is used
-  ** to store the one we have to look for.
-  */
-  matchOther = esc ? esc : pInfo->matchSet;
-
-  while( (c = sqlite3Utf8Read(&zPattern))!=0 ){
+  while( (c = Utf8Read(zPattern))!=0 ){
     if( c==matchAll ){  /* Match "*" */
       /* Skip over multiple "*" characters in the pattern.  If there
       ** are also "?" characters, skip those as well, but consume a
       ** single character of the input string for each "?" skipped */
-      while( (c=sqlite3Utf8Read(&zPattern)) == matchAll
-               || c == matchOne ){
+      while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
         if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
-          return 0;
+          return SQLITE_NOWILDCARDMATCH;
         }
       }
       if( c==0 ){
-        return 1;   /* "*" at the end of the pattern matches */
+        return SQLITE_MATCH;   /* "*" at the end of the pattern matches */
       }else if( c==matchOther ){
-        if( esc ){
+        if( pInfo->matchSet==0 ){
           c = sqlite3Utf8Read(&zPattern);
-          if( c==0 ) return 0;
+          if( c==0 ) return SQLITE_NOWILDCARDMATCH;
         }else{
           /* "[...]" immediately follows the "*".  We have to do a slow
           ** recursive search in this case, but it is an unusual case. */
           assert( matchOther<0x80 );  /* '[' is a single-byte character */
-          while( *zString
-                 && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
+          while( *zString ){
+            int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther);
+            if( bMatch!=SQLITE_NOMATCH ) return bMatch;
             SQLITE_SKIP_UTF8(zString);
           }
-          return *zString!=0;
+          return SQLITE_NOWILDCARDMATCH;
         }
       }
 
       /* At this point variable c contains the first character of the
       ** pattern string past the "*".  Search in the input string for the
-      ** first matching character and recursively contine the match from
+      ** first matching character and recursively continue the match from
       ** that point.
       **
       ** For a case-insensitive search, set variable cx to be the same as
@@ -96037,6 +106995,7 @@ static int patternCompare(
       */
       if( c<=0x80 ){
         u32 cx;
+        int bMatch;
         if( noCase ){
           cx = sqlite3Toupper(c);
           c = sqlite3Tolower(c);
@@ -96045,27 +107004,30 @@ static int patternCompare(
         }
         while( (c2 = *(zString++))!=0 ){
           if( c2!=c && c2!=cx ) continue;
-          if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
+          bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
+          if( bMatch!=SQLITE_NOMATCH ) return bMatch;
         }
       }else{
-        while( (c2 = sqlite3Utf8Read(&zString))!=0 ){
+        int bMatch;
+        while( (c2 = Utf8Read(zString))!=0 ){
           if( c2!=c ) continue;
-          if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
+          bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
+          if( bMatch!=SQLITE_NOMATCH ) return bMatch;
         }
       }
-      return 0;
+      return SQLITE_NOWILDCARDMATCH;
     }
     if( c==matchOther ){
-      if( esc ){
+      if( pInfo->matchSet==0 ){
         c = sqlite3Utf8Read(&zPattern);
-        if( c==0 ) return 0;
+        if( c==0 ) return SQLITE_NOMATCH;
         zEscaped = zPattern;
       }else{
         u32 prior_c = 0;
         int seen = 0;
         int invert = 0;
         c = sqlite3Utf8Read(&zString);
-        if( c==0 ) return 0;
+        if( c==0 ) return SQLITE_NOMATCH;
         c2 = sqlite3Utf8Read(&zPattern);
         if( c2=='^' ){
           invert = 1;
@@ -96089,27 +107051,36 @@ static int patternCompare(
           c2 = sqlite3Utf8Read(&zPattern);
         }
         if( c2==0 || (seen ^ invert)==0 ){
-          return 0;
+          return SQLITE_NOMATCH;
         }
         continue;
       }
     }
-    c2 = sqlite3Utf8Read(&zString);
+    c2 = Utf8Read(zString);
     if( c==c2 ) continue;
-    if( noCase && c<0x80 && c2<0x80 && sqlite3Tolower(c)==sqlite3Tolower(c2) ){
+    if( noCase  && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){
       continue;
     }
     if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;
-    return 0;
+    return SQLITE_NOMATCH;
   }
-  return *zString==0;
+  return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH;
 }
 
 /*
-** The sqlite3_strglob() interface.
+** The sqlite3_strglob() interface.  Return 0 on a match (like strcmp()) and
+** non-zero if there is no match.
 */
 SQLITE_API int sqlite3_strglob(const char *zGlobPattern, const char *zString){
-  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, 0)==0;
+  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');
+}
+
+/*
+** The sqlite3_strlike() interface.  Return 0 on a match and non-zero for
+** a miss - like strcmp().
+*/
+SQLITE_API int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
+  return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);
 }
 
 /*
@@ -96140,10 +107111,22 @@ static void likeFunc(
   sqlite3_value **argv
 ){
   const unsigned char *zA, *zB;
-  u32 escape = 0;
+  u32 escape;
   int nPat;
   sqlite3 *db = sqlite3_context_db_handle(context);
+  struct compareInfo *pInfo = sqlite3_user_data(context);
 
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
+   || sqlite3_value_type(argv[1])==SQLITE_BLOB
+  ){
+#ifdef SQLITE_TEST
+    sqlite3_like_count++;
+#endif
+    sqlite3_result_int(context, 0);
+    return;
+  }
+#endif
   zB = sqlite3_value_text(argv[0]);
   zA = sqlite3_value_text(argv[1]);
 
@@ -96171,14 +107154,14 @@ static void likeFunc(
       return;
     }
     escape = sqlite3Utf8Read(&zEsc);
+  }else{
+    escape = pInfo->matchSet;
   }
   if( zA && zB ){
-    struct compareInfo *pInfo = sqlite3_user_data(context);
 #ifdef SQLITE_TEST
     sqlite3_like_count++;
 #endif
-    
-    sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
+    sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);
   }
 }
 
@@ -96403,7 +107386,7 @@ static void charFunc(
 ){
   unsigned char *z, *zOut;
   int i;
-  zOut = z = sqlite3_malloc( argc*4+1 );
+  zOut = z = sqlite3_malloc64( argc*4+1 );
   if( z==0 ){
     sqlite3_result_error_nomem(context);
     return;
@@ -96471,16 +107454,14 @@ static void zeroblobFunc(
   sqlite3_value **argv
 ){
   i64 n;
-  sqlite3 *db = sqlite3_context_db_handle(context);
+  int rc;
   assert( argc==1 );
   UNUSED_PARAMETER(argc);
   n = sqlite3_value_int64(argv[0]);
-  testcase( n==db->aLimit[SQLITE_LIMIT_LENGTH] );
-  testcase( n==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
-  if( n>db->aLimit[SQLITE_LIMIT_LENGTH] ){
-    sqlite3_result_error_toobig(context);
-  }else{
-    sqlite3_result_zeroblob(context, (int)n); /* IMP: R-00293-64994 */
+  if( n<0 ) n = 0;
+  rc = sqlite3_result_zeroblob64(context, n); /* IMP: R-00293-64994 */
+  if( rc ){
+    sqlite3_result_error_code(context, rc);
   }
 }
 
@@ -96551,7 +107532,7 @@ static void replaceFunc(
         return;
       }
       zOld = zOut;
-      zOut = sqlite3_realloc(zOut, (int)nOut);
+      zOut = sqlite3_realloc64(zOut, (int)nOut);
       if( zOut==0 ){
         sqlite3_result_error_nomem(context);
         sqlite3_free(zOld);
@@ -96655,6 +107636,26 @@ static void trimFunc(
 }
 
 
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+/*
+** The "unknown" function is automatically substituted in place of
+** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
+** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.
+** When the "sqlite3" command-line shell is built using this functionality,
+** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
+** involving application-defined functions to be examined in a generic
+** sqlite3 shell.
+*/
+static void unknownFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  /* no-op */
+}
+#endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/
+
+
 /* IMP: R-25361-16150 This function is omitted from SQLite by default. It
 ** is only available if the SQLITE_SOUNDEX compile-time option is used
 ** when SQLite is built.
@@ -96725,6 +107726,14 @@ static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
   sqlite3 *db = sqlite3_context_db_handle(context);
   char *zErrMsg = 0;
 
+  /* Disallow the load_extension() SQL function unless the SQLITE_LoadExtFunc
+  ** flag is set.  See the sqlite3_enable_load_extension() API.
+  */
+  if( (db->flags & SQLITE_LoadExtFunc)==0 ){
+    sqlite3_result_error(context, "not authorized", -1);
+    return;
+  }
+
   if( argc==2 ){
     zProc = (const char *)sqlite3_value_text(argv[1]);
   }else{
@@ -96913,8 +107922,7 @@ static void groupConcatStep(
 
   if( pAccum ){
     sqlite3 *db = sqlite3_context_db_handle(context);
-    int firstTerm = pAccum->useMalloc==0;
-    pAccum->useMalloc = 2;
+    int firstTerm = pAccum->mxAlloc==0;
     pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
     if( !firstTerm ){
       if( argc==2 ){
@@ -96924,7 +107932,7 @@ static void groupConcatStep(
         zSep = ",";
         nSep = 1;
       }
-      if( nSep ) sqlite3StrAccumAppend(pAccum, zSep, nSep);
+      if( zSep ) sqlite3StrAccumAppend(pAccum, zSep, nSep);
     }
     zVal = (char*)sqlite3_value_text(argv[0]);
     nVal = sqlite3_value_bytes(argv[0]);
@@ -96951,11 +107959,11 @@ static void groupConcatFinalize(sqlite3_context *context){
 ** of the built-in functions above are part of the global function set.
 ** This routine only deals with those that are not global.
 */
-SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
+SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3 *db){
   int rc = sqlite3_overload_function(db, "MATCH", 2);
   assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
   if( rc==SQLITE_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
 }
 
@@ -96964,8 +107972,7 @@ SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
 */
 static void setLikeOptFlag(sqlite3 *db, const char *zName, u8 flagVal){
   FuncDef *pDef;
-  pDef = sqlite3FindFunction(db, zName, sqlite3Strlen30(zName),
-                             2, SQLITE_UTF8, 0);
+  pDef = sqlite3FindFunction(db, zName, 2, SQLITE_UTF8, 0);
   if( ALWAYS(pDef) ){
     pDef->funcFlags |= flagVal;
   }
@@ -96998,6 +108005,11 @@ SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive)
 ** then set aWc[0] through aWc[2] to the wildcard characters and
 ** return TRUE.  If the function is not a LIKE-style function then
 ** return FALSE.
+**
+** *pIsNocase is set to true if uppercase and lowercase are equivalent for
+** the function (default for LIKE).  If the function makes the distinction
+** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to
+** false.
 */
 SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
   FuncDef *pDef;
@@ -97008,9 +108020,7 @@ SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocas
     return 0;
   }
   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-  pDef = sqlite3FindFunction(db, pExpr->u.zToken, 
-                             sqlite3Strlen30(pExpr->u.zToken),
-                             2, SQLITE_UTF8, 0);
+  pDef = sqlite3FindFunction(db, pExpr->u.zToken, 2, SQLITE_UTF8, 0);
   if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
     return 0;
   }
@@ -97034,7 +108044,7 @@ SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocas
 **
 ** After this routine runs
 */
-SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
+SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void){
   /*
   ** The following array holds FuncDef structures for all of the functions
   ** defined in this file.
@@ -97042,8 +108052,30 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
   ** The array cannot be constant since changes are made to the
   ** FuncDef.pHash elements at start-time.  The elements of this array
   ** are read-only after initialization is complete.
+  **
+  ** For peak efficiency, put the most frequently used function last.
   */
-  static SQLITE_WSD FuncDef aBuiltinFunc[] = {
+  static FuncDef aBuiltinFunc[] = {
+#ifdef SQLITE_SOUNDEX
+    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    VFUNCTION(load_extension,    1, 0, 0, loadExt          ),
+    VFUNCTION(load_extension,    2, 0, 0, loadExt          ),
+#endif
+#if SQLITE_USER_AUTHENTICATION
+    FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
+#endif
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+    DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
+    DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
+#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
+    FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
+    FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
+    FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
+#ifdef SQLITE_DEBUG
+    FUNCTION2(affinity,          1, 0, 0, noopFunc,  SQLITE_FUNC_AFFINITY),
+#endif
     FUNCTION(ltrim,              1, 1, 0, trimFunc         ),
     FUNCTION(ltrim,              2, 1, 0, trimFunc         ),
     FUNCTION(rtrim,              1, 2, 0, trimFunc         ),
@@ -97061,8 +108093,6 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
     FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
     FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
     FUNCTION(instr,              2, 0, 0, instrFunc        ),
-    FUNCTION(substr,             2, 0, 0, substrFunc       ),
-    FUNCTION(substr,             3, 0, 0, substrFunc       ),
     FUNCTION(printf,            -1, 0, 0, printfFunc       ),
     FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),
     FUNCTION(char,              -1, 0, 0, charFunc         ),
@@ -97073,40 +108103,22 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 #endif
     FUNCTION(upper,              1, 0, 0, upperFunc        ),
     FUNCTION(lower,              1, 0, 0, lowerFunc        ),
-    FUNCTION(coalesce,           1, 0, 0, 0                ),
-    FUNCTION(coalesce,           0, 0, 0, 0                ),
-    FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
     FUNCTION(hex,                1, 0, 0, hexFunc          ),
     FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
-    FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
-    FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
-    FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
     VFUNCTION(random,            0, 0, 0, randomFunc       ),
     VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
     FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
-    FUNCTION(sqlite_version,     0, 0, 0, versionFunc      ),
-    FUNCTION(sqlite_source_id,   0, 0, 0, sourceidFunc     ),
+    DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),
+    DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),
     FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
-#if SQLITE_USER_AUTHENTICATION
-    FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
-#endif
-#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
-    FUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
-    FUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
-#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
     FUNCTION(quote,              1, 0, 0, quoteFunc        ),
     VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
     VFUNCTION(changes,           0, 0, 0, changes          ),
     VFUNCTION(total_changes,     0, 0, 0, total_changes    ),
     FUNCTION(replace,            3, 0, 0, replaceFunc      ),
     FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
-  #ifdef SQLITE_SOUNDEX
-    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
-  #endif
-  #ifndef SQLITE_OMIT_LOAD_EXTENSION
-    FUNCTION(load_extension,     1, 0, 0, loadExt          ),
-    FUNCTION(load_extension,     2, 0, 0, loadExt          ),
-  #endif
+    FUNCTION(substr,             2, 0, 0, substrFunc       ),
+    FUNCTION(substr,             3, 0, 0, substrFunc       ),
     AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
     AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
     AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
@@ -97117,28 +108129,43 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
     AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
   
     LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #ifdef SQLITE_CASE_SENSITIVE_LIKE
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
     LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
     LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #else
+#else
     LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
     LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
-  #endif
+#endif
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+    FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),
+#endif
+    FUNCTION(coalesce,           1, 0, 0, 0                ),
+    FUNCTION(coalesce,           0, 0, 0, 0                ),
+    FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
   };
-
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aBuiltinFunc);
-
-  for(i=0; iu.pHash){
+        int n = sqlite3Strlen30(p->zName);
+        int h = p->zName[0] + n;
+        printf(" %s(%d)", p->zName, h);
+      }
+      printf("\n");
+    }
+  }
 #endif
 }
 
@@ -97157,6 +108184,7 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 ** This file contains code used by the compiler to add foreign key
 ** support to compiled SQL statements.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 #ifndef SQLITE_OMIT_TRIGGER
@@ -97364,13 +108392,13 @@ SQLITE_PRIVATE int sqlite3FkLocateIndex(
     }
   }else if( paiCol ){
     assert( nCol>1 );
-    aiCol = (int *)sqlite3DbMallocRaw(pParse->db, nCol*sizeof(int));
+    aiCol = (int *)sqlite3DbMallocRawNN(pParse->db, nCol*sizeof(int));
     if( !aiCol ) return 1;
     *paiCol = aiCol;
   }
 
   for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){
-    if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) ){ 
+    if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) && pIdx->pPartIdxWhere==0 ){ 
       /* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
       ** of columns. If each indexed column corresponds to a foreign key
       ** column of pFKey, then this index is a winner.  */
@@ -97394,16 +108422,16 @@ SQLITE_PRIVATE int sqlite3FkLocateIndex(
         int i, j;
         for(i=0; iaiColumn[i];     /* Index of column in parent tbl */
-          char *zDfltColl;                  /* Def. collation for column */
+          const char *zDfltColl;            /* Def. collation for column */
           char *zIdxCol;                    /* Name of indexed column */
 
+          if( iCol<0 ) break; /* No foreign keys against expression indexes */
+
           /* If the index uses a collation sequence that is different from
           ** the default collation sequence for the column, this index is
           ** unusable. Bail out early in this case.  */
           zDfltColl = pParent->aCol[iCol].zColl;
-          if( !zDfltColl ){
-            zDfltColl = "BINARY";
-          }
+          if( !zDfltColl ) zDfltColl = sqlite3StrBINARY;
           if( sqlite3StrICmp(pIdx->azColl[i], zDfltColl) ) break;
 
           zIdxCol = pParent->aCol[iCol].zName;
@@ -97519,7 +108547,7 @@ static void fkLookupParent(
   
       sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
       sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
+      sqlite3VdbeGoto(v, iOk);
       sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
       sqlite3VdbeJumpHere(v, iMustBeInt);
       sqlite3ReleaseTempReg(pParse, regTemp);
@@ -97549,6 +108577,7 @@ static void fkLookupParent(
         for(i=0; iaiColumn[i]+1+regData;
+          assert( pIdx->aiColumn[i]>=0 );
           assert( aiCol[i]!=pTab->iPKey );
           if( pIdx->aiColumn[i]==pTab->iPKey ){
             /* The parent key is a composite key that includes the IPK column */
@@ -97557,11 +108586,11 @@ static void fkLookupParent(
           sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
           sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
         }
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
+        sqlite3VdbeGoto(v, iOk);
       }
   
       sqlite3VdbeAddOp4(v, OP_MakeRecord, regTemp, nCol, regRec,
-                        sqlite3IndexAffinityStr(v,pIdx), nCol);
+                        sqlite3IndexAffinityStr(pParse->db,pIdx), nCol);
       sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); VdbeCoverage(v);
   
       sqlite3ReleaseTempReg(pParse, regRec);
@@ -97728,7 +108757,7 @@ static void fkScanChildren(
     assert( iCol>=0 );
     zCol = pFKey->pFrom->aCol[iCol].zName;
     pRight = sqlite3Expr(db, TK_ID, zCol);
-    pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
+    pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight);
     pWhere = sqlite3ExprAnd(db, pWhere, pEq);
   }
 
@@ -97750,19 +108779,20 @@ static void fkScanChildren(
     if( HasRowid(pTab) ){
       pLeft = exprTableRegister(pParse, pTab, regData, -1);
       pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);
-      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
+      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight);
     }else{
       Expr *pEq, *pAll = 0;
       Index *pPk = sqlite3PrimaryKeyIndex(pTab);
       assert( pIdx!=0 );
       for(i=0; inKeyCol; i++){
         i16 iCol = pIdx->aiColumn[i];
+        assert( iCol>=0 );
         pLeft = exprTableRegister(pParse, pTab, regData, iCol);
         pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, iCol);
-        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
+        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight);
         pAll = sqlite3ExprAnd(db, pAll, pEq);
       }
-      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0, 0);
+      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0);
     }
     pWhere = sqlite3ExprAnd(db, pWhere, pNe);
   }
@@ -97776,10 +108806,12 @@ static void fkScanChildren(
   /* Create VDBE to loop through the entries in pSrc that match the WHERE
   ** clause. For each row found, increment either the deferred or immediate
   ** foreign key constraint counter. */
-  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
-  sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
-  if( pWInfo ){
-    sqlite3WhereEnd(pWInfo);
+  if( pParse->nErr==0 ){
+    pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
+    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
+    if( pWInfo ){
+      sqlite3WhereEnd(pWInfo);
+    }
   }
 
   /* Clean up the WHERE clause constructed above. */
@@ -98014,7 +109046,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
   if( (db->flags&SQLITE_ForeignKeys)==0 ) return;
 
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-  zDb = db->aDb[iDb].zName;
+  zDb = db->aDb[iDb].zDbSName;
 
   /* Loop through all the foreign key constraints for which pTab is the
   ** child table (the table that the foreign key definition is part of).  */
@@ -98076,6 +109108,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
       if( aiCol[i]==pTab->iPKey ){
         aiCol[i] = -1;
       }
+      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
 #ifndef SQLITE_OMIT_AUTHORIZATION
       /* Request permission to read the parent key columns. If the 
       ** authorization callback returns SQLITE_IGNORE, behave as if any
@@ -98149,7 +109182,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
       struct SrcList_item *pItem = pSrc->a;
       pItem->pTab = pFKey->pFrom;
       pItem->zName = pFKey->pFrom->zName;
-      pItem->pTab->nRef++;
+      pItem->pTab->nTabRef++;
       pItem->iCursor = pParse->nTab++;
   
       if( regNew!=0 ){
@@ -98207,7 +109240,10 @@ SQLITE_PRIVATE u32 sqlite3FkOldmask(
       Index *pIdx = 0;
       sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
       if( pIdx ){
-        for(i=0; inKeyCol; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
+        for(i=0; inKeyCol; i++){
+          assert( pIdx->aiColumn[i]>=0 );
+          mask |= COLUMN_MASK(pIdx->aiColumn[i]);
+        }
       }
     }
   }
@@ -98226,8 +109262,16 @@ SQLITE_PRIVATE u32 sqlite3FkOldmask(
 ** UPDATE statement modifies the rowid fields of the table.
 **
 ** If any foreign key processing will be required, this function returns
-** true. If there is no foreign key related processing, this function 
-** returns false.
+** non-zero. If there is no foreign key related processing, this function 
+** returns zero.
+**
+** For an UPDATE, this function returns 2 if:
+**
+**   * There are any FKs for which pTab is the child and the parent table, or
+**   * the UPDATE modifies one or more parent keys for which the action is
+**     not "NO ACTION" (i.e. is CASCADE, SET DEFAULT or SET NULL).
+**
+** Or, assuming some other foreign key processing is required, 1.
 */
 SQLITE_PRIVATE int sqlite3FkRequired(
   Parse *pParse,                  /* Parse context */
@@ -98235,12 +109279,13 @@ SQLITE_PRIVATE int sqlite3FkRequired(
   int *aChange,                   /* Non-NULL for UPDATE operations */
   int chngRowid                   /* True for UPDATE that affects rowid */
 ){
+  int eRet = 0;
   if( pParse->db->flags&SQLITE_ForeignKeys ){
     if( !aChange ){
       /* A DELETE operation. Foreign key processing is required if the 
       ** table in question is either the child or parent table for any 
       ** foreign key constraint.  */
-      return (sqlite3FkReferences(pTab) || pTab->pFKey);
+      eRet = (sqlite3FkReferences(pTab) || pTab->pFKey);
     }else{
       /* This is an UPDATE. Foreign key processing is only required if the
       ** operation modifies one or more child or parent key columns. */
@@ -98248,16 +109293,22 @@ SQLITE_PRIVATE int sqlite3FkRequired(
 
       /* Check if any child key columns are being modified. */
       for(p=pTab->pFKey; p; p=p->pNextFrom){
-        if( fkChildIsModified(pTab, p, aChange, chngRowid) ) return 1;
+        if( 0==sqlite3_stricmp(pTab->zName, p->zTo) ) return 2;
+        if( fkChildIsModified(pTab, p, aChange, chngRowid) ){
+          eRet = 1;
+        }
       }
 
       /* Check if any parent key columns are being modified. */
       for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
-        if( fkParentIsModified(pTab, p, aChange, chngRowid) ) return 1;
+        if( fkParentIsModified(pTab, p, aChange, chngRowid) ){
+          if( p->aAction[1]!=OE_None ) return 2;
+          eRet = 1;
+        }
       }
     }
   }
-  return 0;
+  return eRet;
 }
 
 /*
@@ -98301,10 +109352,12 @@ static Trigger *fkActionTrigger(
   int iAction = (pChanges!=0);    /* 1 for UPDATE, 0 for DELETE */
 
   action = pFKey->aAction[iAction];
+  if( action==OE_Restrict && (db->flags & SQLITE_DeferFKs) ){
+    return 0;
+  }
   pTrigger = pFKey->apTrigger[iAction];
 
   if( action!=OE_None && !pTrigger ){
-    u8 enableLookaside;           /* Copy of db->lookaside.bEnabled */
     char const *zFrom;            /* Name of child table */
     int nFrom;                    /* Length in bytes of zFrom */
     Index *pIdx = 0;              /* Parent key index for this FK */
@@ -98329,11 +109382,11 @@ static Trigger *fkActionTrigger(
 
       iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
       assert( iFromCol>=0 );
-      tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
-      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;
-
-      tToCol.n = sqlite3Strlen30(tToCol.z);
-      tFromCol.n = sqlite3Strlen30(tFromCol.z);
+      assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKeynCol) );
+      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
+      sqlite3TokenInit(&tToCol,
+                   pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName);
+      sqlite3TokenInit(&tFromCol, pFKey->pFrom->aCol[iFromCol].zName);
 
       /* Create the expression "OLD.zToCol = zFromCol". It is important
       ** that the "OLD.zToCol" term is on the LHS of the = operator, so
@@ -98341,11 +109394,10 @@ static Trigger *fkActionTrigger(
       ** parent table are used for the comparison. */
       pEq = sqlite3PExpr(pParse, TK_EQ,
           sqlite3PExpr(pParse, TK_DOT, 
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
-          , 0),
-          sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol)
-      , 0);
+            sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
+            sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
+          sqlite3ExprAlloc(db, TK_ID, &tFromCol, 0)
+      );
       pWhere = sqlite3ExprAnd(db, pWhere, pEq);
 
       /* For ON UPDATE, construct the next term of the WHEN clause.
@@ -98356,14 +109408,12 @@ static Trigger *fkActionTrigger(
       if( pChanges ){
         pEq = sqlite3PExpr(pParse, TK_IS,
             sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
-              0),
+              sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
+              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
             sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
-              0),
-            0);
+              sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
+              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0))
+            );
         pWhen = sqlite3ExprAnd(db, pWhen, pEq);
       }
   
@@ -98371,18 +109421,17 @@ static Trigger *fkActionTrigger(
         Expr *pNew;
         if( action==OE_Cascade ){
           pNew = sqlite3PExpr(pParse, TK_DOT, 
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
-          , 0);
+            sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
+            sqlite3ExprAlloc(db, TK_ID, &tToCol, 0));
         }else if( action==OE_SetDflt ){
           Expr *pDflt = pFKey->pFrom->aCol[iFromCol].pDflt;
           if( pDflt ){
             pNew = sqlite3ExprDup(db, pDflt, 0);
           }else{
-            pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
+            pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);
           }
         }else{
-          pNew = sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
+          pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);
         }
         pList = sqlite3ExprListAppend(pParse, pList, pNew);
         sqlite3ExprListSetName(pParse, pList, &tFromCol, 0);
@@ -98413,31 +109462,29 @@ static Trigger *fkActionTrigger(
     }
 
     /* Disable lookaside memory allocation */
-    enableLookaside = db->lookaside.bEnabled;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.bDisable++;
 
     pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
         sizeof(Trigger) +         /* struct Trigger */
         sizeof(TriggerStep) +     /* Single step in trigger program */
-        nFrom + 1                 /* Space for pStep->target.z */
+        nFrom + 1                 /* Space for pStep->zTarget */
     );
     if( pTrigger ){
       pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
-      pStep->target.z = (char *)&pStep[1];
-      pStep->target.n = nFrom;
-      memcpy((char *)pStep->target.z, zFrom, nFrom);
+      pStep->zTarget = (char *)&pStep[1];
+      memcpy((char *)pStep->zTarget, zFrom, nFrom);
   
       pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
       pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
       pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
       if( pWhen ){
-        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0, 0);
+        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0);
         pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
       }
     }
 
     /* Re-enable the lookaside buffer, if it was disabled earlier. */
-    db->lookaside.bEnabled = enableLookaside;
+    db->lookaside.bDisable--;
 
     sqlite3ExprDelete(db, pWhere);
     sqlite3ExprDelete(db, pWhen);
@@ -98511,7 +109558,8 @@ SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
   FKey *pFKey;                    /* Iterator variable */
   FKey *pNext;                    /* Copy of pFKey->pNextFrom */
 
-  assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
+  assert( db==0 || IsVirtual(pTab)
+         || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
   for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){
 
     /* Remove the FK from the fkeyHash hash table. */
@@ -98561,6 +109609,7 @@ SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
 ** This file contains C code routines that are called by the parser
 ** to handle INSERT statements in SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Generate code that will 
@@ -98590,7 +109639,7 @@ SQLITE_PRIVATE void sqlite3OpenTable(
   }else{
     Index *pPk = sqlite3PrimaryKeyIndex(pTab);
     assert( pPk!=0 );
-    assert( pPk->tnum=pTab->tnum );
+    assert( pPk->tnum==pTab->tnum );
     sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
     sqlite3VdbeSetP4KeyInfo(pParse, pPk);
     VdbeComment((v, "%s", pTab->zName));
@@ -98604,7 +109653,7 @@ SQLITE_PRIVATE void sqlite3OpenTable(
 **
 **  Character      Column affinity
 **  ------------------------------
-**  'A'            NONE
+**  'A'            BLOB
 **  'B'            TEXT
 **  'C'            NUMERIC
 **  'D'            INTEGER
@@ -98617,7 +109666,7 @@ SQLITE_PRIVATE void sqlite3OpenTable(
 ** is managed along with the rest of the Index structure. It will be
 ** released when sqlite3DeleteIndex() is called.
 */
-SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
+SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
   if( !pIdx->zColAff ){
     /* The first time a column affinity string for a particular index is
     ** required, it is allocated and populated here. It is then stored as
@@ -98629,15 +109678,25 @@ SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
     */
     int n;
     Table *pTab = pIdx->pTable;
-    sqlite3 *db = sqlite3VdbeDb(v);
     pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
     if( !pIdx->zColAff ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return 0;
     }
     for(n=0; nnColumn; n++){
       i16 x = pIdx->aiColumn[n];
-      pIdx->zColAff[n] = x<0 ? SQLITE_AFF_INTEGER : pTab->aCol[x].affinity;
+      if( x>=0 ){
+        pIdx->zColAff[n] = pTab->aCol[x].affinity;
+      }else if( x==XN_ROWID ){
+        pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
+      }else{
+        char aff;
+        assert( x==XN_EXPR );
+        assert( pIdx->aColExpr!=0 );
+        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
+        if( aff==0 ) aff = SQLITE_AFF_BLOB;
+        pIdx->zColAff[n] = aff;
+      }
     }
     pIdx->zColAff[n] = 0;
   }
@@ -98647,9 +109706,9 @@ SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
 
 /*
 ** Compute the affinity string for table pTab, if it has not already been
-** computed.  As an optimization, omit trailing SQLITE_AFF_NONE affinities.
+** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
 **
-** If the affinity exists (if it is no entirely SQLITE_AFF_NONE values) and
+** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
 ** if iReg>0 then code an OP_Affinity opcode that will set the affinities
 ** for register iReg and following.  Or if affinities exists and iReg==0,
 ** then just set the P4 operand of the previous opcode (which should  be
@@ -98659,7 +109718,7 @@ SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
 **
 **  Character      Column affinity
 **  ------------------------------
-**  'A'            NONE
+**  'A'            BLOB
 **  'B'            TEXT
 **  'C'            NUMERIC
 **  'D'            INTEGER
@@ -98672,7 +109731,7 @@ SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
     sqlite3 *db = sqlite3VdbeDb(v);
     zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
     if( !zColAff ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return;
     }
 
@@ -98681,7 +109740,7 @@ SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
     }
     do{
       zColAff[i--] = 0;
-    }while( i>=0 && zColAff[i]==SQLITE_AFF_NONE );
+    }while( i>=0 && zColAff[i]==SQLITE_AFF_BLOB );
     pTab->zColAff = zColAff;
   }
   i = sqlite3Strlen30(zColAff);
@@ -98738,7 +109797,9 @@ static int readsTable(Parse *p, int iDb, Table *pTab){
 /*
 ** Locate or create an AutoincInfo structure associated with table pTab
 ** which is in database iDb.  Return the register number for the register
-** that holds the maximum rowid.
+** that holds the maximum rowid.  Return zero if pTab is not an AUTOINCREMENT
+** table.  (Also return zero when doing a VACUUM since we do not want to
+** update the AUTOINCREMENT counters during a VACUUM.)
 **
 ** There is at most one AutoincInfo structure per table even if the
 ** same table is autoincremented multiple times due to inserts within
@@ -98761,14 +109822,16 @@ static int autoIncBegin(
   Table *pTab         /* The table we are writing to */
 ){
   int memId = 0;      /* Register holding maximum rowid */
-  if( pTab->tabFlags & TF_Autoincrement ){
+  if( (pTab->tabFlags & TF_Autoincrement)!=0
+   && (pParse->db->flags & SQLITE_Vacuum)==0
+  ){
     Parse *pToplevel = sqlite3ParseToplevel(pParse);
     AutoincInfo *pInfo;
 
     pInfo = pToplevel->pAinc;
     while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
     if( pInfo==0 ){
-      pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
+      pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
       if( pInfo==0 ) return 0;
       pInfo->pNext = pToplevel->pAinc;
       pToplevel->pAinc = pInfo;
@@ -98792,43 +109855,55 @@ SQLITE_PRIVATE void sqlite3AutoincrementBegin(Parse *pParse){
   sqlite3 *db = pParse->db;  /* The database connection */
   Db *pDb;                   /* Database only autoinc table */
   int memId;                 /* Register holding max rowid */
-  int addr;                  /* A VDBE address */
   Vdbe *v = pParse->pVdbe;   /* VDBE under construction */
 
   /* This routine is never called during trigger-generation.  It is
   ** only called from the top-level */
   assert( pParse->pTriggerTab==0 );
-  assert( pParse==sqlite3ParseToplevel(pParse) );
+  assert( sqlite3IsToplevel(pParse) );
 
   assert( v );   /* We failed long ago if this is not so */
   for(p = pParse->pAinc; p; p = p->pNext){
+    static const int iLn = VDBE_OFFSET_LINENO(2);
+    static const VdbeOpList autoInc[] = {
+      /* 0  */ {OP_Null,    0,  0, 0},
+      /* 1  */ {OP_Rewind,  0,  9, 0},
+      /* 2  */ {OP_Column,  0,  0, 0},
+      /* 3  */ {OP_Ne,      0,  7, 0},
+      /* 4  */ {OP_Rowid,   0,  0, 0},
+      /* 5  */ {OP_Column,  0,  1, 0},
+      /* 6  */ {OP_Goto,    0,  9, 0},
+      /* 7  */ {OP_Next,    0,  2, 0},
+      /* 8  */ {OP_Integer, 0,  0, 0},
+      /* 9  */ {OP_Close,   0,  0, 0} 
+    };
+    VdbeOp *aOp;
     pDb = &db->aDb[p->iDb];
     memId = p->regCtr;
     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
-    sqlite3VdbeAddOp3(v, OP_Null, 0, memId, memId+1);
-    addr = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, p->pTab->zName, 0);
-    sqlite3VdbeAddOp2(v, OP_Rewind, 0, addr+9); VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_Column, 0, 0, memId);
-    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId); VdbeCoverage(v);
-    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
-    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
-    sqlite3VdbeAddOp3(v, OP_Column, 0, 1, memId);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+9);
-    sqlite3VdbeAddOp2(v, OP_Next, 0, addr+2); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
-    sqlite3VdbeAddOp0(v, OP_Close);
+    sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
+    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
+    if( aOp==0 ) break;
+    aOp[0].p2 = memId;
+    aOp[0].p3 = memId+1;
+    aOp[2].p3 = memId;
+    aOp[3].p1 = memId-1;
+    aOp[3].p3 = memId;
+    aOp[3].p5 = SQLITE_JUMPIFNULL;
+    aOp[4].p2 = memId+1;
+    aOp[5].p3 = memId;
+    aOp[8].p2 = memId;
   }
 }
 
 /*
 ** Update the maximum rowid for an autoincrement calculation.
 **
-** This routine should be called when the top of the stack holds a
+** This routine should be called when the regRowid register holds a
 ** new rowid that is about to be inserted.  If that new rowid is
 ** larger than the maximum rowid in the memId memory cell, then the
-** memory cell is updated.  The stack is unchanged.
+** memory cell is updated.
 */
 static void autoIncStep(Parse *pParse, int memId, int regRowid){
   if( memId>0 ){
@@ -98843,31 +109918,44 @@ static void autoIncStep(Parse *pParse, int memId, int regRowid){
 ** table (either directly or through triggers) needs to call this
 ** routine just before the "exit" code.
 */
-SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
+static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
   AutoincInfo *p;
   Vdbe *v = pParse->pVdbe;
   sqlite3 *db = pParse->db;
 
   assert( v );
   for(p = pParse->pAinc; p; p = p->pNext){
+    static const int iLn = VDBE_OFFSET_LINENO(2);
+    static const VdbeOpList autoIncEnd[] = {
+      /* 0 */ {OP_NotNull,     0, 2, 0},
+      /* 1 */ {OP_NewRowid,    0, 0, 0},
+      /* 2 */ {OP_MakeRecord,  0, 2, 0},
+      /* 3 */ {OP_Insert,      0, 0, 0},
+      /* 4 */ {OP_Close,       0, 0, 0}
+    };
+    VdbeOp *aOp;
     Db *pDb = &db->aDb[p->iDb];
-    int j1;
     int iRec;
     int memId = p->regCtr;
 
     iRec = sqlite3GetTempReg(pParse);
     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
-    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, memId+1);
-    sqlite3VdbeJumpHere(v, j1);
-    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
-    sqlite3VdbeAddOp3(v, OP_Insert, 0, iRec, memId+1);
-    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-    sqlite3VdbeAddOp0(v, OP_Close);
+    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
+    if( aOp==0 ) break;
+    aOp[0].p1 = memId+1;
+    aOp[1].p2 = memId+1;
+    aOp[2].p1 = memId-1;
+    aOp[2].p3 = iRec;
+    aOp[3].p2 = iRec;
+    aOp[3].p3 = memId+1;
+    aOp[3].p5 = OPFLAG_APPEND;
     sqlite3ReleaseTempReg(pParse, iRec);
   }
 }
+SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
+  if( pParse->pAinc ) autoIncrementEnd(pParse);
+}
 #else
 /*
 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
@@ -98890,20 +109978,23 @@ static int xferOptimization(
 /*
 ** This routine is called to handle SQL of the following forms:
 **
-**    insert into TABLE (IDLIST) values(EXPRLIST)
+**    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
 **    insert into TABLE (IDLIST) select
+**    insert into TABLE (IDLIST) default values
 **
 ** The IDLIST following the table name is always optional.  If omitted,
-** then a list of all columns for the table is substituted.  The IDLIST
-** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
+** then a list of all (non-hidden) columns for the table is substituted.
+** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST
+** is omitted.
 **
-** The pList parameter holds EXPRLIST in the first form of the INSERT
-** statement above, and pSelect is NULL.  For the second form, pList is
-** NULL and pSelect is a pointer to the select statement used to generate
-** data for the insert.
+** For the pSelect parameter holds the values to be inserted for the
+** first two forms shown above.  A VALUES clause is really just short-hand
+** for a SELECT statement that omits the FROM clause and everything else
+** that follows.  If the pSelect parameter is NULL, that means that the
+** DEFAULT VALUES form of the INSERT statement is intended.
 **
 ** The code generated follows one of four templates.  For a simple
-** insert with data coming from a VALUES clause, the code executes
+** insert with data coming from a single-row VALUES clause, the code executes
 ** once straight down through.  Pseudo-code follows (we call this
 ** the "1st template"):
 **
@@ -98991,8 +110082,7 @@ SQLITE_PRIVATE void sqlite3Insert(
   sqlite3 *db;          /* The main database structure */
   Table *pTab;          /* The table to insert into.  aka TABLE */
   char *zTab;           /* Name of the table into which we are inserting */
-  const char *zDb;      /* Name of the database holding this table */
-  int i, j, idx;        /* Loop counters */
+  int i, j;             /* Loop counters */
   Vdbe *v;              /* Generate code into this virtual machine */
   Index *pIdx;          /* For looping over indices of the table */
   int nColumn;          /* Number of columns in the data */
@@ -99006,11 +110096,10 @@ SQLITE_PRIVATE void sqlite3Insert(
   int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
   SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
   int iDb;              /* Index of database holding TABLE */
-  Db *pDb;              /* The database containing table being inserted into */
   u8 useTempTable = 0;  /* Store SELECT results in intermediate table */
   u8 appendFlag = 0;    /* True if the insert is likely to be an append */
   u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */
-  u8 bIdListInOrder = 1; /* True if IDLIST is in table order */
+  u8 bIdListInOrder;    /* True if IDLIST is in table order */
   ExprList *pList = 0;  /* List of VALUES() to be inserted  */
 
   /* Register allocations */
@@ -99029,14 +110118,14 @@ SQLITE_PRIVATE void sqlite3Insert(
 #endif
 
   db = pParse->db;
-  memset(&dest, 0, sizeof(dest));
   if( pParse->nErr || db->mallocFailed ){
     goto insert_cleanup;
   }
+  dest.iSDParm = 0;  /* Suppress a harmless compiler warning */
 
   /* If the Select object is really just a simple VALUES() list with a
-  ** single row values (the common case) then keep that one row of values
-  ** and go ahead and discard the Select object
+  ** single row (the common case) then keep that one row of values
+  ** and discard the other (unused) parts of the pSelect object
   */
   if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
     pList = pSelect->pEList;
@@ -99056,9 +110145,8 @@ SQLITE_PRIVATE void sqlite3Insert(
   }
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
   assert( iDbnDb );
-  pDb = &db->aDb[iDb];
-  zDb = pDb->zName;
-  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
+  if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,
+                       db->aDb[iDb].zDbSName) ){
     goto insert_cleanup;
   }
   withoutRowid = !HasRowid(pTab);
@@ -99144,6 +110232,7 @@ SQLITE_PRIVATE void sqlite3Insert(
   ** is appears in the original table.  (The index of the INTEGER
   ** PRIMARY KEY in the original table is pTab->iPKey.)
   */
+  bIdListInOrder = (pTab->tabFlags & TF_OOOHidden)==0;
   if( pColumn ){
     for(i=0; inId; i++){
       pColumn->a[i].idx = -1;
@@ -99179,7 +110268,8 @@ SQLITE_PRIVATE void sqlite3Insert(
   ** co-routine is the common header to the 3rd and 4th templates.
   */
   if( pSelect ){
-    /* Data is coming from a SELECT.  Generate a co-routine to run the SELECT */
+    /* Data is coming from a SELECT or from a multi-row VALUES clause.
+    ** Generate a co-routine to run the SELECT. */
     int regYield;       /* Register holding co-routine entry-point */
     int addrTop;        /* Top of the co-routine */
     int rc;             /* Result code */
@@ -99192,9 +110282,8 @@ SQLITE_PRIVATE void sqlite3Insert(
     dest.nSdst = pTab->nCol;
     rc = sqlite3Select(pParse, pSelect, &dest);
     regFromSelect = dest.iSdst;
-    assert( pParse->nErr==0 || rc );
-    if( rc || db->mallocFailed ) goto insert_cleanup;
-    sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
+    if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
+    sqlite3VdbeEndCoroutine(v, regYield);
     sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
     assert( pSelect->pEList );
     nColumn = pSelect->pEList->nExpr;
@@ -99235,25 +110324,27 @@ SQLITE_PRIVATE void sqlite3Insert(
       sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
       sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
       sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrL);
+      sqlite3VdbeGoto(v, addrL);
       sqlite3VdbeJumpHere(v, addrL);
       sqlite3ReleaseTempReg(pParse, regRec);
       sqlite3ReleaseTempReg(pParse, regTempRowid);
     }
   }else{
-    /* This is the case if the data for the INSERT is coming from a VALUES
-    ** clause
+    /* This is the case if the data for the INSERT is coming from a 
+    ** single-row VALUES clause
     */
     NameContext sNC;
     memset(&sNC, 0, sizeof(sNC));
     sNC.pParse = pParse;
     srcTab = -1;
     assert( useTempTable==0 );
-    nColumn = pList ? pList->nExpr : 0;
-    for(i=0; ia[i].pExpr) ){
+    if( pList ){
+      nColumn = pList->nExpr;
+      if( sqlite3ResolveExprListNames(&sNC, pList) ){
         goto insert_cleanup;
       }
+    }else{
+      nColumn = 0;
     }
   }
 
@@ -99268,10 +110359,8 @@ SQLITE_PRIVATE void sqlite3Insert(
   /* Make sure the number of columns in the source data matches the number
   ** of columns to be inserted into the table.
   */
-  if( IsVirtual(pTab) ){
-    for(i=0; inCol; i++){
-      nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
-    }
+  for(i=0; inCol; i++){
+    nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
   }
   if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
     sqlite3ErrorMsg(pParse, 
@@ -99294,14 +110383,16 @@ SQLITE_PRIVATE void sqlite3Insert(
   /* If this is not a view, open the table and and all indices */
   if( !isView ){
     int nIdx;
-    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, -1, 0,
+    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
                                       &iDataCur, &iIdxCur);
-    aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
+    aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+1));
     if( aRegIdx==0 ){
       goto insert_cleanup;
     }
-    for(i=0; ipIndex; ipNext, i++){
+      assert( pIdx );
       aRegIdx[i] = ++pParse->nMem;
+      pParse->nMem += pIdx->nColumn;
     }
   }
 
@@ -99346,7 +110437,7 @@ SQLITE_PRIVATE void sqlite3Insert(
     if( ipkColumn<0 ){
       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
     }else{
-      int j1;
+      int addr1;
       assert( !withoutRowid );
       if( useTempTable ){
         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
@@ -99354,9 +110445,9 @@ SQLITE_PRIVATE void sqlite3Insert(
         assert( pSelect==0 );  /* Otherwise useTempTable is true */
         sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
       }
-      j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
+      addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
-      sqlite3VdbeJumpHere(v, j1);
+      sqlite3VdbeJumpHere(v, addr1);
       sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
     }
 
@@ -99367,15 +110458,14 @@ SQLITE_PRIVATE void sqlite3Insert(
 
     /* Create the new column data
     */
-    for(i=0; inCol; i++){
-      if( pColumn==0 ){
-        j = i;
-      }else{
+    for(i=j=0; inCol; i++){
+      if( pColumn ){
         for(j=0; jnId; j++){
           if( pColumn->a[j].idx==i ) break;
         }
       }
-      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId) ){
+      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId)
+            || (pColumn==0 && IsOrdinaryHiddenColumn(&pTab->aCol[i])) ){
         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
       }else if( useTempTable ){
         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1); 
@@ -99383,6 +110473,7 @@ SQLITE_PRIVATE void sqlite3Insert(
         assert( pSelect==0 ); /* Otherwise useTempTable is true */
         sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
       }
+      if( pColumn==0 && !IsOrdinaryHiddenColumn(&pTab->aCol[i]) ) j++;
     }
 
     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
@@ -99430,14 +110521,14 @@ SQLITE_PRIVATE void sqlite3Insert(
       ** to generate a unique primary key value.
       */
       if( !appendFlag ){
-        int j1;
+        int addr1;
         if( !IsVirtual(pTab) ){
-          j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
+          addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
-          sqlite3VdbeJumpHere(v, j1);
+          sqlite3VdbeJumpHere(v, addr1);
         }else{
-          j1 = sqlite3VdbeCurrentAddr(v);
-          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, j1+2); VdbeCoverage(v);
+          addr1 = sqlite3VdbeCurrentAddr(v);
+          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
         }
         sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
       }
@@ -99466,7 +110557,6 @@ SQLITE_PRIVATE void sqlite3Insert(
       }
       if( pColumn==0 ){
         if( IsHiddenColumn(&pTab->aCol[i]) ){
-          assert( IsVirtual(pTab) );
           j = -1;
           nHidden++;
         }else{
@@ -99504,12 +110594,26 @@ SQLITE_PRIVATE void sqlite3Insert(
 #endif
     {
       int isReplace;    /* Set to true if constraints may cause a replace */
+      int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */
       sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
-          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace
+          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0
       );
       sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
+
+      /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
+      ** constraints or (b) there are no triggers and this table is not a
+      ** parent table in a foreign key constraint. It is safe to set the
+      ** flag in the second case as if any REPLACE constraint is hit, an
+      ** OP_Delete or OP_IdxDelete instruction will be executed on each 
+      ** cursor that is disturbed. And these instructions both clear the
+      ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
+      ** functionality.  */
+      bUseSeek = (isReplace==0 || (pTrigger==0 &&
+          ((db->flags & SQLITE_ForeignKeys)==0 || sqlite3FkReferences(pTab)==0)
+      ));
       sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
-                               regIns, aRegIdx, 0, appendFlag, isReplace==0);
+          regIns, aRegIdx, 0, appendFlag, bUseSeek
+      );
     }
   }
 
@@ -99534,18 +110638,10 @@ SQLITE_PRIVATE void sqlite3Insert(
     sqlite3VdbeJumpHere(v, addrInsTop);
     sqlite3VdbeAddOp1(v, OP_Close, srcTab);
   }else if( pSelect ){
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
+    sqlite3VdbeGoto(v, addrCont);
     sqlite3VdbeJumpHere(v, addrInsTop);
   }
 
-  if( !IsVirtual(pTab) && !isView ){
-    /* Close all tables opened */
-    if( iDataCurpIndex; pIdx; pIdx=pIdx->pNext, idx++){
-      sqlite3VdbeAddOp1(v, OP_Close, idx+iIdxCur);
-    }
-  }
-
 insert_end:
   /* Update the sqlite_sequence table by storing the content of the
   ** maximum rowid counter values recorded while inserting into
@@ -99587,6 +110683,59 @@ insert_cleanup:
  #undef tmask
 #endif
 
+/*
+** Meanings of bits in of pWalker->eCode for checkConstraintUnchanged()
+*/
+#define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */
+#define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */
+
+/* This is the Walker callback from checkConstraintUnchanged().  Set
+** bit 0x01 of pWalker->eCode if
+** pWalker->eCode to 0 if this expression node references any of the
+** columns that are being modifed by an UPDATE statement.
+*/
+static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN ){
+    assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
+    if( pExpr->iColumn>=0 ){
+      if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
+        pWalker->eCode |= CKCNSTRNT_COLUMN;
+      }
+    }else{
+      pWalker->eCode |= CKCNSTRNT_ROWID;
+    }
+  }
+  return WRC_Continue;
+}
+
+/*
+** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The
+** only columns that are modified by the UPDATE are those for which
+** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
+**
+** Return true if CHECK constraint pExpr does not use any of the
+** changing columns (or the rowid if it is changing).  In other words,
+** return true if this CHECK constraint can be skipped when validating
+** the new row in the UPDATE statement.
+*/
+static int checkConstraintUnchanged(Expr *pExpr, int *aiChng, int chngRowid){
+  Walker w;
+  memset(&w, 0, sizeof(w));
+  w.eCode = 0;
+  w.xExprCallback = checkConstraintExprNode;
+  w.u.aiCol = aiChng;
+  sqlite3WalkExpr(&w, pExpr);
+  if( !chngRowid ){
+    testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
+    w.eCode &= ~CKCNSTRNT_ROWID;
+  }
+  testcase( w.eCode==0 );
+  testcase( w.eCode==CKCNSTRNT_COLUMN );
+  testcase( w.eCode==CKCNSTRNT_ROWID );
+  testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
+  return !w.eCode;
+}
+
 /*
 ** Generate code to do constraint checks prior to an INSERT or an UPDATE
 ** on table pTab.
@@ -99681,7 +110830,8 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
   u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
   u8 overrideError,    /* Override onError to this if not OE_Default */
   int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
-  int *pbMayReplace    /* OUT: Set to true if constraint may cause a replace */
+  int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */
+  int *aiChng          /* column i is unchanged if aiChng[i]<0 */
 ){
   Vdbe *v;             /* VDBE under constrution */
   Index *pIdx;         /* Pointer to one of the indices */
@@ -99691,14 +110841,13 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
   int ix;              /* Index loop counter */
   int nCol;            /* Number of columns */
   int onError;         /* Conflict resolution strategy */
-  int j1;              /* Address of jump instruction */
+  int addr1;           /* Address of jump instruction */
   int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
   int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
   int ipkTop = 0;      /* Top of the rowid change constraint check */
   int ipkBottom = 0;   /* Bottom of the rowid change constraint check */
   u8 isUpdate;         /* True if this is an UPDATE operation */
   u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
-  int regRowid = -1;   /* Register holding ROWID value */
 
   isUpdate = regOldData!=0;
   db = pParse->db;
@@ -99727,10 +110876,14 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
   */
   for(i=0; iiPKey ){
+      continue;        /* ROWID is never NULL */
+    }
+    if( aiChng && aiChng[i]<0 ){
+      /* Don't bother checking for NOT NULL on columns that do not change */
       continue;
     }
     onError = pTab->aCol[i].notNull;
-    if( onError==OE_None ) continue;
+    if( onError==OE_None ) continue;  /* This column is allowed to be NULL */
     if( overrideError!=OE_Default ){
       onError = overrideError;
     }else if( onError==OE_Default ){
@@ -99749,8 +110902,9 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
       case OE_Fail: {
         char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
                                     pTab->aCol[i].zName);
-        sqlite3VdbeAddOp4(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL, onError,
-                          regNewData+1+i, zMsg, P4_DYNAMIC);
+        sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL, onError,
+                          regNewData+1+i);
+        sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
         sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
         VdbeCoverage(v);
         break;
@@ -99762,9 +110916,10 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
       }
       default: {
         assert( onError==OE_Replace );
-        j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regNewData+1+i); VdbeCoverage(v);
+        addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regNewData+1+i);
+           VdbeCoverage(v);
         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regNewData+1+i);
-        sqlite3VdbeJumpHere(v, j1);
+        sqlite3VdbeJumpHere(v, addr1);
         break;
       }
     }
@@ -99775,13 +110930,16 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
 #ifndef SQLITE_OMIT_CHECK
   if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
     ExprList *pCheck = pTab->pCheck;
-    pParse->ckBase = regNewData+1;
+    pParse->iSelfTab = -(regNewData+1);
     onError = overrideError!=OE_Default ? overrideError : OE_Abort;
     for(i=0; inExpr; i++){
-      int allOk = sqlite3VdbeMakeLabel(v);
-      sqlite3ExprIfTrue(pParse, pCheck->a[i].pExpr, allOk, SQLITE_JUMPIFNULL);
+      int allOk;
+      Expr *pExpr = pCheck->a[i].pExpr;
+      if( aiChng && checkConstraintUnchanged(pExpr, aiChng, pkChng) ) continue;
+      allOk = sqlite3VdbeMakeLabel(v);
+      sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);
       if( onError==OE_Ignore ){
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        sqlite3VdbeGoto(v, ignoreDest);
       }else{
         char *zName = pCheck->a[i].zName;
         if( zName==0 ) zName = pTab->zName;
@@ -99792,6 +110950,7 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
       }
       sqlite3VdbeResolveLabel(v, allOk);
     }
+    pParse->iSelfTab = 0;
   }
 #endif /* !defined(SQLITE_OMIT_CHECK) */
 
@@ -99810,7 +110969,7 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     }
 
     if( isUpdate ){
-      /* pkChng!=0 does not mean that the rowid has change, only that
+      /* pkChng!=0 does not mean that the rowid has changed, only that
       ** it might have changed.  Skip the conflict logic below if the rowid
       ** is unchanged. */
       sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
@@ -99879,17 +111038,29 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
         if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
           sqlite3MultiWrite(pParse);
           sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
-                                   regNewData, 1, 0, OE_Replace, 1);
-        }else if( pTab->pIndex ){
-          sqlite3MultiWrite(pParse);
-          sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
+                                   regNewData, 1, 0, OE_Replace, 1, -1);
+        }else{
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+          if( HasRowid(pTab) ){
+            /* This OP_Delete opcode fires the pre-update-hook only. It does
+            ** not modify the b-tree. It is more efficient to let the coming
+            ** OP_Insert replace the existing entry than it is to delete the
+            ** existing entry and then insert a new one. */
+            sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
+            sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
+          }
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+          if( pTab->pIndex ){
+            sqlite3MultiWrite(pParse);
+            sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
+          }
         }
         seenReplace = 1;
         break;
       }
       case OE_Ignore: {
         /*assert( seenReplace==0 );*/
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        sqlite3VdbeGoto(v, ignoreDest);
         break;
       }
     }
@@ -99924,32 +111095,39 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     /* Skip partial indices for which the WHERE clause is not true */
     if( pIdx->pPartIdxWhere ){
       sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
-      pParse->ckBase = regNewData+1;
-      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
-                         SQLITE_JUMPIFNULL);
-      pParse->ckBase = 0;
+      pParse->iSelfTab = -(regNewData+1);
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
+                            SQLITE_JUMPIFNULL);
+      pParse->iSelfTab = 0;
     }
 
     /* Create a record for this index entry as it should appear after
     ** the insert or update.  Store that record in the aRegIdx[ix] register
     */
-    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
+    regIdx = aRegIdx[ix]+1;
     for(i=0; inColumn; i++){
       int iField = pIdx->aiColumn[i];
       int x;
-      if( iField<0 || iField==pTab->iPKey ){
-        if( regRowid==regIdx+i ) continue; /* ROWID already in regIdx+i */
-        x = regNewData;
-        regRowid =  pIdx->pPartIdxWhere ? -1 : regIdx+i;
+      if( iField==XN_EXPR ){
+        pParse->iSelfTab = -(regNewData+1);
+        sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
+        pParse->iSelfTab = 0;
+        VdbeComment((v, "%s column %d", pIdx->zName, i));
       }else{
-        x = iField + regNewData + 1;
+        if( iField==XN_ROWID || iField==pTab->iPKey ){
+          x = regNewData;
+        }else{
+          x = iField + regNewData + 1;
+        }
+        sqlite3VdbeAddOp2(v, iField<0 ? OP_IntCopy : OP_SCopy, x, regIdx+i);
+        VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
       }
-      sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
-      VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
     }
     sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
     VdbeComment((v, "for %s", pIdx->zName));
-    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn);
+#ifdef SQLITE_ENABLE_NULL_TRIM
+    if( pIdx->idxType==2 ) sqlite3SetMakeRecordP5(v, pIdx->pTable);
+#endif
 
     /* In an UPDATE operation, if this index is the PRIMARY KEY index 
     ** of a WITHOUT ROWID table and there has been no change the
@@ -99963,7 +111141,6 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     /* Find out what action to take in case there is a uniqueness conflict */
     onError = pIdx->onError;
     if( onError==OE_None ){ 
-      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
       sqlite3VdbeResolveLabel(v, addrUniqueOk);
       continue;  /* pIdx is not a UNIQUE index */
     }
@@ -99972,7 +111149,26 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     }else if( onError==OE_Default ){
       onError = OE_Abort;
     }
-    
+
+    /* Collision detection may be omitted if all of the following are true:
+    **   (1) The conflict resolution algorithm is REPLACE
+    **   (2) The table is a WITHOUT ROWID table
+    **   (3) There are no secondary indexes on the table
+    **   (4) No delete triggers need to be fired if there is a conflict
+    **   (5) No FK constraint counters need to be updated if a conflict occurs.
+    */ 
+    if( (ix==0 && pIdx->pNext==0)                   /* Condition 3 */
+     && pPk==pIdx                                   /* Condition 2 */
+     && onError==OE_Replace                         /* Condition 1 */
+     && ( 0==(db->flags&SQLITE_RecTriggers) ||      /* Condition 4 */
+          0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))
+     && ( 0==(db->flags&SQLITE_ForeignKeys) ||      /* Condition 5 */
+         (0==pTab->pFKey && 0==sqlite3FkReferences(pTab)))
+    ){
+      sqlite3VdbeResolveLabel(v, addrUniqueOk);
+      continue;
+    }
+
     /* Check to see if the new index entry will be unique */
     sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
                          regIdx, pIdx->nKeyCol); VdbeCoverage(v);
@@ -99995,6 +111191,7 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
         ** store it in registers regR..regR+nPk-1 */
         if( pIdx!=pPk ){
           for(i=0; inKeyCol; i++){
+            assert( pPk->aiColumn[i]>=0 );
             x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
             sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
             VdbeComment((v, "%s.%s", pTab->zName,
@@ -100016,6 +111213,7 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
           for(i=0; inKeyCol; i++){
             char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
             x = pPk->aiColumn[i];
+            assert( x>=0 );
             if( i==(pPk->nKeyCol-1) ){
               addrJump = addrUniqueOk;
               op = OP_Eq;
@@ -100042,7 +111240,7 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
         break;
       }
       case OE_Ignore: {
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        sqlite3VdbeGoto(v, ignoreDest);
         break;
       }
       default: {
@@ -100053,17 +111251,17 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
         }
         sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
-                                 regR, nPkField, 0, OE_Replace, pIdx==pPk);
+            regR, nPkField, 0, OE_Replace,
+            (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
         seenReplace = 1;
         break;
       }
     }
     sqlite3VdbeResolveLabel(v, addrUniqueOk);
-    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
     if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
   }
   if( ipkTop ){
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, ipkTop+1);
+    sqlite3VdbeGoto(v, ipkTop+1);
     sqlite3VdbeJumpHere(v, ipkBottom);
   }
   
@@ -100071,6 +111269,28 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
   VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
 }
 
+#ifdef SQLITE_ENABLE_NULL_TRIM
+/*
+** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)
+** to be the number of columns in table pTab that must not be NULL-trimmed.
+**
+** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.
+*/
+SQLITE_PRIVATE void sqlite3SetMakeRecordP5(Vdbe *v, Table *pTab){
+  u16 i;
+
+  /* Records with omitted columns are only allowed for schema format
+  ** version 2 and later (SQLite version 3.1.4, 2005-02-20). */
+  if( pTab->pSchema->file_format<2 ) return;
+
+  for(i=pTab->nCol-1; i>0; i--){
+    if( pTab->aCol[i].pDflt!=0 ) break;
+    if( pTab->aCol[i].colFlags & COLFLAG_PRIMKEY ) break;
+  }
+  sqlite3VdbeChangeP5(v, i+1);
+}
+#endif
+
 /*
 ** This routine generates code to finish the INSERT or UPDATE operation
 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
@@ -100087,7 +111307,7 @@ SQLITE_PRIVATE void sqlite3CompleteInsertion(
   int iIdxCur,        /* First index cursor */
   int regNewData,     /* Range of content */
   int *aRegIdx,       /* Register used by each index.  0 for unused indices */
-  int isUpdate,       /* True for UPDATE, False for INSERT */
+  int update_flags,   /* True for UPDATE, False for INSERT */
   int appendBias,     /* True if this is likely to be an append */
   int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
 ){
@@ -100099,6 +111319,11 @@ SQLITE_PRIVATE void sqlite3CompleteInsertion(
   int i;              /* Loop counter */
   u8 bAffinityDone = 0; /* True if OP_Affinity has been run already */
 
+  assert( update_flags==0
+       || update_flags==OPFLAG_ISUPDATE
+       || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
+  );
+
   v = sqlite3GetVdbe(pParse);
   assert( v!=0 );
   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
@@ -100109,26 +111334,39 @@ SQLITE_PRIVATE void sqlite3CompleteInsertion(
       sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
       VdbeCoverage(v);
     }
-    sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i]);
-    pik_flags = 0;
-    if( useSeekResult ) pik_flags = OPFLAG_USESEEKRESULT;
+    pik_flags = (useSeekResult ? OPFLAG_USESEEKRESULT : 0);
     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
       assert( pParse->nested==0 );
       pik_flags |= OPFLAG_NCHANGE;
+      pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+      if( update_flags==0 ){
+        sqlite3VdbeAddOp4(v, OP_InsertInt, 
+            iIdxCur+i, aRegIdx[i], 0, (char*)pTab, P4_TABLE
+        );
+        sqlite3VdbeChangeP5(v, OPFLAG_ISNOOP);
+      }
+#endif
     }
-    if( pik_flags )  sqlite3VdbeChangeP5(v, pik_flags);
+    sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],
+                         aRegIdx[i]+1,
+                         pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);
+    sqlite3VdbeChangeP5(v, pik_flags);
   }
   if( !HasRowid(pTab) ) return;
   regData = regNewData + 1;
   regRec = sqlite3GetTempReg(pParse);
   sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
-  if( !bAffinityDone ) sqlite3TableAffinity(v, pTab, 0);
-  sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
+  sqlite3SetMakeRecordP5(v, pTab);
+  if( !bAffinityDone ){
+    sqlite3TableAffinity(v, pTab, 0);
+    sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
+  }
   if( pParse->nested ){
     pik_flags = 0;
   }else{
     pik_flags = OPFLAG_NCHANGE;
-    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
+    pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);
   }
   if( appendBias ){
     pik_flags |= OPFLAG_APPEND;
@@ -100138,7 +111376,7 @@ SQLITE_PRIVATE void sqlite3CompleteInsertion(
   }
   sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, regRec, regNewData);
   if( !pParse->nested ){
-    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
+    sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
   }
   sqlite3VdbeChangeP5(v, pik_flags);
 }
@@ -100168,6 +111406,7 @@ SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
   Parse *pParse,   /* Parsing context */
   Table *pTab,     /* Table to be opened */
   int op,          /* OP_OpenRead or OP_OpenWrite */
+  u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
   int iBase,       /* Use this for the table cursor, if there is one */
   u8 *aToOpen,     /* If not NULL: boolean for each table and index */
   int *piDataCur,  /* Write the database source cursor number here */
@@ -100180,6 +111419,7 @@ SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
   Vdbe *v;
 
   assert( op==OP_OpenRead || op==OP_OpenWrite );
+  assert( op==OP_OpenWrite || p5==0 );
   if( IsVirtual(pTab) ){
     /* This routine is a no-op for virtual tables. Leave the output
     ** variables *piDataCur and *piIdxCur uninitialized so that valgrind
@@ -100201,12 +111441,14 @@ SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
     int iIdxCur = iBase++;
     assert( pIdx->pSchema==pTab->pSchema );
-    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) && piDataCur ){
-      *piDataCur = iIdxCur;
+    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
+      if( piDataCur ) *piDataCur = iIdxCur;
+      p5 = 0;
     }
     if( aToOpen==0 || aToOpen[i+1] ){
       sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
       sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+      sqlite3VdbeChangeP5(v, p5);
       VdbeComment((v, "%s", pIdx->zName));
     }
   }
@@ -100227,20 +111469,6 @@ SQLITE_API int sqlite3_xferopt_count;
 
 
 #ifndef SQLITE_OMIT_XFER_OPT
-/*
-** Check to collation names to see if they are compatible.
-*/
-static int xferCompatibleCollation(const char *z1, const char *z2){
-  if( z1==0 ){
-    return z2==0;
-  }
-  if( z2==0 ){
-    return 0;
-  }
-  return sqlite3StrICmp(z1, z2)==0;
-}
-
-
 /*
 ** Check to see if index pSrc is compatible as a source of data
 ** for index pDest in an insert transfer optimization.  The rules
@@ -100266,14 +111494,21 @@ static int xferCompatibleIndex(Index *pDest, Index *pSrc){
     if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
       return 0;   /* Different columns indexed */
     }
+    if( pSrc->aiColumn[i]==XN_EXPR ){
+      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
+      if( sqlite3ExprCompare(0, pSrc->aColExpr->a[i].pExpr,
+                             pDest->aColExpr->a[i].pExpr, -1)!=0 ){
+        return 0;   /* Different expressions in the index */
+      }
+    }
     if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
       return 0;   /* Different sort orders */
     }
-    if( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
+    if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
       return 0;   /* Different collating sequences */
     }
   }
-  if( sqlite3ExprCompare(pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
+  if( sqlite3ExprCompare(0, pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
     return 0;     /* Different WHERE clauses */
   }
 
@@ -100313,6 +111548,7 @@ static int xferOptimization(
   int onError,          /* How to handle constraint errors */
   int iDbDest           /* The database of pDest */
 ){
+  sqlite3 *db = pParse->db;
   ExprList *pEList;                /* The result set of the SELECT */
   Table *pSrc;                     /* The table in the FROM clause of SELECT */
   Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
@@ -100341,7 +111577,7 @@ static int xferOptimization(
     return 0;   /* tab1 must not have triggers */
   }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  if( pDest->tabFlags & TF_Virtual ){
+  if( IsVirtual(pDest) ){
     return 0;   /* tab1 must not be a virtual table */
   }
 #endif
@@ -100383,7 +111619,7 @@ static int xferOptimization(
     return 0;   /* The result set must have exactly one column */
   }
   assert( pEList->a[0].pExpr );
-  if( pEList->a[0].pExpr->op!=TK_ALL ){
+  if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
     return 0;   /* The result set must be the special operator "*" */
   }
 
@@ -100403,7 +111639,7 @@ static int xferOptimization(
     return 0;   /* source and destination must both be WITHOUT ROWID or not */
   }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  if( pSrc->tabFlags & TF_Virtual ){
+  if( IsVirtual(pSrc) ){
     return 0;   /* tab2 must not be a virtual table */
   }
 #endif
@@ -100419,21 +111655,32 @@ static int xferOptimization(
   for(i=0; inCol; i++){
     Column *pDestCol = &pDest->aCol[i];
     Column *pSrcCol = &pSrc->aCol[i];
+#ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
+    if( (db->flags & SQLITE_Vacuum)==0 
+     && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN 
+    ){
+      return 0;    /* Neither table may have __hidden__ columns */
+    }
+#endif
     if( pDestCol->affinity!=pSrcCol->affinity ){
       return 0;    /* Affinity must be the same on all columns */
     }
-    if( !xferCompatibleCollation(pDestCol->zColl, pSrcCol->zColl) ){
+    if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){
       return 0;    /* Collating sequence must be the same on all columns */
     }
     if( pDestCol->notNull && !pSrcCol->notNull ){
       return 0;    /* tab2 must be NOT NULL if tab1 is */
     }
     /* Default values for second and subsequent columns need to match. */
-    if( i>0
-     && ((pDestCol->zDflt==0)!=(pSrcCol->zDflt==0) 
-         || (pDestCol->zDflt && strcmp(pDestCol->zDflt, pSrcCol->zDflt)!=0))
-    ){
-      return 0;    /* Default values must be the same for all columns */
+    if( i>0 ){
+      assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );
+      assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );
+      if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0) 
+       || (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,
+                                       pSrcCol->pDflt->u.zToken)!=0)
+      ){
+        return 0;    /* Default values must be the same for all columns */
+      }
     }
   }
   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
@@ -100460,11 +111707,11 @@ static int xferOptimization(
   ** the extra complication to make this rule less restrictive is probably
   ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
   */
-  if( (pParse->db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
+  if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
     return 0;
   }
 #endif
-  if( (pParse->db->flags & SQLITE_CountRows)!=0 ){
+  if( (db->flags & SQLITE_CountRows)!=0 ){
     return 0;  /* xfer opt does not play well with PRAGMA count_changes */
   }
 
@@ -100475,7 +111722,7 @@ static int xferOptimization(
 #ifdef SQLITE_TEST
   sqlite3_xferopt_count++;
 #endif
-  iDbSrc = sqlite3SchemaToIndex(pParse->db, pSrc->pSchema);
+  iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
   v = sqlite3GetVdbe(pParse);
   sqlite3CodeVerifySchema(pParse, iDbSrc);
   iSrc = pParse->nTab++;
@@ -100485,14 +111732,18 @@ static int xferOptimization(
   regRowid = sqlite3GetTempReg(pParse);
   sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
   assert( HasRowid(pDest) || destHasUniqueIdx );
-  if( (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
+  if( (db->flags & SQLITE_Vacuum)==0 && (
+      (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
    || destHasUniqueIdx                              /* (2) */
    || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
-  ){
+  )){
     /* In some circumstances, we are able to run the xfer optimization
-    ** only if the destination table is initially empty.  This code makes
-    ** that determination.  Conditions under which the destination must
-    ** be empty:
+    ** only if the destination table is initially empty. Unless the
+    ** SQLITE_Vacuum flag is set, this block generates code to make
+    ** that determination. If SQLITE_Vacuum is set, then the destination
+    ** table is always empty.
+    **
+    ** Conditions under which the destination must be empty:
     **
     ** (1) There is no INTEGER PRIMARY KEY but there are indices.
     **     (If the destination is not initially empty, the rowid fields
@@ -100504,10 +111755,11 @@ static int xferOptimization(
     ** (3) onError is something other than OE_Abort and OE_Rollback.
     */
     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
-    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
     sqlite3VdbeJumpHere(v, addr1);
   }
   if( HasRowid(pSrc) ){
+    u8 insFlags;
     sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
     emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
     if( pDest->iPKey>=0 ){
@@ -100523,10 +111775,17 @@ static int xferOptimization(
       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
       assert( (pDest->tabFlags & TF_Autoincrement)==0 );
     }
-    sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
-    sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
-    sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
-    sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
+    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
+    if( db->flags & SQLITE_Vacuum ){
+      sqlite3VdbeAddOp3(v, OP_Last, iDest, 0, -1);
+      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|
+                           OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
+    }else{
+      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
+    }
+    sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
+                      (char*)pDest, P4_TABLE);
+    sqlite3VdbeChangeP5(v, insFlags);
     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
@@ -100535,6 +111794,7 @@ static int xferOptimization(
     sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
   }
   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
+    u8 idxInsFlags = 0;
     for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
     }
@@ -100547,8 +111807,36 @@ static int xferOptimization(
     sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
     VdbeComment((v, "%s", pDestIdx->zName));
     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
-    sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
+    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
+    if( db->flags & SQLITE_Vacuum ){
+      /* This INSERT command is part of a VACUUM operation, which guarantees
+      ** that the destination table is empty. If all indexed columns use
+      ** collation sequence BINARY, then it can also be assumed that the
+      ** index will be populated by inserting keys in strictly sorted 
+      ** order. In this case, instead of seeking within the b-tree as part
+      ** of every OP_IdxInsert opcode, an OP_Last is added before the
+      ** OP_IdxInsert to seek to the point within the b-tree where each key 
+      ** should be inserted. This is faster.
+      **
+      ** If any of the indexed columns use a collation sequence other than
+      ** BINARY, this optimization is disabled. This is because the user 
+      ** might change the definition of a collation sequence and then run
+      ** a VACUUM command. In that case keys may not be written in strictly
+      ** sorted order.  */
+      for(i=0; inColumn; i++){
+        const char *zColl = pSrcIdx->azColl[i];
+        if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
+      }
+      if( i==pSrcIdx->nColumn ){
+        idxInsFlags = OPFLAG_USESEEKRESULT;
+        sqlite3VdbeAddOp3(v, OP_Last, iDest, 0, -1);
+      }
+    }
+    if( !HasRowid(pSrc) && pDestIdx->idxType==2 ){
+      idxInsFlags |= OPFLAG_NCHANGE;
+    }
+    sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
+    sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
     sqlite3VdbeJumpHere(v, addr1);
     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
@@ -100558,6 +111846,7 @@ static int xferOptimization(
   sqlite3ReleaseTempReg(pParse, regRowid);
   sqlite3ReleaseTempReg(pParse, regData);
   if( emptyDestTest ){
+    sqlite3AutoincrementEnd(pParse);
     sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
     sqlite3VdbeJumpHere(v, emptyDestTest);
     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
@@ -100587,6 +111876,7 @@ static int xferOptimization(
 ** accessed by users of the library.
 */
 
+/* #include "sqliteInt.h" */
 
 /*
 ** Execute SQL code.  Return one of the SQLITE_ success/failure
@@ -100644,7 +111934,7 @@ SQLITE_API int sqlite3_exec(
           (SQLITE_DONE==rc && !callbackIsInit
                            && db->flags&SQLITE_NullCallback)) ){
         if( !callbackIsInit ){
-          azCols = sqlite3DbMallocZero(db, 2*nCol*sizeof(const char*) + 1);
+          azCols = sqlite3DbMallocRaw(db, (2*nCol+1)*sizeof(const char*));
           if( azCols==0 ){
             goto exec_out;
           }
@@ -100661,10 +111951,11 @@ SQLITE_API int sqlite3_exec(
           for(i=0; imallocFailed = 1;
+              sqlite3OomFault(db);
               goto exec_out;
             }
           }
+          azVals[i] = 0;
         }
         if( xCallback(pArg, nCol, azVals, azCols) ){
           /* EVIDENCE-OF: R-38229-40159 If the callback function to
@@ -100697,12 +111988,9 @@ exec_out:
 
   rc = sqlite3ApiExit(db, rc);
   if( rc!=SQLITE_OK && pzErrMsg ){
-    int nErrMsg = 1 + sqlite3Strlen30(sqlite3_errmsg(db));
-    *pzErrMsg = sqlite3Malloc(nErrMsg);
-    if( *pzErrMsg ){
-      memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
-    }else{
-      rc = SQLITE_NOMEM;
+    *pzErrMsg = sqlite3DbStrDup(0, sqlite3_errmsg(db));
+    if( *pzErrMsg==0 ){
+      rc = SQLITE_NOMEM_BKPT;
       sqlite3Error(db, SQLITE_NOMEM);
     }
   }else if( pzErrMsg ){
@@ -100753,10 +112041,9 @@ exec_out:
 ** as extensions by SQLite should #include this file instead of 
 ** sqlite3.h.
 */
-#ifndef _SQLITE3EXT_H_
-#define _SQLITE3EXT_H_
-
-typedef struct sqlite3_api_routines sqlite3_api_routines;
+#ifndef SQLITE3EXT_H
+#define SQLITE3EXT_H
+/* #include "sqlite3.h" */
 
 /*
 ** The following structure holds pointers to all of the SQLite API
@@ -101004,8 +112291,45 @@ struct sqlite3_api_routines {
   void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
                          void(*)(void*), unsigned char);
   int (*strglob)(const char*,const char*);
+  /* Version 3.8.11 and later */
+  sqlite3_value *(*value_dup)(const sqlite3_value*);
+  void (*value_free)(sqlite3_value*);
+  int (*result_zeroblob64)(sqlite3_context*,sqlite3_uint64);
+  int (*bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);
+  /* Version 3.9.0 and later */
+  unsigned int (*value_subtype)(sqlite3_value*);
+  void (*result_subtype)(sqlite3_context*,unsigned int);
+  /* Version 3.10.0 and later */
+  int (*status64)(int,sqlite3_int64*,sqlite3_int64*,int);
+  int (*strlike)(const char*,const char*,unsigned int);
+  int (*db_cacheflush)(sqlite3*);
+  /* Version 3.12.0 and later */
+  int (*system_errno)(sqlite3*);
+  /* Version 3.14.0 and later */
+  int (*trace_v2)(sqlite3*,unsigned,int(*)(unsigned,void*,void*,void*),void*);
+  char *(*expanded_sql)(sqlite3_stmt*);
+  /* Version 3.18.0 and later */
+  void (*set_last_insert_rowid)(sqlite3*,sqlite3_int64);
+  /* Version 3.20.0 and later */
+  int (*prepare_v3)(sqlite3*,const char*,int,unsigned int,
+                    sqlite3_stmt**,const char**);
+  int (*prepare16_v3)(sqlite3*,const void*,int,unsigned int,
+                      sqlite3_stmt**,const void**);
+  int (*bind_pointer)(sqlite3_stmt*,int,void*,const char*,void(*)(void*));
+  void (*result_pointer)(sqlite3_context*,void*,const char*,void(*)(void*));
+  void *(*value_pointer)(sqlite3_value*,const char*);
 };
 
+/*
+** This is the function signature used for all extension entry points.  It
+** is also defined in the file "loadext.c".
+*/
+typedef int (*sqlite3_loadext_entry)(
+  sqlite3 *db,                       /* Handle to the database. */
+  char **pzErrMsg,                   /* Used to set error string on failure. */
+  const sqlite3_api_routines *pThunk /* Extension API function pointers. */
+);
+
 /*
 ** The following macros redefine the API routines so that they are
 ** redirected through the global sqlite3_api structure.
@@ -101017,7 +112341,7 @@ struct sqlite3_api_routines {
 ** the API.  So the redefinition macros are only valid if the
 ** SQLITE_CORE macros is undefined.
 */
-#ifndef SQLITE_CORE
+#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
 #define sqlite3_aggregate_context      sqlite3_api->aggregate_context
 #ifndef SQLITE_OMIT_DEPRECATED
 #define sqlite3_aggregate_count        sqlite3_api->aggregate_count
@@ -101144,6 +112468,7 @@ struct sqlite3_api_routines {
 #define sqlite3_value_text16le         sqlite3_api->value_text16le
 #define sqlite3_value_type             sqlite3_api->value_type
 #define sqlite3_vmprintf               sqlite3_api->vmprintf
+#define sqlite3_vsnprintf              sqlite3_api->vsnprintf
 #define sqlite3_overload_function      sqlite3_api->overload_function
 #define sqlite3_prepare_v2             sqlite3_api->prepare_v2
 #define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2
@@ -101234,9 +112559,34 @@ struct sqlite3_api_routines {
 #define sqlite3_result_blob64          sqlite3_api->result_blob64
 #define sqlite3_result_text64          sqlite3_api->result_text64
 #define sqlite3_strglob                sqlite3_api->strglob
-#endif /* SQLITE_CORE */
-
-#ifndef SQLITE_CORE
+/* Version 3.8.11 and later */
+#define sqlite3_value_dup              sqlite3_api->value_dup
+#define sqlite3_value_free             sqlite3_api->value_free
+#define sqlite3_result_zeroblob64      sqlite3_api->result_zeroblob64
+#define sqlite3_bind_zeroblob64        sqlite3_api->bind_zeroblob64
+/* Version 3.9.0 and later */
+#define sqlite3_value_subtype          sqlite3_api->value_subtype
+#define sqlite3_result_subtype         sqlite3_api->result_subtype
+/* Version 3.10.0 and later */
+#define sqlite3_status64               sqlite3_api->status64
+#define sqlite3_strlike                sqlite3_api->strlike
+#define sqlite3_db_cacheflush          sqlite3_api->db_cacheflush
+/* Version 3.12.0 and later */
+#define sqlite3_system_errno           sqlite3_api->system_errno
+/* Version 3.14.0 and later */
+#define sqlite3_trace_v2               sqlite3_api->trace_v2
+#define sqlite3_expanded_sql           sqlite3_api->expanded_sql
+/* Version 3.18.0 and later */
+#define sqlite3_set_last_insert_rowid  sqlite3_api->set_last_insert_rowid
+/* Version 3.20.0 and later */
+#define sqlite3_prepare_v3             sqlite3_api->prepare_v3
+#define sqlite3_prepare16_v3           sqlite3_api->prepare16_v3
+#define sqlite3_bind_pointer           sqlite3_api->bind_pointer
+#define sqlite3_result_pointer         sqlite3_api->result_pointer
+#define sqlite3_value_pointer          sqlite3_api->value_pointer
+#endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */
+
+#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
   /* This case when the file really is being compiled as a loadable 
   ** extension */
 # define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
@@ -101251,14 +112601,13 @@ struct sqlite3_api_routines {
 # define SQLITE_EXTENSION_INIT3     /*no-op*/
 #endif
 
-#endif /* _SQLITE3EXT_H_ */
+#endif /* SQLITE3EXT_H */
 
 /************** End of sqlite3ext.h ******************************************/
 /************** Continuing where we left off in loadext.c ********************/
-/* #include  */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
-
 /*
 ** Some API routines are omitted when various features are
 ** excluded from a build of SQLite.  Substitute a NULL pointer
@@ -101290,6 +112639,7 @@ struct sqlite3_api_routines {
 # define sqlite3_open16                 0
 # define sqlite3_prepare16              0
 # define sqlite3_prepare16_v2           0
+# define sqlite3_prepare16_v3           0
 # define sqlite3_result_error16         0
 # define sqlite3_result_text16          0
 # define sqlite3_result_text16be        0
@@ -101328,7 +112678,7 @@ struct sqlite3_api_routines {
 # define sqlite3_enable_shared_cache 0
 #endif
 
-#ifdef SQLITE_OMIT_TRACE
+#if defined(SQLITE_OMIT_TRACE) || defined(SQLITE_OMIT_DEPRECATED)
 # define sqlite3_profile       0
 # define sqlite3_trace         0
 #endif
@@ -101348,6 +112698,10 @@ struct sqlite3_api_routines {
 #define sqlite3_blob_reopen    0
 #endif
 
+#if defined(SQLITE_OMIT_TRACE)
+# define sqlite3_trace_v2      0
+#endif
+
 /*
 ** The following structure contains pointers to all SQLite API routines.
 ** A pointer to this structure is passed into extensions when they are
@@ -101639,7 +112993,32 @@ static const sqlite3_api_routines sqlite3Apis = {
   sqlite3_reset_auto_extension,
   sqlite3_result_blob64,
   sqlite3_result_text64,
-  sqlite3_strglob
+  sqlite3_strglob,
+  /* Version 3.8.11 and later */
+  (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
+  sqlite3_value_free,
+  sqlite3_result_zeroblob64,
+  sqlite3_bind_zeroblob64,
+  /* Version 3.9.0 and later */
+  sqlite3_value_subtype,
+  sqlite3_result_subtype,
+  /* Version 3.10.0 and later */
+  sqlite3_status64,
+  sqlite3_strlike,
+  sqlite3_db_cacheflush,
+  /* Version 3.12.0 and later */
+  sqlite3_system_errno,
+  /* Version 3.14.0 and later */
+  sqlite3_trace_v2,
+  sqlite3_expanded_sql,
+  /* Version 3.18.0 and later */
+  sqlite3_set_last_insert_rowid,
+  /* Version 3.20.0 and later */
+  sqlite3_prepare_v3,
+  sqlite3_prepare16_v3,
+  sqlite3_bind_pointer,
+  sqlite3_result_pointer,
+  sqlite3_value_pointer
 };
 
 /*
@@ -101662,13 +113041,14 @@ static int sqlite3LoadExtension(
 ){
   sqlite3_vfs *pVfs = db->pVfs;
   void *handle;
-  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  sqlite3_loadext_entry xInit;
   char *zErrmsg = 0;
   const char *zEntry;
   char *zAltEntry = 0;
   void **aHandle;
-  int nMsg = 300 + sqlite3Strlen30(zFile);
+  u64 nMsg = 300 + sqlite3Strlen30(zFile);
   int ii;
+  int rc;
 
   /* Shared library endings to try if zFile cannot be loaded as written */
   static const char *azEndings[] = {
@@ -101687,8 +113067,9 @@ static int sqlite3LoadExtension(
   /* Ticket #1863.  To avoid a creating security problems for older
   ** applications that relink against newer versions of SQLite, the
   ** ability to run load_extension is turned off by default.  One
-  ** must call sqlite3_enable_load_extension() to turn on extension
-  ** loading.  Otherwise you get the following error.
+  ** must call either sqlite3_enable_load_extension(db) or
+  ** sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, 0)
+  ** to turn on extension loading.
   */
   if( (db->flags & SQLITE_LoadExtension)==0 ){
     if( pzErrMsg ){
@@ -101703,14 +113084,14 @@ static int sqlite3LoadExtension(
 #if SQLITE_OS_UNIX || SQLITE_OS_WIN
   for(ii=0; ii=0 && zFile[iFile]!='/'; iFile--){}
@@ -101752,13 +113132,12 @@ static int sqlite3LoadExtension(
     }
     memcpy(zAltEntry+iEntry, "_init", 6);
     zEntry = zAltEntry;
-    xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
-                     sqlite3OsDlSym(pVfs, handle, zEntry);
+    xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);
   }
   if( xInit==0 ){
     if( pzErrMsg ){
       nMsg += sqlite3Strlen30(zEntry);
-      *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
+      *pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);
       if( zErrmsg ){
         sqlite3_snprintf(nMsg, zErrmsg,
             "no entry point [%s] in shared library [%s]", zEntry, zFile);
@@ -101770,7 +113149,9 @@ static int sqlite3LoadExtension(
     return SQLITE_ERROR;
   }
   sqlite3_free(zAltEntry);
-  if( xInit(db, &zErrmsg, &sqlite3Apis) ){
+  rc = xInit(db, &zErrmsg, &sqlite3Apis);
+  if( rc ){
+    if( rc==SQLITE_OK_LOAD_PERMANENTLY ) return SQLITE_OK;
     if( pzErrMsg ){
       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
     }
@@ -101782,7 +113163,7 @@ static int sqlite3LoadExtension(
   /* Append the new shared library handle to the db->aExtension array. */
   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
   if( aHandle==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   if( db->nExtension>0 ){
     memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
@@ -101827,26 +113208,15 @@ SQLITE_PRIVATE void sqlite3CloseExtensions(sqlite3 *db){
 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
   sqlite3_mutex_enter(db->mutex);
   if( onoff ){
-    db->flags |= SQLITE_LoadExtension;
+    db->flags |= SQLITE_LoadExtension|SQLITE_LoadExtFunc;
   }else{
-    db->flags &= ~SQLITE_LoadExtension;
+    db->flags &= ~(SQLITE_LoadExtension|SQLITE_LoadExtFunc);
   }
   sqlite3_mutex_leave(db->mutex);
   return SQLITE_OK;
 }
 
-#endif /* SQLITE_OMIT_LOAD_EXTENSION */
-
-/*
-** The auto-extension code added regardless of whether or not extension
-** loading is supported.  We need a dummy sqlite3Apis pointer for that
-** code if regular extension loading is not available.  This is that
-** dummy pointer.
-*/
-#ifdef SQLITE_OMIT_LOAD_EXTENSION
-static const sqlite3_api_routines sqlite3Apis = { 0 };
-#endif
-
+#endif /* !defined(SQLITE_OMIT_LOAD_EXTENSION) */
 
 /*
 ** The following object holds the list of automatically loaded
@@ -101857,7 +113227,7 @@ static const sqlite3_api_routines sqlite3Apis = { 0 };
 */
 typedef struct sqlite3AutoExtList sqlite3AutoExtList;
 static SQLITE_WSD struct sqlite3AutoExtList {
-  int nExt;              /* Number of entries in aExt[] */          
+  u32 nExt;              /* Number of entries in aExt[] */          
   void (**aExt)(void);   /* Pointers to the extension init functions */
 } sqlite3Autoext = { 0, 0 };
 
@@ -101881,7 +113251,9 @@ static SQLITE_WSD struct sqlite3AutoExtList {
 ** Register a statically linked extension that is automatically
 ** loaded by every new database connection.
 */
-SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
+SQLITE_API int sqlite3_auto_extension(
+  void (*xInit)(void)
+){
   int rc = SQLITE_OK;
 #ifndef SQLITE_OMIT_AUTOINIT
   rc = sqlite3_initialize();
@@ -101890,7 +113262,7 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
   }else
 #endif
   {
-    int i;
+    u32 i;
 #if SQLITE_THREADSAFE
     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
 #endif
@@ -101900,11 +113272,11 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
       if( wsdAutoext.aExt[i]==xInit ) break;
     }
     if( i==wsdAutoext.nExt ){
-      int nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
+      u64 nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
       void (**aNew)(void);
-      aNew = sqlite3_realloc(wsdAutoext.aExt, nByte);
+      aNew = sqlite3_realloc64(wsdAutoext.aExt, nByte);
       if( aNew==0 ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
       }else{
         wsdAutoext.aExt = aNew;
         wsdAutoext.aExt[wsdAutoext.nExt] = xInit;
@@ -101926,7 +113298,9 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
 ** Return 1 if xInit was found on the list and removed.  Return 0 if xInit
 ** was not on the list.
 */
-SQLITE_API int sqlite3_cancel_auto_extension(void (*xInit)(void)){
+SQLITE_API int sqlite3_cancel_auto_extension(
+  void (*xInit)(void)
+){
 #if SQLITE_THREADSAFE
   sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
 #endif
@@ -101934,7 +113308,7 @@ SQLITE_API int sqlite3_cancel_auto_extension(void (*xInit)(void)){
   int n = 0;
   wsdAutoextInit;
   sqlite3_mutex_enter(mutex);
-  for(i=wsdAutoext.nExt-1; i>=0; i--){
+  for(i=(int)wsdAutoext.nExt-1; i>=0; i--){
     if( wsdAutoext.aExt[i]==xInit ){
       wsdAutoext.nExt--;
       wsdAutoext.aExt[i] = wsdAutoext.aExt[wsdAutoext.nExt];
@@ -101972,10 +113346,10 @@ SQLITE_API void sqlite3_reset_auto_extension(void){
 ** If anything goes wrong, set an error in the database connection.
 */
 SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
-  int i;
+  u32 i;
   int go = 1;
   int rc;
-  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  sqlite3_loadext_entry xInit;
 
   wsdAutoextInit;
   if( wsdAutoext.nExt==0 ){
@@ -101986,18 +113360,22 @@ SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
     char *zErrmsg;
 #if SQLITE_THREADSAFE
     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+#ifdef SQLITE_OMIT_LOAD_EXTENSION
+    const sqlite3_api_routines *pThunk = 0;
+#else
+    const sqlite3_api_routines *pThunk = &sqlite3Apis;
 #endif
     sqlite3_mutex_enter(mutex);
     if( i>=wsdAutoext.nExt ){
       xInit = 0;
       go = 0;
     }else{
-      xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
-              wsdAutoext.aExt[i];
+      xInit = (sqlite3_loadext_entry)wsdAutoext.aExt[i];
     }
     sqlite3_mutex_leave(mutex);
     zErrmsg = 0;
-    if( xInit && (rc = xInit(db, &zErrmsg, &sqlite3Apis))!=0 ){
+    if( xInit && (rc = xInit(db, &zErrmsg, pThunk))!=0 ){
       sqlite3ErrorWithMsg(db, rc,
             "automatic extension loading failed: %s", zErrmsg);
       go = 0;
@@ -102021,6 +113399,7 @@ SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
 *************************************************************************
 ** This file contains code used to implement the PRAGMA command.
 */
+/* #include "sqliteInt.h" */
 
 #if !defined(SQLITE_ENABLE_LOCKING_STYLE)
 #  if defined(__APPLE__)
@@ -102031,469 +113410,671 @@ SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
 #endif
 
 /***************************************************************************
-** The next block of code, including the PragTyp_XXXX macro definitions and
-** the aPragmaName[] object is composed of generated code. DO NOT EDIT.
-**
-** To add new pragmas, edit the code in ../tool/mkpragmatab.tcl and rerun
-** that script.  Then copy/paste the output in place of the following:
-*/
+** The "pragma.h" include file is an automatically generated file that
+** that includes the PragType_XXXX macro definitions and the aPragmaName[]
+** object.  This ensures that the aPragmaName[] table is arranged in
+** lexicographical order to facility a binary search of the pragma name.
+** Do not edit pragma.h directly.  Edit and rerun the script in at 
+** ../tool/mkpragmatab.tcl. */
+/************** Include pragma.h in the middle of pragma.c *******************/
+/************** Begin file pragma.h ******************************************/
+/* DO NOT EDIT!
+** This file is automatically generated by the script at
+** ../tool/mkpragmatab.tcl.  To update the set of pragmas, edit
+** that script and rerun it.
+*/
+
+/* The various pragma types */
 #define PragTyp_HEADER_VALUE                   0
 #define PragTyp_AUTO_VACUUM                    1
 #define PragTyp_FLAG                           2
 #define PragTyp_BUSY_TIMEOUT                   3
 #define PragTyp_CACHE_SIZE                     4
-#define PragTyp_CASE_SENSITIVE_LIKE            5
-#define PragTyp_COLLATION_LIST                 6
-#define PragTyp_COMPILE_OPTIONS                7
-#define PragTyp_DATA_STORE_DIRECTORY           8
-#define PragTyp_DATABASE_LIST                  9
-#define PragTyp_DEFAULT_CACHE_SIZE            10
-#define PragTyp_ENCODING                      11
-#define PragTyp_FOREIGN_KEY_CHECK             12
-#define PragTyp_FOREIGN_KEY_LIST              13
-#define PragTyp_INCREMENTAL_VACUUM            14
-#define PragTyp_INDEX_INFO                    15
-#define PragTyp_INDEX_LIST                    16
-#define PragTyp_INTEGRITY_CHECK               17
-#define PragTyp_JOURNAL_MODE                  18
-#define PragTyp_JOURNAL_SIZE_LIMIT            19
-#define PragTyp_LOCK_PROXY_FILE               20
-#define PragTyp_LOCKING_MODE                  21
-#define PragTyp_PAGE_COUNT                    22
-#define PragTyp_MMAP_SIZE                     23
-#define PragTyp_PAGE_SIZE                     24
-#define PragTyp_SECURE_DELETE                 25
-#define PragTyp_SHRINK_MEMORY                 26
-#define PragTyp_SOFT_HEAP_LIMIT               27
-#define PragTyp_STATS                         28
-#define PragTyp_SYNCHRONOUS                   29
-#define PragTyp_TABLE_INFO                    30
-#define PragTyp_TEMP_STORE                    31
-#define PragTyp_TEMP_STORE_DIRECTORY          32
-#define PragTyp_THREADS                       33
-#define PragTyp_WAL_AUTOCHECKPOINT            34
-#define PragTyp_WAL_CHECKPOINT                35
-#define PragTyp_ACTIVATE_EXTENSIONS           36
-#define PragTyp_HEXKEY                        37
-#define PragTyp_KEY                           38
-#define PragTyp_REKEY                         39
-#define PragTyp_LOCK_STATUS                   40
-#define PragTyp_PARSER_TRACE                  41
-#define PragFlag_NeedSchema           0x01
-#define PragFlag_ReadOnly             0x02
-static const struct sPragmaNames {
-  const char *const zName;  /* Name of pragma */
-  u8 ePragTyp;              /* PragTyp_XXX value */
-  u8 mPragFlag;             /* Zero or more PragFlag_XXX values */
-  u32 iArg;                 /* Extra argument */
-} aPragmaNames[] = {
+#define PragTyp_CACHE_SPILL                    5
+#define PragTyp_CASE_SENSITIVE_LIKE            6
+#define PragTyp_COLLATION_LIST                 7
+#define PragTyp_COMPILE_OPTIONS                8
+#define PragTyp_DATA_STORE_DIRECTORY           9
+#define PragTyp_DATABASE_LIST                 10
+#define PragTyp_DEFAULT_CACHE_SIZE            11
+#define PragTyp_ENCODING                      12
+#define PragTyp_FOREIGN_KEY_CHECK             13
+#define PragTyp_FOREIGN_KEY_LIST              14
+#define PragTyp_FUNCTION_LIST                 15
+#define PragTyp_INCREMENTAL_VACUUM            16
+#define PragTyp_INDEX_INFO                    17
+#define PragTyp_INDEX_LIST                    18
+#define PragTyp_INTEGRITY_CHECK               19
+#define PragTyp_JOURNAL_MODE                  20
+#define PragTyp_JOURNAL_SIZE_LIMIT            21
+#define PragTyp_LOCK_PROXY_FILE               22
+#define PragTyp_LOCKING_MODE                  23
+#define PragTyp_PAGE_COUNT                    24
+#define PragTyp_MMAP_SIZE                     25
+#define PragTyp_MODULE_LIST                   26
+#define PragTyp_OPTIMIZE                      27
+#define PragTyp_PAGE_SIZE                     28
+#define PragTyp_PRAGMA_LIST                   29
+#define PragTyp_SECURE_DELETE                 30
+#define PragTyp_SHRINK_MEMORY                 31
+#define PragTyp_SOFT_HEAP_LIMIT               32
+#define PragTyp_SYNCHRONOUS                   33
+#define PragTyp_TABLE_INFO                    34
+#define PragTyp_TEMP_STORE                    35
+#define PragTyp_TEMP_STORE_DIRECTORY          36
+#define PragTyp_THREADS                       37
+#define PragTyp_WAL_AUTOCHECKPOINT            38
+#define PragTyp_WAL_CHECKPOINT                39
+#define PragTyp_ACTIVATE_EXTENSIONS           40
+#define PragTyp_HEXKEY                        41
+#define PragTyp_KEY                           42
+#define PragTyp_REKEY                         43
+#define PragTyp_LOCK_STATUS                   44
+#define PragTyp_PARSER_TRACE                  45
+#define PragTyp_STATS                         46
+
+/* Property flags associated with various pragma. */
+#define PragFlg_NeedSchema 0x01 /* Force schema load before running */
+#define PragFlg_NoColumns  0x02 /* OP_ResultRow called with zero columns */
+#define PragFlg_NoColumns1 0x04 /* zero columns if RHS argument is present */
+#define PragFlg_ReadOnly   0x08 /* Read-only HEADER_VALUE */
+#define PragFlg_Result0    0x10 /* Acts as query when no argument */
+#define PragFlg_Result1    0x20 /* Acts as query when has one argument */
+#define PragFlg_SchemaOpt  0x40 /* Schema restricts name search if present */
+#define PragFlg_SchemaReq  0x80 /* Schema required - "main" is default */
+
+/* Names of columns for pragmas that return multi-column result
+** or that return single-column results where the name of the
+** result column is different from the name of the pragma
+*/
+static const char *const pragCName[] = {
+  /*   0 */ "cache_size",  /* Used by: default_cache_size */
+  /*   1 */ "cid",         /* Used by: table_info */
+  /*   2 */ "name",       
+  /*   3 */ "type",       
+  /*   4 */ "notnull",    
+  /*   5 */ "dflt_value", 
+  /*   6 */ "pk",         
+  /*   7 */ "tbl",         /* Used by: stats */
+  /*   8 */ "idx",        
+  /*   9 */ "wdth",       
+  /*  10 */ "hght",       
+  /*  11 */ "flgs",       
+  /*  12 */ "seqno",       /* Used by: index_info */
+  /*  13 */ "cid",        
+  /*  14 */ "name",       
+  /*  15 */ "seqno",       /* Used by: index_xinfo */
+  /*  16 */ "cid",        
+  /*  17 */ "name",       
+  /*  18 */ "desc",       
+  /*  19 */ "coll",       
+  /*  20 */ "key",        
+  /*  21 */ "seq",         /* Used by: index_list */
+  /*  22 */ "name",       
+  /*  23 */ "unique",     
+  /*  24 */ "origin",     
+  /*  25 */ "partial",    
+  /*  26 */ "seq",         /* Used by: database_list */
+  /*  27 */ "name",       
+  /*  28 */ "file",       
+  /*  29 */ "name",        /* Used by: function_list */
+  /*  30 */ "builtin",    
+  /*  31 */ "name",        /* Used by: module_list pragma_list */
+  /*  32 */ "seq",         /* Used by: collation_list */
+  /*  33 */ "name",       
+  /*  34 */ "id",          /* Used by: foreign_key_list */
+  /*  35 */ "seq",        
+  /*  36 */ "table",      
+  /*  37 */ "from",       
+  /*  38 */ "to",         
+  /*  39 */ "on_update",  
+  /*  40 */ "on_delete",  
+  /*  41 */ "match",      
+  /*  42 */ "table",       /* Used by: foreign_key_check */
+  /*  43 */ "rowid",      
+  /*  44 */ "parent",     
+  /*  45 */ "fkid",       
+  /*  46 */ "busy",        /* Used by: wal_checkpoint */
+  /*  47 */ "log",        
+  /*  48 */ "checkpointed",
+  /*  49 */ "timeout",     /* Used by: busy_timeout */
+  /*  50 */ "database",    /* Used by: lock_status */
+  /*  51 */ "status",     
+};
+
+/* Definitions of all built-in pragmas */
+typedef struct PragmaName {
+  const char *const zName; /* Name of pragma */
+  u8 ePragTyp;             /* PragTyp_XXX value */
+  u8 mPragFlg;             /* Zero or more PragFlg_XXX values */
+  u8 iPragCName;           /* Start of column names in pragCName[] */
+  u8 nPragCName;           /* Num of col names. 0 means use pragma name */
+  u32 iArg;                /* Extra argument */
+} PragmaName;
+static const PragmaName aPragmaName[] = {
 #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
-  { /* zName:     */ "activate_extensions",
-    /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "activate_extensions",
+  /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
-  { /* zName:     */ "application_id",
-    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ BTREE_APPLICATION_ID },
+ {/* zName:     */ "application_id",
+  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+  /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ BTREE_APPLICATION_ID },
 #endif
 #if !defined(SQLITE_OMIT_AUTOVACUUM)
-  { /* zName:     */ "auto_vacuum",
-    /* ePragTyp:  */ PragTyp_AUTO_VACUUM,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "auto_vacuum",
+  /* ePragTyp:  */ PragTyp_AUTO_VACUUM,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)
-  { /* zName:     */ "automatic_index",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_AutoIndex },
-#endif
-#endif
-  { /* zName:     */ "busy_timeout",
-    /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "automatic_index",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_AutoIndex },
+#endif
+#endif
+ {/* zName:     */ "busy_timeout",
+  /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 49, 1,
+  /* iArg:      */ 0 },
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "cache_size",
-    /* ePragTyp:  */ PragTyp_CACHE_SIZE,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "cache_size",
+  /* ePragTyp:  */ PragTyp_CACHE_SIZE,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "cache_spill",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_CacheSpill },
-#endif
-  { /* zName:     */ "case_sensitive_like",
-    /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "cache_spill",
+  /* ePragTyp:  */ PragTyp_CACHE_SPILL,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#endif
+ {/* zName:     */ "case_sensitive_like",
+  /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
+  /* ePragFlg:  */ PragFlg_NoColumns,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "cell_size_check",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_CellSizeCk },
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "checkpoint_fullfsync",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_CkptFullFSync },
+ {/* zName:     */ "checkpoint_fullfsync",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_CkptFullFSync },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
-  { /* zName:     */ "collation_list",
-    /* ePragTyp:  */ PragTyp_COLLATION_LIST,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "collation_list",
+  /* ePragTyp:  */ PragTyp_COLLATION_LIST,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 32, 2,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)
-  { /* zName:     */ "compile_options",
-    /* ePragTyp:  */ PragTyp_COMPILE_OPTIONS,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "compile_options",
+  /* ePragTyp:  */ PragTyp_COMPILE_OPTIONS,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "count_changes",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_CountRows },
+ {/* zName:     */ "count_changes",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_CountRows },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN
-  { /* zName:     */ "data_store_directory",
-    /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "data_store_directory",
+  /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,
+  /* ePragFlg:  */ PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
-  { /* zName:     */ "data_version",
-    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-    /* ePragFlag: */ PragFlag_ReadOnly,
-    /* iArg:      */ BTREE_DATA_VERSION },
+ {/* zName:     */ "data_version",
+  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+  /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ BTREE_DATA_VERSION },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
-  { /* zName:     */ "database_list",
-    /* ePragTyp:  */ PragTyp_DATABASE_LIST,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "database_list",
+  /* ePragTyp:  */ PragTyp_DATABASE_LIST,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0,
+  /* ColNames:  */ 26, 3,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
-  { /* zName:     */ "default_cache_size",
-    /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "default_cache_size",
+  /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 1,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-  { /* zName:     */ "defer_foreign_keys",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_DeferFKs },
+ {/* zName:     */ "defer_foreign_keys",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_DeferFKs },
 #endif
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "empty_result_callbacks",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_NullCallback },
+ {/* zName:     */ "empty_result_callbacks",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_NullCallback },
 #endif
 #if !defined(SQLITE_OMIT_UTF16)
-  { /* zName:     */ "encoding",
-    /* ePragTyp:  */ PragTyp_ENCODING,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "encoding",
+  /* ePragTyp:  */ PragTyp_ENCODING,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-  { /* zName:     */ "foreign_key_check",
-    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_CHECK,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "foreign_key_check",
+  /* ePragTyp:  */ PragTyp_FOREIGN_KEY_CHECK,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0,
+  /* ColNames:  */ 42, 4,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FOREIGN_KEY)
-  { /* zName:     */ "foreign_key_list",
-    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "foreign_key_list",
+  /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ColNames:  */ 34, 8,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-  { /* zName:     */ "foreign_keys",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_ForeignKeys },
+ {/* zName:     */ "foreign_keys",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_ForeignKeys },
 #endif
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
-  { /* zName:     */ "freelist_count",
-    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-    /* ePragFlag: */ PragFlag_ReadOnly,
-    /* iArg:      */ BTREE_FREE_PAGE_COUNT },
+ {/* zName:     */ "freelist_count",
+  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+  /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ BTREE_FREE_PAGE_COUNT },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "full_column_names",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_FullColNames },
-  { /* zName:     */ "fullfsync",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_FullFSync },
+ {/* zName:     */ "full_column_names",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_FullColNames },
+ {/* zName:     */ "fullfsync",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_FullFSync },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+#if defined(SQLITE_INTROSPECTION_PRAGMAS)
+ {/* zName:     */ "function_list",
+  /* ePragTyp:  */ PragTyp_FUNCTION_LIST,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 29, 2,
+  /* iArg:      */ 0 },
+#endif
 #endif
 #if defined(SQLITE_HAS_CODEC)
-  { /* zName:     */ "hexkey",
-    /* ePragTyp:  */ PragTyp_HEXKEY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "hexrekey",
-    /* ePragTyp:  */ PragTyp_HEXKEY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "hexkey",
+  /* ePragTyp:  */ PragTyp_HEXKEY,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "hexrekey",
+  /* ePragTyp:  */ PragTyp_HEXKEY,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_CHECK)
-  { /* zName:     */ "ignore_check_constraints",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_IgnoreChecks },
+ {/* zName:     */ "ignore_check_constraints",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_IgnoreChecks },
 #endif
 #endif
 #if !defined(SQLITE_OMIT_AUTOVACUUM)
-  { /* zName:     */ "incremental_vacuum",
-    /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "incremental_vacuum",
+  /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_NoColumns,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
-  { /* zName:     */ "index_info",
-    /* ePragTyp:  */ PragTyp_INDEX_INFO,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "index_list",
-    /* ePragTyp:  */ PragTyp_INDEX_LIST,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "index_info",
+  /* ePragTyp:  */ PragTyp_INDEX_INFO,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ColNames:  */ 12, 3,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "index_list",
+  /* ePragTyp:  */ PragTyp_INDEX_LIST,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ColNames:  */ 21, 5,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "index_xinfo",
+  /* ePragTyp:  */ PragTyp_INDEX_INFO,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ColNames:  */ 15, 6,
+  /* iArg:      */ 1 },
 #endif
 #if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
-  { /* zName:     */ "integrity_check",
-    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "integrity_check",
+  /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "journal_mode",
-    /* ePragTyp:  */ PragTyp_JOURNAL_MODE,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "journal_size_limit",
-    /* ePragTyp:  */ PragTyp_JOURNAL_SIZE_LIMIT,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "journal_mode",
+  /* ePragTyp:  */ PragTyp_JOURNAL_MODE,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "journal_size_limit",
+  /* ePragTyp:  */ PragTyp_JOURNAL_SIZE_LIMIT,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if defined(SQLITE_HAS_CODEC)
-  { /* zName:     */ "key",
-    /* ePragTyp:  */ PragTyp_KEY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "key",
+  /* ePragTyp:  */ PragTyp_KEY,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "legacy_file_format",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_LegacyFileFmt },
+ {/* zName:     */ "legacy_file_format",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_LegacyFileFmt },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
-  { /* zName:     */ "lock_proxy_file",
-    /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "lock_proxy_file",
+  /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,
+  /* ePragFlg:  */ PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
-  { /* zName:     */ "lock_status",
-    /* ePragTyp:  */ PragTyp_LOCK_STATUS,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "lock_status",
+  /* ePragTyp:  */ PragTyp_LOCK_STATUS,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 50, 2,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "locking_mode",
-    /* ePragTyp:  */ PragTyp_LOCKING_MODE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "max_page_count",
-    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "mmap_size",
-    /* ePragTyp:  */ PragTyp_MMAP_SIZE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "page_count",
-    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "page_size",
-    /* ePragTyp:  */ PragTyp_PAGE_SIZE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "locking_mode",
+  /* ePragTyp:  */ PragTyp_LOCKING_MODE,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "max_page_count",
+  /* ePragTyp:  */ PragTyp_PAGE_COUNT,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "mmap_size",
+  /* ePragTyp:  */ PragTyp_MMAP_SIZE,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+#if !defined(SQLITE_OMIT_VIRTUALTABLE)
+#if defined(SQLITE_INTROSPECTION_PRAGMAS)
+ {/* zName:     */ "module_list",
+  /* ePragTyp:  */ PragTyp_MODULE_LIST,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 31, 1,
+  /* iArg:      */ 0 },
 #endif
-#if defined(SQLITE_DEBUG)
-  { /* zName:     */ "parser_trace",
-    /* ePragTyp:  */ PragTyp_PARSER_TRACE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+#endif
+#endif
+ {/* zName:     */ "optimize",
+  /* ePragTyp:  */ PragTyp_OPTIMIZE,
+  /* ePragFlg:  */ PragFlg_Result1|PragFlg_NeedSchema,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+ {/* zName:     */ "page_count",
+  /* ePragTyp:  */ PragTyp_PAGE_COUNT,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "page_size",
+  /* ePragTyp:  */ PragTyp_PAGE_SIZE,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#endif
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_PARSER_TRACE)
+ {/* zName:     */ "parser_trace",
+  /* ePragTyp:  */ PragTyp_PARSER_TRACE,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#endif
+#if defined(SQLITE_INTROSPECTION_PRAGMAS)
+ {/* zName:     */ "pragma_list",
+  /* ePragTyp:  */ PragTyp_PRAGMA_LIST,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 31, 1,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "query_only",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_QueryOnly },
+ {/* zName:     */ "query_only",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_QueryOnly },
 #endif
 #if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
-  { /* zName:     */ "quick_check",
-    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "quick_check",
+  /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "read_uncommitted",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_ReadUncommitted },
-  { /* zName:     */ "recursive_triggers",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_RecTriggers },
+ {/* zName:     */ "read_uncommitted",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_ReadUncommit },
+ {/* zName:     */ "recursive_triggers",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_RecTriggers },
 #endif
 #if defined(SQLITE_HAS_CODEC)
-  { /* zName:     */ "rekey",
-    /* ePragTyp:  */ PragTyp_REKEY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "rekey",
+  /* ePragTyp:  */ PragTyp_REKEY,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "reverse_unordered_selects",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_ReverseOrder },
+ {/* zName:     */ "reverse_unordered_selects",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_ReverseOrder },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
-  { /* zName:     */ "schema_version",
-    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ BTREE_SCHEMA_VERSION },
+ {/* zName:     */ "schema_version",
+  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+  /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ BTREE_SCHEMA_VERSION },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "secure_delete",
-    /* ePragTyp:  */ PragTyp_SECURE_DELETE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "secure_delete",
+  /* ePragTyp:  */ PragTyp_SECURE_DELETE,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "short_column_names",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_ShortColNames },
-#endif
-  { /* zName:     */ "shrink_memory",
-    /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "soft_heap_limit",
-    /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "short_column_names",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_ShortColNames },
+#endif
+ {/* zName:     */ "shrink_memory",
+  /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,
+  /* ePragFlg:  */ PragFlg_NoColumns,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "soft_heap_limit",
+  /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if defined(SQLITE_DEBUG)
-  { /* zName:     */ "sql_trace",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_SqlTrace },
+ {/* zName:     */ "sql_trace",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_SqlTrace },
 #endif
 #endif
-#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
-  { /* zName:     */ "stats",
-    /* ePragTyp:  */ PragTyp_STATS,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && defined(SQLITE_DEBUG)
+ {/* zName:     */ "stats",
+  /* ePragTyp:  */ PragTyp_STATS,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ColNames:  */ 7, 5,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "synchronous",
-    /* ePragTyp:  */ PragTyp_SYNCHRONOUS,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "synchronous",
+  /* ePragTyp:  */ PragTyp_SYNCHRONOUS,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
-  { /* zName:     */ "table_info",
-    /* ePragTyp:  */ PragTyp_TABLE_INFO,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "table_info",
+  /* ePragTyp:  */ PragTyp_TABLE_INFO,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ColNames:  */ 1, 6,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
-  { /* zName:     */ "temp_store",
-    /* ePragTyp:  */ PragTyp_TEMP_STORE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "temp_store_directory",
-    /* ePragTyp:  */ PragTyp_TEMP_STORE_DIRECTORY,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-#endif
-  { /* zName:     */ "threads",
-    /* ePragTyp:  */ PragTyp_THREADS,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "temp_store",
+  /* ePragTyp:  */ PragTyp_TEMP_STORE,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "temp_store_directory",
+  /* ePragTyp:  */ PragTyp_TEMP_STORE_DIRECTORY,
+  /* ePragFlg:  */ PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+#endif
+ {/* zName:     */ "threads",
+  /* ePragTyp:  */ PragTyp_THREADS,
+  /* ePragFlg:  */ PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
-  { /* zName:     */ "user_version",
-    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ BTREE_USER_VERSION },
+ {/* zName:     */ "user_version",
+  /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+  /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ BTREE_USER_VERSION },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if defined(SQLITE_DEBUG)
-  { /* zName:     */ "vdbe_addoptrace",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_VdbeAddopTrace },
-  { /* zName:     */ "vdbe_debug",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },
-  { /* zName:     */ "vdbe_eqp",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_VdbeEQP },
-  { /* zName:     */ "vdbe_listing",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_VdbeListing },
-  { /* zName:     */ "vdbe_trace",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_VdbeTrace },
+ {/* zName:     */ "vdbe_addoptrace",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_VdbeAddopTrace },
+ {/* zName:     */ "vdbe_debug",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },
+ {/* zName:     */ "vdbe_eqp",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_VdbeEQP },
+ {/* zName:     */ "vdbe_listing",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_VdbeListing },
+ {/* zName:     */ "vdbe_trace",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_VdbeTrace },
 #endif
 #endif
 #if !defined(SQLITE_OMIT_WAL)
-  { /* zName:     */ "wal_autocheckpoint",
-    /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ 0 },
-  { /* zName:     */ "wal_checkpoint",
-    /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,
-    /* ePragFlag: */ PragFlag_NeedSchema,
-    /* iArg:      */ 0 },
+ {/* zName:     */ "wal_autocheckpoint",
+  /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,
+  /* ePragFlg:  */ 0,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ 0 },
+ {/* zName:     */ "wal_checkpoint",
+  /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,
+  /* ePragFlg:  */ PragFlg_NeedSchema,
+  /* ColNames:  */ 46, 3,
+  /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
-  { /* zName:     */ "writable_schema",
-    /* ePragTyp:  */ PragTyp_FLAG,
-    /* ePragFlag: */ 0,
-    /* iArg:      */ SQLITE_WriteSchema|SQLITE_RecoveryMode },
+ {/* zName:     */ "writable_schema",
+  /* ePragTyp:  */ PragTyp_FLAG,
+  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
+  /* ColNames:  */ 0, 0,
+  /* iArg:      */ SQLITE_WriteSchema },
 #endif
 };
-/* Number of pragmas: 58 on by default, 71 total. */
-/* End of the automatically generated pragma table.
-***************************************************************************/
+/* Number of pragmas: 60 on by default, 77 total. */
+
+/************** End of pragma.h **********************************************/
+/************** Continuing where we left off in pragma.c *********************/
 
 /*
 ** Interpret the given string as a safety level.  Return 0 for OFF,
-** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
-** unrecognized string argument.  The FULL option is disallowed
+** 1 for ON or NORMAL, 2 for FULL, and 3 for EXTRA.  Return 1 for an empty or 
+** unrecognized string argument.  The FULL and EXTRA option is disallowed
 ** if the omitFull parameter it 1.
 **
 ** Note that the values returned are one less that the values that
@@ -102502,18 +114083,21 @@ static const struct sPragmaNames {
 ** and older scripts may have used numbers 0 for OFF and 1 for ON.
 */
 static u8 getSafetyLevel(const char *z, int omitFull, u8 dflt){
-                             /* 123456789 123456789 */
-  static const char zText[] = "onoffalseyestruefull";
-  static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 16};
-  static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 4};
-  static const u8 iValue[] =  {1, 0, 0, 0, 1, 1, 2};
+                             /* 123456789 123456789 123 */
+  static const char zText[] = "onoffalseyestruextrafull";
+  static const u8 iOffset[] = {0, 1, 2,  4,    9,  12,  15,   20};
+  static const u8 iLength[] = {2, 2, 3,  5,    3,   4,   5,    4};
+  static const u8 iValue[] =  {1, 0, 0,  0,    1,   1,   3,    2};
+                            /* on no off false yes true extra full */
   int i, n;
   if( sqlite3Isdigit(*z) ){
     return (u8)sqlite3Atoi(z);
   }
   n = sqlite3Strlen30(z);
-  for(i=0; inPragCName;
+  sqlite3VdbeSetNumCols(v, n==0 ? 1 : n);
+  if( n==0 ){
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, pPragma->zName, SQLITE_STATIC);
+  }else{
+    int i, j;
+    for(i=0, j=pPragma->iPragCName; inMem;
-  i64 *pI64 = sqlite3DbMallocRaw(pParse->db, sizeof(value));
-  if( pI64 ){
-    memcpy(pI64, &value, sizeof(value));
+static void returnSingleInt(Vdbe *v, i64 value){
+  sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, 1, 0, (const u8*)&value, P4_INT64);
+  sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+}
+
+/*
+** Generate code to return a single text value.
+*/
+static void returnSingleText(
+  Vdbe *v,                /* Prepared statement under construction */
+  const char *zValue      /* Value to be returned */
+){
+  if( zValue ){
+    sqlite3VdbeLoadString(v, 1, (const char*)zValue);
+    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
   }
-  sqlite3VdbeAddOp4(v, OP_Int64, 0, mem, 0, (char*)pI64, P4_INT64);
-  sqlite3VdbeSetNumCols(v, 1);
-  sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, SQLITE_STATIC);
-  sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
 }
 
 
@@ -102708,12 +114316,48 @@ SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){
   return azModeName[eMode];
 }
 
+/*
+** Locate a pragma in the aPragmaName[] array.
+*/
+static const PragmaName *pragmaLocate(const char *zName){
+  int upr, lwr, mid = 0, rc;
+  lwr = 0;
+  upr = ArraySize(aPragmaName)-1;
+  while( lwr<=upr ){
+    mid = (lwr+upr)/2;
+    rc = sqlite3_stricmp(zName, aPragmaName[mid].zName);
+    if( rc==0 ) break;
+    if( rc<0 ){
+      upr = mid - 1;
+    }else{
+      lwr = mid + 1;
+    }
+  }
+  return lwr>upr ? 0 : &aPragmaName[mid];
+}
+
+/*
+** Helper subroutine for PRAGMA integrity_check:
+**
+** Generate code to output a single-column result row with the result
+** held in register regResult.  Decrement the result count and halt if
+** the maximum number of result rows have been issued.
+*/
+static int integrityCheckResultRow(Vdbe *v, int regResult){
+  int addr;
+  sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 1);
+  addr = sqlite3VdbeAddOp3(v, OP_IfPos, 1, sqlite3VdbeCurrentAddr(v)+2, 1);
+  VdbeCoverage(v);
+  sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
+  return addr;
+}
+
 /*
 ** Process a pragma statement.  
 **
 ** Pragmas are of this form:
 **
-**      PRAGMA [database.]id [= value]
+**      PRAGMA [schema.]id [= value]
 **
 ** The identifier might also be a string.  The value is a string, and
 ** identifier, or a number.  If minusFlag is true, then the value is
@@ -102725,8 +114369,8 @@ SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){
 */
 SQLITE_PRIVATE void sqlite3Pragma(
   Parse *pParse, 
-  Token *pId1,        /* First part of [database.]id field */
-  Token *pId2,        /* Second part of [database.]id field, or NULL */
+  Token *pId1,        /* First part of [schema.]id field */
+  Token *pId2,        /* Second part of [schema.]id field, or NULL */
   Token *pValue,      /* Token for , or NULL */
   int minusFlag       /* True if a '-' sign preceded  */
 ){
@@ -102736,17 +114380,17 @@ SQLITE_PRIVATE void sqlite3Pragma(
   Token *pId;            /* Pointer to  token */
   char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
   int iDb;               /* Database index for  */
-  int lwr, upr, mid = 0;       /* Binary search bounds */
   int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
   sqlite3 *db = pParse->db;    /* The database connection */
   Db *pDb;                     /* The specific database being pragmaed */
   Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
+  const PragmaName *pPragma;   /* The pragma */
 
   if( v==0 ) return;
   sqlite3VdbeRunOnlyOnce(v);
   pParse->nMem = 2;
 
-  /* Interpret the [database.] part of the pragma statement. iDb is the
+  /* Interpret the [schema.] part of the pragma statement. iDb is the
   ** index of the database this pragma is being applied to in db.aDb[]. */
   iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
   if( iDb<0 ) return;
@@ -102768,7 +114412,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   }
 
   assert( pId2 );
-  zDb = pId2->n>0 ? pDb->zName : 0;
+  zDb = pId2->n>0 ? pDb->zDbSName : 0;
   if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
     goto pragma_out;
   }
@@ -102776,6 +114420,17 @@ SQLITE_PRIVATE void sqlite3Pragma(
   /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
   ** connection.  If it returns SQLITE_OK, then assume that the VFS
   ** handled the pragma and generate a no-op prepared statement.
+  **
+  ** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,
+  ** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
+  ** object corresponding to the database file to which the pragma
+  ** statement refers.
+  **
+  ** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
+  ** file control is an array of pointers to strings (char**) in which the
+  ** second element of the array is the name of the pragma and the third
+  ** element is the argument to the pragma or NULL if the pragma has no
+  ** argument.
   */
   aFcntl[0] = 0;
   aFcntl[1] = zLeft;
@@ -102784,14 +114439,10 @@ SQLITE_PRIVATE void sqlite3Pragma(
   db->busyHandler.nBusy = 0;
   rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);
   if( rc==SQLITE_OK ){
-    if( aFcntl[0] ){
-      int mem = ++pParse->nMem;
-      sqlite3VdbeAddOp4(v, OP_String8, 0, mem, 0, aFcntl[0], 0);
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "result", SQLITE_STATIC);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
-      sqlite3_free(aFcntl[0]);
-    }
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, aFcntl[0], SQLITE_TRANSIENT);
+    returnSingleText(v, aFcntl[0]);
+    sqlite3_free(aFcntl[0]);
     goto pragma_out;
   }
   if( rc!=SQLITE_NOTFOUND ){
@@ -102805,32 +114456,28 @@ SQLITE_PRIVATE void sqlite3Pragma(
   }
 
   /* Locate the pragma in the lookup table */
-  lwr = 0;
-  upr = ArraySize(aPragmaNames)-1;
-  while( lwr<=upr ){
-    mid = (lwr+upr)/2;
-    rc = sqlite3_stricmp(zLeft, aPragmaNames[mid].zName);
-    if( rc==0 ) break;
-    if( rc<0 ){
-      upr = mid - 1;
-    }else{
-      lwr = mid + 1;
-    }
-  }
-  if( lwr>upr ) goto pragma_out;
+  pPragma = pragmaLocate(zLeft);
+  if( pPragma==0 ) goto pragma_out;
 
   /* Make sure the database schema is loaded if the pragma requires that */
-  if( (aPragmaNames[mid].mPragFlag & PragFlag_NeedSchema)!=0 ){
+  if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
   }
 
+  /* Register the result column names for pragmas that return results */
+  if( (pPragma->mPragFlg & PragFlg_NoColumns)==0 
+   && ((pPragma->mPragFlg & PragFlg_NoColumns1)==0 || zRight==0)
+  ){
+    setPragmaResultColumnNames(v, pPragma);
+  }
+
   /* Jump to the appropriate pragma handler */
-  switch( aPragmaNames[mid].ePragTyp ){
+  switch( pPragma->ePragTyp ){
   
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
   /*
-  **  PRAGMA [database.]default_cache_size
-  **  PRAGMA [database.]default_cache_size=N
+  **  PRAGMA [schema.]default_cache_size
+  **  PRAGMA [schema.]default_cache_size=N
   **
   ** The first form reports the current persistent setting for the
   ** page cache size.  The value returned is the maximum number of
@@ -102857,21 +114504,20 @@ SQLITE_PRIVATE void sqlite3Pragma(
       { OP_Noop,        0, 0,        0},
       { OP_ResultRow,   1, 1,        0},
     };
-    int addr;
+    VdbeOp *aOp;
     sqlite3VdbeUsesBtree(v, iDb);
     if( !zRight ){
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", SQLITE_STATIC);
       pParse->nMem += 2;
-      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize,iLn);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, iDb);
-      sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE);
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(getCacheSize));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;
     }else{
       int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
       sqlite3BeginWriteOperation(pParse, 0, iDb);
-      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
-      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
+      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);
       assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
       pDb->pSchema->cache_size = size;
       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
@@ -102882,8 +114528,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
   /*
-  **  PRAGMA [database.]page_size
-  **  PRAGMA [database.]page_size=N
+  **  PRAGMA [schema.]page_size
+  **  PRAGMA [schema.]page_size=N
   **
   ** The first form reports the current setting for the
   ** database page size in bytes.  The second form sets the
@@ -102895,33 +114541,37 @@ SQLITE_PRIVATE void sqlite3Pragma(
     assert( pBt!=0 );
     if( !zRight ){
       int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
-      returnSingleInt(pParse, "page_size", size);
+      returnSingleInt(v, size);
     }else{
       /* Malloc may fail when setting the page-size, as there is an internal
       ** buffer that the pager module resizes using sqlite3_realloc().
       */
       db->nextPagesize = sqlite3Atoi(zRight);
       if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
     }
     break;
   }
 
   /*
-  **  PRAGMA [database.]secure_delete
-  **  PRAGMA [database.]secure_delete=ON/OFF
+  **  PRAGMA [schema.]secure_delete
+  **  PRAGMA [schema.]secure_delete=ON/OFF/FAST
   **
   ** The first form reports the current setting for the
   ** secure_delete flag.  The second form changes the secure_delete
-  ** flag setting and reports thenew value.
+  ** flag setting and reports the new value.
   */
   case PragTyp_SECURE_DELETE: {
     Btree *pBt = pDb->pBt;
     int b = -1;
     assert( pBt!=0 );
     if( zRight ){
-      b = sqlite3GetBoolean(zRight, 0);
+      if( sqlite3_stricmp(zRight, "fast")==0 ){
+        b = 2;
+      }else{
+        b = sqlite3GetBoolean(zRight, 0);
+      }
     }
     if( pId2->n==0 && b>=0 ){
       int ii;
@@ -102930,13 +114580,13 @@ SQLITE_PRIVATE void sqlite3Pragma(
       }
     }
     b = sqlite3BtreeSecureDelete(pBt, b);
-    returnSingleInt(pParse, "secure_delete", b);
+    returnSingleInt(v, b);
     break;
   }
 
   /*
-  **  PRAGMA [database.]max_page_count
-  **  PRAGMA [database.]max_page_count=N
+  **  PRAGMA [schema.]max_page_count
+  **  PRAGMA [schema.]max_page_count=N
   **
   ** The first form reports the current setting for the
   ** maximum number of pages in the database file.  The 
@@ -102947,7 +114597,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** change.  The only purpose is to provide an easy way to test
   ** the sqlite3AbsInt32() function.
   **
-  **  PRAGMA [database.]page_count
+  **  PRAGMA [schema.]page_count
   **
   ** Return the number of pages in the specified database.
   */
@@ -102962,14 +114612,12 @@ SQLITE_PRIVATE void sqlite3Pragma(
                         sqlite3AbsInt32(sqlite3Atoi(zRight)));
     }
     sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
     break;
   }
 
   /*
-  **  PRAGMA [database.]locking_mode
-  **  PRAGMA [database.]locking_mode = (normal|exclusive)
+  **  PRAGMA [schema.]locking_mode
+  **  PRAGMA [schema.]locking_mode = (normal|exclusive)
   */
   case PragTyp_LOCKING_MODE: {
     const char *zRet = "normal";
@@ -103009,25 +114657,19 @@ SQLITE_PRIVATE void sqlite3Pragma(
     if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
       zRet = "exclusive";
     }
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", SQLITE_STATIC);
-    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
-    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+    returnSingleText(v, zRet);
     break;
   }
 
   /*
-  **  PRAGMA [database.]journal_mode
-  **  PRAGMA [database.]journal_mode =
+  **  PRAGMA [schema.]journal_mode
+  **  PRAGMA [schema.]journal_mode =
   **                      (delete|persist|off|truncate|memory|wal|off)
   */
   case PragTyp_JOURNAL_MODE: {
     int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */
     int ii;           /* Loop counter */
 
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);
-
     if( zRight==0 ){
       /* If there is no "=MODE" part of the pragma, do a query for the
       ** current mode */
@@ -103060,8 +114702,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
   }
 
   /*
-  **  PRAGMA [database.]journal_size_limit
-  **  PRAGMA [database.]journal_size_limit=N
+  **  PRAGMA [schema.]journal_size_limit
+  **  PRAGMA [schema.]journal_size_limit=N
   **
   ** Get or set the size limit on rollback journal files.
   */
@@ -103073,15 +114715,15 @@ SQLITE_PRIVATE void sqlite3Pragma(
       if( iLimit<-1 ) iLimit = -1;
     }
     iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
-    returnSingleInt(pParse, "journal_size_limit", iLimit);
+    returnSingleInt(v, iLimit);
     break;
   }
 
 #endif /* SQLITE_OMIT_PAGER_PRAGMAS */
 
   /*
-  **  PRAGMA [database.]auto_vacuum
-  **  PRAGMA [database.]auto_vacuum=N
+  **  PRAGMA [schema.]auto_vacuum
+  **  PRAGMA [schema.]auto_vacuum=N
   **
   ** Get or set the value of the database 'auto-vacuum' parameter.
   ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL
@@ -103091,7 +114733,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
     Btree *pBt = pDb->pBt;
     assert( pBt!=0 );
     if( !zRight ){
-      returnSingleInt(pParse, "auto_vacuum", sqlite3BtreeGetAutoVacuum(pBt));
+      returnSingleInt(v, sqlite3BtreeGetAutoVacuum(pBt));
     }else{
       int eAuto = getAutoVacuum(zRight);
       assert( eAuto>=0 && eAuto<=2 );
@@ -103114,16 +114756,18 @@ SQLITE_PRIVATE void sqlite3Pragma(
           { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
           { OP_If,             1,         0,                 0},    /* 2 */
           { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
-          { OP_Integer,        0,         1,                 0},    /* 4 */
-          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
+          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 0},    /* 4 */
         };
-        int iAddr;
-        iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
-        sqlite3VdbeChangeP1(v, iAddr, iDb);
-        sqlite3VdbeChangeP1(v, iAddr+1, iDb);
-        sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
-        sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
-        sqlite3VdbeChangeP1(v, iAddr+5, iDb);
+        VdbeOp *aOp;
+        int iAddr = sqlite3VdbeCurrentAddr(v);
+        sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));
+        aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
+        if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+        aOp[0].p1 = iDb;
+        aOp[1].p1 = iDb;
+        aOp[2].p2 = iAddr+4;
+        aOp[4].p1 = iDb;
+        aOp[4].p3 = eAuto - 1;
         sqlite3VdbeUsesBtree(v, iDb);
       }
     }
@@ -103132,7 +114776,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
 #endif
 
   /*
-  **  PRAGMA [database.]incremental_vacuum(N)
+  **  PRAGMA [schema.]incremental_vacuum(N)
   **
   ** Do N steps of incremental vacuuming on a database.
   */
@@ -103155,8 +114799,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
   /*
-  **  PRAGMA [database.]cache_size
-  **  PRAGMA [database.]cache_size=N
+  **  PRAGMA [schema.]cache_size
+  **  PRAGMA [schema.]cache_size=N
   **
   ** The first form reports the current local setting for the
   ** page cache size. The second form sets the local
@@ -103168,7 +114812,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   case PragTyp_CACHE_SIZE: {
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     if( !zRight ){
-      returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
+      returnSingleInt(v, pDb->pSchema->cache_size);
     }else{
       int size = sqlite3Atoi(zRight);
       pDb->pSchema->cache_size = size;
@@ -103178,7 +114822,50 @@ SQLITE_PRIVATE void sqlite3Pragma(
   }
 
   /*
-  **  PRAGMA [database.]mmap_size(N)
+  **  PRAGMA [schema.]cache_spill
+  **  PRAGMA cache_spill=BOOLEAN
+  **  PRAGMA [schema.]cache_spill=N
+  **
+  ** The first form reports the current local setting for the
+  ** page cache spill size. The second form turns cache spill on
+  ** or off.  When turnning cache spill on, the size is set to the
+  ** current cache_size.  The third form sets a spill size that
+  ** may be different form the cache size.
+  ** If N is positive then that is the
+  ** number of pages in the cache.  If N is negative, then the
+  ** number of pages is adjusted so that the cache uses -N kibibytes
+  ** of memory.
+  **
+  ** If the number of cache_spill pages is less then the number of
+  ** cache_size pages, no spilling occurs until the page count exceeds
+  ** the number of cache_size pages.
+  **
+  ** The cache_spill=BOOLEAN setting applies to all attached schemas,
+  ** not just the schema specified.
+  */
+  case PragTyp_CACHE_SPILL: {
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( !zRight ){
+      returnSingleInt(v,
+         (db->flags & SQLITE_CacheSpill)==0 ? 0 : 
+            sqlite3BtreeSetSpillSize(pDb->pBt,0));
+    }else{
+      int size = 1;
+      if( sqlite3GetInt32(zRight, &size) ){
+        sqlite3BtreeSetSpillSize(pDb->pBt, size);
+      }
+      if( sqlite3GetBoolean(zRight, size!=0) ){
+        db->flags |= SQLITE_CacheSpill;
+      }else{
+        db->flags &= ~SQLITE_CacheSpill;
+      }
+      setAllPagerFlags(db);
+    }
+    break;
+  }
+
+  /*
+  **  PRAGMA [schema.]mmap_size(N)
   **
   ** Used to set mapping size limit. The mapping size limit is
   ** used to limit the aggregate size of all memory mapped regions of the
@@ -103213,7 +114900,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
     rc = SQLITE_OK;
 #endif
     if( rc==SQLITE_OK ){
-      returnSingleInt(pParse, "mmap_size", sz);
+      returnSingleInt(v, sz);
     }else if( rc!=SQLITE_NOTFOUND ){
       pParse->nErr++;
       pParse->rc = rc;
@@ -103234,7 +114921,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   */
   case PragTyp_TEMP_STORE: {
     if( !zRight ){
-      returnSingleInt(pParse, "temp_store", db->temp_store);
+      returnSingleInt(v, db->temp_store);
     }else{
       changeTempStorage(pParse, zRight);
     }
@@ -103253,13 +114940,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   */
   case PragTyp_TEMP_STORE_DIRECTORY: {
     if( !zRight ){
-      if( sqlite3_temp_directory ){
-        sqlite3VdbeSetNumCols(v, 1);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
-            "temp_store_directory", SQLITE_STATIC);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-      }
+      returnSingleText(v, sqlite3_temp_directory);
     }else{
 #ifndef SQLITE_OMIT_WSD
       if( zRight[0] ){
@@ -103303,13 +114984,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   */
   case PragTyp_DATA_STORE_DIRECTORY: {
     if( !zRight ){
-      if( sqlite3_data_directory ){
-        sqlite3VdbeSetNumCols(v, 1);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
-            "data_store_directory", SQLITE_STATIC);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_data_directory, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-      }
+      returnSingleText(v, sqlite3_data_directory);
     }else{
 #ifndef SQLITE_OMIT_WSD
       if( zRight[0] ){
@@ -103334,8 +115009,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
 #if SQLITE_ENABLE_LOCKING_STYLE
   /*
-  **   PRAGMA [database.]lock_proxy_file
-  **   PRAGMA [database.]lock_proxy_file = ":auto:"|"lock_file_path"
+  **   PRAGMA [schema.]lock_proxy_file
+  **   PRAGMA [schema.]lock_proxy_file = ":auto:"|"lock_file_path"
   **
   ** Return or set the value of the lock_proxy_file flag.  Changing
   ** the value sets a specific file to be used for database access locks.
@@ -103348,14 +115023,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
       sqlite3_file *pFile = sqlite3PagerFile(pPager);
       sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE, 
                            &proxy_file_path);
-      
-      if( proxy_file_path ){
-        sqlite3VdbeSetNumCols(v, 1);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
-                              "lock_proxy_file", SQLITE_STATIC);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, proxy_file_path, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-      }
+      returnSingleText(v, proxy_file_path);
     }else{
       Pager *pPager = sqlite3BtreePager(pDb->pBt);
       sqlite3_file *pFile = sqlite3PagerFile(pPager);
@@ -103377,8 +115045,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
 #endif /* SQLITE_ENABLE_LOCKING_STYLE */      
     
   /*
-  **   PRAGMA [database.]synchronous
-  **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
+  **   PRAGMA [schema.]synchronous
+  **   PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL|EXTRA
   **
   ** Return or set the local value of the synchronous flag.  Changing
   ** the local value does not make changes to the disk file and the
@@ -103387,13 +115055,16 @@ SQLITE_PRIVATE void sqlite3Pragma(
   */
   case PragTyp_SYNCHRONOUS: {
     if( !zRight ){
-      returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
+      returnSingleInt(v, pDb->safety_level-1);
     }else{
       if( !db->autoCommit ){
         sqlite3ErrorMsg(pParse, 
             "Safety level may not be changed inside a transaction");
-      }else{
-        pDb->safety_level = getSafetyLevel(zRight,0,1)+1;
+      }else if( iDb!=1 ){
+        int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;
+        if( iLevel==0 ) iLevel = 1;
+        pDb->safety_level = iLevel;
+        pDb->bSyncSet = 1;
         setAllPagerFlags(db);
       }
     }
@@ -103404,10 +115075,10 @@ SQLITE_PRIVATE void sqlite3Pragma(
 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
   case PragTyp_FLAG: {
     if( zRight==0 ){
-      returnSingleInt(pParse, aPragmaNames[mid].zName,
-                     (db->flags & aPragmaNames[mid].iArg)!=0 );
+      setPragmaResultColumnNames(v, pPragma);
+      returnSingleInt(v, (db->flags & pPragma->iArg)!=0 );
     }else{
-      int mask = aPragmaNames[mid].iArg;    /* Mask of bits to set or clear. */
+      int mask = pPragma->iArg;    /* Mask of bits to set or clear. */
       if( db->autoCommit==0 ){
         /* Foreign key support may not be enabled or disabled while not
         ** in auto-commit mode.  */
@@ -103431,7 +115102,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
       ** compiler (eg. count_changes). So add an opcode to expire all
       ** compiled SQL statements after modifying a pragma value.
       */
-      sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+      sqlite3VdbeAddOp0(v, OP_Expire);
       setAllPagerFlags(db);
     }
     break;
@@ -103453,82 +115124,66 @@ SQLITE_PRIVATE void sqlite3Pragma(
   */
   case PragTyp_TABLE_INFO: if( zRight ){
     Table *pTab;
-    pTab = sqlite3FindTable(db, zRight, zDb);
+    pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
     if( pTab ){
       int i, k;
       int nHidden = 0;
       Column *pCol;
       Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-      sqlite3VdbeSetNumCols(v, 6);
       pParse->nMem = 6;
       sqlite3CodeVerifySchema(pParse, iDb);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", SQLITE_STATIC);
       sqlite3ViewGetColumnNames(pParse, pTab);
       for(i=0, pCol=pTab->aCol; inCol; i++, pCol++){
         if( IsHiddenColumn(pCol) ){
           nHidden++;
           continue;
         }
-        sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-           pCol->zType ? pCol->zType : "", 0);
-        sqlite3VdbeAddOp2(v, OP_Integer, (pCol->notNull ? 1 : 0), 4);
-        if( pCol->zDflt ){
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pCol->zDflt, 0);
-        }else{
-          sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
-        }
         if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){
           k = 0;
         }else if( pPk==0 ){
           k = 1;
         }else{
-          for(k=1; ALWAYS(k<=pTab->nCol) && pPk->aiColumn[k-1]!=i; k++){}
+          for(k=1; k<=pTab->nCol && pPk->aiColumn[k-1]!=i; k++){}
         }
-        sqlite3VdbeAddOp2(v, OP_Integer, k, 6);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
+        assert( pCol->pDflt==0 || pCol->pDflt->op==TK_SPAN );
+        sqlite3VdbeMultiLoad(v, 1, "issisi",
+               i-nHidden,
+               pCol->zName,
+               sqlite3ColumnType(pCol,""),
+               pCol->notNull ? 1 : 0,
+               pCol->pDflt ? pCol->pDflt->u.zToken : 0,
+               k);
       }
     }
   }
   break;
 
+#ifdef SQLITE_DEBUG
   case PragTyp_STATS: {
     Index *pIdx;
     HashElem *i;
-    v = sqlite3GetVdbe(pParse);
-    sqlite3VdbeSetNumCols(v, 4);
-    pParse->nMem = 4;
+    pParse->nMem = 5;
     sqlite3CodeVerifySchema(pParse, iDb);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "table", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "index", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "width", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "height", SQLITE_STATIC);
     for(i=sqliteHashFirst(&pDb->pSchema->tblHash); i; i=sqliteHashNext(i)){
       Table *pTab = sqliteHashData(i);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, pTab->zName, 0);
-      sqlite3VdbeAddOp2(v, OP_Null, 0, 2);
-      sqlite3VdbeAddOp2(v, OP_Integer,
-                           (int)sqlite3LogEstToInt(pTab->szTabRow), 3);
-      sqlite3VdbeAddOp2(v, OP_Integer, 
-          (int)sqlite3LogEstToInt(pTab->nRowLogEst), 4);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
+      sqlite3VdbeMultiLoad(v, 1, "ssiii",
+           pTab->zName,
+           0,
+           pTab->szTabRow,
+           pTab->nRowLogEst,
+           pTab->tabFlags);
       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
-        sqlite3VdbeAddOp2(v, OP_Integer,
-                             (int)sqlite3LogEstToInt(pIdx->szIdxRow), 3);
-        sqlite3VdbeAddOp2(v, OP_Integer, 
-            (int)sqlite3LogEstToInt(pIdx->aiRowLogEst[0]), 4);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
+        sqlite3VdbeMultiLoad(v, 2, "siiiX",
+           pIdx->zName,
+           pIdx->szIdxRow,
+           pIdx->aiRowLogEst[0],
+           pIdx->hasStat1);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
       }
     }
   }
   break;
+#endif
 
   case PragTyp_INDEX_INFO: if( zRight ){
     Index *pIdx;
@@ -103536,20 +115191,30 @@ SQLITE_PRIVATE void sqlite3Pragma(
     pIdx = sqlite3FindIndex(db, zRight, zDb);
     if( pIdx ){
       int i;
+      int mx;
+      if( pPragma->iArg ){
+        /* PRAGMA index_xinfo (newer version with more rows and columns) */
+        mx = pIdx->nColumn;
+        pParse->nMem = 6;
+      }else{
+        /* PRAGMA index_info (legacy version) */
+        mx = pIdx->nKeyCol;
+        pParse->nMem = 3;
+      }
       pTab = pIdx->pTable;
-      sqlite3VdbeSetNumCols(v, 3);
-      pParse->nMem = 3;
       sqlite3CodeVerifySchema(pParse, iDb);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE_STATIC);
-      for(i=0; inKeyCol; i++){
+      assert( pParse->nMem<=pPragma->nPragCName );
+      for(i=0; iaiColumn[i];
-        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
-        assert( pTab->nCol>cnum );
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+        sqlite3VdbeMultiLoad(v, 1, "iisX", i, cnum,
+                             cnum<0 ? 0 : pTab->aCol[cnum].zName);
+        if( pPragma->iArg ){
+          sqlite3VdbeMultiLoad(v, 4, "isiX",
+            pIdx->aSortOrder[i],
+            pIdx->azColl[i],
+            inKeyCol);
+        }
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, pParse->nMem);
       }
     }
   }
@@ -103561,18 +115226,16 @@ SQLITE_PRIVATE void sqlite3Pragma(
     int i;
     pTab = sqlite3FindTable(db, zRight, zDb);
     if( pTab ){
-      v = sqlite3GetVdbe(pParse);
-      sqlite3VdbeSetNumCols(v, 3);
-      pParse->nMem = 3;
+      pParse->nMem = 5;
       sqlite3CodeVerifySchema(pParse, iDb);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
       for(pIdx=pTab->pIndex, i=0; pIdx; pIdx=pIdx->pNext, i++){
-        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
-        sqlite3VdbeAddOp2(v, OP_Integer, IsUniqueIndex(pIdx), 3);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+        const char *azOrigin[] = { "c", "u", "pk" };
+        sqlite3VdbeMultiLoad(v, 1, "isisi",
+           i,
+           pIdx->zName,
+           IsUniqueIndex(pIdx),
+           azOrigin[pIdx->idxType],
+           pIdx->pPartIdxWhere!=0);
       }
     }
   }
@@ -103580,19 +115243,14 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
   case PragTyp_DATABASE_LIST: {
     int i;
-    sqlite3VdbeSetNumCols(v, 3);
     pParse->nMem = 3;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE_STATIC);
     for(i=0; inDb; i++){
       if( db->aDb[i].pBt==0 ) continue;
-      assert( db->aDb[i].zName!=0 );
-      sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+      assert( db->aDb[i].zDbSName!=0 );
+      sqlite3VdbeMultiLoad(v, 1, "iss",
+         i,
+         db->aDb[i].zDbSName,
+         sqlite3BtreeGetFilename(db->aDb[i].pBt));
     }
   }
   break;
@@ -103600,18 +115258,57 @@ SQLITE_PRIVATE void sqlite3Pragma(
   case PragTyp_COLLATION_LIST: {
     int i = 0;
     HashElem *p;
-    sqlite3VdbeSetNumCols(v, 2);
     pParse->nMem = 2;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
     for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
       CollSeq *pColl = (CollSeq *)sqliteHashData(p);
-      sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
+      sqlite3VdbeMultiLoad(v, 1, "is", i++, pColl->zName);
+    }
+  }
+  break;
+
+#ifdef SQLITE_INTROSPECTION_PRAGMAS
+  case PragTyp_FUNCTION_LIST: {
+    int i;
+    HashElem *j;
+    FuncDef *p;
+    pParse->nMem = 2;
+    for(i=0; iu.pHash ){
+        sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 1);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
+      }
+    }
+    for(j=sqliteHashFirst(&db->aFunc); j; j=sqliteHashNext(j)){
+      p = (FuncDef*)sqliteHashData(j);
+      sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 0);
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
     }
   }
   break;
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  case PragTyp_MODULE_LIST: {
+    HashElem *j;
+    pParse->nMem = 1;
+    for(j=sqliteHashFirst(&db->aModule); j; j=sqliteHashNext(j)){
+      Module *pMod = (Module*)sqliteHashData(j);
+      sqlite3VdbeMultiLoad(v, 1, "s", pMod->zName);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+    }
+  }
+  break;
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+  case PragTyp_PRAGMA_LIST: {
+    int i;
+    for(i=0; ipFKey;
       if( pFK ){
         int i = 0; 
-        sqlite3VdbeSetNumCols(v, 8);
         pParse->nMem = 8;
         sqlite3CodeVerifySchema(pParse, iDb);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "on_update", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 6, COLNAME_NAME, "on_delete", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 7, COLNAME_NAME, "match", SQLITE_STATIC);
         while(pFK){
           int j;
           for(j=0; jnCol; j++){
-            char *zCol = pFK->aCol[j].zCol;
-            char *zOnDelete = (char *)actionName(pFK->aAction[0]);
-            char *zOnUpdate = (char *)actionName(pFK->aAction[1]);
-            sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-            sqlite3VdbeAddOp2(v, OP_Integer, j, 2);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
-                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
-            sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 6, 0, zOnUpdate, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 7, 0, zOnDelete, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 8, 0, "NONE", 0);
-            sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 8);
+            sqlite3VdbeMultiLoad(v, 1, "iissssss",
+                   i,
+                   j,
+                   pFK->zTo,
+                   pTab->aCol[pFK->aCol[j].iFrom].zName,
+                   pFK->aCol[j].zCol,
+                   actionName(pFK->aAction[1]),  /* ON UPDATE */
+                   actionName(pFK->aAction[0]),  /* ON DELETE */
+                   "NONE");
           }
           ++i;
           pFK = pFK->pNextFrom;
@@ -103683,12 +115366,6 @@ SQLITE_PRIVATE void sqlite3Pragma(
     pParse->nMem += 4;
     regKey = ++pParse->nMem;
     regRow = ++pParse->nMem;
-    v = sqlite3GetVdbe(pParse);
-    sqlite3VdbeSetNumCols(v, 4);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "table", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "rowid", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "parent", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "fkid", SQLITE_STATIC);
     sqlite3CodeVerifySchema(pParse, iDb);
     k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);
     while( k ){
@@ -103703,8 +115380,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
       sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
       if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;
       sqlite3OpenTable(pParse, 0, iDb, pTab, OP_OpenRead);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, regResult, 0, pTab->zName,
-                        P4_TRANSIENT);
+      sqlite3VdbeLoadString(v, regResult, pTab->zName);
       for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
         pParent = sqlite3FindTable(db, pFK->zTo, zDb);
         if( pParent==0 ) continue;
@@ -103736,38 +115412,38 @@ SQLITE_PRIVATE void sqlite3Pragma(
           assert( x==0 );
         }
         addrOk = sqlite3VdbeMakeLabel(v);
-        if( pParent && pIdx==0 ){
-          int iKey = pFK->aCol[0].iFrom;
-          assert( iKey>=0 && iKeynCol );
-          if( iKey!=pTab->iPKey ){
-            sqlite3VdbeAddOp3(v, OP_Column, 0, iKey, regRow);
-            sqlite3ColumnDefault(v, pTab, iKey, regRow);
-            sqlite3VdbeAddOp2(v, OP_IsNull, regRow, addrOk); VdbeCoverage(v);
-            sqlite3VdbeAddOp2(v, OP_MustBeInt, regRow, 
-               sqlite3VdbeCurrentAddr(v)+3); VdbeCoverage(v);
-          }else{
-            sqlite3VdbeAddOp2(v, OP_Rowid, 0, regRow);
-          }
-          sqlite3VdbeAddOp3(v, OP_NotExists, i, 0, regRow); VdbeCoverage(v);
-          sqlite3VdbeAddOp2(v, OP_Goto, 0, addrOk);
-          sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
+
+        /* Generate code to read the child key values into registers
+        ** regRow..regRow+n. If any of the child key values are NULL, this 
+        ** row cannot cause an FK violation. Jump directly to addrOk in 
+        ** this case. */
+        for(j=0; jnCol; j++){
+          int iCol = aiCols ? aiCols[j] : pFK->aCol[j].iFrom;
+          sqlite3ExprCodeGetColumnOfTable(v, pTab, 0, iCol, regRow+j);
+          sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
+        }
+
+        /* Generate code to query the parent index for a matching parent
+        ** key. If a match is found, jump to addrOk. */
+        if( pIdx ){
+          sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,
+              sqlite3IndexAffinityStr(db,pIdx), pFK->nCol);
+          sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
+          VdbeCoverage(v);
+        }else if( pParent ){
+          int jmp = sqlite3VdbeCurrentAddr(v)+2;
+          sqlite3VdbeAddOp3(v, OP_SeekRowid, i, jmp, regRow); VdbeCoverage(v);
+          sqlite3VdbeGoto(v, addrOk);
+          assert( pFK->nCol==1 );
+        }
+
+        /* Generate code to report an FK violation to the caller. */
+        if( HasRowid(pTab) ){
+          sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
         }else{
-          for(j=0; jnCol; j++){
-            sqlite3ExprCodeGetColumnOfTable(v, pTab, 0,
-                            aiCols ? aiCols[j] : pFK->aCol[j].iFrom, regRow+j);
-            sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
-          }
-          if( pParent ){
-            sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,
-                              sqlite3IndexAffinityStr(v,pIdx), pFK->nCol);
-            sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
-            VdbeCoverage(v);
-          }
+          sqlite3VdbeAddOp2(v, OP_Null, 0, regResult+1);
         }
-        sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, regResult+2, 0, 
-                          pFK->zTo, P4_TRANSIENT);
-        sqlite3VdbeAddOp2(v, OP_Integer, i-1, regResult+3);
+        sqlite3VdbeMultiLoad(v, regResult+2, "siX", pFK->zTo, i-1);
         sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
         sqlite3VdbeResolveLabel(v, addrOk);
         sqlite3DbFree(db, aiCols);
@@ -103784,7 +115460,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   case PragTyp_PARSER_TRACE: {
     if( zRight ){
       if( sqlite3GetBoolean(zRight, 0) ){
-        sqlite3ParserTrace(stderr, "parser: ");
+        sqlite3ParserTrace(stdout, "parser: ");
       }else{
         sqlite3ParserTrace(0, 0);
       }
@@ -103808,24 +115484,21 @@ SQLITE_PRIVATE void sqlite3Pragma(
 #endif
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
-  /* Pragma "quick_check" is reduced version of 
+  /*    PRAGMA integrity_check
+  **    PRAGMA integrity_check(N)
+  **    PRAGMA quick_check
+  **    PRAGMA quick_check(N)
+  **
+  ** Verify the integrity of the database.
+  **
+  ** The "quick_check" is reduced version of 
   ** integrity_check designed to detect most database corruption
-  ** without most of the overhead of a full integrity-check.
+  ** without the overhead of cross-checking indexes.  Quick_check
+  ** is linear time wherease integrity_check is O(NlogN).
   */
   case PragTyp_INTEGRITY_CHECK: {
     int i, j, addr, mxErr;
 
-    /* Code that appears at the end of the integrity check.  If no error
-    ** messages have been generated, output OK.  Otherwise output the
-    ** error message
-    */
-    static const int iLn = VDBE_OFFSET_LINENO(2);
-    static const VdbeOpList endCode[] = {
-      { OP_IfNeg,       1, 0,        0},    /* 0 */
-      { OP_String8,     0, 3,        0},    /* 1 */
-      { OP_ResultRow,   3, 1,        0},
-    };
-
     int isQuick = (sqlite3Tolower(zLeft[0])=='q');
 
     /* If the PRAGMA command was of the form "PRAGMA .integrity_check",
@@ -103843,8 +115516,6 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
     /* Initialize the VDBE program */
     pParse->nMem = 6;
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", SQLITE_STATIC);
 
     /* Set the maximum error count */
     mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
@@ -103854,63 +115525,67 @@ SQLITE_PRIVATE void sqlite3Pragma(
         mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
       }
     }
-    sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1);  /* reg[1] holds errors left */
+    sqlite3VdbeAddOp2(v, OP_Integer, mxErr-1, 1); /* reg[1] holds errors left */
 
     /* Do an integrity check on each database file */
     for(i=0; inDb; i++){
       HashElem *x;
       Hash *pTbls;
+      int *aRoot;
       int cnt = 0;
+      int mxIdx = 0;
+      int nIdx;
 
       if( OMIT_TEMPDB && i==1 ) continue;
       if( iDb>=0 && i!=iDb ) continue;
 
       sqlite3CodeVerifySchema(pParse, i);
-      addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
-      VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
-      sqlite3VdbeJumpHere(v, addr);
 
       /* Do an integrity check of the B-Tree
       **
-      ** Begin by filling registers 2, 3, ... with the root pages numbers
+      ** Begin by finding the root pages numbers
       ** for all tables and indices in the database.
       */
       assert( sqlite3SchemaMutexHeld(db, i, 0) );
       pTbls = &db->aDb[i].pSchema->tblHash;
-      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
+      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
         Table *pTab = sqliteHashData(x);
         Index *pIdx;
-        if( HasRowid(pTab) ){
-          sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
-          VdbeComment((v, "%s", pTab->zName));
-          cnt++;
-        }
+        if( HasRowid(pTab) ) cnt++;
+        for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ cnt++; }
+        if( nIdx>mxIdx ) mxIdx = nIdx;
+      }
+      aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));
+      if( aRoot==0 ) break;
+      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
+        Table *pTab = sqliteHashData(x);
+        Index *pIdx;
+        if( HasRowid(pTab) ) aRoot[cnt++] = pTab->tnum;
         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
-          VdbeComment((v, "%s", pIdx->zName));
-          cnt++;
+          aRoot[cnt++] = pIdx->tnum;
         }
       }
+      aRoot[cnt] = 0;
 
       /* Make sure sufficient number of registers have been allocated */
-      pParse->nMem = MAX( pParse->nMem, cnt+8 );
+      pParse->nMem = MAX( pParse->nMem, 8+mxIdx );
+      sqlite3ClearTempRegCache(pParse);
 
       /* Do the b-tree integrity checks */
-      sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
+      sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
       sqlite3VdbeChangeP5(v, (u8)i);
       addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
       sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
+         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zDbSName),
          P4_DYNAMIC);
       sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1);
       sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1);
+      integrityCheckResultRow(v, 2);
       sqlite3VdbeJumpHere(v, addr);
 
       /* Make sure all the indices are constructed correctly.
       */
-      for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
+      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
         Table *pTab = sqliteHashData(x);
         Index *pIdx, *pPk;
         Index *pPrior = 0;
@@ -103918,43 +115593,68 @@ SQLITE_PRIVATE void sqlite3Pragma(
         int iDataCur, iIdxCur;
         int r1 = -1;
 
-        if( pTab->pIndex==0 ) continue;
+        if( pTab->tnum<1 ) continue;  /* Skip VIEWs or VIRTUAL TABLEs */
+        if( pTab->pCheck==0
+         && (pTab->tabFlags & TF_HasNotNull)==0
+         && (pTab->pIndex==0 || isQuick)
+        ){
+          continue;  /* No additional checks needed for this table */
+        }
         pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
-        addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);  /* Stop if out of errors */
-        VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
-        sqlite3VdbeJumpHere(v, addr);
         sqlite3ExprCacheClear(pParse);
-        sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead,
+        sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead, 0,
                                    1, 0, &iDataCur, &iIdxCur);
         sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);
         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
           sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */
         }
-        pParse->nMem = MAX(pParse->nMem, 8+j);
+        assert( pParse->nMem>=8+j );
+        assert( sqlite3NoTempsInRange(pParse,1,7+j) );
         sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);
         loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);
         /* Verify that all NOT NULL columns really are NOT NULL */
         for(j=0; jnCol; j++){
           char *zErr;
-          int jmp2, jmp3;
+          int jmp2;
           if( j==pTab->iPKey ) continue;
           if( pTab->aCol[j].notNull==0 ) continue;
           sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);
           sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
           jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);
-          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
           zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
                               pTab->aCol[j].zName);
           sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
-          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
-          jmp3 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
-          sqlite3VdbeAddOp0(v, OP_Halt);
+          integrityCheckResultRow(v, 3);
           sqlite3VdbeJumpHere(v, jmp2);
-          sqlite3VdbeJumpHere(v, jmp3);
+        }
+        /* Verify CHECK constraints */
+        if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
+          ExprList *pCheck = sqlite3ExprListDup(db, pTab->pCheck, 0);
+          if( db->mallocFailed==0 ){
+            int addrCkFault = sqlite3VdbeMakeLabel(v);
+            int addrCkOk = sqlite3VdbeMakeLabel(v);
+            char *zErr;
+            int k;
+            pParse->iSelfTab = iDataCur + 1;
+            sqlite3ExprCachePush(pParse);
+            for(k=pCheck->nExpr-1; k>0; k--){
+              sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);
+            }
+            sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk, 
+                SQLITE_JUMPIFNULL);
+            sqlite3VdbeResolveLabel(v, addrCkFault);
+            pParse->iSelfTab = 0;
+            zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",
+                pTab->zName);
+            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
+            integrityCheckResultRow(v, 3);
+            sqlite3VdbeResolveLabel(v, addrCkOk);
+            sqlite3ExprCachePop(pParse);
+          }
+          sqlite3ExprListDelete(db, pCheck);
         }
         /* Validate index entries for the current row */
-        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+        for(j=0, pIdx=pTab->pIndex; pIdx && !isQuick; pIdx=pIdx->pNext, j++){
           int jmp2, jmp3, jmp4, jmp5;
           int ckUniq = sqlite3VdbeMakeLabel(v);
           if( pPk==pIdx ) continue;
@@ -103965,18 +115665,13 @@ SQLITE_PRIVATE void sqlite3Pragma(
           /* Verify that an index entry exists for the current table row */
           jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,
                                       pIdx->nColumn); VdbeCoverage(v);
-          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, "row ", P4_STATIC);
+          sqlite3VdbeLoadString(v, 3, "row ");
           sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0, 
-                            " missing from index ", P4_STATIC);
+          sqlite3VdbeLoadString(v, 4, " missing from index ");
           sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
-          jmp5 = sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
-                                   pIdx->zName, P4_TRANSIENT);
+          jmp5 = sqlite3VdbeLoadString(v, 4, pIdx->zName);
           sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
-          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
-          jmp4 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
-          sqlite3VdbeAddOp0(v, OP_Halt);
+          jmp4 = integrityCheckResultRow(v, 3);
           sqlite3VdbeJumpHere(v, jmp2);
           /* For UNIQUE indexes, verify that only one entry exists with the
           ** current key.  The entry is unique if (1) any column is NULL
@@ -103987,20 +115682,18 @@ SQLITE_PRIVATE void sqlite3Pragma(
             int kk;
             for(kk=0; kknKeyCol; kk++){
               int iCol = pIdx->aiColumn[kk];
-              assert( iCol>=0 && iColnCol );
-              if( pTab->aCol[iCol].notNull ) continue;
+              assert( iCol!=XN_ROWID && iColnCol );
+              if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
               sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
               VdbeCoverage(v);
             }
             jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
-            sqlite3VdbeAddOp2(v, OP_Goto, 0, uniqOk);
+            sqlite3VdbeGoto(v, uniqOk);
             sqlite3VdbeJumpHere(v, jmp6);
             sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,
                                  pIdx->nKeyCol); VdbeCoverage(v);
-            sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-                              "non-unique entry in index ", P4_STATIC);
-            sqlite3VdbeAddOp2(v, OP_Goto, 0, jmp5);
+            sqlite3VdbeLoadString(v, 3, "non-unique entry in index ");
+            sqlite3VdbeGoto(v, jmp5);
             sqlite3VdbeResolveLabel(v, uniqOk);
           }
           sqlite3VdbeJumpHere(v, jmp4);
@@ -104009,28 +115702,39 @@ SQLITE_PRIVATE void sqlite3Pragma(
         sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
         sqlite3VdbeJumpHere(v, loopTop-1);
 #ifndef SQLITE_OMIT_BTREECOUNT
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, 
-                     "wrong # of entries in index ", P4_STATIC);
-        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-          if( pPk==pIdx ) continue;
-          addr = sqlite3VdbeCurrentAddr(v);
-          sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr+2); VdbeCoverage(v);
-          sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
-          sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
-          sqlite3VdbeAddOp3(v, OP_Eq, 8+j, addr+8, 3); VdbeCoverage(v);
-          sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
-          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pIdx->zName, P4_TRANSIENT);
-          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
-          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
+        if( !isQuick ){
+          sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");
+          for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+            if( pPk==pIdx ) continue;
+            sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
+            addr = sqlite3VdbeAddOp3(v, OP_Eq, 8+j, 0, 3); VdbeCoverage(v);
+            sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
+            sqlite3VdbeLoadString(v, 3, pIdx->zName);
+            sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
+            integrityCheckResultRow(v, 7);
+            sqlite3VdbeJumpHere(v, addr);
+          }
         }
 #endif /* SQLITE_OMIT_BTREECOUNT */
       } 
     }
-    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
-    sqlite3VdbeChangeP3(v, addr, -mxErr);
-    sqlite3VdbeJumpHere(v, addr);
-    sqlite3VdbeChangeP4(v, addr+1, "ok", P4_STATIC);
+    {
+      static const int iLn = VDBE_OFFSET_LINENO(2);
+      static const VdbeOpList endCode[] = {
+        { OP_AddImm,      1, 0,        0},    /* 0 */
+        { OP_IfNotZero,   1, 4,        0},    /* 1 */
+        { OP_String8,     0, 3,        0},    /* 2 */
+        { OP_ResultRow,   3, 1,        0},    /* 3 */
+      };
+      VdbeOp *aOp;
+
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
+      if( aOp ){
+        aOp[0].p2 = 1-mxErr;
+        aOp[2].p4type = P4_STATIC;
+        aOp[2].p4.z = "ok";
+      }
+    }
   }
   break;
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
@@ -104076,14 +115780,10 @@ SQLITE_PRIVATE void sqlite3Pragma(
     const struct EncName *pEnc;
     if( !zRight ){    /* "PRAGMA encoding" */
       if( sqlite3ReadSchema(pParse) ) goto pragma_out;
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", SQLITE_STATIC);
-      sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
       assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );
       assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );
       assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );
-      sqlite3VdbeChangeP4(v, -1, encnames[ENC(pParse->db)].zName, P4_STATIC);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+      returnSingleText(v, encnames[ENC(pParse->db)].zName);
     }else{                        /* "PRAGMA encoding = XXX" */
       /* Only change the value of sqlite.enc if the database handle is not
       ** initialized. If the main database exists, the new sqlite.enc value
@@ -104112,16 +115812,18 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
 #ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
   /*
-  **   PRAGMA [database.]schema_version
-  **   PRAGMA [database.]schema_version = 
+  **   PRAGMA [schema.]schema_version
+  **   PRAGMA [schema.]schema_version = 
   **
-  **   PRAGMA [database.]user_version
-  **   PRAGMA [database.]user_version = 
+  **   PRAGMA [schema.]user_version
+  **   PRAGMA [schema.]user_version = 
   **
-  **   PRAGMA [database.]freelist_count = 
+  **   PRAGMA [schema.]freelist_count
   **
-  **   PRAGMA [database.]application_id
-  **   PRAGMA [database.]application_id = 
+  **   PRAGMA [schema.]data_version
+  **
+  **   PRAGMA [schema.]application_id
+  **   PRAGMA [schema.]application_id = 
   **
   ** The pragma's schema_version and user_version are used to set or get
   ** the value of the schema-version and user-version, respectively. Both
@@ -104142,20 +115844,22 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** applications for any purpose.
   */
   case PragTyp_HEADER_VALUE: {
-    int iCookie = aPragmaNames[mid].iArg;  /* Which cookie to read or write */
+    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
     sqlite3VdbeUsesBtree(v, iDb);
-    if( zRight && (aPragmaNames[mid].mPragFlag & PragFlag_ReadOnly)==0 ){
+    if( zRight && (pPragma->mPragFlg & PragFlg_ReadOnly)==0 ){
       /* Write the specified cookie value */
       static const VdbeOpList setCookie[] = {
         { OP_Transaction,    0,  1,  0},    /* 0 */
-        { OP_Integer,        0,  1,  0},    /* 1 */
-        { OP_SetCookie,      0,  0,  1},    /* 2 */
+        { OP_SetCookie,      0,  0,  0},    /* 1 */
       };
-      int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, sqlite3Atoi(zRight));
-      sqlite3VdbeChangeP1(v, addr+2, iDb);
-      sqlite3VdbeChangeP2(v, addr+2, iCookie);
+      VdbeOp *aOp;
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[1].p2 = iCookie;
+      aOp[1].p3 = sqlite3Atoi(zRight);
     }else{
       /* Read the specified cookie value */
       static const VdbeOpList readCookie[] = {
@@ -104163,12 +115867,14 @@ SQLITE_PRIVATE void sqlite3Pragma(
         { OP_ReadCookie,      0,  1,  0},    /* 1 */
         { OP_ResultRow,       1,  1,  0}
       };
-      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie, 0);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, iDb);
-      sqlite3VdbeChangeP3(v, addr+1, iCookie);
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
+      VdbeOp *aOp;
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(readCookie));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[1].p3 = iCookie;
+      sqlite3VdbeReusable(v);
     }
   }
   break;
@@ -104184,20 +115890,19 @@ SQLITE_PRIVATE void sqlite3Pragma(
   case PragTyp_COMPILE_OPTIONS: {
     int i = 0;
     const char *zOpt;
-    sqlite3VdbeSetNumCols(v, 1);
     pParse->nMem = 1;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
     while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
+      sqlite3VdbeLoadString(v, 1, zOpt);
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
     }
+    sqlite3VdbeReusable(v);
   }
   break;
 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
 
 #ifndef SQLITE_OMIT_WAL
   /*
-  **   PRAGMA [database.]wal_checkpoint = passive|full|restart|truncate
+  **   PRAGMA [schema.]wal_checkpoint = passive|full|restart|truncate
   **
   ** Checkpoint the database.
   */
@@ -104213,12 +115918,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
         eMode = SQLITE_CHECKPOINT_TRUNCATE;
       }
     }
-    sqlite3VdbeSetNumCols(v, 3);
     pParse->nMem = 3;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "busy", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "log", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "checkpointed", SQLITE_STATIC);
-
     sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);
     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
   }
@@ -104236,7 +115936,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
     if( zRight ){
       sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));
     }
-    returnSingleInt(pParse, "wal_autocheckpoint", 
+    returnSingleInt(v, 
        db->xWalCallback==sqlite3WalDefaultHook ? 
            SQLITE_PTR_TO_INT(db->pWalArg) : 0);
   }
@@ -104246,14 +115946,128 @@ SQLITE_PRIVATE void sqlite3Pragma(
   /*
   **  PRAGMA shrink_memory
   **
-  ** This pragma attempts to free as much memory as possible from the
-  ** current database connection.
+  ** IMPLEMENTATION-OF: R-23445-46109 This pragma causes the database
+  ** connection on which it is invoked to free up as much memory as it
+  ** can, by calling sqlite3_db_release_memory().
   */
   case PragTyp_SHRINK_MEMORY: {
     sqlite3_db_release_memory(db);
     break;
   }
 
+  /*
+  **  PRAGMA optimize
+  **  PRAGMA optimize(MASK)
+  **  PRAGMA schema.optimize
+  **  PRAGMA schema.optimize(MASK)
+  **
+  ** Attempt to optimize the database.  All schemas are optimized in the first
+  ** two forms, and only the specified schema is optimized in the latter two.
+  **
+  ** The details of optimizations performed by this pragma are expected
+  ** to change and improve over time.  Applications should anticipate that
+  ** this pragma will perform new optimizations in future releases.
+  **
+  ** The optional argument is a bitmask of optimizations to perform:
+  **
+  **    0x0001    Debugging mode.  Do not actually perform any optimizations
+  **              but instead return one line of text for each optimization
+  **              that would have been done.  Off by default.
+  **
+  **    0x0002    Run ANALYZE on tables that might benefit.  On by default.
+  **              See below for additional information.
+  **
+  **    0x0004    (Not yet implemented) Record usage and performance 
+  **              information from the current session in the
+  **              database file so that it will be available to "optimize"
+  **              pragmas run by future database connections.
+  **
+  **    0x0008    (Not yet implemented) Create indexes that might have
+  **              been helpful to recent queries
+  **
+  ** The default MASK is and always shall be 0xfffe.  0xfffe means perform all
+  ** of the optimizations listed above except Debug Mode, including new
+  ** optimizations that have not yet been invented.  If new optimizations are
+  ** ever added that should be off by default, those off-by-default 
+  ** optimizations will have bitmasks of 0x10000 or larger.
+  **
+  ** DETERMINATION OF WHEN TO RUN ANALYZE
+  **
+  ** In the current implementation, a table is analyzed if only if all of
+  ** the following are true:
+  **
+  ** (1) MASK bit 0x02 is set.
+  **
+  ** (2) The query planner used sqlite_stat1-style statistics for one or
+  **     more indexes of the table at some point during the lifetime of
+  **     the current connection.
+  **
+  ** (3) One or more indexes of the table are currently unanalyzed OR
+  **     the number of rows in the table has increased by 25 times or more
+  **     since the last time ANALYZE was run.
+  **
+  ** The rules for when tables are analyzed are likely to change in
+  ** future releases.
+  */
+  case PragTyp_OPTIMIZE: {
+    int iDbLast;           /* Loop termination point for the schema loop */
+    int iTabCur;           /* Cursor for a table whose size needs checking */
+    HashElem *k;           /* Loop over tables of a schema */
+    Schema *pSchema;       /* The current schema */
+    Table *pTab;           /* A table in the schema */
+    Index *pIdx;           /* An index of the table */
+    LogEst szThreshold;    /* Size threshold above which reanalysis is needd */
+    char *zSubSql;         /* SQL statement for the OP_SqlExec opcode */
+    u32 opMask;            /* Mask of operations to perform */
+
+    if( zRight ){
+      opMask = (u32)sqlite3Atoi(zRight);
+      if( (opMask & 0x02)==0 ) break;
+    }else{
+      opMask = 0xfffe;
+    }
+    iTabCur = pParse->nTab++;
+    for(iDbLast = zDb?iDb:db->nDb-1; iDb<=iDbLast; iDb++){
+      if( iDb==1 ) continue;
+      sqlite3CodeVerifySchema(pParse, iDb);
+      pSchema = db->aDb[iDb].pSchema;
+      for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
+        pTab = (Table*)sqliteHashData(k);
+
+        /* If table pTab has not been used in a way that would benefit from
+        ** having analysis statistics during the current session, then skip it.
+        ** This also has the effect of skipping virtual tables and views */
+        if( (pTab->tabFlags & TF_StatsUsed)==0 ) continue;
+
+        /* Reanalyze if the table is 25 times larger than the last analysis */
+        szThreshold = pTab->nRowLogEst + 46; assert( sqlite3LogEst(25)==46 );
+        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+          if( !pIdx->hasStat1 ){
+            szThreshold = 0; /* Always analyze if any index lacks statistics */
+            break;
+          }
+        }
+        if( szThreshold ){
+          sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
+          sqlite3VdbeAddOp3(v, OP_IfSmaller, iTabCur, 
+                         sqlite3VdbeCurrentAddr(v)+2+(opMask&1), szThreshold);
+          VdbeCoverage(v);
+        }
+        zSubSql = sqlite3MPrintf(db, "ANALYZE \"%w\".\"%w\"",
+                                 db->aDb[iDb].zDbSName, pTab->zName);
+        if( opMask & 0x01 ){
+          int r1 = sqlite3GetTempReg(pParse);
+          sqlite3VdbeAddOp4(v, OP_String8, 0, r1, 0, zSubSql, P4_DYNAMIC);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, r1, 1);
+        }else{
+          sqlite3VdbeAddOp4(v, OP_SqlExec, 0, 0, 0, zSubSql, P4_DYNAMIC);
+        }
+      }
+    }
+    sqlite3VdbeAddOp0(v, OP_Expire);
+    break;
+  }
+
   /*
   **   PRAGMA busy_timeout
   **   PRAGMA busy_timeout = N
@@ -104264,11 +116078,11 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** disables the timeout.
   */
   /*case PragTyp_BUSY_TIMEOUT*/ default: {
-    assert( aPragmaNames[mid].ePragTyp==PragTyp_BUSY_TIMEOUT );
+    assert( pPragma->ePragTyp==PragTyp_BUSY_TIMEOUT );
     if( zRight ){
       sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
     }
-    returnSingleInt(pParse, "timeout",  db->busyTimeout);
+    returnSingleInt(v, db->busyTimeout);
     break;
   }
 
@@ -104276,15 +116090,19 @@ SQLITE_PRIVATE void sqlite3Pragma(
   **   PRAGMA soft_heap_limit
   **   PRAGMA soft_heap_limit = N
   **
-  ** Call sqlite3_soft_heap_limit64(N).  Return the result.  If N is omitted,
-  ** use -1.
+  ** IMPLEMENTATION-OF: R-26343-45930 This pragma invokes the
+  ** sqlite3_soft_heap_limit64() interface with the argument N, if N is
+  ** specified and is a non-negative integer.
+  ** IMPLEMENTATION-OF: R-64451-07163 The soft_heap_limit pragma always
+  ** returns the same integer that would be returned by the
+  ** sqlite3_soft_heap_limit64(-1) C-language function.
   */
   case PragTyp_SOFT_HEAP_LIMIT: {
     sqlite3_int64 N;
     if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
       sqlite3_soft_heap_limit64(N);
     }
-    returnSingleInt(pParse, "soft_heap_limit",  sqlite3_soft_heap_limit64(-1));
+    returnSingleInt(v, sqlite3_soft_heap_limit64(-1));
     break;
   }
 
@@ -104303,8 +116121,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
     ){
       sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));
     }
-    returnSingleInt(pParse, "threads",
-                    sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
+    returnSingleInt(v, sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
     break;
   }
 
@@ -104317,25 +116134,20 @@ SQLITE_PRIVATE void sqlite3Pragma(
       "unlocked", "shared", "reserved", "pending", "exclusive"
     };
     int i;
-    sqlite3VdbeSetNumCols(v, 2);
     pParse->nMem = 2;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", SQLITE_STATIC);
     for(i=0; inDb; i++){
       Btree *pBt;
       const char *zState = "unknown";
       int j;
-      if( db->aDb[i].zName==0 ) continue;
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC);
+      if( db->aDb[i].zDbSName==0 ) continue;
       pBt = db->aDb[i].pBt;
       if( pBt==0 || sqlite3BtreePager(pBt)==0 ){
         zState = "closed";
-      }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0, 
+      }else if( sqlite3_file_control(db, i ? db->aDb[i].zDbSName : 0, 
                                      SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
          zState = azLockName[j];
       }
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
+      sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zDbSName, zState);
     }
     break;
   }
@@ -104386,10 +116198,329 @@ SQLITE_PRIVATE void sqlite3Pragma(
 
   } /* End of the PRAGMA switch */
 
+  /* The following block is a no-op unless SQLITE_DEBUG is defined. Its only
+  ** purpose is to execute assert() statements to verify that if the
+  ** PragFlg_NoColumns1 flag is set and the caller specified an argument
+  ** to the PRAGMA, the implementation has not added any OP_ResultRow 
+  ** instructions to the VM.  */
+  if( (pPragma->mPragFlg & PragFlg_NoColumns1) && zRight ){
+    sqlite3VdbeVerifyNoResultRow(v);
+  }
+
 pragma_out:
   sqlite3DbFree(db, zLeft);
   sqlite3DbFree(db, zRight);
 }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*****************************************************************************
+** Implementation of an eponymous virtual table that runs a pragma.
+**
+*/
+typedef struct PragmaVtab PragmaVtab;
+typedef struct PragmaVtabCursor PragmaVtabCursor;
+struct PragmaVtab {
+  sqlite3_vtab base;        /* Base class.  Must be first */
+  sqlite3 *db;              /* The database connection to which it belongs */
+  const PragmaName *pName;  /* Name of the pragma */
+  u8 nHidden;               /* Number of hidden columns */
+  u8 iHidden;               /* Index of the first hidden column */
+};
+struct PragmaVtabCursor {
+  sqlite3_vtab_cursor base; /* Base class.  Must be first */
+  sqlite3_stmt *pPragma;    /* The pragma statement to run */
+  sqlite_int64 iRowid;      /* Current rowid */
+  char *azArg[2];           /* Value of the argument and schema */
+};
+
+/* 
+** Pragma virtual table module xConnect method.
+*/
+static int pragmaVtabConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  const PragmaName *pPragma = (const PragmaName*)pAux;
+  PragmaVtab *pTab = 0;
+  int rc;
+  int i, j;
+  char cSep = '(';
+  StrAccum acc;
+  char zBuf[200];
+
+  UNUSED_PARAMETER(argc);
+  UNUSED_PARAMETER(argv);
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
+  sqlite3StrAccumAppendAll(&acc, "CREATE TABLE x");
+  for(i=0, j=pPragma->iPragCName; inPragCName; i++, j++){
+    sqlite3XPrintf(&acc, "%c\"%s\"", cSep, pragCName[j]);
+    cSep = ',';
+  }
+  if( i==0 ){
+    sqlite3XPrintf(&acc, "(\"%s\"", pPragma->zName);
+    cSep = ',';
+    i++;
+  }
+  j = 0;
+  if( pPragma->mPragFlg & PragFlg_Result1 ){
+    sqlite3StrAccumAppendAll(&acc, ",arg HIDDEN");
+    j++;
+  }
+  if( pPragma->mPragFlg & (PragFlg_SchemaOpt|PragFlg_SchemaReq) ){
+    sqlite3StrAccumAppendAll(&acc, ",schema HIDDEN");
+    j++;
+  }
+  sqlite3StrAccumAppend(&acc, ")", 1);
+  sqlite3StrAccumFinish(&acc);
+  assert( strlen(zBuf) < sizeof(zBuf)-1 );
+  rc = sqlite3_declare_vtab(db, zBuf);
+  if( rc==SQLITE_OK ){
+    pTab = (PragmaVtab*)sqlite3_malloc(sizeof(PragmaVtab));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pTab, 0, sizeof(PragmaVtab));
+      pTab->pName = pPragma;
+      pTab->db = db;
+      pTab->iHidden = i;
+      pTab->nHidden = j;
+    }
+  }else{
+    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+  }
+
+  *ppVtab = (sqlite3_vtab*)pTab;
+  return rc;
+}
+
+/* 
+** Pragma virtual table module xDisconnect method.
+*/
+static int pragmaVtabDisconnect(sqlite3_vtab *pVtab){
+  PragmaVtab *pTab = (PragmaVtab*)pVtab;
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/* Figure out the best index to use to search a pragma virtual table.
+**
+** There are not really any index choices.  But we want to encourage the
+** query planner to give == constraints on as many hidden parameters as
+** possible, and especially on the first hidden parameter.  So return a
+** high cost if hidden parameters are unconstrained.
+*/
+static int pragmaVtabBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  PragmaVtab *pTab = (PragmaVtab*)tab;
+  const struct sqlite3_index_constraint *pConstraint;
+  int i, j;
+  int seen[2];
+
+  pIdxInfo->estimatedCost = (double)1;
+  if( pTab->nHidden==0 ){ return SQLITE_OK; }
+  pConstraint = pIdxInfo->aConstraint;
+  seen[0] = 0;
+  seen[1] = 0;
+  for(i=0; inConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
+    if( pConstraint->iColumn < pTab->iHidden ) continue;
+    j = pConstraint->iColumn - pTab->iHidden;
+    assert( j < 2 );
+    seen[j] = i+1;
+  }
+  if( seen[0]==0 ){
+    pIdxInfo->estimatedCost = (double)2147483647;
+    pIdxInfo->estimatedRows = 2147483647;
+    return SQLITE_OK;
+  }
+  j = seen[0]-1;
+  pIdxInfo->aConstraintUsage[j].argvIndex = 1;
+  pIdxInfo->aConstraintUsage[j].omit = 1;
+  if( seen[1]==0 ) return SQLITE_OK;
+  pIdxInfo->estimatedCost = (double)20;
+  pIdxInfo->estimatedRows = 20;
+  j = seen[1]-1;
+  pIdxInfo->aConstraintUsage[j].argvIndex = 2;
+  pIdxInfo->aConstraintUsage[j].omit = 1;
+  return SQLITE_OK;
+}
+
+/* Create a new cursor for the pragma virtual table */
+static int pragmaVtabOpen(sqlite3_vtab *pVtab, sqlite3_vtab_cursor **ppCursor){
+  PragmaVtabCursor *pCsr;
+  pCsr = (PragmaVtabCursor*)sqlite3_malloc(sizeof(*pCsr));
+  if( pCsr==0 ) return SQLITE_NOMEM;
+  memset(pCsr, 0, sizeof(PragmaVtabCursor));
+  pCsr->base.pVtab = pVtab;
+  *ppCursor = &pCsr->base;
+  return SQLITE_OK;
+}
+
+/* Clear all content from pragma virtual table cursor. */
+static void pragmaVtabCursorClear(PragmaVtabCursor *pCsr){
+  int i;
+  sqlite3_finalize(pCsr->pPragma);
+  pCsr->pPragma = 0;
+  for(i=0; iazArg); i++){
+    sqlite3_free(pCsr->azArg[i]);
+    pCsr->azArg[i] = 0;
+  }
+}
+
+/* Close a pragma virtual table cursor */
+static int pragmaVtabClose(sqlite3_vtab_cursor *cur){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)cur;
+  pragmaVtabCursorClear(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/* Advance the pragma virtual table cursor to the next row */
+static int pragmaVtabNext(sqlite3_vtab_cursor *pVtabCursor){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  int rc = SQLITE_OK;
+
+  /* Increment the xRowid value */
+  pCsr->iRowid++;
+  assert( pCsr->pPragma );
+  if( SQLITE_ROW!=sqlite3_step(pCsr->pPragma) ){
+    rc = sqlite3_finalize(pCsr->pPragma);
+    pCsr->pPragma = 0;
+    pragmaVtabCursorClear(pCsr);
+  }
+  return rc;
+}
+
+/* 
+** Pragma virtual table module xFilter method.
+*/
+static int pragmaVtabFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
+  int rc;
+  int i, j;
+  StrAccum acc;
+  char *zSql;
+
+  UNUSED_PARAMETER(idxNum);
+  UNUSED_PARAMETER(idxStr);
+  pragmaVtabCursorClear(pCsr);
+  j = (pTab->pName->mPragFlg & PragFlg_Result1)!=0 ? 0 : 1;
+  for(i=0; iazArg) );
+    assert( pCsr->azArg[j]==0 );
+    if( zText ){
+      pCsr->azArg[j] = sqlite3_mprintf("%s", zText);
+      if( pCsr->azArg[j]==0 ){
+        return SQLITE_NOMEM;
+      }
+    }
+  }
+  sqlite3StrAccumInit(&acc, 0, 0, 0, pTab->db->aLimit[SQLITE_LIMIT_SQL_LENGTH]);
+  sqlite3StrAccumAppendAll(&acc, "PRAGMA ");
+  if( pCsr->azArg[1] ){
+    sqlite3XPrintf(&acc, "%Q.", pCsr->azArg[1]);
+  }
+  sqlite3StrAccumAppendAll(&acc, pTab->pName->zName);
+  if( pCsr->azArg[0] ){
+    sqlite3XPrintf(&acc, "=%Q", pCsr->azArg[0]);
+  }
+  zSql = sqlite3StrAccumFinish(&acc);
+  if( zSql==0 ) return SQLITE_NOMEM;
+  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pPragma, 0);
+  sqlite3_free(zSql);
+  if( rc!=SQLITE_OK ){
+    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
+    return rc;
+  }
+  return pragmaVtabNext(pVtabCursor);
+}
+
+/*
+** Pragma virtual table module xEof method.
+*/
+static int pragmaVtabEof(sqlite3_vtab_cursor *pVtabCursor){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  return (pCsr->pPragma==0);
+}
+
+/* The xColumn method simply returns the corresponding column from
+** the PRAGMA.  
+*/
+static int pragmaVtabColumn(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  sqlite3_context *ctx, 
+  int i
+){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
+  if( iiHidden ){
+    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pPragma, i));
+  }else{
+    sqlite3_result_text(ctx, pCsr->azArg[i-pTab->iHidden],-1,SQLITE_TRANSIENT);
+  }
+  return SQLITE_OK;
+}
+
+/* 
+** Pragma virtual table module xRowid method.
+*/
+static int pragmaVtabRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *p){
+  PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
+  *p = pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/* The pragma virtual table object */
+static const sqlite3_module pragmaVtabModule = {
+  0,                           /* iVersion */
+  0,                           /* xCreate - create a table */
+  pragmaVtabConnect,           /* xConnect - connect to an existing table */
+  pragmaVtabBestIndex,         /* xBestIndex - Determine search strategy */
+  pragmaVtabDisconnect,        /* xDisconnect - Disconnect from a table */
+  0,                           /* xDestroy - Drop a table */
+  pragmaVtabOpen,              /* xOpen - open a cursor */
+  pragmaVtabClose,             /* xClose - close a cursor */
+  pragmaVtabFilter,            /* xFilter - configure scan constraints */
+  pragmaVtabNext,              /* xNext - advance a cursor */
+  pragmaVtabEof,               /* xEof */
+  pragmaVtabColumn,            /* xColumn - read data */
+  pragmaVtabRowid,             /* xRowid - read data */
+  0,                           /* xUpdate - write data */
+  0,                           /* xBegin - begin transaction */
+  0,                           /* xSync - sync transaction */
+  0,                           /* xCommit - commit transaction */
+  0,                           /* xRollback - rollback transaction */
+  0,                           /* xFindFunction - function overloading */
+  0,                           /* xRename - rename the table */
+  0,                           /* xSavepoint */
+  0,                           /* xRelease */
+  0                            /* xRollbackTo */
+};
+
+/*
+** Check to see if zTabName is really the name of a pragma.  If it is,
+** then register an eponymous virtual table for that pragma and return
+** a pointer to the Module object for the new virtual table.
+*/
+SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){
+  const PragmaName *pName;
+  assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );
+  pName = pragmaLocate(zName+7);
+  if( pName==0 ) return 0;
+  if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;
+  assert( sqlite3HashFind(&db->aModule, zName)==0 );
+  return sqlite3VtabCreateModule(db, zName, &pragmaVtabModule, (void*)pName, 0);
+}
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #endif /* SQLITE_OMIT_PRAGMA */
 
@@ -104410,6 +116541,7 @@ pragma_out:
 ** interface, and routines that contribute to loading the database schema
 ** from disk.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Fill the InitData structure with an error message that indicates
@@ -104421,16 +116553,15 @@ static void corruptSchema(
   const char *zExtra   /* Error information */
 ){
   sqlite3 *db = pData->db;
-  if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){
+  if( !db->mallocFailed && (db->flags & SQLITE_WriteSchema)==0 ){
+    char *z;
     if( zObj==0 ) zObj = "?";
-    sqlite3SetString(pData->pzErrMsg, db,
-      "malformed database schema (%s)", zObj);
-    if( zExtra ){
-      *pData->pzErrMsg = sqlite3MAppendf(db, *pData->pzErrMsg, 
-                                 "%s - %s", *pData->pzErrMsg, zExtra);
-    }
+    z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj);
+    if( zExtra ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra);
+    sqlite3DbFree(db, *pData->pzErrMsg);
+    *pData->pzErrMsg = z;
   }
-  pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT;
+  pData->rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_CORRUPT_BKPT;
 }
 
 /*
@@ -104463,13 +116594,14 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
   if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
   if( argv[1]==0 ){
     corruptSchema(pData, argv[0], 0);
-  }else if( argv[2] && argv[2][0] ){
+  }else if( sqlite3_strnicmp(argv[2],"create ",7)==0 ){
     /* Call the parser to process a CREATE TABLE, INDEX or VIEW.
     ** But because db->init.busy is set to 1, no VDBE code is generated
     ** or executed.  All the parser does is build the internal data
     ** structures that describe the table, index, or view.
     */
     int rc;
+    u8 saved_iDb = db->init.iDb;
     sqlite3_stmt *pStmt;
     TESTONLY(int rcp);            /* Return code from sqlite3_prepare() */
 
@@ -104480,22 +116612,23 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
     TESTONLY(rcp = ) sqlite3_prepare(db, argv[2], -1, &pStmt, 0);
     rc = db->errCode;
     assert( (rc&0xFF)==(rcp&0xFF) );
-    db->init.iDb = 0;
+    db->init.iDb = saved_iDb;
+    assert( saved_iDb==0 || (db->flags & SQLITE_Vacuum)!=0 );
     if( SQLITE_OK!=rc ){
       if( db->init.orphanTrigger ){
         assert( iDb==1 );
       }else{
         pData->rc = rc;
         if( rc==SQLITE_NOMEM ){
-          db->mallocFailed = 1;
+          sqlite3OomFault(db);
         }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
           corruptSchema(pData, argv[0], sqlite3_errmsg(db));
         }
       }
     }
     sqlite3_finalize(pStmt);
-  }else if( argv[0]==0 ){
-    corruptSchema(pData, 0, 0);
+  }else if( argv[0]==0 || (argv[2]!=0 && argv[2][0]!=0) ){
+    corruptSchema(pData, argv[0], 0);
   }else{
     /* If the SQL column is blank it means this is an index that
     ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
@@ -104504,7 +116637,7 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
     ** to do here is record the root page number for that index.
     */
     Index *pIndex;
-    pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName);
+    pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zDbSName);
     if( pIndex==0 ){
       /* This can occur if there exists an index on a TEMP table which
       ** has the same name as another index on a permanent index.  Since
@@ -104533,61 +116666,27 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
 #ifndef SQLITE_OMIT_DEPRECATED
   int size;
 #endif
-  Table *pTab;
   Db *pDb;
   char const *azArg[4];
   int meta[5];
   InitData initData;
-  char const *zMasterSchema;
-  char const *zMasterName;
+  const char *zMasterName;
   int openedTransaction = 0;
 
-  /*
-  ** The master database table has a structure like this
-  */
-  static const char master_schema[] = 
-     "CREATE TABLE sqlite_master(\n"
-     "  type text,\n"
-     "  name text,\n"
-     "  tbl_name text,\n"
-     "  rootpage integer,\n"
-     "  sql text\n"
-     ")"
-  ;
-#ifndef SQLITE_OMIT_TEMPDB
-  static const char temp_master_schema[] = 
-     "CREATE TEMP TABLE sqlite_temp_master(\n"
-     "  type text,\n"
-     "  name text,\n"
-     "  tbl_name text,\n"
-     "  rootpage integer,\n"
-     "  sql text\n"
-     ")"
-  ;
-#else
-  #define temp_master_schema 0
-#endif
-
   assert( iDb>=0 && iDbnDb );
   assert( db->aDb[iDb].pSchema );
   assert( sqlite3_mutex_held(db->mutex) );
   assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
 
-  /* zMasterSchema and zInitScript are set to point at the master schema
-  ** and initialisation script appropriate for the database being
-  ** initialized. zMasterName is the name of the master table.
-  */
-  if( !OMIT_TEMPDB && iDb==1 ){
-    zMasterSchema = temp_master_schema;
-  }else{
-    zMasterSchema = master_schema;
-  }
-  zMasterName = SCHEMA_TABLE(iDb);
-
-  /* Construct the schema tables.  */
-  azArg[0] = zMasterName;
+  /* Construct the in-memory representation schema tables (sqlite_master or
+  ** sqlite_temp_master) by invoking the parser directly.  The appropriate
+  ** table name will be inserted automatically by the parser so we can just
+  ** use the abbreviation "x" here.  The parser will also automatically tag
+  ** the schema table as read-only. */
+  azArg[0] = zMasterName = SCHEMA_TABLE(iDb);
   azArg[1] = "1";
-  azArg[2] = zMasterSchema;
+  azArg[2] = "CREATE TABLE x(type text,name text,tbl_name text,"
+                            "rootpage integer,sql text)";
   azArg[3] = 0;
   initData.db = db;
   initData.iDb = iDb;
@@ -104598,10 +116697,6 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
     rc = initData.rc;
     goto error_out;
   }
-  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
-  if( ALWAYS(pTab) ){
-    pTab->tabFlags |= TF_Readonly;
-  }
 
   /* Create a cursor to hold the database open
   */
@@ -104620,7 +116715,7 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){
     rc = sqlite3BtreeBeginTrans(pDb->pBt, 0);
     if( rc!=SQLITE_OK ){
-      sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
+      sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
       goto initone_error_out;
     }
     openedTransaction = 1;
@@ -104720,8 +116815,8 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   {
     char *zSql;
     zSql = sqlite3MPrintf(db, 
-        "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid",
-        db->aDb[iDb].zName, zMasterName);
+        "SELECT name, rootpage, sql FROM \"%w\".%s ORDER BY rowid",
+        db->aDb[iDb].zDbSName, zMasterName);
 #ifndef SQLITE_OMIT_AUTHORIZATION
     {
       sqlite3_xauth xAuth;
@@ -104742,11 +116837,11 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
 #endif
   }
   if( db->mallocFailed ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     sqlite3ResetAllSchemasOfConnection(db);
   }
-  if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
-    /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
+  if( rc==SQLITE_OK || (db->flags&SQLITE_WriteSchema)){
+    /* Black magic: If the SQLITE_WriteSchema flag is set, then consider
     ** the schema loaded, even if errors occurred. In this situation the 
     ** current sqlite3_prepare() operation will fail, but the following one
     ** will attempt to compile the supplied statement against whatever subset
@@ -104770,7 +116865,7 @@ initone_error_out:
 
 error_out:
   if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return rc;
 }
@@ -104868,7 +116963,7 @@ static void schemaIsValid(Parse *pParse){
     if( !sqlite3BtreeIsInReadTrans(pBt) ){
       rc = sqlite3BtreeBeginTrans(pBt, 0);
       if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
       if( rc!=SQLITE_OK ) return;
       openedTransaction = 1;
@@ -104931,6 +117026,11 @@ SQLITE_PRIVATE void sqlite3ParserReset(Parse *pParse){
     sqlite3 *db = pParse->db;
     sqlite3DbFree(db, pParse->aLabel);
     sqlite3ExprListDelete(db, pParse->pConstExpr);
+    if( db ){
+      assert( db->lookaside.bDisable >= pParse->disableLookaside );
+      db->lookaside.bDisable -= pParse->disableLookaside;
+    }
+    pParse->disableLookaside = 0;
   }
 }
 
@@ -104941,27 +117041,31 @@ static int sqlite3Prepare(
   sqlite3 *db,              /* Database handle. */
   const char *zSql,         /* UTF-8 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
-  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
   Vdbe *pReprepare,         /* VM being reprepared */
   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
   const char **pzTail       /* OUT: End of parsed string */
 ){
-  Parse *pParse;            /* Parsing context */
   char *zErrMsg = 0;        /* Error message */
   int rc = SQLITE_OK;       /* Result code */
   int i;                    /* Loop counter */
+  Parse sParse;             /* Parsing context */
 
-  /* Allocate the parsing context */
-  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
-  if( pParse==0 ){
-    rc = SQLITE_NOMEM;
-    goto end_prepare;
-  }
-  pParse->pReprepare = pReprepare;
+  memset(&sParse, 0, PARSE_HDR_SZ);
+  memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);
+  sParse.pReprepare = pReprepare;
   assert( ppStmt && *ppStmt==0 );
-  assert( !db->mallocFailed );
+  /* assert( !db->mallocFailed ); // not true with SQLITE_USE_ALLOCA */
   assert( sqlite3_mutex_held(db->mutex) );
 
+  /* For a long-term use prepared statement avoid the use of
+  ** lookaside memory.
+  */
+  if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
+    sParse.disableLookaside++;
+    db->lookaside.bDisable++;
+  }
+
   /* Check to verify that it is possible to get a read lock on all
   ** database schemas.  The inability to get a read lock indicates that
   ** some other database connection is holding a write-lock, which in
@@ -104991,9 +117095,9 @@ static int sqlite3Prepare(
       assert( sqlite3BtreeHoldsMutex(pBt) );
       rc = sqlite3BtreeSchemaLocked(pBt);
       if( rc ){
-        const char *zDb = db->aDb[i].zName;
+        const char *zDb = db->aDb[i].zDbSName;
         sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);
-        testcase( db->flags & SQLITE_ReadUncommitted );
+        testcase( db->flags & SQLITE_ReadUncommit );
         goto end_prepare;
       }
     }
@@ -105001,8 +117105,7 @@ static int sqlite3Prepare(
 
   sqlite3VtabUnlockList(db);
 
-  pParse->db = db;
-  pParse->nQueryLoop = 0;  /* Logarithmic, so 0 really means 1 */
+  sParse.db = db;
   if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
     char *zSqlCopy;
     int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
@@ -105015,64 +117118,60 @@ static int sqlite3Prepare(
     }
     zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
     if( zSqlCopy ){
-      sqlite3RunParser(pParse, zSqlCopy, &zErrMsg);
+      sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
+      sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
       sqlite3DbFree(db, zSqlCopy);
-      pParse->zTail = &zSql[pParse->zTail-zSqlCopy];
     }else{
-      pParse->zTail = &zSql[nBytes];
+      sParse.zTail = &zSql[nBytes];
     }
   }else{
-    sqlite3RunParser(pParse, zSql, &zErrMsg);
+    sqlite3RunParser(&sParse, zSql, &zErrMsg);
   }
-  assert( 0==pParse->nQueryLoop );
+  assert( 0==sParse.nQueryLoop );
 
-  if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
-  }
-  if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
-  if( pParse->checkSchema ){
-    schemaIsValid(pParse);
+  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
+  if( sParse.checkSchema ){
+    schemaIsValid(&sParse);
   }
   if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
+    sParse.rc = SQLITE_NOMEM_BKPT;
   }
   if( pzTail ){
-    *pzTail = pParse->zTail;
+    *pzTail = sParse.zTail;
   }
-  rc = pParse->rc;
+  rc = sParse.rc;
 
 #ifndef SQLITE_OMIT_EXPLAIN
-  if( rc==SQLITE_OK && pParse->pVdbe && pParse->explain ){
+  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
     static const char * const azColName[] = {
        "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment",
        "selectid", "order", "from", "detail"
     };
     int iFirst, mx;
-    if( pParse->explain==2 ){
-      sqlite3VdbeSetNumCols(pParse->pVdbe, 4);
+    if( sParse.explain==2 ){
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 4);
       iFirst = 8;
       mx = 12;
     }else{
-      sqlite3VdbeSetNumCols(pParse->pVdbe, 8);
+      sqlite3VdbeSetNumCols(sParse.pVdbe, 8);
       iFirst = 0;
       mx = 8;
     }
     for(i=iFirst; ipVdbe, i-iFirst, COLNAME_NAME,
+      sqlite3VdbeSetColName(sParse.pVdbe, i-iFirst, COLNAME_NAME,
                             azColName[i], SQLITE_STATIC);
     }
   }
 #endif
 
   if( db->init.busy==0 ){
-    Vdbe *pVdbe = pParse->pVdbe;
-    sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag);
+    sqlite3VdbeSetSql(sParse.pVdbe, zSql, (int)(sParse.zTail-zSql), prepFlags);
   }
-  if( pParse->pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){
-    sqlite3VdbeFinalize(pParse->pVdbe);
+  if( sParse.pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){
+    sqlite3VdbeFinalize(sParse.pVdbe);
     assert(!(*ppStmt));
   }else{
-    *ppStmt = (sqlite3_stmt*)pParse->pVdbe;
+    *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
   }
 
   if( zErrMsg ){
@@ -105083,16 +117182,15 @@ static int sqlite3Prepare(
   }
 
   /* Delete any TriggerPrg structures allocated while parsing this statement. */
-  while( pParse->pTriggerPrg ){
-    TriggerPrg *pT = pParse->pTriggerPrg;
-    pParse->pTriggerPrg = pT->pNext;
+  while( sParse.pTriggerPrg ){
+    TriggerPrg *pT = sParse.pTriggerPrg;
+    sParse.pTriggerPrg = pT->pNext;
     sqlite3DbFree(db, pT);
   }
 
 end_prepare:
 
-  sqlite3ParserReset(pParse);
-  sqlite3StackFree(db, pParse);
+  sqlite3ParserReset(&sParse);
   rc = sqlite3ApiExit(db, rc);
   assert( (rc&db->errMask)==rc );
   return rc;
@@ -105101,7 +117199,7 @@ static int sqlite3LockAndPrepare(
   sqlite3 *db,              /* Database handle. */
   const char *zSql,         /* UTF-8 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
-  int saveSqlFlag,          /* True to copy SQL text into the sqlite3_stmt */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
   Vdbe *pOld,               /* VM being reprepared */
   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
   const char **pzTail       /* OUT: End of parsed string */
@@ -105117,10 +117215,10 @@ static int sqlite3LockAndPrepare(
   }
   sqlite3_mutex_enter(db->mutex);
   sqlite3BtreeEnterAll(db);
-  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
+  rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
   if( rc==SQLITE_SCHEMA ){
     sqlite3_finalize(*ppStmt);
-    rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail);
+    rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
   }
   sqlite3BtreeLeaveAll(db);
   sqlite3_mutex_leave(db->mutex);
@@ -105141,16 +117239,18 @@ SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){
   sqlite3_stmt *pNew;
   const char *zSql;
   sqlite3 *db;
+  u8 prepFlags;
 
   assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
   zSql = sqlite3_sql((sqlite3_stmt *)p);
   assert( zSql!=0 );  /* Reprepare only called for prepare_v2() statements */
   db = sqlite3VdbeDb(p);
   assert( sqlite3_mutex_held(db->mutex) );
-  rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0);
+  prepFlags = sqlite3VdbePrepareFlags(p);
+  rc = sqlite3LockAndPrepare(db, zSql, -1, prepFlags, p, &pNew, 0);
   if( rc ){
     if( rc==SQLITE_NOMEM ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
     }
     assert( pNew==0 );
     return rc;
@@ -105193,8 +117293,36 @@ SQLITE_API int sqlite3_prepare_v2(
   const char **pzTail       /* OUT: End of parsed string */
 ){
   int rc;
-  rc = sqlite3LockAndPrepare(db,zSql,nBytes,1,0,ppStmt,pzTail);
-  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  /* EVIDENCE-OF: R-37923-12173 The sqlite3_prepare_v2() interface works
+  ** exactly the same as sqlite3_prepare_v3() with a zero prepFlags
+  ** parameter.
+  **
+  ** Proof in that the 5th parameter to sqlite3LockAndPrepare is 0 */
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,0,
+                             ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
+  return rc;
+}
+SQLITE_API int sqlite3_prepare_v3(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  /* EVIDENCE-OF: R-56861-42673 sqlite3_prepare_v3() differs from
+  ** sqlite3_prepare_v2() only in having the extra prepFlags parameter,
+  ** which is a bit array consisting of zero or more of the
+  ** SQLITE_PREPARE_* flags.
+  **
+  ** Proof by comparison to the implementation of sqlite3_prepare_v2()
+  ** directly above. */
+  rc = sqlite3LockAndPrepare(db,zSql,nBytes,
+                 SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
+                 0,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
   return rc;
 }
 
@@ -105207,7 +117335,7 @@ static int sqlite3Prepare16(
   sqlite3 *db,              /* Database handle. */ 
   const void *zSql,         /* UTF-16 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
-  int saveSqlFlag,          /* True to save SQL text into the sqlite3_stmt */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
   const void **pzTail       /* OUT: End of parsed string */
 ){
@@ -105235,7 +117363,7 @@ static int sqlite3Prepare16(
   sqlite3_mutex_enter(db->mutex);
   zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
   if( zSql8 ){
-    rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, 0, ppStmt, &zTail8);
+    rc = sqlite3LockAndPrepare(db, zSql8, -1, prepFlags, 0, ppStmt, &zTail8);
   }
 
   if( zTail8 && pzTail ){
@@ -105281,7 +117409,22 @@ SQLITE_API int sqlite3_prepare16_v2(
   const void **pzTail       /* OUT: End of parsed string */
 ){
   int rc;
-  rc = sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
+  rc = sqlite3Prepare16(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,ppStmt,pzTail);
+  assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
+  return rc;
+}
+SQLITE_API int sqlite3_prepare16_v3(
+  sqlite3 *db,              /* Database handle. */ 
+  const void *zSql,         /* UTF-16 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const void **pzTail       /* OUT: End of parsed string */
+){
+  int rc;
+  rc = sqlite3Prepare16(db,zSql,nBytes,
+         SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
+         ppStmt,pzTail);
   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
   return rc;
 }
@@ -105304,6 +117447,7 @@ SQLITE_API int sqlite3_prepare16_v2(
 ** This file contains C code routines that are called by the parser
 ** to handle SELECT statements in SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Trace output macros
@@ -105312,7 +117456,8 @@ SQLITE_API int sqlite3_prepare16_v2(
 /***/ int sqlite3SelectTrace = 0;
 # define SELECTTRACE(K,P,S,X)  \
   if(sqlite3SelectTrace&(K))   \
-    sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",(S)->zSelName,(S)),\
+    sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",\
+        (S)->zSelName,(S)),\
     sqlite3DebugPrintf X
 #else
 # define SELECTTRACE(K,P,S,X)
@@ -105344,7 +117489,9 @@ struct SortCtx {
   int regReturn;        /* Register holding block-output return address */
   int labelBkOut;       /* Start label for the block-output subroutine */
   int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */
+  int labelDone;        /* Jump here when done, ex: LIMIT reached */
   u8 sortFlags;         /* Zero or more SORTFLAG_* bits */
+  u8 bOrderedInnerLoop; /* ORDER BY correctly sorts the inner loop */
 };
 #define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */
 
@@ -105363,8 +117510,8 @@ static void clearSelect(sqlite3 *db, Select *p, int bFree){
     sqlite3ExprListDelete(db, p->pOrderBy);
     sqlite3ExprDelete(db, p->pLimit);
     sqlite3ExprDelete(db, p->pOffset);
-    sqlite3WithDelete(db, p->pWith);
-    if( bFree ) sqlite3DbFree(db, p);
+    if( p->pWith ) sqlite3WithDelete(db, p->pWith);
+    if( bFree ) sqlite3DbFreeNN(db, p);
     p = pPrior;
     bFree = 1;
   }
@@ -105376,7 +117523,7 @@ static void clearSelect(sqlite3 *db, Select *p, int bFree){
 SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
   pDest->eDest = (u8)eDest;
   pDest->iSDParm = iParm;
-  pDest->affSdst = 0;
+  pDest->zAffSdst = 0;
   pDest->iSdst = 0;
   pDest->nSdst = 0;
 }
@@ -105394,39 +117541,45 @@ SQLITE_PRIVATE Select *sqlite3SelectNew(
   ExprList *pGroupBy,   /* the GROUP BY clause */
   Expr *pHaving,        /* the HAVING clause */
   ExprList *pOrderBy,   /* the ORDER BY clause */
-  u16 selFlags,         /* Flag parameters, such as SF_Distinct */
+  u32 selFlags,         /* Flag parameters, such as SF_Distinct */
   Expr *pLimit,         /* LIMIT value.  NULL means not used */
   Expr *pOffset         /* OFFSET value.  NULL means no offset */
 ){
   Select *pNew;
   Select standin;
-  sqlite3 *db = pParse->db;
-  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
-  assert( db->mallocFailed || !pOffset || pLimit ); /* OFFSET implies LIMIT */
+  pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
   if( pNew==0 ){
-    assert( db->mallocFailed );
+    assert( pParse->db->mallocFailed );
     pNew = &standin;
-    memset(pNew, 0, sizeof(*pNew));
   }
   if( pEList==0 ){
-    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0));
+    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(pParse->db,TK_ASTERISK,0));
   }
   pNew->pEList = pEList;
-  if( pSrc==0 ) pSrc = sqlite3DbMallocZero(db, sizeof(*pSrc));
+  pNew->op = TK_SELECT;
+  pNew->selFlags = selFlags;
+  pNew->iLimit = 0;
+  pNew->iOffset = 0;
+#if SELECTTRACE_ENABLED
+  pNew->zSelName[0] = 0;
+#endif
+  pNew->addrOpenEphm[0] = -1;
+  pNew->addrOpenEphm[1] = -1;
+  pNew->nSelectRow = 0;
+  if( pSrc==0 ) pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*pSrc));
   pNew->pSrc = pSrc;
   pNew->pWhere = pWhere;
   pNew->pGroupBy = pGroupBy;
   pNew->pHaving = pHaving;
   pNew->pOrderBy = pOrderBy;
-  pNew->selFlags = selFlags;
-  pNew->op = TK_SELECT;
+  pNew->pPrior = 0;
+  pNew->pNext = 0;
   pNew->pLimit = pLimit;
   pNew->pOffset = pOffset;
-  assert( pOffset==0 || pLimit!=0 );
-  pNew->addrOpenEphm[0] = -1;
-  pNew->addrOpenEphm[1] = -1;
-  if( db->mallocFailed ) {
-    clearSelect(db, pNew, pNew!=&standin);
+  pNew->pWith = 0;
+  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0 || pParse->db->mallocFailed!=0 );
+  if( pParse->db->mallocFailed ) {
+    clearSelect(pParse->db, pNew, pNew!=&standin);
     pNew = 0;
   }else{
     assert( pNew->pSrc!=0 || pParse->nErr>0 );
@@ -105451,7 +117604,7 @@ SQLITE_PRIVATE void sqlite3SelectSetName(Select *p, const char *zName){
 ** Delete the given Select structure and all of its substructures.
 */
 SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3 *db, Select *p){
-  clearSelect(db, p, 1);
+  if( p ) clearSelect(db, p, 1);
 }
 
 /*
@@ -105615,7 +117768,7 @@ static void addWhereTerm(
   pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
   pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);
 
-  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
+  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2);
   if( pEq && isOuterJoin ){
     ExprSetProperty(pEq, EP_FromJoin);
     assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
@@ -105657,6 +117810,12 @@ static void setJoinExpr(Expr *p, int iTable){
     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
     ExprSetVVAProperty(p, EP_NoReduce);
     p->iRightJoinTable = (i16)iTable;
+    if( p->op==TK_FUNCTION && p->x.pList ){
+      int i;
+      for(i=0; ix.pList->nExpr; i++){
+        setJoinExpr(p->x.pList->a[i].pExpr, iTable);
+      }
+    }
     setJoinExpr(p->pLeft, iTable);
     p = p->pRight;
   } 
@@ -105691,12 +117850,12 @@ static int sqliteProcessJoin(Parse *pParse, Select *p){
     int isOuter;
 
     if( NEVER(pLeftTab==0 || pRightTab==0) ) continue;
-    isOuter = (pRight->jointype & JT_OUTER)!=0;
+    isOuter = (pRight->fg.jointype & JT_OUTER)!=0;
 
     /* When the NATURAL keyword is present, add WHERE clause terms for
     ** every column that the two tables have in common.
     */
-    if( pRight->jointype & JT_NATURAL ){
+    if( pRight->fg.jointype & JT_NATURAL ){
       if( pRight->pOn || pRight->pUsing ){
         sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
            "an ON or USING clause", 0);
@@ -105781,6 +117940,7 @@ static void pushOntoSorter(
   SortCtx *pSort,        /* Information about the ORDER BY clause */
   Select *pSelect,       /* The whole SELECT statement */
   int regData,           /* First register holding data to be sorted */
+  int regOrigData,       /* First register holding data before packing */
   int nData,             /* Number of elements in the data array */
   int nPrefixReg         /* No. of reg prior to regData available for use */
 ){
@@ -105792,8 +117952,10 @@ static void pushOntoSorter(
   int regRecord = ++pParse->nMem;                  /* Assembled sorter record */
   int nOBSat = pSort->nOBSat;                      /* ORDER BY terms to skip */
   int op;                            /* Opcode to add sorter record to sorter */
+  int iLimit;                        /* LIMIT counter */
 
   assert( bSeq==0 || bSeq==1 );
+  assert( nData==1 || regData==regOrigData || regOrigData==0 );
   if( nPrefixReg ){
     assert( nPrefixReg==nExpr+bSeq );
     regBase = regData - nExpr - bSeq;
@@ -105801,14 +117963,17 @@ static void pushOntoSorter(
     regBase = pParse->nMem + 1;
     pParse->nMem += nBase;
   }
-  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, SQLITE_ECEL_DUP);
+  assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );
+  iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
+  pSort->labelDone = sqlite3VdbeMakeLabel(v);
+  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
+                          SQLITE_ECEL_DUP | (regOrigData? SQLITE_ECEL_REF : 0));
   if( bSeq ){
     sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
   }
-  if( nPrefixReg==0 ){
+  if( nPrefixReg==0 && nData>0 ){
     sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
   }
-
   sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
   if( nOBSat>0 ){
     int regPrevKey;   /* The first nOBSat columns of the previous row */
@@ -105843,6 +118008,10 @@ static void pushOntoSorter(
     pSort->regReturn = ++pParse->nMem;
     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
     sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
+    if( iLimit ){
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);
+      VdbeCoverage(v);
+    }
     sqlite3VdbeJumpHere(v, addrFirst);
     sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
     sqlite3VdbeJumpHere(v, addrJmp);
@@ -105852,22 +118021,35 @@ static void pushOntoSorter(
   }else{
     op = OP_IdxInsert;
   }
-  sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
-  if( pSelect->iLimit ){
-    int addr1, addr2;
-    int iLimit;
-    if( pSelect->iOffset ){
-      iLimit = pSelect->iOffset+1;
-    }else{
-      iLimit = pSelect->iLimit;
-    }
-    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1);
-    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
-    sqlite3VdbeJumpHere(v, addr1);
+  sqlite3VdbeAddOp4Int(v, op, pSort->iECursor, regRecord,
+                       regBase+nOBSat, nBase-nOBSat);
+  if( iLimit ){
+    int addr;
+    int r1 = 0;
+    /* Fill the sorter until it contains LIMIT+OFFSET entries.  (The iLimit
+    ** register is initialized with value of LIMIT+OFFSET.)  After the sorter
+    ** fills up, delete the least entry in the sorter after each insert.
+    ** Thus we never hold more than the LIMIT+OFFSET rows in memory at once */
+    addr = sqlite3VdbeAddOp1(v, OP_IfNotZero, iLimit); VdbeCoverage(v);
     sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
+    if( pSort->bOrderedInnerLoop ){
+      r1 = ++pParse->nMem;
+      sqlite3VdbeAddOp3(v, OP_Column, pSort->iECursor, nExpr, r1);
+      VdbeComment((v, "seq"));
+    }
     sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
-    sqlite3VdbeJumpHere(v, addr2);
+    if( pSort->bOrderedInnerLoop ){
+      /* If the inner loop is driven by an index such that values from
+      ** the same iteration of the inner loop are in sorted order, then
+      ** immediately jump to the next iteration of an inner loop if the
+      ** entry from the current iteration does not fit into the top
+      ** LIMIT+OFFSET entries of the sorter. */
+      int iBrk = sqlite3VdbeCurrentAddr(v) + 2;
+      sqlite3VdbeAddOp3(v, OP_Eq, regBase+nExpr, iBrk, r1);
+      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+      VdbeCoverage(v);
+    }
+    sqlite3VdbeJumpHere(v, addr);
   }
 }
 
@@ -105880,11 +118062,8 @@ static void codeOffset(
   int iContinue     /* Jump here to skip the current record */
 ){
   if( iOffset>0 ){
-    int addr;
-    addr = sqlite3VdbeAddOp3(v, OP_IfNeg, iOffset, 0, -1); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue);
-    VdbeComment((v, "skip OFFSET records"));
-    sqlite3VdbeJumpHere(v, addr);
+    sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);
+    VdbeComment((v, "OFFSET"));
   }
 }
 
@@ -105911,34 +118090,11 @@ static void codeDistinct(
   r1 = sqlite3GetTempReg(pParse);
   sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
   sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
-  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
+  sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r1, iMem, N);
+  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
   sqlite3ReleaseTempReg(pParse, r1);
 }
 
-#ifndef SQLITE_OMIT_SUBQUERY
-/*
-** Generate an error message when a SELECT is used within a subexpression
-** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
-** column.  We do this in a subroutine because the error used to occur
-** in multiple places.  (The error only occurs in one place now, but we
-** retain the subroutine to minimize code disruption.)
-*/
-static int checkForMultiColumnSelectError(
-  Parse *pParse,       /* Parse context. */
-  SelectDest *pDest,   /* Destination of SELECT results */
-  int nExpr            /* Number of result columns returned by SELECT */
-){
-  int eDest = pDest->eDest;
-  if( nExpr>1 && (eDest==SRT_Mem || eDest==SRT_Set) ){
-    sqlite3ErrorMsg(pParse, "only a single result allowed for "
-       "a SELECT that is part of an expression");
-    return 1;
-  }else{
-    return 0;
-  }
-}
-#endif
-
 /*
 ** This routine generates the code for the inside of the inner loop
 ** of a SELECT.
@@ -105946,7 +118102,7 @@ static int checkForMultiColumnSelectError(
 ** If srcTab is negative, then the pEList expressions
 ** are evaluated in order to get the data for this row.  If srcTab is
 ** zero or more, then data is pulled from srcTab and pEList is used only 
-** to get number columns and the datatype for each column.
+** to get the number of columns and the collation sequence for each column.
 */
 static void selectInnerLoop(
   Parse *pParse,          /* The parser context */
@@ -105961,13 +118117,20 @@ static void selectInnerLoop(
 ){
   Vdbe *v = pParse->pVdbe;
   int i;
-  int hasDistinct;        /* True if the DISTINCT keyword is present */
-  int regResult;              /* Start of memory holding result set */
+  int hasDistinct;            /* True if the DISTINCT keyword is present */
   int eDest = pDest->eDest;   /* How to dispose of results */
   int iParm = pDest->iSDParm; /* First argument to disposal method */
   int nResultCol;             /* Number of result columns */
   int nPrefixReg = 0;         /* Number of extra registers before regResult */
 
+  /* Usually, regResult is the first cell in an array of memory cells
+  ** containing the current result row. In this case regOrig is set to the
+  ** same value. However, if the results are being sent to the sorter, the
+  ** values for any expressions that are also part of the sort-key are omitted
+  ** from this array. In this case regOrig is set to zero.  */
+  int regResult;              /* Start of memory holding current results */
+  int regOrig;                /* Start of memory holding full result (or 0) */
+
   assert( v );
   assert( pEList!=0 );
   hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
@@ -105998,7 +118161,7 @@ static void selectInnerLoop(
     pParse->nMem += nResultCol;
   }
   pDest->nSdst = nResultCol;
-  regResult = pDest->iSdst;
+  regOrig = regResult = pDest->iSdst;
   if( srcTab>=0 ){
     for(i=0; ipOrderBy), set the associated 
+      ** iOrderByCol value to one more than the index of the ORDER BY 
+      ** expression within the sort-key that pushOntoSorter() will generate.
+      ** This allows the pEList field to be omitted from the sorted record,
+      ** saving space and CPU cycles.  */
+      ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);
+      for(i=pSort->nOBSat; ipOrderBy->nExpr; i++){
+        int j;
+        if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){
+          pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;
+        }
+      }
+      regOrig = 0;
+      assert( eDest==SRT_Set || eDest==SRT_Mem 
+           || eDest==SRT_Coroutine || eDest==SRT_Output );
+    }
+    nResultCol = sqlite3ExprCodeExprList(pParse,pEList,regResult,0,ecelFlags);
   }
 
   /* If the DISTINCT keyword was present on the SELECT statement
@@ -106064,7 +118250,8 @@ static void selectInnerLoop(
 
       default: {
         assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
-        codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol, regResult);
+        codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,
+                     regResult);
         break;
       }
     }
@@ -106082,7 +118269,7 @@ static void selectInnerLoop(
       int r1;
       r1 = sqlite3GetTempReg(pParse);
       sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
       sqlite3ReleaseTempReg(pParse, r1);
       break;
     }
@@ -106106,6 +118293,8 @@ static void selectInnerLoop(
       int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
       testcase( eDest==SRT_Table );
       testcase( eDest==SRT_EphemTab );
+      testcase( eDest==SRT_Fifo );
+      testcase( eDest==SRT_DistFifo );
       sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
 #ifndef SQLITE_OMIT_CTE
       if( eDest==SRT_DistFifo ){
@@ -106115,13 +118304,14 @@ static void selectInnerLoop(
         ** current row to the index and proceed with writing it to the
         ** output table as well.  */
         int addr = sqlite3VdbeCurrentAddr(v) + 4;
-        sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1);
+        sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);
+        VdbeCoverage(v);
+        sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm+1, r1,regResult,nResultCol);
         assert( pSort==0 );
       }
 #endif
       if( pSort ){
-        pushOntoSorter(pParse, pSort, p, r1+nPrefixReg, 1, nPrefixReg);
+        pushOntoSorter(pParse, pSort, p, r1+nPrefixReg,regResult,1,nPrefixReg);
       }else{
         int r2 = sqlite3GetTempReg(pParse);
         sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
@@ -106139,20 +118329,20 @@ static void selectInnerLoop(
     ** item into the set table with bogus data.
     */
     case SRT_Set: {
-      assert( nResultCol==1 );
-      pDest->affSdst =
-                  sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst);
       if( pSort ){
         /* At first glance you would think we could optimize out the
         ** ORDER BY in this case since the order of entries in the set
         ** does not matter.  But there might be a LIMIT clause, in which
         ** case the order does matter */
-        pushOntoSorter(pParse, pSort, p, regResult, 1, nPrefixReg);
+        pushOntoSorter(
+            pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
       }else{
         int r1 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult,1,r1, &pDest->affSdst, 1);
-        sqlite3ExprCacheAffinityChange(pParse, regResult, 1);
-        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+        assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol );
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, nResultCol, 
+            r1, pDest->zAffSdst, nResultCol);
+        sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
+        sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
         sqlite3ReleaseTempReg(pParse, r1);
       }
       break;
@@ -106167,14 +118357,16 @@ static void selectInnerLoop(
     }
 
     /* If this is a scalar select that is part of an expression, then
-    ** store the results in the appropriate memory cell and break out
-    ** of the scan loop.
+    ** store the results in the appropriate memory cell or array of 
+    ** memory cells and break out of the scan loop.
     */
     case SRT_Mem: {
-      assert( nResultCol==1 );
       if( pSort ){
-        pushOntoSorter(pParse, pSort, p, regResult, 1, nPrefixReg);
+        assert( nResultCol<=pDest->nSdst );
+        pushOntoSorter(
+            pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
       }else{
+        assert( nResultCol==pDest->nSdst );
         assert( regResult==iParm );
         /* The LIMIT clause will jump out of the loop for us */
       }
@@ -106187,7 +118379,8 @@ static void selectInnerLoop(
       testcase( eDest==SRT_Coroutine );
       testcase( eDest==SRT_Output );
       if( pSort ){
-        pushOntoSorter(pParse, pSort, p, regResult, nResultCol, nPrefixReg);
+        pushOntoSorter(pParse, pSort, p, regResult, regOrig, nResultCol,
+                       nPrefixReg);
       }else if( eDest==SRT_Coroutine ){
         sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
       }else{
@@ -106236,7 +118429,7 @@ static void selectInnerLoop(
       }
       sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);
       sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, r2, nKey+2);
       if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);
       sqlite3ReleaseTempReg(pParse, r1);
       sqlite3ReleaseTempRange(pParse, r2, nKey+2);
@@ -106264,7 +118457,7 @@ static void selectInnerLoop(
   ** the output for us.
   */
   if( pSort==0 && p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
   }
 }
 
@@ -106273,8 +118466,8 @@ static void selectInnerLoop(
 ** X extra columns.
 */
 SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
-  KeyInfo *p = sqlite3DbMallocZero(0, 
-                   sizeof(KeyInfo) + (N+X)*(sizeof(CollSeq*)+1));
+  int nExtra = (N+X)*(sizeof(CollSeq*)+1) - sizeof(CollSeq*);
+  KeyInfo *p = sqlite3DbMallocRawNN(db, sizeof(KeyInfo) + nExtra);
   if( p ){
     p->aSortOrder = (u8*)&p->aColl[N+X];
     p->nField = (u16)N;
@@ -106282,8 +118475,9 @@ SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
     p->enc = ENC(db);
     p->db = db;
     p->nRef = 1;
+    memset(&p[1], 0, nExtra);
   }else{
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return p;
 }
@@ -106295,7 +118489,7 @@ SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo *p){
   if( p ){
     assert( p->nRef>0 );
     p->nRef--;
-    if( p->nRef==0 ) sqlite3DbFree(0, p);
+    if( p->nRef==0 ) sqlite3DbFreeNN(p->db, p);
   }
 }
 
@@ -106361,7 +118555,6 @@ static KeyInfo *keyInfoFromExprList(
   return pInfo;
 }
 
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
 /*
 ** Name of the connection operator, used for error messages.
 */
@@ -106375,7 +118568,6 @@ static const char *selectOpName(int id){
   }
   return z;
 }
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
 
 #ifndef SQLITE_OMIT_EXPLAIN
 /*
@@ -106462,7 +118654,7 @@ static void generateSortTail(
   SelectDest *pDest /* Write the sorted results here */
 ){
   Vdbe *v = pParse->pVdbe;                     /* The prepared statement */
-  int addrBreak = sqlite3VdbeMakeLabel(v);     /* Jump here to exit loop */
+  int addrBreak = pSort->labelDone;            /* Jump here to exit loop */
   int addrContinue = sqlite3VdbeMakeLabel(v);  /* Jump here for next cycle */
   int addr;
   int addrOnce = 0;
@@ -106472,36 +118664,36 @@ static void generateSortTail(
   int iParm = pDest->iSDParm;
   int regRow;
   int regRowid;
+  int iCol;
   int nKey;
   int iSortTab;                   /* Sorter cursor to read from */
   int nSortData;                  /* Trailing values to read from sorter */
   int i;
   int bSeq;                       /* True if sorter record includes seq. no. */
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   struct ExprList_item *aOutEx = p->pEList->a;
-#endif
 
+  assert( addrBreak<0 );
   if( pSort->labelBkOut ){
     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak);
+    sqlite3VdbeGoto(v, addrBreak);
     sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
   }
   iTab = pSort->iECursor;
-  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
+  if( eDest==SRT_Output || eDest==SRT_Coroutine || eDest==SRT_Mem ){
     regRowid = 0;
     regRow = pDest->iSdst;
     nSortData = nColumn;
   }else{
     regRowid = sqlite3GetTempReg(pParse);
-    regRow = sqlite3GetTempReg(pParse);
-    nSortData = 1;
+    regRow = sqlite3GetTempRange(pParse, nColumn);
+    nSortData = nColumn;
   }
   nKey = pOrderBy->nExpr - pSort->nOBSat;
   if( pSort->sortFlags & SORTFLAG_UseSorter ){
     int regSortOut = ++pParse->nMem;
     iSortTab = pParse->nTab++;
     if( pSort->labelBkOut ){
-      addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+      addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
     }
     sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, nKey+1+nSortData);
     if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
@@ -106516,15 +118708,19 @@ static void generateSortTail(
     iSortTab = iTab;
     bSeq = 1;
   }
-  for(i=0; iaffSdst, 1);
-      sqlite3ExprCacheAffinityChange(pParse, regRow, 1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
+      assert( nColumn==sqlite3Strlen30(pDest->zAffSdst) );
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, nColumn, regRowid,
+                        pDest->zAffSdst, nColumn);
+      sqlite3ExprCacheAffinityChange(pParse, regRow, nColumn);
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, regRowid, regRow, nColumn);
       break;
     }
     case SRT_Mem: {
-      assert( nColumn==1 );
-      sqlite3ExprCodeMove(pParse, regRow, iParm, 1);
       /* The LIMIT clause will terminate the loop for us */
       break;
     }
@@ -106560,7 +118754,11 @@ static void generateSortTail(
     }
   }
   if( regRowid ){
-    sqlite3ReleaseTempReg(pParse, regRow);
+    if( eDest==SRT_Set ){
+      sqlite3ReleaseTempRange(pParse, regRow, nColumn);
+    }else{
+      sqlite3ReleaseTempReg(pParse, regRow);
+    }
     sqlite3ReleaseTempReg(pParse, regRowid);
   }
   /* The bottom of the loop
@@ -106601,30 +118799,30 @@ static void generateSortTail(
 */
 #ifdef SQLITE_ENABLE_COLUMN_METADATA
 # define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,C,D,E,F)
+#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
+# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F)
+#endif
 static const char *columnTypeImpl(
   NameContext *pNC, 
   Expr *pExpr,
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
   const char **pzOrigDb,
   const char **pzOrigTab,
   const char **pzOrigCol,
+#endif
   u8 *pEstWidth
 ){
-  char const *zOrigDb = 0;
-  char const *zOrigTab = 0;
-  char const *zOrigCol = 0;
-#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
-# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F)
-static const char *columnTypeImpl(
-  NameContext *pNC, 
-  Expr *pExpr,
-  u8 *pEstWidth
-){
-#endif /* !defined(SQLITE_ENABLE_COLUMN_METADATA) */
   char const *zType = 0;
   int j;
   u8 estWidth = 1;
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+  char const *zOrigDb = 0;
+  char const *zOrigTab = 0;
+  char const *zOrigCol = 0;
+#endif
 
-  if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0;
+  assert( pExpr!=0 );
+  assert( pNC->pSrcList!=0 );
   switch( pExpr->op ){
     case TK_AGG_COLUMN:
     case TK_COLUMN: {
@@ -106675,7 +118873,7 @@ static const char *columnTypeImpl(
         ** of the SELECT statement. Return the declaration type and origin
         ** data for the result-set column of the sub-select.
         */
-        if( iCol>=0 && ALWAYS(iColpEList->nExpr) ){
+        if( iCol>=0 && iColpEList->nExpr ){
           /* If iCol is less than zero, then the expression requests the
           ** rowid of the sub-select or view. This expression is legal (see 
           ** test case misc2.2.2) - it always evaluates to NULL.
@@ -106697,20 +118895,20 @@ static const char *columnTypeImpl(
           zType = "INTEGER";
           zOrigCol = "rowid";
         }else{
-          zType = pTab->aCol[iCol].zType;
           zOrigCol = pTab->aCol[iCol].zName;
+          zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
           estWidth = pTab->aCol[iCol].szEst;
         }
         zOrigTab = pTab->zName;
         if( pNC->pParse ){
           int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
-          zOrigDb = pNC->pParse->db->aDb[iDb].zName;
+          zOrigDb = pNC->pParse->db->aDb[iDb].zDbSName;
         }
 #else
         if( iCol<0 ){
           zType = "INTEGER";
         }else{
-          zType = pTab->aCol[iCol].zType;
+          zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
           estWidth = pTab->aCol[iCol].szEst;
         }
 #endif
@@ -106763,6 +118961,7 @@ static void generateColumnTypes(
   NameContext sNC;
   sNC.pSrcList = pTabList;
   sNC.pParse = pParse;
+  sNC.pNext = 0;
   for(i=0; inExpr; i++){
     Expr *p = pEList->a[i].pExpr;
     const char *zType;
@@ -106787,20 +118986,49 @@ static void generateColumnTypes(
 #endif /* !defined(SQLITE_OMIT_DECLTYPE) */
 }
 
+
 /*
-** Generate code that will tell the VDBE the names of columns
-** in the result set.  This information is used to provide the
-** azCol[] values in the callback.
+** Compute the column names for a SELECT statement.
+**
+** The only guarantee that SQLite makes about column names is that if the
+** column has an AS clause assigning it a name, that will be the name used.
+** That is the only documented guarantee.  However, countless applications
+** developed over the years have made baseless assumptions about column names
+** and will break if those assumptions changes.  Hence, use extreme caution
+** when modifying this routine to avoid breaking legacy.
+**
+** See Also: sqlite3ColumnsFromExprList()
+**
+** The PRAGMA short_column_names and PRAGMA full_column_names settings are
+** deprecated.  The default setting is short=ON, full=OFF.  99.9% of all
+** applications should operate this way.  Nevertheless, we need to support the
+** other modes for legacy:
+**
+**    short=OFF, full=OFF:      Column name is the text of the expression has it
+**                              originally appears in the SELECT statement.  In
+**                              other words, the zSpan of the result expression.
+**
+**    short=ON, full=OFF:       (This is the default setting).  If the result
+**                              refers directly to a table column, then the result
+**                              column name is just the table column name: COLUMN. 
+**                              Otherwise use zSpan.
+**
+**    full=ON, short=ANY:       If the result refers directly to a table column,
+**                              then the result column name with the table name
+**                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.
 */
 static void generateColumnNames(
   Parse *pParse,      /* Parser context */
-  SrcList *pTabList,  /* List of tables */
-  ExprList *pEList    /* Expressions defining the result set */
+  Select *pSelect     /* Generate column names for this SELECT statement */
 ){
   Vdbe *v = pParse->pVdbe;
-  int i, j;
+  int i;
+  Table *pTab;
+  SrcList *pTabList;
+  ExprList *pEList;
   sqlite3 *db = pParse->db;
-  int fullNames, shortNames;
+  int fullName;    /* TABLE.COLUMN if no AS clause and is a direct table ref */
+  int srcName;     /* COLUMN or TABLE.COLUMN if no AS clause and is direct */
 
 #ifndef SQLITE_OMIT_EXPLAIN
   /* If this is an EXPLAIN, skip this step */
@@ -106809,27 +119037,30 @@ static void generateColumnNames(
   }
 #endif
 
-  if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return;
+  if( pParse->colNamesSet || db->mallocFailed ) return;
+  /* Column names are determined by the left-most term of a compound select */
+  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
+  pTabList = pSelect->pSrc;
+  pEList = pSelect->pEList;
+  assert( v!=0 );
+  assert( pTabList!=0 );
   pParse->colNamesSet = 1;
-  fullNames = (db->flags & SQLITE_FullColNames)!=0;
-  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
+  fullName = (db->flags & SQLITE_FullColNames)!=0;
+  srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
   sqlite3VdbeSetNumCols(v, pEList->nExpr);
   for(i=0; inExpr; i++){
-    Expr *p;
-    p = pEList->a[i].pExpr;
-    if( NEVER(p==0) ) continue;
+    Expr *p = pEList->a[i].pExpr;
+
+    assert( p!=0 );
     if( pEList->a[i].zName ){
+      /* An AS clause always takes first priority */
       char *zName = pEList->a[i].zName;
       sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
-    }else if( (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN) && pTabList ){
-      Table *pTab;
+    }else if( srcName && p->op==TK_COLUMN ){
       char *zCol;
       int iCol = p->iColumn;
-      for(j=0; ALWAYS(jnSrc); j++){
-        if( pTabList->a[j].iCursor==p->iTable ) break;
-      }
-      assert( jnSrc );
-      pTab = pTabList->a[j].pTab;
+      pTab = p->pTab;
+      assert( pTab!=0 );
       if( iCol<0 ) iCol = pTab->iPKey;
       assert( iCol==-1 || (iCol>=0 && iColnCol) );
       if( iCol<0 ){
@@ -106837,10 +119068,7 @@ static void generateColumnNames(
       }else{
         zCol = pTab->aCol[iCol].zName;
       }
-      if( !shortNames && !fullNames ){
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, 
-            sqlite3DbStrDup(db, pEList->a[i].zSpan), SQLITE_DYNAMIC);
-      }else if( fullNames ){
+      if( fullName ){
         char *zName = 0;
         zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);
         sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);
@@ -106868,8 +119096,17 @@ static void generateColumnNames(
 **
 ** Return SQLITE_OK on success.  If a memory allocation error occurs,
 ** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.
+**
+** The only guarantee that SQLite makes about column names is that if the
+** column has an AS clause assigning it a name, that will be the name used.
+** That is the only documented guarantee.  However, countless applications
+** developed over the years have made baseless assumptions about column names
+** and will break if those assumptions changes.  Hence, use extreme caution
+** when modifying this routine to avoid breaking legacy.
+**
+** See Also: generateColumnNames()
 */
-static int selectColumnsFromExprList(
+SQLITE_PRIVATE int sqlite3ColumnsFromExprList(
   Parse *pParse,          /* Parsing context */
   ExprList *pEList,       /* Expr list from which to derive column names */
   i16 *pnCol,             /* Write the number of columns here */
@@ -106877,13 +119114,14 @@ static int selectColumnsFromExprList(
 ){
   sqlite3 *db = pParse->db;   /* Database connection */
   int i, j;                   /* Loop counters */
-  int cnt;                    /* Index added to make the name unique */
+  u32 cnt;                    /* Index added to make the name unique */
   Column *aCol, *pCol;        /* For looping over result columns */
   int nCol;                   /* Number of columns in the result set */
-  Expr *p;                    /* Expression for a single result column */
   char *zName;                /* Column name */
   int nName;                  /* Size of name in zName[] */
+  Hash ht;                    /* Hash table of column names */
 
+  sqlite3HashInit(&ht);
   if( pEList ){
     nCol = pEList->nExpr;
     aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
@@ -106892,63 +119130,61 @@ static int selectColumnsFromExprList(
     nCol = 0;
     aCol = 0;
   }
+  assert( nCol==(i16)nCol );
   *pnCol = nCol;
   *paCol = aCol;
 
-  for(i=0, pCol=aCol; imallocFailed; i++, pCol++){
     /* Get an appropriate name for the column
     */
-    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
     if( (zName = pEList->a[i].zName)!=0 ){
       /* If the column contains an "AS " phrase, use  as the name */
-      zName = sqlite3DbStrDup(db, zName);
     }else{
-      Expr *pColExpr = p;  /* The expression that is the result column name */
-      Table *pTab;         /* Table associated with this expression */
+      Expr *pColExpr = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
       while( pColExpr->op==TK_DOT ){
         pColExpr = pColExpr->pRight;
         assert( pColExpr!=0 );
       }
-      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
+      if( pColExpr->op==TK_COLUMN && pColExpr->pTab!=0 ){
         /* For columns use the column name name */
         int iCol = pColExpr->iColumn;
-        pTab = pColExpr->pTab;
+        Table *pTab = pColExpr->pTab;
         if( iCol<0 ) iCol = pTab->iPKey;
-        zName = sqlite3MPrintf(db, "%s",
-                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
+        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
       }else if( pColExpr->op==TK_ID ){
         assert( !ExprHasProperty(pColExpr, EP_IntValue) );
-        zName = sqlite3MPrintf(db, "%s", pColExpr->u.zToken);
+        zName = pColExpr->u.zToken;
       }else{
         /* Use the original text of the column expression as its name */
-        zName = sqlite3MPrintf(db, "%s", pEList->a[i].zSpan);
+        zName = pEList->a[i].zSpan;
       }
     }
-    if( db->mallocFailed ){
-      sqlite3DbFree(db, zName);
-      break;
+    if( zName ){
+      zName = sqlite3DbStrDup(db, zName);
+    }else{
+      zName = sqlite3MPrintf(db,"column%d",i+1);
     }
 
     /* Make sure the column name is unique.  If the name is not unique,
     ** append an integer to the name so that it becomes unique.
     */
-    nName = sqlite3Strlen30(zName);
-    for(j=cnt=0; j1 && sqlite3Isdigit(zName[k]); k--){}
-        if( k>=0 && zName[k]==':' ) nName = k;
-        zName[nName] = 0;
-        zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt);
-        sqlite3DbFree(db, zName);
-        zName = zNewName;
-        j = -1;
-        if( zName==0 ) break;
+    cnt = 0;
+    while( zName && sqlite3HashFind(&ht, zName)!=0 ){
+      nName = sqlite3Strlen30(zName);
+      if( nName>0 ){
+        for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
+        if( zName[j]==':' ) nName = j;
       }
+      zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
+      if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
     }
     pCol->zName = zName;
+    sqlite3ColumnPropertiesFromName(0, pCol);
+    if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
+      sqlite3OomFault(db);
+    }
   }
+  sqlite3HashClear(&ht);
   if( db->mallocFailed ){
     for(j=0; jpSrc;
   a = pSelect->pEList->a;
   for(i=0, pCol=pTab->aCol; inCol; i++, pCol++){
+    const char *zType;
+    int n, m;
     p = a[i].pExpr;
-    pCol->zType = sqlite3DbStrDup(db, columnType(&sNC, p,0,0,0, &pCol->szEst));
+    zType = columnType(&sNC, p, 0, 0, 0, &pCol->szEst);
     szAll += pCol->szEst;
     pCol->affinity = sqlite3ExprAffinity(p);
-    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_NONE;
+    if( zType && (m = sqlite3Strlen30(zType))>0 ){
+      n = sqlite3Strlen30(pCol->zName);
+      pCol->zName = sqlite3DbReallocOrFree(db, pCol->zName, n+m+2);
+      if( pCol->zName ){
+        memcpy(&pCol->zName[n+1], zType, m+1);
+        pCol->colFlags |= COLFLAG_HASTYPE;
+      }
+    }
+    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB;
     pColl = sqlite3ExprCollSeq(pParse, p);
-    if( pColl ){
+    if( pColl && pCol->zColl==0 ){
       pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
     }
   }
@@ -107029,12 +119275,12 @@ SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
   }
   /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
   ** is disabled */
-  assert( db->lookaside.bEnabled==0 );
-  pTab->nRef = 1;
+  assert( db->lookaside.bDisable );
+  pTab->nTabRef = 1;
   pTab->zName = 0;
   pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
-  selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
-  selectAddColumnTypeAndCollation(pParse, pTab, pSelect);
+  sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
+  sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSelect);
   pTab->iPKey = -1;
   if( db->mallocFailed ){
     sqlite3DeleteTable(db, pTab);
@@ -107047,20 +119293,20 @@ SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
 ** Get a VDBE for the given parser context.  Create a new one if necessary.
 ** If an error occurs, return NULL and leave a message in pParse.
 */
-SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
-  Vdbe *v = pParse->pVdbe;
-  if( v==0 ){
-    v = pParse->pVdbe = sqlite3VdbeCreate(pParse);
-    if( v ) sqlite3VdbeAddOp0(v, OP_Init);
-    if( pParse->pToplevel==0
-     && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
-    ){
-      pParse->okConstFactor = 1;
-    }
-
+static SQLITE_NOINLINE Vdbe *allocVdbe(Parse *pParse){
+  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(pParse);
+  if( v ) sqlite3VdbeAddOp2(v, OP_Init, 0, 1);
+  if( pParse->pToplevel==0
+   && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
+  ){
+    pParse->okConstFactor = 1;
   }
   return v;
 }
+SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
+  Vdbe *v = pParse->pVdbe;
+  return v ? v : allocVdbe(pParse);
+}
 
 
 /*
@@ -107090,7 +119336,7 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
   Vdbe *v = 0;
   int iLimit = 0;
   int iOffset;
-  int addr1, n;
+  int n;
   if( p->iLimit ) return;
 
   /* 
@@ -107109,15 +119355,16 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
       sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
       VdbeComment((v, "LIMIT counter"));
       if( n==0 ){
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
-      }else if( n>=0 && p->nSelectRow>(u64)n ){
-        p->nSelectRow = n;
+        sqlite3VdbeGoto(v, iBreak);
+      }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
+        p->nSelectRow = sqlite3LogEst((u64)n);
+        p->selFlags |= SF_FixedLimit;
       }
     }else{
       sqlite3ExprCode(pParse, p->pLimit, iLimit);
       sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
       VdbeComment((v, "LIMIT counter"));
-      sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak); VdbeCoverage(v);
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
     }
     if( p->pOffset ){
       p->iOffset = iOffset = ++pParse->nMem;
@@ -107125,14 +119372,8 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
       sqlite3ExprCode(pParse, p->pOffset, iOffset);
       sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
       VdbeComment((v, "OFFSET counter"));
-      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset);
-      sqlite3VdbeJumpHere(v, addr1);
-      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
+      sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
       VdbeComment((v, "LIMIT+OFFSET"));
-      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit); VdbeCoverage(v);
-      sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1);
-      sqlite3VdbeJumpHere(v, addr1);
     }
   }
 }
@@ -107154,7 +119395,10 @@ static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
     pRet = 0;
   }
   assert( iCol>=0 );
-  if( pRet==0 && iColpEList->nExpr ){
+  /* iCol must be less than p->pEList->nExpr.  Otherwise an error would
+  ** have been thrown during name resolution and we would not have gotten
+  ** this far */
+  if( pRet==0 && ALWAYS(iColpEList->nExpr) ){
     pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
   }
   return pRet;
@@ -107209,7 +119453,7 @@ static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){
 **
 **
 ** There is exactly one reference to the recursive-table in the FROM clause
-** of recursive-query, marked with the SrcList->a[].isRecursive flag.
+** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
 **
 ** The setup-query runs once to generate an initial set of rows that go
 ** into a Queue table.  Rows are extracted from the Queue table one by
@@ -107263,6 +119507,7 @@ static void generateWithRecursiveQuery(
 
   /* Process the LIMIT and OFFSET clauses, if they exist */
   addrBreak = sqlite3VdbeMakeLabel(v);
+  p->nSelectRow = 320;  /* 4 billion rows */
   computeLimitRegisters(pParse, p, addrBreak);
   pLimit = p->pLimit;
   pOffset = p->pOffset;
@@ -107274,7 +119519,7 @@ static void generateWithRecursiveQuery(
 
   /* Locate the cursor number of the Current table */
   for(i=0; ALWAYS(inSrc); i++){
-    if( pSrc->a[i].isRecursive ){
+    if( pSrc->a[i].fg.isRecursive ){
       iCurrent = pSrc->a[i].iCursor;
       break;
     }
@@ -107336,7 +119581,7 @@ static void generateWithRecursiveQuery(
   selectInnerLoop(pParse, p, p->pEList, iCurrent,
       0, 0, pDest, addrCont, addrBreak);
   if( regLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, regLimit, addrBreak, -1);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
     VdbeCoverage(v);
   }
   sqlite3VdbeResolveLabel(v, addrCont);
@@ -107344,13 +119589,17 @@ static void generateWithRecursiveQuery(
   /* Execute the recursive SELECT taking the single row in Current as
   ** the value for the recursive-table. Store the results in the Queue.
   */
-  p->pPrior = 0;
-  sqlite3Select(pParse, p, &destQueue);
-  assert( p->pPrior==0 );
-  p->pPrior = pSetup;
+  if( p->selFlags & SF_Aggregate ){
+    sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
+  }else{
+    p->pPrior = 0;
+    sqlite3Select(pParse, p, &destQueue);
+    assert( p->pPrior==0 );
+    p->pPrior = pSetup;
+  }
 
   /* Keep running the loop until the Queue is empty */
-  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
+  sqlite3VdbeGoto(v, addrTop);
   sqlite3VdbeResolveLabel(v, addrBreak);
 
 end_of_recursive_query:
@@ -107369,19 +119618,6 @@ static int multiSelectOrderBy(
   SelectDest *pDest     /* What to do with query results */
 );
 
-/*
-** Error message for when two or more terms of a compound select have different
-** size result sets.
-*/
-static void selectWrongNumTermsError(Parse *pParse, Select *p){
-  if( p->selFlags & SF_Values ){
-    sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
-  }else{
-    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
-      " do not have the same number of result columns", selectOpName(p->op));
-  }
-}
-
 /*
 ** Handle the special case of a compound-select that originates from a
 ** VALUES clause.  By handling this as a special case, we avoid deep
@@ -107399,20 +119635,15 @@ static int multiSelectValues(
   SelectDest *pDest     /* What to do with query results */
 ){
   Select *pPrior;
-  int nExpr = p->pEList->nExpr;
   int nRow = 1;
   int rc = 0;
-  assert( p->pNext==0 );
-  assert( p->selFlags & SF_AllValues );
+  assert( p->selFlags & SF_MultiValue );
   do{
     assert( p->selFlags & SF_Values );
     assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
     assert( p->pLimit==0 );
     assert( p->pOffset==0 );
-    if( p->pEList->nExpr!=nExpr ){
-      selectWrongNumTermsError(pParse, p);
-      return 1;
-    }
+    assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
     if( p->pPrior==0 ) break;
     assert( p->pPrior->pNext==p );
     p = p->pPrior;
@@ -107506,13 +119737,12 @@ static int multiSelect(
   if( dest.eDest==SRT_EphemTab ){
     assert( p->pEList );
     sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);
-    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
     dest.eDest = SRT_Table;
   }
 
   /* Special handling for a compound-select that originates as a VALUES clause.
   */
-  if( p->selFlags & SF_AllValues ){
+  if( p->selFlags & SF_MultiValue ){
     rc = multiSelectValues(pParse, p, &dest);
     goto multi_select_end;
   }
@@ -107521,11 +119751,7 @@ static int multiSelect(
   ** in their result sets.
   */
   assert( p->pEList && pPrior->pEList );
-  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
-    selectWrongNumTermsError(pParse, p);
-    rc = 1;
-    goto multi_select_end;
-  }
+  assert( p->pEList->nExpr==pPrior->pEList->nExpr );
 
 #ifndef SQLITE_OMIT_CTE
   if( p->selFlags & SF_Recursive ){
@@ -107561,20 +119787,24 @@ static int multiSelect(
       p->iLimit = pPrior->iLimit;
       p->iOffset = pPrior->iOffset;
       if( p->iLimit ){
-        addr = sqlite3VdbeAddOp1(v, OP_IfZero, p->iLimit); VdbeCoverage(v);
+        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
         VdbeComment((v, "Jump ahead if LIMIT reached"));
+        if( p->iOffset ){
+          sqlite3VdbeAddOp3(v, OP_OffsetLimit,
+                            p->iLimit, p->iOffset+1, p->iOffset);
+        }
       }
       explainSetInteger(iSub2, pParse->iNextSelectId);
       rc = sqlite3Select(pParse, p, &dest);
       testcase( rc!=SQLITE_OK );
       pDelete = p->pPrior;
       p->pPrior = pPrior;
-      p->nSelectRow += pPrior->nSelectRow;
+      p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
       if( pPrior->pLimit
        && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
-       && nLimit>0 && p->nSelectRow > (u64)nLimit 
+       && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit) 
       ){
-        p->nSelectRow = nLimit;
+        p->nSelectRow = sqlite3LogEst((u64)nLimit);
       }
       if( addr ){
         sqlite3VdbeJumpHere(v, addr);
@@ -107646,7 +119876,9 @@ static int multiSelect(
       pDelete = p->pPrior;
       p->pPrior = pPrior;
       p->pOrderBy = 0;
-      if( p->op==TK_UNION ) p->nSelectRow += pPrior->nSelectRow;
+      if( p->op==TK_UNION ){
+        p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
+      }
       sqlite3ExprDelete(db, p->pLimit);
       p->pLimit = pLimit;
       p->pOffset = pOffset;
@@ -107660,11 +119892,6 @@ static int multiSelect(
       if( dest.eDest!=priorOp ){
         int iCont, iBreak, iStart;
         assert( p->pEList );
-        if( dest.eDest==SRT_Output ){
-          Select *pFirst = p;
-          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-          generateColumnNames(pParse, 0, pFirst->pEList);
-        }
         iBreak = sqlite3VdbeMakeLabel(v);
         iCont = sqlite3VdbeMakeLabel(v);
         computeLimitRegisters(pParse, p, iBreak);
@@ -107735,17 +119962,12 @@ static int multiSelect(
       ** tables.
       */
       assert( p->pEList );
-      if( dest.eDest==SRT_Output ){
-        Select *pFirst = p;
-        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-        generateColumnNames(pParse, 0, pFirst->pEList);
-      }
       iBreak = sqlite3VdbeMakeLabel(v);
       iCont = sqlite3VdbeMakeLabel(v);
       computeLimitRegisters(pParse, p, iBreak);
       sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
       r1 = sqlite3GetTempReg(pParse);
-      iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);
+      iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
       sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);
       sqlite3ReleaseTempReg(pParse, r1);
       selectInnerLoop(pParse, p, p->pEList, tab1,
@@ -107781,7 +120003,7 @@ static int multiSelect(
     nCol = p->pEList->nExpr;
     pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
     if( !pKeyInfo ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto multi_select_end;
     }
     for(i=0, apColl=pKeyInfo->aColl; iselFlags & SF_Values ){
+    sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
+  }else{
+    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
+      " do not have the same number of result columns", selectOpName(p->op));
+  }
+}
+
 /*
 ** Code an output subroutine for a coroutine implementation of a
 ** SELECT statment.
@@ -107857,12 +120092,12 @@ static int generateOutputSubroutine(
   /* Suppress duplicates for UNION, EXCEPT, and INTERSECT 
   */
   if( regPrev ){
-    int j1, j2;
-    j1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
-    j2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
+    int addr1, addr2;
+    addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
+    addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
                               (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
-    sqlite3VdbeAddOp3(v, OP_Jump, j2+2, iContinue, j2+2); VdbeCoverage(v);
-    sqlite3VdbeJumpHere(v, j1);
+    sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr1);
     sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);
     sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
   }
@@ -107872,15 +120107,14 @@ static int generateOutputSubroutine(
   */
   codeOffset(v, p->iOffset, iContinue);
 
+  assert( pDest->eDest!=SRT_Exists );
+  assert( pDest->eDest!=SRT_Table );
   switch( pDest->eDest ){
     /* Store the result as data using a unique key.
     */
-    case SRT_Table:
     case SRT_EphemTab: {
       int r1 = sqlite3GetTempReg(pParse);
       int r2 = sqlite3GetTempReg(pParse);
-      testcase( pDest->eDest==SRT_Table );
-      testcase( pDest->eDest==SRT_EphemTab );
       sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);
       sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);
       sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);
@@ -107891,39 +120125,27 @@ static int generateOutputSubroutine(
     }
 
 #ifndef SQLITE_OMIT_SUBQUERY
-    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
-    ** then there should be a single item on the stack.  Write this
-    ** item into the set table with bogus data.
+    /* If we are creating a set for an "expr IN (SELECT ...)".
     */
     case SRT_Set: {
       int r1;
-      assert( pIn->nSdst==1 );
-      pDest->affSdst = 
-         sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affSdst);
+      testcase( pIn->nSdst>1 );
       r1 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, 1, r1, &pDest->affSdst,1);
-      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, 1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iSDParm, r1);
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, 
+          r1, pDest->zAffSdst, pIn->nSdst);
+      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pDest->iSDParm, r1,
+                           pIn->iSdst, pIn->nSdst);
       sqlite3ReleaseTempReg(pParse, r1);
       break;
     }
 
-#if 0  /* Never occurs on an ORDER BY query */
-    /* If any row exist in the result set, record that fact and abort.
-    */
-    case SRT_Exists: {
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, pDest->iSDParm);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-#endif
-
     /* If this is a scalar select that is part of an expression, then
     ** store the results in the appropriate memory cell and break out
     ** of the scan loop.
     */
     case SRT_Mem: {
-      assert( pIn->nSdst==1 );
+      assert( pIn->nSdst==1 || pParse->nErr>0 );  testcase( pIn->nSdst!=1 );
       sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1);
       /* The LIMIT clause will jump out of the loop for us */
       break;
@@ -107938,7 +120160,7 @@ static int generateOutputSubroutine(
         pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);
         pDest->nSdst = pIn->nSdst;
       }
-      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pDest->nSdst);
+      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);
       sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
       break;
     }
@@ -107962,7 +120184,7 @@ static int generateOutputSubroutine(
   /* Jump to the end of the loop if the LIMIT is reached.
   */
   if( p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
   }
 
   /* Generate the subroutine return
@@ -108090,7 +120312,7 @@ static int multiSelectOrderBy(
   int savedOffset;      /* Saved value of p->iOffset */
   int labelCmpr;        /* Label for the start of the merge algorithm */
   int labelEnd;         /* Label for the end of the overall SELECT stmt */
-  int j1;               /* Jump instructions that get retargetted */
+  int addr1;            /* Jump instructions that get retargetted */
   int op;               /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
   KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */
   KeyInfo *pKeyMerge;   /* Comparison information for merging rows */
@@ -108134,10 +120356,10 @@ static int multiSelectOrderBy(
       }
       if( j==nOrderBy ){
         Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
-        if( pNew==0 ) return SQLITE_NOMEM;
+        if( pNew==0 ) return SQLITE_NOMEM_BKPT;
         pNew->flags |= EP_IntValue;
         pNew->u.iValue = i;
-        pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
+        p->pOrderBy = pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
         if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;
       }
     }
@@ -108150,12 +120372,13 @@ static int multiSelectOrderBy(
   ** to the right and the left are evaluated, they use the correct
   ** collation.
   */
-  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
+  aPermute = sqlite3DbMallocRawNN(db, sizeof(int)*(nOrderBy + 1));
   if( aPermute ){
     struct ExprList_item *pItem;
-    for(i=0, pItem=pOrderBy->a; iu.x.iOrderByCol>0
-          && pItem->u.x.iOrderByCol<=p->pEList->nExpr );
+    aPermute[0] = nOrderBy;
+    for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){
+      assert( pItem->u.x.iOrderByCol>0 );
+      assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
       aPermute[i] = pItem->u.x.iOrderByCol - 1;
     }
     pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
@@ -108226,19 +120449,19 @@ static int multiSelectOrderBy(
   ** left of the compound operator - the "A" select.
   */
   addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
-  j1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
+  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
   VdbeComment((v, "left SELECT"));
   pPrior->iLimit = regLimitA;
   explainSetInteger(iSub1, pParse->iNextSelectId);
   sqlite3Select(pParse, pPrior, &destA);
-  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrA);
-  sqlite3VdbeJumpHere(v, j1);
+  sqlite3VdbeEndCoroutine(v, regAddrA);
+  sqlite3VdbeJumpHere(v, addr1);
 
   /* Generate a coroutine to evaluate the SELECT statement on 
   ** the right - the "B" select
   */
   addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
-  j1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
+  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
   VdbeComment((v, "right SELECT"));
   savedLimit = p->iLimit;
   savedOffset = p->iOffset;
@@ -108248,7 +120471,7 @@ static int multiSelectOrderBy(
   sqlite3Select(pParse, p, &destB);
   p->iLimit = savedLimit;
   p->iOffset = savedOffset;
-  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrB);
+  sqlite3VdbeEndCoroutine(v, regAddrB);
 
   /* Generate a subroutine that outputs the current row of the A
   ** select as the next output row of the compound select.
@@ -108279,8 +120502,8 @@ static int multiSelectOrderBy(
     addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
     addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);
                                      VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofA);
-    p->nSelectRow += pPrior->nSelectRow;
+    sqlite3VdbeGoto(v, addrEofA);
+    p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
   }
 
   /* Generate a subroutine to run when the results from select B
@@ -108293,7 +120516,7 @@ static int multiSelectOrderBy(
     VdbeNoopComment((v, "eof-B subroutine"));
     addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
     sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofB);
+    sqlite3VdbeGoto(v, addrEofB);
   }
 
   /* Generate code to handle the case of AB
@@ -108325,11 +120548,11 @@ static int multiSelectOrderBy(
     sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
   }
   sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
-  sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+  sqlite3VdbeGoto(v, labelCmpr);
 
   /* This code runs once to initialize everything.
   */
-  sqlite3VdbeJumpHere(v, j1);
+  sqlite3VdbeJumpHere(v, addr1);
   sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);
   sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
 
@@ -108346,14 +120569,6 @@ static int multiSelectOrderBy(
   */
   sqlite3VdbeResolveLabel(v, labelEnd);
 
-  /* Set the number of output columns
-  */
-  if( pDest->eDest==SRT_Output ){
-    Select *pFirst = pPrior;
-    while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-    generateColumnNames(pParse, 0, pFirst->pEList);
-  }
-
   /* Reassembly the compound query so that it will be freed correctly
   ** by the calling function */
   if( p->pPrior ){
@@ -108365,14 +120580,29 @@ static int multiSelectOrderBy(
   /*** TBD:  Insert subroutine calls to close cursors on incomplete
   **** subqueries ****/
   explainComposite(pParse, p->op, iSub1, iSub2, 0);
-  return SQLITE_OK;
+  return pParse->nErr!=0;
 }
 #endif
 
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+
+/* An instance of the SubstContext object describes an substitution edit
+** to be performed on a parse tree.
+**
+** All references to columns in table iTable are to be replaced by corresponding
+** expressions in pEList.
+*/
+typedef struct SubstContext {
+  Parse *pParse;            /* The parsing context */
+  int iTable;               /* Replace references to this table */
+  int iNewTable;            /* New table number */
+  int isLeftJoin;           /* Add TK_IF_NULL_ROW opcodes on each replacement */
+  ExprList *pEList;         /* Replacement expressions */
+} SubstContext;
+
 /* Forward Declarations */
-static void substExprList(sqlite3*, ExprList*, int, ExprList*);
-static void substSelect(sqlite3*, Select *, int, ExprList *);
+static void substExprList(SubstContext*, ExprList*);
+static void substSelect(SubstContext*, Select*, int);
 
 /*
 ** Scan through the expression pExpr.  Replace every reference to
@@ -108383,74 +120613,98 @@ static void substSelect(sqlite3*, Select *, int, ExprList *);
 ** This routine is part of the flattening procedure.  A subquery
 ** whose result set is defined by pEList appears as entry in the
 ** FROM clause of a SELECT such that the VDBE cursor assigned to that
-** FORM clause entry is iTable.  This routine make the necessary 
+** FORM clause entry is iTable.  This routine makes the necessary 
 ** changes to pExpr so that it refers directly to the source table
 ** of the subquery rather the result set of the subquery.
 */
 static Expr *substExpr(
-  sqlite3 *db,        /* Report malloc errors to this connection */
-  Expr *pExpr,        /* Expr in which substitution occurs */
-  int iTable,         /* Table to be substituted */
-  ExprList *pEList    /* Substitute expressions */
+  SubstContext *pSubst,  /* Description of the substitution */
+  Expr *pExpr            /* Expr in which substitution occurs */
 ){
   if( pExpr==0 ) return 0;
-  if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
+  if( ExprHasProperty(pExpr, EP_FromJoin) && pExpr->iRightJoinTable==pSubst->iTable ){
+    pExpr->iRightJoinTable = pSubst->iNewTable;
+  }
+  if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
     if( pExpr->iColumn<0 ){
       pExpr->op = TK_NULL;
     }else{
       Expr *pNew;
-      assert( pEList!=0 && pExpr->iColumnnExpr );
+      Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
+      Expr ifNullRow;
+      assert( pSubst->pEList!=0 && pExpr->iColumnpEList->nExpr );
       assert( pExpr->pLeft==0 && pExpr->pRight==0 );
-      pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0);
-      sqlite3ExprDelete(db, pExpr);
-      pExpr = pNew;
+      if( sqlite3ExprIsVector(pCopy) ){
+        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
+      }else{
+        sqlite3 *db = pSubst->pParse->db;
+        if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
+          memset(&ifNullRow, 0, sizeof(ifNullRow));
+          ifNullRow.op = TK_IF_NULL_ROW;
+          ifNullRow.pLeft = pCopy;
+          ifNullRow.iTable = pSubst->iNewTable;
+          pCopy = &ifNullRow;
+        }
+        pNew = sqlite3ExprDup(db, pCopy, 0);
+        if( pNew && pSubst->isLeftJoin ){
+          ExprSetProperty(pNew, EP_CanBeNull);
+        }
+        if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){
+          pNew->iRightJoinTable = pExpr->iRightJoinTable;
+          ExprSetProperty(pNew, EP_FromJoin);
+        }
+        sqlite3ExprDelete(db, pExpr);
+        pExpr = pNew;
+      }
     }
   }else{
-    pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList);
-    pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList);
+    if( pExpr->op==TK_IF_NULL_ROW && pExpr->iTable==pSubst->iTable ){
+      pExpr->iTable = pSubst->iNewTable;
+    }
+    pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);
+    pExpr->pRight = substExpr(pSubst, pExpr->pRight);
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      substSelect(db, pExpr->x.pSelect, iTable, pEList);
+      substSelect(pSubst, pExpr->x.pSelect, 1);
     }else{
-      substExprList(db, pExpr->x.pList, iTable, pEList);
+      substExprList(pSubst, pExpr->x.pList);
     }
   }
   return pExpr;
 }
 static void substExprList(
-  sqlite3 *db,         /* Report malloc errors here */
-  ExprList *pList,     /* List to scan and in which to make substitutes */
-  int iTable,          /* Table to be substituted */
-  ExprList *pEList     /* Substitute values */
+  SubstContext *pSubst, /* Description of the substitution */
+  ExprList *pList       /* List to scan and in which to make substitutes */
 ){
   int i;
   if( pList==0 ) return;
   for(i=0; inExpr; i++){
-    pList->a[i].pExpr = substExpr(db, pList->a[i].pExpr, iTable, pEList);
+    pList->a[i].pExpr = substExpr(pSubst, pList->a[i].pExpr);
   }
 }
 static void substSelect(
-  sqlite3 *db,         /* Report malloc errors here */
-  Select *p,           /* SELECT statement in which to make substitutions */
-  int iTable,          /* Table to be replaced */
-  ExprList *pEList     /* Substitute values */
+  SubstContext *pSubst, /* Description of the substitution */
+  Select *p,            /* SELECT statement in which to make substitutions */
+  int doPrior           /* Do substitutes on p->pPrior too */
 ){
   SrcList *pSrc;
   struct SrcList_item *pItem;
   int i;
   if( !p ) return;
-  substExprList(db, p->pEList, iTable, pEList);
-  substExprList(db, p->pGroupBy, iTable, pEList);
-  substExprList(db, p->pOrderBy, iTable, pEList);
-  p->pHaving = substExpr(db, p->pHaving, iTable, pEList);
-  p->pWhere = substExpr(db, p->pWhere, iTable, pEList);
-  substSelect(db, p->pPrior, iTable, pEList);
-  pSrc = p->pSrc;
-  assert( pSrc );  /* Even for (SELECT 1) we have: pSrc!=0 but pSrc->nSrc==0 */
-  if( ALWAYS(pSrc) ){
+  do{
+    substExprList(pSubst, p->pEList);
+    substExprList(pSubst, p->pGroupBy);
+    substExprList(pSubst, p->pOrderBy);
+    p->pHaving = substExpr(pSubst, p->pHaving);
+    p->pWhere = substExpr(pSubst, p->pWhere);
+    pSrc = p->pSrc;
+    assert( pSrc!=0 );
     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
-      substSelect(db, pItem->pSelect, iTable, pEList);
+      substSelect(pSubst, pItem->pSelect, 1);
+      if( pItem->fg.isTabFunc ){
+        substExprList(pSubst, pItem->u1.pFuncArg);
+      }
     }
-  }
+  }while( doPrior && (p = p->pPrior)!=0 );
 }
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
@@ -108485,10 +120739,15 @@ static void substSelect(
 **
 **   (1)  The subquery and the outer query do not both use aggregates.
 **
-**   (2)  The subquery is not an aggregate or the outer query is not a join.
+**   (2)  The subquery is not an aggregate or (2a) the outer query is not a join
+**        and (2b) the outer query does not use subqueries other than the one
+**        FROM-clause subquery that is a candidate for flattening.  (2b is
+**        due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
 **
-**   (3)  The subquery is not the right operand of a left outer join
-**        (Originally ticket #306.  Strengthened by ticket #3300)
+**   (3)  The subquery is not the right operand of a LEFT JOIN
+**        or (a) the subquery is not itself a join and (b) the FROM clause
+**        of the subquery does not contain a virtual table and (c) the 
+**        outer query is not an aggregate.
 **
 **   (4)  The subquery is not DISTINCT.
 **
@@ -108500,7 +120759,7 @@ static void substSelect(
 **        DISTINCT.
 **
 **   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
-**        A FROM clause, consider adding a FROM close with the special
+**        A FROM clause, consider adding a FROM clause with the special
 **        table sqlite_once that consists of a single row containing a
 **        single NULL.
 **
@@ -108511,8 +120770,8 @@ static void substSelect(
 **
 **  (**)  Restriction (10) was removed from the code on 2005-02-05 but we
 **        accidently carried the comment forward until 2014-09-15.  Original
-**        text: "The subquery does not use aggregates or the outer query does not
-**        use LIMIT."
+**        text: "The subquery does not use aggregates or the outer query 
+**        does not use LIMIT."
 **
 **  (11)  The subquery and the outer query do not both have ORDER BY clauses.
 **
@@ -108599,13 +120858,14 @@ static int flattenSubquery(
   int subqueryIsAgg    /* True if the subquery uses aggregate functions */
 ){
   const char *zSavedAuthContext = pParse->zAuthContext;
-  Select *pParent;
+  Select *pParent;    /* Current UNION ALL term of the other query */
   Select *pSub;       /* The inner query or "subquery" */
   Select *pSub1;      /* Pointer to the rightmost select in sub-query */
   SrcList *pSrc;      /* The FROM clause of the outer query */
   SrcList *pSubSrc;   /* The FROM clause of the subquery */
-  ExprList *pList;    /* The result set of the outer query */
   int iParent;        /* VDBE cursor number of the pSub result set temp table */
+  int iNewParent = -1;/* Replacement table for iParent */
+  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
   int i;              /* Loop counter */
   Expr *pWhere;                    /* The WHERE clause */
   struct SrcList_item *pSubitem;   /* The subquery */
@@ -108622,8 +120882,17 @@ static int flattenSubquery(
   iParent = pSubitem->iCursor;
   pSub = pSubitem->pSelect;
   assert( pSub!=0 );
-  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
-  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
+  if( subqueryIsAgg ){
+    if( isAgg ) return 0;                                /* Restriction (1)   */
+    if( pSrc->nSrc>1 ) return 0;                         /* Restriction (2a)  */
+    if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
+     || (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
+     || (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
+    ){
+      return 0;                                          /* Restriction (2b)  */
+    }
+  }
+
   pSubSrc = pSub->pSrc;
   assert( pSubSrc );
   /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
@@ -108661,10 +120930,9 @@ static int flattenSubquery(
     return 0; /* Restriction (23) */
   }
 
-  /* OBSOLETE COMMENT 1:
-  ** Restriction 3:  If the subquery is a join, make sure the subquery is 
-  ** not used as the right operand of an outer join.  Examples of why this
-  ** is not allowed:
+  /*
+  ** If the subquery is the right operand of a LEFT JOIN, then the
+  ** subquery may not be a join itself.  Example of why this is not allowed:
   **
   **         t1 LEFT OUTER JOIN (t2 JOIN t3)
   **
@@ -108674,28 +120942,27 @@ static int flattenSubquery(
   **
   ** which is not at all the same thing.
   **
-  ** OBSOLETE COMMENT 2:
-  ** Restriction 12:  If the subquery is the right operand of a left outer
-  ** join, make sure the subquery has no WHERE clause.
-  ** An examples of why this is not allowed:
-  **
-  **         t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
-  **
-  ** If we flatten the above, we would get
-  **
-  **         (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
-  **
-  ** But the t2.x>0 test will always fail on a NULL row of t2, which
-  ** effectively converts the OUTER JOIN into an INNER JOIN.
+  ** If the subquery is the right operand of a LEFT JOIN, then the outer
+  ** query cannot be an aggregate.  This is an artifact of the way aggregates
+  ** are processed - there is no mechanism to determine if the LEFT JOIN
+  ** table should be all-NULL.
   **
-  ** THIS OVERRIDES OBSOLETE COMMENTS 1 AND 2 ABOVE:
-  ** Ticket #3300 shows that flattening the right term of a LEFT JOIN
-  ** is fraught with danger.  Best to avoid the whole thing.  If the
-  ** subquery is the right term of a LEFT JOIN, then do not flatten.
+  ** See also tickets #306, #350, and #3300.
   */
-  if( (pSubitem->jointype & JT_OUTER)!=0 ){
-    return 0;
+  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
+    isLeftJoin = 1;
+    if( pSubSrc->nSrc>1 || isAgg || IsVirtual(pSubSrc->a[0].pTab) ){
+      return 0; /* Restriction (3) */
+    }
+  }
+#ifdef SQLITE_EXTRA_IFNULLROW
+  else if( iFrom>0 && !isAgg ){
+    /* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for
+    ** every reference to any result column from subquery in a join, even though
+    ** they are not necessary.  This will stress-test the OP_IfNullRow opcode. */
+    isLeftJoin = -1;
   }
+#endif
 
   /* Restriction 17: If the sub-query is a compound SELECT, then it must
   ** use only the UNION ALL operator. And none of the simple select queries
@@ -108713,10 +120980,10 @@ static int flattenSubquery(
       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
       assert( pSub->pSrc!=0 );
+      assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
       if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0
        || (pSub1->pPrior && pSub1->op!=TK_ALL) 
        || pSub1->pSrc->nSrc<1
-       || pSub->pEList->nExpr!=pSub1->pEList->nExpr
       ){
         return 0;
       }
@@ -108832,12 +121099,12 @@ static int flattenSubquery(
   */
   if( ALWAYS(pSubitem->pTab!=0) ){
     Table *pTabToDel = pSubitem->pTab;
-    if( pTabToDel->nRef==1 ){
+    if( pTabToDel->nTabRef==1 ){
       Parse *pToplevel = sqlite3ParseToplevel(pParse);
       pTabToDel->pNextZombie = pToplevel->pZombieTab;
       pToplevel->pZombieTab = pTabToDel;
     }else{
-      pTabToDel->nRef--;
+      pTabToDel->nTabRef--;
     }
     pSubitem->pTab = 0;
   }
@@ -108864,7 +121131,7 @@ static int flattenSubquery(
 
     if( pSrc ){
       assert( pParent==p );  /* First time through the loop */
-      jointype = pSubitem->jointype;
+      jointype = pSubitem->fg.jointype;
     }else{
       assert( pParent!=p );  /* 2nd and subsequent times through the loop */
       pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
@@ -108885,9 +121152,9 @@ static int flattenSubquery(
     **
     ** The outer query has 3 slots in its FROM clause.  One slot of the
     ** outer query (the middle slot) is used by the subquery.  The next
-    ** block of code will expand the out query to 4 slots.  The middle
-    ** slot is expanded to two slots in order to make space for the
-    ** two elements in the FROM clause of the subquery.
+    ** block of code will expand the outer query FROM clause to 4 slots.
+    ** The middle slot is expanded to two slots in order to make space
+    ** for the two elements in the FROM clause of the subquery.
     */
     if( nSubSrc>1 ){
       pParent->pSrc = pSrc = sqlite3SrcListEnlarge(db, pSrc, nSubSrc-1,iFrom+1);
@@ -108901,10 +121168,12 @@ static int flattenSubquery(
     */
     for(i=0; ia[i+iFrom].pUsing);
+      assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
       pSrc->a[i+iFrom] = pSubSrc->a[i];
+      iNewParent = pSubSrc->a[i].iCursor;
       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
     }
-    pSrc->a[iFrom].jointype = jointype;
+    pSrc->a[iFrom].fg.jointype = jointype;
   
     /* Now begin substituting subquery result set expressions for 
     ** references to the iParent in the outer query.
@@ -108918,19 +121187,6 @@ static int flattenSubquery(
     ** We look at every expression in the outer query and every place we see
     ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
     */
-    pList = pParent->pEList;
-    for(i=0; inExpr; i++){
-      if( pList->a[i].zName==0 ){
-        char *zName = sqlite3DbStrDup(db, pList->a[i].zSpan);
-        sqlite3Dequote(zName);
-        pList->a[i].zName = zName;
-      }
-    }
-    substExprList(db, pParent->pEList, iParent, pSub->pEList);
-    if( isAgg ){
-      substExprList(db, pParent->pGroupBy, iParent, pSub->pEList);
-      pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList);
-    }
     if( pSub->pOrderBy ){
       /* At this point, any non-zero iOrderByCol values indicate that the
       ** ORDER BY column expression is identical to the iOrderByCol'th
@@ -108950,26 +121206,31 @@ static int flattenSubquery(
       assert( pSub->pPrior==0 );
       pParent->pOrderBy = pOrderBy;
       pSub->pOrderBy = 0;
-    }else if( pParent->pOrderBy ){
-      substExprList(db, pParent->pOrderBy, iParent, pSub->pEList);
     }
-    if( pSub->pWhere ){
-      pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
-    }else{
-      pWhere = 0;
+    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
+    if( isLeftJoin>0 ){
+      setJoinExpr(pWhere, iNewParent);
     }
     if( subqueryIsAgg ){
       assert( pParent->pHaving==0 );
       pParent->pHaving = pParent->pWhere;
       pParent->pWhere = pWhere;
-      pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList);
-      pParent->pHaving = sqlite3ExprAnd(db, pParent->pHaving, 
-                                  sqlite3ExprDup(db, pSub->pHaving, 0));
+      pParent->pHaving = sqlite3ExprAnd(db, 
+          sqlite3ExprDup(db, pSub->pHaving, 0), pParent->pHaving
+      );
       assert( pParent->pGroupBy==0 );
       pParent->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy, 0);
     }else{
-      pParent->pWhere = substExpr(db, pParent->pWhere, iParent, pSub->pEList);
-      pParent->pWhere = sqlite3ExprAnd(db, pParent->pWhere, pWhere);
+      pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
+    }
+    if( db->mallocFailed==0 ){
+      SubstContext x;
+      x.pParse = pParse;
+      x.iTable = iParent;
+      x.iNewTable = iNewParent;
+      x.isLeftJoin = isLeftJoin;
+      x.pEList = pSub->pEList;
+      substSelect(&x, pParent, 0);
     }
   
     /* The flattened query is distinct if either the inner or the
@@ -108996,7 +121257,7 @@ static int flattenSubquery(
 
 #if SELECTTRACE_ENABLED
   if( sqlite3SelectTrace & 0x100 ){
-    sqlite3DebugPrintf("After flattening:\n");
+    SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
     sqlite3TreeViewSelect(0, p, 0);
   }
 #endif
@@ -109005,6 +121266,89 @@ static int flattenSubquery(
 }
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
+
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+/*
+** Make copies of relevant WHERE clause terms of the outer query into
+** the WHERE clause of subquery.  Example:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
+**
+** Transformed into:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
+**     WHERE x=5 AND y=10;
+**
+** The hope is that the terms added to the inner query will make it more
+** efficient.
+**
+** Do not attempt this optimization if:
+**
+**   (1) The inner query is an aggregate.  (In that case, we'd really want
+**       to copy the outer WHERE-clause terms onto the HAVING clause of the
+**       inner query.  But they probably won't help there so do not bother.)
+**
+**   (2) The inner query is the recursive part of a common table expression.
+**
+**   (3) The inner query has a LIMIT clause (since the changes to the WHERE
+**       close would change the meaning of the LIMIT).
+**
+**   (4) The inner query is the right operand of a LEFT JOIN.  (The caller
+**       enforces this restriction since this routine does not have enough
+**       information to know.)
+**
+**   (5) The WHERE clause expression originates in the ON or USING clause
+**       of a LEFT JOIN.
+**
+** Return 0 if no changes are made and non-zero if one or more WHERE clause
+** terms are duplicated into the subquery.
+*/
+static int pushDownWhereTerms(
+  Parse *pParse,        /* Parse context (for malloc() and error reporting) */
+  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
+  Expr *pWhere,         /* The WHERE clause of the outer query */
+  int iCursor           /* Cursor number of the subquery */
+){
+  Expr *pNew;
+  int nChng = 0;
+  Select *pX;           /* For looping over compound SELECTs in pSubq */
+  if( pWhere==0 ) return 0;
+  for(pX=pSubq; pX; pX=pX->pPrior){
+    if( (pX->selFlags & (SF_Aggregate|SF_Recursive))!=0 ){
+      testcase( pX->selFlags & SF_Aggregate );
+      testcase( pX->selFlags & SF_Recursive );
+      testcase( pX!=pSubq );
+      return 0; /* restrictions (1) and (2) */
+    }
+  }
+  if( pSubq->pLimit!=0 ){
+    return 0; /* restriction (3) */
+  }
+  while( pWhere->op==TK_AND ){
+    nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight, iCursor);
+    pWhere = pWhere->pLeft;
+  }
+  if( ExprHasProperty(pWhere,EP_FromJoin) ) return 0; /* restriction 5 */
+  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
+    nChng++;
+    while( pSubq ){
+      SubstContext x;
+      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
+      x.pParse = pParse;
+      x.iTable = iCursor;
+      x.iNewTable = iCursor;
+      x.isLeftJoin = 0;
+      x.pEList = pSubq->pEList;
+      pNew = substExpr(&x, pNew);
+      pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
+      pSubq = pSubq->pPrior;
+    }
+  }
+  return nChng;
+}
+#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
+
 /*
 ** Based on the contents of the AggInfo structure indicated by the first
 ** argument, this function checks if the following are true:
@@ -109088,20 +121432,20 @@ static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
 ** pFrom->pIndex and return SQLITE_OK.
 */
 SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
-  if( pFrom->pTab && pFrom->zIndex ){
+  if( pFrom->pTab && pFrom->fg.isIndexedBy ){
     Table *pTab = pFrom->pTab;
-    char *zIndex = pFrom->zIndex;
+    char *zIndexedBy = pFrom->u1.zIndexedBy;
     Index *pIdx;
     for(pIdx=pTab->pIndex; 
-        pIdx && sqlite3StrICmp(pIdx->zName, zIndex); 
+        pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); 
         pIdx=pIdx->pNext
     );
     if( !pIdx ){
-      sqlite3ErrorMsg(pParse, "no such index: %s", zIndex, 0);
+      sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
       pParse->checkSchema = 1;
       return SQLITE_ERROR;
     }
-    pFrom->pIndex = pIdx;
+    pFrom->pIBIndex = pIdx;
   }
   return SQLITE_OK;
 }
@@ -109157,7 +121501,7 @@ static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
   if( pNewSrc==0 ) return WRC_Abort;
   *pNew = *p;
   p->pSrc = pNewSrc;
-  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ALL, 0));
+  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));
   p->op = TK_SELECT;
   p->pWhere = 0;
   pNew->pGroupBy = 0;
@@ -109165,7 +121509,10 @@ static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
   pNew->pOrderBy = 0;
   p->pPrior = 0;
   p->pNext = 0;
+  p->pWith = 0;
   p->selFlags &= ~SF_Compound;
+  assert( (p->selFlags & SF_Converted)==0 );
+  p->selFlags |= SF_Converted;
   assert( pNew->pPrior!=0 );
   pNew->pPrior->pNext = pNew;
   pNew->pLimit = 0;
@@ -109173,6 +121520,19 @@ static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
   return WRC_Continue;
 }
 
+/*
+** Check to see if the FROM clause term pFrom has table-valued function
+** arguments.  If it does, leave an error message in pParse and return
+** non-zero, since pFrom is not allowed to be a table-valued function.
+*/
+static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){
+  if( pFrom->fg.isTabFunc ){
+    sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);
+    return 1;
+  }
+  return 0;
+}
+
 #ifndef SQLITE_OMIT_CTE
 /*
 ** Argument pWith (which may be NULL) points to a linked list of nested 
@@ -109185,7 +121545,7 @@ static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
 ** object that the returned CTE belongs to.
 */
 static struct Cte *searchWith(
-  With *pWith,                    /* Current outermost WITH clause */
+  With *pWith,                    /* Current innermost WITH clause */
   struct SrcList_item *pItem,     /* FROM clause element to resolve */
   With **ppContext                /* OUT: WITH clause return value belongs to */
 ){
@@ -109216,11 +121576,12 @@ static struct Cte *searchWith(
 ** statement with which it is associated.
 */
 SQLITE_PRIVATE void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){
-  assert( bFree==0 || pParse->pWith==0 );
+  assert( bFree==0 || (pParse->pWith==0 && pParse->pWithToFree==0) );
   if( pWith ){
+    assert( pParse->pWith!=pWith );
     pWith->pOuter = pParse->pWith;
     pParse->pWith = pWith;
-    pParse->bFreeWith = bFree;
+    if( bFree ) pParse->pWithToFree = pWith;
   }
 }
 
@@ -109259,25 +121620,26 @@ static int withExpand(
     int bMayRecursive;            /* True if compound joined by UNION [ALL] */
     With *pSavedWith;             /* Initial value of pParse->pWith */
 
-    /* If pCte->zErr is non-NULL at this point, then this is an illegal
+    /* If pCte->zCteErr is non-NULL at this point, then this is an illegal
     ** recursive reference to CTE pCte. Leave an error in pParse and return
-    ** early. If pCte->zErr is NULL, then this is not a recursive reference.
+    ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
     ** In this case, proceed.  */
-    if( pCte->zErr ){
-      sqlite3ErrorMsg(pParse, pCte->zErr, pCte->zName);
+    if( pCte->zCteErr ){
+      sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
       return SQLITE_ERROR;
     }
+    if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;
 
     assert( pFrom->pTab==0 );
     pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
     if( pTab==0 ) return WRC_Abort;
-    pTab->nRef = 1;
+    pTab->nTabRef = 1;
     pTab->zName = sqlite3DbStrDup(db, pCte->zName);
     pTab->iPKey = -1;
     pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
-    pTab->tabFlags |= TF_Ephemeral;
+    pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
     pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
-    if( db->mallocFailed ) return SQLITE_NOMEM;
+    if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
     assert( pFrom->pSelect );
 
     /* Check if this is a recursive CTE. */
@@ -109293,31 +121655,40 @@ static int withExpand(
          && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
           ){
           pItem->pTab = pTab;
-          pItem->isRecursive = 1;
-          pTab->nRef++;
+          pItem->fg.isRecursive = 1;
+          pTab->nTabRef++;
           pSel->selFlags |= SF_Recursive;
         }
       }
     }
 
     /* Only one recursive reference is permitted. */ 
-    if( pTab->nRef>2 ){
+    if( pTab->nTabRef>2 ){
       sqlite3ErrorMsg(
           pParse, "multiple references to recursive table: %s", pCte->zName
       );
       return SQLITE_ERROR;
     }
-    assert( pTab->nRef==1 || ((pSel->selFlags&SF_Recursive) && pTab->nRef==2 ));
+    assert( pTab->nTabRef==1 || ((pSel->selFlags&SF_Recursive) && pTab->nTabRef==2 ));
 
-    pCte->zErr = "circular reference: %s";
+    pCte->zCteErr = "circular reference: %s";
     pSavedWith = pParse->pWith;
     pParse->pWith = pWith;
-    sqlite3WalkSelect(pWalker, bMayRecursive ? pSel->pPrior : pSel);
+    if( bMayRecursive ){
+      Select *pPrior = pSel->pPrior;
+      assert( pPrior->pWith==0 );
+      pPrior->pWith = pSel->pWith;
+      sqlite3WalkSelect(pWalker, pPrior);
+      pPrior->pWith = 0;
+    }else{
+      sqlite3WalkSelect(pWalker, pSel);
+    }
+    pParse->pWith = pWith;
 
     for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);
     pEList = pLeft->pEList;
     if( pCte->pCols ){
-      if( pEList->nExpr!=pCte->pCols->nExpr ){
+      if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){
         sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",
             pCte->zName, pEList->nExpr, pCte->pCols->nExpr
         );
@@ -109327,16 +121698,16 @@ static int withExpand(
       pEList = pCte->pCols;
     }
 
-    selectColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
+    sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
     if( bMayRecursive ){
       if( pSel->selFlags & SF_Recursive ){
-        pCte->zErr = "multiple recursive references: %s";
+        pCte->zCteErr = "multiple recursive references: %s";
       }else{
-        pCte->zErr = "recursive reference in a subquery: %s";
+        pCte->zCteErr = "recursive reference in a subquery: %s";
       }
       sqlite3WalkSelect(pWalker, pSel);
     }
-    pCte->zErr = 0;
+    pCte->zCteErr = 0;
     pParse->pWith = pSavedWith;
   }
 
@@ -109355,10 +121726,12 @@ static int withExpand(
 */
 static void selectPopWith(Walker *pWalker, Select *p){
   Parse *pParse = pWalker->pParse;
-  With *pWith = findRightmost(p)->pWith;
-  if( pWith!=0 ){
-    assert( pParse->pWith==pWith );
-    pParse->pWith = pWith->pOuter;
+  if( pParse->pWith && p->pPrior==0 ){
+    With *pWith = findRightmost(p)->pWith;
+    if( pWith!=0 ){
+      assert( pParse->pWith==pWith );
+      pParse->pWith = pWith->pOuter;
+    }
   }
 }
 #else
@@ -109408,8 +121781,8 @@ static int selectExpander(Walker *pWalker, Select *p){
   }
   pTabList = p->pSrc;
   pEList = p->pEList;
-  if( pWalker->xSelectCallback2==selectPopWith ){
-    sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
+  if( p->pWith ){
+    sqlite3WithPush(pParse, p->pWith, 0);
   }
 
   /* Make sure cursor numbers have been assigned to all entries in
@@ -109423,17 +121796,9 @@ static int selectExpander(Walker *pWalker, Select *p){
   */
   for(i=0, pFrom=pTabList->a; inSrc; i++, pFrom++){
     Table *pTab;
-    assert( pFrom->isRecursive==0 || pFrom->pTab );
-    if( pFrom->isRecursive ) continue;
-    if( pFrom->pTab!=0 ){
-      /* This statement has already been prepared.  There is no need
-      ** to go further. */
-      assert( i==0 );
-#ifndef SQLITE_OMIT_CTE
-      selectPopWith(pWalker, p);
-#endif
-      return WRC_Prune;
-    }
+    assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
+    if( pFrom->fg.isRecursive ) continue;
+    assert( pFrom->pTab==0 );
 #ifndef SQLITE_OMIT_CTE
     if( withExpand(pWalker, pFrom) ) return WRC_Abort;
     if( pFrom->pTab ) {} else
@@ -109444,13 +121809,13 @@ static int selectExpander(Walker *pWalker, Select *p){
       /* A sub-query in the FROM clause of a SELECT */
       assert( pSel!=0 );
       assert( pFrom->pTab==0 );
-      sqlite3WalkSelect(pWalker, pSel);
+      if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
       pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
       if( pTab==0 ) return WRC_Abort;
-      pTab->nRef = 1;
+      pTab->nTabRef = 1;
       pTab->zName = sqlite3MPrintf(db, "sqlite_sq_%p", (void*)pTab);
       while( pSel->pPrior ){ pSel = pSel->pPrior; }
-      selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol);
+      sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
       pTab->iPKey = -1;
       pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
       pTab->tabFlags |= TF_Ephemeral;
@@ -109460,21 +121825,27 @@ static int selectExpander(Walker *pWalker, Select *p){
       assert( pFrom->pTab==0 );
       pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
       if( pTab==0 ) return WRC_Abort;
-      if( pTab->nRef==0xffff ){
+      if( pTab->nTabRef>=0xffff ){
         sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
            pTab->zName);
         pFrom->pTab = 0;
         return WRC_Abort;
       }
-      pTab->nRef++;
+      pTab->nTabRef++;
+      if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
+        return WRC_Abort;
+      }
 #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
-      if( pTab->pSelect || IsVirtual(pTab) ){
-        /* We reach here if the named table is a really a view */
+      if( IsVirtual(pTab) || pTab->pSelect ){
+        i16 nCol;
         if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
         assert( pFrom->pSelect==0 );
         pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
         sqlite3SelectSetName(pFrom->pSelect, pTab->zName);
+        nCol = pTab->nCol;
+        pTab->nCol = -1;
         sqlite3WalkSelect(pWalker, pFrom->pSelect);
+        pTab->nCol = nCol;
       }
 #endif
     }
@@ -109494,19 +121865,20 @@ static int selectExpander(Walker *pWalker, Select *p){
   /* For every "*" that occurs in the column list, insert the names of
   ** all columns in all tables.  And for every TABLE.* insert the names
   ** of all columns in TABLE.  The parser inserted a special expression
-  ** with the TK_ALL operator for each "*" that it found in the column list.
-  ** The following code just has to locate the TK_ALL expressions and expand
-  ** each one to the list of all columns in all tables.
+  ** with the TK_ASTERISK operator for each "*" that it found in the column
+  ** list.  The following code just has to locate the TK_ASTERISK
+  ** expressions and expand each one to the list of all columns in
+  ** all tables.
   **
   ** The first loop just checks to see if there are any "*" operators
   ** that need expanding.
   */
   for(k=0; knExpr; k++){
     pE = pEList->a[k].pExpr;
-    if( pE->op==TK_ALL ) break;
+    if( pE->op==TK_ASTERISK ) break;
     assert( pE->op!=TK_DOT || pE->pRight!=0 );
     assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
-    if( pE->op==TK_DOT && pE->pRight->op==TK_ALL ) break;
+    if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;
   }
   if( knExpr ){
     /*
@@ -109520,18 +121892,13 @@ static int selectExpander(Walker *pWalker, Select *p){
     int longNames = (flags & SQLITE_FullColNames)!=0
                       && (flags & SQLITE_ShortColNames)==0;
 
-    /* When processing FROM-clause subqueries, it is always the case
-    ** that full_column_names=OFF and short_column_names=ON.  The
-    ** sqlite3ResultSetOfSelect() routine makes it so. */
-    assert( (p->selFlags & SF_NestedFrom)==0
-          || ((flags & SQLITE_FullColNames)==0 &&
-              (flags & SQLITE_ShortColNames)!=0) );
-
     for(k=0; knExpr; k++){
       pE = a[k].pExpr;
       pRight = pE->pRight;
       assert( pE->op!=TK_DOT || pRight!=0 );
-      if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pRight->op!=TK_ALL) ){
+      if( pE->op!=TK_ASTERISK
+       && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
+      ){
         /* This particular expression does not need to be expanded.
         */
         pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
@@ -109568,7 +121935,7 @@ static int selectExpander(Walker *pWalker, Select *p){
               continue;
             }
             iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-            zSchemaName = iDb>=0 ? db->aDb[iDb].zName : "*";
+            zSchemaName = iDb>=0 ? db->aDb[iDb].zDbSName : "*";
           }
           for(j=0; jnCol; j++){
             char *zName = pTab->aCol[j].zName;
@@ -109583,18 +121950,19 @@ static int selectExpander(Walker *pWalker, Select *p){
               continue;
             }
 
-            /* If a column is marked as 'hidden' (currently only possible
-            ** for virtual tables), do not include it in the expanded
-            ** result-set list.
+            /* If a column is marked as 'hidden', omit it from the expanded
+            ** result-set list unless the SELECT has the SF_IncludeHidden
+            ** bit set.
             */
-            if( IsHiddenColumn(&pTab->aCol[j]) ){
-              assert(IsVirtual(pTab));
+            if( (p->selFlags & SF_IncludeHidden)==0
+             && IsHiddenColumn(&pTab->aCol[j]) 
+            ){
               continue;
             }
             tableSeen = 1;
 
             if( i>0 && zTName==0 ){
-              if( (pFrom->jointype & JT_NATURAL)!=0
+              if( (pFrom->fg.jointype & JT_NATURAL)!=0
                 && tableAndColumnIndex(pTabList, i, zName, 0, 0)
               ){
                 /* In a NATURAL join, omit the join columns from the 
@@ -109613,10 +121981,10 @@ static int selectExpander(Walker *pWalker, Select *p){
             if( longNames || pTabList->nSrc>1 ){
               Expr *pLeft;
               pLeft = sqlite3Expr(db, TK_ID, zTabName);
-              pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+              pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);
               if( zSchemaName ){
                 pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
-                pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr, 0);
+                pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr);
               }
               if( longNames ){
                 zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
@@ -109626,8 +121994,7 @@ static int selectExpander(Walker *pWalker, Select *p){
               pExpr = pRight;
             }
             pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
-            sColname.z = zColname;
-            sColname.n = sqlite3Strlen30(zColname);
+            sqlite3TokenInit(&sColname, zColname);
             sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
             if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
               struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
@@ -109659,6 +122026,7 @@ static int selectExpander(Walker *pWalker, Select *p){
 #if SQLITE_MAX_COLUMN
   if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many columns in result set");
+    return WRC_Abort;
   }
 #endif
   return WRC_Continue;
@@ -109673,11 +122041,30 @@ static int selectExpander(Walker *pWalker, Select *p){
 ** Walker.xSelectCallback is set to do something useful for every 
 ** subquery in the parser tree.
 */
-static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
+SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
+  UNUSED_PARAMETER2(NotUsed, NotUsed2);
+  return WRC_Continue;
+}
+
+/*
+** No-op routine for the parse-tree walker for SELECT statements.
+** subquery in the parser tree.
+*/
+SQLITE_PRIVATE int sqlite3SelectWalkNoop(Walker *NotUsed, Select *NotUsed2){
   UNUSED_PARAMETER2(NotUsed, NotUsed2);
   return WRC_Continue;
 }
 
+#if SQLITE_DEBUG
+/*
+** Always assert.  This xSelectCallback2 implementation proves that the
+** xSelectCallback2 is never invoked.
+*/
+SQLITE_PRIVATE void sqlite3SelectWalkAssert2(Walker *NotUsed, Select *NotUsed2){
+  UNUSED_PARAMETER2(NotUsed, NotUsed2);
+  assert( 0 );
+}
+#endif
 /*
 ** This routine "expands" a SELECT statement and all of its subqueries.
 ** For additional information on what it means to "expand" a SELECT
@@ -109693,17 +122080,15 @@ static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
 */
 static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
   Walker w;
-  memset(&w, 0, sizeof(w));
-  w.xExprCallback = exprWalkNoop;
+  w.xExprCallback = sqlite3ExprWalkNoop;
   w.pParse = pParse;
   if( pParse->hasCompound ){
     w.xSelectCallback = convertCompoundSelectToSubquery;
+    w.xSelectCallback2 = 0;
     sqlite3WalkSelect(&w, pSelect);
   }
   w.xSelectCallback = selectExpander;
-  if( (pSelect->selFlags & SF_AllValues)==0 ){
-    w.xSelectCallback2 = selectPopWith;
-  }
+  w.xSelectCallback2 = selectPopWith;
   sqlite3WalkSelect(&w, pSelect);
 }
 
@@ -109729,19 +122114,19 @@ static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
   struct SrcList_item *pFrom;
 
   assert( p->selFlags & SF_Resolved );
-  if( (p->selFlags & SF_HasTypeInfo)==0 ){
-    p->selFlags |= SF_HasTypeInfo;
-    pParse = pWalker->pParse;
-    pTabList = p->pSrc;
-    for(i=0, pFrom=pTabList->a; inSrc; i++, pFrom++){
-      Table *pTab = pFrom->pTab;
-      if( ALWAYS(pTab!=0) && (pTab->tabFlags & TF_Ephemeral)!=0 ){
-        /* A sub-query in the FROM clause of a SELECT */
-        Select *pSel = pFrom->pSelect;
-        if( pSel ){
-          while( pSel->pPrior ) pSel = pSel->pPrior;
-          selectAddColumnTypeAndCollation(pParse, pTab, pSel);
-        }
+  assert( (p->selFlags & SF_HasTypeInfo)==0 );
+  p->selFlags |= SF_HasTypeInfo;
+  pParse = pWalker->pParse;
+  pTabList = p->pSrc;
+  for(i=0, pFrom=pTabList->a; inSrc; i++, pFrom++){
+    Table *pTab = pFrom->pTab;
+    assert( pTab!=0 );
+    if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
+      /* A sub-query in the FROM clause of a SELECT */
+      Select *pSel = pFrom->pSelect;
+      if( pSel ){
+        while( pSel->pPrior ) pSel = pSel->pPrior;
+        sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSel);
       }
     }
   }
@@ -109759,9 +122144,9 @@ static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
 static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
 #ifndef SQLITE_OMIT_SUBQUERY
   Walker w;
-  memset(&w, 0, sizeof(w));
+  w.xSelectCallback = sqlite3SelectWalkNoop;
   w.xSelectCallback2 = selectAddSubqueryTypeInfo;
-  w.xExprCallback = exprWalkNoop;
+  w.xExprCallback = sqlite3ExprWalkNoop;
   w.pParse = pParse;
   sqlite3WalkSelect(&w, pSelect);
 #endif
@@ -109853,8 +122238,8 @@ static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
   for(i=0, pF=pAggInfo->aFunc; inFunc; i++, pF++){
     ExprList *pList = pF->pExpr->x.pList;
     assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
-    sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0,
-                      (void*)pF->pFunc, P4_FUNCDEF);
+    sqlite3VdbeAddOp2(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0);
+    sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
   }
 }
 
@@ -109880,14 +122265,15 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
     if( pList ){
       nArg = pList->nExpr;
       regAgg = sqlite3GetTempRange(pParse, nArg);
-      sqlite3ExprCodeExprList(pParse, pList, regAgg, SQLITE_ECEL_DUP);
+      sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);
     }else{
       nArg = 0;
       regAgg = 0;
     }
     if( pF->iDistinct>=0 ){
       addrNext = sqlite3VdbeMakeLabel(v);
-      assert( nArg==1 );
+      testcase( nArg==0 );  /* Error condition */
+      testcase( nArg>1 );   /* Also an error */
       codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
     }
     if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
@@ -109904,8 +122290,8 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
       if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;
       sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);
     }
-    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
-                      (void*)pF->pFunc, P4_FUNCDEF);
+    sqlite3VdbeAddOp3(v, OP_AggStep0, 0, regAgg, pF->iMem);
+    sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
     sqlite3VdbeChangeP5(v, (u8)nArg);
     sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
     sqlite3ReleaseTempRange(pParse, regAgg, nArg);
@@ -109965,6 +122351,187 @@ static void explainSimpleCount(
 # define explainSimpleCount(a,b,c)
 #endif
 
+/*
+** Context object for havingToWhereExprCb().
+*/
+struct HavingToWhereCtx {
+  Expr **ppWhere;
+  ExprList *pGroupBy;
+};
+
+/*
+** sqlite3WalkExpr() callback used by havingToWhere().
+**
+** If the node passed to the callback is a TK_AND node, return 
+** WRC_Continue to tell sqlite3WalkExpr() to iterate through child nodes.
+**
+** Otherwise, return WRC_Prune. In this case, also check if the 
+** sub-expression matches the criteria for being moved to the WHERE
+** clause. If so, add it to the WHERE clause and replace the sub-expression
+** within the HAVING expression with a constant "1".
+*/
+static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op!=TK_AND ){
+    struct HavingToWhereCtx *p = pWalker->u.pHavingCtx;
+    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, p->pGroupBy) ){
+      sqlite3 *db = pWalker->pParse->db;
+      Expr *pNew = sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[1], 0);
+      if( pNew ){
+        Expr *pWhere = *(p->ppWhere);
+        SWAP(Expr, *pNew, *pExpr);
+        pNew = sqlite3ExprAnd(db, pWhere, pNew);
+        *(p->ppWhere) = pNew;
+      }
+    }
+    return WRC_Prune;
+  }
+  return WRC_Continue;
+}
+
+/*
+** Transfer eligible terms from the HAVING clause of a query, which is
+** processed after grouping, to the WHERE clause, which is processed before
+** grouping. For example, the query:
+**
+**   SELECT * FROM  WHERE a=? GROUP BY b HAVING b=? AND c=?
+**
+** can be rewritten as:
+**
+**   SELECT * FROM  WHERE a=? AND b=? GROUP BY b HAVING c=?
+**
+** A term of the HAVING expression is eligible for transfer if it consists
+** entirely of constants and expressions that are also GROUP BY terms that
+** use the "BINARY" collation sequence.
+*/
+static void havingToWhere(
+  Parse *pParse,
+  ExprList *pGroupBy,
+  Expr *pHaving, 
+  Expr **ppWhere
+){
+  struct HavingToWhereCtx sCtx;
+  Walker sWalker;
+
+  sCtx.ppWhere = ppWhere;
+  sCtx.pGroupBy = pGroupBy;
+
+  memset(&sWalker, 0, sizeof(sWalker));
+  sWalker.pParse = pParse;
+  sWalker.xExprCallback = havingToWhereExprCb;
+  sWalker.u.pHavingCtx = &sCtx;
+  sqlite3WalkExpr(&sWalker, pHaving);
+}
+
+/*
+** Check to see if the pThis entry of pTabList is a self-join of a prior view.
+** If it is, then return the SrcList_item for the prior view.  If it is not,
+** then return 0.
+*/
+static struct SrcList_item *isSelfJoinView(
+  SrcList *pTabList,           /* Search for self-joins in this FROM clause */
+  struct SrcList_item *pThis   /* Search for prior reference to this subquery */
+){
+  struct SrcList_item *pItem;
+  for(pItem = pTabList->a; pItempSelect==0 ) continue;
+    if( pItem->fg.viaCoroutine ) continue;
+    if( pItem->zName==0 ) continue;
+    if( sqlite3_stricmp(pItem->zDatabase, pThis->zDatabase)!=0 ) continue;
+    if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
+    if( sqlite3ExprCompare(0, 
+          pThis->pSelect->pWhere, pItem->pSelect->pWhere, -1) 
+    ){
+      /* The view was modified by some other optimization such as
+      ** pushDownWhereTerms() */
+      continue;
+    }
+    return pItem;
+  }
+  return 0;
+}
+
+#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
+/*
+** Attempt to transform a query of the form
+**
+**    SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)
+**
+** Into this:
+**
+**    SELECT (SELECT count(*) FROM t1)+(SELECT count(*) FROM t2)
+**
+** The transformation only works if all of the following are true:
+**
+**   *  The subquery is a UNION ALL of two or more terms
+**   *  There is no WHERE or GROUP BY or HAVING clauses on the subqueries
+**   *  The outer query is a simple count(*)
+**
+** Return TRUE if the optimization is undertaken.
+*/
+static int countOfViewOptimization(Parse *pParse, Select *p){
+  Select *pSub, *pPrior;
+  Expr *pExpr;
+  Expr *pCount;
+  sqlite3 *db;
+  if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate query */
+  if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
+  pExpr = p->pEList->a[0].pExpr;
+  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
+  if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Must be count() */
+  if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */
+  if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in the FROM clause */
+  pSub = p->pSrc->a[0].pSelect;
+  if( pSub==0 ) return 0;                           /* The FROM is a subquery */
+  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound subquery */
+  do{
+    if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
+    if( pSub->pWhere ) return 0;                      /* No WHERE clause */
+    if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */
+    pSub = pSub->pPrior;                              /* Repeat over compound terms */
+  }while( pSub );
+
+  /* If we reach this point, that means it is OK to perform the transformation */
+
+  db = pParse->db;
+  pCount = pExpr;
+  pExpr = 0;
+  pSub = p->pSrc->a[0].pSelect;
+  p->pSrc->a[0].pSelect = 0;
+  sqlite3SrcListDelete(db, p->pSrc);
+  p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));
+  while( pSub ){
+    Expr *pTerm;
+    pPrior = pSub->pPrior;
+    pSub->pPrior = 0;
+    pSub->pNext = 0;
+    pSub->selFlags |= SF_Aggregate;
+    pSub->selFlags &= ~SF_Compound;
+    pSub->nSelectRow = 0;
+    sqlite3ExprListDelete(db, pSub->pEList);
+    pTerm = pPrior ? sqlite3ExprDup(db, pCount, 0) : pCount;
+    pSub->pEList = sqlite3ExprListAppend(pParse, 0, pTerm);
+    pTerm = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
+    sqlite3PExprAddSelect(pParse, pTerm, pSub);
+    if( pExpr==0 ){
+      pExpr = pTerm;
+    }else{
+      pExpr = sqlite3PExpr(pParse, TK_PLUS, pTerm, pExpr);
+    }
+    pSub = pPrior;
+  }
+  p->pEList->a[0].pExpr = pExpr;
+  p->selFlags &= ~SF_Aggregate;
+
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x400 ){
+    SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
+  return 1;
+}
+#endif /* SQLITE_COUNTOFVIEW_OPTIMIZATION */
+
 /*
 ** Generate code for the SELECT statement given in the p argument.  
 **
@@ -109987,7 +122554,7 @@ SQLITE_PRIVATE int sqlite3Select(
   WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */
   Vdbe *v;               /* The virtual machine under construction */
   int isAgg;             /* True for select lists like "count(*)" */
-  ExprList *pEList;      /* List of columns to extract. */
+  ExprList *pEList = 0;  /* List of columns to extract. */
   SrcList *pTabList;     /* List of tables to select from */
   Expr *pWhere;          /* The WHERE clause.  May be NULL */
   ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */
@@ -110037,36 +122604,108 @@ SQLITE_PRIVATE int sqlite3Select(
   memset(&sSort, 0, sizeof(sSort));
   sSort.pOrderBy = p->pOrderBy;
   pTabList = p->pSrc;
-  pEList = p->pEList;
   if( pParse->nErr || db->mallocFailed ){
     goto select_end;
   }
+  assert( p->pEList!=0 );
   isAgg = (p->selFlags & SF_Aggregate)!=0;
-  assert( pEList!=0 );
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x100 ){
+    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
 
-  /* Begin generating code.
-  */
+  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
+  ** does not already exist */
   v = sqlite3GetVdbe(pParse);
   if( v==0 ) goto select_end;
-
-  /* If writing to memory or generating a set
-  ** only a single column may be output.
-  */
-#ifndef SQLITE_OMIT_SUBQUERY
-  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
-    goto select_end;
+  if( pDest->eDest==SRT_Output ){
+    generateColumnNames(pParse, p);
   }
-#endif
 
-  /* Generate code for all sub-queries in the FROM clause
+  /* Try to flatten subqueries in the FROM clause up into the main query
   */
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
   for(i=0; !p->pPrior && inSrc; i++){
     struct SrcList_item *pItem = &pTabList->a[i];
-    SelectDest dest;
     Select *pSub = pItem->pSelect;
     int isAggSub;
+    Table *pTab = pItem->pTab;
+    if( pSub==0 ) continue;
+
+    /* Catch mismatch in the declared columns of a view and the number of
+    ** columns in the SELECT on the RHS */
+    if( pTab->nCol!=pSub->pEList->nExpr ){
+      sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
+                      pTab->nCol, pTab->zName, pSub->pEList->nExpr);
+      goto select_end;
+    }
+
+    isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
+    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
+      /* This subquery can be absorbed into its parent. */
+      if( isAggSub ){
+        isAgg = 1;
+        p->selFlags |= SF_Aggregate;
+      }
+      i = -1;
+    }
+    pTabList = p->pSrc;
+    if( db->mallocFailed ) goto select_end;
+    if( !IgnorableOrderby(pDest) ){
+      sSort.pOrderBy = p->pOrderBy;
+    }
+  }
+#endif
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+  /* Handle compound SELECT statements using the separate multiSelect()
+  ** procedure.
+  */
+  if( p->pPrior ){
+    rc = multiSelect(pParse, p, pDest);
+    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
+#if SELECTTRACE_ENABLED
+    SELECTTRACE(1,pParse,p,("end compound-select processing\n"));
+    pParse->nSelectIndent--;
+#endif
+    return rc;
+  }
+#endif
 
+  /* For each term in the FROM clause, do two things:
+  ** (1) Authorized unreferenced tables
+  ** (2) Generate code for all sub-queries
+  */
+  for(i=0; inSrc; i++){
+    struct SrcList_item *pItem = &pTabList->a[i];
+    SelectDest dest;
+    Select *pSub;
+
+    /* Issue SQLITE_READ authorizations with a fake column name for any tables that
+    ** are referenced but from which no values are extracted. Examples of where these
+    ** kinds of null SQLITE_READ authorizations would occur:
+    **
+    **     SELECT count(*) FROM t1;   -- SQLITE_READ t1.""
+    **     SELECT t1.* FROM t1, t2;   -- SQLITE_READ t2.""
+    **
+    ** The fake column name is an empty string.  It is possible for a table to
+    ** have a column named by the empty string, in which case there is no way to
+    ** distinguish between an unreferenced table and an actual reference to the
+    ** "" column.  The original design was for the fake column name to be a NULL,
+    ** which would be unambiguous.  But legacy authorization callbacks might
+    ** assume the column name is non-NULL and segfault.  The use of an empty string
+    ** for the fake column name seems safer.
+    */
+    if( pItem->colUsed==0 ){
+      sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", pItem->zDatabase);
+    }
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+    /* Generate code for all sub-queries in the FROM clause
+    */
+    pSub = pItem->pSelect;
     if( pSub==0 ) continue;
 
     /* Sometimes the code for a subquery will be generated more than
@@ -110076,7 +122715,11 @@ SQLITE_PRIVATE int sqlite3Select(
     ** is sufficient, though the subroutine to manifest the view does need
     ** to be invoked again. */
     if( pItem->addrFillSub ){
-      if( pItem->viaCoroutine==0 ){
+      if( pItem->fg.viaCoroutine==0 ){
+        /* The subroutine that manifests the view might be a one-time routine,
+        ** or it might need to be rerun on each iteration because it
+        ** encodes a correlated subquery. */
+        testcase( sqlite3VdbeGetOp(v, pItem->addrFillSub)->opcode==OP_Once );
         sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
       }
       continue;
@@ -110091,16 +122734,39 @@ SQLITE_PRIVATE int sqlite3Select(
     */
     pParse->nHeight += sqlite3SelectExprHeight(p);
 
-    isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
-    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
-      /* This subquery can be absorbed into its parent. */
-      if( isAggSub ){
-        isAgg = 1;
-        p->selFlags |= SF_Aggregate;
+    /* Make copies of constant WHERE-clause terms in the outer query down
+    ** inside the subquery.  This can help the subquery to run more efficiently.
+    */
+    if( (pItem->fg.jointype & JT_OUTER)==0
+     && pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor)
+    ){
+#if SELECTTRACE_ENABLED
+      if( sqlite3SelectTrace & 0x100 ){
+        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
+        sqlite3TreeViewSelect(0, p, 0);
       }
-      i = -1;
-    }else if( pTabList->nSrc==1
-           && OptimizationEnabled(db, SQLITE_SubqCoroutine)
+#endif
+    }
+
+    /* Generate code to implement the subquery
+    **
+    ** The subquery is implemented as a co-routine if all of these are true:
+    **   (1)  The subquery is guaranteed to be the outer loop (so that it
+    **        does not need to be computed more than once)
+    **   (2)  The ALL keyword after SELECT is omitted.  (Applications are
+    **        allowed to say "SELECT ALL" instead of just "SELECT" to disable
+    **        the use of co-routines.)
+    **   (3)  Co-routines are not disabled using sqlite3_test_control()
+    **        with SQLITE_TESTCTRL_OPTIMIZATIONS.
+    **
+    ** TODO: Are there other reasons beside (1) to use a co-routine
+    ** implementation?
+    */
+    if( i==0
+     && (pTabList->nSrc==1
+            || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */
+     && (p->selFlags & SF_All)==0                                   /* (2) */
+     && OptimizationEnabled(db, SQLITE_SubqCoroutine)               /* (3) */
     ){
       /* Implement a co-routine that will return a single row of the result
       ** set on each invocation.
@@ -110113,10 +122779,10 @@ SQLITE_PRIVATE int sqlite3Select(
       sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
       explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
       sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
-      pItem->viaCoroutine = 1;
+      pItem->pTab->nRowLogEst = pSub->nSelectRow;
+      pItem->fg.viaCoroutine = 1;
       pItem->regResult = dest.iSdst;
-      sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
+      sqlite3VdbeEndCoroutine(v, pItem->regReturn);
       sqlite3VdbeJumpHere(v, addrTop-1);
       sqlite3ClearTempRegCache(pParse);
     }else{
@@ -110128,56 +122794,66 @@ SQLITE_PRIVATE int sqlite3Select(
       int topAddr;
       int onceAddr = 0;
       int retAddr;
+      struct SrcList_item *pPrior;
+
       assert( pItem->addrFillSub==0 );
       pItem->regReturn = ++pParse->nMem;
       topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
       pItem->addrFillSub = topAddr+1;
-      if( pItem->isCorrelated==0 ){
+      if( pItem->fg.isCorrelated==0 ){
         /* If the subquery is not correlated and if we are not inside of
         ** a trigger, then we only need to compute the value of the subquery
         ** once. */
-        onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+        onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
         VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
       }else{
         VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
       }
-      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
-      sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
+      pPrior = isSelfJoinView(pTabList, pItem);
+      if( pPrior ){
+        sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);
+        explainSetInteger(pItem->iSelectId, pPrior->iSelectId);
+        assert( pPrior->pSelect!=0 );
+        pSub->nSelectRow = pPrior->pSelect->nSelectRow;
+      }else{
+        sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
+        explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
+        sqlite3Select(pParse, pSub, &dest);
+      }
+      pItem->pTab->nRowLogEst = pSub->nSelectRow;
       if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
       retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
       VdbeComment((v, "end %s", pItem->pTab->zName));
       sqlite3VdbeChangeP1(v, topAddr, retAddr);
       sqlite3ClearTempRegCache(pParse);
     }
-    if( /*pParse->nErr ||*/ db->mallocFailed ){
-      goto select_end;
-    }
+    if( db->mallocFailed ) goto select_end;
     pParse->nHeight -= sqlite3SelectExprHeight(p);
-    pTabList = p->pSrc;
-    if( !IgnorableOrderby(pDest) ){
-      sSort.pOrderBy = p->pOrderBy;
-    }
+#endif
   }
+
+  /* Various elements of the SELECT copied into local variables for
+  ** convenience */
   pEList = p->pEList;
-#endif
   pWhere = p->pWhere;
   pGroupBy = p->pGroupBy;
   pHaving = p->pHaving;
   sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;
 
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-  /* If there is are a sequence of queries, do the earlier ones first.
-  */
-  if( p->pPrior ){
-    rc = multiSelect(pParse, p, pDest);
-    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
 #if SELECTTRACE_ENABLED
-    SELECTTRACE(1,pParse,p,("end compound-select processing\n"));
-    pParse->nSelectIndent--;
+  if( sqlite3SelectTrace & 0x400 ){
+    SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
 #endif
-    return rc;
+
+#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
+  if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
+   && countOfViewOptimization(pParse, p)
+  ){
+    if( db->mallocFailed ) goto select_end;
+    pEList = p->pEList;
+    pTabList = p->pSrc;
   }
 #endif
 
@@ -110197,23 +122873,30 @@ SQLITE_PRIVATE int sqlite3Select(
   ** BY and DISTINCT, and an index or separate temp-table for the other.
   */
   if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
-   && sqlite3ExprListCompare(sSort.pOrderBy, p->pEList, -1)==0
+   && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
   ){
     p->selFlags &= ~SF_Distinct;
-    p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0);
-    pGroupBy = p->pGroupBy;
+    pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
     /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
     ** the sDistinct.isTnct is still set.  Hence, isTnct represents the
     ** original setting of the SF_Distinct flag, not the current setting */
     assert( sDistinct.isTnct );
+
+#if SELECTTRACE_ENABLED
+    if( sqlite3SelectTrace & 0x400 ){
+      SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));
+      sqlite3TreeViewSelect(0, p, 0);
+    }
+#endif
   }
 
-  /* If there is an ORDER BY clause, then this sorting
-  ** index might end up being unused if the data can be 
-  ** extracted in pre-sorted order.  If that is the case, then the
-  ** OP_OpenEphemeral instruction will be changed to an OP_Noop once
-  ** we figure out that the sorting index is not needed.  The addrSortIndex
-  ** variable is used to facilitate that change.
+  /* If there is an ORDER BY clause, then create an ephemeral index to
+  ** do the sorting.  But this sorting ephemeral index might end up
+  ** being unused if the data can be extracted in pre-sorted order.
+  ** If that is the case, then the OP_OpenEphemeral instruction will be
+  ** changed to an OP_Noop once we figure out that the sorting index is
+  ** not needed.  The sSort.addrSortIndex variable is used to facilitate
+  ** that change.
   */
   if( sSort.pOrderBy ){
     KeyInfo *pKeyInfo;
@@ -110237,21 +122920,23 @@ SQLITE_PRIVATE int sqlite3Select(
   /* Set the limiter.
   */
   iEnd = sqlite3VdbeMakeLabel(v);
-  p->nSelectRow = LARGEST_INT64;
+  if( (p->selFlags & SF_FixedLimit)==0 ){
+    p->nSelectRow = 320;  /* 4 billion rows */
+  }
   computeLimitRegisters(pParse, p, iEnd);
   if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
-    sqlite3VdbeGetOp(v, sSort.addrSortIndex)->opcode = OP_SorterOpen;
+    sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
     sSort.sortFlags |= SORTFLAG_UseSorter;
   }
 
-  /* Open a virtual index to use for the distinct set.
+  /* Open an ephemeral index to use for the distinct set.
   */
   if( p->selFlags & SF_Distinct ){
     sDistinct.tabTnct = pParse->nTab++;
     sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
-                                sDistinct.tabTnct, 0, 0,
-                                (char*)keyInfoFromExprList(pParse, p->pEList,0,0),
-                                P4_KEYINFO);
+                             sDistinct.tabTnct, 0, 0,
+                             (char*)keyInfoFromExprList(pParse, p->pEList,0,0),
+                             P4_KEYINFO);
     sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
     sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
   }else{
@@ -110261,10 +122946,12 @@ SQLITE_PRIVATE int sqlite3Select(
   if( !isAgg && pGroupBy==0 ){
     /* No aggregate functions and no GROUP BY clause */
     u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0);
+    assert( WHERE_USE_LIMIT==SF_FixedLimit );
+    wctrlFlags |= p->selFlags & SF_FixedLimit;
 
     /* Begin the database scan. */
     pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
-                               p->pEList, wctrlFlags, 0);
+                               p->pEList, wctrlFlags, p->nSelectRow);
     if( pWInfo==0 ) goto select_end;
     if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
       p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
@@ -110274,6 +122961,7 @@ SQLITE_PRIVATE int sqlite3Select(
     }
     if( sSort.pOrderBy ){
       sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
+      sSort.bOrderedInnerLoop = sqlite3WhereOrderedInnerLoop(pWInfo);
       if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
         sSort.pOrderBy = 0;
       }
@@ -110324,16 +123012,17 @@ SQLITE_PRIVATE int sqlite3Select(
       for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
         pItem->u.x.iAlias = 0;
       }
-      if( p->nSelectRow>100 ) p->nSelectRow = 100;
+      assert( 66==sqlite3LogEst(100) );
+      if( p->nSelectRow>66 ) p->nSelectRow = 66;
     }else{
-      p->nSelectRow = 1;
+      assert( 0==sqlite3LogEst(1) );
+      p->nSelectRow = 0;
     }
 
-
     /* If there is both a GROUP BY and an ORDER BY clause and they are
     ** identical, then it may be possible to disable the ORDER BY clause 
     ** on the grounds that the GROUP BY will cause elements to come out 
-    ** in the correct order. It also may not - the GROUP BY may use a
+    ** in the correct order. It also may not - the GROUP BY might use a
     ** database index that causes rows to be grouped together as required
     ** but not actually sorted. Either way, record the fact that the
     ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp
@@ -110359,6 +123048,11 @@ SQLITE_PRIVATE int sqlite3Select(
     sqlite3ExprAnalyzeAggList(&sNC, pEList);
     sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);
     if( pHaving ){
+      if( pGroupBy ){
+        assert( pWhere==p->pWhere );
+        havingToWhere(pParse, pGroupBy, pHaving, &p->pWhere);
+        pWhere = p->pWhere;
+      }
       sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
     }
     sAggInfo.nAccumulator = sAggInfo.nColumn;
@@ -110376,7 +123070,7 @@ SQLITE_PRIVATE int sqlite3Select(
     */
     if( pGroupBy ){
       KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
-      int j1;             /* A-vs-B comparision jump */
+      int addr1;          /* A-vs-B comparision jump */
       int addrOutputRow;  /* Start of subroutine that outputs a result row */
       int regOutputRow;   /* Return address register for output subroutine */
       int addrSetAbort;   /* Set the abort flag and return */
@@ -110457,19 +123151,14 @@ SQLITE_PRIVATE int sqlite3Select(
         }
         regBase = sqlite3GetTempRange(pParse, nCol);
         sqlite3ExprCacheClear(pParse);
-        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0);
+        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);
         j = nGroupBy;
         for(i=0; iiSorterColumn>=j ){
             int r1 = j + regBase;
-            int r2;
-
-            r2 = sqlite3ExprCodeGetColumn(pParse, 
-                               pCol->pTab, pCol->iColumn, pCol->iTable, r1, 0);
-            if( r1!=r2 ){
-              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
-            }
+            sqlite3ExprCodeGetColumnToReg(pParse, 
+                               pCol->pTab, pCol->iColumn, pCol->iTable, r1);
             j++;
           }
         }
@@ -110511,7 +123200,8 @@ SQLITE_PRIVATE int sqlite3Select(
       addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
       sqlite3ExprCacheClear(pParse);
       if( groupBySort ){
-        sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx, sortOut,sortPTab);
+        sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx,
+                          sortOut, sortPTab);
       }
       for(j=0; jnExpr; j++){
         if( groupBySort ){
@@ -110523,8 +123213,8 @@ SQLITE_PRIVATE int sqlite3Select(
       }
       sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
                           (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
-      j1 = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp3(v, OP_Jump, j1+1, 0, j1+1); VdbeCoverage(v);
+      addr1 = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);
 
       /* Generate code that runs whenever the GROUP BY changes.
       ** Changes in the GROUP BY are detected by the previous code
@@ -110546,7 +123236,7 @@ SQLITE_PRIVATE int sqlite3Select(
       /* Update the aggregate accumulators based on the content of
       ** the current row
       */
-      sqlite3VdbeJumpHere(v, j1);
+      sqlite3VdbeJumpHere(v, addr1);
       updateAccumulator(pParse, &sAggInfo);
       sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
       VdbeComment((v, "indicate data in accumulator"));
@@ -110568,7 +123258,7 @@ SQLITE_PRIVATE int sqlite3Select(
 
       /* Jump over the subroutines
       */
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEnd);
+      sqlite3VdbeGoto(v, addrEnd);
 
       /* Generate a subroutine that outputs a single row of the result
       ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
@@ -110583,7 +123273,8 @@ SQLITE_PRIVATE int sqlite3Select(
       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
       sqlite3VdbeResolveLabel(v, addrOutputRow);
       addrOutputRow = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2); VdbeCoverage(v);
+      sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
+      VdbeCoverage(v);
       VdbeComment((v, "Groupby result generator entry point"));
       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
       finalizeAggFunctions(pParse, &sAggInfo);
@@ -110702,7 +123393,8 @@ SQLITE_PRIVATE int sqlite3Select(
         if( flag ){
           pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
           pDel = pMinMax;
-          if( pMinMax && !db->mallocFailed ){
+          assert( db->mallocFailed || pMinMax!=0 );
+          if( !db->mallocFailed ){
             pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
             pMinMax->a[0].pExpr->op = TK_COLUMN;
           }
@@ -110713,7 +123405,7 @@ SQLITE_PRIVATE int sqlite3Select(
         ** of output.
         */
         resetAccumulator(pParse, &sAggInfo);
-        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMax,0,flag,0);
+        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMax, 0,flag,0);
         if( pWInfo==0 ){
           sqlite3ExprListDelete(db, pDel);
           goto select_end;
@@ -110721,7 +123413,7 @@ SQLITE_PRIVATE int sqlite3Select(
         updateAccumulator(pParse, &sAggInfo);
         assert( pMinMax==0 || pMinMax->nExpr==1 );
         if( sqlite3WhereIsOrdered(pWInfo)>0 ){
-          sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3WhereBreakLabel(pWInfo));
+          sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
           VdbeComment((v, "%s() by index",
                 (flag==WHERE_ORDERBY_MIN?"min":"max")));
         }
@@ -110747,7 +123439,8 @@ SQLITE_PRIVATE int sqlite3Select(
   ** and send them to the callback one by one.
   */
   if( sSort.pOrderBy ){
-    explainTempTable(pParse, sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
+    explainTempTable(pParse,
+                     sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
     generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
   }
 
@@ -110755,10 +123448,9 @@ SQLITE_PRIVATE int sqlite3Select(
   */
   sqlite3VdbeResolveLabel(v, iEnd);
 
-  /* The SELECT was successfully coded.   Set the return code to 0
-  ** to indicate no errors.
-  */
-  rc = 0;
+  /* The SELECT has been coded. If there is an error in the Parse structure,
+  ** set the return code to 1. Otherwise 0. */
+  rc = (pParse->nErr>0);
 
   /* Control jumps to here if an error is encountered above, or upon
   ** successful coding of the SELECT.
@@ -110766,12 +123458,6 @@ SQLITE_PRIVATE int sqlite3Select(
 select_end:
   explainSetInteger(pParse->iSelectId, iRestoreSelectId);
 
-  /* Identify column names if results of the SELECT are to be output.
-  */
-  if( rc==SQLITE_OK && pDest->eDest==SRT_Output ){
-    generateColumnNames(pParse, pTabList, pEList);
-  }
-
   sqlite3DbFree(db, sAggInfo.aCol);
   sqlite3DbFree(db, sAggInfo.aFunc);
 #if SELECTTRACE_ENABLED
@@ -110781,100 +123467,6 @@ select_end:
   return rc;
 }
 
-#ifdef SQLITE_DEBUG
-/*
-** Generate a human-readable description of a the Select object.
-*/
-SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){
-  int n = 0;
-  pView = sqlite3TreeViewPush(pView, moreToFollow);
-  sqlite3TreeViewLine(pView, "SELECT%s%s",
-    ((p->selFlags & SF_Distinct) ? " DISTINCT" : ""),
-    ((p->selFlags & SF_Aggregate) ? " agg_flag" : "")
-  );
-  if( p->pSrc && p->pSrc->nSrc ) n++;
-  if( p->pWhere ) n++;
-  if( p->pGroupBy ) n++;
-  if( p->pHaving ) n++;
-  if( p->pOrderBy ) n++;
-  if( p->pLimit ) n++;
-  if( p->pOffset ) n++;
-  if( p->pPrior ) n++;
-  sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");
-  if( p->pSrc && p->pSrc->nSrc ){
-    int i;
-    pView = sqlite3TreeViewPush(pView, (n--)>0);
-    sqlite3TreeViewLine(pView, "FROM");
-    for(i=0; ipSrc->nSrc; i++){
-      struct SrcList_item *pItem = &p->pSrc->a[i];
-      StrAccum x;
-      char zLine[100];
-      sqlite3StrAccumInit(&x, zLine, sizeof(zLine), 0);
-      sqlite3XPrintf(&x, 0, "{%d,*}", pItem->iCursor);
-      if( pItem->zDatabase ){
-        sqlite3XPrintf(&x, 0, " %s.%s", pItem->zDatabase, pItem->zName);
-      }else if( pItem->zName ){
-        sqlite3XPrintf(&x, 0, " %s", pItem->zName);
-      }
-      if( pItem->pTab ){
-        sqlite3XPrintf(&x, 0, " tabname=%Q", pItem->pTab->zName);
-      }
-      if( pItem->zAlias ){
-        sqlite3XPrintf(&x, 0, " (AS %s)", pItem->zAlias);
-      }
-      if( pItem->jointype & JT_LEFT ){
-        sqlite3XPrintf(&x, 0, " LEFT-JOIN");
-      }
-      sqlite3StrAccumFinish(&x);
-      sqlite3TreeViewItem(pView, zLine, ipSrc->nSrc-1); 
-      if( pItem->pSelect ){
-        sqlite3TreeViewSelect(pView, pItem->pSelect, 0);
-      }
-      sqlite3TreeViewPop(pView);
-    }
-    sqlite3TreeViewPop(pView);
-  }
-  if( p->pWhere ){
-    sqlite3TreeViewItem(pView, "WHERE", (n--)>0);
-    sqlite3TreeViewExpr(pView, p->pWhere, 0);
-    sqlite3TreeViewPop(pView);
-  }
-  if( p->pGroupBy ){
-    sqlite3TreeViewExprList(pView, p->pGroupBy, (n--)>0, "GROUPBY");
-  }
-  if( p->pHaving ){
-    sqlite3TreeViewItem(pView, "HAVING", (n--)>0);
-    sqlite3TreeViewExpr(pView, p->pHaving, 0);
-    sqlite3TreeViewPop(pView);
-  }
-  if( p->pOrderBy ){
-    sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");
-  }
-  if( p->pLimit ){
-    sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);
-    sqlite3TreeViewExpr(pView, p->pLimit, 0);
-    sqlite3TreeViewPop(pView);
-  }
-  if( p->pOffset ){
-    sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);
-    sqlite3TreeViewExpr(pView, p->pOffset, 0);
-    sqlite3TreeViewPop(pView);
-  }
-  if( p->pPrior ){
-    const char *zOp = "UNION";
-    switch( p->op ){
-      case TK_ALL:         zOp = "UNION ALL";  break;
-      case TK_INTERSECT:   zOp = "INTERSECT";  break;
-      case TK_EXCEPT:      zOp = "EXCEPT";     break;
-    }
-    sqlite3TreeViewItem(pView, zOp, (n--)>0);
-    sqlite3TreeViewSelect(pView, p->pPrior, 0);
-    sqlite3TreeViewPop(pView);
-  }
-  sqlite3TreeViewPop(pView);
-}
-#endif /* SQLITE_DEBUG */
-
 /************** End of select.c **********************************************/
 /************** Begin file table.c *******************************************/
 /*
@@ -110895,8 +123487,7 @@ SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 m
 ** These routines are in a separate files so that they will not be linked
 ** if they are not used.
 */
-/* #include  */
-/* #include  */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_GET_TABLE
 
@@ -110968,7 +123559,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
         z = 0;
       }else{
         int n = sqlite3Strlen30(argv[i])+1;
-        z = sqlite3_malloc( n );
+        z = sqlite3_malloc64( n );
         if( z==0 ) goto malloc_failed;
         memcpy(z, argv[i], n);
       }
@@ -110979,7 +123570,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
   return 0;
 
 malloc_failed:
-  p->rc = SQLITE_NOMEM;
+  p->rc = SQLITE_NOMEM_BKPT;
   return 1;
 }
 
@@ -111017,10 +123608,10 @@ SQLITE_API int sqlite3_get_table(
   res.nData = 1;
   res.nAlloc = 20;
   res.rc = SQLITE_OK;
-  res.azResult = sqlite3_malloc(sizeof(char*)*res.nAlloc );
+  res.azResult = sqlite3_malloc64(sizeof(char*)*res.nAlloc );
   if( res.azResult==0 ){
      db->errCode = SQLITE_NOMEM;
-     return SQLITE_NOMEM;
+     return SQLITE_NOMEM_BKPT;
   }
   res.azResult[0] = 0;
   rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
@@ -111045,11 +123636,11 @@ SQLITE_API int sqlite3_get_table(
   }
   if( res.nAlloc>res.nData ){
     char **azNew;
-    azNew = sqlite3_realloc( res.azResult, sizeof(char*)*res.nData );
+    azNew = sqlite3_realloc64( res.azResult, sizeof(char*)*res.nData );
     if( azNew==0 ){
       sqlite3_free_table(&res.azResult[1]);
       db->errCode = SQLITE_NOMEM;
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     res.azResult = azNew;
   }
@@ -111091,6 +123682,7 @@ SQLITE_API void sqlite3_free_table(
 *************************************************************************
 ** This file contains the implementation for TRIGGERs
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_TRIGGER
 /*
@@ -111176,7 +123768,6 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
   int iDb;                /* The database to store the trigger in */
   Token *pName;           /* The unqualified db name */
   DbFixer sFix;           /* State vector for the DB fixer */
-  int iTabDb;             /* Index of the database holding pTab */
 
   assert( pName1!=0 );   /* pName1->z might be NULL, but not pName1 itself */
   assert( pName2!=0 );
@@ -111273,7 +123864,6 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
   /* Do not create a trigger on a system table */
   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
     sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
-    pParse->nErr++;
     goto trigger_cleanup;
   }
 
@@ -111290,13 +123880,13 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
         " trigger on table: %S", pTableName, 0);
     goto trigger_cleanup;
   }
-  iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
 
 #ifndef SQLITE_OMIT_AUTHORIZATION
   {
+    int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
     int code = SQLITE_CREATE_TRIGGER;
-    const char *zDb = db->aDb[iTabDb].zName;
-    const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
+    const char *zDb = db->aDb[iTabDb].zDbSName;
+    const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : zDb;
     if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
     if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
       goto trigger_cleanup;
@@ -111368,8 +123958,7 @@ SQLITE_PRIVATE void sqlite3FinishTrigger(
     pStepList->pTrig = pTrig;
     pStepList = pStepList->pNext;
   }
-  nameToken.z = pTrig->zName;
-  nameToken.n = sqlite3Strlen30(nameToken.z);
+  sqlite3TokenInit(&nameToken, pTrig->zName);
   sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
   if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 
    || sqlite3FixExpr(&sFix, pTrig->pWhen) 
@@ -111389,9 +123978,10 @@ SQLITE_PRIVATE void sqlite3FinishTrigger(
     if( v==0 ) goto triggerfinish_cleanup;
     sqlite3BeginWriteOperation(pParse, 0, iDb);
     z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
+    testcase( z==0 );
     sqlite3NestedParse(pParse,
        "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
-       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), zName,
+       db->aDb[iDb].zDbSName, MASTER_NAME, zName,
        pTrig->table, z);
     sqlite3DbFree(db, z);
     sqlite3ChangeCookie(pParse, iDb);
@@ -111405,7 +123995,7 @@ SQLITE_PRIVATE void sqlite3FinishTrigger(
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     pTrig = sqlite3HashInsert(pHash, zName, pTrig);
     if( pTrig ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
     }else if( pLink->pSchema==pLink->pTabSchema ){
       Table *pTab;
       pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);
@@ -111453,12 +124043,12 @@ static TriggerStep *triggerStepAllocate(
 ){
   TriggerStep *pTriggerStep;
 
-  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n);
+  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);
   if( pTriggerStep ){
     char *z = (char*)&pTriggerStep[1];
     memcpy(z, pName->z, pName->n);
-    pTriggerStep->target.z = z;
-    pTriggerStep->target.n = pName->n;
+    sqlite3Dequote(z);
+    pTriggerStep->zTarget = z;
     pTriggerStep->op = op;
   }
   return pTriggerStep;
@@ -111580,7 +124170,7 @@ SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr)
   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
   for(i=OMIT_TEMPDB; inDb; i++){
     int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
-    if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
+    if( zDb && sqlite3StrICmp(db->aDb[j].zDbSName, zDb) ) continue;
     assert( sqlite3SchemaMutexHeld(db, j, 0) );
     pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);
     if( pTrigger ) break;
@@ -111626,7 +124216,7 @@ SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
 #ifndef SQLITE_OMIT_AUTHORIZATION
   {
     int code = SQLITE_DROP_TRIGGER;
-    const char *zDb = db->aDb[iDb].zName;
+    const char *zDb = db->aDb[iDb].zDbSName;
     const char *zTab = SCHEMA_TABLE(iDb);
     if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
     if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
@@ -111640,31 +124230,12 @@ SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
   */
   assert( pTable!=0 );
   if( (v = sqlite3GetVdbe(pParse))!=0 ){
-    int base;
-    static const int iLn = VDBE_OFFSET_LINENO(2);
-    static const VdbeOpList dropTrigger[] = {
-      { OP_Rewind,     0, ADDR(9),  0},
-      { OP_String8,    0, 1,        0}, /* 1 */
-      { OP_Column,     0, 1,        2},
-      { OP_Ne,         2, ADDR(8),  1},
-      { OP_String8,    0, 1,        0}, /* 4: "trigger" */
-      { OP_Column,     0, 0,        2},
-      { OP_Ne,         2, ADDR(8),  1},
-      { OP_Delete,     0, 0,        0},
-      { OP_Next,       0, ADDR(1),  0}, /* 8 */
-    };
-
-    sqlite3BeginWriteOperation(pParse, 0, iDb);
-    sqlite3OpenMasterTable(pParse, iDb);
-    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger, iLn);
-    sqlite3VdbeChangeP4(v, base+1, pTrigger->zName, P4_TRANSIENT);
-    sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC);
+    sqlite3NestedParse(pParse,
+       "DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",
+       db->aDb[iDb].zDbSName, MASTER_NAME, pTrigger->zName
+    );
     sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
     sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
-    if( pParse->nMem<3 ){
-      pParse->nMem = 3;
-    }
   }
 }
 
@@ -111741,7 +124312,7 @@ SQLITE_PRIVATE Trigger *sqlite3TriggersExist(
 }
 
 /*
-** Convert the pStep->target token into a SrcList and return a pointer
+** Convert the pStep->zTarget string into a SrcList and return a pointer
 ** to that SrcList.
 **
 ** This routine adds a specific database name, if needed, to the target when
@@ -111754,18 +124325,20 @@ static SrcList *targetSrcList(
   Parse *pParse,       /* The parsing context */
   TriggerStep *pStep   /* The trigger containing the target token */
 ){
+  sqlite3 *db = pParse->db;
   int iDb;             /* Index of the database to use */
   SrcList *pSrc;       /* SrcList to be returned */
 
-  pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0);
+  pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
   if( pSrc ){
     assert( pSrc->nSrc>0 );
-    assert( pSrc->a!=0 );
-    iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema);
+    pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);
+    iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);
     if( iDb==0 || iDb>=2 ){
-      sqlite3 *db = pParse->db;
-      assert( iDbdb->nDb );
-      pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
+      const char *zDb;
+      assert( iDbnDb );
+      zDb = db->aDb[iDb].zDbSName;
+      pSrc->a[pSrc->nSrc-1].zDatabase =  sqlite3DbStrDup(db, zDb);
     }
   }
   return pSrc;
@@ -111876,6 +124449,7 @@ static void transferParseError(Parse *pTo, Parse *pFrom){
   if( pTo->nErr==0 ){
     pTo->zErrMsg = pFrom->zErrMsg;
     pTo->nErr = pFrom->nErr;
+    pTo->rc = pFrom->rc;
   }else{
     sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
   }
@@ -111978,7 +124552,6 @@ static TriggerPrg *codeRowTrigger(
     }
     pProgram->nMem = pSubParse->nMem;
     pProgram->nCsr = pSubParse->nTab;
-    pProgram->nOnce = pSubParse->nOnce;
     pProgram->token = (void *)pTrigger;
     pPrg->aColmask[0] = pSubParse->oldmask;
     pPrg->aColmask[1] = pSubParse->newmask;
@@ -112051,8 +124624,8 @@ SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(
   if( pPrg ){
     int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));
 
-    sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem);
-    sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM);
+    sqlite3VdbeAddOp4(v, OP_Program, reg, ignoreJump, ++pParse->nMem,
+                      (const char *)pPrg->pProgram, P4_SUBPROGRAM);
     VdbeComment(
         (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));
 
@@ -112214,6 +124787,7 @@ SQLITE_PRIVATE u32 sqlite3TriggerColmask(
 ** This file contains C code routines that are called by the parser
 ** to handle UPDATE statements.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /* Forward declaration */
@@ -112270,14 +124844,14 @@ SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
     sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
                          pCol->affinity, &pValue);
     if( pValue ){
-      sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
+      sqlite3VdbeAppendP4(v, pValue, P4_MEM);
     }
+  }
 #ifndef SQLITE_OMIT_FLOATING_POINT
-    if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
-      sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
-    }
-#endif
+  if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
+    sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
   }
+#endif
 }
 
 /*
@@ -112306,7 +124880,7 @@ SQLITE_PRIVATE void sqlite3Update(
   int iDataCur;          /* Cursor for the canonical data btree */
   int iIdxCur;           /* Cursor for the first index */
   sqlite3 *db;           /* The database structure */
-  int *aRegIdx = 0;      /* One register assigned to each index to be updated */
+  int *aRegIdx = 0;      /* First register in array assigned to each index */
   int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
                          ** an expression for the i-th column of the table.
                          ** aXRef[i]==-1 if the i-th column is not changed. */
@@ -112318,10 +124892,11 @@ SQLITE_PRIVATE void sqlite3Update(
   AuthContext sContext;  /* The authorization context */
   NameContext sNC;       /* The name-context to resolve expressions in */
   int iDb;               /* Database containing the table being updated */
-  int okOnePass;         /* True for one-pass algorithm without the FIFO */
+  int eOnePass;          /* ONEPASS_XXX value from where.c */
   int hasFK;             /* True if foreign key processing is required */
   int labelBreak;        /* Jump here to break out of UPDATE loop */
   int labelContinue;     /* Jump here to continue next step of UPDATE loop */
+  int flags;             /* Flags for sqlite3WhereBegin() */
 
 #ifndef SQLITE_OMIT_TRIGGER
   int isView;            /* True when updating a view (INSTEAD OF trigger) */
@@ -112332,12 +124907,16 @@ SQLITE_PRIVATE void sqlite3Update(
   int iEph = 0;          /* Ephemeral table holding all primary key values */
   int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
+  int addrOpen = 0;      /* Address of OP_OpenEphemeral */
+  int iPk = 0;           /* First of nPk cells holding PRIMARY KEY value */
+  i16 nPk = 0;           /* Number of components of the PRIMARY KEY */
+  int bReplace = 0;      /* True if REPLACE conflict resolution might happen */
 
   /* Register Allocations */
   int regRowCount = 0;   /* A count of rows changed */
-  int regOldRowid;       /* The old rowid */
-  int regNewRowid;       /* The new rowid */
-  int regNew;            /* Content of the NEW.* table in triggers */
+  int regOldRowid = 0;   /* The old rowid */
+  int regNewRowid = 0;   /* The new rowid */
+  int regNew = 0;        /* Content of the NEW.* table in triggers */
   int regOld = 0;        /* Content of OLD.* table in triggers */
   int regRowSet = 0;     /* Rowset of rows to be updated */
   int regKey = 0;        /* composite PRIMARY KEY value */
@@ -112398,7 +124977,7 @@ SQLITE_PRIVATE void sqlite3Update(
   /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  
   ** Initialize aXRef[] and aToOpen[] to their default values.
   */
-  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
+  aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
   if( aXRef==0 ) goto update_cleanup;
   aRegIdx = aXRef+pTab->nCol;
   aToOpen = (u8*)(aRegIdx+nIdx);
@@ -112450,7 +125029,7 @@ SQLITE_PRIVATE void sqlite3Update(
       int rc;
       rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
                             j<0 ? "ROWID" : pTab->aCol[j].zName,
-                            db->aDb[iDb].zName);
+                            db->aDb[iDb].zDbSName);
       if( rc==SQLITE_DENY ){
         goto update_cleanup;
       }else if( rc==SQLITE_IGNORE ){
@@ -112464,26 +125043,38 @@ SQLITE_PRIVATE void sqlite3Update(
   assert( chngPk==0 || chngPk==1 );
   chngKey = chngRowid + chngPk;
 
-  /* The SET expressions are not actually used inside the WHERE loop.
-  ** So reset the colUsed mask
+  /* The SET expressions are not actually used inside the WHERE loop.  
+  ** So reset the colUsed mask. Unless this is a virtual table. In that
+  ** case, set all bits of the colUsed mask (to ensure that the virtual
+  ** table implementation makes all columns available).
   */
-  pTabList->a[0].colUsed = 0;
+  pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
 
   hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
 
   /* There is one entry in the aRegIdx[] array for each index on the table
   ** being updated.  Fill in aRegIdx[] with a register number that will hold
-  ** the key for accessing each index.  
+  ** the key for accessing each index.
+  **
+  ** FIXME:  Be smarter about omitting indexes that use expressions.
   */
   for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
     int reg;
-    if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
+    if( chngKey || hasFK>1 || pIdx->pPartIdxWhere || pIdx==pPk ){
       reg = ++pParse->nMem;
+      pParse->nMem += pIdx->nColumn;
     }else{
       reg = 0;
       for(i=0; inKeyCol; i++){
-        if( aXRef[pIdx->aiColumn[i]]>=0 ){
+        i16 iIdxCol = pIdx->aiColumn[i];
+        if( iIdxCol<0 || aXRef[iIdxCol]>=0 ){
           reg = ++pParse->nMem;
+          pParse->nMem += pIdx->nColumn;
+          if( (onError==OE_Replace)
+           || (onError==OE_Default && pIdx->onError==OE_Replace) 
+          ){
+            bReplace = 1;
+          }
           break;
         }
       }
@@ -112491,6 +125082,11 @@ SQLITE_PRIVATE void sqlite3Update(
     if( reg==0 ) aToOpen[j+1] = 0;
     aRegIdx[j] = reg;
   }
+  if( bReplace ){
+    /* If REPLACE conflict resolution might be invoked, open cursors on all 
+    ** indexes in case they are needed to delete records.  */
+    memset(aToOpen, 1, nIdx+1);
+  }
 
   /* Begin generating code. */
   v = sqlite3GetVdbe(pParse);
@@ -112498,29 +125094,20 @@ SQLITE_PRIVATE void sqlite3Update(
   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
   sqlite3BeginWriteOperation(pParse, 1, iDb);
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  /* Virtual tables must be handled separately */
-  if( IsVirtual(pTab) ){
-    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
-                       pWhere, onError);
-    pWhere = 0;
-    pTabList = 0;
-    goto update_cleanup;
-  }
-#endif
-
   /* Allocate required registers. */
-  regRowSet = ++pParse->nMem;
-  regOldRowid = regNewRowid = ++pParse->nMem;
-  if( chngPk || pTrigger || hasFK ){
-    regOld = pParse->nMem + 1;
+  if( !IsVirtual(pTab) ){
+    regRowSet = ++pParse->nMem;
+    regOldRowid = regNewRowid = ++pParse->nMem;
+    if( chngPk || pTrigger || hasFK ){
+      regOld = pParse->nMem + 1;
+      pParse->nMem += pTab->nCol;
+    }
+    if( chngKey || pTrigger || hasFK ){
+      regNewRowid = ++pParse->nMem;
+    }
+    regNew = pParse->nMem + 1;
     pParse->nMem += pTab->nCol;
   }
-  if( chngKey || pTrigger || hasFK ){
-    regNewRowid = ++pParse->nMem;
-  }
-  regNew = pParse->nMem + 1;
-  pParse->nMem += pTab->nCol;
 
   /* Start the view context. */
   if( isView ){
@@ -112543,108 +125130,139 @@ SQLITE_PRIVATE void sqlite3Update(
     goto update_cleanup;
   }
 
-  /* Begin the database scan
-  */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Virtual tables must be handled separately */
+  if( IsVirtual(pTab) ){
+    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
+                       pWhere, onError);
+    goto update_cleanup;
+  }
+#endif
+
+  /* Initialize the count of updated rows */
+  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){
+    regRowCount = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  }
+
   if( HasRowid(pTab) ){
     sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
-    pWInfo = sqlite3WhereBegin(
-        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
-    );
-    if( pWInfo==0 ) goto update_cleanup;
-    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
-  
-    /* Remember the rowid of every item to be updated.
-    */
-    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
-    if( !okOnePass ){
-      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
-    }
-  
-    /* End the database scan loop.
-    */
-    sqlite3WhereEnd(pWInfo);
   }else{
-    int iPk;         /* First of nPk memory cells holding PRIMARY KEY value */
-    i16 nPk;         /* Number of components of the PRIMARY KEY */
-    int addrOpen;    /* Address of the OpenEphemeral instruction */
-
     assert( pPk!=0 );
     nPk = pPk->nKeyCol;
     iPk = pParse->nMem+1;
     pParse->nMem += nPk;
     regKey = ++pParse->nMem;
     iEph = pParse->nTab++;
+
     sqlite3VdbeAddOp2(v, OP_Null, 0, iPk);
     addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
     sqlite3VdbeSetP4KeyInfo(pParse, pPk);
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
-                               WHERE_ONEPASS_DESIRED, iIdxCur);
-    if( pWInfo==0 ) goto update_cleanup;
-    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+  }
+
+  /* Begin the database scan. 
+  **
+  ** Do not consider a single-pass strategy for a multi-row update if
+  ** there are any triggers or foreign keys to process, or rows may
+  ** be deleted as a result of REPLACE conflict handling. Any of these
+  ** things might disturb a cursor being used to scan through the table
+  ** or index, causing a single-pass approach to malfunction.  */
+  flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE;
+  if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
+    flags |= WHERE_ONEPASS_MULTIROW;
+  }
+  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags, iIdxCur);
+  if( pWInfo==0 ) goto update_cleanup;
+
+  /* A one-pass strategy that might update more than one row may not
+  ** be used if any column of the index used for the scan is being
+  ** updated. Otherwise, if there is an index on "b", statements like
+  ** the following could create an infinite loop:
+  **
+  **   UPDATE t1 SET b=b+1 WHERE b>?
+  **
+  ** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI
+  ** strategy that uses an index for which one or more columns are being
+  ** updated.  */
+  eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+  if( eOnePass==ONEPASS_MULTI ){
+    int iCur = aiCurOnePass[1];
+    if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){
+      eOnePass = ONEPASS_OFF;
+    }
+    assert( iCur!=iDataCur || !HasRowid(pTab) );
+  }
+  
+  if( HasRowid(pTab) ){
+    /* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF
+    ** mode, write the rowid into the FIFO. In either of the one-pass modes,
+    ** leave it in register regOldRowid.  */
+    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
+    if( eOnePass==ONEPASS_OFF ){
+      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+    }
+  }else{
+    /* Read the PK of the current row into an array of registers. In
+    ** ONEPASS_OFF mode, serialize the array into a record and store it in
+    ** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change
+    ** the OP_OpenEphemeral instruction to a Noop (the ephemeral table 
+    ** is not required) and leave the PK fields in the array of registers.  */
     for(i=0; iaiColumn[i],
-                                      iPk+i);
+      assert( pPk->aiColumn[i]>=0 );
+      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,pPk->aiColumn[i],iPk+i);
     }
-    if( okOnePass ){
+    if( eOnePass ){
       sqlite3VdbeChangeToNoop(v, addrOpen);
       nKey = nPk;
       regKey = iPk;
     }else{
       sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
-                        sqlite3IndexAffinityStr(v, pPk), nPk);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey);
+                        sqlite3IndexAffinityStr(db, pPk), nPk);
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk);
     }
-    sqlite3WhereEnd(pWInfo);
   }
 
-  /* Initialize the count of updated rows
-  */
-  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){
-    regRowCount = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  if( eOnePass!=ONEPASS_MULTI ){
+    sqlite3WhereEnd(pWInfo);
   }
 
   labelBreak = sqlite3VdbeMakeLabel(v);
   if( !isView ){
-    /* 
-    ** Open every index that needs updating.  Note that if any
-    ** index could potentially invoke a REPLACE conflict resolution 
-    ** action, then we need to open all indices because we might need
-    ** to be deleting some records.
-    */
-    if( onError==OE_Replace ){
-      memset(aToOpen, 1, nIdx+1);
-    }else{
-      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-        if( pIdx->onError==OE_Replace ){
-          memset(aToOpen, 1, nIdx+1);
-          break;
-        }
-      }
-    }
-    if( okOnePass ){
+    int addrOnce = 0;
+
+    /* Open every index that needs updating. */
+    if( eOnePass!=ONEPASS_OFF ){
       if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
       if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
     }
-    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen,
+
+    if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){
+      addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+    }
+    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen,
                                0, 0);
+    if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
   }
 
   /* Top of the update loop */
-  if( okOnePass ){
-    if( aToOpen[iDataCur-iBaseCur] && !isView ){
+  if( eOnePass!=ONEPASS_OFF ){
+    if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){
       assert( pPk );
       sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
       VdbeCoverageNeverTaken(v);
     }
-    labelContinue = labelBreak;
+    if( eOnePass==ONEPASS_SINGLE ){
+      labelContinue = labelBreak;
+    }else{
+      labelContinue = sqlite3VdbeMakeLabel(v);
+    }
     sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
     VdbeCoverageIf(v, pPk==0);
     VdbeCoverageIf(v, pPk!=0);
   }else if( pPk ){
     labelContinue = sqlite3VdbeMakeLabel(v);
     sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
-    addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey);
+    addrTop = sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey);
     sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
     VdbeCoverage(v);
   }else{
@@ -112704,7 +125322,6 @@ SQLITE_PRIVATE void sqlite3Update(
   newmask = sqlite3TriggerColmask(
       pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
   );
-  /*sqlite3VdbeAddOp3(v, OP_Null, 0, regNew, regNew+pTab->nCol-1);*/
   for(i=0; inCol; i++){
     if( i==pTab->iPKey ){
       sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
@@ -112720,7 +125337,7 @@ SQLITE_PRIVATE void sqlite3Update(
         */
         testcase( i==31 );
         testcase( i==32 );
-        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
+        sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i);
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
       }
@@ -112762,13 +125379,13 @@ SQLITE_PRIVATE void sqlite3Update(
   }
 
   if( !isView ){
-    int j1 = 0;           /* Address of jump instruction */
-    int bReplace = 0;     /* True if REPLACE conflict resolution might happen */
+    int addr1 = 0;        /* Address of jump instruction */
 
     /* Do constraint checks. */
     assert( regOldRowid>0 );
     sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
-        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace);
+        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,
+        aXRef);
 
     /* Do FK constraint checks. */
     if( hasFK ){
@@ -112778,20 +125395,43 @@ SQLITE_PRIVATE void sqlite3Update(
     /* Delete the index entries associated with the current record.  */
     if( bReplace || chngKey ){
       if( pPk ){
-        j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
+        addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
       }else{
-        j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
+        addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
       }
       VdbeCoverageNeverTaken(v);
     }
-    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
-  
-    /* If changing the record number, delete the old record.  */
-    if( hasFK || chngKey || pPk!=0 ){
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
+
+    /* If changing the rowid value, or if there are foreign key constraints
+    ** to process, delete the old record. Otherwise, add a noop OP_Delete
+    ** to invoke the pre-update hook.
+    **
+    ** That (regNew==regnewRowid+1) is true is also important for the 
+    ** pre-update hook. If the caller invokes preupdate_new(), the returned
+    ** value is copied from memory cell (regNewRowid+1+iCol), where iCol
+    ** is the column index supplied by the user.
+    */
+    assert( regNew==regNewRowid+1 );
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+    sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
+        OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP),
+        regNewRowid
+    );
+    if( eOnePass==ONEPASS_MULTI ){
+      assert( hasFK==0 && chngKey==0 );
+      sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);
+    }
+    if( !pParse->nested ){
+      sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
+    }
+#else
+    if( hasFK>1 || chngKey ){
       sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
     }
+#endif
     if( bReplace || chngKey ){
-      sqlite3VdbeJumpHere(v, j1);
+      sqlite3VdbeJumpHere(v, addr1);
     }
 
     if( hasFK ){
@@ -112799,8 +125439,11 @@ SQLITE_PRIVATE void sqlite3Update(
     }
   
     /* Insert the new index entries and the new record. */
-    sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
-                             regNewRowid, aRegIdx, 1, 0, 0);
+    sqlite3CompleteInsertion(
+        pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, 
+        OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0), 
+        0, 0
+    );
 
     /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
     ** handle rows (possibly in other tables) that refer via a foreign key
@@ -112822,25 +125465,19 @@ SQLITE_PRIVATE void sqlite3Update(
   /* Repeat the above with the next record to be updated, until
   ** all record selected by the WHERE clause have been updated.
   */
-  if( okOnePass ){
+  if( eOnePass==ONEPASS_SINGLE ){
     /* Nothing to do at end-of-loop for a single-pass */
+  }else if( eOnePass==ONEPASS_MULTI ){
+    sqlite3VdbeResolveLabel(v, labelContinue);
+    sqlite3WhereEnd(pWInfo);
   }else if( pPk ){
     sqlite3VdbeResolveLabel(v, labelContinue);
     sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
   }else{
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, labelContinue);
+    sqlite3VdbeGoto(v, labelContinue);
   }
   sqlite3VdbeResolveLabel(v, labelBreak);
 
-  /* Close all tables */
-  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
-    assert( aRegIdx );
-    if( aToOpen[i+1] ){
-      sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0);
-    }
-  }
-  if( iDataCurpVdbe;  /* Virtual machine under construction */
-  ExprList *pEList = 0;     /* The result set of the SELECT statement */
-  Select *pSelect = 0;      /* The SELECT statement */
-  Expr *pExpr;              /* Temporary expression */
   int ephemTab;             /* Table holding the result of the SELECT */
   int i;                    /* Loop counter */
-  int addr;                 /* Address of top of loop */
-  int iReg;                 /* First register in set passed to OP_VUpdate */
   sqlite3 *db = pParse->db; /* Database connection */
   const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
-  SelectDest dest;
-
-  /* Construct the SELECT statement that will find the new values for
-  ** all updated rows. 
-  */
-  pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
+  WhereInfo *pWInfo;
+  int nArg = 2 + pTab->nCol;      /* Number of arguments to VUpdate */
+  int regArg;                     /* First register in VUpdate arg array */
+  int regRec;                     /* Register in which to assemble record */
+  int regRowid;                   /* Register for ephem table rowid */
+  int iCsr = pSrc->a[0].iCursor;  /* Cursor used for virtual table scan */
+  int aDummy[2];                  /* Unused arg for sqlite3WhereOkOnePass() */
+  int bOnePass;                   /* True to use onepass strategy */
+  int addr;                       /* Address of OP_OpenEphemeral */
+
+  /* Allocate nArg registers to martial the arguments to VUpdate. Then
+  ** create and open the ephemeral table in which the records created from
+  ** these arguments will be temporarily stored. */
+  assert( v );
+  ephemTab = pParse->nTab++;
+  addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
+  regArg = pParse->nMem + 1;
+  pParse->nMem += nArg;
+  regRec = ++pParse->nMem;
+  regRowid = ++pParse->nMem;
+
+  /* Start scanning the virtual table */
+  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
+  if( pWInfo==0 ) return;
+
+  /* Populate the argument registers. */
+  sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
   if( pRowid ){
-    pEList = sqlite3ExprListAppend(pParse, pEList,
-                                   sqlite3ExprDup(db, pRowid, 0));
+    sqlite3ExprCode(pParse, pRowid, regArg+1);
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
   }
-  assert( pTab->iPKey<0 );
   for(i=0; inCol; i++){
     if( aXRef[i]>=0 ){
-      pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
+      sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
     }else{
-      pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);
+      sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
     }
-    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
   }
-  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
-  
-  /* Create the ephemeral table into which the update results will
-  ** be stored.
-  */
-  assert( v );
-  ephemTab = pParse->nTab++;
-  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
-  sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
 
-  /* fill the ephemeral table 
-  */
-  sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
-  sqlite3Select(pParse, pSelect, &dest);
+  bOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);
 
-  /* Generate code to scan the ephemeral table and call VUpdate. */
-  iReg = ++pParse->nMem;
-  pParse->nMem += pTab->nCol+1;
-  addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0); VdbeCoverage(v);
-  sqlite3VdbeAddOp3(v, OP_Column,  ephemTab, 0, iReg);
-  sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
-  for(i=0; inCol; i++){
-    sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
+  if( bOnePass ){
+    /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
+    ** above. Also, if this is a top-level parse (not a trigger), clear the
+    ** multi-write flag so that the VM does not open a statement journal */
+    sqlite3VdbeChangeToNoop(v, addr);
+    if( sqlite3IsToplevel(pParse) ){
+      pParse->isMultiWrite = 0;
+    }
+  }else{
+    /* Create a record from the argument register contents and insert it into
+    ** the ephemeral table. */
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);
+  }
+
+
+  if( bOnePass==0 ){
+    /* End the virtual table scan */
+    sqlite3WhereEnd(pWInfo);
+
+    /* Begin scannning through the ephemeral table. */
+    addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);
+
+    /* Extract arguments from the current row of the ephemeral table and 
+    ** invoke the VUpdate method.  */
+    for(i=0; inCol+2, iReg, pVTab, P4_VTAB);
+  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
   sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
   sqlite3MayAbort(pParse);
-  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
-  sqlite3VdbeJumpHere(v, addr);
-  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
 
-  /* Cleanup */
-  sqlite3SelectDelete(db, pSelect);  
+  /* End of the ephemeral table scan. Or, if using the onepass strategy,
+  ** jump to here if the scan visited zero rows. */
+  if( bOnePass==0 ){
+    sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr);
+    sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
+  }else{
+    sqlite3WhereEnd(pWInfo);
+  }
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -112992,59 +125659,56 @@ static void updateVirtualTable(
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
-/*
-** Finalize a prepared statement.  If there was an error, store the
-** text of the error message in *pzErrMsg.  Return the result code.
-*/
-static int vacuumFinalize(sqlite3 *db, sqlite3_stmt *pStmt, char **pzErrMsg){
-  int rc;
-  rc = sqlite3VdbeFinalize((Vdbe*)pStmt);
-  if( rc ){
-    sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
-  }
-  return rc;
-}
 
 /*
-** Execute zSql on database db. Return an error code.
+** Execute zSql on database db.
+**
+** If zSql returns rows, then each row will have exactly one
+** column.  (This will only happen if zSql begins with "SELECT".)
+** Take each row of result and call execSql() again recursively.
+**
+** The execSqlF() routine does the same thing, except it accepts
+** a format string as its third argument
 */
 static int execSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
-  sqlite3_stmt *pStmt;
-  VVA_ONLY( int rc; )
-  if( !zSql ){
-    return SQLITE_NOMEM;
-  }
-  if( SQLITE_OK!=sqlite3_prepare(db, zSql, -1, &pStmt, 0) ){
-    sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
-    return sqlite3_errcode(db);
-  }
-  VVA_ONLY( rc = ) sqlite3_step(pStmt);
-  assert( rc!=SQLITE_ROW || (db->flags&SQLITE_CountRows) );
-  return vacuumFinalize(db, pStmt, pzErrMsg);
-}
-
-/*
-** Execute zSql on database db. The statement returns exactly
-** one column. Execute this as SQL on the same database.
-*/
-static int execExecSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
   sqlite3_stmt *pStmt;
   int rc;
 
-  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  /* printf("SQL: [%s]\n", zSql); fflush(stdout); */
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
   if( rc!=SQLITE_OK ) return rc;
-
-  while( SQLITE_ROW==sqlite3_step(pStmt) ){
-    rc = execSql(db, pzErrMsg, (char*)sqlite3_column_text(pStmt, 0));
-    if( rc!=SQLITE_OK ){
-      vacuumFinalize(db, pStmt, pzErrMsg);
-      return rc;
+  while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
+    const char *zSubSql = (const char*)sqlite3_column_text(pStmt,0);
+    assert( sqlite3_strnicmp(zSql,"SELECT",6)==0 );
+    if( zSubSql ){
+      assert( zSubSql[0]!='S' );
+      rc = execSql(db, pzErrMsg, zSubSql);
+      if( rc!=SQLITE_OK ) break;
     }
   }
-
-  return vacuumFinalize(db, pStmt, pzErrMsg);
+  assert( rc!=SQLITE_ROW );
+  if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  if( rc ){
+    sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
+  }
+  (void)sqlite3_finalize(pStmt);
+  return rc;
+}
+static int execSqlF(sqlite3 *db, char **pzErrMsg, const char *zSql, ...){
+  char *z;
+  va_list ap;
+  int rc;
+  va_start(ap, zSql);
+  z = sqlite3VMPrintf(db, zSql, ap);
+  va_end(ap);
+  if( z==0 ) return SQLITE_NOMEM;
+  rc = execSql(db, pzErrMsg, z);
+  sqlite3DbFree(db, z);
+  return rc;
 }
 
 /*
@@ -113077,11 +125741,29 @@ static int execExecSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
 ** transient would cause the database file to appear to be deleted
 ** following reboot.
 */
-SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse){
+SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse, Token *pNm){
   Vdbe *v = sqlite3GetVdbe(pParse);
-  if( v ){
-    sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
-    sqlite3VdbeUsesBtree(v, 0);
+  int iDb = 0;
+  if( v==0 ) return;
+  if( pNm ){
+#ifndef SQLITE_BUG_COMPATIBLE_20160819
+    /* Default behavior:  Report an error if the argument to VACUUM is
+    ** not recognized */
+    iDb = sqlite3TwoPartName(pParse, pNm, pNm, &pNm);
+    if( iDb<0 ) return;
+#else
+    /* When SQLITE_BUG_COMPATIBLE_20160819 is defined, unrecognized arguments
+    ** to VACUUM are silently ignored.  This is a back-out of a bug fix that
+    ** occurred on 2016-08-19 (https://www.sqlite.org/src/info/083f9e6270).
+    ** The buggy behavior is required for binary compatibility with some
+    ** legacy applications. */
+    iDb = sqlite3FindDb(pParse->db, pNm);
+    if( iDb<0 ) iDb = 0;
+#endif
+  }
+  if( iDb!=1 ){
+    sqlite3VdbeAddOp1(v, OP_Vacuum, iDb);
+    sqlite3VdbeUsesBtree(v, iDb);
   }
   return;
 }
@@ -113089,19 +125771,19 @@ SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse){
 /*
 ** This routine implements the OP_Vacuum opcode of the VDBE.
 */
-SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
+SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db, int iDb){
   int rc = SQLITE_OK;     /* Return code from service routines */
   Btree *pMain;           /* The database being vacuumed */
   Btree *pTemp;           /* The temporary database we vacuum into */
-  char *zSql = 0;         /* SQL statements */
   int saved_flags;        /* Saved value of the db->flags */
   int saved_nChange;      /* Saved value of db->nChange */
   int saved_nTotalChange; /* Saved value of db->nTotalChange */
-  void (*saved_xTrace)(void*,const char*);  /* Saved db->xTrace */
+  u8 saved_mTrace;        /* Saved trace settings */
   Db *pDb = 0;            /* Database to detach at end of vacuum */
   int isMemDb;            /* True if vacuuming a :memory: database */
   int nRes;               /* Bytes of reserved space at the end of each page */
   int nDb;                /* Number of attached databases */
+  const char *zDbMain;    /* Schema name of database to vacuum */
 
   if( !db->autoCommit ){
     sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
@@ -113118,12 +125800,14 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   saved_flags = db->flags;
   saved_nChange = db->nChange;
   saved_nTotalChange = db->nTotalChange;
-  saved_xTrace = db->xTrace;
-  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks | SQLITE_PreferBuiltin;
-  db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder);
-  db->xTrace = 0;
-
-  pMain = db->aDb[0].pBt;
+  saved_mTrace = db->mTrace;
+  db->flags |= (SQLITE_WriteSchema | SQLITE_IgnoreChecks
+                 | SQLITE_PreferBuiltin | SQLITE_Vacuum);
+  db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder | SQLITE_CountRows);
+  db->mTrace = 0;
+
+  zDbMain = db->aDb[iDb].zDbSName;
+  pMain = db->aDb[iDb].pBt;
   isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
 
   /* Attach the temporary database as 'vacuum_db'. The synchronous pragma
@@ -113141,18 +125825,12 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** to write the journal header file.
   */
   nDb = db->nDb;
-  if( sqlite3TempInMemory(db) ){
-    zSql = "ATTACH ':memory:' AS vacuum_db;";
-  }else{
-    zSql = "ATTACH '' AS vacuum_db;";
-  }
-  rc = execSql(db, pzErrMsg, zSql);
-  if( db->nDb>nDb ){
-    pDb = &db->aDb[db->nDb-1];
-    assert( strcmp(pDb->zName,"vacuum_db")==0 );
-  }
+  rc = execSql(db, pzErrMsg, "ATTACH''AS vacuum_db");
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
-  pTemp = db->aDb[db->nDb-1].pBt;
+  assert( (db->nDb-1)==nDb );
+  pDb = &db->aDb[nDb];
+  assert( strcmp(pDb->zDbSName,"vacuum_db")==0 );
+  pTemp = pDb->pBt;
 
   /* The call to execSql() to attach the temp database has left the file
   ** locked (as there was more than one active statement when the transaction
@@ -113160,7 +125838,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** cause problems for the call to BtreeSetPageSize() below.  */
   sqlite3BtreeCommit(pTemp);
 
-  nRes = sqlite3BtreeGetReserve(pMain);
+  nRes = sqlite3BtreeGetOptimalReserve(pMain);
 
   /* A VACUUM cannot change the pagesize of an encrypted database. */
 #ifdef SQLITE_HAS_CODEC
@@ -113168,19 +125846,20 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
     extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
     int nKey;
     char *zKey;
-    sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
+    sqlite3CodecGetKey(db, iDb, (void**)&zKey, &nKey);
     if( nKey ) db->nextPagesize = 0;
   }
 #endif
 
-  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
-  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);
+  sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain,0));
+  sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF|PAGER_CACHESPILL);
 
   /* Begin a transaction and take an exclusive lock on the main database
   ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
   ** to ensure that we do not try to change the page-size on a WAL database.
   */
-  rc = execSql(db, pzErrMsg, "BEGIN;");
+  rc = execSql(db, pzErrMsg, "BEGIN");
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
   rc = sqlite3BtreeBeginTrans(pMain, 2);
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
@@ -113195,7 +125874,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
    || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
    || NEVER(db->mallocFailed)
   ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto end_of_vacuum;
   }
 
@@ -113207,60 +125886,48 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   /* Query the schema of the main database. Create a mirror schema
   ** in the temporary database.
   */
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
-      "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
-      "   AND coalesce(rootpage,1)>0"
+  db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */
+  rc = execSqlF(db, pzErrMsg,
+      "SELECT sql FROM \"%w\".sqlite_master"
+      " WHERE type='table'AND name<>'sqlite_sequence'"
+      " AND coalesce(rootpage,1)>0",
+      zDbMain
   );
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14)"
-      "  FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
-  if( rc!=SQLITE_OK ) goto end_of_vacuum;
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21) "
-      "  FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
+  rc = execSqlF(db, pzErrMsg,
+      "SELECT sql FROM \"%w\".sqlite_master"
+      " WHERE type='index' AND length(sql)>10",
+      zDbMain
+  );
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  db->init.iDb = 0;
 
   /* Loop through the tables in the main database. For each, do
   ** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
   ** the contents to the temporary database.
   */
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
-      "|| ' SELECT * FROM main.' || quote(name) || ';'"
-      "FROM main.sqlite_master "
-      "WHERE type = 'table' AND name!='sqlite_sequence' "
-      "  AND coalesce(rootpage,1)>0"
-  );
-  if( rc!=SQLITE_OK ) goto end_of_vacuum;
-
-  /* Copy over the sequence table
-  */
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
-      "FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
-  );
-  if( rc!=SQLITE_OK ) goto end_of_vacuum;
-  rc = execExecSql(db, pzErrMsg,
-      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
-      "|| ' SELECT * FROM main.' || quote(name) || ';' "
-      "FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
+  rc = execSqlF(db, pzErrMsg,
+      "SELECT'INSERT INTO vacuum_db.'||quote(name)"
+      "||' SELECT*FROM\"%w\".'||quote(name)"
+      "FROM vacuum_db.sqlite_master "
+      "WHERE type='table'AND coalesce(rootpage,1)>0",
+      zDbMain
   );
+  assert( (db->flags & SQLITE_Vacuum)!=0 );
+  db->flags &= ~SQLITE_Vacuum;
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
 
-
   /* Copy the triggers, views, and virtual tables from the main database
   ** over to the temporary database.  None of these objects has any
   ** associated storage, so all we have to do is copy their entries
   ** from the SQLITE_MASTER table.
   */
-  rc = execSql(db, pzErrMsg,
-      "INSERT INTO vacuum_db.sqlite_master "
-      "  SELECT type, name, tbl_name, rootpage, sql"
-      "    FROM main.sqlite_master"
-      "   WHERE type='view' OR type='trigger'"
-      "      OR (type='table' AND rootpage=0)"
+  rc = execSqlF(db, pzErrMsg,
+      "INSERT INTO vacuum_db.sqlite_master"
+      " SELECT*FROM \"%w\".sqlite_master"
+      " WHERE type IN('view','trigger')"
+      " OR(type='table'AND rootpage=0)",
+      zDbMain
   );
   if( rc ) goto end_of_vacuum;
 
@@ -113314,10 +125981,11 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
 
 end_of_vacuum:
   /* Restore the original value of db->flags */
+  db->init.iDb = 0;
   db->flags = saved_flags;
   db->nChange = saved_nChange;
   db->nTotalChange = saved_nTotalChange;
-  db->xTrace = saved_xTrace;
+  db->mTrace = saved_mTrace;
   sqlite3BtreeSetPageSize(pMain, -1, -1, 1);
 
   /* Currently there is an SQL level transaction open on the vacuum
@@ -113360,6 +126028,7 @@ end_of_vacuum:
 ** This file contains code used to help implement virtual tables.
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
+/* #include "sqliteInt.h" */
 
 /*
 ** Before a virtual table xCreate() or xConnect() method is invoked, the
@@ -113371,8 +126040,45 @@ end_of_vacuum:
 struct VtabCtx {
   VTable *pVTable;    /* The virtual table being constructed */
   Table *pTab;        /* The Table object to which the virtual table belongs */
+  VtabCtx *pPrior;    /* Parent context (if any) */
+  int bDeclared;      /* True after sqlite3_declare_vtab() is called */
 };
 
+/*
+** Construct and install a Module object for a virtual table.  When this
+** routine is called, it is guaranteed that all appropriate locks are held
+** and the module is not already part of the connection.
+*/
+SQLITE_PRIVATE Module *sqlite3VtabCreateModule(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+){
+  Module *pMod;
+  int nName = sqlite3Strlen30(zName);
+  pMod = (Module *)sqlite3DbMallocRawNN(db, sizeof(Module) + nName + 1);
+  if( pMod ){
+    Module *pDel;
+    char *zCopy = (char *)(&pMod[1]);
+    memcpy(zCopy, zName, nName+1);
+    pMod->zName = zCopy;
+    pMod->pModule = pModule;
+    pMod->pAux = pAux;
+    pMod->xDestroy = xDestroy;
+    pMod->pEpoTab = 0;
+    pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
+    assert( pDel==0 || pDel==pMod );
+    if( pDel ){
+      sqlite3OomFault(db);
+      sqlite3DbFree(db, pDel);
+      pMod = 0;
+    }
+  }
+  return pMod;
+}
+
 /*
 ** The actual function that does the work of creating a new module.
 ** This function implements the sqlite3_create_module() and
@@ -113386,34 +126092,15 @@ static int createModule(
   void (*xDestroy)(void *)        /* Module destructor function */
 ){
   int rc = SQLITE_OK;
-  int nName;
 
   sqlite3_mutex_enter(db->mutex);
-  nName = sqlite3Strlen30(zName);
   if( sqlite3HashFind(&db->aModule, zName) ){
     rc = SQLITE_MISUSE_BKPT;
   }else{
-    Module *pMod;
-    pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
-    if( pMod ){
-      Module *pDel;
-      char *zCopy = (char *)(&pMod[1]);
-      memcpy(zCopy, zName, nName+1);
-      pMod->zName = zCopy;
-      pMod->pModule = pModule;
-      pMod->pAux = pAux;
-      pMod->xDestroy = xDestroy;
-      pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
-      assert( pDel==0 || pDel==pMod );
-      if( pDel ){
-        db->mallocFailed = 1;
-        sqlite3DbFree(db, pDel);
-      }
-    }
+    (void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy);
   }
   rc = sqlite3ApiExit(db, rc);
   if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
-
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
@@ -113630,23 +126317,17 @@ SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){
 ** deleted.
 */
 static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){
-  int i = pTable->nModuleArg++;
-  int nBytes = sizeof(char *)*(1+pTable->nModuleArg);
+  int nBytes = sizeof(char *)*(2+pTable->nModuleArg);
   char **azModuleArg;
   azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
   if( azModuleArg==0 ){
-    int j;
-    for(j=0; jazModuleArg[j]);
-    }
     sqlite3DbFree(db, zArg);
-    sqlite3DbFree(db, pTable->azModuleArg);
-    pTable->nModuleArg = 0;
   }else{
+    int i = pTable->nModuleArg++;
     azModuleArg[i] = zArg;
     azModuleArg[i+1] = 0;
+    pTable->azModuleArg = azModuleArg;
   }
-  pTable->azModuleArg = azModuleArg;
 }
 
 /*
@@ -113674,8 +126355,7 @@ SQLITE_PRIVATE void sqlite3VtabBeginParse(
   iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
   assert( iDb>=0 );
 
-  pTable->tabFlags |= TF_Virtual;
-  pTable->nModuleArg = 0;
+  assert( pTable->nModuleArg==0 );
   addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
   addModuleArgument(db, pTable, 0);
   addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
@@ -113694,7 +126374,7 @@ SQLITE_PRIVATE void sqlite3VtabBeginParse(
   */
   if( pTable->azModuleArg ){
     sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
-            pTable->azModuleArg[0], pParse->db->aDb[iDb].zName);
+            pTable->azModuleArg[0], pParse->db->aDb[iDb].zDbSName);
   }
 #endif
 }
@@ -113736,6 +126416,7 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     char *zStmt;
     char *zWhere;
     int iDb;
+    int iReg;
     Vdbe *v;
 
     /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
@@ -113757,7 +126438,7 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
       "UPDATE %Q.%s "
          "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
        "WHERE rowid=#%d",
-      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+      db->aDb[iDb].zDbSName, MASTER_NAME,
       pTab->zName,
       pTab->zName,
       zStmt,
@@ -113767,11 +126448,13 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     v = sqlite3GetVdbe(pParse);
     sqlite3ChangeCookie(pParse, iDb);
 
-    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+    sqlite3VdbeAddOp0(v, OP_Expire);
     zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
     sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
-    sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, 
-                         pTab->zName, sqlite3Strlen30(pTab->zName) + 1);
+
+    iReg = ++pParse->nMem;
+    sqlite3VdbeLoadString(v, iReg, pTab->zName);
+    sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
   }
 
   /* If we are rereading the sqlite_master table create the in-memory
@@ -113786,7 +126469,7 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
     pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
     if( pOld ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
       return;
     }
@@ -113814,7 +126497,7 @@ SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse *pParse, Token *p){
     pArg->z = p->z;
     pArg->n = p->n;
   }else{
-    assert(pArg->z < p->z);
+    assert(pArg->z <= p->z);
     pArg->n = (int)(&p->z[p->n] - pArg->z);
   }
 }
@@ -113831,40 +126514,54 @@ static int vtabCallConstructor(
   int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
   char **pzErr
 ){
-  VtabCtx sCtx, *pPriorCtx;
+  VtabCtx sCtx;
   VTable *pVTable;
   int rc;
   const char *const*azArg = (const char *const*)pTab->azModuleArg;
   int nArg = pTab->nModuleArg;
   char *zErr = 0;
-  char *zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
+  char *zModuleName;
   int iDb;
+  VtabCtx *pCtx;
 
+  /* Check that the virtual-table is not already being initialized */
+  for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){
+    if( pCtx->pTab==pTab ){
+      *pzErr = sqlite3MPrintf(db, 
+          "vtable constructor called recursively: %s", pTab->zName
+      );
+      return SQLITE_LOCKED;
+    }
+  }
+
+  zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
   if( !zModuleName ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   pVTable = sqlite3DbMallocZero(db, sizeof(VTable));
   if( !pVTable ){
     sqlite3DbFree(db, zModuleName);
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pVTable->db = db;
   pVTable->pMod = pMod;
 
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-  pTab->azModuleArg[1] = db->aDb[iDb].zName;
+  pTab->azModuleArg[1] = db->aDb[iDb].zDbSName;
 
   /* Invoke the virtual table constructor */
   assert( &db->pVtabCtx );
   assert( xConstruct );
   sCtx.pTab = pTab;
   sCtx.pVTable = pVTable;
-  pPriorCtx = db->pVtabCtx;
+  sCtx.pPrior = db->pVtabCtx;
+  sCtx.bDeclared = 0;
   db->pVtabCtx = &sCtx;
   rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
-  db->pVtabCtx = pPriorCtx;
-  if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+  db->pVtabCtx = sCtx.pPrior;
+  if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
+  assert( sCtx.pTab==pTab );
 
   if( SQLITE_OK!=rc ){
     if( zErr==0 ){
@@ -113880,13 +126577,14 @@ static int vtabCallConstructor(
     memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));
     pVTable->pVtab->pModule = pMod->pModule;
     pVTable->nRef = 1;
-    if( sCtx.pTab ){
+    if( sCtx.bDeclared==0 ){
       const char *zFormat = "vtable constructor did not declare schema: %s";
       *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
       sqlite3VtabUnlock(pVTable);
       rc = SQLITE_ERROR;
     }else{
       int iCol;
+      u8 oooHidden = 0;
       /* If everything went according to plan, link the new VTable structure
       ** into the linked list headed by pTab->pVTable. Then loop through the 
       ** columns of the table to see if any of them contain the token "hidden".
@@ -113896,19 +126594,16 @@ static int vtabCallConstructor(
       pTab->pVTable = pVTable;
 
       for(iCol=0; iColnCol; iCol++){
-        char *zType = pTab->aCol[iCol].zType;
+        char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");
         int nType;
         int i = 0;
-        if( !zType ) continue;
         nType = sqlite3Strlen30(zType);
-        if( sqlite3StrNICmp("hidden", zType, 6)||(zType[6] && zType[6]!=' ') ){
-          for(i=0; iaCol[iCol].colFlags |= COLFLAG_HIDDEN;
+          oooHidden = TF_OOOHidden;
+        }else{
+          pTab->tabFlags |= oooHidden;
         }
       }
     }
@@ -113945,7 +126643,7 @@ SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
   int rc;
 
   assert( pTab );
-  if( (pTab->tabFlags & TF_Virtual)==0 || sqlite3GetVTable(db, pTab) ){
+  if( !IsVirtual(pTab) || sqlite3GetVTable(db, pTab) ){
     return SQLITE_OK;
   }
 
@@ -113981,7 +126679,7 @@ static int growVTrans(sqlite3 *db){
     int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR);
     aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
     if( !aVTrans ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
     db->aVTrans = aVTrans;
@@ -114004,7 +126702,7 @@ static void addToVTrans(sqlite3 *db, VTable *pVTab){
 ** This function is invoked by the vdbe to call the xCreate method
 ** of the virtual table named zTab in database iDb. 
 **
-** If an error occurs, *pzErr is set to point an an English language
+** If an error occurs, *pzErr is set to point to an English language
 ** description of the error and an SQLITE_XXX error code is returned.
 ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
 */
@@ -114014,8 +126712,8 @@ SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab,
   Module *pMod;
   const char *zMod;
 
-  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
-  assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable );
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
+  assert( pTab && IsVirtual(pTab) && !pTab->pVTable );
 
   /* Locate the required virtual table module */
   zMod = pTab->azModuleArg[0];
@@ -114025,7 +126723,7 @@ SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab,
   ** invoke it now. If the module has not been registered, return an 
   ** error. Otherwise, do nothing.
   */
-  if( !pMod ){
+  if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
     *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
     rc = SQLITE_ERROR;
   }else{
@@ -114050,26 +126748,30 @@ SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab,
 ** virtual table module.
 */
 SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
+  VtabCtx *pCtx;
   Parse *pParse;
-
   int rc = SQLITE_OK;
   Table *pTab;
   char *zErr = 0;
 
 #ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+  if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
 #endif
   sqlite3_mutex_enter(db->mutex);
-  if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
+  pCtx = db->pVtabCtx;
+  if( !pCtx || pCtx->bDeclared ){
     sqlite3Error(db, SQLITE_MISUSE);
     sqlite3_mutex_leave(db->mutex);
     return SQLITE_MISUSE_BKPT;
   }
-  assert( (pTab->tabFlags & TF_Virtual)!=0 );
+  pTab = pCtx->pTab;
+  assert( IsVirtual(pTab) );
 
   pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
   if( pParse==0 ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }else{
     pParse->declareVtab = 1;
     pParse->db = db;
@@ -114079,15 +126781,29 @@ SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
      && pParse->pNewTable
      && !db->mallocFailed
      && !pParse->pNewTable->pSelect
-     && (pParse->pNewTable->tabFlags & TF_Virtual)==0
+     && !IsVirtual(pParse->pNewTable)
     ){
       if( !pTab->aCol ){
-        pTab->aCol = pParse->pNewTable->aCol;
-        pTab->nCol = pParse->pNewTable->nCol;
-        pParse->pNewTable->nCol = 0;
-        pParse->pNewTable->aCol = 0;
+        Table *pNew = pParse->pNewTable;
+        Index *pIdx;
+        pTab->aCol = pNew->aCol;
+        pTab->nCol = pNew->nCol;
+        pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
+        pNew->nCol = 0;
+        pNew->aCol = 0;
+        assert( pTab->pIndex==0 );
+        if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){
+          rc = SQLITE_ERROR;
+        }
+        pIdx = pNew->pIndex;
+        if( pIdx ){
+          assert( pIdx->pNext==0 );
+          pTab->pIndex = pIdx;
+          pNew->pIndex = 0;
+          pIdx->pTable = pTab;
+        }
       }
-      db->pVtabCtx->pTab = 0;
+      pCtx->bDeclared = 1;
     }else{
       sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
       sqlite3DbFree(db, zErr);
@@ -114120,13 +126836,20 @@ SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab
   int rc = SQLITE_OK;
   Table *pTab;
 
-  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
-  if( ALWAYS(pTab!=0 && pTab->pVTable!=0) ){
-    VTable *p = vtabDisconnectAll(db, pTab);
-
-    assert( rc==SQLITE_OK );
-    rc = p->pMod->pModule->xDestroy(p->pVtab);
-
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
+  if( pTab!=0 && ALWAYS(pTab->pVTable!=0) ){
+    VTable *p;
+    int (*xDestroy)(sqlite3_vtab *);
+    for(p=pTab->pVTable; p; p=p->pNext){
+      assert( p->pVtab );
+      if( p->pVtab->nRef>0 ){
+        return SQLITE_LOCKED;
+      }
+    }
+    p = vtabDisconnectAll(db, pTab);
+    xDestroy = p->pMod->pModule->xDestroy;
+    assert( xDestroy!=0 );  /* Checked before the virtual table is created */
+    rc = xDestroy(p->pVtab);
     /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */
     if( rc==SQLITE_OK ){
       assert( pTab->pVTable==p && p->pNext==0 );
@@ -114150,8 +126873,10 @@ SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab
 static void callFinaliser(sqlite3 *db, int offset){
   int i;
   if( db->aVTrans ){
+    VTable **aVTrans = db->aVTrans;
+    db->aVTrans = 0;
     for(i=0; inVTrans; i++){
-      VTable *pVTab = db->aVTrans[i];
+      VTable *pVTab = aVTrans[i];
       sqlite3_vtab *p = pVTab->pVtab;
       if( p ){
         int (*x)(sqlite3_vtab *);
@@ -114161,9 +126886,8 @@ static void callFinaliser(sqlite3 *db, int offset){
       pVTab->iSavepoint = 0;
       sqlite3VtabUnlock(pVTab);
     }
-    sqlite3DbFree(db, db->aVTrans);
+    sqlite3DbFree(db, aVTrans);
     db->nVTrans = 0;
-    db->aVTrans = 0;
   }
 }
 
@@ -114251,7 +126975,12 @@ SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){
     if( rc==SQLITE_OK ){
       rc = pModule->xBegin(pVTab->pVtab);
       if( rc==SQLITE_OK ){
+        int iSvpt = db->nStatement + db->nSavepoint;
         addToVTrans(db, pVTab);
+        if( iSvpt && pModule->xSavepoint ){
+          pVTab->iSavepoint = iSvpt;
+          rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1);
+        }
       }
     }
   }
@@ -114277,7 +127006,7 @@ SQLITE_PRIVATE int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
   int rc = SQLITE_OK;
 
   assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );
-  assert( iSavepoint>=0 );
+  assert( iSavepoint>=-1 );
   if( db->aVTrans ){
     int i;
     for(i=0; rc==SQLITE_OK && inVTrans; i++){
@@ -114328,7 +127057,7 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
   Table *pTab;
   sqlite3_vtab *pVtab;
   sqlite3_module *pMod;
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
   void *pArg = 0;
   FuncDef *pNew;
   int rc = 0;
@@ -114340,8 +127069,8 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
   if( NEVER(pExpr==0) ) return pDef;
   if( pExpr->op!=TK_COLUMN ) return pDef;
   pTab = pExpr->pTab;
-  if( NEVER(pTab==0) ) return pDef;
-  if( (pTab->tabFlags & TF_Virtual)==0 ) return pDef;
+  if( pTab==0 ) return pDef;
+  if( !IsVirtual(pTab) ) return pDef;
   pVtab = sqlite3GetVTable(db, pTab)->pVtab;
   assert( pVtab!=0 );
   assert( pVtab->pModule!=0 );
@@ -114356,7 +127085,7 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
     for(z=(unsigned char*)zLowerName; *z; z++){
       *z = sqlite3UpperToLower[*z];
     }
-    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
+    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xSFunc, &pArg);
     sqlite3DbFree(db, zLowerName);
   }
   if( rc==0 ){
@@ -114371,9 +127100,9 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
     return pDef;
   }
   *pNew = *pDef;
-  pNew->zName = (char *)&pNew[1];
-  memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1);
-  pNew->xFunc = xFunc;
+  pNew->zName = (const char*)&pNew[1];
+  memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1);
+  pNew->xSFunc = xSFunc;
   pNew->pUserData = pArg;
   pNew->funcFlags |= SQLITE_FUNC_EPHEM;
   return pNew;
@@ -114395,12 +127124,75 @@ SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
     if( pTab==pToplevel->apVtabLock[i] ) return;
   }
   n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
-  apVtabLock = sqlite3_realloc(pToplevel->apVtabLock, n);
+  apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n);
   if( apVtabLock ){
     pToplevel->apVtabLock = apVtabLock;
     pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
   }else{
-    pToplevel->db->mallocFailed = 1;
+    sqlite3OomFault(pToplevel->db);
+  }
+}
+
+/*
+** Check to see if virtual table module pMod can be have an eponymous
+** virtual table instance.  If it can, create one if one does not already
+** exist. Return non-zero if the eponymous virtual table instance exists
+** when this routine returns, and return zero if it does not exist.
+**
+** An eponymous virtual table instance is one that is named after its
+** module, and more importantly, does not require a CREATE VIRTUAL TABLE
+** statement in order to come into existance.  Eponymous virtual table
+** instances always exist.  They cannot be DROP-ed.
+**
+** Any virtual table module for which xConnect and xCreate are the same
+** method can have an eponymous virtual table instance.
+*/
+SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
+  const sqlite3_module *pModule = pMod->pModule;
+  Table *pTab;
+  char *zErr = 0;
+  int rc;
+  sqlite3 *db = pParse->db;
+  if( pMod->pEpoTab ) return 1;
+  if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
+  pTab = sqlite3DbMallocZero(db, sizeof(Table));
+  if( pTab==0 ) return 0;
+  pTab->zName = sqlite3DbStrDup(db, pMod->zName);
+  if( pTab->zName==0 ){
+    sqlite3DbFree(db, pTab);
+    return 0;
+  }
+  pMod->pEpoTab = pTab;
+  pTab->nTabRef = 1;
+  pTab->pSchema = db->aDb[0].pSchema;
+  assert( pTab->nModuleArg==0 );
+  pTab->iPKey = -1;
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  addModuleArgument(db, pTab, 0);
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
+  if( rc ){
+    sqlite3ErrorMsg(pParse, "%s", zErr);
+    sqlite3DbFree(db, zErr);
+    sqlite3VtabEponymousTableClear(db, pMod);
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Erase the eponymous virtual table instance associated with
+** virtual table module pMod, if it exists.
+*/
+SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){
+  Table *pTab = pMod->pEpoTab;
+  if( pTab!=0 ){
+    /* Mark the table as Ephemeral prior to deleting it, so that the
+    ** sqlite3DeleteTable() routine will know that it is not stored in 
+    ** the schema. */
+    pTab->tabFlags |= TF_Ephemeral;
+    sqlite3DeleteTable(db, pTab);
+    pMod->pEpoTab = 0;
   }
 }
 
@@ -114444,7 +127236,7 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
       if( !p ){
         rc = SQLITE_MISUSE_BKPT;
       }else{
-        assert( p->pTab==0 || (p->pTab->tabFlags & TF_Virtual)!=0 );
+        assert( p->pTab==0 || IsVirtual(p->pTab) );
         p->pVTable->bConstraint = (u8)va_arg(ap, int);
       }
       break;
@@ -114463,9 +127255,9 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 /************** End of vtab.c ************************************************/
-/************** Begin file where.c *******************************************/
+/************** Begin file wherecode.c ***************************************/
 /*
-** 2001 September 15
+** 2015-06-06
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -114476,13 +127268,15 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
 **
 *************************************************************************
 ** This module contains C code that generates VDBE code used to process
-** the WHERE clause of SQL statements.  This module is responsible for
-** generating the code that loops through a table looking for applicable
-** rows.  Indices are selected and used to speed the search when doing
-** so is applicable.  Because this module is responsible for selecting
-** indices, you might also think of this module as the "query optimizer".
+** the WHERE clause of SQL statements.
+**
+** This file was split off from where.c on 2015-06-06 in order to reduce the
+** size of where.c and make it easier to edit.  This file contains the routines
+** that actually generate the bulk of the WHERE loop code.  The original where.c
+** file retains the code that does query planning and analysis.
 */
-/************** Include whereInt.h in the middle of where.c ******************/
+/* #include "sqliteInt.h" */
+/************** Include whereInt.h in the middle of wherecode.c **************/
 /************** Begin file whereInt.h ****************************************/
 /*
 ** 2013-11-12
@@ -114505,7 +127299,7 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
 ** Trace output macros
 */
 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
-/***/ int sqlite3WhereTrace = 0;
+/***/ int sqlite3WhereTrace;
 #endif
 #if defined(SQLITE_DEBUG) \
     && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
@@ -114555,6 +127349,10 @@ struct WhereLevel {
   int addrCont;         /* Jump here to continue with the next loop cycle */
   int addrFirst;        /* First instruction of interior of the loop */
   int addrBody;         /* Beginning of the body of this loop */
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  u32 iLikeRepCntr;     /* LIKE range processing counter register (times 2) */
+  int addrLikeRep;      /* LIKE range processing address */
+#endif
   u8 iFrom;             /* Which entry in the FROM clause */
   u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
   int p1, p2;           /* Operands of the opcode used to ends the loop */
@@ -114604,6 +127402,9 @@ struct WhereLoop {
   union {
     struct {               /* Information for internal btree tables */
       u16 nEq;               /* Number of equality constraints */
+      u16 nBtm;              /* Size of BTM vector */
+      u16 nTop;              /* Size of TOP vector */
+      u16 nIdxCol;           /* Index column used for ORDER BY */
       Index *pIndex;         /* Index used, or NULL */
     } btree;
     struct {               /* Information for virtual tables */
@@ -114645,10 +127446,6 @@ struct WhereOrSet {
   WhereOrCost a[N_OR_COST];   /* Set of best costs */
 };
 
-
-/* Forward declaration of methods */
-static int whereLoopResize(sqlite3*, WhereLoop*, int);
-
 /*
 ** Each instance of this object holds a sequence of WhereLoop objects
 ** that implement some or all of a query plan.
@@ -114730,18 +127527,20 @@ struct WherePath {
 */
 struct WhereTerm {
   Expr *pExpr;            /* Pointer to the subexpression that is this term */
+  WhereClause *pWC;       /* The clause this term is part of */
+  LogEst truthProb;       /* Probability of truth for this expression */
+  u16 wtFlags;            /* TERM_xxx bit flags.  See below */
+  u16 eOperator;          /* A WO_xx value describing  */
+  u8 nChild;              /* Number of children that must disable us */
+  u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
   int iParent;            /* Disable pWC->a[iParent] when this term disabled */
   int leftCursor;         /* Cursor number of X in "X  " */
+  int iField;             /* Field in (?,?,?) IN (SELECT...) vector */
   union {
     int leftColumn;         /* Column number of X in "X  " */
     WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
     WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
   } u;
-  LogEst truthProb;       /* Probability of truth for this expression */
-  u16 eOperator;          /* A WO_xx value describing  */
-  u8 wtFlags;             /* TERM_xxx bit flags.  See below */
-  u8 nChild;              /* Number of children that must disable us */
-  WhereClause *pWC;       /* The clause this term is part of */
   Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */
   Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */
 };
@@ -114761,6 +127560,11 @@ struct WhereTerm {
 #else
 #  define TERM_VNULL    0x00   /* Disabled if not using stat3 */
 #endif
+#define TERM_LIKEOPT    0x100  /* Virtual terms from the LIKE optimization */
+#define TERM_LIKECOND   0x200  /* Conditionally this LIKE operator term */
+#define TERM_LIKE       0x400  /* The original LIKE operator */
+#define TERM_IS         0x800  /* Term.pExpr is an IS operator */
+#define TERM_VARSELECT  0x1000 /* Term.pExpr contains a correlated sub-query */
 
 /*
 ** An instance of the WhereScan object is used as an iterator for locating
@@ -114769,13 +127573,15 @@ struct WhereTerm {
 struct WhereScan {
   WhereClause *pOrigWC;      /* Original, innermost WhereClause */
   WhereClause *pWC;          /* WhereClause currently being scanned */
-  char *zCollName;           /* Required collating sequence, if not NULL */
+  const char *zCollName;     /* Required collating sequence, if not NULL */
+  Expr *pIdxExpr;            /* Search for this index expression */
   char idxaff;               /* Must match this affinity, if zCollName!=NULL */
   unsigned char nEquiv;      /* Number of entries in aEquiv[] */
   unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
   u32 opMask;                /* Acceptable operators */
   int k;                     /* Resume scanning at this->pWC->a[this->k] */
-  int aEquiv[22];            /* Cursor,Column pairs for equivalence classes */
+  int aiCur[11];             /* Cursors in the equivalence class */
+  i16 aiColumn[11];          /* Corresponding column number in the eq-class */
 };
 
 /*
@@ -114848,10 +127654,16 @@ struct WhereAndInfo {
 ** no gaps.
 */
 struct WhereMaskSet {
+  int bVarSelect;               /* Used by sqlite3WhereExprUsage() */
   int n;                        /* Number of assigned cursor values */
   int ix[BMS];                  /* Cursor assigned to each bit */
 };
 
+/*
+** Initialize a WhereMaskSet object
+*/
+#define initMaskSet(P)  (P)->n=0
+
 /*
 ** This object is a convenience wrapper holding all information needed
 ** to construct WhereLoop objects for a particular query.
@@ -114866,8 +127678,13 @@ struct WhereLoopBuilder {
   UnpackedRecord *pRec;     /* Probe for stat4 (if required) */
   int nRecValid;            /* Number of valid fields currently in pRec */
 #endif
+  unsigned int bldFlags;    /* SQLITE_BLDF_* flags */
 };
 
+/* Allowed values for WhereLoopBuider.bldFlags */
+#define SQLITE_BLDF_INDEXED  0x0001   /* An index is used */
+#define SQLITE_BLDF_UNIQUE   0x0002   /* All keys of a UNIQUE index used */
+
 /*
 ** The WHERE clause processing routine has two halves.  The
 ** first part does the start of the WHERE loop and the second
@@ -114882,48 +127699,120 @@ struct WhereInfo {
   Parse *pParse;            /* Parsing and code generating context */
   SrcList *pTabList;        /* List of tables in the join */
   ExprList *pOrderBy;       /* The ORDER BY clause or NULL */
-  ExprList *pResultSet;     /* Result set. DISTINCT operates on these */
-  WhereLoop *pLoops;        /* List of all WhereLoop objects */
-  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
-  LogEst nRowOut;           /* Estimated number of output rows */
+  ExprList *pResultSet;     /* Result set of the query */
+  Expr *pWhere;             /* The complete WHERE clause */
+  LogEst iLimit;            /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
+  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
+  int iContinue;            /* Jump here to continue with next record */
+  int iBreak;               /* Jump here to break out of the loop */
+  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
   u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
+  u8 nLevel;                /* Number of nested loop */
   i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
   u8 sorted;                /* True if really sorted (not just grouped) */
-  u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
+  u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */
   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
-  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
-  u8 nLevel;                /* Number of nested loop */
+  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values */
+  u8 bOrderedInnerLoop;     /* True if only the inner-most loop is ordered */
   int iTop;                 /* The very beginning of the WHERE loop */
-  int iContinue;            /* Jump here to continue with next record */
-  int iBreak;               /* Jump here to break out of the loop */
-  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
-  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
-  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
+  WhereLoop *pLoops;        /* List of all WhereLoop objects */
+  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
+  LogEst nRowOut;           /* Estimated number of output rows */
   WhereClause sWC;          /* Decomposition of the WHERE clause */
+  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
   WhereLevel a[1];          /* Information about each nest loop in WHERE */
 };
 
+/*
+** Private interfaces - callable only by other where.c routines.
+**
+** where.c:
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
+#ifdef WHERETRACE_ENABLED
+SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC);
+#endif
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+);
+
+/* wherecode.c: */
+#ifndef SQLITE_OMIT_EXPLAIN
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+);
+#else
+# define sqlite3WhereExplainOneScan(u,v,w,x,y,z) 0
+#endif /* SQLITE_OMIT_EXPLAIN */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
+);
+#else
+# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
+#endif
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
+);
+
+/* whereexpr.c: */
+SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);
+
+
+
+
+
 /*
 ** Bitmasks for the operators on WhereTerm objects.  These are all
 ** operators that are of interest to the query planner.  An
 ** OR-ed combination of these values can be used when searching for
 ** particular WhereTerms within a WhereClause.
+**
+** Value constraints:
+**     WO_EQ    == SQLITE_INDEX_CONSTRAINT_EQ
+**     WO_LT    == SQLITE_INDEX_CONSTRAINT_LT
+**     WO_LE    == SQLITE_INDEX_CONSTRAINT_LE
+**     WO_GT    == SQLITE_INDEX_CONSTRAINT_GT
+**     WO_GE    == SQLITE_INDEX_CONSTRAINT_GE
+**     WO_MATCH == SQLITE_INDEX_CONSTRAINT_MATCH
 */
-#define WO_IN     0x001
-#define WO_EQ     0x002
+#define WO_IN     0x0001
+#define WO_EQ     0x0002
 #define WO_LT     (WO_EQ<<(TK_LT-TK_EQ))
 #define WO_LE     (WO_EQ<<(TK_LE-TK_EQ))
 #define WO_GT     (WO_EQ<<(TK_GT-TK_EQ))
 #define WO_GE     (WO_EQ<<(TK_GE-TK_EQ))
-#define WO_MATCH  0x040
-#define WO_ISNULL 0x080
-#define WO_OR     0x100       /* Two or more OR-connected terms */
-#define WO_AND    0x200       /* Two or more AND-connected terms */
-#define WO_EQUIV  0x400       /* Of the form A==B, both columns */
-#define WO_NOOP   0x800       /* This term does not restrict search space */
+#define WO_MATCH  0x0040
+#define WO_IS     0x0080
+#define WO_ISNULL 0x0100
+#define WO_OR     0x0200       /* Two or more OR-connected terms */
+#define WO_AND    0x0400       /* Two or more AND-connected terms */
+#define WO_EQUIV  0x0800       /* Of the form A==B, both columns */
+#define WO_NOOP   0x1000       /* This term does not restrict search space */
 
-#define WO_ALL    0xfff       /* Mask of all possible WO_* values */
-#define WO_SINGLE 0x0ff       /* Mask of all non-compound WO_* values */
+#define WO_ALL    0x1fff       /* Mask of all possible WO_* values */
+#define WO_SINGLE 0x01ff       /* Mask of all non-compound WO_* values */
 
 /*
 ** These are definitions of bits in the WhereLoop.wsFlags field.
@@ -114951,10274 +127840,36660 @@ struct WhereInfo {
 #define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */
 
 /************** End of whereInt.h ********************************************/
-/************** Continuing where we left off in where.c **********************/
+/************** Continuing where we left off in wherecode.c ******************/
 
-/*
-** Return the estimated number of output rows from a WHERE clause
-*/
-SQLITE_PRIVATE u64 sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
-  return sqlite3LogEstToInt(pWInfo->nRowOut);
-}
+#ifndef SQLITE_OMIT_EXPLAIN
 
 /*
-** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
-** WHERE clause returns outputs for DISTINCT processing.
+** Return the name of the i-th column of the pIdx index.
 */
-SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
-  return pWInfo->eDistinct;
+static const char *explainIndexColumnName(Index *pIdx, int i){
+  i = pIdx->aiColumn[i];
+  if( i==XN_EXPR ) return "";
+  if( i==XN_ROWID ) return "rowid";
+  return pIdx->pTable->aCol[i].zName;
 }
 
 /*
-** Return TRUE if the WHERE clause returns rows in ORDER BY order.
-** Return FALSE if the output needs to be sorted.
+** This routine is a helper for explainIndexRange() below
+**
+** pStr holds the text of an expression that we are building up one term
+** at a time.  This routine adds a new term to the end of the expression.
+** Terms are separated by AND so add the "AND" text for second and subsequent
+** terms only.
 */
-SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
-  return pWInfo->nOBSat;
-}
+static void explainAppendTerm(
+  StrAccum *pStr,             /* The text expression being built */
+  Index *pIdx,                /* Index to read column names from */
+  int nTerm,                  /* Number of terms */
+  int iTerm,                  /* Zero-based index of first term. */
+  int bAnd,                   /* Non-zero to append " AND " */
+  const char *zOp             /* Name of the operator */
+){
+  int i;
 
-/*
-** Return the VDBE address or label to jump to in order to continue
-** immediately with the next row of a WHERE clause.
-*/
-SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
-  assert( pWInfo->iContinue!=0 );
-  return pWInfo->iContinue;
-}
+  assert( nTerm>=1 );
+  if( bAnd ) sqlite3StrAccumAppend(pStr, " AND ", 5);
 
-/*
-** Return the VDBE address or label to jump to in order to break
-** out of a WHERE loop.
-*/
-SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
-  return pWInfo->iBreak;
+  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, "(", 1);
+  for(i=0; i1 ) sqlite3StrAccumAppend(pStr, ")", 1);
+
+  sqlite3StrAccumAppend(pStr, zOp, 1);
+
+  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, "(", 1);
+  for(i=0; i1 ) sqlite3StrAccumAppend(pStr, ")", 1);
 }
 
 /*
-** Return TRUE if an UPDATE or DELETE statement can operate directly on
-** the rowids returned by a WHERE clause.  Return FALSE if doing an
-** UPDATE or DELETE might change subsequent WHERE clause results.
+** Argument pLevel describes a strategy for scanning table pTab. This 
+** function appends text to pStr that describes the subset of table
+** rows scanned by the strategy in the form of an SQL expression.
 **
-** If the ONEPASS optimization is used (if this routine returns true)
-** then also write the indices of open cursors used by ONEPASS
-** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
-** table and iaCur[1] gets the cursor used by an auxiliary index.
-** Either value may be -1, indicating that cursor is not used.
-** Any cursors returned will have been opened for writing.
+** For example, if the query:
 **
-** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
-** unable to use the ONEPASS optimization.
+**   SELECT * FROM t1 WHERE a=1 AND b>2;
+**
+** is run and there is an index on (a, b), then this function returns a
+** string similar to:
+**
+**   "a=? AND b>?"
 */
-SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
-  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
-  return pWInfo->okOnePass;
-}
+static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){
+  Index *pIndex = pLoop->u.btree.pIndex;
+  u16 nEq = pLoop->u.btree.nEq;
+  u16 nSkip = pLoop->nSkip;
+  int i, j;
 
-/*
-** Move the content of pSrc into pDest
-*/
-static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
-  pDest->n = pSrc->n;
-  memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
+  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
+  sqlite3StrAccumAppend(pStr, " (", 2);
+  for(i=0; i=nSkip ? "%s=?" : "ANY(%s)", z);
+  }
+
+  j = i;
+  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
+    explainAppendTerm(pStr, pIndex, pLoop->u.btree.nBtm, j, i, ">");
+    i = 1;
+  }
+  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
+    explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");
+  }
+  sqlite3StrAccumAppend(pStr, ")", 1);
 }
 
 /*
-** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
+** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
+** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
+** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 
+** is added to the output to describe the table scan strategy in pLevel.
 **
-** The new entry might overwrite an existing entry, or it might be
-** appended, or it might be discarded.  Do whatever is the right thing
-** so that pSet keeps the N_OR_COST best entries seen so far.
+** If an OP_Explain opcode is added to the VM, its address is returned.
+** Otherwise, if no OP_Explain is coded, zero is returned.
 */
-static int whereOrInsert(
-  WhereOrSet *pSet,      /* The WhereOrSet to be updated */
-  Bitmask prereq,        /* Prerequisites of the new entry */
-  LogEst rRun,           /* Run-cost of the new entry */
-  LogEst nOut            /* Number of outputs for the new entry */
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
 ){
-  u16 i;
-  WhereOrCost *p;
-  for(i=pSet->n, p=pSet->a; i>0; i--, p++){
-    if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
-      goto whereOrInsert_done;
+  int ret = 0;
+#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
+  if( pParse->explain==2 )
+#endif
+  {
+    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
+    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
+    sqlite3 *db = pParse->db;     /* Database handle */
+    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
+    int isSearch;                 /* True for a SEARCH. False for SCAN. */
+    WhereLoop *pLoop;             /* The controlling WhereLoop object */
+    u32 flags;                    /* Flags that describe this loop */
+    char *zMsg;                   /* Text to add to EQP output */
+    StrAccum str;                 /* EQP output string */
+    char zBuf[100];               /* Initial space for EQP output string */
+
+    pLoop = pLevel->pWLoop;
+    flags = pLoop->wsFlags;
+    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;
+
+    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+
+    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
+    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
+    if( pItem->pSelect ){
+      sqlite3XPrintf(&str, " SUBQUERY %d", pItem->iSelectId);
+    }else{
+      sqlite3XPrintf(&str, " TABLE %s", pItem->zName);
     }
-    if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
-      return 0;
+
+    if( pItem->zAlias ){
+      sqlite3XPrintf(&str, " AS %s", pItem->zAlias);
     }
-  }
-  if( pSet->na[pSet->n++];
-    p->nOut = nOut;
-  }else{
-    p = pSet->a;
-    for(i=1; in; i++){
-      if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
+    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
+      const char *zFmt = 0;
+      Index *pIdx;
+
+      assert( pLoop->u.btree.pIndex!=0 );
+      pIdx = pLoop->u.btree.pIndex;
+      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
+      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
+        if( isSearch ){
+          zFmt = "PRIMARY KEY";
+        }
+      }else if( flags & WHERE_PARTIALIDX ){
+        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
+      }else if( flags & WHERE_AUTO_INDEX ){
+        zFmt = "AUTOMATIC COVERING INDEX";
+      }else if( flags & WHERE_IDX_ONLY ){
+        zFmt = "COVERING INDEX %s";
+      }else{
+        zFmt = "INDEX %s";
+      }
+      if( zFmt ){
+        sqlite3StrAccumAppend(&str, " USING ", 7);
+        sqlite3XPrintf(&str, zFmt, pIdx->zName);
+        explainIndexRange(&str, pLoop);
+      }
+    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
+      const char *zRangeOp;
+      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
+        zRangeOp = "=";
+      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
+        zRangeOp = ">? AND rowid<";
+      }else if( flags&WHERE_BTM_LIMIT ){
+        zRangeOp = ">";
+      }else{
+        assert( flags&WHERE_TOP_LIMIT);
+        zRangeOp = "<";
+      }
+      sqlite3XPrintf(&str, " USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
     }
-    if( p->rRun<=rRun ) return 0;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
+      sqlite3XPrintf(&str, " VIRTUAL TABLE INDEX %d:%s",
+                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
+    }
+#endif
+#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
+    if( pLoop->nOut>=10 ){
+      sqlite3XPrintf(&str, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
+    }else{
+      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
+    }
+#endif
+    zMsg = sqlite3StrAccumFinish(&str);
+    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
   }
-whereOrInsert_done:
-  p->prereq = prereq;
-  p->rRun = rRun;
-  if( p->nOut>nOut ) p->nOut = nOut;
-  return 1;
+  return ret;
 }
+#endif /* SQLITE_OMIT_EXPLAIN */
 
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 /*
-** Initialize a preallocated WhereClause structure.
+** Configure the VM passed as the first argument with an
+** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 
+** implement level pLvl. Argument pSrclist is a pointer to the FROM 
+** clause that the scan reads data from.
+**
+** If argument addrExplain is not 0, it must be the address of an 
+** OP_Explain instruction that describes the same loop.
 */
-static void whereClauseInit(
-  WhereClause *pWC,        /* The WhereClause to be initialized */
-  WhereInfo *pWInfo        /* The WHERE processing context */
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
 ){
-  pWC->pWInfo = pWInfo;
-  pWC->pOuter = 0;
-  pWC->nTerm = 0;
-  pWC->nSlot = ArraySize(pWC->aStatic);
-  pWC->a = pWC->aStatic;
+  const char *zObj = 0;
+  WhereLoop *pLoop = pLvl->pWLoop;
+  if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
+    zObj = pLoop->u.btree.pIndex->zName;
+  }else{
+    zObj = pSrclist->a[pLvl->iFrom].zName;
+  }
+  sqlite3VdbeScanStatus(
+      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
+  );
 }
+#endif
 
-/* Forward reference */
-static void whereClauseClear(WhereClause*);
 
 /*
-** Deallocate all memory associated with a WhereOrInfo object.
+** Disable a term in the WHERE clause.  Except, do not disable the term
+** if it controls a LEFT OUTER JOIN and it did not originate in the ON
+** or USING clause of that join.
+**
+** Consider the term t2.z='ok' in the following queries:
+**
+**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
+**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
+**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+**
+** The t2.z='ok' is disabled in the in (2) because it originates
+** in the ON clause.  The term is disabled in (3) because it is not part
+** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
+**
+** Disabling a term causes that term to not be tested in the inner loop
+** of the join.  Disabling is an optimization.  When terms are satisfied
+** by indices, we disable them to prevent redundant tests in the inner
+** loop.  We would get the correct results if nothing were ever disabled,
+** but joins might run a little slower.  The trick is to disable as much
+** as we can without disabling too much.  If we disabled in (1), we'd get
+** the wrong answer.  See ticket #813.
+**
+** If all the children of a term are disabled, then that term is also
+** automatically disabled.  In this way, terms get disabled if derived
+** virtual terms are tested first.  For example:
+**
+**      x GLOB 'abc*' AND x>='abc' AND x<'acd'
+**      \___________/     \______/     \_____/
+**         parent          child1       child2
+**
+** Only the parent term was in the original WHERE clause.  The child1
+** and child2 terms were added by the LIKE optimization.  If both of
+** the virtual child terms are valid, then testing of the parent can be 
+** skipped.
+**
+** Usually the parent term is marked as TERM_CODED.  But if the parent
+** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
+** The TERM_LIKECOND marking indicates that the term should be coded inside
+** a conditional such that is only evaluated on the second pass of a
+** LIKE-optimization loop, when scanning BLOBs instead of strings.
 */
-static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
-  whereClauseClear(&p->wc);
-  sqlite3DbFree(db, p);
+static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
+  int nLoop = 0;
+  while( ALWAYS(pTerm!=0)
+      && (pTerm->wtFlags & TERM_CODED)==0
+      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+      && (pLevel->notReady & pTerm->prereqAll)==0
+  ){
+    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
+      pTerm->wtFlags |= TERM_LIKECOND;
+    }else{
+      pTerm->wtFlags |= TERM_CODED;
+    }
+    if( pTerm->iParent<0 ) break;
+    pTerm = &pTerm->pWC->a[pTerm->iParent];
+    pTerm->nChild--;
+    if( pTerm->nChild!=0 ) break;
+    nLoop++;
+  }
 }
 
 /*
-** Deallocate all memory associated with a WhereAndInfo object.
+** Code an OP_Affinity opcode to apply the column affinity string zAff
+** to the n registers starting at base. 
+**
+** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the
+** beginning and end of zAff are ignored.  If all entries in zAff are
+** SQLITE_AFF_BLOB, then no code gets generated.
+**
+** This routine makes its own copy of zAff so that the caller is free
+** to modify zAff after this routine returns.
 */
-static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
-  whereClauseClear(&p->wc);
-  sqlite3DbFree(db, p);
+static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
+  Vdbe *v = pParse->pVdbe;
+  if( zAff==0 ){
+    assert( pParse->db->mallocFailed );
+    return;
+  }
+  assert( v!=0 );
+
+  /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning
+  ** and end of the affinity string.
+  */
+  while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){
+    n--;
+    base++;
+    zAff++;
+  }
+  while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
+    n--;
+  }
+
+  /* Code the OP_Affinity opcode if there is anything left to do. */
+  if( n>0 ){
+    sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);
+    sqlite3ExprCacheAffinityChange(pParse, base, n);
+  }
 }
 
 /*
-** Deallocate a WhereClause structure.  The WhereClause structure
-** itself is not freed.  This routine is the inverse of whereClauseInit().
+** Expression pRight, which is the RHS of a comparison operation, is 
+** either a vector of n elements or, if n==1, a scalar expression.
+** Before the comparison operation, affinity zAff is to be applied
+** to the pRight values. This function modifies characters within the
+** affinity string to SQLITE_AFF_BLOB if either:
+**
+**   * the comparison will be performed with no affinity, or
+**   * the affinity change in zAff is guaranteed not to change the value.
 */
-static void whereClauseClear(WhereClause *pWC){
+static void updateRangeAffinityStr(
+  Expr *pRight,                   /* RHS of comparison */
+  int n,                          /* Number of vector elements in comparison */
+  char *zAff                      /* Affinity string to modify */
+){
   int i;
-  WhereTerm *a;
-  sqlite3 *db = pWC->pWInfo->pParse->db;
-  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
-    if( a->wtFlags & TERM_DYNAMIC ){
-      sqlite3ExprDelete(db, a->pExpr);
-    }
-    if( a->wtFlags & TERM_ORINFO ){
-      whereOrInfoDelete(db, a->u.pOrInfo);
-    }else if( a->wtFlags & TERM_ANDINFO ){
-      whereAndInfoDelete(db, a->u.pAndInfo);
+  for(i=0; ia!=pWC->aStatic ){
-    sqlite3DbFree(db, pWC->a);
-  }
 }
 
 /*
-** Add a single new WhereTerm entry to the WhereClause object pWC.
-** The new WhereTerm object is constructed from Expr p and with wtFlags.
-** The index in pWC->a[] of the new WhereTerm is returned on success.
-** 0 is returned if the new WhereTerm could not be added due to a memory
-** allocation error.  The memory allocation failure will be recorded in
-** the db->mallocFailed flag so that higher-level functions can detect it.
-**
-** This routine will increase the size of the pWC->a[] array as necessary.
+** Generate code for a single equality term of the WHERE clause.  An equality
+** term can be either X=expr or X IN (...).   pTerm is the term to be 
+** coded.
 **
-** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
-** for freeing the expression p is assumed by the WhereClause object pWC.
-** This is true even if this routine fails to allocate a new WhereTerm.
+** The current value for the constraint is left in a register, the index
+** of which is returned.  An attempt is made store the result in iTarget but
+** this is only guaranteed for TK_ISNULL and TK_IN constraints.  If the
+** constraint is a TK_EQ or TK_IS, then the current value might be left in
+** some other register and it is the caller's responsibility to compensate.
 **
-** WARNING:  This routine might reallocate the space used to store
-** WhereTerms.  All pointers to WhereTerms should be invalidated after
-** calling this routine.  Such pointers may be reinitialized by referencing
-** the pWC->a[] array.
+** For a constraint of the form X=expr, the expression is evaluated in
+** straight-line code.  For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
 */
-static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
-  WhereTerm *pTerm;
-  int idx;
-  testcase( wtFlags & TERM_VIRTUAL );
-  if( pWC->nTerm>=pWC->nSlot ){
-    WhereTerm *pOld = pWC->a;
-    sqlite3 *db = pWC->pWInfo->pParse->db;
-    pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
-    if( pWC->a==0 ){
-      if( wtFlags & TERM_DYNAMIC ){
-        sqlite3ExprDelete(db, p);
+static int codeEqualityTerm(
+  Parse *pParse,      /* The parsing context */
+  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
+  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
+  int iEq,            /* Index of the equality term within this level */
+  int bRev,           /* True for reverse-order IN operations */
+  int iTarget         /* Attempt to leave results in this register */
+){
+  Expr *pX = pTerm->pExpr;
+  Vdbe *v = pParse->pVdbe;
+  int iReg;                  /* Register holding results */
+
+  assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );
+  assert( iTarget>0 );
+  if( pX->op==TK_EQ || pX->op==TK_IS ){
+    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+  }else if( pX->op==TK_ISNULL ){
+    iReg = iTarget;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
+  }else{
+    int eType = IN_INDEX_NOOP;
+    int iTab;
+    struct InLoop *pIn;
+    WhereLoop *pLoop = pLevel->pWLoop;
+    int i;
+    int nEq = 0;
+    int *aiMap = 0;
+
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+      && pLoop->u.btree.pIndex!=0
+      && pLoop->u.btree.pIndex->aSortOrder[iEq]
+    ){
+      testcase( iEq==0 );
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    assert( pX->op==TK_IN );
+    iReg = iTarget;
+
+    for(i=0; iaLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){
+        disableTerm(pLevel, pTerm);
+        return iTarget;
       }
-      pWC->a = pOld;
-      return 0;
     }
-    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
-    if( pOld!=pWC->aStatic ){
-      sqlite3DbFree(db, pOld);
+    for(i=iEq;inLTerm; i++){
+      if( ALWAYS(pLoop->aLTerm[i]) && pLoop->aLTerm[i]->pExpr==pX ) nEq++;
     }
-    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
-    memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm));
-  }
-  pTerm = &pWC->a[idx = pWC->nTerm++];
-  if( p && ExprHasProperty(p, EP_Unlikely) ){
-    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
-  }else{
-    pTerm->truthProb = 1;
+
+    if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){
+      eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0);
+    }else{
+      Select *pSelect = pX->x.pSelect;
+      sqlite3 *db = pParse->db;
+      u16 savedDbOptFlags = db->dbOptFlags;
+      ExprList *pOrigRhs = pSelect->pEList;
+      ExprList *pOrigLhs = pX->pLeft->x.pList;
+      ExprList *pRhs = 0;         /* New Select.pEList for RHS */
+      ExprList *pLhs = 0;         /* New pX->pLeft vector */
+
+      for(i=iEq;inLTerm; i++){
+        if( pLoop->aLTerm[i]->pExpr==pX ){
+          int iField = pLoop->aLTerm[i]->iField - 1;
+          Expr *pNewRhs = sqlite3ExprDup(db, pOrigRhs->a[iField].pExpr, 0);
+          Expr *pNewLhs = sqlite3ExprDup(db, pOrigLhs->a[iField].pExpr, 0);
+
+          pRhs = sqlite3ExprListAppend(pParse, pRhs, pNewRhs);
+          pLhs = sqlite3ExprListAppend(pParse, pLhs, pNewLhs);
+        }
+      }
+      if( !db->mallocFailed ){
+        Expr *pLeft = pX->pLeft;
+
+        if( pSelect->pOrderBy ){
+          /* If the SELECT statement has an ORDER BY clause, zero the 
+          ** iOrderByCol variables. These are set to non-zero when an 
+          ** ORDER BY term exactly matches one of the terms of the 
+          ** result-set. Since the result-set of the SELECT statement may
+          ** have been modified or reordered, these variables are no longer 
+          ** set correctly.  Since setting them is just an optimization, 
+          ** it's easiest just to zero them here.  */
+          ExprList *pOrderBy = pSelect->pOrderBy;
+          for(i=0; inExpr; i++){
+            pOrderBy->a[i].u.x.iOrderByCol = 0;
+          }
+        }
+
+        /* Take care here not to generate a TK_VECTOR containing only a
+        ** single value. Since the parser never creates such a vector, some
+        ** of the subroutines do not handle this case.  */
+        if( pLhs->nExpr==1 ){
+          pX->pLeft = pLhs->a[0].pExpr;
+        }else{
+          pLeft->x.pList = pLhs;
+          aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int) * nEq);
+          testcase( aiMap==0 );
+        }
+        pSelect->pEList = pRhs;
+        db->dbOptFlags |= SQLITE_QueryFlattener;
+        eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap);
+        db->dbOptFlags = savedDbOptFlags;
+        testcase( aiMap!=0 && aiMap[0]!=0 );
+        pSelect->pEList = pOrigRhs;
+        pLeft->x.pList = pOrigLhs;
+        pX->pLeft = pLeft;
+      }
+      sqlite3ExprListDelete(pParse->db, pLhs);
+      sqlite3ExprListDelete(pParse->db, pRhs);
+    }
+
+    if( eType==IN_INDEX_INDEX_DESC ){
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    iTab = pX->iTable;
+    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
+    VdbeCoverageIf(v, bRev);
+    VdbeCoverageIf(v, !bRev);
+    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+
+    pLoop->wsFlags |= WHERE_IN_ABLE;
+    if( pLevel->u.in.nIn==0 ){
+      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+    }
+
+    i = pLevel->u.in.nIn;
+    pLevel->u.in.nIn += nEq;
+    pLevel->u.in.aInLoop =
+       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
+                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
+    pIn = pLevel->u.in.aInLoop;
+    if( pIn ){
+      int iMap = 0;               /* Index in aiMap[] */
+      pIn += i;
+      for(i=iEq;inLTerm; i++){
+        if( pLoop->aLTerm[i]->pExpr==pX ){
+          int iOut = iReg + i - iEq;
+          if( eType==IN_INDEX_ROWID ){
+            testcase( nEq>1 );  /* Happens with a UNIQUE index on ROWID */
+            pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iOut);
+          }else{
+            int iCol = aiMap ? aiMap[iMap++] : 0;
+            pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);
+          }
+          sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);
+          if( i==iEq ){
+            pIn->iCur = iTab;
+            pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
+          }else{
+            pIn->eEndLoopOp = OP_Noop;
+          }
+          pIn++;
+        }
+      }
+    }else{
+      pLevel->u.in.nIn = 0;
+    }
+    sqlite3DbFree(pParse->db, aiMap);
+#endif
   }
-  pTerm->pExpr = sqlite3ExprSkipCollate(p);
-  pTerm->wtFlags = wtFlags;
-  pTerm->pWC = pWC;
-  pTerm->iParent = -1;
-  return idx;
+  disableTerm(pLevel, pTerm);
+  return iReg;
 }
 
 /*
-** This routine identifies subexpressions in the WHERE clause where
-** each subexpression is separated by the AND operator or some other
-** operator specified in the op parameter.  The WhereClause structure
-** is filled with pointers to subexpressions.  For example:
+** Generate code that will evaluate all == and IN constraints for an
+** index scan.
 **
-**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
-**           \________/     \_______________/     \________________/
-**            slot[0]            slot[1]               slot[2]
+** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
+** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
+** The index has as many as three equality constraints, but in this
+** example, the third "c" value is an inequality.  So only two 
+** constraints are coded.  This routine will generate code to evaluate
+** a==5 and b IN (1,2,3).  The current values for a and b will be stored
+** in consecutive registers and the index of the first register is returned.
 **
-** The original WHERE clause in pExpr is unaltered.  All this routine
-** does is make slot[] entries point to substructure within pExpr.
+** In the example above nEq==2.  But this subroutine works for any value
+** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
+** The only thing it does is allocate the pLevel->iMem memory cell and
+** compute the affinity string.
 **
-** In the previous sentence and in the diagram, "slot[]" refers to
-** the WhereClause.a[] array.  The slot[] array grows as needed to contain
-** all terms of the WHERE clause.
+** The nExtraReg parameter is 0 or 1.  It is 0 if all WHERE clause constraints
+** are == or IN and are covered by the nEq.  nExtraReg is 1 if there is
+** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
+** occurs after the nEq quality constraints.
+**
+** This routine allocates a range of nEq+nExtraReg memory cells and returns
+** the index of the first memory cell in that range. The code that
+** calls this routine will use that memory range to store keys for
+** start and termination conditions of the loop.
+** key value of the loop.  If one or more IN operators appear, then
+** this routine allocates an additional nEq memory cells for internal
+** use.
+**
+** Before returning, *pzAff is set to point to a buffer containing a
+** copy of the column affinity string of the index allocated using
+** sqlite3DbMalloc(). Except, entries in the copy of the string associated
+** with equality constraints that use BLOB or NONE affinity are set to
+** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
+**
+**   CREATE TABLE t1(a TEXT PRIMARY KEY, b);
+**   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
+**
+** In the example above, the index on t1(a) has TEXT affinity. But since
+** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
+** no conversion should be attempted before using a t2.b value as part of
+** a key to search the index. Hence the first byte in the returned affinity
+** string in this example would be set to SQLITE_AFF_BLOB.
 */
-static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
-  pWC->op = op;
-  if( pExpr==0 ) return;
-  if( pExpr->op!=op ){
-    whereClauseInsert(pWC, pExpr, 0);
-  }else{
-    whereSplit(pWC, pExpr->pLeft, op);
-    whereSplit(pWC, pExpr->pRight, op);
-  }
-}
+static int codeAllEqualityTerms(
+  Parse *pParse,        /* Parsing context */
+  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
+  int bRev,             /* Reverse the order of IN operators */
+  int nExtraReg,        /* Number of extra registers to allocate */
+  char **pzAff          /* OUT: Set to point to affinity string */
+){
+  u16 nEq;                      /* The number of == or IN constraints to code */
+  u16 nSkip;                    /* Number of left-most columns to skip */
+  Vdbe *v = pParse->pVdbe;      /* The vm under construction */
+  Index *pIdx;                  /* The index being used for this loop */
+  WhereTerm *pTerm;             /* A single constraint term */
+  WhereLoop *pLoop;             /* The WhereLoop object */
+  int j;                        /* Loop counter */
+  int regBase;                  /* Base register */
+  int nReg;                     /* Number of registers to allocate */
+  char *zAff;                   /* Affinity string to return */
 
-/*
-** Initialize a WhereMaskSet object
-*/
-#define initMaskSet(P)  (P)->n=0
+  /* This module is only called on query plans that use an index. */
+  pLoop = pLevel->pWLoop;
+  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  nEq = pLoop->u.btree.nEq;
+  nSkip = pLoop->nSkip;
+  pIdx = pLoop->u.btree.pIndex;
+  assert( pIdx!=0 );
 
-/*
-** Return the bitmask for the given cursor number.  Return 0 if
-** iCursor is not in the set.
-*/
-static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
-  int i;
-  assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
-  for(i=0; in; i++){
-    if( pMaskSet->ix[i]==iCursor ){
-      return MASKBIT(i);
+  /* Figure out how many memory cells we will need then allocate them.
+  */
+  regBase = pParse->nMem + 1;
+  nReg = pLoop->u.btree.nEq + nExtraReg;
+  pParse->nMem += nReg;
+
+  zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
+  assert( zAff!=0 || pParse->db->mallocFailed );
+
+  if( nSkip ){
+    int iIdxCur = pLevel->iIdxCur;
+    sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
+    j = sqlite3VdbeAddOp0(v, OP_Goto);
+    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
+                            iIdxCur, 0, regBase, nSkip);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    sqlite3VdbeJumpHere(v, j);
+    for(j=0; jaiColumn[j]==XN_EXPR );
+      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
+    }
+  }    
+
+  /* Evaluate the equality constraints
+  */
+  assert( zAff==0 || (int)strlen(zAff)>=nEq );
+  for(j=nSkip; jaLTerm[j];
+    assert( pTerm!=0 );
+    /* The following testcase is true for indices with redundant columns. 
+    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
+    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
+    if( r1!=regBase+j ){
+      if( nReg==1 ){
+        sqlite3ReleaseTempReg(pParse, regBase);
+        regBase = r1;
+      }else{
+        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+      }
+    }
+    if( pTerm->eOperator & WO_IN ){
+      if( pTerm->pExpr->flags & EP_xIsSelect ){
+        /* No affinity ever needs to be (or should be) applied to a value
+        ** from the RHS of an "? IN (SELECT ...)" expression. The 
+        ** sqlite3FindInIndex() routine has already ensured that the 
+        ** affinity of the comparison has been applied to the value.  */
+        if( zAff ) zAff[j] = SQLITE_AFF_BLOB;
+      }
+    }else if( (pTerm->eOperator & WO_ISNULL)==0 ){
+      Expr *pRight = pTerm->pExpr->pRight;
+      if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
+        VdbeCoverage(v);
+      }
+      if( zAff ){
+        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+        if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+      }
     }
   }
-  return 0;
+  *pzAff = zAff;
+  return regBase;
 }
 
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
 /*
-** Create a new mask for cursor iCursor.
+** If the most recently coded instruction is a constant range constraint
+** (a string literal) that originated from the LIKE optimization, then 
+** set P3 and P5 on the OP_String opcode so that the string will be cast
+** to a BLOB at appropriate times.
 **
-** There is one cursor per table in the FROM clause.  The number of
-** tables in the FROM clause is limited by a test early in the
-** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
-** array will never overflow.
+** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
+** expression: "x>='ABC' AND x<'abd'".  But this requires that the range
+** scan loop run twice, once for strings and a second time for BLOBs.
+** The OP_String opcodes on the second pass convert the upper and lower
+** bound string constants to blobs.  This routine makes the necessary changes
+** to the OP_String opcodes for that to happen.
+**
+** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
+** only the one pass through the string space is required, so this routine
+** becomes a no-op.
 */
-static void createMask(WhereMaskSet *pMaskSet, int iCursor){
-  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
-  pMaskSet->ix[pMaskSet->n++] = iCursor;
+static void whereLikeOptimizationStringFixup(
+  Vdbe *v,                /* prepared statement under construction */
+  WhereLevel *pLevel,     /* The loop that contains the LIKE operator */
+  WhereTerm *pTerm        /* The upper or lower bound just coded */
+){
+  if( pTerm->wtFlags & TERM_LIKEOPT ){
+    VdbeOp *pOp;
+    assert( pLevel->iLikeRepCntr>0 );
+    pOp = sqlite3VdbeGetOp(v, -1);
+    assert( pOp!=0 );
+    assert( pOp->opcode==OP_String8 
+            || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
+    pOp->p3 = (int)(pLevel->iLikeRepCntr>>1);  /* Register holding counter */
+    pOp->p5 = (u8)(pLevel->iLikeRepCntr&1);    /* ASC or DESC */
+  }
 }
+#else
+# define whereLikeOptimizationStringFixup(A,B,C)
+#endif
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
 /*
-** These routines walk (recursively) an expression tree and generate
-** a bitmask indicating which tables are used in that expression
-** tree.
+** Information is passed from codeCursorHint() down to individual nodes of
+** the expression tree (by sqlite3WalkExpr()) using an instance of this
+** structure.
 */
-static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
-static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
-static Bitmask exprTableUsage(WhereMaskSet *pMaskSet, Expr *p){
-  Bitmask mask = 0;
-  if( p==0 ) return 0;
-  if( p->op==TK_COLUMN ){
-    mask = getMask(pMaskSet, p->iTable);
-    return mask;
-  }
-  mask = exprTableUsage(pMaskSet, p->pRight);
-  mask |= exprTableUsage(pMaskSet, p->pLeft);
-  if( ExprHasProperty(p, EP_xIsSelect) ){
-    mask |= exprSelectTableUsage(pMaskSet, p->x.pSelect);
-  }else{
-    mask |= exprListTableUsage(pMaskSet, p->x.pList);
-  }
-  return mask;
-}
-static Bitmask exprListTableUsage(WhereMaskSet *pMaskSet, ExprList *pList){
-  int i;
-  Bitmask mask = 0;
-  if( pList ){
-    for(i=0; inExpr; i++){
-      mask |= exprTableUsage(pMaskSet, pList->a[i].pExpr);
-    }
-  }
-  return mask;
-}
-static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
-  Bitmask mask = 0;
-  while( pS ){
-    SrcList *pSrc = pS->pSrc;
-    mask |= exprListTableUsage(pMaskSet, pS->pEList);
-    mask |= exprListTableUsage(pMaskSet, pS->pGroupBy);
-    mask |= exprListTableUsage(pMaskSet, pS->pOrderBy);
-    mask |= exprTableUsage(pMaskSet, pS->pWhere);
-    mask |= exprTableUsage(pMaskSet, pS->pHaving);
-    if( ALWAYS(pSrc!=0) ){
-      int i;
-      for(i=0; inSrc; i++){
-        mask |= exprSelectTableUsage(pMaskSet, pSrc->a[i].pSelect);
-        mask |= exprTableUsage(pMaskSet, pSrc->a[i].pOn);
-      }
-    }
-    pS = pS->pPrior;
-  }
-  return mask;
-}
+struct CCurHint {
+  int iTabCur;    /* Cursor for the main table */
+  int iIdxCur;    /* Cursor for the index, if pIdx!=0.  Unused otherwise */
+  Index *pIdx;    /* The index used to access the table */
+};
 
 /*
-** Return TRUE if the given operator is one of the operators that is
-** allowed for an indexable WHERE clause term.  The allowed operators are
-** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
+** This function is called for every node of an expression that is a candidate
+** for a cursor hint on an index cursor.  For TK_COLUMN nodes that reference
+** the table CCurHint.iTabCur, verify that the same column can be
+** accessed through the index.  If it cannot, then set pWalker->eCode to 1.
 */
-static int allowedOp(int op){
-  assert( TK_GT>TK_EQ && TK_GTTK_EQ && TK_LTTK_EQ && TK_LE=TK_EQ && op<=TK_GE) || op==TK_ISNULL;
+static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  assert( pHint->pIdx!=0 );
+  if( pExpr->op==TK_COLUMN
+   && pExpr->iTable==pHint->iTabCur
+   && sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn)<0
+  ){
+    pWalker->eCode = 1;
+  }
+  return WRC_Continue;
 }
 
 /*
-** Commute a comparison operator.  Expressions of the form "X op Y"
-** are converted into "Y op X".
+** Test whether or not expression pExpr, which was part of a WHERE clause,
+** should be included in the cursor-hint for a table that is on the rhs
+** of a LEFT JOIN. Set Walker.eCode to non-zero before returning if the 
+** expression is not suitable.
 **
-** If left/right precedence rules come into play when determining the
-** collating sequence, then COLLATE operators are adjusted to ensure
-** that the collating sequence does not change.  For example:
-** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
-** the left hand side of a comparison overrides any collation sequence 
-** attached to the right. For the same reason the EP_Collate flag
-** is not commuted.
+** An expression is unsuitable if it might evaluate to non NULL even if
+** a TK_COLUMN node that does affect the value of the expression is set
+** to NULL. For example:
+**
+**   col IS NULL
+**   col IS NOT NULL
+**   coalesce(col, 1)
+**   CASE WHEN col THEN 0 ELSE 1 END
 */
-static void exprCommute(Parse *pParse, Expr *pExpr){
-  u16 expRight = (pExpr->pRight->flags & EP_Collate);
-  u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
-  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
-  if( expRight==expLeft ){
-    /* Either X and Y both have COLLATE operator or neither do */
-    if( expRight ){
-      /* Both X and Y have COLLATE operators.  Make sure X is always
-      ** used by clearing the EP_Collate flag from Y. */
-      pExpr->pRight->flags &= ~EP_Collate;
-    }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){
-      /* Neither X nor Y have COLLATE operators, but X has a non-default
-      ** collating sequence.  So add the EP_Collate marker on X to cause
-      ** it to be searched first. */
-      pExpr->pLeft->flags |= EP_Collate;
+static int codeCursorHintIsOrFunction(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_IS 
+   || pExpr->op==TK_ISNULL || pExpr->op==TK_ISNOT 
+   || pExpr->op==TK_NOTNULL || pExpr->op==TK_CASE 
+  ){
+    pWalker->eCode = 1;
+  }else if( pExpr->op==TK_FUNCTION ){
+    int d1;
+    char d2[3];
+    if( 0==sqlite3IsLikeFunction(pWalker->pParse->db, pExpr, &d1, d2) ){
+      pWalker->eCode = 1;
     }
   }
-  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
-  if( pExpr->op>=TK_GT ){
-    assert( TK_LT==TK_GT+2 );
-    assert( TK_GE==TK_LE+2 );
-    assert( TK_GT>TK_EQ );
-    assert( TK_GTop>=TK_GT && pExpr->op<=TK_GE );
-    pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
-  }
+
+  return WRC_Continue;
 }
 
+
 /*
-** Translate from TK_xx operator to WO_xx bitmask.
+** This function is called on every node of an expression tree used as an
+** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN
+** that accesses any table other than the one identified by
+** CCurHint.iTabCur, then do the following:
+**
+**   1) allocate a register and code an OP_Column instruction to read 
+**      the specified column into the new register, and
+**
+**   2) transform the expression node to a TK_REGISTER node that reads 
+**      from the newly populated register.
+**
+** Also, if the node is a TK_COLUMN that does access the table idenified
+** by pCCurHint.iTabCur, and an index is being used (which we will
+** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
+** an access of the index rather than the original table.
 */
-static u16 operatorMask(int op){
-  u16 c;
-  assert( allowedOp(op) );
-  if( op==TK_IN ){
-    c = WO_IN;
-  }else if( op==TK_ISNULL ){
-    c = WO_ISNULL;
-  }else{
-    assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
-    c = (u16)(WO_EQ<<(op-TK_EQ));
+static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
+  int rc = WRC_Continue;
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  if( pExpr->op==TK_COLUMN ){
+    if( pExpr->iTable!=pHint->iTabCur ){
+      Vdbe *v = pWalker->pParse->pVdbe;
+      int reg = ++pWalker->pParse->nMem;   /* Register for column value */
+      sqlite3ExprCodeGetColumnOfTable(
+          v, pExpr->pTab, pExpr->iTable, pExpr->iColumn, reg
+      );
+      pExpr->op = TK_REGISTER;
+      pExpr->iTable = reg;
+    }else if( pHint->pIdx!=0 ){
+      pExpr->iTable = pHint->iIdxCur;
+      pExpr->iColumn = sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn);
+      assert( pExpr->iColumn>=0 );
+    }
+  }else if( pExpr->op==TK_AGG_FUNCTION ){
+    /* An aggregate function in the WHERE clause of a query means this must
+    ** be a correlated sub-query, and expression pExpr is an aggregate from
+    ** the parent context. Do not walk the function arguments in this case.
+    **
+    ** todo: It should be possible to replace this node with a TK_REGISTER
+    ** expression, as the result of the expression must be stored in a 
+    ** register at this point. The same holds for TK_AGG_COLUMN nodes. */
+    rc = WRC_Prune;
   }
-  assert( op!=TK_ISNULL || c==WO_ISNULL );
-  assert( op!=TK_IN || c==WO_IN );
-  assert( op!=TK_EQ || c==WO_EQ );
-  assert( op!=TK_LT || c==WO_LT );
-  assert( op!=TK_LE || c==WO_LE );
-  assert( op!=TK_GT || c==WO_GT );
-  assert( op!=TK_GE || c==WO_GE );
-  return c;
+  return rc;
 }
 
 /*
-** Advance to the next WhereTerm that matches according to the criteria
-** established when the pScan object was initialized by whereScanInit().
-** Return NULL if there are no more matching WhereTerms.
+** Insert an OP_CursorHint instruction if it is appropriate to do so.
 */
-static WhereTerm *whereScanNext(WhereScan *pScan){
-  int iCur;            /* The cursor on the LHS of the term */
-  int iColumn;         /* The column on the LHS of the term.  -1 for IPK */
-  Expr *pX;            /* An expression being tested */
-  WhereClause *pWC;    /* Shorthand for pScan->pWC */
-  WhereTerm *pTerm;    /* The term being tested */
-  int k = pScan->k;    /* Where to start scanning */
+static void codeCursorHint(
+  struct SrcList_item *pTabItem,  /* FROM clause item */
+  WhereInfo *pWInfo,    /* The where clause */
+  WhereLevel *pLevel,   /* Which loop to provide hints for */
+  WhereTerm *pEndRange  /* Hint this end-of-scan boundary term if not NULL */
+){
+  Parse *pParse = pWInfo->pParse;
+  sqlite3 *db = pParse->db;
+  Vdbe *v = pParse->pVdbe;
+  Expr *pExpr = 0;
+  WhereLoop *pLoop = pLevel->pWLoop;
+  int iCur;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  int i, j;
+  struct CCurHint sHint;
+  Walker sWalker;
+
+  if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;
+  iCur = pLevel->iTabCur;
+  assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );
+  sHint.iTabCur = iCur;
+  sHint.iIdxCur = pLevel->iIdxCur;
+  sHint.pIdx = pLoop->u.btree.pIndex;
+  memset(&sWalker, 0, sizeof(sWalker));
+  sWalker.pParse = pParse;
+  sWalker.u.pCCurHint = &sHint;
+  pWC = &pWInfo->sWC;
+  for(i=0; inTerm; i++){
+    pTerm = &pWC->a[i];
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( pTerm->prereqAll & pLevel->notReady ) continue;
 
-  while( pScan->iEquiv<=pScan->nEquiv ){
-    iCur = pScan->aEquiv[pScan->iEquiv-2];
-    iColumn = pScan->aEquiv[pScan->iEquiv-1];
-    while( (pWC = pScan->pWC)!=0 ){
-      for(pTerm=pWC->a+k; knTerm; k++, pTerm++){
-        if( pTerm->leftCursor==iCur
-         && pTerm->u.leftColumn==iColumn
-         && (pScan->iEquiv<=2 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
-        ){
-          if( (pTerm->eOperator & WO_EQUIV)!=0
-           && pScan->nEquivaEquiv)
-          ){
-            int j;
-            pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
-            assert( pX->op==TK_COLUMN );
-            for(j=0; jnEquiv; j+=2){
-              if( pScan->aEquiv[j]==pX->iTable
-               && pScan->aEquiv[j+1]==pX->iColumn ){
-                  break;
-              }
-            }
-            if( j==pScan->nEquiv ){
-              pScan->aEquiv[j] = pX->iTable;
-              pScan->aEquiv[j+1] = pX->iColumn;
-              pScan->nEquiv += 2;
-            }
-          }
-          if( (pTerm->eOperator & pScan->opMask)!=0 ){
-            /* Verify the affinity and collating sequence match */
-            if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
-              CollSeq *pColl;
-              Parse *pParse = pWC->pWInfo->pParse;
-              pX = pTerm->pExpr;
-              if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
-                continue;
-              }
-              assert(pX->pLeft);
-              pColl = sqlite3BinaryCompareCollSeq(pParse,
-                                                  pX->pLeft, pX->pRight);
-              if( pColl==0 ) pColl = pParse->db->pDfltColl;
-              if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
-                continue;
-              }
-            }
-            if( (pTerm->eOperator & WO_EQ)!=0
-             && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
-             && pX->iTable==pScan->aEquiv[0]
-             && pX->iColumn==pScan->aEquiv[1]
-            ){
-              continue;
-            }
-            pScan->k = k+1;
-            return pTerm;
-          }
-        }
+    /* Any terms specified as part of the ON(...) clause for any LEFT 
+    ** JOIN for which the current table is not the rhs are omitted
+    ** from the cursor-hint. 
+    **
+    ** If this table is the rhs of a LEFT JOIN, "IS" or "IS NULL" terms 
+    ** that were specified as part of the WHERE clause must be excluded.
+    ** This is to address the following:
+    **
+    **   SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;
+    **
+    ** Say there is a single row in t2 that matches (t1.a=t2.b), but its
+    ** t2.c values is not NULL. If the (t2.c IS NULL) constraint is 
+    ** pushed down to the cursor, this row is filtered out, causing
+    ** SQLite to synthesize a row of NULL values. Which does match the
+    ** WHERE clause, and so the query returns a row. Which is incorrect.
+    **
+    ** For the same reason, WHERE terms such as:
+    **
+    **   WHERE 1 = (t2.c IS NULL)
+    **
+    ** are also excluded. See codeCursorHintIsOrFunction() for details.
+    */
+    if( pTabItem->fg.jointype & JT_LEFT ){
+      Expr *pExpr = pTerm->pExpr;
+      if( !ExprHasProperty(pExpr, EP_FromJoin) 
+       || pExpr->iRightJoinTable!=pTabItem->iCursor
+      ){
+        sWalker.eCode = 0;
+        sWalker.xExprCallback = codeCursorHintIsOrFunction;
+        sqlite3WalkExpr(&sWalker, pTerm->pExpr);
+        if( sWalker.eCode ) continue;
       }
-      pScan->pWC = pScan->pWC->pOuter;
-      k = 0;
+    }else{
+      if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
     }
-    pScan->pWC = pScan->pOrigWC;
-    k = 0;
-    pScan->iEquiv += 2;
+
+    /* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
+    ** the cursor.  These terms are not needed as hints for a pure range
+    ** scan (that has no == terms) so omit them. */
+    if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){
+      for(j=0; jnLTerm && pLoop->aLTerm[j]!=pTerm; j++){}
+      if( jnLTerm ) continue;
+    }
+
+    /* No subqueries or non-deterministic functions allowed */
+    if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;
+
+    /* For an index scan, make sure referenced columns are actually in
+    ** the index. */
+    if( sHint.pIdx!=0 ){
+      sWalker.eCode = 0;
+      sWalker.xExprCallback = codeCursorHintCheckExpr;
+      sqlite3WalkExpr(&sWalker, pTerm->pExpr);
+      if( sWalker.eCode ) continue;
+    }
+
+    /* If we survive all prior tests, that means this term is worth hinting */
+    pExpr = sqlite3ExprAnd(db, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
+  }
+  if( pExpr!=0 ){
+    sWalker.xExprCallback = codeCursorHintFixExpr;
+    sqlite3WalkExpr(&sWalker, pExpr);
+    sqlite3VdbeAddOp4(v, OP_CursorHint, 
+                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
+                      (const char*)pExpr, P4_EXPR);
   }
-  return 0;
 }
+#else
+# define codeCursorHint(A,B,C,D)  /* No-op */
+#endif /* SQLITE_ENABLE_CURSOR_HINTS */
 
 /*
-** Initialize a WHERE clause scanner object.  Return a pointer to the
-** first match.  Return NULL if there are no matches.
+** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains
+** a rowid value just read from cursor iIdxCur, open on index pIdx. This
+** function generates code to do a deferred seek of cursor iCur to the 
+** rowid stored in register iRowid.
 **
-** The scanner will be searching the WHERE clause pWC.  It will look
-** for terms of the form "X  " where X is column iColumn of table
-** iCur.  The  must be one of the operators described by opMask.
+** Normally, this is just:
 **
-** If the search is for X and the WHERE clause contains terms of the
-** form X=Y then this routine might also return terms of the form
-** "Y  ".  The number of levels of transitivity is limited,
-** but is enough to handle most commonly occurring SQL statements.
+**   OP_DeferredSeek $iCur $iRowid
 **
-** If X is not the INTEGER PRIMARY KEY then X must be compatible with
-** index pIdx.
+** However, if the scan currently being coded is a branch of an OR-loop and
+** the statement currently being coded is a SELECT, then P3 of OP_DeferredSeek
+** is set to iIdxCur and P4 is set to point to an array of integers
+** containing one entry for each column of the table cursor iCur is open 
+** on. For each table column, if the column is the i'th column of the 
+** index, then the corresponding array entry is set to (i+1). If the column
+** does not appear in the index at all, the array entry is set to 0.
 */
-static WhereTerm *whereScanInit(
-  WhereScan *pScan,       /* The WhereScan object being initialized */
-  WhereClause *pWC,       /* The WHERE clause to be scanned */
-  int iCur,               /* Cursor to scan for */
-  int iColumn,            /* Column to scan for */
-  u32 opMask,             /* Operator(s) to scan for */
-  Index *pIdx             /* Must be compatible with this index */
+static void codeDeferredSeek(
+  WhereInfo *pWInfo,              /* Where clause context */
+  Index *pIdx,                    /* Index scan is using */
+  int iCur,                       /* Cursor for IPK b-tree */
+  int iIdxCur                     /* Index cursor */
 ){
-  int j;
+  Parse *pParse = pWInfo->pParse; /* Parse context */
+  Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */
 
-  /* memset(pScan, 0, sizeof(*pScan)); */
-  pScan->pOrigWC = pWC;
-  pScan->pWC = pWC;
-  if( pIdx && iColumn>=0 ){
-    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
-    for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
-      if( NEVER(j>pIdx->nColumn) ) return 0;
+  assert( iIdxCur>0 );
+  assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
+  
+  sqlite3VdbeAddOp3(v, OP_DeferredSeek, iIdxCur, 0, iCur);
+  if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
+   && DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
+  ){
+    int i;
+    Table *pTab = pIdx->pTable;
+    int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
+    if( ai ){
+      ai[0] = pTab->nCol;
+      for(i=0; inColumn-1; i++){
+        assert( pIdx->aiColumn[i]nCol );
+        if( pIdx->aiColumn[i]>=0 ) ai[pIdx->aiColumn[i]+1] = i+1;
+      }
+      sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
     }
-    pScan->zCollName = pIdx->azColl[j];
-  }else{
-    pScan->idxaff = 0;
-    pScan->zCollName = 0;
   }
-  pScan->opMask = opMask;
-  pScan->k = 0;
-  pScan->aEquiv[0] = iCur;
-  pScan->aEquiv[1] = iColumn;
-  pScan->nEquiv = 2;
-  pScan->iEquiv = 2;
-  return whereScanNext(pScan);
 }
 
 /*
-** Search for a term in the WHERE clause that is of the form "X  "
-** where X is a reference to the iColumn of table iCur and  is one of
-** the WO_xx operator codes specified by the op parameter.
-** Return a pointer to the term.  Return 0 if not found.
-**
-** The term returned might by Y= if there is another constraint in
-** the WHERE clause that specifies that X=Y.  Any such constraints will be
-** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
-** aEquiv[] array holds X and all its equivalents, with each SQL variable
-** taking up two slots in aEquiv[].  The first slot is for the cursor number
-** and the second is for the column number.  There are 22 slots in aEquiv[]
-** so that means we can look for X plus up to 10 other equivalent values.
-** Hence a search for X will return  if X=A1 and A1=A2 and A2=A3
-** and ... and A9=A10 and A10=.
+** If the expression passed as the second argument is a vector, generate
+** code to write the first nReg elements of the vector into an array
+** of registers starting with iReg.
 **
-** If there are multiple terms in the WHERE clause of the form "X  "
-** then try for the one with no dependencies on  - in other words where
-**  is a constant expression of some kind.  Only return entries of
-** the form "X  Y" where Y is a column in another table if no terms of
-** the form "X  " exist.   If no terms with a constant RHS
-** exist, try to return a term that does not use WO_EQUIV.
+** If the expression is not a vector, then nReg must be passed 1. In
+** this case, generate code to evaluate the expression and leave the
+** result in register iReg.
 */
-static WhereTerm *findTerm(
-  WhereClause *pWC,     /* The WHERE clause to be searched */
-  int iCur,             /* Cursor number of LHS */
-  int iColumn,          /* Column number of LHS */
-  Bitmask notReady,     /* RHS must not overlap with this mask */
-  u32 op,               /* Mask of WO_xx values describing operator */
-  Index *pIdx           /* Must be compatible with this index, if not NULL */
-){
-  WhereTerm *pResult = 0;
-  WhereTerm *p;
-  WhereScan scan;
-
-  p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
-  while( p ){
-    if( (p->prereqRight & notReady)==0 ){
-      if( p->prereqRight==0 && (p->eOperator&WO_EQ)!=0 ){
-        return p;
+static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){
+  assert( nReg>0 );
+  if( sqlite3ExprIsVector(p) ){
+#ifndef SQLITE_OMIT_SUBQUERY
+    if( (p->flags & EP_xIsSelect) ){
+      Vdbe *v = pParse->pVdbe;
+      int iSelect = sqlite3CodeSubselect(pParse, p, 0, 0);
+      sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1);
+    }else
+#endif
+    {
+      int i;
+      ExprList *pList = p->x.pList;
+      assert( nReg<=pList->nExpr );
+      for(i=0; ia[i].pExpr, iReg+i);
       }
-      if( pResult==0 ) pResult = p;
     }
-    p = whereScanNext(&scan);
+  }else{
+    assert( nReg==1 );
+    sqlite3ExprCode(pParse, p, iReg);
   }
-  return pResult;
 }
 
-/* Forward reference */
-static void exprAnalyze(SrcList*, WhereClause*, int);
-
-/*
-** Call exprAnalyze on all terms in a WHERE clause.  
+/* An instance of the IdxExprTrans object carries information about a
+** mapping from an expression on table columns into a column in an index
+** down through the Walker.
 */
-static void exprAnalyzeAll(
-  SrcList *pTabList,       /* the FROM clause */
-  WhereClause *pWC         /* the WHERE clause to be analyzed */
-){
-  int i;
-  for(i=pWC->nTerm-1; i>=0; i--){
-    exprAnalyze(pTabList, pWC, i);
-  }
-}
+typedef struct IdxExprTrans {
+  Expr *pIdxExpr;    /* The index expression */
+  int iTabCur;       /* The cursor of the corresponding table */
+  int iIdxCur;       /* The cursor for the index */
+  int iIdxCol;       /* The column for the index */
+} IdxExprTrans;
 
-#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
-/*
-** Check to see if the given expression is a LIKE or GLOB operator that
-** can be optimized using inequality constraints.  Return TRUE if it is
-** so and false if not.
+/* The walker node callback used to transform matching expressions into
+** a reference to an index column for an index on an expression.
 **
-** In order for the operator to be optimizible, the RHS must be a string
-** literal that does not begin with a wildcard.  
+** If pExpr matches, then transform it into a reference to the index column
+** that contains the value of pExpr.
 */
-static int isLikeOrGlob(
-  Parse *pParse,    /* Parsing and code generating context */
-  Expr *pExpr,      /* Test this expression */
-  Expr **ppPrefix,  /* Pointer to TK_STRING expression with pattern prefix */
-  int *pisComplete, /* True if the only wildcard is % in the last character */
-  int *pnoCase      /* True if uppercase is equivalent to lowercase */
-){
-  const char *z = 0;         /* String on RHS of LIKE operator */
-  Expr *pRight, *pLeft;      /* Right and left size of LIKE operator */
-  ExprList *pList;           /* List of operands to the LIKE operator */
-  int c;                     /* One character in z[] */
-  int cnt;                   /* Number of non-wildcard prefix characters */
-  char wc[3];                /* Wildcard characters */
-  sqlite3 *db = pParse->db;  /* Database connection */
-  sqlite3_value *pVal = 0;
-  int op;                    /* Opcode of pRight */
-
-  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
-    return 0;
-  }
-#ifdef SQLITE_EBCDIC
-  if( *pnoCase ) return 0;
-#endif
-  pList = pExpr->x.pList;
-  pLeft = pList->a[1].pExpr;
-  if( pLeft->op!=TK_COLUMN 
-   || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT 
-   || IsVirtual(pLeft->pTab)
-  ){
-    /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must
-    ** be the name of an indexed column with TEXT affinity. */
-    return 0;
-  }
-  assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */
-
-  pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
-  op = pRight->op;
-  if( op==TK_VARIABLE ){
-    Vdbe *pReprepare = pParse->pReprepare;
-    int iCol = pRight->iColumn;
-    pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_NONE);
-    if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
-      z = (char *)sqlite3_value_text(pVal);
-    }
-    sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);
-    assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
-  }else if( op==TK_STRING ){
-    z = pRight->u.zToken;
-  }
-  if( z ){
-    cnt = 0;
-    while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
-      cnt++;
-    }
-    if( cnt!=0 && 255!=(u8)z[cnt-1] ){
-      Expr *pPrefix;
-      *pisComplete = c==wc[0] && z[cnt+1]==0;
-      pPrefix = sqlite3Expr(db, TK_STRING, z);
-      if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
-      *ppPrefix = pPrefix;
-      if( op==TK_VARIABLE ){
-        Vdbe *v = pParse->pVdbe;
-        sqlite3VdbeSetVarmask(v, pRight->iColumn);
-        if( *pisComplete && pRight->u.zToken[1] ){
-          /* If the rhs of the LIKE expression is a variable, and the current
-          ** value of the variable means there is no need to invoke the LIKE
-          ** function, then no OP_Variable will be added to the program.
-          ** This causes problems for the sqlite3_bind_parameter_name()
-          ** API. To work around them, add a dummy OP_Variable here.
-          */ 
-          int r1 = sqlite3GetTempReg(pParse);
-          sqlite3ExprCodeTarget(pParse, pRight, r1);
-          sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
-          sqlite3ReleaseTempReg(pParse, r1);
-        }
-      }
-    }else{
-      z = 0;
-    }
+static int whereIndexExprTransNode(Walker *p, Expr *pExpr){
+  IdxExprTrans *pX = p->u.pIdxTrans;
+  if( sqlite3ExprCompare(0, pExpr, pX->pIdxExpr, pX->iTabCur)==0 ){
+    pExpr->op = TK_COLUMN;
+    pExpr->iTable = pX->iIdxCur;
+    pExpr->iColumn = pX->iIdxCol;
+    pExpr->pTab = 0;
+    return WRC_Prune;
+  }else{
+    return WRC_Continue;
   }
-
-  sqlite3ValueFree(pVal);
-  return (z!=0);
 }
-#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
-
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
-** Check to see if the given expression is of the form
-**
-**         column MATCH expr
-**
-** If it is then return TRUE.  If not, return FALSE.
+** For an indexes on expression X, locate every instance of expression X in pExpr
+** and change that subexpression into a reference to the appropriate column of
+** the index.
 */
-static int isMatchOfColumn(
-  Expr *pExpr      /* Test this expression */
+static void whereIndexExprTrans(
+  Index *pIdx,      /* The Index */
+  int iTabCur,      /* Cursor of the table that is being indexed */
+  int iIdxCur,      /* Cursor of the index itself */
+  WhereInfo *pWInfo /* Transform expressions in this WHERE clause */
 ){
-  ExprList *pList;
-
-  if( pExpr->op!=TK_FUNCTION ){
-    return 0;
-  }
-  if( sqlite3StrICmp(pExpr->u.zToken,"match")!=0 ){
-    return 0;
-  }
-  pList = pExpr->x.pList;
-  if( pList->nExpr!=2 ){
-    return 0;
-  }
-  if( pList->a[1].pExpr->op != TK_COLUMN ){
-    return 0;
-  }
-  return 1;
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-/*
-** If the pBase expression originated in the ON or USING clause of
-** a join, then transfer the appropriate markings over to derived.
-*/
-static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
-  if( pDerived ){
-    pDerived->flags |= pBase->flags & EP_FromJoin;
-    pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  int iIdxCol;               /* Column number of the index */
+  ExprList *aColExpr;        /* Expressions that are indexed */
+  Walker w;
+  IdxExprTrans x;
+  aColExpr = pIdx->aColExpr;
+  if( aColExpr==0 ) return;  /* Not an index on expressions */
+  memset(&w, 0, sizeof(w));
+  w.xExprCallback = whereIndexExprTransNode;
+  w.u.pIdxTrans = &x;
+  x.iTabCur = iTabCur;
+  x.iIdxCur = iIdxCur;
+  for(iIdxCol=0; iIdxColnExpr; iIdxCol++){
+    if( pIdx->aiColumn[iIdxCol]!=XN_EXPR ) continue;
+    assert( aColExpr->a[iIdxCol].pExpr!=0 );
+    x.iIdxCol = iIdxCol;
+    x.pIdxExpr = aColExpr->a[iIdxCol].pExpr;
+    sqlite3WalkExpr(&w, pWInfo->pWhere);
+    sqlite3WalkExprList(&w, pWInfo->pOrderBy);
+    sqlite3WalkExprList(&w, pWInfo->pResultSet);
   }
 }
 
 /*
-** Mark term iChild as being a child of term iParent
-*/
-static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
-  pWC->a[iChild].iParent = iParent;
-  pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
-  pWC->a[iParent].nChild++;
-}
-
-#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
-/*
-** Analyze a term that consists of two or more OR-connected
-** subterms.  So in:
-**
-**     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
-**                          ^^^^^^^^^^^^^^^^^^^^
-**
-** This routine analyzes terms such as the middle term in the above example.
-** A WhereOrTerm object is computed and attached to the term under
-** analysis, regardless of the outcome of the analysis.  Hence:
-**
-**     WhereTerm.wtFlags   |=  TERM_ORINFO
-**     WhereTerm.u.pOrInfo  =  a dynamically allocated WhereOrTerm object
-**
-** The term being analyzed must have two or more of OR-connected subterms.
-** A single subterm might be a set of AND-connected sub-subterms.
-** Examples of terms under analysis:
-**
-**     (A)     t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5
-**     (B)     x=expr1 OR expr2=x OR x=expr3
-**     (C)     t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
-**     (D)     x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
-**     (E)     (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
-**
-** CASE 1:
-**
-** If all subterms are of the form T.C=expr for some single column of C and
-** a single table T (as shown in example B above) then create a new virtual
-** term that is an equivalent IN expression.  In other words, if the term
-** being analyzed is:
-**
-**      x = expr1  OR  expr2 = x  OR  x = expr3
-**
-** then create a new virtual term like this:
-**
-**      x IN (expr1,expr2,expr3)
-**
-** CASE 2:
-**
-** If all subterms are indexable by a single table T, then set
-**
-**     WhereTerm.eOperator              =  WO_OR
-**     WhereTerm.u.pOrInfo->indexable  |=  the cursor number for table T
-**
-** A subterm is "indexable" if it is of the form
-** "T.C  " where C is any column of table T and 
-**  is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
-** A subterm is also indexable if it is an AND of two or more
-** subsubterms at least one of which is indexable.  Indexable AND 
-** subterms have their eOperator set to WO_AND and they have
-** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
-**
-** From another point of view, "indexable" means that the subterm could
-** potentially be used with an index if an appropriate index exists.
-** This analysis does not consider whether or not the index exists; that
-** is decided elsewhere.  This analysis only looks at whether subterms
-** appropriate for indexing exist.
-**
-** All examples A through E above satisfy case 2.  But if a term
-** also satisfies case 1 (such as B) we know that the optimizer will
-** always prefer case 1, so in that case we pretend that case 2 is not
-** satisfied.
-**
-** It might be the case that multiple tables are indexable.  For example,
-** (E) above is indexable on tables P, Q, and R.
-**
-** Terms that satisfy case 2 are candidates for lookup by using
-** separate indices to find rowids for each subterm and composing
-** the union of all rowids using a RowSet object.  This is similar
-** to "bitmap indices" in other database engines.
-**
-** OTHERWISE:
-**
-** If neither case 1 nor case 2 apply, then leave the eOperator set to
-** zero.  This term is not useful for search.
+** Generate code for the start of the iLevel-th loop in the WHERE clause
+** implementation described by pWInfo.
 */
-static void exprAnalyzeOrTerm(
-  SrcList *pSrc,            /* the FROM clause */
-  WhereClause *pWC,         /* the complete WHERE clause */
-  int idxTerm               /* Index of the OR-term to be analyzed */
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
 ){
-  WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */
-  Parse *pParse = pWInfo->pParse;         /* Parser context */
-  sqlite3 *db = pParse->db;               /* Database connection */
-  WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */
-  Expr *pExpr = pTerm->pExpr;             /* The expression of the term */
-  int i;                                  /* Loop counters */
-  WhereClause *pOrWc;       /* Breakup of pTerm into subterms */
-  WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */
-  WhereOrInfo *pOrInfo;     /* Additional information associated with pTerm */
-  Bitmask chngToIN;         /* Tables that might satisfy case 1 */
-  Bitmask indexable;        /* Tables that are indexable, satisfying case 2 */
+  int j, k;            /* Loop counters */
+  int iCur;            /* The VDBE cursor for the table */
+  int addrNxt;         /* Where to jump to continue with the next IN case */
+  int omitTable;       /* True if we use the index only */
+  int bRev;            /* True if we need to scan in reverse order */
+  WhereLevel *pLevel;  /* The where level to be coded */
+  WhereLoop *pLoop;    /* The WhereLoop object being coded */
+  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
+  WhereTerm *pTerm;               /* A WHERE clause term */
+  Parse *pParse;                  /* Parsing context */
+  sqlite3 *db;                    /* Database connection */
+  Vdbe *v;                        /* The prepared stmt under constructions */
+  struct SrcList_item *pTabItem;  /* FROM clause term being coded */
+  int addrBrk;                    /* Jump here to break out of the loop */
+  int addrHalt;                   /* addrBrk for the outermost loop */
+  int addrCont;                   /* Jump here to continue with next cycle */
+  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
+  int iReleaseReg = 0;      /* Temp register to free before returning */
+  Index *pIdx = 0;          /* Index used by loop (if any) */
+  int iLoop;                /* Iteration of constraint generator loop */
 
-  /*
-  ** Break the OR clause into its separate subterms.  The subterms are
-  ** stored in a WhereClause structure containing within the WhereOrInfo
-  ** object that is attached to the original OR clause term.
+  pParse = pWInfo->pParse;
+  v = pParse->pVdbe;
+  pWC = &pWInfo->sWC;
+  db = pParse->db;
+  pLevel = &pWInfo->a[iLevel];
+  pLoop = pLevel->pWLoop;
+  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
+  iCur = pTabItem->iCursor;
+  pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+  bRev = (pWInfo->revMask>>iLevel)&1;
+  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
+           && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;
+  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
+
+  /* Create labels for the "break" and "continue" instructions
+  ** for the current loop.  Jump to addrBrk to break out of a loop.
+  ** Jump to cont to go immediately to the next iteration of the
+  ** loop.
+  **
+  ** When there is an IN operator, we also have a "addrNxt" label that
+  ** means to continue with the next IN value combination.  When
+  ** there are no IN operators in the constraints, the "addrNxt" label
+  ** is the same as "addrBrk".
   */
-  assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );
-  assert( pExpr->op==TK_OR );
-  pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));
-  if( pOrInfo==0 ) return;
-  pTerm->wtFlags |= TERM_ORINFO;
-  pOrWc = &pOrInfo->wc;
-  whereClauseInit(pOrWc, pWInfo);
-  whereSplit(pOrWc, pExpr, TK_OR);
-  exprAnalyzeAll(pSrc, pOrWc);
-  if( db->mallocFailed ) return;
-  assert( pOrWc->nTerm>=2 );
+  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
 
-  /*
-  ** Compute the set of tables that might satisfy cases 1 or 2.
+  /* If this is the right table of a LEFT OUTER JOIN, allocate and
+  ** initialize a memory cell that records if this table matches any
+  ** row of the left table of the join.
   */
-  indexable = ~(Bitmask)0;
-  chngToIN = ~(Bitmask)0;
-  for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
-    if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
-      WhereAndInfo *pAndInfo;
-      assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
-      chngToIN = 0;
-      pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
-      if( pAndInfo ){
-        WhereClause *pAndWC;
-        WhereTerm *pAndTerm;
-        int j;
-        Bitmask b = 0;
-        pOrTerm->u.pAndInfo = pAndInfo;
-        pOrTerm->wtFlags |= TERM_ANDINFO;
-        pOrTerm->eOperator = WO_AND;
-        pAndWC = &pAndInfo->wc;
-        whereClauseInit(pAndWC, pWC->pWInfo);
-        whereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
-        exprAnalyzeAll(pSrc, pAndWC);
-        pAndWC->pOuter = pWC;
-        testcase( db->mallocFailed );
-        if( !db->mallocFailed ){
-          for(j=0, pAndTerm=pAndWC->a; jnTerm; j++, pAndTerm++){
-            assert( pAndTerm->pExpr );
-            if( allowedOp(pAndTerm->pExpr->op) ){
-              b |= getMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
-            }
-          }
-        }
-        indexable &= b;
-      }
-    }else if( pOrTerm->wtFlags & TERM_COPIED ){
-      /* Skip this term for now.  We revisit it when we process the
-      ** corresponding TERM_VIRTUAL term */
-    }else{
-      Bitmask b;
-      b = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
-      if( pOrTerm->wtFlags & TERM_VIRTUAL ){
-        WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
-        b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor);
-      }
-      indexable &= b;
-      if( (pOrTerm->eOperator & WO_EQ)==0 ){
-        chngToIN = 0;
-      }else{
-        chngToIN &= b;
-      }
-    }
+  if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
+    pLevel->iLeftJoin = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+    VdbeComment((v, "init LEFT JOIN no-match flag"));
   }
 
-  /*
-  ** Record the set of tables that satisfy case 2.  The set might be
-  ** empty.
-  */
-  pOrInfo->indexable = indexable;
-  pTerm->eOperator = indexable==0 ? 0 : WO_OR;
+  /* Compute a safe address to jump to if we discover that the table for
+  ** this loop is empty and can never contribute content. */
+  for(j=iLevel; j>0 && pWInfo->a[j].iLeftJoin==0; j--){}
+  addrHalt = pWInfo->a[j].addrBrk;
 
-  /*
-  ** chngToIN holds a set of tables that *might* satisfy case 1.  But
-  ** we have to do some additional checking to see if case 1 really
-  ** is satisfied.
-  **
-  ** chngToIN will hold either 0, 1, or 2 bits.  The 0-bit case means
-  ** that there is no possibility of transforming the OR clause into an
-  ** IN operator because one or more terms in the OR clause contain
-  ** something other than == on a column in the single table.  The 1-bit
-  ** case means that every term of the OR clause is of the form
-  ** "table.column=expr" for some single table.  The one bit that is set
-  ** will correspond to the common table.  We still need to check to make
-  ** sure the same column is used on all terms.  The 2-bit case is when
-  ** the all terms are of the form "table1.column=table2.column".  It
-  ** might be possible to form an IN operator with either table1.column
-  ** or table2.column as the LHS if either is common to every term of
-  ** the OR clause.
-  **
-  ** Note that terms of the form "table.column1=table.column2" (the
-  ** same table on both sizes of the ==) cannot be optimized.
-  */
-  if( chngToIN ){
-    int okToChngToIN = 0;     /* True if the conversion to IN is valid */
-    int iColumn = -1;         /* Column index on lhs of IN operator */
-    int iCursor = -1;         /* Table cursor common to all terms */
-    int j = 0;                /* Loop counter */
+  /* Special case of a FROM clause subquery implemented as a co-routine */
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+    pLevel->op = OP_Goto;
+  }else
 
-    /* Search for a table and column that appears on one side or the
-    ** other of the == operator in every subterm.  That table and column
-    ** will be recorded in iCursor and iColumn.  There might not be any
-    ** such table and column.  Set okToChngToIN if an appropriate table
-    ** and column is found but leave okToChngToIN false if not found.
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
+    **          to access the data.
     */
-    for(j=0; j<2 && !okToChngToIN; j++){
-      pOrTerm = pOrWc->a;
-      for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
-        assert( pOrTerm->eOperator & WO_EQ );
-        pOrTerm->wtFlags &= ~TERM_OR_OK;
-        if( pOrTerm->leftCursor==iCursor ){
-          /* This is the 2-bit case and we are on the second iteration and
-          ** current term is from the first iteration.  So skip this term. */
-          assert( j==1 );
-          continue;
-        }
-        if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
-          /* This term must be of the form t1.a==t2.b where t2 is in the
-          ** chngToIN set but t1 is not.  This term will be either preceded
-          ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
-          ** and use its inversion. */
-          testcase( pOrTerm->wtFlags & TERM_COPIED );
-          testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
-          assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
-          continue;
-        }
-        iColumn = pOrTerm->u.leftColumn;
-        iCursor = pOrTerm->leftCursor;
-        break;
-      }
-      if( i<0 ){
-        /* No candidate table+column was found.  This can only occur
-        ** on the second iteration */
-        assert( j==1 );
-        assert( IsPowerOfTwo(chngToIN) );
-        assert( chngToIN==getMask(&pWInfo->sMaskSet, iCursor) );
-        break;
-      }
-      testcase( j==1 );
+    int iReg;   /* P3 Value for OP_VFilter */
+    int addrNotFound;
+    int nConstraint = pLoop->nLTerm;
+    int iIn;    /* Counter for IN constraints */
 
-      /* We have found a candidate table and column.  Check to see if that
-      ** table and column is common to every term in the OR clause */
-      okToChngToIN = 1;
-      for(; i>=0 && okToChngToIN; i--, pOrTerm++){
-        assert( pOrTerm->eOperator & WO_EQ );
-        if( pOrTerm->leftCursor!=iCursor ){
-          pOrTerm->wtFlags &= ~TERM_OR_OK;
-        }else if( pOrTerm->u.leftColumn!=iColumn ){
-          okToChngToIN = 0;
-        }else{
-          int affLeft, affRight;
-          /* If the right-hand side is also a column, then the affinities
-          ** of both right and left sides must be such that no type
-          ** conversions are required on the right.  (Ticket #2249)
-          */
-          affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);
-          affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
-          if( affRight!=0 && affRight!=affLeft ){
-            okToChngToIN = 0;
-          }else{
-            pOrTerm->wtFlags |= TERM_OR_OK;
+    sqlite3ExprCachePush(pParse);
+    iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+    addrNotFound = pLevel->addrBrk;
+    for(j=0; jaLTerm[j];
+      if( NEVER(pTerm==0) ) continue;
+      if( pTerm->eOperator & WO_IN ){
+        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+        addrNotFound = pLevel->addrNxt;
+      }else{
+        Expr *pRight = pTerm->pExpr->pRight;
+        codeExprOrVector(pParse, pRight, iTarget, 1);
+      }
+    }
+    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+                      pLoop->u.vtab.idxStr,
+                      pLoop->u.vtab.needFree ? P4_DYNAMIC : P4_STATIC);
+    VdbeCoverage(v);
+    pLoop->u.vtab.needFree = 0;
+    pLevel->p1 = iCur;
+    pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+    iIn = pLevel->u.in.nIn;
+    for(j=nConstraint-1; j>=0; j--){
+      pTerm = pLoop->aLTerm[j];
+      if( j<16 && (pLoop->u.vtab.omitMask>>j)&1 ){
+        disableTerm(pLevel, pTerm);
+      }else if( (pTerm->eOperator & WO_IN)!=0 ){
+        Expr *pCompare;  /* The comparison operator */
+        Expr *pRight;    /* RHS of the comparison */
+        VdbeOp *pOp;     /* Opcode to access the value of the IN constraint */
+
+        /* Reload the constraint value into reg[iReg+j+2].  The same value
+        ** was loaded into the same register prior to the OP_VFilter, but
+        ** the xFilter implementation might have changed the datatype or
+        ** encoding of the value in the register, so it *must* be reloaded. */
+        assert( pLevel->u.in.aInLoop!=0 || db->mallocFailed );
+        if( !db->mallocFailed ){
+          assert( iIn>0 );
+          pOp = sqlite3VdbeGetOp(v, pLevel->u.in.aInLoop[--iIn].addrInTop);
+          assert( pOp->opcode==OP_Column || pOp->opcode==OP_Rowid );
+          assert( pOp->opcode!=OP_Column || pOp->p3==iReg+j+2 );
+          assert( pOp->opcode!=OP_Rowid || pOp->p2==iReg+j+2 );
+          testcase( pOp->opcode==OP_Rowid );
+          sqlite3VdbeAddOp3(v, pOp->opcode, pOp->p1, pOp->p2, pOp->p3);
+        }
+
+        /* Generate code that will continue to the next row if 
+        ** the IN constraint is not satisfied */
+        pCompare = sqlite3PExpr(pParse, TK_EQ, 0, 0);
+        assert( pCompare!=0 || db->mallocFailed );
+        if( pCompare ){
+          pCompare->pLeft = pTerm->pExpr->pLeft;
+          pCompare->pRight = pRight = sqlite3Expr(db, TK_REGISTER, 0);
+          if( pRight ){
+            pRight->iTable = iReg+j+2;
+            sqlite3ExprIfFalse(pParse, pCompare, pLevel->addrCont, 0);
           }
+          pCompare->pLeft = 0;
+          sqlite3ExprDelete(db, pCompare);
         }
       }
     }
+    /* These registers need to be preserved in case there is an IN operator
+    ** loop.  So we could deallocate the registers here (and potentially
+    ** reuse them later) if (pLoop->wsFlags & WHERE_IN_ABLE)==0.  But it seems
+    ** simpler and safer to simply not reuse the registers.
+    **
+    **    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+    */
+    sqlite3ExprCachePop(pParse);
+  }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
 
-    /* At this point, okToChngToIN is true if original pTerm satisfies
-    ** case 1.  In that case, construct a new virtual term that is 
-    ** pTerm converted into an IN operator.
+  if( (pLoop->wsFlags & WHERE_IPK)!=0
+   && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+  ){
+    /* Case 2:  We can directly reference a single row using an
+    **          equality comparison against the ROWID field.  Or
+    **          we reference multiple rows using a "rowid IN (...)"
+    **          construct.
     */
-    if( okToChngToIN ){
-      Expr *pDup;            /* A transient duplicate expression */
-      ExprList *pList = 0;   /* The RHS of the IN operator */
-      Expr *pLeft = 0;       /* The LHS of the IN operator */
-      Expr *pNew;            /* The complete IN operator */
+    assert( pLoop->u.btree.nEq==1 );
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->pExpr!=0 );
+    assert( omitTable==0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    iReleaseReg = ++pParse->nMem;
+    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
+    if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
+    addrNxt = pLevel->addrNxt;
+    sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);
+    VdbeCoverage(v);
+    sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
+    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+    VdbeComment((v, "pk"));
+    pLevel->op = OP_Noop;
+  }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+         && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+  ){
+    /* Case 3:  We have an inequality comparison against the ROWID field.
+    */
+    int testOp = OP_Noop;
+    int start;
+    int memEndValue = 0;
+    WhereTerm *pStart, *pEnd;
 
-      for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
-        if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
-        assert( pOrTerm->eOperator & WO_EQ );
-        assert( pOrTerm->leftCursor==iCursor );
-        assert( pOrTerm->u.leftColumn==iColumn );
-        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
-        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
-        pLeft = pOrTerm->pExpr->pLeft;
+    assert( omitTable==0 );
+    j = 0;
+    pStart = pEnd = 0;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+    assert( pStart!=0 || pEnd!=0 );
+    if( bRev ){
+      pTerm = pStart;
+      pStart = pEnd;
+      pEnd = pTerm;
+    }
+    codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
+    if( pStart ){
+      Expr *pX;             /* The expression that defines the start bound */
+      int r1, rTemp;        /* Registers for holding the start boundary */
+      int op;               /* Cursor seek operation */
+
+      /* The following constant maps TK_xx codes into corresponding 
+      ** seek opcodes.  It depends on a particular ordering of TK_xx
+      */
+      const u8 aMoveOp[] = {
+           /* TK_GT */  OP_SeekGT,
+           /* TK_LE */  OP_SeekLE,
+           /* TK_LT */  OP_SeekLT,
+           /* TK_GE */  OP_SeekGE
+      };
+      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
+      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
+      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
+
+      assert( (pStart->wtFlags & TERM_VNULL)==0 );
+      testcase( pStart->wtFlags & TERM_VIRTUAL );
+      pX = pStart->pExpr;
+      assert( pX!=0 );
+      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
+      if( sqlite3ExprIsVector(pX->pRight) ){
+        r1 = rTemp = sqlite3GetTempReg(pParse);
+        codeExprOrVector(pParse, pX->pRight, r1, 1);
+        op = aMoveOp[(pX->op - TK_GT) | 0x0001];
+      }else{
+        r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
+        disableTerm(pLevel, pStart);
+        op = aMoveOp[(pX->op - TK_GT)];
       }
-      assert( pLeft!=0 );
-      pDup = sqlite3ExprDup(db, pLeft, 0);
-      pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0, 0);
-      if( pNew ){
-        int idxNew;
-        transferJoinMarkings(pNew, pExpr);
-        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
-        pNew->x.pList = pList;
-        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
-        testcase( idxNew==0 );
-        exprAnalyze(pSrc, pWC, idxNew);
-        pTerm = &pWC->a[idxTerm];
-        markTermAsChild(pWC, idxNew, idxTerm);
+      sqlite3VdbeAddOp3(v, op, iCur, addrBrk, r1);
+      VdbeComment((v, "pk"));
+      VdbeCoverageIf(v, pX->op==TK_GT);
+      VdbeCoverageIf(v, pX->op==TK_LE);
+      VdbeCoverageIf(v, pX->op==TK_LT);
+      VdbeCoverageIf(v, pX->op==TK_GE);
+      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
+      sqlite3ReleaseTempReg(pParse, rTemp);
+    }else{
+      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrHalt);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+    }
+    if( pEnd ){
+      Expr *pX;
+      pX = pEnd->pExpr;
+      assert( pX!=0 );
+      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
+      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
+      testcase( pEnd->wtFlags & TERM_VIRTUAL );
+      memEndValue = ++pParse->nMem;
+      codeExprOrVector(pParse, pX->pRight, memEndValue, 1);
+      if( 0==sqlite3ExprIsVector(pX->pRight) 
+       && (pX->op==TK_LT || pX->op==TK_GT) 
+      ){
+        testOp = bRev ? OP_Le : OP_Ge;
       }else{
-        sqlite3ExprListDelete(db, pList);
+        testOp = bRev ? OP_Lt : OP_Gt;
+      }
+      if( 0==sqlite3ExprIsVector(pX->pRight) ){
+        disableTerm(pLevel, pEnd);
       }
-      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 2 */
     }
-  }
-}
-#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
+    start = sqlite3VdbeCurrentAddr(v);
+    pLevel->op = bRev ? OP_Prev : OP_Next;
+    pLevel->p1 = iCur;
+    pLevel->p2 = start;
+    assert( pLevel->p5==0 );
+    if( testOp!=OP_Noop ){
+      iRowidReg = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
+      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
+      VdbeCoverageIf(v, testOp==OP_Le);
+      VdbeCoverageIf(v, testOp==OP_Lt);
+      VdbeCoverageIf(v, testOp==OP_Ge);
+      VdbeCoverageIf(v, testOp==OP_Gt);
+      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+    }
+  }else if( pLoop->wsFlags & WHERE_INDEXED ){
+    /* Case 4: A scan using an index.
+    **
+    **         The WHERE clause may contain zero or more equality 
+    **         terms ("==" or "IN" operators) that refer to the N
+    **         left-most columns of the index. It may also contain
+    **         inequality constraints (>, <, >= or <=) on the indexed
+    **         column that immediately follows the N equalities. Only 
+    **         the right-most column can be an inequality - the rest must
+    **         use the "==" and "IN" operators. For example, if the 
+    **         index is on (x,y,z), then the following clauses are all 
+    **         optimized:
+    **
+    **            x=5
+    **            x=5 AND y=10
+    **            x=5 AND y<10
+    **            x=5 AND y>5 AND y<10
+    **            x=5 AND y=5 AND z<=10
+    **
+    **         The z<10 term of the following cannot be used, only
+    **         the x=5 term:
+    **
+    **            x=5 AND z<10
+    **
+    **         N may be zero if there are inequality constraints.
+    **         If there are no inequality constraints, then N is at
+    **         least one.
+    **
+    **         This case is also used when there are no WHERE clause
+    **         constraints but an index is selected anyway, in order
+    **         to force the output order to conform to an ORDER BY.
+    */  
+    static const u8 aStartOp[] = {
+      0,
+      0,
+      OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
+      OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
+      OP_SeekGT,           /* 4: (start_constraints  && !startEq && !bRev) */
+      OP_SeekLT,           /* 5: (start_constraints  && !startEq &&  bRev) */
+      OP_SeekGE,           /* 6: (start_constraints  &&  startEq && !bRev) */
+      OP_SeekLE            /* 7: (start_constraints  &&  startEq &&  bRev) */
+    };
+    static const u8 aEndOp[] = {
+      OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */
+      OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */
+      OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */
+      OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */
+    };
+    u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */
+    u16 nBtm = pLoop->u.btree.nBtm;   /* Length of BTM vector */
+    u16 nTop = pLoop->u.btree.nTop;   /* Length of TOP vector */
+    int regBase;                 /* Base register holding constraint values */
+    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
+    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
+    int startEq;                 /* True if range start uses ==, >= or <= */
+    int endEq;                   /* True if range end uses ==, >= or <= */
+    int start_constraints;       /* Start of range is constrained */
+    int nConstraint;             /* Number of constraint terms */
+    int iIdxCur;                 /* The VDBE cursor for the index */
+    int nExtraReg = 0;           /* Number of extra registers needed */
+    int op;                      /* Instruction opcode */
+    char *zStartAff;             /* Affinity for start of range constraint */
+    char *zEndAff = 0;           /* Affinity for end of range constraint */
+    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
+    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */
 
-/*
-** The input to this routine is an WhereTerm structure with only the
-** "pExpr" field filled in.  The job of this routine is to analyze the
-** subexpression and populate all the other fields of the WhereTerm
-** structure.
-**
-** If the expression is of the form "  X" it gets commuted
-** to the standard form of "X  ".
-**
-** If the expression is of the form "X  Y" where both X and Y are
-** columns, then the original expression is unchanged and a new virtual
-** term of the form "Y  X" is added to the WHERE clause and
-** analyzed separately.  The original term is marked with TERM_COPIED
-** and the new term is marked with TERM_DYNAMIC (because it's pExpr
-** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it
-** is a commuted copy of a prior term.)  The original term has nChild=1
-** and the copy has idxParent set to the index of the original term.
-*/
-static void exprAnalyze(
-  SrcList *pSrc,            /* the FROM clause */
-  WhereClause *pWC,         /* the WHERE clause */
-  int idxTerm               /* Index of the term to be analyzed */
-){
-  WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
-  WhereTerm *pTerm;                /* The term to be analyzed */
-  WhereMaskSet *pMaskSet;          /* Set of table index masks */
-  Expr *pExpr;                     /* The expression to be analyzed */
-  Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */
-  Bitmask prereqAll;               /* Prerequesites of pExpr */
-  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
-  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
-  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
-  int noCase = 0;                  /* LIKE/GLOB distinguishes case */
-  int op;                          /* Top-level operator.  pExpr->op */
-  Parse *pParse = pWInfo->pParse;  /* Parsing context */
-  sqlite3 *db = pParse->db;        /* Database connection */
+    pIdx = pLoop->u.btree.pIndex;
+    iIdxCur = pLevel->iIdxCur;
+    assert( nEq>=pLoop->nSkip );
 
-  if( db->mallocFailed ){
-    return;
-  }
-  pTerm = &pWC->a[idxTerm];
-  pMaskSet = &pWInfo->sMaskSet;
-  pExpr = pTerm->pExpr;
-  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
-  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
-  op = pExpr->op;
-  if( op==TK_IN ){
-    assert( pExpr->pRight==0 );
-    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      pTerm->prereqRight = exprSelectTableUsage(pMaskSet, pExpr->x.pSelect);
-    }else{
-      pTerm->prereqRight = exprListTableUsage(pMaskSet, pExpr->x.pList);
+    /* If this loop satisfies a sort order (pOrderBy) request that 
+    ** was passed to this function to implement a "SELECT min(x) ..." 
+    ** query, then the caller will only allow the loop to run for
+    ** a single iteration. This means that the first row returned
+    ** should not have a NULL value stored in 'x'. If column 'x' is
+    ** the first one after the nEq equality constraints in the index,
+    ** this requires some special handling.
+    */
+    assert( pWInfo->pOrderBy==0
+         || pWInfo->pOrderBy->nExpr==1
+         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
+    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+     && pWInfo->nOBSat>0
+     && (pIdx->nKeyCol>nEq)
+    ){
+      assert( pLoop->nSkip==0 );
+      bSeekPastNull = 1;
+      nExtraReg = 1;
     }
-  }else if( op==TK_ISNULL ){
-    pTerm->prereqRight = 0;
-  }else{
-    pTerm->prereqRight = exprTableUsage(pMaskSet, pExpr->pRight);
-  }
-  prereqAll = exprTableUsage(pMaskSet, pExpr);
-  if( ExprHasProperty(pExpr, EP_FromJoin) ){
-    Bitmask x = getMask(pMaskSet, pExpr->iRightJoinTable);
-    prereqAll |= x;
-    extraRight = x-1;  /* ON clause terms may not be used with an index
-                       ** on left table of a LEFT JOIN.  Ticket #3015 */
-  }
-  pTerm->prereqAll = prereqAll;
-  pTerm->leftCursor = -1;
-  pTerm->iParent = -1;
-  pTerm->eOperator = 0;
-  if( allowedOp(op) ){
-    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
-    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
-    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
-    if( pLeft->op==TK_COLUMN ){
-      pTerm->leftCursor = pLeft->iTable;
-      pTerm->u.leftColumn = pLeft->iColumn;
-      pTerm->eOperator = operatorMask(op) & opMask;
+
+    /* Find any inequality constraint terms for the start and end 
+    ** of the range. 
+    */
+    j = nEq;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+      pRangeStart = pLoop->aLTerm[j++];
+      nExtraReg = MAX(nExtraReg, pLoop->u.btree.nBtm);
+      /* Like optimization range constraints always occur in pairs */
+      assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 
+              (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
     }
-    if( pRight && pRight->op==TK_COLUMN ){
-      WhereTerm *pNew;
-      Expr *pDup;
-      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
-      if( pTerm->leftCursor>=0 ){
-        int idxNew;
-        pDup = sqlite3ExprDup(db, pExpr, 0);
-        if( db->mallocFailed ){
-          sqlite3ExprDelete(db, pDup);
-          return;
-        }
-        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
-        if( idxNew==0 ) return;
-        pNew = &pWC->a[idxNew];
-        markTermAsChild(pWC, idxNew, idxTerm);
-        pTerm = &pWC->a[idxTerm];
-        pTerm->wtFlags |= TERM_COPIED;
-        if( pExpr->op==TK_EQ
-         && !ExprHasProperty(pExpr, EP_FromJoin)
-         && OptimizationEnabled(db, SQLITE_Transitive)
-        ){
-          pTerm->eOperator |= WO_EQUIV;
-          eExtraOp = WO_EQUIV;
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+      pRangeEnd = pLoop->aLTerm[j++];
+      nExtraReg = MAX(nExtraReg, pLoop->u.btree.nTop);
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
+        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
+        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
+        pLevel->iLikeRepCntr = (u32)++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
+        VdbeComment((v, "LIKE loop counter"));
+        pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
+        /* iLikeRepCntr actually stores 2x the counter register number.  The
+        ** bottom bit indicates whether the search order is ASC or DESC. */
+        testcase( bRev );
+        testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
+        assert( (bRev & ~1)==0 );
+        pLevel->iLikeRepCntr <<=1;
+        pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);
+      }
+#endif
+      if( pRangeStart==0 ){
+        j = pIdx->aiColumn[nEq];
+        if( (j>=0 && pIdx->pTable->aCol[j].notNull==0) || j==XN_EXPR ){
+          bSeekPastNull = 1;
         }
-      }else{
-        pDup = pExpr;
-        pNew = pTerm;
       }
-      exprCommute(pParse, pDup);
-      pLeft = sqlite3ExprSkipCollate(pDup->pLeft);
-      pNew->leftCursor = pLeft->iTable;
-      pNew->u.leftColumn = pLeft->iColumn;
-      testcase( (prereqLeft | extraRight) != prereqLeft );
-      pNew->prereqRight = prereqLeft | extraRight;
-      pNew->prereqAll = prereqAll;
-      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
     }
-  }
+    assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
 
-#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
-  /* If a term is the BETWEEN operator, create two new virtual terms
-  ** that define the range that the BETWEEN implements.  For example:
-  **
-  **      a BETWEEN b AND c
-  **
-  ** is converted into:
-  **
-  **      (a BETWEEN b AND c) AND (a>=b) AND (a<=c)
-  **
-  ** The two new terms are added onto the end of the WhereClause object.
-  ** The new terms are "dynamic" and are children of the original BETWEEN
-  ** term.  That means that if the BETWEEN term is coded, the children are
-  ** skipped.  Or, if the children are satisfied by an index, the original
-  ** BETWEEN term is skipped.
-  */
-  else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){
-    ExprList *pList = pExpr->x.pList;
-    int i;
-    static const u8 ops[] = {TK_GE, TK_LE};
-    assert( pList!=0 );
-    assert( pList->nExpr==2 );
-    for(i=0; i<2; i++){
-      Expr *pNewExpr;
-      int idxNew;
-      pNewExpr = sqlite3PExpr(pParse, ops[i], 
-                             sqlite3ExprDup(db, pExpr->pLeft, 0),
-                             sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
-      transferJoinMarkings(pNewExpr, pExpr);
-      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
-      testcase( idxNew==0 );
-      exprAnalyze(pSrc, pWC, idxNew);
-      pTerm = &pWC->a[idxTerm];
-      markTermAsChild(pWC, idxNew, idxTerm);
+    /* If we are doing a reverse order scan on an ascending index, or
+    ** a forward order scan on a descending index, interchange the 
+    ** start and end terms (pRangeStart and pRangeEnd).
+    */
+    if( (nEqnKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
+     || (bRev && pIdx->nKeyCol==nEq)
+    ){
+      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+      SWAP(u8, bSeekPastNull, bStopAtNull);
+      SWAP(u8, nBtm, nTop);
     }
-  }
-#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
 
-#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
-  /* Analyze a term that is composed of two or more subterms connected by
-  ** an OR operator.
-  */
-  else if( pExpr->op==TK_OR ){
-    assert( pWC->op==TK_AND );
-    exprAnalyzeOrTerm(pSrc, pWC, idxTerm);
-    pTerm = &pWC->a[idxTerm];
-  }
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+    /* Generate code to evaluate all constraint terms using == or IN
+    ** and store the values of those terms in an array of registers
+    ** starting at regBase.
+    */
+    codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
+    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
+    assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
+    if( zStartAff && nTop ){
+      zEndAff = sqlite3DbStrDup(db, &zStartAff[nEq]);
+    }
+    addrNxt = pLevel->addrNxt;
 
-#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
-  /* Add constraints to reduce the search space on a LIKE or GLOB
-  ** operator.
-  **
-  ** A like pattern of the form "x LIKE 'abc%'" is changed into constraints
-  **
-  **          x>='abc' AND x<'abd' AND x LIKE 'abc%'
-  **
-  ** The last character of the prefix "abc" is incremented to form the
-  ** termination condition "abd".
-  */
-  if( pWC->op==TK_AND 
-   && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
-  ){
-    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
-    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
-    Expr *pNewExpr1;
-    Expr *pNewExpr2;
-    int idxNew1;
-    int idxNew2;
-    Token sCollSeqName;  /* Name of collating sequence */
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
+    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+    start_constraints = pRangeStart || nEq>0;
 
-    pLeft = pExpr->x.pList->a[1].pExpr;
-    pStr2 = sqlite3ExprDup(db, pStr1, 0);
-    if( !db->mallocFailed ){
-      u8 c, *pC;       /* Last character before the first wildcard */
-      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
-      c = *pC;
-      if( noCase ){
-        /* The point is to increment the last character before the first
-        ** wildcard.  But if we increment '@', that will push it into the
-        ** alphabetic range where case conversions will mess up the 
-        ** inequality.  To avoid this, make sure to also run the full
-        ** LIKE on all candidate expressions by clearing the isComplete flag
-        */
-        if( c=='A'-1 ) isComplete = 0;
-        c = sqlite3UpperToLower[c];
+    /* Seek the index cursor to the start of the range. */
+    nConstraint = nEq;
+    if( pRangeStart ){
+      Expr *pRight = pRangeStart->pExpr->pRight;
+      codeExprOrVector(pParse, pRight, regBase+nEq, nBtm);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
+      if( (pRangeStart->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
       }
-      *pC = c + 1;
+      if( zStartAff ){
+        updateRangeAffinityStr(pRight, nBtm, &zStartAff[nEq]);
+      }  
+      nConstraint += nBtm;
+      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
+      if( sqlite3ExprIsVector(pRight)==0 ){
+        disableTerm(pLevel, pRangeStart);
+      }else{
+        startEq = 1;
+      }
+      bSeekPastNull = 0;
+    }else if( bSeekPastNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      nConstraint++;
+      startEq = 0;
+      start_constraints = 1;
     }
-    sCollSeqName.z = noCase ? "NOCASE" : "BINARY";
-    sCollSeqName.n = 6;
-    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
-    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 
-           sqlite3ExprAddCollateToken(pParse,pNewExpr1,&sCollSeqName),
-           pStr1, 0);
-    transferJoinMarkings(pNewExpr1, pExpr);
-    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
-    testcase( idxNew1==0 );
-    exprAnalyze(pSrc, pWC, idxNew1);
-    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
-    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
-           sqlite3ExprAddCollateToken(pParse,pNewExpr2,&sCollSeqName),
-           pStr2, 0);
-    transferJoinMarkings(pNewExpr2, pExpr);
-    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
-    testcase( idxNew2==0 );
-    exprAnalyze(pSrc, pWC, idxNew2);
-    pTerm = &pWC->a[idxTerm];
-    if( isComplete ){
-      markTermAsChild(pWC, idxNew1, idxTerm);
-      markTermAsChild(pWC, idxNew2, idxTerm);
+    codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
+    if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){
+      /* The skip-scan logic inside the call to codeAllEqualityConstraints()
+      ** above has already left the cursor sitting on the correct row,
+      ** so no further seeking is needed */
+    }else{
+      op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+      assert( op!=0 );
+      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+      VdbeCoverage(v);
+      VdbeCoverageIf(v, op==OP_Rewind);  testcase( op==OP_Rewind );
+      VdbeCoverageIf(v, op==OP_Last);    testcase( op==OP_Last );
+      VdbeCoverageIf(v, op==OP_SeekGT);  testcase( op==OP_SeekGT );
+      VdbeCoverageIf(v, op==OP_SeekGE);  testcase( op==OP_SeekGE );
+      VdbeCoverageIf(v, op==OP_SeekLE);  testcase( op==OP_SeekLE );
+      VdbeCoverageIf(v, op==OP_SeekLT);  testcase( op==OP_SeekLT );
     }
-  }
-#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  /* Add a WO_MATCH auxiliary term to the constraint set if the
-  ** current expression is of the form:  column MATCH expr.
-  ** This information is used by the xBestIndex methods of
-  ** virtual tables.  The native query optimizer does not attempt
-  ** to do anything with MATCH functions.
-  */
-  if( isMatchOfColumn(pExpr) ){
-    int idxNew;
-    Expr *pRight, *pLeft;
-    WhereTerm *pNewTerm;
-    Bitmask prereqColumn, prereqExpr;
+    /* Load the value for the inequality constraint at the end of the
+    ** range (if any).
+    */
+    nConstraint = nEq;
+    if( pRangeEnd ){
+      Expr *pRight = pRangeEnd->pExpr->pRight;
+      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
+      codeExprOrVector(pParse, pRight, regBase+nEq, nTop);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
+      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
+      }
+      if( zEndAff ){
+        updateRangeAffinityStr(pRight, nTop, zEndAff);
+        codeApplyAffinity(pParse, regBase+nEq, nTop, zEndAff);
+      }else{
+        assert( pParse->db->mallocFailed );
+      }
+      nConstraint += nTop;
+      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
 
-    pRight = pExpr->x.pList->a[0].pExpr;
-    pLeft = pExpr->x.pList->a[1].pExpr;
-    prereqExpr = exprTableUsage(pMaskSet, pRight);
-    prereqColumn = exprTableUsage(pMaskSet, pLeft);
-    if( (prereqExpr & prereqColumn)==0 ){
-      Expr *pNewExpr;
-      pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 
-                              0, sqlite3ExprDup(db, pRight, 0), 0);
-      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
-      testcase( idxNew==0 );
-      pNewTerm = &pWC->a[idxNew];
-      pNewTerm->prereqRight = prereqExpr;
-      pNewTerm->leftCursor = pLeft->iTable;
-      pNewTerm->u.leftColumn = pLeft->iColumn;
-      pNewTerm->eOperator = WO_MATCH;
-      markTermAsChild(pWC, idxNew, idxTerm);
-      pTerm = &pWC->a[idxTerm];
-      pTerm->wtFlags |= TERM_COPIED;
-      pNewTerm->prereqAll = pTerm->prereqAll;
+      if( sqlite3ExprIsVector(pRight)==0 ){
+        disableTerm(pLevel, pRangeEnd);
+      }else{
+        endEq = 1;
+      }
+    }else if( bStopAtNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      endEq = 0;
+      nConstraint++;
     }
-  }
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
+    sqlite3DbFree(db, zStartAff);
+    sqlite3DbFree(db, zEndAff);
 
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-  /* When sqlite_stat3 histogram data is available an operator of the
-  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
-  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
-  ** virtual term of that form.
-  **
-  ** Note that the virtual term must be tagged with TERM_VNULL.  This
-  ** TERM_VNULL tag will suppress the not-null check at the beginning
-  ** of the loop.  Without the TERM_VNULL flag, the not-null check at
-  ** the start of the loop will prevent any results from being returned.
-  */
-  if( pExpr->op==TK_NOTNULL
-   && pExpr->pLeft->op==TK_COLUMN
-   && pExpr->pLeft->iColumn>=0
-   && OptimizationEnabled(db, SQLITE_Stat34)
-  ){
-    Expr *pNewExpr;
-    Expr *pLeft = pExpr->pLeft;
-    int idxNew;
-    WhereTerm *pNewTerm;
+    /* Top of the loop body */
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
 
-    pNewExpr = sqlite3PExpr(pParse, TK_GT,
-                            sqlite3ExprDup(db, pLeft, 0),
-                            sqlite3PExpr(pParse, TK_NULL, 0, 0, 0), 0);
+    /* Check if the index cursor is past the end of the range. */
+    if( nConstraint ){
+      op = aEndOp[bRev*2 + endEq];
+      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+      testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );
+      testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
+      testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
+      testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
+    }
 
-    idxNew = whereClauseInsert(pWC, pNewExpr,
-                              TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
-    if( idxNew ){
-      pNewTerm = &pWC->a[idxNew];
-      pNewTerm->prereqRight = 0;
-      pNewTerm->leftCursor = pLeft->iTable;
-      pNewTerm->u.leftColumn = pLeft->iColumn;
-      pNewTerm->eOperator = WO_GT;
-      markTermAsChild(pWC, idxNew, idxTerm);
-      pTerm = &pWC->a[idxTerm];
-      pTerm->wtFlags |= TERM_COPIED;
-      pNewTerm->prereqAll = pTerm->prereqAll;
+    /* Seek the table cursor, if required */
+    if( omitTable ){
+      /* pIdx is a covering index.  No need to access the main table. */
+    }else if( HasRowid(pIdx->pTable) ){
+      if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE) || (
+          (pWInfo->wctrlFlags & WHERE_SEEK_UNIQ_TABLE) 
+       && (pWInfo->eOnePass==ONEPASS_SINGLE)
+      )){
+        iRowidReg = ++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
+        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
+        VdbeCoverage(v);
+      }else{
+        codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);
+      }
+    }else if( iCur!=iIdxCur ){
+      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
+      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
+      for(j=0; jnKeyCol; j++){
+        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
+      }
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
+                           iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
     }
-  }
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
-  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
-  ** an index for tables to the left of the join.
-  */
-  pTerm->prereqRight |= extraRight;
-}
+    /* If pIdx is an index on one or more expressions, then look through
+    ** all the expressions in pWInfo and try to transform matching expressions
+    ** into reference to index columns.
+    */
+    whereIndexExprTrans(pIdx, iCur, iIdxCur, pWInfo);
 
-/*
-** This function searches pList for an entry that matches the iCol-th column
-** of index pIdx.
-**
-** If such an expression is found, its index in pList->a[] is returned. If
-** no expression is found, -1 is returned.
-*/
-static int findIndexCol(
-  Parse *pParse,                  /* Parse context */
-  ExprList *pList,                /* Expression list to search */
-  int iBase,                      /* Cursor for table associated with pIdx */
-  Index *pIdx,                    /* Index to match column of */
-  int iCol                        /* Column of index to match */
-){
-  int i;
-  const char *zColl = pIdx->azColl[iCol];
 
-  for(i=0; inExpr; i++){
-    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
-    if( p->op==TK_COLUMN
-     && p->iColumn==pIdx->aiColumn[iCol]
-     && p->iTable==iBase
-    ){
-      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
-      if( ALWAYS(pColl) && 0==sqlite3StrICmp(pColl->zName, zColl) ){
-        return i;
+    /* Record the instruction used to terminate the loop. */
+    if( pLoop->wsFlags & WHERE_ONEROW ){
+      pLevel->op = OP_Noop;
+    }else if( bRev ){
+      pLevel->op = OP_Prev;
+    }else{
+      pLevel->op = OP_Next;
+    }
+    pLevel->p1 = iIdxCur;
+    pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
+    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }else{
+      assert( pLevel->p5==0 );
+    }
+    if( omitTable ) pIdx = 0;
+  }else
+
+#ifndef SQLITE_OMIT_OR_OPTIMIZATION
+  if( pLoop->wsFlags & WHERE_MULTI_OR ){
+    /* Case 5:  Two or more separately indexed terms connected by OR
+    **
+    ** Example:
+    **
+    **   CREATE TABLE t1(a,b,c,d);
+    **   CREATE INDEX i1 ON t1(a);
+    **   CREATE INDEX i2 ON t1(b);
+    **   CREATE INDEX i3 ON t1(c);
+    **
+    **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
+    **
+    ** In the example, there are three indexed terms connected by OR.
+    ** The top of the loop looks like this:
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **
+    ** Then, for each indexed term, the following. The arguments to
+    ** RowSetTest are such that the rowid of the current row is inserted
+    ** into the RowSet. If it is already present, control skips the
+    ** Gosub opcode and jumps straight to the code generated by WhereEnd().
+    **
+    **        sqlite3WhereBegin()
+    **          RowSetTest                  # Insert rowid into rowset
+    **          Gosub      2 A
+    **        sqlite3WhereEnd()
+    **
+    ** Following the above, code to terminate the loop. Label A, the target
+    ** of the Gosub above, jumps to the instruction right after the Goto.
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **          Goto       B                # The loop is finished.
+    **
+    **       A:                  # Return data, whatever.
+    **
+    **          Return     2                # Jump back to the Gosub
+    **
+    **       B: 
+    **
+    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
+    ** use an ephemeral index instead of a RowSet to record the primary
+    ** keys of the rows we have already seen.
+    **
+    */
+    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
+    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
+    Index *pCov = 0;             /* Potential covering index (or NULL) */
+    int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */
+
+    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
+    int regRowset = 0;                        /* Register for RowSet object */
+    int regRowid = 0;                         /* Register holding rowid */
+    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
+    int iRetInit;                             /* Address of regReturn init */
+    int untestedTerms = 0;             /* Some terms not completely tested */
+    int ii;                            /* Loop counter */
+    u16 wctrlFlags;                    /* Flags for sub-WHERE clause */
+    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
+    Table *pTab = pTabItem->pTab;
+
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->eOperator & WO_OR );
+    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
+    pOrWc = &pTerm->u.pOrInfo->wc;
+    pLevel->op = OP_Return;
+    pLevel->p1 = regReturn;
+
+    /* Set up a new SrcList in pOrTab containing the table being scanned
+    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
+    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
+    */
+    if( pWInfo->nLevel>1 ){
+      int nNotReady;                 /* The number of notReady tables */
+      struct SrcList_item *origSrc;     /* Original list of tables */
+      nNotReady = pWInfo->nLevel - iLevel - 1;
+      pOrTab = sqlite3StackAllocRaw(db,
+                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
+      if( pOrTab==0 ) return notReady;
+      pOrTab->nAlloc = (u8)(nNotReady + 1);
+      pOrTab->nSrc = pOrTab->nAlloc;
+      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
+      origSrc = pWInfo->pTabList->a;
+      for(k=1; k<=nNotReady; k++){
+        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
       }
+    }else{
+      pOrTab = pWInfo->pTabList;
     }
-  }
 
-  return -1;
-}
+    /* Initialize the rowset register to contain NULL. An SQL NULL is 
+    ** equivalent to an empty rowset.  Or, create an ephemeral index
+    ** capable of holding primary keys in the case of a WITHOUT ROWID.
+    **
+    ** Also initialize regReturn to contain the address of the instruction 
+    ** immediately following the OP_Return at the bottom of the loop. This
+    ** is required in a few obscure LEFT JOIN cases where control jumps
+    ** over the top of the loop into the body of it. In this case the 
+    ** correct response for the end-of-loop code (the OP_Return) is to 
+    ** fall through to the next instruction, just as an OP_Next does if
+    ** called on an uninitialized cursor.
+    */
+    if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+      if( HasRowid(pTab) ){
+        regRowset = ++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
+      }else{
+        Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+        regRowset = pParse->nTab++;
+        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
+        sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+      }
+      regRowid = ++pParse->nMem;
+    }
+    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
 
-/*
-** Return true if the DISTINCT expression-list passed as the third argument
-** is redundant.
-**
-** A DISTINCT list is redundant if the database contains some subset of
-** columns that are unique and non-null.
-*/
-static int isDistinctRedundant(
-  Parse *pParse,            /* Parsing context */
-  SrcList *pTabList,        /* The FROM clause */
-  WhereClause *pWC,         /* The WHERE clause */
-  ExprList *pDistinct       /* The result set that needs to be DISTINCT */
-){
-  Table *pTab;
-  Index *pIdx;
-  int i;                          
-  int iBase;
+    /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y
+    ** Then for every term xN, evaluate as the subexpression: xN AND z
+    ** That way, terms in y that are factored into the disjunction will
+    ** be picked up by the recursive calls to sqlite3WhereBegin() below.
+    **
+    ** Actually, each subexpression is converted to "xN AND w" where w is
+    ** the "interesting" terms of z - terms that did not originate in the
+    ** ON or USING clause of a LEFT JOIN, and terms that are usable as 
+    ** indices.
+    **
+    ** This optimization also only applies if the (x1 OR x2 OR ...) term
+    ** is not contained in the ON clause of a LEFT JOIN.
+    ** See ticket http://www.sqlite.org/src/info/f2369304e4
+    */
+    if( pWC->nTerm>1 ){
+      int iTerm;
+      for(iTerm=0; iTermnTerm; iTerm++){
+        Expr *pExpr = pWC->a[iTerm].pExpr;
+        if( &pWC->a[iTerm] == pTerm ) continue;
+        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
+        testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
+        testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
+        if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
+        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
+        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
+        pExpr = sqlite3ExprDup(db, pExpr, 0);
+        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
+      }
+      if( pAndExpr ){
+        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr);
+      }
+    }
 
-  /* If there is more than one table or sub-select in the FROM clause of
-  ** this query, then it will not be possible to show that the DISTINCT 
-  ** clause is redundant. */
-  if( pTabList->nSrc!=1 ) return 0;
-  iBase = pTabList->a[0].iCursor;
-  pTab = pTabList->a[0].pTab;
+    /* Run a separate WHERE clause for each term of the OR clause.  After
+    ** eliminating duplicates from other WHERE clauses, the action for each
+    ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
+    */
+    wctrlFlags =  WHERE_OR_SUBCLAUSE | (pWInfo->wctrlFlags & WHERE_SEEK_TABLE);
+    for(ii=0; iinTerm; ii++){
+      WhereTerm *pOrTerm = &pOrWc->a[ii];
+      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
+        WhereInfo *pSubWInfo;           /* Info for single OR-term scan */
+        Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
+        int jmp1 = 0;                   /* Address of jump operation */
+        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
+          pAndExpr->pLeft = pOrExpr;
+          pOrExpr = pAndExpr;
+        }
+        /* Loop through table entries that match term pOrTerm. */
+        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
+        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
+                                      wctrlFlags, iCovCur);
+        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
+        if( pSubWInfo ){
+          WhereLoop *pSubLoop;
+          int addrExplain = sqlite3WhereExplainOneScan(
+              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
+          );
+          sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
 
-  /* If any of the expressions is an IPK column on table iBase, then return 
-  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
-  ** current SELECT is a correlated sub-query.
-  */
-  for(i=0; inExpr; i++){
-    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
-    if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
+          /* This is the sub-WHERE clause body.  First skip over
+          ** duplicate rows from prior sub-WHERE clauses, and record the
+          ** rowid (or PRIMARY KEY) for the current row so that the same
+          ** row will be skipped in subsequent sub-WHERE clauses.
+          */
+          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+            int r;
+            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
+            if( HasRowid(pTab) ){
+              r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
+              jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,
+                                           r,iSet);
+              VdbeCoverage(v);
+            }else{
+              Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+              int nPk = pPk->nKeyCol;
+              int iPk;
+
+              /* Read the PK into an array of temp registers. */
+              r = sqlite3GetTempRange(pParse, nPk);
+              for(iPk=0; iPkaiColumn[iPk];
+                sqlite3ExprCodeGetColumnToReg(pParse, pTab, iCol, iCur, r+iPk);
+              }
+
+              /* Check if the temp table already contains this key. If so,
+              ** the row has already been included in the result set and
+              ** can be ignored (by jumping past the Gosub below). Otherwise,
+              ** insert the key into the temp table and proceed with processing
+              ** the row.
+              **
+              ** Use some of the same optimizations as OP_RowSetTest: If iSet
+              ** is zero, assume that the key cannot already be present in
+              ** the temp table. And if iSet is -1, assume that there is no 
+              ** need to insert the key into the temp table, as it will never 
+              ** be tested for.  */ 
+              if( iSet ){
+                jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
+                VdbeCoverage(v);
+              }
+              if( iSet>=0 ){
+                sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
+                sqlite3VdbeAddOp4Int(v, OP_IdxInsert, regRowset, regRowid,
+                                     r, nPk);
+                if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+              }
+
+              /* Release the array of temp registers */
+              sqlite3ReleaseTempRange(pParse, r, nPk);
+            }
+          }
+
+          /* Invoke the main loop body as a subroutine */
+          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+
+          /* Jump here (skipping the main loop body subroutine) if the
+          ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
+          if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);
+
+          /* The pSubWInfo->untestedTerms flag means that this OR term
+          ** contained one or more AND term from a notReady table.  The
+          ** terms from the notReady table could not be tested and will
+          ** need to be tested later.
+          */
+          if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+
+          /* If all of the OR-connected terms are optimized using the same
+          ** index, and the index is opened using the same cursor number
+          ** by each call to sqlite3WhereBegin() made by this loop, it may
+          ** be possible to use that index as a covering index.
+          **
+          ** If the call to sqlite3WhereBegin() above resulted in a scan that
+          ** uses an index, and this is either the first OR-connected term
+          ** processed or the index is the same as that used by all previous
+          ** terms, set pCov to the candidate covering index. Otherwise, set 
+          ** pCov to NULL to indicate that no candidate covering index will 
+          ** be available.
+          */
+          pSubLoop = pSubWInfo->a[0].pWLoop;
+          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
+           && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
+          ){
+            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+            pCov = pSubLoop->u.btree.pIndex;
+          }else{
+            pCov = 0;
+          }
+
+          /* Finish the loop through table entries that match term pOrTerm. */
+          sqlite3WhereEnd(pSubWInfo);
+        }
+      }
+    }
+    pLevel->u.pCovidx = pCov;
+    if( pCov ) pLevel->iIdxCur = iCovCur;
+    if( pAndExpr ){
+      pAndExpr->pLeft = 0;
+      sqlite3ExprDelete(db, pAndExpr);
+    }
+    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
+    sqlite3VdbeGoto(v, pLevel->addrBrk);
+    sqlite3VdbeResolveLabel(v, iLoopBody);
+
+    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
+    if( !untestedTerms ) disableTerm(pLevel, pTerm);
+  }else
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+  {
+    /* Case 6:  There is no usable index.  We must do a complete
+    **          scan of the entire table.
+    */
+    static const u8 aStep[] = { OP_Next, OP_Prev };
+    static const u8 aStart[] = { OP_Rewind, OP_Last };
+    assert( bRev==0 || bRev==1 );
+    if( pTabItem->fg.isRecursive ){
+      /* Tables marked isRecursive have only a single row that is stored in
+      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
+      pLevel->op = OP_Noop;
+    }else{
+      codeCursorHint(pTabItem, pWInfo, pLevel, 0);
+      pLevel->op = aStep[bRev];
+      pLevel->p1 = iCur;
+      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrHalt);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }
   }
 
-  /* Loop through all indices on the table, checking each to see if it makes
-  ** the DISTINCT qualifier redundant. It does so if:
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
+#endif
+
+  /* Insert code to test every subexpression that can be completely
+  ** computed using the current set of tables.
   **
-  **   1. The index is itself UNIQUE, and
+  ** This loop may run between one and three times, depending on the
+  ** constraints to be generated. The value of stack variable iLoop
+  ** determines the constraints coded by each iteration, as follows:
   **
-  **   2. All of the columns in the index are either part of the pDistinct
-  **      list, or else the WHERE clause contains a term of the form "col=X",
-  **      where X is a constant value. The collation sequences of the
-  **      comparison and select-list expressions must match those of the index.
+  ** iLoop==1: Code only expressions that are entirely covered by pIdx.
+  ** iLoop==2: Code remaining expressions that do not contain correlated
+  **           sub-queries.  
+  ** iLoop==3: Code all remaining expressions.
   **
-  **   3. All of those index columns for which the WHERE clause does not
-  **      contain a "col=X" term are subject to a NOT NULL constraint.
+  ** An effort is made to skip unnecessary iterations of the loop.
   */
-  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-    if( !IsUniqueIndex(pIdx) ) continue;
-    for(i=0; inKeyCol; i++){
-      i16 iCol = pIdx->aiColumn[i];
-      if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){
-        int iIdxCol = findIndexCol(pParse, pDistinct, iBase, pIdx, i);
-        if( iIdxCol<0 || pTab->aCol[iCol].notNull==0 ){
-          break;
-        }
+  iLoop = (pIdx ? 1 : 2);
+  do{
+    int iNext = 0;                /* Next value for iLoop */
+    for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+      Expr *pE;
+      int skipLikeAddr = 0;
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
+      testcase( pTerm->wtFlags & TERM_CODED );
+      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+        testcase( pWInfo->untestedTerms==0
+            && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
+        pWInfo->untestedTerms = 1;
+        continue;
+      }
+      pE = pTerm->pExpr;
+      assert( pE!=0 );
+      if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+        continue;
+      }
+      
+      if( iLoop==1 && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
+        iNext = 2;
+        continue;
+      }
+      if( iLoop<3 && (pTerm->wtFlags & TERM_VARSELECT) ){
+        if( iNext==0 ) iNext = 3;
+        continue;
       }
+
+      if( pTerm->wtFlags & TERM_LIKECOND ){
+        /* If the TERM_LIKECOND flag is set, that means that the range search
+        ** is sufficient to guarantee that the LIKE operator is true, so we
+        ** can skip the call to the like(A,B) function.  But this only works
+        ** for strings.  So do not skip the call to the function on the pass
+        ** that compares BLOBs. */
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+        continue;
+#else
+        u32 x = pLevel->iLikeRepCntr;
+        assert( x>0 );
+        skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If, (int)(x>>1));
+        VdbeCoverage(v);
+#endif
+      }
+#ifdef WHERETRACE_ENABLED /* 0xffff */
+      if( sqlite3WhereTrace ){
+        VdbeNoopComment((v, "WhereTerm[%d] (%p) priority=%d",
+                         pWC->nTerm-j, pTerm, iLoop));
+      }
+#endif
+      sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+      if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
+      pTerm->wtFlags |= TERM_CODED;
     }
-    if( i==pIdx->nKeyCol ){
-      /* This index implies that the DISTINCT qualifier is redundant. */
-      return 1;
+    iLoop = iNext;
+  }while( iLoop>0 );
+
+  /* Insert code to test for implied constraints based on transitivity
+  ** of the "==" operator.
+  **
+  ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
+  ** and we are coding the t1 loop and the t2 loop has not yet coded,
+  ** then we cannot use the "t1.a=t2.b" constraint, but we can code
+  ** the implied "t1.a=123" constraint.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE, sEAlt;
+    WhereTerm *pAlt;
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
+    if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
+    if( pTerm->leftCursor!=iCur ) continue;
+    if( pLevel->iLeftJoin ) continue;
+    pE = pTerm->pExpr;
+    assert( !ExprHasProperty(pE, EP_FromJoin) );
+    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
+    pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
+                    WO_EQ|WO_IN|WO_IS, 0);
+    if( pAlt==0 ) continue;
+    if( pAlt->wtFlags & (TERM_CODED) ) continue;
+    testcase( pAlt->eOperator & WO_EQ );
+    testcase( pAlt->eOperator & WO_IS );
+    testcase( pAlt->eOperator & WO_IN );
+    VdbeModuleComment((v, "begin transitive constraint"));
+    sEAlt = *pAlt->pExpr;
+    sEAlt.pLeft = pE->pLeft;
+    sqlite3ExprIfFalse(pParse, &sEAlt, addrCont, SQLITE_JUMPIFNULL);
+  }
+
+  /* For a LEFT OUTER JOIN, generate code that will record the fact that
+  ** at least one row of the right table has matched the left table.  
+  */
+  if( pLevel->iLeftJoin ){
+    pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+    VdbeComment((v, "record LEFT JOIN hit"));
+    sqlite3ExprCacheClear(pParse);
+    for(pTerm=pWC->a, j=0; jnTerm; j++, pTerm++){
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
+      testcase( pTerm->wtFlags & TERM_CODED );
+      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+        assert( pWInfo->untestedTerms );
+        continue;
+      }
+      assert( pTerm->pExpr );
+      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
+      pTerm->wtFlags |= TERM_CODED;
     }
   }
 
-  return 0;
+  return pLevel->notReady;
 }
 
+/************** End of wherecode.c *******************************************/
+/************** Begin file whereexpr.c ***************************************/
+/*
+** 2015-06-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.
+**
+** This file was originally part of where.c but was split out to improve
+** readability and editabiliity.  This file contains utility routines for
+** analyzing Expr objects in the WHERE clause.
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declarations */
+static void exprAnalyze(SrcList*, WhereClause*, int);
 
 /*
-** Estimate the logarithm of the input value to base 2.
+** Deallocate all memory associated with a WhereOrInfo object.
 */
-static LogEst estLog(LogEst N){
-  return N<=10 ? 0 : sqlite3LogEst(N) - 33;
+static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
 }
 
 /*
-** Two routines for printing the content of an sqlite3_index_info
-** structure.  Used for testing and debugging only.  If neither
-** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
-** are no-ops.
+** Deallocate all memory associated with a WhereAndInfo object.
 */
-#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
-static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
-  int i;
-  if( !sqlite3WhereTrace ) return;
-  for(i=0; inConstraint; i++){
-    sqlite3DebugPrintf("  constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
-       i,
-       p->aConstraint[i].iColumn,
-       p->aConstraint[i].iTermOffset,
-       p->aConstraint[i].op,
-       p->aConstraint[i].usable);
+static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Add a single new WhereTerm entry to the WhereClause object pWC.
+** The new WhereTerm object is constructed from Expr p and with wtFlags.
+** The index in pWC->a[] of the new WhereTerm is returned on success.
+** 0 is returned if the new WhereTerm could not be added due to a memory
+** allocation error.  The memory allocation failure will be recorded in
+** the db->mallocFailed flag so that higher-level functions can detect it.
+**
+** This routine will increase the size of the pWC->a[] array as necessary.
+**
+** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
+** for freeing the expression p is assumed by the WhereClause object pWC.
+** This is true even if this routine fails to allocate a new WhereTerm.
+**
+** WARNING:  This routine might reallocate the space used to store
+** WhereTerms.  All pointers to WhereTerms should be invalidated after
+** calling this routine.  Such pointers may be reinitialized by referencing
+** the pWC->a[] array.
+*/
+static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
+  WhereTerm *pTerm;
+  int idx;
+  testcase( wtFlags & TERM_VIRTUAL );
+  if( pWC->nTerm>=pWC->nSlot ){
+    WhereTerm *pOld = pWC->a;
+    sqlite3 *db = pWC->pWInfo->pParse->db;
+    pWC->a = sqlite3DbMallocRawNN(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
+    if( pWC->a==0 ){
+      if( wtFlags & TERM_DYNAMIC ){
+        sqlite3ExprDelete(db, p);
+      }
+      pWC->a = pOld;
+      return 0;
+    }
+    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
+    if( pOld!=pWC->aStatic ){
+      sqlite3DbFree(db, pOld);
+    }
+    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
   }
-  for(i=0; inOrderBy; i++){
-    sqlite3DebugPrintf("  orderby[%d]: col=%d desc=%d\n",
-       i,
-       p->aOrderBy[i].iColumn,
-       p->aOrderBy[i].desc);
+  pTerm = &pWC->a[idx = pWC->nTerm++];
+  if( p && ExprHasProperty(p, EP_Unlikely) ){
+    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
+  }else{
+    pTerm->truthProb = 1;
   }
+  pTerm->pExpr = sqlite3ExprSkipCollate(p);
+  pTerm->wtFlags = wtFlags;
+  pTerm->pWC = pWC;
+  pTerm->iParent = -1;
+  memset(&pTerm->eOperator, 0,
+         sizeof(WhereTerm) - offsetof(WhereTerm,eOperator));
+  return idx;
 }
-static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
-  int i;
-  if( !sqlite3WhereTrace ) return;
-  for(i=0; inConstraint; i++){
-    sqlite3DebugPrintf("  usage[%d]: argvIdx=%d omit=%d\n",
-       i,
-       p->aConstraintUsage[i].argvIndex,
-       p->aConstraintUsage[i].omit);
+
+/*
+** Return TRUE if the given operator is one of the operators that is
+** allowed for an indexable WHERE clause term.  The allowed operators are
+** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL"
+*/
+static int allowedOp(int op){
+  assert( TK_GT>TK_EQ && TK_GTTK_EQ && TK_LTTK_EQ && TK_LE=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;
+}
+
+/*
+** Commute a comparison operator.  Expressions of the form "X op Y"
+** are converted into "Y op X".
+**
+** If left/right precedence rules come into play when determining the
+** collating sequence, then COLLATE operators are adjusted to ensure
+** that the collating sequence does not change.  For example:
+** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
+** the left hand side of a comparison overrides any collation sequence 
+** attached to the right. For the same reason the EP_Collate flag
+** is not commuted.
+*/
+static void exprCommute(Parse *pParse, Expr *pExpr){
+  u16 expRight = (pExpr->pRight->flags & EP_Collate);
+  u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
+  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
+  if( expRight==expLeft ){
+    /* Either X and Y both have COLLATE operator or neither do */
+    if( expRight ){
+      /* Both X and Y have COLLATE operators.  Make sure X is always
+      ** used by clearing the EP_Collate flag from Y. */
+      pExpr->pRight->flags &= ~EP_Collate;
+    }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){
+      /* Neither X nor Y have COLLATE operators, but X has a non-default
+      ** collating sequence.  So add the EP_Collate marker on X to cause
+      ** it to be searched first. */
+      pExpr->pLeft->flags |= EP_Collate;
+    }
+  }
+  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
+  if( pExpr->op>=TK_GT ){
+    assert( TK_LT==TK_GT+2 );
+    assert( TK_GE==TK_LE+2 );
+    assert( TK_GT>TK_EQ );
+    assert( TK_GTop>=TK_GT && pExpr->op<=TK_GE );
+    pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
   }
-  sqlite3DebugPrintf("  idxNum=%d\n", p->idxNum);
-  sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);
-  sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);
-  sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);
-  sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);
 }
-#else
-#define TRACE_IDX_INPUTS(A)
-#define TRACE_IDX_OUTPUTS(A)
-#endif
 
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
-** Return TRUE if the WHERE clause term pTerm is of a form where it
-** could be used with an index to access pSrc, assuming an appropriate
-** index existed.
+** Translate from TK_xx operator to WO_xx bitmask.
 */
-static int termCanDriveIndex(
-  WhereTerm *pTerm,              /* WHERE clause term to check */
-  struct SrcList_item *pSrc,     /* Table we are trying to access */
-  Bitmask notReady               /* Tables in outer loops of the join */
-){
-  char aff;
-  if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
-  if( (pTerm->eOperator & WO_EQ)==0 ) return 0;
-  if( (pTerm->prereqRight & notReady)!=0 ) return 0;
-  if( pTerm->u.leftColumn<0 ) return 0;
-  aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
-  if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
-  return 1;
+static u16 operatorMask(int op){
+  u16 c;
+  assert( allowedOp(op) );
+  if( op==TK_IN ){
+    c = WO_IN;
+  }else if( op==TK_ISNULL ){
+    c = WO_ISNULL;
+  }else if( op==TK_IS ){
+    c = WO_IS;
+  }else{
+    assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
+    c = (u16)(WO_EQ<<(op-TK_EQ));
+  }
+  assert( op!=TK_ISNULL || c==WO_ISNULL );
+  assert( op!=TK_IN || c==WO_IN );
+  assert( op!=TK_EQ || c==WO_EQ );
+  assert( op!=TK_LT || c==WO_LT );
+  assert( op!=TK_LE || c==WO_LE );
+  assert( op!=TK_GT || c==WO_GT );
+  assert( op!=TK_GE || c==WO_GE );
+  assert( op!=TK_IS || c==WO_IS );
+  return c;
 }
-#endif
 
 
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
 /*
-** Generate code to construct the Index object for an automatic index
-** and to set up the WhereLevel object pLevel so that the code generator
-** makes use of the automatic index.
+** Check to see if the given expression is a LIKE or GLOB operator that
+** can be optimized using inequality constraints.  Return TRUE if it is
+** so and false if not.
+**
+** In order for the operator to be optimizible, the RHS must be a string
+** literal that does not begin with a wildcard.  The LHS must be a column
+** that may only be NULL, a string, or a BLOB, never a number. (This means
+** that virtual tables cannot participate in the LIKE optimization.)  The
+** collating sequence for the column on the LHS must be appropriate for
+** the operator.
 */
-static void constructAutomaticIndex(
-  Parse *pParse,              /* The parsing context */
-  WhereClause *pWC,           /* The WHERE clause */
-  struct SrcList_item *pSrc,  /* The FROM clause term to get the next index */
-  Bitmask notReady,           /* Mask of cursors that are not available */
-  WhereLevel *pLevel          /* Write new index here */
+static int isLikeOrGlob(
+  Parse *pParse,    /* Parsing and code generating context */
+  Expr *pExpr,      /* Test this expression */
+  Expr **ppPrefix,  /* Pointer to TK_STRING expression with pattern prefix */
+  int *pisComplete, /* True if the only wildcard is % in the last character */
+  int *pnoCase      /* True if uppercase is equivalent to lowercase */
 ){
-  int nKeyCol;                /* Number of columns in the constructed index */
-  WhereTerm *pTerm;           /* A single term of the WHERE clause */
-  WhereTerm *pWCEnd;          /* End of pWC->a[] */
-  Index *pIdx;                /* Object describing the transient index */
-  Vdbe *v;                    /* Prepared statement under construction */
-  int addrInit;               /* Address of the initialization bypass jump */
-  Table *pTable;              /* The table being indexed */
-  int addrTop;                /* Top of the index fill loop */
-  int regRecord;              /* Register holding an index record */
-  int n;                      /* Column counter */
-  int i;                      /* Loop counter */
-  int mxBitCol;               /* Maximum column in pSrc->colUsed */
-  CollSeq *pColl;             /* Collating sequence to on a column */
-  WhereLoop *pLoop;           /* The Loop object */
-  char *zNotUsed;             /* Extra space on the end of pIdx */
-  Bitmask idxCols;            /* Bitmap of columns used for indexing */
-  Bitmask extraCols;          /* Bitmap of additional columns */
-  u8 sentWarning = 0;         /* True if a warnning has been issued */
-  Expr *pPartial = 0;         /* Partial Index Expression */
-  int iContinue = 0;          /* Jump here to skip excluded rows */
+  const char *z = 0;         /* String on RHS of LIKE operator */
+  Expr *pRight, *pLeft;      /* Right and left size of LIKE operator */
+  ExprList *pList;           /* List of operands to the LIKE operator */
+  int c;                     /* One character in z[] */
+  int cnt;                   /* Number of non-wildcard prefix characters */
+  char wc[3];                /* Wildcard characters */
+  sqlite3 *db = pParse->db;  /* Database connection */
+  sqlite3_value *pVal = 0;
+  int op;                    /* Opcode of pRight */
+  int rc;                    /* Result code to return */
 
-  /* Generate code to skip over the creation and initialization of the
-  ** transient index on 2nd and subsequent iterations of the loop. */
-  v = pParse->pVdbe;
-  assert( v!=0 );
-  addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
+    return 0;
+  }
+#ifdef SQLITE_EBCDIC
+  if( *pnoCase ) return 0;
+#endif
+  pList = pExpr->x.pList;
+  pLeft = pList->a[1].pExpr;
 
-  /* Count the number of columns that will be added to the index
-  ** and used to match WHERE clause constraints */
-  nKeyCol = 0;
-  pTable = pSrc->pTab;
-  pWCEnd = &pWC->a[pWC->nTerm];
-  pLoop = pLevel->pWLoop;
-  idxCols = 0;
-  for(pTerm=pWC->a; pTermprereq==0
-     && (pTerm->wtFlags & TERM_VIRTUAL)==0
-     && sqlite3ExprIsTableConstant(pTerm->pExpr, pSrc->iCursor) ){
-      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
-                                sqlite3ExprDup(pParse->db, pTerm->pExpr, 0));
+  pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
+  op = pRight->op;
+  if( op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){
+    Vdbe *pReprepare = pParse->pReprepare;
+    int iCol = pRight->iColumn;
+    pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);
+    if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
+      z = (char *)sqlite3_value_text(pVal);
     }
-    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
-      int iCol = pTerm->u.leftColumn;
-      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
-      testcase( iCol==BMS );
-      testcase( iCol==BMS-1 );
-      if( !sentWarning ){
-        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
-            "automatic index on %s(%s)", pTable->zName,
-            pTable->aCol[iCol].zName);
-        sentWarning = 1;
+    sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);
+    assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
+  }else if( op==TK_STRING ){
+    z = pRight->u.zToken;
+  }
+  if( z ){
+
+    /* If the RHS begins with a digit or a minus sign, then the LHS must
+    ** be an ordinary column (not a virtual table column) with TEXT affinity.
+    ** Otherwise the LHS might be numeric and "lhs >= rhs" would be false
+    ** even though "lhs LIKE rhs" is true.  But if the RHS does not start
+    ** with a digit or '-', then "lhs LIKE rhs" will always be false if
+    ** the LHS is numeric and so the optimization still works.
+    */
+    if( sqlite3Isdigit(z[0]) || z[0]=='-' ){
+      if( pLeft->op!=TK_COLUMN 
+       || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT 
+       || IsVirtual(pLeft->pTab)  /* Value might be numeric */
+      ){
+        sqlite3ValueFree(pVal);
+        return 0;
       }
-      if( (idxCols & cMask)==0 ){
-        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
-          goto end_auto_index_create;
+    }
+    cnt = 0;
+    while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
+      cnt++;
+    }
+    if( cnt!=0 && 255!=(u8)z[cnt-1] ){
+      Expr *pPrefix;
+      *pisComplete = c==wc[0] && z[cnt+1]==0;
+      pPrefix = sqlite3Expr(db, TK_STRING, z);
+      if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
+      *ppPrefix = pPrefix;
+      if( op==TK_VARIABLE ){
+        Vdbe *v = pParse->pVdbe;
+        sqlite3VdbeSetVarmask(v, pRight->iColumn);
+        if( *pisComplete && pRight->u.zToken[1] ){
+          /* If the rhs of the LIKE expression is a variable, and the current
+          ** value of the variable means there is no need to invoke the LIKE
+          ** function, then no OP_Variable will be added to the program.
+          ** This causes problems for the sqlite3_bind_parameter_name()
+          ** API. To work around them, add a dummy OP_Variable here.
+          */ 
+          int r1 = sqlite3GetTempReg(pParse);
+          sqlite3ExprCodeTarget(pParse, pRight, r1);
+          sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
+          sqlite3ReleaseTempReg(pParse, r1);
         }
-        pLoop->aLTerm[nKeyCol++] = pTerm;
-        idxCols |= cMask;
       }
+    }else{
+      z = 0;
     }
   }
-  assert( nKeyCol>0 );
-  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
-  pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
-                     | WHERE_AUTO_INDEX;
 
-  /* Count the number of additional columns needed to create a
-  ** covering index.  A "covering index" is an index that contains all
-  ** columns that are needed by the query.  With a covering index, the
-  ** original table never needs to be accessed.  Automatic indices must
-  ** be a covering index because the index will not be updated if the
-  ** original table changes and the index and table cannot both be used
-  ** if they go out of sync.
-  */
-  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
-  mxBitCol = MIN(BMS-1,pTable->nCol);
-  testcase( pTable->nCol==BMS-1 );
-  testcase( pTable->nCol==BMS-2 );
-  for(i=0; iop!=TK_FUNCTION ){
+    return 0;
   }
-  if( pSrc->colUsed & MASKBIT(BMS-1) ){
-    nKeyCol += pTable->nCol - BMS + 1;
+  pList = pExpr->x.pList;
+  if( pList==0 || pList->nExpr!=2 ){
+    return 0;
   }
-
-  /* Construct the Index object to describe this index */
-  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
-  if( pIdx==0 ) goto end_auto_index_create;
-  pLoop->u.btree.pIndex = pIdx;
-  pIdx->zName = "auto-index";
-  pIdx->pTable = pTable;
-  n = 0;
-  idxCols = 0;
-  for(pTerm=pWC->a; pTermu.leftColumn;
-      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
-      testcase( iCol==BMS-1 );
-      testcase( iCol==BMS );
-      if( (idxCols & cMask)==0 ){
-        Expr *pX = pTerm->pExpr;
-        idxCols |= cMask;
-        pIdx->aiColumn[n] = pTerm->u.leftColumn;
-        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-        pIdx->azColl[n] = ALWAYS(pColl) ? pColl->zName : "BINARY";
-        n++;
-      }
-    }
+  pCol = pList->a[1].pExpr;
+  if( pCol->op!=TK_COLUMN || !IsVirtual(pCol->pTab) ){
+    return 0;
   }
-  assert( (u32)n==pLoop->u.btree.nEq );
-
-  /* Add additional columns needed to make the automatic index into
-  ** a covering index */
-  for(i=0; iaiColumn[n] = i;
-      pIdx->azColl[n] = "BINARY";
-      n++;
+  for(i=0; iu.zToken, aOp[i].zOp)==0 ){
+      *peOp2 = aOp[i].eOp2;
+      return 1;
     }
   }
-  if( pSrc->colUsed & MASKBIT(BMS-1) ){
-    for(i=BMS-1; inCol; i++){
-      pIdx->aiColumn[n] = i;
-      pIdx->azColl[n] = "BINARY";
-      n++;
-    }
+  return 0;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** If the pBase expression originated in the ON or USING clause of
+** a join, then transfer the appropriate markings over to derived.
+*/
+static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
+  if( pDerived ){
+    pDerived->flags |= pBase->flags & EP_FromJoin;
+    pDerived->iRightJoinTable = pBase->iRightJoinTable;
   }
-  assert( n==nKeyCol );
-  pIdx->aiColumn[n] = -1;
-  pIdx->azColl[n] = "BINARY";
+}
 
-  /* Create the automatic index */
-  assert( pLevel->iIdxCur>=0 );
-  pLevel->iIdxCur = pParse->nTab++;
-  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
-  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
-  VdbeComment((v, "for %s", pTable->zName));
+/*
+** Mark term iChild as being a child of term iParent
+*/
+static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
+  pWC->a[iChild].iParent = iParent;
+  pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
+  pWC->a[iParent].nChild++;
+}
 
-  /* Fill the automatic index with content */
-  sqlite3ExprCachePush(pParse);
-  addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
-  if( pPartial ){
-    iContinue = sqlite3VdbeMakeLabel(v);
-    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
-    pLoop->wsFlags |= WHERE_PARTIALIDX;
+/*
+** Return the N-th AND-connected subterm of pTerm.  Or if pTerm is not
+** a conjunction, then return just pTerm when N==0.  If N is exceeds
+** the number of available subterms, return NULL.
+*/
+static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){
+  if( pTerm->eOperator!=WO_AND ){
+    return N==0 ? pTerm : 0;
   }
-  regRecord = sqlite3GetTempReg(pParse);
-  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0);
-  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
-  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
-  sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
-  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
-  sqlite3VdbeJumpHere(v, addrTop);
-  sqlite3ReleaseTempReg(pParse, regRecord);
-  sqlite3ExprCachePop(pParse);
-  
-  /* Jump here when skipping the initialization */
-  sqlite3VdbeJumpHere(v, addrInit);
-
-end_auto_index_create:
-  sqlite3ExprDelete(pParse->db, pPartial);
+  if( Nu.pAndInfo->wc.nTerm ){
+    return &pTerm->u.pAndInfo->wc.a[N];
+  }
+  return 0;
 }
-#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
-** Allocate and populate an sqlite3_index_info structure. It is the 
-** responsibility of the caller to eventually release the structure
-** by passing the pointer returned by this function to sqlite3_free().
+** Subterms pOne and pTwo are contained within WHERE clause pWC.  The
+** two subterms are in disjunction - they are OR-ed together.
+**
+** If these two terms are both of the form:  "A op B" with the same
+** A and B values but different operators and if the operators are
+** compatible (if one is = and the other is <, for example) then
+** add a new virtual AND term to pWC that is the combination of the
+** two.
+**
+** Some examples:
+**
+**    x     x<=y
+**    x=y OR x=y    -->     x=y
+**    x<=y OR x     x<=y
+**
+** The following is NOT generated:
+**
+**    xy    -->     x!=y     
 */
-static sqlite3_index_info *allocateIndexInfo(
-  Parse *pParse,
-  WhereClause *pWC,
-  struct SrcList_item *pSrc,
-  ExprList *pOrderBy
+static void whereCombineDisjuncts(
+  SrcList *pSrc,         /* the FROM clause */
+  WhereClause *pWC,      /* The complete WHERE clause */
+  WhereTerm *pOne,       /* First disjunct */
+  WhereTerm *pTwo        /* Second disjunct */
 ){
-  int i, j;
-  int nTerm;
-  struct sqlite3_index_constraint *pIdxCons;
-  struct sqlite3_index_orderby *pIdxOrderBy;
-  struct sqlite3_index_constraint_usage *pUsage;
-  WhereTerm *pTerm;
-  int nOrderBy;
-  sqlite3_index_info *pIdxInfo;
-
-  /* Count the number of possible WHERE clause constraints referring
-  ** to this virtual table */
-  for(i=nTerm=0, pTerm=pWC->a; inTerm; i++, pTerm++){
-    if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
-    testcase( pTerm->eOperator & WO_IN );
-    testcase( pTerm->eOperator & WO_ISNULL );
-    testcase( pTerm->eOperator & WO_ALL );
-    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV))==0 ) continue;
-    if( pTerm->wtFlags & TERM_VNULL ) continue;
-    nTerm++;
-  }
+  u16 eOp = pOne->eOperator | pTwo->eOperator;
+  sqlite3 *db;           /* Database connection (for malloc) */
+  Expr *pNew;            /* New virtual expression */
+  int op;                /* Operator for the combined expression */
+  int idxNew;            /* Index in pWC of the next virtual term */
 
-  /* If the ORDER BY clause contains only columns in the current 
-  ** virtual table then allocate space for the aOrderBy part of
-  ** the sqlite3_index_info structure.
-  */
-  nOrderBy = 0;
-  if( pOrderBy ){
-    int n = pOrderBy->nExpr;
-    for(i=0; ia[i].pExpr;
-      if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
-    }
-    if( i==n){
-      nOrderBy = n;
+  if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
+   && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
+  assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
+  assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
+  if( sqlite3ExprCompare(0,pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
+  if( sqlite3ExprCompare(0,pOne->pExpr->pRight, pTwo->pExpr->pRight,-1) )return;
+  /* If we reach this point, it means the two subterms can be combined */
+  if( (eOp & (eOp-1))!=0 ){
+    if( eOp & (WO_LT|WO_LE) ){
+      eOp = WO_LE;
+    }else{
+      assert( eOp & (WO_GT|WO_GE) );
+      eOp = WO_GE;
     }
   }
+  db = pWC->pWInfo->pParse->db;
+  pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
+  if( pNew==0 ) return;
+  for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( opop = op;
+  idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+  exprAnalyze(pSrc, pWC, idxNew);
+}
 
-  /* Allocate the sqlite3_index_info structure
-  */
-  pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)
-                           + (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm
-                           + sizeof(*pIdxOrderBy)*nOrderBy );
-  if( pIdxInfo==0 ){
-    sqlite3ErrorMsg(pParse, "out of memory");
-    return 0;
-  }
-
-  /* Initialize the structure.  The sqlite3_index_info structure contains
-  ** many fields that are declared "const" to prevent xBestIndex from
-  ** changing them.  We have to do some funky casting in order to
-  ** initialize those fields.
-  */
-  pIdxCons = (struct sqlite3_index_constraint*)&pIdxInfo[1];
-  pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
-  pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
-  *(int*)&pIdxInfo->nConstraint = nTerm;
-  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
-  *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;
-  *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;
-  *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =
-                                                                   pUsage;
-
-  for(i=j=0, pTerm=pWC->a; inTerm; i++, pTerm++){
-    u8 op;
-    if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
-    testcase( pTerm->eOperator & WO_IN );
-    testcase( pTerm->eOperator & WO_ISNULL );
-    testcase( pTerm->eOperator & WO_ALL );
-    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV))==0 ) continue;
-    if( pTerm->wtFlags & TERM_VNULL ) continue;
-    pIdxCons[j].iColumn = pTerm->u.leftColumn;
-    pIdxCons[j].iTermOffset = i;
-    op = (u8)pTerm->eOperator & WO_ALL;
-    if( op==WO_IN ) op = WO_EQ;
-    pIdxCons[j].op = op;
-    /* The direct assignment in the previous line is possible only because
-    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
-    ** following asserts verify this fact. */
-    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
-    assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
-    assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
-    assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
-    assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
-    assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
-    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
-    j++;
-  }
-  for(i=0; ia[i].pExpr;
-    pIdxOrderBy[i].iColumn = pExpr->iColumn;
-    pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;
-  }
-
-  return pIdxInfo;
-}
-
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
 /*
-** The table object reference passed as the second argument to this function
-** must represent a virtual table. This function invokes the xBestIndex()
-** method of the virtual table with the sqlite3_index_info object that
-** comes in as the 3rd argument to this function.
+** Analyze a term that consists of two or more OR-connected
+** subterms.  So in:
 **
-** If an error occurs, pParse is populated with an error message and a
-** non-zero value is returned. Otherwise, 0 is returned and the output
-** part of the sqlite3_index_info structure is left populated.
+**     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
+**                          ^^^^^^^^^^^^^^^^^^^^
 **
-** Whether or not an error is returned, it is the responsibility of the
-** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates
-** that this is required.
-*/
-static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
-  sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
-  int i;
-  int rc;
-
-  TRACE_IDX_INPUTS(p);
-  rc = pVtab->pModule->xBestIndex(pVtab, p);
-  TRACE_IDX_OUTPUTS(p);
-
-  if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_NOMEM ){
-      pParse->db->mallocFailed = 1;
-    }else if( !pVtab->zErrMsg ){
-      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
-    }else{
-      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
-    }
-  }
-  sqlite3_free(pVtab->zErrMsg);
-  pVtab->zErrMsg = 0;
-
-  for(i=0; inConstraint; i++){
-    if( !p->aConstraint[i].usable && p->aConstraintUsage[i].argvIndex>0 ){
-      sqlite3ErrorMsg(pParse, 
-          "table %s: xBestIndex returned an invalid plan", pTab->zName);
-    }
-  }
-
-  return pParse->nErr;
-}
-#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
-
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-/*
-** Estimate the location of a particular key among all keys in an
-** index.  Store the results in aStat as follows:
+** This routine analyzes terms such as the middle term in the above example.
+** A WhereOrTerm object is computed and attached to the term under
+** analysis, regardless of the outcome of the analysis.  Hence:
 **
-**    aStat[0]      Est. number of rows less than pVal
-**    aStat[1]      Est. number of rows equal to pVal
+**     WhereTerm.wtFlags   |=  TERM_ORINFO
+**     WhereTerm.u.pOrInfo  =  a dynamically allocated WhereOrTerm object
 **
-** Return the index of the sample that is the smallest sample that
-** is greater than or equal to pRec.
-*/
-static int whereKeyStats(
-  Parse *pParse,              /* Database connection */
-  Index *pIdx,                /* Index to consider domain of */
-  UnpackedRecord *pRec,       /* Vector of values to consider */
-  int roundUp,                /* Round up if true.  Round down if false */
-  tRowcnt *aStat              /* OUT: stats written here */
-){
-  IndexSample *aSample = pIdx->aSample;
-  int iCol;                   /* Index of required stats in anEq[] etc. */
-  int iMin = 0;               /* Smallest sample not yet tested */
-  int i = pIdx->nSample;      /* Smallest sample larger than or equal to pRec */
-  int iTest;                  /* Next sample to test */
-  int res;                    /* Result of comparison operation */
-
-#ifndef SQLITE_DEBUG
-  UNUSED_PARAMETER( pParse );
-#endif
-  assert( pRec!=0 );
-  iCol = pRec->nField - 1;
-  assert( pIdx->nSample>0 );
-  assert( pRec->nField>0 && iColnSampleCol );
-  do{
-    iTest = (iMin+i)/2;
-    res = sqlite3VdbeRecordCompare(aSample[iTest].n, aSample[iTest].p, pRec);
-    if( res<0 ){
-      iMin = iTest+1;
-    }else{
-      i = iTest;
-    }
-  }while( res && iMinnSample );
-    assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)
-         || pParse->db->mallocFailed );
-  }else{
-    /* Otherwise, pRec must be smaller than sample $i and larger than
-    ** sample ($i-1).  */
-    assert( i==pIdx->nSample 
-         || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
-         || pParse->db->mallocFailed );
-    assert( i==0
-         || sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
-         || pParse->db->mallocFailed );
-  }
-#endif /* ifdef SQLITE_DEBUG */
-
-  /* At this point, aSample[i] is the first sample that is greater than
-  ** or equal to pVal.  Or if i==pIdx->nSample, then all samples are less
-  ** than pVal.  If aSample[i]==pVal, then res==0.
-  */
-  if( res==0 ){
-    aStat[0] = aSample[i].anLt[iCol];
-    aStat[1] = aSample[i].anEq[iCol];
-  }else{
-    tRowcnt iLower, iUpper, iGap;
-    if( i==0 ){
-      iLower = 0;
-      iUpper = aSample[0].anLt[iCol];
-    }else{
-      i64 nRow0 = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
-      iUpper = i>=pIdx->nSample ? nRow0 : aSample[i].anLt[iCol];
-      iLower = aSample[i-1].anEq[iCol] + aSample[i-1].anLt[iCol];
-    }
-    aStat[1] = pIdx->aAvgEq[iCol];
-    if( iLower>=iUpper ){
-      iGap = 0;
-    }else{
-      iGap = iUpper - iLower;
-    }
-    if( roundUp ){
-      iGap = (iGap*2)/3;
-    }else{
-      iGap = iGap/3;
-    }
-    aStat[0] = iLower + iGap;
-  }
-  return i;
-}
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
-
-/*
-** If it is not NULL, pTerm is a term that provides an upper or lower
-** bound on a range scan. Without considering pTerm, it is estimated 
-** that the scan will visit nNew rows. This function returns the number
-** estimated to be visited after taking pTerm into account.
+** The term being analyzed must have two or more of OR-connected subterms.
+** A single subterm might be a set of AND-connected sub-subterms.
+** Examples of terms under analysis:
 **
-** If the user explicitly specified a likelihood() value for this term,
-** then the return value is the likelihood multiplied by the number of
-** input rows. Otherwise, this function assumes that an "IS NOT NULL" term
-** has a likelihood of 0.50, and any other term a likelihood of 0.25.
-*/
-static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
-  LogEst nRet = nNew;
-  if( pTerm ){
-    if( pTerm->truthProb<=0 ){
-      nRet += pTerm->truthProb;
-    }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){
-      nRet -= 20;        assert( 20==sqlite3LogEst(4) );
-    }
-  }
-  return nRet;
-}
-
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-/* 
-** This function is called to estimate the number of rows visited by a
-** range-scan on a skip-scan index. For example:
+**     (A)     t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5
+**     (B)     x=expr1 OR expr2=x OR x=expr3
+**     (C)     t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
+**     (D)     x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
+**     (E)     (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
+**     (F)     x>A OR (x=A AND y>=B)
 **
-**   CREATE INDEX i1 ON t1(a, b, c);
-**   SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;
+** CASE 1:
 **
-** Value pLoop->nOut is currently set to the estimated number of rows 
-** visited for scanning (a=? AND b=?). This function reduces that estimate 
-** by some factor to account for the (c BETWEEN ? AND ?) expression based
-** on the stat4 data for the index. this scan will be peformed multiple 
-** times (once for each (a,b) combination that matches a=?) is dealt with 
-** by the caller.
+** If all subterms are of the form T.C=expr for some single column of C and
+** a single table T (as shown in example B above) then create a new virtual
+** term that is an equivalent IN expression.  In other words, if the term
+** being analyzed is:
 **
-** It does this by scanning through all stat4 samples, comparing values
-** extracted from pLower and pUpper with the corresponding column in each
-** sample. If L and U are the number of samples found to be less than or
-** equal to the values extracted from pLower and pUpper respectively, and
-** N is the total number of samples, the pLoop->nOut value is adjusted
-** as follows:
+**      x = expr1  OR  expr2 = x  OR  x = expr3
 **
-**   nOut = nOut * ( min(U - L, 1) / N )
+** then create a new virtual term like this:
 **
-** If pLower is NULL, or a value cannot be extracted from the term, L is
-** set to zero. If pUpper is NULL, or a value cannot be extracted from it,
-** U is set to N.
+**      x IN (expr1,expr2,expr3)
 **
-** Normally, this function sets *pbDone to 1 before returning. However,
-** if no value can be extracted from either pLower or pUpper (and so the
-** estimate of the number of rows delivered remains unchanged), *pbDone
-** is left as is.
+** CASE 2:
 **
-** If an error occurs, an SQLite error code is returned. Otherwise, 
-** SQLITE_OK.
-*/
-static int whereRangeSkipScanEst(
-  Parse *pParse,       /* Parsing & code generating context */
-  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
-  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
-  WhereLoop *pLoop,    /* Update the .nOut value of this loop */
-  int *pbDone          /* Set to true if at least one expr. value extracted */
-){
-  Index *p = pLoop->u.btree.pIndex;
-  int nEq = pLoop->u.btree.nEq;
-  sqlite3 *db = pParse->db;
-  int nLower = -1;
-  int nUpper = p->nSample+1;
-  int rc = SQLITE_OK;
-  int iCol = p->aiColumn[nEq];
-  u8 aff = iCol>=0 ? p->pTable->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
-  CollSeq *pColl;
-  
-  sqlite3_value *p1 = 0;          /* Value extracted from pLower */
-  sqlite3_value *p2 = 0;          /* Value extracted from pUpper */
-  sqlite3_value *pVal = 0;        /* Value extracted from record */
-
-  pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);
-  if( pLower ){
-    rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);
-    nLower = 0;
-  }
-  if( pUpper && rc==SQLITE_OK ){
-    rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);
-    nUpper = p2 ? 0 : p->nSample;
-  }
-
-  if( p1 || p2 ){
-    int i;
-    int nDiff;
-    for(i=0; rc==SQLITE_OK && inSample; i++){
-      rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);
-      if( rc==SQLITE_OK && p1 ){
-        int res = sqlite3MemCompare(p1, pVal, pColl);
-        if( res>=0 ) nLower++;
-      }
-      if( rc==SQLITE_OK && p2 ){
-        int res = sqlite3MemCompare(p2, pVal, pColl);
-        if( res>=0 ) nUpper++;
-      }
-    }
-    nDiff = (nUpper - nLower);
-    if( nDiff<=0 ) nDiff = 1;
-
-    /* If there is both an upper and lower bound specified, and the 
-    ** comparisons indicate that they are close together, use the fallback
-    ** method (assume that the scan visits 1/64 of the rows) for estimating
-    ** the number of rows visited. Otherwise, estimate the number of rows
-    ** using the method described in the header comment for this function. */
-    if( nDiff!=1 || pUpper==0 || pLower==0 ){
-      int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));
-      pLoop->nOut -= nAdjust;
-      *pbDone = 1;
-      WHERETRACE(0x10, ("range skip-scan regions: %u..%u  adjust=%d est=%d\n",
-                           nLower, nUpper, nAdjust*-1, pLoop->nOut));
-    }
-
-  }else{
-    assert( *pbDone==0 );
-  }
-
-  sqlite3ValueFree(p1);
-  sqlite3ValueFree(p2);
-  sqlite3ValueFree(pVal);
-
-  return rc;
-}
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
-
-/*
-** This function is used to estimate the number of rows that will be visited
-** by scanning an index for a range of values. The range may have an upper
-** bound, a lower bound, or both. The WHERE clause terms that set the upper
-** and lower bounds are represented by pLower and pUpper respectively. For
-** example, assuming that index p is on t1(a):
+** If there are exactly two disjuncts and one side has x>A and the other side
+** has x=A (for the same x and A) then add a new virtual conjunct term to the
+** WHERE clause of the form "x>=A".  Example:
 **
-**   ... FROM t1 WHERE a > ? AND a < ? ...
-**                    |_____|   |_____|
-**                       |         |
-**                     pLower    pUpper
+**      x>A OR (x=A AND y>B)    adds:    x>=A
 **
-** If either of the upper or lower bound is not present, then NULL is passed in
-** place of the corresponding WhereTerm.
+** The added conjunct can sometimes be helpful in query planning.
 **
-** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
-** column subject to the range constraint. Or, equivalently, the number of
-** equality constraints optimized by the proposed index scan. For example,
-** assuming index p is on t1(a, b), and the SQL query is:
+** CASE 3:
 **
-**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
+** If all subterms are indexable by a single table T, then set
 **
-** then nEq is set to 1 (as the range restricted column, b, is the second 
-** left-most column of the index). Or, if the query is:
+**     WhereTerm.eOperator              =  WO_OR
+**     WhereTerm.u.pOrInfo->indexable  |=  the cursor number for table T
 **
-**   ... FROM t1 WHERE a > ? AND a < ? ...
+** A subterm is "indexable" if it is of the form
+** "T.C  " where C is any column of table T and 
+**  is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
+** A subterm is also indexable if it is an AND of two or more
+** subsubterms at least one of which is indexable.  Indexable AND 
+** subterms have their eOperator set to WO_AND and they have
+** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
 **
-** then nEq is set to 0.
+** From another point of view, "indexable" means that the subterm could
+** potentially be used with an index if an appropriate index exists.
+** This analysis does not consider whether or not the index exists; that
+** is decided elsewhere.  This analysis only looks at whether subterms
+** appropriate for indexing exist.
 **
-** When this function is called, *pnOut is set to the sqlite3LogEst() of the
-** number of rows that the index scan is expected to visit without 
-** considering the range constraints. If nEq is 0, then *pnOut is the number of 
-** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
-** to account for the range constraints pLower and pUpper.
-** 
-** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
-** used, a single range inequality reduces the search space by a factor of 4. 
-** and a pair of constraints (x>? AND x123" Might be NULL */
-  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
-  WhereLoop *pLoop     /* Modify the .nOut and maybe .rRun fields */
+static void exprAnalyzeOrTerm(
+  SrcList *pSrc,            /* the FROM clause */
+  WhereClause *pWC,         /* the complete WHERE clause */
+  int idxTerm               /* Index of the OR-term to be analyzed */
 ){
-  int rc = SQLITE_OK;
-  int nOut = pLoop->nOut;
-  LogEst nNew;
-
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-  Index *p = pLoop->u.btree.pIndex;
-  int nEq = pLoop->u.btree.nEq;
-
-  if( p->nSample>0 && nEqnSampleCol ){
-    if( nEq==pBuilder->nRecValid ){
-      UnpackedRecord *pRec = pBuilder->pRec;
-      tRowcnt a[2];
-      u8 aff;
+  WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */
+  Parse *pParse = pWInfo->pParse;         /* Parser context */
+  sqlite3 *db = pParse->db;               /* Database connection */
+  WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */
+  Expr *pExpr = pTerm->pExpr;             /* The expression of the term */
+  int i;                                  /* Loop counters */
+  WhereClause *pOrWc;       /* Breakup of pTerm into subterms */
+  WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */
+  WhereOrInfo *pOrInfo;     /* Additional information associated with pTerm */
+  Bitmask chngToIN;         /* Tables that might satisfy case 1 */
+  Bitmask indexable;        /* Tables that are indexable, satisfying case 2 */
 
-      /* Variable iLower will be set to the estimate of the number of rows in 
-      ** the index that are less than the lower bound of the range query. The
-      ** lower bound being the concatenation of $P and $L, where $P is the
-      ** key-prefix formed by the nEq values matched against the nEq left-most
-      ** columns of the index, and $L is the value in pLower.
-      **
-      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
-      ** is not a simple variable or literal value), the lower bound of the
-      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
-      ** if $L is available, whereKeyStats() is called for both ($P) and 
-      ** ($P:$L) and the larger of the two returned values is used.
-      **
-      ** Similarly, iUpper is to be set to the estimate of the number of rows
-      ** less than the upper bound of the range query. Where the upper bound
-      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
-      ** of iUpper are requested of whereKeyStats() and the smaller used.
-      **
-      ** The number of rows between the two bounds is then just iUpper-iLower.
-      */
-      tRowcnt iLower;     /* Rows less than the lower bound */
-      tRowcnt iUpper;     /* Rows less than the upper bound */
-      int iLwrIdx = -2;   /* aSample[] for the lower bound */
-      int iUprIdx = -1;   /* aSample[] for the upper bound */
+  /*
+  ** Break the OR clause into its separate subterms.  The subterms are
+  ** stored in a WhereClause structure containing within the WhereOrInfo
+  ** object that is attached to the original OR clause term.
+  */
+  assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );
+  assert( pExpr->op==TK_OR );
+  pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));
+  if( pOrInfo==0 ) return;
+  pTerm->wtFlags |= TERM_ORINFO;
+  pOrWc = &pOrInfo->wc;
+  memset(pOrWc->aStatic, 0, sizeof(pOrWc->aStatic));
+  sqlite3WhereClauseInit(pOrWc, pWInfo);
+  sqlite3WhereSplit(pOrWc, pExpr, TK_OR);
+  sqlite3WhereExprAnalyze(pSrc, pOrWc);
+  if( db->mallocFailed ) return;
+  assert( pOrWc->nTerm>=2 );
 
-      if( pRec ){
-        testcase( pRec->nField!=pBuilder->nRecValid );
-        pRec->nField = pBuilder->nRecValid;
+  /*
+  ** Compute the set of tables that might satisfy cases 1 or 3.
+  */
+  indexable = ~(Bitmask)0;
+  chngToIN = ~(Bitmask)0;
+  for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
+    if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
+      WhereAndInfo *pAndInfo;
+      assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
+      chngToIN = 0;
+      pAndInfo = sqlite3DbMallocRawNN(db, sizeof(*pAndInfo));
+      if( pAndInfo ){
+        WhereClause *pAndWC;
+        WhereTerm *pAndTerm;
+        int j;
+        Bitmask b = 0;
+        pOrTerm->u.pAndInfo = pAndInfo;
+        pOrTerm->wtFlags |= TERM_ANDINFO;
+        pOrTerm->eOperator = WO_AND;
+        pAndWC = &pAndInfo->wc;
+        memset(pAndWC->aStatic, 0, sizeof(pAndWC->aStatic));
+        sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
+        sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
+        sqlite3WhereExprAnalyze(pSrc, pAndWC);
+        pAndWC->pOuter = pWC;
+        if( !db->mallocFailed ){
+          for(j=0, pAndTerm=pAndWC->a; jnTerm; j++, pAndTerm++){
+            assert( pAndTerm->pExpr );
+            if( allowedOp(pAndTerm->pExpr->op) 
+             || pAndTerm->eOperator==WO_MATCH 
+            ){
+              b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
+            }
+          }
+        }
+        indexable &= b;
       }
-      if( nEq==p->nKeyCol ){
-        aff = SQLITE_AFF_INTEGER;
-      }else{
-        aff = p->pTable->aCol[p->aiColumn[nEq]].affinity;
+    }else if( pOrTerm->wtFlags & TERM_COPIED ){
+      /* Skip this term for now.  We revisit it when we process the
+      ** corresponding TERM_VIRTUAL term */
+    }else{
+      Bitmask b;
+      b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
+      if( pOrTerm->wtFlags & TERM_VIRTUAL ){
+        WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
+        b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
       }
-      /* Determine iLower and iUpper using ($P) only. */
-      if( nEq==0 ){
-        iLower = 0;
-        iUpper = p->nRowEst0;
+      indexable &= b;
+      if( (pOrTerm->eOperator & WO_EQ)==0 ){
+        chngToIN = 0;
       }else{
-        /* Note: this call could be optimized away - since the same values must 
-        ** have been requested when testing key $P in whereEqualScanEst().  */
-        whereKeyStats(pParse, p, pRec, 0, a);
-        iLower = a[0];
-        iUpper = a[0] + a[1];
+        chngToIN &= b;
       }
+    }
+  }
 
-      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
-      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
-      assert( p->aSortOrder!=0 );
-      if( p->aSortOrder[nEq] ){
-        /* The roles of pLower and pUpper are swapped for a DESC index */
-        SWAP(WhereTerm*, pLower, pUpper);
-      }
+  /*
+  ** Record the set of tables that satisfy case 3.  The set might be
+  ** empty.
+  */
+  pOrInfo->indexable = indexable;
+  pTerm->eOperator = indexable==0 ? 0 : WO_OR;
 
-      /* If possible, improve on the iLower estimate using ($P:$L). */
-      if( pLower ){
-        int bOk;                    /* True if value is extracted from pExpr */
-        Expr *pExpr = pLower->pExpr->pRight;
-        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
-        if( rc==SQLITE_OK && bOk ){
-          tRowcnt iNew;
-          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
-          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
-          if( iNew>iLower ) iLower = iNew;
-          nOut--;
-          pLower = 0;
-        }
+  /* For a two-way OR, attempt to implementation case 2.
+  */
+  if( indexable && pOrWc->nTerm==2 ){
+    int iOne = 0;
+    WhereTerm *pOne;
+    while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){
+      int iTwo = 0;
+      WhereTerm *pTwo;
+      while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){
+        whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);
       }
+    }
+  }
 
-      /* If possible, improve on the iUpper estimate using ($P:$U). */
-      if( pUpper ){
-        int bOk;                    /* True if value is extracted from pExpr */
-        Expr *pExpr = pUpper->pExpr->pRight;
-        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
-        if( rc==SQLITE_OK && bOk ){
-          tRowcnt iNew;
-          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
-          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
-          if( iNewa;
+      for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
+        assert( pOrTerm->eOperator & WO_EQ );
+        pOrTerm->wtFlags &= ~TERM_OR_OK;
+        if( pOrTerm->leftCursor==iCursor ){
+          /* This is the 2-bit case and we are on the second iteration and
+          ** current term is from the first iteration.  So skip this term. */
+          assert( j==1 );
+          continue;
+        }
+        if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,
+                                            pOrTerm->leftCursor))==0 ){
+          /* This term must be of the form t1.a==t2.b where t2 is in the
+          ** chngToIN set but t1 is not.  This term will be either preceded
+          ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
+          ** and use its inversion. */
+          testcase( pOrTerm->wtFlags & TERM_COPIED );
+          testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
+          assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
+          continue;
         }
+        iColumn = pOrTerm->u.leftColumn;
+        iCursor = pOrTerm->leftCursor;
+        break;
+      }
+      if( i<0 ){
+        /* No candidate table+column was found.  This can only occur
+        ** on the second iteration */
+        assert( j==1 );
+        assert( IsPowerOfTwo(chngToIN) );
+        assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
+        break;
       }
+      testcase( j==1 );
 
-      pBuilder->pRec = pRec;
-      if( rc==SQLITE_OK ){
-        if( iUpper>iLower ){
-          nNew = sqlite3LogEst(iUpper - iLower);
-          /* TUNING:  If both iUpper and iLower are derived from the same
-          ** sample, then assume they are 4x more selective.  This brings
-          ** the estimated selectivity more in line with what it would be
-          ** if estimated without the use of STAT3/4 tables. */
-          if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );
+      /* We have found a candidate table and column.  Check to see if that
+      ** table and column is common to every term in the OR clause */
+      okToChngToIN = 1;
+      for(; i>=0 && okToChngToIN; i--, pOrTerm++){
+        assert( pOrTerm->eOperator & WO_EQ );
+        if( pOrTerm->leftCursor!=iCursor ){
+          pOrTerm->wtFlags &= ~TERM_OR_OK;
+        }else if( pOrTerm->u.leftColumn!=iColumn ){
+          okToChngToIN = 0;
         }else{
-          nNew = 10;        assert( 10==sqlite3LogEst(2) );
-        }
-        if( nNewpExpr->pRight);
+          affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
+          if( affRight!=0 && affRight!=affLeft ){
+            okToChngToIN = 0;
+          }else{
+            pOrTerm->wtFlags |= TERM_OR_OK;
+          }
         }
-        WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",
-                           (u32)iLower, (u32)iUpper, nOut));
       }
-    }else{
-      int bDone = 0;
-      rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone);
-      if( bDone ) return rc;
     }
-  }
-#else
-  UNUSED_PARAMETER(pParse);
-  UNUSED_PARAMETER(pBuilder);
-  assert( pLower || pUpper );
-#endif
-  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
-  nNew = whereRangeAdjust(pLower, nOut);
-  nNew = whereRangeAdjust(pUpper, nNew);
 
-  /* TUNING: If there is both an upper and lower limit and neither limit
-  ** has an application-defined likelihood(), assume the range is
-  ** reduced by an additional 75%. This means that, by default, an open-ended
-  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
-  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
-  ** match 1/64 of the index. */ 
-  if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
-    nNew -= 20;
-  }
+    /* At this point, okToChngToIN is true if original pTerm satisfies
+    ** case 1.  In that case, construct a new virtual term that is 
+    ** pTerm converted into an IN operator.
+    */
+    if( okToChngToIN ){
+      Expr *pDup;            /* A transient duplicate expression */
+      ExprList *pList = 0;   /* The RHS of the IN operator */
+      Expr *pLeft = 0;       /* The LHS of the IN operator */
+      Expr *pNew;            /* The complete IN operator */
 
-  nOut -= (pLower!=0) + (pUpper!=0);
-  if( nNew<10 ) nNew = 10;
-  if( nNewnOut>nOut ){
-    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
-                    pLoop->nOut, nOut));
+      for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
+        if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
+        assert( pOrTerm->eOperator & WO_EQ );
+        assert( pOrTerm->leftCursor==iCursor );
+        assert( pOrTerm->u.leftColumn==iColumn );
+        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
+        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
+        pLeft = pOrTerm->pExpr->pLeft;
+      }
+      assert( pLeft!=0 );
+      pDup = sqlite3ExprDup(db, pLeft, 0);
+      pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0);
+      if( pNew ){
+        int idxNew;
+        transferJoinMarkings(pNew, pExpr);
+        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
+        pNew->x.pList = pList;
+        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+        testcase( idxNew==0 );
+        exprAnalyze(pSrc, pWC, idxNew);
+        pTerm = &pWC->a[idxTerm];
+        markTermAsChild(pWC, idxNew, idxTerm);
+      }else{
+        sqlite3ExprListDelete(db, pList);
+      }
+      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 3 */
+    }
   }
-#endif
-  pLoop->nOut = (LogEst)nOut;
-  return rc;
 }
+#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
 
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
-** Estimate the number of rows that will be returned based on
-** an equality constraint x=VALUE and where that VALUE occurs in
-** the histogram data.  This only works when x is the left-most
-** column of an index and sqlite_stat3 histogram data is available
-** for that index.  When pExpr==NULL that means the constraint is
-** "x IS NULL" instead of "x=VALUE".
-**
-** Write the estimated row count into *pnRow and return SQLITE_OK. 
-** If unable to make an estimate, leave *pnRow unchanged and return
-** non-zero.
-**
-** This routine can fail if it is unable to load a collating sequence
-** required for string comparison, or if unable to allocate memory
-** for a UTF conversion required for comparison.  The error is stored
-** in the pParse structure.
-*/
-static int whereEqualScanEst(
-  Parse *pParse,       /* Parsing & code generating context */
-  WhereLoopBuilder *pBuilder,
-  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
-  tRowcnt *pnRow       /* Write the revised row estimate here */
-){
-  Index *p = pBuilder->pNew->u.btree.pIndex;
-  int nEq = pBuilder->pNew->u.btree.nEq;
-  UnpackedRecord *pRec = pBuilder->pRec;
-  u8 aff;                   /* Column affinity */
-  int rc;                   /* Subfunction return code */
-  tRowcnt a[2];             /* Statistics */
-  int bOk;
-
-  assert( nEq>=1 );
-  assert( nEq<=p->nColumn );
-  assert( p->aSample!=0 );
-  assert( p->nSample>0 );
-  assert( pBuilder->nRecValidnRecValid<(nEq-1) ){
-    return SQLITE_NOTFOUND;
-  }
-
-  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
-  ** below would return the same value.  */
-  if( nEq>=p->nColumn ){
-    *pnRow = 1;
-    return SQLITE_OK;
+** We already know that pExpr is a binary operator where both operands are
+** column references.  This routine checks to see if pExpr is an equivalence
+** relation:
+**   1.  The SQLITE_Transitive optimization must be enabled
+**   2.  Must be either an == or an IS operator
+**   3.  Not originating in the ON clause of an OUTER JOIN
+**   4.  The affinities of A and B must be compatible
+**   5a. Both operands use the same collating sequence OR
+**   5b. The overall collating sequence is BINARY
+** If this routine returns TRUE, that means that the RHS can be substituted
+** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
+** This is an optimization.  No harm comes from returning 0.  But if 1 is
+** returned when it should not be, then incorrect answers might result.
+*/
+static int termIsEquivalence(Parse *pParse, Expr *pExpr){
+  char aff1, aff2;
+  CollSeq *pColl;
+  const char *zColl1, *zColl2;
+  if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
+  if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
+  if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
+  aff1 = sqlite3ExprAffinity(pExpr->pLeft);
+  aff2 = sqlite3ExprAffinity(pExpr->pRight);
+  if( aff1!=aff2
+   && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
+  ){
+    return 0;
   }
-
-  aff = p->pTable->aCol[p->aiColumn[nEq-1]].affinity;
-  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq-1, &bOk);
-  pBuilder->pRec = pRec;
-  if( rc!=SQLITE_OK ) return rc;
-  if( bOk==0 ) return SQLITE_NOTFOUND;
-  pBuilder->nRecValid = nEq;
-
-  whereKeyStats(pParse, p, pRec, 0, a);
-  WHERETRACE(0x10,("equality scan regions: %d\n", (int)a[1]));
-  *pnRow = a[1];
-  
-  return rc;
+  pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
+  if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+  zColl1 = pColl ? pColl->zName : 0;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
+  zColl2 = pColl ? pColl->zName : 0;
+  return sqlite3_stricmp(zColl1, zColl2)==0;
 }
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
-** Estimate the number of rows that will be returned based on
-** an IN constraint where the right-hand side of the IN operator
-** is a list of values.  Example:
-**
-**        WHERE x IN (1,2,3,4)
-**
-** Write the estimated row count into *pnRow and return SQLITE_OK. 
-** If unable to make an estimate, leave *pnRow unchanged and return
-** non-zero.
-**
-** This routine can fail if it is unable to load a collating sequence
-** required for string comparison, or if unable to allocate memory
-** for a UTF conversion required for comparison.  The error is stored
-** in the pParse structure.
+** Recursively walk the expressions of a SELECT statement and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
 */
-static int whereInScanEst(
-  Parse *pParse,       /* Parsing & code generating context */
-  WhereLoopBuilder *pBuilder,
-  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
-  tRowcnt *pnRow       /* Write the revised row estimate here */
-){
-  Index *p = pBuilder->pNew->u.btree.pIndex;
-  i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);
-  int nRecValid = pBuilder->nRecValid;
-  int rc = SQLITE_OK;     /* Subfunction return code */
-  tRowcnt nEst;           /* Number of rows for a single term */
-  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
-  int i;                  /* Loop counter */
-
-  assert( p->aSample!=0 );
-  for(i=0; rc==SQLITE_OK && inExpr; i++){
-    nEst = nRow0;
-    rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
-    nRowEst += nEst;
-    pBuilder->nRecValid = nRecValid;
-  }
-
-  if( rc==SQLITE_OK ){
-    if( nRowEst > nRow0 ) nRowEst = nRow0;
-    *pnRow = nRowEst;
-    WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
+static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){
+  Bitmask mask = 0;
+  while( pS ){
+    SrcList *pSrc = pS->pSrc;
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
+    if( ALWAYS(pSrc!=0) ){
+      int i;
+      for(i=0; inSrc; i++){
+        mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);
+        mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
+      }
+    }
+    pS = pS->pPrior;
   }
-  assert( pBuilder->nRecValid==nRecValid );
-  return rc;
+  return mask;
 }
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
 /*
-** Disable a term in the WHERE clause.  Except, do not disable the term
-** if it controls a LEFT OUTER JOIN and it did not originate in the ON
-** or USING clause of that join.
-**
-** Consider the term t2.z='ok' in the following queries:
-**
-**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
-**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
-**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+** Expression pExpr is one operand of a comparison operator that might
+** be useful for indexing.  This routine checks to see if pExpr appears
+** in any index.  Return TRUE (1) if pExpr is an indexed term and return
+** FALSE (0) if not.  If TRUE is returned, also set aiCurCol[0] to the cursor
+** number of the table that is indexed and aiCurCol[1] to the column number
+** of the column that is indexed, or XN_EXPR (-2) if an expression is being
+** indexed.
 **
-** The t2.z='ok' is disabled in the in (2) because it originates
-** in the ON clause.  The term is disabled in (3) because it is not part
-** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
-**
-** Disabling a term causes that term to not be tested in the inner loop
-** of the join.  Disabling is an optimization.  When terms are satisfied
-** by indices, we disable them to prevent redundant tests in the inner
-** loop.  We would get the correct results if nothing were ever disabled,
-** but joins might run a little slower.  The trick is to disable as much
-** as we can without disabling too much.  If we disabled in (1), we'd get
-** the wrong answer.  See ticket #813.
+** If pExpr is a TK_COLUMN column reference, then this routine always returns
+** true even if that particular column is not indexed, because the column
+** might be added to an automatic index later.
 */
-static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
-  if( pTerm
-      && (pTerm->wtFlags & TERM_CODED)==0
-      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
-      && (pLevel->notReady & pTerm->prereqAll)==0
-  ){
-    pTerm->wtFlags |= TERM_CODED;
-    if( pTerm->iParent>=0 ){
-      WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
-      if( (--pOther->nChild)==0 ){
-        disableTerm(pLevel, pOther);
+static SQLITE_NOINLINE int exprMightBeIndexed2(
+  SrcList *pFrom,        /* The FROM clause */
+  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
+  int *aiCurCol,         /* Write the referenced table cursor and column here */
+  Expr *pExpr            /* An operand of a comparison operator */
+){
+  Index *pIdx;
+  int i;
+  int iCur;
+  for(i=0; mPrereq>1; i++, mPrereq>>=1){}
+  iCur = pFrom->a[i].iCursor;
+  for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    if( pIdx->aColExpr==0 ) continue;
+    for(i=0; inKeyCol; i++){
+      if( pIdx->aiColumn[i]!=XN_EXPR ) continue;
+      if( sqlite3ExprCompareSkip(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
+        aiCurCol[0] = iCur;
+        aiCurCol[1] = XN_EXPR;
+        return 1;
       }
     }
   }
+  return 0;
 }
-
-/*
-** Code an OP_Affinity opcode to apply the column affinity string zAff
-** to the n registers starting at base. 
-**
-** As an optimization, SQLITE_AFF_NONE entries (which are no-ops) at the
-** beginning and end of zAff are ignored.  If all entries in zAff are
-** SQLITE_AFF_NONE, then no code gets generated.
-**
-** This routine makes its own copy of zAff so that the caller is free
-** to modify zAff after this routine returns.
-*/
-static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
-  Vdbe *v = pParse->pVdbe;
-  if( zAff==0 ){
-    assert( pParse->db->mallocFailed );
-    return;
-  }
-  assert( v!=0 );
-
-  /* Adjust base and n to skip over SQLITE_AFF_NONE entries at the beginning
-  ** and end of the affinity string.
-  */
-  while( n>0 && zAff[0]==SQLITE_AFF_NONE ){
-    n--;
-    base++;
-    zAff++;
-  }
-  while( n>1 && zAff[n-1]==SQLITE_AFF_NONE ){
-    n--;
-  }
-
-  /* Code the OP_Affinity opcode if there is anything left to do. */
-  if( n>0 ){
-    sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
-    sqlite3VdbeChangeP4(v, -1, zAff, n);
-    sqlite3ExprCacheAffinityChange(pParse, base, n);
+static int exprMightBeIndexed(
+  SrcList *pFrom,        /* The FROM clause */
+  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
+  int *aiCurCol,         /* Write the referenced table cursor & column here */
+  Expr *pExpr,           /* An operand of a comparison operator */
+  int op                 /* The specific comparison operator */
+){
+  /* If this expression is a vector to the left or right of a 
+  ** inequality constraint (>, <, >= or <=), perform the processing 
+  ** on the first element of the vector.  */
+  assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE );
+  assert( TK_ISop==TK_VECTOR && (op>=TK_GT && ALWAYS(op<=TK_GE)) ){
+    pExpr = pExpr->x.pList->a[0].pExpr;
+  }
+
+  if( pExpr->op==TK_COLUMN ){
+    aiCurCol[0] = pExpr->iTable;
+    aiCurCol[1] = pExpr->iColumn;
+    return 1;
   }
+  if( mPrereq==0 ) return 0;                 /* No table references */
+  if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */
+  return exprMightBeIndexed2(pFrom,mPrereq,aiCurCol,pExpr);
 }
 
-
 /*
-** Generate code for a single equality term of the WHERE clause.  An equality
-** term can be either X=expr or X IN (...).   pTerm is the term to be 
-** coded.
+** The input to this routine is an WhereTerm structure with only the
+** "pExpr" field filled in.  The job of this routine is to analyze the
+** subexpression and populate all the other fields of the WhereTerm
+** structure.
 **
-** The current value for the constraint is left in register iReg.
+** If the expression is of the form "  X" it gets commuted
+** to the standard form of "X  ".
 **
-** For a constraint of the form X=expr, the expression is evaluated and its
-** result is left on the stack.  For constraints of the form X IN (...)
-** this routine sets up a loop that will iterate over all values of X.
+** If the expression is of the form "X  Y" where both X and Y are
+** columns, then the original expression is unchanged and a new virtual
+** term of the form "Y  X" is added to the WHERE clause and
+** analyzed separately.  The original term is marked with TERM_COPIED
+** and the new term is marked with TERM_DYNAMIC (because it's pExpr
+** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it
+** is a commuted copy of a prior term.)  The original term has nChild=1
+** and the copy has idxParent set to the index of the original term.
 */
-static int codeEqualityTerm(
-  Parse *pParse,      /* The parsing context */
-  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
-  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
-  int iEq,            /* Index of the equality term within this level */
-  int bRev,           /* True for reverse-order IN operations */
-  int iTarget         /* Attempt to leave results in this register */
+static void exprAnalyze(
+  SrcList *pSrc,            /* the FROM clause */
+  WhereClause *pWC,         /* the WHERE clause */
+  int idxTerm               /* Index of the term to be analyzed */
 ){
-  Expr *pX = pTerm->pExpr;
-  Vdbe *v = pParse->pVdbe;
-  int iReg;                  /* Register holding results */
+  WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
+  WhereTerm *pTerm;                /* The term to be analyzed */
+  WhereMaskSet *pMaskSet;          /* Set of table index masks */
+  Expr *pExpr;                     /* The expression to be analyzed */
+  Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */
+  Bitmask prereqAll;               /* Prerequesites of pExpr */
+  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
+  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
+  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
+  int noCase = 0;                  /* uppercase equivalent to lowercase */
+  int op;                          /* Top-level operator.  pExpr->op */
+  Parse *pParse = pWInfo->pParse;  /* Parsing context */
+  sqlite3 *db = pParse->db;        /* Database connection */
+  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */
+  int nLeft;                       /* Number of elements on left side vector */
 
-  assert( iTarget>0 );
-  if( pX->op==TK_EQ ){
-    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
-  }else if( pX->op==TK_ISNULL ){
-    iReg = iTarget;
-    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
-#ifndef SQLITE_OMIT_SUBQUERY
+  if( db->mallocFailed ){
+    return;
+  }
+  pTerm = &pWC->a[idxTerm];
+  pMaskSet = &pWInfo->sMaskSet;
+  pExpr = pTerm->pExpr;
+  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
+  prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
+  op = pExpr->op;
+  if( op==TK_IN ){
+    assert( pExpr->pRight==0 );
+    if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
+    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+      pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
+    }else{
+      pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
+    }
+  }else if( op==TK_ISNULL ){
+    pTerm->prereqRight = 0;
   }else{
-    int eType;
-    int iTab;
-    struct InLoop *pIn;
-    WhereLoop *pLoop = pLevel->pWLoop;
-
-    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
-      && pLoop->u.btree.pIndex!=0
-      && pLoop->u.btree.pIndex->aSortOrder[iEq]
-    ){
-      testcase( iEq==0 );
-      testcase( bRev );
-      bRev = !bRev;
+    pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
+  }
+  pMaskSet->bVarSelect = 0;
+  prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr);
+  if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT;
+  if( ExprHasProperty(pExpr, EP_FromJoin) ){
+    Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
+    prereqAll |= x;
+    extraRight = x-1;  /* ON clause terms may not be used with an index
+                       ** on left table of a LEFT JOIN.  Ticket #3015 */
+    if( (prereqAll>>1)>=x ){
+      sqlite3ErrorMsg(pParse, "ON clause references tables to its right");
+      return;
     }
-    assert( pX->op==TK_IN );
-    iReg = iTarget;
-    eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0);
-    if( eType==IN_INDEX_INDEX_DESC ){
-      testcase( bRev );
-      bRev = !bRev;
+  }
+  pTerm->prereqAll = prereqAll;
+  pTerm->leftCursor = -1;
+  pTerm->iParent = -1;
+  pTerm->eOperator = 0;
+  if( allowedOp(op) ){
+    int aiCurCol[2];
+    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
+    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
+    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
+
+    if( pTerm->iField>0 ){
+      assert( op==TK_IN );
+      assert( pLeft->op==TK_VECTOR );
+      pLeft = pLeft->x.pList->a[pTerm->iField-1].pExpr;
     }
-    iTab = pX->iTable;
-    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
-    VdbeCoverageIf(v, bRev);
-    VdbeCoverageIf(v, !bRev);
-    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
-    pLoop->wsFlags |= WHERE_IN_ABLE;
-    if( pLevel->u.in.nIn==0 ){
-      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+
+    if( exprMightBeIndexed(pSrc, prereqLeft, aiCurCol, pLeft, op) ){
+      pTerm->leftCursor = aiCurCol[0];
+      pTerm->u.leftColumn = aiCurCol[1];
+      pTerm->eOperator = operatorMask(op) & opMask;
     }
-    pLevel->u.in.nIn++;
-    pLevel->u.in.aInLoop =
-       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
-                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
-    pIn = pLevel->u.in.aInLoop;
-    if( pIn ){
-      pIn += pLevel->u.in.nIn - 1;
-      pIn->iCur = iTab;
-      if( eType==IN_INDEX_ROWID ){
-        pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+    if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
+    if( pRight 
+     && exprMightBeIndexed(pSrc, pTerm->prereqRight, aiCurCol, pRight, op)
+    ){
+      WhereTerm *pNew;
+      Expr *pDup;
+      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
+      assert( pTerm->iField==0 );
+      if( pTerm->leftCursor>=0 ){
+        int idxNew;
+        pDup = sqlite3ExprDup(db, pExpr, 0);
+        if( db->mallocFailed ){
+          sqlite3ExprDelete(db, pDup);
+          return;
+        }
+        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
+        if( idxNew==0 ) return;
+        pNew = &pWC->a[idxNew];
+        markTermAsChild(pWC, idxNew, idxTerm);
+        if( op==TK_IS ) pNew->wtFlags |= TERM_IS;
+        pTerm = &pWC->a[idxTerm];
+        pTerm->wtFlags |= TERM_COPIED;
+
+        if( termIsEquivalence(pParse, pDup) ){
+          pTerm->eOperator |= WO_EQUIV;
+          eExtraOp = WO_EQUIV;
+        }
       }else{
-        pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+        pDup = pExpr;
+        pNew = pTerm;
       }
-      pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
-      sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v);
-    }else{
-      pLevel->u.in.nIn = 0;
+      exprCommute(pParse, pDup);
+      pNew->leftCursor = aiCurCol[0];
+      pNew->u.leftColumn = aiCurCol[1];
+      testcase( (prereqLeft | extraRight) != prereqLeft );
+      pNew->prereqRight = prereqLeft | extraRight;
+      pNew->prereqAll = prereqAll;
+      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
     }
-#endif
   }
-  disableTerm(pLevel, pTerm);
-  return iReg;
-}
 
-/*
-** Generate code that will evaluate all == and IN constraints for an
-** index scan.
-**
-** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
-** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
-** The index has as many as three equality constraints, but in this
-** example, the third "c" value is an inequality.  So only two 
-** constraints are coded.  This routine will generate code to evaluate
-** a==5 and b IN (1,2,3).  The current values for a and b will be stored
-** in consecutive registers and the index of the first register is returned.
-**
-** In the example above nEq==2.  But this subroutine works for any value
-** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
-** The only thing it does is allocate the pLevel->iMem memory cell and
-** compute the affinity string.
-**
-** The nExtraReg parameter is 0 or 1.  It is 0 if all WHERE clause constraints
-** are == or IN and are covered by the nEq.  nExtraReg is 1 if there is
-** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
-** occurs after the nEq quality constraints.
-**
-** This routine allocates a range of nEq+nExtraReg memory cells and returns
-** the index of the first memory cell in that range. The code that
-** calls this routine will use that memory range to store keys for
-** start and termination conditions of the loop.
-** key value of the loop.  If one or more IN operators appear, then
-** this routine allocates an additional nEq memory cells for internal
-** use.
-**
-** Before returning, *pzAff is set to point to a buffer containing a
-** copy of the column affinity string of the index allocated using
-** sqlite3DbMalloc(). Except, entries in the copy of the string associated
-** with equality constraints that use NONE affinity are set to
-** SQLITE_AFF_NONE. This is to deal with SQL such as the following:
-**
-**   CREATE TABLE t1(a TEXT PRIMARY KEY, b);
-**   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
-**
-** In the example above, the index on t1(a) has TEXT affinity. But since
-** the right hand side of the equality constraint (t2.b) has NONE affinity,
-** no conversion should be attempted before using a t2.b value as part of
-** a key to search the index. Hence the first byte in the returned affinity
-** string in this example would be set to SQLITE_AFF_NONE.
-*/
-static int codeAllEqualityTerms(
-  Parse *pParse,        /* Parsing context */
-  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
-  int bRev,             /* Reverse the order of IN operators */
-  int nExtraReg,        /* Number of extra registers to allocate */
-  char **pzAff          /* OUT: Set to point to affinity string */
-){
-  u16 nEq;                      /* The number of == or IN constraints to code */
-  u16 nSkip;                    /* Number of left-most columns to skip */
-  Vdbe *v = pParse->pVdbe;      /* The vm under construction */
-  Index *pIdx;                  /* The index being used for this loop */
-  WhereTerm *pTerm;             /* A single constraint term */
-  WhereLoop *pLoop;             /* The WhereLoop object */
-  int j;                        /* Loop counter */
-  int regBase;                  /* Base register */
-  int nReg;                     /* Number of registers to allocate */
-  char *zAff;                   /* Affinity string to return */
+#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
+  /* If a term is the BETWEEN operator, create two new virtual terms
+  ** that define the range that the BETWEEN implements.  For example:
+  **
+  **      a BETWEEN b AND c
+  **
+  ** is converted into:
+  **
+  **      (a BETWEEN b AND c) AND (a>=b) AND (a<=c)
+  **
+  ** The two new terms are added onto the end of the WhereClause object.
+  ** The new terms are "dynamic" and are children of the original BETWEEN
+  ** term.  That means that if the BETWEEN term is coded, the children are
+  ** skipped.  Or, if the children are satisfied by an index, the original
+  ** BETWEEN term is skipped.
+  */
+  else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){
+    ExprList *pList = pExpr->x.pList;
+    int i;
+    static const u8 ops[] = {TK_GE, TK_LE};
+    assert( pList!=0 );
+    assert( pList->nExpr==2 );
+    for(i=0; i<2; i++){
+      Expr *pNewExpr;
+      int idxNew;
+      pNewExpr = sqlite3PExpr(pParse, ops[i], 
+                             sqlite3ExprDup(db, pExpr->pLeft, 0),
+                             sqlite3ExprDup(db, pList->a[i].pExpr, 0));
+      transferJoinMarkings(pNewExpr, pExpr);
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      testcase( idxNew==0 );
+      exprAnalyze(pSrc, pWC, idxNew);
+      pTerm = &pWC->a[idxTerm];
+      markTermAsChild(pWC, idxNew, idxTerm);
+    }
+  }
+#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
 
-  /* This module is only called on query plans that use an index. */
-  pLoop = pLevel->pWLoop;
-  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
-  nEq = pLoop->u.btree.nEq;
-  nSkip = pLoop->nSkip;
-  pIdx = pLoop->u.btree.pIndex;
-  assert( pIdx!=0 );
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
+  /* Analyze a term that is composed of two or more subterms connected by
+  ** an OR operator.
+  */
+  else if( pExpr->op==TK_OR ){
+    assert( pWC->op==TK_AND );
+    exprAnalyzeOrTerm(pSrc, pWC, idxTerm);
+    pTerm = &pWC->a[idxTerm];
+  }
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
 
-  /* Figure out how many memory cells we will need then allocate them.
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
+  /* Add constraints to reduce the search space on a LIKE or GLOB
+  ** operator.
+  **
+  ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints
+  **
+  **          x>='ABC' AND x<'abd' AND x LIKE 'aBc%'
+  **
+  ** The last character of the prefix "abc" is incremented to form the
+  ** termination condition "abd".  If case is not significant (the default
+  ** for LIKE) then the lower-bound is made all uppercase and the upper-
+  ** bound is made all lowercase so that the bounds also work when comparing
+  ** BLOBs.
   */
-  regBase = pParse->nMem + 1;
-  nReg = pLoop->u.btree.nEq + nExtraReg;
-  pParse->nMem += nReg;
+  if( pWC->op==TK_AND 
+   && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
+  ){
+    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
+    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
+    Expr *pNewExpr1;
+    Expr *pNewExpr2;
+    int idxNew1;
+    int idxNew2;
+    const char *zCollSeqName;     /* Name of collating sequence */
+    const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;
 
-  zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
-  if( !zAff ){
-    pParse->db->mallocFailed = 1;
-  }
+    pLeft = pExpr->x.pList->a[1].pExpr;
+    pStr2 = sqlite3ExprDup(db, pStr1, 0);
 
-  if( nSkip ){
-    int iIdxCur = pLevel->iIdxCur;
-    sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
-    VdbeCoverageIf(v, bRev==0);
-    VdbeCoverageIf(v, bRev!=0);
-    VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
-    j = sqlite3VdbeAddOp0(v, OP_Goto);
-    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
-                            iIdxCur, 0, regBase, nSkip);
-    VdbeCoverageIf(v, bRev==0);
-    VdbeCoverageIf(v, bRev!=0);
-    sqlite3VdbeJumpHere(v, j);
-    for(j=0; jaiColumn[j]>=0 );
-      VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName));
+    /* Convert the lower bound to upper-case and the upper bound to
+    ** lower-case (upper-case is less than lower-case in ASCII) so that
+    ** the range constraints also work for BLOBs
+    */
+    if( noCase && !pParse->db->mallocFailed ){
+      int i;
+      char c;
+      pTerm->wtFlags |= TERM_LIKE;
+      for(i=0; (c = pStr1->u.zToken[i])!=0; i++){
+        pStr1->u.zToken[i] = sqlite3Toupper(c);
+        pStr2->u.zToken[i] = sqlite3Tolower(c);
+      }
     }
-  }    
 
-  /* Evaluate the equality constraints
-  */
-  assert( zAff==0 || (int)strlen(zAff)>=nEq );
-  for(j=nSkip; jaLTerm[j];
-    assert( pTerm!=0 );
-    /* The following testcase is true for indices with redundant columns. 
-    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
-    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL );
-    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
-    if( r1!=regBase+j ){
-      if( nReg==1 ){
-        sqlite3ReleaseTempReg(pParse, regBase);
-        regBase = r1;
-      }else{
-        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+    if( !db->mallocFailed ){
+      u8 c, *pC;       /* Last character before the first wildcard */
+      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
+      c = *pC;
+      if( noCase ){
+        /* The point is to increment the last character before the first
+        ** wildcard.  But if we increment '@', that will push it into the
+        ** alphabetic range where case conversions will mess up the 
+        ** inequality.  To avoid this, make sure to also run the full
+        ** LIKE on all candidate expressions by clearing the isComplete flag
+        */
+        if( c=='A'-1 ) isComplete = 0;
+        c = sqlite3UpperToLower[c];
       }
+      *pC = c + 1;
     }
-    testcase( pTerm->eOperator & WO_ISNULL );
-    testcase( pTerm->eOperator & WO_IN );
-    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
-      Expr *pRight = pTerm->pExpr->pRight;
-      if( sqlite3ExprCanBeNull(pRight) ){
-        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
-        VdbeCoverage(v);
-      }
-      if( zAff ){
-        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){
-          zAff[j] = SQLITE_AFF_NONE;
-        }
-        if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
-          zAff[j] = SQLITE_AFF_NONE;
-        }
+    zCollSeqName = noCase ? "NOCASE" : "BINARY";
+    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
+    pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
+           sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
+           pStr1);
+    transferJoinMarkings(pNewExpr1, pExpr);
+    idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
+    testcase( idxNew1==0 );
+    exprAnalyze(pSrc, pWC, idxNew1);
+    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
+    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
+           sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),
+           pStr2);
+    transferJoinMarkings(pNewExpr2, pExpr);
+    idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);
+    testcase( idxNew2==0 );
+    exprAnalyze(pSrc, pWC, idxNew2);
+    pTerm = &pWC->a[idxTerm];
+    if( isComplete ){
+      markTermAsChild(pWC, idxNew1, idxTerm);
+      markTermAsChild(pWC, idxNew2, idxTerm);
+    }
+  }
+#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Add a WO_MATCH auxiliary term to the constraint set if the
+  ** current expression is of the form:  column MATCH expr.
+  ** This information is used by the xBestIndex methods of
+  ** virtual tables.  The native query optimizer does not attempt
+  ** to do anything with MATCH functions.
+  */
+  if( pWC->op==TK_AND && isMatchOfColumn(pExpr, &eOp2) ){
+    int idxNew;
+    Expr *pRight, *pLeft;
+    WhereTerm *pNewTerm;
+    Bitmask prereqColumn, prereqExpr;
+
+    pRight = pExpr->x.pList->a[0].pExpr;
+    pLeft = pExpr->x.pList->a[1].pExpr;
+    prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
+    prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
+    if( (prereqExpr & prereqColumn)==0 ){
+      Expr *pNewExpr;
+      pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 
+                              0, sqlite3ExprDup(db, pRight, 0));
+      if( ExprHasProperty(pExpr, EP_FromJoin) && pNewExpr ){
+        ExprSetProperty(pNewExpr, EP_FromJoin);
       }
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      testcase( idxNew==0 );
+      pNewTerm = &pWC->a[idxNew];
+      pNewTerm->prereqRight = prereqExpr;
+      pNewTerm->leftCursor = pLeft->iTable;
+      pNewTerm->u.leftColumn = pLeft->iColumn;
+      pNewTerm->eOperator = WO_MATCH;
+      pNewTerm->eMatchOp = eOp2;
+      markTermAsChild(pWC, idxNew, idxTerm);
+      pTerm = &pWC->a[idxTerm];
+      pTerm->wtFlags |= TERM_COPIED;
+      pNewTerm->prereqAll = pTerm->prereqAll;
     }
   }
-  *pzAff = zAff;
-  return regBase;
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+  /* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create
+  ** new terms for each component comparison - "a = ?" and "b = ?".  The
+  ** new terms completely replace the original vector comparison, which is
+  ** no longer used.
+  **
+  ** This is only required if at least one side of the comparison operation
+  ** is not a sub-select.  */
+  if( pWC->op==TK_AND 
+  && (pExpr->op==TK_EQ || pExpr->op==TK_IS)
+  && (nLeft = sqlite3ExprVectorSize(pExpr->pLeft))>1
+  && sqlite3ExprVectorSize(pExpr->pRight)==nLeft
+  && ( (pExpr->pLeft->flags & EP_xIsSelect)==0 
+    || (pExpr->pRight->flags & EP_xIsSelect)==0)
+  ){
+    int i;
+    for(i=0; ipLeft, i);
+      Expr *pRight = sqlite3ExprForVectorField(pParse, pExpr->pRight, i);
+
+      pNew = sqlite3PExpr(pParse, pExpr->op, pLeft, pRight);
+      transferJoinMarkings(pNew, pExpr);
+      idxNew = whereClauseInsert(pWC, pNew, TERM_DYNAMIC);
+      exprAnalyze(pSrc, pWC, idxNew);
+    }
+    pTerm = &pWC->a[idxTerm];
+    pTerm->wtFlags = TERM_CODED|TERM_VIRTUAL;  /* Disable the original */
+    pTerm->eOperator = 0;
+  }
+
+  /* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create
+  ** a virtual term for each vector component. The expression object
+  ** used by each such virtual term is pExpr (the full vector IN(...) 
+  ** expression). The WhereTerm.iField variable identifies the index within
+  ** the vector on the LHS that the virtual term represents.
+  **
+  ** This only works if the RHS is a simple SELECT, not a compound
+  */
+  if( pWC->op==TK_AND && pExpr->op==TK_IN && pTerm->iField==0
+   && pExpr->pLeft->op==TK_VECTOR
+   && pExpr->x.pSelect->pPrior==0
+  ){
+    int i;
+    for(i=0; ipLeft); i++){
+      int idxNew;
+      idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL);
+      pWC->a[idxNew].iField = i+1;
+      exprAnalyze(pSrc, pWC, idxNew);
+      markTermAsChild(pWC, idxNew, idxTerm);
+    }
+  }
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  /* When sqlite_stat3 histogram data is available an operator of the
+  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
+  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
+  ** virtual term of that form.
+  **
+  ** Note that the virtual term must be tagged with TERM_VNULL.
+  */
+  if( pExpr->op==TK_NOTNULL
+   && pExpr->pLeft->op==TK_COLUMN
+   && pExpr->pLeft->iColumn>=0
+   && OptimizationEnabled(db, SQLITE_Stat34)
+  ){
+    Expr *pNewExpr;
+    Expr *pLeft = pExpr->pLeft;
+    int idxNew;
+    WhereTerm *pNewTerm;
+
+    pNewExpr = sqlite3PExpr(pParse, TK_GT,
+                            sqlite3ExprDup(db, pLeft, 0),
+                            sqlite3ExprAlloc(db, TK_NULL, 0, 0));
+
+    idxNew = whereClauseInsert(pWC, pNewExpr,
+                              TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
+    if( idxNew ){
+      pNewTerm = &pWC->a[idxNew];
+      pNewTerm->prereqRight = 0;
+      pNewTerm->leftCursor = pLeft->iTable;
+      pNewTerm->u.leftColumn = pLeft->iColumn;
+      pNewTerm->eOperator = WO_GT;
+      markTermAsChild(pWC, idxNew, idxTerm);
+      pTerm = &pWC->a[idxTerm];
+      pTerm->wtFlags |= TERM_COPIED;
+      pNewTerm->prereqAll = pTerm->prereqAll;
+    }
+  }
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
+  ** an index for tables to the left of the join.
+  */
+  testcase( pTerm!=&pWC->a[idxTerm] );
+  pTerm = &pWC->a[idxTerm];
+  pTerm->prereqRight |= extraRight;
 }
 
-#ifndef SQLITE_OMIT_EXPLAIN
+/***************************************************************************
+** Routines with file scope above.  Interface to the rest of the where.c
+** subsystem follows.
+***************************************************************************/
+
 /*
-** This routine is a helper for explainIndexRange() below
+** This routine identifies subexpressions in the WHERE clause where
+** each subexpression is separated by the AND operator or some other
+** operator specified in the op parameter.  The WhereClause structure
+** is filled with pointers to subexpressions.  For example:
 **
-** pStr holds the text of an expression that we are building up one term
-** at a time.  This routine adds a new term to the end of the expression.
-** Terms are separated by AND so add the "AND" text for second and subsequent
-** terms only.
+**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
+**           \________/     \_______________/     \________________/
+**            slot[0]            slot[1]               slot[2]
+**
+** The original WHERE clause in pExpr is unaltered.  All this routine
+** does is make slot[] entries point to substructure within pExpr.
+**
+** In the previous sentence and in the diagram, "slot[]" refers to
+** the WhereClause.a[] array.  The slot[] array grows as needed to contain
+** all terms of the WHERE clause.
 */
-static void explainAppendTerm(
-  StrAccum *pStr,             /* The text expression being built */
-  int iTerm,                  /* Index of this term.  First is zero */
-  const char *zColumn,        /* Name of the column */
-  const char *zOp             /* Name of the operator */
-){
-  if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
-  sqlite3StrAccumAppendAll(pStr, zColumn);
-  sqlite3StrAccumAppend(pStr, zOp, 1);
-  sqlite3StrAccumAppend(pStr, "?", 1);
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
+  Expr *pE2 = sqlite3ExprSkipCollate(pExpr);
+  pWC->op = op;
+  if( pE2==0 ) return;
+  if( pE2->op!=op ){
+    whereClauseInsert(pWC, pExpr, 0);
+  }else{
+    sqlite3WhereSplit(pWC, pE2->pLeft, op);
+    sqlite3WhereSplit(pWC, pE2->pRight, op);
+  }
 }
 
 /*
-** Argument pLevel describes a strategy for scanning table pTab. This 
-** function appends text to pStr that describes the subset of table
-** rows scanned by the strategy in the form of an SQL expression.
-**
-** For example, if the query:
-**
-**   SELECT * FROM t1 WHERE a=1 AND b>2;
-**
-** is run and there is an index on (a, b), then this function returns a
-** string similar to:
-**
-**   "a=? AND b>?"
+** Initialize a preallocated WhereClause structure.
 */
-static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
-  Index *pIndex = pLoop->u.btree.pIndex;
-  u16 nEq = pLoop->u.btree.nEq;
-  u16 nSkip = pLoop->nSkip;
-  int i, j;
-  Column *aCol = pTab->aCol;
-  i16 *aiColumn = pIndex->aiColumn;
+SQLITE_PRIVATE void sqlite3WhereClauseInit(
+  WhereClause *pWC,        /* The WhereClause to be initialized */
+  WhereInfo *pWInfo        /* The WHERE processing context */
+){
+  pWC->pWInfo = pWInfo;
+  pWC->pOuter = 0;
+  pWC->nTerm = 0;
+  pWC->nSlot = ArraySize(pWC->aStatic);
+  pWC->a = pWC->aStatic;
+}
 
-  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
-  sqlite3StrAccumAppend(pStr, " (", 2);
-  for(i=0; i=nSkip ){
-      explainAppendTerm(pStr, i, z, "=");
-    }else{
-      if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
-      sqlite3XPrintf(pStr, 0, "ANY(%s)", z);
+/*
+** Deallocate a WhereClause structure.  The WhereClause structure
+** itself is not freed.  This routine is the inverse of
+** sqlite3WhereClauseInit().
+*/
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause *pWC){
+  int i;
+  WhereTerm *a;
+  sqlite3 *db = pWC->pWInfo->pParse->db;
+  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
+    if( a->wtFlags & TERM_DYNAMIC ){
+      sqlite3ExprDelete(db, a->pExpr);
+    }
+    if( a->wtFlags & TERM_ORINFO ){
+      whereOrInfoDelete(db, a->u.pOrInfo);
+    }else if( a->wtFlags & TERM_ANDINFO ){
+      whereAndInfoDelete(db, a->u.pAndInfo);
     }
   }
+  if( pWC->a!=pWC->aStatic ){
+    sqlite3DbFree(db, pWC->a);
+  }
+}
 
-  j = i;
-  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
-    char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
-    explainAppendTerm(pStr, i++, z, ">");
+
+/*
+** These routines walk (recursively) an expression tree and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
+  Bitmask mask;
+  if( p==0 ) return 0;
+  if( p->op==TK_COLUMN ){
+    return sqlite3WhereGetMask(pMaskSet, p->iTable);
+  }
+  mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0;
+  assert( !ExprHasProperty(p, EP_TokenOnly) );
+  if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
+  if( p->pRight ){
+    mask |= sqlite3WhereExprUsage(pMaskSet, p->pRight);
+    assert( p->x.pList==0 );
+  }else if( ExprHasProperty(p, EP_xIsSelect) ){
+    if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1;
+    mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
+  }else if( p->x.pList ){
+    mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
   }
-  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
-    char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
-    explainAppendTerm(pStr, i, z, "<");
+  return mask;
+}
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
+  int i;
+  Bitmask mask = 0;
+  if( pList ){
+    for(i=0; inExpr; i++){
+      mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
+    }
   }
-  sqlite3StrAccumAppend(pStr, ")", 1);
+  return mask;
 }
 
+
 /*
-** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
-** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
-** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 
-** is added to the output to describe the table scan strategy in pLevel.
+** Call exprAnalyze on all terms in a WHERE clause.  
 **
-** If an OP_Explain opcode is added to the VM, its address is returned.
-** Otherwise, if no OP_Explain is coded, zero is returned.
+** Note that exprAnalyze() might add new virtual terms onto the
+** end of the WHERE clause.  We do not want to analyze these new
+** virtual terms, so start analyzing at the end and work forward
+** so that the added virtual terms are never processed.
 */
-static int explainOneScan(
-  Parse *pParse,                  /* Parse context */
-  SrcList *pTabList,              /* Table list this loop refers to */
-  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
-  int iLevel,                     /* Value for "level" column of output */
-  int iFrom,                      /* Value for "from" column of output */
-  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(
+  SrcList *pTabList,       /* the FROM clause */
+  WhereClause *pWC         /* the WHERE clause to be analyzed */
 ){
-  int ret = 0;
-#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
-  if( pParse->explain==2 )
+  int i;
+  for(i=pWC->nTerm-1; i>=0; i--){
+    exprAnalyze(pTabList, pWC, i);
+  }
+}
+
+/*
+** For table-valued-functions, transform the function arguments into
+** new WHERE clause terms.  
+**
+** Each function argument translates into an equality constraint against
+** a HIDDEN column in the table.
+*/
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(
+  Parse *pParse,                    /* Parsing context */
+  struct SrcList_item *pItem,       /* The FROM clause term to process */
+  WhereClause *pWC                  /* Xfer function arguments to here */
+){
+  Table *pTab;
+  int j, k;
+  ExprList *pArgs;
+  Expr *pColRef;
+  Expr *pTerm;
+  if( pItem->fg.isTabFunc==0 ) return;
+  pTab = pItem->pTab;
+  assert( pTab!=0 );
+  pArgs = pItem->u1.pFuncArg;
+  if( pArgs==0 ) return;
+  for(j=k=0; jnExpr; j++){
+    while( knCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
+    if( k>=pTab->nCol ){
+      sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
+                      pTab->zName, j);
+      return;
+    }
+    pColRef = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);
+    if( pColRef==0 ) return;
+    pColRef->iTable = pItem->iCursor;
+    pColRef->iColumn = k++;
+    pColRef->pTab = pTab;
+    pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef,
+                         sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0));
+    whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
+  }
+}
+
+/************** End of whereexpr.c *******************************************/
+/************** Begin file where.c *******************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.  This module is responsible for
+** generating the code that loops through a table looking for applicable
+** rows.  Indices are selected and used to speed the search when doing
+** so is applicable.  Because this module is responsible for selecting
+** indices, you might also think of this module as the "query optimizer".
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/* Test variable that can be set to enable WHERE tracing */
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+/***/ int sqlite3WhereTrace = 0;
 #endif
-  {
-    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
-    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
-    sqlite3 *db = pParse->db;     /* Database handle */
-    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
-    int isSearch;                 /* True for a SEARCH. False for SCAN. */
-    WhereLoop *pLoop;             /* The controlling WhereLoop object */
-    u32 flags;                    /* Flags that describe this loop */
-    char *zMsg;                   /* Text to add to EQP output */
-    StrAccum str;                 /* EQP output string */
-    char zBuf[100];               /* Initial space for EQP output string */
 
-    pLoop = pLevel->pWLoop;
-    flags = pLoop->wsFlags;
-    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return 0;
 
-    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
-            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
-            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+/*
+** Return the estimated number of output rows from a WHERE clause
+*/
+SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
+  return pWInfo->nRowOut;
+}
 
-    sqlite3StrAccumInit(&str, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
-    str.db = db;
-    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
-    if( pItem->pSelect ){
-      sqlite3XPrintf(&str, 0, " SUBQUERY %d", pItem->iSelectId);
-    }else{
-      sqlite3XPrintf(&str, 0, " TABLE %s", pItem->zName);
+/*
+** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
+** WHERE clause returns outputs for DISTINCT processing.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
+  return pWInfo->eDistinct;
+}
+
+/*
+** Return TRUE if the WHERE clause returns rows in ORDER BY order.
+** Return FALSE if the output needs to be sorted.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
+  return pWInfo->nOBSat;
+}
+
+/*
+** Return TRUE if the innermost loop of the WHERE clause implementation
+** returns rows in ORDER BY order for complete run of the inner loop.
+**
+** Across multiple iterations of outer loops, the output rows need not be
+** sorted.  As long as rows are sorted for just the innermost loop, this
+** routine can return TRUE.
+*/
+SQLITE_PRIVATE int sqlite3WhereOrderedInnerLoop(WhereInfo *pWInfo){
+  return pWInfo->bOrderedInnerLoop;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to continue
+** immediately with the next row of a WHERE clause.
+*/
+SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
+  assert( pWInfo->iContinue!=0 );
+  return pWInfo->iContinue;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to break
+** out of a WHERE loop.
+*/
+SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
+  return pWInfo->iBreak;
+}
+
+/*
+** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to
+** operate directly on the rowis returned by a WHERE clause.  Return
+** ONEPASS_SINGLE (1) if the statement can operation directly because only
+** a single row is to be changed.  Return ONEPASS_MULTI (2) if the one-pass
+** optimization can be used on multiple 
+**
+** If the ONEPASS optimization is used (if this routine returns true)
+** then also write the indices of open cursors used by ONEPASS
+** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
+** table and iaCur[1] gets the cursor used by an auxiliary index.
+** Either value may be -1, indicating that cursor is not used.
+** Any cursors returned will have been opened for writing.
+**
+** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
+** unable to use the ONEPASS optimization.
+*/
+SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
+  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){
+    sqlite3DebugPrintf("%s cursors: %d %d\n",
+         pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",
+         aiCur[0], aiCur[1]);
+  }
+#endif
+  return pWInfo->eOnePass;
+}
+
+/*
+** Move the content of pSrc into pDest
+*/
+static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
+  pDest->n = pSrc->n;
+  memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
+}
+
+/*
+** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
+**
+** The new entry might overwrite an existing entry, or it might be
+** appended, or it might be discarded.  Do whatever is the right thing
+** so that pSet keeps the N_OR_COST best entries seen so far.
+*/
+static int whereOrInsert(
+  WhereOrSet *pSet,      /* The WhereOrSet to be updated */
+  Bitmask prereq,        /* Prerequisites of the new entry */
+  LogEst rRun,           /* Run-cost of the new entry */
+  LogEst nOut            /* Number of outputs for the new entry */
+){
+  u16 i;
+  WhereOrCost *p;
+  for(i=pSet->n, p=pSet->a; i>0; i--, p++){
+    if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
+      goto whereOrInsert_done;
+    }
+    if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
+      return 0;
+    }
+  }
+  if( pSet->na[pSet->n++];
+    p->nOut = nOut;
+  }else{
+    p = pSet->a;
+    for(i=1; in; i++){
+      if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
     }
+    if( p->rRun<=rRun ) return 0;
+  }
+whereOrInsert_done:
+  p->prereq = prereq;
+  p->rRun = rRun;
+  if( p->nOut>nOut ) p->nOut = nOut;
+  return 1;
+}
 
-    if( pItem->zAlias ){
-      sqlite3XPrintf(&str, 0, " AS %s", pItem->zAlias);
+/*
+** Return the bitmask for the given cursor number.  Return 0 if
+** iCursor is not in the set.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
+  int i;
+  assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
+  for(i=0; in; i++){
+    if( pMaskSet->ix[i]==iCursor ){
+      return MASKBIT(i);
     }
-    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
-      const char *zFmt = 0;
-      Index *pIdx;
+  }
+  return 0;
+}
 
-      assert( pLoop->u.btree.pIndex!=0 );
-      pIdx = pLoop->u.btree.pIndex;
-      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
-      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
-        if( isSearch ){
-          zFmt = "PRIMARY KEY";
+/*
+** Create a new mask for cursor iCursor.
+**
+** There is one cursor per table in the FROM clause.  The number of
+** tables in the FROM clause is limited by a test early in the
+** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
+** array will never overflow.
+*/
+static void createMask(WhereMaskSet *pMaskSet, int iCursor){
+  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
+  pMaskSet->ix[pMaskSet->n++] = iCursor;
+}
+
+/*
+** Advance to the next WhereTerm that matches according to the criteria
+** established when the pScan object was initialized by whereScanInit().
+** Return NULL if there are no more matching WhereTerms.
+*/
+static WhereTerm *whereScanNext(WhereScan *pScan){
+  int iCur;            /* The cursor on the LHS of the term */
+  i16 iColumn;         /* The column on the LHS of the term.  -1 for IPK */
+  Expr *pX;            /* An expression being tested */
+  WhereClause *pWC;    /* Shorthand for pScan->pWC */
+  WhereTerm *pTerm;    /* The term being tested */
+  int k = pScan->k;    /* Where to start scanning */
+
+  assert( pScan->iEquiv<=pScan->nEquiv );
+  pWC = pScan->pWC;
+  while(1){
+    iColumn = pScan->aiColumn[pScan->iEquiv-1];
+    iCur = pScan->aiCur[pScan->iEquiv-1];
+    assert( pWC!=0 );
+    do{
+      for(pTerm=pWC->a+k; knTerm; k++, pTerm++){
+        if( pTerm->leftCursor==iCur
+         && pTerm->u.leftColumn==iColumn
+         && (iColumn!=XN_EXPR
+             || sqlite3ExprCompareSkip(pTerm->pExpr->pLeft,
+                                       pScan->pIdxExpr,iCur)==0)
+         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+        ){
+          if( (pTerm->eOperator & WO_EQUIV)!=0
+           && pScan->nEquivaiCur)
+           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
+          ){
+            int j;
+            for(j=0; jnEquiv; j++){
+              if( pScan->aiCur[j]==pX->iTable
+               && pScan->aiColumn[j]==pX->iColumn ){
+                  break;
+              }
+            }
+            if( j==pScan->nEquiv ){
+              pScan->aiCur[j] = pX->iTable;
+              pScan->aiColumn[j] = pX->iColumn;
+              pScan->nEquiv++;
+            }
+          }
+          if( (pTerm->eOperator & pScan->opMask)!=0 ){
+            /* Verify the affinity and collating sequence match */
+            if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
+              CollSeq *pColl;
+              Parse *pParse = pWC->pWInfo->pParse;
+              pX = pTerm->pExpr;
+              if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
+                continue;
+              }
+              assert(pX->pLeft);
+              pColl = sqlite3BinaryCompareCollSeq(pParse,
+                                                  pX->pLeft, pX->pRight);
+              if( pColl==0 ) pColl = pParse->db->pDfltColl;
+              if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
+                continue;
+              }
+            }
+            if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
+             && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
+             && pX->iTable==pScan->aiCur[0]
+             && pX->iColumn==pScan->aiColumn[0]
+            ){
+              testcase( pTerm->eOperator & WO_IS );
+              continue;
+            }
+            pScan->pWC = pWC;
+            pScan->k = k+1;
+            return pTerm;
+          }
         }
-      }else if( flags & WHERE_PARTIALIDX ){
-        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
-      }else if( flags & WHERE_AUTO_INDEX ){
-        zFmt = "AUTOMATIC COVERING INDEX";
-      }else if( flags & WHERE_IDX_ONLY ){
-        zFmt = "COVERING INDEX %s";
-      }else{
-        zFmt = "INDEX %s";
-      }
-      if( zFmt ){
-        sqlite3StrAccumAppend(&str, " USING ", 7);
-        sqlite3XPrintf(&str, 0, zFmt, pIdx->zName);
-        explainIndexRange(&str, pLoop, pItem->pTab);
       }
-    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
-      const char *zRange;
-      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
-        zRange = "(rowid=?)";
-      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
-        zRange = "(rowid>? AND rowid?)";
-      }else{
-        assert( flags&WHERE_TOP_LIMIT);
-        zRange = "(rowidpOuter;
+      k = 0;
+    }while( pWC!=0 );
+    if( pScan->iEquiv>=pScan->nEquiv ) break;
+    pWC = pScan->pOrigWC;
+    k = 0;
+    pScan->iEquiv++;
+  }
+  return 0;
+}
+
+/*
+** Initialize a WHERE clause scanner object.  Return a pointer to the
+** first match.  Return NULL if there are no matches.
+**
+** The scanner will be searching the WHERE clause pWC.  It will look
+** for terms of the form "X  " where X is column iColumn of table
+** iCur.   Or if pIdx!=0 then X is column iColumn of index pIdx.  pIdx
+** must be one of the indexes of table iCur.
+**
+** The  must be one of the operators described by opMask.
+**
+** If the search is for X and the WHERE clause contains terms of the
+** form X=Y then this routine might also return terms of the form
+** "Y  ".  The number of levels of transitivity is limited,
+** but is enough to handle most commonly occurring SQL statements.
+**
+** If X is not the INTEGER PRIMARY KEY then X must be compatible with
+** index pIdx.
+*/
+static WhereTerm *whereScanInit(
+  WhereScan *pScan,       /* The WhereScan object being initialized */
+  WhereClause *pWC,       /* The WHERE clause to be scanned */
+  int iCur,               /* Cursor to scan for */
+  int iColumn,            /* Column to scan for */
+  u32 opMask,             /* Operator(s) to scan for */
+  Index *pIdx             /* Must be compatible with this index */
+){
+  pScan->pOrigWC = pWC;
+  pScan->pWC = pWC;
+  pScan->pIdxExpr = 0;
+  pScan->idxaff = 0;
+  pScan->zCollName = 0;
+  if( pIdx ){
+    int j = iColumn;
+    iColumn = pIdx->aiColumn[j];
+    if( iColumn==XN_EXPR ){
+      pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
+      pScan->zCollName = pIdx->azColl[j];
+    }else if( iColumn==pIdx->pTable->iPKey ){
+      iColumn = XN_ROWID;
+    }else if( iColumn>=0 ){
+      pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
+      pScan->zCollName = pIdx->azColl[j];
+    }
+  }else if( iColumn==XN_EXPR ){
+    return 0;
+  }
+  pScan->opMask = opMask;
+  pScan->k = 0;
+  pScan->aiCur[0] = iCur;
+  pScan->aiColumn[0] = iColumn;
+  pScan->nEquiv = 1;
+  pScan->iEquiv = 1;
+  return whereScanNext(pScan);
+}
+
+/*
+** Search for a term in the WHERE clause that is of the form "X  "
+** where X is a reference to the iColumn of table iCur or of index pIdx
+** if pIdx!=0 and  is one of the WO_xx operator codes specified by
+** the op parameter.  Return a pointer to the term.  Return 0 if not found.
+**
+** If pIdx!=0 then it must be one of the indexes of table iCur.  
+** Search for terms matching the iColumn-th column of pIdx
+** rather than the iColumn-th column of table iCur.
+**
+** The term returned might by Y= if there is another constraint in
+** the WHERE clause that specifies that X=Y.  Any such constraints will be
+** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
+** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
+** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
+** other equivalent values.  Hence a search for X will return  if X=A1
+** and A1=A2 and A2=A3 and ... and A9=A10 and A10=.
+**
+** If there are multiple terms in the WHERE clause of the form "X  "
+** then try for the one with no dependencies on  - in other words where
+**  is a constant expression of some kind.  Only return entries of
+** the form "X  Y" where Y is a column in another table if no terms of
+** the form "X  " exist.   If no terms with a constant RHS
+** exist, try to return a term that does not use WO_EQUIV.
+*/
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+){
+  WhereTerm *pResult = 0;
+  WhereTerm *p;
+  WhereScan scan;
+
+  p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
+  op &= WO_EQ|WO_IS;
+  while( p ){
+    if( (p->prereqRight & notReady)==0 ){
+      if( p->prereqRight==0 && (p->eOperator&op)!=0 ){
+        testcase( p->eOperator & WO_IS );
+        return p;
       }
-      sqlite3StrAccumAppendAll(&str, " USING INTEGER PRIMARY KEY ");
-      sqlite3StrAccumAppendAll(&str, zRange);
-    }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
-      sqlite3XPrintf(&str, 0, " VIRTUAL TABLE INDEX %d:%s",
-                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
-    }
-#endif
-#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
-    if( pLoop->nOut>=10 ){
-      sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
-    }else{
-      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
+      if( pResult==0 ) pResult = p;
     }
-#endif
-    zMsg = sqlite3StrAccumFinish(&str);
-    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
+    p = whereScanNext(&scan);
   }
-  return ret;
+  return pResult;
 }
-#else
-# define explainOneScan(u,v,w,x,y,z) 0
-#endif /* SQLITE_OMIT_EXPLAIN */
 
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 /*
-** Configure the VM passed as the first argument with an
-** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 
-** implement level pLvl. Argument pSrclist is a pointer to the FROM 
-** clause that the scan reads data from.
+** This function searches pList for an entry that matches the iCol-th column
+** of index pIdx.
 **
-** If argument addrExplain is not 0, it must be the address of an 
-** OP_Explain instruction that describes the same loop.
+** If such an expression is found, its index in pList->a[] is returned. If
+** no expression is found, -1 is returned.
 */
-static void addScanStatus(
-  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
-  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
-  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
-  int addrExplain                 /* Address of OP_Explain (or 0) */
+static int findIndexCol(
+  Parse *pParse,                  /* Parse context */
+  ExprList *pList,                /* Expression list to search */
+  int iBase,                      /* Cursor for table associated with pIdx */
+  Index *pIdx,                    /* Index to match column of */
+  int iCol                        /* Column of index to match */
 ){
-  const char *zObj = 0;
-  WhereLoop *pLoop = pLvl->pWLoop;
-  if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
-    zObj = pLoop->u.btree.pIndex->zName;
-  }else{
-    zObj = pSrclist->a[pLvl->iFrom].zName;
+  int i;
+  const char *zColl = pIdx->azColl[iCol];
+
+  for(i=0; inExpr; i++){
+    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
+    if( p->op==TK_COLUMN
+     && p->iColumn==pIdx->aiColumn[iCol]
+     && p->iTable==iBase
+    ){
+      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
+      if( pColl && 0==sqlite3StrICmp(pColl->zName, zColl) ){
+        return i;
+      }
+    }
   }
-  sqlite3VdbeScanStatus(
-      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
-  );
+
+  return -1;
 }
-#else
-# define addScanStatus(a, b, c, d) ((void)d)
-#endif
 
+/*
+** Return TRUE if the iCol-th column of index pIdx is NOT NULL
+*/
+static int indexColumnNotNull(Index *pIdx, int iCol){
+  int j;
+  assert( pIdx!=0 );
+  assert( iCol>=0 && iColnColumn );
+  j = pIdx->aiColumn[iCol];
+  if( j>=0 ){
+    return pIdx->pTable->aCol[j].notNull;
+  }else if( j==(-1) ){
+    return 1;
+  }else{
+    assert( j==(-2) );
+    return 0;  /* Assume an indexed expression can always yield a NULL */
 
+  }
+}
 
 /*
-** Generate code for the start of the iLevel-th loop in the WHERE clause
-** implementation described by pWInfo.
+** Return true if the DISTINCT expression-list passed as the third argument
+** is redundant.
+**
+** A DISTINCT list is redundant if any subset of the columns in the
+** DISTINCT list are collectively unique and individually non-null.
 */
-static Bitmask codeOneLoopStart(
-  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
-  int iLevel,          /* Which level of pWInfo->a[] should be coded */
-  Bitmask notReady     /* Which tables are currently available */
+static int isDistinctRedundant(
+  Parse *pParse,            /* Parsing context */
+  SrcList *pTabList,        /* The FROM clause */
+  WhereClause *pWC,         /* The WHERE clause */
+  ExprList *pDistinct       /* The result set that needs to be DISTINCT */
 ){
-  int j, k;            /* Loop counters */
-  int iCur;            /* The VDBE cursor for the table */
-  int addrNxt;         /* Where to jump to continue with the next IN case */
-  int omitTable;       /* True if we use the index only */
-  int bRev;            /* True if we need to scan in reverse order */
-  WhereLevel *pLevel;  /* The where level to be coded */
-  WhereLoop *pLoop;    /* The WhereLoop object being coded */
-  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
-  WhereTerm *pTerm;               /* A WHERE clause term */
-  Parse *pParse;                  /* Parsing context */
-  sqlite3 *db;                    /* Database connection */
-  Vdbe *v;                        /* The prepared stmt under constructions */
-  struct SrcList_item *pTabItem;  /* FROM clause term being coded */
-  int addrBrk;                    /* Jump here to break out of the loop */
-  int addrCont;                   /* Jump here to continue with next cycle */
-  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
-  int iReleaseReg = 0;      /* Temp register to free before returning */
+  Table *pTab;
+  Index *pIdx;
+  int i;                          
+  int iBase;
 
-  pParse = pWInfo->pParse;
-  v = pParse->pVdbe;
-  pWC = &pWInfo->sWC;
-  db = pParse->db;
-  pLevel = &pWInfo->a[iLevel];
-  pLoop = pLevel->pWLoop;
-  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
-  iCur = pTabItem->iCursor;
-  pLevel->notReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
-  bRev = (pWInfo->revMask>>iLevel)&1;
-  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
-           && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
-  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
+  /* If there is more than one table or sub-select in the FROM clause of
+  ** this query, then it will not be possible to show that the DISTINCT 
+  ** clause is redundant. */
+  if( pTabList->nSrc!=1 ) return 0;
+  iBase = pTabList->a[0].iCursor;
+  pTab = pTabList->a[0].pTab;
 
-  /* Create labels for the "break" and "continue" instructions
-  ** for the current loop.  Jump to addrBrk to break out of a loop.
-  ** Jump to cont to go immediately to the next iteration of the
-  ** loop.
-  **
-  ** When there is an IN operator, we also have a "addrNxt" label that
-  ** means to continue with the next IN value combination.  When
-  ** there are no IN operators in the constraints, the "addrNxt" label
-  ** is the same as "addrBrk".
+  /* If any of the expressions is an IPK column on table iBase, then return 
+  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
+  ** current SELECT is a correlated sub-query.
   */
-  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
-  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+  for(i=0; inExpr; i++){
+    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
+    if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
+  }
 
-  /* If this is the right table of a LEFT OUTER JOIN, allocate and
-  ** initialize a memory cell that records if this table matches any
-  ** row of the left table of the join.
+  /* Loop through all indices on the table, checking each to see if it makes
+  ** the DISTINCT qualifier redundant. It does so if:
+  **
+  **   1. The index is itself UNIQUE, and
+  **
+  **   2. All of the columns in the index are either part of the pDistinct
+  **      list, or else the WHERE clause contains a term of the form "col=X",
+  **      where X is a constant value. The collation sequences of the
+  **      comparison and select-list expressions must match those of the index.
+  **
+  **   3. All of those index columns for which the WHERE clause does not
+  **      contain a "col=X" term are subject to a NOT NULL constraint.
   */
-  if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
-    pLevel->iLeftJoin = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
-    VdbeComment((v, "init LEFT JOIN no-match flag"));
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    if( !IsUniqueIndex(pIdx) ) continue;
+    for(i=0; inKeyCol; i++){
+      if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){
+        if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;
+        if( indexColumnNotNull(pIdx, i)==0 ) break;
+      }
+    }
+    if( i==pIdx->nKeyCol ){
+      /* This index implies that the DISTINCT qualifier is redundant. */
+      return 1;
+    }
   }
 
-  /* Special case of a FROM clause subquery implemented as a co-routine */
-  if( pTabItem->viaCoroutine ){
-    int regYield = pTabItem->regReturn;
-    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
-    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
-    VdbeCoverage(v);
-    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
-    pLevel->op = OP_Goto;
-  }else
+  return 0;
+}
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
-    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
-    **          to access the data.
-    */
-    int iReg;   /* P3 Value for OP_VFilter */
-    int addrNotFound;
-    int nConstraint = pLoop->nLTerm;
 
-    sqlite3ExprCachePush(pParse);
-    iReg = sqlite3GetTempRange(pParse, nConstraint+2);
-    addrNotFound = pLevel->addrBrk;
-    for(j=0; jaLTerm[j];
-      if( pTerm==0 ) continue;
-      if( pTerm->eOperator & WO_IN ){
-        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
-        addrNotFound = pLevel->addrNxt;
+/*
+** Estimate the logarithm of the input value to base 2.
+*/
+static LogEst estLog(LogEst N){
+  return N<=10 ? 0 : sqlite3LogEst(N) - 33;
+}
+
+/*
+** Convert OP_Column opcodes to OP_Copy in previously generated code.
+**
+** This routine runs over generated VDBE code and translates OP_Column
+** opcodes into OP_Copy when the table is being accessed via co-routine 
+** instead of via table lookup.
+**
+** If the bIncrRowid parameter is 0, then any OP_Rowid instructions on
+** cursor iTabCur are transformed into OP_Null. Or, if bIncrRowid is non-zero,
+** then each OP_Rowid is transformed into an instruction to increment the
+** value stored in its output register.
+*/
+static void translateColumnToCopy(
+  Parse *pParse,      /* Parsing context */
+  int iStart,         /* Translate from this opcode to the end */
+  int iTabCur,        /* OP_Column/OP_Rowid references to this table */
+  int iRegister,      /* The first column is in this register */
+  int bIncrRowid      /* If non-zero, transform OP_rowid to OP_AddImm(1) */
+){
+  Vdbe *v = pParse->pVdbe;
+  VdbeOp *pOp = sqlite3VdbeGetOp(v, iStart);
+  int iEnd = sqlite3VdbeCurrentAddr(v);
+  if( pParse->db->mallocFailed ) return;
+  for(; iStartp1!=iTabCur ) continue;
+    if( pOp->opcode==OP_Column ){
+      pOp->opcode = OP_Copy;
+      pOp->p1 = pOp->p2 + iRegister;
+      pOp->p2 = pOp->p3;
+      pOp->p3 = 0;
+    }else if( pOp->opcode==OP_Rowid ){
+      if( bIncrRowid ){
+        /* Increment the value stored in the P2 operand of the OP_Rowid. */
+        pOp->opcode = OP_AddImm;
+        pOp->p1 = pOp->p2;
+        pOp->p2 = 1;
       }else{
-        sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
-      }
-    }
-    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
-    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
-    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
-                      pLoop->u.vtab.idxStr,
-                      pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
-    VdbeCoverage(v);
-    pLoop->u.vtab.needFree = 0;
-    for(j=0; ju.vtab.omitMask>>j)&1 ){
-        disableTerm(pLevel, pLoop->aLTerm[j]);
+        pOp->opcode = OP_Null;
+        pOp->p1 = 0;
+        pOp->p3 = 0;
       }
     }
-    pLevel->op = OP_VNext;
-    pLevel->p1 = iCur;
-    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
-    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
-    sqlite3ExprCachePop(pParse);
-  }else
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-  if( (pLoop->wsFlags & WHERE_IPK)!=0
-   && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
-  ){
-    /* Case 2:  We can directly reference a single row using an
-    **          equality comparison against the ROWID field.  Or
-    **          we reference multiple rows using a "rowid IN (...)"
-    **          construct.
-    */
-    assert( pLoop->u.btree.nEq==1 );
-    pTerm = pLoop->aLTerm[0];
-    assert( pTerm!=0 );
-    assert( pTerm->pExpr!=0 );
-    assert( omitTable==0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL );
-    iReleaseReg = ++pParse->nMem;
-    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
-    if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
-    addrNxt = pLevel->addrNxt;
-    sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
-    VdbeCoverage(v);
-    sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
-    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-    VdbeComment((v, "pk"));
-    pLevel->op = OP_Noop;
-  }else if( (pLoop->wsFlags & WHERE_IPK)!=0
-         && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
-  ){
-    /* Case 3:  We have an inequality comparison against the ROWID field.
-    */
-    int testOp = OP_Noop;
-    int start;
-    int memEndValue = 0;
-    WhereTerm *pStart, *pEnd;
-
-    assert( omitTable==0 );
-    j = 0;
-    pStart = pEnd = 0;
-    if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
-    if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
-    assert( pStart!=0 || pEnd!=0 );
-    if( bRev ){
-      pTerm = pStart;
-      pStart = pEnd;
-      pEnd = pTerm;
-    }
-    if( pStart ){
-      Expr *pX;             /* The expression that defines the start bound */
-      int r1, rTemp;        /* Registers for holding the start boundary */
+  }
+}
 
-      /* The following constant maps TK_xx codes into corresponding 
-      ** seek opcodes.  It depends on a particular ordering of TK_xx
-      */
-      const u8 aMoveOp[] = {
-           /* TK_GT */  OP_SeekGT,
-           /* TK_LE */  OP_SeekLE,
-           /* TK_LT */  OP_SeekLT,
-           /* TK_GE */  OP_SeekGE
-      };
-      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
-      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
-      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
+/*
+** Two routines for printing the content of an sqlite3_index_info
+** structure.  Used for testing and debugging only.  If neither
+** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
+** are no-ops.
+*/
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
+static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; inConstraint; i++){
+    sqlite3DebugPrintf("  constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
+       i,
+       p->aConstraint[i].iColumn,
+       p->aConstraint[i].iTermOffset,
+       p->aConstraint[i].op,
+       p->aConstraint[i].usable);
+  }
+  for(i=0; inOrderBy; i++){
+    sqlite3DebugPrintf("  orderby[%d]: col=%d desc=%d\n",
+       i,
+       p->aOrderBy[i].iColumn,
+       p->aOrderBy[i].desc);
+  }
+}
+static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; inConstraint; i++){
+    sqlite3DebugPrintf("  usage[%d]: argvIdx=%d omit=%d\n",
+       i,
+       p->aConstraintUsage[i].argvIndex,
+       p->aConstraintUsage[i].omit);
+  }
+  sqlite3DebugPrintf("  idxNum=%d\n", p->idxNum);
+  sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);
+  sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);
+  sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);
+  sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);
+}
+#else
+#define TRACE_IDX_INPUTS(A)
+#define TRACE_IDX_OUTPUTS(A)
+#endif
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+/*
+** Return TRUE if the WHERE clause term pTerm is of a form where it
+** could be used with an index to access pSrc, assuming an appropriate
+** index existed.
+*/
+static int termCanDriveIndex(
+  WhereTerm *pTerm,              /* WHERE clause term to check */
+  struct SrcList_item *pSrc,     /* Table we are trying to access */
+  Bitmask notReady               /* Tables in outer loops of the join */
+){
+  char aff;
+  if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
+  if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;
+  if( (pSrc->fg.jointype & JT_LEFT) 
+   && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+   && (pTerm->eOperator & WO_IS)
+  ){
+    /* Cannot use an IS term from the WHERE clause as an index driver for
+    ** the RHS of a LEFT JOIN. Such a term can only be used if it is from
+    ** the ON clause.  */
+    return 0;
+  }
+  if( (pTerm->prereqRight & notReady)!=0 ) return 0;
+  if( pTerm->u.leftColumn<0 ) return 0;
+  aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
+  if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
+  testcase( pTerm->pExpr->op==TK_IS );
+  return 1;
+}
+#endif
+
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+/*
+** Generate code to construct the Index object for an automatic index
+** and to set up the WhereLevel object pLevel so that the code generator
+** makes use of the automatic index.
+*/
+static void constructAutomaticIndex(
+  Parse *pParse,              /* The parsing context */
+  WhereClause *pWC,           /* The WHERE clause */
+  struct SrcList_item *pSrc,  /* The FROM clause term to get the next index */
+  Bitmask notReady,           /* Mask of cursors that are not available */
+  WhereLevel *pLevel          /* Write new index here */
+){
+  int nKeyCol;                /* Number of columns in the constructed index */
+  WhereTerm *pTerm;           /* A single term of the WHERE clause */
+  WhereTerm *pWCEnd;          /* End of pWC->a[] */
+  Index *pIdx;                /* Object describing the transient index */
+  Vdbe *v;                    /* Prepared statement under construction */
+  int addrInit;               /* Address of the initialization bypass jump */
+  Table *pTable;              /* The table being indexed */
+  int addrTop;                /* Top of the index fill loop */
+  int regRecord;              /* Register holding an index record */
+  int n;                      /* Column counter */
+  int i;                      /* Loop counter */
+  int mxBitCol;               /* Maximum column in pSrc->colUsed */
+  CollSeq *pColl;             /* Collating sequence to on a column */
+  WhereLoop *pLoop;           /* The Loop object */
+  char *zNotUsed;             /* Extra space on the end of pIdx */
+  Bitmask idxCols;            /* Bitmap of columns used for indexing */
+  Bitmask extraCols;          /* Bitmap of additional columns */
+  u8 sentWarning = 0;         /* True if a warnning has been issued */
+  Expr *pPartial = 0;         /* Partial Index Expression */
+  int iContinue = 0;          /* Jump here to skip excluded rows */
+  struct SrcList_item *pTabItem;  /* FROM clause term being indexed */
+  int addrCounter = 0;        /* Address where integer counter is initialized */
+  int regBase;                /* Array of registers where record is assembled */
+
+  /* Generate code to skip over the creation and initialization of the
+  ** transient index on 2nd and subsequent iterations of the loop. */
+  v = pParse->pVdbe;
+  assert( v!=0 );
+  addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+
+  /* Count the number of columns that will be added to the index
+  ** and used to match WHERE clause constraints */
+  nKeyCol = 0;
+  pTable = pSrc->pTab;
+  pWCEnd = &pWC->a[pWC->nTerm];
+  pLoop = pLevel->pWLoop;
+  idxCols = 0;
+  for(pTerm=pWC->a; pTermpExpr;
+    assert( !ExprHasProperty(pExpr, EP_FromJoin)    /* prereq always non-zero */
+         || pExpr->iRightJoinTable!=pSrc->iCursor   /*   for the right-hand   */
+         || pLoop->prereq!=0 );                     /*   table of a LEFT JOIN */
+    if( pLoop->prereq==0
+     && (pTerm->wtFlags & TERM_VIRTUAL)==0
+     && !ExprHasProperty(pExpr, EP_FromJoin)
+     && sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){
+      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
+                                sqlite3ExprDup(pParse->db, pExpr, 0));
+    }
+    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
+      int iCol = pTerm->u.leftColumn;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS );
+      testcase( iCol==BMS-1 );
+      if( !sentWarning ){
+        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
+            "automatic index on %s(%s)", pTable->zName,
+            pTable->aCol[iCol].zName);
+        sentWarning = 1;
+      }
+      if( (idxCols & cMask)==0 ){
+        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
+          goto end_auto_index_create;
+        }
+        pLoop->aLTerm[nKeyCol++] = pTerm;
+        idxCols |= cMask;
+      }
+    }
+  }
+  assert( nKeyCol>0 );
+  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
+  pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
+                     | WHERE_AUTO_INDEX;
+
+  /* Count the number of additional columns needed to create a
+  ** covering index.  A "covering index" is an index that contains all
+  ** columns that are needed by the query.  With a covering index, the
+  ** original table never needs to be accessed.  Automatic indices must
+  ** be a covering index because the index will not be updated if the
+  ** original table changes and the index and table cannot both be used
+  ** if they go out of sync.
+  */
+  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
+  mxBitCol = MIN(BMS-1,pTable->nCol);
+  testcase( pTable->nCol==BMS-1 );
+  testcase( pTable->nCol==BMS-2 );
+  for(i=0; icolUsed & MASKBIT(BMS-1) ){
+    nKeyCol += pTable->nCol - BMS + 1;
+  }
+
+  /* Construct the Index object to describe this index */
+  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
+  if( pIdx==0 ) goto end_auto_index_create;
+  pLoop->u.btree.pIndex = pIdx;
+  pIdx->zName = "auto-index";
+  pIdx->pTable = pTable;
+  n = 0;
+  idxCols = 0;
+  for(pTerm=pWC->a; pTermu.leftColumn;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS-1 );
+      testcase( iCol==BMS );
+      if( (idxCols & cMask)==0 ){
+        Expr *pX = pTerm->pExpr;
+        idxCols |= cMask;
+        pIdx->aiColumn[n] = pTerm->u.leftColumn;
+        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
+        pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
+        n++;
+      }
+    }
+  }
+  assert( (u32)n==pLoop->u.btree.nEq );
+
+  /* Add additional columns needed to make the automatic index into
+  ** a covering index */
+  for(i=0; iaiColumn[n] = i;
+      pIdx->azColl[n] = sqlite3StrBINARY;
+      n++;
+    }
+  }
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
+    for(i=BMS-1; inCol; i++){
+      pIdx->aiColumn[n] = i;
+      pIdx->azColl[n] = sqlite3StrBINARY;
+      n++;
+    }
+  }
+  assert( n==nKeyCol );
+  pIdx->aiColumn[n] = XN_ROWID;
+  pIdx->azColl[n] = sqlite3StrBINARY;
+
+  /* Create the automatic index */
+  assert( pLevel->iIdxCur>=0 );
+  pLevel->iIdxCur = pParse->nTab++;
+  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
+  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+  VdbeComment((v, "for %s", pTable->zName));
+
+  /* Fill the automatic index with content */
+  sqlite3ExprCachePush(pParse);
+  pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+  }else{
+    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
+  }
+  if( pPartial ){
+    iContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
+    pLoop->wsFlags |= WHERE_PARTIALIDX;
+  }
+  regRecord = sqlite3GetTempReg(pParse);
+  regBase = sqlite3GenerateIndexKey(
+      pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
+  );
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
+  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
+  if( pTabItem->fg.viaCoroutine ){
+    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
+    testcase( pParse->db->mallocFailed );
+    translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,
+                          pTabItem->regResult, 1);
+    sqlite3VdbeGoto(v, addrTop);
+    pTabItem->fg.viaCoroutine = 0;
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
+  }
+  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
+  sqlite3VdbeJumpHere(v, addrTop);
+  sqlite3ReleaseTempReg(pParse, regRecord);
+  sqlite3ExprCachePop(pParse);
+  
+  /* Jump here when skipping the initialization */
+  sqlite3VdbeJumpHere(v, addrInit);
+
+end_auto_index_create:
+  sqlite3ExprDelete(pParse->db, pPartial);
+}
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Allocate and populate an sqlite3_index_info structure. It is the 
+** responsibility of the caller to eventually release the structure
+** by passing the pointer returned by this function to sqlite3_free().
+*/
+static sqlite3_index_info *allocateIndexInfo(
+  Parse *pParse,
+  WhereClause *pWC,
+  Bitmask mUnusable,              /* Ignore terms with these prereqs */
+  struct SrcList_item *pSrc,
+  ExprList *pOrderBy,
+  u16 *pmNoOmit                   /* Mask of terms not to omit */
+){
+  int i, j;
+  int nTerm;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_orderby *pIdxOrderBy;
+  struct sqlite3_index_constraint_usage *pUsage;
+  WhereTerm *pTerm;
+  int nOrderBy;
+  sqlite3_index_info *pIdxInfo;
+  u16 mNoOmit = 0;
+
+  /* Count the number of possible WHERE clause constraints referring
+  ** to this virtual table */
+  for(i=nTerm=0, pTerm=pWC->a; inTerm; i++, pTerm++){
+    if( pTerm->leftCursor != pSrc->iCursor ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
+    if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
+    nTerm++;
+  }
+
+  /* If the ORDER BY clause contains only columns in the current 
+  ** virtual table then allocate space for the aOrderBy part of
+  ** the sqlite3_index_info structure.
+  */
+  nOrderBy = 0;
+  if( pOrderBy ){
+    int n = pOrderBy->nExpr;
+    for(i=0; ia[i].pExpr;
+      if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
+    }
+    if( i==n){
+      nOrderBy = n;
+    }
+  }
+
+  /* Allocate the sqlite3_index_info structure
+  */
+  pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)
+                           + (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm
+                           + sizeof(*pIdxOrderBy)*nOrderBy );
+  if( pIdxInfo==0 ){
+    sqlite3ErrorMsg(pParse, "out of memory");
+    return 0;
+  }
+
+  /* Initialize the structure.  The sqlite3_index_info structure contains
+  ** many fields that are declared "const" to prevent xBestIndex from
+  ** changing them.  We have to do some funky casting in order to
+  ** initialize those fields.
+  */
+  pIdxCons = (struct sqlite3_index_constraint*)&pIdxInfo[1];
+  pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
+  pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
+  *(int*)&pIdxInfo->nConstraint = nTerm;
+  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
+  *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;
+  *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;
+  *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =
+                                                                   pUsage;
+
+  for(i=j=0, pTerm=pWC->a; inTerm; i++, pTerm++){
+    u8 op;
+    if( pTerm->leftCursor != pSrc->iCursor ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
+    if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
+    pIdxCons[j].iColumn = pTerm->u.leftColumn;
+    pIdxCons[j].iTermOffset = i;
+    op = (u8)pTerm->eOperator & WO_ALL;
+    if( op==WO_IN ) op = WO_EQ;
+    if( op==WO_MATCH ){
+      op = pTerm->eMatchOp;
+    }
+    pIdxCons[j].op = op;
+    /* The direct assignment in the previous line is possible only because
+    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
+    ** following asserts verify this fact. */
+    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
+    assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
+    assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
+    assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
+    assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
+    assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
+    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
+
+    if( op & (WO_LT|WO_LE|WO_GT|WO_GE)
+     && sqlite3ExprIsVector(pTerm->pExpr->pRight) 
+    ){
+      if( i<16 ) mNoOmit |= (1 << i);
+      if( op==WO_LT ) pIdxCons[j].op = WO_LE;
+      if( op==WO_GT ) pIdxCons[j].op = WO_GE;
+    }
+
+    j++;
+  }
+  for(i=0; ia[i].pExpr;
+    pIdxOrderBy[i].iColumn = pExpr->iColumn;
+    pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;
+  }
+
+  *pmNoOmit = mNoOmit;
+  return pIdxInfo;
+}
+
+/*
+** The table object reference passed as the second argument to this function
+** must represent a virtual table. This function invokes the xBestIndex()
+** method of the virtual table with the sqlite3_index_info object that
+** comes in as the 3rd argument to this function.
+**
+** If an error occurs, pParse is populated with an error message and a
+** non-zero value is returned. Otherwise, 0 is returned and the output
+** part of the sqlite3_index_info structure is left populated.
+**
+** Whether or not an error is returned, it is the responsibility of the
+** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates
+** that this is required.
+*/
+static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
+  sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
+  int rc;
+
+  TRACE_IDX_INPUTS(p);
+  rc = pVtab->pModule->xBestIndex(pVtab, p);
+  TRACE_IDX_OUTPUTS(p);
+
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_NOMEM ){
+      sqlite3OomFault(pParse->db);
+    }else if( !pVtab->zErrMsg ){
+      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
+    }else{
+      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
+    }
+  }
+  sqlite3_free(pVtab->zErrMsg);
+  pVtab->zErrMsg = 0;
+
+#if 0
+  /* This error is now caught by the caller.
+  ** Search for "xBestIndex malfunction" below */
+  for(i=0; inConstraint; i++){
+    if( !p->aConstraint[i].usable && p->aConstraintUsage[i].argvIndex>0 ){
+      sqlite3ErrorMsg(pParse, 
+          "table %s: xBestIndex returned an invalid plan", pTab->zName);
+    }
+  }
+#endif
+
+  return pParse->nErr;
+}
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the location of a particular key among all keys in an
+** index.  Store the results in aStat as follows:
+**
+**    aStat[0]      Est. number of rows less than pRec
+**    aStat[1]      Est. number of rows equal to pRec
+**
+** Return the index of the sample that is the smallest sample that
+** is greater than or equal to pRec. Note that this index is not an index
+** into the aSample[] array - it is an index into a virtual set of samples
+** based on the contents of aSample[] and the number of fields in record 
+** pRec. 
+*/
+static int whereKeyStats(
+  Parse *pParse,              /* Database connection */
+  Index *pIdx,                /* Index to consider domain of */
+  UnpackedRecord *pRec,       /* Vector of values to consider */
+  int roundUp,                /* Round up if true.  Round down if false */
+  tRowcnt *aStat              /* OUT: stats written here */
+){
+  IndexSample *aSample = pIdx->aSample;
+  int iCol;                   /* Index of required stats in anEq[] etc. */
+  int i;                      /* Index of first sample >= pRec */
+  int iSample;                /* Smallest sample larger than or equal to pRec */
+  int iMin = 0;               /* Smallest sample not yet tested */
+  int iTest;                  /* Next sample to test */
+  int res;                    /* Result of comparison operation */
+  int nField;                 /* Number of fields in pRec */
+  tRowcnt iLower = 0;         /* anLt[] + anEq[] of largest sample pRec is > */
+
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER( pParse );
+#endif
+  assert( pRec!=0 );
+  assert( pIdx->nSample>0 );
+  assert( pRec->nField>0 && pRec->nField<=pIdx->nSampleCol );
+
+  /* Do a binary search to find the first sample greater than or equal
+  ** to pRec. If pRec contains a single field, the set of samples to search
+  ** is simply the aSample[] array. If the samples in aSample[] contain more
+  ** than one fields, all fields following the first are ignored.
+  **
+  ** If pRec contains N fields, where N is more than one, then as well as the
+  ** samples in aSample[] (truncated to N fields), the search also has to
+  ** consider prefixes of those samples. For example, if the set of samples
+  ** in aSample is:
+  **
+  **     aSample[0] = (a, 5) 
+  **     aSample[1] = (a, 10) 
+  **     aSample[2] = (b, 5) 
+  **     aSample[3] = (c, 100) 
+  **     aSample[4] = (c, 105)
+  **
+  ** Then the search space should ideally be the samples above and the 
+  ** unique prefixes [a], [b] and [c]. But since that is hard to organize, 
+  ** the code actually searches this set:
+  **
+  **     0: (a) 
+  **     1: (a, 5) 
+  **     2: (a, 10) 
+  **     3: (a, 10) 
+  **     4: (b) 
+  **     5: (b, 5) 
+  **     6: (c) 
+  **     7: (c, 100) 
+  **     8: (c, 105)
+  **     9: (c, 105)
+  **
+  ** For each sample in the aSample[] array, N samples are present in the
+  ** effective sample array. In the above, samples 0 and 1 are based on 
+  ** sample aSample[0]. Samples 2 and 3 on aSample[1] etc.
+  **
+  ** Often, sample i of each block of N effective samples has (i+1) fields.
+  ** Except, each sample may be extended to ensure that it is greater than or
+  ** equal to the previous sample in the array. For example, in the above, 
+  ** sample 2 is the first sample of a block of N samples, so at first it 
+  ** appears that it should be 1 field in size. However, that would make it 
+  ** smaller than sample 1, so the binary search would not work. As a result, 
+  ** it is extended to two fields. The duplicates that this creates do not 
+  ** cause any problems.
+  */
+  nField = pRec->nField;
+  iCol = 0;
+  iSample = pIdx->nSample * nField;
+  do{
+    int iSamp;                    /* Index in aSample[] of test sample */
+    int n;                        /* Number of fields in test sample */
+
+    iTest = (iMin+iSample)/2;
+    iSamp = iTest / nField;
+    if( iSamp>0 ){
+      /* The proposed effective sample is a prefix of sample aSample[iSamp].
+      ** Specifically, the shortest prefix of at least (1 + iTest%nField) 
+      ** fields that is greater than the previous effective sample.  */
+      for(n=(iTest % nField) + 1; nnField = n;
+    res = sqlite3VdbeRecordCompare(aSample[iSamp].n, aSample[iSamp].p, pRec);
+    if( res<0 ){
+      iLower = aSample[iSamp].anLt[n-1] + aSample[iSamp].anEq[n-1];
+      iMin = iTest+1;
+    }else if( res==0 && ndb->mallocFailed==0 ){
+    if( res==0 ){
+      /* If (res==0) is true, then pRec must be equal to sample i. */
+      assert( inSample );
+      assert( iCol==nField-1 );
+      pRec->nField = nField;
+      assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec) 
+           || pParse->db->mallocFailed 
+      );
+    }else{
+      /* Unless i==pIdx->nSample, indicating that pRec is larger than
+      ** all samples in the aSample[] array, pRec must be smaller than the
+      ** (iCol+1) field prefix of sample i.  */
+      assert( i<=pIdx->nSample && i>=0 );
+      pRec->nField = iCol+1;
+      assert( i==pIdx->nSample 
+           || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
+           || pParse->db->mallocFailed );
+
+      /* if i==0 and iCol==0, then record pRec is smaller than all samples
+      ** in the aSample[] array. Otherwise, if (iCol>0) then pRec must
+      ** be greater than or equal to the (iCol) field prefix of sample i.
+      ** If (i>0), then pRec must also be greater than sample (i-1).  */
+      if( iCol>0 ){
+        pRec->nField = iCol;
+        assert( sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)<=0
+             || pParse->db->mallocFailed );
+      }
+      if( i>0 ){
+        pRec->nField = nField;
+        assert( sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
+             || pParse->db->mallocFailed );
+      }
+    }
+  }
+#endif /* ifdef SQLITE_DEBUG */
+
+  if( res==0 ){
+    /* Record pRec is equal to sample i */
+    assert( iCol==nField-1 );
+    aStat[0] = aSample[i].anLt[iCol];
+    aStat[1] = aSample[i].anEq[iCol];
+  }else{
+    /* At this point, the (iCol+1) field prefix of aSample[i] is the first 
+    ** sample that is greater than pRec. Or, if i==pIdx->nSample then pRec
+    ** is larger than all samples in the array. */
+    tRowcnt iUpper, iGap;
+    if( i>=pIdx->nSample ){
+      iUpper = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
+    }else{
+      iUpper = aSample[i].anLt[iCol];
+    }
+
+    if( iLower>=iUpper ){
+      iGap = 0;
+    }else{
+      iGap = iUpper - iLower;
+    }
+    if( roundUp ){
+      iGap = (iGap*2)/3;
+    }else{
+      iGap = iGap/3;
+    }
+    aStat[0] = iLower + iGap;
+    aStat[1] = pIdx->aAvgEq[nField-1];
+  }
+
+  /* Restore the pRec->nField value before returning.  */
+  pRec->nField = nField;
+  return i;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** If it is not NULL, pTerm is a term that provides an upper or lower
+** bound on a range scan. Without considering pTerm, it is estimated 
+** that the scan will visit nNew rows. This function returns the number
+** estimated to be visited after taking pTerm into account.
+**
+** If the user explicitly specified a likelihood() value for this term,
+** then the return value is the likelihood multiplied by the number of
+** input rows. Otherwise, this function assumes that an "IS NOT NULL" term
+** has a likelihood of 0.50, and any other term a likelihood of 0.25.
+*/
+static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
+  LogEst nRet = nNew;
+  if( pTerm ){
+    if( pTerm->truthProb<=0 ){
+      nRet += pTerm->truthProb;
+    }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){
+      nRet -= 20;        assert( 20==sqlite3LogEst(4) );
+    }
+  }
+  return nRet;
+}
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Return the affinity for a single column of an index.
+*/
+SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){
+  assert( iCol>=0 && iColnColumn );
+  if( !pIdx->zColAff ){
+    if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;
+  }
+  return pIdx->zColAff[iCol];
+}
+#endif
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/* 
+** This function is called to estimate the number of rows visited by a
+** range-scan on a skip-scan index. For example:
+**
+**   CREATE INDEX i1 ON t1(a, b, c);
+**   SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;
+**
+** Value pLoop->nOut is currently set to the estimated number of rows 
+** visited for scanning (a=? AND b=?). This function reduces that estimate 
+** by some factor to account for the (c BETWEEN ? AND ?) expression based
+** on the stat4 data for the index. this scan will be peformed multiple 
+** times (once for each (a,b) combination that matches a=?) is dealt with 
+** by the caller.
+**
+** It does this by scanning through all stat4 samples, comparing values
+** extracted from pLower and pUpper with the corresponding column in each
+** sample. If L and U are the number of samples found to be less than or
+** equal to the values extracted from pLower and pUpper respectively, and
+** N is the total number of samples, the pLoop->nOut value is adjusted
+** as follows:
+**
+**   nOut = nOut * ( min(U - L, 1) / N )
+**
+** If pLower is NULL, or a value cannot be extracted from the term, L is
+** set to zero. If pUpper is NULL, or a value cannot be extracted from it,
+** U is set to N.
+**
+** Normally, this function sets *pbDone to 1 before returning. However,
+** if no value can be extracted from either pLower or pUpper (and so the
+** estimate of the number of rows delivered remains unchanged), *pbDone
+** is left as is.
+**
+** If an error occurs, an SQLite error code is returned. Otherwise, 
+** SQLITE_OK.
+*/
+static int whereRangeSkipScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
+  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
+  WhereLoop *pLoop,    /* Update the .nOut value of this loop */
+  int *pbDone          /* Set to true if at least one expr. value extracted */
+){
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+  sqlite3 *db = pParse->db;
+  int nLower = -1;
+  int nUpper = p->nSample+1;
+  int rc = SQLITE_OK;
+  u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);
+  CollSeq *pColl;
+  
+  sqlite3_value *p1 = 0;          /* Value extracted from pLower */
+  sqlite3_value *p2 = 0;          /* Value extracted from pUpper */
+  sqlite3_value *pVal = 0;        /* Value extracted from record */
+
+  pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);
+  if( pLower ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);
+    nLower = 0;
+  }
+  if( pUpper && rc==SQLITE_OK ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);
+    nUpper = p2 ? 0 : p->nSample;
+  }
+
+  if( p1 || p2 ){
+    int i;
+    int nDiff;
+    for(i=0; rc==SQLITE_OK && inSample; i++){
+      rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);
+      if( rc==SQLITE_OK && p1 ){
+        int res = sqlite3MemCompare(p1, pVal, pColl);
+        if( res>=0 ) nLower++;
+      }
+      if( rc==SQLITE_OK && p2 ){
+        int res = sqlite3MemCompare(p2, pVal, pColl);
+        if( res>=0 ) nUpper++;
+      }
+    }
+    nDiff = (nUpper - nLower);
+    if( nDiff<=0 ) nDiff = 1;
+
+    /* If there is both an upper and lower bound specified, and the 
+    ** comparisons indicate that they are close together, use the fallback
+    ** method (assume that the scan visits 1/64 of the rows) for estimating
+    ** the number of rows visited. Otherwise, estimate the number of rows
+    ** using the method described in the header comment for this function. */
+    if( nDiff!=1 || pUpper==0 || pLower==0 ){
+      int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));
+      pLoop->nOut -= nAdjust;
+      *pbDone = 1;
+      WHERETRACE(0x10, ("range skip-scan regions: %u..%u  adjust=%d est=%d\n",
+                           nLower, nUpper, nAdjust*-1, pLoop->nOut));
+    }
+
+  }else{
+    assert( *pbDone==0 );
+  }
+
+  sqlite3ValueFree(p1);
+  sqlite3ValueFree(p2);
+  sqlite3ValueFree(pVal);
+
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** This function is used to estimate the number of rows that will be visited
+** by scanning an index for a range of values. The range may have an upper
+** bound, a lower bound, or both. The WHERE clause terms that set the upper
+** and lower bounds are represented by pLower and pUpper respectively. For
+** example, assuming that index p is on t1(a):
+**
+**   ... FROM t1 WHERE a > ? AND a < ? ...
+**                    |_____|   |_____|
+**                       |         |
+**                     pLower    pUpper
+**
+** If either of the upper or lower bound is not present, then NULL is passed in
+** place of the corresponding WhereTerm.
+**
+** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
+** column subject to the range constraint. Or, equivalently, the number of
+** equality constraints optimized by the proposed index scan. For example,
+** assuming index p is on t1(a, b), and the SQL query is:
+**
+**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
+**
+** then nEq is set to 1 (as the range restricted column, b, is the second 
+** left-most column of the index). Or, if the query is:
+**
+**   ... FROM t1 WHERE a > ? AND a < ? ...
+**
+** then nEq is set to 0.
+**
+** When this function is called, *pnOut is set to the sqlite3LogEst() of the
+** number of rows that the index scan is expected to visit without 
+** considering the range constraints. If nEq is 0, then *pnOut is the number of 
+** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
+** to account for the range constraints pLower and pUpper.
+** 
+** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
+** used, a single range inequality reduces the search space by a factor of 4. 
+** and a pair of constraints (x>? AND x123" Might be NULL */
+  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
+  WhereLoop *pLoop     /* Modify the .nOut and maybe .rRun fields */
+){
+  int rc = SQLITE_OK;
+  int nOut = pLoop->nOut;
+  LogEst nNew;
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+
+  if( p->nSample>0 && nEqnSampleCol ){
+    if( nEq==pBuilder->nRecValid ){
+      UnpackedRecord *pRec = pBuilder->pRec;
+      tRowcnt a[2];
+      int nBtm = pLoop->u.btree.nBtm;
+      int nTop = pLoop->u.btree.nTop;
+
+      /* Variable iLower will be set to the estimate of the number of rows in 
+      ** the index that are less than the lower bound of the range query. The
+      ** lower bound being the concatenation of $P and $L, where $P is the
+      ** key-prefix formed by the nEq values matched against the nEq left-most
+      ** columns of the index, and $L is the value in pLower.
+      **
+      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
+      ** is not a simple variable or literal value), the lower bound of the
+      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
+      ** if $L is available, whereKeyStats() is called for both ($P) and 
+      ** ($P:$L) and the larger of the two returned values is used.
+      **
+      ** Similarly, iUpper is to be set to the estimate of the number of rows
+      ** less than the upper bound of the range query. Where the upper bound
+      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
+      ** of iUpper are requested of whereKeyStats() and the smaller used.
+      **
+      ** The number of rows between the two bounds is then just iUpper-iLower.
+      */
+      tRowcnt iLower;     /* Rows less than the lower bound */
+      tRowcnt iUpper;     /* Rows less than the upper bound */
+      int iLwrIdx = -2;   /* aSample[] for the lower bound */
+      int iUprIdx = -1;   /* aSample[] for the upper bound */
+
+      if( pRec ){
+        testcase( pRec->nField!=pBuilder->nRecValid );
+        pRec->nField = pBuilder->nRecValid;
+      }
+      /* Determine iLower and iUpper using ($P) only. */
+      if( nEq==0 ){
+        iLower = 0;
+        iUpper = p->nRowEst0;
+      }else{
+        /* Note: this call could be optimized away - since the same values must 
+        ** have been requested when testing key $P in whereEqualScanEst().  */
+        whereKeyStats(pParse, p, pRec, 0, a);
+        iLower = a[0];
+        iUpper = a[0] + a[1];
+      }
+
+      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
+      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
+      assert( p->aSortOrder!=0 );
+      if( p->aSortOrder[nEq] ){
+        /* The roles of pLower and pUpper are swapped for a DESC index */
+        SWAP(WhereTerm*, pLower, pUpper);
+        SWAP(int, nBtm, nTop);
+      }
+
+      /* If possible, improve on the iLower estimate using ($P:$L). */
+      if( pLower ){
+        int n;                    /* Values extracted from pExpr */
+        Expr *pExpr = pLower->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nBtm, nEq, &n);
+        if( rc==SQLITE_OK && n ){
+          tRowcnt iNew;
+          u16 mask = WO_GT|WO_LE;
+          if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
+          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
+          iNew = a[0] + ((pLower->eOperator & mask) ? a[1] : 0);
+          if( iNew>iLower ) iLower = iNew;
+          nOut--;
+          pLower = 0;
+        }
+      }
+
+      /* If possible, improve on the iUpper estimate using ($P:$U). */
+      if( pUpper ){
+        int n;                    /* Values extracted from pExpr */
+        Expr *pExpr = pUpper->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nTop, nEq, &n);
+        if( rc==SQLITE_OK && n ){
+          tRowcnt iNew;
+          u16 mask = WO_GT|WO_LE;
+          if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
+          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
+          iNew = a[0] + ((pUpper->eOperator & mask) ? a[1] : 0);
+          if( iNewpRec = pRec;
+      if( rc==SQLITE_OK ){
+        if( iUpper>iLower ){
+          nNew = sqlite3LogEst(iUpper - iLower);
+          /* TUNING:  If both iUpper and iLower are derived from the same
+          ** sample, then assume they are 4x more selective.  This brings
+          ** the estimated selectivity more in line with what it would be
+          ** if estimated without the use of STAT3/4 tables. */
+          if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );
+        }else{
+          nNew = 10;        assert( 10==sqlite3LogEst(2) );
+        }
+        if( nNewwtFlags & TERM_VNULL)==0 );
+  nNew = whereRangeAdjust(pLower, nOut);
+  nNew = whereRangeAdjust(pUpper, nNew);
+
+  /* TUNING: If there is both an upper and lower limit and neither limit
+  ** has an application-defined likelihood(), assume the range is
+  ** reduced by an additional 75%. This means that, by default, an open-ended
+  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
+  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
+  ** match 1/64 of the index. */ 
+  if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
+    nNew -= 20;
+  }
+
+  nOut -= (pLower!=0) + (pUpper!=0);
+  if( nNew<10 ) nNew = 10;
+  if( nNewnOut>nOut ){
+    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
+                    pLoop->nOut, nOut));
+  }
+#endif
+  pLoop->nOut = (LogEst)nOut;
+  return rc;
+}
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the number of rows that will be returned based on
+** an equality constraint x=VALUE and where that VALUE occurs in
+** the histogram data.  This only works when x is the left-most
+** column of an index and sqlite_stat3 histogram data is available
+** for that index.  When pExpr==NULL that means the constraint is
+** "x IS NULL" instead of "x=VALUE".
+**
+** Write the estimated row count into *pnRow and return SQLITE_OK. 
+** If unable to make an estimate, leave *pnRow unchanged and return
+** non-zero.
+**
+** This routine can fail if it is unable to load a collating sequence
+** required for string comparison, or if unable to allocate memory
+** for a UTF conversion required for comparison.  The error is stored
+** in the pParse structure.
+*/
+static int whereEqualScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereLoopBuilder *pBuilder,
+  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
+){
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  int nEq = pBuilder->pNew->u.btree.nEq;
+  UnpackedRecord *pRec = pBuilder->pRec;
+  int rc;                   /* Subfunction return code */
+  tRowcnt a[2];             /* Statistics */
+  int bOk;
+
+  assert( nEq>=1 );
+  assert( nEq<=p->nColumn );
+  assert( p->aSample!=0 );
+  assert( p->nSample>0 );
+  assert( pBuilder->nRecValidnRecValid<(nEq-1) ){
+    return SQLITE_NOTFOUND;
+  }
+
+  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
+  ** below would return the same value.  */
+  if( nEq>=p->nColumn ){
+    *pnRow = 1;
+    return SQLITE_OK;
+  }
+
+  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, 1, nEq-1, &bOk);
+  pBuilder->pRec = pRec;
+  if( rc!=SQLITE_OK ) return rc;
+  if( bOk==0 ) return SQLITE_NOTFOUND;
+  pBuilder->nRecValid = nEq;
+
+  whereKeyStats(pParse, p, pRec, 0, a);
+  WHERETRACE(0x10,("equality scan regions %s(%d): %d\n",
+                   p->zName, nEq-1, (int)a[1]));
+  *pnRow = a[1];
+  
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the number of rows that will be returned based on
+** an IN constraint where the right-hand side of the IN operator
+** is a list of values.  Example:
+**
+**        WHERE x IN (1,2,3,4)
+**
+** Write the estimated row count into *pnRow and return SQLITE_OK. 
+** If unable to make an estimate, leave *pnRow unchanged and return
+** non-zero.
+**
+** This routine can fail if it is unable to load a collating sequence
+** required for string comparison, or if unable to allocate memory
+** for a UTF conversion required for comparison.  The error is stored
+** in the pParse structure.
+*/
+static int whereInScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereLoopBuilder *pBuilder,
+  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
+){
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);
+  int nRecValid = pBuilder->nRecValid;
+  int rc = SQLITE_OK;     /* Subfunction return code */
+  tRowcnt nEst;           /* Number of rows for a single term */
+  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
+  int i;                  /* Loop counter */
+
+  assert( p->aSample!=0 );
+  for(i=0; rc==SQLITE_OK && inExpr; i++){
+    nEst = nRow0;
+    rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
+    nRowEst += nEst;
+    pBuilder->nRecValid = nRecValid;
+  }
+
+  if( rc==SQLITE_OK ){
+    if( nRowEst > nRow0 ) nRowEst = nRow0;
+    *pnRow = nRowEst;
+    WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
+  }
+  assert( pBuilder->nRecValid==nRecValid );
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+
+#ifdef WHERETRACE_ENABLED
+/*
+** Print the content of a WhereTerm object
+*/
+static void whereTermPrint(WhereTerm *pTerm, int iTerm){
+  if( pTerm==0 ){
+    sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
+  }else{
+    char zType[4];
+    char zLeft[50];
+    memcpy(zType, "...", 4);
+    if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
+    if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';
+    if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
+    if( pTerm->eOperator & WO_SINGLE ){
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"left={%d:%d}",
+                       pTerm->leftCursor, pTerm->u.leftColumn);
+    }else if( (pTerm->eOperator & WO_OR)!=0 && pTerm->u.pOrInfo!=0 ){
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"indexable=0x%lld", 
+                       pTerm->u.pOrInfo->indexable);
+    }else{
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"left=%d", pTerm->leftCursor);
+    }
+    sqlite3DebugPrintf(
+       "TERM-%-3d %p %s %-12s prob=%-3d op=0x%03x wtFlags=0x%04x",
+       iTerm, pTerm, zType, zLeft, pTerm->truthProb,
+       pTerm->eOperator, pTerm->wtFlags);
+    if( pTerm->iField ){
+      sqlite3DebugPrintf(" iField=%d\n", pTerm->iField);
+    }else{
+      sqlite3DebugPrintf("\n");
+    }
+    sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
+  }
+}
+#endif
+
+#ifdef WHERETRACE_ENABLED
+/*
+** Show the complete content of a WhereClause
+*/
+SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC){
+  int i;
+  for(i=0; inTerm; i++){
+    whereTermPrint(&pWC->a[i], i);
+  }
+}
+#endif
+
+#ifdef WHERETRACE_ENABLED
+/*
+** Print a WhereLoop object for debugging purposes
+*/
+static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
+  WhereInfo *pWInfo = pWC->pWInfo;
+  int nb = 1+(pWInfo->pTabList->nSrc+3)/4;
+  struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
+  Table *pTab = pItem->pTab;
+  Bitmask mAll = (((Bitmask)1)<<(nb*4)) - 1;
+  sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
+                     p->iTab, nb, p->maskSelf, nb, p->prereq & mAll);
+  sqlite3DebugPrintf(" %12s",
+                     pItem->zAlias ? pItem->zAlias : pTab->zName);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    const char *zName;
+    if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
+      if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
+        int i = sqlite3Strlen30(zName) - 1;
+        while( zName[i]!='_' ) i--;
+        zName += i;
+      }
+      sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
+    }else{
+      sqlite3DebugPrintf("%20s","");
+    }
+  }else{
+    char *z;
+    if( p->u.vtab.idxStr ){
+      z = sqlite3_mprintf("(%d,\"%s\",%x)",
+                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+    }else{
+      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
+    }
+    sqlite3DebugPrintf(" %-19s", z);
+    sqlite3_free(z);
+  }
+  if( p->wsFlags & WHERE_SKIPSCAN ){
+    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
+  }else{
+    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
+  }
+  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
+    int i;
+    for(i=0; inLTerm; i++){
+      whereTermPrint(p->aLTerm[i], i);
+    }
+  }
+}
+#endif
+
+/*
+** Convert bulk memory into a valid WhereLoop that can be passed
+** to whereLoopClear harmlessly.
+*/
+static void whereLoopInit(WhereLoop *p){
+  p->aLTerm = p->aLTermSpace;
+  p->nLTerm = 0;
+  p->nLSlot = ArraySize(p->aLTermSpace);
+  p->wsFlags = 0;
+}
+
+/*
+** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.
+*/
+static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
+  if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
+    if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
+      sqlite3_free(p->u.vtab.idxStr);
+      p->u.vtab.needFree = 0;
+      p->u.vtab.idxStr = 0;
+    }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
+      sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
+      sqlite3DbFreeNN(db, p->u.btree.pIndex);
+      p->u.btree.pIndex = 0;
+    }
+  }
+}
+
+/*
+** Deallocate internal memory used by a WhereLoop object
+*/
+static void whereLoopClear(sqlite3 *db, WhereLoop *p){
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);
+  whereLoopClearUnion(db, p);
+  whereLoopInit(p);
+}
+
+/*
+** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+*/
+static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
+  WhereTerm **paNew;
+  if( p->nLSlot>=n ) return SQLITE_OK;
+  n = (n+7)&~7;
+  paNew = sqlite3DbMallocRawNN(db, sizeof(p->aLTerm[0])*n);
+  if( paNew==0 ) return SQLITE_NOMEM_BKPT;
+  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);
+  p->aLTerm = paNew;
+  p->nLSlot = n;
+  return SQLITE_OK;
+}
+
+/*
+** Transfer content from the second pLoop into the first.
+*/
+static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
+  whereLoopClearUnion(db, pTo);
+  if( whereLoopResize(db, pTo, pFrom->nLTerm) ){
+    memset(&pTo->u, 0, sizeof(pTo->u));
+    return SQLITE_NOMEM_BKPT;
+  }
+  memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
+  memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
+  if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
+    pFrom->u.vtab.needFree = 0;
+  }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+    pFrom->u.btree.pIndex = 0;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Delete a WhereLoop object
+*/
+static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
+  whereLoopClear(db, p);
+  sqlite3DbFreeNN(db, p);
+}
+
+/*
+** Free a WhereInfo structure
+*/
+static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
+  if( ALWAYS(pWInfo) ){
+    int i;
+    for(i=0; inLevel; i++){
+      WhereLevel *pLevel = &pWInfo->a[i];
+      if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
+        sqlite3DbFree(db, pLevel->u.in.aInLoop);
+      }
+    }
+    sqlite3WhereClauseClear(&pWInfo->sWC);
+    while( pWInfo->pLoops ){
+      WhereLoop *p = pWInfo->pLoops;
+      pWInfo->pLoops = p->pNextLoop;
+      whereLoopDelete(db, p);
+    }
+    sqlite3DbFreeNN(db, pWInfo);
+  }
+}
+
+/*
+** Return TRUE if all of the following are true:
+**
+**   (1)  X has the same or lower cost that Y
+**   (2)  X is a proper subset of Y
+**   (3)  X skips at least as many columns as Y
+**
+** By "proper subset" we mean that X uses fewer WHERE clause terms
+** than Y and that every WHERE clause term used by X is also used
+** by Y.
+**
+** If X is a proper subset of Y then Y is a better choice and ought
+** to have a lower cost.  This routine returns TRUE when that cost 
+** relationship is inverted and needs to be adjusted.  The third rule
+** was added because if X uses skip-scan less than Y it still might
+** deserve a lower cost even if it is a proper subset of Y.
+*/
+static int whereLoopCheaperProperSubset(
+  const WhereLoop *pX,       /* First WhereLoop to compare */
+  const WhereLoop *pY        /* Compare against this WhereLoop */
+){
+  int i, j;
+  if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
+    return 0; /* X is not a subset of Y */
+  }
+  if( pY->nSkip > pX->nSkip ) return 0;
+  if( pX->rRun >= pY->rRun ){
+    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
+    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
+  }
+  for(i=pX->nLTerm-1; i>=0; i--){
+    if( pX->aLTerm[i]==0 ) continue;
+    for(j=pY->nLTerm-1; j>=0; j--){
+      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
+    }
+    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
+  }
+  return 1;  /* All conditions meet */
+}
+
+/*
+** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so
+** that:
+**
+**   (1) pTemplate costs less than any other WhereLoops that are a proper
+**       subset of pTemplate
+**
+**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
+**       is a proper subset.
+**
+** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
+** WHERE clause terms than Y and that every WHERE clause term used by X is
+** also used by Y.
+*/
+static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
+  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
+  for(; p; p=p->pNextLoop){
+    if( p->iTab!=pTemplate->iTab ) continue;
+    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
+    if( whereLoopCheaperProperSubset(p, pTemplate) ){
+      /* Adjust pTemplate cost downward so that it is cheaper than its 
+      ** subset p. */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut - 1;
+    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
+      /* Adjust pTemplate cost upward so that it is costlier than p since
+      ** pTemplate is a proper subset of p */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut + 1;
+    }
+  }
+}
+
+/*
+** Search the list of WhereLoops in *ppPrev looking for one that can be
+** replaced by pTemplate.
+**
+** Return NULL if pTemplate does not belong on the WhereLoop list.
+** In other words if pTemplate ought to be dropped from further consideration.
+**
+** If pX is a WhereLoop that pTemplate can replace, then return the
+** link that points to pX.
+**
+** If pTemplate cannot replace any existing element of the list but needs
+** to be added to the list as a new entry, then return a pointer to the
+** tail of the list.
+*/
+static WhereLoop **whereLoopFindLesser(
+  WhereLoop **ppPrev,
+  const WhereLoop *pTemplate
+){
+  WhereLoop *p;
+  for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
+    if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
+      /* If either the iTab or iSortIdx values for two WhereLoop are different
+      ** then those WhereLoops need to be considered separately.  Neither is
+      ** a candidate to replace the other. */
+      continue;
+    }
+    /* In the current implementation, the rSetup value is either zero
+    ** or the cost of building an automatic index (NlogN) and the NlogN
+    ** is the same for compatible WhereLoops. */
+    assert( p->rSetup==0 || pTemplate->rSetup==0 
+                 || p->rSetup==pTemplate->rSetup );
+
+    /* whereLoopAddBtree() always generates and inserts the automatic index
+    ** case first.  Hence compatible candidate WhereLoops never have a larger
+    ** rSetup. Call this SETUP-INVARIANT */
+    assert( p->rSetup>=pTemplate->rSetup );
+
+    /* Any loop using an appliation-defined index (or PRIMARY KEY or
+    ** UNIQUE constraint) with one or more == constraints is better
+    ** than an automatic index. Unless it is a skip-scan. */
+    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
+     && (pTemplate->nSkip)==0
+     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
+     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
+    ){
+      break;
+    }
+
+    /* If existing WhereLoop p is better than pTemplate, pTemplate can be
+    ** discarded.  WhereLoop p is better if:
+    **   (1)  p has no more dependencies than pTemplate, and
+    **   (2)  p has an equal or lower cost than pTemplate
+    */
+    if( (p->prereq & pTemplate->prereq)==p->prereq    /* (1)  */
+     && p->rSetup<=pTemplate->rSetup                  /* (2a) */
+     && p->rRun<=pTemplate->rRun                      /* (2b) */
+     && p->nOut<=pTemplate->nOut                      /* (2c) */
+    ){
+      return 0;  /* Discard pTemplate */
+    }
+
+    /* If pTemplate is always better than p, then cause p to be overwritten
+    ** with pTemplate.  pTemplate is better than p if:
+    **   (1)  pTemplate has no more dependences than p, and
+    **   (2)  pTemplate has an equal or lower cost than p.
+    */
+    if( (p->prereq & pTemplate->prereq)==pTemplate->prereq   /* (1)  */
+     && p->rRun>=pTemplate->rRun                             /* (2a) */
+     && p->nOut>=pTemplate->nOut                             /* (2b) */
+    ){
+      assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
+      break;   /* Cause p to be overwritten by pTemplate */
+    }
+  }
+  return ppPrev;
+}
+
+/*
+** Insert or replace a WhereLoop entry using the template supplied.
+**
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies.  Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template.  Otherwise a new WhereLoop is
+** added based on the template.
+**
+** If pBuilder->pOrSet is not NULL then we care about only the
+** prerequisites and rRun and nOut costs of the N best loops.  That
+** information is gathered in the pBuilder->pOrSet object.  This special
+** processing mode is used only for OR clause processing.
+**
+** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
+** still might overwrite similar loops with the new template if the
+** new template is better.  Loops may be overwritten if the following 
+** conditions are met:
+**
+**    (1)  They have the same iTab.
+**    (2)  They have the same iSortIdx.
+**    (3)  The template has same or fewer dependencies than the current loop
+**    (4)  The template has the same or lower cost than the current loop
+*/
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+  WhereLoop **ppPrev, *p;
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  sqlite3 *db = pWInfo->pParse->db;
+  int rc;
+
+  /* If pBuilder->pOrSet is defined, then only keep track of the costs
+  ** and prereqs.
+  */
+  if( pBuilder->pOrSet!=0 ){
+    if( pTemplate->nLTerm ){
+#if WHERETRACE_ENABLED
+      u16 n = pBuilder->pOrSet->n;
+      int x =
+#endif
+      whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+                                    pTemplate->nOut);
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
+        whereLoopPrint(pTemplate, pBuilder->pWC);
+      }
+#endif
+    }
+    return SQLITE_OK;
+  }
+
+  /* Look for an existing WhereLoop to replace with pTemplate
+  */
+  whereLoopAdjustCost(pWInfo->pLoops, pTemplate);
+  ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
+
+  if( ppPrev==0 ){
+    /* There already exists a WhereLoop on the list that is better
+    ** than pTemplate, so just ignore pTemplate */
+#if WHERETRACE_ENABLED /* 0x8 */
+    if( sqlite3WhereTrace & 0x8 ){
+      sqlite3DebugPrintf("   skip: ");
+      whereLoopPrint(pTemplate, pBuilder->pWC);
+    }
+#endif
+    return SQLITE_OK;  
+  }else{
+    p = *ppPrev;
+  }
+
+  /* If we reach this point it means that either p[] should be overwritten
+  ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
+  ** WhereLoop and insert it.
+  */
+#if WHERETRACE_ENABLED /* 0x8 */
+  if( sqlite3WhereTrace & 0x8 ){
+    if( p!=0 ){
+      sqlite3DebugPrintf("replace: ");
+      whereLoopPrint(p, pBuilder->pWC);
+      sqlite3DebugPrintf("   with: ");
+    }else{
+      sqlite3DebugPrintf("    add: ");
+    }
+    whereLoopPrint(pTemplate, pBuilder->pWC);
+  }
+#endif
+  if( p==0 ){
+    /* Allocate a new WhereLoop to add to the end of the list */
+    *ppPrev = p = sqlite3DbMallocRawNN(db, sizeof(WhereLoop));
+    if( p==0 ) return SQLITE_NOMEM_BKPT;
+    whereLoopInit(p);
+    p->pNextLoop = 0;
+  }else{
+    /* We will be overwriting WhereLoop p[].  But before we do, first
+    ** go through the rest of the list and delete any other entries besides
+    ** p[] that are also supplated by pTemplate */
+    WhereLoop **ppTail = &p->pNextLoop;
+    WhereLoop *pToDel;
+    while( *ppTail ){
+      ppTail = whereLoopFindLesser(ppTail, pTemplate);
+      if( ppTail==0 ) break;
+      pToDel = *ppTail;
+      if( pToDel==0 ) break;
+      *ppTail = pToDel->pNextLoop;
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(" delete: ");
+        whereLoopPrint(pToDel, pBuilder->pWC);
+      }
+#endif
+      whereLoopDelete(db, pToDel);
+    }
+  }
+  rc = whereLoopXfer(db, p, pTemplate);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    Index *pIndex = p->u.btree.pIndex;
+    if( pIndex && pIndex->tnum==0 ){
+      p->u.btree.pIndex = 0;
+    }
+  }
+  return rc;
+}
+
+/*
+** Adjust the WhereLoop.nOut value downward to account for terms of the
+** WHERE clause that reference the loop but which are not used by an
+** index.
+*
+** For every WHERE clause term that is not used by the index
+** and which has a truth probability assigned by one of the likelihood(),
+** likely(), or unlikely() SQL functions, reduce the estimated number
+** of output rows by the probability specified.
+**
+** TUNING:  For every WHERE clause term that is not used by the index
+** and which does not have an assigned truth probability, heuristics
+** described below are used to try to estimate the truth probability.
+** TODO --> Perhaps this is something that could be improved by better
+** table statistics.
+**
+** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%
+** value corresponds to -1 in LogEst notation, so this means decrement
+** the WhereLoop.nOut field for every such WHERE clause term.
+**
+** Heuristic 2:  If there exists one or more WHERE clause terms of the
+** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
+** final output row estimate is no greater than 1/4 of the total number
+** of rows in the table.  In other words, assume that x==EXPR will filter
+** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the
+** "x" column is boolean or else -1 or 0 or 1 is a common default value
+** on the "x" column and so in that case only cap the output row estimate
+** at 1/2 instead of 1/4.
+*/
+static void whereLoopOutputAdjust(
+  WhereClause *pWC,      /* The WHERE clause */
+  WhereLoop *pLoop,      /* The loop to adjust downward */
+  LogEst nRow            /* Number of rows in the entire table */
+){
+  WhereTerm *pTerm, *pX;
+  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
+  int i, j, k;
+  LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */
+
+  assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
+    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
+    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
+    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
+    for(j=pLoop->nLTerm-1; j>=0; j--){
+      pX = pLoop->aLTerm[j];
+      if( pX==0 ) continue;
+      if( pX==pTerm ) break;
+      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
+    }
+    if( j<0 ){
+      if( pTerm->truthProb<=0 ){
+        /* If a truth probability is specified using the likelihood() hints,
+        ** then use the probability provided by the application. */
+        pLoop->nOut += pTerm->truthProb;
+      }else{
+        /* In the absence of explicit truth probabilities, use heuristics to
+        ** guess a reasonable truth probability. */
+        pLoop->nOut--;
+        if( pTerm->eOperator&(WO_EQ|WO_IS) ){
+          Expr *pRight = pTerm->pExpr->pRight;
+          testcase( pTerm->pExpr->op==TK_IS );
+          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
+            k = 10;
+          }else{
+            k = 20;
+          }
+          if( iReducenOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
+}
+
+/* 
+** Term pTerm is a vector range comparison operation. The first comparison
+** in the vector can be optimized using column nEq of the index. This
+** function returns the total number of vector elements that can be used
+** as part of the range comparison.
+**
+** For example, if the query is:
+**
+**   WHERE a = ? AND (b, c, d) > (?, ?, ?)
+**
+** and the index:
+**
+**   CREATE INDEX ... ON (a, b, c, d, e)
+**
+** then this function would be invoked with nEq=1. The value returned in
+** this case is 3.
+*/
+static int whereRangeVectorLen(
+  Parse *pParse,       /* Parsing context */
+  int iCur,            /* Cursor open on pIdx */
+  Index *pIdx,         /* The index to be used for a inequality constraint */
+  int nEq,             /* Number of prior equality constraints on same index */
+  WhereTerm *pTerm     /* The vector inequality constraint */
+){
+  int nCmp = sqlite3ExprVectorSize(pTerm->pExpr->pLeft);
+  int i;
+
+  nCmp = MIN(nCmp, (pIdx->nColumn - nEq));
+  for(i=1; ipExpr->pLeft->x.pList->a[i].pExpr;
+    Expr *pRhs = pTerm->pExpr->pRight;
+    if( pRhs->flags & EP_xIsSelect ){
+      pRhs = pRhs->x.pSelect->pEList->a[i].pExpr;
+    }else{
+      pRhs = pRhs->x.pList->a[i].pExpr;
+    }
+
+    /* Check that the LHS of the comparison is a column reference to
+    ** the right column of the right source table. And that the sort
+    ** order of the index column is the same as the sort order of the
+    ** leftmost index column.  */
+    if( pLhs->op!=TK_COLUMN 
+     || pLhs->iTable!=iCur 
+     || pLhs->iColumn!=pIdx->aiColumn[i+nEq] 
+     || pIdx->aSortOrder[i+nEq]!=pIdx->aSortOrder[nEq]
+    ){
+      break;
+    }
+
+    testcase( pLhs->iColumn==XN_ROWID );
+    aff = sqlite3CompareAffinity(pRhs, sqlite3ExprAffinity(pLhs));
+    idxaff = sqlite3TableColumnAffinity(pIdx->pTable, pLhs->iColumn);
+    if( aff!=idxaff ) break;
+
+    pColl = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
+    if( pColl==0 ) break;
+    if( sqlite3StrICmp(pColl->zName, pIdx->azColl[i+nEq]) ) break;
+  }
+  return i;
+}
+
+/*
+** Adjust the cost C by the costMult facter T.  This only occurs if
+** compiled with -DSQLITE_ENABLE_COSTMULT
+*/
+#ifdef SQLITE_ENABLE_COSTMULT
+# define ApplyCostMultiplier(C,T)  C += T
+#else
+# define ApplyCostMultiplier(C,T)
+#endif
+
+/*
+** We have so far matched pBuilder->pNew->u.btree.nEq terms of the 
+** index pIndex. Try to match one more.
+**
+** When this function is called, pBuilder->pNew->nOut contains the 
+** number of rows expected to be visited by filtering using the nEq 
+** terms only. If it is modified, this value is restored before this 
+** function returns.
+**
+** If pProbe->tnum==0, that means pIndex is a fake index used for the
+** INTEGER PRIMARY KEY.
+*/
+static int whereLoopAddBtreeIndex(
+  WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */
+  struct SrcList_item *pSrc,      /* FROM clause term being analyzed */
+  Index *pProbe,                  /* An index on pSrc */
+  LogEst nInMul                   /* log(Number of iterations due to IN) */
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */
+  Parse *pParse = pWInfo->pParse;        /* Parsing context */
+  sqlite3 *db = pParse->db;       /* Database connection malloc context */
+  WhereLoop *pNew;                /* Template WhereLoop under construction */
+  WhereTerm *pTerm;               /* A WhereTerm under consideration */
+  int opMask;                     /* Valid operators for constraints */
+  WhereScan scan;                 /* Iterator for WHERE terms */
+  Bitmask saved_prereq;           /* Original value of pNew->prereq */
+  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
+  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
+  u16 saved_nBtm;                 /* Original value of pNew->u.btree.nBtm */
+  u16 saved_nTop;                 /* Original value of pNew->u.btree.nTop */
+  u16 saved_nSkip;                /* Original value of pNew->nSkip */
+  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
+  LogEst saved_nOut;              /* Original value of pNew->nOut */
+  int rc = SQLITE_OK;             /* Return code */
+  LogEst rSize;                   /* Number of rows in the table */
+  LogEst rLogSize;                /* Logarithm of table size */
+  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
+
+  pNew = pBuilder->pNew;
+  if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
+  WHERETRACE(0x800, ("BEGIN addBtreeIdx(%s), nEq=%d\n",
+                     pProbe->zName, pNew->u.btree.nEq));
+
+  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
+  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
+    opMask = WO_LT|WO_LE;
+  }else{
+    assert( pNew->u.btree.nBtm==0 );
+    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
+  }
+  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+
+  assert( pNew->u.btree.nEqnColumn );
+
+  saved_nEq = pNew->u.btree.nEq;
+  saved_nBtm = pNew->u.btree.nBtm;
+  saved_nTop = pNew->u.btree.nTop;
+  saved_nSkip = pNew->nSkip;
+  saved_nLTerm = pNew->nLTerm;
+  saved_wsFlags = pNew->wsFlags;
+  saved_prereq = pNew->prereq;
+  saved_nOut = pNew->nOut;
+  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
+                        opMask, pProbe);
+  pNew->rSetup = 0;
+  rSize = pProbe->aiRowLogEst[0];
+  rLogSize = estLog(rSize);
+  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
+    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
+    LogEst rCostIdx;
+    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
+    int nIn = 0;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    int nRecValid = pBuilder->nRecValid;
+#endif
+    if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
+     && indexColumnNotNull(pProbe, saved_nEq)
+    ){
+      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
+    }
+    if( pTerm->prereqRight & pNew->maskSelf ) continue;
+
+    /* Do not allow the upper bound of a LIKE optimization range constraint
+    ** to mix with a lower range bound from some other source */
+    if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue;
+
+    /* Do not allow IS constraints from the WHERE clause to be used by the
+    ** right table of a LEFT JOIN.  Only constraints in the ON clause are
+    ** allowed */
+    if( (pSrc->fg.jointype & JT_LEFT)!=0
+     && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+     && (eOp & (WO_IS|WO_ISNULL))!=0
+    ){
+      testcase( eOp & WO_IS );
+      testcase( eOp & WO_ISNULL );
+      continue;
+    }
+
+    if( IsUniqueIndex(pProbe) && saved_nEq==pProbe->nKeyCol-1 ){
+      pBuilder->bldFlags |= SQLITE_BLDF_UNIQUE;
+    }else{
+      pBuilder->bldFlags |= SQLITE_BLDF_INDEXED;
+    }
+    pNew->wsFlags = saved_wsFlags;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->u.btree.nBtm = saved_nBtm;
+    pNew->u.btree.nTop = saved_nTop;
+    pNew->nLTerm = saved_nLTerm;
+    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+    pNew->aLTerm[pNew->nLTerm++] = pTerm;
+    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
+
+    assert( nInMul==0
+        || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 
+        || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 
+        || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 
+    );
+
+    if( eOp & WO_IN ){
+      Expr *pExpr = pTerm->pExpr;
+      pNew->wsFlags |= WHERE_COLUMN_IN;
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
+        int i;
+        nIn = 46;  assert( 46==sqlite3LogEst(25) );
+
+        /* The expression may actually be of the form (x, y) IN (SELECT...).
+        ** In this case there is a separate term for each of (x) and (y).
+        ** However, the nIn multiplier should only be applied once, not once
+        ** for each such term. The following loop checks that pTerm is the
+        ** first such term in use, and sets nIn back to 0 if it is not. */
+        for(i=0; inLTerm-1; i++){
+          if( pNew->aLTerm[i] && pNew->aLTerm[i]->pExpr==pExpr ) nIn = 0;
+        }
+      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
+        /* "x IN (value, value, ...)" */
+        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
+        assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
+                          ** changes "x IN (?)" into "x=?". */
+      }
+    }else if( eOp & (WO_EQ|WO_IS) ){
+      int iCol = pProbe->aiColumn[saved_nEq];
+      pNew->wsFlags |= WHERE_COLUMN_EQ;
+      assert( saved_nEq==pNew->u.btree.nEq );
+      if( iCol==XN_ROWID 
+       || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
+      ){
+        if( iCol>=0 && pProbe->uniqNotNull==0 ){
+          pNew->wsFlags |= WHERE_UNQ_WANTED;
+        }else{
+          pNew->wsFlags |= WHERE_ONEROW;
+        }
+      }
+    }else if( eOp & WO_ISNULL ){
+      pNew->wsFlags |= WHERE_COLUMN_NULL;
+    }else if( eOp & (WO_GT|WO_GE) ){
+      testcase( eOp & WO_GT );
+      testcase( eOp & WO_GE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
+      pNew->u.btree.nBtm = whereRangeVectorLen(
+          pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
+      );
+      pBtm = pTerm;
+      pTop = 0;
+      if( pTerm->wtFlags & TERM_LIKEOPT ){
+        /* Range contraints that come from the LIKE optimization are
+        ** always used in pairs. */
+        pTop = &pTerm[1];
+        assert( (pTop-(pTerm->pWC->a))pWC->nTerm );
+        assert( pTop->wtFlags & TERM_LIKEOPT );
+        assert( pTop->eOperator==WO_LT );
+        if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+        pNew->aLTerm[pNew->nLTerm++] = pTop;
+        pNew->wsFlags |= WHERE_TOP_LIMIT;
+        pNew->u.btree.nTop = 1;
+      }
+    }else{
+      assert( eOp & (WO_LT|WO_LE) );
+      testcase( eOp & WO_LT );
+      testcase( eOp & WO_LE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
+      pNew->u.btree.nTop = whereRangeVectorLen(
+          pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
+      );
+      pTop = pTerm;
+      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
+                     pNew->aLTerm[pNew->nLTerm-2] : 0;
+    }
+
+    /* At this point pNew->nOut is set to the number of rows expected to
+    ** be visited by the index scan before considering term pTerm, or the
+    ** values of nIn and nInMul. In other words, assuming that all 
+    ** "x IN(...)" terms are replaced with "x = ?". This block updates
+    ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul).  */
+    assert( pNew->nOut==saved_nOut );
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4
+      ** data, using some other estimate.  */
+      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
+    }else{
+      int nEq = ++pNew->u.btree.nEq;
+      assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );
+
+      assert( pNew->nOut==saved_nOut );
+      if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
+        assert( (eOp & WO_IN) || nIn==0 );
+        testcase( eOp & WO_IN );
+        pNew->nOut += pTerm->truthProb;
+        pNew->nOut -= nIn;
+      }else{
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+        tRowcnt nOut = 0;
+        if( nInMul==0 
+         && pProbe->nSample 
+         && pNew->u.btree.nEq<=pProbe->nSampleCol
+         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
+        ){
+          Expr *pExpr = pTerm->pExpr;
+          if( (eOp & (WO_EQ|WO_ISNULL|WO_IS))!=0 ){
+            testcase( eOp & WO_EQ );
+            testcase( eOp & WO_IS );
+            testcase( eOp & WO_ISNULL );
+            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
+          }else{
+            rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
+          }
+          if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+          if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */
+          if( nOut ){
+            pNew->nOut = sqlite3LogEst(nOut);
+            if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;
+            pNew->nOut -= nIn;
+          }
+        }
+        if( nOut==0 )
+#endif
+        {
+          pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);
+          if( eOp & WO_ISNULL ){
+            /* TUNING: If there is no likelihood() value, assume that a 
+            ** "col IS NULL" expression matches twice as many rows 
+            ** as (col=?). */
+            pNew->nOut += 10;
+          }
+        }
+      }
+    }
+
+    /* Set rCostIdx to the cost of visiting selected rows in index. Add
+    ** it to pNew->rRun, which is currently set to the cost of the index
+    ** seek only. Then, if this is a non-covering index, add the cost of
+    ** visiting the rows in the main table.  */
+    rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
+    pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
+    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+      pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
+    }
+    ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
+
+    nOutUnadjusted = pNew->nOut;
+    pNew->rRun += nInMul + nIn;
+    pNew->nOut += nInMul + nIn;
+    whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
+    rc = whereLoopInsert(pBuilder, pNew);
+
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      pNew->nOut = saved_nOut;
+    }else{
+      pNew->nOut = nOutUnadjusted;
+    }
+
+    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
+     && pNew->u.btree.nEqnColumn
+    ){
+      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
+    }
+    pNew->nOut = saved_nOut;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    pBuilder->nRecValid = nRecValid;
+#endif
+  }
+  pNew->prereq = saved_prereq;
+  pNew->u.btree.nEq = saved_nEq;
+  pNew->u.btree.nBtm = saved_nBtm;
+  pNew->u.btree.nTop = saved_nTop;
+  pNew->nSkip = saved_nSkip;
+  pNew->wsFlags = saved_wsFlags;
+  pNew->nOut = saved_nOut;
+  pNew->nLTerm = saved_nLTerm;
+
+  /* Consider using a skip-scan if there are no WHERE clause constraints
+  ** available for the left-most terms of the index, and if the average
+  ** number of repeats in the left-most terms is at least 18. 
+  **
+  ** The magic number 18 is selected on the basis that scanning 17 rows
+  ** is almost always quicker than an index seek (even though if the index
+  ** contains fewer than 2^17 rows we assume otherwise in other parts of
+  ** the code). And, even if it is not, it should not be too much slower. 
+  ** On the other hand, the extra seeks could end up being significantly
+  ** more expensive.  */
+  assert( 42==sqlite3LogEst(18) );
+  if( saved_nEq==saved_nSkip
+   && saved_nEq+1nKeyCol
+   && pProbe->noSkipScan==0
+   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
+   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
+  ){
+    LogEst nIter;
+    pNew->u.btree.nEq++;
+    pNew->nSkip++;
+    pNew->aLTerm[pNew->nLTerm++] = 0;
+    pNew->wsFlags |= WHERE_SKIPSCAN;
+    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
+    pNew->nOut -= nIter;
+    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
+    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
+    nIter += 5;
+    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
+    pNew->nOut = saved_nOut;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nSkip = saved_nSkip;
+    pNew->wsFlags = saved_wsFlags;
+  }
+
+  WHERETRACE(0x800, ("END addBtreeIdx(%s), nEq=%d, rc=%d\n",
+                      pProbe->zName, saved_nEq, rc));
+  return rc;
+}
+
+/*
+** Return True if it is possible that pIndex might be useful in
+** implementing the ORDER BY clause in pBuilder.
+**
+** Return False if pBuilder does not contain an ORDER BY clause or
+** if there is no way for pIndex to be useful in implementing that
+** ORDER BY clause.
+*/
+static int indexMightHelpWithOrderBy(
+  WhereLoopBuilder *pBuilder,
+  Index *pIndex,
+  int iCursor
+){
+  ExprList *pOB;
+  ExprList *aColExpr;
+  int ii, jj;
+
+  if( pIndex->bUnordered ) return 0;
+  if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
+  for(ii=0; iinExpr; ii++){
+    Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
+    if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
+      if( pExpr->iColumn<0 ) return 1;
+      for(jj=0; jjnKeyCol; jj++){
+        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
+      }
+    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
+      for(jj=0; jjnKeyCol; jj++){
+        if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
+        if( sqlite3ExprCompare(0, pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
+          return 1;
+        }
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Return a bitmask where 1s indicate that the corresponding column of
+** the table is used by an index.  Only the first 63 columns are considered.
+*/
+static Bitmask columnsInIndex(Index *pIdx){
+  Bitmask m = 0;
+  int j;
+  for(j=pIdx->nColumn-1; j>=0; j--){
+    int x = pIdx->aiColumn[j];
+    if( x>=0 ){
+      testcase( x==BMS-1 );
+      testcase( x==BMS-2 );
+      if( xpWInfo->pParse;
+  while( pWhere->op==TK_AND ){
+    if( !whereUsablePartialIndex(iTab,pWC,pWhere->pLeft) ) return 0;
+    pWhere = pWhere->pRight;
+  }
+  if( pParse->db->flags & SQLITE_EnableQPSG ) pParse = 0;
+  for(i=0, pTerm=pWC->a; inTerm; i++, pTerm++){
+    Expr *pExpr = pTerm->pExpr;
+    if( (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)
+     && sqlite3ExprImpliesExpr(pParse, pExpr, pWhere, iTab) 
+    ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+** Add all WhereLoop objects for a single table of the join where the table
+** is identified by pBuilder->pNew->iTab.  That table is guaranteed to be
+** a b-tree table, not a virtual table.
+**
+** The costs (WhereLoop.rRun) of the b-tree loops added by this function
+** are calculated as follows:
+**
+** For a full scan, assuming the table (or index) contains nRow rows:
+**
+**     cost = nRow * 3.0                    // full-table scan
+**     cost = nRow * K                      // scan of covering index
+**     cost = nRow * (K+3.0)                // scan of non-covering index
+**
+** where K is a value between 1.1 and 3.0 set based on the relative 
+** estimated average size of the index and table records.
+**
+** For an index scan, where nVisit is the number of index rows visited
+** by the scan, and nSeek is the number of seek operations required on 
+** the index b-tree:
+**
+**     cost = nSeek * (log(nRow) + K * nVisit)          // covering index
+**     cost = nSeek * (log(nRow) + (K+3.0) * nVisit)    // non-covering index
+**
+** Normally, nSeek is 1. nSeek values greater than 1 come about if the 
+** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when 
+** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.
+**
+** The estimated values (nRow, nVisit, nSeek) often contain a large amount
+** of uncertainty.  For this reason, scoring is designed to pick plans that
+** "do the least harm" if the estimates are inaccurate.  For example, a
+** log(nRow) factor is omitted from a non-covering index scan in order to
+** bias the scoring in favor of using an index, since the worst-case
+** performance of using an index is far better than the worst-case performance
+** of a full table scan.
+*/
+static int whereLoopAddBtree(
+  WhereLoopBuilder *pBuilder, /* WHERE clause information */
+  Bitmask mPrereq             /* Extra prerequesites for using this table */
+){
+  WhereInfo *pWInfo;          /* WHERE analysis context */
+  Index *pProbe;              /* An index we are evaluating */
+  Index sPk;                  /* A fake index object for the primary key */
+  LogEst aiRowEstPk[2];       /* The aiRowLogEst[] value for the sPk index */
+  i16 aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
+  SrcList *pTabList;          /* The FROM clause */
+  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
+  WhereLoop *pNew;            /* Template WhereLoop object */
+  int rc = SQLITE_OK;         /* Return code */
+  int iSortIdx = 1;           /* Index number */
+  int b;                      /* A boolean value */
+  LogEst rSize;               /* number of rows in the table */
+  LogEst rLogSize;            /* Logarithm of the number of rows in the table */
+  WhereClause *pWC;           /* The parsed WHERE clause */
+  Table *pTab;                /* Table being queried */
+  
+  pNew = pBuilder->pNew;
+  pWInfo = pBuilder->pWInfo;
+  pTabList = pWInfo->pTabList;
+  pSrc = pTabList->a + pNew->iTab;
+  pTab = pSrc->pTab;
+  pWC = pBuilder->pWC;
+  assert( !IsVirtual(pSrc->pTab) );
+
+  if( pSrc->pIBIndex ){
+    /* An INDEXED BY clause specifies a particular index to use */
+    pProbe = pSrc->pIBIndex;
+  }else if( !HasRowid(pTab) ){
+    pProbe = pTab->pIndex;
+  }else{
+    /* There is no INDEXED BY clause.  Create a fake Index object in local
+    ** variable sPk to represent the rowid primary key index.  Make this
+    ** fake index the first in a chain of Index objects with all of the real
+    ** indices to follow */
+    Index *pFirst;                  /* First of real indices on the table */
+    memset(&sPk, 0, sizeof(Index));
+    sPk.nKeyCol = 1;
+    sPk.nColumn = 1;
+    sPk.aiColumn = &aiColumnPk;
+    sPk.aiRowLogEst = aiRowEstPk;
+    sPk.onError = OE_Replace;
+    sPk.pTable = pTab;
+    sPk.szIdxRow = pTab->szTabRow;
+    aiRowEstPk[0] = pTab->nRowLogEst;
+    aiRowEstPk[1] = 0;
+    pFirst = pSrc->pTab->pIndex;
+    if( pSrc->fg.notIndexed==0 ){
+      /* The real indices of the table are only considered if the
+      ** NOT INDEXED qualifier is omitted from the FROM clause */
+      sPk.pNext = pFirst;
+    }
+    pProbe = &sPk;
+  }
+  rSize = pTab->nRowLogEst;
+  rLogSize = estLog(rSize);
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+  /* Automatic indexes */
+  if( !pBuilder->pOrSet      /* Not part of an OR optimization */
+   && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
+   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
+   && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */
+   && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */
+   && HasRowid(pTab)         /* Not WITHOUT ROWID table. (FIXME: Why not?) */
+   && !pSrc->fg.isCorrelated /* Not a correlated subquery */
+   && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */
+  ){
+    /* Generate auto-index WhereLoops */
+    WhereTerm *pTerm;
+    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
+    for(pTerm=pWC->a; rc==SQLITE_OK && pTermprereqRight & pNew->maskSelf ) continue;
+      if( termCanDriveIndex(pTerm, pSrc, 0) ){
+        pNew->u.btree.nEq = 1;
+        pNew->nSkip = 0;
+        pNew->u.btree.pIndex = 0;
+        pNew->nLTerm = 1;
+        pNew->aLTerm[0] = pTerm;
+        /* TUNING: One-time cost for computing the automatic index is
+        ** estimated to be X*N*log2(N) where N is the number of rows in
+        ** the table being indexed and where X is 7 (LogEst=28) for normal
+        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
+        ** of X is smaller for views and subqueries so that the query planner
+        ** will be more aggressive about generating automatic indexes for
+        ** those objects, since there is no opportunity to add schema
+        ** indexes on subqueries and views. */
+        pNew->rSetup = rLogSize + rSize + 4;
+        if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){
+          pNew->rSetup += 24;
+        }
+        ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
+        if( pNew->rSetup<0 ) pNew->rSetup = 0;
+        /* TUNING: Each index lookup yields 20 rows in the table.  This
+        ** is more than the usual guess of 10 rows, since we have no way
+        ** of knowing how selective the index will ultimately be.  It would
+        ** not be unreasonable to make this value much larger. */
+        pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );
+        pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
+        pNew->wsFlags = WHERE_AUTO_INDEX;
+        pNew->prereq = mPrereq | pTerm->prereqRight;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+    }
+  }
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+  /* Loop over all indices
+  */
+  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
+    if( pProbe->pPartIdxWhere!=0
+     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
+      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
+      continue;  /* Partial index inappropriate for this query */
+    }
+    rSize = pProbe->aiRowLogEst[0];
+    pNew->u.btree.nEq = 0;
+    pNew->u.btree.nBtm = 0;
+    pNew->u.btree.nTop = 0;
+    pNew->nSkip = 0;
+    pNew->nLTerm = 0;
+    pNew->iSortIdx = 0;
+    pNew->rSetup = 0;
+    pNew->prereq = mPrereq;
+    pNew->nOut = rSize;
+    pNew->u.btree.pIndex = pProbe;
+    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
+    if( pProbe->tnum<=0 ){
+      /* Integer primary key index */
+      pNew->wsFlags = WHERE_IPK;
+
+      /* Full table scan */
+      pNew->iSortIdx = b ? iSortIdx : 0;
+      /* TUNING: Cost of full table scan is (N*3.0). */
+      pNew->rRun = rSize + 16;
+      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+      whereLoopOutputAdjust(pWC, pNew, rSize);
+      rc = whereLoopInsert(pBuilder, pNew);
+      pNew->nOut = rSize;
+      if( rc ) break;
+    }else{
+      Bitmask m;
+      if( pProbe->isCovering ){
+        pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
+        m = 0;
+      }else{
+        m = pSrc->colUsed & ~columnsInIndex(pProbe);
+        pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
+      }
+
+      /* Full scan via index */
+      if( b
+       || !HasRowid(pTab)
+       || pProbe->pPartIdxWhere!=0
+       || ( m==0
+         && pProbe->bUnordered==0
+         && (pProbe->szIdxRowszTabRow)
+         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+         && sqlite3GlobalConfig.bUseCis
+         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+          )
+      ){
+        pNew->iSortIdx = b ? iSortIdx : 0;
+
+        /* The cost of visiting the index rows is N*K, where K is
+        ** between 1.1 and 3.0, depending on the relative sizes of the
+        ** index and table rows. */
+        pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
+        if( m!=0 ){
+          /* If this is a non-covering index scan, add in the cost of
+          ** doing table lookups.  The cost will be 3x the number of
+          ** lookups.  Take into account WHERE clause terms that can be
+          ** satisfied using just the index, and that do not require a
+          ** table lookup. */
+          LogEst nLookup = rSize + 16;  /* Base cost:  N*3 */
+          int ii;
+          int iCur = pSrc->iCursor;
+          WhereClause *pWC2 = &pWInfo->sWC;
+          for(ii=0; iinTerm; ii++){
+            WhereTerm *pTerm = &pWC2->a[ii];
+            if( !sqlite3ExprCoveredByIndex(pTerm->pExpr, iCur, pProbe) ){
+              break;
+            }
+            /* pTerm can be evaluated using just the index.  So reduce
+            ** the expected number of table lookups accordingly */
+            if( pTerm->truthProb<=0 ){
+              nLookup += pTerm->truthProb;
+            }else{
+              nLookup--;
+              if( pTerm->eOperator & (WO_EQ|WO_IS) ) nLookup -= 19;
+            }
+          }
+          
+          pNew->rRun = sqlite3LogEstAdd(pNew->rRun, nLookup);
+        }
+        ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+        whereLoopOutputAdjust(pWC, pNew, rSize);
+        rc = whereLoopInsert(pBuilder, pNew);
+        pNew->nOut = rSize;
+        if( rc ) break;
+      }
+    }
+
+    pBuilder->bldFlags = 0;
+    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
+    if( pBuilder->bldFlags==SQLITE_BLDF_INDEXED ){
+      /* If a non-unique index is used, or if a prefix of the key for
+      ** unique index is used (making the index functionally non-unique)
+      ** then the sqlite_stat1 data becomes important for scoring the
+      ** plan */
+      pTab->tabFlags |= TF_StatsUsed;
+    }
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    sqlite3Stat4ProbeFree(pBuilder->pRec);
+    pBuilder->nRecValid = 0;
+    pBuilder->pRec = 0;
+#endif
+
+    /* If there was an INDEXED BY clause, then only that one index is
+    ** considered. */
+    if( pSrc->pIBIndex ) break;
+  }
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Argument pIdxInfo is already populated with all constraints that may
+** be used by the virtual table identified by pBuilder->pNew->iTab. This
+** function marks a subset of those constraints usable, invokes the
+** xBestIndex method and adds the returned plan to pBuilder.
+**
+** A constraint is marked usable if:
+**
+**   * Argument mUsable indicates that its prerequisites are available, and
+**
+**   * It is not one of the operators specified in the mExclude mask passed
+**     as the fourth argument (which in practice is either WO_IN or 0).
+**
+** Argument mPrereq is a mask of tables that must be scanned before the
+** virtual table in question. These are added to the plans prerequisites
+** before it is added to pBuilder.
+**
+** Output parameter *pbIn is set to true if the plan added to pBuilder
+** uses one or more WO_IN terms, or false otherwise.
+*/
+static int whereLoopAddVirtualOne(
+  WhereLoopBuilder *pBuilder,
+  Bitmask mPrereq,                /* Mask of tables that must be used. */
+  Bitmask mUsable,                /* Mask of usable tables */
+  u16 mExclude,                   /* Exclude terms using these operators */
+  sqlite3_index_info *pIdxInfo,   /* Populated object for xBestIndex */
+  u16 mNoOmit,                    /* Do not omit these constraints */
+  int *pbIn                       /* OUT: True if plan uses an IN(...) op */
+){
+  WhereClause *pWC = pBuilder->pWC;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;
+  int i;
+  int mxTerm;
+  int rc = SQLITE_OK;
+  WhereLoop *pNew = pBuilder->pNew;
+  Parse *pParse = pBuilder->pWInfo->pParse;
+  struct SrcList_item *pSrc = &pBuilder->pWInfo->pTabList->a[pNew->iTab];
+  int nConstraint = pIdxInfo->nConstraint;
+
+  assert( (mUsable & mPrereq)==mPrereq );
+  *pbIn = 0;
+  pNew->prereq = mPrereq;
+
+  /* Set the usable flag on the subset of constraints identified by 
+  ** arguments mUsable and mExclude. */
+  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+  for(i=0; ia[pIdxCons->iTermOffset];
+    pIdxCons->usable = 0;
+    if( (pTerm->prereqRight & mUsable)==pTerm->prereqRight 
+     && (pTerm->eOperator & mExclude)==0
+    ){
+      pIdxCons->usable = 1;
+    }
+  }
+
+  /* Initialize the output fields of the sqlite3_index_info structure */
+  memset(pUsage, 0, sizeof(pUsage[0])*nConstraint);
+  assert( pIdxInfo->needToFreeIdxStr==0 );
+  pIdxInfo->idxStr = 0;
+  pIdxInfo->idxNum = 0;
+  pIdxInfo->orderByConsumed = 0;
+  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
+  pIdxInfo->estimatedRows = 25;
+  pIdxInfo->idxFlags = 0;
+  pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;
+
+  /* Invoke the virtual table xBestIndex() method */
+  rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);
+  if( rc ) return rc;
+
+  mxTerm = -1;
+  assert( pNew->nLSlot>=nConstraint );
+  for(i=0; iaLTerm[i] = 0;
+  pNew->u.vtab.omitMask = 0;
+  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+  for(i=0; i=0 ){
+      WhereTerm *pTerm;
+      int j = pIdxCons->iTermOffset;
+      if( iTerm>=nConstraint
+       || j<0
+       || j>=pWC->nTerm
+       || pNew->aLTerm[iTerm]!=0
+       || pIdxCons->usable==0
+      ){
+        rc = SQLITE_ERROR;
+        sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);
+        return rc;
+      }
+      testcase( iTerm==nConstraint-1 );
+      testcase( j==0 );
+      testcase( j==pWC->nTerm-1 );
+      pTerm = &pWC->a[j];
+      pNew->prereq |= pTerm->prereqRight;
+      assert( iTermnLSlot );
+      pNew->aLTerm[iTerm] = pTerm;
+      if( iTerm>mxTerm ) mxTerm = iTerm;
+      testcase( iTerm==15 );
+      testcase( iTerm==16 );
+      if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<eOperator & WO_IN)!=0 ){
+        /* A virtual table that is constrained by an IN clause may not
+        ** consume the ORDER BY clause because (1) the order of IN terms
+        ** is not necessarily related to the order of output terms and
+        ** (2) Multiple outputs from a single IN value will not merge
+        ** together.  */
+        pIdxInfo->orderByConsumed = 0;
+        pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
+        *pbIn = 1; assert( (mExclude & WO_IN)==0 );
+      }
+    }
+  }
+  pNew->u.vtab.omitMask &= ~mNoOmit;
+
+  pNew->nLTerm = mxTerm+1;
+  assert( pNew->nLTerm<=pNew->nLSlot );
+  pNew->u.vtab.idxNum = pIdxInfo->idxNum;
+  pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
+  pIdxInfo->needToFreeIdxStr = 0;
+  pNew->u.vtab.idxStr = pIdxInfo->idxStr;
+  pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
+      pIdxInfo->nOrderBy : 0);
+  pNew->rSetup = 0;
+  pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
+  pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);
+
+  /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
+  ** that the scan will visit at most one row. Clear it otherwise. */
+  if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){
+    pNew->wsFlags |= WHERE_ONEROW;
+  }else{
+    pNew->wsFlags &= ~WHERE_ONEROW;
+  }
+  rc = whereLoopInsert(pBuilder, pNew);
+  if( pNew->u.vtab.needFree ){
+    sqlite3_free(pNew->u.vtab.idxStr);
+    pNew->u.vtab.needFree = 0;
+  }
+  WHERETRACE(0xffff, ("  bIn=%d prereqIn=%04llx prereqOut=%04llx\n",
+                      *pbIn, (sqlite3_uint64)mPrereq,
+                      (sqlite3_uint64)(pNew->prereq & ~mPrereq)));
+
+  return rc;
+}
+
+
+/*
+** Add all WhereLoop objects for a table of the join identified by
+** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
+**
+** If there are no LEFT or CROSS JOIN joins in the query, both mPrereq and
+** mUnusable are set to 0. Otherwise, mPrereq is a mask of all FROM clause
+** entries that occur before the virtual table in the FROM clause and are
+** separated from it by at least one LEFT or CROSS JOIN. Similarly, the
+** mUnusable mask contains all FROM clause entries that occur after the
+** virtual table and are separated from it by at least one LEFT or 
+** CROSS JOIN. 
+**
+** For example, if the query were:
+**
+**   ... FROM t1, t2 LEFT JOIN t3, t4, vt CROSS JOIN t5, t6;
+**
+** then mPrereq corresponds to (t1, t2) and mUnusable to (t5, t6).
+**
+** All the tables in mPrereq must be scanned before the current virtual 
+** table. So any terms for which all prerequisites are satisfied by 
+** mPrereq may be specified as "usable" in all calls to xBestIndex. 
+** Conversely, all tables in mUnusable must be scanned after the current
+** virtual table, so any terms for which the prerequisites overlap with
+** mUnusable should always be configured as "not-usable" for xBestIndex.
+*/
+static int whereLoopAddVirtual(
+  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
+  Bitmask mPrereq,             /* Tables that must be scanned before this one */
+  Bitmask mUnusable            /* Tables that must be scanned after this one */
+){
+  int rc = SQLITE_OK;          /* Return code */
+  WhereInfo *pWInfo;           /* WHERE analysis context */
+  Parse *pParse;               /* The parsing context */
+  WhereClause *pWC;            /* The WHERE clause */
+  struct SrcList_item *pSrc;   /* The FROM clause term to search */
+  sqlite3_index_info *p;       /* Object to pass to xBestIndex() */
+  int nConstraint;             /* Number of constraints in p */
+  int bIn;                     /* True if plan uses IN(...) operator */
+  WhereLoop *pNew;
+  Bitmask mBest;               /* Tables used by best possible plan */
+  u16 mNoOmit;
+
+  assert( (mPrereq & mUnusable)==0 );
+  pWInfo = pBuilder->pWInfo;
+  pParse = pWInfo->pParse;
+  pWC = pBuilder->pWC;
+  pNew = pBuilder->pNew;
+  pSrc = &pWInfo->pTabList->a[pNew->iTab];
+  assert( IsVirtual(pSrc->pTab) );
+  p = allocateIndexInfo(pParse, pWC, mUnusable, pSrc, pBuilder->pOrderBy, 
+      &mNoOmit);
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  pNew->rSetup = 0;
+  pNew->wsFlags = WHERE_VIRTUALTABLE;
+  pNew->nLTerm = 0;
+  pNew->u.vtab.needFree = 0;
+  nConstraint = p->nConstraint;
+  if( whereLoopResize(pParse->db, pNew, nConstraint) ){
+    sqlite3DbFree(pParse->db, p);
+    return SQLITE_NOMEM_BKPT;
+  }
+
+  /* First call xBestIndex() with all constraints usable. */
+  WHERETRACE(0x40, ("  VirtualOne: all usable\n"));
+  rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn);
+
+  /* If the call to xBestIndex() with all terms enabled produced a plan
+  ** that does not require any source tables (IOW: a plan with mBest==0),
+  ** then there is no point in making any further calls to xBestIndex() 
+  ** since they will all return the same result (if the xBestIndex()
+  ** implementation is sane). */
+  if( rc==SQLITE_OK && (mBest = (pNew->prereq & ~mPrereq))!=0 ){
+    int seenZero = 0;             /* True if a plan with no prereqs seen */
+    int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
+    Bitmask mPrev = 0;
+    Bitmask mBestNoIn = 0;
+
+    /* If the plan produced by the earlier call uses an IN(...) term, call
+    ** xBestIndex again, this time with IN(...) terms disabled. */
+    if( bIn ){
+      WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));
+      rc = whereLoopAddVirtualOne(
+          pBuilder, mPrereq, ALLBITS, WO_IN, p, mNoOmit, &bIn);
+      assert( bIn==0 );
+      mBestNoIn = pNew->prereq & ~mPrereq;
+      if( mBestNoIn==0 ){
+        seenZero = 1;
+        seenZeroNoIN = 1;
+      }
+    }
+
+    /* Call xBestIndex once for each distinct value of (prereqRight & ~mPrereq) 
+    ** in the set of terms that apply to the current virtual table.  */
+    while( rc==SQLITE_OK ){
+      int i;
+      Bitmask mNext = ALLBITS;
+      assert( mNext>0 );
+      for(i=0; ia[p->aConstraint[i].iTermOffset].prereqRight & ~mPrereq
+        );
+        if( mThis>mPrev && mThisprereq==mPrereq ){
+        seenZero = 1;
+        if( bIn==0 ) seenZeroNoIN = 1;
+      }
+    }
+
+    /* If the calls to xBestIndex() in the above loop did not find a plan
+    ** that requires no source tables at all (i.e. one guaranteed to be
+    ** usable), make a call here with all source tables disabled */
+    if( rc==SQLITE_OK && seenZero==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));
+      rc = whereLoopAddVirtualOne(
+          pBuilder, mPrereq, mPrereq, 0, p, mNoOmit, &bIn);
+      if( bIn==0 ) seenZeroNoIN = 1;
+    }
+
+    /* If the calls to xBestIndex() have so far failed to find a plan
+    ** that requires no source tables at all and does not use an IN(...)
+    ** operator, make a final call to obtain one here.  */
+    if( rc==SQLITE_OK && seenZeroNoIN==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));
+      rc = whereLoopAddVirtualOne(
+          pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn);
+    }
+  }
+
+  if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);
+  sqlite3DbFreeNN(pParse->db, p);
+  return rc;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Add WhereLoop entries to handle OR terms.  This works for either
+** btrees or virtual tables.
+*/
+static int whereLoopAddOr(
+  WhereLoopBuilder *pBuilder, 
+  Bitmask mPrereq, 
+  Bitmask mUnusable
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  WhereClause *pWC;
+  WhereLoop *pNew;
+  WhereTerm *pTerm, *pWCEnd;
+  int rc = SQLITE_OK;
+  int iCur;
+  WhereClause tempWC;
+  WhereLoopBuilder sSubBuild;
+  WhereOrSet sSum, sCur;
+  struct SrcList_item *pItem;
+  
+  pWC = pBuilder->pWC;
+  pWCEnd = pWC->a + pWC->nTerm;
+  pNew = pBuilder->pNew;
+  memset(&sSum, 0, sizeof(sSum));
+  pItem = pWInfo->pTabList->a + pNew->iTab;
+  iCur = pItem->iCursor;
+
+  for(pTerm=pWC->a; pTermeOperator & WO_OR)!=0
+     && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 
+    ){
+      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
+      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
+      WhereTerm *pOrTerm;
+      int once = 1;
+      int i, j;
+    
+      sSubBuild = *pBuilder;
+      sSubBuild.pOrderBy = 0;
+      sSubBuild.pOrSet = &sCur;
+
+      WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));
+      for(pOrTerm=pOrWC->a; pOrTermeOperator & WO_AND)!=0 ){
+          sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
+        }else if( pOrTerm->leftCursor==iCur ){
+          tempWC.pWInfo = pWC->pWInfo;
+          tempWC.pOuter = pWC;
+          tempWC.op = TK_AND;
+          tempWC.nTerm = 1;
+          tempWC.a = pOrTerm;
+          sSubBuild.pWC = &tempWC;
+        }else{
+          continue;
+        }
+        sCur.n = 0;
+#ifdef WHERETRACE_ENABLED
+        WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n", 
+                   (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
+        if( sqlite3WhereTrace & 0x400 ){
+          sqlite3WhereClausePrint(sSubBuild.pWC);
+        }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+        if( IsVirtual(pItem->pTab) ){
+          rc = whereLoopAddVirtual(&sSubBuild, mPrereq, mUnusable);
+        }else
+#endif
+        {
+          rc = whereLoopAddBtree(&sSubBuild, mPrereq);
+        }
+        if( rc==SQLITE_OK ){
+          rc = whereLoopAddOr(&sSubBuild, mPrereq, mUnusable);
+        }
+        assert( rc==SQLITE_OK || sCur.n==0 );
+        if( sCur.n==0 ){
+          sSum.n = 0;
+          break;
+        }else if( once ){
+          whereOrMove(&sSum, &sCur);
+          once = 0;
+        }else{
+          WhereOrSet sPrev;
+          whereOrMove(&sPrev, &sSum);
+          sSum.n = 0;
+          for(i=0; inLTerm = 1;
+      pNew->aLTerm[0] = pTerm;
+      pNew->wsFlags = WHERE_MULTI_OR;
+      pNew->rSetup = 0;
+      pNew->iSortIdx = 0;
+      memset(&pNew->u, 0, sizeof(pNew->u));
+      for(i=0; rc==SQLITE_OK && irRun = sSum.a[i].rRun + 1;
+        pNew->nOut = sSum.a[i].nOut;
+        pNew->prereq = sSum.a[i].prereq;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+      WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));
+    }
+  }
+  return rc;
+}
+
+/*
+** Add all WhereLoop objects for all tables 
+*/
+static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  Bitmask mPrereq = 0;
+  Bitmask mPrior = 0;
+  int iTab;
+  SrcList *pTabList = pWInfo->pTabList;
+  struct SrcList_item *pItem;
+  struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];
+  sqlite3 *db = pWInfo->pParse->db;
+  int rc = SQLITE_OK;
+  WhereLoop *pNew;
+  u8 priorJointype = 0;
+
+  /* Loop over the tables in the join, from left to right */
+  pNew = pBuilder->pNew;
+  whereLoopInit(pNew);
+  for(iTab=0, pItem=pTabList->a; pItemiTab = iTab;
+    pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
+    if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){
+      /* This condition is true when pItem is the FROM clause term on the
+      ** right-hand-side of a LEFT or CROSS JOIN.  */
+      mPrereq = mPrior;
+    }
+    priorJointype = pItem->fg.jointype;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( IsVirtual(pItem->pTab) ){
+      struct SrcList_item *p;
+      for(p=&pItem[1]; pfg.jointype & (JT_LEFT|JT_CROSS)) ){
+          mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
+        }
+      }
+      rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);
+    }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+    {
+      rc = whereLoopAddBtree(pBuilder, mPrereq);
+    }
+    if( rc==SQLITE_OK ){
+      rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);
+    }
+    mPrior |= pNew->maskSelf;
+    if( rc || db->mallocFailed ) break;
+  }
+
+  whereLoopClear(db, pNew);
+  return rc;
+}
+
+/*
+** Examine a WherePath (with the addition of the extra WhereLoop of the 6th
+** parameters) to see if it outputs rows in the requested ORDER BY
+** (or GROUP BY) without requiring a separate sort operation.  Return N:
+** 
+**   N>0:   N terms of the ORDER BY clause are satisfied
+**   N==0:  No terms of the ORDER BY clause are satisfied
+**   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   
+**
+** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
+** strict.  With GROUP BY and DISTINCT the only requirement is that
+** equivalent rows appear immediately adjacent to one another.  GROUP BY
+** and DISTINCT do not require rows to appear in any particular order as long
+** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT
+** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
+** pOrderBy terms must be matched in strict left-to-right order.
+*/
+static i8 wherePathSatisfiesOrderBy(
+  WhereInfo *pWInfo,    /* The WHERE clause */
+  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
+  WherePath *pPath,     /* The WherePath to check */
+  u16 wctrlFlags,       /* WHERE_GROUPBY or _DISTINCTBY or _ORDERBY_LIMIT */
+  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
+  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
+  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
+){
+  u8 revSet;            /* True if rev is known */
+  u8 rev;               /* Composite sort order */
+  u8 revIdx;            /* Index sort order */
+  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
+  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
+  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
+  u16 eqOpMask;         /* Allowed equality operators */
+  u16 nKeyCol;          /* Number of key columns in pIndex */
+  u16 nColumn;          /* Total number of ordered columns in the index */
+  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
+  int iLoop;            /* Index of WhereLoop in pPath being processed */
+  int i, j;             /* Loop counters */
+  int iCur;             /* Cursor number for current WhereLoop */
+  int iColumn;          /* A column number within table iCur */
+  WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
+  WhereTerm *pTerm;     /* A single term of the WHERE clause */
+  Expr *pOBExpr;        /* An expression from the ORDER BY clause */
+  CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */
+  Index *pIndex;        /* The index associated with pLoop */
+  sqlite3 *db = pWInfo->pParse->db;  /* Database connection */
+  Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */
+  Bitmask obDone;       /* Mask of all ORDER BY terms */
+  Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */
+  Bitmask ready;              /* Mask of inner loops */
+
+  /*
+  ** We say the WhereLoop is "one-row" if it generates no more than one
+  ** row of output.  A WhereLoop is one-row if all of the following are true:
+  **  (a) All index columns match with WHERE_COLUMN_EQ.
+  **  (b) The index is unique
+  ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
+  ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
+  **
+  ** We say the WhereLoop is "order-distinct" if the set of columns from
+  ** that WhereLoop that are in the ORDER BY clause are different for every
+  ** row of the WhereLoop.  Every one-row WhereLoop is automatically
+  ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause
+  ** is not order-distinct. To be order-distinct is not quite the same as being
+  ** UNIQUE since a UNIQUE column or index can have multiple rows that 
+  ** are NULL and NULL values are equivalent for the purpose of order-distinct.
+  ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
+  **
+  ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
+  ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
+  ** automatically order-distinct.
+  */
+
+  assert( pOrderBy!=0 );
+  if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+
+  nOrderBy = pOrderBy->nExpr;
+  testcase( nOrderBy==BMS-1 );
+  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
+  isOrderDistinct = 1;
+  obDone = MASKBIT(nOrderBy)-1;
+  orderDistinctMask = 0;
+  ready = 0;
+  eqOpMask = WO_EQ | WO_IS | WO_ISNULL;
+  if( wctrlFlags & WHERE_ORDERBY_LIMIT ) eqOpMask |= WO_IN;
+  for(iLoop=0; isOrderDistinct && obSat0 ) ready |= pLoop->maskSelf;
+    if( iLoopaLoop[iLoop];
+      if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
+    }else{
+      pLoop = pLast;
+    }
+    if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
+      if( pLoop->u.vtab.isOrdered ) obSat = obDone;
+      break;
+    }else{
+      pLoop->u.btree.nIdxCol = 0;
+    }
+    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
+
+    /* Mark off any ORDER BY term X that is a column in the table of
+    ** the current loop for which there is term in the WHERE
+    ** clause of the form X IS NULL or X=? that reference only outer
+    ** loops.
+    */
+    for(i=0; ia[i].pExpr);
+      if( pOBExpr->op!=TK_COLUMN ) continue;
+      if( pOBExpr->iTable!=iCur ) continue;
+      pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+                       ~ready, eqOpMask, 0);
+      if( pTerm==0 ) continue;
+      if( pTerm->eOperator==WO_IN ){
+        /* IN terms are only valid for sorting in the ORDER BY LIMIT 
+        ** optimization, and then only if they are actually used
+        ** by the query plan */
+        assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
+        for(j=0; jnLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
+        if( j>=pLoop->nLTerm ) continue;
+      }
+      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
+        const char *z1, *z2;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z1 = pColl->zName;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z2 = pColl->zName;
+        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+        testcase( pTerm->pExpr->op==TK_IS );
+      }
+      obSat |= MASKBIT(i);
+    }
+
+    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
+      if( pLoop->wsFlags & WHERE_IPK ){
+        pIndex = 0;
+        nKeyCol = 0;
+        nColumn = 1;
+      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
+        return 0;
+      }else{
+        nKeyCol = pIndex->nKeyCol;
+        nColumn = pIndex->nColumn;
+        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
+        assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
+                          || !HasRowid(pIndex->pTable));
+        isOrderDistinct = IsUniqueIndex(pIndex);
+      }
+
+      /* Loop through all columns of the index and deal with the ones
+      ** that are not constrained by == or IN.
+      */
+      rev = revSet = 0;
+      distinctColumns = 0;
+      for(j=0; j=pLoop->u.btree.nEq 
+            || (pLoop->aLTerm[j]==0)==(jnSkip)
+        );
+        if( ju.btree.nEq && j>=pLoop->nSkip ){
+          u16 eOp = pLoop->aLTerm[j]->eOperator;
+
+          /* Skip over == and IS and ISNULL terms.  (Also skip IN terms when
+          ** doing WHERE_ORDERBY_LIMIT processing). 
+          **
+          ** If the current term is a column of an ((?,?) IN (SELECT...)) 
+          ** expression for which the SELECT returns more than one column,
+          ** check that it is the only column used by this loop. Otherwise,
+          ** if it is one of two or more, none of the columns can be
+          ** considered to match an ORDER BY term.  */
+          if( (eOp & eqOpMask)!=0 ){
+            if( eOp & WO_ISNULL ){
+              testcase( isOrderDistinct );
+              isOrderDistinct = 0;
+            }
+            continue;  
+          }else if( ALWAYS(eOp & WO_IN) ){
+            /* ALWAYS() justification: eOp is an equality operator due to the
+            ** ju.btree.nEq constraint above.  Any equality other
+            ** than WO_IN is captured by the previous "if".  So this one
+            ** always has to be WO_IN. */
+            Expr *pX = pLoop->aLTerm[j]->pExpr;
+            for(i=j+1; iu.btree.nEq; i++){
+              if( pLoop->aLTerm[i]->pExpr==pX ){
+                assert( (pLoop->aLTerm[i]->eOperator & WO_IN) );
+                bOnce = 0;
+                break;
+              }
+            }
+          }
+        }
+
+        /* Get the column number in the table (iColumn) and sort order
+        ** (revIdx) for the j-th column of the index.
+        */
+        if( pIndex ){
+          iColumn = pIndex->aiColumn[j];
+          revIdx = pIndex->aSortOrder[j];
+          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
+        }else{
+          iColumn = XN_ROWID;
+          revIdx = 0;
+        }
+
+        /* An unconstrained column that might be NULL means that this
+        ** WhereLoop is not well-ordered
+        */
+        if( isOrderDistinct
+         && iColumn>=0
+         && j>=pLoop->u.btree.nEq
+         && pIndex->pTable->aCol[iColumn].notNull==0
+        ){
+          isOrderDistinct = 0;
+        }
+
+        /* Find the ORDER BY term that corresponds to the j-th column
+        ** of the index and mark that ORDER BY term off 
+        */
+        isMatch = 0;
+        for(i=0; bOnce && ia[i].pExpr);
+          testcase( wctrlFlags & WHERE_GROUPBY );
+          testcase( wctrlFlags & WHERE_DISTINCTBY );
+          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
+          if( iColumn>=(-1) ){
+            if( pOBExpr->op!=TK_COLUMN ) continue;
+            if( pOBExpr->iTable!=iCur ) continue;
+            if( pOBExpr->iColumn!=iColumn ) continue;
+          }else{
+            if( sqlite3ExprCompare(0,
+                  pOBExpr,pIndex->aColExpr->a[j].pExpr,iCur) ){
+              continue;
+            }
+          }
+          if( iColumn>=0 ){
+            pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+            if( !pColl ) pColl = db->pDfltColl;
+            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
+          }
+          pLoop->u.btree.nIdxCol = j+1;
+          isMatch = 1;
+          break;
+        }
+        if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
+          /* Make sure the sort order is compatible in an ORDER BY clause.
+          ** Sort order is irrelevant for a GROUP BY clause. */
+          if( revSet ){
+            if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0;
+          }else{
+            rev = revIdx ^ pOrderBy->a[i].sortOrder;
+            if( rev ) *pRevMask |= MASKBIT(iLoop);
+            revSet = 1;
+          }
+        }
+        if( isMatch ){
+          if( iColumn==XN_ROWID ){
+            testcase( distinctColumns==0 );
+            distinctColumns = 1;
+          }
+          obSat |= MASKBIT(i);
+        }else{
+          /* No match found */
+          if( j==0 || jmaskSelf;
+      for(i=0; ia[i].pExpr;
+        mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);
+        if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
+        if( (mTerm&~orderDistinctMask)==0 ){
+          obSat |= MASKBIT(i);
+        }
+      }
+    }
+  } /* End the loop over all WhereLoops from outer-most down to inner-most */
+  if( obSat==obDone ) return (i8)nOrderBy;
+  if( !isOrderDistinct ){
+    for(i=nOrderBy-1; i>0; i--){
+      Bitmask m = MASKBIT(i) - 1;
+      if( (obSat&m)==m ) return i;
+    }
+    return 0;
+  }
+  return -1;
+}
+
+
+/*
+** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),
+** the planner assumes that the specified pOrderBy list is actually a GROUP
+** BY clause - and so any order that groups rows as required satisfies the
+** request.
+**
+** Normally, in this case it is not possible for the caller to determine
+** whether or not the rows are really being delivered in sorted order, or
+** just in some other order that provides the required grouping. However,
+** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then
+** this function may be called on the returned WhereInfo object. It returns
+** true if the rows really will be sorted in the specified order, or false
+** otherwise.
+**
+** For example, assuming:
+**
+**   CREATE INDEX i1 ON t1(x, Y);
+**
+** then
+**
+**   SELECT * FROM t1 GROUP BY x,y ORDER BY x,y;   -- IsSorted()==1
+**   SELECT * FROM t1 GROUP BY y,x ORDER BY y,x;   -- IsSorted()==0
+*/
+SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){
+  assert( pWInfo->wctrlFlags & WHERE_GROUPBY );
+  assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );
+  return pWInfo->sorted;
+}
+
+#ifdef WHERETRACE_ENABLED
+/* For debugging use only: */
+static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
+  static char zName[65];
+  int i;
+  for(i=0; iaLoop[i]->cId; }
+  if( pLast ) zName[i++] = pLast->cId;
+  zName[i] = 0;
+  return zName;
+}
+#endif
+
+/*
+** Return the cost of sorting nRow rows, assuming that the keys have 
+** nOrderby columns and that the first nSorted columns are already in
+** order.
+*/
+static LogEst whereSortingCost(
+  WhereInfo *pWInfo,
+  LogEst nRow,
+  int nOrderBy,
+  int nSorted
+){
+  /* TUNING: Estimated cost of a full external sort, where N is 
+  ** the number of rows to sort is:
+  **
+  **   cost = (3.0 * N * log(N)).
+  ** 
+  ** Or, if the order-by clause has X terms but only the last Y 
+  ** terms are out of order, then block-sorting will reduce the 
+  ** sorting cost to:
+  **
+  **   cost = (3.0 * N * log(N)) * (Y/X)
+  **
+  ** The (Y/X) term is implemented using stack variable rScale
+  ** below.  */
+  LogEst rScale, rSortCost;
+  assert( nOrderBy>0 && 66==sqlite3LogEst(100) );
+  rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;
+  rSortCost = nRow + rScale + 16;
+
+  /* Multiple by log(M) where M is the number of output rows.
+  ** Use the LIMIT for M if it is smaller */
+  if( (pWInfo->wctrlFlags & WHERE_USE_LIMIT)!=0 && pWInfo->iLimitiLimit;
+  }
+  rSortCost += estLog(nRow);
+  return rSortCost;
+}
+
+/*
+** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
+** attempts to find the lowest cost path that visits each WhereLoop
+** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
+**
+** Assume that the total number of output rows that will need to be sorted
+** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting
+** costs if nRowEst==0.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
+** error occurs.
+*/
+static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
+  int mxChoice;             /* Maximum number of simultaneous paths tracked */
+  int nLoop;                /* Number of terms in the join */
+  Parse *pParse;            /* Parsing context */
+  sqlite3 *db;              /* The database connection */
+  int iLoop;                /* Loop counter over the terms of the join */
+  int ii, jj;               /* Loop counters */
+  int mxI = 0;              /* Index of next entry to replace */
+  int nOrderBy;             /* Number of ORDER BY clause terms */
+  LogEst mxCost = 0;        /* Maximum cost of a set of paths */
+  LogEst mxUnsorted = 0;    /* Maximum unsorted cost of a set of path */
+  int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
+  WherePath *aFrom;         /* All nFrom paths at the previous level */
+  WherePath *aTo;           /* The nTo best paths at the current level */
+  WherePath *pFrom;         /* An element of aFrom[] that we are working on */
+  WherePath *pTo;           /* An element of aTo[] that we are working on */
+  WhereLoop *pWLoop;        /* One of the WhereLoop objects */
+  WhereLoop **pX;           /* Used to divy up the pSpace memory */
+  LogEst *aSortCost = 0;    /* Sorting and partial sorting costs */
+  char *pSpace;             /* Temporary memory used by this routine */
+  int nSpace;               /* Bytes of space allocated at pSpace */
+
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  nLoop = pWInfo->nLevel;
+  /* TUNING: For simple queries, only the best path is tracked.
+  ** For 2-way joins, the 5 best paths are followed.
+  ** For joins of 3 or more tables, track the 10 best paths */
+  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);
+  assert( nLoop<=pWInfo->pTabList->nSrc );
+  WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d)\n", nRowEst));
+
+  /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this
+  ** case the purpose of this call is to estimate the number of rows returned
+  ** by the overall query. Once this estimate has been obtained, the caller
+  ** will invoke this function a second time, passing the estimate as the
+  ** nRowEst parameter.  */
+  if( pWInfo->pOrderBy==0 || nRowEst==0 ){
+    nOrderBy = 0;
+  }else{
+    nOrderBy = pWInfo->pOrderBy->nExpr;
+  }
+
+  /* Allocate and initialize space for aTo, aFrom and aSortCost[] */
+  nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
+  nSpace += sizeof(LogEst) * nOrderBy;
+  pSpace = sqlite3DbMallocRawNN(db, nSpace);
+  if( pSpace==0 ) return SQLITE_NOMEM_BKPT;
+  aTo = (WherePath*)pSpace;
+  aFrom = aTo+mxChoice;
+  memset(aFrom, 0, sizeof(aFrom[0]));
+  pX = (WhereLoop**)(aFrom+mxChoice);
+  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
+    pFrom->aLoop = pX;
+  }
+  if( nOrderBy ){
+    /* If there is an ORDER BY clause and it is not being ignored, set up
+    ** space for the aSortCost[] array. Each element of the aSortCost array
+    ** is either zero - meaning it has not yet been initialized - or the
+    ** cost of sorting nRowEst rows of data where the first X terms of
+    ** the ORDER BY clause are already in order, where X is the array 
+    ** index.  */
+    aSortCost = (LogEst*)pX;
+    memset(aSortCost, 0, sizeof(LogEst) * nOrderBy);
+  }
+  assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] );
+  assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX );
+
+  /* Seed the search with a single WherePath containing zero WhereLoops.
+  **
+  ** TUNING: Do not let the number of iterations go above 28.  If the cost
+  ** of computing an automatic index is not paid back within the first 28
+  ** rows, then do not use the automatic index. */
+  aFrom[0].nRow = MIN(pParse->nQueryLoop, 48);  assert( 48==sqlite3LogEst(28) );
+  nFrom = 1;
+  assert( aFrom[0].isOrdered==0 );
+  if( nOrderBy ){
+    /* If nLoop is zero, then there are no FROM terms in the query. Since
+    ** in this case the query may return a maximum of one row, the results
+    ** are already in the requested order. Set isOrdered to nOrderBy to
+    ** indicate this. Or, if nLoop is greater than zero, set isOrdered to
+    ** -1, indicating that the result set may or may not be ordered, 
+    ** depending on the loops added to the current plan.  */
+    aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy;
+  }
+
+  /* Compute successively longer WherePaths using the previous generation
+  ** of WherePaths as the basis for the next.  Keep track of the mxChoice
+  ** best paths at each generation */
+  for(iLoop=0; iLooppLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
+        LogEst nOut;                      /* Rows visited by (pFrom+pWLoop) */
+        LogEst rCost;                     /* Cost of path (pFrom+pWLoop) */
+        LogEst rUnsorted;                 /* Unsorted cost of (pFrom+pWLoop) */
+        i8 isOrdered = pFrom->isOrdered;  /* isOrdered for (pFrom+pWLoop) */
+        Bitmask maskNew;                  /* Mask of src visited by (..) */
+        Bitmask revMask = 0;              /* Mask of rev-order loops for (..) */
+
+        if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 && pFrom->nRow<10 ){
+          /* Do not use an automatic index if the this loop is expected
+          ** to run less than 2 times. */
+          assert( 10==sqlite3LogEst(2) );
+          continue;
+        }
+        /* At this point, pWLoop is a candidate to be the next loop. 
+        ** Compute its cost */
+        rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
+        rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted);
+        nOut = pFrom->nRow + pWLoop->nOut;
+        maskNew = pFrom->maskLoop | pWLoop->maskSelf;
+        if( isOrdered<0 ){
+          isOrdered = wherePathSatisfiesOrderBy(pWInfo,
+                       pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
+                       iLoop, pWLoop, &revMask);
+        }else{
+          revMask = pFrom->revLoop;
+        }
+        if( isOrdered>=0 && isOrderedisOrdered^isOrdered)&0x80)==0" is equivalent
+        ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range
+        ** of legal values for isOrdered, -1..64.
+        */
+        for(jj=0, pTo=aTo; jjmaskLoop==maskNew
+           && ((pTo->isOrdered^isOrdered)&0x80)==0
+          ){
+            testcase( jj==nTo-1 );
+            break;
+          }
+        }
+        if( jj>=nTo ){
+          /* None of the existing best-so-far paths match the candidate. */
+          if( nTo>=mxChoice
+           && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted))
+          ){
+            /* The current candidate is no better than any of the mxChoice
+            ** paths currently in the best-so-far buffer.  So discard
+            ** this candidate as not viable. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+            }
+#endif
+            continue;
+          }
+          /* If we reach this points it means that the new candidate path
+          ** needs to be added to the set of best-so-far paths. */
+          if( nTo=0 ? isOrdered+'0' : '?');
+          }
+#endif
+        }else{
+          /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
+          ** same set of loops and has the same isOrdered setting as the
+          ** candidate path.  Check to see if the candidate should replace
+          ** pTo or if the candidate should be skipped.
+          ** 
+          ** The conditional is an expanded vector comparison equivalent to:
+          **   (pTo->rCost,pTo->nRow,pTo->rUnsorted) <= (rCost,nOut,rUnsorted)
+          */
+          if( pTo->rCostrCost==rCost
+               && (pTo->nRownRow==nOut && pTo->rUnsorted<=rUnsorted)
+                  )
+              )
+          ){
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf(
+                  "Skip   %s cost=%-3d,%3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%3d,%3d order=%c\n",
+                  wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                  pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+            }
+#endif
+            /* Discard the candidate path from further consideration */
+            testcase( pTo->rCost==rCost );
+            continue;
+          }
+          testcase( pTo->rCost==rCost+1 );
+          /* Control reaches here if the candidate path is better than the
+          ** pTo path.  Replace pTo with the candidate. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf(
+                "Update %s cost=%-3d,%3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
+                isOrdered>=0 ? isOrdered+'0' : '?');
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d,%3d order=%c\n",
+                wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+          }
+#endif
+        }
+        /* pWLoop is a winner.  Add it to the set of best so far */
+        pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
+        pTo->revLoop = revMask;
+        pTo->nRow = nOut;
+        pTo->rCost = rCost;
+        pTo->rUnsorted = rUnsorted;
+        pTo->isOrdered = isOrdered;
+        memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
+        pTo->aLoop[iLoop] = pWLoop;
+        if( nTo>=mxChoice ){
+          mxI = 0;
+          mxCost = aTo[0].rCost;
+          mxUnsorted = aTo[0].nRow;
+          for(jj=1, pTo=&aTo[1]; jjrCost>mxCost 
+             || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) 
+            ){
+              mxCost = pTo->rCost;
+              mxUnsorted = pTo->rUnsorted;
+              mxI = jj;
+            }
+          }
+        }
+      }
+    }
+
+#ifdef WHERETRACE_ENABLED  /* >=2 */
+    if( sqlite3WhereTrace & 0x02 ){
+      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
+      for(ii=0, pTo=aTo; iirCost, pTo->nRow,
+           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
+        if( pTo->isOrdered>0 ){
+          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
+        }else{
+          sqlite3DebugPrintf("\n");
+        }
+      }
+    }
+#endif
+
+    /* Swap the roles of aFrom and aTo for the next generation */
+    pFrom = aTo;
+    aTo = aFrom;
+    aFrom = pFrom;
+    nFrom = nTo;
+  }
+
+  if( nFrom==0 ){
+    sqlite3ErrorMsg(pParse, "no query solution");
+    sqlite3DbFreeNN(db, pSpace);
+    return SQLITE_ERROR;
+  }
+  
+  /* Find the lowest cost path.  pFrom will be left pointing to that path */
+  pFrom = aFrom;
+  for(ii=1; iirCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
+  }
+  assert( pWInfo->nLevel==nLoop );
+  /* Load the lowest cost path into pWInfo */
+  for(iLoop=0; iLoopa + iLoop;
+    pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
+    pLevel->iFrom = pWLoop->iTab;
+    pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
+  }
+  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
+   && nRowEst
+  ){
+    Bitmask notUsed;
+    int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,
+                 WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], ¬Used);
+    if( rc==pWInfo->pResultSet->nExpr ){
+      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+    }
+  }
+  if( pWInfo->pOrderBy ){
+    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
+      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
+        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+      }
+    }else{
+      pWInfo->nOBSat = pFrom->isOrdered;
+      pWInfo->revMask = pFrom->revLoop;
+      if( pWInfo->nOBSat<=0 ){
+        pWInfo->nOBSat = 0;
+        if( nLoop>0 ){
+          u32 wsFlags = pFrom->aLoop[nLoop-1]->wsFlags;
+          if( (wsFlags & WHERE_ONEROW)==0 
+           && (wsFlags&(WHERE_IPK|WHERE_COLUMN_IN))!=(WHERE_IPK|WHERE_COLUMN_IN)
+          ){
+            Bitmask m = 0;
+            int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,
+                      WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);
+            testcase( wsFlags & WHERE_IPK );
+            testcase( wsFlags & WHERE_COLUMN_IN );
+            if( rc==pWInfo->pOrderBy->nExpr ){
+              pWInfo->bOrderedInnerLoop = 1;
+              pWInfo->revMask = m;
+            }
+          }
+        }
+      }
+    }
+    if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
+        && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
+    ){
+      Bitmask revMask = 0;
+      int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 
+          pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask
+      );
+      assert( pWInfo->sorted==0 );
+      if( nOrder==pWInfo->pOrderBy->nExpr ){
+        pWInfo->sorted = 1;
+        pWInfo->revMask = revMask;
+      }
+    }
+  }
+
+
+  pWInfo->nRowOut = pFrom->nRow;
+
+  /* Free temporary memory and return success */
+  sqlite3DbFreeNN(db, pSpace);
+  return SQLITE_OK;
+}
+
+/*
+** Most queries use only a single table (they are not joins) and have
+** simple == constraints against indexed fields.  This routine attempts
+** to plan those simple cases using much less ceremony than the
+** general-purpose query planner, and thereby yield faster sqlite3_prepare()
+** times for the common case.
+**
+** Return non-zero on success, if this query can be handled by this
+** no-frills query planner.  Return zero if this query needs the 
+** general-purpose query planner.
+*/
+static int whereShortCut(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo;
+  struct SrcList_item *pItem;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  WhereLoop *pLoop;
+  int iCur;
+  int j;
+  Table *pTab;
+  Index *pIdx;
+
+  pWInfo = pBuilder->pWInfo;
+  if( pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE ) return 0;
+  assert( pWInfo->pTabList->nSrc>=1 );
+  pItem = pWInfo->pTabList->a;
+  pTab = pItem->pTab;
+  if( IsVirtual(pTab) ) return 0;
+  if( pItem->fg.isIndexedBy ) return 0;
+  iCur = pItem->iCursor;
+  pWC = &pWInfo->sWC;
+  pLoop = pBuilder->pNew;
+  pLoop->wsFlags = 0;
+  pLoop->nSkip = 0;
+  pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
+  if( pTerm ){
+    testcase( pTerm->eOperator & WO_IS );
+    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
+    pLoop->aLTerm[0] = pTerm;
+    pLoop->nLTerm = 1;
+    pLoop->u.btree.nEq = 1;
+    /* TUNING: Cost of a rowid lookup is 10 */
+    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
+  }else{
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      int opMask;
+      assert( pLoop->aLTermSpace==pLoop->aLTerm );
+      if( !IsUniqueIndex(pIdx)
+       || pIdx->pPartIdxWhere!=0 
+       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
+      ) continue;
+      opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;
+      for(j=0; jnKeyCol; j++){
+        pTerm = sqlite3WhereFindTerm(pWC, iCur, j, 0, opMask, pIdx);
+        if( pTerm==0 ) break;
+        testcase( pTerm->eOperator & WO_IS );
+        pLoop->aLTerm[j] = pTerm;
+      }
+      if( j!=pIdx->nKeyCol ) continue;
+      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
+      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
+        pLoop->wsFlags |= WHERE_IDX_ONLY;
+      }
+      pLoop->nLTerm = j;
+      pLoop->u.btree.nEq = j;
+      pLoop->u.btree.pIndex = pIdx;
+      /* TUNING: Cost of a unique index lookup is 15 */
+      pLoop->rRun = 39;  /* 39==sqlite3LogEst(15) */
+      break;
+    }
+  }
+  if( pLoop->wsFlags ){
+    pLoop->nOut = (LogEst)1;
+    pWInfo->a[0].pWLoop = pLoop;
+    assert( pWInfo->sMaskSet.n==1 && iCur==pWInfo->sMaskSet.ix[0] );
+    pLoop->maskSelf = 1; /* sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur); */
+    pWInfo->a[0].iTabCur = iCur;
+    pWInfo->nRowOut = 1;
+    if( pWInfo->pOrderBy ) pWInfo->nOBSat =  pWInfo->pOrderBy->nExpr;
+    if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+#ifdef SQLITE_DEBUG
+    pLoop->cId = '0';
+#endif
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Helper function for exprIsDeterministic().
+*/
+static int exprNodeIsDeterministic(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_ConstFunc)==0 ){
+    pWalker->eCode = 0;
+    return WRC_Abort;
+  }
+  return WRC_Continue;
+}
+
+/*
+** Return true if the expression contains no non-deterministic SQL 
+** functions. Do not consider non-deterministic SQL functions that are 
+** part of sub-select statements.
+*/
+static int exprIsDeterministic(Expr *p){
+  Walker w;
+  memset(&w, 0, sizeof(w));
+  w.eCode = 1;
+  w.xExprCallback = exprNodeIsDeterministic;
+  sqlite3WalkExpr(&w, p);
+  return w.eCode;
+}
+
+/*
+** Generate the beginning of the loop used for WHERE clause processing.
+** The return value is a pointer to an opaque structure that contains
+** information needed to terminate the loop.  Later, the calling routine
+** should invoke sqlite3WhereEnd() with the return value of this function
+** in order to complete the WHERE clause processing.
+**
+** If an error occurs, this routine returns NULL.
+**
+** The basic idea is to do a nested loop, one loop for each table in
+** the FROM clause of a select.  (INSERT and UPDATE statements are the
+** same as a SELECT with only a single table in the FROM clause.)  For
+** example, if the SQL is this:
+**
+**       SELECT * FROM t1, t2, t3 WHERE ...;
+**
+** Then the code generated is conceptually like the following:
+**
+**      foreach row1 in t1 do       \    Code generated
+**        foreach row2 in t2 do      |-- by sqlite3WhereBegin()
+**          foreach row3 in t3 do   /
+**            ...
+**          end                     \    Code generated
+**        end                        |-- by sqlite3WhereEnd()
+**      end                         /
+**
+** Note that the loops might not be nested in the order in which they
+** appear in the FROM clause if a different order is better able to make
+** use of indices.  Note also that when the IN operator appears in
+** the WHERE clause, it might result in additional nested loops for
+** scanning through all values on the right-hand side of the IN.
+**
+** There are Btree cursors associated with each table.  t1 uses cursor
+** number pTabList->a[0].iCursor.  t2 uses the cursor pTabList->a[1].iCursor.
+** And so forth.  This routine generates code to open those VDBE cursors
+** and sqlite3WhereEnd() generates the code to close them.
+**
+** The code that sqlite3WhereBegin() generates leaves the cursors named
+** in pTabList pointing at their appropriate entries.  The [...] code
+** can use OP_Column and OP_Rowid opcodes on these cursors to extract
+** data from the various tables of the loop.
+**
+** If the WHERE clause is empty, the foreach loops must each scan their
+** entire tables.  Thus a three-way join is an O(N^3) operation.  But if
+** the tables have indices and there are terms in the WHERE clause that
+** refer to those indices, a complete table scan can be avoided and the
+** code will run much faster.  Most of the work of this routine is checking
+** to see if there are indices that can be used to speed up the loop.
+**
+** Terms of the WHERE clause are also used to limit which rows actually
+** make it to the "..." in the middle of the loop.  After each "foreach",
+** terms of the WHERE clause that use only terms in that loop and outer
+** loops are evaluated and if false a jump is made around all subsequent
+** inner loops (or around the "..." if the test occurs within the inner-
+** most loop)
+**
+** OUTER JOINS
+**
+** An outer join of tables t1 and t2 is conceptally coded as follows:
+**
+**    foreach row1 in t1 do
+**      flag = 0
+**      foreach row2 in t2 do
+**        start:
+**          ...
+**          flag = 1
+**      end
+**      if flag==0 then
+**        move the row2 cursor to a null row
+**        goto start
+**      fi
+**    end
+**
+** ORDER BY CLAUSE PROCESSING
+**
+** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
+** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
+** if there is one.  If there is no ORDER BY clause or if this routine
+** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
+**
+** The iIdxCur parameter is the cursor number of an index.  If 
+** WHERE_OR_SUBCLAUSE is set, iIdxCur is the cursor number of an index
+** to use for OR clause processing.  The WHERE clause should use this
+** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
+** the first cursor in an array of cursors for all indices.  iIdxCur should
+** be used to compute the appropriate cursor depending on which index is
+** used.
+*/
+SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
+  Parse *pParse,          /* The parser context */
+  SrcList *pTabList,      /* FROM clause: A list of all tables to be scanned */
+  Expr *pWhere,           /* The WHERE clause */
+  ExprList *pOrderBy,     /* An ORDER BY (or GROUP BY) clause, or NULL */
+  ExprList *pResultSet,   /* Query result set.  Req'd for DISTINCT */
+  u16 wctrlFlags,         /* The WHERE_* flags defined in sqliteInt.h */
+  int iAuxArg             /* If WHERE_OR_SUBCLAUSE is set, index cursor number
+                          ** If WHERE_USE_LIMIT, then the limit amount */
+){
+  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
+  int nTabList;              /* Number of elements in pTabList */
+  WhereInfo *pWInfo;         /* Will become the return value of this function */
+  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
+  Bitmask notReady;          /* Cursors that are not yet positioned */
+  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
+  WhereMaskSet *pMaskSet;    /* The expression mask set */
+  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
+  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
+  int ii;                    /* Loop counter */
+  sqlite3 *db;               /* Database connection */
+  int rc;                    /* Return code */
+  u8 bFordelete = 0;         /* OPFLAG_FORDELETE or zero, as appropriate */
+
+  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
+        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
+     && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 
+  ));
+
+  /* Only one of WHERE_OR_SUBCLAUSE or WHERE_USE_LIMIT */
+  assert( (wctrlFlags & WHERE_OR_SUBCLAUSE)==0
+            || (wctrlFlags & WHERE_USE_LIMIT)==0 );
+
+  /* Variable initialization */
+  db = pParse->db;
+  memset(&sWLB, 0, sizeof(sWLB));
+
+  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
+  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
+  if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0;
+  sWLB.pOrderBy = pOrderBy;
+
+  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+    wctrlFlags &= ~WHERE_WANT_DISTINCT;
+  }
+
+  /* The number of tables in the FROM clause is limited by the number of
+  ** bits in a Bitmask 
+  */
+  testcase( pTabList->nSrc==BMS );
+  if( pTabList->nSrc>BMS ){
+    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
+    return 0;
+  }
+
+  /* This function normally generates a nested loop for all tables in 
+  ** pTabList.  But if the WHERE_OR_SUBCLAUSE flag is set, then we should
+  ** only generate code for the first table in pTabList and assume that
+  ** any cursors associated with subsequent tables are uninitialized.
+  */
+  nTabList = (wctrlFlags & WHERE_OR_SUBCLAUSE) ? 1 : pTabList->nSrc;
+
+  /* Allocate and initialize the WhereInfo structure that will become the
+  ** return value. A single allocation is used to store the WhereInfo
+  ** struct, the contents of WhereInfo.a[], the WhereClause structure
+  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
+  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
+  ** some architectures. Hence the ROUND8() below.
+  */
+  nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
+  pWInfo = sqlite3DbMallocRawNN(db, nByteWInfo + sizeof(WhereLoop));
+  if( db->mallocFailed ){
+    sqlite3DbFree(db, pWInfo);
+    pWInfo = 0;
+    goto whereBeginError;
+  }
+  pWInfo->pParse = pParse;
+  pWInfo->pTabList = pTabList;
+  pWInfo->pOrderBy = pOrderBy;
+  pWInfo->pWhere = pWhere;
+  pWInfo->pResultSet = pResultSet;
+  pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;
+  pWInfo->nLevel = nTabList;
+  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
+  pWInfo->wctrlFlags = wctrlFlags;
+  pWInfo->iLimit = iAuxArg;
+  pWInfo->savedNQueryLoop = pParse->nQueryLoop;
+  memset(&pWInfo->nOBSat, 0, 
+         offsetof(WhereInfo,sWC) - offsetof(WhereInfo,nOBSat));
+  memset(&pWInfo->a[0], 0, sizeof(WhereLoop)+nTabList*sizeof(WhereLevel));
+  assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */
+  pMaskSet = &pWInfo->sMaskSet;
+  sWLB.pWInfo = pWInfo;
+  sWLB.pWC = &pWInfo->sWC;
+  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
+  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
+  whereLoopInit(sWLB.pNew);
+#ifdef SQLITE_DEBUG
+  sWLB.pNew->cId = '*';
+#endif
+
+  /* Split the WHERE clause into separate subexpressions where each
+  ** subexpression is separated by an AND operator.
+  */
+  initMaskSet(pMaskSet);
+  sqlite3WhereClauseInit(&pWInfo->sWC, pWInfo);
+  sqlite3WhereSplit(&pWInfo->sWC, pWhere, TK_AND);
+    
+  /* Special case: No FROM clause
+  */
+  if( nTabList==0 ){
+    if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
+    if( wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+  }
+
+  /* Assign a bit from the bitmask to every term in the FROM clause.
+  **
+  ** The N-th term of the FROM clause is assigned a bitmask of 1<nSrc tables in
+  ** pTabList, not just the first nTabList tables.  nTabList is normally
+  ** equal to pTabList->nSrc but might be shortened to 1 if the
+  ** WHERE_OR_SUBCLAUSE flag is set.
+  */
+  for(ii=0; iinSrc; ii++){
+    createMask(pMaskSet, pTabList->a[ii].iCursor);
+    sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
+  }
+#ifdef SQLITE_DEBUG
+  {
+    Bitmask mx = 0;
+    for(ii=0; iinSrc; ii++){
+      Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
+      assert( m>=mx );
+      mx = m;
+    }
+  }
+#endif
+
+  /* Analyze all of the subexpressions. */
+  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
+  if( db->mallocFailed ) goto whereBeginError;
+
+  /* Special case: WHERE terms that do not refer to any tables in the join
+  ** (constant expressions). Evaluate each such term, and jump over all the
+  ** generated code if the result is not true.  
+  **
+  ** Do not do this if the expression contains non-deterministic functions
+  ** that are not within a sub-select. This is not strictly required, but
+  ** preserves SQLite's legacy behaviour in the following two cases:
+  **
+  **   FROM ... WHERE random()>0;           -- eval random() once per row
+  **   FROM ... WHERE (SELECT random())>0;  -- eval random() once overall
+  */
+  for(ii=0; iinTerm; ii++){
+    WhereTerm *pT = &sWLB.pWC->a[ii];
+    if( pT->prereqAll==0 && (nTabList==0 || exprIsDeterministic(pT->pExpr)) ){
+      sqlite3ExprIfFalse(pParse, pT->pExpr, pWInfo->iBreak, SQLITE_JUMPIFNULL);
+      pT->wtFlags |= TERM_CODED;
+    }
+  }
+
+  if( wctrlFlags & WHERE_WANT_DISTINCT ){
+    if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
+      /* The DISTINCT marking is pointless.  Ignore it. */
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }else if( pOrderBy==0 ){
+      /* Try to ORDER BY the result set to make distinct processing easier */
+      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
+      pWInfo->pOrderBy = pResultSet;
+    }
+  }
+
+  /* Construct the WhereLoop objects */
+#if defined(WHERETRACE_ENABLED)
+  if( sqlite3WhereTrace & 0xffff ){
+    sqlite3DebugPrintf("*** Optimizer Start *** (wctrlFlags: 0x%x",wctrlFlags);
+    if( wctrlFlags & WHERE_USE_LIMIT ){
+      sqlite3DebugPrintf(", limit: %d", iAuxArg);
+    }
+    sqlite3DebugPrintf(")\n");
+  }
+  if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */
+    sqlite3WhereClausePrint(sWLB.pWC);
+  }
+#endif
+
+  if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
+    rc = whereLoopAddAll(&sWLB);
+    if( rc ) goto whereBeginError;
+  
+#ifdef WHERETRACE_ENABLED
+    if( sqlite3WhereTrace ){    /* Display all of the WhereLoop objects */
+      WhereLoop *p;
+      int i;
+      static const char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
+                                             "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+        p->cId = zLabel[i%(sizeof(zLabel)-1)];
+        whereLoopPrint(p, sWLB.pWC);
+      }
+    }
+#endif
+  
+    wherePathSolver(pWInfo, 0);
+    if( db->mallocFailed ) goto whereBeginError;
+    if( pWInfo->pOrderBy ){
+       wherePathSolver(pWInfo, pWInfo->nRowOut+1);
+       if( db->mallocFailed ) goto whereBeginError;
+    }
+  }
+  if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
+     pWInfo->revMask = ALLBITS;
+  }
+  if( pParse->nErr || NEVER(db->mallocFailed) ){
+    goto whereBeginError;
+  }
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace ){
+    sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
+    if( pWInfo->nOBSat>0 ){
+      sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);
+    }
+    switch( pWInfo->eDistinct ){
+      case WHERE_DISTINCT_UNIQUE: {
+        sqlite3DebugPrintf("  DISTINCT=unique");
+        break;
+      }
+      case WHERE_DISTINCT_ORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=ordered");
+        break;
+      }
+      case WHERE_DISTINCT_UNORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=unordered");
+        break;
+      }
+    }
+    sqlite3DebugPrintf("\n");
+    for(ii=0; iinLevel; ii++){
+      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
+    }
+  }
+#endif
+  /* Attempt to omit tables from the join that do not effect the result */
+  if( pWInfo->nLevel>=2
+   && pResultSet!=0
+   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
+  ){
+    Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet);
+    if( sWLB.pOrderBy ){
+      tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);
+    }
+    while( pWInfo->nLevel>=2 ){
+      WhereTerm *pTerm, *pEnd;
+      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+      if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break;
+      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
+       && (pLoop->wsFlags & WHERE_ONEROW)==0
+      ){
+        break;
+      }
+      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
+      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
+      for(pTerm=sWLB.pWC->a; pTermprereqAll & pLoop->maskSelf)!=0
+         && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+        ){
+          break;
+        }
+      }
+      if( pTerm drop loop %c not used\n", pLoop->cId));
+      pWInfo->nLevel--;
+      nTabList--;
+    }
+  }
+  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
+  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
+
+  /* If the caller is an UPDATE or DELETE statement that is requesting
+  ** to use a one-pass algorithm, determine if this is appropriate.
+  */
+  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
+  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
+    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
+    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
+    if( bOnerow
+     || ((wctrlFlags & WHERE_ONEPASS_MULTIROW)!=0
+           && 0==(wsFlags & WHERE_VIRTUALTABLE))
+    ){
+      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
+      if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){
+        if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){
+          bFordelete = OPFLAG_FORDELETE;
+        }
+        pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);
+      }
+    }
+  }
+
+  /* Open all tables in the pTabList and any indices selected for
+  ** searching those tables.
+  */
+  for(ii=0, pLevel=pWInfo->a; iia[pLevel->iFrom];
+    pTab = pTabItem->pTab;
+    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    pLoop = pLevel->pWLoop;
+    if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
+      /* Do nothing */
+    }else
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
+      int iCur = pTabItem->iCursor;
+      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
+    }else if( IsVirtual(pTab) ){
+      /* noop */
+    }else
+#endif
+    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+         && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){
+      int op = OP_OpenRead;
+      if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
+      };
+      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
+      assert( pTabItem->iCursor==pLevel->iTabCur );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );
+      if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nColcolUsed;
+        int n = 0;
+        for(; b; b=b>>1, n++){}
+        sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(n), P4_INT32);
+        assert( n<=pTab->nCol );
+      }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+      if( pLoop->u.btree.pIndex!=0 ){
+        sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);
+      }else
+#endif
+      {
+        sqlite3VdbeChangeP5(v, bFordelete);
+      }
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+      sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,
+                            (const u8*)&pTabItem->colUsed, P4_INT64);
+#endif
+    }else{
+      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+    }
+    if( pLoop->wsFlags & WHERE_INDEXED ){
+      Index *pIx = pLoop->u.btree.pIndex;
+      int iIndexCur;
+      int op = OP_OpenRead;
+      /* iAuxArg is always set if to a positive value if ONEPASS is possible */
+      assert( iAuxArg!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );
+      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
+       && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0
+      ){
+        /* This is one term of an OR-optimization using the PRIMARY KEY of a
+        ** WITHOUT ROWID table.  No need for a separate index */
+        iIndexCur = pLevel->iTabCur;
+        op = 0;
+      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        Index *pJ = pTabItem->pTab->pIndex;
+        iIndexCur = iAuxArg;
+        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
+        while( ALWAYS(pJ) && pJ!=pIx ){
+          iIndexCur++;
+          pJ = pJ->pNext;
+        }
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[1] = iIndexCur;
+      }else if( iAuxArg && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 ){
+        iIndexCur = iAuxArg;
+        op = OP_ReopenIdx;
+      }else{
+        iIndexCur = pParse->nTab++;
+      }
+      pLevel->iIdxCur = iIndexCur;
+      assert( pIx->pSchema==pTab->pSchema );
+      assert( iIndexCur>=0 );
+      if( op ){
+        sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb);
+        sqlite3VdbeSetP4KeyInfo(pParse, pIx);
+        if( (pLoop->wsFlags & WHERE_CONSTRAINT)!=0
+         && (pLoop->wsFlags & (WHERE_COLUMN_RANGE|WHERE_SKIPSCAN))==0
+         && (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0
+         && pWInfo->eDistinct!=WHERE_DISTINCT_ORDERED
+        ){
+          sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Hint to COMDB2 */
+        }
+        VdbeComment((v, "%s", pIx->zName));
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+        {
+          u64 colUsed = 0;
+          int ii, jj;
+          for(ii=0; iinColumn; ii++){
+            jj = pIx->aiColumn[ii];
+            if( jj<0 ) continue;
+            if( jj>63 ) jj = 63;
+            if( (pTabItem->colUsed & MASKBIT(jj))==0 ) continue;
+            colUsed |= ((u64)1)<<(ii<63 ? ii : 63);
+          }
+          sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, iIndexCur, 0, 0,
+                                (u8*)&colUsed, P4_INT64);
+        }
+#endif /* SQLITE_ENABLE_COLUMN_USED_MASK */
+      }
+    }
+    if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);
+  }
+  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
+  if( db->mallocFailed ) goto whereBeginError;
+
+  /* Generate the code to do the search.  Each iteration of the for
+  ** loop below generates code for a single nested loop of the VM
+  ** program.
+  */
+  notReady = ~(Bitmask)0;
+  for(ii=0; iia[ii];
+    wsFlags = pLevel->pWLoop->wsFlags;
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+      constructAutomaticIndex(pParse, &pWInfo->sWC,
+                &pTabList->a[pLevel->iFrom], notReady, pLevel);
+      if( db->mallocFailed ) goto whereBeginError;
+    }
+#endif
+    addrExplain = sqlite3WhereExplainOneScan(
+        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
+    );
+    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
+    notReady = sqlite3WhereCodeOneLoopStart(pWInfo, ii, notReady);
+    pWInfo->iContinue = pLevel->addrCont;
+    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_OR_SUBCLAUSE)==0 ){
+      sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);
+    }
+  }
+
+  /* Done. */
+  VdbeModuleComment((v, "Begin WHERE-core"));
+  return pWInfo;
+
+  /* Jump here if malloc fails */
+whereBeginError:
+  if( pWInfo ){
+    pParse->nQueryLoop = pWInfo->savedNQueryLoop;
+    whereInfoFree(db, pWInfo);
+  }
+  return 0;
+}
+
+/*
+** Generate the end of the WHERE loop.  See comments on 
+** sqlite3WhereBegin() for additional information.
+*/
+SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
+  Parse *pParse = pWInfo->pParse;
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  WhereLevel *pLevel;
+  WhereLoop *pLoop;
+  SrcList *pTabList = pWInfo->pTabList;
+  sqlite3 *db = pParse->db;
+
+  /* Generate loop termination code.
+  */
+  VdbeModuleComment((v, "End WHERE-core"));
+  sqlite3ExprCacheClear(pParse);
+  for(i=pWInfo->nLevel-1; i>=0; i--){
+    int addr;
+    pLevel = &pWInfo->a[i];
+    pLoop = pLevel->pWLoop;
+    if( pLevel->op!=OP_Noop ){
+#ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT
+      int addrSeek = 0;
+      Index *pIdx;
+      int n;
+      if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED
+       && (pLoop->wsFlags & WHERE_INDEXED)!=0
+       && (pIdx = pLoop->u.btree.pIndex)->hasStat1
+       && (n = pLoop->u.btree.nIdxCol)>0
+       && pIdx->aiRowLogEst[n]>=36
+      ){
+        int r1 = pParse->nMem+1;
+        int j, op;
+        for(j=0; jiIdxCur, j, r1+j);
+        }
+        pParse->nMem += n+1;
+        op = pLevel->op==OP_Prev ? OP_SeekLT : OP_SeekGT;
+        addrSeek = sqlite3VdbeAddOp4Int(v, op, pLevel->iIdxCur, 0, r1, n);
+        VdbeCoverageIf(v, op==OP_SeekLT);
+        VdbeCoverageIf(v, op==OP_SeekGT);
+        sqlite3VdbeAddOp2(v, OP_Goto, 1, pLevel->p2);
+      }
+#endif /* SQLITE_DISABLE_SKIPAHEAD_DISTINCT */
+      /* The common case: Advance to the next row */
+      sqlite3VdbeResolveLabel(v, pLevel->addrCont);
+      sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);
+      sqlite3VdbeChangeP5(v, pLevel->p5);
+      VdbeCoverage(v);
+      VdbeCoverageIf(v, pLevel->op==OP_Next);
+      VdbeCoverageIf(v, pLevel->op==OP_Prev);
+      VdbeCoverageIf(v, pLevel->op==OP_VNext);
+#ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT
+      if( addrSeek ) sqlite3VdbeJumpHere(v, addrSeek);
+#endif
+    }else{
+      sqlite3VdbeResolveLabel(v, pLevel->addrCont);
+    }
+    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
+      struct InLoop *pIn;
+      int j;
+      sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
+      for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
+        sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
+        if( pIn->eEndLoopOp!=OP_Noop ){
+          sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
+          VdbeCoverage(v);
+          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
+          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
+        }
+        sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
+      }
+    }
+    sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
+    if( pLevel->addrSkip ){
+      sqlite3VdbeGoto(v, pLevel->addrSkip);
+      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
+    }
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+    if( pLevel->addrLikeRep ){
+      sqlite3VdbeAddOp2(v, OP_DecrJumpZero, (int)(pLevel->iLikeRepCntr>>1),
+                        pLevel->addrLikeRep);
+      VdbeCoverage(v);
+    }
+#endif
+    if( pLevel->iLeftJoin ){
+      int ws = pLoop->wsFlags;
+      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
+      assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 );
+      if( (ws & WHERE_IDX_ONLY)==0 ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
+      }
+      if( (ws & WHERE_INDEXED) 
+       || ((ws & WHERE_MULTI_OR) && pLevel->u.pCovidx) 
+      ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
+      }
+      if( pLevel->op==OP_Return ){
+        sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
+      }else{
+        sqlite3VdbeGoto(v, pLevel->addrFirst);
+      }
+      sqlite3VdbeJumpHere(v, addr);
+    }
+    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
+                     pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));
+  }
+
+  /* The "break" point is here, just past the end of the outer loop.
+  ** Set it.
+  */
+  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);
+
+  assert( pWInfo->nLevel<=pTabList->nSrc );
+  for(i=0, pLevel=pWInfo->a; inLevel; i++, pLevel++){
+    int k, last;
+    VdbeOp *pOp;
+    Index *pIdx = 0;
+    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
+    Table *pTab = pTabItem->pTab;
+    assert( pTab!=0 );
+    pLoop = pLevel->pWLoop;
+
+    /* For a co-routine, change all OP_Column references to the table of
+    ** the co-routine into OP_Copy of result contained in a register.
+    ** OP_Rowid becomes OP_Null.
+    */
+    if( pTabItem->fg.viaCoroutine ){
+      testcase( pParse->db->mallocFailed );
+      translateColumnToCopy(pParse, pLevel->addrBody, pLevel->iTabCur,
+                            pTabItem->regResult, 0);
+      continue;
+    }
+
+    /* If this scan uses an index, make VDBE code substitutions to read data
+    ** from the index instead of from the table where possible.  In some cases
+    ** this optimization prevents the table from ever being read, which can
+    ** yield a significant performance boost.
+    ** 
+    ** Calls to the code generator in between sqlite3WhereBegin and
+    ** sqlite3WhereEnd will have created code that references the table
+    ** directly.  This loop scans all that code looking for opcodes
+    ** that reference the table and converts them into opcodes that
+    ** reference the index.
+    */
+    if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
+      pIdx = pLoop->u.btree.pIndex;
+    }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
+      pIdx = pLevel->u.pCovidx;
+    }
+    if( pIdx
+     && (pWInfo->eOnePass==ONEPASS_OFF || !HasRowid(pIdx->pTable))
+     && !db->mallocFailed
+    ){
+      last = sqlite3VdbeCurrentAddr(v);
+      k = pLevel->addrBody;
+      pOp = sqlite3VdbeGetOp(v, k);
+      for(; kp1!=pLevel->iTabCur ) continue;
+        if( pOp->opcode==OP_Column ){
+          int x = pOp->p2;
+          assert( pIdx->pTable==pTab );
+          if( !HasRowid(pTab) ){
+            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+            x = pPk->aiColumn[x];
+            assert( x>=0 );
+          }
+          x = sqlite3ColumnOfIndex(pIdx, x);
+          if( x>=0 ){
+            pOp->p2 = x;
+            pOp->p1 = pLevel->iIdxCur;
+          }
+          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 
+              || pWInfo->eOnePass );
+        }else if( pOp->opcode==OP_Rowid ){
+          pOp->p1 = pLevel->iIdxCur;
+          pOp->opcode = OP_IdxRowid;
+        }else if( pOp->opcode==OP_IfNullRow ){
+          pOp->p1 = pLevel->iIdxCur;
+        }
+      }
+    }
+  }
+
+  /* Final cleanup
+  */
+  pParse->nQueryLoop = pWInfo->savedNQueryLoop;
+  whereInfoFree(db, pWInfo);
+  return;
+}
+
+/************** End of where.c ***********************************************/
+/************** Begin file parse.c *******************************************/
+/*
+** 2000-05-29
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Driver template for the LEMON parser generator.
+**
+** The "lemon" program processes an LALR(1) input grammar file, then uses
+** this template to construct a parser.  The "lemon" program inserts text
+** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the
+** interstitial "-" characters) contained in this template is changed into
+** the value of the %name directive from the grammar.  Otherwise, the content
+** of this template is copied straight through into the generate parser
+** source file.
+**
+** The following is the concatenation of all %include directives from the
+** input grammar file:
+*/
+/* #include  */
+/************ Begin %include sections from the grammar ************************/
+
+/* #include "sqliteInt.h" */
+
+/*
+** Disable all error recovery processing in the parser push-down
+** automaton.
+*/
+#define YYNOERRORRECOVERY 1
+
+/*
+** Make yytestcase() the same as testcase()
+*/
+#define yytestcase(X) testcase(X)
+
+/*
+** Indicate that sqlite3ParserFree() will never be called with a null
+** pointer.
+*/
+#define YYPARSEFREENEVERNULL 1
+
+/*
+** In the amalgamation, the parse.c file generated by lemon and the
+** tokenize.c file are concatenated.  In that case, sqlite3RunParser()
+** has access to the the size of the yyParser object and so the parser
+** engine can be allocated from stack.  In that case, only the
+** sqlite3ParserInit() and sqlite3ParserFinalize() routines are invoked
+** and the sqlite3ParserAlloc() and sqlite3ParserFree() routines can be
+** omitted.
+*/
+#ifdef SQLITE_AMALGAMATION
+# define sqlite3Parser_ENGINEALWAYSONSTACK 1
+#endif
+
+/*
+** Alternative datatype for the argument to the malloc() routine passed
+** into sqlite3ParserAlloc().  The default is size_t.
+*/
+#define YYMALLOCARGTYPE  u64
+
+/*
+** An instance of this structure holds information about the
+** LIMIT clause of a SELECT statement.
+*/
+struct LimitVal {
+  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
+  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
+};
+
+/*
+** An instance of the following structure describes the event of a
+** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
+** TK_DELETE, or TK_INSTEAD.  If the event is of the form
+**
+**      UPDATE ON (a,b,c)
+**
+** Then the "b" IdList records the list "a,b,c".
+*/
+struct TrigEvent { int a; IdList * b; };
+
+/*
+** Disable lookaside memory allocation for objects that might be
+** shared across database connections.
+*/
+static void disableLookaside(Parse *pParse){
+  pParse->disableLookaside++;
+  pParse->db->lookaside.bDisable++;
+}
+
+
+  /*
+  ** For a compound SELECT statement, make sure p->pPrior->pNext==p for
+  ** all elements in the list.  And make sure list length does not exceed
+  ** SQLITE_LIMIT_COMPOUND_SELECT.
+  */
+  static void parserDoubleLinkSelect(Parse *pParse, Select *p){
+    if( p->pPrior ){
+      Select *pNext = 0, *pLoop;
+      int mxSelect, cnt = 0;
+      for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){
+        pLoop->pNext = pNext;
+        pLoop->selFlags |= SF_Compound;
+      }
+      if( (p->selFlags & SF_MultiValue)==0 && 
+        (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0 &&
+        cnt>mxSelect
+      ){
+        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
+      }
+    }
+  }
+
+  /* This is a utility routine used to set the ExprSpan.zStart and
+  ** ExprSpan.zEnd values of pOut so that the span covers the complete
+  ** range of text beginning with pStart and going to the end of pEnd.
+  */
+  static void spanSet(ExprSpan *pOut, Token *pStart, Token *pEnd){
+    pOut->zStart = pStart->z;
+    pOut->zEnd = &pEnd->z[pEnd->n];
+  }
+
+  /* Construct a new Expr object from a single identifier.  Use the
+  ** new Expr to populate pOut.  Set the span of pOut to be the identifier
+  ** that created the expression.
+  */
+  static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token t){
+    Expr *p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)+t.n+1);
+    if( p ){
+      memset(p, 0, sizeof(Expr));
+      p->op = (u8)op;
+      p->flags = EP_Leaf;
+      p->iAgg = -1;
+      p->u.zToken = (char*)&p[1];
+      memcpy(p->u.zToken, t.z, t.n);
+      p->u.zToken[t.n] = 0;
+      if( sqlite3Isquote(p->u.zToken[0]) ){
+        if( p->u.zToken[0]=='"' ) p->flags |= EP_DblQuoted;
+        sqlite3Dequote(p->u.zToken);
+      }
+#if SQLITE_MAX_EXPR_DEPTH>0
+      p->nHeight = 1;
+#endif  
+    }
+    pOut->pExpr = p;
+    pOut->zStart = t.z;
+    pOut->zEnd = &t.z[t.n];
+  }
+
+  /* This routine constructs a binary expression node out of two ExprSpan
+  ** objects and uses the result to populate a new ExprSpan object.
+  */
+  static void spanBinaryExpr(
+    Parse *pParse,      /* The parsing context.  Errors accumulate here */
+    int op,             /* The binary operation */
+    ExprSpan *pLeft,    /* The left operand, and output */
+    ExprSpan *pRight    /* The right operand */
+  ){
+    pLeft->pExpr = sqlite3PExpr(pParse, op, pLeft->pExpr, pRight->pExpr);
+    pLeft->zEnd = pRight->zEnd;
+  }
+
+  /* If doNot is true, then add a TK_NOT Expr-node wrapper around the
+  ** outside of *ppExpr.
+  */
+  static void exprNot(Parse *pParse, int doNot, ExprSpan *pSpan){
+    if( doNot ){
+      pSpan->pExpr = sqlite3PExpr(pParse, TK_NOT, pSpan->pExpr, 0);
+    }
+  }
+
+  /* Construct an expression node for a unary postfix operator
+  */
+  static void spanUnaryPostfix(
+    Parse *pParse,         /* Parsing context to record errors */
+    int op,                /* The operator */
+    ExprSpan *pOperand,    /* The operand, and output */
+    Token *pPostOp         /* The operand token for setting the span */
+  ){
+    pOperand->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0);
+    pOperand->zEnd = &pPostOp->z[pPostOp->n];
+  }                           
+
+  /* A routine to convert a binary TK_IS or TK_ISNOT expression into a
+  ** unary TK_ISNULL or TK_NOTNULL expression. */
+  static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){
+    sqlite3 *db = pParse->db;
+    if( pA && pY && pY->op==TK_NULL ){
+      pA->op = (u8)op;
+      sqlite3ExprDelete(db, pA->pRight);
+      pA->pRight = 0;
+    }
+  }
+
+  /* Construct an expression node for a unary prefix operator
+  */
+  static void spanUnaryPrefix(
+    ExprSpan *pOut,        /* Write the new expression node here */
+    Parse *pParse,         /* Parsing context to record errors */
+    int op,                /* The operator */
+    ExprSpan *pOperand,    /* The operand */
+    Token *pPreOp         /* The operand token for setting the span */
+  ){
+    pOut->zStart = pPreOp->z;
+    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0);
+    pOut->zEnd = pOperand->zEnd;
+  }
+
+  /* Add a single new term to an ExprList that is used to store a
+  ** list of identifiers.  Report an error if the ID list contains
+  ** a COLLATE clause or an ASC or DESC keyword, except ignore the
+  ** error while parsing a legacy schema.
+  */
+  static ExprList *parserAddExprIdListTerm(
+    Parse *pParse,
+    ExprList *pPrior,
+    Token *pIdToken,
+    int hasCollate,
+    int sortOrder
+  ){
+    ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);
+    if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)
+        && pParse->db->init.busy==0
+    ){
+      sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",
+                         pIdToken->n, pIdToken->z);
+    }
+    sqlite3ExprListSetName(pParse, p, pIdToken, 1);
+    return p;
+  }
+/**************** End of %include directives **********************************/
+/* These constants specify the various numeric values for terminal symbols
+** in a format understandable to "makeheaders".  This section is blank unless
+** "lemon" is run with the "-m" command-line option.
+***************** Begin makeheaders token definitions *************************/
+/**************** End makeheaders token definitions ***************************/
+
+/* The next sections is a series of control #defines.
+** various aspects of the generated parser.
+**    YYCODETYPE         is the data type used to store the integer codes
+**                       that represent terminal and non-terminal symbols.
+**                       "unsigned char" is used if there are fewer than
+**                       256 symbols.  Larger types otherwise.
+**    YYNOCODE           is a number of type YYCODETYPE that is not used for
+**                       any terminal or nonterminal symbol.
+**    YYFALLBACK         If defined, this indicates that one or more tokens
+**                       (also known as: "terminal symbols") have fall-back
+**                       values which should be used if the original symbol
+**                       would not parse.  This permits keywords to sometimes
+**                       be used as identifiers, for example.
+**    YYACTIONTYPE       is the data type used for "action codes" - numbers
+**                       that indicate what to do in response to the next
+**                       token.
+**    sqlite3ParserTOKENTYPE     is the data type used for minor type for terminal
+**                       symbols.  Background: A "minor type" is a semantic
+**                       value associated with a terminal or non-terminal
+**                       symbols.  For example, for an "ID" terminal symbol,
+**                       the minor type might be the name of the identifier.
+**                       Each non-terminal can have a different minor type.
+**                       Terminal symbols all have the same minor type, though.
+**                       This macros defines the minor type for terminal 
+**                       symbols.
+**    YYMINORTYPE        is the data type used for all minor types.
+**                       This is typically a union of many types, one of
+**                       which is sqlite3ParserTOKENTYPE.  The entry in the union
+**                       for terminal symbols is called "yy0".
+**    YYSTACKDEPTH       is the maximum depth of the parser's stack.  If
+**                       zero the stack is dynamically sized using realloc()
+**    sqlite3ParserARG_SDECL     A static variable declaration for the %extra_argument
+**    sqlite3ParserARG_PDECL     A parameter declaration for the %extra_argument
+**    sqlite3ParserARG_STORE     Code to store %extra_argument into yypParser
+**    sqlite3ParserARG_FETCH     Code to extract %extra_argument from yypParser
+**    YYERRORSYMBOL      is the code number of the error symbol.  If not
+**                       defined, then do no error processing.
+**    YYNSTATE           the combined number of states.
+**    YYNRULE            the number of rules in the grammar
+**    YY_MAX_SHIFT       Maximum value for shift actions
+**    YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
+**    YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
+**    YY_MIN_REDUCE      Maximum value for reduce actions
+**    YY_ERROR_ACTION    The yy_action[] code for syntax error
+**    YY_ACCEPT_ACTION   The yy_action[] code for accept
+**    YY_NO_ACTION       The yy_action[] code for no-op
+*/
+#ifndef INTERFACE
+# define INTERFACE 1
+#endif
+/************* Begin control #defines *****************************************/
+#define YYCODETYPE unsigned char
+#define YYNOCODE 252
+#define YYACTIONTYPE unsigned short int
+#define YYWILDCARD 69
+#define sqlite3ParserTOKENTYPE Token
+typedef union {
+  int yyinit;
+  sqlite3ParserTOKENTYPE yy0;
+  Expr* yy72;
+  TriggerStep* yy145;
+  ExprList* yy148;
+  SrcList* yy185;
+  ExprSpan yy190;
+  int yy194;
+  Select* yy243;
+  IdList* yy254;
+  With* yy285;
+  struct TrigEvent yy332;
+  struct LimitVal yy354;
+  struct {int value; int mask;} yy497;
+} YYMINORTYPE;
+#ifndef YYSTACKDEPTH
+#define YYSTACKDEPTH 100
+#endif
+#define sqlite3ParserARG_SDECL Parse *pParse;
+#define sqlite3ParserARG_PDECL ,Parse *pParse
+#define sqlite3ParserARG_FETCH Parse *pParse = yypParser->pParse
+#define sqlite3ParserARG_STORE yypParser->pParse = pParse
+#define YYFALLBACK 1
+#define YYNSTATE             455
+#define YYNRULE              329
+#define YY_MAX_SHIFT         454
+#define YY_MIN_SHIFTREDUCE   664
+#define YY_MAX_SHIFTREDUCE   992
+#define YY_MIN_REDUCE        993
+#define YY_MAX_REDUCE        1321
+#define YY_ERROR_ACTION      1322
+#define YY_ACCEPT_ACTION     1323
+#define YY_NO_ACTION         1324
+/************* End control #defines *******************************************/
+
+/* Define the yytestcase() macro to be a no-op if is not already defined
+** otherwise.
+**
+** Applications can choose to define yytestcase() in the %include section
+** to a macro that can assist in verifying code coverage.  For production
+** code the yytestcase() macro should be turned off.  But it is useful
+** for testing.
+*/
+#ifndef yytestcase
+# define yytestcase(X)
+#endif
+
+
+/* Next are the tables used to determine what action to take based on the
+** current state and lookahead token.  These tables are used to implement
+** functions that take a state number and lookahead value and return an
+** action integer.  
+**
+** Suppose the action integer is N.  Then the action is determined as
+** follows
+**
+**   0 <= N <= YY_MAX_SHIFT             Shift N.  That is, push the lookahead
+**                                      token onto the stack and goto state N.
+**
+**   N between YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then
+**     and YY_MAX_SHIFTREDUCE           reduce by rule N-YY_MIN_SHIFTREDUCE.
+**
+**   N between YY_MIN_REDUCE            Reduce by rule N-YY_MIN_REDUCE
+**     and YY_MAX_REDUCE
+**
+**   N == YY_ERROR_ACTION               A syntax error has occurred.
+**
+**   N == YY_ACCEPT_ACTION              The parser accepts its input.
+**
+**   N == YY_NO_ACTION                  No such action.  Denotes unused
+**                                      slots in the yy_action[] table.
+**
+** The action table is constructed as a single large table named yy_action[].
+** Given state S and lookahead X, the action is computed as either:
+**
+**    (A)   N = yy_action[ yy_shift_ofst[S] + X ]
+**    (B)   N = yy_default[S]
+**
+** The (A) formula is preferred.  The B formula is used instead if:
+**    (1)  The yy_shift_ofst[S]+X value is out of range, or
+**    (2)  yy_lookahead[yy_shift_ofst[S]+X] is not equal to X, or
+**    (3)  yy_shift_ofst[S] equal YY_SHIFT_USE_DFLT.
+** (Implementation note: YY_SHIFT_USE_DFLT is chosen so that
+** YY_SHIFT_USE_DFLT+X will be out of range for all possible lookaheads X.
+** Hence only tests (1) and (2) need to be evaluated.)
+**
+** The formulas above are for computing the action when the lookahead is
+** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
+** a reduce action) then the yy_reduce_ofst[] array is used in place of
+** the yy_shift_ofst[] array and YY_REDUCE_USE_DFLT is used in place of
+** YY_SHIFT_USE_DFLT.
+**
+** The following are the tables generated in this section:
+**
+**  yy_action[]        A single table containing all actions.
+**  yy_lookahead[]     A table containing the lookahead for each entry in
+**                     yy_action.  Used to detect hash collisions.
+**  yy_shift_ofst[]    For each state, the offset into yy_action for
+**                     shifting terminals.
+**  yy_reduce_ofst[]   For each state, the offset into yy_action for
+**                     shifting non-terminals after a reduce.
+**  yy_default[]       Default action for each state.
+**
+*********** Begin parsing tables **********************************************/
+#define YY_ACTTAB_COUNT (1565)
+static const YYACTIONTYPE yy_action[] = {
+ /*     0 */   324,  410,  342,  747,  747,  203,  939,  353,  969,   98,
+ /*    10 */    98,   98,   98,   91,   96,   96,   96,   96,   95,   95,
+ /*    20 */    94,   94,   94,   93,  350, 1323,  155,  155,    2,  808,
+ /*    30 */   971,  971,   98,   98,   98,   98,   20,   96,   96,   96,
+ /*    40 */    96,   95,   95,   94,   94,   94,   93,  350,   92,   89,
+ /*    50 */   178,   99,  100,   90,  847,  850,  839,  839,   97,   97,
+ /*    60 */    98,   98,   98,   98,  350,   96,   96,   96,   96,   95,
+ /*    70 */    95,   94,   94,   94,   93,  350,  324,  339,  969,  262,
+ /*    80 */   364,  251,  212,  169,  287,  404,  282,  403,  199,  786,
+ /*    90 */   242,  411,   21,  950,  378,  280,   93,  350,  787,   95,
+ /*   100 */    95,   94,   94,   94,   93,  350,  971,  971,   96,   96,
+ /*   110 */    96,   96,   95,   95,   94,   94,   94,   93,  350,  808,
+ /*   120 */   328,  242,  411, 1235,  826, 1235,  132,   99,  100,   90,
+ /*   130 */   847,  850,  839,  839,   97,   97,   98,   98,   98,   98,
+ /*   140 */   449,   96,   96,   96,   96,   95,   95,   94,   94,   94,
+ /*   150 */    93,  350,  324,  819,  348,  347,  120,  818,  120,   75,
+ /*   160 */    52,   52,  950,  951,  952, 1084,  977,  146,  360,  262,
+ /*   170 */   369,  261,  950,  975,  954,  976,   92,   89,  178,  370,
+ /*   180 */   230,  370,  971,  971, 1141,  360,  359,  101,  818,  818,
+ /*   190 */   820,  383,   24, 1286,  380,  427,  412,  368,  978,  379,
+ /*   200 */   978, 1032,  324,   99,  100,   90,  847,  850,  839,  839,
+ /*   210 */    97,   97,   98,   98,   98,   98,  372,   96,   96,   96,
+ /*   220 */    96,   95,   95,   94,   94,   94,   93,  350,  950,  132,
+ /*   230 */   890,  449,  971,  971,  890,   60,   94,   94,   94,   93,
+ /*   240 */   350,  950,  951,  952,  954,  103,  360,  950,  384,  333,
+ /*   250 */   697,   52,   52,   99,  100,   90,  847,  850,  839,  839,
+ /*   260 */    97,   97,   98,   98,   98,   98, 1022,   96,   96,   96,
+ /*   270 */    96,   95,   95,   94,   94,   94,   93,  350,  324,  454,
+ /*   280 */   995,  449,  227,   61,  157,  243,  343,  114, 1025, 1211,
+ /*   290 */   147,  826,  950,  372, 1071,  950,  319,  950,  951,  952,
+ /*   300 */   194,   10,   10,  401,  398,  397, 1211, 1213,  971,  971,
+ /*   310 */   757,  171,  170,  157,  396,  336,  950,  951,  952,  697,
+ /*   320 */   819,  310,  153,  950,  818,  320,   82,   23,   80,   99,
+ /*   330 */   100,   90,  847,  850,  839,  839,   97,   97,   98,   98,
+ /*   340 */    98,   98,  888,   96,   96,   96,   96,   95,   95,   94,
+ /*   350 */    94,   94,   93,  350,  324,  818,  818,  820,  277,  231,
+ /*   360 */   300,  950,  951,  952,  950,  951,  952, 1211,  194,   25,
+ /*   370 */   449,  401,  398,  397,  950,  354,  300,  449,  950,   74,
+ /*   380 */   449,    1,  396,  132,  971,  971,  950,  224,  224,  808,
+ /*   390 */    10,   10,  950,  951,  952, 1290,  132,   52,   52,  414,
+ /*   400 */    52,   52, 1063, 1063,  338,   99,  100,   90,  847,  850,
+ /*   410 */   839,  839,   97,   97,   98,   98,   98,   98, 1114,   96,
+ /*   420 */    96,   96,   96,   95,   95,   94,   94,   94,   93,  350,
+ /*   430 */   324, 1113,  427,  417,  701,  427,  426, 1260, 1260,  262,
+ /*   440 */   369,  261,  950,  950,  951,  952,  752,  950,  951,  952,
+ /*   450 */   449,  751,  449, 1058, 1037,  950,  951,  952,  442,  706,
+ /*   460 */   971,  971, 1058,  393,   92,   89,  178,  446,  446,  446,
+ /*   470 */    51,   51,   52,   52,  438,  773, 1024,   92,   89,  178,
+ /*   480 */   172,   99,  100,   90,  847,  850,  839,  839,   97,   97,
+ /*   490 */    98,   98,   98,   98,  198,   96,   96,   96,   96,   95,
+ /*   500 */    95,   94,   94,   94,   93,  350,  324,  427,  407,  909,
+ /*   510 */   694,  950,  951,  952,   92,   89,  178,  224,  224,  157,
+ /*   520 */   241,  221,  418,  299,  771,  910,  415,  374,  449,  414,
+ /*   530 */    58,  323, 1061, 1061, 1242,  378,  971,  971,  378,  772,
+ /*   540 */   448,  911,  362,  735,  296,  681,    9,    9,   52,   52,
+ /*   550 */   234,  329,  234,  256,  416,  736,  280,   99,  100,   90,
+ /*   560 */   847,  850,  839,  839,   97,   97,   98,   98,   98,   98,
+ /*   570 */   449,   96,   96,   96,   96,   95,   95,   94,   94,   94,
+ /*   580 */    93,  350,  324,  422,   72,  449,  827,  120,  367,  449,
+ /*   590 */    10,   10,    5,  301,  203,  449,  177,  969,  253,  419,
+ /*   600 */   255,  771,  200,  175,  233,   10,   10,  836,  836,   36,
+ /*   610 */    36, 1289,  971,  971,  724,   37,   37,  348,  347,  424,
+ /*   620 */   203,  260,  771,  969,  232,  930, 1316,  870,  337, 1316,
+ /*   630 */   421,  848,  851,   99,  100,   90,  847,  850,  839,  839,
+ /*   640 */    97,   97,   98,   98,   98,   98,  268,   96,   96,   96,
+ /*   650 */    96,   95,   95,   94,   94,   94,   93,  350,  324,  840,
+ /*   660 */   449,  978,  813,  978, 1200,  449,  909,  969,  715,  349,
+ /*   670 */   349,  349,  928,  177,  449,  930, 1317,  254,  198, 1317,
+ /*   680 */    12,   12,  910,  402,  449,   27,   27,  250,  971,  971,
+ /*   690 */   118,  716,  162,  969,   38,   38,  268,  176,  911,  771,
+ /*   700 */   432, 1265,  939,  353,   39,   39,  316,  991,  324,   99,
+ /*   710 */   100,   90,  847,  850,  839,  839,   97,   97,   98,   98,
+ /*   720 */    98,   98,  928,   96,   96,   96,   96,   95,   95,   94,
+ /*   730 */    94,   94,   93,  350,  449,  329,  449,  357,  971,  971,
+ /*   740 */  1041,  316,  929,  340,  893,  893,  386,  669,  670,  671,
+ /*   750 */   275, 1318,  317,  992,   40,   40,   41,   41,  268,   99,
+ /*   760 */   100,   90,  847,  850,  839,  839,   97,   97,   98,   98,
+ /*   770 */    98,   98,  449,   96,   96,   96,   96,   95,   95,   94,
+ /*   780 */    94,   94,   93,  350,  324,  449,  355,  449,  992,  449,
+ /*   790 */  1016,  330,   42,   42,  786,  270,  449,  273,  449,  228,
+ /*   800 */   449,  298,  449,  787,  449,   28,   28,   29,   29,   31,
+ /*   810 */    31,  449, 1141,  449,  971,  971,   43,   43,   44,   44,
+ /*   820 */    45,   45,   11,   11,   46,   46,  887,   78,  887,  268,
+ /*   830 */   268,  105,  105,   47,   47,   99,  100,   90,  847,  850,
+ /*   840 */   839,  839,   97,   97,   98,   98,   98,   98,  449,   96,
+ /*   850 */    96,   96,   96,   95,   95,   94,   94,   94,   93,  350,
+ /*   860 */   324,  449,  117,  449, 1073,  158,  449,  691,   48,   48,
+ /*   870 */   229, 1241,  449, 1250,  449,  414,  449,  334,  449,  245,
+ /*   880 */   449,   33,   33,   49,   49,  449,   50,   50,  246, 1141,
+ /*   890 */   971,  971,   34,   34,  122,  122,  123,  123,  124,  124,
+ /*   900 */    56,   56,  268,   81,  249,   35,   35,  197,  196,  195,
+ /*   910 */   324,   99,  100,   90,  847,  850,  839,  839,   97,   97,
+ /*   920 */    98,   98,   98,   98,  449,   96,   96,   96,   96,   95,
+ /*   930 */    95,   94,   94,   94,   93,  350,  449,  691,  449, 1141,
+ /*   940 */   971,  971,  968, 1207,  106,  106,  268, 1209,  268, 1266,
+ /*   950 */     2,  886,  268,  886,  335, 1040,   53,   53,  107,  107,
+ /*   960 */   324,   99,  100,   90,  847,  850,  839,  839,   97,   97,
+ /*   970 */    98,   98,   98,   98,  449,   96,   96,   96,   96,   95,
+ /*   980 */    95,   94,   94,   94,   93,  350,  449, 1070,  449, 1066,
+ /*   990 */   971,  971, 1039,  267,  108,  108,  445,  330,  331,  133,
+ /*  1000 */   223,  175,  301,  225,  385, 1255,  104,  104,  121,  121,
+ /*  1010 */   324,   99,   88,   90,  847,  850,  839,  839,   97,   97,
+ /*  1020 */    98,   98,   98,   98, 1141,   96,   96,   96,   96,   95,
+ /*  1030 */    95,   94,   94,   94,   93,  350,  449,  346,  449,  167,
+ /*  1040 */   971,  971,  925,  810,  371,  318,  202,  202,  373,  263,
+ /*  1050 */   394,  202,   74,  208,  721,  722,  119,  119,  112,  112,
+ /*  1060 */   324,  406,  100,   90,  847,  850,  839,  839,   97,   97,
+ /*  1070 */    98,   98,   98,   98,  449,   96,   96,   96,   96,   95,
+ /*  1080 */    95,   94,   94,   94,   93,  350,  449,  752,  449,  344,
+ /*  1090 */   971,  971,  751,  278,  111,  111,   74,  714,  713,  704,
+ /*  1100 */   286,  877,  749, 1279,  257,   77,  109,  109,  110,  110,
+ /*  1110 */  1230,  285, 1134,   90,  847,  850,  839,  839,   97,   97,
+ /*  1120 */    98,   98,   98,   98, 1233,   96,   96,   96,   96,   95,
+ /*  1130 */    95,   94,   94,   94,   93,  350,   86,  444,  449,    3,
+ /*  1140 */  1193,  449, 1069,  132,  351,  120, 1013,   86,  444,  780,
+ /*  1150 */     3, 1091,  202,  376,  447,  351, 1229,  120,   55,   55,
+ /*  1160 */   449,   57,   57,  822,  873,  447,  449,  208,  449,  704,
+ /*  1170 */   449,  877,  237,  433,  435,  120,  439,  428,  361,  120,
+ /*  1180 */    54,   54,  132,  449,  433,  826,   52,   52,   26,   26,
+ /*  1190 */    30,   30,  381,  132,  408,  443,  826,  689,  264,  389,
+ /*  1200 */   116,  269,  272,   32,   32,   83,   84,  120,  274,  120,
+ /*  1210 */   120,  276,   85,  351,  451,  450,   83,   84,  818, 1054,
+ /*  1220 */  1038,  427,  429,   85,  351,  451,  450,  120,  120,  818,
+ /*  1230 */   377,  218,  281,  822, 1107, 1140,   86,  444,  409,    3,
+ /*  1240 */  1087, 1098,  430,  431,  351,  302,  303, 1146, 1021,  818,
+ /*  1250 */   818,  820,  821,   19,  447, 1015, 1004, 1003, 1005, 1273,
+ /*  1260 */   818,  818,  820,  821,   19,  289,  159,  291,  293,    7,
+ /*  1270 */   315,  173,  259,  433, 1129,  363,  252, 1232,  375, 1037,
+ /*  1280 */   295,  434,  168,  986,  399,  826,  284, 1204, 1203,  205,
+ /*  1290 */  1276,  308, 1249,   86,  444,  983,    3, 1247,  332,  144,
+ /*  1300 */   130,  351,   72,  135,   59,   83,   84,  756,  137,  365,
+ /*  1310 */  1126,  447,   85,  351,  451,  450,  139,  226,  818,  140,
+ /*  1320 */   156,   62,  314,  314,  313,  215,  311,  366,  392,  678,
+ /*  1330 */   433,  185,  141, 1234,  142,  160,  148, 1136, 1198,  382,
+ /*  1340 */   189,   67,  826,  180,  388,  248, 1218, 1099,  219,  818,
+ /*  1350 */   818,  820,  821,   19,  247,  190,  266,  154,  390,  271,
+ /*  1360 */   191,  192,   83,   84, 1006,  405, 1057,  182,  321,   85,
+ /*  1370 */   351,  451,  450, 1056,  183,  818,  341,  132,  181,  706,
+ /*  1380 */  1055,  420,   76,  444, 1029,    3,  322, 1028,  283, 1048,
+ /*  1390 */   351, 1095, 1027, 1288, 1047,   71,  204,    6,  288,  290,
+ /*  1400 */   447, 1096, 1094, 1093,   79,  292,  818,  818,  820,  821,
+ /*  1410 */    19,  294,  297,  437,  345,  441,  102, 1184, 1077,  433,
+ /*  1420 */   238,  425,   73,  305,  239,  304,  325,  240,  423,  306,
+ /*  1430 */   307,  826,  213, 1012,   22,  945,  452,  214,  216,  217,
+ /*  1440 */   453, 1001,  115,  996,  125,  126,  235,  127,  665,  352,
+ /*  1450 */   326,   83,   84,  358,  166,  244,  179,  327,   85,  351,
+ /*  1460 */   451,  450,  134,  356,  818,  113,  885,  806,  883,  136,
+ /*  1470 */   128,  138,  738,  258,  184,  899,  143,  145,   63,   64,
+ /*  1480 */    65,   66,  129,  902,  187,  186,  898,    8,   13,  188,
+ /*  1490 */   265,  891,  149,  202,  980,  818,  818,  820,  821,   19,
+ /*  1500 */   150,  387,  161,  680,  285,  391,  151,  395,  400,  193,
+ /*  1510 */    68,   14,  236,  279,   15,   69,  717,  825,  131,  824,
+ /*  1520 */   853,   70,  746,   16,  413,  750,    4,  174,  220,  222,
+ /*  1530 */   152,  779,  857,  774,  201,   77,   74,  868,   17,  854,
+ /*  1540 */   852,  908,   18,  907,  207,  206,  934,  163,  436,  210,
+ /*  1550 */   935,  164,  209,  165,  440,  856,  823,  690,   87,  211,
+ /*  1560 */   309,  312, 1281,  940, 1280,
+};
+static const YYCODETYPE yy_lookahead[] = {
+ /*     0 */    19,  115,   19,  117,  118,   24,    1,    2,   27,   79,
+ /*    10 */    80,   81,   82,   83,   84,   85,   86,   87,   88,   89,
+ /*    20 */    90,   91,   92,   93,   94,  144,  145,  146,  147,   58,
+ /*    30 */    49,   50,   79,   80,   81,   82,   22,   84,   85,   86,
+ /*    40 */    87,   88,   89,   90,   91,   92,   93,   94,  221,  222,
+ /*    50 */   223,   70,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*    60 */    79,   80,   81,   82,   94,   84,   85,   86,   87,   88,
+ /*    70 */    89,   90,   91,   92,   93,   94,   19,   94,   97,  108,
+ /*    80 */   109,  110,   99,  100,  101,  102,  103,  104,  105,   32,
+ /*    90 */   119,  120,   78,   27,  152,  112,   93,   94,   41,   88,
+ /*   100 */    89,   90,   91,   92,   93,   94,   49,   50,   84,   85,
+ /*   110 */    86,   87,   88,   89,   90,   91,   92,   93,   94,   58,
+ /*   120 */   157,  119,  120,  163,   68,  163,   65,   70,   71,   72,
+ /*   130 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
+ /*   140 */   152,   84,   85,   86,   87,   88,   89,   90,   91,   92,
+ /*   150 */    93,   94,   19,   97,   88,   89,  196,  101,  196,   26,
+ /*   160 */   172,  173,   96,   97,   98,  210,  100,   22,  152,  108,
+ /*   170 */   109,  110,   27,  107,   27,  109,  221,  222,  223,  219,
+ /*   180 */   238,  219,   49,   50,  152,  169,  170,   54,  132,  133,
+ /*   190 */   134,  228,  232,  171,  231,  207,  208,  237,  132,  237,
+ /*   200 */   134,  179,   19,   70,   71,   72,   73,   74,   75,   76,
+ /*   210 */    77,   78,   79,   80,   81,   82,  152,   84,   85,   86,
+ /*   220 */    87,   88,   89,   90,   91,   92,   93,   94,   27,   65,
+ /*   230 */    30,  152,   49,   50,   34,   52,   90,   91,   92,   93,
+ /*   240 */    94,   96,   97,   98,   97,   22,  230,   27,   48,  217,
+ /*   250 */    27,  172,  173,   70,   71,   72,   73,   74,   75,   76,
+ /*   260 */    77,   78,   79,   80,   81,   82,  172,   84,   85,   86,
+ /*   270 */    87,   88,   89,   90,   91,   92,   93,   94,   19,  148,
+ /*   280 */   149,  152,  218,   24,  152,  154,  207,  156,  172,  152,
+ /*   290 */    22,   68,   27,  152,  163,   27,  164,   96,   97,   98,
+ /*   300 */    99,  172,  173,  102,  103,  104,  169,  170,   49,   50,
+ /*   310 */    90,   88,   89,  152,  113,  186,   96,   97,   98,   96,
+ /*   320 */    97,  160,   57,   27,  101,  164,  137,  196,  139,   70,
+ /*   330 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
+ /*   340 */    81,   82,   11,   84,   85,   86,   87,   88,   89,   90,
+ /*   350 */    91,   92,   93,   94,   19,  132,  133,  134,   23,  218,
+ /*   360 */   152,   96,   97,   98,   96,   97,   98,  230,   99,   22,
+ /*   370 */   152,  102,  103,  104,   27,  244,  152,  152,   27,   26,
+ /*   380 */   152,   22,  113,   65,   49,   50,   27,  194,  195,   58,
+ /*   390 */   172,  173,   96,   97,   98,  185,   65,  172,  173,  206,
+ /*   400 */   172,  173,  190,  191,  186,   70,   71,   72,   73,   74,
+ /*   410 */    75,   76,   77,   78,   79,   80,   81,   82,  175,   84,
+ /*   420 */    85,   86,   87,   88,   89,   90,   91,   92,   93,   94,
+ /*   430 */    19,  175,  207,  208,   23,  207,  208,  119,  120,  108,
+ /*   440 */   109,  110,   27,   96,   97,   98,  116,   96,   97,   98,
+ /*   450 */   152,  121,  152,  179,  180,   96,   97,   98,  250,  106,
+ /*   460 */    49,   50,  188,   19,  221,  222,  223,  168,  169,  170,
+ /*   470 */   172,  173,  172,  173,  250,  124,  172,  221,  222,  223,
+ /*   480 */    26,   70,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*   490 */    79,   80,   81,   82,   50,   84,   85,   86,   87,   88,
+ /*   500 */    89,   90,   91,   92,   93,   94,   19,  207,  208,   12,
+ /*   510 */    23,   96,   97,   98,  221,  222,  223,  194,  195,  152,
+ /*   520 */   199,   23,   19,  225,   26,   28,  152,  152,  152,  206,
+ /*   530 */   209,  164,  190,  191,  241,  152,   49,   50,  152,  124,
+ /*   540 */   152,   44,  219,   46,  152,   21,  172,  173,  172,  173,
+ /*   550 */   183,  107,  185,   16,  163,   58,  112,   70,   71,   72,
+ /*   560 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
+ /*   570 */   152,   84,   85,   86,   87,   88,   89,   90,   91,   92,
+ /*   580 */    93,   94,   19,  207,  130,  152,   23,  196,   64,  152,
+ /*   590 */   172,  173,   22,  152,   24,  152,   98,   27,   61,   96,
+ /*   600 */    63,   26,  211,  212,  186,  172,  173,   49,   50,  172,
+ /*   610 */   173,   23,   49,   50,   26,  172,  173,   88,   89,  186,
+ /*   620 */    24,  238,  124,   27,  238,   22,   23,  103,  187,   26,
+ /*   630 */   152,   73,   74,   70,   71,   72,   73,   74,   75,   76,
+ /*   640 */    77,   78,   79,   80,   81,   82,  152,   84,   85,   86,
+ /*   650 */    87,   88,   89,   90,   91,   92,   93,   94,   19,  101,
+ /*   660 */   152,  132,   23,  134,  140,  152,   12,   97,   36,  168,
+ /*   670 */   169,  170,   69,   98,  152,   22,   23,  140,   50,   26,
+ /*   680 */   172,  173,   28,   51,  152,  172,  173,  193,   49,   50,
+ /*   690 */    22,   59,   24,   97,  172,  173,  152,  152,   44,  124,
+ /*   700 */    46,    0,    1,    2,  172,  173,   22,   23,   19,   70,
+ /*   710 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
+ /*   720 */    81,   82,   69,   84,   85,   86,   87,   88,   89,   90,
+ /*   730 */    91,   92,   93,   94,  152,  107,  152,  193,   49,   50,
+ /*   740 */   181,   22,   23,  111,  108,  109,  110,    7,    8,    9,
+ /*   750 */    16,  247,  248,   69,  172,  173,  172,  173,  152,   70,
+ /*   760 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
+ /*   770 */    81,   82,  152,   84,   85,   86,   87,   88,   89,   90,
+ /*   780 */    91,   92,   93,   94,   19,  152,  242,  152,   69,  152,
+ /*   790 */   166,  167,  172,  173,   32,   61,  152,   63,  152,  193,
+ /*   800 */   152,  152,  152,   41,  152,  172,  173,  172,  173,  172,
+ /*   810 */   173,  152,  152,  152,   49,   50,  172,  173,  172,  173,
+ /*   820 */   172,  173,  172,  173,  172,  173,  132,  138,  134,  152,
+ /*   830 */   152,  172,  173,  172,  173,   70,   71,   72,   73,   74,
+ /*   840 */    75,   76,   77,   78,   79,   80,   81,   82,  152,   84,
+ /*   850 */    85,   86,   87,   88,   89,   90,   91,   92,   93,   94,
+ /*   860 */    19,  152,   22,  152,  195,   24,  152,   27,  172,  173,
+ /*   870 */   193,  193,  152,  152,  152,  206,  152,  217,  152,  152,
+ /*   880 */   152,  172,  173,  172,  173,  152,  172,  173,  152,  152,
+ /*   890 */    49,   50,  172,  173,  172,  173,  172,  173,  172,  173,
+ /*   900 */   172,  173,  152,  138,  152,  172,  173,  108,  109,  110,
+ /*   910 */    19,   70,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*   920 */    79,   80,   81,   82,  152,   84,   85,   86,   87,   88,
+ /*   930 */    89,   90,   91,   92,   93,   94,  152,   97,  152,  152,
+ /*   940 */    49,   50,   26,  193,  172,  173,  152,  152,  152,  146,
+ /*   950 */   147,  132,  152,  134,  217,  181,  172,  173,  172,  173,
+ /*   960 */    19,   70,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*   970 */    79,   80,   81,   82,  152,   84,   85,   86,   87,   88,
+ /*   980 */    89,   90,   91,   92,   93,   94,  152,  193,  152,  193,
+ /*   990 */    49,   50,  181,  193,  172,  173,  166,  167,  245,  246,
+ /*  1000 */   211,  212,  152,   22,  217,  152,  172,  173,  172,  173,
+ /*  1010 */    19,   70,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*  1020 */    79,   80,   81,   82,  152,   84,   85,   86,   87,   88,
+ /*  1030 */    89,   90,   91,   92,   93,   94,  152,  187,  152,  123,
+ /*  1040 */    49,   50,   23,   23,   23,   26,   26,   26,   23,   23,
+ /*  1050 */    23,   26,   26,   26,    7,    8,  172,  173,  172,  173,
+ /*  1060 */    19,   90,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*  1070 */    79,   80,   81,   82,  152,   84,   85,   86,   87,   88,
+ /*  1080 */    89,   90,   91,   92,   93,   94,  152,  116,  152,  217,
+ /*  1090 */    49,   50,  121,   23,  172,  173,   26,  100,  101,   27,
+ /*  1100 */   101,   27,   23,  122,  152,   26,  172,  173,  172,  173,
+ /*  1110 */   152,  112,  163,   72,   73,   74,   75,   76,   77,   78,
+ /*  1120 */    79,   80,   81,   82,  163,   84,   85,   86,   87,   88,
+ /*  1130 */    89,   90,   91,   92,   93,   94,   19,   20,  152,   22,
+ /*  1140 */    23,  152,  163,   65,   27,  196,  163,   19,   20,   23,
+ /*  1150 */    22,  213,   26,   19,   37,   27,  152,  196,  172,  173,
+ /*  1160 */   152,  172,  173,   27,   23,   37,  152,   26,  152,   97,
+ /*  1170 */   152,   97,  210,   56,  163,  196,  163,  163,  100,  196,
+ /*  1180 */   172,  173,   65,  152,   56,   68,  172,  173,  172,  173,
+ /*  1190 */   172,  173,  152,   65,  163,  163,   68,   23,  152,  234,
+ /*  1200 */    26,  152,  152,  172,  173,   88,   89,  196,  152,  196,
+ /*  1210 */   196,  152,   95,   96,   97,   98,   88,   89,  101,  152,
+ /*  1220 */   152,  207,  208,   95,   96,   97,   98,  196,  196,  101,
+ /*  1230 */    96,  233,  152,   97,  152,  152,   19,   20,  207,   22,
+ /*  1240 */   152,  152,  152,  191,   27,  152,  152,  152,  152,  132,
+ /*  1250 */   133,  134,  135,  136,   37,  152,  152,  152,  152,  152,
+ /*  1260 */   132,  133,  134,  135,  136,  210,  197,  210,  210,  198,
+ /*  1270 */   150,  184,  239,   56,  201,  214,  214,  201,  239,  180,
+ /*  1280 */   214,  227,  198,   38,  176,   68,  175,  175,  175,  122,
+ /*  1290 */   155,  200,  159,   19,   20,   40,   22,  159,  159,   22,
+ /*  1300 */    70,   27,  130,  243,  240,   88,   89,   90,  189,   18,
+ /*  1310 */   201,   37,   95,   96,   97,   98,  192,    5,  101,  192,
+ /*  1320 */   220,  240,   10,   11,   12,   13,   14,  159,   18,   17,
+ /*  1330 */    56,  158,  192,  201,  192,  220,  189,  189,  201,  159,
+ /*  1340 */   158,  137,   68,   31,   45,   33,  236,  159,  159,  132,
+ /*  1350 */   133,  134,  135,  136,   42,  158,  235,   22,  177,  159,
+ /*  1360 */   158,  158,   88,   89,  159,  107,  174,   55,  177,   95,
+ /*  1370 */    96,   97,   98,  174,   62,  101,   47,   65,   66,  106,
+ /*  1380 */   174,  125,   19,   20,  174,   22,  177,  176,  174,  182,
+ /*  1390 */    27,  216,  174,  174,  182,  107,  159,   22,  215,  215,
+ /*  1400 */    37,  216,  216,  216,  137,  215,  132,  133,  134,  135,
+ /*  1410 */   136,  215,  159,  177,   94,  177,  129,  224,  205,   56,
+ /*  1420 */   226,  126,  128,  203,  229,  204,  114,  229,  127,  202,
+ /*  1430 */   201,   68,   25,  162,   26,   13,  161,  153,  153,    6,
+ /*  1440 */   151,  151,  178,  151,  165,  165,  178,  165,    4,    3,
+ /*  1450 */   249,   88,   89,  141,   22,  142,   15,  249,   95,   96,
+ /*  1460 */    97,   98,  246,   67,  101,   16,   23,  120,   23,  131,
+ /*  1470 */   111,  123,   20,   16,  125,    1,  123,  131,   78,   78,
+ /*  1480 */    78,   78,  111,   96,  122,   35,    1,    5,   22,  107,
+ /*  1490 */   140,   53,   53,   26,   60,  132,  133,  134,  135,  136,
+ /*  1500 */   107,   43,   24,   20,  112,   19,   22,   52,   52,  105,
+ /*  1510 */    22,   22,   52,   23,   22,   22,   29,   23,   39,   23,
+ /*  1520 */    23,   26,  116,   22,   26,   23,   22,  122,   23,   23,
+ /*  1530 */    22,   96,   11,  124,   35,   26,   26,   23,   35,   23,
+ /*  1540 */    23,   23,   35,   23,   22,   26,   23,   22,   24,  122,
+ /*  1550 */    23,   22,   26,   22,   24,   23,   23,   23,   22,  122,
+ /*  1560 */    23,   15,  122,    1,  122,
+};
+#define YY_SHIFT_USE_DFLT (1565)
+#define YY_SHIFT_COUNT    (454)
+#define YY_SHIFT_MIN      (-114)
+#define YY_SHIFT_MAX      (1562)
+static const short yy_shift_ofst[] = {
+ /*     0 */     5, 1117, 1312, 1128, 1274, 1274, 1274, 1274,   61,  -19,
+ /*    10 */    57,   57,  183, 1274, 1274, 1274, 1274, 1274, 1274, 1274,
+ /*    20 */    66,   66,  201,  -29,  331,  318,  133,  259,  335,  411,
+ /*    30 */   487,  563,  639,  689,  765,  841,  891,  891,  891,  891,
+ /*    40 */   891,  891,  891,  891,  891,  891,  891,  891,  891,  891,
+ /*    50 */   891,  891,  891,  941,  891,  991, 1041, 1041, 1217, 1274,
+ /*    60 */  1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274,
+ /*    70 */  1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274,
+ /*    80 */  1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274,
+ /*    90 */  1363, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274, 1274,
+ /*   100 */  1274, 1274, 1274, 1274,  -70,  -47,  -47,  -47,  -47,  -47,
+ /*   110 */    24,   11,  146,  296,  524,  444,  529,  529,  296,    3,
+ /*   120 */     2,  -30, 1565, 1565, 1565,  -17,  -17,  -17,  145,  145,
+ /*   130 */   497,  497,  265,  603,  653,  296,  296,  296,  296,  296,
+ /*   140 */   296,  296,  296,  296,  296,  296,  296,  296,  296,  296,
+ /*   150 */   296,  296,  296,  296,  296,  701, 1078,  147,  147,    2,
+ /*   160 */   164,  164,  164,  164,  164,  164, 1565, 1565, 1565,  223,
+ /*   170 */    56,   56,  268,  269,  220,  347,  351,  415,  359,  296,
+ /*   180 */   296,  296,  296,  296,  296,  296,  296,  296,  296,  296,
+ /*   190 */   296,  296,  296,  296,  296,  632,  632,  632,  296,  296,
+ /*   200 */   498,  296,  296,  296,  570,  296,  296,  654,  296,  296,
+ /*   210 */   296,  296,  296,  296,  296,  296,  296,  296,  636,  200,
+ /*   220 */   596,  596,  596,  575, -114,  971,  740,  454,  503,  503,
+ /*   230 */  1134,  454, 1134,  353,  588,  628,  762,  503,  189,  762,
+ /*   240 */   762,  916,  330,  668, 1245, 1167, 1167, 1255, 1255, 1167,
+ /*   250 */  1277, 1230, 1172, 1291, 1291, 1291, 1291, 1167, 1310, 1172,
+ /*   260 */  1277, 1230, 1230, 1172, 1167, 1310, 1204, 1299, 1167, 1167,
+ /*   270 */  1310, 1335, 1167, 1310, 1167, 1310, 1335, 1258, 1258, 1258,
+ /*   280 */  1329, 1335, 1258, 1273, 1258, 1329, 1258, 1258, 1256, 1288,
+ /*   290 */  1256, 1288, 1256, 1288, 1256, 1288, 1167, 1375, 1167, 1267,
+ /*   300 */  1335, 1320, 1320, 1335, 1287, 1295, 1294, 1301, 1172, 1407,
+ /*   310 */  1408, 1422, 1422, 1433, 1433, 1433, 1565, 1565, 1565, 1565,
+ /*   320 */  1565, 1565, 1565, 1565,  558,  537,  684,  719,  734,  799,
+ /*   330 */   840, 1019,   14, 1020, 1021, 1025, 1026, 1027, 1070, 1072,
+ /*   340 */   997, 1047,  999, 1079, 1126, 1074, 1141,  694,  819, 1174,
+ /*   350 */  1136,  981, 1444, 1446, 1432, 1313, 1441, 1396, 1449, 1443,
+ /*   360 */  1445, 1347, 1338, 1359, 1348, 1452, 1349, 1457, 1474, 1353,
+ /*   370 */  1346, 1400, 1401, 1402, 1403, 1371, 1387, 1450, 1362, 1485,
+ /*   380 */  1482, 1466, 1382, 1350, 1438, 1467, 1439, 1434, 1458, 1393,
+ /*   390 */  1478, 1483, 1486, 1392, 1404, 1484, 1455, 1488, 1489, 1490,
+ /*   400 */  1492, 1456, 1487, 1493, 1460, 1479, 1494, 1496, 1497, 1495,
+ /*   410 */  1406, 1501, 1502, 1504, 1498, 1405, 1505, 1506, 1435, 1499,
+ /*   420 */  1508, 1409, 1509, 1503, 1510, 1507, 1514, 1509, 1516, 1517,
+ /*   430 */  1518, 1519, 1520, 1522, 1521, 1523, 1525, 1524, 1526, 1527,
+ /*   440 */  1529, 1530, 1526, 1532, 1531, 1533, 1534, 1536, 1427, 1437,
+ /*   450 */  1440, 1442, 1537, 1546, 1562,
+};
+#define YY_REDUCE_USE_DFLT (-174)
+#define YY_REDUCE_COUNT (323)
+#define YY_REDUCE_MIN   (-173)
+#define YY_REDUCE_MAX   (1292)
+static const short yy_reduce_ofst[] = {
+ /*     0 */  -119, 1014,  131, 1031,  -12,  225,  228,  300,  -40,  -45,
+ /*    10 */   243,  256,  293,  129,  218,  418,   79,  376,  433,  298,
+ /*    20 */    16,  137,  367,  323,  -38,  391, -173, -173, -173, -173,
+ /*    30 */  -173, -173, -173, -173, -173, -173, -173, -173, -173, -173,
+ /*    40 */  -173, -173, -173, -173, -173, -173, -173, -173, -173, -173,
+ /*    50 */  -173, -173, -173, -173, -173, -173, -173, -173,  374,  437,
+ /*    60 */   443,  508,  513,  522,  532,  582,  584,  620,  633,  635,
+ /*    70 */   637,  644,  646,  648,  650,  652,  659,  661,  696,  709,
+ /*    80 */   711,  714,  720,  722,  724,  726,  728,  733,  772,  784,
+ /*    90 */   786,  822,  834,  836,  884,  886,  922,  934,  936,  986,
+ /*   100 */   989, 1008, 1016, 1018, -173, -173, -173, -173, -173, -173,
+ /*   110 */  -173, -173, -173,  544,  -37,  274,  299,  501,  161, -173,
+ /*   120 */   193, -173, -173, -173, -173,   22,   22,   22,   64,  141,
+ /*   130 */   212,  342,  208,  504,  504,  132,  494,  606,  677,  678,
+ /*   140 */   750,  794,  796,  -58,   32,  383,  660,  737,  386,  787,
+ /*   150 */   800,  441,  872,  224,  850,  803,  949,  624,  830,  669,
+ /*   160 */   961,  979,  983, 1011, 1013, 1032,  753,  789,  321,   94,
+ /*   170 */   116,  304,  375,  210,  388,  392,  478,  545,  649,  721,
+ /*   180 */   727,  736,  752,  795,  853,  952,  958, 1004, 1040, 1046,
+ /*   190 */  1049, 1050, 1056, 1059, 1067,  559,  774,  811, 1068, 1080,
+ /*   200 */   938, 1082, 1083, 1088,  962, 1089, 1090, 1052, 1093, 1094,
+ /*   210 */  1095,  388, 1096, 1103, 1104, 1105, 1106, 1107,  965,  998,
+ /*   220 */  1055, 1057, 1058,  938, 1069, 1071, 1120, 1073, 1061, 1062,
+ /*   230 */  1033, 1076, 1039, 1108, 1087, 1099, 1111, 1066, 1054, 1112,
+ /*   240 */  1113, 1091, 1084, 1135, 1060, 1133, 1138, 1064, 1081, 1139,
+ /*   250 */  1100, 1119, 1109, 1124, 1127, 1140, 1142, 1168, 1173, 1132,
+ /*   260 */  1115, 1147, 1148, 1137, 1180, 1182, 1110, 1121, 1188, 1189,
+ /*   270 */  1197, 1181, 1200, 1202, 1205, 1203, 1191, 1192, 1199, 1206,
+ /*   280 */  1207, 1209, 1210, 1211, 1214, 1212, 1218, 1219, 1175, 1183,
+ /*   290 */  1185, 1184, 1186, 1190, 1187, 1196, 1237, 1193, 1253, 1194,
+ /*   300 */  1236, 1195, 1198, 1238, 1213, 1221, 1220, 1227, 1229, 1271,
+ /*   310 */  1275, 1284, 1285, 1289, 1290, 1292, 1201, 1208, 1216, 1279,
+ /*   320 */  1280, 1264, 1268, 1282,
+};
+static const YYACTIONTYPE yy_default[] = {
+ /*     0 */  1270, 1260, 1260, 1260, 1193, 1193, 1193, 1193, 1260, 1088,
+ /*    10 */  1117, 1117, 1244, 1322, 1322, 1322, 1322, 1322, 1322, 1192,
+ /*    20 */  1322, 1322, 1322, 1322, 1260, 1092, 1123, 1322, 1322, 1322,
+ /*    30 */  1322, 1194, 1195, 1322, 1322, 1322, 1243, 1245, 1133, 1132,
+ /*    40 */  1131, 1130, 1226, 1104, 1128, 1121, 1125, 1194, 1188, 1189,
+ /*    50 */  1187, 1191, 1195, 1322, 1124, 1158, 1172, 1157, 1322, 1322,
+ /*    60 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*    70 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*    80 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*    90 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   100 */  1322, 1322, 1322, 1322, 1166, 1171, 1178, 1170, 1167, 1160,
+ /*   110 */  1159, 1161, 1162, 1322, 1011, 1059, 1322, 1322, 1322, 1163,
+ /*   120 */  1322, 1164, 1175, 1174, 1173, 1251, 1278, 1277, 1322, 1322,
+ /*   130 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   140 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   150 */  1322, 1322, 1322, 1322, 1322, 1270, 1260, 1017, 1017, 1322,
+ /*   160 */  1260, 1260, 1260, 1260, 1260, 1260, 1256, 1092, 1083, 1322,
+ /*   170 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   180 */  1248, 1246, 1322, 1208, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   190 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   200 */  1322, 1322, 1322, 1322, 1088, 1322, 1322, 1322, 1322, 1322,
+ /*   210 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1272, 1322, 1221,
+ /*   220 */  1088, 1088, 1088, 1090, 1072, 1082,  997, 1127, 1106, 1106,
+ /*   230 */  1311, 1127, 1311, 1034, 1292, 1031, 1117, 1106, 1190, 1117,
+ /*   240 */  1117, 1089, 1082, 1322, 1314, 1097, 1097, 1313, 1313, 1097,
+ /*   250 */  1138, 1062, 1127, 1068, 1068, 1068, 1068, 1097, 1008, 1127,
+ /*   260 */  1138, 1062, 1062, 1127, 1097, 1008, 1225, 1308, 1097, 1097,
+ /*   270 */  1008, 1201, 1097, 1008, 1097, 1008, 1201, 1060, 1060, 1060,
+ /*   280 */  1049, 1201, 1060, 1034, 1060, 1049, 1060, 1060, 1110, 1105,
+ /*   290 */  1110, 1105, 1110, 1105, 1110, 1105, 1097, 1196, 1097, 1322,
+ /*   300 */  1201, 1205, 1205, 1201, 1122, 1111, 1120, 1118, 1127, 1014,
+ /*   310 */  1052, 1275, 1275, 1271, 1271, 1271, 1319, 1319, 1256, 1287,
+ /*   320 */  1287, 1036, 1036, 1287, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   330 */  1282, 1322, 1210, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   340 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   350 */  1322, 1143, 1322,  993, 1253, 1322, 1322, 1252, 1322, 1322,
+ /*   360 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   370 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1310, 1322,
+ /*   380 */  1322, 1322, 1322, 1322, 1322, 1224, 1223, 1322, 1322, 1322,
+ /*   390 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   400 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322,
+ /*   410 */  1074, 1322, 1322, 1322, 1296, 1322, 1322, 1322, 1322, 1322,
+ /*   420 */  1322, 1322, 1119, 1322, 1112, 1322, 1322, 1301, 1322, 1322,
+ /*   430 */  1322, 1322, 1322, 1322, 1322, 1322, 1322, 1322, 1262, 1322,
+ /*   440 */  1322, 1322, 1261, 1322, 1322, 1322, 1322, 1322, 1145, 1322,
+ /*   450 */  1144, 1148, 1322, 1002, 1322,
+};
+/********** End of lemon-generated parsing tables *****************************/
+
+/* The next table maps tokens (terminal symbols) into fallback tokens.  
+** If a construct like the following:
+** 
+**      %fallback ID X Y Z.
+**
+** appears in the grammar, then ID becomes a fallback token for X, Y,
+** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
+** but it does not parse, the type of the token is changed to ID and
+** the parse is retried before an error is thrown.
+**
+** This feature can be used, for example, to cause some keywords in a language
+** to revert to identifiers if they keyword does not apply in the context where
+** it appears.
+*/
+#ifdef YYFALLBACK
+static const YYCODETYPE yyFallback[] = {
+    0,  /*          $ => nothing */
+    0,  /*       SEMI => nothing */
+   27,  /*    EXPLAIN => ID */
+   27,  /*      QUERY => ID */
+   27,  /*       PLAN => ID */
+   27,  /*      BEGIN => ID */
+    0,  /* TRANSACTION => nothing */
+   27,  /*   DEFERRED => ID */
+   27,  /*  IMMEDIATE => ID */
+   27,  /*  EXCLUSIVE => ID */
+    0,  /*     COMMIT => nothing */
+   27,  /*        END => ID */
+   27,  /*   ROLLBACK => ID */
+   27,  /*  SAVEPOINT => ID */
+   27,  /*    RELEASE => ID */
+    0,  /*         TO => nothing */
+    0,  /*      TABLE => nothing */
+    0,  /*     CREATE => nothing */
+   27,  /*         IF => ID */
+    0,  /*        NOT => nothing */
+    0,  /*     EXISTS => nothing */
+   27,  /*       TEMP => ID */
+    0,  /*         LP => nothing */
+    0,  /*         RP => nothing */
+    0,  /*         AS => nothing */
+   27,  /*    WITHOUT => ID */
+    0,  /*      COMMA => nothing */
+    0,  /*         ID => nothing */
+   27,  /*      ABORT => ID */
+   27,  /*     ACTION => ID */
+   27,  /*      AFTER => ID */
+   27,  /*    ANALYZE => ID */
+   27,  /*        ASC => ID */
+   27,  /*     ATTACH => ID */
+   27,  /*     BEFORE => ID */
+   27,  /*         BY => ID */
+   27,  /*    CASCADE => ID */
+   27,  /*       CAST => ID */
+   27,  /*   COLUMNKW => ID */
+   27,  /*   CONFLICT => ID */
+   27,  /*   DATABASE => ID */
+   27,  /*       DESC => ID */
+   27,  /*     DETACH => ID */
+   27,  /*       EACH => ID */
+   27,  /*       FAIL => ID */
+   27,  /*        FOR => ID */
+   27,  /*     IGNORE => ID */
+   27,  /*  INITIALLY => ID */
+   27,  /*    INSTEAD => ID */
+   27,  /*    LIKE_KW => ID */
+   27,  /*      MATCH => ID */
+   27,  /*         NO => ID */
+   27,  /*        KEY => ID */
+   27,  /*         OF => ID */
+   27,  /*     OFFSET => ID */
+   27,  /*     PRAGMA => ID */
+   27,  /*      RAISE => ID */
+   27,  /*  RECURSIVE => ID */
+   27,  /*    REPLACE => ID */
+   27,  /*   RESTRICT => ID */
+   27,  /*        ROW => ID */
+   27,  /*    TRIGGER => ID */
+   27,  /*     VACUUM => ID */
+   27,  /*       VIEW => ID */
+   27,  /*    VIRTUAL => ID */
+   27,  /*       WITH => ID */
+   27,  /*    REINDEX => ID */
+   27,  /*     RENAME => ID */
+   27,  /*   CTIME_KW => ID */
+};
+#endif /* YYFALLBACK */
+
+/* The following structure represents a single element of the
+** parser's stack.  Information stored includes:
+**
+**   +  The state number for the parser at this level of the stack.
+**
+**   +  The value of the token stored at this level of the stack.
+**      (In other words, the "major" token.)
+**
+**   +  The semantic value stored at this level of the stack.  This is
+**      the information used by the action routines in the grammar.
+**      It is sometimes called the "minor" token.
+**
+** After the "shift" half of a SHIFTREDUCE action, the stateno field
+** actually contains the reduce action for the second half of the
+** SHIFTREDUCE.
+*/
+struct yyStackEntry {
+  YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */
+  YYCODETYPE major;      /* The major token value.  This is the code
+                         ** number for the token at this stack level */
+  YYMINORTYPE minor;     /* The user-supplied minor token value.  This
+                         ** is the value of the token  */
+};
+typedef struct yyStackEntry yyStackEntry;
+
+/* The state of the parser is completely contained in an instance of
+** the following structure */
+struct yyParser {
+  yyStackEntry *yytos;          /* Pointer to top element of the stack */
+#ifdef YYTRACKMAXSTACKDEPTH
+  int yyhwm;                    /* High-water mark of the stack */
+#endif
+#ifndef YYNOERRORRECOVERY
+  int yyerrcnt;                 /* Shifts left before out of the error */
+#endif
+  sqlite3ParserARG_SDECL                /* A place to hold %extra_argument */
+#if YYSTACKDEPTH<=0
+  int yystksz;                  /* Current side of the stack */
+  yyStackEntry *yystack;        /* The parser's stack */
+  yyStackEntry yystk0;          /* First stack entry */
+#else
+  yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */
+  yyStackEntry *yystackEnd;            /* Last entry in the stack */
+#endif
+};
+typedef struct yyParser yyParser;
+
+#ifndef NDEBUG
+/* #include  */
+static FILE *yyTraceFILE = 0;
+static char *yyTracePrompt = 0;
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* 
+** Turn parser tracing on by giving a stream to which to write the trace
+** and a prompt to preface each trace message.  Tracing is turned off
+** by making either argument NULL 
+**
+** Inputs:
+** 
      
+** 
    •  A FILE* to which trace output should be written.
+**      If NULL, then tracing is turned off.
+** 
    •  A prefix string written at the beginning of every
+**      line of trace output.  If NULL, then tracing is
+**      turned off.
+** 
    
+**
+** Outputs:
+** None.
+*/
+SQLITE_PRIVATE void sqlite3ParserTrace(FILE *TraceFILE, char *zTracePrompt){
+  yyTraceFILE = TraceFILE;
+  yyTracePrompt = zTracePrompt;
+  if( yyTraceFILE==0 ) yyTracePrompt = 0;
+  else if( yyTracePrompt==0 ) yyTraceFILE = 0;
+}
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing shifts, the names of all terminals and nonterminals
+** are required.  The following table supplies these names */
+static const char *const yyTokenName[] = { 
+  "$",             "SEMI",          "EXPLAIN",       "QUERY",       
+  "PLAN",          "BEGIN",         "TRANSACTION",   "DEFERRED",    
+  "IMMEDIATE",     "EXCLUSIVE",     "COMMIT",        "END",         
+  "ROLLBACK",      "SAVEPOINT",     "RELEASE",       "TO",          
+  "TABLE",         "CREATE",        "IF",            "NOT",         
+  "EXISTS",        "TEMP",          "LP",            "RP",          
+  "AS",            "WITHOUT",       "COMMA",         "ID",          
+  "ABORT",         "ACTION",        "AFTER",         "ANALYZE",     
+  "ASC",           "ATTACH",        "BEFORE",        "BY",          
+  "CASCADE",       "CAST",          "COLUMNKW",      "CONFLICT",    
+  "DATABASE",      "DESC",          "DETACH",        "EACH",        
+  "FAIL",          "FOR",           "IGNORE",        "INITIALLY",   
+  "INSTEAD",       "LIKE_KW",       "MATCH",         "NO",          
+  "KEY",           "OF",            "OFFSET",        "PRAGMA",      
+  "RAISE",         "RECURSIVE",     "REPLACE",       "RESTRICT",    
+  "ROW",           "TRIGGER",       "VACUUM",        "VIEW",        
+  "VIRTUAL",       "WITH",          "REINDEX",       "RENAME",      
+  "CTIME_KW",      "ANY",           "OR",            "AND",         
+  "IS",            "BETWEEN",       "IN",            "ISNULL",      
+  "NOTNULL",       "NE",            "EQ",            "GT",          
+  "LE",            "LT",            "GE",            "ESCAPE",      
+  "BITAND",        "BITOR",         "LSHIFT",        "RSHIFT",      
+  "PLUS",          "MINUS",         "STAR",          "SLASH",       
+  "REM",           "CONCAT",        "COLLATE",       "BITNOT",      
+  "INDEXED",       "STRING",        "JOIN_KW",       "CONSTRAINT",  
+  "DEFAULT",       "NULL",          "PRIMARY",       "UNIQUE",      
+  "CHECK",         "REFERENCES",    "AUTOINCR",      "ON",          
+  "INSERT",        "DELETE",        "UPDATE",        "SET",         
+  "DEFERRABLE",    "FOREIGN",       "DROP",          "UNION",       
+  "ALL",           "EXCEPT",        "INTERSECT",     "SELECT",      
+  "VALUES",        "DISTINCT",      "DOT",           "FROM",        
+  "JOIN",          "USING",         "ORDER",         "GROUP",       
+  "HAVING",        "LIMIT",         "WHERE",         "INTO",        
+  "FLOAT",         "BLOB",          "INTEGER",       "VARIABLE",    
+  "CASE",          "WHEN",          "THEN",          "ELSE",        
+  "INDEX",         "ALTER",         "ADD",           "error",       
+  "input",         "cmdlist",       "ecmd",          "explain",     
+  "cmdx",          "cmd",           "transtype",     "trans_opt",   
+  "nm",            "savepoint_opt",  "create_table",  "create_table_args",
+  "createkw",      "temp",          "ifnotexists",   "dbnm",        
+  "columnlist",    "conslist_opt",  "table_options",  "select",      
+  "columnname",    "carglist",      "typetoken",     "typename",    
+  "signed",        "plus_num",      "minus_num",     "ccons",       
+  "term",          "expr",          "onconf",        "sortorder",   
+  "autoinc",       "eidlist_opt",   "refargs",       "defer_subclause",
+  "refarg",        "refact",        "init_deferred_pred_opt",  "conslist",    
+  "tconscomma",    "tcons",         "sortlist",      "eidlist",     
+  "defer_subclause_opt",  "orconf",        "resolvetype",   "raisetype",   
+  "ifexists",      "fullname",      "selectnowith",  "oneselect",   
+  "with",          "multiselect_op",  "distinct",      "selcollist",  
+  "from",          "where_opt",     "groupby_opt",   "having_opt",  
+  "orderby_opt",   "limit_opt",     "values",        "nexprlist",   
+  "exprlist",      "sclp",          "as",            "seltablist",  
+  "stl_prefix",    "joinop",        "indexed_opt",   "on_opt",      
+  "using_opt",     "idlist",        "setlist",       "insert_cmd",  
+  "idlist_opt",    "likeop",        "between_op",    "in_op",       
+  "paren_exprlist",  "case_operand",  "case_exprlist",  "case_else",   
+  "uniqueflag",    "collate",       "nmnum",         "trigger_decl",
+  "trigger_cmd_list",  "trigger_time",  "trigger_event",  "foreach_clause",
+  "when_clause",   "trigger_cmd",   "trnm",          "tridxby",     
+  "database_kw_opt",  "key_opt",       "add_column_fullname",  "kwcolumn_opt",
+  "create_vtab",   "vtabarglist",   "vtabarg",       "vtabargtoken",
+  "lp",            "anylist",       "wqlist",      
+};
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing reduce actions, the names of all rules are required.
+*/
+static const char *const yyRuleName[] = {
+ /*   0 */ "explain ::= EXPLAIN",
+ /*   1 */ "explain ::= EXPLAIN QUERY PLAN",
+ /*   2 */ "cmdx ::= cmd",
+ /*   3 */ "cmd ::= BEGIN transtype trans_opt",
+ /*   4 */ "transtype ::=",
+ /*   5 */ "transtype ::= DEFERRED",
+ /*   6 */ "transtype ::= IMMEDIATE",
+ /*   7 */ "transtype ::= EXCLUSIVE",
+ /*   8 */ "cmd ::= COMMIT|END trans_opt",
+ /*   9 */ "cmd ::= ROLLBACK trans_opt",
+ /*  10 */ "cmd ::= SAVEPOINT nm",
+ /*  11 */ "cmd ::= RELEASE savepoint_opt nm",
+ /*  12 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",
+ /*  13 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",
+ /*  14 */ "createkw ::= CREATE",
+ /*  15 */ "ifnotexists ::=",
+ /*  16 */ "ifnotexists ::= IF NOT EXISTS",
+ /*  17 */ "temp ::= TEMP",
+ /*  18 */ "temp ::=",
+ /*  19 */ "create_table_args ::= LP columnlist conslist_opt RP table_options",
+ /*  20 */ "create_table_args ::= AS select",
+ /*  21 */ "table_options ::=",
+ /*  22 */ "table_options ::= WITHOUT nm",
+ /*  23 */ "columnname ::= nm typetoken",
+ /*  24 */ "typetoken ::=",
+ /*  25 */ "typetoken ::= typename LP signed RP",
+ /*  26 */ "typetoken ::= typename LP signed COMMA signed RP",
+ /*  27 */ "typename ::= typename ID|STRING",
+ /*  28 */ "ccons ::= CONSTRAINT nm",
+ /*  29 */ "ccons ::= DEFAULT term",
+ /*  30 */ "ccons ::= DEFAULT LP expr RP",
+ /*  31 */ "ccons ::= DEFAULT PLUS term",
+ /*  32 */ "ccons ::= DEFAULT MINUS term",
+ /*  33 */ "ccons ::= DEFAULT ID|INDEXED",
+ /*  34 */ "ccons ::= NOT NULL onconf",
+ /*  35 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",
+ /*  36 */ "ccons ::= UNIQUE onconf",
+ /*  37 */ "ccons ::= CHECK LP expr RP",
+ /*  38 */ "ccons ::= REFERENCES nm eidlist_opt refargs",
+ /*  39 */ "ccons ::= defer_subclause",
+ /*  40 */ "ccons ::= COLLATE ID|STRING",
+ /*  41 */ "autoinc ::=",
+ /*  42 */ "autoinc ::= AUTOINCR",
+ /*  43 */ "refargs ::=",
+ /*  44 */ "refargs ::= refargs refarg",
+ /*  45 */ "refarg ::= MATCH nm",
+ /*  46 */ "refarg ::= ON INSERT refact",
+ /*  47 */ "refarg ::= ON DELETE refact",
+ /*  48 */ "refarg ::= ON UPDATE refact",
+ /*  49 */ "refact ::= SET NULL",
+ /*  50 */ "refact ::= SET DEFAULT",
+ /*  51 */ "refact ::= CASCADE",
+ /*  52 */ "refact ::= RESTRICT",
+ /*  53 */ "refact ::= NO ACTION",
+ /*  54 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",
+ /*  55 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",
+ /*  56 */ "init_deferred_pred_opt ::=",
+ /*  57 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",
+ /*  58 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",
+ /*  59 */ "conslist_opt ::=",
+ /*  60 */ "tconscomma ::= COMMA",
+ /*  61 */ "tcons ::= CONSTRAINT nm",
+ /*  62 */ "tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf",
+ /*  63 */ "tcons ::= UNIQUE LP sortlist RP onconf",
+ /*  64 */ "tcons ::= CHECK LP expr RP onconf",
+ /*  65 */ "tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt",
+ /*  66 */ "defer_subclause_opt ::=",
+ /*  67 */ "onconf ::=",
+ /*  68 */ "onconf ::= ON CONFLICT resolvetype",
+ /*  69 */ "orconf ::=",
+ /*  70 */ "orconf ::= OR resolvetype",
+ /*  71 */ "resolvetype ::= IGNORE",
+ /*  72 */ "resolvetype ::= REPLACE",
+ /*  73 */ "cmd ::= DROP TABLE ifexists fullname",
+ /*  74 */ "ifexists ::= IF EXISTS",
+ /*  75 */ "ifexists ::=",
+ /*  76 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select",
+ /*  77 */ "cmd ::= DROP VIEW ifexists fullname",
+ /*  78 */ "cmd ::= select",
+ /*  79 */ "select ::= with selectnowith",
+ /*  80 */ "selectnowith ::= selectnowith multiselect_op oneselect",
+ /*  81 */ "multiselect_op ::= UNION",
+ /*  82 */ "multiselect_op ::= UNION ALL",
+ /*  83 */ "multiselect_op ::= EXCEPT|INTERSECT",
+ /*  84 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",
+ /*  85 */ "values ::= VALUES LP nexprlist RP",
+ /*  86 */ "values ::= values COMMA LP exprlist RP",
+ /*  87 */ "distinct ::= DISTINCT",
+ /*  88 */ "distinct ::= ALL",
+ /*  89 */ "distinct ::=",
+ /*  90 */ "sclp ::=",
+ /*  91 */ "selcollist ::= sclp expr as",
+ /*  92 */ "selcollist ::= sclp STAR",
+ /*  93 */ "selcollist ::= sclp nm DOT STAR",
+ /*  94 */ "as ::= AS nm",
+ /*  95 */ "as ::=",
+ /*  96 */ "from ::=",
+ /*  97 */ "from ::= FROM seltablist",
+ /*  98 */ "stl_prefix ::= seltablist joinop",
+ /*  99 */ "stl_prefix ::=",
+ /* 100 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",
+ /* 101 */ "seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt",
+ /* 102 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",
+ /* 103 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",
+ /* 104 */ "dbnm ::=",
+ /* 105 */ "dbnm ::= DOT nm",
+ /* 106 */ "fullname ::= nm dbnm",
+ /* 107 */ "joinop ::= COMMA|JOIN",
+ /* 108 */ "joinop ::= JOIN_KW JOIN",
+ /* 109 */ "joinop ::= JOIN_KW nm JOIN",
+ /* 110 */ "joinop ::= JOIN_KW nm nm JOIN",
+ /* 111 */ "on_opt ::= ON expr",
+ /* 112 */ "on_opt ::=",
+ /* 113 */ "indexed_opt ::=",
+ /* 114 */ "indexed_opt ::= INDEXED BY nm",
+ /* 115 */ "indexed_opt ::= NOT INDEXED",
+ /* 116 */ "using_opt ::= USING LP idlist RP",
+ /* 117 */ "using_opt ::=",
+ /* 118 */ "orderby_opt ::=",
+ /* 119 */ "orderby_opt ::= ORDER BY sortlist",
+ /* 120 */ "sortlist ::= sortlist COMMA expr sortorder",
+ /* 121 */ "sortlist ::= expr sortorder",
+ /* 122 */ "sortorder ::= ASC",
+ /* 123 */ "sortorder ::= DESC",
+ /* 124 */ "sortorder ::=",
+ /* 125 */ "groupby_opt ::=",
+ /* 126 */ "groupby_opt ::= GROUP BY nexprlist",
+ /* 127 */ "having_opt ::=",
+ /* 128 */ "having_opt ::= HAVING expr",
+ /* 129 */ "limit_opt ::=",
+ /* 130 */ "limit_opt ::= LIMIT expr",
+ /* 131 */ "limit_opt ::= LIMIT expr OFFSET expr",
+ /* 132 */ "limit_opt ::= LIMIT expr COMMA expr",
+ /* 133 */ "cmd ::= with DELETE FROM fullname indexed_opt where_opt",
+ /* 134 */ "where_opt ::=",
+ /* 135 */ "where_opt ::= WHERE expr",
+ /* 136 */ "cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt",
+ /* 137 */ "setlist ::= setlist COMMA nm EQ expr",
+ /* 138 */ "setlist ::= setlist COMMA LP idlist RP EQ expr",
+ /* 139 */ "setlist ::= nm EQ expr",
+ /* 140 */ "setlist ::= LP idlist RP EQ expr",
+ /* 141 */ "cmd ::= with insert_cmd INTO fullname idlist_opt select",
+ /* 142 */ "cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES",
+ /* 143 */ "insert_cmd ::= INSERT orconf",
+ /* 144 */ "insert_cmd ::= REPLACE",
+ /* 145 */ "idlist_opt ::=",
+ /* 146 */ "idlist_opt ::= LP idlist RP",
+ /* 147 */ "idlist ::= idlist COMMA nm",
+ /* 148 */ "idlist ::= nm",
+ /* 149 */ "expr ::= LP expr RP",
+ /* 150 */ "expr ::= ID|INDEXED",
+ /* 151 */ "expr ::= JOIN_KW",
+ /* 152 */ "expr ::= nm DOT nm",
+ /* 153 */ "expr ::= nm DOT nm DOT nm",
+ /* 154 */ "term ::= NULL|FLOAT|BLOB",
+ /* 155 */ "term ::= STRING",
+ /* 156 */ "term ::= INTEGER",
+ /* 157 */ "expr ::= VARIABLE",
+ /* 158 */ "expr ::= expr COLLATE ID|STRING",
+ /* 159 */ "expr ::= CAST LP expr AS typetoken RP",
+ /* 160 */ "expr ::= ID|INDEXED LP distinct exprlist RP",
+ /* 161 */ "expr ::= ID|INDEXED LP STAR RP",
+ /* 162 */ "term ::= CTIME_KW",
+ /* 163 */ "expr ::= LP nexprlist COMMA expr RP",
+ /* 164 */ "expr ::= expr AND expr",
+ /* 165 */ "expr ::= expr OR expr",
+ /* 166 */ "expr ::= expr LT|GT|GE|LE expr",
+ /* 167 */ "expr ::= expr EQ|NE expr",
+ /* 168 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",
+ /* 169 */ "expr ::= expr PLUS|MINUS expr",
+ /* 170 */ "expr ::= expr STAR|SLASH|REM expr",
+ /* 171 */ "expr ::= expr CONCAT expr",
+ /* 172 */ "likeop ::= NOT LIKE_KW|MATCH",
+ /* 173 */ "expr ::= expr likeop expr",
+ /* 174 */ "expr ::= expr likeop expr ESCAPE expr",
+ /* 175 */ "expr ::= expr ISNULL|NOTNULL",
+ /* 176 */ "expr ::= expr NOT NULL",
+ /* 177 */ "expr ::= expr IS expr",
+ /* 178 */ "expr ::= expr IS NOT expr",
+ /* 179 */ "expr ::= NOT expr",
+ /* 180 */ "expr ::= BITNOT expr",
+ /* 181 */ "expr ::= MINUS expr",
+ /* 182 */ "expr ::= PLUS expr",
+ /* 183 */ "between_op ::= BETWEEN",
+ /* 184 */ "between_op ::= NOT BETWEEN",
+ /* 185 */ "expr ::= expr between_op expr AND expr",
+ /* 186 */ "in_op ::= IN",
+ /* 187 */ "in_op ::= NOT IN",
+ /* 188 */ "expr ::= expr in_op LP exprlist RP",
+ /* 189 */ "expr ::= LP select RP",
+ /* 190 */ "expr ::= expr in_op LP select RP",
+ /* 191 */ "expr ::= expr in_op nm dbnm paren_exprlist",
+ /* 192 */ "expr ::= EXISTS LP select RP",
+ /* 193 */ "expr ::= CASE case_operand case_exprlist case_else END",
+ /* 194 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",
+ /* 195 */ "case_exprlist ::= WHEN expr THEN expr",
+ /* 196 */ "case_else ::= ELSE expr",
+ /* 197 */ "case_else ::=",
+ /* 198 */ "case_operand ::= expr",
+ /* 199 */ "case_operand ::=",
+ /* 200 */ "exprlist ::=",
+ /* 201 */ "nexprlist ::= nexprlist COMMA expr",
+ /* 202 */ "nexprlist ::= expr",
+ /* 203 */ "paren_exprlist ::=",
+ /* 204 */ "paren_exprlist ::= LP exprlist RP",
+ /* 205 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt",
+ /* 206 */ "uniqueflag ::= UNIQUE",
+ /* 207 */ "uniqueflag ::=",
+ /* 208 */ "eidlist_opt ::=",
+ /* 209 */ "eidlist_opt ::= LP eidlist RP",
+ /* 210 */ "eidlist ::= eidlist COMMA nm collate sortorder",
+ /* 211 */ "eidlist ::= nm collate sortorder",
+ /* 212 */ "collate ::=",
+ /* 213 */ "collate ::= COLLATE ID|STRING",
+ /* 214 */ "cmd ::= DROP INDEX ifexists fullname",
+ /* 215 */ "cmd ::= VACUUM",
+ /* 216 */ "cmd ::= VACUUM nm",
+ /* 217 */ "cmd ::= PRAGMA nm dbnm",
+ /* 218 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",
+ /* 219 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",
+ /* 220 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",
+ /* 221 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",
+ /* 222 */ "plus_num ::= PLUS INTEGER|FLOAT",
+ /* 223 */ "minus_num ::= MINUS INTEGER|FLOAT",
+ /* 224 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",
+ /* 225 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",
+ /* 226 */ "trigger_time ::= BEFORE|AFTER",
+ /* 227 */ "trigger_time ::= INSTEAD OF",
+ /* 228 */ "trigger_time ::=",
+ /* 229 */ "trigger_event ::= DELETE|INSERT",
+ /* 230 */ "trigger_event ::= UPDATE",
+ /* 231 */ "trigger_event ::= UPDATE OF idlist",
+ /* 232 */ "when_clause ::=",
+ /* 233 */ "when_clause ::= WHEN expr",
+ /* 234 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",
+ /* 235 */ "trigger_cmd_list ::= trigger_cmd SEMI",
+ /* 236 */ "trnm ::= nm DOT nm",
+ /* 237 */ "tridxby ::= INDEXED BY nm",
+ /* 238 */ "tridxby ::= NOT INDEXED",
+ /* 239 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt",
+ /* 240 */ "trigger_cmd ::= insert_cmd INTO trnm idlist_opt select",
+ /* 241 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt",
+ /* 242 */ "trigger_cmd ::= select",
+ /* 243 */ "expr ::= RAISE LP IGNORE RP",
+ /* 244 */ "expr ::= RAISE LP raisetype COMMA nm RP",
+ /* 245 */ "raisetype ::= ROLLBACK",
+ /* 246 */ "raisetype ::= ABORT",
+ /* 247 */ "raisetype ::= FAIL",
+ /* 248 */ "cmd ::= DROP TRIGGER ifexists fullname",
+ /* 249 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",
+ /* 250 */ "cmd ::= DETACH database_kw_opt expr",
+ /* 251 */ "key_opt ::=",
+ /* 252 */ "key_opt ::= KEY expr",
+ /* 253 */ "cmd ::= REINDEX",
+ /* 254 */ "cmd ::= REINDEX nm dbnm",
+ /* 255 */ "cmd ::= ANALYZE",
+ /* 256 */ "cmd ::= ANALYZE nm dbnm",
+ /* 257 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",
+ /* 258 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist",
+ /* 259 */ "add_column_fullname ::= fullname",
+ /* 260 */ "cmd ::= create_vtab",
+ /* 261 */ "cmd ::= create_vtab LP vtabarglist RP",
+ /* 262 */ "create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm",
+ /* 263 */ "vtabarg ::=",
+ /* 264 */ "vtabargtoken ::= ANY",
+ /* 265 */ "vtabargtoken ::= lp anylist RP",
+ /* 266 */ "lp ::= LP",
+ /* 267 */ "with ::=",
+ /* 268 */ "with ::= WITH wqlist",
+ /* 269 */ "with ::= WITH RECURSIVE wqlist",
+ /* 270 */ "wqlist ::= nm eidlist_opt AS LP select RP",
+ /* 271 */ "wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP",
+ /* 272 */ "input ::= cmdlist",
+ /* 273 */ "cmdlist ::= cmdlist ecmd",
+ /* 274 */ "cmdlist ::= ecmd",
+ /* 275 */ "ecmd ::= SEMI",
+ /* 276 */ "ecmd ::= explain cmdx SEMI",
+ /* 277 */ "explain ::=",
+ /* 278 */ "trans_opt ::=",
+ /* 279 */ "trans_opt ::= TRANSACTION",
+ /* 280 */ "trans_opt ::= TRANSACTION nm",
+ /* 281 */ "savepoint_opt ::= SAVEPOINT",
+ /* 282 */ "savepoint_opt ::=",
+ /* 283 */ "cmd ::= create_table create_table_args",
+ /* 284 */ "columnlist ::= columnlist COMMA columnname carglist",
+ /* 285 */ "columnlist ::= columnname carglist",
+ /* 286 */ "nm ::= ID|INDEXED",
+ /* 287 */ "nm ::= STRING",
+ /* 288 */ "nm ::= JOIN_KW",
+ /* 289 */ "typetoken ::= typename",
+ /* 290 */ "typename ::= ID|STRING",
+ /* 291 */ "signed ::= plus_num",
+ /* 292 */ "signed ::= minus_num",
+ /* 293 */ "carglist ::= carglist ccons",
+ /* 294 */ "carglist ::=",
+ /* 295 */ "ccons ::= NULL onconf",
+ /* 296 */ "conslist_opt ::= COMMA conslist",
+ /* 297 */ "conslist ::= conslist tconscomma tcons",
+ /* 298 */ "conslist ::= tcons",
+ /* 299 */ "tconscomma ::=",
+ /* 300 */ "defer_subclause_opt ::= defer_subclause",
+ /* 301 */ "resolvetype ::= raisetype",
+ /* 302 */ "selectnowith ::= oneselect",
+ /* 303 */ "oneselect ::= values",
+ /* 304 */ "sclp ::= selcollist COMMA",
+ /* 305 */ "as ::= ID|STRING",
+ /* 306 */ "expr ::= term",
+ /* 307 */ "likeop ::= LIKE_KW|MATCH",
+ /* 308 */ "exprlist ::= nexprlist",
+ /* 309 */ "nmnum ::= plus_num",
+ /* 310 */ "nmnum ::= nm",
+ /* 311 */ "nmnum ::= ON",
+ /* 312 */ "nmnum ::= DELETE",
+ /* 313 */ "nmnum ::= DEFAULT",
+ /* 314 */ "plus_num ::= INTEGER|FLOAT",
+ /* 315 */ "foreach_clause ::=",
+ /* 316 */ "foreach_clause ::= FOR EACH ROW",
+ /* 317 */ "trnm ::= nm",
+ /* 318 */ "tridxby ::=",
+ /* 319 */ "database_kw_opt ::= DATABASE",
+ /* 320 */ "database_kw_opt ::=",
+ /* 321 */ "kwcolumn_opt ::=",
+ /* 322 */ "kwcolumn_opt ::= COLUMNKW",
+ /* 323 */ "vtabarglist ::= vtabarg",
+ /* 324 */ "vtabarglist ::= vtabarglist COMMA vtabarg",
+ /* 325 */ "vtabarg ::= vtabarg vtabargtoken",
+ /* 326 */ "anylist ::=",
+ /* 327 */ "anylist ::= anylist LP anylist RP",
+ /* 328 */ "anylist ::= anylist ANY",
+};
+#endif /* NDEBUG */
+
+
+#if YYSTACKDEPTH<=0
+/*
+** Try to increase the size of the parser stack.  Return the number
+** of errors.  Return 0 on success.
+*/
+static int yyGrowStack(yyParser *p){
+  int newSize;
+  int idx;
+  yyStackEntry *pNew;
+
+  newSize = p->yystksz*2 + 100;
+  idx = p->yytos ? (int)(p->yytos - p->yystack) : 0;
+  if( p->yystack==&p->yystk0 ){
+    pNew = malloc(newSize*sizeof(pNew[0]));
+    if( pNew ) pNew[0] = p->yystk0;
+  }else{
+    pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));
+  }
+  if( pNew ){
+    p->yystack = pNew;
+    p->yytos = &p->yystack[idx];
+#ifndef NDEBUG
+    if( yyTraceFILE ){
+      fprintf(yyTraceFILE,"%sStack grows from %d to %d entries.\n",
+              yyTracePrompt, p->yystksz, newSize);
+    }
+#endif
+    p->yystksz = newSize;
+  }
+  return pNew==0; 
+}
+#endif
+
+/* Datatype of the argument to the memory allocated passed as the
+** second argument to sqlite3ParserAlloc() below.  This can be changed by
+** putting an appropriate #define in the %include section of the input
+** grammar.
+*/
+#ifndef YYMALLOCARGTYPE
+# define YYMALLOCARGTYPE size_t
+#endif
+
+/* Initialize a new parser that has already been allocated.
+*/
+SQLITE_PRIVATE void sqlite3ParserInit(void *yypParser){
+  yyParser *pParser = (yyParser*)yypParser;
+#ifdef YYTRACKMAXSTACKDEPTH
+  pParser->yyhwm = 0;
+#endif
+#if YYSTACKDEPTH<=0
+  pParser->yytos = NULL;
+  pParser->yystack = NULL;
+  pParser->yystksz = 0;
+  if( yyGrowStack(pParser) ){
+    pParser->yystack = &pParser->yystk0;
+    pParser->yystksz = 1;
+  }
+#endif
+#ifndef YYNOERRORRECOVERY
+  pParser->yyerrcnt = -1;
+#endif
+  pParser->yytos = pParser->yystack;
+  pParser->yystack[0].stateno = 0;
+  pParser->yystack[0].major = 0;
+#if YYSTACKDEPTH>0
+  pParser->yystackEnd = &pParser->yystack[YYSTACKDEPTH-1];
+#endif
+}
+
+#ifndef sqlite3Parser_ENGINEALWAYSONSTACK
+/* 
+** This function allocates a new parser.
+** The only argument is a pointer to a function which works like
+** malloc.
+**
+** Inputs:
+** A pointer to the function used to allocate memory.
+**
+** Outputs:
+** A pointer to a parser.  This pointer is used in subsequent calls
+** to sqlite3Parser and sqlite3ParserFree.
+*/
+SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(YYMALLOCARGTYPE)){
+  yyParser *pParser;
+  pParser = (yyParser*)(*mallocProc)( (YYMALLOCARGTYPE)sizeof(yyParser) );
+  if( pParser ) sqlite3ParserInit(pParser);
+  return pParser;
+}
+#endif /* sqlite3Parser_ENGINEALWAYSONSTACK */
+
+
+/* The following function deletes the "minor type" or semantic value
+** associated with a symbol.  The symbol can be either a terminal
+** or nonterminal. "yymajor" is the symbol code, and "yypminor" is
+** a pointer to the value to be deleted.  The code used to do the 
+** deletions is derived from the %destructor and/or %token_destructor
+** directives of the input grammar.
+*/
+static void yy_destructor(
+  yyParser *yypParser,    /* The parser */
+  YYCODETYPE yymajor,     /* Type code for object to destroy */
+  YYMINORTYPE *yypminor   /* The object to be destroyed */
+){
+  sqlite3ParserARG_FETCH;
+  switch( yymajor ){
+    /* Here is inserted the actions which take place when a
+    ** terminal or non-terminal is destroyed.  This can happen
+    ** when the symbol is popped from the stack during a
+    ** reduce or during error processing or when a parser is 
+    ** being destroyed before it is finished parsing.
+    **
+    ** Note: during a reduce, the only symbols destroyed are those
+    ** which appear on the RHS of the rule, but which are *not* used
+    ** inside the C code.
+    */
+/********* Begin destructor definitions ***************************************/
+    case 163: /* select */
+    case 194: /* selectnowith */
+    case 195: /* oneselect */
+    case 206: /* values */
+{
+sqlite3SelectDelete(pParse->db, (yypminor->yy243));
+}
+      break;
+    case 172: /* term */
+    case 173: /* expr */
+{
+sqlite3ExprDelete(pParse->db, (yypminor->yy190).pExpr);
+}
+      break;
+    case 177: /* eidlist_opt */
+    case 186: /* sortlist */
+    case 187: /* eidlist */
+    case 199: /* selcollist */
+    case 202: /* groupby_opt */
+    case 204: /* orderby_opt */
+    case 207: /* nexprlist */
+    case 208: /* exprlist */
+    case 209: /* sclp */
+    case 218: /* setlist */
+    case 224: /* paren_exprlist */
+    case 226: /* case_exprlist */
+{
+sqlite3ExprListDelete(pParse->db, (yypminor->yy148));
+}
+      break;
+    case 193: /* fullname */
+    case 200: /* from */
+    case 211: /* seltablist */
+    case 212: /* stl_prefix */
+{
+sqlite3SrcListDelete(pParse->db, (yypminor->yy185));
+}
+      break;
+    case 196: /* with */
+    case 250: /* wqlist */
+{
+sqlite3WithDelete(pParse->db, (yypminor->yy285));
+}
+      break;
+    case 201: /* where_opt */
+    case 203: /* having_opt */
+    case 215: /* on_opt */
+    case 225: /* case_operand */
+    case 227: /* case_else */
+    case 236: /* when_clause */
+    case 241: /* key_opt */
+{
+sqlite3ExprDelete(pParse->db, (yypminor->yy72));
+}
+      break;
+    case 216: /* using_opt */
+    case 217: /* idlist */
+    case 220: /* idlist_opt */
+{
+sqlite3IdListDelete(pParse->db, (yypminor->yy254));
+}
+      break;
+    case 232: /* trigger_cmd_list */
+    case 237: /* trigger_cmd */
+{
+sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy145));
+}
+      break;
+    case 234: /* trigger_event */
+{
+sqlite3IdListDelete(pParse->db, (yypminor->yy332).b);
+}
+      break;
+/********* End destructor definitions *****************************************/
+    default:  break;   /* If no destructor action specified: do nothing */
+  }
+}
+
+/*
+** Pop the parser's stack once.
+**
+** If there is a destructor routine associated with the token which
+** is popped from the stack, then call it.
+*/
+static void yy_pop_parser_stack(yyParser *pParser){
+  yyStackEntry *yytos;
+  assert( pParser->yytos!=0 );
+  assert( pParser->yytos > pParser->yystack );
+  yytos = pParser->yytos--;
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sPopping %s\n",
+      yyTracePrompt,
+      yyTokenName[yytos->major]);
+  }
+#endif
+  yy_destructor(pParser, yytos->major, &yytos->minor);
+}
+
+/*
+** Clear all secondary memory allocations from the parser
+*/
+SQLITE_PRIVATE void sqlite3ParserFinalize(void *p){
+  yyParser *pParser = (yyParser*)p;
+  while( pParser->yytos>pParser->yystack ) yy_pop_parser_stack(pParser);
+#if YYSTACKDEPTH<=0
+  if( pParser->yystack!=&pParser->yystk0 ) free(pParser->yystack);
+#endif
+}
+
+#ifndef sqlite3Parser_ENGINEALWAYSONSTACK
+/* 
+** Deallocate and destroy a parser.  Destructors are called for
+** all stack elements before shutting the parser down.
+**
+** If the YYPARSEFREENEVERNULL macro exists (for example because it
+** is defined in a %include section of the input grammar) then it is
+** assumed that the input pointer is never NULL.
+*/
+SQLITE_PRIVATE void sqlite3ParserFree(
+  void *p,                    /* The parser to be deleted */
+  void (*freeProc)(void*)     /* Function used to reclaim memory */
+){
+#ifndef YYPARSEFREENEVERNULL
+  if( p==0 ) return;
+#endif
+  sqlite3ParserFinalize(p);
+  (*freeProc)(p);
+}
+#endif /* sqlite3Parser_ENGINEALWAYSONSTACK */
+
+/*
+** Return the peak depth of the stack for a parser.
+*/
+#ifdef YYTRACKMAXSTACKDEPTH
+SQLITE_PRIVATE int sqlite3ParserStackPeak(void *p){
+  yyParser *pParser = (yyParser*)p;
+  return pParser->yyhwm;
+}
+#endif
+
+/*
+** Find the appropriate action for a parser given the terminal
+** look-ahead token iLookAhead.
+*/
+static unsigned int yy_find_shift_action(
+  yyParser *pParser,        /* The parser */
+  YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+  int stateno = pParser->yytos->stateno;
+ 
+  if( stateno>=YY_MIN_REDUCE ) return stateno;
+  assert( stateno <= YY_SHIFT_COUNT );
+  do{
+    i = yy_shift_ofst[stateno];
+    assert( iLookAhead!=YYNOCODE );
+    i += iLookAhead;
+    if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
+#ifdef YYFALLBACK
+      YYCODETYPE iFallback;            /* Fallback token */
+      if( iLookAhead %s\n",
+             yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);
+        }
+#endif
+        assert( yyFallback[iFallback]==0 ); /* Fallback loop must terminate */
+        iLookAhead = iFallback;
+        continue;
+      }
+#endif
+#ifdef YYWILDCARD
+      {
+        int j = i - iLookAhead + YYWILDCARD;
+        if( 
+#if YY_SHIFT_MIN+YYWILDCARD<0
+          j>=0 &&
+#endif
+#if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT
+          j0
+        ){
+#ifndef NDEBUG
+          if( yyTraceFILE ){
+            fprintf(yyTraceFILE, "%sWILDCARD %s => %s\n",
+               yyTracePrompt, yyTokenName[iLookAhead],
+               yyTokenName[YYWILDCARD]);
+          }
+#endif /* NDEBUG */
+          return yy_action[j];
+        }
+      }
+#endif /* YYWILDCARD */
+      return yy_default[stateno];
+    }else{
+      return yy_action[i];
+    }
+  }while(1);
+}
+
+/*
+** Find the appropriate action for a parser given the non-terminal
+** look-ahead token iLookAhead.
+*/
+static int yy_find_reduce_action(
+  int stateno,              /* Current state number */
+  YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+#ifdef YYERRORSYMBOL
+  if( stateno>YY_REDUCE_COUNT ){
+    return yy_default[stateno];
+  }
+#else
+  assert( stateno<=YY_REDUCE_COUNT );
+#endif
+  i = yy_reduce_ofst[stateno];
+  assert( i!=YY_REDUCE_USE_DFLT );
+  assert( iLookAhead!=YYNOCODE );
+  i += iLookAhead;
+#ifdef YYERRORSYMBOL
+  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
+    return yy_default[stateno];
+  }
+#else
+  assert( i>=0 && iyytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);
+   /* Here code is inserted which will execute if the parser
+   ** stack every overflows */
+/******** Begin %stack_overflow code ******************************************/
+
+  sqlite3ErrorMsg(pParse, "parser stack overflow");
+/******** End %stack_overflow code ********************************************/
+   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
+}
+
+/*
+** Print tracing information for a SHIFT action
+*/
+#ifndef NDEBUG
+static void yyTraceShift(yyParser *yypParser, int yyNewState){
+  if( yyTraceFILE ){
+    if( yyNewStateyytos->major],
+         yyNewState);
+    }else{
+      fprintf(yyTraceFILE,"%sShift '%s'\n",
+         yyTracePrompt,yyTokenName[yypParser->yytos->major]);
+    }
+  }
+}
+#else
+# define yyTraceShift(X,Y)
+#endif
+
+/*
+** Perform a shift action.
+*/
+static void yy_shift(
+  yyParser *yypParser,          /* The parser to be shifted */
+  int yyNewState,               /* The new state to shift in */
+  int yyMajor,                  /* The major token to shift in */
+  sqlite3ParserTOKENTYPE yyMinor        /* The minor token to shift in */
+){
+  yyStackEntry *yytos;
+  yypParser->yytos++;
+#ifdef YYTRACKMAXSTACKDEPTH
+  if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
+    yypParser->yyhwm++;
+    assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack) );
+  }
+#endif
+#if YYSTACKDEPTH>0 
+  if( yypParser->yytos>yypParser->yystackEnd ){
+    yypParser->yytos--;
+    yyStackOverflow(yypParser);
+    return;
+  }
+#else
+  if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz] ){
+    if( yyGrowStack(yypParser) ){
+      yypParser->yytos--;
+      yyStackOverflow(yypParser);
+      return;
+    }
+  }
+#endif
+  if( yyNewState > YY_MAX_SHIFT ){
+    yyNewState += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
+  }
+  yytos = yypParser->yytos;
+  yytos->stateno = (YYACTIONTYPE)yyNewState;
+  yytos->major = (YYCODETYPE)yyMajor;
+  yytos->minor.yy0 = yyMinor;
+  yyTraceShift(yypParser, yyNewState);
+}
+
+/* The following table contains information about every rule that
+** is used during the reduce.
+*/
+static const struct {
+  YYCODETYPE lhs;       /* Symbol on the left-hand side of the rule */
+  signed char nrhs;     /* Negative of the number of RHS symbols in the rule */
+} yyRuleInfo[] = {
+  { 147, -1 },
+  { 147, -3 },
+  { 148, -1 },
+  { 149, -3 },
+  { 150, 0 },
+  { 150, -1 },
+  { 150, -1 },
+  { 150, -1 },
+  { 149, -2 },
+  { 149, -2 },
+  { 149, -2 },
+  { 149, -3 },
+  { 149, -5 },
+  { 154, -6 },
+  { 156, -1 },
+  { 158, 0 },
+  { 158, -3 },
+  { 157, -1 },
+  { 157, 0 },
+  { 155, -5 },
+  { 155, -2 },
+  { 162, 0 },
+  { 162, -2 },
+  { 164, -2 },
+  { 166, 0 },
+  { 166, -4 },
+  { 166, -6 },
+  { 167, -2 },
+  { 171, -2 },
+  { 171, -2 },
+  { 171, -4 },
+  { 171, -3 },
+  { 171, -3 },
+  { 171, -2 },
+  { 171, -3 },
+  { 171, -5 },
+  { 171, -2 },
+  { 171, -4 },
+  { 171, -4 },
+  { 171, -1 },
+  { 171, -2 },
+  { 176, 0 },
+  { 176, -1 },
+  { 178, 0 },
+  { 178, -2 },
+  { 180, -2 },
+  { 180, -3 },
+  { 180, -3 },
+  { 180, -3 },
+  { 181, -2 },
+  { 181, -2 },
+  { 181, -1 },
+  { 181, -1 },
+  { 181, -2 },
+  { 179, -3 },
+  { 179, -2 },
+  { 182, 0 },
+  { 182, -2 },
+  { 182, -2 },
+  { 161, 0 },
+  { 184, -1 },
+  { 185, -2 },
+  { 185, -7 },
+  { 185, -5 },
+  { 185, -5 },
+  { 185, -10 },
+  { 188, 0 },
+  { 174, 0 },
+  { 174, -3 },
+  { 189, 0 },
+  { 189, -2 },
+  { 190, -1 },
+  { 190, -1 },
+  { 149, -4 },
+  { 192, -2 },
+  { 192, 0 },
+  { 149, -9 },
+  { 149, -4 },
+  { 149, -1 },
+  { 163, -2 },
+  { 194, -3 },
+  { 197, -1 },
+  { 197, -2 },
+  { 197, -1 },
+  { 195, -9 },
+  { 206, -4 },
+  { 206, -5 },
+  { 198, -1 },
+  { 198, -1 },
+  { 198, 0 },
+  { 209, 0 },
+  { 199, -3 },
+  { 199, -2 },
+  { 199, -4 },
+  { 210, -2 },
+  { 210, 0 },
+  { 200, 0 },
+  { 200, -2 },
+  { 212, -2 },
+  { 212, 0 },
+  { 211, -7 },
+  { 211, -9 },
+  { 211, -7 },
+  { 211, -7 },
+  { 159, 0 },
+  { 159, -2 },
+  { 193, -2 },
+  { 213, -1 },
+  { 213, -2 },
+  { 213, -3 },
+  { 213, -4 },
+  { 215, -2 },
+  { 215, 0 },
+  { 214, 0 },
+  { 214, -3 },
+  { 214, -2 },
+  { 216, -4 },
+  { 216, 0 },
+  { 204, 0 },
+  { 204, -3 },
+  { 186, -4 },
+  { 186, -2 },
+  { 175, -1 },
+  { 175, -1 },
+  { 175, 0 },
+  { 202, 0 },
+  { 202, -3 },
+  { 203, 0 },
+  { 203, -2 },
+  { 205, 0 },
+  { 205, -2 },
+  { 205, -4 },
+  { 205, -4 },
+  { 149, -6 },
+  { 201, 0 },
+  { 201, -2 },
+  { 149, -8 },
+  { 218, -5 },
+  { 218, -7 },
+  { 218, -3 },
+  { 218, -5 },
+  { 149, -6 },
+  { 149, -7 },
+  { 219, -2 },
+  { 219, -1 },
+  { 220, 0 },
+  { 220, -3 },
+  { 217, -3 },
+  { 217, -1 },
+  { 173, -3 },
+  { 173, -1 },
+  { 173, -1 },
+  { 173, -3 },
+  { 173, -5 },
+  { 172, -1 },
+  { 172, -1 },
+  { 172, -1 },
+  { 173, -1 },
+  { 173, -3 },
+  { 173, -6 },
+  { 173, -5 },
+  { 173, -4 },
+  { 172, -1 },
+  { 173, -5 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -3 },
+  { 221, -2 },
+  { 173, -3 },
+  { 173, -5 },
+  { 173, -2 },
+  { 173, -3 },
+  { 173, -3 },
+  { 173, -4 },
+  { 173, -2 },
+  { 173, -2 },
+  { 173, -2 },
+  { 173, -2 },
+  { 222, -1 },
+  { 222, -2 },
+  { 173, -5 },
+  { 223, -1 },
+  { 223, -2 },
+  { 173, -5 },
+  { 173, -3 },
+  { 173, -5 },
+  { 173, -5 },
+  { 173, -4 },
+  { 173, -5 },
+  { 226, -5 },
+  { 226, -4 },
+  { 227, -2 },
+  { 227, 0 },
+  { 225, -1 },
+  { 225, 0 },
+  { 208, 0 },
+  { 207, -3 },
+  { 207, -1 },
+  { 224, 0 },
+  { 224, -3 },
+  { 149, -12 },
+  { 228, -1 },
+  { 228, 0 },
+  { 177, 0 },
+  { 177, -3 },
+  { 187, -5 },
+  { 187, -3 },
+  { 229, 0 },
+  { 229, -2 },
+  { 149, -4 },
+  { 149, -1 },
+  { 149, -2 },
+  { 149, -3 },
+  { 149, -5 },
+  { 149, -6 },
+  { 149, -5 },
+  { 149, -6 },
+  { 169, -2 },
+  { 170, -2 },
+  { 149, -5 },
+  { 231, -11 },
+  { 233, -1 },
+  { 233, -2 },
+  { 233, 0 },
+  { 234, -1 },
+  { 234, -1 },
+  { 234, -3 },
+  { 236, 0 },
+  { 236, -2 },
+  { 232, -3 },
+  { 232, -2 },
+  { 238, -3 },
+  { 239, -3 },
+  { 239, -2 },
+  { 237, -7 },
+  { 237, -5 },
+  { 237, -5 },
+  { 237, -1 },
+  { 173, -4 },
+  { 173, -6 },
+  { 191, -1 },
+  { 191, -1 },
+  { 191, -1 },
+  { 149, -4 },
+  { 149, -6 },
+  { 149, -3 },
+  { 241, 0 },
+  { 241, -2 },
+  { 149, -1 },
+  { 149, -3 },
+  { 149, -1 },
+  { 149, -3 },
+  { 149, -6 },
+  { 149, -7 },
+  { 242, -1 },
+  { 149, -1 },
+  { 149, -4 },
+  { 244, -8 },
+  { 246, 0 },
+  { 247, -1 },
+  { 247, -3 },
+  { 248, -1 },
+  { 196, 0 },
+  { 196, -2 },
+  { 196, -3 },
+  { 250, -6 },
+  { 250, -8 },
+  { 144, -1 },
+  { 145, -2 },
+  { 145, -1 },
+  { 146, -1 },
+  { 146, -3 },
+  { 147, 0 },
+  { 151, 0 },
+  { 151, -1 },
+  { 151, -2 },
+  { 153, -1 },
+  { 153, 0 },
+  { 149, -2 },
+  { 160, -4 },
+  { 160, -2 },
+  { 152, -1 },
+  { 152, -1 },
+  { 152, -1 },
+  { 166, -1 },
+  { 167, -1 },
+  { 168, -1 },
+  { 168, -1 },
+  { 165, -2 },
+  { 165, 0 },
+  { 171, -2 },
+  { 161, -2 },
+  { 183, -3 },
+  { 183, -1 },
+  { 184, 0 },
+  { 188, -1 },
+  { 190, -1 },
+  { 194, -1 },
+  { 195, -1 },
+  { 209, -2 },
+  { 210, -1 },
+  { 173, -1 },
+  { 221, -1 },
+  { 208, -1 },
+  { 230, -1 },
+  { 230, -1 },
+  { 230, -1 },
+  { 230, -1 },
+  { 230, -1 },
+  { 169, -1 },
+  { 235, 0 },
+  { 235, -3 },
+  { 238, -1 },
+  { 239, 0 },
+  { 240, -1 },
+  { 240, 0 },
+  { 243, 0 },
+  { 243, -1 },
+  { 245, -1 },
+  { 245, -3 },
+  { 246, -2 },
+  { 249, 0 },
+  { 249, -4 },
+  { 249, -2 },
+};
+
+static void yy_accept(yyParser*);  /* Forward Declaration */
+
+/*
+** Perform a reduce action and the shift that must immediately
+** follow the reduce.
+*/
+static void yy_reduce(
+  yyParser *yypParser,         /* The parser */
+  unsigned int yyruleno        /* Number of the rule by which to reduce */
+){
+  int yygoto;                     /* The next state */
+  int yyact;                      /* The next action */
+  yyStackEntry *yymsp;            /* The top of the parser's stack */
+  int yysize;                     /* Amount to pop the stack */
+  sqlite3ParserARG_FETCH;
+  yymsp = yypParser->yytos;
+#ifndef NDEBUG
+  if( yyTraceFILE && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
+    yysize = yyRuleInfo[yyruleno].nrhs;
+    fprintf(yyTraceFILE, "%sReduce [%s], go to state %d.\n", yyTracePrompt,
+      yyRuleName[yyruleno], yymsp[yysize].stateno);
+  }
+#endif /* NDEBUG */
+
+  /* Check that the stack is large enough to grow by a single entry
+  ** if the RHS of the rule is empty.  This ensures that there is room
+  ** enough on the stack to push the LHS value */
+  if( yyRuleInfo[yyruleno].nrhs==0 ){
+#ifdef YYTRACKMAXSTACKDEPTH
+    if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
+      yypParser->yyhwm++;
+      assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack));
+    }
+#endif
+#if YYSTACKDEPTH>0 
+    if( yypParser->yytos>=yypParser->yystackEnd ){
+      yyStackOverflow(yypParser);
+      return;
+    }
+#else
+    if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz-1] ){
+      if( yyGrowStack(yypParser) ){
+        yyStackOverflow(yypParser);
+        return;
+      }
+      yymsp = yypParser->yytos;
+    }
+#endif
+  }
+
+  switch( yyruleno ){
+  /* Beginning here are the reduction cases.  A typical example
+  ** follows:
+  **   case 0:
+  **  #line  
+  **     { ... }           // User supplied code
+  **  #line  
+  **     break;
+  */
+/********** Begin reduce actions **********************************************/
+        YYMINORTYPE yylhsminor;
+      case 0: /* explain ::= EXPLAIN */
+{ pParse->explain = 1; }
+        break;
+      case 1: /* explain ::= EXPLAIN QUERY PLAN */
+{ pParse->explain = 2; }
+        break;
+      case 2: /* cmdx ::= cmd */
+{ sqlite3FinishCoding(pParse); }
+        break;
+      case 3: /* cmd ::= BEGIN transtype trans_opt */
+{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy194);}
+        break;
+      case 4: /* transtype ::= */
+{yymsp[1].minor.yy194 = TK_DEFERRED;}
+        break;
+      case 5: /* transtype ::= DEFERRED */
+      case 6: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==6);
+      case 7: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==7);
+{yymsp[0].minor.yy194 = yymsp[0].major; /*A-overwrites-X*/}
+        break;
+      case 8: /* cmd ::= COMMIT|END trans_opt */
+      case 9: /* cmd ::= ROLLBACK trans_opt */ yytestcase(yyruleno==9);
+{sqlite3EndTransaction(pParse,yymsp[-1].major);}
+        break;
+      case 10: /* cmd ::= SAVEPOINT nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &yymsp[0].minor.yy0);
+}
+        break;
+      case 11: /* cmd ::= RELEASE savepoint_opt nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &yymsp[0].minor.yy0);
+}
+        break;
+      case 12: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &yymsp[0].minor.yy0);
+}
+        break;
+      case 13: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
+{
+   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy194,0,0,yymsp[-2].minor.yy194);
+}
+        break;
+      case 14: /* createkw ::= CREATE */
+{disableLookaside(pParse);}
+        break;
+      case 15: /* ifnotexists ::= */
+      case 18: /* temp ::= */ yytestcase(yyruleno==18);
+      case 21: /* table_options ::= */ yytestcase(yyruleno==21);
+      case 41: /* autoinc ::= */ yytestcase(yyruleno==41);
+      case 56: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==56);
+      case 66: /* defer_subclause_opt ::= */ yytestcase(yyruleno==66);
+      case 75: /* ifexists ::= */ yytestcase(yyruleno==75);
+      case 89: /* distinct ::= */ yytestcase(yyruleno==89);
+      case 212: /* collate ::= */ yytestcase(yyruleno==212);
+{yymsp[1].minor.yy194 = 0;}
+        break;
+      case 16: /* ifnotexists ::= IF NOT EXISTS */
+{yymsp[-2].minor.yy194 = 1;}
+        break;
+      case 17: /* temp ::= TEMP */
+      case 42: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==42);
+{yymsp[0].minor.yy194 = 1;}
+        break;
+      case 19: /* create_table_args ::= LP columnlist conslist_opt RP table_options */
+{
+  sqlite3EndTable(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,yymsp[0].minor.yy194,0);
+}
+        break;
+      case 20: /* create_table_args ::= AS select */
+{
+  sqlite3EndTable(pParse,0,0,0,yymsp[0].minor.yy243);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy243);
+}
+        break;
+      case 22: /* table_options ::= WITHOUT nm */
+{
+  if( yymsp[0].minor.yy0.n==5 && sqlite3_strnicmp(yymsp[0].minor.yy0.z,"rowid",5)==0 ){
+    yymsp[-1].minor.yy194 = TF_WithoutRowid | TF_NoVisibleRowid;
+  }else{
+    yymsp[-1].minor.yy194 = 0;
+    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", yymsp[0].minor.yy0.n, yymsp[0].minor.yy0.z);
+  }
+}
+        break;
+      case 23: /* columnname ::= nm typetoken */
+{sqlite3AddColumn(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}
+        break;
+      case 24: /* typetoken ::= */
+      case 59: /* conslist_opt ::= */ yytestcase(yyruleno==59);
+      case 95: /* as ::= */ yytestcase(yyruleno==95);
+{yymsp[1].minor.yy0.n = 0; yymsp[1].minor.yy0.z = 0;}
+        break;
+      case 25: /* typetoken ::= typename LP signed RP */
+{
+  yymsp[-3].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);
+}
+        break;
+      case 26: /* typetoken ::= typename LP signed COMMA signed RP */
+{
+  yymsp[-5].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);
+}
+        break;
+      case 27: /* typename ::= typename ID|STRING */
+{yymsp[-1].minor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}
+        break;
+      case 28: /* ccons ::= CONSTRAINT nm */
+      case 61: /* tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==61);
+{pParse->constraintName = yymsp[0].minor.yy0;}
+        break;
+      case 29: /* ccons ::= DEFAULT term */
+      case 31: /* ccons ::= DEFAULT PLUS term */ yytestcase(yyruleno==31);
+{sqlite3AddDefaultValue(pParse,&yymsp[0].minor.yy190);}
+        break;
+      case 30: /* ccons ::= DEFAULT LP expr RP */
+{sqlite3AddDefaultValue(pParse,&yymsp[-1].minor.yy190);}
+        break;
+      case 32: /* ccons ::= DEFAULT MINUS term */
+{
+  ExprSpan v;
+  v.pExpr = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy190.pExpr, 0);
+  v.zStart = yymsp[-1].minor.yy0.z;
+  v.zEnd = yymsp[0].minor.yy190.zEnd;
+  sqlite3AddDefaultValue(pParse,&v);
+}
+        break;
+      case 33: /* ccons ::= DEFAULT ID|INDEXED */
+{
+  ExprSpan v;
+  spanExpr(&v, pParse, TK_STRING, yymsp[0].minor.yy0);
+  sqlite3AddDefaultValue(pParse,&v);
+}
+        break;
+      case 34: /* ccons ::= NOT NULL onconf */
+{sqlite3AddNotNull(pParse, yymsp[0].minor.yy194);}
+        break;
+      case 35: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */
+{sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy194,yymsp[0].minor.yy194,yymsp[-2].minor.yy194);}
+        break;
+      case 36: /* ccons ::= UNIQUE onconf */
+{sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy194,0,0,0,0,
+                                   SQLITE_IDXTYPE_UNIQUE);}
+        break;
+      case 37: /* ccons ::= CHECK LP expr RP */
+{sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy190.pExpr);}
+        break;
+      case 38: /* ccons ::= REFERENCES nm eidlist_opt refargs */
+{sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy148,yymsp[0].minor.yy194);}
+        break;
+      case 39: /* ccons ::= defer_subclause */
+{sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy194);}
+        break;
+      case 40: /* ccons ::= COLLATE ID|STRING */
+{sqlite3AddCollateType(pParse, &yymsp[0].minor.yy0);}
+        break;
+      case 43: /* refargs ::= */
+{ yymsp[1].minor.yy194 = OE_None*0x0101; /* EV: R-19803-45884 */}
+        break;
+      case 44: /* refargs ::= refargs refarg */
+{ yymsp[-1].minor.yy194 = (yymsp[-1].minor.yy194 & ~yymsp[0].minor.yy497.mask) | yymsp[0].minor.yy497.value; }
+        break;
+      case 45: /* refarg ::= MATCH nm */
+{ yymsp[-1].minor.yy497.value = 0;     yymsp[-1].minor.yy497.mask = 0x000000; }
+        break;
+      case 46: /* refarg ::= ON INSERT refact */
+{ yymsp[-2].minor.yy497.value = 0;     yymsp[-2].minor.yy497.mask = 0x000000; }
+        break;
+      case 47: /* refarg ::= ON DELETE refact */
+{ yymsp[-2].minor.yy497.value = yymsp[0].minor.yy194;     yymsp[-2].minor.yy497.mask = 0x0000ff; }
+        break;
+      case 48: /* refarg ::= ON UPDATE refact */
+{ yymsp[-2].minor.yy497.value = yymsp[0].minor.yy194<<8;  yymsp[-2].minor.yy497.mask = 0x00ff00; }
+        break;
+      case 49: /* refact ::= SET NULL */
+{ yymsp[-1].minor.yy194 = OE_SetNull;  /* EV: R-33326-45252 */}
+        break;
+      case 50: /* refact ::= SET DEFAULT */
+{ yymsp[-1].minor.yy194 = OE_SetDflt;  /* EV: R-33326-45252 */}
+        break;
+      case 51: /* refact ::= CASCADE */
+{ yymsp[0].minor.yy194 = OE_Cascade;  /* EV: R-33326-45252 */}
+        break;
+      case 52: /* refact ::= RESTRICT */
+{ yymsp[0].minor.yy194 = OE_Restrict; /* EV: R-33326-45252 */}
+        break;
+      case 53: /* refact ::= NO ACTION */
+{ yymsp[-1].minor.yy194 = OE_None;     /* EV: R-33326-45252 */}
+        break;
+      case 54: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */
+{yymsp[-2].minor.yy194 = 0;}
+        break;
+      case 55: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */
+      case 70: /* orconf ::= OR resolvetype */ yytestcase(yyruleno==70);
+      case 143: /* insert_cmd ::= INSERT orconf */ yytestcase(yyruleno==143);
+{yymsp[-1].minor.yy194 = yymsp[0].minor.yy194;}
+        break;
+      case 57: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */
+      case 74: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==74);
+      case 184: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==184);
+      case 187: /* in_op ::= NOT IN */ yytestcase(yyruleno==187);
+      case 213: /* collate ::= COLLATE ID|STRING */ yytestcase(yyruleno==213);
+{yymsp[-1].minor.yy194 = 1;}
+        break;
+      case 58: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */
+{yymsp[-1].minor.yy194 = 0;}
+        break;
+      case 60: /* tconscomma ::= COMMA */
+{pParse->constraintName.n = 0;}
+        break;
+      case 62: /* tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */
+{sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy148,yymsp[0].minor.yy194,yymsp[-2].minor.yy194,0);}
+        break;
+      case 63: /* tcons ::= UNIQUE LP sortlist RP onconf */
+{sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy148,yymsp[0].minor.yy194,0,0,0,0,
+                                       SQLITE_IDXTYPE_UNIQUE);}
+        break;
+      case 64: /* tcons ::= CHECK LP expr RP onconf */
+{sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy190.pExpr);}
+        break;
+      case 65: /* tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */
+{
+    sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy148, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy148, yymsp[-1].minor.yy194);
+    sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy194);
+}
+        break;
+      case 67: /* onconf ::= */
+      case 69: /* orconf ::= */ yytestcase(yyruleno==69);
+{yymsp[1].minor.yy194 = OE_Default;}
+        break;
+      case 68: /* onconf ::= ON CONFLICT resolvetype */
+{yymsp[-2].minor.yy194 = yymsp[0].minor.yy194;}
+        break;
+      case 71: /* resolvetype ::= IGNORE */
+{yymsp[0].minor.yy194 = OE_Ignore;}
+        break;
+      case 72: /* resolvetype ::= REPLACE */
+      case 144: /* insert_cmd ::= REPLACE */ yytestcase(yyruleno==144);
+{yymsp[0].minor.yy194 = OE_Replace;}
+        break;
+      case 73: /* cmd ::= DROP TABLE ifexists fullname */
+{
+  sqlite3DropTable(pParse, yymsp[0].minor.yy185, 0, yymsp[-1].minor.yy194);
+}
+        break;
+      case 76: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */
+{
+  sqlite3CreateView(pParse, &yymsp[-8].minor.yy0, &yymsp[-4].minor.yy0, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy148, yymsp[0].minor.yy243, yymsp[-7].minor.yy194, yymsp[-5].minor.yy194);
+}
+        break;
+      case 77: /* cmd ::= DROP VIEW ifexists fullname */
+{
+  sqlite3DropTable(pParse, yymsp[0].minor.yy185, 1, yymsp[-1].minor.yy194);
+}
+        break;
+      case 78: /* cmd ::= select */
+{
+  SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};
+  sqlite3Select(pParse, yymsp[0].minor.yy243, &dest);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy243);
+}
+        break;
+      case 79: /* select ::= with selectnowith */
+{
+  Select *p = yymsp[0].minor.yy243;
+  if( p ){
+    p->pWith = yymsp[-1].minor.yy285;
+    parserDoubleLinkSelect(pParse, p);
+  }else{
+    sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy285);
+  }
+  yymsp[-1].minor.yy243 = p; /*A-overwrites-W*/
+}
+        break;
+      case 80: /* selectnowith ::= selectnowith multiselect_op oneselect */
+{
+  Select *pRhs = yymsp[0].minor.yy243;
+  Select *pLhs = yymsp[-2].minor.yy243;
+  if( pRhs && pRhs->pPrior ){
+    SrcList *pFrom;
+    Token x;
+    x.n = 0;
+    parserDoubleLinkSelect(pParse, pRhs);
+    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
+    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0,0);
+  }
+  if( pRhs ){
+    pRhs->op = (u8)yymsp[-1].minor.yy194;
+    pRhs->pPrior = pLhs;
+    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
+    pRhs->selFlags &= ~SF_MultiValue;
+    if( yymsp[-1].minor.yy194!=TK_ALL ) pParse->hasCompound = 1;
+  }else{
+    sqlite3SelectDelete(pParse->db, pLhs);
+  }
+  yymsp[-2].minor.yy243 = pRhs;
+}
+        break;
+      case 81: /* multiselect_op ::= UNION */
+      case 83: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==83);
+{yymsp[0].minor.yy194 = yymsp[0].major; /*A-overwrites-OP*/}
+        break;
+      case 82: /* multiselect_op ::= UNION ALL */
+{yymsp[-1].minor.yy194 = TK_ALL;}
+        break;
+      case 84: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */
+{
+#if SELECTTRACE_ENABLED
+  Token s = yymsp[-8].minor.yy0; /*A-overwrites-S*/
+#endif
+  yymsp[-8].minor.yy243 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy148,yymsp[-5].minor.yy185,yymsp[-4].minor.yy72,yymsp[-3].minor.yy148,yymsp[-2].minor.yy72,yymsp[-1].minor.yy148,yymsp[-7].minor.yy194,yymsp[0].minor.yy354.pLimit,yymsp[0].minor.yy354.pOffset);
+#if SELECTTRACE_ENABLED
+  /* Populate the Select.zSelName[] string that is used to help with
+  ** query planner debugging, to differentiate between multiple Select
+  ** objects in a complex query.
+  **
+  ** If the SELECT keyword is immediately followed by a C-style comment
+  ** then extract the first few alphanumeric characters from within that
+  ** comment to be the zSelName value.  Otherwise, the label is #N where
+  ** is an integer that is incremented with each SELECT statement seen.
+  */
+  if( yymsp[-8].minor.yy243!=0 ){
+    const char *z = s.z+6;
+    int i;
+    sqlite3_snprintf(sizeof(yymsp[-8].minor.yy243->zSelName), yymsp[-8].minor.yy243->zSelName, "#%d",
+                     ++pParse->nSelect);
+    while( z[0]==' ' ) z++;
+    if( z[0]=='/' && z[1]=='*' ){
+      z += 2;
+      while( z[0]==' ' ) z++;
+      for(i=0; sqlite3Isalnum(z[i]); i++){}
+      sqlite3_snprintf(sizeof(yymsp[-8].minor.yy243->zSelName), yymsp[-8].minor.yy243->zSelName, "%.*s", i, z);
+    }
+  }
+#endif /* SELECTRACE_ENABLED */
+}
+        break;
+      case 85: /* values ::= VALUES LP nexprlist RP */
+{
+  yymsp[-3].minor.yy243 = sqlite3SelectNew(pParse,yymsp[-1].minor.yy148,0,0,0,0,0,SF_Values,0,0);
+}
+        break;
+      case 86: /* values ::= values COMMA LP exprlist RP */
+{
+  Select *pRight, *pLeft = yymsp[-4].minor.yy243;
+  pRight = sqlite3SelectNew(pParse,yymsp[-1].minor.yy148,0,0,0,0,0,SF_Values|SF_MultiValue,0,0);
+  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
+  if( pRight ){
+    pRight->op = TK_ALL;
+    pRight->pPrior = pLeft;
+    yymsp[-4].minor.yy243 = pRight;
+  }else{
+    yymsp[-4].minor.yy243 = pLeft;
+  }
+}
+        break;
+      case 87: /* distinct ::= DISTINCT */
+{yymsp[0].minor.yy194 = SF_Distinct;}
+        break;
+      case 88: /* distinct ::= ALL */
+{yymsp[0].minor.yy194 = SF_All;}
+        break;
+      case 90: /* sclp ::= */
+      case 118: /* orderby_opt ::= */ yytestcase(yyruleno==118);
+      case 125: /* groupby_opt ::= */ yytestcase(yyruleno==125);
+      case 200: /* exprlist ::= */ yytestcase(yyruleno==200);
+      case 203: /* paren_exprlist ::= */ yytestcase(yyruleno==203);
+      case 208: /* eidlist_opt ::= */ yytestcase(yyruleno==208);
+{yymsp[1].minor.yy148 = 0;}
+        break;
+      case 91: /* selcollist ::= sclp expr as */
+{
+   yymsp[-2].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy148, yymsp[-1].minor.yy190.pExpr);
+   if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yymsp[-2].minor.yy148, &yymsp[0].minor.yy0, 1);
+   sqlite3ExprListSetSpan(pParse,yymsp[-2].minor.yy148,&yymsp[-1].minor.yy190);
+}
+        break;
+      case 92: /* selcollist ::= sclp STAR */
+{
+  Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
+  yymsp[-1].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-1].minor.yy148, p);
+}
+        break;
+      case 93: /* selcollist ::= sclp nm DOT STAR */
+{
+  Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0);
+  Expr *pLeft = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);
+  Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148, pDot);
+}
+        break;
+      case 94: /* as ::= AS nm */
+      case 105: /* dbnm ::= DOT nm */ yytestcase(yyruleno==105);
+      case 222: /* plus_num ::= PLUS INTEGER|FLOAT */ yytestcase(yyruleno==222);
+      case 223: /* minus_num ::= MINUS INTEGER|FLOAT */ yytestcase(yyruleno==223);
+{yymsp[-1].minor.yy0 = yymsp[0].minor.yy0;}
+        break;
+      case 96: /* from ::= */
+{yymsp[1].minor.yy185 = sqlite3DbMallocZero(pParse->db, sizeof(*yymsp[1].minor.yy185));}
+        break;
+      case 97: /* from ::= FROM seltablist */
+{
+  yymsp[-1].minor.yy185 = yymsp[0].minor.yy185;
+  sqlite3SrcListShiftJoinType(yymsp[-1].minor.yy185);
+}
+        break;
+      case 98: /* stl_prefix ::= seltablist joinop */
+{
+   if( ALWAYS(yymsp[-1].minor.yy185 && yymsp[-1].minor.yy185->nSrc>0) ) yymsp[-1].minor.yy185->a[yymsp[-1].minor.yy185->nSrc-1].fg.jointype = (u8)yymsp[0].minor.yy194;
+}
+        break;
+      case 99: /* stl_prefix ::= */
+{yymsp[1].minor.yy185 = 0;}
+        break;
+      case 100: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */
+{
+  yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-6].minor.yy185, &yymsp[-2].minor.yy0);
+}
+        break;
+      case 101: /* seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */
+{
+  yymsp[-8].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-8].minor.yy185,&yymsp[-7].minor.yy0,&yymsp[-6].minor.yy0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+  sqlite3SrcListFuncArgs(pParse, yymsp[-8].minor.yy185, yymsp[-4].minor.yy148);
+}
+        break;
+      case 102: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */
+{
+    yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy243,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+  }
+        break;
+      case 103: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */
+{
+    if( yymsp[-6].minor.yy185==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy72==0 && yymsp[0].minor.yy254==0 ){
+      yymsp[-6].minor.yy185 = yymsp[-4].minor.yy185;
+    }else if( yymsp[-4].minor.yy185->nSrc==1 ){
+      yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+      if( yymsp[-6].minor.yy185 ){
+        struct SrcList_item *pNew = &yymsp[-6].minor.yy185->a[yymsp[-6].minor.yy185->nSrc-1];
+        struct SrcList_item *pOld = yymsp[-4].minor.yy185->a;
+        pNew->zName = pOld->zName;
+        pNew->zDatabase = pOld->zDatabase;
+        pNew->pSelect = pOld->pSelect;
+        pOld->zName = pOld->zDatabase = 0;
+        pOld->pSelect = 0;
+      }
+      sqlite3SrcListDelete(pParse->db, yymsp[-4].minor.yy185);
+    }else{
+      Select *pSubquery;
+      sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy185);
+      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy185,0,0,0,0,SF_NestedFrom,0,0);
+      yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+    }
+  }
+        break;
+      case 104: /* dbnm ::= */
+      case 113: /* indexed_opt ::= */ yytestcase(yyruleno==113);
+{yymsp[1].minor.yy0.z=0; yymsp[1].minor.yy0.n=0;}
+        break;
+      case 106: /* fullname ::= nm dbnm */
+{yymsp[-1].minor.yy185 = sqlite3SrcListAppend(pParse->db,0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/}
+        break;
+      case 107: /* joinop ::= COMMA|JOIN */
+{ yymsp[0].minor.yy194 = JT_INNER; }
+        break;
+      case 108: /* joinop ::= JOIN_KW JOIN */
+{yymsp[-1].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0);  /*X-overwrites-A*/}
+        break;
+      case 109: /* joinop ::= JOIN_KW nm JOIN */
+{yymsp[-2].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); /*X-overwrites-A*/}
+        break;
+      case 110: /* joinop ::= JOIN_KW nm nm JOIN */
+{yymsp[-3].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);/*X-overwrites-A*/}
+        break;
+      case 111: /* on_opt ::= ON expr */
+      case 128: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==128);
+      case 135: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==135);
+      case 196: /* case_else ::= ELSE expr */ yytestcase(yyruleno==196);
+{yymsp[-1].minor.yy72 = yymsp[0].minor.yy190.pExpr;}
+        break;
+      case 112: /* on_opt ::= */
+      case 127: /* having_opt ::= */ yytestcase(yyruleno==127);
+      case 134: /* where_opt ::= */ yytestcase(yyruleno==134);
+      case 197: /* case_else ::= */ yytestcase(yyruleno==197);
+      case 199: /* case_operand ::= */ yytestcase(yyruleno==199);
+{yymsp[1].minor.yy72 = 0;}
+        break;
+      case 114: /* indexed_opt ::= INDEXED BY nm */
+{yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;}
+        break;
+      case 115: /* indexed_opt ::= NOT INDEXED */
+{yymsp[-1].minor.yy0.z=0; yymsp[-1].minor.yy0.n=1;}
+        break;
+      case 116: /* using_opt ::= USING LP idlist RP */
+{yymsp[-3].minor.yy254 = yymsp[-1].minor.yy254;}
+        break;
+      case 117: /* using_opt ::= */
+      case 145: /* idlist_opt ::= */ yytestcase(yyruleno==145);
+{yymsp[1].minor.yy254 = 0;}
+        break;
+      case 119: /* orderby_opt ::= ORDER BY sortlist */
+      case 126: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==126);
+{yymsp[-2].minor.yy148 = yymsp[0].minor.yy148;}
+        break;
+      case 120: /* sortlist ::= sortlist COMMA expr sortorder */
+{
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148,yymsp[-1].minor.yy190.pExpr);
+  sqlite3ExprListSetSortOrder(yymsp[-3].minor.yy148,yymsp[0].minor.yy194);
+}
+        break;
+      case 121: /* sortlist ::= expr sortorder */
+{
+  yymsp[-1].minor.yy148 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy190.pExpr); /*A-overwrites-Y*/
+  sqlite3ExprListSetSortOrder(yymsp[-1].minor.yy148,yymsp[0].minor.yy194);
+}
+        break;
+      case 122: /* sortorder ::= ASC */
+{yymsp[0].minor.yy194 = SQLITE_SO_ASC;}
+        break;
+      case 123: /* sortorder ::= DESC */
+{yymsp[0].minor.yy194 = SQLITE_SO_DESC;}
+        break;
+      case 124: /* sortorder ::= */
+{yymsp[1].minor.yy194 = SQLITE_SO_UNDEFINED;}
+        break;
+      case 129: /* limit_opt ::= */
+{yymsp[1].minor.yy354.pLimit = 0; yymsp[1].minor.yy354.pOffset = 0;}
+        break;
+      case 130: /* limit_opt ::= LIMIT expr */
+{yymsp[-1].minor.yy354.pLimit = yymsp[0].minor.yy190.pExpr; yymsp[-1].minor.yy354.pOffset = 0;}
+        break;
+      case 131: /* limit_opt ::= LIMIT expr OFFSET expr */
+{yymsp[-3].minor.yy354.pLimit = yymsp[-2].minor.yy190.pExpr; yymsp[-3].minor.yy354.pOffset = yymsp[0].minor.yy190.pExpr;}
+        break;
+      case 132: /* limit_opt ::= LIMIT expr COMMA expr */
+{yymsp[-3].minor.yy354.pOffset = yymsp[-2].minor.yy190.pExpr; yymsp[-3].minor.yy354.pLimit = yymsp[0].minor.yy190.pExpr;}
+        break;
+      case 133: /* cmd ::= with DELETE FROM fullname indexed_opt where_opt */
+{
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy285, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy185, &yymsp[-1].minor.yy0);
+  sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy185,yymsp[0].minor.yy72);
+}
+        break;
+      case 136: /* cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt */
+{
+  sqlite3WithPush(pParse, yymsp[-7].minor.yy285, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy185, &yymsp[-3].minor.yy0);
+  sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy148,"set list"); 
+  sqlite3Update(pParse,yymsp[-4].minor.yy185,yymsp[-1].minor.yy148,yymsp[0].minor.yy72,yymsp[-5].minor.yy194);
+}
+        break;
+      case 137: /* setlist ::= setlist COMMA nm EQ expr */
+{
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy148, yymsp[0].minor.yy190.pExpr);
+  sqlite3ExprListSetName(pParse, yymsp[-4].minor.yy148, &yymsp[-2].minor.yy0, 1);
+}
+        break;
+      case 138: /* setlist ::= setlist COMMA LP idlist RP EQ expr */
+{
+  yymsp[-6].minor.yy148 = sqlite3ExprListAppendVector(pParse, yymsp[-6].minor.yy148, yymsp[-3].minor.yy254, yymsp[0].minor.yy190.pExpr);
+}
+        break;
+      case 139: /* setlist ::= nm EQ expr */
+{
+  yylhsminor.yy148 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy190.pExpr);
+  sqlite3ExprListSetName(pParse, yylhsminor.yy148, &yymsp[-2].minor.yy0, 1);
+}
+  yymsp[-2].minor.yy148 = yylhsminor.yy148;
+        break;
+      case 140: /* setlist ::= LP idlist RP EQ expr */
+{
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppendVector(pParse, 0, yymsp[-3].minor.yy254, yymsp[0].minor.yy190.pExpr);
+}
+        break;
+      case 141: /* cmd ::= with insert_cmd INTO fullname idlist_opt select */
+{
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy285, 1);
+  sqlite3Insert(pParse, yymsp[-2].minor.yy185, yymsp[0].minor.yy243, yymsp[-1].minor.yy254, yymsp[-4].minor.yy194);
+}
+        break;
+      case 142: /* cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES */
+{
+  sqlite3WithPush(pParse, yymsp[-6].minor.yy285, 1);
+  sqlite3Insert(pParse, yymsp[-3].minor.yy185, 0, yymsp[-2].minor.yy254, yymsp[-5].minor.yy194);
+}
+        break;
+      case 146: /* idlist_opt ::= LP idlist RP */
+{yymsp[-2].minor.yy254 = yymsp[-1].minor.yy254;}
+        break;
+      case 147: /* idlist ::= idlist COMMA nm */
+{yymsp[-2].minor.yy254 = sqlite3IdListAppend(pParse->db,yymsp[-2].minor.yy254,&yymsp[0].minor.yy0);}
+        break;
+      case 148: /* idlist ::= nm */
+{yymsp[0].minor.yy254 = sqlite3IdListAppend(pParse->db,0,&yymsp[0].minor.yy0); /*A-overwrites-Y*/}
+        break;
+      case 149: /* expr ::= LP expr RP */
+{spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/  yymsp[-2].minor.yy190.pExpr = yymsp[-1].minor.yy190.pExpr;}
+        break;
+      case 150: /* expr ::= ID|INDEXED */
+      case 151: /* expr ::= JOIN_KW */ yytestcase(yyruleno==151);
+{spanExpr(&yymsp[0].minor.yy190,pParse,TK_ID,yymsp[0].minor.yy0); /*A-overwrites-X*/}
+        break;
+      case 152: /* expr ::= nm DOT nm */
+{
+  Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);
+  Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[0].minor.yy0, 1);
+  spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-2].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp2);
+}
+        break;
+      case 153: /* expr ::= nm DOT nm DOT nm */
+{
+  Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-4].minor.yy0, 1);
+  Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);
+  Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[0].minor.yy0, 1);
+  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3);
+  spanSet(&yymsp[-4].minor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4);
+}
+        break;
+      case 154: /* term ::= NULL|FLOAT|BLOB */
+      case 155: /* term ::= STRING */ yytestcase(yyruleno==155);
+{spanExpr(&yymsp[0].minor.yy190,pParse,yymsp[0].major,yymsp[0].minor.yy0); /*A-overwrites-X*/}
+        break;
+      case 156: /* term ::= INTEGER */
+{
+  yylhsminor.yy190.pExpr = sqlite3ExprAlloc(pParse->db, TK_INTEGER, &yymsp[0].minor.yy0, 1);
+  yylhsminor.yy190.zStart = yymsp[0].minor.yy0.z;
+  yylhsminor.yy190.zEnd = yymsp[0].minor.yy0.z + yymsp[0].minor.yy0.n;
+}
+  yymsp[0].minor.yy190 = yylhsminor.yy190;
+        break;
+      case 157: /* expr ::= VARIABLE */
+{
+  if( !(yymsp[0].minor.yy0.z[0]=='#' && sqlite3Isdigit(yymsp[0].minor.yy0.z[1])) ){
+    u32 n = yymsp[0].minor.yy0.n;
+    spanExpr(&yymsp[0].minor.yy190, pParse, TK_VARIABLE, yymsp[0].minor.yy0);
+    sqlite3ExprAssignVarNumber(pParse, yymsp[0].minor.yy190.pExpr, n);
+  }else{
+    /* When doing a nested parse, one can include terms in an expression
+    ** that look like this:   #1 #2 ...  These terms refer to registers
+    ** in the virtual machine.  #N is the N-th register. */
+    Token t = yymsp[0].minor.yy0; /*A-overwrites-X*/
+    assert( t.n>=2 );
+    spanSet(&yymsp[0].minor.yy190, &t, &t);
+    if( pParse->nested==0 ){
+      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);
+      yymsp[0].minor.yy190.pExpr = 0;
+    }else{
+      yymsp[0].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0);
+      if( yymsp[0].minor.yy190.pExpr ) sqlite3GetInt32(&t.z[1], &yymsp[0].minor.yy190.pExpr->iTable);
+    }
+  }
+}
+        break;
+      case 158: /* expr ::= expr COLLATE ID|STRING */
+{
+  yymsp[-2].minor.yy190.pExpr = sqlite3ExprAddCollateToken(pParse, yymsp[-2].minor.yy190.pExpr, &yymsp[0].minor.yy0, 1);
+  yymsp[-2].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+}
+        break;
+      case 159: /* expr ::= CAST LP expr AS typetoken RP */
+{
+  spanSet(&yymsp[-5].minor.yy190,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-5].minor.yy190.pExpr = sqlite3ExprAlloc(pParse->db, TK_CAST, &yymsp[-1].minor.yy0, 1);
+  sqlite3ExprAttachSubtrees(pParse->db, yymsp[-5].minor.yy190.pExpr, yymsp[-3].minor.yy190.pExpr, 0);
+}
+        break;
+      case 160: /* expr ::= ID|INDEXED LP distinct exprlist RP */
+{
+  if( yymsp[-1].minor.yy148 && yymsp[-1].minor.yy148->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
+    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &yymsp[-4].minor.yy0);
+  }
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy148, &yymsp[-4].minor.yy0);
+  spanSet(&yylhsminor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
+  if( yymsp[-2].minor.yy194==SF_Distinct && yylhsminor.yy190.pExpr ){
+    yylhsminor.yy190.pExpr->flags |= EP_Distinct;
+  }
+}
+  yymsp[-4].minor.yy190 = yylhsminor.yy190;
+        break;
+      case 161: /* expr ::= ID|INDEXED LP STAR RP */
+{
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0);
+  spanSet(&yylhsminor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);
+}
+  yymsp[-3].minor.yy190 = yylhsminor.yy190;
+        break;
+      case 162: /* term ::= CTIME_KW */
+{
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[0].minor.yy0);
+  spanSet(&yylhsminor.yy190, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
+}
+  yymsp[0].minor.yy190 = yylhsminor.yy190;
+        break;
+      case 163: /* expr ::= LP nexprlist COMMA expr RP */
+{
+  ExprList *pList = sqlite3ExprListAppend(pParse, yymsp[-3].minor.yy148, yymsp[-1].minor.yy190.pExpr);
+  yylhsminor.yy190.pExpr = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
+  if( yylhsminor.yy190.pExpr ){
+    yylhsminor.yy190.pExpr->x.pList = pList;
+    spanSet(&yylhsminor.yy190, &yymsp[-4].minor.yy0, &yymsp[0].minor.yy0);
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  }
+}
+  yymsp[-4].minor.yy190 = yylhsminor.yy190;
+        break;
+      case 164: /* expr ::= expr AND expr */
+      case 165: /* expr ::= expr OR expr */ yytestcase(yyruleno==165);
+      case 166: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==166);
+      case 167: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==167);
+      case 168: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==168);
+      case 169: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==169);
+      case 170: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==170);
+      case 171: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==171);
+{spanBinaryExpr(pParse,yymsp[-1].major,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy190);}
+        break;
+      case 172: /* likeop ::= NOT LIKE_KW|MATCH */
+{yymsp[-1].minor.yy0=yymsp[0].minor.yy0; yymsp[-1].minor.yy0.n|=0x80000000; /*yymsp[-1].minor.yy0-overwrite-yymsp[0].minor.yy0*/}
+        break;
+      case 173: /* expr ::= expr likeop expr */
+{
+  ExprList *pList;
+  int bNot = yymsp[-1].minor.yy0.n & 0x80000000;
+  yymsp[-1].minor.yy0.n &= 0x7fffffff;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-2].minor.yy190.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy0);
+  exprNot(pParse, bNot, &yymsp[-2].minor.yy190);
+  yymsp[-2].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
+  if( yymsp[-2].minor.yy190.pExpr ) yymsp[-2].minor.yy190.pExpr->flags |= EP_InfixFunc;
+}
+        break;
+      case 174: /* expr ::= expr likeop expr ESCAPE expr */
+{
+  ExprList *pList;
+  int bNot = yymsp[-3].minor.yy0.n & 0x80000000;
+  yymsp[-3].minor.yy0.n &= 0x7fffffff;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy190.pExpr);
+  yymsp[-4].minor.yy190.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy0);
+  exprNot(pParse, bNot, &yymsp[-4].minor.yy190);
+  yymsp[-4].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
+  if( yymsp[-4].minor.yy190.pExpr ) yymsp[-4].minor.yy190.pExpr->flags |= EP_InfixFunc;
+}
+        break;
+      case 175: /* expr ::= expr ISNULL|NOTNULL */
+{spanUnaryPostfix(pParse,yymsp[0].major,&yymsp[-1].minor.yy190,&yymsp[0].minor.yy0);}
+        break;
+      case 176: /* expr ::= expr NOT NULL */
+{spanUnaryPostfix(pParse,TK_NOTNULL,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy0);}
+        break;
+      case 177: /* expr ::= expr IS expr */
+{
+  spanBinaryExpr(pParse,TK_IS,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy190);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy190.pExpr, yymsp[-2].minor.yy190.pExpr, TK_ISNULL);
+}
+        break;
+      case 178: /* expr ::= expr IS NOT expr */
+{
+  spanBinaryExpr(pParse,TK_ISNOT,&yymsp[-3].minor.yy190,&yymsp[0].minor.yy190);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy190.pExpr, yymsp[-3].minor.yy190.pExpr, TK_NOTNULL);
+}
+        break;
+      case 179: /* expr ::= NOT expr */
+      case 180: /* expr ::= BITNOT expr */ yytestcase(yyruleno==180);
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,yymsp[-1].major,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
+        break;
+      case 181: /* expr ::= MINUS expr */
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,TK_UMINUS,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
+        break;
+      case 182: /* expr ::= PLUS expr */
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,TK_UPLUS,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
+        break;
+      case 183: /* between_op ::= BETWEEN */
+      case 186: /* in_op ::= IN */ yytestcase(yyruleno==186);
+{yymsp[0].minor.yy194 = 0;}
+        break;
+      case 185: /* expr ::= expr between_op expr AND expr */
+{
+  ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy190.pExpr);
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy190.pExpr, 0);
+  if( yymsp[-4].minor.yy190.pExpr ){
+    yymsp[-4].minor.yy190.pExpr->x.pList = pList;
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  } 
+  exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+  yymsp[-4].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
+}
+        break;
+      case 188: /* expr ::= expr in_op LP exprlist RP */
+{
+    if( yymsp[-1].minor.yy148==0 ){
+      /* Expressions of the form
+      **
+      **      expr1 IN ()
+      **      expr1 NOT IN ()
+      **
+      ** simplify to constants 0 (false) and 1 (true), respectively,
+      ** regardless of the value of expr1.
+      */
+      sqlite3ExprDelete(pParse->db, yymsp[-4].minor.yy190.pExpr);
+      yymsp[-4].minor.yy190.pExpr = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[yymsp[-3].minor.yy194],1);
+    }else if( yymsp[-1].minor.yy148->nExpr==1 ){
+      /* Expressions of the form:
+      **
+      **      expr1 IN (?1)
+      **      expr1 NOT IN (?2)
+      **
+      ** with exactly one value on the RHS can be simplified to something
+      ** like this:
+      **
+      **      expr1 == ?1
+      **      expr1 <> ?2
+      **
+      ** But, the RHS of the == or <> is marked with the EP_Generic flag
+      ** so that it may not contribute to the computation of comparison
+      ** affinity or the collating sequence to use for comparison.  Otherwise,
+      ** the semantics would be subtly different from IN or NOT IN.
+      */
+      Expr *pRHS = yymsp[-1].minor.yy148->a[0].pExpr;
+      yymsp[-1].minor.yy148->a[0].pExpr = 0;
+      sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy148);
+      /* pRHS cannot be NULL because a malloc error would have been detected
+      ** before now and control would have never reached this point */
+      if( ALWAYS(pRHS) ){
+        pRHS->flags &= ~EP_Collate;
+        pRHS->flags |= EP_Generic;
+      }
+      yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, yymsp[-3].minor.yy194 ? TK_NE : TK_EQ, yymsp[-4].minor.yy190.pExpr, pRHS);
+    }else{
+      yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0);
+      if( yymsp[-4].minor.yy190.pExpr ){
+        yymsp[-4].minor.yy190.pExpr->x.pList = yymsp[-1].minor.yy148;
+        sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy190.pExpr);
+      }else{
+        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy148);
+      }
+      exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+    }
+    yymsp[-4].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 189: /* expr ::= LP select RP */
+{
+    spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/
+    yymsp[-2].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-2].minor.yy190.pExpr, yymsp[-1].minor.yy243);
+  }
+        break;
+      case 190: /* expr ::= expr in_op LP select RP */
+{
+    yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy190.pExpr, yymsp[-1].minor.yy243);
+    exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+    yymsp[-4].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 191: /* expr ::= expr in_op nm dbnm paren_exprlist */
+{
+    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);
+    Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
+    if( yymsp[0].minor.yy148 )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, yymsp[0].minor.yy148);
+    yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy190.pExpr, pSelect);
+    exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+    yymsp[-4].minor.yy190.zEnd = yymsp[-1].minor.yy0.z ? &yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n] : &yymsp[-2].minor.yy0.z[yymsp[-2].minor.yy0.n];
+  }
+        break;
+      case 192: /* expr ::= EXISTS LP select RP */
+{
+    Expr *p;
+    spanSet(&yymsp[-3].minor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/
+    p = yymsp[-3].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0);
+    sqlite3PExprAddSelect(pParse, p, yymsp[-1].minor.yy243);
+  }
+        break;
+      case 193: /* expr ::= CASE case_operand case_exprlist case_else END */
+{
+  spanSet(&yymsp[-4].minor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-C*/
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy72, 0);
+  if( yymsp[-4].minor.yy190.pExpr ){
+    yymsp[-4].minor.yy190.pExpr->x.pList = yymsp[-1].minor.yy72 ? sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy148,yymsp[-1].minor.yy72) : yymsp[-2].minor.yy148;
+    sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy190.pExpr);
+  }else{
+    sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy148);
+    sqlite3ExprDelete(pParse->db, yymsp[-1].minor.yy72);
+  }
+}
+        break;
+      case 194: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */
+{
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy148, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy148, yymsp[0].minor.yy190.pExpr);
+}
+        break;
+      case 195: /* case_exprlist ::= WHEN expr THEN expr */
+{
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148, yymsp[0].minor.yy190.pExpr);
+}
+        break;
+      case 198: /* case_operand ::= expr */
+{yymsp[0].minor.yy72 = yymsp[0].minor.yy190.pExpr; /*A-overwrites-X*/}
+        break;
+      case 201: /* nexprlist ::= nexprlist COMMA expr */
+{yymsp[-2].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy148,yymsp[0].minor.yy190.pExpr);}
+        break;
+      case 202: /* nexprlist ::= expr */
+{yymsp[0].minor.yy148 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy190.pExpr); /*A-overwrites-Y*/}
+        break;
+      case 204: /* paren_exprlist ::= LP exprlist RP */
+      case 209: /* eidlist_opt ::= LP eidlist RP */ yytestcase(yyruleno==209);
+{yymsp[-2].minor.yy148 = yymsp[-1].minor.yy148;}
+        break;
+      case 205: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */
+{
+  sqlite3CreateIndex(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, 
+                     sqlite3SrcListAppend(pParse->db,0,&yymsp[-4].minor.yy0,0), yymsp[-2].minor.yy148, yymsp[-10].minor.yy194,
+                      &yymsp[-11].minor.yy0, yymsp[0].minor.yy72, SQLITE_SO_ASC, yymsp[-8].minor.yy194, SQLITE_IDXTYPE_APPDEF);
+}
+        break;
+      case 206: /* uniqueflag ::= UNIQUE */
+      case 246: /* raisetype ::= ABORT */ yytestcase(yyruleno==246);
+{yymsp[0].minor.yy194 = OE_Abort;}
+        break;
+      case 207: /* uniqueflag ::= */
+{yymsp[1].minor.yy194 = OE_None;}
+        break;
+      case 210: /* eidlist ::= eidlist COMMA nm collate sortorder */
+{
+  yymsp[-4].minor.yy148 = parserAddExprIdListTerm(pParse, yymsp[-4].minor.yy148, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy194, yymsp[0].minor.yy194);
+}
+        break;
+      case 211: /* eidlist ::= nm collate sortorder */
+{
+  yymsp[-2].minor.yy148 = parserAddExprIdListTerm(pParse, 0, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy194, yymsp[0].minor.yy194); /*A-overwrites-Y*/
+}
+        break;
+      case 214: /* cmd ::= DROP INDEX ifexists fullname */
+{sqlite3DropIndex(pParse, yymsp[0].minor.yy185, yymsp[-1].minor.yy194);}
+        break;
+      case 215: /* cmd ::= VACUUM */
+{sqlite3Vacuum(pParse,0);}
+        break;
+      case 216: /* cmd ::= VACUUM nm */
+{sqlite3Vacuum(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 217: /* cmd ::= PRAGMA nm dbnm */
+{sqlite3Pragma(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0,0);}
+        break;
+      case 218: /* cmd ::= PRAGMA nm dbnm EQ nmnum */
+{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,0);}
+        break;
+      case 219: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */
+{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,0);}
+        break;
+      case 220: /* cmd ::= PRAGMA nm dbnm EQ minus_num */
+{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,1);}
+        break;
+      case 221: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */
+{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,1);}
+        break;
+      case 224: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */
+{
+  Token all;
+  all.z = yymsp[-3].minor.yy0.z;
+  all.n = (int)(yymsp[0].minor.yy0.z - yymsp[-3].minor.yy0.z) + yymsp[0].minor.yy0.n;
+  sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy145, &all);
+}
+        break;
+      case 225: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */
+{
+  sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy194, yymsp[-4].minor.yy332.a, yymsp[-4].minor.yy332.b, yymsp[-2].minor.yy185, yymsp[0].minor.yy72, yymsp[-10].minor.yy194, yymsp[-8].minor.yy194);
+  yymsp[-10].minor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0); /*A-overwrites-T*/
+}
+        break;
+      case 226: /* trigger_time ::= BEFORE|AFTER */
+{ yymsp[0].minor.yy194 = yymsp[0].major; /*A-overwrites-X*/ }
+        break;
+      case 227: /* trigger_time ::= INSTEAD OF */
+{ yymsp[-1].minor.yy194 = TK_INSTEAD;}
+        break;
+      case 228: /* trigger_time ::= */
+{ yymsp[1].minor.yy194 = TK_BEFORE; }
+        break;
+      case 229: /* trigger_event ::= DELETE|INSERT */
+      case 230: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==230);
+{yymsp[0].minor.yy332.a = yymsp[0].major; /*A-overwrites-X*/ yymsp[0].minor.yy332.b = 0;}
+        break;
+      case 231: /* trigger_event ::= UPDATE OF idlist */
+{yymsp[-2].minor.yy332.a = TK_UPDATE; yymsp[-2].minor.yy332.b = yymsp[0].minor.yy254;}
+        break;
+      case 232: /* when_clause ::= */
+      case 251: /* key_opt ::= */ yytestcase(yyruleno==251);
+{ yymsp[1].minor.yy72 = 0; }
+        break;
+      case 233: /* when_clause ::= WHEN expr */
+      case 252: /* key_opt ::= KEY expr */ yytestcase(yyruleno==252);
+{ yymsp[-1].minor.yy72 = yymsp[0].minor.yy190.pExpr; }
+        break;
+      case 234: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */
+{
+  assert( yymsp[-2].minor.yy145!=0 );
+  yymsp[-2].minor.yy145->pLast->pNext = yymsp[-1].minor.yy145;
+  yymsp[-2].minor.yy145->pLast = yymsp[-1].minor.yy145;
+}
+        break;
+      case 235: /* trigger_cmd_list ::= trigger_cmd SEMI */
+{ 
+  assert( yymsp[-1].minor.yy145!=0 );
+  yymsp[-1].minor.yy145->pLast = yymsp[-1].minor.yy145;
+}
+        break;
+      case 236: /* trnm ::= nm DOT nm */
+{
+  yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;
+  sqlite3ErrorMsg(pParse, 
+        "qualified table names are not allowed on INSERT, UPDATE, and DELETE "
+        "statements within triggers");
+}
+        break;
+      case 237: /* tridxby ::= INDEXED BY nm */
+{
+  sqlite3ErrorMsg(pParse,
+        "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "
+        "within triggers");
+}
+        break;
+      case 238: /* tridxby ::= NOT INDEXED */
+{
+  sqlite3ErrorMsg(pParse,
+        "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "
+        "within triggers");
+}
+        break;
+      case 239: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt */
+{yymsp[-6].minor.yy145 = sqlite3TriggerUpdateStep(pParse->db, &yymsp[-4].minor.yy0, yymsp[-1].minor.yy148, yymsp[0].minor.yy72, yymsp[-5].minor.yy194);}
+        break;
+      case 240: /* trigger_cmd ::= insert_cmd INTO trnm idlist_opt select */
+{yymsp[-4].minor.yy145 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy254, yymsp[0].minor.yy243, yymsp[-4].minor.yy194);/*A-overwrites-R*/}
+        break;
+      case 241: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt */
+{yymsp[-4].minor.yy145 = sqlite3TriggerDeleteStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[0].minor.yy72);}
+        break;
+      case 242: /* trigger_cmd ::= select */
+{yymsp[0].minor.yy145 = sqlite3TriggerSelectStep(pParse->db, yymsp[0].minor.yy243); /*A-overwrites-X*/}
+        break;
+      case 243: /* expr ::= RAISE LP IGNORE RP */
+{
+  spanSet(&yymsp[-3].minor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-X*/
+  yymsp[-3].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0); 
+  if( yymsp[-3].minor.yy190.pExpr ){
+    yymsp[-3].minor.yy190.pExpr->affinity = OE_Ignore;
+  }
+}
+        break;
+      case 244: /* expr ::= RAISE LP raisetype COMMA nm RP */
+{
+  spanSet(&yymsp[-5].minor.yy190,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-X*/
+  yymsp[-5].minor.yy190.pExpr = sqlite3ExprAlloc(pParse->db, TK_RAISE, &yymsp[-1].minor.yy0, 1); 
+  if( yymsp[-5].minor.yy190.pExpr ) {
+    yymsp[-5].minor.yy190.pExpr->affinity = (char)yymsp[-3].minor.yy194;
+  }
+}
+        break;
+      case 245: /* raisetype ::= ROLLBACK */
+{yymsp[0].minor.yy194 = OE_Rollback;}
+        break;
+      case 247: /* raisetype ::= FAIL */
+{yymsp[0].minor.yy194 = OE_Fail;}
+        break;
+      case 248: /* cmd ::= DROP TRIGGER ifexists fullname */
+{
+  sqlite3DropTrigger(pParse,yymsp[0].minor.yy185,yymsp[-1].minor.yy194);
+}
+        break;
+      case 249: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */
+{
+  sqlite3Attach(pParse, yymsp[-3].minor.yy190.pExpr, yymsp[-1].minor.yy190.pExpr, yymsp[0].minor.yy72);
+}
+        break;
+      case 250: /* cmd ::= DETACH database_kw_opt expr */
+{
+  sqlite3Detach(pParse, yymsp[0].minor.yy190.pExpr);
+}
+        break;
+      case 253: /* cmd ::= REINDEX */
+{sqlite3Reindex(pParse, 0, 0);}
+        break;
+      case 254: /* cmd ::= REINDEX nm dbnm */
+{sqlite3Reindex(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
+        break;
+      case 255: /* cmd ::= ANALYZE */
+{sqlite3Analyze(pParse, 0, 0);}
+        break;
+      case 256: /* cmd ::= ANALYZE nm dbnm */
+{sqlite3Analyze(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
+        break;
+      case 257: /* cmd ::= ALTER TABLE fullname RENAME TO nm */
+{
+  sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy185,&yymsp[0].minor.yy0);
+}
+        break;
+      case 258: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist */
+{
+  yymsp[-1].minor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-1].minor.yy0.z) + pParse->sLastToken.n;
+  sqlite3AlterFinishAddColumn(pParse, &yymsp[-1].minor.yy0);
+}
+        break;
+      case 259: /* add_column_fullname ::= fullname */
+{
+  disableLookaside(pParse);
+  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy185);
+}
+        break;
+      case 260: /* cmd ::= create_vtab */
+{sqlite3VtabFinishParse(pParse,0);}
+        break;
+      case 261: /* cmd ::= create_vtab LP vtabarglist RP */
+{sqlite3VtabFinishParse(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 262: /* create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */
+{
+    sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0, yymsp[-4].minor.yy194);
+}
+        break;
+      case 263: /* vtabarg ::= */
+{sqlite3VtabArgInit(pParse);}
+        break;
+      case 264: /* vtabargtoken ::= ANY */
+      case 265: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==265);
+      case 266: /* lp ::= LP */ yytestcase(yyruleno==266);
+{sqlite3VtabArgExtend(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 267: /* with ::= */
+{yymsp[1].minor.yy285 = 0;}
+        break;
+      case 268: /* with ::= WITH wqlist */
+{ yymsp[-1].minor.yy285 = yymsp[0].minor.yy285; }
+        break;
+      case 269: /* with ::= WITH RECURSIVE wqlist */
+{ yymsp[-2].minor.yy285 = yymsp[0].minor.yy285; }
+        break;
+      case 270: /* wqlist ::= nm eidlist_opt AS LP select RP */
+{
+  yymsp[-5].minor.yy285 = sqlite3WithAdd(pParse, 0, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy148, yymsp[-1].minor.yy243); /*A-overwrites-X*/
+}
+        break;
+      case 271: /* wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */
+{
+  yymsp[-7].minor.yy285 = sqlite3WithAdd(pParse, yymsp[-7].minor.yy285, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy148, yymsp[-1].minor.yy243);
+}
+        break;
+      default:
+      /* (272) input ::= cmdlist */ yytestcase(yyruleno==272);
+      /* (273) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==273);
+      /* (274) cmdlist ::= ecmd (OPTIMIZED OUT) */ assert(yyruleno!=274);
+      /* (275) ecmd ::= SEMI */ yytestcase(yyruleno==275);
+      /* (276) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==276);
+      /* (277) explain ::= */ yytestcase(yyruleno==277);
+      /* (278) trans_opt ::= */ yytestcase(yyruleno==278);
+      /* (279) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==279);
+      /* (280) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==280);
+      /* (281) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==281);
+      /* (282) savepoint_opt ::= */ yytestcase(yyruleno==282);
+      /* (283) cmd ::= create_table create_table_args */ yytestcase(yyruleno==283);
+      /* (284) columnlist ::= columnlist COMMA columnname carglist */ yytestcase(yyruleno==284);
+      /* (285) columnlist ::= columnname carglist */ yytestcase(yyruleno==285);
+      /* (286) nm ::= ID|INDEXED */ yytestcase(yyruleno==286);
+      /* (287) nm ::= STRING */ yytestcase(yyruleno==287);
+      /* (288) nm ::= JOIN_KW */ yytestcase(yyruleno==288);
+      /* (289) typetoken ::= typename */ yytestcase(yyruleno==289);
+      /* (290) typename ::= ID|STRING */ yytestcase(yyruleno==290);
+      /* (291) signed ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=291);
+      /* (292) signed ::= minus_num (OPTIMIZED OUT) */ assert(yyruleno!=292);
+      /* (293) carglist ::= carglist ccons */ yytestcase(yyruleno==293);
+      /* (294) carglist ::= */ yytestcase(yyruleno==294);
+      /* (295) ccons ::= NULL onconf */ yytestcase(yyruleno==295);
+      /* (296) conslist_opt ::= COMMA conslist */ yytestcase(yyruleno==296);
+      /* (297) conslist ::= conslist tconscomma tcons */ yytestcase(yyruleno==297);
+      /* (298) conslist ::= tcons (OPTIMIZED OUT) */ assert(yyruleno!=298);
+      /* (299) tconscomma ::= */ yytestcase(yyruleno==299);
+      /* (300) defer_subclause_opt ::= defer_subclause (OPTIMIZED OUT) */ assert(yyruleno!=300);
+      /* (301) resolvetype ::= raisetype (OPTIMIZED OUT) */ assert(yyruleno!=301);
+      /* (302) selectnowith ::= oneselect (OPTIMIZED OUT) */ assert(yyruleno!=302);
+      /* (303) oneselect ::= values */ yytestcase(yyruleno==303);
+      /* (304) sclp ::= selcollist COMMA */ yytestcase(yyruleno==304);
+      /* (305) as ::= ID|STRING */ yytestcase(yyruleno==305);
+      /* (306) expr ::= term (OPTIMIZED OUT) */ assert(yyruleno!=306);
+      /* (307) likeop ::= LIKE_KW|MATCH */ yytestcase(yyruleno==307);
+      /* (308) exprlist ::= nexprlist */ yytestcase(yyruleno==308);
+      /* (309) nmnum ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=309);
+      /* (310) nmnum ::= nm (OPTIMIZED OUT) */ assert(yyruleno!=310);
+      /* (311) nmnum ::= ON */ yytestcase(yyruleno==311);
+      /* (312) nmnum ::= DELETE */ yytestcase(yyruleno==312);
+      /* (313) nmnum ::= DEFAULT */ yytestcase(yyruleno==313);
+      /* (314) plus_num ::= INTEGER|FLOAT */ yytestcase(yyruleno==314);
+      /* (315) foreach_clause ::= */ yytestcase(yyruleno==315);
+      /* (316) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==316);
+      /* (317) trnm ::= nm */ yytestcase(yyruleno==317);
+      /* (318) tridxby ::= */ yytestcase(yyruleno==318);
+      /* (319) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==319);
+      /* (320) database_kw_opt ::= */ yytestcase(yyruleno==320);
+      /* (321) kwcolumn_opt ::= */ yytestcase(yyruleno==321);
+      /* (322) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==322);
+      /* (323) vtabarglist ::= vtabarg */ yytestcase(yyruleno==323);
+      /* (324) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==324);
+      /* (325) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==325);
+      /* (326) anylist ::= */ yytestcase(yyruleno==326);
+      /* (327) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==327);
+      /* (328) anylist ::= anylist ANY */ yytestcase(yyruleno==328);
+        break;
+/********** End reduce actions ************************************************/
+  };
+  assert( yyrulenoYY_MAX_SHIFT && yyact<=YY_MAX_SHIFTREDUCE) );
+
+  /* It is not possible for a REDUCE to be followed by an error */
+  assert( yyact!=YY_ERROR_ACTION );
+
+  if( yyact==YY_ACCEPT_ACTION ){
+    yypParser->yytos += yysize;
+    yy_accept(yypParser);
+  }else{
+    yymsp += yysize+1;
+    yypParser->yytos = yymsp;
+    yymsp->stateno = (YYACTIONTYPE)yyact;
+    yymsp->major = (YYCODETYPE)yygoto;
+    yyTraceShift(yypParser, yyact);
+  }
+}
+
+/*
+** The following code executes when the parse fails
+*/
+#ifndef YYNOERRORRECOVERY
+static void yy_parse_failed(
+  yyParser *yypParser           /* The parser */
+){
+  sqlite3ParserARG_FETCH;
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt);
+  }
+#endif
+  while( yypParser->yytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);
+  /* Here code is inserted which will be executed whenever the
+  ** parser fails */
+/************ Begin %parse_failure code ***************************************/
+/************ End %parse_failure code *****************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+#endif /* YYNOERRORRECOVERY */
+
+/*
+** The following code executes when a syntax error first occurs.
+*/
+static void yy_syntax_error(
+  yyParser *yypParser,           /* The parser */
+  int yymajor,                   /* The major type of the error token */
+  sqlite3ParserTOKENTYPE yyminor         /* The minor type of the error token */
+){
+  sqlite3ParserARG_FETCH;
+#define TOKEN yyminor
+/************ Begin %syntax_error code ****************************************/
+
+  UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */
+  assert( TOKEN.z[0] );  /* The tokenizer always gives us a token */
+  sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
+/************ End %syntax_error code ******************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/*
+** The following is executed when the parser accepts
+*/
+static void yy_accept(
+  yyParser *yypParser           /* The parser */
+){
+  sqlite3ParserARG_FETCH;
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sAccept!\n",yyTracePrompt);
+  }
+#endif
+#ifndef YYNOERRORRECOVERY
+  yypParser->yyerrcnt = -1;
+#endif
+  assert( yypParser->yytos==yypParser->yystack );
+  /* Here code is inserted which will be executed whenever the
+  ** parser accepts */
+/*********** Begin %parse_accept code *****************************************/
+/*********** End %parse_accept code *******************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/* The main parser program.
+** The first argument is a pointer to a structure obtained from
+** "sqlite3ParserAlloc" which describes the current state of the parser.
+** The second argument is the major token number.  The third is
+** the minor token.  The fourth optional argument is whatever the
+** user wants (and specified in the grammar) and is available for
+** use by the action routines.
+**
+** Inputs:
+** 
      
+** 
    •  A pointer to the parser (an opaque structure.)
+** 
    •  The major token number.
+** 
    •  The minor token number.
+** 
    •  An option argument of a grammar-specified type.
+** 
    
+**
+** Outputs:
+** None.
+*/
+SQLITE_PRIVATE void sqlite3Parser(
+  void *yyp,                   /* The parser */
+  int yymajor,                 /* The major token code number */
+  sqlite3ParserTOKENTYPE yyminor       /* The value for the token */
+  sqlite3ParserARG_PDECL               /* Optional %extra_argument parameter */
+){
+  YYMINORTYPE yyminorunion;
+  unsigned int yyact;   /* The parser action. */
+#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
+  int yyendofinput;     /* True if we are at the end of input */
+#endif
+#ifdef YYERRORSYMBOL
+  int yyerrorhit = 0;   /* True if yymajor has invoked an error */
+#endif
+  yyParser *yypParser;  /* The parser */
+
+  yypParser = (yyParser*)yyp;
+  assert( yypParser->yytos!=0 );
+#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
+  yyendofinput = (yymajor==0);
+#endif
+  sqlite3ParserARG_STORE;
+
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sInput '%s'\n",yyTracePrompt,yyTokenName[yymajor]);
+  }
+#endif
+
+  do{
+    yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
+    if( yyact <= YY_MAX_SHIFTREDUCE ){
+      yy_shift(yypParser,yyact,yymajor,yyminor);
+#ifndef YYNOERRORRECOVERY
+      yypParser->yyerrcnt--;
+#endif
+      yymajor = YYNOCODE;
+    }else if( yyact <= YY_MAX_REDUCE ){
+      yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
+    }else{
+      assert( yyact == YY_ERROR_ACTION );
+      yyminorunion.yy0 = yyminor;
+#ifdef YYERRORSYMBOL
+      int yymx;
+#endif
+#ifndef NDEBUG
+      if( yyTraceFILE ){
+        fprintf(yyTraceFILE,"%sSyntax Error!\n",yyTracePrompt);
+      }
+#endif
+#ifdef YYERRORSYMBOL
+      /* A syntax error has occurred.
+      ** The response to an error depends upon whether or not the
+      ** grammar defines an error token "ERROR".  
+      **
+      ** This is what we do if the grammar does define ERROR:
+      **
+      **  * Call the %syntax_error function.
+      **
+      **  * Begin popping the stack until we enter a state where
+      **    it is legal to shift the error symbol, then shift
+      **    the error symbol.
+      **
+      **  * Set the error count to three.
+      **
+      **  * Begin accepting and shifting new tokens.  No new error
+      **    processing will occur until three tokens have been
+      **    shifted successfully.
+      **
+      */
+      if( yypParser->yyerrcnt<0 ){
+        yy_syntax_error(yypParser,yymajor,yyminor);
+      }
+      yymx = yypParser->yytos->major;
+      if( yymx==YYERRORSYMBOL || yyerrorhit ){
+#ifndef NDEBUG
+        if( yyTraceFILE ){
+          fprintf(yyTraceFILE,"%sDiscard input token %s\n",
+             yyTracePrompt,yyTokenName[yymajor]);
+        }
+#endif
+        yy_destructor(yypParser, (YYCODETYPE)yymajor, &yyminorunion);
+        yymajor = YYNOCODE;
+      }else{
+        while( yypParser->yytos >= yypParser->yystack
+            && yymx != YYERRORSYMBOL
+            && (yyact = yy_find_reduce_action(
+                        yypParser->yytos->stateno,
+                        YYERRORSYMBOL)) >= YY_MIN_REDUCE
+        ){
+          yy_pop_parser_stack(yypParser);
+        }
+        if( yypParser->yytos < yypParser->yystack || yymajor==0 ){
+          yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+          yy_parse_failed(yypParser);
+#ifndef YYNOERRORRECOVERY
+          yypParser->yyerrcnt = -1;
+#endif
+          yymajor = YYNOCODE;
+        }else if( yymx!=YYERRORSYMBOL ){
+          yy_shift(yypParser,yyact,YYERRORSYMBOL,yyminor);
+        }
+      }
+      yypParser->yyerrcnt = 3;
+      yyerrorhit = 1;
+#elif defined(YYNOERRORRECOVERY)
+      /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to
+      ** do any kind of error recovery.  Instead, simply invoke the syntax
+      ** error routine and continue going as if nothing had happened.
+      **
+      ** Applications can set this macro (for example inside %include) if
+      ** they intend to abandon the parse upon the first syntax error seen.
+      */
+      yy_syntax_error(yypParser,yymajor, yyminor);
+      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+      yymajor = YYNOCODE;
+      
+#else  /* YYERRORSYMBOL is not defined */
+      /* This is what we do if the grammar does not define ERROR:
+      **
+      **  * Report an error message, and throw away the input token.
+      **
+      **  * If the input token is $, then fail the parse.
+      **
+      ** As before, subsequent error messages are suppressed until
+      ** three input tokens have been successfully shifted.
+      */
+      if( yypParser->yyerrcnt<=0 ){
+        yy_syntax_error(yypParser,yymajor, yyminor);
+      }
+      yypParser->yyerrcnt = 3;
+      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+      if( yyendofinput ){
+        yy_parse_failed(yypParser);
+#ifndef YYNOERRORRECOVERY
+        yypParser->yyerrcnt = -1;
+#endif
+      }
+      yymajor = YYNOCODE;
+#endif
+    }
+  }while( yymajor!=YYNOCODE && yypParser->yytos>yypParser->yystack );
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    yyStackEntry *i;
+    char cDiv = '[';
+    fprintf(yyTraceFILE,"%sReturn. Stack=",yyTracePrompt);
+    for(i=&yypParser->yystack[1]; i<=yypParser->yytos; i++){
+      fprintf(yyTraceFILE,"%c%s", cDiv, yyTokenName[i->major]);
+      cDiv = ' ';
+    }
+    fprintf(yyTraceFILE,"]\n");
+  }
+#endif
+  return;
+}
+
+/************** End of parse.c ***********************************************/
+/************** Begin file tokenize.c ****************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that splits an SQL input string up into
+** individual tokens and sends those tokens one-by-one over to the
+** parser for analysis.
+*/
+/* #include "sqliteInt.h" */
+/* #include  */
+
+/* Character classes for tokenizing
+**
+** In the sqlite3GetToken() function, a switch() on aiClass[c] is implemented
+** using a lookup table, whereas a switch() directly on c uses a binary search.
+** The lookup table is much faster.  To maximize speed, and to ensure that
+** a lookup table is used, all of the classes need to be small integers and
+** all of them need to be used within the switch.
+*/
+#define CC_X          0    /* The letter 'x', or start of BLOB literal */
+#define CC_KYWD       1    /* Alphabetics or '_'.  Usable in a keyword */
+#define CC_ID         2    /* unicode characters usable in IDs */
+#define CC_DIGIT      3    /* Digits */
+#define CC_DOLLAR     4    /* '$' */
+#define CC_VARALPHA   5    /* '@', '#', ':'.  Alphabetic SQL variables */
+#define CC_VARNUM     6    /* '?'.  Numeric SQL variables */
+#define CC_SPACE      7    /* Space characters */
+#define CC_QUOTE      8    /* '"', '\'', or '`'.  String literals, quoted ids */
+#define CC_QUOTE2     9    /* '['.   [...] style quoted ids */
+#define CC_PIPE      10    /* '|'.   Bitwise OR or concatenate */
+#define CC_MINUS     11    /* '-'.  Minus or SQL-style comment */
+#define CC_LT        12    /* '<'.  Part of < or <= or <> */
+#define CC_GT        13    /* '>'.  Part of > or >= */
+#define CC_EQ        14    /* '='.  Part of = or == */
+#define CC_BANG      15    /* '!'.  Part of != */
+#define CC_SLASH     16    /* '/'.  / or c-style comment */
+#define CC_LP        17    /* '(' */
+#define CC_RP        18    /* ')' */
+#define CC_SEMI      19    /* ';' */
+#define CC_PLUS      20    /* '+' */
+#define CC_STAR      21    /* '*' */
+#define CC_PERCENT   22    /* '%' */
+#define CC_COMMA     23    /* ',' */
+#define CC_AND       24    /* '&' */
+#define CC_TILDA     25    /* '~' */
+#define CC_DOT       26    /* '.' */
+#define CC_ILLEGAL   27    /* Illegal character */
+
+static const unsigned char aiClass[] = {
+#ifdef SQLITE_ASCII
+/*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
+/* 0x */   27, 27, 27, 27, 27, 27, 27, 27, 27,  7,  7, 27,  7,  7, 27, 27,
+/* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 2x */    7, 15,  8,  5,  4, 22, 24,  8, 17, 18, 21, 20, 23, 11, 26, 16,
+/* 3x */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  5, 19, 12, 14, 13,  6,
+/* 4x */    5,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+/* 5x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1,  9, 27, 27, 27,  1,
+/* 6x */    8,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+/* 7x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1, 27, 10, 27, 25, 27,
+/* 8x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* 9x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Ax */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Bx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Cx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Dx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Ex */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Fx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2
+#endif
+#ifdef SQLITE_EBCDIC
+/*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
+/* 0x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27,  7,  7, 27, 27,
+/* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 2x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 3x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 4x */    7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 26, 12, 17, 20, 10,
+/* 5x */   24, 27, 27, 27, 27, 27, 27, 27, 27, 27, 15,  4, 21, 18, 19, 27,
+/* 6x */   11, 16, 27, 27, 27, 27, 27, 27, 27, 27, 27, 23, 22,  1, 13,  6,
+/* 7x */   27, 27, 27, 27, 27, 27, 27, 27, 27,  8,  5,  5,  5,  8, 14,  8,
+/* 8x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* 9x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Ax */   27, 25,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Bx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27,  9, 27, 27, 27, 27, 27,
+/* Cx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Dx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Ex */   27, 27,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Fx */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3, 27, 27, 27, 27, 27, 27,
+#endif
+};
+
+/*
+** The charMap() macro maps alphabetic characters (only) into their
+** lower-case ASCII equivalent.  On ASCII machines, this is just
+** an upper-to-lower case map.  On EBCDIC machines we also need
+** to adjust the encoding.  The mapping is only valid for alphabetics
+** which are the only characters for which this feature is used. 
+**
+** Used by keywordhash.h
+*/
+#ifdef SQLITE_ASCII
+# define charMap(X) sqlite3UpperToLower[(unsigned char)X]
+#endif
+#ifdef SQLITE_EBCDIC
+# define charMap(X) ebcdicToAscii[(unsigned char)X]
+const unsigned char ebcdicToAscii[] = {
+/* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */
+};
+#endif
+
+/*
+** The sqlite3KeywordCode function looks up an identifier to determine if
+** it is a keyword.  If it is a keyword, the token code of that keyword is 
+** returned.  If the input is not a keyword, TK_ID is returned.
+**
+** The implementation of this routine was generated by a program,
+** mkkeywordhash.c, located in the tool subdirectory of the distribution.
+** The output of the mkkeywordhash.c program is written into a file
+** named keywordhash.h and then included into this source file by
+** the #include below.
+*/
+/************** Include keywordhash.h in the middle of tokenize.c ************/
+/************** Begin file keywordhash.h *************************************/
+/***** This file contains automatically generated code ******
+**
+** The code in this file has been automatically generated by
+**
+**   sqlite/tool/mkkeywordhash.c
+**
+** The code in this file implements a function that determines whether
+** or not a given identifier is really an SQL keyword.  The same thing
+** might be implemented more directly using a hand-written hash table.
+** But by using this automatically generated code, the size of the code
+** is substantially reduced.  This is important for embedded applications
+** on platforms with limited memory.
+*/
+/* Hash score: 182 */
+/* zKWText[] encodes 834 bytes of keyword text in 554 bytes */
+/*   REINDEXEDESCAPEACHECKEYBEFOREIGNOREGEXPLAINSTEADDATABASELECT       */
+/*   ABLEFTHENDEFERRABLELSEXCEPTRANSACTIONATURALTERAISEXCLUSIVE         */
+/*   XISTSAVEPOINTERSECTRIGGEREFERENCESCONSTRAINTOFFSETEMPORARY         */
+/*   UNIQUERYWITHOUTERELEASEATTACHAVINGROUPDATEBEGINNERECURSIVE         */
+/*   BETWEENOTNULLIKECASCADELETECASECOLLATECREATECURRENT_DATEDETACH     */
+/*   IMMEDIATEJOINSERTMATCHPLANALYZEPRAGMABORTVALUESVIRTUALIMITWHEN     */
+/*   WHERENAMEAFTEREPLACEANDEFAULTAUTOINCREMENTCASTCOLUMNCOMMIT         */
+/*   CONFLICTCROSSCURRENT_TIMESTAMPRIMARYDEFERREDISTINCTDROPFAIL        */
+/*   FROMFULLGLOBYIFISNULLORDERESTRICTRIGHTROLLBACKROWUNIONUSING        */
+/*   VACUUMVIEWINITIALLY                                                */
+static const char zKWText[553] = {
+  'R','E','I','N','D','E','X','E','D','E','S','C','A','P','E','A','C','H',
+  'E','C','K','E','Y','B','E','F','O','R','E','I','G','N','O','R','E','G',
+  'E','X','P','L','A','I','N','S','T','E','A','D','D','A','T','A','B','A',
+  'S','E','L','E','C','T','A','B','L','E','F','T','H','E','N','D','E','F',
+  'E','R','R','A','B','L','E','L','S','E','X','C','E','P','T','R','A','N',
+  'S','A','C','T','I','O','N','A','T','U','R','A','L','T','E','R','A','I',
+  'S','E','X','C','L','U','S','I','V','E','X','I','S','T','S','A','V','E',
+  'P','O','I','N','T','E','R','S','E','C','T','R','I','G','G','E','R','E',
+  'F','E','R','E','N','C','E','S','C','O','N','S','T','R','A','I','N','T',
+  'O','F','F','S','E','T','E','M','P','O','R','A','R','Y','U','N','I','Q',
+  'U','E','R','Y','W','I','T','H','O','U','T','E','R','E','L','E','A','S',
+  'E','A','T','T','A','C','H','A','V','I','N','G','R','O','U','P','D','A',
+  'T','E','B','E','G','I','N','N','E','R','E','C','U','R','S','I','V','E',
+  'B','E','T','W','E','E','N','O','T','N','U','L','L','I','K','E','C','A',
+  'S','C','A','D','E','L','E','T','E','C','A','S','E','C','O','L','L','A',
+  'T','E','C','R','E','A','T','E','C','U','R','R','E','N','T','_','D','A',
+  'T','E','D','E','T','A','C','H','I','M','M','E','D','I','A','T','E','J',
+  'O','I','N','S','E','R','T','M','A','T','C','H','P','L','A','N','A','L',
+  'Y','Z','E','P','R','A','G','M','A','B','O','R','T','V','A','L','U','E',
+  'S','V','I','R','T','U','A','L','I','M','I','T','W','H','E','N','W','H',
+  'E','R','E','N','A','M','E','A','F','T','E','R','E','P','L','A','C','E',
+  'A','N','D','E','F','A','U','L','T','A','U','T','O','I','N','C','R','E',
+  'M','E','N','T','C','A','S','T','C','O','L','U','M','N','C','O','M','M',
+  'I','T','C','O','N','F','L','I','C','T','C','R','O','S','S','C','U','R',
+  'R','E','N','T','_','T','I','M','E','S','T','A','M','P','R','I','M','A',
+  'R','Y','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T','D',
+  'R','O','P','F','A','I','L','F','R','O','M','F','U','L','L','G','L','O',
+  'B','Y','I','F','I','S','N','U','L','L','O','R','D','E','R','E','S','T',
+  'R','I','C','T','R','I','G','H','T','R','O','L','L','B','A','C','K','R',
+  'O','W','U','N','I','O','N','U','S','I','N','G','V','A','C','U','U','M',
+  'V','I','E','W','I','N','I','T','I','A','L','L','Y',
+};
+/* aKWHash[i] is the hash value for the i-th keyword */
+static const unsigned char aKWHash[127] = {
+    76, 105, 117,  74,   0,  45,   0,   0,  82,   0,  77,   0,   0,
+    42,  12,  78,  15,   0, 116,  85,  54, 112,   0,  19,   0,   0,
+   121,   0, 119, 115,   0,  22,  93,   0,   9,   0,   0,  70,  71,
+     0,  69,   6,   0,  48,  90, 102,   0, 118, 101,   0,   0,  44,
+     0, 103,  24,   0,  17,   0, 122,  53,  23,   0,   5, 110,  25,
+    96,   0,   0, 124, 106,  60, 123,  57,  28,  55,   0,  91,   0,
+   100,  26,   0,  99,   0,   0,   0,  95,  92,  97,  88, 109,  14,
+    39, 108,   0,  81,   0,  18,  89, 111,  32,   0, 120,  80, 113,
+    62,  46,  84,   0,   0,  94,  40,  59, 114,   0,  36,   0,   0,
+    29,   0,  86,  63,  64,   0,  20,  61,   0,  56,
+};
+/* aKWNext[] forms the hash collision chain.  If aKWHash[i]==0
+** then the i-th keyword has no more hash collisions.  Otherwise,
+** the next keyword with the same hash is aKWHash[i]-1. */
+static const unsigned char aKWNext[124] = {
+     0,   0,   0,   0,   4,   0,   0,   0,   0,   0,   0,   0,   0,
+     0,   2,   0,   0,   0,   0,   0,   0,  13,   0,   0,   0,   0,
+     0,   7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+     0,   0,   0,   0,  33,   0,  21,   0,   0,   0,   0,   0,  50,
+     0,  43,   3,  47,   0,   0,   0,   0,  30,   0,  58,   0,  38,
+     0,   0,   0,   1,  66,   0,   0,  67,   0,  41,   0,   0,   0,
+     0,   0,   0,  49,  65,   0,   0,   0,   0,  31,  52,  16,  34,
+    10,   0,   0,   0,   0,   0,   0,   0,  11,  72,  79,   0,   8,
+     0, 104,  98,   0, 107,   0,  87,   0,  75,  51,   0,  27,  37,
+    73,  83,   0,  35,  68,   0,   0,
+};
+/* aKWLen[i] is the length (in bytes) of the i-th keyword */
+static const unsigned char aKWLen[124] = {
+     7,   7,   5,   4,   6,   4,   5,   3,   6,   7,   3,   6,   6,
+     7,   7,   3,   8,   2,   6,   5,   4,   4,   3,  10,   4,   6,
+    11,   6,   2,   7,   5,   5,   9,   6,   9,   9,   7,  10,  10,
+     4,   6,   2,   3,   9,   4,   2,   6,   5,   7,   4,   5,   7,
+     6,   6,   5,   6,   5,   5,   9,   7,   7,   3,   2,   4,   4,
+     7,   3,   6,   4,   7,   6,  12,   6,   9,   4,   6,   5,   4,
+     7,   6,   5,   6,   7,   5,   4,   5,   6,   5,   7,   3,   7,
+    13,   2,   2,   4,   6,   6,   8,   5,  17,  12,   7,   8,   8,
+     2,   4,   4,   4,   4,   4,   2,   2,   6,   5,   8,   5,   8,
+     3,   5,   5,   6,   4,   9,   3,
+};
+/* aKWOffset[i] is the index into zKWText[] of the start of
+** the text for the i-th keyword. */
+static const unsigned short int aKWOffset[124] = {
+     0,   2,   2,   8,   9,  14,  16,  20,  23,  25,  25,  29,  33,
+    36,  41,  46,  48,  53,  54,  59,  62,  65,  67,  69,  78,  81,
+    86,  91,  95,  96, 101, 105, 109, 117, 122, 128, 136, 142, 152,
+   159, 162, 162, 165, 167, 167, 171, 176, 179, 184, 184, 188, 192,
+   199, 204, 209, 212, 218, 221, 225, 234, 240, 240, 240, 243, 246,
+   250, 251, 255, 261, 265, 272, 278, 290, 296, 305, 307, 313, 318,
+   320, 327, 332, 337, 343, 349, 354, 358, 361, 367, 371, 378, 380,
+   387, 389, 391, 400, 404, 410, 416, 424, 429, 429, 445, 452, 459,
+   460, 467, 471, 475, 479, 483, 486, 488, 490, 496, 500, 508, 513,
+   521, 524, 529, 534, 540, 544, 549,
+};
+/* aKWCode[i] is the parser symbol code for the i-th keyword */
+static const unsigned char aKWCode[124] = {
+  TK_REINDEX,    TK_INDEXED,    TK_INDEX,      TK_DESC,       TK_ESCAPE,     
+  TK_EACH,       TK_CHECK,      TK_KEY,        TK_BEFORE,     TK_FOREIGN,    
+  TK_FOR,        TK_IGNORE,     TK_LIKE_KW,    TK_EXPLAIN,    TK_INSTEAD,    
+  TK_ADD,        TK_DATABASE,   TK_AS,         TK_SELECT,     TK_TABLE,      
+  TK_JOIN_KW,    TK_THEN,       TK_END,        TK_DEFERRABLE, TK_ELSE,       
+  TK_EXCEPT,     TK_TRANSACTION,TK_ACTION,     TK_ON,         TK_JOIN_KW,    
+  TK_ALTER,      TK_RAISE,      TK_EXCLUSIVE,  TK_EXISTS,     TK_SAVEPOINT,  
+  TK_INTERSECT,  TK_TRIGGER,    TK_REFERENCES, TK_CONSTRAINT, TK_INTO,       
+  TK_OFFSET,     TK_OF,         TK_SET,        TK_TEMP,       TK_TEMP,       
+  TK_OR,         TK_UNIQUE,     TK_QUERY,      TK_WITHOUT,    TK_WITH,       
+  TK_JOIN_KW,    TK_RELEASE,    TK_ATTACH,     TK_HAVING,     TK_GROUP,      
+  TK_UPDATE,     TK_BEGIN,      TK_JOIN_KW,    TK_RECURSIVE,  TK_BETWEEN,    
+  TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       TK_LIKE_KW,    
+  TK_CASCADE,    TK_ASC,        TK_DELETE,     TK_CASE,       TK_COLLATE,    
+  TK_CREATE,     TK_CTIME_KW,   TK_DETACH,     TK_IMMEDIATE,  TK_JOIN,       
+  TK_INSERT,     TK_MATCH,      TK_PLAN,       TK_ANALYZE,    TK_PRAGMA,     
+  TK_ABORT,      TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      TK_WHEN,       
+  TK_WHERE,      TK_RENAME,     TK_AFTER,      TK_REPLACE,    TK_AND,        
+  TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         TK_CAST,       
+  TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   
+  TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   TK_IS,         
+  TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    TK_LIKE_KW,    
+  TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   
+  TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        TK_UNION,      TK_USING,      
+  TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  TK_ALL,        
+};
+/* Check to see if z[0..n-1] is a keyword. If it is, write the
+** parser symbol code for that keyword into *pType.  Always
+** return the integer n (the length of the token). */
+static int keywordCode(const char *z, int n, int *pType){
+  int i, j;
+  const char *zKW;
+  if( n>=2 ){
+    i = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) % 127;
+    for(i=((int)aKWHash[i])-1; i>=0; i=((int)aKWNext[i])-1){
+      if( aKWLen[i]!=n ) continue;
+      j = 0;
+      zKW = &zKWText[aKWOffset[i]];
+#ifdef SQLITE_ASCII
+      while( j=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+
+/* Make the IdChar function accessible from ctime.c */
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }
+#endif
+
+
+/*
+** Return the length (in bytes) of the token that begins at z[0]. 
+** Store the token type in *tokenType before returning.
+*/
+SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
+  int i, c;
+  switch( aiClass[*z] ){  /* Switch on the character-class of the first byte
+                          ** of the token. See the comment on the CC_ defines
+                          ** above. */
+    case CC_SPACE: {
+      testcase( z[0]==' ' );
+      testcase( z[0]=='\t' );
+      testcase( z[0]=='\n' );
+      testcase( z[0]=='\f' );
+      testcase( z[0]=='\r' );
+      for(i=1; sqlite3Isspace(z[i]); i++){}
+      *tokenType = TK_SPACE;
+      return i;
+    }
+    case CC_MINUS: {
+      if( z[1]=='-' ){
+        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
+        *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
+        return i;
+      }
+      *tokenType = TK_MINUS;
+      return 1;
+    }
+    case CC_LP: {
+      *tokenType = TK_LP;
+      return 1;
+    }
+    case CC_RP: {
+      *tokenType = TK_RP;
+      return 1;
+    }
+    case CC_SEMI: {
+      *tokenType = TK_SEMI;
+      return 1;
+    }
+    case CC_PLUS: {
+      *tokenType = TK_PLUS;
+      return 1;
+    }
+    case CC_STAR: {
+      *tokenType = TK_STAR;
+      return 1;
+    }
+    case CC_SLASH: {
+      if( z[1]!='*' || z[2]==0 ){
+        *tokenType = TK_SLASH;
+        return 1;
+      }
+      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
+      if( c ) i++;
+      *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
+      return i;
+    }
+    case CC_PERCENT: {
+      *tokenType = TK_REM;
+      return 1;
+    }
+    case CC_EQ: {
+      *tokenType = TK_EQ;
+      return 1 + (z[1]=='=');
+    }
+    case CC_LT: {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_LE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_NE;
+        return 2;
+      }else if( c=='<' ){
+        *tokenType = TK_LSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_LT;
+        return 1;
+      }
+    }
+    case CC_GT: {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_GE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_RSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_GT;
+        return 1;
+      }
+    }
+    case CC_BANG: {
+      if( z[1]!='=' ){
+        *tokenType = TK_ILLEGAL;
+        return 1;
+      }else{
+        *tokenType = TK_NE;
+        return 2;
+      }
+    }
+    case CC_PIPE: {
+      if( z[1]!='|' ){
+        *tokenType = TK_BITOR;
+        return 1;
+      }else{
+        *tokenType = TK_CONCAT;
+        return 2;
+      }
+    }
+    case CC_COMMA: {
+      *tokenType = TK_COMMA;
+      return 1;
+    }
+    case CC_AND: {
+      *tokenType = TK_BITAND;
+      return 1;
+    }
+    case CC_TILDA: {
+      *tokenType = TK_BITNOT;
+      return 1;
+    }
+    case CC_QUOTE: {
+      int delim = z[0];
+      testcase( delim=='`' );
+      testcase( delim=='\'' );
+      testcase( delim=='"' );
+      for(i=1; (c=z[i])!=0; i++){
+        if( c==delim ){
+          if( z[i+1]==delim ){
+            i++;
+          }else{
+            break;
+          }
+        }
+      }
+      if( c=='\'' ){
+        *tokenType = TK_STRING;
+        return i+1;
+      }else if( c!=0 ){
+        *tokenType = TK_ID;
+        return i+1;
+      }else{
+        *tokenType = TK_ILLEGAL;
+        return i;
+      }
+    }
+    case CC_DOT: {
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( !sqlite3Isdigit(z[1]) )
+#endif
+      {
+        *tokenType = TK_DOT;
+        return 1;
+      }
+      /* If the next character is a digit, this is a floating point
+      ** number that begins with ".".  Fall thru into the next case */
+    }
+    case CC_DIGIT: {
+      testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
+      testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
+      testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
+      testcase( z[0]=='9' );
+      *tokenType = TK_INTEGER;
+#ifndef SQLITE_OMIT_HEX_INTEGER
+      if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
+        for(i=3; sqlite3Isxdigit(z[i]); i++){}
+        return i;
+      }
+#endif
+      for(i=0; sqlite3Isdigit(z[i]); i++){}
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( z[i]=='.' ){
+        i++;
+        while( sqlite3Isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+      if( (z[i]=='e' || z[i]=='E') &&
+           ( sqlite3Isdigit(z[i+1]) 
+            || ((z[i+1]=='+' || z[i+1]=='-') && sqlite3Isdigit(z[i+2]))
+           )
+      ){
+        i += 2;
+        while( sqlite3Isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+#endif
+      while( IdChar(z[i]) ){
+        *tokenType = TK_ILLEGAL;
+        i++;
+      }
+      return i;
+    }
+    case CC_QUOTE2: {
+      for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
+      *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
+      return i;
+    }
+    case CC_VARNUM: {
+      *tokenType = TK_VARIABLE;
+      for(i=1; sqlite3Isdigit(z[i]); i++){}
+      return i;
+    }
+    case CC_DOLLAR:
+    case CC_VARALPHA: {
+      int n = 0;
+      testcase( z[0]=='$' );  testcase( z[0]=='@' );
+      testcase( z[0]==':' );  testcase( z[0]=='#' );
+      *tokenType = TK_VARIABLE;
+      for(i=1; (c=z[i])!=0; i++){
+        if( IdChar(c) ){
+          n++;
+#ifndef SQLITE_OMIT_TCL_VARIABLE
+        }else if( c=='(' && n>0 ){
+          do{
+            i++;
+          }while( (c=z[i])!=0 && !sqlite3Isspace(c) && c!=')' );
+          if( c==')' ){
+            i++;
+          }else{
+            *tokenType = TK_ILLEGAL;
+          }
+          break;
+        }else if( c==':' && z[i+1]==':' ){
+          i++;
+#endif
+        }else{
+          break;
+        }
+      }
+      if( n==0 ) *tokenType = TK_ILLEGAL;
+      return i;
+    }
+    case CC_KYWD: {
+      for(i=1; aiClass[z[i]]<=CC_KYWD; i++){}
+      if( IdChar(z[i]) ){
+        /* This token started out using characters that can appear in keywords,
+        ** but z[i] is a character not allowed within keywords, so this must
+        ** be an identifier instead */
+        i++;
+        break;
+      }
+      *tokenType = TK_ID;
+      return keywordCode((char*)z, i, tokenType);
+    }
+    case CC_X: {
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+      testcase( z[0]=='x' ); testcase( z[0]=='X' );
+      if( z[1]=='\'' ){
+        *tokenType = TK_BLOB;
+        for(i=2; sqlite3Isxdigit(z[i]); i++){}
+        if( z[i]!='\'' || i%2 ){
+          *tokenType = TK_ILLEGAL;
+          while( z[i] && z[i]!='\'' ){ i++; }
+        }
+        if( z[i] ) i++;
+        return i;
+      }
+#endif
+      /* If it is not a BLOB literal, then it must be an ID, since no
+      ** SQL keywords start with the letter 'x'.  Fall through */
+    }
+    case CC_ID: {
+      i = 1;
+      break;
+    }
+    default: {
+      *tokenType = TK_ILLEGAL;
+      return 1;
+    }
+  }
+  while( IdChar(z[i]) ){ i++; }
+  *tokenType = TK_ID;
+  return i;
+}
+
+/*
+** Run the parser on the given SQL string.  The parser structure is
+** passed in.  An SQLITE_ status code is returned.  If an error occurs
+** then an and attempt is made to write an error message into 
+** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
+** error message.
+*/
+SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
+  int nErr = 0;                   /* Number of errors encountered */
+  void *pEngine;                  /* The LEMON-generated LALR(1) parser */
+  int n = 0;                      /* Length of the next token token */
+  int tokenType;                  /* type of the next token */
+  int lastTokenParsed = -1;       /* type of the previous token */
+  sqlite3 *db = pParse->db;       /* The database connection */
+  int mxSqlLen;                   /* Max length of an SQL string */
+#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
+  yyParser sEngine;    /* Space to hold the Lemon-generated Parser object */
+#endif
+
+  assert( zSql!=0 );
+  mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
+  if( db->nVdbeActive==0 ){
+    db->u1.isInterrupted = 0;
+  }
+  pParse->rc = SQLITE_OK;
+  pParse->zTail = zSql;
+  assert( pzErrMsg!=0 );
+  /* sqlite3ParserTrace(stdout, "parser: "); */
+#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
+  pEngine = &sEngine;
+  sqlite3ParserInit(pEngine);
+#else
+  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
+  if( pEngine==0 ){
+    sqlite3OomFault(db);
+    return SQLITE_NOMEM_BKPT;
+  }
+#endif
+  assert( pParse->pNewTable==0 );
+  assert( pParse->pNewTrigger==0 );
+  assert( pParse->nVar==0 );
+  assert( pParse->pVList==0 );
+  while( 1 ){
+    if( zSql[0]!=0 ){
+      n = sqlite3GetToken((u8*)zSql, &tokenType);
+      mxSqlLen -= n;
+      if( mxSqlLen<0 ){
+        pParse->rc = SQLITE_TOOBIG;
+        break;
+      }
+    }else{
+      /* Upon reaching the end of input, call the parser two more times
+      ** with tokens TK_SEMI and 0, in that order. */
+      if( lastTokenParsed==TK_SEMI ){
+        tokenType = 0;
+      }else if( lastTokenParsed==0 ){
+        break;
+      }else{
+        tokenType = TK_SEMI;
+      }
+      zSql -= n;
+    }
+    if( tokenType>=TK_SPACE ){
+      assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
+      if( db->u1.isInterrupted ){
+        pParse->rc = SQLITE_INTERRUPT;
+        break;
+      }
+      if( tokenType==TK_ILLEGAL ){
+        sqlite3ErrorMsg(pParse, "unrecognized token: \"%.*s\"", n, zSql);
+        break;
+      }
+      zSql += n;
+    }else{
+      pParse->sLastToken.z = zSql;
+      pParse->sLastToken.n = n;
+      sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
+      lastTokenParsed = tokenType;
+      zSql += n;
+      if( pParse->rc!=SQLITE_OK || db->mallocFailed ) break;
+    }
+  }
+  assert( nErr==0 );
+  pParse->zTail = zSql;
+#ifdef YYTRACKMAXSTACKDEPTH
+  sqlite3_mutex_enter(sqlite3MallocMutex());
+  sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
+      sqlite3ParserStackPeak(pEngine)
+  );
+  sqlite3_mutex_leave(sqlite3MallocMutex());
+#endif /* YYDEBUG */
+#ifdef sqlite3Parser_ENGINEALWAYSONSTACK
+  sqlite3ParserFinalize(pEngine);
+#else
+  sqlite3ParserFree(pEngine, sqlite3_free);
+#endif
+  if( db->mallocFailed ){
+    pParse->rc = SQLITE_NOMEM_BKPT;
+  }
+  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
+    pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
+  }
+  assert( pzErrMsg!=0 );
+  if( pParse->zErrMsg ){
+    *pzErrMsg = pParse->zErrMsg;
+    sqlite3_log(pParse->rc, "%s", *pzErrMsg);
+    pParse->zErrMsg = 0;
+    nErr++;
+  }
+  if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
+    sqlite3VdbeDelete(pParse->pVdbe);
+    pParse->pVdbe = 0;
+  }
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( pParse->nested==0 ){
+    sqlite3DbFree(db, pParse->aTableLock);
+    pParse->aTableLock = 0;
+    pParse->nTableLock = 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_free(pParse->apVtabLock);
+#endif
+
+  if( !IN_DECLARE_VTAB ){
+    /* If the pParse->declareVtab flag is set, do not delete any table 
+    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
+    ** will take responsibility for freeing the Table structure.
+    */
+    sqlite3DeleteTable(db, pParse->pNewTable);
+  }
+
+  if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);
+  sqlite3DeleteTrigger(db, pParse->pNewTrigger);
+  sqlite3DbFree(db, pParse->pVList);
+  while( pParse->pAinc ){
+    AutoincInfo *p = pParse->pAinc;
+    pParse->pAinc = p->pNext;
+    sqlite3DbFreeNN(db, p);
+  }
+  while( pParse->pZombieTab ){
+    Table *p = pParse->pZombieTab;
+    pParse->pZombieTab = p->pNextZombie;
+    sqlite3DeleteTable(db, p);
+  }
+  assert( nErr==0 || pParse->rc!=SQLITE_OK );
+  return nErr;
+}
+
+/************** End of tokenize.c ********************************************/
+/************** Begin file complete.c ****************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that implements the sqlite3_complete() API.
+** This code used to be part of the tokenizer.c source file.  But by
+** separating it out, the code will be automatically omitted from
+** static links that do not use it.
+*/
+/* #include "sqliteInt.h" */
+#ifndef SQLITE_OMIT_COMPLETE
+
+/*
+** This is defined in tokenize.c.  We just have to import the definition.
+*/
+#ifndef SQLITE_AMALGAMATION
+#ifdef SQLITE_ASCII
+#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
+#endif
+#ifdef SQLITE_EBCDIC
+SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
+#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+#endif /* SQLITE_AMALGAMATION */
+
+
+/*
+** Token types used by the sqlite3_complete() routine.  See the header
+** comments on that procedure for additional information.
+*/
+#define tkSEMI    0
+#define tkWS      1
+#define tkOTHER   2
+#ifndef SQLITE_OMIT_TRIGGER
+#define tkEXPLAIN 3
+#define tkCREATE  4
+#define tkTEMP    5
+#define tkTRIGGER 6
+#define tkEND     7
+#endif
+
+/*
+** Return TRUE if the given SQL string ends in a semicolon.
+**
+** Special handling is require for CREATE TRIGGER statements.
+** Whenever the CREATE TRIGGER keywords are seen, the statement
+** must end with ";END;".
+**
+** This implementation uses a state machine with 8 states:
+**
+**   (0) INVALID   We have not yet seen a non-whitespace character.
+**
+**   (1) START     At the beginning or end of an SQL statement.  This routine
+**                 returns 1 if it ends in the START state and 0 if it ends
+**                 in any other state.
+**
+**   (2) NORMAL    We are in the middle of statement which ends with a single
+**                 semicolon.
+**
+**   (3) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 
+**                 a statement.
+**
+**   (4) CREATE    The keyword CREATE has been seen at the beginning of a
+**                 statement, possibly preceded by EXPLAIN and/or followed by
+**                 TEMP or TEMPORARY
+**
+**   (5) TRIGGER   We are in the middle of a trigger definition that must be
+**                 ended by a semicolon, the keyword END, and another semicolon.
+**
+**   (6) SEMI      We've seen the first semicolon in the ";END;" that occurs at
+**                 the end of a trigger definition.
+**
+**   (7) END       We've seen the ";END" of the ";END;" that occurs at the end
+**                 of a trigger definition.
+**
+** Transitions between states above are determined by tokens extracted
+** from the input.  The following tokens are significant:
+**
+**   (0) tkSEMI      A semicolon.
+**   (1) tkWS        Whitespace.
+**   (2) tkOTHER     Any other SQL token.
+**   (3) tkEXPLAIN   The "explain" keyword.
+**   (4) tkCREATE    The "create" keyword.
+**   (5) tkTEMP      The "temp" or "temporary" keyword.
+**   (6) tkTRIGGER   The "trigger" keyword.
+**   (7) tkEND       The "end" keyword.
+**
+** Whitespace never causes a state transition and is always ignored.
+** This means that a SQL string of all whitespace is invalid.
+**
+** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
+** to recognize the end of a trigger can be omitted.  All we have to do
+** is look for a semicolon that is not part of an string or comment.
+*/
+SQLITE_API int sqlite3_complete(const char *zSql){
+  u8 state = 0;   /* Current state, using numbers defined in header comment */
+  u8 token;       /* Value of the next token */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* A complex statement machine used to detect the end of a CREATE TRIGGER
+  ** statement.  This is the normal case.
+  */
+  static const u8 trans[8][8] = {
+                     /* Token:                                                */
+     /* State:       **  SEMI  WS  OTHER  EXPLAIN  CREATE  TEMP  TRIGGER  END */
+     /* 0 INVALID: */ {    1,  0,     2,       3,      4,    2,       2,   2, },
+     /* 1   START: */ {    1,  1,     2,       3,      4,    2,       2,   2, },
+     /* 2  NORMAL: */ {    1,  2,     2,       2,      2,    2,       2,   2, },
+     /* 3 EXPLAIN: */ {    1,  3,     3,       2,      4,    2,       2,   2, },
+     /* 4  CREATE: */ {    1,  4,     2,       2,      2,    4,       5,   2, },
+     /* 5 TRIGGER: */ {    6,  5,     5,       5,      5,    5,       5,   5, },
+     /* 6    SEMI: */ {    6,  6,     5,       5,      5,    5,       5,   7, },
+     /* 7     END: */ {    1,  7,     5,       5,      5,    5,       5,   5, },
+  };
+#else
+  /* If triggers are not supported by this compile then the statement machine
+  ** used to detect the end of a statement is much simpler
+  */
+  static const u8 trans[3][3] = {
+                     /* Token:           */
+     /* State:       **  SEMI  WS  OTHER */
+     /* 0 INVALID: */ {    1,  0,     2, },
+     /* 1   START: */ {    1,  1,     2, },
+     /* 2  NORMAL: */ {    1,  2,     2, },
+  };
+#endif /* SQLITE_OMIT_TRIGGER */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( zSql==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+
+  while( *zSql ){
+    switch( *zSql ){
+      case ';': {  /* A semicolon */
+        token = tkSEMI;
+        break;
+      }
+      case ' ':
+      case '\r':
+      case '\t':
+      case '\n':
+      case '\f': {  /* White space is ignored */
+        token = tkWS;
+        break;
+      }
+      case '/': {   /* C-style comments */
+        if( zSql[1]!='*' ){
+          token = tkOTHER;
+          break;
+        }
+        zSql += 2;
+        while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
+        if( zSql[0]==0 ) return 0;
+        zSql++;
+        token = tkWS;
+        break;
+      }
+      case '-': {   /* SQL-style comments from "--" to end of line */
+        if( zSql[1]!='-' ){
+          token = tkOTHER;
+          break;
+        }
+        while( *zSql && *zSql!='\n' ){ zSql++; }
+        if( *zSql==0 ) return state==1;
+        token = tkWS;
+        break;
+      }
+      case '[': {   /* Microsoft-style identifiers in [...] */
+        zSql++;
+        while( *zSql && *zSql!=']' ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      case '`':     /* Grave-accent quoted symbols used by MySQL */
+      case '"':     /* single- and double-quoted strings */
+      case '\'': {
+        int c = *zSql;
+        zSql++;
+        while( *zSql && *zSql!=c ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      default: {
+#ifdef SQLITE_EBCDIC
+        unsigned char c;
+#endif
+        if( IdChar((u8)*zSql) ){
+          /* Keywords and unquoted identifiers */
+          int nId;
+          for(nId=1; IdChar(zSql[nId]); nId++){}
+#ifdef SQLITE_OMIT_TRIGGER
+          token = tkOTHER;
+#else
+          switch( *zSql ){
+            case 'c': case 'C': {
+              if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
+                token = tkCREATE;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 't': case 'T': {
+              if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
+                token = tkTRIGGER;
+              }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
+                token = tkTEMP;
+              }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
+                token = tkTEMP;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 'e':  case 'E': {
+              if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
+                token = tkEND;
+              }else
+#ifndef SQLITE_OMIT_EXPLAIN
+              if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
+                token = tkEXPLAIN;
+              }else
+#endif
+              {
+                token = tkOTHER;
+              }
+              break;
+            }
+            default: {
+              token = tkOTHER;
+              break;
+            }
+          }
+#endif /* SQLITE_OMIT_TRIGGER */
+          zSql += nId-1;
+        }else{
+          /* Operators and special symbols */
+          token = tkOTHER;
+        }
+        break;
+      }
+    }
+    state = trans[state][token];
+    zSql++;
+  }
+  return state==1;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** This routine is the same as the sqlite3_complete() routine described
+** above, except that the parameter is required to be UTF-16 encoded, not
+** UTF-8.
+*/
+SQLITE_API int sqlite3_complete16(const void *zSql){
+  sqlite3_value *pVal;
+  char const *zSql8;
+  int rc;
+
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
+  if( zSql8 ){
+    rc = sqlite3_complete(zSql8);
+  }else{
+    rc = SQLITE_NOMEM_BKPT;
+  }
+  sqlite3ValueFree(pVal);
+  return rc & 0xff;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_OMIT_COMPLETE */
+
+/************** End of complete.c ********************************************/
+/************** Begin file main.c ********************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Main file for the SQLite library.  The routines in this file
+** implement the programmer interface to the library.  Routines in
+** other files are for internal use by SQLite and should not be
+** accessed by users of the library.
+*/
+/* #include "sqliteInt.h" */
+
+#ifdef SQLITE_ENABLE_FTS3
+/************** Include fts3.h in the middle of main.c ***********************/
+/************** Begin file fts3.h ********************************************/
+/*
+** 2006 Oct 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** FTS3 library.  All it does is declare the sqlite3Fts3Init() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+/************** End of fts3.h ************************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_RTREE
+/************** Include rtree.h in the middle of main.c **********************/
+/************** Begin file rtree.h *******************************************/
+/*
+** 2008 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+/************** End of rtree.h ***********************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_ICU
+/************** Include sqliteicu.h in the middle of main.c ******************/
+/************** Begin file sqliteicu.h ***************************************/
+/*
+** 2008 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** ICU extension.  All it does is declare the sqlite3IcuInit() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+
+/************** End of sqliteicu.h *******************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_JSON1
+SQLITE_PRIVATE int sqlite3Json1Init(sqlite3*);
+#endif
+#ifdef SQLITE_ENABLE_STMTVTAB
+SQLITE_PRIVATE int sqlite3StmtVtabInit(sqlite3*);
+#endif
+#ifdef SQLITE_ENABLE_FTS5
+SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3*);
+#endif
+
+#ifndef SQLITE_AMALGAMATION
+/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
+** contains the text of SQLITE_VERSION macro. 
+*/
+SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
+#endif
+
+/* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
+** a pointer to the to the sqlite3_version[] string constant. 
+*/
+SQLITE_API const char *sqlite3_libversion(void){ return sqlite3_version; }
+
+/* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
+** pointer to a string constant whose value is the same as the
+** SQLITE_SOURCE_ID C preprocessor macro. 
+*/
+SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
+
+/* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
+** returns an integer equal to SQLITE_VERSION_NUMBER.
+*/
+SQLITE_API int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
+
+/* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
+** zero if and only if SQLite was compiled with mutexing code omitted due to
+** the SQLITE_THREADSAFE compile-time option being set to 0.
+*/
+SQLITE_API int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+
+/*
+** When compiling the test fixture or with debugging enabled (on Win32),
+** this variable being set to non-zero will cause OSTRACE macros to emit
+** extra diagnostic information.
+*/
+#ifdef SQLITE_HAVE_OS_TRACE
+# ifndef SQLITE_DEBUG_OS_TRACE
+#   define SQLITE_DEBUG_OS_TRACE 0
+# endif
+  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
+#endif
+
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+/*
+** If the following function pointer is not NULL and if
+** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
+** I/O active are written using this function.  These messages
+** are intended for debugging activity only.
+*/
+SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
+#endif
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** temporary files.
+**
+** See also the "PRAGMA temp_store_directory" SQL command.
+*/
+SQLITE_API char *sqlite3_temp_directory = 0;
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** all database files specified with a relative pathname.
+**
+** See also the "PRAGMA data_store_directory" SQL command.
+*/
+SQLITE_API char *sqlite3_data_directory = 0;
+
+/*
+** Initialize SQLite.  
+**
+** This routine must be called to initialize the memory allocation,
+** VFS, and mutex subsystems prior to doing any serious work with
+** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
+** this routine will be called automatically by key routines such as
+** sqlite3_open().  
+**
+** This routine is a no-op except on its very first call for the process,
+** or for the first call after a call to sqlite3_shutdown.
+**
+** The first thread to call this routine runs the initialization to
+** completion.  If subsequent threads call this routine before the first
+** thread has finished the initialization process, then the subsequent
+** threads must block until the first thread finishes with the initialization.
+**
+** The first thread might call this routine recursively.  Recursive
+** calls to this routine should not block, of course.  Otherwise the
+** initialization process would never complete.
+**
+** Let X be the first thread to enter this routine.  Let Y be some other
+** thread.  Then while the initial invocation of this routine by X is
+** incomplete, it is required that:
+**
+**    *  Calls to this routine from Y must block until the outer-most
+**       call by X completes.
+**
+**    *  Recursive calls to this routine from thread X return immediately
+**       without blocking.
+*/
+SQLITE_API int sqlite3_initialize(void){
+  MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
+  int rc;                                      /* Result code */
+#ifdef SQLITE_EXTRA_INIT
+  int bRunExtraInit = 0;                       /* Extra initialization needed */
+#endif
+
+#ifdef SQLITE_OMIT_WSD
+  rc = sqlite3_wsd_init(4096, 24);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+#endif
+
+  /* If the following assert() fails on some obscure processor/compiler
+  ** combination, the work-around is to set the correct pointer
+  ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
+  assert( SQLITE_PTRSIZE==sizeof(char*) );
+
+  /* If SQLite is already completely initialized, then this call
+  ** to sqlite3_initialize() should be a no-op.  But the initialization
+  ** must be complete.  So isInit must not be set until the very end
+  ** of this routine.
+  */
+  if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
+
+  /* Make sure the mutex subsystem is initialized.  If unable to 
+  ** initialize the mutex subsystem, return early with the error.
+  ** If the system is so sick that we are unable to allocate a mutex,
+  ** there is not much SQLite is going to be able to do.
+  **
+  ** The mutex subsystem must take care of serializing its own
+  ** initialization.
+  */
+  rc = sqlite3MutexInit();
+  if( rc ) return rc;
+
+  /* Initialize the malloc() system and the recursive pInitMutex mutex.
+  ** This operation is protected by the STATIC_MASTER mutex.  Note that
+  ** MutexAlloc() is called for a static mutex prior to initializing the
+  ** malloc subsystem - this implies that the allocation of a static
+  ** mutex must not require support from the malloc subsystem.
+  */
+  MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
+  sqlite3_mutex_enter(pMaster);
+  sqlite3GlobalConfig.isMutexInit = 1;
+  if( !sqlite3GlobalConfig.isMallocInit ){
+    rc = sqlite3MallocInit();
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3GlobalConfig.isMallocInit = 1;
+    if( !sqlite3GlobalConfig.pInitMutex ){
+      sqlite3GlobalConfig.pInitMutex =
+           sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+      if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
+        rc = SQLITE_NOMEM_BKPT;
+      }
+    }
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3GlobalConfig.nRefInitMutex++;
+  }
+  sqlite3_mutex_leave(pMaster);
+
+  /* If rc is not SQLITE_OK at this point, then either the malloc
+  ** subsystem could not be initialized or the system failed to allocate
+  ** the pInitMutex mutex. Return an error in either case.  */
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* Do the rest of the initialization under the recursive mutex so
+  ** that we will be able to handle recursive calls into
+  ** sqlite3_initialize().  The recursive calls normally come through
+  ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
+  ** recursive calls might also be possible.
+  **
+  ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
+  ** to the xInit method, so the xInit method need not be threadsafe.
+  **
+  ** The following mutex is what serializes access to the appdef pcache xInit
+  ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
+  ** call to sqlite3PcacheInitialize().
+  */
+  sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
+  if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
+    sqlite3GlobalConfig.inProgress = 1;
+#ifdef SQLITE_ENABLE_SQLLOG
+    {
+      extern void sqlite3_init_sqllog(void);
+      sqlite3_init_sqllog();
+    }
+#endif
+    memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
+    sqlite3RegisterBuiltinFunctions();
+    if( sqlite3GlobalConfig.isPCacheInit==0 ){
+      rc = sqlite3PcacheInitialize();
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3GlobalConfig.isPCacheInit = 1;
+      rc = sqlite3OsInit();
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
+          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
+      sqlite3GlobalConfig.isInit = 1;
+#ifdef SQLITE_EXTRA_INIT
+      bRunExtraInit = 1;
+#endif
+    }
+    sqlite3GlobalConfig.inProgress = 0;
+  }
+  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
+
+  /* Go back under the static mutex and clean up the recursive
+  ** mutex to prevent a resource leak.
+  */
+  sqlite3_mutex_enter(pMaster);
+  sqlite3GlobalConfig.nRefInitMutex--;
+  if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
+    assert( sqlite3GlobalConfig.nRefInitMutex==0 );
+    sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
+    sqlite3GlobalConfig.pInitMutex = 0;
+  }
+  sqlite3_mutex_leave(pMaster);
+
+  /* The following is just a sanity check to make sure SQLite has
+  ** been compiled correctly.  It is important to run this code, but
+  ** we don't want to run it too often and soak up CPU cycles for no
+  ** reason.  So we run it once during initialization.
+  */
+#ifndef NDEBUG
+#ifndef SQLITE_OMIT_FLOATING_POINT
+  /* This section of code's only "output" is via assert() statements. */
+  if ( rc==SQLITE_OK ){
+    u64 x = (((u64)1)<<63)-1;
+    double y;
+    assert(sizeof(x)==8);
+    assert(sizeof(x)==sizeof(y));
+    memcpy(&y, &x, 8);
+    assert( sqlite3IsNaN(y) );
+  }
+#endif
+#endif
+
+  /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
+  ** compile-time option.
+  */
+#ifdef SQLITE_EXTRA_INIT
+  if( bRunExtraInit ){
+    int SQLITE_EXTRA_INIT(const char*);
+    rc = SQLITE_EXTRA_INIT(0);
+  }
+#endif
+
+  return rc;
+}
+
+/*
+** Undo the effects of sqlite3_initialize().  Must not be called while
+** there are outstanding database connections or memory allocations or
+** while any part of SQLite is otherwise in use in any thread.  This
+** routine is not threadsafe.  But it is safe to invoke this routine
+** on when SQLite is already shut down.  If SQLite is already shut down
+** when this routine is invoked, then this routine is a harmless no-op.
+*/
+SQLITE_API int sqlite3_shutdown(void){
+#ifdef SQLITE_OMIT_WSD
+  int rc = sqlite3_wsd_init(4096, 24);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+#endif
+
+  if( sqlite3GlobalConfig.isInit ){
+#ifdef SQLITE_EXTRA_SHUTDOWN
+    void SQLITE_EXTRA_SHUTDOWN(void);
+    SQLITE_EXTRA_SHUTDOWN();
+#endif
+    sqlite3_os_end();
+    sqlite3_reset_auto_extension();
+    sqlite3GlobalConfig.isInit = 0;
+  }
+  if( sqlite3GlobalConfig.isPCacheInit ){
+    sqlite3PcacheShutdown();
+    sqlite3GlobalConfig.isPCacheInit = 0;
+  }
+  if( sqlite3GlobalConfig.isMallocInit ){
+    sqlite3MallocEnd();
+    sqlite3GlobalConfig.isMallocInit = 0;
+
+#ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
+    /* The heap subsystem has now been shutdown and these values are supposed
+    ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
+    ** which would rely on that heap subsystem; therefore, make sure these
+    ** values cannot refer to heap memory that was just invalidated when the
+    ** heap subsystem was shutdown.  This is only done if the current call to
+    ** this function resulted in the heap subsystem actually being shutdown.
+    */
+    sqlite3_data_directory = 0;
+    sqlite3_temp_directory = 0;
+#endif
+  }
+  if( sqlite3GlobalConfig.isMutexInit ){
+    sqlite3MutexEnd();
+    sqlite3GlobalConfig.isMutexInit = 0;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** This API allows applications to modify the global configuration of
+** the SQLite library at run-time.
+**
+** This routine should only be called when there are no outstanding
+** database connections or memory allocations.  This routine is not
+** threadsafe.  Failure to heed these warnings can lead to unpredictable
+** behavior.
+*/
+SQLITE_API int sqlite3_config(int op, ...){
+  va_list ap;
+  int rc = SQLITE_OK;
+
+  /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
+  ** the SQLite library is in use. */
+  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
+
+  va_start(ap, op);
+  switch( op ){
+
+    /* Mutex configuration options are only available in a threadsafe
+    ** compile.
+    */
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
+    case SQLITE_CONFIG_SINGLETHREAD: {
+      /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
+      ** Single-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
+    case SQLITE_CONFIG_MULTITHREAD: {
+      /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
+      ** Multi-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
+    case SQLITE_CONFIG_SERIALIZED: {
+      /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
+      ** Serialized. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
+    case SQLITE_CONFIG_MUTEX: {
+      /* Specify an alternative mutex implementation */
+      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
+    case SQLITE_CONFIG_GETMUTEX: {
+      /* Retrieve the current mutex implementation */
+      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_MALLOC: {
+      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The argument specifies alternative
+      ** low-level memory allocation routines to be used in place of the memory
+      ** allocation routines built into SQLite. */
+      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
+      break;
+    }
+    case SQLITE_CONFIG_GETMALLOC: {
+      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
+      ** filled with the currently defined memory allocation routines. */
+      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
+      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
+      break;
+    }
+    case SQLITE_CONFIG_MEMSTATUS: {
+      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
+      ** single argument of type int, interpreted as a boolean, which enables
+      ** or disables the collection of memory allocation statistics. */
+      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_SCRATCH: {
+      /* EVIDENCE-OF: R-08404-60887 There are three arguments to
+      ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
+      ** which the scratch allocations will be drawn, the size of each scratch
+      ** allocation (sz), and the maximum number of scratch allocations (N). */
+      sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
+      sqlite3GlobalConfig.szScratch = va_arg(ap, int);
+      sqlite3GlobalConfig.nScratch = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_PAGECACHE: {
+      /* EVIDENCE-OF: R-18761-36601 There are three arguments to
+      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
+      ** the size of each page cache line (sz), and the number of cache lines
+      ** (N). */
+      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
+      sqlite3GlobalConfig.szPage = va_arg(ap, int);
+      sqlite3GlobalConfig.nPage = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_PCACHE_HDRSZ: {
+      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
+      ** a single parameter which is a pointer to an integer and writes into
+      ** that integer the number of extra bytes per page required for each page
+      ** in SQLITE_CONFIG_PAGECACHE. */
+      *va_arg(ap, int*) = 
+          sqlite3HeaderSizeBtree() +
+          sqlite3HeaderSizePcache() +
+          sqlite3HeaderSizePcache1();
+      break;
+    }
+
+    case SQLITE_CONFIG_PCACHE: {
+      /* no-op */
+      break;
+    }
+    case SQLITE_CONFIG_GETPCACHE: {
+      /* now an error */
+      rc = SQLITE_ERROR;
+      break;
+    }
+
+    case SQLITE_CONFIG_PCACHE2: {
+      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. This object specifies the interface to a custom page cache
+      ** implementation. */
+      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
+      break;
+    }
+    case SQLITE_CONFIG_GETPCACHE2: {
+      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. SQLite copies of the current page cache implementation into
+      ** that object. */
+      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
+        sqlite3PCacheSetDefault();
+      }
+      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
+      break;
+    }
+
+/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
+** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
+** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
+#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
+    case SQLITE_CONFIG_HEAP: {
+      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
+      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
+      ** number of bytes in the memory buffer, and the minimum allocation size.
+      */
+      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
+      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
+      sqlite3GlobalConfig.mnReq = va_arg(ap, int);
+
+      if( sqlite3GlobalConfig.mnReq<1 ){
+        sqlite3GlobalConfig.mnReq = 1;
+      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
+        /* cap min request size at 2^12 */
+        sqlite3GlobalConfig.mnReq = (1<<12);
+      }
+
+      if( sqlite3GlobalConfig.pHeap==0 ){
+        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
+        ** is NULL, then SQLite reverts to using its default memory allocator
+        ** (the system malloc() implementation), undoing any prior invocation of
+        ** SQLITE_CONFIG_MALLOC.
+        **
+        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
+        ** revert to its default implementation when sqlite3_initialize() is run
+        */
+        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
+      }else{
+        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
+        ** alternative memory allocator is engaged to handle all of SQLites
+        ** memory allocation needs. */
+#ifdef SQLITE_ENABLE_MEMSYS3
+        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
+#endif
+#ifdef SQLITE_ENABLE_MEMSYS5
+        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
+#endif
+      }
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_LOOKASIDE: {
+      sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
+      sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
+      break;
+    }
+    
+    /* Record a pointer to the logger function and its first argument.
+    ** The default is NULL.  Logging is disabled if the function pointer is
+    ** NULL.
+    */
+    case SQLITE_CONFIG_LOG: {
+      /* MSVC is picky about pulling func ptrs from va lists.
+      ** http://support.microsoft.com/kb/47961
+      ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
+      */
+      typedef void(*LOGFUNC_t)(void*,int,const char*);
+      sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
+      sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
+      break;
+    }
+
+    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
+    ** can be changed at start-time using the
+    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
+    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
+    */
+    case SQLITE_CONFIG_URI: {
+      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
+      ** argument of type int. If non-zero, then URI handling is globally
+      ** enabled. If the parameter is zero, then URI handling is globally
+      ** disabled. */
+      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
+      break;
+    }
+
+    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
+      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
+      ** option takes a single integer argument which is interpreted as a
+      ** boolean in order to enable or disable the use of covering indices for
+      ** full table scans in the query optimizer. */
+      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
+      break;
+    }
+
+#ifdef SQLITE_ENABLE_SQLLOG
+    case SQLITE_CONFIG_SQLLOG: {
+      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
+      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
+      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_MMAP_SIZE: {
+      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
+      ** integer (sqlite3_int64) values that are the default mmap size limit
+      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
+      ** mmap size limit. */
+      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
+      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
+      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
+      ** negative, then that argument is changed to its compile-time default.
+      **
+      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
+      ** silently truncated if necessary so that it does not exceed the
+      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
+      ** compile-time option.
+      */
+      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
+        mxMmap = SQLITE_MAX_MMAP_SIZE;
+      }
+      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
+      if( szMmap>mxMmap) szMmap = mxMmap;
+      sqlite3GlobalConfig.mxMmap = mxMmap;
+      sqlite3GlobalConfig.szMmap = szMmap;
+      break;
+    }
+
+#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
+    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
+      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
+      ** unsigned integer value that specifies the maximum size of the created
+      ** heap. */
+      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_PMASZ: {
+      sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
+      break;
+    }
+
+    case SQLITE_CONFIG_STMTJRNL_SPILL: {
+      sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
+      break;
+    }
+
+    default: {
+      rc = SQLITE_ERROR;
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+/*
+** Set up the lookaside buffers for a database connection.
+** Return SQLITE_OK on success.  
+** If lookaside is already active, return SQLITE_BUSY.
+**
+** The sz parameter is the number of bytes in each lookaside slot.
+** The cnt parameter is the number of slots.  If pStart is NULL the
+** space for the lookaside memory is obtained from sqlite3_malloc().
+** If pStart is not NULL then it is sz*cnt bytes of memory to use for
+** the lookaside memory.
+*/
+static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
+#ifndef SQLITE_OMIT_LOOKASIDE
+  void *pStart;
+  if( db->lookaside.nOut ){
+    return SQLITE_BUSY;
+  }
+  /* Free any existing lookaside buffer for this handle before
+  ** allocating a new one so we don't have to have space for 
+  ** both at the same time.
+  */
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
+  ** than a pointer to be useful.
+  */
+  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
+  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
+  if( cnt<0 ) cnt = 0;
+  if( sz==0 || cnt==0 ){
+    sz = 0;
+    pStart = 0;
+  }else if( pBuf==0 ){
+    sqlite3BeginBenignMalloc();
+    pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
+    sqlite3EndBenignMalloc();
+    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
+  }else{
+    pStart = pBuf;
+  }
+  db->lookaside.pStart = pStart;
+  db->lookaside.pFree = 0;
+  db->lookaside.sz = (u16)sz;
+  if( pStart ){
+    int i;
+    LookasideSlot *p;
+    assert( sz > (int)sizeof(LookasideSlot*) );
+    p = (LookasideSlot*)pStart;
+    for(i=cnt-1; i>=0; i--){
+      p->pNext = db->lookaside.pFree;
+      db->lookaside.pFree = p;
+      p = (LookasideSlot*)&((u8*)p)[sz];
+    }
+    db->lookaside.pEnd = p;
+    db->lookaside.bDisable = 0;
+    db->lookaside.bMalloced = pBuf==0 ?1:0;
+  }else{
+    db->lookaside.pStart = db;
+    db->lookaside.pEnd = db;
+    db->lookaside.bDisable = 1;
+    db->lookaside.bMalloced = 0;
+  }
+#endif /* SQLITE_OMIT_LOOKASIDE */
+  return SQLITE_OK;
+}
+
+/*
+** Return the mutex associated with a database connection.
+*/
+SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->mutex;
+}
+
+/*
+** Free up as much memory as we can from the given database
+** connection.
+*/
+SQLITE_API int sqlite3_db_release_memory(sqlite3 *db){
+  int i;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; inDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      sqlite3PagerShrink(pPager);
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Flush any dirty pages in the pager-cache for any attached database
+** to disk.
+*/
+SQLITE_API int sqlite3_db_cacheflush(sqlite3 *db){
+  int i;
+  int rc = SQLITE_OK;
+  int bSeenBusy = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; rc==SQLITE_OK && inDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      rc = sqlite3PagerFlush(pPager);
+      if( rc==SQLITE_BUSY ){
+        bSeenBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
+}
+
+/*
+** Configuration settings for an individual database connection
+*/
+SQLITE_API int sqlite3_db_config(sqlite3 *db, int op, ...){
+  va_list ap;
+  int rc;
+  va_start(ap, op);
+  switch( op ){
+    case SQLITE_DBCONFIG_MAINDBNAME: {
+      /* IMP: R-06824-28531 */
+      /* IMP: R-36257-52125 */
+      db->aDb[0].zDbSName = va_arg(ap,char*);
+      rc = SQLITE_OK;
+      break;
+    }
+    case SQLITE_DBCONFIG_LOOKASIDE: {
+      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
+      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
+      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
+      rc = setupLookaside(db, pBuf, sz, cnt);
+      break;
+    }
+    default: {
+      static const struct {
+        int op;      /* The opcode */
+        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
+      } aFlagOp[] = {
+        { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
+        { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
+        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
+        { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
+        { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
+        { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
+      };
+      unsigned int i;
+      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
+      for(i=0; iflags;
+          if( onoff>0 ){
+            db->flags |= aFlagOp[i].mask;
+          }else if( onoff==0 ){
+            db->flags &= ~aFlagOp[i].mask;
+          }
+          if( oldFlags!=db->flags ){
+            sqlite3ExpirePreparedStatements(db);
+          }
+          if( pRes ){
+            *pRes = (db->flags & aFlagOp[i].mask)!=0;
+          }
+          rc = SQLITE_OK;
+          break;
+        }
+      }
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+
+/*
+** Return true if the buffer z[0..n-1] contains all spaces.
+*/
+static int allSpaces(const char *z, int n){
+  while( n>0 && z[n-1]==' ' ){ n--; }
+  return n==0;
+}
+
+/*
+** This is the default collating function named "BINARY" which is always
+** available.
+**
+** If the padFlag argument is not NULL then space padding at the end
+** of strings is ignored.  This implements the RTRIM collation.
+*/
+static int binCollFunc(
+  void *padFlag,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int rc, n;
+  n = nKey1lastRowid;
+}
+
+/*
+** Set the value returned by the sqlite3_last_insert_rowid() API function.
+*/
+SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->lastRowid = iRowid;
+  sqlite3_mutex_leave(db->mutex);
+}
+
+/*
+** Return the number of changes in the most recent call to sqlite3_exec().
+*/
+SQLITE_API int sqlite3_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->nChange;
+}
+
+/*
+** Return the number of changes since the database handle was opened.
+*/
+SQLITE_API int sqlite3_total_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->nTotalChange;
+}
+
+/*
+** Close all open savepoints. This function only manipulates fields of the
+** database handle object, it does not close any savepoints that may be open
+** at the b-tree/pager level.
+*/
+SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *db){
+  while( db->pSavepoint ){
+    Savepoint *pTmp = db->pSavepoint;
+    db->pSavepoint = pTmp->pNext;
+    sqlite3DbFree(db, pTmp);
+  }
+  db->nSavepoint = 0;
+  db->nStatement = 0;
+  db->isTransactionSavepoint = 0;
+}
+
+/*
+** Invoke the destructor function associated with FuncDef p, if any. Except,
+** if this is not the last copy of the function, do not invoke it. Multiple
+** copies of a single function are created when create_function() is called
+** with SQLITE_ANY as the encoding.
+*/
+static void functionDestroy(sqlite3 *db, FuncDef *p){
+  FuncDestructor *pDestructor = p->u.pDestructor;
+  if( pDestructor ){
+    pDestructor->nRef--;
+    if( pDestructor->nRef==0 ){
+      pDestructor->xDestroy(pDestructor->pUserData);
+      sqlite3DbFree(db, pDestructor);
+    }
+  }
+}
+
+/*
+** Disconnect all sqlite3_vtab objects that belong to database connection
+** db. This is called when db is being closed.
+*/
+static void disconnectAllVtab(sqlite3 *db){
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  int i;
+  HashElem *p;
+  sqlite3BtreeEnterAll(db);
+  for(i=0; inDb; i++){
+    Schema *pSchema = db->aDb[i].pSchema;
+    if( db->aDb[i].pSchema ){
+      for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
+        Table *pTab = (Table *)sqliteHashData(p);
+        if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
+      }
+    }
+  }
+  for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
+    Module *pMod = (Module *)sqliteHashData(p);
+    if( pMod->pEpoTab ){
+      sqlite3VtabDisconnect(db, pMod->pEpoTab);
+    }
+  }
+  sqlite3VtabUnlockList(db);
+  sqlite3BtreeLeaveAll(db);
+#else
+  UNUSED_PARAMETER(db);
+#endif
+}
+
+/*
+** Return TRUE if database connection db has unfinalized prepared
+** statements or unfinished sqlite3_backup objects.  
+*/
+static int connectionIsBusy(sqlite3 *db){
+  int j;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->pVdbe ) return 1;
+  for(j=0; jnDb; j++){
+    Btree *pBt = db->aDb[j].pBt;
+    if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Close an existing SQLite database
+*/
+static int sqlite3Close(sqlite3 *db, int forceZombie){
+  if( !db ){
+    /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
+    ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
+    return SQLITE_OK;
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  if( db->mTrace & SQLITE_TRACE_CLOSE ){
+    db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
+  }
+
+  /* Force xDisconnect calls on all virtual tables */
+  disconnectAllVtab(db);
+
+  /* If a transaction is open, the disconnectAllVtab() call above
+  ** will not have called the xDisconnect() method on any virtual
+  ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
+  ** call will do so. We need to do this before the check for active
+  ** SQL statements below, as the v-table implementation may be storing
+  ** some prepared statements internally.
+  */
+  sqlite3VtabRollback(db);
+
+  /* Legacy behavior (sqlite3_close() behavior) is to return
+  ** SQLITE_BUSY if the connection can not be closed immediately.
+  */
+  if( !forceZombie && connectionIsBusy(db) ){
+    sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
+       "statements or unfinished backups");
+    sqlite3_mutex_leave(db->mutex);
+    return SQLITE_BUSY;
+  }
+
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Closing the handle. Fourth parameter is passed the value 2. */
+    sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
+  }
+#endif
+
+  /* Convert the connection into a zombie and then close it.
+  */
+  db->magic = SQLITE_MAGIC_ZOMBIE;
+  sqlite3LeaveMutexAndCloseZombie(db);
+  return SQLITE_OK;
+}
+
+/*
+** Two variations on the public interface for closing a database
+** connection. The sqlite3_close() version returns SQLITE_BUSY and
+** leaves the connection option if there are unfinalized prepared
+** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
+** version forces the connection to become a zombie if there are
+** unclosed resources, and arranges for deallocation when the last
+** prepare statement or sqlite3_backup closes.
+*/
+SQLITE_API int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
+SQLITE_API int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
+
+
+/*
+** Close the mutex on database connection db.
+**
+** Furthermore, if database connection db is a zombie (meaning that there
+** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
+** every sqlite3_stmt has now been finalized and every sqlite3_backup has
+** finished, then free all resources.
+*/
+SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
+  HashElem *i;                    /* Hash table iterator */
+  int j;
+
+  /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
+  ** or if the connection has not yet been closed by sqlite3_close_v2(),
+  ** then just leave the mutex and return.
+  */
+  if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
+    sqlite3_mutex_leave(db->mutex);
+    return;
+  }
+
+  /* If we reach this point, it means that the database connection has
+  ** closed all sqlite3_stmt and sqlite3_backup objects and has been
+  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
+  ** go ahead and free all resources.
+  */
+
+  /* If a transaction is open, roll it back. This also ensures that if
+  ** any database schemas have been modified by an uncommitted transaction
+  ** they are reset. And that the required b-tree mutex is held to make
+  ** the pager rollback and schema reset an atomic operation. */
+  sqlite3RollbackAll(db, SQLITE_OK);
+
+  /* Free any outstanding Savepoint structures. */
+  sqlite3CloseSavepoints(db);
+
+  /* Close all database connections */
+  for(j=0; jnDb; j++){
+    struct Db *pDb = &db->aDb[j];
+    if( pDb->pBt ){
+      sqlite3BtreeClose(pDb->pBt);
+      pDb->pBt = 0;
+      if( j!=1 ){
+        pDb->pSchema = 0;
+      }
+    }
+  }
+  /* Clear the TEMP schema separately and last */
+  if( db->aDb[1].pSchema ){
+    sqlite3SchemaClear(db->aDb[1].pSchema);
+  }
+  sqlite3VtabUnlockList(db);
+
+  /* Free up the array of auxiliary databases */
+  sqlite3CollapseDatabaseArray(db);
+  assert( db->nDb<=2 );
+  assert( db->aDb==db->aDbStatic );
+
+  /* Tell the code in notify.c that the connection no longer holds any
+  ** locks and does not require any further unlock-notify callbacks.
+  */
+  sqlite3ConnectionClosed(db);
+
+  for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
+    FuncDef *pNext, *p;
+    p = sqliteHashData(i);
+    do{
+      functionDestroy(db, p);
+      pNext = p->pNext;
+      sqlite3DbFree(db, p);
+      p = pNext;
+    }while( p );
+  }
+  sqlite3HashClear(&db->aFunc);
+  for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
+    CollSeq *pColl = (CollSeq *)sqliteHashData(i);
+    /* Invoke any destructors registered for collation sequence user data. */
+    for(j=0; j<3; j++){
+      if( pColl[j].xDel ){
+        pColl[j].xDel(pColl[j].pUser);
+      }
+    }
+    sqlite3DbFree(db, pColl);
+  }
+  sqlite3HashClear(&db->aCollSeq);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
+    Module *pMod = (Module *)sqliteHashData(i);
+    if( pMod->xDestroy ){
+      pMod->xDestroy(pMod->pAux);
+    }
+    sqlite3VtabEponymousTableClear(db, pMod);
+    sqlite3DbFree(db, pMod);
+  }
+  sqlite3HashClear(&db->aModule);
+#endif
+
+  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
+  sqlite3ValueFree(db->pErr);
+  sqlite3CloseExtensions(db);
+#if SQLITE_USER_AUTHENTICATION
+  sqlite3_free(db->auth.zAuthUser);
+  sqlite3_free(db->auth.zAuthPW);
+#endif
+
+  db->magic = SQLITE_MAGIC_ERROR;
+
+  /* The temp-database schema is allocated differently from the other schema
+  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
+  ** So it needs to be freed here. Todo: Why not roll the temp schema into
+  ** the same sqliteMalloc() as the one that allocates the database 
+  ** structure?
+  */
+  sqlite3DbFree(db, db->aDb[1].pSchema);
+  sqlite3_mutex_leave(db->mutex);
+  db->magic = SQLITE_MAGIC_CLOSED;
+  sqlite3_mutex_free(db->mutex);
+  assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  sqlite3_free(db);
+}
+
+/*
+** Rollback all database files.  If tripCode is not SQLITE_OK, then
+** any write cursors are invalidated ("tripped" - as in "tripping a circuit
+** breaker") and made to return tripCode if there are any further
+** attempts to use that cursor.  Read cursors remain open and valid
+** but are "saved" in case the table pages are moved around.
+*/
+SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){
+  int i;
+  int inTrans = 0;
+  int schemaChange;
+  assert( sqlite3_mutex_held(db->mutex) );
+  sqlite3BeginBenignMalloc();
+
+  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
+  ** This is important in case the transaction being rolled back has
+  ** modified the database schema. If the b-tree mutexes are not taken
+  ** here, then another shared-cache connection might sneak in between
+  ** the database rollback and schema reset, which can cause false
+  ** corruption reports in some cases.  */
+  sqlite3BtreeEnterAll(db);
+  schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
+
+  for(i=0; inDb; i++){
+    Btree *p = db->aDb[i].pBt;
+    if( p ){
+      if( sqlite3BtreeIsInTrans(p) ){
+        inTrans = 1;
+      }
+      sqlite3BtreeRollback(p, tripCode, !schemaChange);
+    }
+  }
+  sqlite3VtabRollback(db);
+  sqlite3EndBenignMalloc();
+
+  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
+    sqlite3ExpirePreparedStatements(db);
+    sqlite3ResetAllSchemasOfConnection(db);
+  }
+  sqlite3BtreeLeaveAll(db);
+
+  /* Any deferred constraint violations have now been resolved. */
+  db->nDeferredCons = 0;
+  db->nDeferredImmCons = 0;
+  db->flags &= ~SQLITE_DeferFKs;
+
+  /* If one has been configured, invoke the rollback-hook callback */
+  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
+    db->xRollbackCallback(db->pRollbackArg);
+  }
+}
+
+/*
+** Return a static string containing the name corresponding to the error code
+** specified in the argument.
+*/
+#if defined(SQLITE_NEED_ERR_NAME)
+SQLITE_PRIVATE const char *sqlite3ErrName(int rc){
+  const char *zName = 0;
+  int i, origRc = rc;
+  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
+    switch( rc ){
+      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
+      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
+      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
+      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
+      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
+      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
+      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
+      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
+      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
+      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
+      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
+      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
+      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
+      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
+      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
+      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
+      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
+      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
+      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
+      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
+      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
+      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
+      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
+      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
+      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
+      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
+      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
+      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
+      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
+      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
+      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
+      case SQLITE_IOERR_CHECKRESERVEDLOCK:
+                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
+      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
+      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
+      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
+      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
+      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
+      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
+      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
+      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
+      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
+      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
+      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
+      case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
+      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
+      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
+      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
+      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
+      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
+      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
+      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
+      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
+      case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
+      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
+      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
+      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
+      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
+      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
+      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
+      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
+      case SQLITE_CONSTRAINT_FOREIGNKEY:
+                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
+      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
+      case SQLITE_CONSTRAINT_PRIMARYKEY:
+                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
+      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
+      case SQLITE_CONSTRAINT_COMMITHOOK:
+                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
+      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
+      case SQLITE_CONSTRAINT_FUNCTION:
+                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
+      case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
+      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
+      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
+      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
+      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
+      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
+      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
+      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
+      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
+      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
+      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
+      case SQLITE_NOTICE_RECOVER_ROLLBACK:
+                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
+      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
+      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
+      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
+    }
+  }
+  if( zName==0 ){
+    static char zBuf[50];
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
+    zName = zBuf;
+  }
+  return zName;
+}
+#endif
+
+/*
+** Return a static string that describes the kind of error specified in the
+** argument.
+*/
+SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){
+  static const char* const aMsg[] = {
+    /* SQLITE_OK          */ "not an error",
+    /* SQLITE_ERROR       */ "SQL logic error",
+    /* SQLITE_INTERNAL    */ 0,
+    /* SQLITE_PERM        */ "access permission denied",
+    /* SQLITE_ABORT       */ "query aborted",
+    /* SQLITE_BUSY        */ "database is locked",
+    /* SQLITE_LOCKED      */ "database table is locked",
+    /* SQLITE_NOMEM       */ "out of memory",
+    /* SQLITE_READONLY    */ "attempt to write a readonly database",
+    /* SQLITE_INTERRUPT   */ "interrupted",
+    /* SQLITE_IOERR       */ "disk I/O error",
+    /* SQLITE_CORRUPT     */ "database disk image is malformed",
+    /* SQLITE_NOTFOUND    */ "unknown operation",
+    /* SQLITE_FULL        */ "database or disk is full",
+    /* SQLITE_CANTOPEN    */ "unable to open database file",
+    /* SQLITE_PROTOCOL    */ "locking protocol",
+    /* SQLITE_EMPTY       */ 0,
+    /* SQLITE_SCHEMA      */ "database schema has changed",
+    /* SQLITE_TOOBIG      */ "string or blob too big",
+    /* SQLITE_CONSTRAINT  */ "constraint failed",
+    /* SQLITE_MISMATCH    */ "datatype mismatch",
+    /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
+#ifdef SQLITE_DISABLE_LFS
+    /* SQLITE_NOLFS       */ "large file support is disabled",
+#else
+    /* SQLITE_NOLFS       */ 0,
+#endif
+    /* SQLITE_AUTH        */ "authorization denied",
+    /* SQLITE_FORMAT      */ 0,
+    /* SQLITE_RANGE       */ "column index out of range",
+    /* SQLITE_NOTADB      */ "file is not a database",
+  };
+  const char *zErr = "unknown error";
+  switch( rc ){
+    case SQLITE_ABORT_ROLLBACK: {
+      zErr = "abort due to ROLLBACK";
+      break;
+    }
+    default: {
+      rc &= 0xff;
+      if( ALWAYS(rc>=0) && rcbusyTimeout;
+  int delay, prior;
+
+  assert( count>=0 );
+  if( count < NDELAY ){
+    delay = delays[count];
+    prior = totals[count];
+  }else{
+    delay = delays[NDELAY-1];
+    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
+  }
+  if( prior + delay > timeout ){
+    delay = timeout - prior;
+    if( delay<=0 ) return 0;
+  }
+  sqlite3OsSleep(db->pVfs, delay*1000);
+  return 1;
+#else
+  sqlite3 *db = (sqlite3 *)ptr;
+  int timeout = ((sqlite3 *)ptr)->busyTimeout;
+  if( (count+1)*1000 > timeout ){
+    return 0;
+  }
+  sqlite3OsSleep(db->pVfs, 1000000);
+  return 1;
+#endif
+}
+
+/*
+** Invoke the given busy handler.
+**
+** This routine is called when an operation failed with a lock.
+** If this routine returns non-zero, the lock is retried.  If it
+** returns 0, the operation aborts with an SQLITE_BUSY error.
+*/
+SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler *p){
+  int rc;
+  if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
+  rc = p->xFunc(p->pArg, p->nBusy);
+  if( rc==0 ){
+    p->nBusy = -1;
+  }else{
+    p->nBusy++;
+  }
+  return rc; 
+}
+
+/*
+** This routine sets the busy callback for an Sqlite database to the
+** given callback function with the given argument.
+*/
+SQLITE_API int sqlite3_busy_handler(
+  sqlite3 *db,
+  int (*xBusy)(void*,int),
+  void *pArg
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->busyHandler.xFunc = xBusy;
+  db->busyHandler.pArg = pArg;
+  db->busyHandler.nBusy = 0;
+  db->busyTimeout = 0;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+/*
+** This routine sets the progress callback for an Sqlite database to the
+** given callback function with the given argument. The progress callback will
+** be invoked every nOps opcodes.
+*/
+SQLITE_API void sqlite3_progress_handler(
+  sqlite3 *db, 
+  int nOps,
+  int (*xProgress)(void*), 
+  void *pArg
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( nOps>0 ){
+    db->xProgress = xProgress;
+    db->nProgressOps = (unsigned)nOps;
+    db->pProgressArg = pArg;
+  }else{
+    db->xProgress = 0;
+    db->nProgressOps = 0;
+    db->pProgressArg = 0;
+  }
+  sqlite3_mutex_leave(db->mutex);
+}
+#endif
+
+
+/*
+** This routine installs a default busy handler that waits for the
+** specified number of milliseconds before returning 0.
+*/
+SQLITE_API int sqlite3_busy_timeout(sqlite3 *db, int ms){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  if( ms>0 ){
+    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
+    db->busyTimeout = ms;
+  }else{
+    sqlite3_busy_handler(db, 0, 0);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Cause any pending operation to stop at its earliest opportunity.
+*/
+SQLITE_API void sqlite3_interrupt(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+  db->u1.isInterrupted = 1;
+}
+
+
+/*
+** This function is exactly the same as sqlite3_create_function(), except
+** that it is designed to be called by internal code. The difference is
+** that if a malloc() fails in sqlite3_create_function(), an error code
+** is returned and the mallocFailed flag cleared. 
+*/
+SQLITE_PRIVATE int sqlite3CreateFunc(
+  sqlite3 *db,
+  const char *zFunctionName,
+  int nArg,
+  int enc,
+  void *pUserData,
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*),
+  FuncDestructor *pDestructor
+){
+  FuncDef *p;
+  int nName;
+  int extraFlags;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( zFunctionName==0 ||
+      (xSFunc && (xFinal || xStep)) || 
+      (!xSFunc && (xFinal && !xStep)) ||
+      (!xSFunc && (!xFinal && xStep)) ||
+      (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
+      (255<(nName = sqlite3Strlen30( zFunctionName))) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+
+  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
+  extraFlags = enc &  SQLITE_DETERMINISTIC;
+  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
+  
+#ifndef SQLITE_OMIT_UTF16
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  **
+  ** If SQLITE_ANY is specified, add three versions of the function
+  ** to the hash table.
+  */
+  if( enc==SQLITE_UTF16 ){
+    enc = SQLITE_UTF16NATIVE;
+  }else if( enc==SQLITE_ANY ){
+    int rc;
+    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
+         pUserData, xSFunc, xStep, xFinal, pDestructor);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
+          pUserData, xSFunc, xStep, xFinal, pDestructor);
+    }
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    enc = SQLITE_UTF16BE;
+  }
+#else
+  enc = SQLITE_UTF8;
+#endif
+  
+  /* Check if an existing function is being overridden or deleted. If so,
+  ** and there are active VMs, then return SQLITE_BUSY. If a function
+  ** is being overridden/deleted but there are no active VMs, allow the
+  ** operation to continue but invalidate all precompiled statements.
+  */
+  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
+  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
+        "unable to delete/modify user-function due to active statements");
+      assert( !db->mallocFailed );
+      return SQLITE_BUSY;
+    }else{
+      sqlite3ExpirePreparedStatements(db);
+    }
+  }
+
+  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
+  assert(p || db->mallocFailed);
+  if( !p ){
+    return SQLITE_NOMEM_BKPT;
+  }
+
+  /* If an older version of the function with a configured destructor is
+  ** being replaced invoke the destructor function here. */
+  functionDestroy(db, p);
+
+  if( pDestructor ){
+    pDestructor->nRef++;
+  }
+  p->u.pDestructor = pDestructor;
+  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
+  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
+  p->xSFunc = xSFunc ? xSFunc : xStep;
+  p->xFinalize = xFinal;
+  p->pUserData = pUserData;
+  p->nArg = (u16)nArg;
+  return SQLITE_OK;
+}
+
+/*
+** Create new user functions.
+*/
+SQLITE_API int sqlite3_create_function(
+  sqlite3 *db,
+  const char *zFunc,
+  int nArg,
+  int enc,
+  void *p,
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*)
+){
+  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
+                                    xFinal, 0);
+}
+
+SQLITE_API int sqlite3_create_function_v2(
+  sqlite3 *db,
+  const char *zFunc,
+  int nArg,
+  int enc,
+  void *p,
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*),
+  void (*xDestroy)(void *)
+){
+  int rc = SQLITE_ERROR;
+  FuncDestructor *pArg = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( xDestroy ){
+    pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
+    if( !pArg ){
+      xDestroy(p);
+      goto out;
+    }
+    pArg->xDestroy = xDestroy;
+    pArg->pUserData = p;
+  }
+  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
+  if( pArg && pArg->nRef==0 ){
+    assert( rc!=SQLITE_OK );
+    xDestroy(p);
+    sqlite3DbFree(db, pArg);
+  }
+
+ out:
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+SQLITE_API int sqlite3_create_function16(
+  sqlite3 *db,
+  const void *zFunctionName,
+  int nArg,
+  int eTextRep,
+  void *p,
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
+  void (*xFinal)(sqlite3_context*)
+){
+  int rc;
+  char *zFunc8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
+  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
+  sqlite3DbFree(db, zFunc8);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif
+
+
+/*
+** Declare that a function has been overloaded by a virtual table.
+**
+** If the function already exists as a regular global function, then
+** this routine is a no-op.  If the function does not exist, then create
+** a new one that always throws a run-time error.  
+**
+** When virtual tables intend to provide an overloaded function, they
+** should call this routine to make sure the global function exists.
+** A global function must exist in order for name resolution to work
+** properly.
+*/
+SQLITE_API int sqlite3_overload_function(
+  sqlite3 *db,
+  const char *zName,
+  int nArg
+){
+  int rc = SQLITE_OK;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)==0 ){
+    rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
+                           0, sqlite3InvalidFunction, 0, 0, 0);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_TRACE
+/*
+** Register a trace function.  The pArg from the previously registered trace
+** is returned.  
+**
+** A NULL trace function means that no tracing is executes.  A non-NULL
+** trace is a pointer to a function that is invoked at the start of each
+** SQL statement.
+*/
+#ifndef SQLITE_OMIT_DEPRECATED
+SQLITE_API void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pTraceArg;
+  db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
+  db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
+  db->pTraceArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+#endif /* SQLITE_OMIT_DEPRECATED */
+
+/* Register a trace callback using the version-2 interface.
+*/
+SQLITE_API int sqlite3_trace_v2(
+  sqlite3 *db,                               /* Trace this connection */
+  unsigned mTrace,                           /* Mask of events to be traced */
+  int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
+  void *pArg                                 /* Context */
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( mTrace==0 ) xTrace = 0;
+  if( xTrace==0 ) mTrace = 0;
+  db->mTrace = mTrace;
+  db->xTrace = xTrace;
+  db->pTraceArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/*
+** Register a profile function.  The pArg from the previously registered 
+** profile function is returned.  
+**
+** A NULL profile function means that no profiling is executes.  A non-NULL
+** profile is a pointer to a function that is invoked at the conclusion of
+** each SQL statement that is run.
+*/
+SQLITE_API void *sqlite3_profile(
+  sqlite3 *db,
+  void (*xProfile)(void*,const char*,sqlite_uint64),
+  void *pArg
+){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pProfileArg;
+  db->xProfile = xProfile;
+  db->pProfileArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+#endif /* SQLITE_OMIT_DEPRECATED */
+#endif /* SQLITE_OMIT_TRACE */
+
+/*
+** Register a function to be invoked when a transaction commits.
+** If the invoked function returns non-zero, then the commit becomes a
+** rollback.
+*/
+SQLITE_API void *sqlite3_commit_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  int (*xCallback)(void*),  /* Function to invoke on each commit */
+  void *pArg                /* Argument to the function */
+){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pCommitArg;
+  db->xCommitCallback = xCallback;
+  db->pCommitArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+SQLITE_API void *sqlite3_update_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pUpdateArg;
+  db->xUpdateCallback = xCallback;
+  db->pUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+/*
+** Register a callback to be invoked each time a transaction is rolled
+** back by this database connection.
+*/
+SQLITE_API void *sqlite3_rollback_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*), /* Callback function */
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pRollbackArg;
+  db->xRollbackCallback = xCallback;
+  db->pRollbackArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+SQLITE_API void *sqlite3_preupdate_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void(*xCallback)(         /* Callback function */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
+  void *pArg                /* First callback argument */
+){
+  void *pRet;
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pPreUpdateArg;
+  db->xPreUpdateCallback = xCallback;
+  db->pPreUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifndef SQLITE_OMIT_WAL
+/*
+** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
+** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
+** is greater than sqlite3.pWalArg cast to an integer (the value configured by
+** wal_autocheckpoint()).
+*/ 
+SQLITE_PRIVATE int sqlite3WalDefaultHook(
+  void *pClientData,     /* Argument */
+  sqlite3 *db,           /* Connection */
+  const char *zDb,       /* Database */
+  int nFrame             /* Size of WAL */
+){
+  if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
+    sqlite3BeginBenignMalloc();
+    sqlite3_wal_checkpoint(db, zDb);
+    sqlite3EndBenignMalloc();
+  }
+  return SQLITE_OK;
+}
+#endif /* SQLITE_OMIT_WAL */
+
+/*
+** Configure an sqlite3_wal_hook() callback to automatically checkpoint
+** a database after committing a transaction if there are nFrame or
+** more frames in the log file. Passing zero or a negative value as the
+** nFrame parameter disables automatic checkpoints entirely.
+**
+** The callback registered by this function replaces any existing callback
+** registered using sqlite3_wal_hook(). Likewise, registering a callback
+** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
+** configured by this function.
+*/
+SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
+#ifdef SQLITE_OMIT_WAL
+  UNUSED_PARAMETER(db);
+  UNUSED_PARAMETER(nFrame);
+#else
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  if( nFrame>0 ){
+    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
+  }else{
+    sqlite3_wal_hook(db, 0, 0);
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Register a callback to be invoked each time a transaction is written
+** into the write-ahead-log by this database connection.
+*/
+SQLITE_API void *sqlite3_wal_hook(
+  sqlite3 *db,                    /* Attach the hook to this db handle */
+  int(*xCallback)(void *, sqlite3*, const char*, int),
+  void *pArg                      /* First argument passed to xCallback() */
+){
+#ifndef SQLITE_OMIT_WAL
+  void *pRet;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pWalArg;
+  db->xWalCallback = xCallback;
+  db->pWalArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+#else
+  return 0;
+#endif
+}
+
+/*
+** Checkpoint database zDb.
+*/
+SQLITE_API int sqlite3_wal_checkpoint_v2(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of attached database (or NULL) */
+  int eMode,                      /* SQLITE_CHECKPOINT_* value */
+  int *pnLog,                     /* OUT: Size of WAL log in frames */
+  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
+){
+#ifdef SQLITE_OMIT_WAL
+  return SQLITE_OK;
+#else
+  int rc;                         /* Return code */
+  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+
+  /* Initialize the output variables to -1 in case an error occurs. */
+  if( pnLog ) *pnLog = -1;
+  if( pnCkpt ) *pnCkpt = -1;
+
+  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
+  assert( SQLITE_CHECKPOINT_FULL==1 );
+  assert( SQLITE_CHECKPOINT_RESTART==2 );
+  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
+  if( eModeSQLITE_CHECKPOINT_TRUNCATE ){
+    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
+    ** mode: */
+    return SQLITE_MISUSE;
+  }
+
+  sqlite3_mutex_enter(db->mutex);
+  if( zDb && zDb[0] ){
+    iDb = sqlite3FindDbName(db, zDb);
+  }
+  if( iDb<0 ){
+    rc = SQLITE_ERROR;
+    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
+  }else{
+    db->busyHandler.nBusy = 0;
+    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
+    sqlite3Error(db, rc);
+  }
+  rc = sqlite3ApiExit(db, rc);
+
+  /* If there are no active statements, clear the interrupt flag at this
+  ** point.  */
+  if( db->nVdbeActive==0 ){
+    db->u1.isInterrupted = 0;
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+#endif
+}
+
+
+/*
+** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
+** to contains a zero-length string, all attached databases are 
+** checkpointed.
+*/
+SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
+  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
+  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
+  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
+}
+
+#ifndef SQLITE_OMIT_WAL
+/*
+** Run a checkpoint on database iDb. This is a no-op if database iDb is
+** not currently open in WAL mode.
+**
+** If a transaction is open on the database being checkpointed, this 
+** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
+** an error occurs while running the checkpoint, an SQLite error code is 
+** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
+**
+** The mutex on database handle db should be held by the caller. The mutex
+** associated with the specific b-tree being checkpointed is taken by
+** this function while the checkpoint is running.
+**
+** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
+** checkpointed. If an error is encountered it is returned immediately -
+** no attempt is made to checkpoint any remaining databases.
+**
+** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
+*/
+SQLITE_PRIVATE int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* Used to iterate through attached dbs */
+  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( !pnLog || *pnLog==-1 );
+  assert( !pnCkpt || *pnCkpt==-1 );
+
+  for(i=0; inDb && rc==SQLITE_OK; i++){
+    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
+      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
+      pnLog = 0;
+      pnCkpt = 0;
+      if( rc==SQLITE_BUSY ){
+        bBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+
+  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
+}
+#endif /* SQLITE_OMIT_WAL */
+
+/*
+** This function returns true if main-memory should be used instead of
+** a temporary file for transient pager files and statement journals.
+** The value returned depends on the value of db->temp_store (runtime
+** parameter) and the compile time value of SQLITE_TEMP_STORE. The
+** following table describes the relationship between these two values
+** and this functions return value.
+**
+**   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
+**   -----------------     --------------     ------------------------------
+**   0                     any                file      (return 0)
+**   1                     1                  file      (return 0)
+**   1                     2                  memory    (return 1)
+**   1                     0                  file      (return 0)
+**   2                     1                  file      (return 0)
+**   2                     2                  memory    (return 1)
+**   2                     0                  memory    (return 1)
+**   3                     any                memory    (return 1)
+*/
+SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){
+#if SQLITE_TEMP_STORE==1
+  return ( db->temp_store==2 );
+#endif
+#if SQLITE_TEMP_STORE==2
+  return ( db->temp_store!=1 );
+#endif
+#if SQLITE_TEMP_STORE==3
+  UNUSED_PARAMETER(db);
+  return 1;
+#endif
+#if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
+  UNUSED_PARAMETER(db);
+  return 0;
+#endif
+}
+
+/*
+** Return UTF-8 encoded English language explanation of the most recent
+** error.
+*/
+SQLITE_API const char *sqlite3_errmsg(sqlite3 *db){
+  const char *z;
+  if( !db ){
+    return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
+  }
+  sqlite3_mutex_enter(db->mutex);
+  if( db->mallocFailed ){
+    z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
+  }else{
+    testcase( db->pErr==0 );
+    z = (char*)sqlite3_value_text(db->pErr);
+    assert( !db->mallocFailed );
+    if( z==0 ){
+      z = sqlite3ErrStr(db->errCode);
+    }
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Return UTF-16 encoded English language explanation of the most recent
+** error.
+*/
+SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
+  static const u16 outOfMem[] = {
+    'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
+  };
+  static const u16 misuse[] = {
+    'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
+    'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
+    'm', 'i', 's', 'u', 's', 'e', 0
+  };
+
+  const void *z;
+  if( !db ){
+    return (void *)outOfMem;
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return (void *)misuse;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  if( db->mallocFailed ){
+    z = (void *)outOfMem;
+  }else{
+    z = sqlite3_value_text16(db->pErr);
+    if( z==0 ){
+      sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
+      z = sqlite3_value_text16(db->pErr);
+    }
+    /* A malloc() may have failed within the call to sqlite3_value_text16()
+    ** above. If this is the case, then the db->mallocFailed flag needs to
+    ** be cleared before returning. Do this directly, instead of via
+    ** sqlite3ApiExit(), to avoid setting the database handle error message.
+    */
+    sqlite3OomClear(db);
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Return the most recent error code generated by an SQLite routine. If NULL is
+** passed to this function, we assume a malloc() failed during sqlite3_open().
+*/
+SQLITE_API int sqlite3_errcode(sqlite3 *db){
+  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  if( !db || db->mallocFailed ){
+    return SQLITE_NOMEM_BKPT;
+  }
+  return db->errCode & db->errMask;
+}
+SQLITE_API int sqlite3_extended_errcode(sqlite3 *db){
+  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  if( !db || db->mallocFailed ){
+    return SQLITE_NOMEM_BKPT;
+  }
+  return db->errCode;
+}
+SQLITE_API int sqlite3_system_errno(sqlite3 *db){
+  return db ? db->iSysErrno : 0;
+}  
+
+/*
+** Return a string that describes the kind of error specified in the
+** argument.  For now, this simply calls the internal sqlite3ErrStr()
+** function.
+*/
+SQLITE_API const char *sqlite3_errstr(int rc){
+  return sqlite3ErrStr(rc);
+}
+
+/*
+** Create a new collating function for database "db".  The name is zName
+** and the encoding is enc.
+*/
+static int createCollation(
+  sqlite3* db,
+  const char *zName, 
+  u8 enc,
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*),
+  void(*xDel)(void*)
+){
+  CollSeq *pColl;
+  int enc2;
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  */
+  enc2 = enc;
+  testcase( enc2==SQLITE_UTF16 );
+  testcase( enc2==SQLITE_UTF16_ALIGNED );
+  if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
+    enc2 = SQLITE_UTF16NATIVE;
+  }
+  if( enc2SQLITE_UTF16BE ){
+    return SQLITE_MISUSE_BKPT;
+  }
+
+  /* Check if this call is removing or replacing an existing collation 
+  ** sequence. If so, and there are active VMs, return busy. If there
+  ** are no active VMs, invalidate any pre-compiled statements.
+  */
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
+  if( pColl && pColl->xCmp ){
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
+        "unable to delete/modify collation sequence due to active statements");
+      return SQLITE_BUSY;
+    }
+    sqlite3ExpirePreparedStatements(db);
+
+    /* If collation sequence pColl was created directly by a call to
+    ** sqlite3_create_collation, and not generated by synthCollSeq(),
+    ** then any copies made by synthCollSeq() need to be invalidated.
+    ** Also, collation destructor - CollSeq.xDel() - function may need
+    ** to be called.
+    */ 
+    if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
+      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
+      int j;
+      for(j=0; j<3; j++){
+        CollSeq *p = &aColl[j];
+        if( p->enc==pColl->enc ){
+          if( p->xDel ){
+            p->xDel(p->pUser);
+          }
+          p->xCmp = 0;
+        }
+      }
+    }
+  }
+
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
+  if( pColl==0 ) return SQLITE_NOMEM_BKPT;
+  pColl->xCmp = xCompare;
+  pColl->pUser = pCtx;
+  pColl->xDel = xDel;
+  pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
+  sqlite3Error(db, SQLITE_OK);
+  return SQLITE_OK;
+}
+
+
+/*
+** This array defines hard upper bounds on limit values.  The
+** initializer must be kept in sync with the SQLITE_LIMIT_*
+** #defines in sqlite3.h.
+*/
+static const int aHardLimit[] = {
+  SQLITE_MAX_LENGTH,
+  SQLITE_MAX_SQL_LENGTH,
+  SQLITE_MAX_COLUMN,
+  SQLITE_MAX_EXPR_DEPTH,
+  SQLITE_MAX_COMPOUND_SELECT,
+  SQLITE_MAX_VDBE_OP,
+  SQLITE_MAX_FUNCTION_ARG,
+  SQLITE_MAX_ATTACHED,
+  SQLITE_MAX_LIKE_PATTERN_LENGTH,
+  SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
+  SQLITE_MAX_TRIGGER_DEPTH,
+  SQLITE_MAX_WORKER_THREADS,
+};
+
+/*
+** Make sure the hard limits are set to reasonable values
+*/
+#if SQLITE_MAX_LENGTH<100
+# error SQLITE_MAX_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH<100
+# error SQLITE_MAX_SQL_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
+# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
+#endif
+#if SQLITE_MAX_COMPOUND_SELECT<2
+# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
+#endif
+#if SQLITE_MAX_VDBE_OP<40
+# error SQLITE_MAX_VDBE_OP must be at least 40
+#endif
+#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
+# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
+#endif
+#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
+# error SQLITE_MAX_ATTACHED must be between 0 and 125
+#endif
+#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
+# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
+#endif
+#if SQLITE_MAX_COLUMN>32767
+# error SQLITE_MAX_COLUMN must not exceed 32767
+#endif
+#if SQLITE_MAX_TRIGGER_DEPTH<1
+# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
+#endif
+#if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
+# error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
+#endif
+
+
+/*
+** Change the value of a limit.  Report the old value.
+** If an invalid limit index is supplied, report -1.
+** Make no changes but still report the old value if the
+** new limit is negative.
+**
+** A new lower limit does not shrink existing constructs.
+** It merely prevents new constructs that exceed the limit
+** from forming.
+*/
+SQLITE_API int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
+  int oldLimit;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+
+  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
+  ** there is a hard upper bound set at compile-time by a C preprocessor
+  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
+  ** "_MAX_".)
+  */
+  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
+  assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
+  assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
+  assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
+  assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
+  assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
+  assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
+                                               SQLITE_MAX_LIKE_PATTERN_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
+  assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
+  assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
+  assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
+
+
+  if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
+    return -1;
+  }
+  oldLimit = db->aLimit[limitId];
+  if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
+    if( newLimit>aHardLimit[limitId] ){
+      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
+    }
+    db->aLimit[limitId] = newLimit;
+  }
+  return oldLimit;                     /* IMP: R-53341-35419 */
+}
+
+/*
+** This function is used to parse both URIs and non-URI filenames passed by the
+** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
+** URIs specified as part of ATTACH statements.
+**
+** The first argument to this function is the name of the VFS to use (or
+** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
+** query parameter. The second argument contains the URI (or non-URI filename)
+** itself. When this function is called the *pFlags variable should contain
+** the default flags to open the database handle with. The value stored in
+** *pFlags may be updated before returning if the URI filename contains 
+** "cache=xxx" or "mode=xxx" query parameters.
+**
+** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
+** the VFS that should be used to open the database file. *pzFile is set to
+** point to a buffer containing the name of the file to open. It is the 
+** responsibility of the caller to eventually call sqlite3_free() to release
+** this buffer.
+**
+** If an error occurs, then an SQLite error code is returned and *pzErrMsg
+** may be set to point to a buffer containing an English language error 
+** message. It is the responsibility of the caller to eventually release
+** this buffer by calling sqlite3_free().
+*/
+SQLITE_PRIVATE int sqlite3ParseUri(
+  const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
+  const char *zUri,               /* Nul-terminated URI to parse */
+  unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
+  sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
+  char **pzFile,                  /* OUT: Filename component of URI */
+  char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
+){
+  int rc = SQLITE_OK;
+  unsigned int flags = *pFlags;
+  const char *zVfs = zDefaultVfs;
+  char *zFile;
+  char c;
+  int nUri = sqlite3Strlen30(zUri);
+
+  assert( *pzErrMsg==0 );
+
+  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
+            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
+   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
+  ){
+    char *zOpt;
+    int eState;                   /* Parser state when parsing URI */
+    int iIn;                      /* Input character index */
+    int iOut = 0;                 /* Output character index */
+    u64 nByte = nUri+2;           /* Bytes of space to allocate */
+
+    /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
+    ** method that there may be extra parameters following the file-name.  */
+    flags |= SQLITE_OPEN_URI;
+
+    for(iIn=0; iIn=0 && octet<256 );
+        if( octet==0 ){
+#ifndef SQLITE_ENABLE_URI_00_ERROR
+          /* This branch is taken when "%00" appears within the URI. In this
+          ** case we ignore all text in the remainder of the path, name or
+          ** value currently being parsed. So ignore the current character
+          ** and skip to the next "?", "=" or "&", as appropriate. */
+          while( (c = zUri[iIn])!=0 && c!='#' 
+              && (eState!=0 || c!='?')
+              && (eState!=1 || (c!='=' && c!='&'))
+              && (eState!=2 || c!='&')
+          ){
+            iIn++;
+          }
+          continue;
+#else
+          /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
+          *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
+          rc = SQLITE_ERROR;
+          goto parse_uri_out;
+#endif
+        }
+        c = octet;
+      }else if( eState==1 && (c=='&' || c=='=') ){
+        if( zFile[iOut-1]==0 ){
+          /* An empty option name. Ignore this option altogether. */
+          while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
+          continue;
+        }
+        if( c=='&' ){
+          zFile[iOut++] = '\0';
+        }else{
+          eState = 2;
+        }
+        c = 0;
+      }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
+        c = 0;
+        eState = 1;
+      }
+      zFile[iOut++] = c;
+    }
+    if( eState==1 ) zFile[iOut++] = '\0';
+    zFile[iOut++] = '\0';
+    zFile[iOut++] = '\0';
+
+    /* Check if there were any options specified that should be interpreted 
+    ** here. Options that are interpreted here include "vfs" and those that
+    ** correspond to flags that may be passed to the sqlite3_open_v2()
+    ** method. */
+    zOpt = &zFile[sqlite3Strlen30(zFile)+1];
+    while( zOpt[0] ){
+      int nOpt = sqlite3Strlen30(zOpt);
+      char *zVal = &zOpt[nOpt+1];
+      int nVal = sqlite3Strlen30(zVal);
+
+      if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
+        zVfs = zVal;
+      }else{
+        struct OpenMode {
+          const char *z;
+          int mode;
+        } *aMode = 0;
+        char *zModeType = 0;
+        int mask = 0;
+        int limit = 0;
+
+        if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
+          static struct OpenMode aCacheMode[] = {
+            { "shared",  SQLITE_OPEN_SHAREDCACHE },
+            { "private", SQLITE_OPEN_PRIVATECACHE },
+            { 0, 0 }
+          };
+
+          mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
+          aMode = aCacheMode;
+          limit = mask;
+          zModeType = "cache";
+        }
+        if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
+          static struct OpenMode aOpenMode[] = {
+            { "ro",  SQLITE_OPEN_READONLY },
+            { "rw",  SQLITE_OPEN_READWRITE }, 
+            { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
+            { "memory", SQLITE_OPEN_MEMORY },
+            { 0, 0 }
+          };
+
+          mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
+                   | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
+          aMode = aOpenMode;
+          limit = mask & flags;
+          zModeType = "access";
+        }
+
+        if( aMode ){
+          int i;
+          int mode = 0;
+          for(i=0; aMode[i].z; i++){
+            const char *z = aMode[i].z;
+            if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
+              mode = aMode[i].mode;
+              break;
+            }
+          }
+          if( mode==0 ){
+            *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
+            rc = SQLITE_ERROR;
+            goto parse_uri_out;
+          }
+          if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
+            *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
+                                        zModeType, zVal);
+            rc = SQLITE_PERM;
+            goto parse_uri_out;
+          }
+          flags = (flags & ~mask) | mode;
+        }
+      }
+
+      zOpt = &zVal[nVal+1];
+    }
+
+  }else{
+    zFile = sqlite3_malloc64(nUri+2);
+    if( !zFile ) return SQLITE_NOMEM_BKPT;
+    if( nUri ){
+      memcpy(zFile, zUri, nUri);
+    }
+    zFile[nUri] = '\0';
+    zFile[nUri+1] = '\0';
+    flags &= ~SQLITE_OPEN_URI;
+  }
+
+  *ppVfs = sqlite3_vfs_find(zVfs);
+  if( *ppVfs==0 ){
+    *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
+    rc = SQLITE_ERROR;
+  }
+ parse_uri_out:
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(zFile);
+    zFile = 0;
+  }
+  *pFlags = flags;
+  *pzFile = zFile;
+  return rc;
+}
+
+
+/*
+** This routine does the work of opening a database on behalf of
+** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
+** is UTF-8 encoded.
+*/
+static int openDatabase(
+  const char *zFilename, /* Database filename UTF-8 encoded */
+  sqlite3 **ppDb,        /* OUT: Returned database handle */
+  unsigned int flags,    /* Operational flags */
+  const char *zVfs       /* Name of the VFS to use */
+){
+  sqlite3 *db;                    /* Store allocated handle here */
+  int rc;                         /* Return code */
+  int isThreadsafe;               /* True for threadsafe connections */
+  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
+  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  *ppDb = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+
+  if( sqlite3GlobalConfig.bCoreMutex==0 ){
+    isThreadsafe = 0;
+  }else if( flags & SQLITE_OPEN_NOMUTEX ){
+    isThreadsafe = 0;
+  }else if( flags & SQLITE_OPEN_FULLMUTEX ){
+    isThreadsafe = 1;
+  }else{
+    isThreadsafe = sqlite3GlobalConfig.bFullMutex;
+  }
+  if( flags & SQLITE_OPEN_PRIVATECACHE ){
+    flags &= ~SQLITE_OPEN_SHAREDCACHE;
+  }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
+    flags |= SQLITE_OPEN_SHAREDCACHE;
+  }
+
+  /* Remove harmful bits from the flags parameter
+  **
+  ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
+  ** dealt with in the previous code block.  Besides these, the only
+  ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
+  ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
+  ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
+  ** off all other flags.
+  */
+  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
+               SQLITE_OPEN_EXCLUSIVE |
+               SQLITE_OPEN_MAIN_DB |
+               SQLITE_OPEN_TEMP_DB | 
+               SQLITE_OPEN_TRANSIENT_DB | 
+               SQLITE_OPEN_MAIN_JOURNAL | 
+               SQLITE_OPEN_TEMP_JOURNAL | 
+               SQLITE_OPEN_SUBJOURNAL | 
+               SQLITE_OPEN_MASTER_JOURNAL |
+               SQLITE_OPEN_NOMUTEX |
+               SQLITE_OPEN_FULLMUTEX |
+               SQLITE_OPEN_WAL
+             );
+
+  /* Allocate the sqlite data structure */
+  db = sqlite3MallocZero( sizeof(sqlite3) );
+  if( db==0 ) goto opendb_out;
+  if( isThreadsafe ){
+    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+    if( db->mutex==0 ){
+      sqlite3_free(db);
+      db = 0;
+      goto opendb_out;
+    }
+  }
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = 0xff;
+  db->nDb = 2;
+  db->magic = SQLITE_MAGIC_BUSY;
+  db->aDb = db->aDbStatic;
+
+  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
+  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
+  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
+  db->autoCommit = 1;
+  db->nextAutovac = -1;
+  db->szMmap = sqlite3GlobalConfig.szMmap;
+  db->nextPagesize = 0;
+  db->nMaxSorterMmap = 0x7FFFFFFF;
+  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
+#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
+                 | SQLITE_AutoIndex
+#endif
+#if SQLITE_DEFAULT_CKPTFULLFSYNC
+                 | SQLITE_CkptFullFSync
+#endif
+#if SQLITE_DEFAULT_FILE_FORMAT<4
+                 | SQLITE_LegacyFileFmt
+#endif
+#ifdef SQLITE_ENABLE_LOAD_EXTENSION
+                 | SQLITE_LoadExtension
+#endif
+#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
+                 | SQLITE_RecTriggers
+#endif
+#if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
+                 | SQLITE_ForeignKeys
+#endif
+#if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
+                 | SQLITE_ReverseOrder
+#endif
+#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
+                 | SQLITE_CellSizeCk
+#endif
+#if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
+                 | SQLITE_Fts3Tokenizer
+#endif
+#if defined(SQLITE_ENABLE_QPSG)
+                 | SQLITE_EnableQPSG
+#endif
+      ;
+  sqlite3HashInit(&db->aCollSeq);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3HashInit(&db->aModule);
+#endif
+
+  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
+  ** and UTF-16, so add a version for each to avoid any unnecessary
+  ** conversions. The only error that can occur here is a malloc() failure.
+  **
+  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
+  ** functions:
+  */
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
+  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
+  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
+  if( db->mallocFailed ){
+    goto opendb_out;
+  }
+  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
+  ** strings is BINARY. 
+  */
+  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
+  assert( db->pDfltColl!=0 );
+
+  /* Parse the filename/URI argument
+  **
+  ** Only allow sensible combinations of bits in the flags argument.  
+  ** Throw an error if any non-sense combination is used.  If we
+  ** do not block illegal combinations here, it could trigger
+  ** assert() statements in deeper layers.  Sensible combinations
+  ** are:
+  **
+  **  1:  SQLITE_OPEN_READONLY
+  **  2:  SQLITE_OPEN_READWRITE
+  **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
+  */
+  db->openFlags = flags;
+  assert( SQLITE_OPEN_READONLY  == 0x01 );
+  assert( SQLITE_OPEN_READWRITE == 0x02 );
+  assert( SQLITE_OPEN_CREATE    == 0x04 );
+  testcase( (1<<(flags&7))==0x02 ); /* READONLY */
+  testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
+  testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
+  if( ((1<<(flags&7)) & 0x46)==0 ){
+    rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
+  }else{
+    rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
+  }
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
+    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
+    sqlite3_free(zErrMsg);
+    goto opendb_out;
+  }
+
+  /* Open the backend database driver */
+  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
+                        flags | SQLITE_OPEN_MAIN_DB);
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_IOERR_NOMEM ){
+      rc = SQLITE_NOMEM_BKPT;
+    }
+    sqlite3Error(db, rc);
+    goto opendb_out;
+  }
+  sqlite3BtreeEnter(db->aDb[0].pBt);
+  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
+  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
+  sqlite3BtreeLeave(db->aDb[0].pBt);
+  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
+
+  /* The default safety_level for the main database is FULL; for the temp
+  ** database it is OFF. This matches the pager layer defaults.  
+  */
+  db->aDb[0].zDbSName = "main";
+  db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
+  db->aDb[1].zDbSName = "temp";
+  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
+
+  db->magic = SQLITE_MAGIC_OPEN;
+  if( db->mallocFailed ){
+    goto opendb_out;
+  }
+
+  /* Register all built-in functions, but do not attempt to read the
+  ** database schema yet. This is delayed until the first time the database
+  ** is accessed.
+  */
+  sqlite3Error(db, SQLITE_OK);
+  sqlite3RegisterPerConnectionBuiltinFunctions(db);
+  rc = sqlite3_errcode(db);
+
+#ifdef SQLITE_ENABLE_FTS5
+  /* Register any built-in FTS5 module before loading the automatic
+  ** extensions. This allows automatic extensions to register FTS5 
+  ** tokenizers and auxiliary functions.  */
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts5Init(db);
+  }
+#endif
+
+  /* Load automatic extensions - extensions that have been registered
+  ** using the sqlite3_automatic_extension() API.
+  */
+  if( rc==SQLITE_OK ){
+    sqlite3AutoLoadExtensions(db);
+    rc = sqlite3_errcode(db);
+    if( rc!=SQLITE_OK ){
+      goto opendb_out;
+    }
+  }
+
+#ifdef SQLITE_ENABLE_FTS1
+  if( !db->mallocFailed ){
+    extern int sqlite3Fts1Init(sqlite3*);
+    rc = sqlite3Fts1Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS2
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    extern int sqlite3Fts2Init(sqlite3*);
+    rc = sqlite3Fts2Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts3Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3IcuInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_RTREE
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3RtreeInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_DBSTAT_VTAB
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3DbstatRegister(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_JSON1
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3Json1Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_STMTVTAB
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3StmtVtabInit(db);
+  }
+#endif
+
+  /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
+  ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
+  ** mode.  Doing nothing at all also makes NORMAL the default.
+  */
+#ifdef SQLITE_DEFAULT_LOCKING_MODE
+  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
+  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
+                          SQLITE_DEFAULT_LOCKING_MODE);
+#endif
+
+  if( rc ) sqlite3Error(db, rc);
+
+  /* Enable the lookaside-malloc subsystem */
+  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
+                        sqlite3GlobalConfig.nLookaside);
+
+  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
+
+opendb_out:
+  if( db ){
+    assert( db->mutex!=0 || isThreadsafe==0
+           || sqlite3GlobalConfig.bFullMutex==0 );
+    sqlite3_mutex_leave(db->mutex);
+  }
+  rc = sqlite3_errcode(db);
+  assert( db!=0 || rc==SQLITE_NOMEM );
+  if( rc==SQLITE_NOMEM ){
+    sqlite3_close(db);
+    db = 0;
+  }else if( rc!=SQLITE_OK ){
+    db->magic = SQLITE_MAGIC_SICK;
+  }
+  *ppDb = db;
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Opening a db handle. Fourth parameter is passed 0. */
+    void *pArg = sqlite3GlobalConfig.pSqllogArg;
+    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
+  }
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  if( rc==SQLITE_OK ){
+    const char *zKey;
+    if( (zKey = sqlite3_uri_parameter(zOpen, "hexkey"))!=0 && zKey[0] ){
+      u8 iByte;
+      int i;
+      char zDecoded[40];
+      for(i=0, iByte=0; imutex);
+  assert( !db->mallocFailed );
+  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a new collation sequence with the database handle db.
+*/
+SQLITE_API int sqlite3_create_collation16(
+  sqlite3* db, 
+  const void *zName,
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*)
+){
+  int rc = SQLITE_OK;
+  char *zName8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
+  if( zName8 ){
+    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
+    sqlite3DbFree(db, zName8);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+SQLITE_API int sqlite3_collation_needed(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = xCollNeeded;
+  db->xCollNeeded16 = 0;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+SQLITE_API int sqlite3_collation_needed16(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = 0;
+  db->xCollNeeded16 = xCollNeeded16;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/*
+** This function is now an anachronism. It used to be used to recover from a
+** malloc() failure, but SQLite now does this automatically.
+*/
+SQLITE_API int sqlite3_global_recover(void){
+  return SQLITE_OK;
+}
+#endif
+
+/*
+** Test to see whether or not the database connection is in autocommit
+** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
+** by default.  Autocommit is disabled by a BEGIN statement and reenabled
+** by the next COMMIT or ROLLBACK.
+*/
+SQLITE_API int sqlite3_get_autocommit(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->autoCommit;
+}
+
+/*
+** The following routines are substitutes for constants SQLITE_CORRUPT,
+** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
+** constants.  They serve two purposes:
+**
+**   1.  Serve as a convenient place to set a breakpoint in a debugger
+**       to detect when version error conditions occurs.
+**
+**   2.  Invoke sqlite3_log() to provide the source code location where
+**       a low-level error is first detected.
+*/
+static int reportError(int iErr, int lineno, const char *zType){
+  sqlite3_log(iErr, "%s at line %d of [%.10s]",
+              zType, lineno, 20+sqlite3_sourceid());
+  return iErr;
+}
+SQLITE_PRIVATE int sqlite3CorruptError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_CORRUPT, lineno, "database corruption");
+}
+SQLITE_PRIVATE int sqlite3MisuseError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_MISUSE, lineno, "misuse");
+}
+SQLITE_PRIVATE int sqlite3CantopenError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_CANTOPEN, lineno, "cannot open file");
+}
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
+  char zMsg[100];
+  sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_CORRUPT, lineno, zMsg);
+}
+SQLITE_PRIVATE int sqlite3NomemError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_NOMEM, lineno, "OOM");
+}
+SQLITE_PRIVATE int sqlite3IoerrnomemError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
+}
+#endif
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/*
+** This is a convenience routine that makes sure that all thread-specific
+** data for this thread has been deallocated.
+**
+** SQLite no longer uses thread-specific data so this routine is now a
+** no-op.  It is retained for historical compatibility.
+*/
+SQLITE_API void sqlite3_thread_cleanup(void){
+}
+#endif
+
+/*
+** Return meta information about a specific column of a database table.
+** See comment in sqlite3.h (sqlite.h.in) for details.
+*/
+SQLITE_API int sqlite3_table_column_metadata(
+  sqlite3 *db,                /* Connection handle */
+  const char *zDbName,        /* Database name or NULL */
+  const char *zTableName,     /* Table name */
+  const char *zColumnName,    /* Column name */
+  char const **pzDataType,    /* OUTPUT: Declared data type */
+  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
+  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
+  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
+  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
+){
+  int rc;
+  char *zErrMsg = 0;
+  Table *pTab = 0;
+  Column *pCol = 0;
+  int iCol = 0;
+  char const *zDataType = 0;
+  char const *zCollSeq = 0;
+  int notnull = 0;
+  int primarykey = 0;
+  int autoinc = 0;
+
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+
+  /* Ensure the database schema has been loaded */
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  rc = sqlite3Init(db, &zErrMsg);
+  if( SQLITE_OK!=rc ){
+    goto error_out;
+  }
+
+  /* Locate the table in question */
+  pTab = sqlite3FindTable(db, zTableName, zDbName);
+  if( !pTab || pTab->pSelect ){
+    pTab = 0;
+    goto error_out;
+  }
+
+  /* Find the column for which info is requested */
+  if( zColumnName==0 ){
+    /* Query for existance of table only */
+  }else{
+    for(iCol=0; iColnCol; iCol++){
+      pCol = &pTab->aCol[iCol];
+      if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
+        break;
+      }
+    }
+    if( iCol==pTab->nCol ){
+      if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
+        iCol = pTab->iPKey;
+        pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
+      }else{
+        pTab = 0;
+        goto error_out;
+      }
+    }
+  }
+
+  /* The following block stores the meta information that will be returned
+  ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
+  ** and autoinc. At this point there are two possibilities:
+  ** 
+  **     1. The specified column name was rowid", "oid" or "_rowid_" 
+  **        and there is no explicitly declared IPK column. 
+  **
+  **     2. The table is not a view and the column name identified an 
+  **        explicitly declared column. Copy meta information from *pCol.
+  */ 
+  if( pCol ){
+    zDataType = sqlite3ColumnType(pCol,0);
+    zCollSeq = pCol->zColl;
+    notnull = pCol->notNull!=0;
+    primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
+    autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
+  }else{
+    zDataType = "INTEGER";
+    primarykey = 1;
+  }
+  if( !zCollSeq ){
+    zCollSeq = sqlite3StrBINARY;
+  }
+
+error_out:
+  sqlite3BtreeLeaveAll(db);
+
+  /* Whether the function call succeeded or failed, set the output parameters
+  ** to whatever their local counterparts contain. If an error did occur,
+  ** this has the effect of zeroing all output parameters.
+  */
+  if( pzDataType ) *pzDataType = zDataType;
+  if( pzCollSeq ) *pzCollSeq = zCollSeq;
+  if( pNotNull ) *pNotNull = notnull;
+  if( pPrimaryKey ) *pPrimaryKey = primarykey;
+  if( pAutoinc ) *pAutoinc = autoinc;
+
+  if( SQLITE_OK==rc && !pTab ){
+    sqlite3DbFree(db, zErrMsg);
+    zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
+        zColumnName);
+    rc = SQLITE_ERROR;
+  }
+  sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
+  sqlite3DbFree(db, zErrMsg);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+*/
+SQLITE_API int sqlite3_sleep(int ms){
+  sqlite3_vfs *pVfs;
+  int rc;
+  pVfs = sqlite3_vfs_find(0);
+  if( pVfs==0 ) return 0;
+
+  /* This function works in milliseconds, but the underlying OsSleep() 
+  ** API uses microseconds. Hence the 1000's.
+  */
+  rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
+  return rc;
+}
+
+/*
+** Enable or disable the extended result codes.
+*/
+SQLITE_API int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = onoff ? 0xffffffff : 0xff;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Invoke the xFileControl method on a particular database.
+*/
+SQLITE_API int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
+  int rc = SQLITE_ERROR;
+  Btree *pBtree;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pBtree = sqlite3DbNameToBtree(db, zDbName);
+  if( pBtree ){
+    Pager *pPager;
+    sqlite3_file *fd;
+    sqlite3BtreeEnter(pBtree);
+    pPager = sqlite3BtreePager(pBtree);
+    assert( pPager!=0 );
+    fd = sqlite3PagerFile(pPager);
+    assert( fd!=0 );
+    if( op==SQLITE_FCNTL_FILE_POINTER ){
+      *(sqlite3_file**)pArg = fd;
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_VFS_POINTER ){
+      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
+      *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
+      rc = SQLITE_OK;
+    }else if( fd->pMethods ){
+      rc = sqlite3OsFileControl(fd, op, pArg);
+    }else{
+      rc = SQLITE_NOTFOUND;
+    }
+    sqlite3BtreeLeave(pBtree);
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Interface to the testing logic.
+*/
+SQLITE_API int sqlite3_test_control(int op, ...){
+  int rc = 0;
+#ifdef SQLITE_UNTESTABLE
+  UNUSED_PARAMETER(op);
+#else
+  va_list ap;
+  va_start(ap, op);
+  switch( op ){
+
+    /*
+    ** Save the current state of the PRNG.
+    */
+    case SQLITE_TESTCTRL_PRNG_SAVE: {
+      sqlite3PrngSaveState();
+      break;
+    }
+
+    /*
+    ** Restore the state of the PRNG to the last state saved using
+    ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
+    ** this verb acts like PRNG_RESET.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESTORE: {
+      sqlite3PrngRestoreState();
+      break;
+    }
+
+    /*
+    ** Reset the PRNG back to its uninitialized state.  The next call
+    ** to sqlite3_randomness() will reseed the PRNG using a single call
+    ** to the xRandomness method of the default VFS.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESET: {
+      sqlite3_randomness(0,0);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BITVEC_TEST, size, program)
+    **
+    ** Run a test against a Bitvec object of size.  The program argument
+    ** is an array of integers that defines the test.  Return -1 on a
+    ** memory allocation error, 0 on success, or non-zero for an error.
+    ** See the sqlite3BitvecBuiltinTest() for additional information.
+    */
+    case SQLITE_TESTCTRL_BITVEC_TEST: {
+      int sz = va_arg(ap, int);
+      int *aProg = va_arg(ap, int*);
+      rc = sqlite3BitvecBuiltinTest(sz, aProg);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(FAULT_INSTALL, xCallback)
+    **
+    ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
+    ** if xCallback is not NULL.
+    **
+    ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
+    ** is called immediately after installing the new callback and the return
+    ** value from sqlite3FaultSim(0) becomes the return from
+    ** sqlite3_test_control().
+    */
+    case SQLITE_TESTCTRL_FAULT_INSTALL: {
+      /* MSVC is picky about pulling func ptrs from va lists.
+      ** http://support.microsoft.com/kb/47961
+      ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
+      */
+      typedef int(*TESTCALLBACKFUNC_t)(int);
+      sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
+      rc = sqlite3FaultSim(0);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
+    **
+    ** Register hooks to call to indicate which malloc() failures 
+    ** are benign.
+    */
+    case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
+      typedef void (*void_function)(void);
+      void_function xBenignBegin;
+      void_function xBenignEnd;
+      xBenignBegin = va_arg(ap, void_function);
+      xBenignEnd = va_arg(ap, void_function);
+      sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
+    **
+    ** Set the PENDING byte to the value in the argument, if X>0.
+    ** Make no changes if X==0.  Return the value of the pending byte
+    ** as it existing before this routine was called.
+    **
+    ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
+    ** an incompatible database file format.  Changing the PENDING byte
+    ** while any database connection is open results in undefined and
+    ** deleterious behavior.
+    */
+    case SQLITE_TESTCTRL_PENDING_BYTE: {
+      rc = PENDING_BYTE;
+#ifndef SQLITE_OMIT_WSD
+      {
+        unsigned int newVal = va_arg(ap, unsigned int);
+        if( newVal ) sqlite3PendingByte = newVal;
+      }
+#endif
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
+    **
+    ** This action provides a run-time test to see whether or not
+    ** assert() was enabled at compile-time.  If X is true and assert()
+    ** is enabled, then the return value is true.  If X is true and
+    ** assert() is disabled, then the return value is zero.  If X is
+    ** false and assert() is enabled, then the assertion fires and the
+    ** process aborts.  If X is false and assert() is disabled, then the
+    ** return value is zero.
+    */
+    case SQLITE_TESTCTRL_ASSERT: {
+      volatile int x = 0;
+      assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
+      rc = x;
+      break;
+    }
+
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
+    **
+    ** This action provides a run-time test to see how the ALWAYS and
+    ** NEVER macros were defined at compile-time.
+    **
+    ** The return value is ALWAYS(X).  
+    **
+    ** The recommended test is X==2.  If the return value is 2, that means
+    ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
+    ** default setting.  If the return value is 1, then ALWAYS() is either
+    ** hard-coded to true or else it asserts if its argument is false.
+    ** The first behavior (hard-coded to true) is the case if
+    ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
+    ** behavior (assert if the argument to ALWAYS() is false) is the case if
+    ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
+    **
+    ** The run-time test procedure might look something like this:
+    **
+    **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
+    **      // ALWAYS() and NEVER() are no-op pass-through macros
+    **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
+    **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
+    **    }else{
+    **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
+    **    }
+    */
+    case SQLITE_TESTCTRL_ALWAYS: {
+      int x = va_arg(ap,int);
+      rc = ALWAYS(x);
+      break;
+    }
+
+    /*
+    **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
+    **
+    ** The integer returned reveals the byte-order of the computer on which
+    ** SQLite is running:
+    **
+    **       1     big-endian,    determined at run-time
+    **      10     little-endian, determined at run-time
+    **  432101     big-endian,    determined at compile-time
+    **  123410     little-endian, determined at compile-time
+    */ 
+    case SQLITE_TESTCTRL_BYTEORDER: {
+      rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
+    **
+    ** Set the nReserve size to N for the main database on the database
+    ** connection db.
+    */
+    case SQLITE_TESTCTRL_RESERVE: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      int x = va_arg(ap,int);
+      sqlite3_mutex_enter(db->mutex);
+      sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
+      sqlite3_mutex_leave(db->mutex);
+      break;
+    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
+    **
+    ** Enable or disable various optimizations for testing purposes.  The 
+    ** argument N is a bitmask of optimizations to be disabled.  For normal
+    ** operation N should be 0.  The idea is that a test program (like the
+    ** SQL Logic Test or SLT test module) can run the same SQL multiple times
+    ** with various optimizations disabled to verify that the same answer
+    ** is obtained in every case.
+    */
+    case SQLITE_TESTCTRL_OPTIMIZATIONS: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
+      break;
+    }
+
+#ifdef SQLITE_N_KEYWORD
+    /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
+    **
+    ** If zWord is a keyword recognized by the parser, then return the
+    ** number of keywords.  Or if zWord is not a keyword, return 0.
+    ** 
+    ** This test feature is only available in the amalgamation since
+    ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
+    ** is built using separate source files.
+    */
+    case SQLITE_TESTCTRL_ISKEYWORD: {
+      const char *zWord = va_arg(ap, const char*);
+      int n = sqlite3Strlen30(zWord);
+      rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
+      break;
+    }
+#endif 
+
+    /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
+    **
+    ** Pass pFree into sqlite3ScratchFree(). 
+    ** If sz>0 then allocate a scratch buffer into pNew.  
+    */
+    case SQLITE_TESTCTRL_SCRATCHMALLOC: {
+      void *pFree, **ppNew;
+      int sz;
+      sz = va_arg(ap, int);
+      ppNew = va_arg(ap, void**);
+      pFree = va_arg(ap, void*);
+      if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
+      sqlite3ScratchFree(pFree);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
+    **
+    ** If parameter onoff is non-zero, configure the wrappers so that all
+    ** subsequent calls to localtime() and variants fail. If onoff is zero,
+    ** undo this setting.
+    */
+    case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
+      sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
+    **
+    ** Set or clear a flag that indicates that the database file is always well-
+    ** formed and never corrupt.  This flag is clear by default, indicating that
+    ** database files might have arbitrary corruption.  Setting the flag during
+    ** testing causes certain assert() statements in the code to be activated
+    ** that demonstrat invariants on well-formed database files.
+    */
+    case SQLITE_TESTCTRL_NEVER_CORRUPT: {
+      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
+      break;
+    }
+
+    /* Set the threshold at which OP_Once counters reset back to zero.
+    ** By default this is 0x7ffffffe (over 2 billion), but that value is
+    ** too big to test in a reasonable amount of time, so this control is
+    ** provided to set a small and easily reachable reset value.
+    */
+    case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
+      sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
+    **
+    ** Set the VDBE coverage callback function to xCallback with context 
+    ** pointer ptr.
+    */
+    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
+#ifdef SQLITE_VDBE_COVERAGE
+      typedef void (*branch_callback)(void*,int,u8,u8);
+      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
+      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
+#endif
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
+    case SQLITE_TESTCTRL_SORTER_MMAP: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      db->nMaxSorterMmap = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
+    **
+    ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
+    ** not.
+    */
+    case SQLITE_TESTCTRL_ISINIT: {
+      if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
+      break;
+    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
+    **
+    ** This test control is used to create imposter tables.  "db" is a pointer
+    ** to the database connection.  dbName is the database name (ex: "main" or
+    ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
+    ** or off.  "tnum" is the root page of the b-tree to which the imposter
+    ** table should connect.
+    **
+    ** Enable imposter mode only when the schema has already been parsed.  Then
+    ** run a single CREATE TABLE statement to construct the imposter table in
+    ** the parsed schema.  Then turn imposter mode back off again.
+    **
+    ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
+    ** the schema to be reparsed the next time it is needed.  This has the
+    ** effect of erasing all imposter tables.
+    */
+    case SQLITE_TESTCTRL_IMPOSTER: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      sqlite3_mutex_enter(db->mutex);
+      db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
+      db->init.busy = db->init.imposterTable = va_arg(ap,int);
+      db->init.newTnum = va_arg(ap,int);
+      if( db->init.busy==0 && db->init.newTnum>0 ){
+        sqlite3ResetAllSchemasOfConnection(db);
+      }
+      sqlite3_mutex_leave(db->mutex);
+      break;
+    }
+  }
+  va_end(ap);
+#endif /* SQLITE_UNTESTABLE */
+  return rc;
+}
+
+/*
+** This is a utility routine, useful to VFS implementations, that checks
+** to see if a database file was a URI that contained a specific query 
+** parameter, and if so obtains the value of the query parameter.
+**
+** The zFilename argument is the filename pointer passed into the xOpen()
+** method of a VFS implementation.  The zParam argument is the name of the
+** query parameter we seek.  This routine returns the value of the zParam
+** parameter if it exists.  If the parameter does not exist, this routine
+** returns a NULL pointer.
+*/
+SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
+  if( zFilename==0 || zParam==0 ) return 0;
+  zFilename += sqlite3Strlen30(zFilename) + 1;
+  while( zFilename[0] ){
+    int x = strcmp(zFilename, zParam);
+    zFilename += sqlite3Strlen30(zFilename) + 1;
+    if( x==0 ) return zFilename;
+    zFilename += sqlite3Strlen30(zFilename) + 1;
+  }
+  return 0;
+}
+
+/*
+** Return a boolean value for a query parameter.
+*/
+SQLITE_API int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  bDflt = bDflt!=0;
+  return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
+}
+
+/*
+** Return a 64-bit integer value for a query parameter.
+*/
+SQLITE_API sqlite3_int64 sqlite3_uri_int64(
+  const char *zFilename,    /* Filename as passed to xOpen */
+  const char *zParam,       /* URI parameter sought */
+  sqlite3_int64 bDflt       /* return if parameter is missing */
+){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  sqlite3_int64 v;
+  if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
+    bDflt = v;
+  }
+  return bDflt;
+}
+
+/*
+** Return the Btree pointer identified by zDbName.  Return NULL if not found.
+*/
+SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
+  int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
+  return iDb<0 ? 0 : db->aDb[iDb].pBt;
+}
+
+/*
+** Return the filename of the database associated with a database
+** connection.
+*/
+SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
+}
+
+/*
+** Return 1 if database is read-only or 0 if read/write.  Return -1 if
+** no such database exists.
+*/
+SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
+}
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/*
+** Obtain a snapshot handle for the snapshot of database zDb currently 
+** being read by handle db.
+*/
+SQLITE_API int sqlite3_snapshot_get(
+  sqlite3 *db, 
+  const char *zDb,
+  sqlite3_snapshot **ppSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+
+  if( db->autoCommit==0 ){
+    int iDb = sqlite3FindDbName(db, zDb);
+    if( iDb==0 || iDb>1 ){
+      Btree *pBt = db->aDb[iDb].pBt;
+      if( 0==sqlite3BtreeIsInTrans(pBt) ){
+        rc = sqlite3BtreeBeginTrans(pBt, 0);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
+        }
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Open a read-transaction on the snapshot idendified by pSnapshot.
+*/
+SQLITE_API int sqlite3_snapshot_open(
+  sqlite3 *db, 
+  const char *zDb, 
+  sqlite3_snapshot *pSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( db->autoCommit==0 ){
+    int iDb;
+    iDb = sqlite3FindDbName(db, zDb);
+    if( iDb==0 || iDb>1 ){
+      Btree *pBt = db->aDb[iDb].pBt;
+      if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
+        rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3BtreeBeginTrans(pBt, 0);
+          sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
+        }
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Recover as many snapshots as possible from the wal file associated with
+** schema zDb of database db.
+*/
+SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
+  int rc = SQLITE_ERROR;
+  int iDb;
+#ifndef SQLITE_OMIT_WAL
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+
+  sqlite3_mutex_enter(db->mutex);
+  iDb = sqlite3FindDbName(db, zDb);
+  if( iDb==0 || iDb>1 ){
+    Btree *pBt = db->aDb[iDb].pBt;
+    if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
+      rc = sqlite3BtreeBeginTrans(pBt, 0);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
+        sqlite3BtreeCommit(pBt);
+      }
+    }
+  }
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Free a snapshot handle obtained from sqlite3_snapshot_get().
+*/
+SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
+  sqlite3_free(pSnapshot);
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
+
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+/*
+** Given the name of a compile-time option, return true if that option
+** was used and false if not.
+**
+** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
+** is not required for a match.
+*/
+SQLITE_API int sqlite3_compileoption_used(const char *zOptName){
+  int i, n;
+  int nOpt;
+  const char **azCompileOpt;
+ 
+#if SQLITE_ENABLE_API_ARMOR
+  if( zOptName==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+
+  azCompileOpt = sqlite3CompileOptions(&nOpt);
+
+  if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
+  n = sqlite3Strlen30(zOptName);
+
+  /* Since nOpt is normally in single digits, a linear search is 
+  ** adequate. No need for a binary search. */
+  for(i=0; i=0 && NpNextBlocked){
+    int seen = 0;
+    sqlite3 *p2;
+
+    /* Verify property (1) */
+    assert( p->pUnlockConnection || p->pBlockingConnection );
+
+    /* Verify property (2) */
+    for(p2=sqlite3BlockedList; p2!=p; p2=p2->pNextBlocked){
+      if( p2->xUnlockNotify==p->xUnlockNotify ) seen = 1;
+      assert( p2->xUnlockNotify==p->xUnlockNotify || !seen );
+      assert( db==0 || p->pUnlockConnection!=db );
+      assert( db==0 || p->pBlockingConnection!=db );
+    }
+  }
+}
+#else
+# define checkListProperties(x)
+#endif
+
+/*
+** Remove connection db from the blocked connections list. If connection
+** db is not currently a part of the list, this function is a no-op.
+*/
+static void removeFromBlockedList(sqlite3 *db){
+  sqlite3 **pp;
+  assertMutexHeld();
+  for(pp=&sqlite3BlockedList; *pp; pp = &(*pp)->pNextBlocked){
+    if( *pp==db ){
+      *pp = (*pp)->pNextBlocked;
+      break;
+    }
+  }
+}
+
+/*
+** Add connection db to the blocked connections list. It is assumed
+** that it is not already a part of the list.
+*/
+static void addToBlockedList(sqlite3 *db){
+  sqlite3 **pp;
+  assertMutexHeld();
+  for(
+    pp=&sqlite3BlockedList; 
+    *pp && (*pp)->xUnlockNotify!=db->xUnlockNotify; 
+    pp=&(*pp)->pNextBlocked
+  );
+  db->pNextBlocked = *pp;
+  *pp = db;
+}
+
+/*
+** Obtain the STATIC_MASTER mutex.
+*/
+static void enterMutex(void){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  checkListProperties(0);
+}
+
+/*
+** Release the STATIC_MASTER mutex.
+*/
+static void leaveMutex(void){
+  assertMutexHeld();
+  checkListProperties(0);
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+}
+
+/*
+** Register an unlock-notify callback.
+**
+** This is called after connection "db" has attempted some operation
+** but has received an SQLITE_LOCKED error because another connection
+** (call it pOther) in the same process was busy using the same shared
+** cache.  pOther is found by looking at db->pBlockingConnection.
+**
+** If there is no blocking connection, the callback is invoked immediately,
+** before this routine returns.
+**
+** If pOther is already blocked on db, then report SQLITE_LOCKED, to indicate
+** a deadlock.
+**
+** Otherwise, make arrangements to invoke xNotify when pOther drops
+** its locks.
+**
+** Each call to this routine overrides any prior callbacks registered
+** on the same "db".  If xNotify==0 then any prior callbacks are immediately
+** cancelled.
+*/
+SQLITE_API int sqlite3_unlock_notify(
+  sqlite3 *db,
+  void (*xNotify)(void **, int),
+  void *pArg
+){
+  int rc = SQLITE_OK;
+
+  sqlite3_mutex_enter(db->mutex);
+  enterMutex();
+
+  if( xNotify==0 ){
+    removeFromBlockedList(db);
+    db->pBlockingConnection = 0;
+    db->pUnlockConnection = 0;
+    db->xUnlockNotify = 0;
+    db->pUnlockArg = 0;
+  }else if( 0==db->pBlockingConnection ){
+    /* The blocking transaction has been concluded. Or there never was a 
+    ** blocking transaction. In either case, invoke the notify callback
+    ** immediately. 
+    */
+    xNotify(&pArg, 1);
+  }else{
+    sqlite3 *p;
+
+    for(p=db->pBlockingConnection; p && p!=db; p=p->pUnlockConnection){}
+    if( p ){
+      rc = SQLITE_LOCKED;              /* Deadlock detected. */
+    }else{
+      db->pUnlockConnection = db->pBlockingConnection;
+      db->xUnlockNotify = xNotify;
+      db->pUnlockArg = pArg;
+      removeFromBlockedList(db);
+      addToBlockedList(db);
+    }
+  }
+
+  leaveMutex();
+  assert( !db->mallocFailed );
+  sqlite3ErrorWithMsg(db, rc, (rc?"database is deadlocked":0));
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** This function is called while stepping or preparing a statement 
+** associated with connection db. The operation will return SQLITE_LOCKED
+** to the user because it requires a lock that will not be available
+** until connection pBlocker concludes its current transaction.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionBlocked(sqlite3 *db, sqlite3 *pBlocker){
+  enterMutex();
+  if( db->pBlockingConnection==0 && db->pUnlockConnection==0 ){
+    addToBlockedList(db);
+  }
+  db->pBlockingConnection = pBlocker;
+  leaveMutex();
+}
+
+/*
+** This function is called when
+** the transaction opened by database db has just finished. Locks held 
+** by database connection db have been released.
+**
+** This function loops through each entry in the blocked connections
+** list and does the following:
+**
+**   1) If the sqlite3.pBlockingConnection member of a list entry is
+**      set to db, then set pBlockingConnection=0.
+**
+**   2) If the sqlite3.pUnlockConnection member of a list entry is
+**      set to db, then invoke the configured unlock-notify callback and
+**      set pUnlockConnection=0.
+**
+**   3) If the two steps above mean that pBlockingConnection==0 and
+**      pUnlockConnection==0, remove the entry from the blocked connections
+**      list.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionUnlocked(sqlite3 *db){
+  void (*xUnlockNotify)(void **, int) = 0; /* Unlock-notify cb to invoke */
+  int nArg = 0;                            /* Number of entries in aArg[] */
+  sqlite3 **pp;                            /* Iterator variable */
+  void **aArg;               /* Arguments to the unlock callback */
+  void **aDyn = 0;           /* Dynamically allocated space for aArg[] */
+  void *aStatic[16];         /* Starter space for aArg[].  No malloc required */
+
+  aArg = aStatic;
+  enterMutex();         /* Enter STATIC_MASTER mutex */
+
+  /* This loop runs once for each entry in the blocked-connections list. */
+  for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){
+    sqlite3 *p = *pp;
+
+    /* Step 1. */
+    if( p->pBlockingConnection==db ){
+      p->pBlockingConnection = 0;
+    }
+
+    /* Step 2. */
+    if( p->pUnlockConnection==db ){
+      assert( p->xUnlockNotify );
+      if( p->xUnlockNotify!=xUnlockNotify && nArg!=0 ){
+        xUnlockNotify(aArg, nArg);
+        nArg = 0;
+      }
+
+      sqlite3BeginBenignMalloc();
+      assert( aArg==aDyn || (aDyn==0 && aArg==aStatic) );
+      assert( nArg<=(int)ArraySize(aStatic) || aArg==aDyn );
+      if( (!aDyn && nArg==(int)ArraySize(aStatic))
+       || (aDyn && nArg==(int)(sqlite3MallocSize(aDyn)/sizeof(void*)))
+      ){
+        /* The aArg[] array needs to grow. */
+        void **pNew = (void **)sqlite3Malloc(nArg*sizeof(void *)*2);
+        if( pNew ){
+          memcpy(pNew, aArg, nArg*sizeof(void *));
+          sqlite3_free(aDyn);
+          aDyn = aArg = pNew;
+        }else{
+          /* This occurs when the array of context pointers that need to
+          ** be passed to the unlock-notify callback is larger than the
+          ** aStatic[] array allocated on the stack and the attempt to 
+          ** allocate a larger array from the heap has failed.
+          **
+          ** This is a difficult situation to handle. Returning an error
+          ** code to the caller is insufficient, as even if an error code
+          ** is returned the transaction on connection db will still be
+          ** closed and the unlock-notify callbacks on blocked connections
+          ** will go unissued. This might cause the application to wait
+          ** indefinitely for an unlock-notify callback that will never 
+          ** arrive.
+          **
+          ** Instead, invoke the unlock-notify callback with the context
+          ** array already accumulated. We can then clear the array and
+          ** begin accumulating any further context pointers without 
+          ** requiring any dynamic allocation. This is sub-optimal because
+          ** it means that instead of one callback with a large array of
+          ** context pointers the application will receive two or more
+          ** callbacks with smaller arrays of context pointers, which will
+          ** reduce the applications ability to prioritize multiple 
+          ** connections. But it is the best that can be done under the
+          ** circumstances.
+          */
+          xUnlockNotify(aArg, nArg);
+          nArg = 0;
+        }
+      }
+      sqlite3EndBenignMalloc();
+
+      aArg[nArg++] = p->pUnlockArg;
+      xUnlockNotify = p->xUnlockNotify;
+      p->pUnlockConnection = 0;
+      p->xUnlockNotify = 0;
+      p->pUnlockArg = 0;
+    }
+
+    /* Step 3. */
+    if( p->pBlockingConnection==0 && p->pUnlockConnection==0 ){
+      /* Remove connection p from the blocked connections list. */
+      *pp = p->pNextBlocked;
+      p->pNextBlocked = 0;
+    }else{
+      pp = &p->pNextBlocked;
+    }
+  }
+
+  if( nArg!=0 ){
+    xUnlockNotify(aArg, nArg);
+  }
+  sqlite3_free(aDyn);
+  leaveMutex();         /* Leave STATIC_MASTER mutex */
+}
+
+/*
+** This is called when the database connection passed as an argument is 
+** being closed. The connection is removed from the blocked list.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
+  sqlite3ConnectionUnlocked(db);
+  enterMutex();
+  removeFromBlockedList(db);
+  checkListProperties(db);
+  leaveMutex();
+}
+#endif
+
+/************** End of notify.c **********************************************/
+/************** Begin file fts3.c ********************************************/
+/*
+** 2006 Oct 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is an SQLite module implementing full-text search.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+**     * The FTS3 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS3 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+
+/* The full-text index is stored in a series of b+tree (-like)
+** structures called segments which map terms to doclists.  The
+** structures are like b+trees in layout, but are constructed from the
+** bottom up in optimal fashion and are not updatable.  Since trees
+** are built from the bottom up, things will be described from the
+** bottom up.
+**
+**
+**** Varints ****
+** The basic unit of encoding is a variable-length integer called a
+** varint.  We encode variable-length integers in little-endian order
+** using seven bits * per byte as follows:
+**
+** KEY:
+**         A = 0xxxxxxx    7 bits of data and one flag bit
+**         B = 1xxxxxxx    7 bits of data and one flag bit
+**
+**  7 bits - A
+** 14 bits - BA
+** 21 bits - BBA
+** and so on.
+**
+** This is similar in concept to how sqlite encodes "varints" but
+** the encoding is not the same.  SQLite varints are big-endian
+** are are limited to 9 bytes in length whereas FTS3 varints are
+** little-endian and can be up to 10 bytes in length (in theory).
+**
+** Example encodings:
+**
+**     1:    0x01
+**   127:    0x7f
+**   128:    0x81 0x00
+**
+**
+**** Document lists ****
+** A doclist (document list) holds a docid-sorted list of hits for a
+** given term.  Doclists hold docids and associated token positions.
+** A docid is the unique integer identifier for a single document.
+** A position is the index of a word within the document.  The first 
+** word of the document has a position of 0.
+**
+** FTS3 used to optionally store character offsets using a compile-time
+** option.  But that functionality is no longer supported.
+**
+** A doclist is stored like this:
+**
+** array {
+**   varint docid;          (delta from previous doclist)
+**   array {                (position list for column 0)
+**     varint position;     (2 more than the delta from previous position)
+**   }
+**   array {
+**     varint POS_COLUMN;   (marks start of position list for new column)
+**     varint column;       (index of new column)
+**     array {
+**       varint position;   (2 more than the delta from previous position)
+**     }
+**   }
+**   varint POS_END;        (marks end of positions for this document.
+** }
+**
+** Here, array { X } means zero or more occurrences of X, adjacent in
+** memory.  A "position" is an index of a token in the token stream
+** generated by the tokenizer. Note that POS_END and POS_COLUMN occur 
+** in the same logical place as the position element, and act as sentinals
+** ending a position list array.  POS_END is 0.  POS_COLUMN is 1.
+** The positions numbers are not stored literally but rather as two more
+** than the difference from the prior position, or the just the position plus
+** 2 for the first position.  Example:
+**
+**   label:       A B C D E  F  G H   I  J K
+**   value:     123 5 9 1 1 14 35 0 234 72 0
+**
+** The 123 value is the first docid.  For column zero in this document
+** there are two matches at positions 3 and 10 (5-2 and 9-2+3).  The 1
+** at D signals the start of a new column; the 1 at E indicates that the
+** new column is column number 1.  There are two positions at 12 and 45
+** (14-2 and 35-2+12).  The 0 at H indicate the end-of-document.  The
+** 234 at I is the delta to next docid (357).  It has one position 70
+** (72-2) and then terminates with the 0 at K.
+**
+** A "position-list" is the list of positions for multiple columns for
+** a single docid.  A "column-list" is the set of positions for a single
+** column.  Hence, a position-list consists of one or more column-lists,
+** a document record consists of a docid followed by a position-list and
+** a doclist consists of one or more document records.
+**
+** A bare doclist omits the position information, becoming an 
+** array of varint-encoded docids.
+**
+**** Segment leaf nodes ****
+** Segment leaf nodes store terms and doclists, ordered by term.  Leaf
+** nodes are written using LeafWriter, and read using LeafReader (to
+** iterate through a single leaf node's data) and LeavesReader (to
+** iterate through a segment's entire leaf layer).  Leaf nodes have
+** the format:
+**
+** varint iHeight;             (height from leaf level, always 0)
+** varint nTerm;               (length of first term)
+** char pTerm[nTerm];          (content of first term)
+** varint nDoclist;            (length of term's associated doclist)
+** char pDoclist[nDoclist];    (content of doclist)
+** array {
+**                             (further terms are delta-encoded)
+**   varint nPrefix;           (length of prefix shared with previous term)
+**   varint nSuffix;           (length of unshared suffix)
+**   char pTermSuffix[nSuffix];(unshared suffix of next term)
+**   varint nDoclist;          (length of term's associated doclist)
+**   char pDoclist[nDoclist];  (content of doclist)
+** }
+**
+** Here, array { X } means zero or more occurrences of X, adjacent in
+** memory.
+**
+** Leaf nodes are broken into blocks which are stored contiguously in
+** the %_segments table in sorted order.  This means that when the end
+** of a node is reached, the next term is in the node with the next
+** greater node id.
+**
+** New data is spilled to a new leaf node when the current node
+** exceeds LEAF_MAX bytes (default 2048).  New data which itself is
+** larger than STANDALONE_MIN (default 1024) is placed in a standalone
+** node (a leaf node with a single term and doclist).  The goal of
+** these settings is to pack together groups of small doclists while
+** making it efficient to directly access large doclists.  The
+** assumption is that large doclists represent terms which are more
+** likely to be query targets.
+**
+** TODO(shess) It may be useful for blocking decisions to be more
+** dynamic.  For instance, it may make more sense to have a 2.5k leaf
+** node rather than splitting into 2k and .5k nodes.  My intuition is
+** that this might extend through 2x or 4x the pagesize.
+**
+**
+**** Segment interior nodes ****
+** Segment interior nodes store blockids for subtree nodes and terms
+** to describe what data is stored by the each subtree.  Interior
+** nodes are written using InteriorWriter, and read using
+** InteriorReader.  InteriorWriters are created as needed when
+** SegmentWriter creates new leaf nodes, or when an interior node
+** itself grows too big and must be split.  The format of interior
+** nodes:
+**
+** varint iHeight;           (height from leaf level, always >0)
+** varint iBlockid;          (block id of node's leftmost subtree)
+** optional {
+**   varint nTerm;           (length of first term)
+**   char pTerm[nTerm];      (content of first term)
+**   array {
+**                                (further terms are delta-encoded)
+**     varint nPrefix;            (length of shared prefix with previous term)
+**     varint nSuffix;            (length of unshared suffix)
+**     char pTermSuffix[nSuffix]; (unshared suffix of next term)
+**   }
+** }
+**
+** Here, optional { X } means an optional element, while array { X }
+** means zero or more occurrences of X, adjacent in memory.
+**
+** An interior node encodes n terms separating n+1 subtrees.  The
+** subtree blocks are contiguous, so only the first subtree's blockid
+** is encoded.  The subtree at iBlockid will contain all terms less
+** than the first term encoded (or all terms if no term is encoded).
+** Otherwise, for terms greater than or equal to pTerm[i] but less
+** than pTerm[i+1], the subtree for that term will be rooted at
+** iBlockid+i.  Interior nodes only store enough term data to
+** distinguish adjacent children (if the rightmost term of the left
+** child is "something", and the leftmost term of the right child is
+** "wicked", only "w" is stored).
+**
+** New data is spilled to a new interior node at the same height when
+** the current node exceeds INTERIOR_MAX bytes (default 2048).
+** INTERIOR_MIN_TERMS (default 7) keeps large terms from monopolizing
+** interior nodes and making the tree too skinny.  The interior nodes
+** at a given height are naturally tracked by interior nodes at
+** height+1, and so on.
+**
+**
+**** Segment directory ****
+** The segment directory in table %_segdir stores meta-information for
+** merging and deleting segments, and also the root node of the
+** segment's tree.
+**
+** The root node is the top node of the segment's tree after encoding
+** the entire segment, restricted to ROOT_MAX bytes (default 1024).
+** This could be either a leaf node or an interior node.  If the top
+** node requires more than ROOT_MAX bytes, it is flushed to %_segments
+** and a new root interior node is generated (which should always fit
+** within ROOT_MAX because it only needs space for 2 varints, the
+** height and the blockid of the previous root).
+**
+** The meta-information in the segment directory is:
+**   level               - segment level (see below)
+**   idx                 - index within level
+**                       - (level,idx uniquely identify a segment)
+**   start_block         - first leaf node
+**   leaves_end_block    - last leaf node
+**   end_block           - last block (including interior nodes)
+**   root                - contents of root node
+**
+** If the root node is a leaf node, then start_block,
+** leaves_end_block, and end_block are all 0.
+**
+**
+**** Segment merging ****
+** To amortize update costs, segments are grouped into levels and
+** merged in batches.  Each increase in level represents exponentially
+** more documents.
+**
+** New documents (actually, document updates) are tokenized and
+** written individually (using LeafWriter) to a level 0 segment, with
+** incrementing idx.  When idx reaches MERGE_COUNT (default 16), all
+** level 0 segments are merged into a single level 1 segment.  Level 1
+** is populated like level 0, and eventually MERGE_COUNT level 1
+** segments are merged to a single level 2 segment (representing
+** MERGE_COUNT^2 updates), and so on.
+**
+** A segment merge traverses all segments at a given level in
+** parallel, performing a straightforward sorted merge.  Since segment
+** leaf nodes are written in to the %_segments table in order, this
+** merge traverses the underlying sqlite disk structures efficiently.
+** After the merge, all segment blocks from the merged level are
+** deleted.
+**
+** MERGE_COUNT controls how often we merge segments.  16 seems to be
+** somewhat of a sweet spot for insertion performance.  32 and 64 show
+** very similar performance numbers to 16 on insertion, though they're
+** a tiny bit slower (perhaps due to more overhead in merge-time
+** sorting).  8 is about 20% slower than 16, 4 about 50% slower than
+** 16, 2 about 66% slower than 16.
+**
+** At query time, high MERGE_COUNT increases the number of segments
+** which need to be scanned and merged.  For instance, with 100k docs
+** inserted:
+**
+**    MERGE_COUNT   segments
+**       16           25
+**        8           12
+**        4           10
+**        2            6
+**
+** This appears to have only a moderate impact on queries for very
+** frequent terms (which are somewhat dominated by segment merge
+** costs), and infrequent and non-existent terms still seem to be fast
+** even with many segments.
+**
+** TODO(shess) That said, it would be nice to have a better query-side
+** argument for MERGE_COUNT of 16.  Also, it is possible/likely that
+** optimizations to things like doclist merging will swing the sweet
+** spot around.
+**
+**
+**
+**** Handling of deletions and updates ****
+** Since we're using a segmented structure, with no docid-oriented
+** index into the term index, we clearly cannot simply update the term
+** index when a document is deleted or updated.  For deletions, we
+** write an empty doclist (varint(docid) varint(POS_END)), for updates
+** we simply write the new doclist.  Segment merges overwrite older
+** data for a particular docid with newer data, so deletes or updates
+** will eventually overtake the earlier data and knock it out.  The
+** query logic likewise merges doclists so that newer data knocks out
+** older data.
+*/
+
+/************** Include fts3Int.h in the middle of fts3.c ********************/
+/************** Begin file fts3Int.h *****************************************/
+/*
+** 2009 Nov 12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+#ifndef _FTSINT_H
+#define _FTSINT_H
+
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
+# define NDEBUG 1
+#endif
+
+/* FTS3/FTS4 require virtual tables */
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+# undef SQLITE_ENABLE_FTS3
+# undef SQLITE_ENABLE_FTS4
+#endif
+
+/*
+** FTS4 is really an extension for FTS3.  It is enabled using the
+** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
+** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
+*/
+#if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
+# define SQLITE_ENABLE_FTS3
+#endif
+
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* If not building as part of the core, include sqlite3ext.h. */
+#ifndef SQLITE_CORE
+/* # include "sqlite3ext.h"  */
+SQLITE_EXTENSION_INIT3
+#endif
+
+/* #include "sqlite3.h" */
+/************** Include fts3_tokenizer.h in the middle of fts3Int.h **********/
+/************** Begin file fts3_tokenizer.h **********************************/
+/*
+** 2006 July 10
+**
+** The author disclaims copyright to this source code.
+**
+*************************************************************************
+** Defines the interface to tokenizers used by fulltext-search.  There
+** are three basic components:
+**
+** sqlite3_tokenizer_module is a singleton defining the tokenizer
+** interface functions.  This is essentially the class structure for
+** tokenizers.
+**
+** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
+** including customization information defined at creation time.
+**
+** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
+** tokens from a particular input.
+*/
+#ifndef _FTS3_TOKENIZER_H_
+#define _FTS3_TOKENIZER_H_
+
+/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
+** If tokenizers are to be allowed to call sqlite3_*() functions, then
+** we will need a way to register the API consistently.
+*/
+/* #include "sqlite3.h" */
+
+/*
+** Structures used by the tokenizer interface. When a new tokenizer
+** implementation is registered, the caller provides a pointer to
+** an sqlite3_tokenizer_module containing pointers to the callback
+** functions that make up an implementation.
+**
+** When an fts3 table is created, it passes any arguments passed to
+** the tokenizer clause of the CREATE VIRTUAL TABLE statement to the
+** sqlite3_tokenizer_module.xCreate() function of the requested tokenizer
+** implementation. The xCreate() function in turn returns an 
+** sqlite3_tokenizer structure representing the specific tokenizer to
+** be used for the fts3 table (customized by the tokenizer clause arguments).
+**
+** To tokenize an input buffer, the sqlite3_tokenizer_module.xOpen()
+** method is called. It returns an sqlite3_tokenizer_cursor object
+** that may be used to tokenize a specific input buffer based on
+** the tokenization rules supplied by a specific sqlite3_tokenizer
+** object.
+*/
+typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
+typedef struct sqlite3_tokenizer sqlite3_tokenizer;
+typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
+
+struct sqlite3_tokenizer_module {
+
+  /*
+  ** Structure version. Should always be set to 0 or 1.
+  */
+  int iVersion;
+
+  /*
+  ** Create a new tokenizer. The values in the argv[] array are the
+  ** arguments passed to the "tokenizer" clause of the CREATE VIRTUAL
+  ** TABLE statement that created the fts3 table. For example, if
+  ** the following SQL is executed:
+  **
+  **   CREATE .. USING fts3( ... , tokenizer  arg1 arg2)
+  **
+  ** then argc is set to 2, and the argv[] array contains pointers
+  ** to the strings "arg1" and "arg2".
+  **
+  ** This method should return either SQLITE_OK (0), or an SQLite error 
+  ** code. If SQLITE_OK is returned, then *ppTokenizer should be set
+  ** to point at the newly created tokenizer structure. The generic
+  ** sqlite3_tokenizer.pModule variable should not be initialized by
+  ** this callback. The caller will do so.
+  */
+  int (*xCreate)(
+    int argc,                           /* Size of argv array */
+    const char *const*argv,             /* Tokenizer argument strings */
+    sqlite3_tokenizer **ppTokenizer     /* OUT: Created tokenizer */
+  );
+
+  /*
+  ** Destroy an existing tokenizer. The fts3 module calls this method
+  ** exactly once for each successful call to xCreate().
+  */
+  int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
+
+  /*
+  ** Create a tokenizer cursor to tokenize an input buffer. The caller
+  ** is responsible for ensuring that the input buffer remains valid
+  ** until the cursor is closed (using the xClose() method). 
+  */
+  int (*xOpen)(
+    sqlite3_tokenizer *pTokenizer,       /* Tokenizer object */
+    const char *pInput, int nBytes,      /* Input buffer */
+    sqlite3_tokenizer_cursor **ppCursor  /* OUT: Created tokenizer cursor */
+  );
+
+  /*
+  ** Destroy an existing tokenizer cursor. The fts3 module calls this 
+  ** method exactly once for each successful call to xOpen().
+  */
+  int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
+
+  /*
+  ** Retrieve the next token from the tokenizer cursor pCursor. This
+  ** method should either return SQLITE_OK and set the values of the
+  ** "OUT" variables identified below, or SQLITE_DONE to indicate that
+  ** the end of the buffer has been reached, or an SQLite error code.
+  **
+  ** *ppToken should be set to point at a buffer containing the 
+  ** normalized version of the token (i.e. after any case-folding and/or
+  ** stemming has been performed). *pnBytes should be set to the length
+  ** of this buffer in bytes. The input text that generated the token is
+  ** identified by the byte offsets returned in *piStartOffset and
+  ** *piEndOffset. *piStartOffset should be set to the index of the first
+  ** byte of the token in the input buffer. *piEndOffset should be set
+  ** to the index of the first byte just past the end of the token in
+  ** the input buffer.
+  **
+  ** The buffer *ppToken is set to point at is managed by the tokenizer
+  ** implementation. It is only required to be valid until the next call
+  ** to xNext() or xClose(). 
+  */
+  /* TODO(shess) current implementation requires pInput to be
+  ** nul-terminated.  This should either be fixed, or pInput/nBytes
+  ** should be converted to zInput.
+  */
+  int (*xNext)(
+    sqlite3_tokenizer_cursor *pCursor,   /* Tokenizer cursor */
+    const char **ppToken, int *pnBytes,  /* OUT: Normalized text for token */
+    int *piStartOffset,  /* OUT: Byte offset of token in input buffer */
+    int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */
+    int *piPosition      /* OUT: Number of tokens returned before this one */
+  );
+
+  /***********************************************************************
+  ** Methods below this point are only available if iVersion>=1.
+  */
+
+  /* 
+  ** Configure the language id of a tokenizer cursor.
+  */
+  int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
+};
+
+struct sqlite3_tokenizer {
+  const sqlite3_tokenizer_module *pModule;  /* The module for this tokenizer */
+  /* Tokenizer implementations will typically add additional fields */
+};
+
+struct sqlite3_tokenizer_cursor {
+  sqlite3_tokenizer *pTokenizer;       /* Tokenizer for this cursor. */
+  /* Tokenizer implementations will typically add additional fields */
+};
+
+int fts3_global_term_cnt(int iTerm, int iCol);
+int fts3_term_cnt(int iTerm, int iCol);
+
+
+#endif /* _FTS3_TOKENIZER_H_ */
+
+/************** End of fts3_tokenizer.h **************************************/
+/************** Continuing where we left off in fts3Int.h ********************/
+/************** Include fts3_hash.h in the middle of fts3Int.h ***************/
+/************** Begin file fts3_hash.h ***************************************/
+/*
+** 2001 September 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the header file for the generic hash-table implementation
+** used in SQLite.  We've modified it slightly to serve as a standalone
+** hash table implementation for the full-text indexing module.
+**
+*/
+#ifndef _FTS3_HASH_H_
+#define _FTS3_HASH_H_
+
+/* Forward declarations of structures. */
+typedef struct Fts3Hash Fts3Hash;
+typedef struct Fts3HashElem Fts3HashElem;
+
+/* A complete hash table is an instance of the following structure.
+** The internals of this structure are intended to be opaque -- client
+** code should not attempt to access or modify the fields of this structure
+** directly.  Change this structure only by using the routines below.
+** However, many of the "procedures" and "functions" for modifying and
+** accessing this structure are really macros, so we can't really make
+** this structure opaque.
+*/
+struct Fts3Hash {
+  char keyClass;          /* HASH_INT, _POINTER, _STRING, _BINARY */
+  char copyKey;           /* True if copy of key made on insert */
+  int count;              /* Number of entries in this table */
+  Fts3HashElem *first;    /* The first element of the array */
+  int htsize;             /* Number of buckets in the hash table */
+  struct _fts3ht {        /* the hash table */
+    int count;               /* Number of entries with this hash */
+    Fts3HashElem *chain;     /* Pointer to first entry with this hash */
+  } *ht;
+};
+
+/* Each element in the hash table is an instance of the following 
+** structure.  All elements are stored on a single doubly-linked list.
+**
+** Again, this structure is intended to be opaque, but it can't really
+** be opaque because it is used by macros.
+*/
+struct Fts3HashElem {
+  Fts3HashElem *next, *prev; /* Next and previous elements in the table */
+  void *data;                /* Data associated with this element */
+  void *pKey; int nKey;      /* Key associated with this element */
+};
+
+/*
+** There are 2 different modes of operation for a hash table:
+**
+**   FTS3_HASH_STRING        pKey points to a string that is nKey bytes long
+**                           (including the null-terminator, if any).  Case
+**                           is respected in comparisons.
+**
+**   FTS3_HASH_BINARY        pKey points to binary data nKey bytes long. 
+**                           memcmp() is used to compare keys.
+**
+** A copy of the key is made if the copyKey parameter to fts3HashInit is 1.  
+*/
+#define FTS3_HASH_STRING    1
+#define FTS3_HASH_BINARY    2
+
+/*
+** Access routines.  To delete, insert a NULL pointer.
+*/
+SQLITE_PRIVATE void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey);
+SQLITE_PRIVATE void *sqlite3Fts3HashInsert(Fts3Hash*, const void *pKey, int nKey, void *pData);
+SQLITE_PRIVATE void *sqlite3Fts3HashFind(const Fts3Hash*, const void *pKey, int nKey);
+SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash*);
+SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const void *, int);
+
+/*
+** Shorthand for the functions above
+*/
+#define fts3HashInit     sqlite3Fts3HashInit
+#define fts3HashInsert   sqlite3Fts3HashInsert
+#define fts3HashFind     sqlite3Fts3HashFind
+#define fts3HashClear    sqlite3Fts3HashClear
+#define fts3HashFindElem sqlite3Fts3HashFindElem
+
+/*
+** Macros for looping over all elements of a hash table.  The idiom is
+** like this:
+**
+**   Fts3Hash h;
+**   Fts3HashElem *p;
+**   ...
+**   for(p=fts3HashFirst(&h); p; p=fts3HashNext(p)){
+**     SomeStructure *pData = fts3HashData(p);
+**     // do something with pData
+**   }
+*/
+#define fts3HashFirst(H)  ((H)->first)
+#define fts3HashNext(E)   ((E)->next)
+#define fts3HashData(E)   ((E)->data)
+#define fts3HashKey(E)    ((E)->pKey)
+#define fts3HashKeysize(E) ((E)->nKey)
+
+/*
+** Number of entries in a hash table
+*/
+#define fts3HashCount(H)  ((H)->count)
+
+#endif /* _FTS3_HASH_H_ */
+
+/************** End of fts3_hash.h *******************************************/
+/************** Continuing where we left off in fts3Int.h ********************/
+
+/*
+** This constant determines the maximum depth of an FTS expression tree
+** that the library will create and use. FTS uses recursion to perform 
+** various operations on the query tree, so the disadvantage of a large
+** limit is that it may allow very large queries to use large amounts
+** of stack space (perhaps causing a stack overflow).
+*/
+#ifndef SQLITE_FTS3_MAX_EXPR_DEPTH
+# define SQLITE_FTS3_MAX_EXPR_DEPTH 12
+#endif
+
+
+/*
+** This constant controls how often segments are merged. Once there are
+** FTS3_MERGE_COUNT segments of level N, they are merged into a single
+** segment of level N+1.
+*/
+#define FTS3_MERGE_COUNT 16
+
+/*
+** This is the maximum amount of data (in bytes) to store in the 
+** Fts3Table.pendingTerms hash table. Normally, the hash table is
+** populated as documents are inserted/updated/deleted in a transaction
+** and used to create a new segment when the transaction is committed.
+** However if this limit is reached midway through a transaction, a new 
+** segment is created and the hash table cleared immediately.
+*/
+#define FTS3_MAX_PENDING_DATA (1*1024*1024)
+
+/*
+** Macro to return the number of elements in an array. SQLite has a
+** similar macro called ArraySize(). Use a different name to avoid
+** a collision when building an amalgamation with built-in FTS3.
+*/
+#define SizeofArray(X) ((int)(sizeof(X)/sizeof(X[0])))
+
+
+#ifndef MIN
+# define MIN(x,y) ((x)<(y)?(x):(y))
+#endif
+#ifndef MAX
+# define MAX(x,y) ((x)>(y)?(x):(y))
+#endif
+
+/*
+** Maximum length of a varint encoded integer. The varint format is different
+** from that used by SQLite, so the maximum length is 10, not 9.
+*/
+#define FTS3_VARINT_MAX 10
+
+/*
+** FTS4 virtual tables may maintain multiple indexes - one index of all terms
+** in the document set and zero or more prefix indexes. All indexes are stored
+** as one or more b+-trees in the %_segments and %_segdir tables. 
+**
+** It is possible to determine which index a b+-tree belongs to based on the
+** value stored in the "%_segdir.level" column. Given this value L, the index
+** that the b+-tree belongs to is (L<<10). In other words, all b+-trees with
+** level values between 0 and 1023 (inclusive) belong to index 0, all levels
+** between 1024 and 2047 to index 1, and so on.
+**
+** It is considered impossible for an index to use more than 1024 levels. In 
+** theory though this may happen, but only after at least 
+** (FTS3_MERGE_COUNT^1024) separate flushes of the pending-terms tables.
+*/
+#define FTS3_SEGDIR_MAXLEVEL      1024
+#define FTS3_SEGDIR_MAXLEVEL_STR "1024"
+
+/*
+** The testcase() macro is only used by the amalgamation.  If undefined,
+** make it a no-op.
+*/
+#ifndef testcase
+# define testcase(X)
+#endif
+
+/*
+** Terminator values for position-lists and column-lists.
+*/
+#define POS_COLUMN  (1)     /* Column-list terminator */
+#define POS_END     (0)     /* Position-list terminator */ 
+
+/*
+** This section provides definitions to allow the
+** FTS3 extension to be compiled outside of the 
+** amalgamation.
+*/
+#ifndef SQLITE_AMALGAMATION
+/*
+** Macros indicating that conditional expressions are always true or
+** false.
+*/
+#ifdef SQLITE_COVERAGE_TEST
+# define ALWAYS(x) (1)
+# define NEVER(X)  (0)
+#elif defined(SQLITE_DEBUG)
+# define ALWAYS(x) sqlite3Fts3Always((x)!=0)
+# define NEVER(x) sqlite3Fts3Never((x)!=0)
+SQLITE_PRIVATE int sqlite3Fts3Always(int b);
+SQLITE_PRIVATE int sqlite3Fts3Never(int b);
+#else
+# define ALWAYS(x) (x)
+# define NEVER(x)  (x)
+#endif
+
+/*
+** Internal types used by SQLite.
+*/
+typedef unsigned char u8;         /* 1-byte (or larger) unsigned integer */
+typedef short int i16;            /* 2-byte (or larger) signed integer */
+typedef unsigned int u32;         /* 4-byte unsigned integer */
+typedef sqlite3_uint64 u64;       /* 8-byte unsigned integer */
+typedef sqlite3_int64 i64;        /* 8-byte signed integer */
+
+/*
+** Macro used to suppress compiler warnings for unused parameters.
+*/
+#define UNUSED_PARAMETER(x) (void)(x)
+
+/*
+** Activate assert() only if SQLITE_TEST is enabled.
+*/
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
+# define NDEBUG 1
+#endif
+
+/*
+** The TESTONLY macro is used to enclose variable declarations or
+** other bits of code that are needed to support the arguments
+** within testcase() and assert() macros.
+*/
+#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
+# define TESTONLY(X)  X
+#else
+# define TESTONLY(X)
+#endif
+
+#endif /* SQLITE_AMALGAMATION */
+
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3Fts3Corrupt(void);
+# define FTS_CORRUPT_VTAB sqlite3Fts3Corrupt()
+#else
+# define FTS_CORRUPT_VTAB SQLITE_CORRUPT_VTAB
+#endif
+
+typedef struct Fts3Table Fts3Table;
+typedef struct Fts3Cursor Fts3Cursor;
+typedef struct Fts3Expr Fts3Expr;
+typedef struct Fts3Phrase Fts3Phrase;
+typedef struct Fts3PhraseToken Fts3PhraseToken;
+
+typedef struct Fts3Doclist Fts3Doclist;
+typedef struct Fts3SegFilter Fts3SegFilter;
+typedef struct Fts3DeferredToken Fts3DeferredToken;
+typedef struct Fts3SegReader Fts3SegReader;
+typedef struct Fts3MultiSegReader Fts3MultiSegReader;
+
+typedef struct MatchinfoBuffer MatchinfoBuffer;
+
+/*
+** A connection to a fulltext index is an instance of the following
+** structure. The xCreate and xConnect methods create an instance
+** of this structure and xDestroy and xDisconnect free that instance.
+** All other methods receive a pointer to the structure as one of their
+** arguments.
+*/
+struct Fts3Table {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  sqlite3 *db;                    /* The database connection */
+  const char *zDb;                /* logical database name */
+  const char *zName;              /* virtual table name */
+  int nColumn;                    /* number of named columns in virtual table */
+  char **azColumn;                /* column names.  malloced */
+  u8 *abNotindexed;               /* True for 'notindexed' columns */
+  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
+  char *zContentTbl;              /* content=xxx option, or NULL */
+  char *zLanguageid;              /* languageid=xxx option, or NULL */
+  int nAutoincrmerge;             /* Value configured by 'automerge' */
+  u32 nLeafAdd;                   /* Number of leaf blocks added this trans */
+
+  /* Precompiled statements used by the implementation. Each of these 
+  ** statements is run and reset within a single virtual table API call. 
+  */
+  sqlite3_stmt *aStmt[40];
+  sqlite3_stmt *pSeekStmt;        /* Cache for fts3CursorSeekStmt() */
+
+  char *zReadExprlist;
+  char *zWriteExprlist;
+
+  int nNodeSize;                  /* Soft limit for node size */
+  u8 bFts4;                       /* True for FTS4, false for FTS3 */
+  u8 bHasStat;                    /* True if %_stat table exists (2==unknown) */
+  u8 bHasDocsize;                 /* True if %_docsize table exists */
+  u8 bDescIdx;                    /* True if doclists are in reverse order */
+  u8 bIgnoreSavepoint;            /* True to ignore xSavepoint invocations */
+  int nPgsz;                      /* Page size for host database */
+  char *zSegmentsTbl;             /* Name of %_segments table */
+  sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */
+
+  /* 
+  ** The following array of hash tables is used to buffer pending index 
+  ** updates during transactions. All pending updates buffered at any one
+  ** time must share a common language-id (see the FTS4 langid= feature).
+  ** The current language id is stored in variable iPrevLangid.
+  **
+  ** A single FTS4 table may have multiple full-text indexes. For each index
+  ** there is an entry in the aIndex[] array. Index 0 is an index of all the
+  ** terms that appear in the document set. Each subsequent index in aIndex[]
+  ** is an index of prefixes of a specific length.
+  **
+  ** Variable nPendingData contains an estimate the memory consumed by the 
+  ** pending data structures, including hash table overhead, but not including
+  ** malloc overhead.  When nPendingData exceeds nMaxPendingData, all hash
+  ** tables are flushed to disk. Variable iPrevDocid is the docid of the most 
+  ** recently inserted record.
+  */
+  int nIndex;                     /* Size of aIndex[] */
+  struct Fts3Index {
+    int nPrefix;                  /* Prefix length (0 for main terms index) */
+    Fts3Hash hPending;            /* Pending terms table for this index */
+  } *aIndex;
+  int nMaxPendingData;            /* Max pending data before flush to disk */
+  int nPendingData;               /* Current bytes of pending data */
+  sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */
+  int iPrevLangid;                /* Langid of recently inserted document */
+  int bPrevDelete;                /* True if last operation was a delete */
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
+  /* State variables used for validating that the transaction control
+  ** methods of the virtual table are called at appropriate times.  These
+  ** values do not contribute to FTS functionality; they are used for
+  ** verifying the operation of the SQLite core.
+  */
+  int inTransaction;     /* True after xBegin but before xCommit/xRollback */
+  int mxSavepoint;       /* Largest valid xSavepoint integer */
+#endif
+
+#ifdef SQLITE_TEST
+  /* True to disable the incremental doclist optimization. This is controled
+  ** by special insert command 'test-no-incr-doclist'.  */
+  int bNoIncrDoclist;
+#endif
+};
+
+/*
+** When the core wants to read from the virtual table, it creates a
+** virtual table cursor (an instance of the following structure) using
+** the xOpen method. Cursors are destroyed using the xClose method.
+*/
+struct Fts3Cursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  i16 eSearch;                    /* Search strategy (see below) */
+  u8 isEof;                       /* True if at End Of Results */
+  u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
+  u8 bSeekStmt;                   /* True if pStmt is a seek */
+  sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
+  Fts3Expr *pExpr;                /* Parsed MATCH query string */
+  int iLangid;                    /* Language being queried for */
+  int nPhrase;                    /* Number of matchable phrases in query */
+  Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
+  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
+  char *pNextId;                  /* Pointer into the body of aDoclist */
+  char *aDoclist;                 /* List of docids for full-text queries */
+  int nDoclist;                   /* Size of buffer at aDoclist */
+  u8 bDesc;                       /* True to sort in descending order */
+  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
+  int nRowAvg;                    /* Average size of database rows, in pages */
+  sqlite3_int64 nDoc;             /* Documents in table */
+  i64 iMinDocid;                  /* Minimum docid to return */
+  i64 iMaxDocid;                  /* Maximum docid to return */
+  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
+  MatchinfoBuffer *pMIBuffer;     /* Buffer for matchinfo data */
+};
+
+#define FTS3_EVAL_FILTER    0
+#define FTS3_EVAL_NEXT      1
+#define FTS3_EVAL_MATCHINFO 2
+
+/*
+** The Fts3Cursor.eSearch member is always set to one of the following.
+** Actualy, Fts3Cursor.eSearch can be greater than or equal to
+** FTS3_FULLTEXT_SEARCH.  If so, then Fts3Cursor.eSearch - 2 is the index
+** of the column to be searched.  For example, in
+**
+**     CREATE VIRTUAL TABLE ex1 USING fts3(a,b,c,d);
+**     SELECT docid FROM ex1 WHERE b MATCH 'one two three';
+** 
+** Because the LHS of the MATCH operator is 2nd column "b",
+** Fts3Cursor.eSearch will be set to FTS3_FULLTEXT_SEARCH+1.  (+0 for a,
+** +1 for b, +2 for c, +3 for d.)  If the LHS of MATCH were "ex1" 
+** indicating that all columns should be searched,
+** then eSearch would be set to FTS3_FULLTEXT_SEARCH+4.
+*/
+#define FTS3_FULLSCAN_SEARCH 0    /* Linear scan of %_content table */
+#define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
+#define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */
+
+/*
+** The lower 16-bits of the sqlite3_index_info.idxNum value set by
+** the xBestIndex() method contains the Fts3Cursor.eSearch value described
+** above. The upper 16-bits contain a combination of the following
+** bits, used to describe extra constraints on full-text searches.
+*/
+#define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */
+#define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */
+#define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */
+
+struct Fts3Doclist {
+  char *aAll;                    /* Array containing doclist (or NULL) */
+  int nAll;                      /* Size of a[] in bytes */
+  char *pNextDocid;              /* Pointer to next docid */
+
+  sqlite3_int64 iDocid;          /* Current docid (if pList!=0) */
+  int bFreeList;                 /* True if pList should be sqlite3_free()d */
+  char *pList;                   /* Pointer to position list following iDocid */
+  int nList;                     /* Length of position list */
+};
+
+/*
+** A "phrase" is a sequence of one or more tokens that must match in
+** sequence.  A single token is the base case and the most common case.
+** For a sequence of tokens contained in double-quotes (i.e. "one two three")
+** nToken will be the number of tokens in the string.
+*/
+struct Fts3PhraseToken {
+  char *z;                        /* Text of the token */
+  int n;                          /* Number of bytes in buffer z */
+  int isPrefix;                   /* True if token ends with a "*" character */
+  int bFirst;                     /* True if token must appear at position 0 */
+
+  /* Variables above this point are populated when the expression is
+  ** parsed (by code in fts3_expr.c). Below this point the variables are
+  ** used when evaluating the expression. */
+  Fts3DeferredToken *pDeferred;   /* Deferred token object for this token */
+  Fts3MultiSegReader *pSegcsr;    /* Segment-reader for this token */
+};
+
+struct Fts3Phrase {
+  /* Cache of doclist for this phrase. */
+  Fts3Doclist doclist;
+  int bIncr;                 /* True if doclist is loaded incrementally */
+  int iDoclistToken;
+
+  /* Used by sqlite3Fts3EvalPhrasePoslist() if this is a descendent of an
+  ** OR condition.  */
+  char *pOrPoslist;
+  i64 iOrDocid;
+
+  /* Variables below this point are populated by fts3_expr.c when parsing 
+  ** a MATCH expression. Everything above is part of the evaluation phase. 
+  */
+  int nToken;                /* Number of tokens in the phrase */
+  int iColumn;               /* Index of column this phrase must match */
+  Fts3PhraseToken aToken[1]; /* One entry for each token in the phrase */
+};
+
+/*
+** A tree of these objects forms the RHS of a MATCH operator.
+**
+** If Fts3Expr.eType is FTSQUERY_PHRASE and isLoaded is true, then aDoclist 
+** points to a malloced buffer, size nDoclist bytes, containing the results 
+** of this phrase query in FTS3 doclist format. As usual, the initial 
+** "Length" field found in doclists stored on disk is omitted from this 
+** buffer.
+**
+** Variable aMI is used only for FTSQUERY_NEAR nodes to store the global
+** matchinfo data. If it is not NULL, it points to an array of size nCol*3,
+** where nCol is the number of columns in the queried FTS table. The array
+** is populated as follows:
+**
+**   aMI[iCol*3 + 0] = Undefined
+**   aMI[iCol*3 + 1] = Number of occurrences
+**   aMI[iCol*3 + 2] = Number of rows containing at least one instance
+**
+** The aMI array is allocated using sqlite3_malloc(). It should be freed 
+** when the expression node is.
+*/
+struct Fts3Expr {
+  int eType;                 /* One of the FTSQUERY_XXX values defined below */
+  int nNear;                 /* Valid if eType==FTSQUERY_NEAR */
+  Fts3Expr *pParent;         /* pParent->pLeft==this or pParent->pRight==this */
+  Fts3Expr *pLeft;           /* Left operand */
+  Fts3Expr *pRight;          /* Right operand */
+  Fts3Phrase *pPhrase;       /* Valid if eType==FTSQUERY_PHRASE */
+
+  /* The following are used by the fts3_eval.c module. */
+  sqlite3_int64 iDocid;      /* Current docid */
+  u8 bEof;                   /* True this expression is at EOF already */
+  u8 bStart;                 /* True if iDocid is valid */
+  u8 bDeferred;              /* True if this expression is entirely deferred */
+
+  /* The following are used by the fts3_snippet.c module. */
+  int iPhrase;               /* Index of this phrase in matchinfo() results */
+  u32 *aMI;                  /* See above */
+};
+
+/*
+** Candidate values for Fts3Query.eType. Note that the order of the first
+** four values is in order of precedence when parsing expressions. For 
+** example, the following:
+**
+**   "a OR b AND c NOT d NEAR e"
+**
+** is equivalent to:
+**
+**   "a OR (b AND (c NOT (d NEAR e)))"
+*/
+#define FTSQUERY_NEAR   1
+#define FTSQUERY_NOT    2
+#define FTSQUERY_AND    3
+#define FTSQUERY_OR     4
+#define FTSQUERY_PHRASE 5
+
+
+/* fts3_write.c */
+SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
+SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *);
+SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *);
+SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *);
+SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,
+  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
+SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
+  Fts3Table*,int,const char*,int,int,Fts3SegReader**);
+SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *);
+SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
+SQLITE_PRIVATE int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);
+
+SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
+SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);
+
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
+SQLITE_PRIVATE int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
+SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
+SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
+SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, int *);
+#else
+# define sqlite3Fts3FreeDeferredTokens(x)
+# define sqlite3Fts3DeferToken(x,y,z) SQLITE_OK
+# define sqlite3Fts3CacheDeferredDoclists(x) SQLITE_OK
+# define sqlite3Fts3FreeDeferredDoclists(x)
+# define sqlite3Fts3DeferredTokenList(x,y,z) SQLITE_OK
+#endif
+
+SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *);
+SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *, int *);
+
+/* Special values interpreted by sqlite3SegReaderCursor() */
+#define FTS3_SEGCURSOR_PENDING        -1
+#define FTS3_SEGCURSOR_ALL            -2
+
+SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Fts3SegFilter*);
+SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);
+SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);
+
+SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(Fts3Table *, 
+    int, int, int, const char *, int, int, int, Fts3MultiSegReader *);
+
+/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
+#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
+#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
+#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
+#define FTS3_SEGMENT_PREFIX        0x00000008
+#define FTS3_SEGMENT_SCAN          0x00000010
+#define FTS3_SEGMENT_FIRST         0x00000020
+
+/* Type passed as 4th argument to SegmentReaderIterate() */
+struct Fts3SegFilter {
+  const char *zTerm;
+  int nTerm;
+  int iCol;
+  int flags;
+};
+
+struct Fts3MultiSegReader {
+  /* Used internally by sqlite3Fts3SegReaderXXX() calls */
+  Fts3SegReader **apSegment;      /* Array of Fts3SegReader objects */
+  int nSegment;                   /* Size of apSegment array */
+  int nAdvance;                   /* How many seg-readers to advance */
+  Fts3SegFilter *pFilter;         /* Pointer to filter object */
+  char *aBuffer;                  /* Buffer to merge doclists in */
+  int nBuffer;                    /* Allocated size of aBuffer[] in bytes */
+
+  int iColFilter;                 /* If >=0, filter for this column */
+  int bRestart;
+
+  /* Used by fts3.c only. */
+  int nCost;                      /* Cost of running iterator */
+  int bLookup;                    /* True if a lookup of a single entry. */
+
+  /* Output values. Valid only after Fts3SegReaderStep() returns SQLITE_ROW. */
+  char *zTerm;                    /* Pointer to term buffer */
+  int nTerm;                      /* Size of zTerm in bytes */
+  char *aDoclist;                 /* Pointer to doclist buffer */
+  int nDoclist;                   /* Size of aDoclist[] in bytes */
+};
+
+SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table*,int,int);
+
+#define fts3GetVarint32(p, piVal) (                                           \
+  (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \
+)
+
+/* fts3.c */
+SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char**,const char*,...);
+SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *, sqlite3_int64);
+SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
+SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *, int *);
+SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64);
+SQLITE_PRIVATE void sqlite3Fts3Dequote(char *);
+SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
+SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
+SQLITE_PRIVATE int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
+SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
+SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);
+
+/* fts3_tokenizer.c */
+SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *, int *);
+SQLITE_PRIVATE int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
+SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
+    sqlite3_tokenizer **, char **
+);
+SQLITE_PRIVATE int sqlite3Fts3IsIdChar(char);
+
+/* fts3_snippet.c */
+SQLITE_PRIVATE void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
+SQLITE_PRIVATE void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
+  const char *, const char *, int, int
+);
+SQLITE_PRIVATE void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);
+SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p);
+
+/* fts3_expr.c */
+SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
+  char **, int, int, int, const char *, int, Fts3Expr **, char **
+);
+SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *);
+#ifdef SQLITE_TEST
+SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
+SQLITE_PRIVATE int sqlite3Fts3InitTerm(sqlite3 *db);
+#endif
+
+SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
+  sqlite3_tokenizer_cursor **
+);
+
+/* fts3_aux.c */
+SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db);
+
+SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);
+
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(
+    Fts3Table*, Fts3MultiSegReader*, int, const char*, int);
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
+    Fts3Table *, Fts3MultiSegReader *, sqlite3_int64 *, char **, int *);
+SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol, char **); 
+SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(Fts3Cursor *, Fts3MultiSegReader *, int *);
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);
+
+/* fts3_tokenize_vtab.c */
+SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);
+
+/* fts3_unicode2.c (functions generated by parsing unicode text files) */
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int, int);
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int);
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int);
+#endif
+
+#endif /* !SQLITE_CORE || SQLITE_ENABLE_FTS3 */
+#endif /* _FTSINT_H */
+
+/************** End of fts3Int.h *********************************************/
+/************** Continuing where we left off in fts3.c ***********************/
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
+# define SQLITE_CORE 1
+#endif
+
+/* #include  */
+/* #include  */
+/* #include  */
+/* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "fts3.h" */
+#ifndef SQLITE_CORE 
+/* # include "sqlite3ext.h" */
+  SQLITE_EXTENSION_INIT1
+#endif
+
+static int fts3EvalNext(Fts3Cursor *pCsr);
+static int fts3EvalStart(Fts3Cursor *pCsr);
+static int fts3TermSegReaderCursor(
+    Fts3Cursor *, const char *, int, int, Fts3MultiSegReader **);
+
+#ifndef SQLITE_AMALGAMATION
+# if defined(SQLITE_DEBUG)
+SQLITE_PRIVATE int sqlite3Fts3Always(int b) { assert( b ); return b; }
+SQLITE_PRIVATE int sqlite3Fts3Never(int b)  { assert( !b ); return b; }
+# endif
+#endif
+
+/* 
+** Write a 64-bit variable-length integer to memory starting at p[0].
+** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
+** The number of bytes written is returned.
+*/
+SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
+  unsigned char *q = (unsigned char *) p;
+  sqlite_uint64 vu = v;
+  do{
+    *q++ = (unsigned char) ((vu & 0x7f) | 0x80);
+    vu >>= 7;
+  }while( vu!=0 );
+  q[-1] &= 0x7f;  /* turn off high bit in final byte */
+  assert( q - (unsigned char *)p <= FTS3_VARINT_MAX );
+  return (int) (q - (unsigned char *)p);
+}
+
+#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (v & mask1) | ( (*ptr++) << shift );                    \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (*ptr++);                                               \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+
+/* 
+** Read a 64-bit variable-length integer from memory starting at p[0].
+** Return the number of bytes read, or 0 on error.
+** The value is stored in *v.
+*/
+SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *pBuf, sqlite_int64 *v){
+  const unsigned char *p = (const unsigned char*)pBuf;
+  const unsigned char *pStart = p;
+  u32 a;
+  u64 b;
+  int shift;
+
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
+  b = (a & 0x0FFFFFFF );
+
+  for(shift=28; shift<=63; shift+=7){
+    u64 c = *p++;
+    b += (c&0x7F) << shift;
+    if( (c & 0x80)==0 ) break;
+  }
+  *v = b;
+  return (int)(p - pStart);
+}
+
+/*
+** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to 
+** a non-negative 32-bit integer before it is returned.
+*/
+SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *p, int *pi){
+  u32 a;
+
+#ifndef fts3GetVarint32
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
+#else
+  a = (*p++);
+  assert( a & 0x80 );
+#endif
+
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *pi, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *pi, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *pi, 4);
+  a = (a & 0x0FFFFFFF );
+  *pi = (int)(a | ((u32)(*p & 0x07) << 28));
+  assert( 0==(a & 0x80000000) );
+  assert( *pi>=0 );
+  return 5;
+}
+
+/*
+** Return the number of bytes required to encode v as a varint
+*/
+SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64 v){
+  int i = 0;
+  do{
+    i++;
+    v >>= 7;
+  }while( v!=0 );
+  return i;
+}
+
+/*
+** Convert an SQL-style quoted string into a normal string by removing
+** the quote characters.  The conversion is done in-place.  If the
+** input does not begin with a quote character, then this routine
+** is a no-op.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+**
+*/
+SQLITE_PRIVATE void sqlite3Fts3Dequote(char *z){
+  char quote;                     /* Quote character (if any ) */
+
+  quote = z[0];
+  if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
+    int iIn = 1;                  /* Index of next byte to read from input */
+    int iOut = 0;                 /* Index of next byte to write to output */
+
+    /* If the first byte was a '[', then the close-quote character is a ']' */
+    if( quote=='[' ) quote = ']';  
+
+    while( z[iIn] ){
+      if( z[iIn]==quote ){
+        if( z[iIn+1]!=quote ) break;
+        z[iOut++] = quote;
+        iIn += 2;
+      }else{
+        z[iOut++] = z[iIn++];
+      }
+    }
+    z[iOut] = '\0';
+  }
+}
+
+/*
+** Read a single varint from the doclist at *pp and advance *pp to point
+** to the first byte past the end of the varint.  Add the value of the varint
+** to *pVal.
+*/
+static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
+  sqlite3_int64 iVal;
+  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
+  *pVal += iVal;
+}
+
+/*
+** When this function is called, *pp points to the first byte following a
+** varint that is part of a doclist (or position-list, or any other list
+** of varints). This function moves *pp to point to the start of that varint,
+** and sets *pVal by the varint value.
+**
+** Argument pStart points to the first byte of the doclist that the
+** varint is part of.
+*/
+static void fts3GetReverseVarint(
+  char **pp, 
+  char *pStart, 
+  sqlite3_int64 *pVal
+){
+  sqlite3_int64 iVal;
+  char *p;
+
+  /* Pointer p now points at the first byte past the varint we are 
+  ** interested in. So, unless the doclist is corrupt, the 0x80 bit is
+  ** clear on character p[-1]. */
+  for(p = (*pp)-2; p>=pStart && *p&0x80; p--);
+  p++;
+  *pp = p;
+
+  sqlite3Fts3GetVarint(p, &iVal);
+  *pVal = iVal;
+}
+
+/*
+** The xDisconnect() virtual table method.
+*/
+static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
+  Fts3Table *p = (Fts3Table *)pVtab;
+  int i;
+
+  assert( p->nPendingData==0 );
+  assert( p->pSegments==0 );
+
+  /* Free any prepared statements held */
+  sqlite3_finalize(p->pSeekStmt);
+  for(i=0; iaStmt); i++){
+    sqlite3_finalize(p->aStmt[i]);
+  }
+  sqlite3_free(p->zSegmentsTbl);
+  sqlite3_free(p->zReadExprlist);
+  sqlite3_free(p->zWriteExprlist);
+  sqlite3_free(p->zContentTbl);
+  sqlite3_free(p->zLanguageid);
+
+  /* Invoke the tokenizer destructor to free the tokenizer. */
+  p->pTokenizer->pModule->xDestroy(p->pTokenizer);
+
+  sqlite3_free(p);
+  return SQLITE_OK;
+}
+
+/*
+** Write an error message into *pzErr
+*/
+SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char **pzErr, const char *zFormat, ...){
+  va_list ap;
+  sqlite3_free(*pzErr);
+  va_start(ap, zFormat);
+  *pzErr = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+}
+
+/*
+** Construct one or more SQL statements from the format string given
+** and then evaluate those statements. The success code is written
+** into *pRc.
+**
+** If *pRc is initially non-zero then this routine is a no-op.
+*/
+static void fts3DbExec(
+  int *pRc,              /* Success code */
+  sqlite3 *db,           /* Database in which to run SQL */
+  const char *zFormat,   /* Format string for SQL */
+  ...                    /* Arguments to the format string */
+){
+  va_list ap;
+  char *zSql;
+  if( *pRc ) return;
+  va_start(ap, zFormat);
+  zSql = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  if( zSql==0 ){
+    *pRc = SQLITE_NOMEM;
+  }else{
+    *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+  }
+}
+
+/*
+** The xDestroy() virtual table method.
+*/
+static int fts3DestroyMethod(sqlite3_vtab *pVtab){
+  Fts3Table *p = (Fts3Table *)pVtab;
+  int rc = SQLITE_OK;              /* Return code */
+  const char *zDb = p->zDb;        /* Name of database (e.g. "main", "temp") */
+  sqlite3 *db = p->db;             /* Database handle */
+
+  /* Drop the shadow tables */
+  if( p->zContentTbl==0 ){
+    fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_content'", zDb, p->zName);
+  }
+  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segments'", zDb,p->zName);
+  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segdir'", zDb, p->zName);
+  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_docsize'", zDb, p->zName);
+  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_stat'", zDb, p->zName);
+
+  /* If everything has worked, invoke fts3DisconnectMethod() to free the
+  ** memory associated with the Fts3Table structure and return SQLITE_OK.
+  ** Otherwise, return an SQLite error code.
+  */
+  return (rc==SQLITE_OK ? fts3DisconnectMethod(pVtab) : rc);
+}
+
+
+/*
+** Invoke sqlite3_declare_vtab() to declare the schema for the FTS3 table
+** passed as the first argument. This is done as part of the xConnect()
+** and xCreate() methods.
+**
+** If *pRc is non-zero when this function is called, it is a no-op. 
+** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
+** before returning.
+*/
+static void fts3DeclareVtab(int *pRc, Fts3Table *p){
+  if( *pRc==SQLITE_OK ){
+    int i;                        /* Iterator variable */
+    int rc;                       /* Return code */
+    char *zSql;                   /* SQL statement passed to declare_vtab() */
+    char *zCols;                  /* List of user defined columns */
+    const char *zLanguageid;
+
+    zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");
+    sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
+
+    /* Create a list of user columns for the virtual table */
+    zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
+    for(i=1; zCols && inColumn; i++){
+      zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
+    }
+
+    /* Create the whole "CREATE TABLE" statement to pass to SQLite */
+    zSql = sqlite3_mprintf(
+        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)", 
+        zCols, p->zName, zLanguageid
+    );
+    if( !zCols || !zSql ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_declare_vtab(p->db, zSql);
+    }
+
+    sqlite3_free(zSql);
+    sqlite3_free(zCols);
+    *pRc = rc;
+  }
+}
+
+/*
+** Create the %_stat table if it does not already exist.
+*/
+SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int *pRc, Fts3Table *p){
+  fts3DbExec(pRc, p->db, 
+      "CREATE TABLE IF NOT EXISTS %Q.'%q_stat'"
+          "(id INTEGER PRIMARY KEY, value BLOB);",
+      p->zDb, p->zName
+  );
+  if( (*pRc)==SQLITE_OK ) p->bHasStat = 1;
+}
+
+/*
+** Create the backing store tables (%_content, %_segments and %_segdir)
+** required by the FTS3 table passed as the only argument. This is done
+** as part of the vtab xCreate() method.
+**
+** If the p->bHasDocsize boolean is true (indicating that this is an
+** FTS4 table, not an FTS3 table) then also create the %_docsize and
+** %_stat tables required by FTS4.
+*/
+static int fts3CreateTables(Fts3Table *p){
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* Iterator variable */
+  sqlite3 *db = p->db;            /* The database connection */
+
+  if( p->zContentTbl==0 ){
+    const char *zLanguageid = p->zLanguageid;
+    char *zContentCols;           /* Columns of %_content table */
+
+    /* Create a list of user columns for the content table */
+    zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
+    for(i=0; zContentCols && inColumn; i++){
+      char *z = p->azColumn[i];
+      zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
+    }
+    if( zLanguageid && zContentCols ){
+      zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);
+    }
+    if( zContentCols==0 ) rc = SQLITE_NOMEM;
+  
+    /* Create the content table */
+    fts3DbExec(&rc, db, 
+       "CREATE TABLE %Q.'%q_content'(%s)",
+       p->zDb, p->zName, zContentCols
+    );
+    sqlite3_free(zContentCols);
+  }
+
+  /* Create other tables */
+  fts3DbExec(&rc, db, 
+      "CREATE TABLE %Q.'%q_segments'(blockid INTEGER PRIMARY KEY, block BLOB);",
+      p->zDb, p->zName
+  );
+  fts3DbExec(&rc, db, 
+      "CREATE TABLE %Q.'%q_segdir'("
+        "level INTEGER,"
+        "idx INTEGER,"
+        "start_block INTEGER,"
+        "leaves_end_block INTEGER,"
+        "end_block INTEGER,"
+        "root BLOB,"
+        "PRIMARY KEY(level, idx)"
+      ");",
+      p->zDb, p->zName
+  );
+  if( p->bHasDocsize ){
+    fts3DbExec(&rc, db, 
+        "CREATE TABLE %Q.'%q_docsize'(docid INTEGER PRIMARY KEY, size BLOB);",
+        p->zDb, p->zName
+    );
+  }
+  assert( p->bHasStat==p->bFts4 );
+  if( p->bHasStat ){
+    sqlite3Fts3CreateStatTable(&rc, p);
+  }
+  return rc;
+}
+
+/*
+** Store the current database page-size in bytes in p->nPgsz.
+**
+** If *pRc is non-zero when this function is called, it is a no-op. 
+** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
+** before returning.
+*/
+static void fts3DatabasePageSize(int *pRc, Fts3Table *p){
+  if( *pRc==SQLITE_OK ){
+    int rc;                       /* Return code */
+    char *zSql;                   /* SQL text "PRAGMA %Q.page_size" */
+    sqlite3_stmt *pStmt;          /* Compiled "PRAGMA %Q.page_size" statement */
+  
+    zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
+      if( rc==SQLITE_OK ){
+        sqlite3_step(pStmt);
+        p->nPgsz = sqlite3_column_int(pStmt, 0);
+        rc = sqlite3_finalize(pStmt);
+      }else if( rc==SQLITE_AUTH ){
+        p->nPgsz = 1024;
+        rc = SQLITE_OK;
+      }
+    }
+    assert( p->nPgsz>0 || rc!=SQLITE_OK );
+    sqlite3_free(zSql);
+    *pRc = rc;
+  }
+}
+
+/*
+** "Special" FTS4 arguments are column specifications of the following form:
+**
+**    = 
+**
+** There may not be whitespace surrounding the "=" character. The  
+** term may be quoted, but the  may not.
+*/
+static int fts3IsSpecialColumn(
+  const char *z, 
+  int *pnKey,
+  char **pzValue
+){
+  char *zValue;
+  const char *zCsr = z;
+
+  while( *zCsr!='=' ){
+    if( *zCsr=='\0' ) return 0;
+    zCsr++;
+  }
+
+  *pnKey = (int)(zCsr-z);
+  zValue = sqlite3_mprintf("%s", &zCsr[1]);
+  if( zValue ){
+    sqlite3Fts3Dequote(zValue);
+  }
+  *pzValue = zValue;
+  return 1;
+}
+
+/*
+** Append the output of a printf() style formatting to an existing string.
+*/
+static void fts3Appendf(
+  int *pRc,                       /* IN/OUT: Error code */
+  char **pz,                      /* IN/OUT: Pointer to string buffer */
+  const char *zFormat,            /* Printf format string to append */
+  ...                             /* Arguments for printf format string */
+){
+  if( *pRc==SQLITE_OK ){
+    va_list ap;
+    char *z;
+    va_start(ap, zFormat);
+    z = sqlite3_vmprintf(zFormat, ap);
+    va_end(ap);
+    if( z && *pz ){
+      char *z2 = sqlite3_mprintf("%s%s", *pz, z);
+      sqlite3_free(z);
+      z = z2;
+    }
+    if( z==0 ) *pRc = SQLITE_NOMEM;
+    sqlite3_free(*pz);
+    *pz = z;
+  }
+}
+
+/*
+** Return a copy of input string zInput enclosed in double-quotes (") and
+** with all double quote characters escaped. For example:
+**
+**     fts3QuoteId("un \"zip\"")   ->    "un \"\"zip\"\""
+**
+** The pointer returned points to memory obtained from sqlite3_malloc(). It
+** is the callers responsibility to call sqlite3_free() to release this
+** memory.
+*/
+static char *fts3QuoteId(char const *zInput){
+  int nRet;
+  char *zRet;
+  nRet = 2 + (int)strlen(zInput)*2 + 1;
+  zRet = sqlite3_malloc(nRet);
+  if( zRet ){
+    int i;
+    char *z = zRet;
+    *(z++) = '"';
+    for(i=0; zInput[i]; i++){
+      if( zInput[i]=='"' ) *(z++) = '"';
+      *(z++) = zInput[i];
+    }
+    *(z++) = '"';
+    *(z++) = '\0';
+  }
+  return zRet;
+}
+
+/*
+** Return a list of comma separated SQL expressions and a FROM clause that 
+** could be used in a SELECT statement such as the following:
+**
+**     SELECT  FROM %_content AS x ...
+**
+** to return the docid, followed by each column of text data in order
+** from left to write. If parameter zFunc is not NULL, then instead of
+** being returned directly each column of text data is passed to an SQL
+** function named zFunc first. For example, if zFunc is "unzip" and the
+** table has the three user-defined columns "a", "b", and "c", the following
+** string is returned:
+**
+**     "docid, unzip(x.'a'), unzip(x.'b'), unzip(x.'c') FROM %_content AS x"
+**
+** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
+** is the responsibility of the caller to eventually free it.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
+** a NULL pointer is returned). Otherwise, if an OOM error is encountered
+** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
+** no error occurs, *pRc is left unmodified.
+*/
+static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){
+  char *zRet = 0;
+  char *zFree = 0;
+  char *zFunction;
+  int i;
+
+  if( p->zContentTbl==0 ){
+    if( !zFunc ){
+      zFunction = "";
+    }else{
+      zFree = zFunction = fts3QuoteId(zFunc);
+    }
+    fts3Appendf(pRc, &zRet, "docid");
+    for(i=0; inColumn; i++){
+      fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
+    }
+    if( p->zLanguageid ){
+      fts3Appendf(pRc, &zRet, ", x.%Q", "langid");
+    }
+    sqlite3_free(zFree);
+  }else{
+    fts3Appendf(pRc, &zRet, "rowid");
+    for(i=0; inColumn; i++){
+      fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
+    }
+    if( p->zLanguageid ){
+      fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);
+    }
+  }
+  fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x", 
+      p->zDb,
+      (p->zContentTbl ? p->zContentTbl : p->zName),
+      (p->zContentTbl ? "" : "_content")
+  );
+  return zRet;
+}
+
+/*
+** Return a list of N comma separated question marks, where N is the number
+** of columns in the %_content table (one for the docid plus one for each
+** user-defined text column).
+**
+** If argument zFunc is not NULL, then all but the first question mark
+** is preceded by zFunc and an open bracket, and followed by a closed
+** bracket. For example, if zFunc is "zip" and the FTS3 table has three 
+** user-defined text columns, the following string is returned:
+**
+**     "?, zip(?), zip(?), zip(?)"
+**
+** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
+** is the responsibility of the caller to eventually free it.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
+** a NULL pointer is returned). Otherwise, if an OOM error is encountered
+** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
+** no error occurs, *pRc is left unmodified.
+*/
+static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
+  char *zRet = 0;
+  char *zFree = 0;
+  char *zFunction;
+  int i;
+
+  if( !zFunc ){
+    zFunction = "";
+  }else{
+    zFree = zFunction = fts3QuoteId(zFunc);
+  }
+  fts3Appendf(pRc, &zRet, "?");
+  for(i=0; inColumn; i++){
+    fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
+  }
+  if( p->zLanguageid ){
+    fts3Appendf(pRc, &zRet, ", ?");
+  }
+  sqlite3_free(zFree);
+  return zRet;
+}
+
+/*
+** This function interprets the string at (*pp) as a non-negative integer
+** value. It reads the integer and sets *pnOut to the value read, then 
+** sets *pp to point to the byte immediately following the last byte of
+** the integer value.
+**
+** Only decimal digits ('0'..'9') may be part of an integer value. 
+**
+** If *pp does not being with a decimal digit SQLITE_ERROR is returned and
+** the output value undefined. Otherwise SQLITE_OK is returned.
+**
+** This function is used when parsing the "prefix=" FTS4 parameter.
+*/
+static int fts3GobbleInt(const char **pp, int *pnOut){
+  const int MAX_NPREFIX = 10000000;
+  const char *p;                  /* Iterator pointer */
+  int nInt = 0;                   /* Output value */
+
+  for(p=*pp; p[0]>='0' && p[0]<='9'; p++){
+    nInt = nInt * 10 + (p[0] - '0');
+    if( nInt>MAX_NPREFIX ){
+      nInt = 0;
+      break;
+    }
+  }
+  if( p==*pp ) return SQLITE_ERROR;
+  *pnOut = nInt;
+  *pp = p;
+  return SQLITE_OK;
+}
+
+/*
+** This function is called to allocate an array of Fts3Index structures
+** representing the indexes maintained by the current FTS table. FTS tables
+** always maintain the main "terms" index, but may also maintain one or
+** more "prefix" indexes, depending on the value of the "prefix=" parameter
+** (if any) specified as part of the CREATE VIRTUAL TABLE statement.
+**
+** Argument zParam is passed the value of the "prefix=" option if one was
+** specified, or NULL otherwise.
+**
+** If no error occurs, SQLITE_OK is returned and *apIndex set to point to
+** the allocated array. *pnIndex is set to the number of elements in the
+** array. If an error does occur, an SQLite error code is returned.
+**
+** Regardless of whether or not an error is returned, it is the responsibility
+** of the caller to call sqlite3_free() on the output array to free it.
+*/
+static int fts3PrefixParameter(
+  const char *zParam,             /* ABC in prefix=ABC parameter to parse */
+  int *pnIndex,                   /* OUT: size of *apIndex[] array */
+  struct Fts3Index **apIndex      /* OUT: Array of indexes for this table */
+){
+  struct Fts3Index *aIndex;       /* Allocated array */
+  int nIndex = 1;                 /* Number of entries in array */
+
+  if( zParam && zParam[0] ){
+    const char *p;
+    nIndex++;
+    for(p=zParam; *p; p++){
+      if( *p==',' ) nIndex++;
+    }
+  }
+
+  aIndex = sqlite3_malloc(sizeof(struct Fts3Index) * nIndex);
+  *apIndex = aIndex;
+  if( !aIndex ){
+    return SQLITE_NOMEM;
+  }
+
+  memset(aIndex, 0, sizeof(struct Fts3Index) * nIndex);
+  if( zParam ){
+    const char *p = zParam;
+    int i;
+    for(i=1; i=0 );
+      if( nPrefix==0 ){
+        nIndex--;
+        i--;
+      }else{
+        aIndex[i].nPrefix = nPrefix;
+      }
+      p++;
+    }
+  }
+
+  *pnIndex = nIndex;
+  return SQLITE_OK;
+}
+
+/*
+** This function is called when initializing an FTS4 table that uses the
+** content=xxx option. It determines the number of and names of the columns
+** of the new FTS4 table.
+**
+** The third argument passed to this function is the value passed to the
+** config=xxx option (i.e. "xxx"). This function queries the database for
+** a table of that name. If found, the output variables are populated
+** as follows:
+**
+**   *pnCol:   Set to the number of columns table xxx has,
+**
+**   *pnStr:   Set to the total amount of space required to store a copy
+**             of each columns name, including the nul-terminator.
+**
+**   *pazCol:  Set to point to an array of *pnCol strings. Each string is
+**             the name of the corresponding column in table xxx. The array
+**             and its contents are allocated using a single allocation. It
+**             is the responsibility of the caller to free this allocation
+**             by eventually passing the *pazCol value to sqlite3_free().
+**
+** If the table cannot be found, an error code is returned and the output
+** variables are undefined. Or, if an OOM is encountered, SQLITE_NOMEM is
+** returned (and the output variables are undefined).
+*/
+static int fts3ContentColumns(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of db (i.e. "main", "temp" etc.) */
+  const char *zTbl,               /* Name of content table */
+  const char ***pazCol,           /* OUT: Malloc'd array of column names */
+  int *pnCol,                     /* OUT: Size of array *pazCol */
+  int *pnStr,                     /* OUT: Bytes of string content */
+  char **pzErr                    /* OUT: error message */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  char *zSql;                     /* "SELECT *" statement on zTbl */  
+  sqlite3_stmt *pStmt = 0;        /* Compiled version of zSql */
+
+  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", zDb, zTbl);
+  if( !zSql ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+    if( rc!=SQLITE_OK ){
+      sqlite3Fts3ErrMsg(pzErr, "%s", sqlite3_errmsg(db));
+    }
+  }
+  sqlite3_free(zSql);
+
+  if( rc==SQLITE_OK ){
+    const char **azCol;           /* Output array */
+    int nStr = 0;                 /* Size of all column names (incl. 0x00) */
+    int nCol;                     /* Number of table columns */
+    int i;                        /* Used to iterate through columns */
+
+    /* Loop through the returned columns. Set nStr to the number of bytes of
+    ** space required to store a copy of each column name, including the
+    ** nul-terminator byte.  */
+    nCol = sqlite3_column_count(pStmt);
+    for(i=0; i module name  ("fts3" or "fts4")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[...] -> "column name" and other module argument fields.
+*/
+static int fts3InitVtab(
+  int isCreate,                   /* True for xCreate, false for xConnect */
+  sqlite3 *db,                    /* The SQLite database connection */
+  void *pAux,                     /* Hash table containing tokenizers */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
+  char **pzErr                    /* Write any error message here */
+){
+  Fts3Hash *pHash = (Fts3Hash *)pAux;
+  Fts3Table *p = 0;               /* Pointer to allocated vtab */
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* Iterator variable */
+  int nByte;                      /* Size of allocation used for *p */
+  int iCol;                       /* Column index */
+  int nString = 0;                /* Bytes required to hold all column names */
+  int nCol = 0;                   /* Number of columns in the FTS table */
+  char *zCsr;                     /* Space for holding column names */
+  int nDb;                        /* Bytes required to hold database name */
+  int nName;                      /* Bytes required to hold table name */
+  int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */
+  const char **aCol;              /* Array of column names */
+  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */
+
+  int nIndex = 0;                 /* Size of aIndex[] array */
+  struct Fts3Index *aIndex = 0;   /* Array of indexes for this table */
+
+  /* The results of parsing supported FTS4 key=value options: */
+  int bNoDocsize = 0;             /* True to omit %_docsize table */
+  int bDescIdx = 0;               /* True to store descending indexes */
+  char *zPrefix = 0;              /* Prefix parameter value (or NULL) */
+  char *zCompress = 0;            /* compress=? parameter (or NULL) */
+  char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
+  char *zContent = 0;             /* content=? parameter (or NULL) */
+  char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */
+  char **azNotindexed = 0;        /* The set of notindexed= columns */
+  int nNotindexed = 0;            /* Size of azNotindexed[] array */
+
+  assert( strlen(argv[0])==4 );
+  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
+       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
+  );
+
+  nDb = (int)strlen(argv[1]) + 1;
+  nName = (int)strlen(argv[2]) + 1;
+
+  nByte = sizeof(const char *) * (argc-2);
+  aCol = (const char **)sqlite3_malloc(nByte);
+  if( aCol ){
+    memset((void*)aCol, 0, nByte);
+    azNotindexed = (char **)sqlite3_malloc(nByte);
+  }
+  if( azNotindexed ){
+    memset(azNotindexed, 0, nByte);
+  }
+  if( !aCol || !azNotindexed ){
+    rc = SQLITE_NOMEM;
+    goto fts3_init_out;
+  }
+
+  /* Loop through all of the arguments passed by the user to the FTS3/4
+  ** module (i.e. all the column names and special arguments). This loop
+  ** does the following:
+  **
+  **   + Figures out the number of columns the FTSX table will have, and
+  **     the number of bytes of space that must be allocated to store copies
+  **     of the column names.
+  **
+  **   + If there is a tokenizer specification included in the arguments,
+  **     initializes the tokenizer pTokenizer.
+  */
+  for(i=3; rc==SQLITE_OK && i8
+     && 0==sqlite3_strnicmp(z, "tokenize", 8) 
+     && 0==sqlite3Fts3IsIdChar(z[8])
+    ){
+      rc = sqlite3Fts3InitTokenizer(pHash, &z[9], &pTokenizer, pzErr);
+    }
+
+    /* Check if it is an FTS4 special argument. */
+    else if( isFts4 && fts3IsSpecialColumn(z, &nKey, &zVal) ){
+      struct Fts4Option {
+        const char *zOpt;
+        int nOpt;
+      } aFts4Opt[] = {
+        { "matchinfo",   9 },     /* 0 -> MATCHINFO */
+        { "prefix",      6 },     /* 1 -> PREFIX */
+        { "compress",    8 },     /* 2 -> COMPRESS */
+        { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
+        { "order",       5 },     /* 4 -> ORDER */
+        { "content",     7 },     /* 5 -> CONTENT */
+        { "languageid", 10 },     /* 6 -> LANGUAGEID */
+        { "notindexed", 10 }      /* 7 -> NOTINDEXED */
+      };
+
+      int iOpt;
+      if( !zVal ){
+        rc = SQLITE_NOMEM;
+      }else{
+        for(iOpt=0; iOptnOpt && !sqlite3_strnicmp(z, pOp->zOpt, pOp->nOpt) ){
+            break;
+          }
+        }
+        switch( iOpt ){
+          case 0:               /* MATCHINFO */
+            if( strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "fts3", 4) ){
+              sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo: %s", zVal);
+              rc = SQLITE_ERROR;
+            }
+            bNoDocsize = 1;
+            break;
+
+          case 1:               /* PREFIX */
+            sqlite3_free(zPrefix);
+            zPrefix = zVal;
+            zVal = 0;
+            break;
+
+          case 2:               /* COMPRESS */
+            sqlite3_free(zCompress);
+            zCompress = zVal;
+            zVal = 0;
+            break;
+
+          case 3:               /* UNCOMPRESS */
+            sqlite3_free(zUncompress);
+            zUncompress = zVal;
+            zVal = 0;
+            break;
+
+          case 4:               /* ORDER */
+            if( (strlen(zVal)!=3 || sqlite3_strnicmp(zVal, "asc", 3)) 
+             && (strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "desc", 4)) 
+            ){
+              sqlite3Fts3ErrMsg(pzErr, "unrecognized order: %s", zVal);
+              rc = SQLITE_ERROR;
+            }
+            bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
+            break;
+
+          case 5:              /* CONTENT */
+            sqlite3_free(zContent);
+            zContent = zVal;
+            zVal = 0;
+            break;
+
+          case 6:              /* LANGUAGEID */
+            assert( iOpt==6 );
+            sqlite3_free(zLanguageid);
+            zLanguageid = zVal;
+            zVal = 0;
+            break;
+
+          case 7:              /* NOTINDEXED */
+            azNotindexed[nNotindexed++] = zVal;
+            zVal = 0;
+            break;
+
+          default:
+            assert( iOpt==SizeofArray(aFts4Opt) );
+            sqlite3Fts3ErrMsg(pzErr, "unrecognized parameter: %s", z);
+            rc = SQLITE_ERROR;
+            break;
+        }
+        sqlite3_free(zVal);
+      }
+    }
+
+    /* Otherwise, the argument is a column name. */
+    else {
+      nString += (int)(strlen(z) + 1);
+      aCol[nCol++] = z;
+    }
+  }
+
+  /* If a content=xxx option was specified, the following:
+  **
+  **   1. Ignore any compress= and uncompress= options.
+  **
+  **   2. If no column names were specified as part of the CREATE VIRTUAL
+  **      TABLE statement, use all columns from the content table.
+  */
+  if( rc==SQLITE_OK && zContent ){
+    sqlite3_free(zCompress); 
+    sqlite3_free(zUncompress); 
+    zCompress = 0;
+    zUncompress = 0;
+    if( nCol==0 ){
+      sqlite3_free((void*)aCol); 
+      aCol = 0;
+      rc = fts3ContentColumns(db, argv[1], zContent,&aCol,&nCol,&nString,pzErr);
+
+      /* If a languageid= option was specified, remove the language id
+      ** column from the aCol[] array. */ 
+      if( rc==SQLITE_OK && zLanguageid ){
+        int j;
+        for(j=0; jdb = db;
+  p->nColumn = nCol;
+  p->nPendingData = 0;
+  p->azColumn = (char **)&p[1];
+  p->pTokenizer = pTokenizer;
+  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
+  p->bHasDocsize = (isFts4 && bNoDocsize==0);
+  p->bHasStat = (u8)isFts4;
+  p->bFts4 = (u8)isFts4;
+  p->bDescIdx = (u8)bDescIdx;
+  p->nAutoincrmerge = 0xff;   /* 0xff means setting unknown */
+  p->zContentTbl = zContent;
+  p->zLanguageid = zLanguageid;
+  zContent = 0;
+  zLanguageid = 0;
+  TESTONLY( p->inTransaction = -1 );
+  TESTONLY( p->mxSavepoint = -1 );
+
+  p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];
+  memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);
+  p->nIndex = nIndex;
+  for(i=0; iaIndex[i].hPending, FTS3_HASH_STRING, 1);
+  }
+  p->abNotindexed = (u8 *)&p->aIndex[nIndex];
+
+  /* Fill in the zName and zDb fields of the vtab structure. */
+  zCsr = (char *)&p->abNotindexed[nCol];
+  p->zName = zCsr;
+  memcpy(zCsr, argv[2], nName);
+  zCsr += nName;
+  p->zDb = zCsr;
+  memcpy(zCsr, argv[1], nDb);
+  zCsr += nDb;
+
+  /* Fill in the azColumn array */
+  for(iCol=0; iCol0 ){
+      memcpy(zCsr, z, n);
+    }
+    zCsr[n] = '\0';
+    sqlite3Fts3Dequote(zCsr);
+    p->azColumn[iCol] = zCsr;
+    zCsr += n+1;
+    assert( zCsr <= &((char *)p)[nByte] );
+  }
+
+  /* Fill in the abNotindexed array */
+  for(iCol=0; iColazColumn[iCol]);
+    for(i=0; iazColumn[iCol], zNot, n) 
+      ){
+        p->abNotindexed[iCol] = 1;
+        sqlite3_free(zNot);
+        azNotindexed[i] = 0;
+      }
+    }
+  }
+  for(i=0; izReadExprlist = fts3ReadExprList(p, zUncompress, &rc);
+  p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);
+  if( rc!=SQLITE_OK ) goto fts3_init_out;
+
+  /* If this is an xCreate call, create the underlying tables in the 
+  ** database. TODO: For xConnect(), it could verify that said tables exist.
+  */
+  if( isCreate ){
+    rc = fts3CreateTables(p);
+  }
+
+  /* Check to see if a legacy fts3 table has been "upgraded" by the
+  ** addition of a %_stat table so that it can use incremental merge.
+  */
+  if( !isFts4 && !isCreate ){
+    p->bHasStat = 2;
+  }
+
+  /* Figure out the page-size for the database. This is required in order to
+  ** estimate the cost of loading large doclists from the database.  */
+  fts3DatabasePageSize(&rc, p);
+  p->nNodeSize = p->nPgsz-35;
+
+  /* Declare the table schema to SQLite. */
+  fts3DeclareVtab(&rc, p);
+
+fts3_init_out:
+  sqlite3_free(zPrefix);
+  sqlite3_free(aIndex);
+  sqlite3_free(zCompress);
+  sqlite3_free(zUncompress);
+  sqlite3_free(zContent);
+  sqlite3_free(zLanguageid);
+  for(i=0; ipModule->xDestroy(pTokenizer);
+    }
+  }else{
+    assert( p->pSegments==0 );
+    *ppVTab = &p->base;
+  }
+  return rc;
+}
+
+/*
+** The xConnect() and xCreate() methods for the virtual table. All the
+** work is done in function fts3InitVtab().
+*/
+static int fts3ConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts3InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);
+}
+static int fts3CreateMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+  if( sqlite3_libversion_number()>=3008002 ){
+    pIdxInfo->estimatedRows = nRow;
+  }
+#endif
+}
+
+/*
+** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support index-info flags. In that case this function is a no-op.
+*/
+static void fts3SetUniqueFlag(sqlite3_index_info *pIdxInfo){
+#if SQLITE_VERSION_NUMBER>=3008012
+  if( sqlite3_libversion_number()>=3008012 ){
+    pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;
+  }
+#endif
+}
+
+/* 
+** Implementation of the xBestIndex method for FTS3 tables. There
+** are three possible strategies, in order of preference:
+**
+**   1. Direct lookup by rowid or docid. 
+**   2. Full-text search using a MATCH operator on a non-docid column.
+**   3. Linear scan of %_content table.
+*/
+static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
+  Fts3Table *p = (Fts3Table *)pVTab;
+  int i;                          /* Iterator variable */
+  int iCons = -1;                 /* Index of constraint to use */
+
+  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
+  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
+  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
+  int iIdx;
+
+  /* By default use a full table scan. This is an expensive option,
+  ** so search through the constraints to see if a more efficient 
+  ** strategy is possible.
+  */
+  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+  pInfo->estimatedCost = 5000000;
+  for(i=0; inConstraint; i++){
+    int bDocid;                 /* True if this constraint is on docid */
+    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
+    if( pCons->usable==0 ){
+      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+        /* There exists an unusable MATCH constraint. This means that if
+        ** the planner does elect to use the results of this call as part
+        ** of the overall query plan the user will see an "unable to use
+        ** function MATCH in the requested context" error. To discourage
+        ** this, return a very high cost here.  */
+        pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+        pInfo->estimatedCost = 1e50;
+        fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
+        return SQLITE_OK;
+      }
+      continue;
+    }
+
+    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);
+
+    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
+    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
+      pInfo->idxNum = FTS3_DOCID_SEARCH;
+      pInfo->estimatedCost = 1.0;
+      iCons = i;
+    }
+
+    /* A MATCH constraint. Use a full-text search.
+    **
+    ** If there is more than one MATCH constraint available, use the first
+    ** one encountered. If there is both a MATCH constraint and a direct
+    ** rowid/docid lookup, prefer the MATCH strategy. This is done even 
+    ** though the rowid/docid lookup is faster than a MATCH query, selecting
+    ** it would lead to an "unable to use function MATCH in the requested 
+    ** context" error.
+    */
+    if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
+     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
+    ){
+      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
+      pInfo->estimatedCost = 2.0;
+      iCons = i;
+    }
+
+    /* Equality constraint on the langid column */
+    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
+     && pCons->iColumn==p->nColumn + 2
+    ){
+      iLangidCons = i;
+    }
+
+    if( bDocid ){
+      switch( pCons->op ){
+        case SQLITE_INDEX_CONSTRAINT_GE:
+        case SQLITE_INDEX_CONSTRAINT_GT:
+          iDocidGe = i;
+          break;
+
+        case SQLITE_INDEX_CONSTRAINT_LE:
+        case SQLITE_INDEX_CONSTRAINT_LT:
+          iDocidLe = i;
+          break;
+      }
+    }
+  }
+
+  /* If using a docid=? or rowid=? strategy, set the UNIQUE flag. */
+  if( pInfo->idxNum==FTS3_DOCID_SEARCH ) fts3SetUniqueFlag(pInfo);
+
+  iIdx = 1;
+  if( iCons>=0 ){
+    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
+    pInfo->aConstraintUsage[iCons].omit = 1;
+  } 
+  if( iLangidCons>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_LANGID;
+    pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
+  } 
+  if( iDocidGe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
+    pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
+  } 
+  if( iDocidLe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
+    pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
+  } 
+
+  /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
+  ** docid) order. Both ascending and descending are possible. 
+  */
+  if( pInfo->nOrderBy==1 ){
+    struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];
+    if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){
+      if( pOrder->desc ){
+        pInfo->idxStr = "DESC";
+      }else{
+        pInfo->idxStr = "ASC";
+      }
+      pInfo->orderByConsumed = 1;
+    }
+  }
+
+  assert( p->pSegments==0 );
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of xOpen method.
+*/
+static int fts3OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  sqlite3_vtab_cursor *pCsr;               /* Allocated cursor */
+
+  UNUSED_PARAMETER(pVTab);
+
+  /* Allocate a buffer large enough for an Fts3Cursor structure. If the
+  ** allocation succeeds, zero it and return SQLITE_OK. Otherwise, 
+  ** if the allocation fails, return SQLITE_NOMEM.
+  */
+  *ppCsr = pCsr = (sqlite3_vtab_cursor *)sqlite3_malloc(sizeof(Fts3Cursor));
+  if( !pCsr ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(Fts3Cursor));
+  return SQLITE_OK;
+}
+
+/*
+** Finalize the statement handle at pCsr->pStmt.
+**
+** Or, if that statement handle is one created by fts3CursorSeekStmt(),
+** and the Fts3Table.pSeekStmt slot is currently NULL, save the statement
+** pointer there instead of finalizing it.
+*/
+static void fts3CursorFinalizeStmt(Fts3Cursor *pCsr){
+  if( pCsr->bSeekStmt ){
+    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+    if( p->pSeekStmt==0 ){
+      p->pSeekStmt = pCsr->pStmt;
+      sqlite3_reset(pCsr->pStmt);
+      pCsr->pStmt = 0;
+    }
+    pCsr->bSeekStmt = 0;
+  }
+  sqlite3_finalize(pCsr->pStmt);
+}
+
+/*
+** Free all resources currently held by the cursor passed as the only
+** argument.
+*/
+static void fts3ClearCursor(Fts3Cursor *pCsr){
+  fts3CursorFinalizeStmt(pCsr);
+  sqlite3Fts3FreeDeferredTokens(pCsr);
+  sqlite3_free(pCsr->aDoclist);
+  sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
+  sqlite3Fts3ExprFree(pCsr->pExpr);
+  memset(&(&pCsr->base)[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
+}
+
+/*
+** Close the cursor.  For additional information see the documentation
+** on the xClose method of the virtual table interface.
+*/
+static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
+  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+  fts3ClearCursor(pCsr);
+  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** If pCsr->pStmt has not been prepared (i.e. if pCsr->pStmt==0), then
+** compose and prepare an SQL statement of the form:
+**
+**    "SELECT  FROM %_content WHERE rowid = ?"
+**
+** (or the equivalent for a content=xxx table) and set pCsr->pStmt to
+** it. If an error occurs, return an SQLite error code.
+*/
+static int fts3CursorSeekStmt(Fts3Cursor *pCsr){
+  int rc = SQLITE_OK;
+  if( pCsr->pStmt==0 ){
+    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+    char *zSql;
+    if( p->pSeekStmt ){
+      pCsr->pStmt = p->pSeekStmt;
+      p->pSeekStmt = 0;
+    }else{
+      zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);
+      if( !zSql ) return SQLITE_NOMEM;
+      rc = sqlite3_prepare_v3(p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);
+      sqlite3_free(zSql);
+    }
+    if( rc==SQLITE_OK ) pCsr->bSeekStmt = 1;
+  }
+  return rc;
+}
+
+/*
+** Position the pCsr->pStmt statement so that it is on the row
+** of the %_content table that contains the last match.  Return
+** SQLITE_OK on success.  
+*/
+static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
+  int rc = SQLITE_OK;
+  if( pCsr->isRequireSeek ){
+    rc = fts3CursorSeekStmt(pCsr);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
+      pCsr->isRequireSeek = 0;
+      if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
+        return SQLITE_OK;
+      }else{
+        rc = sqlite3_reset(pCsr->pStmt);
+        if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
+          /* If no row was found and no error has occurred, then the %_content
+          ** table is missing a row that is present in the full-text index.
+          ** The data structures are corrupt.  */
+          rc = FTS_CORRUPT_VTAB;
+          pCsr->isEof = 1;
+        }
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK && pContext ){
+    sqlite3_result_error_code(pContext, rc);
+  }
+  return rc;
+}
+
+/*
+** This function is used to process a single interior node when searching
+** a b-tree for a term or term prefix. The node data is passed to this 
+** function via the zNode/nNode parameters. The term to search for is
+** passed in zTerm/nTerm.
+**
+** If piFirst is not NULL, then this function sets *piFirst to the blockid
+** of the child node that heads the sub-tree that may contain the term.
+**
+** If piLast is not NULL, then *piLast is set to the right-most child node
+** that heads a sub-tree that may contain a term for which zTerm/nTerm is
+** a prefix.
+**
+** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
+*/
+static int fts3ScanInteriorNode(
+  const char *zTerm,              /* Term to select leaves for */
+  int nTerm,                      /* Size of term zTerm in bytes */
+  const char *zNode,              /* Buffer containing segment interior node */
+  int nNode,                      /* Size of buffer at zNode */
+  sqlite3_int64 *piFirst,         /* OUT: Selected child node */
+  sqlite3_int64 *piLast           /* OUT: Selected child node */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  const char *zCsr = zNode;       /* Cursor to iterate through node */
+  const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
+  char *zBuffer = 0;              /* Buffer to load terms into */
+  int nAlloc = 0;                 /* Size of allocated buffer */
+  int isFirstTerm = 1;            /* True when processing first term on page */
+  sqlite3_int64 iChild;           /* Block id of child node to descend to */
+
+  /* Skip over the 'height' varint that occurs at the start of every 
+  ** interior node. Then load the blockid of the left-child of the b-tree
+  ** node into variable iChild.  
+  **
+  ** Even if the data structure on disk is corrupted, this (reading two
+  ** varints from the buffer) does not risk an overread. If zNode is a
+  ** root node, then the buffer comes from a SELECT statement. SQLite does
+  ** not make this guarantee explicitly, but in practice there are always
+  ** either more than 20 bytes of allocated space following the nNode bytes of
+  ** contents, or two zero bytes. Or, if the node is read from the %_segments
+  ** table, then there are always 20 bytes of zeroed padding following the
+  ** nNode bytes of content (see sqlite3Fts3ReadBlock() for details).
+  */
+  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
+  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
+  if( zCsr>zEnd ){
+    return FTS_CORRUPT_VTAB;
+  }
+  
+  while( zCsr=0 && nSuffix>=0 );
+    if( &zCsr[nSuffix]>zEnd ){
+      rc = FTS_CORRUPT_VTAB;
+      goto finish_scan;
+    }
+    if( nPrefix+nSuffix>nAlloc ){
+      char *zNew;
+      nAlloc = (nPrefix+nSuffix) * 2;
+      zNew = (char *)sqlite3_realloc(zBuffer, nAlloc);
+      if( !zNew ){
+        rc = SQLITE_NOMEM;
+        goto finish_scan;
+      }
+      zBuffer = zNew;
+    }
+    assert( zBuffer );
+    memcpy(&zBuffer[nPrefix], zCsr, nSuffix);
+    nBuffer = nPrefix + nSuffix;
+    zCsr += nSuffix;
+
+    /* Compare the term we are searching for with the term just loaded from
+    ** the interior node. If the specified term is greater than or equal
+    ** to the term from the interior node, then all terms on the sub-tree 
+    ** headed by node iChild are smaller than zTerm. No need to search 
+    ** iChild.
+    **
+    ** If the interior node term is larger than the specified term, then
+    ** the tree headed by iChild may contain the specified term.
+    */
+    cmp = memcmp(zTerm, zBuffer, (nBuffer>nTerm ? nTerm : nBuffer));
+    if( piFirst && (cmp<0 || (cmp==0 && nBuffer>nTerm)) ){
+      *piFirst = iChild;
+      piFirst = 0;
+    }
+
+    if( piLast && cmp<0 ){
+      *piLast = iChild;
+      piLast = 0;
+    }
+
+    iChild++;
+  };
+
+  if( piFirst ) *piFirst = iChild;
+  if( piLast ) *piLast = iChild;
+
+ finish_scan:
+  sqlite3_free(zBuffer);
+  return rc;
+}
+
+
+/*
+** The buffer pointed to by argument zNode (size nNode bytes) contains an
+** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)
+** contains a term. This function searches the sub-tree headed by the zNode
+** node for the range of leaf nodes that may contain the specified term
+** or terms for which the specified term is a prefix.
+**
+** If piLeaf is not NULL, then *piLeaf is set to the blockid of the 
+** left-most leaf node in the tree that may contain the specified term.
+** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the
+** right-most leaf node that may contain a term for which the specified
+** term is a prefix.
+**
+** It is possible that the range of returned leaf nodes does not contain 
+** the specified term or any terms for which it is a prefix. However, if the 
+** segment does contain any such terms, they are stored within the identified
+** range. Because this function only inspects interior segment nodes (and
+** never loads leaf nodes into memory), it is not possible to be sure.
+**
+** If an error occurs, an error code other than SQLITE_OK is returned.
+*/ 
+static int fts3SelectLeaf(
+  Fts3Table *p,                   /* Virtual table handle */
+  const char *zTerm,              /* Term to select leaves for */
+  int nTerm,                      /* Size of term zTerm in bytes */
+  const char *zNode,              /* Buffer containing segment interior node */
+  int nNode,                      /* Size of buffer at zNode */
+  sqlite3_int64 *piLeaf,          /* Selected leaf node */
+  sqlite3_int64 *piLeaf2          /* Selected leaf node */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  int iHeight;                    /* Height of this node in tree */
+
+  assert( piLeaf || piLeaf2 );
+
+  fts3GetVarint32(zNode, &iHeight);
+  rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
+  assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
+
+  if( rc==SQLITE_OK && iHeight>1 ){
+    char *zBlob = 0;              /* Blob read from %_segments table */
+    int nBlob = 0;                /* Size of zBlob in bytes */
+
+    if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
+      rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);
+      if( rc==SQLITE_OK ){
+        rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);
+      }
+      sqlite3_free(zBlob);
+      piLeaf = 0;
+      zBlob = 0;
+    }
+
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3ReadBlock(p, piLeaf?*piLeaf:*piLeaf2, &zBlob, &nBlob, 0);
+    }
+    if( rc==SQLITE_OK ){
+      rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
+    }
+    sqlite3_free(zBlob);
+  }
+
+  return rc;
+}
+
+/*
+** This function is used to create delta-encoded serialized lists of FTS3 
+** varints. Each call to this function appends a single varint to a list.
+*/
+static void fts3PutDeltaVarint(
+  char **pp,                      /* IN/OUT: Output pointer */
+  sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */
+  sqlite3_int64 iVal              /* Write this value to the list */
+){
+  assert( iVal-*piPrev > 0 || (*piPrev==0 && iVal==0) );
+  *pp += sqlite3Fts3PutVarint(*pp, iVal-*piPrev);
+  *piPrev = iVal;
+}
+
+/*
+** When this function is called, *ppPoslist is assumed to point to the 
+** start of a position-list. After it returns, *ppPoslist points to the
+** first byte after the position-list.
+**
+** A position list is list of positions (delta encoded) and columns for 
+** a single document record of a doclist.  So, in other words, this
+** routine advances *ppPoslist so that it points to the next docid in
+** the doclist, or to the first byte past the end of the doclist.
+**
+** If pp is not NULL, then the contents of the position list are copied
+** to *pp. *pp is set to point to the first byte past the last byte copied
+** before this function returns.
+*/
+static void fts3PoslistCopy(char **pp, char **ppPoslist){
+  char *pEnd = *ppPoslist;
+  char c = 0;
+
+  /* The end of a position list is marked by a zero encoded as an FTS3 
+  ** varint. A single POS_END (0) byte. Except, if the 0 byte is preceded by
+  ** a byte with the 0x80 bit set, then it is not a varint 0, but the tail
+  ** of some other, multi-byte, value.
+  **
+  ** The following while-loop moves pEnd to point to the first byte that is not 
+  ** immediately preceded by a byte with the 0x80 bit set. Then increments
+  ** pEnd once more so that it points to the byte immediately following the
+  ** last byte in the position-list.
+  */
+  while( *pEnd | c ){
+    c = *pEnd++ & 0x80;
+    testcase( c!=0 && (*pEnd)==0 );
+  }
+  pEnd++;  /* Advance past the POS_END terminator byte */
+
+  if( pp ){
+    int n = (int)(pEnd - *ppPoslist);
+    char *p = *pp;
+    memcpy(p, *ppPoslist, n);
+    p += n;
+    *pp = p;
+  }
+  *ppPoslist = pEnd;
+}
+
+/*
+** When this function is called, *ppPoslist is assumed to point to the 
+** start of a column-list. After it returns, *ppPoslist points to the
+** to the terminator (POS_COLUMN or POS_END) byte of the column-list.
+**
+** A column-list is list of delta-encoded positions for a single column
+** within a single document within a doclist.
+**
+** The column-list is terminated either by a POS_COLUMN varint (1) or
+** a POS_END varint (0).  This routine leaves *ppPoslist pointing to
+** the POS_COLUMN or POS_END that terminates the column-list.
+**
+** If pp is not NULL, then the contents of the column-list are copied
+** to *pp. *pp is set to point to the first byte past the last byte copied
+** before this function returns.  The POS_COLUMN or POS_END terminator
+** is not copied into *pp.
+*/
+static void fts3ColumnlistCopy(char **pp, char **ppPoslist){
+  char *pEnd = *ppPoslist;
+  char c = 0;
+
+  /* A column-list is terminated by either a 0x01 or 0x00 byte that is
+  ** not part of a multi-byte varint.
+  */
+  while( 0xFE & (*pEnd | c) ){
+    c = *pEnd++ & 0x80;
+    testcase( c!=0 && ((*pEnd)&0xfe)==0 );
+  }
+  if( pp ){
+    int n = (int)(pEnd - *ppPoslist);
+    char *p = *pp;
+    memcpy(p, *ppPoslist, n);
+    p += n;
+    *pp = p;
+  }
+  *ppPoslist = pEnd;
+}
+
+/*
+** Value used to signify the end of an position-list. This is safe because
+** it is not possible to have a document with 2^31 terms.
+*/
+#define POSITION_LIST_END 0x7fffffff
+
+/*
+** This function is used to help parse position-lists. When this function is
+** called, *pp may point to the start of the next varint in the position-list
+** being parsed, or it may point to 1 byte past the end of the position-list
+** (in which case **pp will be a terminator bytes POS_END (0) or
+** (1)).
+**
+** If *pp points past the end of the current position-list, set *pi to 
+** POSITION_LIST_END and return. Otherwise, read the next varint from *pp,
+** increment the current value of *pi by the value read, and set *pp to
+** point to the next value before returning.
+**
+** Before calling this routine *pi must be initialized to the value of
+** the previous position, or zero if we are reading the first position
+** in the position-list.  Because positions are delta-encoded, the value
+** of the previous position is needed in order to compute the value of
+** the next position.
+*/
+static void fts3ReadNextPos(
+  char **pp,                    /* IN/OUT: Pointer into position-list buffer */
+  sqlite3_int64 *pi             /* IN/OUT: Value read from position-list */
+){
+  if( (**pp)&0xFE ){
+    fts3GetDeltaVarint(pp, pi);
+    *pi -= 2;
+  }else{
+    *pi = POSITION_LIST_END;
+  }
+}
+
+/*
+** If parameter iCol is not 0, write an POS_COLUMN (1) byte followed by
+** the value of iCol encoded as a varint to *pp.   This will start a new
+** column list.
+**
+** Set *pp to point to the byte just after the last byte written before 
+** returning (do not modify it if iCol==0). Return the total number of bytes
+** written (0 if iCol==0).
+*/
+static int fts3PutColNumber(char **pp, int iCol){
+  int n = 0;                      /* Number of bytes written */
+  if( iCol ){
+    char *p = *pp;                /* Output pointer */
+    n = 1 + sqlite3Fts3PutVarint(&p[1], iCol);
+    *p = 0x01;
+    *pp = &p[n];
+  }
+  return n;
+}
+
+/*
+** Compute the union of two position lists.  The output written
+** into *pp contains all positions of both *pp1 and *pp2 in sorted
+** order and with any duplicates removed.  All pointers are
+** updated appropriately.   The caller is responsible for insuring
+** that there is enough space in *pp to hold the complete output.
+*/
+static void fts3PoslistMerge(
+  char **pp,                      /* Output buffer */
+  char **pp1,                     /* Left input list */
+  char **pp2                      /* Right input list */
+){
+  char *p = *pp;
+  char *p1 = *pp1;
+  char *p2 = *pp2;
+
+  while( *p1 || *p2 ){
+    int iCol1;         /* The current column index in pp1 */
+    int iCol2;         /* The current column index in pp2 */
+
+    if( *p1==POS_COLUMN ) fts3GetVarint32(&p1[1], &iCol1);
+    else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;
+    else iCol1 = 0;
+
+    if( *p2==POS_COLUMN ) fts3GetVarint32(&p2[1], &iCol2);
+    else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;
+    else iCol2 = 0;
+
+    if( iCol1==iCol2 ){
+      sqlite3_int64 i1 = 0;       /* Last position from pp1 */
+      sqlite3_int64 i2 = 0;       /* Last position from pp2 */
+      sqlite3_int64 iPrev = 0;
+      int n = fts3PutColNumber(&p, iCol1);
+      p1 += n;
+      p2 += n;
+
+      /* At this point, both p1 and p2 point to the start of column-lists
+      ** for the same column (the column with index iCol1 and iCol2).
+      ** A column-list is a list of non-negative delta-encoded varints, each 
+      ** incremented by 2 before being stored. Each list is terminated by a
+      ** POS_END (0) or POS_COLUMN (1). The following block merges the two lists
+      ** and writes the results to buffer p. p is left pointing to the byte
+      ** after the list written. No terminator (POS_END or POS_COLUMN) is
+      ** written to the output.
+      */
+      fts3GetDeltaVarint(&p1, &i1);
+      fts3GetDeltaVarint(&p2, &i2);
+      do {
+        fts3PutDeltaVarint(&p, &iPrev, (i1pos(*pp1) && pos(*pp2)-pos(*pp1)<=nToken). i.e.
+** when the *pp1 token appears before the *pp2 token, but not more than nToken
+** slots before it.
+**
+** e.g. nToken==1 searches for adjacent positions.
+*/
+static int fts3PoslistPhraseMerge(
+  char **pp,                      /* IN/OUT: Preallocated output buffer */
+  int nToken,                     /* Maximum difference in token positions */
+  int isSaveLeft,                 /* Save the left position */
+  int isExact,                    /* If *pp1 is exactly nTokens before *pp2 */
+  char **pp1,                     /* IN/OUT: Left input list */
+  char **pp2                      /* IN/OUT: Right input list */
+){
+  char *p = *pp;
+  char *p1 = *pp1;
+  char *p2 = *pp2;
+  int iCol1 = 0;
+  int iCol2 = 0;
+
+  /* Never set both isSaveLeft and isExact for the same invocation. */
+  assert( isSaveLeft==0 || isExact==0 );
+
+  assert( p!=0 && *p1!=0 && *p2!=0 );
+  if( *p1==POS_COLUMN ){ 
+    p1++;
+    p1 += fts3GetVarint32(p1, &iCol1);
+  }
+  if( *p2==POS_COLUMN ){ 
+    p2++;
+    p2 += fts3GetVarint32(p2, &iCol2);
+  }
+
+  while( 1 ){
+    if( iCol1==iCol2 ){
+      char *pSave = p;
+      sqlite3_int64 iPrev = 0;
+      sqlite3_int64 iPos1 = 0;
+      sqlite3_int64 iPos2 = 0;
+
+      if( iCol1 ){
+        *p++ = POS_COLUMN;
+        p += sqlite3Fts3PutVarint(p, iCol1);
+      }
+
+      assert( *p1!=POS_END && *p1!=POS_COLUMN );
+      assert( *p2!=POS_END && *p2!=POS_COLUMN );
+      fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
+      fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
+
+      while( 1 ){
+        if( iPos2==iPos1+nToken 
+         || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken) 
+        ){
+          sqlite3_int64 iSave;
+          iSave = isSaveLeft ? iPos1 : iPos2;
+          fts3PutDeltaVarint(&p, &iPrev, iSave+2); iPrev -= 2;
+          pSave = 0;
+          assert( p );
+        }
+        if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){
+          if( (*p2&0xFE)==0 ) break;
+          fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
+        }else{
+          if( (*p1&0xFE)==0 ) break;
+          fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
+        }
+      }
+
+      if( pSave ){
+        assert( pp && p );
+        p = pSave;
+      }
+
+      fts3ColumnlistCopy(0, &p1);
+      fts3ColumnlistCopy(0, &p2);
+      assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );
+      if( 0==*p1 || 0==*p2 ) break;
+
+      p1++;
+      p1 += fts3GetVarint32(p1, &iCol1);
+      p2++;
+      p2 += fts3GetVarint32(p2, &iCol2);
+    }
+
+    /* Advance pointer p1 or p2 (whichever corresponds to the smaller of
+    ** iCol1 and iCol2) so that it points to either the 0x00 that marks the
+    ** end of the position list, or the 0x01 that precedes the next 
+    ** column-number in the position list. 
+    */
+    else if( iCol1=pEnd ){
+    *pp = 0;
+  }else{
+    sqlite3_int64 iVal;
+    *pp += sqlite3Fts3GetVarint(*pp, &iVal);
+    if( bDescIdx ){
+      *pVal -= iVal;
+    }else{
+      *pVal += iVal;
+    }
+  }
+}
+
+/*
+** This function is used to write a single varint to a buffer. The varint
+** is written to *pp. Before returning, *pp is set to point 1 byte past the
+** end of the value written.
+**
+** If *pbFirst is zero when this function is called, the value written to
+** the buffer is that of parameter iVal. 
+**
+** If *pbFirst is non-zero when this function is called, then the value 
+** written is either (iVal-*piPrev) (if bDescIdx is zero) or (*piPrev-iVal)
+** (if bDescIdx is non-zero).
+**
+** Before returning, this function always sets *pbFirst to 1 and *piPrev
+** to the value of parameter iVal.
+*/
+static void fts3PutDeltaVarint3(
+  char **pp,                      /* IN/OUT: Output pointer */
+  int bDescIdx,                   /* True for descending docids */
+  sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */
+  int *pbFirst,                   /* IN/OUT: True after first int written */
+  sqlite3_int64 iVal              /* Write this value to the list */
+){
+  sqlite3_int64 iWrite;
+  if( bDescIdx==0 || *pbFirst==0 ){
+    iWrite = iVal - *piPrev;
+  }else{
+    iWrite = *piPrev - iVal;
+  }
+  assert( *pbFirst || *piPrev==0 );
+  assert( *pbFirst==0 || iWrite>0 );
+  *pp += sqlite3Fts3PutVarint(*pp, iWrite);
+  *piPrev = iVal;
+  *pbFirst = 1;
+}
+
+
+/*
+** This macro is used by various functions that merge doclists. The two
+** arguments are 64-bit docid values. If the value of the stack variable
+** bDescDoclist is 0 when this macro is invoked, then it returns (i1-i2). 
+** Otherwise, (i2-i1).
+**
+** Using this makes it easier to write code that can merge doclists that are
+** sorted in either ascending or descending order.
+*/
+#define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i1-i2))
+
+/*
+** This function does an "OR" merge of two doclists (output contains all
+** positions contained in either argument doclist). If the docids in the 
+** input doclists are sorted in ascending order, parameter bDescDoclist
+** should be false. If they are sorted in ascending order, it should be
+** passed a non-zero value.
+**
+** If no error occurs, *paOut is set to point at an sqlite3_malloc'd buffer
+** containing the output doclist and SQLITE_OK is returned. In this case
+** *pnOut is set to the number of bytes in the output doclist.
+**
+** If an error occurs, an SQLite error code is returned. The output values
+** are undefined in this case.
+*/
+static int fts3DoclistOrMerge(
+  int bDescDoclist,               /* True if arguments are desc */
+  char *a1, int n1,               /* First doclist */
+  char *a2, int n2,               /* Second doclist */
+  char **paOut, int *pnOut        /* OUT: Malloc'd doclist */
+){
+  sqlite3_int64 i1 = 0;
+  sqlite3_int64 i2 = 0;
+  sqlite3_int64 iPrev = 0;
+  char *pEnd1 = &a1[n1];
+  char *pEnd2 = &a2[n2];
+  char *p1 = a1;
+  char *p2 = a2;
+  char *p;
+  char *aOut;
+  int bFirstOut = 0;
+
+  *paOut = 0;
+  *pnOut = 0;
+
+  /* Allocate space for the output. Both the input and output doclists
+  ** are delta encoded. If they are in ascending order (bDescDoclist==0),
+  ** then the first docid in each list is simply encoded as a varint. For
+  ** each subsequent docid, the varint stored is the difference between the
+  ** current and previous docid (a positive number - since the list is in
+  ** ascending order).
+  **
+  ** The first docid written to the output is therefore encoded using the 
+  ** same number of bytes as it is in whichever of the input lists it is
+  ** read from. And each subsequent docid read from the same input list 
+  ** consumes either the same or less bytes as it did in the input (since
+  ** the difference between it and the previous value in the output must
+  ** be a positive value less than or equal to the delta value read from 
+  ** the input list). The same argument applies to all but the first docid
+  ** read from the 'other' list. And to the contents of all position lists
+  ** that will be copied and merged from the input to the output.
+  **
+  ** However, if the first docid copied to the output is a negative number,
+  ** then the encoding of the first docid from the 'other' input list may
+  ** be larger in the output than it was in the input (since the delta value
+  ** may be a larger positive integer than the actual docid).
+  **
+  ** The space required to store the output is therefore the sum of the
+  ** sizes of the two inputs, plus enough space for exactly one of the input
+  ** docids to grow. 
+  **
+  ** A symetric argument may be made if the doclists are in descending 
+  ** order.
+  */
+  aOut = sqlite3_malloc(n1+n2+FTS3_VARINT_MAX-1);
+  if( !aOut ) return SQLITE_NOMEM;
+
+  p = aOut;
+  fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
+  fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
+  while( p1 || p2 ){
+    sqlite3_int64 iDiff = DOCID_CMP(i1, i2);
+
+    if( p2 && p1 && iDiff==0 ){
+      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+      fts3PoslistMerge(&p, &p1, &p2);
+      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+    }else if( !p2 || (p1 && iDiff<0) ){
+      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+      fts3PoslistCopy(&p, &p1);
+      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+    }else{
+      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i2);
+      fts3PoslistCopy(&p, &p2);
+      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+    }
+  }
+
+  *paOut = aOut;
+  *pnOut = (int)(p-aOut);
+  assert( *pnOut<=n1+n2+FTS3_VARINT_MAX-1 );
+  return SQLITE_OK;
+}
+
+/*
+** This function does a "phrase" merge of two doclists. In a phrase merge,
+** the output contains a copy of each position from the right-hand input
+** doclist for which there is a position in the left-hand input doclist
+** exactly nDist tokens before it.
+**
+** If the docids in the input doclists are sorted in ascending order,
+** parameter bDescDoclist should be false. If they are sorted in ascending 
+** order, it should be passed a non-zero value.
+**
+** The right-hand input doclist is overwritten by this function.
+*/
+static int fts3DoclistPhraseMerge(
+  int bDescDoclist,               /* True if arguments are desc */
+  int nDist,                      /* Distance from left to right (1=adjacent) */
+  char *aLeft, int nLeft,         /* Left doclist */
+  char **paRight, int *pnRight    /* IN/OUT: Right/output doclist */
+){
+  sqlite3_int64 i1 = 0;
+  sqlite3_int64 i2 = 0;
+  sqlite3_int64 iPrev = 0;
+  char *aRight = *paRight;
+  char *pEnd1 = &aLeft[nLeft];
+  char *pEnd2 = &aRight[*pnRight];
+  char *p1 = aLeft;
+  char *p2 = aRight;
+  char *p;
+  int bFirstOut = 0;
+  char *aOut;
+
+  assert( nDist>0 );
+  if( bDescDoclist ){
+    aOut = sqlite3_malloc(*pnRight + FTS3_VARINT_MAX);
+    if( aOut==0 ) return SQLITE_NOMEM;
+  }else{
+    aOut = aRight;
+  }
+  p = aOut;
+
+  fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
+  fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
+
+  while( p1 && p2 ){
+    sqlite3_int64 iDiff = DOCID_CMP(i1, i2);
+    if( iDiff==0 ){
+      char *pSave = p;
+      sqlite3_int64 iPrevSave = iPrev;
+      int bFirstOutSave = bFirstOut;
+
+      fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+      if( 0==fts3PoslistPhraseMerge(&p, nDist, 0, 1, &p1, &p2) ){
+        p = pSave;
+        iPrev = iPrevSave;
+        bFirstOut = bFirstOutSave;
+      }
+      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+    }else if( iDiff<0 ){
+      fts3PoslistCopy(0, &p1);
+      fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+    }else{
+      fts3PoslistCopy(0, &p2);
+      fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+    }
+  }
+
+  *pnRight = (int)(p - aOut);
+  if( bDescDoclist ){
+    sqlite3_free(aRight);
+    *paRight = aOut;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Argument pList points to a position list nList bytes in size. This
+** function checks to see if the position list contains any entries for
+** a token in position 0 (of any column). If so, it writes argument iDelta
+** to the output buffer pOut, followed by a position list consisting only
+** of the entries from pList at position 0, and terminated by an 0x00 byte.
+** The value returned is the number of bytes written to pOut (if any).
+*/
+SQLITE_PRIVATE int sqlite3Fts3FirstFilter(
+  sqlite3_int64 iDelta,           /* Varint that may be written to pOut */
+  char *pList,                    /* Position list (no 0x00 term) */
+  int nList,                      /* Size of pList in bytes */
+  char *pOut                      /* Write output here */
+){
+  int nOut = 0;
+  int bWritten = 0;               /* True once iDelta has been written */
+  char *p = pList;
+  char *pEnd = &pList[nList];
+
+  if( *p!=0x01 ){
+    if( *p==0x02 ){
+      nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);
+      pOut[nOut++] = 0x02;
+      bWritten = 1;
+    }
+    fts3ColumnlistCopy(0, &p);
+  }
+
+  while( paaOutput); i++){
+    if( pTS->aaOutput[i] ){
+      if( !aOut ){
+        aOut = pTS->aaOutput[i];
+        nOut = pTS->anOutput[i];
+        pTS->aaOutput[i] = 0;
+      }else{
+        int nNew;
+        char *aNew;
+
+        int rc = fts3DoclistOrMerge(p->bDescIdx, 
+            pTS->aaOutput[i], pTS->anOutput[i], aOut, nOut, &aNew, &nNew
+        );
+        if( rc!=SQLITE_OK ){
+          sqlite3_free(aOut);
+          return rc;
+        }
+
+        sqlite3_free(pTS->aaOutput[i]);
+        sqlite3_free(aOut);
+        pTS->aaOutput[i] = 0;
+        aOut = aNew;
+        nOut = nNew;
+      }
+    }
+  }
+
+  pTS->aaOutput[0] = aOut;
+  pTS->anOutput[0] = nOut;
+  return SQLITE_OK;
+}
+
+/*
+** Merge the doclist aDoclist/nDoclist into the TermSelect object passed
+** as the first argument. The merge is an "OR" merge (see function
+** fts3DoclistOrMerge() for details).
+**
+** This function is called with the doclist for each term that matches
+** a queried prefix. It merges all these doclists into one, the doclist
+** for the specified prefix. Since there can be a very large number of
+** doclists to merge, the merging is done pair-wise using the TermSelect
+** object.
+**
+** This function returns SQLITE_OK if the merge is successful, or an
+** SQLite error code (SQLITE_NOMEM) if an error occurs.
+*/
+static int fts3TermSelectMerge(
+  Fts3Table *p,                   /* FTS table handle */
+  TermSelect *pTS,                /* TermSelect object to merge into */
+  char *aDoclist,                 /* Pointer to doclist */
+  int nDoclist                    /* Size of aDoclist in bytes */
+){
+  if( pTS->aaOutput[0]==0 ){
+    /* If this is the first term selected, copy the doclist to the output
+    ** buffer using memcpy(). 
+    **
+    ** Add FTS3_VARINT_MAX bytes of unused space to the end of the 
+    ** allocation. This is so as to ensure that the buffer is big enough
+    ** to hold the current doclist AND'd with any other doclist. If the
+    ** doclists are stored in order=ASC order, this padding would not be
+    ** required (since the size of [doclistA AND doclistB] is always less
+    ** than or equal to the size of [doclistA] in that case). But this is
+    ** not true for order=DESC. For example, a doclist containing (1, -1) 
+    ** may be smaller than (-1), as in the first example the -1 may be stored
+    ** as a single-byte delta, whereas in the second it must be stored as a
+    ** FTS3_VARINT_MAX byte varint.
+    **
+    ** Similar padding is added in the fts3DoclistOrMerge() function.
+    */
+    pTS->aaOutput[0] = sqlite3_malloc(nDoclist + FTS3_VARINT_MAX + 1);
+    pTS->anOutput[0] = nDoclist;
+    if( pTS->aaOutput[0] ){
+      memcpy(pTS->aaOutput[0], aDoclist, nDoclist);
+    }else{
+      return SQLITE_NOMEM;
+    }
+  }else{
+    char *aMerge = aDoclist;
+    int nMerge = nDoclist;
+    int iOut;
+
+    for(iOut=0; iOutaaOutput); iOut++){
+      if( pTS->aaOutput[iOut]==0 ){
+        assert( iOut>0 );
+        pTS->aaOutput[iOut] = aMerge;
+        pTS->anOutput[iOut] = nMerge;
+        break;
+      }else{
+        char *aNew;
+        int nNew;
+
+        int rc = fts3DoclistOrMerge(p->bDescIdx, aMerge, nMerge, 
+            pTS->aaOutput[iOut], pTS->anOutput[iOut], &aNew, &nNew
+        );
+        if( rc!=SQLITE_OK ){
+          if( aMerge!=aDoclist ) sqlite3_free(aMerge);
+          return rc;
+        }
+
+        if( aMerge!=aDoclist ) sqlite3_free(aMerge);
+        sqlite3_free(pTS->aaOutput[iOut]);
+        pTS->aaOutput[iOut] = 0;
+  
+        aMerge = aNew;
+        nMerge = nNew;
+        if( (iOut+1)==SizeofArray(pTS->aaOutput) ){
+          pTS->aaOutput[iOut] = aMerge;
+          pTS->anOutput[iOut] = nMerge;
+        }
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Append SegReader object pNew to the end of the pCsr->apSegment[] array.
+*/
+static int fts3SegReaderCursorAppend(
+  Fts3MultiSegReader *pCsr, 
+  Fts3SegReader *pNew
+){
+  if( (pCsr->nSegment%16)==0 ){
+    Fts3SegReader **apNew;
+    int nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);
+    apNew = (Fts3SegReader **)sqlite3_realloc(pCsr->apSegment, nByte);
+    if( !apNew ){
+      sqlite3Fts3SegReaderFree(pNew);
+      return SQLITE_NOMEM;
+    }
+    pCsr->apSegment = apNew;
+  }
+  pCsr->apSegment[pCsr->nSegment++] = pNew;
+  return SQLITE_OK;
+}
+
+/*
+** Add seg-reader objects to the Fts3MultiSegReader object passed as the
+** 8th argument.
+**
+** This function returns SQLITE_OK if successful, or an SQLite error code
+** otherwise.
+*/
+static int fts3SegReaderCursor(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id */
+  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
+  int iLevel,                     /* Level of segments to scan */
+  const char *zTerm,              /* Term to query for */
+  int nTerm,                      /* Size of zTerm in bytes */
+  int isPrefix,                   /* True for a prefix search */
+  int isScan,                     /* True to scan from zTerm to EOF */
+  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
+){
+  int rc = SQLITE_OK;             /* Error code */
+  sqlite3_stmt *pStmt = 0;        /* Statement to iterate through segments */
+  int rc2;                        /* Result of sqlite3_reset() */
+
+  /* If iLevel is less than 0 and this is not a scan, include a seg-reader 
+  ** for the pending-terms. If this is a scan, then this call must be being
+  ** made by an fts4aux module, not an FTS table. In this case calling
+  ** Fts3SegReaderPending might segfault, as the data structures used by 
+  ** fts4aux are not completely populated. So it's easiest to filter these
+  ** calls out here.  */
+  if( iLevel<0 && p->aIndex ){
+    Fts3SegReader *pSeg = 0;
+    rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix||isScan, &pSeg);
+    if( rc==SQLITE_OK && pSeg ){
+      rc = fts3SegReaderCursorAppend(pCsr, pSeg);
+    }
+  }
+
+  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3AllSegdirs(p, iLangid, iIndex, iLevel, &pStmt);
+    }
+
+    while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
+      Fts3SegReader *pSeg = 0;
+
+      /* Read the values returned by the SELECT into local variables. */
+      sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);
+      sqlite3_int64 iLeavesEndBlock = sqlite3_column_int64(pStmt, 2);
+      sqlite3_int64 iEndBlock = sqlite3_column_int64(pStmt, 3);
+      int nRoot = sqlite3_column_bytes(pStmt, 4);
+      char const *zRoot = sqlite3_column_blob(pStmt, 4);
+
+      /* If zTerm is not NULL, and this segment is not stored entirely on its
+      ** root node, the range of leaves scanned can be reduced. Do this. */
+      if( iStartBlock && zTerm ){
+        sqlite3_int64 *pi = (isPrefix ? &iLeavesEndBlock : 0);
+        rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &iStartBlock, pi);
+        if( rc!=SQLITE_OK ) goto finished;
+        if( isPrefix==0 && isScan==0 ) iLeavesEndBlock = iStartBlock;
+      }
+ 
+      rc = sqlite3Fts3SegReaderNew(pCsr->nSegment+1, 
+          (isPrefix==0 && isScan==0),
+          iStartBlock, iLeavesEndBlock, 
+          iEndBlock, zRoot, nRoot, &pSeg
+      );
+      if( rc!=SQLITE_OK ) goto finished;
+      rc = fts3SegReaderCursorAppend(pCsr, pSeg);
+    }
+  }
+
+ finished:
+  rc2 = sqlite3_reset(pStmt);
+  if( rc==SQLITE_DONE ) rc = rc2;
+
+  return rc;
+}
+
+/*
+** Set up a cursor object for iterating through a full-text index or a 
+** single level therein.
+*/
+SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language-id to search */
+  int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
+  int iLevel,                     /* Level of segments to scan */
+  const char *zTerm,              /* Term to query for */
+  int nTerm,                      /* Size of zTerm in bytes */
+  int isPrefix,                   /* True for a prefix search */
+  int isScan,                     /* True to scan from zTerm to EOF */
+  Fts3MultiSegReader *pCsr       /* Cursor object to populate */
+){
+  assert( iIndex>=0 && iIndexnIndex );
+  assert( iLevel==FTS3_SEGCURSOR_ALL
+      ||  iLevel==FTS3_SEGCURSOR_PENDING 
+      ||  iLevel>=0
+  );
+  assert( iLevelbase.pVtab;
+
+    if( isPrefix ){
+      for(i=1; bFound==0 && inIndex; i++){
+        if( p->aIndex[i].nPrefix==nTerm ){
+          bFound = 1;
+          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr
+          );
+          pSegcsr->bLookup = 1;
+        }
+      }
+
+      for(i=1; bFound==0 && inIndex; i++){
+        if( p->aIndex[i].nPrefix==nTerm+1 ){
+          bFound = 1;
+          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
+          );
+          if( rc==SQLITE_OK ){
+            rc = fts3SegReaderCursorAddZero(
+                p, pCsr->iLangid, zTerm, nTerm, pSegcsr
+            );
+          }
+        }
+      }
+    }
+
+    if( bFound==0 ){
+      rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+          0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
+      );
+      pSegcsr->bLookup = !isPrefix;
+    }
+  }
+
+  *ppSegcsr = pSegcsr;
+  return rc;
+}
+
+/*
+** Free an Fts3MultiSegReader allocated by fts3TermSegReaderCursor().
+*/
+static void fts3SegReaderCursorFree(Fts3MultiSegReader *pSegcsr){
+  sqlite3Fts3SegReaderFinish(pSegcsr);
+  sqlite3_free(pSegcsr);
+}
+
+/*
+** This function retrieves the doclist for the specified term (or term
+** prefix) from the database.
+*/
+static int fts3TermSelect(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3PhraseToken *pTok,          /* Token to query for */
+  int iColumn,                    /* Column to query (or -ve for all columns) */
+  int *pnOut,                     /* OUT: Size of buffer at *ppOut */
+  char **ppOut                    /* OUT: Malloced result buffer */
+){
+  int rc;                         /* Return code */
+  Fts3MultiSegReader *pSegcsr;    /* Seg-reader cursor for this term */
+  TermSelect tsc;                 /* Object for pair-wise doclist merging */
+  Fts3SegFilter filter;           /* Segment term filter configuration */
+
+  pSegcsr = pTok->pSegcsr;
+  memset(&tsc, 0, sizeof(TermSelect));
+
+  filter.flags = FTS3_SEGMENT_IGNORE_EMPTY | FTS3_SEGMENT_REQUIRE_POS
+        | (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
+        | (pTok->bFirst ? FTS3_SEGMENT_FIRST : 0)
+        | (iColumnnColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
+  filter.iCol = iColumn;
+  filter.zTerm = pTok->z;
+  filter.nTerm = pTok->n;
+
+  rc = sqlite3Fts3SegReaderStart(p, pSegcsr, &filter);
+  while( SQLITE_OK==rc
+      && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pSegcsr)) 
+  ){
+    rc = fts3TermSelectMerge(p, &tsc, pSegcsr->aDoclist, pSegcsr->nDoclist);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = fts3TermSelectFinishMerge(p, &tsc);
+  }
+  if( rc==SQLITE_OK ){
+    *ppOut = tsc.aaOutput[0];
+    *pnOut = tsc.anOutput[0];
+  }else{
+    int i;
+    for(i=0; ipSegcsr = 0;
+  return rc;
+}
+
+/*
+** This function counts the total number of docids in the doclist stored
+** in buffer aList[], size nList bytes.
+**
+** If the isPoslist argument is true, then it is assumed that the doclist
+** contains a position-list following each docid. Otherwise, it is assumed
+** that the doclist is simply a list of docids stored as delta encoded 
+** varints.
+*/
+static int fts3DoclistCountDocids(char *aList, int nList){
+  int nDoc = 0;                   /* Return value */
+  if( aList ){
+    char *aEnd = &aList[nList];   /* Pointer to one byte after EOF */
+    char *p = aList;              /* Cursor */
+    while( peSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){
+    if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
+      pCsr->isEof = 1;
+      rc = sqlite3_reset(pCsr->pStmt);
+    }else{
+      pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
+      rc = SQLITE_OK;
+    }
+  }else{
+    rc = fts3EvalNext((Fts3Cursor *)pCursor);
+  }
+  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+  return rc;
+}
+
+/*
+** The following are copied from sqliteInt.h.
+**
+** Constants for the largest and smallest possible 64-bit signed integers.
+** These macros are designed to work correctly on both 32-bit and 64-bit
+** compilers.
+*/
+#ifndef SQLITE_AMALGAMATION
+# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
+# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
+#endif
+
+/*
+** If the numeric type of argument pVal is "integer", then return it
+** converted to a 64-bit signed integer. Otherwise, return a copy of
+** the second parameter, iDefault.
+*/
+static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
+  if( pVal ){
+    int eType = sqlite3_value_numeric_type(pVal);
+    if( eType==SQLITE_INTEGER ){
+      return sqlite3_value_int64(pVal);
+    }
+  }
+  return iDefault;
+}
+
+/*
+** This is the xFilter interface for the virtual table.  See
+** the virtual table xFilter method documentation for additional
+** information.
+**
+** If idxNum==FTS3_FULLSCAN_SEARCH then do a full table scan against
+** the %_content table.
+**
+** If idxNum==FTS3_DOCID_SEARCH then do a docid lookup for a single entry
+** in the %_content table.
+**
+** If idxNum>=FTS3_FULLTEXT_SEARCH then use the full text index.  The
+** column on the left-hand side of the MATCH operator is column
+** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed.  argv[0] is the right-hand
+** side of the MATCH operator.
+*/
+static int fts3FilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  int rc = SQLITE_OK;
+  char *zSql;                     /* SQL statement used to access %_content */
+  int eSearch;
+  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
+  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
+
+  sqlite3_value *pCons = 0;       /* The MATCH or rowid constraint, if any */
+  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
+  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
+  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
+  int iIdx;
+
+  UNUSED_PARAMETER(idxStr);
+  UNUSED_PARAMETER(nVal);
+
+  eSearch = (idxNum & 0x0000FFFF);
+  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
+  assert( p->pSegments==0 );
+
+  /* Collect arguments into local variables */
+  iIdx = 0;
+  if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
+  assert( iIdx==nVal );
+
+  /* In case the cursor has been used before, clear it now. */
+  fts3ClearCursor(pCsr);
+
+  /* Set the lower and upper bounds on docids to return */
+  pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
+  pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);
+
+  if( idxStr ){
+    pCsr->bDesc = (idxStr[0]=='D');
+  }else{
+    pCsr->bDesc = p->bDescIdx;
+  }
+  pCsr->eSearch = (i16)eSearch;
+
+  if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){
+    int iCol = eSearch-FTS3_FULLTEXT_SEARCH;
+    const char *zQuery = (const char *)sqlite3_value_text(pCons);
+
+    if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){
+      return SQLITE_NOMEM;
+    }
+
+    pCsr->iLangid = 0;
+    if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);
+
+    assert( p->base.zErrMsg==0 );
+    rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
+        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 
+        &p->base.zErrMsg
+    );
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+
+    rc = fts3EvalStart(pCsr);
+    sqlite3Fts3SegmentsClose(p);
+    if( rc!=SQLITE_OK ) return rc;
+    pCsr->pNextId = pCsr->aDoclist;
+    pCsr->iPrevId = 0;
+  }
+
+  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
+  ** statement loops through all rows of the %_content table. For a
+  ** full-text query or docid lookup, the statement retrieves a single
+  ** row by docid.
+  */
+  if( eSearch==FTS3_FULLSCAN_SEARCH ){
+    if( pDocidGe || pDocidLe ){
+      zSql = sqlite3_mprintf(
+          "SELECT %s WHERE rowid BETWEEN %lld AND %lld ORDER BY rowid %s",
+          p->zReadExprlist, pCsr->iMinDocid, pCsr->iMaxDocid,
+          (pCsr->bDesc ? "DESC" : "ASC")
+      );
+    }else{
+      zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s", 
+          p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
+      );
+    }
+    if( zSql ){
+      rc = sqlite3_prepare_v3(p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);
+      sqlite3_free(zSql);
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }else if( eSearch==FTS3_DOCID_SEARCH ){
+    rc = fts3CursorSeekStmt(pCsr);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);
+    }
+  }
+  if( rc!=SQLITE_OK ) return rc;
+
+  return fts3NextMethod(pCursor);
+}
+
+/* 
+** This is the xEof method of the virtual table. SQLite calls this 
+** routine to find out if it has reached the end of a result set.
+*/
+static int fts3EofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3Cursor *pCsr = (Fts3Cursor*)pCursor;
+  if( pCsr->isEof ){
+    fts3ClearCursor(pCsr);
+    pCsr->isEof = 1;
+  }
+  return pCsr->isEof;
+}
+
+/* 
+** This is the xRowid method. The SQLite core calls this routine to
+** retrieve the rowid for the current row of the result set. fts3
+** exposes %_content.docid as the rowid for the virtual table. The
+** rowid should be written to *pRowid.
+*/
+static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
+  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
+  *pRowid = pCsr->iPrevId;
+  return SQLITE_OK;
+}
+
+/* 
+** This is the xColumn method, called by SQLite to request a value from
+** the row that the supplied cursor currently points to.
+**
+** If:
+**
+**   (iCol <  p->nColumn)   -> The value of the iCol'th user column.
+**   (iCol == p->nColumn)   -> Magic column with the same name as the table.
+**   (iCol == p->nColumn+1) -> Docid column
+**   (iCol == p->nColumn+2) -> Langid column
+*/
+static int fts3ColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  int rc = SQLITE_OK;             /* Return Code */
+  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
+  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
+
+  /* The column value supplied by SQLite must be in range. */
+  assert( iCol>=0 && iCol<=p->nColumn+2 );
+
+  switch( iCol-p->nColumn ){
+    case 0:
+      /* The special 'table-name' column */
+      sqlite3_result_pointer(pCtx, pCsr, "fts3cursor", 0);
+      break;
+
+    case 1:
+      /* The docid column */
+      sqlite3_result_int64(pCtx, pCsr->iPrevId);
+      break;
+
+    case 2:
+      if( pCsr->pExpr ){
+        sqlite3_result_int64(pCtx, pCsr->iLangid);
+        break;
+      }else if( p->zLanguageid==0 ){
+        sqlite3_result_int(pCtx, 0);
+        break;
+      }else{
+        iCol = p->nColumn;
+        /* fall-through */
+      }
+
+    default:
+      /* A user column. Or, if this is a full-table scan, possibly the
+      ** language-id column. Seek the cursor. */
+      rc = fts3CursorSeek(0, pCsr);
+      if( rc==SQLITE_OK && sqlite3_data_count(pCsr->pStmt)-1>iCol ){
+        sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));
+      }
+      break;
+  }
+
+  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+  return rc;
+}
+
+/* 
+** This function is the implementation of the xUpdate callback used by 
+** FTS3 virtual tables. It is invoked by SQLite each time a row is to be
+** inserted, updated or deleted.
+*/
+static int fts3UpdateMethod(
+  sqlite3_vtab *pVtab,            /* Virtual table handle */
+  int nArg,                       /* Size of argument array */
+  sqlite3_value **apVal,          /* Array of arguments */
+  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
+){
+  return sqlite3Fts3UpdateMethod(pVtab, nArg, apVal, pRowid);
+}
+
+/*
+** Implementation of xSync() method. Flush the contents of the pending-terms
+** hash-table to the database.
+*/
+static int fts3SyncMethod(sqlite3_vtab *pVtab){
+
+  /* Following an incremental-merge operation, assuming that the input
+  ** segments are not completely consumed (the usual case), they are updated
+  ** in place to remove the entries that have already been merged. This
+  ** involves updating the leaf block that contains the smallest unmerged
+  ** entry and each block (if any) between the leaf and the root node. So
+  ** if the height of the input segment b-trees is N, and input segments
+  ** are merged eight at a time, updating the input segments at the end
+  ** of an incremental-merge requires writing (8*(1+N)) blocks. N is usually
+  ** small - often between 0 and 2. So the overhead of the incremental
+  ** merge is somewhere between 8 and 24 blocks. To avoid this overhead
+  ** dwarfing the actual productive work accomplished, the incremental merge
+  ** is only attempted if it will write at least 64 leaf blocks. Hence
+  ** nMinMerge.
+  **
+  ** Of course, updating the input segments also involves deleting a bunch
+  ** of blocks from the segments table. But this is not considered overhead
+  ** as it would also be required by a crisis-merge that used the same input 
+  ** segments.
+  */
+  const u32 nMinMerge = 64;       /* Minimum amount of incr-merge work to do */
+
+  Fts3Table *p = (Fts3Table*)pVtab;
+  int rc;
+  i64 iLastRowid = sqlite3_last_insert_rowid(p->db);
+
+  rc = sqlite3Fts3PendingTermsFlush(p);
+  if( rc==SQLITE_OK 
+   && p->nLeafAdd>(nMinMerge/16) 
+   && p->nAutoincrmerge && p->nAutoincrmerge!=0xff
+  ){
+    int mxLevel = 0;              /* Maximum relative level value in db */
+    int A;                        /* Incr-merge parameter A */
+
+    rc = sqlite3Fts3MaxLevel(p, &mxLevel);
+    assert( rc==SQLITE_OK || mxLevel==0 );
+    A = p->nLeafAdd * mxLevel;
+    A += (A/2);
+    if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, p->nAutoincrmerge);
+  }
+  sqlite3Fts3SegmentsClose(p);
+  sqlite3_set_last_insert_rowid(p->db, iLastRowid);
+  return rc;
+}
+
+/*
+** If it is currently unknown whether or not the FTS table has an %_stat
+** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat
+** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code
+** if an error occurs.
+*/
+static int fts3SetHasStat(Fts3Table *p){
+  int rc = SQLITE_OK;
+  if( p->bHasStat==2 ){
+    char *zTbl = sqlite3_mprintf("%s_stat", p->zName);
+    if( zTbl ){
+      int res = sqlite3_table_column_metadata(p->db, p->zDb, zTbl, 0,0,0,0,0,0);
+      sqlite3_free(zTbl);
+      p->bHasStat = (res==SQLITE_OK);
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  return rc;
+}
+
+/*
+** Implementation of xBegin() method. 
+*/
+static int fts3BeginMethod(sqlite3_vtab *pVtab){
+  Fts3Table *p = (Fts3Table*)pVtab;
+  UNUSED_PARAMETER(pVtab);
+  assert( p->pSegments==0 );
+  assert( p->nPendingData==0 );
+  assert( p->inTransaction!=1 );
+  TESTONLY( p->inTransaction = 1 );
+  TESTONLY( p->mxSavepoint = -1; );
+  p->nLeafAdd = 0;
+  return fts3SetHasStat(p);
+}
+
+/*
+** Implementation of xCommit() method. This is a no-op. The contents of
+** the pending-terms hash-table have already been flushed into the database
+** by fts3SyncMethod().
+*/
+static int fts3CommitMethod(sqlite3_vtab *pVtab){
+  TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+  UNUSED_PARAMETER(pVtab);
+  assert( p->nPendingData==0 );
+  assert( p->inTransaction!=0 );
+  assert( p->pSegments==0 );
+  TESTONLY( p->inTransaction = 0 );
+  TESTONLY( p->mxSavepoint = -1; );
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of xRollback(). Discard the contents of the pending-terms
+** hash-table. Any changes made to the database are reverted by SQLite.
+*/
+static int fts3RollbackMethod(sqlite3_vtab *pVtab){
+  Fts3Table *p = (Fts3Table*)pVtab;
+  sqlite3Fts3PendingTermsClear(p);
+  assert( p->inTransaction!=0 );
+  TESTONLY( p->inTransaction = 0 );
+  TESTONLY( p->mxSavepoint = -1; );
+  return SQLITE_OK;
+}
+
+/*
+** When called, *ppPoslist must point to the byte immediately following the
+** end of a position-list. i.e. ( (*ppPoslist)[-1]==POS_END ). This function
+** moves *ppPoslist so that it instead points to the first byte of the
+** same position list.
+*/
+static void fts3ReversePoslist(char *pStart, char **ppPoslist){
+  char *p = &(*ppPoslist)[-2];
+  char c = 0;
+
+  /* Skip backwards passed any trailing 0x00 bytes added by NearTrim() */
+  while( p>pStart && (c=*p--)==0 );
+
+  /* Search backwards for a varint with value zero (the end of the previous 
+  ** poslist). This is an 0x00 byte preceded by some byte that does not
+  ** have the 0x80 bit set.  */
+  while( p>pStart && (*p & 0x80) | c ){ 
+    c = *p--; 
+  }
+  assert( p==pStart || c==0 );
+
+  /* At this point p points to that preceding byte without the 0x80 bit
+  ** set. So to find the start of the poslist, skip forward 2 bytes then
+  ** over a varint. 
+  **
+  ** Normally. The other case is that p==pStart and the poslist to return
+  ** is the first in the doclist. In this case do not skip forward 2 bytes.
+  ** The second part of the if condition (c==0 && *ppPoslist>&p[2])
+  ** is required for cases where the first byte of a doclist and the
+  ** doclist is empty. For example, if the first docid is 10, a doclist
+  ** that begins with:
+  **
+  **   0x0A 0x00 
+  */
+  if( p>pStart || (c==0 && *ppPoslist>&p[2]) ){ p = &p[2]; }
+  while( *p++&0x80 );
+  *ppPoslist = p;
+}
+
+/*
+** Helper function used by the implementation of the overloaded snippet(),
+** offsets() and optimize() SQL functions.
+**
+** If the value passed as the third argument is a blob of size
+** sizeof(Fts3Cursor*), then the blob contents are copied to the 
+** output variable *ppCsr and SQLITE_OK is returned. Otherwise, an error
+** message is written to context pContext and SQLITE_ERROR returned. The
+** string passed via zFunc is used as part of the error message.
+*/
+static int fts3FunctionArg(
+  sqlite3_context *pContext,      /* SQL function call context */
+  const char *zFunc,              /* Function name */
+  sqlite3_value *pVal,            /* argv[0] passed to function */
+  Fts3Cursor **ppCsr              /* OUT: Store cursor handle here */
+){
+  int rc;
+  *ppCsr = (Fts3Cursor*)sqlite3_value_pointer(pVal, "fts3cursor");
+  if( (*ppCsr)!=0 ){
+    rc = SQLITE_OK;
+  }else{
+    char *zErr = sqlite3_mprintf("illegal first argument to %s", zFunc);
+    sqlite3_result_error(pContext, zErr, -1);
+    sqlite3_free(zErr);
+    rc = SQLITE_ERROR;
+  }
+  return rc;
+}
+
+/*
+** Implementation of the snippet() function for FTS3
+*/
+static void fts3SnippetFunc(
+  sqlite3_context *pContext,      /* SQLite function call context */
+  int nVal,                       /* Size of apVal[] array */
+  sqlite3_value **apVal           /* Array of arguments */
+){
+  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */
+  const char *zStart = "";
+  const char *zEnd = "";
+  const char *zEllipsis = "...";
+  int iCol = -1;
+  int nToken = 15;                /* Default number of tokens in snippet */
+
+  /* There must be at least one argument passed to this function (otherwise
+  ** the non-overloaded version would have been called instead of this one).
+  */
+  assert( nVal>=1 );
+
+  if( nVal>6 ){
+    sqlite3_result_error(pContext, 
+        "wrong number of arguments to function snippet()", -1);
+    return;
+  }
+  if( fts3FunctionArg(pContext, "snippet", apVal[0], &pCsr) ) return;
+
+  switch( nVal ){
+    case 6: nToken = sqlite3_value_int(apVal[5]);
+    case 5: iCol = sqlite3_value_int(apVal[4]);
+    case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);
+    case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);
+    case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);
+  }
+  if( !zEllipsis || !zEnd || !zStart ){
+    sqlite3_result_error_nomem(pContext);
+  }else if( nToken==0 ){
+    sqlite3_result_text(pContext, "", -1, SQLITE_STATIC);
+  }else if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
+    sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis, iCol, nToken);
+  }
+}
+
+/*
+** Implementation of the offsets() function for FTS3
+*/
+static void fts3OffsetsFunc(
+  sqlite3_context *pContext,      /* SQLite function call context */
+  int nVal,                       /* Size of argument array */
+  sqlite3_value **apVal           /* Array of arguments */
+){
+  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */
+
+  UNUSED_PARAMETER(nVal);
+
+  assert( nVal==1 );
+  if( fts3FunctionArg(pContext, "offsets", apVal[0], &pCsr) ) return;
+  assert( pCsr );
+  if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
+    sqlite3Fts3Offsets(pContext, pCsr);
+  }
+}
+
+/* 
+** Implementation of the special optimize() function for FTS3. This 
+** function merges all segments in the database to a single segment.
+** Example usage is:
+**
+**   SELECT optimize(t) FROM t LIMIT 1;
+**
+** where 't' is the name of an FTS3 table.
+*/
+static void fts3OptimizeFunc(
+  sqlite3_context *pContext,      /* SQLite function call context */
+  int nVal,                       /* Size of argument array */
+  sqlite3_value **apVal           /* Array of arguments */
+){
+  int rc;                         /* Return code */
+  Fts3Table *p;                   /* Virtual table handle */
+  Fts3Cursor *pCursor;            /* Cursor handle passed through apVal[0] */
+
+  UNUSED_PARAMETER(nVal);
+
+  assert( nVal==1 );
+  if( fts3FunctionArg(pContext, "optimize", apVal[0], &pCursor) ) return;
+  p = (Fts3Table *)pCursor->base.pVtab;
+  assert( p );
+
+  rc = sqlite3Fts3Optimize(p);
+
+  switch( rc ){
+    case SQLITE_OK:
+      sqlite3_result_text(pContext, "Index optimized", -1, SQLITE_STATIC);
+      break;
+    case SQLITE_DONE:
+      sqlite3_result_text(pContext, "Index already optimal", -1, SQLITE_STATIC);
+      break;
+    default:
+      sqlite3_result_error_code(pContext, rc);
+      break;
+  }
+}
+
+/*
+** Implementation of the matchinfo() function for FTS3
+*/
+static void fts3MatchinfoFunc(
+  sqlite3_context *pContext,      /* SQLite function call context */
+  int nVal,                       /* Size of argument array */
+  sqlite3_value **apVal           /* Array of arguments */
+){
+  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */
+  assert( nVal==1 || nVal==2 );
+  if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){
+    const char *zArg = 0;
+    if( nVal>1 ){
+      zArg = (const char *)sqlite3_value_text(apVal[1]);
+    }
+    sqlite3Fts3Matchinfo(pContext, pCsr, zArg);
+  }
+}
+
+/*
+** This routine implements the xFindFunction method for the FTS3
+** virtual table.
+*/
+static int fts3FindFunctionMethod(
+  sqlite3_vtab *pVtab,            /* Virtual table handle */
+  int nArg,                       /* Number of SQL function arguments */
+  const char *zName,              /* Name of SQL function */
+  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
+  void **ppArg                    /* Unused */
+){
+  struct Overloaded {
+    const char *zName;
+    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } aOverload[] = {
+    { "snippet", fts3SnippetFunc },
+    { "offsets", fts3OffsetsFunc },
+    { "optimize", fts3OptimizeFunc },
+    { "matchinfo", fts3MatchinfoFunc },
+  };
+  int i;                          /* Iterator variable */
+
+  UNUSED_PARAMETER(pVtab);
+  UNUSED_PARAMETER(nArg);
+  UNUSED_PARAMETER(ppArg);
+
+  for(i=0; idb;            /* Database connection */
+  int rc;                         /* Return Code */
+
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  rc = fts3SetHasStat(p);
+  
+  /* As it happens, the pending terms table is always empty here. This is
+  ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction 
+  ** always opens a savepoint transaction. And the xSavepoint() method 
+  ** flushes the pending terms table. But leave the (no-op) call to
+  ** PendingTermsFlush() in in case that changes.
+  */
+  assert( p->nPendingData==0 );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3PendingTermsFlush(p);
+  }
+
+  if( p->zContentTbl==0 ){
+    fts3DbExec(&rc, db,
+      "ALTER TABLE %Q.'%q_content'  RENAME TO '%q_content';",
+      p->zDb, p->zName, zName
+    );
+  }
+
+  if( p->bHasDocsize ){
+    fts3DbExec(&rc, db,
+      "ALTER TABLE %Q.'%q_docsize'  RENAME TO '%q_docsize';",
+      p->zDb, p->zName, zName
+    );
+  }
+  if( p->bHasStat ){
+    fts3DbExec(&rc, db,
+      "ALTER TABLE %Q.'%q_stat'  RENAME TO '%q_stat';",
+      p->zDb, p->zName, zName
+    );
+  }
+  fts3DbExec(&rc, db,
+    "ALTER TABLE %Q.'%q_segments' RENAME TO '%q_segments';",
+    p->zDb, p->zName, zName
+  );
+  fts3DbExec(&rc, db,
+    "ALTER TABLE %Q.'%q_segdir'   RENAME TO '%q_segdir';",
+    p->zDb, p->zName, zName
+  );
+  return rc;
+}
+
+/*
+** The xSavepoint() method.
+**
+** Flush the contents of the pending-terms table to disk.
+*/
+static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  int rc = SQLITE_OK;
+  UNUSED_PARAMETER(iSavepoint);
+  assert( ((Fts3Table *)pVtab)->inTransaction );
+  assert( ((Fts3Table *)pVtab)->mxSavepoint < iSavepoint );
+  TESTONLY( ((Fts3Table *)pVtab)->mxSavepoint = iSavepoint );
+  if( ((Fts3Table *)pVtab)->bIgnoreSavepoint==0 ){
+    rc = fts3SyncMethod(pVtab);
+  }
+  return rc;
+}
+
+/*
+** The xRelease() method.
+**
+** This is a no-op.
+*/
+static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+  UNUSED_PARAMETER(iSavepoint);
+  UNUSED_PARAMETER(pVtab);
+  assert( p->inTransaction );
+  assert( p->mxSavepoint >= iSavepoint );
+  TESTONLY( p->mxSavepoint = iSavepoint-1 );
+  return SQLITE_OK;
+}
+
+/*
+** The xRollbackTo() method.
+**
+** Discard the contents of the pending terms table.
+*/
+static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  Fts3Table *p = (Fts3Table*)pVtab;
+  UNUSED_PARAMETER(iSavepoint);
+  assert( p->inTransaction );
+  assert( p->mxSavepoint >= iSavepoint );
+  TESTONLY( p->mxSavepoint = iSavepoint );
+  sqlite3Fts3PendingTermsClear(p);
+  return SQLITE_OK;
+}
+
+static const sqlite3_module fts3Module = {
+  /* iVersion      */ 2,
+  /* xCreate       */ fts3CreateMethod,
+  /* xConnect      */ fts3ConnectMethod,
+  /* xBestIndex    */ fts3BestIndexMethod,
+  /* xDisconnect   */ fts3DisconnectMethod,
+  /* xDestroy      */ fts3DestroyMethod,
+  /* xOpen         */ fts3OpenMethod,
+  /* xClose        */ fts3CloseMethod,
+  /* xFilter       */ fts3FilterMethod,
+  /* xNext         */ fts3NextMethod,
+  /* xEof          */ fts3EofMethod,
+  /* xColumn       */ fts3ColumnMethod,
+  /* xRowid        */ fts3RowidMethod,
+  /* xUpdate       */ fts3UpdateMethod,
+  /* xBegin        */ fts3BeginMethod,
+  /* xSync         */ fts3SyncMethod,
+  /* xCommit       */ fts3CommitMethod,
+  /* xRollback     */ fts3RollbackMethod,
+  /* xFindFunction */ fts3FindFunctionMethod,
+  /* xRename */       fts3RenameMethod,
+  /* xSavepoint    */ fts3SavepointMethod,
+  /* xRelease      */ fts3ReleaseMethod,
+  /* xRollbackTo   */ fts3RollbackToMethod,
+};
+
+/*
+** This function is registered as the module destructor (called when an
+** FTS3 enabled database connection is closed). It frees the memory
+** allocated for the tokenizer hash table.
+*/
+static void hashDestroy(void *p){
+  Fts3Hash *pHash = (Fts3Hash *)p;
+  sqlite3Fts3HashClear(pHash);
+  sqlite3_free(pHash);
+}
+
+/*
+** The fts3 built-in tokenizers - "simple", "porter" and "icu"- are 
+** implemented in files fts3_tokenizer1.c, fts3_porter.c and fts3_icu.c
+** respectively. The following three forward declarations are for functions
+** declared in these files used to retrieve the respective implementations.
+**
+** Calling sqlite3Fts3SimpleTokenizerModule() sets the value pointed
+** to by the argument to point to the "simple" tokenizer implementation.
+** And so on.
+*/
+SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const**ppModule);
+#endif
+#ifdef SQLITE_ENABLE_ICU
+SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#endif
+
+/*
+** Initialize the fts3 extension. If this extension is built as part
+** of the sqlite library, then this function is called directly by
+** SQLite. If fts3 is built as a dynamically loadable extension, this
+** function is called by the sqlite3_extension_init() entry point.
+*/
+SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){
+  int rc = SQLITE_OK;
+  Fts3Hash *pHash = 0;
+  const sqlite3_tokenizer_module *pSimple = 0;
+  const sqlite3_tokenizer_module *pPorter = 0;
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+  const sqlite3_tokenizer_module *pUnicode = 0;
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+  const sqlite3_tokenizer_module *pIcu = 0;
+  sqlite3Fts3IcuTokenizerModule(&pIcu);
+#endif
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+  sqlite3Fts3UnicodeTokenizer(&pUnicode);
+#endif
+
+#ifdef SQLITE_TEST
+  rc = sqlite3Fts3InitTerm(db);
+  if( rc!=SQLITE_OK ) return rc;
+#endif
+
+  rc = sqlite3Fts3InitAux(db);
+  if( rc!=SQLITE_OK ) return rc;
+
+  sqlite3Fts3SimpleTokenizerModule(&pSimple);
+  sqlite3Fts3PorterTokenizerModule(&pPorter);
+
+  /* Allocate and initialize the hash-table used to store tokenizers. */
+  pHash = sqlite3_malloc(sizeof(Fts3Hash));
+  if( !pHash ){
+    rc = SQLITE_NOMEM;
+  }else{
+    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
+  }
+
+  /* Load the built-in tokenizers into the hash table */
+  if( rc==SQLITE_OK ){
+    if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)
+     || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+     || sqlite3Fts3HashInsert(pHash, "unicode61", 10, (void *)pUnicode) 
+#endif
+#ifdef SQLITE_ENABLE_ICU
+     || (pIcu && sqlite3Fts3HashInsert(pHash, "icu", 4, (void *)pIcu))
+#endif
+    ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+#ifdef SQLITE_TEST
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3ExprInitTestInterface(db);
+  }
+#endif
+
+  /* Create the virtual table wrapper around the hash-table and overload 
+  ** the four scalar functions. If this is successful, register the
+  ** module with sqlite.
+  */
+  if( SQLITE_OK==rc 
+   && SQLITE_OK==(rc = sqlite3Fts3InitHashTable(db, pHash, "fts3_tokenizer"))
+   && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))
+   && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))
+   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))
+   && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 2))
+   && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))
+  ){
+    rc = sqlite3_create_module_v2(
+        db, "fts3", &fts3Module, (void *)pHash, hashDestroy
+    );
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_create_module_v2(
+          db, "fts4", &fts3Module, (void *)pHash, 0
+      );
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3InitTok(db, (void *)pHash);
+    }
+    return rc;
+  }
+
+
+  /* An error has occurred. Delete the hash table and return the error code. */
+  assert( rc!=SQLITE_OK );
+  if( pHash ){
+    sqlite3Fts3HashClear(pHash);
+    sqlite3_free(pHash);
+  }
+  return rc;
+}
+
+/*
+** Allocate an Fts3MultiSegReader for each token in the expression headed
+** by pExpr. 
+**
+** An Fts3SegReader object is a cursor that can seek or scan a range of
+** entries within a single segment b-tree. An Fts3MultiSegReader uses multiple
+** Fts3SegReader objects internally to provide an interface to seek or scan
+** within the union of all segments of a b-tree. Hence the name.
+**
+** If the allocated Fts3MultiSegReader just seeks to a single entry in a
+** segment b-tree (if the term is not a prefix or it is a prefix for which
+** there exists prefix b-tree of the right length) then it may be traversed
+** and merged incrementally. Otherwise, it has to be merged into an in-memory 
+** doclist and then traversed.
+*/
+static void fts3EvalAllocateReaders(
+  Fts3Cursor *pCsr,               /* FTS cursor handle */
+  Fts3Expr *pExpr,                /* Allocate readers for this expression */
+  int *pnToken,                   /* OUT: Total number of tokens in phrase. */
+  int *pnOr,                      /* OUT: Total number of OR nodes in expr. */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  if( pExpr && SQLITE_OK==*pRc ){
+    if( pExpr->eType==FTSQUERY_PHRASE ){
+      int i;
+      int nToken = pExpr->pPhrase->nToken;
+      *pnToken += nToken;
+      for(i=0; ipPhrase->aToken[i];
+        int rc = fts3TermSegReaderCursor(pCsr, 
+            pToken->z, pToken->n, pToken->isPrefix, &pToken->pSegcsr
+        );
+        if( rc!=SQLITE_OK ){
+          *pRc = rc;
+          return;
+        }
+      }
+      assert( pExpr->pPhrase->iDoclistToken==0 );
+      pExpr->pPhrase->iDoclistToken = -1;
+    }else{
+      *pnOr += (pExpr->eType==FTSQUERY_OR);
+      fts3EvalAllocateReaders(pCsr, pExpr->pLeft, pnToken, pnOr, pRc);
+      fts3EvalAllocateReaders(pCsr, pExpr->pRight, pnToken, pnOr, pRc);
+    }
+  }
+}
+
+/*
+** Arguments pList/nList contain the doclist for token iToken of phrase p.
+** It is merged into the main doclist stored in p->doclist.aAll/nAll.
+**
+** This function assumes that pList points to a buffer allocated using
+** sqlite3_malloc(). This function takes responsibility for eventually
+** freeing the buffer.
+**
+** SQLITE_OK is returned if successful, or SQLITE_NOMEM if an error occurs.
+*/
+static int fts3EvalPhraseMergeToken(
+  Fts3Table *pTab,                /* FTS Table pointer */
+  Fts3Phrase *p,                  /* Phrase to merge pList/nList into */
+  int iToken,                     /* Token pList/nList corresponds to */
+  char *pList,                    /* Pointer to doclist */
+  int nList                       /* Number of bytes in pList */
+){
+  int rc = SQLITE_OK;
+  assert( iToken!=p->iDoclistToken );
+
+  if( pList==0 ){
+    sqlite3_free(p->doclist.aAll);
+    p->doclist.aAll = 0;
+    p->doclist.nAll = 0;
+  }
+
+  else if( p->iDoclistToken<0 ){
+    p->doclist.aAll = pList;
+    p->doclist.nAll = nList;
+  }
+
+  else if( p->doclist.aAll==0 ){
+    sqlite3_free(pList);
+  }
+
+  else {
+    char *pLeft;
+    char *pRight;
+    int nLeft;
+    int nRight;
+    int nDiff;
+
+    if( p->iDoclistTokendoclist.aAll;
+      nLeft = p->doclist.nAll;
+      pRight = pList;
+      nRight = nList;
+      nDiff = iToken - p->iDoclistToken;
+    }else{
+      pRight = p->doclist.aAll;
+      nRight = p->doclist.nAll;
+      pLeft = pList;
+      nLeft = nList;
+      nDiff = p->iDoclistToken - iToken;
+    }
+
+    rc = fts3DoclistPhraseMerge(
+        pTab->bDescIdx, nDiff, pLeft, nLeft, &pRight, &nRight
+    );
+    sqlite3_free(pLeft);
+    p->doclist.aAll = pRight;
+    p->doclist.nAll = nRight;
+  }
+
+  if( iToken>p->iDoclistToken ) p->iDoclistToken = iToken;
+  return rc;
+}
+
+/*
+** Load the doclist for phrase p into p->doclist.aAll/nAll. The loaded doclist
+** does not take deferred tokens into account.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalPhraseLoad(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Phrase *p                   /* Phrase object */
+){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int iToken;
+  int rc = SQLITE_OK;
+
+  for(iToken=0; rc==SQLITE_OK && iTokennToken; iToken++){
+    Fts3PhraseToken *pToken = &p->aToken[iToken];
+    assert( pToken->pDeferred==0 || pToken->pSegcsr==0 );
+
+    if( pToken->pSegcsr ){
+      int nThis = 0;
+      char *pThis = 0;
+      rc = fts3TermSelect(pTab, pToken, p->iColumn, &nThis, &pThis);
+      if( rc==SQLITE_OK ){
+        rc = fts3EvalPhraseMergeToken(pTab, p, iToken, pThis, nThis);
+      }
+    }
+    assert( pToken->pSegcsr==0 );
+  }
+
+  return rc;
+}
+
+/*
+** This function is called on each phrase after the position lists for
+** any deferred tokens have been loaded into memory. It updates the phrases
+** current position list to include only those positions that are really
+** instances of the phrase (after considering deferred tokens). If this
+** means that the phrase does not appear in the current row, doclist.pList
+** and doclist.nList are both zeroed.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
+  int iToken;                     /* Used to iterate through phrase tokens */
+  char *aPoslist = 0;             /* Position list for deferred tokens */
+  int nPoslist = 0;               /* Number of bytes in aPoslist */
+  int iPrev = -1;                 /* Token number of previous deferred token */
+
+  assert( pPhrase->doclist.bFreeList==0 );
+
+  for(iToken=0; iTokennToken; iToken++){
+    Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+    Fts3DeferredToken *pDeferred = pToken->pDeferred;
+
+    if( pDeferred ){
+      char *pList;
+      int nList;
+      int rc = sqlite3Fts3DeferredTokenList(pDeferred, &pList, &nList);
+      if( rc!=SQLITE_OK ) return rc;
+
+      if( pList==0 ){
+        sqlite3_free(aPoslist);
+        pPhrase->doclist.pList = 0;
+        pPhrase->doclist.nList = 0;
+        return SQLITE_OK;
+
+      }else if( aPoslist==0 ){
+        aPoslist = pList;
+        nPoslist = nList;
+
+      }else{
+        char *aOut = pList;
+        char *p1 = aPoslist;
+        char *p2 = aOut;
+
+        assert( iPrev>=0 );
+        fts3PoslistPhraseMerge(&aOut, iToken-iPrev, 0, 1, &p1, &p2);
+        sqlite3_free(aPoslist);
+        aPoslist = pList;
+        nPoslist = (int)(aOut - aPoslist);
+        if( nPoslist==0 ){
+          sqlite3_free(aPoslist);
+          pPhrase->doclist.pList = 0;
+          pPhrase->doclist.nList = 0;
+          return SQLITE_OK;
+        }
+      }
+      iPrev = iToken;
+    }
+  }
+
+  if( iPrev>=0 ){
+    int nMaxUndeferred = pPhrase->iDoclistToken;
+    if( nMaxUndeferred<0 ){
+      pPhrase->doclist.pList = aPoslist;
+      pPhrase->doclist.nList = nPoslist;
+      pPhrase->doclist.iDocid = pCsr->iPrevId;
+      pPhrase->doclist.bFreeList = 1;
+    }else{
+      int nDistance;
+      char *p1;
+      char *p2;
+      char *aOut;
+
+      if( nMaxUndeferred>iPrev ){
+        p1 = aPoslist;
+        p2 = pPhrase->doclist.pList;
+        nDistance = nMaxUndeferred - iPrev;
+      }else{
+        p1 = pPhrase->doclist.pList;
+        p2 = aPoslist;
+        nDistance = iPrev - nMaxUndeferred;
+      }
+
+      aOut = (char *)sqlite3_malloc(nPoslist+8);
+      if( !aOut ){
+        sqlite3_free(aPoslist);
+        return SQLITE_NOMEM;
+      }
+      
+      pPhrase->doclist.pList = aOut;
+      if( fts3PoslistPhraseMerge(&aOut, nDistance, 0, 1, &p1, &p2) ){
+        pPhrase->doclist.bFreeList = 1;
+        pPhrase->doclist.nList = (int)(aOut - pPhrase->doclist.pList);
+      }else{
+        sqlite3_free(aOut);
+        pPhrase->doclist.pList = 0;
+        pPhrase->doclist.nList = 0;
+      }
+      sqlite3_free(aPoslist);
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Maximum number of tokens a phrase may have to be considered for the
+** incremental doclists strategy.
+*/
+#define MAX_INCR_PHRASE_TOKENS 4
+
+/*
+** This function is called for each Fts3Phrase in a full-text query 
+** expression to initialize the mechanism for returning rows. Once this
+** function has been called successfully on an Fts3Phrase, it may be
+** used with fts3EvalPhraseNext() to iterate through the matching docids.
+**
+** If parameter bOptOk is true, then the phrase may (or may not) use the
+** incremental loading strategy. Otherwise, the entire doclist is loaded into
+** memory within this call.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;             /* Error code */
+  int i;
+
+  /* Determine if doclists may be loaded from disk incrementally. This is
+  ** possible if the bOptOk argument is true, the FTS doclists will be
+  ** scanned in forward order, and the phrase consists of 
+  ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
+  ** tokens or prefix tokens that cannot use a prefix-index.  */
+  int bHaveIncr = 0;
+  int bIncrOk = (bOptOk 
+   && pCsr->bDesc==pTab->bDescIdx 
+   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
+#ifdef SQLITE_TEST
+   && pTab->bNoIncrDoclist==0
+#endif
+  );
+  for(i=0; bIncrOk==1 && inToken; i++){
+    Fts3PhraseToken *pToken = &p->aToken[i];
+    if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
+      bIncrOk = 0;
+    }
+    if( pToken->pSegcsr ) bHaveIncr = 1;
+  }
+
+  if( bIncrOk && bHaveIncr ){
+    /* Use the incremental approach. */
+    int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);
+    for(i=0; rc==SQLITE_OK && inToken; i++){
+      Fts3PhraseToken *pToken = &p->aToken[i];
+      Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;
+      if( pSegcsr ){
+        rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);
+      }
+    }
+    p->bIncr = 1;
+  }else{
+    /* Load the full doclist for the phrase into memory. */
+    rc = fts3EvalPhraseLoad(pCsr, p);
+    p->bIncr = 0;
+  }
+
+  assert( rc!=SQLITE_OK || p->nToken<1 || p->aToken[0].pSegcsr==0 || p->bIncr );
+  return rc;
+}
+
+/*
+** This function is used to iterate backwards (from the end to start) 
+** through doclists. It is used by this module to iterate through phrase
+** doclists in reverse and by the fts3_write.c module to iterate through
+** pending-terms lists when writing to databases with "order=desc".
+**
+** The doclist may be sorted in ascending (parameter bDescIdx==0) or 
+** descending (parameter bDescIdx==1) order of docid. Regardless, this
+** function iterates from the end of the doclist to the beginning.
+*/
+SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(
+  int bDescIdx,                   /* True if the doclist is desc */
+  char *aDoclist,                 /* Pointer to entire doclist */
+  int nDoclist,                   /* Length of aDoclist in bytes */
+  char **ppIter,                  /* IN/OUT: Iterator pointer */
+  sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */
+  int *pnList,                    /* OUT: List length pointer */
+  u8 *pbEof                       /* OUT: End-of-file flag */
+){
+  char *p = *ppIter;
+
+  assert( nDoclist>0 );
+  assert( *pbEof==0 );
+  assert( p || *piDocid==0 );
+  assert( !p || (p>aDoclist && p<&aDoclist[nDoclist]) );
+
+  if( p==0 ){
+    sqlite3_int64 iDocid = 0;
+    char *pNext = 0;
+    char *pDocid = aDoclist;
+    char *pEnd = &aDoclist[nDoclist];
+    int iMul = 1;
+
+    while( pDocid0 );
+  assert( *pbEof==0 );
+  assert( p || *piDocid==0 );
+  assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );
+
+  if( p==0 ){
+    p = aDoclist;
+    p += sqlite3Fts3GetVarint(p, piDocid);
+  }else{
+    fts3PoslistCopy(0, &p);
+    while( p<&aDoclist[nDoclist] && *p==0 ) p++; 
+    if( p>=&aDoclist[nDoclist] ){
+      *pbEof = 1;
+    }else{
+      sqlite3_int64 iVar;
+      p += sqlite3Fts3GetVarint(p, &iVar);
+      *piDocid += ((bDescIdx ? -1 : 1) * iVar);
+    }
+  }
+
+  *ppIter = p;
+}
+
+/*
+** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof
+** to true if EOF is reached.
+*/
+static void fts3EvalDlPhraseNext(
+  Fts3Table *pTab,
+  Fts3Doclist *pDL,
+  u8 *pbEof
+){
+  char *pIter;                            /* Used to iterate through aAll */
+  char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
+ 
+  if( pDL->pNextDocid ){
+    pIter = pDL->pNextDocid;
+  }else{
+    pIter = pDL->aAll;
+  }
+
+  if( pIter>=pEnd ){
+    /* We have already reached the end of this doclist. EOF. */
+    *pbEof = 1;
+  }else{
+    sqlite3_int64 iDelta;
+    pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
+    if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
+      pDL->iDocid += iDelta;
+    }else{
+      pDL->iDocid -= iDelta;
+    }
+    pDL->pList = pIter;
+    fts3PoslistCopy(0, &pIter);
+    pDL->nList = (int)(pIter - pDL->pList);
+
+    /* pIter now points just past the 0x00 that terminates the position-
+    ** list for document pDL->iDocid. However, if this position-list was
+    ** edited in place by fts3EvalNearTrim(), then pIter may not actually
+    ** point to the start of the next docid value. The following line deals
+    ** with this case by advancing pIter past the zero-padding added by
+    ** fts3EvalNearTrim().  */
+    while( pIterpNextDocid = pIter;
+    assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
+    *pbEof = 0;
+  }
+}
+
+/*
+** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().
+*/
+typedef struct TokenDoclist TokenDoclist;
+struct TokenDoclist {
+  int bIgnore;
+  sqlite3_int64 iDocid;
+  char *pList;
+  int nList;
+};
+
+/*
+** Token pToken is an incrementally loaded token that is part of a 
+** multi-token phrase. Advance it to the next matching document in the
+** database and populate output variable *p with the details of the new
+** entry. Or, if the iterator has reached EOF, set *pbEof to true.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
+*/
+static int incrPhraseTokenNext(
+  Fts3Table *pTab,                /* Virtual table handle */
+  Fts3Phrase *pPhrase,            /* Phrase to advance token of */
+  int iToken,                     /* Specific token to advance */
+  TokenDoclist *p,                /* OUT: Docid and doclist for new entry */
+  u8 *pbEof                       /* OUT: True if iterator is at EOF */
+){
+  int rc = SQLITE_OK;
+
+  if( pPhrase->iDoclistToken==iToken ){
+    assert( p->bIgnore==0 );
+    assert( pPhrase->aToken[iToken].pSegcsr==0 );
+    fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);
+    p->pList = pPhrase->doclist.pList;
+    p->nList = pPhrase->doclist.nList;
+    p->iDocid = pPhrase->doclist.iDocid;
+  }else{
+    Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+    assert( pToken->pDeferred==0 );
+    assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );
+    if( pToken->pSegcsr ){
+      assert( p->bIgnore==0 );
+      rc = sqlite3Fts3MsrIncrNext(
+          pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList
+      );
+      if( p->pList==0 ) *pbEof = 1;
+    }else{
+      p->bIgnore = 1;
+    }
+  }
+
+  return rc;
+}
+
+
+/*
+** The phrase iterator passed as the second argument:
+**
+**   * features at least one token that uses an incremental doclist, and 
+**
+**   * does not contain any deferred tokens.
+**
+** Advance it to the next matching documnent in the database and populate
+** the Fts3Doclist.pList and nList fields. 
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
+*/
+static int fts3EvalIncrPhraseNext(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
+  u8 *pbEof                       /* OUT: Set to 1 if EOF */
+){
+  int rc = SQLITE_OK;
+  Fts3Doclist *pDL = &p->doclist;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  u8 bEof = 0;
+
+  /* This is only called if it is guaranteed that the phrase has at least
+  ** one incremental token. In which case the bIncr flag is set. */
+  assert( p->bIncr==1 );
+
+  if( p->nToken==1 ){
+    rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr, 
+        &pDL->iDocid, &pDL->pList, &pDL->nList
+    );
+    if( pDL->pList==0 ) bEof = 1;
+  }else{
+    int bDescDoclist = pCsr->bDesc;
+    struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];
+
+    memset(a, 0, sizeof(a));
+    assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );
+    assert( p->iDoclistTokennToken && bEof==0; i++){
+        rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+        if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){
+          iMax = a[i].iDocid;
+          bMaxSet = 1;
+        }
+      }
+      assert( rc!=SQLITE_OK || (p->nToken>=1 && a[p->nToken-1].bIgnore==0) );
+      assert( rc!=SQLITE_OK || bMaxSet );
+
+      /* Keep advancing iterators until they all point to the same document */
+      for(i=0; inToken; i++){
+        while( rc==SQLITE_OK && bEof==0 
+            && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0 
+        ){
+          rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+          if( DOCID_CMP(a[i].iDocid, iMax)>0 ){
+            iMax = a[i].iDocid;
+            i = 0;
+          }
+        }
+      }
+
+      /* Check if the current entries really are a phrase match */
+      if( bEof==0 ){
+        int nList = 0;
+        int nByte = a[p->nToken-1].nList;
+        char *aDoclist = sqlite3_malloc(nByte+1);
+        if( !aDoclist ) return SQLITE_NOMEM;
+        memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);
+
+        for(i=0; i<(p->nToken-1); i++){
+          if( a[i].bIgnore==0 ){
+            char *pL = a[i].pList;
+            char *pR = aDoclist;
+            char *pOut = aDoclist;
+            int nDist = p->nToken-1-i;
+            int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);
+            if( res==0 ) break;
+            nList = (int)(pOut - aDoclist);
+          }
+        }
+        if( i==(p->nToken-1) ){
+          pDL->iDocid = iMax;
+          pDL->pList = aDoclist;
+          pDL->nList = nList;
+          pDL->bFreeList = 1;
+          break;
+        }
+        sqlite3_free(aDoclist);
+      }
+    }
+  }
+
+  *pbEof = bEof;
+  return rc;
+}
+
+/*
+** Attempt to move the phrase iterator to point to the next matching docid. 
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+*/
+static int fts3EvalPhraseNext(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
+  u8 *pbEof                       /* OUT: Set to 1 if EOF */
+){
+  int rc = SQLITE_OK;
+  Fts3Doclist *pDL = &p->doclist;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+
+  if( p->bIncr ){
+    rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);
+  }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){
+    sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll, 
+        &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof
+    );
+    pDL->pList = pDL->pNextDocid;
+  }else{
+    fts3EvalDlPhraseNext(pTab, pDL, pbEof);
+  }
+
+  return rc;
+}
+
+/*
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, fts3EvalPhraseStart() is called on all phrases within the
+** expression. Also the Fts3Expr.bDeferred variable is set to true for any
+** expressions for which all descendent tokens are deferred.
+**
+** If parameter bOptOk is zero, then it is guaranteed that the
+** Fts3Phrase.doclist.aAll/nAll variables contain the entire doclist for
+** each phrase in the expression (subject to deferred token processing).
+** Or, if bOptOk is non-zero, then one or more tokens within the expression
+** may be loaded incrementally, meaning doclist.aAll/nAll is not available.
+**
+** If an error occurs within this function, *pRc is set to an SQLite error
+** code before returning.
+*/
+static void fts3EvalStartReaders(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Expr *pExpr,                /* Expression to initialize phrases in */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  if( pExpr && SQLITE_OK==*pRc ){
+    if( pExpr->eType==FTSQUERY_PHRASE ){
+      int nToken = pExpr->pPhrase->nToken;
+      if( nToken ){
+        int i;
+        for(i=0; ipPhrase->aToken[i].pDeferred==0 ) break;
+        }
+        pExpr->bDeferred = (i==nToken);
+      }
+      *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);
+    }else{
+      fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);
+      fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);
+      pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);
+    }
+  }
+}
+
+/*
+** An array of the following structures is assembled as part of the process
+** of selecting tokens to defer before the query starts executing (as part
+** of the xFilter() method). There is one element in the array for each
+** token in the FTS expression.
+**
+** Tokens are divided into AND/NEAR clusters. All tokens in a cluster belong
+** to phrases that are connected only by AND and NEAR operators (not OR or
+** NOT). When determining tokens to defer, each AND/NEAR cluster is considered
+** separately. The root of a tokens AND/NEAR cluster is stored in 
+** Fts3TokenAndCost.pRoot.
+*/
+typedef struct Fts3TokenAndCost Fts3TokenAndCost;
+struct Fts3TokenAndCost {
+  Fts3Phrase *pPhrase;            /* The phrase the token belongs to */
+  int iToken;                     /* Position of token in phrase */
+  Fts3PhraseToken *pToken;        /* The token itself */
+  Fts3Expr *pRoot;                /* Root of NEAR/AND cluster */
+  int nOvfl;                      /* Number of overflow pages to load doclist */
+  int iCol;                       /* The column the token must match */
+};
+
+/*
+** This function is used to populate an allocated Fts3TokenAndCost array.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, if an error occurs during execution, *pRc is set to an
+** SQLite error code.
+*/
+static void fts3EvalTokenCosts(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Expr *pRoot,                /* Root of current AND/NEAR cluster */
+  Fts3Expr *pExpr,                /* Expression to consider */
+  Fts3TokenAndCost **ppTC,        /* Write new entries to *(*ppTC)++ */
+  Fts3Expr ***ppOr,               /* Write new OR root to *(*ppOr)++ */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  if( *pRc==SQLITE_OK ){
+    if( pExpr->eType==FTSQUERY_PHRASE ){
+      Fts3Phrase *pPhrase = pExpr->pPhrase;
+      int i;
+      for(i=0; *pRc==SQLITE_OK && inToken; i++){
+        Fts3TokenAndCost *pTC = (*ppTC)++;
+        pTC->pPhrase = pPhrase;
+        pTC->iToken = i;
+        pTC->pRoot = pRoot;
+        pTC->pToken = &pPhrase->aToken[i];
+        pTC->iCol = pPhrase->iColumn;
+        *pRc = sqlite3Fts3MsrOvfl(pCsr, pTC->pToken->pSegcsr, &pTC->nOvfl);
+      }
+    }else if( pExpr->eType!=FTSQUERY_NOT ){
+      assert( pExpr->eType==FTSQUERY_OR
+           || pExpr->eType==FTSQUERY_AND
+           || pExpr->eType==FTSQUERY_NEAR
+      );
+      assert( pExpr->pLeft && pExpr->pRight );
+      if( pExpr->eType==FTSQUERY_OR ){
+        pRoot = pExpr->pLeft;
+        **ppOr = pRoot;
+        (*ppOr)++;
+      }
+      fts3EvalTokenCosts(pCsr, pRoot, pExpr->pLeft, ppTC, ppOr, pRc);
+      if( pExpr->eType==FTSQUERY_OR ){
+        pRoot = pExpr->pRight;
+        **ppOr = pRoot;
+        (*ppOr)++;
+      }
+      fts3EvalTokenCosts(pCsr, pRoot, pExpr->pRight, ppTC, ppOr, pRc);
+    }
+  }
+}
+
+/*
+** Determine the average document (row) size in pages. If successful,
+** write this value to *pnPage and return SQLITE_OK. Otherwise, return
+** an SQLite error code.
+**
+** The average document size in pages is calculated by first calculating 
+** determining the average size in bytes, B. If B is less than the amount
+** of data that will fit on a single leaf page of an intkey table in
+** this database, then the average docsize is 1. Otherwise, it is 1 plus
+** the number of overflow pages consumed by a record B bytes in size.
+*/
+static int fts3EvalAverageDocsize(Fts3Cursor *pCsr, int *pnPage){
+  int rc = SQLITE_OK;
+  if( pCsr->nRowAvg==0 ){
+    /* The average document size, which is required to calculate the cost
+    ** of each doclist, has not yet been determined. Read the required 
+    ** data from the %_stat table to calculate it.
+    **
+    ** Entry 0 of the %_stat table is a blob containing (nCol+1) FTS3 
+    ** varints, where nCol is the number of columns in the FTS3 table.
+    ** The first varint is the number of documents currently stored in
+    ** the table. The following nCol varints contain the total amount of
+    ** data stored in all rows of each column of the table, from left
+    ** to right.
+    */
+    Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;
+    sqlite3_stmt *pStmt;
+    sqlite3_int64 nDoc = 0;
+    sqlite3_int64 nByte = 0;
+    const char *pEnd;
+    const char *a;
+
+    rc = sqlite3Fts3SelectDoctotal(p, &pStmt);
+    if( rc!=SQLITE_OK ) return rc;
+    a = sqlite3_column_blob(pStmt, 0);
+    assert( a );
+
+    pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
+    a += sqlite3Fts3GetVarint(a, &nDoc);
+    while( anDoc = nDoc;
+    pCsr->nRowAvg = (int)(((nByte / nDoc) + p->nPgsz) / p->nPgsz);
+    assert( pCsr->nRowAvg>0 ); 
+    rc = sqlite3_reset(pStmt);
+  }
+
+  *pnPage = pCsr->nRowAvg;
+  return rc;
+}
+
+/*
+** This function is called to select the tokens (if any) that will be 
+** deferred. The array aTC[] has already been populated when this is
+** called.
+**
+** This function is called once for each AND/NEAR cluster in the 
+** expression. Each invocation determines which tokens to defer within
+** the cluster with root node pRoot. See comments above the definition
+** of struct Fts3TokenAndCost for more details.
+**
+** If no error occurs, SQLITE_OK is returned and sqlite3Fts3DeferToken()
+** called on each token to defer. Otherwise, an SQLite error code is
+** returned.
+*/
+static int fts3EvalSelectDeferred(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Expr *pRoot,                /* Consider tokens with this root node */
+  Fts3TokenAndCost *aTC,          /* Array of expression tokens and costs */
+  int nTC                         /* Number of entries in aTC[] */
+){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int nDocSize = 0;               /* Number of pages per doc loaded */
+  int rc = SQLITE_OK;             /* Return code */
+  int ii;                         /* Iterator variable for various purposes */
+  int nOvfl = 0;                  /* Total overflow pages used by doclists */
+  int nToken = 0;                 /* Total number of tokens in cluster */
+
+  int nMinEst = 0;                /* The minimum count for any phrase so far. */
+  int nLoad4 = 1;                 /* (Phrases that will be loaded)^4. */
+
+  /* Tokens are never deferred for FTS tables created using the content=xxx
+  ** option. The reason being that it is not guaranteed that the content
+  ** table actually contains the same data as the index. To prevent this from
+  ** causing any problems, the deferred token optimization is completely
+  ** disabled for content=xxx tables. */
+  if( pTab->zContentTbl ){
+    return SQLITE_OK;
+  }
+
+  /* Count the tokens in this AND/NEAR cluster. If none of the doclists
+  ** associated with the tokens spill onto overflow pages, or if there is
+  ** only 1 token, exit early. No tokens to defer in this case. */
+  for(ii=0; ii0 );
+
+
+  /* Iterate through all tokens in this AND/NEAR cluster, in ascending order 
+  ** of the number of overflow pages that will be loaded by the pager layer 
+  ** to retrieve the entire doclist for the token from the full-text index.
+  ** Load the doclists for tokens that are either:
+  **
+  **   a. The cheapest token in the entire query (i.e. the one visited by the
+  **      first iteration of this loop), or
+  **
+  **   b. Part of a multi-token phrase.
+  **
+  ** After each token doclist is loaded, merge it with the others from the
+  ** same phrase and count the number of documents that the merged doclist
+  ** contains. Set variable "nMinEst" to the smallest number of documents in 
+  ** any phrase doclist for which 1 or more token doclists have been loaded.
+  ** Let nOther be the number of other phrases for which it is certain that
+  ** one or more tokens will not be deferred.
+  **
+  ** Then, for each token, defer it if loading the doclist would result in
+  ** loading N or more overflow pages into memory, where N is computed as:
+  **
+  **    (nMinEst + 4^nOther - 1) / (4^nOther)
+  */
+  for(ii=0; iinOvfl) 
+      ){
+        pTC = &aTC[iTC];
+      }
+    }
+    assert( pTC );
+
+    if( ii && pTC->nOvfl>=((nMinEst+(nLoad4/4)-1)/(nLoad4/4))*nDocSize ){
+      /* The number of overflow pages to load for this (and therefore all
+      ** subsequent) tokens is greater than the estimated number of pages 
+      ** that will be loaded if all subsequent tokens are deferred.
+      */
+      Fts3PhraseToken *pToken = pTC->pToken;
+      rc = sqlite3Fts3DeferToken(pCsr, pToken, pTC->iCol);
+      fts3SegReaderCursorFree(pToken->pSegcsr);
+      pToken->pSegcsr = 0;
+    }else{
+      /* Set nLoad4 to the value of (4^nOther) for the next iteration of the
+      ** for-loop. Except, limit the value to 2^24 to prevent it from 
+      ** overflowing the 32-bit integer it is stored in. */
+      if( ii<12 ) nLoad4 = nLoad4*4;
+
+      if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){
+        /* Either this is the cheapest token in the entire query, or it is
+        ** part of a multi-token phrase. Either way, the entire doclist will
+        ** (eventually) be loaded into memory. It may as well be now. */
+        Fts3PhraseToken *pToken = pTC->pToken;
+        int nList = 0;
+        char *pList = 0;
+        rc = fts3TermSelect(pTab, pToken, pTC->iCol, &nList, &pList);
+        assert( rc==SQLITE_OK || pList==0 );
+        if( rc==SQLITE_OK ){
+          rc = fts3EvalPhraseMergeToken(
+              pTab, pTC->pPhrase, pTC->iToken,pList,nList
+          );
+        }
+        if( rc==SQLITE_OK ){
+          int nCount;
+          nCount = fts3DoclistCountDocids(
+              pTC->pPhrase->doclist.aAll, pTC->pPhrase->doclist.nAll
+          );
+          if( ii==0 || nCountpToken = 0;
+  }
+
+  return rc;
+}
+
+/*
+** This function is called from within the xFilter method. It initializes
+** the full-text query currently stored in pCsr->pExpr. To iterate through
+** the results of a query, the caller does:
+**
+**    fts3EvalStart(pCsr);
+**    while( 1 ){
+**      fts3EvalNext(pCsr);
+**      if( pCsr->bEof ) break;
+**      ... return row pCsr->iPrevId to the caller ...
+**    }
+*/
+static int fts3EvalStart(Fts3Cursor *pCsr){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;
+  int nToken = 0;
+  int nOr = 0;
+
+  /* Allocate a MultiSegReader for each token in the expression. */
+  fts3EvalAllocateReaders(pCsr, pCsr->pExpr, &nToken, &nOr, &rc);
+
+  /* Determine which, if any, tokens in the expression should be deferred. */
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+  if( rc==SQLITE_OK && nToken>1 && pTab->bFts4 ){
+    Fts3TokenAndCost *aTC;
+    Fts3Expr **apOr;
+    aTC = (Fts3TokenAndCost *)sqlite3_malloc(
+        sizeof(Fts3TokenAndCost) * nToken
+      + sizeof(Fts3Expr *) * nOr * 2
+    );
+    apOr = (Fts3Expr **)&aTC[nToken];
+
+    if( !aTC ){
+      rc = SQLITE_NOMEM;
+    }else{
+      int ii;
+      Fts3TokenAndCost *pTC = aTC;
+      Fts3Expr **ppOr = apOr;
+
+      fts3EvalTokenCosts(pCsr, 0, pCsr->pExpr, &pTC, &ppOr, &rc);
+      nToken = (int)(pTC-aTC);
+      nOr = (int)(ppOr-apOr);
+
+      if( rc==SQLITE_OK ){
+        rc = fts3EvalSelectDeferred(pCsr, 0, aTC, nToken);
+        for(ii=0; rc==SQLITE_OK && iipExpr, &rc);
+  return rc;
+}
+
+/*
+** Invalidate the current position list for phrase pPhrase.
+*/
+static void fts3EvalInvalidatePoslist(Fts3Phrase *pPhrase){
+  if( pPhrase->doclist.bFreeList ){
+    sqlite3_free(pPhrase->doclist.pList);
+  }
+  pPhrase->doclist.pList = 0;
+  pPhrase->doclist.nList = 0;
+  pPhrase->doclist.bFreeList = 0;
+}
+
+/*
+** This function is called to edit the position list associated with
+** the phrase object passed as the fifth argument according to a NEAR
+** condition. For example:
+**
+**     abc NEAR/5 "def ghi"
+**
+** Parameter nNear is passed the NEAR distance of the expression (5 in
+** the example above). When this function is called, *paPoslist points to
+** the position list, and *pnToken is the number of phrase tokens in, the
+** phrase on the other side of the NEAR operator to pPhrase. For example,
+** if pPhrase refers to the "def ghi" phrase, then *paPoslist points to
+** the position list associated with phrase "abc".
+**
+** All positions in the pPhrase position list that are not sufficiently
+** close to a position in the *paPoslist position list are removed. If this
+** leaves 0 positions, zero is returned. Otherwise, non-zero.
+**
+** Before returning, *paPoslist is set to point to the position lsit 
+** associated with pPhrase. And *pnToken is set to the number of tokens in
+** pPhrase.
+*/
+static int fts3EvalNearTrim(
+  int nNear,                      /* NEAR distance. As in "NEAR/nNear". */
+  char *aTmp,                     /* Temporary space to use */
+  char **paPoslist,               /* IN/OUT: Position list */
+  int *pnToken,                   /* IN/OUT: Tokens in phrase of *paPoslist */
+  Fts3Phrase *pPhrase             /* The phrase object to trim the doclist of */
+){
+  int nParam1 = nNear + pPhrase->nToken;
+  int nParam2 = nNear + *pnToken;
+  int nNew;
+  char *p2; 
+  char *pOut; 
+  int res;
+
+  assert( pPhrase->doclist.pList );
+
+  p2 = pOut = pPhrase->doclist.pList;
+  res = fts3PoslistNearMerge(
+    &pOut, aTmp, nParam1, nParam2, paPoslist, &p2
+  );
+  if( res ){
+    nNew = (int)(pOut - pPhrase->doclist.pList) - 1;
+    assert( pPhrase->doclist.pList[nNew]=='\0' );
+    assert( nNew<=pPhrase->doclist.nList && nNew>0 );
+    memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);
+    pPhrase->doclist.nList = nNew;
+    *paPoslist = pPhrase->doclist.pList;
+    *pnToken = pPhrase->nToken;
+  }
+
+  return res;
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is called.
+** Otherwise, it advances the expression passed as the second argument to
+** point to the next matching row in the database. Expressions iterate through
+** matching rows in docid order. Ascending order if Fts3Cursor.bDesc is zero,
+** or descending if it is non-zero.
+**
+** If an error occurs, *pRc is set to an SQLite error code. Otherwise, if
+** successful, the following variables in pExpr are set:
+**
+**   Fts3Expr.bEof                (non-zero if EOF - there is no next row)
+**   Fts3Expr.iDocid              (valid if bEof==0. The docid of the next row)
+**
+** If the expression is of type FTSQUERY_PHRASE, and the expression is not
+** at EOF, then the following variables are populated with the position list
+** for the phrase for the visited row:
+**
+**   FTs3Expr.pPhrase->doclist.nList        (length of pList in bytes)
+**   FTs3Expr.pPhrase->doclist.pList        (pointer to position list)
+**
+** It says above that this function advances the expression to the next
+** matching row. This is usually true, but there are the following exceptions:
+**
+**   1. Deferred tokens are not taken into account. If a phrase consists
+**      entirely of deferred tokens, it is assumed to match every row in
+**      the db. In this case the position-list is not populated at all. 
+**
+**      Or, if a phrase contains one or more deferred tokens and one or
+**      more non-deferred tokens, then the expression is advanced to the 
+**      next possible match, considering only non-deferred tokens. In other
+**      words, if the phrase is "A B C", and "B" is deferred, the expression
+**      is advanced to the next row that contains an instance of "A * C", 
+**      where "*" may match any single token. The position list in this case
+**      is populated as for "A * C" before returning.
+**
+**   2. NEAR is treated as AND. If the expression is "x NEAR y", it is 
+**      advanced to point to the next row that matches "x AND y".
+** 
+** See sqlite3Fts3EvalTestDeferred() for details on testing if a row is
+** really a match, taking into account deferred tokens and NEAR operators.
+*/
+static void fts3EvalNextRow(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Expr *pExpr,                /* Expr. to advance to next matching row */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  if( *pRc==SQLITE_OK ){
+    int bDescDoclist = pCsr->bDesc;         /* Used by DOCID_CMP() macro */
+    assert( pExpr->bEof==0 );
+    pExpr->bStart = 1;
+
+    switch( pExpr->eType ){
+      case FTSQUERY_NEAR:
+      case FTSQUERY_AND: {
+        Fts3Expr *pLeft = pExpr->pLeft;
+        Fts3Expr *pRight = pExpr->pRight;
+        assert( !pLeft->bDeferred || !pRight->bDeferred );
+
+        if( pLeft->bDeferred ){
+          /* LHS is entirely deferred. So we assume it matches every row.
+          ** Advance the RHS iterator to find the next row visited. */
+          fts3EvalNextRow(pCsr, pRight, pRc);
+          pExpr->iDocid = pRight->iDocid;
+          pExpr->bEof = pRight->bEof;
+        }else if( pRight->bDeferred ){
+          /* RHS is entirely deferred. So we assume it matches every row.
+          ** Advance the LHS iterator to find the next row visited. */
+          fts3EvalNextRow(pCsr, pLeft, pRc);
+          pExpr->iDocid = pLeft->iDocid;
+          pExpr->bEof = pLeft->bEof;
+        }else{
+          /* Neither the RHS or LHS are deferred. */
+          fts3EvalNextRow(pCsr, pLeft, pRc);
+          fts3EvalNextRow(pCsr, pRight, pRc);
+          while( !pLeft->bEof && !pRight->bEof && *pRc==SQLITE_OK ){
+            sqlite3_int64 iDiff = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+            if( iDiff==0 ) break;
+            if( iDiff<0 ){
+              fts3EvalNextRow(pCsr, pLeft, pRc);
+            }else{
+              fts3EvalNextRow(pCsr, pRight, pRc);
+            }
+          }
+          pExpr->iDocid = pLeft->iDocid;
+          pExpr->bEof = (pLeft->bEof || pRight->bEof);
+          if( pExpr->eType==FTSQUERY_NEAR && pExpr->bEof ){
+            assert( pRight->eType==FTSQUERY_PHRASE );
+            if( pRight->pPhrase->doclist.aAll ){
+              Fts3Doclist *pDl = &pRight->pPhrase->doclist;
+              while( *pRc==SQLITE_OK && pRight->bEof==0 ){
+                memset(pDl->pList, 0, pDl->nList);
+                fts3EvalNextRow(pCsr, pRight, pRc);
+              }
+            }
+            if( pLeft->pPhrase && pLeft->pPhrase->doclist.aAll ){
+              Fts3Doclist *pDl = &pLeft->pPhrase->doclist;
+              while( *pRc==SQLITE_OK && pLeft->bEof==0 ){
+                memset(pDl->pList, 0, pDl->nList);
+                fts3EvalNextRow(pCsr, pLeft, pRc);
+              }
+            }
+          }
+        }
+        break;
+      }
+  
+      case FTSQUERY_OR: {
+        Fts3Expr *pLeft = pExpr->pLeft;
+        Fts3Expr *pRight = pExpr->pRight;
+        sqlite3_int64 iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+
+        assert( pLeft->bStart || pLeft->iDocid==pRight->iDocid );
+        assert( pRight->bStart || pLeft->iDocid==pRight->iDocid );
+
+        if( pRight->bEof || (pLeft->bEof==0 && iCmp<0) ){
+          fts3EvalNextRow(pCsr, pLeft, pRc);
+        }else if( pLeft->bEof || iCmp>0 ){
+          fts3EvalNextRow(pCsr, pRight, pRc);
+        }else{
+          fts3EvalNextRow(pCsr, pLeft, pRc);
+          fts3EvalNextRow(pCsr, pRight, pRc);
+        }
+
+        pExpr->bEof = (pLeft->bEof && pRight->bEof);
+        iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+        if( pRight->bEof || (pLeft->bEof==0 &&  iCmp<0) ){
+          pExpr->iDocid = pLeft->iDocid;
+        }else{
+          pExpr->iDocid = pRight->iDocid;
+        }
+
+        break;
+      }
+
+      case FTSQUERY_NOT: {
+        Fts3Expr *pLeft = pExpr->pLeft;
+        Fts3Expr *pRight = pExpr->pRight;
+
+        if( pRight->bStart==0 ){
+          fts3EvalNextRow(pCsr, pRight, pRc);
+          assert( *pRc!=SQLITE_OK || pRight->bStart );
+        }
+
+        fts3EvalNextRow(pCsr, pLeft, pRc);
+        if( pLeft->bEof==0 ){
+          while( !*pRc 
+              && !pRight->bEof 
+              && DOCID_CMP(pLeft->iDocid, pRight->iDocid)>0 
+          ){
+            fts3EvalNextRow(pCsr, pRight, pRc);
+          }
+        }
+        pExpr->iDocid = pLeft->iDocid;
+        pExpr->bEof = pLeft->bEof;
+        break;
+      }
+
+      default: {
+        Fts3Phrase *pPhrase = pExpr->pPhrase;
+        fts3EvalInvalidatePoslist(pPhrase);
+        *pRc = fts3EvalPhraseNext(pCsr, pPhrase, &pExpr->bEof);
+        pExpr->iDocid = pPhrase->doclist.iDocid;
+        break;
+      }
+    }
+  }
+}
+
+/*
+** If *pRc is not SQLITE_OK, or if pExpr is not the root node of a NEAR
+** cluster, then this function returns 1 immediately.
+**
+** Otherwise, it checks if the current row really does match the NEAR 
+** expression, using the data currently stored in the position lists 
+** (Fts3Expr->pPhrase.doclist.pList/nList) for each phrase in the expression. 
+**
+** If the current row is a match, the position list associated with each
+** phrase in the NEAR expression is edited in place to contain only those
+** phrase instances sufficiently close to their peers to satisfy all NEAR
+** constraints. In this case it returns 1. If the NEAR expression does not 
+** match the current row, 0 is returned. The position lists may or may not
+** be edited if 0 is returned.
+*/
+static int fts3EvalNearTest(Fts3Expr *pExpr, int *pRc){
+  int res = 1;
+
+  /* The following block runs if pExpr is the root of a NEAR query.
+  ** For example, the query:
+  **
+  **         "w" NEAR "x" NEAR "y" NEAR "z"
+  **
+  ** which is represented in tree form as:
+  **
+  **                               |
+  **                          +--NEAR--+      <-- root of NEAR query
+  **                          |        |
+  **                     +--NEAR--+   "z"
+  **                     |        |
+  **                +--NEAR--+   "y"
+  **                |        |
+  **               "w"      "x"
+  **
+  ** The right-hand child of a NEAR node is always a phrase. The 
+  ** left-hand child may be either a phrase or a NEAR node. There are
+  ** no exceptions to this - it's the way the parser in fts3_expr.c works.
+  */
+  if( *pRc==SQLITE_OK 
+   && pExpr->eType==FTSQUERY_NEAR 
+   && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
+  ){
+    Fts3Expr *p; 
+    int nTmp = 0;                 /* Bytes of temp space */
+    char *aTmp;                   /* Temp space for PoslistNearMerge() */
+
+    /* Allocate temporary working space. */
+    for(p=pExpr; p->pLeft; p=p->pLeft){
+      assert( p->pRight->pPhrase->doclist.nList>0 );
+      nTmp += p->pRight->pPhrase->doclist.nList;
+    }
+    nTmp += p->pPhrase->doclist.nList;
+    aTmp = sqlite3_malloc(nTmp*2);
+    if( !aTmp ){
+      *pRc = SQLITE_NOMEM;
+      res = 0;
+    }else{
+      char *aPoslist = p->pPhrase->doclist.pList;
+      int nToken = p->pPhrase->nToken;
+
+      for(p=p->pParent;res && p && p->eType==FTSQUERY_NEAR; p=p->pParent){
+        Fts3Phrase *pPhrase = p->pRight->pPhrase;
+        int nNear = p->nNear;
+        res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+      }
+
+      aPoslist = pExpr->pRight->pPhrase->doclist.pList;
+      nToken = pExpr->pRight->pPhrase->nToken;
+      for(p=pExpr->pLeft; p && res; p=p->pLeft){
+        int nNear;
+        Fts3Phrase *pPhrase;
+        assert( p->pParent && p->pParent->pLeft==p );
+        nNear = p->pParent->nNear;
+        pPhrase = (
+            p->eType==FTSQUERY_NEAR ? p->pRight->pPhrase : p->pPhrase
+        );
+        res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+      }
+    }
+
+    sqlite3_free(aTmp);
+  }
+
+  return res;
+}
+
+/*
+** This function is a helper function for sqlite3Fts3EvalTestDeferred().
+** Assuming no error occurs or has occurred, It returns non-zero if the
+** expression passed as the second argument matches the row that pCsr 
+** currently points to, or zero if it does not.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** If an error occurs during execution of this function, *pRc is set to 
+** the appropriate SQLite error code. In this case the returned value is 
+** undefined.
+*/
+static int fts3EvalTestExpr(
+  Fts3Cursor *pCsr,               /* FTS cursor handle */
+  Fts3Expr *pExpr,                /* Expr to test. May or may not be root. */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  int bHit = 1;                   /* Return value */
+  if( *pRc==SQLITE_OK ){
+    switch( pExpr->eType ){
+      case FTSQUERY_NEAR:
+      case FTSQUERY_AND:
+        bHit = (
+            fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)
+         && fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)
+         && fts3EvalNearTest(pExpr, pRc)
+        );
+
+        /* If the NEAR expression does not match any rows, zero the doclist for 
+        ** all phrases involved in the NEAR. This is because the snippet(),
+        ** offsets() and matchinfo() functions are not supposed to recognize 
+        ** any instances of phrases that are part of unmatched NEAR queries. 
+        ** For example if this expression:
+        **
+        **    ... MATCH 'a OR (b NEAR c)'
+        **
+        ** is matched against a row containing:
+        **
+        **        'a b d e'
+        **
+        ** then any snippet() should ony highlight the "a" term, not the "b"
+        ** (as "b" is part of a non-matching NEAR clause).
+        */
+        if( bHit==0 
+         && pExpr->eType==FTSQUERY_NEAR 
+         && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
+        ){
+          Fts3Expr *p;
+          for(p=pExpr; p->pPhrase==0; p=p->pLeft){
+            if( p->pRight->iDocid==pCsr->iPrevId ){
+              fts3EvalInvalidatePoslist(p->pRight->pPhrase);
+            }
+          }
+          if( p->iDocid==pCsr->iPrevId ){
+            fts3EvalInvalidatePoslist(p->pPhrase);
+          }
+        }
+
+        break;
+
+      case FTSQUERY_OR: {
+        int bHit1 = fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc);
+        int bHit2 = fts3EvalTestExpr(pCsr, pExpr->pRight, pRc);
+        bHit = bHit1 || bHit2;
+        break;
+      }
+
+      case FTSQUERY_NOT:
+        bHit = (
+            fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)
+         && !fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)
+        );
+        break;
+
+      default: {
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+        if( pCsr->pDeferred 
+         && (pExpr->iDocid==pCsr->iPrevId || pExpr->bDeferred)
+        ){
+          Fts3Phrase *pPhrase = pExpr->pPhrase;
+          assert( pExpr->bDeferred || pPhrase->doclist.bFreeList==0 );
+          if( pExpr->bDeferred ){
+            fts3EvalInvalidatePoslist(pPhrase);
+          }
+          *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);
+          bHit = (pPhrase->doclist.pList!=0);
+          pExpr->iDocid = pCsr->iPrevId;
+        }else
+#endif
+        {
+          bHit = (pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId);
+        }
+        break;
+      }
+    }
+  }
+  return bHit;
+}
+
+/*
+** This function is called as the second part of each xNext operation when
+** iterating through the results of a full-text query. At this point the
+** cursor points to a row that matches the query expression, with the
+** following caveats:
+**
+**   * Up until this point, "NEAR" operators in the expression have been
+**     treated as "AND".
+**
+**   * Deferred tokens have not yet been considered.
+**
+** If *pRc is not SQLITE_OK when this function is called, it immediately
+** returns 0. Otherwise, it tests whether or not after considering NEAR
+** operators and deferred tokens the current row is still a match for the
+** expression. It returns 1 if both of the following are true:
+**
+**   1. *pRc is SQLITE_OK when this function returns, and
+**
+**   2. After scanning the current FTS table row for the deferred tokens,
+**      it is determined that the row does *not* match the query.
+**
+** Or, if no error occurs and it seems the current row does match the FTS
+** query, return 0.
+*/
+SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc){
+  int rc = *pRc;
+  int bMiss = 0;
+  if( rc==SQLITE_OK ){
+
+    /* If there are one or more deferred tokens, load the current row into
+    ** memory and scan it to determine the position list for each deferred
+    ** token. Then, see if this row is really a match, considering deferred
+    ** tokens and NEAR operators (neither of which were taken into account
+    ** earlier, by fts3EvalNextRow()). 
+    */
+    if( pCsr->pDeferred ){
+      rc = fts3CursorSeek(0, pCsr);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3Fts3CacheDeferredDoclists(pCsr);
+      }
+    }
+    bMiss = (0==fts3EvalTestExpr(pCsr, pCsr->pExpr, &rc));
+
+    /* Free the position-lists accumulated for each deferred token above. */
+    sqlite3Fts3FreeDeferredDoclists(pCsr);
+    *pRc = rc;
+  }
+  return (rc==SQLITE_OK && bMiss);
+}
+
+/*
+** Advance to the next document that matches the FTS expression in
+** Fts3Cursor.pExpr.
+*/
+static int fts3EvalNext(Fts3Cursor *pCsr){
+  int rc = SQLITE_OK;             /* Return Code */
+  Fts3Expr *pExpr = pCsr->pExpr;
+  assert( pCsr->isEof==0 );
+  if( pExpr==0 ){
+    pCsr->isEof = 1;
+  }else{
+    do {
+      if( pCsr->isRequireSeek==0 ){
+        sqlite3_reset(pCsr->pStmt);
+      }
+      assert( sqlite3_data_count(pCsr->pStmt)==0 );
+      fts3EvalNextRow(pCsr, pExpr, &rc);
+      pCsr->isEof = pExpr->bEof;
+      pCsr->isRequireSeek = 1;
+      pCsr->isMatchinfoNeeded = 1;
+      pCsr->iPrevId = pExpr->iDocid;
+    }while( pCsr->isEof==0 && sqlite3Fts3EvalTestDeferred(pCsr, &rc) );
+  }
+
+  /* Check if the cursor is past the end of the docid range specified
+  ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */
+  if( rc==SQLITE_OK && (
+        (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
+     || (pCsr->bDesc!=0 && pCsr->iPrevIdiMinDocid)
+  )){
+    pCsr->isEof = 1;
+  }
+
+  return rc;
+}
+
+/*
+** Restart interation for expression pExpr so that the next call to
+** fts3EvalNext() visits the first row. Do not allow incremental 
+** loading or merging of phrase doclists for this iteration.
+**
+** If *pRc is other than SQLITE_OK when this function is called, it is
+** a no-op. If an error occurs within this function, *pRc is set to an
+** SQLite error code before returning.
+*/
+static void fts3EvalRestart(
+  Fts3Cursor *pCsr,
+  Fts3Expr *pExpr,
+  int *pRc
+){
+  if( pExpr && *pRc==SQLITE_OK ){
+    Fts3Phrase *pPhrase = pExpr->pPhrase;
+
+    if( pPhrase ){
+      fts3EvalInvalidatePoslist(pPhrase);
+      if( pPhrase->bIncr ){
+        int i;
+        for(i=0; inToken; i++){
+          Fts3PhraseToken *pToken = &pPhrase->aToken[i];
+          assert( pToken->pDeferred==0 );
+          if( pToken->pSegcsr ){
+            sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);
+          }
+        }
+        *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);
+      }
+      pPhrase->doclist.pNextDocid = 0;
+      pPhrase->doclist.iDocid = 0;
+      pPhrase->pOrPoslist = 0;
+    }
+
+    pExpr->iDocid = 0;
+    pExpr->bEof = 0;
+    pExpr->bStart = 0;
+
+    fts3EvalRestart(pCsr, pExpr->pLeft, pRc);
+    fts3EvalRestart(pCsr, pExpr->pRight, pRc);
+  }
+}
+
+/*
+** After allocating the Fts3Expr.aMI[] array for each phrase in the 
+** expression rooted at pExpr, the cursor iterates through all rows matched
+** by pExpr, calling this function for each row. This function increments
+** the values in Fts3Expr.aMI[] according to the position-list currently
+** found in Fts3Expr.pPhrase->doclist.pList for each of the phrase 
+** expression nodes.
+*/
+static void fts3EvalUpdateCounts(Fts3Expr *pExpr){
+  if( pExpr ){
+    Fts3Phrase *pPhrase = pExpr->pPhrase;
+    if( pPhrase && pPhrase->doclist.pList ){
+      int iCol = 0;
+      char *p = pPhrase->doclist.pList;
+
+      assert( *p );
+      while( 1 ){
+        u8 c = 0;
+        int iCnt = 0;
+        while( 0xFE & (*p | c) ){
+          if( (c&0x80)==0 ) iCnt++;
+          c = *p++ & 0x80;
+        }
+
+        /* aMI[iCol*3 + 1] = Number of occurrences
+        ** aMI[iCol*3 + 2] = Number of rows containing at least one instance
+        */
+        pExpr->aMI[iCol*3 + 1] += iCnt;
+        pExpr->aMI[iCol*3 + 2] += (iCnt>0);
+        if( *p==0x00 ) break;
+        p++;
+        p += fts3GetVarint32(p, &iCol);
+      }
+    }
+
+    fts3EvalUpdateCounts(pExpr->pLeft);
+    fts3EvalUpdateCounts(pExpr->pRight);
+  }
+}
+
+/*
+** Expression pExpr must be of type FTSQUERY_PHRASE.
+**
+** If it is not already allocated and populated, this function allocates and
+** populates the Fts3Expr.aMI[] array for expression pExpr. If pExpr is part
+** of a NEAR expression, then it also allocates and populates the same array
+** for all other phrases that are part of the NEAR expression.
+**
+** SQLITE_OK is returned if the aMI[] array is successfully allocated and
+** populated. Otherwise, if an error occurs, an SQLite error code is returned.
+*/
+static int fts3EvalGatherStats(
+  Fts3Cursor *pCsr,               /* Cursor object */
+  Fts3Expr *pExpr                 /* FTSQUERY_PHRASE expression */
+){
+  int rc = SQLITE_OK;             /* Return code */
+
+  assert( pExpr->eType==FTSQUERY_PHRASE );
+  if( pExpr->aMI==0 ){
+    Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+    Fts3Expr *pRoot;                /* Root of NEAR expression */
+    Fts3Expr *p;                    /* Iterator used for several purposes */
+
+    sqlite3_int64 iPrevId = pCsr->iPrevId;
+    sqlite3_int64 iDocid;
+    u8 bEof;
+
+    /* Find the root of the NEAR expression */
+    pRoot = pExpr;
+    while( pRoot->pParent && pRoot->pParent->eType==FTSQUERY_NEAR ){
+      pRoot = pRoot->pParent;
+    }
+    iDocid = pRoot->iDocid;
+    bEof = pRoot->bEof;
+    assert( pRoot->bStart );
+
+    /* Allocate space for the aMSI[] array of each FTSQUERY_PHRASE node */
+    for(p=pRoot; p; p=p->pLeft){
+      Fts3Expr *pE = (p->eType==FTSQUERY_PHRASE?p:p->pRight);
+      assert( pE->aMI==0 );
+      pE->aMI = (u32 *)sqlite3_malloc(pTab->nColumn * 3 * sizeof(u32));
+      if( !pE->aMI ) return SQLITE_NOMEM;
+      memset(pE->aMI, 0, pTab->nColumn * 3 * sizeof(u32));
+    }
+
+    fts3EvalRestart(pCsr, pRoot, &rc);
+
+    while( pCsr->isEof==0 && rc==SQLITE_OK ){
+
+      do {
+        /* Ensure the %_content statement is reset. */
+        if( pCsr->isRequireSeek==0 ) sqlite3_reset(pCsr->pStmt);
+        assert( sqlite3_data_count(pCsr->pStmt)==0 );
+
+        /* Advance to the next document */
+        fts3EvalNextRow(pCsr, pRoot, &rc);
+        pCsr->isEof = pRoot->bEof;
+        pCsr->isRequireSeek = 1;
+        pCsr->isMatchinfoNeeded = 1;
+        pCsr->iPrevId = pRoot->iDocid;
+      }while( pCsr->isEof==0 
+           && pRoot->eType==FTSQUERY_NEAR 
+           && sqlite3Fts3EvalTestDeferred(pCsr, &rc) 
+      );
+
+      if( rc==SQLITE_OK && pCsr->isEof==0 ){
+        fts3EvalUpdateCounts(pRoot);
+      }
+    }
+
+    pCsr->isEof = 0;
+    pCsr->iPrevId = iPrevId;
+
+    if( bEof ){
+      pRoot->bEof = bEof;
+    }else{
+      /* Caution: pRoot may iterate through docids in ascending or descending
+      ** order. For this reason, even though it seems more defensive, the 
+      ** do loop can not be written:
+      **
+      **   do {...} while( pRoot->iDocidbEof==0 );
+      }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
+    }
+  }
+  return rc;
+}
+
+/*
+** This function is used by the matchinfo() module to query a phrase 
+** expression node for the following information:
+**
+**   1. The total number of occurrences of the phrase in each column of 
+**      the FTS table (considering all rows), and
+**
+**   2. For each column, the number of rows in the table for which the
+**      column contains at least one instance of the phrase.
+**
+** If no error occurs, SQLITE_OK is returned and the values for each column
+** written into the array aiOut as follows:
+**
+**   aiOut[iCol*3 + 1] = Number of occurrences
+**   aiOut[iCol*3 + 2] = Number of rows containing at least one instance
+**
+** Caveats:
+**
+**   * If a phrase consists entirely of deferred tokens, then all output 
+**     values are set to the number of documents in the table. In other
+**     words we assume that very common tokens occur exactly once in each 
+**     column of each row of the table.
+**
+**   * If a phrase contains some deferred tokens (and some non-deferred 
+**     tokens), count the potential occurrence identified by considering
+**     the non-deferred tokens instead of actual phrase occurrences.
+**
+**   * If the phrase is part of a NEAR expression, then only phrase instances
+**     that meet the NEAR constraint are included in the counts.
+*/
+SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(
+  Fts3Cursor *pCsr,               /* FTS cursor handle */
+  Fts3Expr *pExpr,                /* Phrase expression */
+  u32 *aiOut                      /* Array to write results into (see above) */
+){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;
+  int iCol;
+
+  if( pExpr->bDeferred && pExpr->pParent->eType!=FTSQUERY_NEAR ){
+    assert( pCsr->nDoc>0 );
+    for(iCol=0; iColnColumn; iCol++){
+      aiOut[iCol*3 + 1] = (u32)pCsr->nDoc;
+      aiOut[iCol*3 + 2] = (u32)pCsr->nDoc;
+    }
+  }else{
+    rc = fts3EvalGatherStats(pCsr, pExpr);
+    if( rc==SQLITE_OK ){
+      assert( pExpr->aMI );
+      for(iCol=0; iColnColumn; iCol++){
+        aiOut[iCol*3 + 1] = pExpr->aMI[iCol*3 + 1];
+        aiOut[iCol*3 + 2] = pExpr->aMI[iCol*3 + 2];
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** The expression pExpr passed as the second argument to this function
+** must be of type FTSQUERY_PHRASE. 
+**
+** The returned value is either NULL or a pointer to a buffer containing
+** a position-list indicating the occurrences of the phrase in column iCol
+** of the current row. 
+**
+** More specifically, the returned buffer contains 1 varint for each 
+** occurrence of the phrase in the column, stored using the normal (delta+2) 
+** compression and is terminated by either an 0x01 or 0x00 byte. For example,
+** if the requested column contains "a b X c d X X" and the position-list
+** for 'X' is requested, the buffer returned may contain:
+**
+**     0x04 0x05 0x03 0x01   or   0x04 0x05 0x03 0x00
+**
+** This function works regardless of whether or not the phrase is deferred,
+** incremental, or neither.
+*/
+SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(
+  Fts3Cursor *pCsr,               /* FTS3 cursor object */
+  Fts3Expr *pExpr,                /* Phrase to return doclist for */
+  int iCol,                       /* Column to return position list for */
+  char **ppOut                    /* OUT: Pointer to position list */
+){
+  Fts3Phrase *pPhrase = pExpr->pPhrase;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  char *pIter;
+  int iThis;
+  sqlite3_int64 iDocid;
+
+  /* If this phrase is applies specifically to some column other than 
+  ** column iCol, return a NULL pointer.  */
+  *ppOut = 0;
+  assert( iCol>=0 && iColnColumn );
+  if( (pPhrase->iColumnnColumn && pPhrase->iColumn!=iCol) ){
+    return SQLITE_OK;
+  }
+
+  iDocid = pExpr->iDocid;
+  pIter = pPhrase->doclist.pList;
+  if( iDocid!=pCsr->iPrevId || pExpr->bEof ){
+    int rc = SQLITE_OK;
+    int bDescDoclist = pTab->bDescIdx;      /* For DOCID_CMP macro */
+    int bOr = 0;
+    u8 bTreeEof = 0;
+    Fts3Expr *p;                  /* Used to iterate from pExpr to root */
+    Fts3Expr *pNear;              /* Most senior NEAR ancestor (or pExpr) */
+    int bMatch;
+
+    /* Check if this phrase descends from an OR expression node. If not, 
+    ** return NULL. Otherwise, the entry that corresponds to docid 
+    ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the
+    ** tree that the node is part of has been marked as EOF, but the node
+    ** itself is not EOF, then it may point to an earlier entry. */
+    pNear = pExpr;
+    for(p=pExpr->pParent; p; p=p->pParent){
+      if( p->eType==FTSQUERY_OR ) bOr = 1;
+      if( p->eType==FTSQUERY_NEAR ) pNear = p;
+      if( p->bEof ) bTreeEof = 1;
+    }
+    if( bOr==0 ) return SQLITE_OK;
+
+    /* This is the descendent of an OR node. In this case we cannot use
+    ** an incremental phrase. Load the entire doclist for the phrase
+    ** into memory in this case.  */
+    if( pPhrase->bIncr ){
+      int bEofSave = pNear->bEof;
+      fts3EvalRestart(pCsr, pNear, &rc);
+      while( rc==SQLITE_OK && !pNear->bEof ){
+        fts3EvalNextRow(pCsr, pNear, &rc);
+        if( bEofSave==0 && pNear->iDocid==iDocid ) break;
+      }
+      assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );
+    }
+    if( bTreeEof ){
+      while( rc==SQLITE_OK && !pNear->bEof ){
+        fts3EvalNextRow(pCsr, pNear, &rc);
+      }
+    }
+    if( rc!=SQLITE_OK ) return rc;
+
+    bMatch = 1;
+    for(p=pNear; p; p=p->pLeft){
+      u8 bEof = 0;
+      Fts3Expr *pTest = p;
+      Fts3Phrase *pPh;
+      assert( pTest->eType==FTSQUERY_NEAR || pTest->eType==FTSQUERY_PHRASE );
+      if( pTest->eType==FTSQUERY_NEAR ) pTest = pTest->pRight;
+      assert( pTest->eType==FTSQUERY_PHRASE );
+      pPh = pTest->pPhrase;
+
+      pIter = pPh->pOrPoslist;
+      iDocid = pPh->iOrDocid;
+      if( pCsr->bDesc==bDescDoclist ){
+        bEof = !pPh->doclist.nAll ||
+          (pIter >= (pPh->doclist.aAll + pPh->doclist.nAll));
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
+          sqlite3Fts3DoclistNext(
+              bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 
+              &pIter, &iDocid, &bEof
+          );
+        }
+      }else{
+        bEof = !pPh->doclist.nAll || (pIter && pIter<=pPh->doclist.aAll);
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
+          int dummy;
+          sqlite3Fts3DoclistPrev(
+              bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 
+              &pIter, &iDocid, &dummy, &bEof
+              );
+        }
+      }
+      pPh->pOrPoslist = pIter;
+      pPh->iOrDocid = iDocid;
+      if( bEof || iDocid!=pCsr->iPrevId ) bMatch = 0;
+    }
+
+    if( bMatch ){
+      pIter = pPhrase->pOrPoslist;
+    }else{
+      pIter = 0;
+    }
+  }
+  if( pIter==0 ) return SQLITE_OK;
+
+  if( *pIter==0x01 ){
+    pIter++;
+    pIter += fts3GetVarint32(pIter, &iThis);
+  }else{
+    iThis = 0;
+  }
+  while( iThisdoclist, and
+**   * any Fts3MultiSegReader objects held by phrase tokens.
+*/
+SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *pPhrase){
+  if( pPhrase ){
+    int i;
+    sqlite3_free(pPhrase->doclist.aAll);
+    fts3EvalInvalidatePoslist(pPhrase);
+    memset(&pPhrase->doclist, 0, sizeof(Fts3Doclist));
+    for(i=0; inToken; i++){
+      fts3SegReaderCursorFree(pPhrase->aToken[i].pSegcsr);
+      pPhrase->aToken[i].pSegcsr = 0;
+    }
+  }
+}
+
+
+/*
+** Return SQLITE_CORRUPT_VTAB.
+*/
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3Fts3Corrupt(){
+  return SQLITE_CORRUPT_VTAB;
+}
+#endif
+
+#if !SQLITE_CORE
+/*
+** Initialize API pointer table, if required.
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int sqlite3_fts3_init(
+  sqlite3 *db, 
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi)
+  return sqlite3Fts3Init(db);
+}
+#endif
+
+#endif
+
+/************** End of fts3.c ************************************************/
+/************** Begin file fts3_aux.c ****************************************/
+/*
+** 2011 Jan 27
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+
+typedef struct Fts3auxTable Fts3auxTable;
+typedef struct Fts3auxCursor Fts3auxCursor;
+
+struct Fts3auxTable {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  Fts3Table *pFts3Tab;
+};
+
+struct Fts3auxCursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  Fts3MultiSegReader csr;        /* Must be right after "base" */
+  Fts3SegFilter filter;
+  char *zStop;
+  int nStop;                      /* Byte-length of string zStop */
+  int iLangid;                    /* Language id to query */
+  int isEof;                      /* True if cursor is at EOF */
+  sqlite3_int64 iRowid;           /* Current rowid */
+
+  int iCol;                       /* Current value of 'col' column */
+  int nStat;                      /* Size of aStat[] array */
+  struct Fts3auxColstats {
+    sqlite3_int64 nDoc;           /* 'documents' values for current csr row */
+    sqlite3_int64 nOcc;           /* 'occurrences' values for current csr row */
+  } *aStat;
+};
+
+/*
+** Schema of the terms table.
+*/
+#define FTS3_AUX_SCHEMA \
+  "CREATE TABLE x(term, col, documents, occurrences, languageid HIDDEN)"
+
+/*
+** This function does all the work for both the xConnect and xCreate methods.
+** These tables have no persistent representation of their own, so xConnect
+** and xCreate are identical operations.
+*/
+static int fts3auxConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pUnused,                  /* Unused */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  char const *zDb;                /* Name of database (e.g. "main") */
+  char const *zFts3;              /* Name of fts3 table */
+  int nDb;                        /* Result of strlen(zDb) */
+  int nFts3;                      /* Result of strlen(zFts3) */
+  int nByte;                      /* Bytes of space to allocate here */
+  int rc;                         /* value returned by declare_vtab() */
+  Fts3auxTable *p;                /* Virtual table object to return */
+
+  UNUSED_PARAMETER(pUnused);
+
+  /* The user should invoke this in one of two forms:
+  **
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table);
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table-db, fts4-table);
+  */
+  if( argc!=4 && argc!=5 ) goto bad_args;
+
+  zDb = argv[1]; 
+  nDb = (int)strlen(zDb);
+  if( argc==5 ){
+    if( nDb==4 && 0==sqlite3_strnicmp("temp", zDb, 4) ){
+      zDb = argv[3]; 
+      nDb = (int)strlen(zDb);
+      zFts3 = argv[4];
+    }else{
+      goto bad_args;
+    }
+  }else{
+    zFts3 = argv[3];
+  }
+  nFts3 = (int)strlen(zFts3);
+
+  rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
+  p = (Fts3auxTable *)sqlite3_malloc(nByte);
+  if( !p ) return SQLITE_NOMEM;
+  memset(p, 0, nByte);
+
+  p->pFts3Tab = (Fts3Table *)&p[1];
+  p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1];
+  p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1];
+  p->pFts3Tab->db = db;
+  p->pFts3Tab->nIndex = 1;
+
+  memcpy((char *)p->pFts3Tab->zDb, zDb, nDb);
+  memcpy((char *)p->pFts3Tab->zName, zFts3, nFts3);
+  sqlite3Fts3Dequote((char *)p->pFts3Tab->zName);
+
+  *ppVtab = (sqlite3_vtab *)p;
+  return SQLITE_OK;
+
+ bad_args:
+  sqlite3Fts3ErrMsg(pzErr, "invalid arguments to fts4aux constructor");
+  return SQLITE_ERROR;
+}
+
+/*
+** This function does the work for both the xDisconnect and xDestroy methods.
+** These tables have no persistent representation of their own, so xDisconnect
+** and xDestroy are identical operations.
+*/
+static int fts3auxDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts3auxTable *p = (Fts3auxTable *)pVtab;
+  Fts3Table *pFts3 = p->pFts3Tab;
+  int i;
+
+  /* Free any prepared statements held */
+  for(i=0; iaStmt); i++){
+    sqlite3_finalize(pFts3->aStmt[i]);
+  }
+  sqlite3_free(pFts3->zSegmentsTbl);
+  sqlite3_free(p);
+  return SQLITE_OK;
+}
+
+#define FTS4AUX_EQ_CONSTRAINT 1
+#define FTS4AUX_GE_CONSTRAINT 2
+#define FTS4AUX_LE_CONSTRAINT 4
+
+/*
+** xBestIndex - Analyze a WHERE and ORDER BY clause.
+*/
+static int fts3auxBestIndexMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_index_info *pInfo
+){
+  int i;
+  int iEq = -1;
+  int iGe = -1;
+  int iLe = -1;
+  int iLangid = -1;
+  int iNext = 1;                  /* Next free argvIndex value */
+
+  UNUSED_PARAMETER(pVTab);
+
+  /* This vtab delivers always results in "ORDER BY term ASC" order. */
+  if( pInfo->nOrderBy==1 
+   && pInfo->aOrderBy[0].iColumn==0 
+   && pInfo->aOrderBy[0].desc==0
+  ){
+    pInfo->orderByConsumed = 1;
+  }
+
+  /* Search for equality and range constraints on the "term" column. 
+  ** And equality constraints on the hidden "languageid" column. */
+  for(i=0; inConstraint; i++){
+    if( pInfo->aConstraint[i].usable ){
+      int op = pInfo->aConstraint[i].op;
+      int iCol = pInfo->aConstraint[i].iColumn;
+
+      if( iCol==0 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
+      }
+      if( iCol==4 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iLangid = i;
+      }
+    }
+  }
+
+  if( iEq>=0 ){
+    pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT;
+    pInfo->aConstraintUsage[iEq].argvIndex = iNext++;
+    pInfo->estimatedCost = 5;
+  }else{
+    pInfo->idxNum = 0;
+    pInfo->estimatedCost = 20000;
+    if( iGe>=0 ){
+      pInfo->idxNum += FTS4AUX_GE_CONSTRAINT;
+      pInfo->aConstraintUsage[iGe].argvIndex = iNext++;
+      pInfo->estimatedCost /= 2;
+    }
+    if( iLe>=0 ){
+      pInfo->idxNum += FTS4AUX_LE_CONSTRAINT;
+      pInfo->aConstraintUsage[iLe].argvIndex = iNext++;
+      pInfo->estimatedCost /= 2;
+    }
+  }
+  if( iLangid>=0 ){
+    pInfo->aConstraintUsage[iLangid].argvIndex = iNext++;
+    pInfo->estimatedCost--;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen - Open a cursor.
+*/
+static int fts3auxOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts3auxCursor *pCsr;            /* Pointer to cursor object to return */
+
+  UNUSED_PARAMETER(pVTab);
+
+  pCsr = (Fts3auxCursor *)sqlite3_malloc(sizeof(Fts3auxCursor));
+  if( !pCsr ) return SQLITE_NOMEM;
+  memset(pCsr, 0, sizeof(Fts3auxCursor));
+
+  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** xClose - Close a cursor.
+*/
+static int fts3auxCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
+  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
+
+  sqlite3Fts3SegmentsClose(pFts3);
+  sqlite3Fts3SegReaderFinish(&pCsr->csr);
+  sqlite3_free((void *)pCsr->filter.zTerm);
+  sqlite3_free(pCsr->zStop);
+  sqlite3_free(pCsr->aStat);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+static int fts3auxGrowStatArray(Fts3auxCursor *pCsr, int nSize){
+  if( nSize>pCsr->nStat ){
+    struct Fts3auxColstats *aNew;
+    aNew = (struct Fts3auxColstats *)sqlite3_realloc(pCsr->aStat, 
+        sizeof(struct Fts3auxColstats) * nSize
+    );
+    if( aNew==0 ) return SQLITE_NOMEM;
+    memset(&aNew[pCsr->nStat], 0, 
+        sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat)
+    );
+    pCsr->aStat = aNew;
+    pCsr->nStat = nSize;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** xNext - Advance the cursor to the next row, if any.
+*/
+static int fts3auxNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
+  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
+  int rc;
+
+  /* Increment our pretend rowid value. */
+  pCsr->iRowid++;
+
+  for(pCsr->iCol++; pCsr->iColnStat; pCsr->iCol++){
+    if( pCsr->aStat[pCsr->iCol].nDoc>0 ) return SQLITE_OK;
+  }
+
+  rc = sqlite3Fts3SegReaderStep(pFts3, &pCsr->csr);
+  if( rc==SQLITE_ROW ){
+    int i = 0;
+    int nDoclist = pCsr->csr.nDoclist;
+    char *aDoclist = pCsr->csr.aDoclist;
+    int iCol;
+
+    int eState = 0;
+
+    if( pCsr->zStop ){
+      int n = (pCsr->nStopcsr.nTerm) ? pCsr->nStop : pCsr->csr.nTerm;
+      int mc = memcmp(pCsr->zStop, pCsr->csr.zTerm, n);
+      if( mc<0 || (mc==0 && pCsr->csr.nTerm>pCsr->nStop) ){
+        pCsr->isEof = 1;
+        return SQLITE_OK;
+      }
+    }
+
+    if( fts3auxGrowStatArray(pCsr, 2) ) return SQLITE_NOMEM;
+    memset(pCsr->aStat, 0, sizeof(struct Fts3auxColstats) * pCsr->nStat);
+    iCol = 0;
+
+    while( iaStat[0].nDoc++;
+          eState = 1;
+          iCol = 0;
+          break;
+
+        /* State 1. In this state we are expecting either a 1, indicating
+        ** that the following integer will be a column number, or the
+        ** start of a position list for column 0.  
+        ** 
+        ** The only difference between state 1 and state 2 is that if the
+        ** integer encountered in state 1 is not 0 or 1, then we need to
+        ** increment the column 0 "nDoc" count for this term.
+        */
+        case 1:
+          assert( iCol==0 );
+          if( v>1 ){
+            pCsr->aStat[1].nDoc++;
+          }
+          eState = 2;
+          /* fall through */
+
+        case 2:
+          if( v==0 ){       /* 0x00. Next integer will be a docid. */
+            eState = 0;
+          }else if( v==1 ){ /* 0x01. Next integer will be a column number. */
+            eState = 3;
+          }else{            /* 2 or greater. A position. */
+            pCsr->aStat[iCol+1].nOcc++;
+            pCsr->aStat[0].nOcc++;
+          }
+          break;
+
+        /* State 3. The integer just read is a column number. */
+        default: assert( eState==3 );
+          iCol = (int)v;
+          if( fts3auxGrowStatArray(pCsr, iCol+2) ) return SQLITE_NOMEM;
+          pCsr->aStat[iCol+1].nDoc++;
+          eState = 2;
+          break;
+      }
+    }
+
+    pCsr->iCol = 0;
+    rc = SQLITE_OK;
+  }else{
+    pCsr->isEof = 1;
+  }
+  return rc;
+}
+
+/*
+** xFilter - Initialize a cursor to point at the start of its data.
+*/
+static int fts3auxFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
+  Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
+  int rc;
+  int isScan = 0;
+  int iLangVal = 0;               /* Language id to query */
+
+  int iEq = -1;                   /* Index of term=? value in apVal */
+  int iGe = -1;                   /* Index of term>=? value in apVal */
+  int iLe = -1;                   /* Index of term<=? value in apVal */
+  int iLangid = -1;               /* Index of languageid=? value in apVal */
+  int iNext = 0;
+
+  UNUSED_PARAMETER(nVal);
+  UNUSED_PARAMETER(idxStr);
+
+  assert( idxStr==0 );
+  assert( idxNum==FTS4AUX_EQ_CONSTRAINT || idxNum==0
+       || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT
+       || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT)
+  );
+
+  if( idxNum==FTS4AUX_EQ_CONSTRAINT ){
+    iEq = iNext++;
+  }else{
+    isScan = 1;
+    if( idxNum & FTS4AUX_GE_CONSTRAINT ){
+      iGe = iNext++;
+    }
+    if( idxNum & FTS4AUX_LE_CONSTRAINT ){
+      iLe = iNext++;
+    }
+  }
+  if( iNextfilter.zTerm);
+  sqlite3Fts3SegReaderFinish(&pCsr->csr);
+  sqlite3_free((void *)pCsr->filter.zTerm);
+  sqlite3_free(pCsr->aStat);
+  memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);
+
+  pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
+  if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;
+
+  if( iEq>=0 || iGe>=0 ){
+    const unsigned char *zStr = sqlite3_value_text(apVal[0]);
+    assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) );
+    if( zStr ){
+      pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);
+      pCsr->filter.nTerm = sqlite3_value_bytes(apVal[0]);
+      if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;
+    }
+  }
+
+  if( iLe>=0 ){
+    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe]));
+    pCsr->nStop = sqlite3_value_bytes(apVal[iLe]);
+    if( pCsr->zStop==0 ) return SQLITE_NOMEM;
+  }
+  
+  if( iLangid>=0 ){
+    iLangVal = sqlite3_value_int(apVal[iLangid]);
+
+    /* If the user specified a negative value for the languageid, use zero
+    ** instead. This works, as the "languageid=?" constraint will also
+    ** be tested by the VDBE layer. The test will always be false (since
+    ** this module will not return a row with a negative languageid), and
+    ** so the overall query will return zero rows.  */
+    if( iLangVal<0 ) iLangVal = 0;
+  }
+  pCsr->iLangid = iLangVal;
+
+  rc = sqlite3Fts3SegReaderCursor(pFts3, iLangVal, 0, FTS3_SEGCURSOR_ALL,
+      pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
+  );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);
+  }
+
+  if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);
+  return rc;
+}
+
+/*
+** xEof - Return true if the cursor is at EOF, or false otherwise.
+*/
+static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
+  return pCsr->isEof;
+}
+
+/*
+** xColumn - Return a column value.
+*/
+static int fts3auxColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts3auxCursor *p = (Fts3auxCursor *)pCursor;
+
+  assert( p->isEof==0 );
+  switch( iCol ){
+    case 0: /* term */
+      sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
+      break;
+
+    case 1: /* col */
+      if( p->iCol ){
+        sqlite3_result_int(pCtx, p->iCol-1);
+      }else{
+        sqlite3_result_text(pCtx, "*", -1, SQLITE_STATIC);
+      }
+      break;
+
+    case 2: /* documents */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nDoc);
+      break;
+
+    case 3: /* occurrences */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nOcc);
+      break;
+
+    default: /* languageid */
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, p->iLangid);
+      break;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xRowid - Return the current rowid for the cursor.
+*/
+static int fts3auxRowidMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite_int64 *pRowid            /* OUT: Rowid value */
+){
+  Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
+  *pRowid = pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** Register the fts3aux module with database connection db. Return SQLITE_OK
+** if successful or an error code if sqlite3_create_module() fails.
+*/
+SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db){
+  static const sqlite3_module fts3aux_module = {
+     0,                           /* iVersion      */
+     fts3auxConnectMethod,        /* xCreate       */
+     fts3auxConnectMethod,        /* xConnect      */
+     fts3auxBestIndexMethod,      /* xBestIndex    */
+     fts3auxDisconnectMethod,     /* xDisconnect   */
+     fts3auxDisconnectMethod,     /* xDestroy      */
+     fts3auxOpenMethod,           /* xOpen         */
+     fts3auxCloseMethod,          /* xClose        */
+     fts3auxFilterMethod,         /* xFilter       */
+     fts3auxNextMethod,           /* xNext         */
+     fts3auxEofMethod,            /* xEof          */
+     fts3auxColumnMethod,         /* xColumn       */
+     fts3auxRowidMethod,          /* xRowid        */
+     0,                           /* xUpdate       */
+     0,                           /* xBegin        */
+     0,                           /* xSync         */
+     0,                           /* xCommit       */
+     0,                           /* xRollback     */
+     0,                           /* xFindFunction */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
+  };
+  int rc;                         /* Return code */
+
+  rc = sqlite3_create_module(db, "fts4aux", &fts3aux_module, 0);
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_aux.c ********************************************/
+/************** Begin file fts3_expr.c ***************************************/
+/*
+** 2008 Nov 28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This module contains code that implements a parser for fts3 query strings
+** (the right-hand argument to the MATCH operator). Because the supported 
+** syntax is relatively simple, the whole tokenizer/parser system is
+** hand-coded. 
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/*
+** By default, this module parses the legacy syntax that has been 
+** traditionally used by fts3. Or, if SQLITE_ENABLE_FTS3_PARENTHESIS
+** is defined, then it uses the new syntax. The differences between
+** the new and the old syntaxes are:
+**
+**  a) The new syntax supports parenthesis. The old does not.
+**
+**  b) The new syntax supports the AND and NOT operators. The old does not.
+**
+**  c) The old syntax supports the "-" token qualifier. This is not 
+**     supported by the new syntax (it is replaced by the NOT operator).
+**
+**  d) When using the old syntax, the OR operator has a greater precedence
+**     than an implicit AND. When using the new, both implicity and explicit
+**     AND operators have a higher precedence than OR.
+**
+** If compiled with SQLITE_TEST defined, then this module exports the
+** symbol "int sqlite3_fts3_enable_parentheses". Setting this variable
+** to zero causes the module to use the old syntax. If it is set to 
+** non-zero the new syntax is activated. This is so both syntaxes can
+** be tested using a single build of testfixture.
+**
+** The following describes the syntax supported by the fts3 MATCH
+** operator in a similar format to that used by the lemon parser
+** generator. This module does not use actually lemon, it uses a
+** custom parser.
+**
+**   query ::= andexpr (OR andexpr)*.
+**
+**   andexpr ::= notexpr (AND? notexpr)*.
+**
+**   notexpr ::= nearexpr (NOT nearexpr|-TOKEN)*.
+**   notexpr ::= LP query RP.
+**
+**   nearexpr ::= phrase (NEAR distance_opt nearexpr)*.
+**
+**   distance_opt ::= .
+**   distance_opt ::= / INTEGER.
+**
+**   phrase ::= TOKEN.
+**   phrase ::= COLUMN:TOKEN.
+**   phrase ::= "TOKEN TOKEN TOKEN...".
+*/
+
+#ifdef SQLITE_TEST
+SQLITE_API int sqlite3_fts3_enable_parentheses = 0;
+#else
+# ifdef SQLITE_ENABLE_FTS3_PARENTHESIS 
+#  define sqlite3_fts3_enable_parentheses 1
+# else
+#  define sqlite3_fts3_enable_parentheses 0
+# endif
+#endif
+
+/*
+** Default span for NEAR operators.
+*/
+#define SQLITE_FTS3_DEFAULT_NEAR_PARAM 10
+
+/* #include  */
+/* #include  */
+
+/*
+** isNot:
+**   This variable is used by function getNextNode(). When getNextNode() is
+**   called, it sets ParseContext.isNot to true if the 'next node' is a 
+**   FTSQUERY_PHRASE with a unary "-" attached to it. i.e. "mysql" in the
+**   FTS3 query "sqlite -mysql". Otherwise, ParseContext.isNot is set to
+**   zero.
+*/
+typedef struct ParseContext ParseContext;
+struct ParseContext {
+  sqlite3_tokenizer *pTokenizer;      /* Tokenizer module */
+  int iLangid;                        /* Language id used with tokenizer */
+  const char **azCol;                 /* Array of column names for fts3 table */
+  int bFts4;                          /* True to allow FTS4-only syntax */
+  int nCol;                           /* Number of entries in azCol[] */
+  int iDefaultCol;                    /* Default column to query */
+  int isNot;                          /* True if getNextNode() sees a unary - */
+  sqlite3_context *pCtx;              /* Write error message here */
+  int nNest;                          /* Number of nested brackets */
+};
+
+/*
+** This function is equivalent to the standard isspace() function. 
+**
+** The standard isspace() can be awkward to use safely, because although it
+** is defined to accept an argument of type int, its behavior when passed
+** an integer that falls outside of the range of the unsigned char type
+** is undefined (and sometimes, "undefined" means segfault). This wrapper
+** is defined to accept an argument of type char, and always returns 0 for
+** any values that fall outside of the range of the unsigned char type (i.e.
+** negative values).
+*/
+static int fts3isspace(char c){
+  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
+}
+
+/*
+** Allocate nByte bytes of memory using sqlite3_malloc(). If successful,
+** zero the memory before returning a pointer to it. If unsuccessful, 
+** return NULL.
+*/
+static void *fts3MallocZero(int nByte){
+  void *pRet = sqlite3_malloc(nByte);
+  if( pRet ) memset(pRet, 0, nByte);
+  return pRet;
+}
+
+SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(
+  sqlite3_tokenizer *pTokenizer,
+  int iLangid,
+  const char *z,
+  int n,
+  sqlite3_tokenizer_cursor **ppCsr
+){
+  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
+  sqlite3_tokenizer_cursor *pCsr = 0;
+  int rc;
+
+  rc = pModule->xOpen(pTokenizer, z, n, &pCsr);
+  assert( rc==SQLITE_OK || pCsr==0 );
+  if( rc==SQLITE_OK ){
+    pCsr->pTokenizer = pTokenizer;
+    if( pModule->iVersion>=1 ){
+      rc = pModule->xLanguageid(pCsr, iLangid);
+      if( rc!=SQLITE_OK ){
+        pModule->xClose(pCsr);
+        pCsr = 0;
+      }
+    }
+  }
+  *ppCsr = pCsr;
+  return rc;
+}
+
+/*
+** Function getNextNode(), which is called by fts3ExprParse(), may itself
+** call fts3ExprParse(). So this forward declaration is required.
+*/
+static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);
+
+/*
+** Extract the next token from buffer z (length n) using the tokenizer
+** and other information (column names etc.) in pParse. Create an Fts3Expr
+** structure of type FTSQUERY_PHRASE containing a phrase consisting of this
+** single token and set *ppExpr to point to it. If the end of the buffer is
+** reached before a token is found, set *ppExpr to zero. It is the
+** responsibility of the caller to eventually deallocate the allocated 
+** Fts3Expr structure (if any) by passing it to sqlite3_free().
+**
+** Return SQLITE_OK if successful, or SQLITE_NOMEM if a memory allocation
+** fails.
+*/
+static int getNextToken(
+  ParseContext *pParse,                   /* fts3 query parse context */
+  int iCol,                               /* Value for Fts3Phrase.iColumn */
+  const char *z, int n,                   /* Input string */
+  Fts3Expr **ppExpr,                      /* OUT: expression */
+  int *pnConsumed                         /* OUT: Number of bytes consumed */
+){
+  sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
+  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
+  int rc;
+  sqlite3_tokenizer_cursor *pCursor;
+  Fts3Expr *pRet = 0;
+  int i = 0;
+
+  /* Set variable i to the maximum number of bytes of input to tokenize. */
+  for(i=0; iiLangid, z, i, &pCursor);
+  if( rc==SQLITE_OK ){
+    const char *zToken;
+    int nToken = 0, iStart = 0, iEnd = 0, iPosition = 0;
+    int nByte;                               /* total space to allocate */
+
+    rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);
+    if( rc==SQLITE_OK ){
+      nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;
+      pRet = (Fts3Expr *)fts3MallocZero(nByte);
+      if( !pRet ){
+        rc = SQLITE_NOMEM;
+      }else{
+        pRet->eType = FTSQUERY_PHRASE;
+        pRet->pPhrase = (Fts3Phrase *)&pRet[1];
+        pRet->pPhrase->nToken = 1;
+        pRet->pPhrase->iColumn = iCol;
+        pRet->pPhrase->aToken[0].n = nToken;
+        pRet->pPhrase->aToken[0].z = (char *)&pRet->pPhrase[1];
+        memcpy(pRet->pPhrase->aToken[0].z, zToken, nToken);
+
+        if( iEndpPhrase->aToken[0].isPrefix = 1;
+          iEnd++;
+        }
+
+        while( 1 ){
+          if( !sqlite3_fts3_enable_parentheses 
+           && iStart>0 && z[iStart-1]=='-' 
+          ){
+            pParse->isNot = 1;
+            iStart--;
+          }else if( pParse->bFts4 && iStart>0 && z[iStart-1]=='^' ){
+            pRet->pPhrase->aToken[0].bFirst = 1;
+            iStart--;
+          }else{
+            break;
+          }
+        }
+
+      }
+      *pnConsumed = iEnd;
+    }else if( i && rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
+    }
+
+    pModule->xClose(pCursor);
+  }
+  
+  *ppExpr = pRet;
+  return rc;
+}
+
+
+/*
+** Enlarge a memory allocation.  If an out-of-memory allocation occurs,
+** then free the old allocation.
+*/
+static void *fts3ReallocOrFree(void *pOrig, int nNew){
+  void *pRet = sqlite3_realloc(pOrig, nNew);
+  if( !pRet ){
+    sqlite3_free(pOrig);
+  }
+  return pRet;
+}
+
+/*
+** Buffer zInput, length nInput, contains the contents of a quoted string
+** that appeared as part of an fts3 query expression. Neither quote character
+** is included in the buffer. This function attempts to tokenize the entire
+** input buffer and create an Fts3Expr structure of type FTSQUERY_PHRASE 
+** containing the results.
+**
+** If successful, SQLITE_OK is returned and *ppExpr set to point at the
+** allocated Fts3Expr structure. Otherwise, either SQLITE_NOMEM (out of memory
+** error) or SQLITE_ERROR (tokenization error) is returned and *ppExpr set
+** to 0.
+*/
+static int getNextString(
+  ParseContext *pParse,                   /* fts3 query parse context */
+  const char *zInput, int nInput,         /* Input string */
+  Fts3Expr **ppExpr                       /* OUT: expression */
+){
+  sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;
+  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
+  int rc;
+  Fts3Expr *p = 0;
+  sqlite3_tokenizer_cursor *pCursor = 0;
+  char *zTemp = 0;
+  int nTemp = 0;
+
+  const int nSpace = sizeof(Fts3Expr) + sizeof(Fts3Phrase);
+  int nToken = 0;
+
+  /* The final Fts3Expr data structure, including the Fts3Phrase,
+  ** Fts3PhraseToken structures token buffers are all stored as a single 
+  ** allocation so that the expression can be freed with a single call to
+  ** sqlite3_free(). Setting this up requires a two pass approach.
+  **
+  ** The first pass, in the block below, uses a tokenizer cursor to iterate
+  ** through the tokens in the expression. This pass uses fts3ReallocOrFree()
+  ** to assemble data in two dynamic buffers:
+  **
+  **   Buffer p: Points to the Fts3Expr structure, followed by the Fts3Phrase
+  **             structure, followed by the array of Fts3PhraseToken 
+  **             structures. This pass only populates the Fts3PhraseToken array.
+  **
+  **   Buffer zTemp: Contains copies of all tokens.
+  **
+  ** The second pass, in the block that begins "if( rc==SQLITE_DONE )" below,
+  ** appends buffer zTemp to buffer p, and fills in the Fts3Expr and Fts3Phrase
+  ** structures.
+  */
+  rc = sqlite3Fts3OpenTokenizer(
+      pTokenizer, pParse->iLangid, zInput, nInput, &pCursor);
+  if( rc==SQLITE_OK ){
+    int ii;
+    for(ii=0; rc==SQLITE_OK; ii++){
+      const char *zByte;
+      int nByte = 0, iBegin = 0, iEnd = 0, iPos = 0;
+      rc = pModule->xNext(pCursor, &zByte, &nByte, &iBegin, &iEnd, &iPos);
+      if( rc==SQLITE_OK ){
+        Fts3PhraseToken *pToken;
+
+        p = fts3ReallocOrFree(p, nSpace + ii*sizeof(Fts3PhraseToken));
+        if( !p ) goto no_mem;
+
+        zTemp = fts3ReallocOrFree(zTemp, nTemp + nByte);
+        if( !zTemp ) goto no_mem;
+
+        assert( nToken==ii );
+        pToken = &((Fts3Phrase *)(&p[1]))->aToken[ii];
+        memset(pToken, 0, sizeof(Fts3PhraseToken));
+
+        memcpy(&zTemp[nTemp], zByte, nByte);
+        nTemp += nByte;
+
+        pToken->n = nByte;
+        pToken->isPrefix = (iEndbFirst = (iBegin>0 && zInput[iBegin-1]=='^');
+        nToken = ii+1;
+      }
+    }
+
+    pModule->xClose(pCursor);
+    pCursor = 0;
+  }
+
+  if( rc==SQLITE_DONE ){
+    int jj;
+    char *zBuf = 0;
+
+    p = fts3ReallocOrFree(p, nSpace + nToken*sizeof(Fts3PhraseToken) + nTemp);
+    if( !p ) goto no_mem;
+    memset(p, 0, (char *)&(((Fts3Phrase *)&p[1])->aToken[0])-(char *)p);
+    p->eType = FTSQUERY_PHRASE;
+    p->pPhrase = (Fts3Phrase *)&p[1];
+    p->pPhrase->iColumn = pParse->iDefaultCol;
+    p->pPhrase->nToken = nToken;
+
+    zBuf = (char *)&p->pPhrase->aToken[nToken];
+    if( zTemp ){
+      memcpy(zBuf, zTemp, nTemp);
+      sqlite3_free(zTemp);
+    }else{
+      assert( nTemp==0 );
+    }
+
+    for(jj=0; jjpPhrase->nToken; jj++){
+      p->pPhrase->aToken[jj].z = zBuf;
+      zBuf += p->pPhrase->aToken[jj].n;
+    }
+    rc = SQLITE_OK;
+  }
+
+  *ppExpr = p;
+  return rc;
+no_mem:
+
+  if( pCursor ){
+    pModule->xClose(pCursor);
+  }
+  sqlite3_free(zTemp);
+  sqlite3_free(p);
+  *ppExpr = 0;
+  return SQLITE_NOMEM;
+}
+
+/*
+** The output variable *ppExpr is populated with an allocated Fts3Expr 
+** structure, or set to 0 if the end of the input buffer is reached.
+**
+** Returns an SQLite error code. SQLITE_OK if everything works, SQLITE_NOMEM
+** if a malloc failure occurs, or SQLITE_ERROR if a parse error is encountered.
+** If SQLITE_ERROR is returned, pContext is populated with an error message.
+*/
+static int getNextNode(
+  ParseContext *pParse,                   /* fts3 query parse context */
+  const char *z, int n,                   /* Input string */
+  Fts3Expr **ppExpr,                      /* OUT: expression */
+  int *pnConsumed                         /* OUT: Number of bytes consumed */
+){
+  static const struct Fts3Keyword {
+    char *z;                              /* Keyword text */
+    unsigned char n;                      /* Length of the keyword */
+    unsigned char parenOnly;              /* Only valid in paren mode */
+    unsigned char eType;                  /* Keyword code */
+  } aKeyword[] = {
+    { "OR" ,  2, 0, FTSQUERY_OR   },
+    { "AND",  3, 1, FTSQUERY_AND  },
+    { "NOT",  3, 1, FTSQUERY_NOT  },
+    { "NEAR", 4, 0, FTSQUERY_NEAR }
+  };
+  int ii;
+  int iCol;
+  int iColLen;
+  int rc;
+  Fts3Expr *pRet = 0;
+
+  const char *zInput = z;
+  int nInput = n;
+
+  pParse->isNot = 0;
+
+  /* Skip over any whitespace before checking for a keyword, an open or
+  ** close bracket, or a quoted string. 
+  */
+  while( nInput>0 && fts3isspace(*zInput) ){
+    nInput--;
+    zInput++;
+  }
+  if( nInput==0 ){
+    return SQLITE_DONE;
+  }
+
+  /* See if we are dealing with a keyword. */
+  for(ii=0; ii<(int)(sizeof(aKeyword)/sizeof(struct Fts3Keyword)); ii++){
+    const struct Fts3Keyword *pKey = &aKeyword[ii];
+
+    if( (pKey->parenOnly & ~sqlite3_fts3_enable_parentheses)!=0 ){
+      continue;
+    }
+
+    if( nInput>=pKey->n && 0==memcmp(zInput, pKey->z, pKey->n) ){
+      int nNear = SQLITE_FTS3_DEFAULT_NEAR_PARAM;
+      int nKey = pKey->n;
+      char cNext;
+
+      /* If this is a "NEAR" keyword, check for an explicit nearness. */
+      if( pKey->eType==FTSQUERY_NEAR ){
+        assert( nKey==4 );
+        if( zInput[4]=='/' && zInput[5]>='0' && zInput[5]<='9' ){
+          nNear = 0;
+          for(nKey=5; zInput[nKey]>='0' && zInput[nKey]<='9'; nKey++){
+            nNear = nNear * 10 + (zInput[nKey] - '0');
+          }
+        }
+      }
+
+      /* At this point this is probably a keyword. But for that to be true,
+      ** the next byte must contain either whitespace, an open or close
+      ** parenthesis, a quote character, or EOF. 
+      */
+      cNext = zInput[nKey];
+      if( fts3isspace(cNext) 
+       || cNext=='"' || cNext=='(' || cNext==')' || cNext==0
+      ){
+        pRet = (Fts3Expr *)fts3MallocZero(sizeof(Fts3Expr));
+        if( !pRet ){
+          return SQLITE_NOMEM;
+        }
+        pRet->eType = pKey->eType;
+        pRet->nNear = nNear;
+        *ppExpr = pRet;
+        *pnConsumed = (int)((zInput - z) + nKey);
+        return SQLITE_OK;
+      }
+
+      /* Turns out that wasn't a keyword after all. This happens if the
+      ** user has supplied a token such as "ORacle". Continue.
+      */
+    }
+  }
+
+  /* See if we are dealing with a quoted phrase. If this is the case, then
+  ** search for the closing quote and pass the whole string to getNextString()
+  ** for processing. This is easy to do, as fts3 has no syntax for escaping
+  ** a quote character embedded in a string.
+  */
+  if( *zInput=='"' ){
+    for(ii=1; iinNest++;
+      rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);
+      if( rc==SQLITE_OK && !*ppExpr ){ rc = SQLITE_DONE; }
+      *pnConsumed = (int)(zInput - z) + 1 + nConsumed;
+      return rc;
+    }else if( *zInput==')' ){
+      pParse->nNest--;
+      *pnConsumed = (int)((zInput - z) + 1);
+      *ppExpr = 0;
+      return SQLITE_DONE;
+    }
+  }
+
+  /* If control flows to this point, this must be a regular token, or 
+  ** the end of the input. Read a regular token using the sqlite3_tokenizer
+  ** interface. Before doing so, figure out if there is an explicit
+  ** column specifier for the token. 
+  **
+  ** TODO: Strangely, it is not possible to associate a column specifier
+  ** with a quoted phrase, only with a single token. Not sure if this was
+  ** an implementation artifact or an intentional decision when fts3 was
+  ** first implemented. Whichever it was, this module duplicates the 
+  ** limitation.
+  */
+  iCol = pParse->iDefaultCol;
+  iColLen = 0;
+  for(ii=0; iinCol; ii++){
+    const char *zStr = pParse->azCol[ii];
+    int nStr = (int)strlen(zStr);
+    if( nInput>nStr && zInput[nStr]==':' 
+     && sqlite3_strnicmp(zStr, zInput, nStr)==0 
+    ){
+      iCol = ii;
+      iColLen = (int)((zInput - z) + nStr + 1);
+      break;
+    }
+  }
+  rc = getNextToken(pParse, iCol, &z[iColLen], n-iColLen, ppExpr, pnConsumed);
+  *pnConsumed += iColLen;
+  return rc;
+}
+
+/*
+** The argument is an Fts3Expr structure for a binary operator (any type
+** except an FTSQUERY_PHRASE). Return an integer value representing the
+** precedence of the operator. Lower values have a higher precedence (i.e.
+** group more tightly). For example, in the C language, the == operator
+** groups more tightly than ||, and would therefore have a higher precedence.
+**
+** When using the new fts3 query syntax (when SQLITE_ENABLE_FTS3_PARENTHESIS
+** is defined), the order of the operators in precedence from highest to
+** lowest is:
+**
+**   NEAR
+**   NOT
+**   AND (including implicit ANDs)
+**   OR
+**
+** Note that when using the old query syntax, the OR operator has a higher
+** precedence than the AND operator.
+*/
+static int opPrecedence(Fts3Expr *p){
+  assert( p->eType!=FTSQUERY_PHRASE );
+  if( sqlite3_fts3_enable_parentheses ){
+    return p->eType;
+  }else if( p->eType==FTSQUERY_NEAR ){
+    return 1;
+  }else if( p->eType==FTSQUERY_OR ){
+    return 2;
+  }
+  assert( p->eType==FTSQUERY_AND );
+  return 3;
+}
+
+/*
+** Argument ppHead contains a pointer to the current head of a query 
+** expression tree being parsed. pPrev is the expression node most recently
+** inserted into the tree. This function adds pNew, which is always a binary
+** operator node, into the expression tree based on the relative precedence
+** of pNew and the existing nodes of the tree. This may result in the head
+** of the tree changing, in which case *ppHead is set to the new root node.
+*/
+static void insertBinaryOperator(
+  Fts3Expr **ppHead,       /* Pointer to the root node of a tree */
+  Fts3Expr *pPrev,         /* Node most recently inserted into the tree */
+  Fts3Expr *pNew           /* New binary node to insert into expression tree */
+){
+  Fts3Expr *pSplit = pPrev;
+  while( pSplit->pParent && opPrecedence(pSplit->pParent)<=opPrecedence(pNew) ){
+    pSplit = pSplit->pParent;
+  }
+
+  if( pSplit->pParent ){
+    assert( pSplit->pParent->pRight==pSplit );
+    pSplit->pParent->pRight = pNew;
+    pNew->pParent = pSplit->pParent;
+  }else{
+    *ppHead = pNew;
+  }
+  pNew->pLeft = pSplit;
+  pSplit->pParent = pNew;
+}
+
+/*
+** Parse the fts3 query expression found in buffer z, length n. This function
+** returns either when the end of the buffer is reached or an unmatched 
+** closing bracket - ')' - is encountered.
+**
+** If successful, SQLITE_OK is returned, *ppExpr is set to point to the
+** parsed form of the expression and *pnConsumed is set to the number of
+** bytes read from buffer z. Otherwise, *ppExpr is set to 0 and SQLITE_NOMEM
+** (out of memory error) or SQLITE_ERROR (parse error) is returned.
+*/
+static int fts3ExprParse(
+  ParseContext *pParse,                   /* fts3 query parse context */
+  const char *z, int n,                   /* Text of MATCH query */
+  Fts3Expr **ppExpr,                      /* OUT: Parsed query structure */
+  int *pnConsumed                         /* OUT: Number of bytes consumed */
+){
+  Fts3Expr *pRet = 0;
+  Fts3Expr *pPrev = 0;
+  Fts3Expr *pNotBranch = 0;               /* Only used in legacy parse mode */
+  int nIn = n;
+  const char *zIn = z;
+  int rc = SQLITE_OK;
+  int isRequirePhrase = 1;
+
+  while( rc==SQLITE_OK ){
+    Fts3Expr *p = 0;
+    int nByte = 0;
+
+    rc = getNextNode(pParse, zIn, nIn, &p, &nByte);
+    assert( nByte>0 || (rc!=SQLITE_OK && p==0) );
+    if( rc==SQLITE_OK ){
+      if( p ){
+        int isPhrase;
+
+        if( !sqlite3_fts3_enable_parentheses 
+            && p->eType==FTSQUERY_PHRASE && pParse->isNot 
+        ){
+          /* Create an implicit NOT operator. */
+          Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
+          if( !pNot ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_NOMEM;
+            goto exprparse_out;
+          }
+          pNot->eType = FTSQUERY_NOT;
+          pNot->pRight = p;
+          p->pParent = pNot;
+          if( pNotBranch ){
+            pNot->pLeft = pNotBranch;
+            pNotBranch->pParent = pNot;
+          }
+          pNotBranch = pNot;
+          p = pPrev;
+        }else{
+          int eType = p->eType;
+          isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);
+
+          /* The isRequirePhrase variable is set to true if a phrase or
+          ** an expression contained in parenthesis is required. If a
+          ** binary operator (AND, OR, NOT or NEAR) is encounted when
+          ** isRequirePhrase is set, this is a syntax error.
+          */
+          if( !isPhrase && isRequirePhrase ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase && !isRequirePhrase ){
+            /* Insert an implicit AND operator. */
+            Fts3Expr *pAnd;
+            assert( pRet && pPrev );
+            pAnd = fts3MallocZero(sizeof(Fts3Expr));
+            if( !pAnd ){
+              sqlite3Fts3ExprFree(p);
+              rc = SQLITE_NOMEM;
+              goto exprparse_out;
+            }
+            pAnd->eType = FTSQUERY_AND;
+            insertBinaryOperator(&pRet, pPrev, pAnd);
+            pPrev = pAnd;
+          }
+
+          /* This test catches attempts to make either operand of a NEAR
+           ** operator something other than a phrase. For example, either of
+           ** the following:
+           **
+           **    (bracketed expression) NEAR phrase
+           **    phrase NEAR (bracketed expression)
+           **
+           ** Return an error in either case.
+           */
+          if( pPrev && (
+            (eType==FTSQUERY_NEAR && !isPhrase && pPrev->eType!=FTSQUERY_PHRASE)
+         || (eType!=FTSQUERY_PHRASE && isPhrase && pPrev->eType==FTSQUERY_NEAR)
+          )){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase ){
+            if( pRet ){
+              assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );
+              pPrev->pRight = p;
+              p->pParent = pPrev;
+            }else{
+              pRet = p;
+            }
+          }else{
+            insertBinaryOperator(&pRet, pPrev, p);
+          }
+          isRequirePhrase = !isPhrase;
+        }
+        pPrev = p;
+      }
+      assert( nByte>0 );
+    }
+    assert( rc!=SQLITE_OK || (nByte>0 && nByte<=nIn) );
+    nIn -= nByte;
+    zIn += nByte;
+  }
+
+  if( rc==SQLITE_DONE && pRet && isRequirePhrase ){
+    rc = SQLITE_ERROR;
+  }
+
+  if( rc==SQLITE_DONE ){
+    rc = SQLITE_OK;
+    if( !sqlite3_fts3_enable_parentheses && pNotBranch ){
+      if( !pRet ){
+        rc = SQLITE_ERROR;
+      }else{
+        Fts3Expr *pIter = pNotBranch;
+        while( pIter->pLeft ){
+          pIter = pIter->pLeft;
+        }
+        pIter->pLeft = pRet;
+        pRet->pParent = pIter;
+        pRet = pNotBranch;
+      }
+    }
+  }
+  *pnConsumed = n - nIn;
+
+exprparse_out:
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts3ExprFree(pRet);
+    sqlite3Fts3ExprFree(pNotBranch);
+    pRet = 0;
+  }
+  *ppExpr = pRet;
+  return rc;
+}
+
+/*
+** Return SQLITE_ERROR if the maximum depth of the expression tree passed 
+** as the only argument is more than nMaxDepth.
+*/
+static int fts3ExprCheckDepth(Fts3Expr *p, int nMaxDepth){
+  int rc = SQLITE_OK;
+  if( p ){
+    if( nMaxDepth<0 ){ 
+      rc = SQLITE_TOOBIG;
+    }else{
+      rc = fts3ExprCheckDepth(p->pLeft, nMaxDepth-1);
+      if( rc==SQLITE_OK ){
+        rc = fts3ExprCheckDepth(p->pRight, nMaxDepth-1);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** This function attempts to transform the expression tree at (*pp) to
+** an equivalent but more balanced form. The tree is modified in place.
+** If successful, SQLITE_OK is returned and (*pp) set to point to the 
+** new root expression node. 
+**
+** nMaxDepth is the maximum allowable depth of the balanced sub-tree.
+**
+** Otherwise, if an error occurs, an SQLite error code is returned and 
+** expression (*pp) freed.
+*/
+static int fts3ExprBalance(Fts3Expr **pp, int nMaxDepth){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts3Expr *pRoot = *pp;          /* Initial root node */
+  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
+  int eType = pRoot->eType;       /* Type of node in this tree */
+
+  if( nMaxDepth==0 ){
+    rc = SQLITE_ERROR;
+  }
+
+  if( rc==SQLITE_OK ){
+    if( (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
+      Fts3Expr **apLeaf;
+      apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
+      if( 0==apLeaf ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
+      }
+
+      if( rc==SQLITE_OK ){
+        int i;
+        Fts3Expr *p;
+
+        /* Set $p to point to the left-most leaf in the tree of eType nodes. */
+        for(p=pRoot; p->eType==eType; p=p->pLeft){
+          assert( p->pParent==0 || p->pParent->pLeft==p );
+          assert( p->pLeft && p->pRight );
+        }
+
+        /* This loop runs once for each leaf in the tree of eType nodes. */
+        while( 1 ){
+          int iLvl;
+          Fts3Expr *pParent = p->pParent;     /* Current parent of p */
+
+          assert( pParent==0 || pParent->pLeft==p );
+          p->pParent = 0;
+          if( pParent ){
+            pParent->pLeft = 0;
+          }else{
+            pRoot = 0;
+          }
+          rc = fts3ExprBalance(&p, nMaxDepth-1);
+          if( rc!=SQLITE_OK ) break;
+
+          for(iLvl=0; p && iLvlpLeft = apLeaf[iLvl];
+              pFree->pRight = p;
+              pFree->pLeft->pParent = pFree;
+              pFree->pRight->pParent = pFree;
+
+              p = pFree;
+              pFree = pFree->pParent;
+              p->pParent = 0;
+              apLeaf[iLvl] = 0;
+            }
+          }
+          if( p ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_TOOBIG;
+            break;
+          }
+
+          /* If that was the last leaf node, break out of the loop */
+          if( pParent==0 ) break;
+
+          /* Set $p to point to the next leaf in the tree of eType nodes */
+          for(p=pParent->pRight; p->eType==eType; p=p->pLeft);
+
+          /* Remove pParent from the original tree. */
+          assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
+          pParent->pRight->pParent = pParent->pParent;
+          if( pParent->pParent ){
+            pParent->pParent->pLeft = pParent->pRight;
+          }else{
+            assert( pParent==pRoot );
+            pRoot = pParent->pRight;
+          }
+
+          /* Link pParent into the free node list. It will be used as an
+          ** internal node of the new tree.  */
+          pParent->pParent = pFree;
+          pFree = pParent;
+        }
+
+        if( rc==SQLITE_OK ){
+          p = 0;
+          for(i=0; ipParent = 0;
+              }else{
+                assert( pFree!=0 );
+                pFree->pRight = p;
+                pFree->pLeft = apLeaf[i];
+                pFree->pLeft->pParent = pFree;
+                pFree->pRight->pParent = pFree;
+
+                p = pFree;
+                pFree = pFree->pParent;
+                p->pParent = 0;
+              }
+            }
+          }
+          pRoot = p;
+        }else{
+          /* An error occurred. Delete the contents of the apLeaf[] array 
+          ** and pFree list. Everything else is cleaned up by the call to
+          ** sqlite3Fts3ExprFree(pRoot) below.  */
+          Fts3Expr *pDel;
+          for(i=0; ipParent;
+            sqlite3_free(pDel);
+          }
+        }
+
+        assert( pFree==0 );
+        sqlite3_free( apLeaf );
+      }
+    }else if( eType==FTSQUERY_NOT ){
+      Fts3Expr *pLeft = pRoot->pLeft;
+      Fts3Expr *pRight = pRoot->pRight;
+
+      pRoot->pLeft = 0;
+      pRoot->pRight = 0;
+      pLeft->pParent = 0;
+      pRight->pParent = 0;
+
+      rc = fts3ExprBalance(&pLeft, nMaxDepth-1);
+      if( rc==SQLITE_OK ){
+        rc = fts3ExprBalance(&pRight, nMaxDepth-1);
+      }
+
+      if( rc!=SQLITE_OK ){
+        sqlite3Fts3ExprFree(pRight);
+        sqlite3Fts3ExprFree(pLeft);
+      }else{
+        assert( pLeft && pRight );
+        pRoot->pLeft = pLeft;
+        pLeft->pParent = pRoot;
+        pRoot->pRight = pRight;
+        pRight->pParent = pRoot;
+      }
+    }
+  }
+  
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts3ExprFree(pRoot);
+    pRoot = 0;
+  }
+  *pp = pRoot;
+  return rc;
+}
+
+/*
+** This function is similar to sqlite3Fts3ExprParse(), with the following
+** differences:
+**
+**   1. It does not do expression rebalancing.
+**   2. It does not check that the expression does not exceed the 
+**      maximum allowable depth.
+**   3. Even if it fails, *ppExpr may still be set to point to an 
+**      expression tree. It should be deleted using sqlite3Fts3ExprFree()
+**      in this case.
+*/
+static int fts3ExprParseUnbalanced(
+  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
+  int iLangid,                        /* Language id for tokenizer */
+  char **azCol,                       /* Array of column names for fts3 table */
+  int bFts4,                          /* True to allow FTS4-only syntax */
+  int nCol,                           /* Number of entries in azCol[] */
+  int iDefaultCol,                    /* Default column to query */
+  const char *z, int n,               /* Text of MATCH query */
+  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
+){
+  int nParsed;
+  int rc;
+  ParseContext sParse;
+
+  memset(&sParse, 0, sizeof(ParseContext));
+  sParse.pTokenizer = pTokenizer;
+  sParse.iLangid = iLangid;
+  sParse.azCol = (const char **)azCol;
+  sParse.nCol = nCol;
+  sParse.iDefaultCol = iDefaultCol;
+  sParse.bFts4 = bFts4;
+  if( z==0 ){
+    *ppExpr = 0;
+    return SQLITE_OK;
+  }
+  if( n<0 ){
+    n = (int)strlen(z);
+  }
+  rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);
+  assert( rc==SQLITE_OK || *ppExpr==0 );
+
+  /* Check for mismatched parenthesis */
+  if( rc==SQLITE_OK && sParse.nNest ){
+    rc = SQLITE_ERROR;
+  }
+  
+  return rc;
+}
+
+/*
+** Parameters z and n contain a pointer to and length of a buffer containing
+** an fts3 query expression, respectively. This function attempts to parse the
+** query expression and create a tree of Fts3Expr structures representing the
+** parsed expression. If successful, *ppExpr is set to point to the head
+** of the parsed expression tree and SQLITE_OK is returned. If an error
+** occurs, either SQLITE_NOMEM (out-of-memory error) or SQLITE_ERROR (parse
+** error) is returned and *ppExpr is set to 0.
+**
+** If parameter n is a negative number, then z is assumed to point to a
+** nul-terminated string and the length is determined using strlen().
+**
+** The first parameter, pTokenizer, is passed the fts3 tokenizer module to
+** use to normalize query tokens while parsing the expression. The azCol[]
+** array, which is assumed to contain nCol entries, should contain the names
+** of each column in the target fts3 table, in order from left to right. 
+** Column names must be nul-terminated strings.
+**
+** The iDefaultCol parameter should be passed the index of the table column
+** that appears on the left-hand-side of the MATCH operator (the default
+** column to match against for tokens for which a column name is not explicitly
+** specified as part of the query string), or -1 if tokens may by default
+** match any table column.
+*/
+SQLITE_PRIVATE int sqlite3Fts3ExprParse(
+  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
+  int iLangid,                        /* Language id for tokenizer */
+  char **azCol,                       /* Array of column names for fts3 table */
+  int bFts4,                          /* True to allow FTS4-only syntax */
+  int nCol,                           /* Number of entries in azCol[] */
+  int iDefaultCol,                    /* Default column to query */
+  const char *z, int n,               /* Text of MATCH query */
+  Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
+  char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
+){
+  int rc = fts3ExprParseUnbalanced(
+      pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
+  );
+  
+  /* Rebalance the expression. And check that its depth does not exceed
+  ** SQLITE_FTS3_MAX_EXPR_DEPTH.  */
+  if( rc==SQLITE_OK && *ppExpr ){
+    rc = fts3ExprBalance(ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
+    if( rc==SQLITE_OK ){
+      rc = fts3ExprCheckDepth(*ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts3ExprFree(*ppExpr);
+    *ppExpr = 0;
+    if( rc==SQLITE_TOOBIG ){
+      sqlite3Fts3ErrMsg(pzErr,
+          "FTS expression tree is too large (maximum depth %d)", 
+          SQLITE_FTS3_MAX_EXPR_DEPTH
+      );
+      rc = SQLITE_ERROR;
+    }else if( rc==SQLITE_ERROR ){
+      sqlite3Fts3ErrMsg(pzErr, "malformed MATCH expression: [%s]", z);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Free a single node of an expression tree.
+*/
+static void fts3FreeExprNode(Fts3Expr *p){
+  assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
+  sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
+  sqlite3_free(p->aMI);
+  sqlite3_free(p);
+}
+
+/*
+** Free a parsed fts3 query expression allocated by sqlite3Fts3ExprParse().
+**
+** This function would be simpler if it recursively called itself. But
+** that would mean passing a sufficiently large expression to ExprParse()
+** could cause a stack overflow.
+*/
+SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *pDel){
+  Fts3Expr *p;
+  assert( pDel==0 || pDel->pParent==0 );
+  for(p=pDel; p && (p->pLeft||p->pRight); p=(p->pLeft ? p->pLeft : p->pRight)){
+    assert( p->pParent==0 || p==p->pParent->pRight || p==p->pParent->pLeft );
+  }
+  while( p ){
+    Fts3Expr *pParent = p->pParent;
+    fts3FreeExprNode(p);
+    if( pParent && p==pParent->pLeft && pParent->pRight ){
+      p = pParent->pRight;
+      while( p && (p->pLeft || p->pRight) ){
+        assert( p==p->pParent->pRight || p==p->pParent->pLeft );
+        p = (p->pLeft ? p->pLeft : p->pRight);
+      }
+    }else{
+      p = pParent;
+    }
+  }
+}
+
+/****************************************************************************
+*****************************************************************************
+** Everything after this point is just test code.
+*/
+
+#ifdef SQLITE_TEST
+
+/* #include  */
+
+/*
+** Function to query the hash-table of tokenizers (see README.tokenizers).
+*/
+static int queryTestTokenizer(
+  sqlite3 *db, 
+  const char *zName,  
+  const sqlite3_tokenizer_module **pp
+){
+  int rc;
+  sqlite3_stmt *pStmt;
+  const char zSql[] = "SELECT fts3_tokenizer(?)";
+
+  *pp = 0;
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
+      memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
+    }
+  }
+
+  return sqlite3_finalize(pStmt);
+}
+
+/*
+** Return a pointer to a buffer containing a text representation of the
+** expression passed as the first argument. The buffer is obtained from
+** sqlite3_malloc(). It is the responsibility of the caller to use 
+** sqlite3_free() to release the memory. If an OOM condition is encountered,
+** NULL is returned.
+**
+** If the second argument is not NULL, then its contents are prepended to 
+** the returned expression text and then freed using sqlite3_free().
+*/
+static char *exprToString(Fts3Expr *pExpr, char *zBuf){
+  if( pExpr==0 ){
+    return sqlite3_mprintf("");
+  }
+  switch( pExpr->eType ){
+    case FTSQUERY_PHRASE: {
+      Fts3Phrase *pPhrase = pExpr->pPhrase;
+      int i;
+      zBuf = sqlite3_mprintf(
+          "%zPHRASE %d 0", zBuf, pPhrase->iColumn);
+      for(i=0; zBuf && inToken; i++){
+        zBuf = sqlite3_mprintf("%z %.*s%s", zBuf, 
+            pPhrase->aToken[i].n, pPhrase->aToken[i].z,
+            (pPhrase->aToken[i].isPrefix?"+":"")
+        );
+      }
+      return zBuf;
+    }
+
+    case FTSQUERY_NEAR:
+      zBuf = sqlite3_mprintf("%zNEAR/%d ", zBuf, pExpr->nNear);
+      break;
+    case FTSQUERY_NOT:
+      zBuf = sqlite3_mprintf("%zNOT ", zBuf);
+      break;
+    case FTSQUERY_AND:
+      zBuf = sqlite3_mprintf("%zAND ", zBuf);
+      break;
+    case FTSQUERY_OR:
+      zBuf = sqlite3_mprintf("%zOR ", zBuf);
+      break;
+  }
+
+  if( zBuf ) zBuf = sqlite3_mprintf("%z{", zBuf);
+  if( zBuf ) zBuf = exprToString(pExpr->pLeft, zBuf);
+  if( zBuf ) zBuf = sqlite3_mprintf("%z} {", zBuf);
+
+  if( zBuf ) zBuf = exprToString(pExpr->pRight, zBuf);
+  if( zBuf ) zBuf = sqlite3_mprintf("%z}", zBuf);
+
+  return zBuf;
+}
+
+/*
+** This is the implementation of a scalar SQL function used to test the 
+** expression parser. It should be called as follows:
+**
+**   fts3_exprtest(, , , ...);
+**
+** The first argument, , is the name of the fts3 tokenizer used
+** to parse the query expression (see README.tokenizers). The second argument
+** is the query expression to parse. Each subsequent argument is the name
+** of a column of the fts3 table that the query expression may refer to.
+** For example:
+**
+**   SELECT fts3_exprtest('simple', 'Bill col2:Bloggs', 'col1', 'col2');
+*/
+static void fts3ExprTest(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3_tokenizer_module const *pModule = 0;
+  sqlite3_tokenizer *pTokenizer = 0;
+  int rc;
+  char **azCol = 0;
+  const char *zExpr;
+  int nExpr;
+  int nCol;
+  int ii;
+  Fts3Expr *pExpr;
+  char *zBuf = 0;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+
+  if( argc<3 ){
+    sqlite3_result_error(context, 
+        "Usage: fts3_exprtest(tokenizer, expr, col1, ...", -1
+    );
+    return;
+  }
+
+  rc = queryTestTokenizer(db,
+                          (const char *)sqlite3_value_text(argv[0]), &pModule);
+  if( rc==SQLITE_NOMEM ){
+    sqlite3_result_error_nomem(context);
+    goto exprtest_out;
+  }else if( !pModule ){
+    sqlite3_result_error(context, "No such tokenizer module", -1);
+    goto exprtest_out;
+  }
+
+  rc = pModule->xCreate(0, 0, &pTokenizer);
+  assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
+  if( rc==SQLITE_NOMEM ){
+    sqlite3_result_error_nomem(context);
+    goto exprtest_out;
+  }
+  pTokenizer->pModule = pModule;
+
+  zExpr = (const char *)sqlite3_value_text(argv[1]);
+  nExpr = sqlite3_value_bytes(argv[1]);
+  nCol = argc-2;
+  azCol = (char **)sqlite3_malloc(nCol*sizeof(char *));
+  if( !azCol ){
+    sqlite3_result_error_nomem(context);
+    goto exprtest_out;
+  }
+  for(ii=0; iixDestroy(pTokenizer);
+  }
+  sqlite3_free(azCol);
+}
+
+/*
+** Register the query expression parser test function fts3_exprtest() 
+** with database connection db. 
+*/
+SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
+  int rc = sqlite3_create_function(
+      db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
+  );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 
+        -1, SQLITE_UTF8, (void *)1, fts3ExprTest, 0, 0
+    );
+  }
+  return rc;
+}
+
+#endif
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_expr.c *******************************************/
+/************** Begin file fts3_hash.c ***************************************/
+/*
+** 2001 September 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the implementation of generic hash-tables used in SQLite.
+** We've modified it slightly to serve as a standalone hash table
+** implementation for the full-text indexing module.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+**     * The FTS3 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS3 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "fts3_hash.h" */
+
+/*
+** Malloc and Free functions
+*/
+static void *fts3HashMalloc(int n){
+  void *p = sqlite3_malloc(n);
+  if( p ){
+    memset(p, 0, n);
+  }
+  return p;
+}
+static void fts3HashFree(void *p){
+  sqlite3_free(p);
+}
+
+/* Turn bulk memory into a hash table object by initializing the
+** fields of the Hash structure.
+**
+** "pNew" is a pointer to the hash table that is to be initialized.
+** keyClass is one of the constants 
+** FTS3_HASH_BINARY or FTS3_HASH_STRING.  The value of keyClass 
+** determines what kind of key the hash table will use.  "copyKey" is
+** true if the hash table should make its own private copy of keys and
+** false if it should just use the supplied pointer.
+*/
+SQLITE_PRIVATE void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey){
+  assert( pNew!=0 );
+  assert( keyClass>=FTS3_HASH_STRING && keyClass<=FTS3_HASH_BINARY );
+  pNew->keyClass = keyClass;
+  pNew->copyKey = copyKey;
+  pNew->first = 0;
+  pNew->count = 0;
+  pNew->htsize = 0;
+  pNew->ht = 0;
+}
+
+/* Remove all entries from a hash table.  Reclaim all memory.
+** Call this routine to delete a hash table or to reset a hash table
+** to the empty state.
+*/
+SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash *pH){
+  Fts3HashElem *elem;         /* For looping over all elements of the table */
+
+  assert( pH!=0 );
+  elem = pH->first;
+  pH->first = 0;
+  fts3HashFree(pH->ht);
+  pH->ht = 0;
+  pH->htsize = 0;
+  while( elem ){
+    Fts3HashElem *next_elem = elem->next;
+    if( pH->copyKey && elem->pKey ){
+      fts3HashFree(elem->pKey);
+    }
+    fts3HashFree(elem);
+    elem = next_elem;
+  }
+  pH->count = 0;
+}
+
+/*
+** Hash and comparison functions when the mode is FTS3_HASH_STRING
+*/
+static int fts3StrHash(const void *pKey, int nKey){
+  const char *z = (const char *)pKey;
+  unsigned h = 0;
+  if( nKey<=0 ) nKey = (int) strlen(z);
+  while( nKey > 0  ){
+    h = (h<<3) ^ h ^ *z++;
+    nKey--;
+  }
+  return (int)(h & 0x7fffffff);
+}
+static int fts3StrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  if( n1!=n2 ) return 1;
+  return strncmp((const char*)pKey1,(const char*)pKey2,n1);
+}
+
+/*
+** Hash and comparison functions when the mode is FTS3_HASH_BINARY
+*/
+static int fts3BinHash(const void *pKey, int nKey){
+  int h = 0;
+  const char *z = (const char *)pKey;
+  while( nKey-- > 0 ){
+    h = (h<<3) ^ h ^ *(z++);
+  }
+  return h & 0x7fffffff;
+}
+static int fts3BinCompare(const void *pKey1, int n1, const void *pKey2, int n2){
+  if( n1!=n2 ) return 1;
+  return memcmp(pKey1,pKey2,n1);
+}
+
+/*
+** Return a pointer to the appropriate hash function given the key class.
+**
+** The C syntax in this function definition may be unfamilar to some 
+** programmers, so we provide the following additional explanation:
+**
+** The name of the function is "ftsHashFunction".  The function takes a
+** single parameter "keyClass".  The return value of ftsHashFunction()
+** is a pointer to another function.  Specifically, the return value
+** of ftsHashFunction() is a pointer to a function that takes two parameters
+** with types "const void*" and "int" and returns an "int".
+*/
+static int (*ftsHashFunction(int keyClass))(const void*,int){
+  if( keyClass==FTS3_HASH_STRING ){
+    return &fts3StrHash;
+  }else{
+    assert( keyClass==FTS3_HASH_BINARY );
+    return &fts3BinHash;
+  }
+}
+
+/*
+** Return a pointer to the appropriate hash function given the key class.
+**
+** For help in interpreted the obscure C code in the function definition,
+** see the header comment on the previous function.
+*/
+static int (*ftsCompareFunction(int keyClass))(const void*,int,const void*,int){
+  if( keyClass==FTS3_HASH_STRING ){
+    return &fts3StrCompare;
+  }else{
+    assert( keyClass==FTS3_HASH_BINARY );
+    return &fts3BinCompare;
+  }
+}
+
+/* Link an element into the hash table
+*/
+static void fts3HashInsertElement(
+  Fts3Hash *pH,            /* The complete hash table */
+  struct _fts3ht *pEntry,  /* The entry into which pNew is inserted */
+  Fts3HashElem *pNew       /* The element to be inserted */
+){
+  Fts3HashElem *pHead;     /* First element already in pEntry */
+  pHead = pEntry->chain;
+  if( pHead ){
+    pNew->next = pHead;
+    pNew->prev = pHead->prev;
+    if( pHead->prev ){ pHead->prev->next = pNew; }
+    else             { pH->first = pNew; }
+    pHead->prev = pNew;
+  }else{
+    pNew->next = pH->first;
+    if( pH->first ){ pH->first->prev = pNew; }
+    pNew->prev = 0;
+    pH->first = pNew;
+  }
+  pEntry->count++;
+  pEntry->chain = pNew;
+}
+
+
+/* Resize the hash table so that it cantains "new_size" buckets.
+** "new_size" must be a power of 2.  The hash table might fail 
+** to resize if sqliteMalloc() fails.
+**
+** Return non-zero if a memory allocation error occurs.
+*/
+static int fts3Rehash(Fts3Hash *pH, int new_size){
+  struct _fts3ht *new_ht;          /* The new hash table */
+  Fts3HashElem *elem, *next_elem;  /* For looping over existing elements */
+  int (*xHash)(const void*,int);   /* The hash function */
+
+  assert( (new_size & (new_size-1))==0 );
+  new_ht = (struct _fts3ht *)fts3HashMalloc( new_size*sizeof(struct _fts3ht) );
+  if( new_ht==0 ) return 1;
+  fts3HashFree(pH->ht);
+  pH->ht = new_ht;
+  pH->htsize = new_size;
+  xHash = ftsHashFunction(pH->keyClass);
+  for(elem=pH->first, pH->first=0; elem; elem = next_elem){
+    int h = (*xHash)(elem->pKey, elem->nKey) & (new_size-1);
+    next_elem = elem->next;
+    fts3HashInsertElement(pH, &new_ht[h], elem);
+  }
+  return 0;
+}
+
+/* This function (for internal use only) locates an element in an
+** hash table that matches the given key.  The hash for this key has
+** already been computed and is passed as the 4th parameter.
+*/
+static Fts3HashElem *fts3FindElementByHash(
+  const Fts3Hash *pH, /* The pH to be searched */
+  const void *pKey,   /* The key we are searching for */
+  int nKey,
+  int h               /* The hash for this key. */
+){
+  Fts3HashElem *elem;            /* Used to loop thru the element list */
+  int count;                     /* Number of elements left to test */
+  int (*xCompare)(const void*,int,const void*,int);  /* comparison function */
+
+  if( pH->ht ){
+    struct _fts3ht *pEntry = &pH->ht[h];
+    elem = pEntry->chain;
+    count = pEntry->count;
+    xCompare = ftsCompareFunction(pH->keyClass);
+    while( count-- && elem ){
+      if( (*xCompare)(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 
+        return elem;
+      }
+      elem = elem->next;
+    }
+  }
+  return 0;
+}
+
+/* Remove a single entry from the hash table given a pointer to that
+** element and a hash on the element's key.
+*/
+static void fts3RemoveElementByHash(
+  Fts3Hash *pH,         /* The pH containing "elem" */
+  Fts3HashElem* elem,   /* The element to be removed from the pH */
+  int h                 /* Hash value for the element */
+){
+  struct _fts3ht *pEntry;
+  if( elem->prev ){
+    elem->prev->next = elem->next; 
+  }else{
+    pH->first = elem->next;
+  }
+  if( elem->next ){
+    elem->next->prev = elem->prev;
+  }
+  pEntry = &pH->ht[h];
+  if( pEntry->chain==elem ){
+    pEntry->chain = elem->next;
+  }
+  pEntry->count--;
+  if( pEntry->count<=0 ){
+    pEntry->chain = 0;
+  }
+  if( pH->copyKey && elem->pKey ){
+    fts3HashFree(elem->pKey);
+  }
+  fts3HashFree( elem );
+  pH->count--;
+  if( pH->count<=0 ){
+    assert( pH->first==0 );
+    assert( pH->count==0 );
+    fts3HashClear(pH);
+  }
+}
+
+SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(
+  const Fts3Hash *pH, 
+  const void *pKey, 
+  int nKey
+){
+  int h;                          /* A hash on key */
+  int (*xHash)(const void*,int);  /* The hash function */
+
+  if( pH==0 || pH->ht==0 ) return 0;
+  xHash = ftsHashFunction(pH->keyClass);
+  assert( xHash!=0 );
+  h = (*xHash)(pKey,nKey);
+  assert( (pH->htsize & (pH->htsize-1))==0 );
+  return fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1));
+}
+
+/* 
+** Attempt to locate an element of the hash table pH with a key
+** that matches pKey,nKey.  Return the data for this element if it is
+** found, or NULL if there is no match.
+*/
+SQLITE_PRIVATE void *sqlite3Fts3HashFind(const Fts3Hash *pH, const void *pKey, int nKey){
+  Fts3HashElem *pElem;            /* The element that matches key (if any) */
+
+  pElem = sqlite3Fts3HashFindElem(pH, pKey, nKey);
+  return pElem ? pElem->data : 0;
+}
+
+/* Insert an element into the hash table pH.  The key is pKey,nKey
+** and the data is "data".
+**
+** If no element exists with a matching key, then a new
+** element is created.  A copy of the key is made if the copyKey
+** flag is set.  NULL is returned.
+**
+** If another element already exists with the same key, then the
+** new data replaces the old data and the old data is returned.
+** The key is not copied in this instance.  If a malloc fails, then
+** the new data is returned and the hash table is unchanged.
+**
+** If the "data" parameter to this function is NULL, then the
+** element corresponding to "key" is removed from the hash table.
+*/
+SQLITE_PRIVATE void *sqlite3Fts3HashInsert(
+  Fts3Hash *pH,        /* The hash table to insert into */
+  const void *pKey,    /* The key */
+  int nKey,            /* Number of bytes in the key */
+  void *data           /* The data */
+){
+  int hraw;                 /* Raw hash value of the key */
+  int h;                    /* the hash of the key modulo hash table size */
+  Fts3HashElem *elem;       /* Used to loop thru the element list */
+  Fts3HashElem *new_elem;   /* New element added to the pH */
+  int (*xHash)(const void*,int);  /* The hash function */
+
+  assert( pH!=0 );
+  xHash = ftsHashFunction(pH->keyClass);
+  assert( xHash!=0 );
+  hraw = (*xHash)(pKey, nKey);
+  assert( (pH->htsize & (pH->htsize-1))==0 );
+  h = hraw & (pH->htsize-1);
+  elem = fts3FindElementByHash(pH,pKey,nKey,h);
+  if( elem ){
+    void *old_data = elem->data;
+    if( data==0 ){
+      fts3RemoveElementByHash(pH,elem,h);
+    }else{
+      elem->data = data;
+    }
+    return old_data;
+  }
+  if( data==0 ) return 0;
+  if( (pH->htsize==0 && fts3Rehash(pH,8))
+   || (pH->count>=pH->htsize && fts3Rehash(pH, pH->htsize*2))
+  ){
+    pH->count = 0;
+    return data;
+  }
+  assert( pH->htsize>0 );
+  new_elem = (Fts3HashElem*)fts3HashMalloc( sizeof(Fts3HashElem) );
+  if( new_elem==0 ) return data;
+  if( pH->copyKey && pKey!=0 ){
+    new_elem->pKey = fts3HashMalloc( nKey );
+    if( new_elem->pKey==0 ){
+      fts3HashFree(new_elem);
+      return data;
+    }
+    memcpy((void*)new_elem->pKey, pKey, nKey);
+  }else{
+    new_elem->pKey = (void*)pKey;
+  }
+  new_elem->nKey = nKey;
+  pH->count++;
+  assert( pH->htsize>0 );
+  assert( (pH->htsize & (pH->htsize-1))==0 );
+  h = hraw & (pH->htsize-1);
+  fts3HashInsertElement(pH, &pH->ht[h], new_elem);
+  new_elem->data = data;
+  return 0;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_hash.c *******************************************/
+/************** Begin file fts3_porter.c *************************************/
+/*
+** 2006 September 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Implementation of the full-text-search tokenizer that implements
+** a Porter stemmer.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+**     * The FTS3 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS3 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "fts3_tokenizer.h" */
+
+/*
+** Class derived from sqlite3_tokenizer
+*/
+typedef struct porter_tokenizer {
+  sqlite3_tokenizer base;      /* Base class */
+} porter_tokenizer;
+
+/*
+** Class derived from sqlite3_tokenizer_cursor
+*/
+typedef struct porter_tokenizer_cursor {
+  sqlite3_tokenizer_cursor base;
+  const char *zInput;          /* input we are tokenizing */
+  int nInput;                  /* size of the input */
+  int iOffset;                 /* current position in zInput */
+  int iToken;                  /* index of next token to be returned */
+  char *zToken;                /* storage for current token */
+  int nAllocated;              /* space allocated to zToken buffer */
+} porter_tokenizer_cursor;
+
+
+/*
+** Create a new tokenizer instance.
+*/
+static int porterCreate(
+  int argc, const char * const *argv,
+  sqlite3_tokenizer **ppTokenizer
+){
+  porter_tokenizer *t;
+
+  UNUSED_PARAMETER(argc);
+  UNUSED_PARAMETER(argv);
+
+  t = (porter_tokenizer *) sqlite3_malloc(sizeof(*t));
+  if( t==NULL ) return SQLITE_NOMEM;
+  memset(t, 0, sizeof(*t));
+  *ppTokenizer = &t->base;
+  return SQLITE_OK;
+}
+
+/*
+** Destroy a tokenizer
+*/
+static int porterDestroy(sqlite3_tokenizer *pTokenizer){
+  sqlite3_free(pTokenizer);
+  return SQLITE_OK;
+}
+
+/*
+** Prepare to begin tokenizing a particular string.  The input
+** string to be tokenized is zInput[0..nInput-1].  A cursor
+** used to incrementally tokenize this string is returned in 
+** *ppCursor.
+*/
+static int porterOpen(
+  sqlite3_tokenizer *pTokenizer,         /* The tokenizer */
+  const char *zInput, int nInput,        /* String to be tokenized */
+  sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */
+){
+  porter_tokenizer_cursor *c;
+
+  UNUSED_PARAMETER(pTokenizer);
+
+  c = (porter_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));
+  if( c==NULL ) return SQLITE_NOMEM;
+
+  c->zInput = zInput;
+  if( zInput==0 ){
+    c->nInput = 0;
+  }else if( nInput<0 ){
+    c->nInput = (int)strlen(zInput);
+  }else{
+    c->nInput = nInput;
+  }
+  c->iOffset = 0;                 /* start tokenizing at the beginning */
+  c->iToken = 0;
+  c->zToken = NULL;               /* no space allocated, yet. */
+  c->nAllocated = 0;
+
+  *ppCursor = &c->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a tokenization cursor previously opened by a call to
+** porterOpen() above.
+*/
+static int porterClose(sqlite3_tokenizer_cursor *pCursor){
+  porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;
+  sqlite3_free(c->zToken);
+  sqlite3_free(c);
+  return SQLITE_OK;
+}
+/*
+** Vowel or consonant
+*/
+static const char cType[] = {
+   0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0,
+   1, 1, 1, 2, 1
+};
+
+/*
+** isConsonant() and isVowel() determine if their first character in
+** the string they point to is a consonant or a vowel, according
+** to Porter ruls.  
+**
+** A consonate is any letter other than 'a', 'e', 'i', 'o', or 'u'.
+** 'Y' is a consonant unless it follows another consonant,
+** in which case it is a vowel.
+**
+** In these routine, the letters are in reverse order.  So the 'y' rule
+** is that 'y' is a consonant unless it is followed by another
+** consonent.
+*/
+static int isVowel(const char*);
+static int isConsonant(const char *z){
+  int j;
+  char x = *z;
+  if( x==0 ) return 0;
+  assert( x>='a' && x<='z' );
+  j = cType[x-'a'];
+  if( j<2 ) return j;
+  return z[1]==0 || isVowel(z + 1);
+}
+static int isVowel(const char *z){
+  int j;
+  char x = *z;
+  if( x==0 ) return 0;
+  assert( x>='a' && x<='z' );
+  j = cType[x-'a'];
+  if( j<2 ) return 1-j;
+  return isConsonant(z + 1);
+}
+
+/*
+** Let any sequence of one or more vowels be represented by V and let
+** C be sequence of one or more consonants.  Then every word can be
+** represented as:
+**
+**           [C] (VC){m} [V]
+**
+** In prose:  A word is an optional consonant followed by zero or
+** vowel-consonant pairs followed by an optional vowel.  "m" is the
+** number of vowel consonant pairs.  This routine computes the value
+** of m for the first i bytes of a word.
+**
+** Return true if the m-value for z is 1 or more.  In other words,
+** return true if z contains at least one vowel that is followed
+** by a consonant.
+**
+** In this routine z[] is in reverse order.  So we are really looking
+** for an instance of a consonant followed by a vowel.
+*/
+static int m_gt_0(const char *z){
+  while( isVowel(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isConsonant(z) ){ z++; }
+  return *z!=0;
+}
+
+/* Like mgt0 above except we are looking for a value of m which is
+** exactly 1
+*/
+static int m_eq_1(const char *z){
+  while( isVowel(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isConsonant(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isVowel(z) ){ z++; }
+  if( *z==0 ) return 1;
+  while( isConsonant(z) ){ z++; }
+  return *z==0;
+}
+
+/* Like mgt0 above except we are looking for a value of m>1 instead
+** or m>0
+*/
+static int m_gt_1(const char *z){
+  while( isVowel(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isConsonant(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isVowel(z) ){ z++; }
+  if( *z==0 ) return 0;
+  while( isConsonant(z) ){ z++; }
+  return *z!=0;
+}
+
+/*
+** Return TRUE if there is a vowel anywhere within z[0..n-1]
+*/
+static int hasVowel(const char *z){
+  while( isConsonant(z) ){ z++; }
+  return *z!=0;
+}
+
+/*
+** Return TRUE if the word ends in a double consonant.
+**
+** The text is reversed here. So we are really looking at
+** the first two characters of z[].
+*/
+static int doubleConsonant(const char *z){
+  return isConsonant(z) && z[0]==z[1];
+}
+
+/*
+** Return TRUE if the word ends with three letters which
+** are consonant-vowel-consonent and where the final consonant
+** is not 'w', 'x', or 'y'.
+**
+** The word is reversed here.  So we are really checking the
+** first three letters and the first one cannot be in [wxy].
+*/
+static int star_oh(const char *z){
+  return
+    isConsonant(z) &&
+    z[0]!='w' && z[0]!='x' && z[0]!='y' &&
+    isVowel(z+1) &&
+    isConsonant(z+2);
+}
+
+/*
+** If the word ends with zFrom and xCond() is true for the stem
+** of the word that preceeds the zFrom ending, then change the 
+** ending to zTo.
+**
+** The input word *pz and zFrom are both in reverse order.  zTo
+** is in normal order. 
+**
+** Return TRUE if zFrom matches.  Return FALSE if zFrom does not
+** match.  Not that TRUE is returned even if xCond() fails and
+** no substitution occurs.
+*/
+static int stem(
+  char **pz,             /* The word being stemmed (Reversed) */
+  const char *zFrom,     /* If the ending matches this... (Reversed) */
+  const char *zTo,       /* ... change the ending to this (not reversed) */
+  int (*xCond)(const char*)   /* Condition that must be true */
+){
+  char *z = *pz;
+  while( *zFrom && *zFrom==*z ){ z++; zFrom++; }
+  if( *zFrom!=0 ) return 0;
+  if( xCond && !xCond(z) ) return 1;
+  while( *zTo ){
+    *(--z) = *(zTo++);
+  }
+  *pz = z;
+  return 1;
+}
+
+/*
+** This is the fallback stemmer used when the porter stemmer is
+** inappropriate.  The input word is copied into the output with
+** US-ASCII case folding.  If the input word is too long (more
+** than 20 bytes if it contains no digits or more than 6 bytes if
+** it contains digits) then word is truncated to 20 or 6 bytes
+** by taking 10 or 3 bytes from the beginning and end.
+*/
+static void copy_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
+  int i, mx, j;
+  int hasDigit = 0;
+  for(i=0; i='A' && c<='Z' ){
+      zOut[i] = c - 'A' + 'a';
+    }else{
+      if( c>='0' && c<='9' ) hasDigit = 1;
+      zOut[i] = c;
+    }
+  }
+  mx = hasDigit ? 3 : 10;
+  if( nIn>mx*2 ){
+    for(j=mx, i=nIn-mx; i=(int)sizeof(zReverse)-7 ){
+    /* The word is too big or too small for the porter stemmer.
+    ** Fallback to the copy stemmer */
+    copy_stemmer(zIn, nIn, zOut, pnOut);
+    return;
+  }
+  for(i=0, j=sizeof(zReverse)-6; i='A' && c<='Z' ){
+      zReverse[j] = c + 'a' - 'A';
+    }else if( c>='a' && c<='z' ){
+      zReverse[j] = c;
+    }else{
+      /* The use of a character not in [a-zA-Z] means that we fallback
+      ** to the copy stemmer */
+      copy_stemmer(zIn, nIn, zOut, pnOut);
+      return;
+    }
+  }
+  memset(&zReverse[sizeof(zReverse)-5], 0, 5);
+  z = &zReverse[j+1];
+
+
+  /* Step 1a */
+  if( z[0]=='s' ){
+    if(
+     !stem(&z, "sess", "ss", 0) &&
+     !stem(&z, "sei", "i", 0)  &&
+     !stem(&z, "ss", "ss", 0)
+    ){
+      z++;
+    }
+  }
+
+  /* Step 1b */  
+  z2 = z;
+  if( stem(&z, "dee", "ee", m_gt_0) ){
+    /* Do nothing.  The work was all in the test */
+  }else if( 
+     (stem(&z, "gni", "", hasVowel) || stem(&z, "de", "", hasVowel))
+      && z!=z2
+  ){
+     if( stem(&z, "ta", "ate", 0) ||
+         stem(&z, "lb", "ble", 0) ||
+         stem(&z, "zi", "ize", 0) ){
+       /* Do nothing.  The work was all in the test */
+     }else if( doubleConsonant(z) && (*z!='l' && *z!='s' && *z!='z') ){
+       z++;
+     }else if( m_eq_1(z) && star_oh(z) ){
+       *(--z) = 'e';
+     }
+  }
+
+  /* Step 1c */
+  if( z[0]=='y' && hasVowel(z+1) ){
+    z[0] = 'i';
+  }
+
+  /* Step 2 */
+  switch( z[1] ){
+   case 'a':
+     if( !stem(&z, "lanoita", "ate", m_gt_0) ){
+       stem(&z, "lanoit", "tion", m_gt_0);
+     }
+     break;
+   case 'c':
+     if( !stem(&z, "icne", "ence", m_gt_0) ){
+       stem(&z, "icna", "ance", m_gt_0);
+     }
+     break;
+   case 'e':
+     stem(&z, "rezi", "ize", m_gt_0);
+     break;
+   case 'g':
+     stem(&z, "igol", "log", m_gt_0);
+     break;
+   case 'l':
+     if( !stem(&z, "ilb", "ble", m_gt_0) 
+      && !stem(&z, "illa", "al", m_gt_0)
+      && !stem(&z, "iltne", "ent", m_gt_0)
+      && !stem(&z, "ile", "e", m_gt_0)
+     ){
+       stem(&z, "ilsuo", "ous", m_gt_0);
+     }
+     break;
+   case 'o':
+     if( !stem(&z, "noitazi", "ize", m_gt_0)
+      && !stem(&z, "noita", "ate", m_gt_0)
+     ){
+       stem(&z, "rota", "ate", m_gt_0);
+     }
+     break;
+   case 's':
+     if( !stem(&z, "msila", "al", m_gt_0)
+      && !stem(&z, "ssenevi", "ive", m_gt_0)
+      && !stem(&z, "ssenluf", "ful", m_gt_0)
+     ){
+       stem(&z, "ssensuo", "ous", m_gt_0);
+     }
+     break;
+   case 't':
+     if( !stem(&z, "itila", "al", m_gt_0)
+      && !stem(&z, "itivi", "ive", m_gt_0)
+     ){
+       stem(&z, "itilib", "ble", m_gt_0);
+     }
+     break;
+  }
+
+  /* Step 3 */
+  switch( z[0] ){
+   case 'e':
+     if( !stem(&z, "etaci", "ic", m_gt_0)
+      && !stem(&z, "evita", "", m_gt_0)
+     ){
+       stem(&z, "ezila", "al", m_gt_0);
+     }
+     break;
+   case 'i':
+     stem(&z, "itici", "ic", m_gt_0);
+     break;
+   case 'l':
+     if( !stem(&z, "laci", "ic", m_gt_0) ){
+       stem(&z, "luf", "", m_gt_0);
+     }
+     break;
+   case 's':
+     stem(&z, "ssen", "", m_gt_0);
+     break;
+  }
+
+  /* Step 4 */
+  switch( z[1] ){
+   case 'a':
+     if( z[0]=='l' && m_gt_1(z+2) ){
+       z += 2;
+     }
+     break;
+   case 'c':
+     if( z[0]=='e' && z[2]=='n' && (z[3]=='a' || z[3]=='e')  && m_gt_1(z+4)  ){
+       z += 4;
+     }
+     break;
+   case 'e':
+     if( z[0]=='r' && m_gt_1(z+2) ){
+       z += 2;
+     }
+     break;
+   case 'i':
+     if( z[0]=='c' && m_gt_1(z+2) ){
+       z += 2;
+     }
+     break;
+   case 'l':
+     if( z[0]=='e' && z[2]=='b' && (z[3]=='a' || z[3]=='i') && m_gt_1(z+4) ){
+       z += 4;
+     }
+     break;
+   case 'n':
+     if( z[0]=='t' ){
+       if( z[2]=='a' ){
+         if( m_gt_1(z+3) ){
+           z += 3;
+         }
+       }else if( z[2]=='e' ){
+         if( !stem(&z, "tneme", "", m_gt_1)
+          && !stem(&z, "tnem", "", m_gt_1)
+         ){
+           stem(&z, "tne", "", m_gt_1);
+         }
+       }
+     }
+     break;
+   case 'o':
+     if( z[0]=='u' ){
+       if( m_gt_1(z+2) ){
+         z += 2;
+       }
+     }else if( z[3]=='s' || z[3]=='t' ){
+       stem(&z, "noi", "", m_gt_1);
+     }
+     break;
+   case 's':
+     if( z[0]=='m' && z[2]=='i' && m_gt_1(z+3) ){
+       z += 3;
+     }
+     break;
+   case 't':
+     if( !stem(&z, "eta", "", m_gt_1) ){
+       stem(&z, "iti", "", m_gt_1);
+     }
+     break;
+   case 'u':
+     if( z[0]=='s' && z[2]=='o' && m_gt_1(z+3) ){
+       z += 3;
+     }
+     break;
+   case 'v':
+   case 'z':
+     if( z[0]=='e' && z[2]=='i' && m_gt_1(z+3) ){
+       z += 3;
+     }
+     break;
+  }
+
+  /* Step 5a */
+  if( z[0]=='e' ){
+    if( m_gt_1(z+1) ){
+      z++;
+    }else if( m_eq_1(z+1) && !star_oh(z+1) ){
+      z++;
+    }
+  }
+
+  /* Step 5b */
+  if( m_gt_1(z) && z[0]=='l' && z[1]=='l' ){
+    z++;
+  }
+
+  /* z[] is now the stemmed word in reverse order.  Flip it back
+  ** around into forward order and return.
+  */
+  *pnOut = i = (int)strlen(z);
+  zOut[i] = 0;
+  while( *z ){
+    zOut[--i] = *(z++);
+  }
+}
+
+/*
+** Characters that can be part of a token.  We assume any character
+** whose value is greater than 0x80 (any UTF character) can be
+** part of a token.  In other words, delimiters all must have
+** values of 0x7f or lower.
+*/
+static const char porterIdChar[] = {
+/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 6x */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,  /* 7x */
+};
+#define isDelim(C) (((ch=C)&0x80)==0 && (ch<0x30 || !porterIdChar[ch-0x30]))
+
+/*
+** Extract the next token from a tokenization cursor.  The cursor must
+** have been opened by a prior call to porterOpen().
+*/
+static int porterNext(
+  sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by porterOpen */
+  const char **pzToken,               /* OUT: *pzToken is the token text */
+  int *pnBytes,                       /* OUT: Number of bytes in token */
+  int *piStartOffset,                 /* OUT: Starting offset of token */
+  int *piEndOffset,                   /* OUT: Ending offset of token */
+  int *piPosition                     /* OUT: Position integer of token */
+){
+  porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;
+  const char *z = c->zInput;
+
+  while( c->iOffsetnInput ){
+    int iStartOffset, ch;
+
+    /* Scan past delimiter characters */
+    while( c->iOffsetnInput && isDelim(z[c->iOffset]) ){
+      c->iOffset++;
+    }
+
+    /* Count non-delimiter characters. */
+    iStartOffset = c->iOffset;
+    while( c->iOffsetnInput && !isDelim(z[c->iOffset]) ){
+      c->iOffset++;
+    }
+
+    if( c->iOffset>iStartOffset ){
+      int n = c->iOffset-iStartOffset;
+      if( n>c->nAllocated ){
+        char *pNew;
+        c->nAllocated = n+20;
+        pNew = sqlite3_realloc(c->zToken, c->nAllocated);
+        if( !pNew ) return SQLITE_NOMEM;
+        c->zToken = pNew;
+      }
+      porter_stemmer(&z[iStartOffset], n, c->zToken, pnBytes);
+      *pzToken = c->zToken;
+      *piStartOffset = iStartOffset;
+      *piEndOffset = c->iOffset;
+      *piPosition = c->iToken++;
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_DONE;
+}
+
+/*
+** The set of routines that implement the porter-stemmer tokenizer
+*/
+static const sqlite3_tokenizer_module porterTokenizerModule = {
+  0,
+  porterCreate,
+  porterDestroy,
+  porterOpen,
+  porterClose,
+  porterNext,
+  0
+};
+
+/*
+** Allocate a new porter tokenizer.  Return a pointer to the new
+** tokenizer in *ppModule
+*/
+SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(
+  sqlite3_tokenizer_module const**ppModule
+){
+  *ppModule = &porterTokenizerModule;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_porter.c *****************************************/
+/************** Begin file fts3_tokenizer.c **********************************/
+/*
+** 2007 June 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is part of an SQLite module implementing full-text search.
+** This particular file implements the generic tokenizer interface.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+**     * The FTS3 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS3 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+
+/*
+** Return true if the two-argument version of fts3_tokenizer()
+** has been activated via a prior call to sqlite3_db_config(db,
+** SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);
+*/
+static int fts3TokenizerEnabled(sqlite3_context *context){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int isEnabled = 0;
+  sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled);
+  return isEnabled;
+}
+
+/*
+** Implementation of the SQL scalar function for accessing the underlying 
+** hash table. This function may be called as follows:
+**
+**   SELECT ();
+**   SELECT (, );
+**
+** where  is the name passed as the second argument
+** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer').
+**
+** If the  argument is specified, it must be a blob value
+** containing a pointer to be stored as the hash data corresponding
+** to the string . If  is not specified, then
+** the string  must already exist in the has table. Otherwise,
+** an error is returned.
+**
+** Whether or not the  argument is specified, the value returned
+** is a blob containing the pointer stored as the hash data corresponding
+** to string  (after the hash-table is updated, if applicable).
+*/
+static void fts3TokenizerFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Fts3Hash *pHash;
+  void *pPtr = 0;
+  const unsigned char *zName;
+  int nName;
+
+  assert( argc==1 || argc==2 );
+
+  pHash = (Fts3Hash *)sqlite3_user_data(context);
+
+  zName = sqlite3_value_text(argv[0]);
+  nName = sqlite3_value_bytes(argv[0])+1;
+
+  if( argc==2 ){
+    if( fts3TokenizerEnabled(context) ){
+      void *pOld;
+      int n = sqlite3_value_bytes(argv[1]);
+      if( zName==0 || n!=sizeof(pPtr) ){
+        sqlite3_result_error(context, "argument type mismatch", -1);
+        return;
+      }
+      pPtr = *(void **)sqlite3_value_blob(argv[1]);
+      pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
+      if( pOld==pPtr ){
+        sqlite3_result_error(context, "out of memory", -1);
+      }
+    }else{
+      sqlite3_result_error(context, "fts3tokenize disabled", -1);
+      return;
+    }
+  }else{
+    if( zName ){
+      pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
+    }
+    if( !pPtr ){
+      char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
+      sqlite3_result_error(context, zErr, -1);
+      sqlite3_free(zErr);
+      return;
+    }
+  }
+  sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
+}
+
+SQLITE_PRIVATE int sqlite3Fts3IsIdChar(char c){
+  static const char isFtsIdChar[] = {
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 0x */
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 1x */
+      0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 2x */
+      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */
+      0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */
+      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */
+      0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 6x */
+      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,  /* 7x */
+  };
+  return (c&0x80 || isFtsIdChar[(int)(c)]);
+}
+
+SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *zStr, int *pn){
+  const char *z1;
+  const char *z2 = 0;
+
+  /* Find the start of the next token. */
+  z1 = zStr;
+  while( z2==0 ){
+    char c = *z1;
+    switch( c ){
+      case '\0': return 0;        /* No more tokens here */
+      case '\'':
+      case '"':
+      case '`': {
+        z2 = z1;
+        while( *++z2 && (*z2!=c || *++z2==c) );
+        break;
+      }
+      case '[':
+        z2 = &z1[1];
+        while( *z2 && z2[0]!=']' ) z2++;
+        if( *z2 ) z2++;
+        break;
+
+      default:
+        if( sqlite3Fts3IsIdChar(*z1) ){
+          z2 = &z1[1];
+          while( sqlite3Fts3IsIdChar(*z2) ) z2++;
+        }else{
+          z1++;
+        }
+    }
+  }
+
+  *pn = (int)(z2-z1);
+  return z1;
+}
+
+SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(
+  Fts3Hash *pHash,                /* Tokenizer hash table */
+  const char *zArg,               /* Tokenizer name */
+  sqlite3_tokenizer **ppTok,      /* OUT: Tokenizer (if applicable) */
+  char **pzErr                    /* OUT: Set to malloced error message */
+){
+  int rc;
+  char *z = (char *)zArg;
+  int n = 0;
+  char *zCopy;
+  char *zEnd;                     /* Pointer to nul-term of zCopy */
+  sqlite3_tokenizer_module *m;
+
+  zCopy = sqlite3_mprintf("%s", zArg);
+  if( !zCopy ) return SQLITE_NOMEM;
+  zEnd = &zCopy[strlen(zCopy)];
+
+  z = (char *)sqlite3Fts3NextToken(zCopy, &n);
+  if( z==0 ){
+    assert( n==0 );
+    z = zCopy;
+  }
+  z[n] = '\0';
+  sqlite3Fts3Dequote(z);
+
+  m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);
+  if( !m ){
+    sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", z);
+    rc = SQLITE_ERROR;
+  }else{
+    char const **aArg = 0;
+    int iArg = 0;
+    z = &z[n+1];
+    while( zxCreate(iArg, aArg, ppTok);
+    assert( rc!=SQLITE_OK || *ppTok );
+    if( rc!=SQLITE_OK ){
+      sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer");
+    }else{
+      (*ppTok)->pModule = m; 
+    }
+    sqlite3_free((void *)aArg);
+  }
+
+  sqlite3_free(zCopy);
+  return rc;
+}
+
+
+#ifdef SQLITE_TEST
+
+#if defined(INCLUDE_SQLITE_TCL_H)
+#  include "sqlite_tcl.h"
+#else
+#  include "tcl.h"
+#endif
+/* #include  */
+
+/*
+** Implementation of a special SQL scalar function for testing tokenizers 
+** designed to be used in concert with the Tcl testing framework. This
+** function must be called with two or more arguments:
+**
+**   SELECT (, ..., );
+**
+** where  is the name passed as the second argument
+** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer')
+** concatenated with the string '_test' (e.g. 'fts3_tokenizer_test').
+**
+** The return value is a string that may be interpreted as a Tcl
+** list. For each token in the , three elements are
+** added to the returned list. The first is the token position, the 
+** second is the token text (folded, stemmed, etc.) and the third is the
+** substring of  associated with the token. For example, 
+** using the built-in "simple" tokenizer:
+**
+**   SELECT fts_tokenizer_test('simple', 'I don't see how');
+**
+** will return the string:
+**
+**   "{0 i I 1 dont don't 2 see see 3 how how}"
+**   
+*/
+static void testFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Fts3Hash *pHash;
+  sqlite3_tokenizer_module *p;
+  sqlite3_tokenizer *pTokenizer = 0;
+  sqlite3_tokenizer_cursor *pCsr = 0;
+
+  const char *zErr = 0;
+
+  const char *zName;
+  int nName;
+  const char *zInput;
+  int nInput;
+
+  const char *azArg[64];
+
+  const char *zToken;
+  int nToken = 0;
+  int iStart = 0;
+  int iEnd = 0;
+  int iPos = 0;
+  int i;
+
+  Tcl_Obj *pRet;
+
+  if( argc<2 ){
+    sqlite3_result_error(context, "insufficient arguments", -1);
+    return;
+  }
+
+  nName = sqlite3_value_bytes(argv[0]);
+  zName = (const char *)sqlite3_value_text(argv[0]);
+  nInput = sqlite3_value_bytes(argv[argc-1]);
+  zInput = (const char *)sqlite3_value_text(argv[argc-1]);
+
+  pHash = (Fts3Hash *)sqlite3_user_data(context);
+  p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
+
+  if( !p ){
+    char *zErr2 = sqlite3_mprintf("unknown tokenizer: %s", zName);
+    sqlite3_result_error(context, zErr2, -1);
+    sqlite3_free(zErr2);
+    return;
+  }
+
+  pRet = Tcl_NewObj();
+  Tcl_IncrRefCount(pRet);
+
+  for(i=1; ixCreate(argc-2, azArg, &pTokenizer) ){
+    zErr = "error in xCreate()";
+    goto finish;
+  }
+  pTokenizer->pModule = p;
+  if( sqlite3Fts3OpenTokenizer(pTokenizer, 0, zInput, nInput, &pCsr) ){
+    zErr = "error in xOpen()";
+    goto finish;
+  }
+
+  while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){
+    Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos));
+    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));
+    zToken = &zInput[iStart];
+    nToken = iEnd-iStart;
+    Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));
+  }
+
+  if( SQLITE_OK!=p->xClose(pCsr) ){
+    zErr = "error in xClose()";
+    goto finish;
+  }
+  if( SQLITE_OK!=p->xDestroy(pTokenizer) ){
+    zErr = "error in xDestroy()";
+    goto finish;
+  }
+
+finish:
+  if( zErr ){
+    sqlite3_result_error(context, zErr, -1);
+  }else{
+    sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
+  }
+  Tcl_DecrRefCount(pRet);
+}
+
+static
+int registerTokenizer(
+  sqlite3 *db, 
+  char *zName, 
+  const sqlite3_tokenizer_module *p
+){
+  int rc;
+  sqlite3_stmt *pStmt;
+  const char zSql[] = "SELECT fts3_tokenizer(?, ?)";
+
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
+  sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC);
+  sqlite3_step(pStmt);
+
+  return sqlite3_finalize(pStmt);
+}
+
+
+static
+int queryTokenizer(
+  sqlite3 *db, 
+  char *zName,  
+  const sqlite3_tokenizer_module **pp
+){
+  int rc;
+  sqlite3_stmt *pStmt;
+  const char zSql[] = "SELECT fts3_tokenizer(?)";
+
+  *pp = 0;
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){
+      memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
+    }
+  }
+
+  return sqlite3_finalize(pStmt);
+}
+
+SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+
+/*
+** Implementation of the scalar function fts3_tokenizer_internal_test().
+** This function is used for testing only, it is not included in the
+** build unless SQLITE_TEST is defined.
+**
+** The purpose of this is to test that the fts3_tokenizer() function
+** can be used as designed by the C-code in the queryTokenizer and
+** registerTokenizer() functions above. These two functions are repeated
+** in the README.tokenizer file as an example, so it is important to
+** test them.
+**
+** To run the tests, evaluate the fts3_tokenizer_internal_test() scalar
+** function with no arguments. An assert() will fail if a problem is
+** detected. i.e.:
+**
+**     SELECT fts3_tokenizer_internal_test();
+**
+*/
+static void intTestFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int rc;
+  const sqlite3_tokenizer_module *p1;
+  const sqlite3_tokenizer_module *p2;
+  sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);
+
+  UNUSED_PARAMETER(argc);
+  UNUSED_PARAMETER(argv);
+
+  /* Test the query function */
+  sqlite3Fts3SimpleTokenizerModule(&p1);
+  rc = queryTokenizer(db, "simple", &p2);
+  assert( rc==SQLITE_OK );
+  assert( p1==p2 );
+  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
+  assert( rc==SQLITE_ERROR );
+  assert( p2==0 );
+  assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );
+
+  /* Test the storage function */
+  if( fts3TokenizerEnabled(context) ){
+    rc = registerTokenizer(db, "nosuchtokenizer", p1);
+    assert( rc==SQLITE_OK );
+    rc = queryTokenizer(db, "nosuchtokenizer", &p2);
+    assert( rc==SQLITE_OK );
+    assert( p2==p1 );
+  }
+
+  sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
+}
+
+#endif
+
+/*
+** Set up SQL objects in database db used to access the contents of
+** the hash table pointed to by argument pHash. The hash table must
+** been initialized to use string keys, and to take a private copy 
+** of the key when a value is inserted. i.e. by a call similar to:
+**
+**    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
+**
+** This function adds a scalar function (see header comment above
+** fts3TokenizerFunc() in this file for details) and, if ENABLE_TABLE is
+** defined at compilation time, a temporary virtual table (see header 
+** comment above struct HashTableVtab) to the database schema. Both 
+** provide read/write access to the contents of *pHash.
+**
+** The third argument to this function, zName, is used as the name
+** of both the scalar and, if created, the virtual table.
+*/
+SQLITE_PRIVATE int sqlite3Fts3InitHashTable(
+  sqlite3 *db, 
+  Fts3Hash *pHash, 
+  const char *zName
+){
+  int rc = SQLITE_OK;
+  void *p = (void *)pHash;
+  const int any = SQLITE_ANY;
+
+#ifdef SQLITE_TEST
+  char *zTest = 0;
+  char *zTest2 = 0;
+  void *pdb = (void *)db;
+  zTest = sqlite3_mprintf("%s_test", zName);
+  zTest2 = sqlite3_mprintf("%s_internal_test", zName);
+  if( !zTest || !zTest2 ){
+    rc = SQLITE_NOMEM;
+  }
+#endif
+
+  if( SQLITE_OK==rc ){
+    rc = sqlite3_create_function(db, zName, 1, any, p, fts3TokenizerFunc, 0, 0);
+  }
+  if( SQLITE_OK==rc ){
+    rc = sqlite3_create_function(db, zName, 2, any, p, fts3TokenizerFunc, 0, 0);
+  }
+#ifdef SQLITE_TEST
+  if( SQLITE_OK==rc ){
+    rc = sqlite3_create_function(db, zTest, -1, any, p, testFunc, 0, 0);
+  }
+  if( SQLITE_OK==rc ){
+    rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0);
+  }
+#endif
+
+#ifdef SQLITE_TEST
+  sqlite3_free(zTest);
+  sqlite3_free(zTest2);
+#endif
+
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_tokenizer.c **************************************/
+/************** Begin file fts3_tokenizer1.c *********************************/
+/*
+** 2006 Oct 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Implementation of the "simple" full-text-search tokenizer.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+**     * The FTS3 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS3 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "fts3_tokenizer.h" */
+
+typedef struct simple_tokenizer {
+  sqlite3_tokenizer base;
+  char delim[128];             /* flag ASCII delimiters */
+} simple_tokenizer;
+
+typedef struct simple_tokenizer_cursor {
+  sqlite3_tokenizer_cursor base;
+  const char *pInput;          /* input we are tokenizing */
+  int nBytes;                  /* size of the input */
+  int iOffset;                 /* current position in pInput */
+  int iToken;                  /* index of next token to be returned */
+  char *pToken;                /* storage for current token */
+  int nTokenAllocated;         /* space allocated to zToken buffer */
+} simple_tokenizer_cursor;
+
+
+static int simpleDelim(simple_tokenizer *t, unsigned char c){
+  return c<0x80 && t->delim[c];
+}
+static int fts3_isalnum(int x){
+  return (x>='0' && x<='9') || (x>='A' && x<='Z') || (x>='a' && x<='z');
+}
+
+/*
+** Create a new tokenizer instance.
+*/
+static int simpleCreate(
+  int argc, const char * const *argv,
+  sqlite3_tokenizer **ppTokenizer
+){
+  simple_tokenizer *t;
+
+  t = (simple_tokenizer *) sqlite3_malloc(sizeof(*t));
+  if( t==NULL ) return SQLITE_NOMEM;
+  memset(t, 0, sizeof(*t));
+
+  /* TODO(shess) Delimiters need to remain the same from run to run,
+  ** else we need to reindex.  One solution would be a meta-table to
+  ** track such information in the database, then we'd only want this
+  ** information on the initial create.
+  */
+  if( argc>1 ){
+    int i, n = (int)strlen(argv[1]);
+    for(i=0; i=0x80 ){
+        sqlite3_free(t);
+        return SQLITE_ERROR;
+      }
+      t->delim[ch] = 1;
+    }
+  } else {
+    /* Mark non-alphanumeric ASCII characters as delimiters */
+    int i;
+    for(i=1; i<0x80; i++){
+      t->delim[i] = !fts3_isalnum(i) ? -1 : 0;
+    }
+  }
+
+  *ppTokenizer = &t->base;
+  return SQLITE_OK;
+}
+
+/*
+** Destroy a tokenizer
+*/
+static int simpleDestroy(sqlite3_tokenizer *pTokenizer){
+  sqlite3_free(pTokenizer);
+  return SQLITE_OK;
+}
+
+/*
+** Prepare to begin tokenizing a particular string.  The input
+** string to be tokenized is pInput[0..nBytes-1].  A cursor
+** used to incrementally tokenize this string is returned in 
+** *ppCursor.
+*/
+static int simpleOpen(
+  sqlite3_tokenizer *pTokenizer,         /* The tokenizer */
+  const char *pInput, int nBytes,        /* String to be tokenized */
+  sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */
+){
+  simple_tokenizer_cursor *c;
+
+  UNUSED_PARAMETER(pTokenizer);
+
+  c = (simple_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));
+  if( c==NULL ) return SQLITE_NOMEM;
+
+  c->pInput = pInput;
+  if( pInput==0 ){
+    c->nBytes = 0;
+  }else if( nBytes<0 ){
+    c->nBytes = (int)strlen(pInput);
+  }else{
+    c->nBytes = nBytes;
+  }
+  c->iOffset = 0;                 /* start tokenizing at the beginning */
+  c->iToken = 0;
+  c->pToken = NULL;               /* no space allocated, yet. */
+  c->nTokenAllocated = 0;
+
+  *ppCursor = &c->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a tokenization cursor previously opened by a call to
+** simpleOpen() above.
+*/
+static int simpleClose(sqlite3_tokenizer_cursor *pCursor){
+  simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
+  sqlite3_free(c->pToken);
+  sqlite3_free(c);
+  return SQLITE_OK;
+}
+
+/*
+** Extract the next token from a tokenization cursor.  The cursor must
+** have been opened by a prior call to simpleOpen().
+*/
+static int simpleNext(
+  sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by simpleOpen */
+  const char **ppToken,               /* OUT: *ppToken is the token text */
+  int *pnBytes,                       /* OUT: Number of bytes in token */
+  int *piStartOffset,                 /* OUT: Starting offset of token */
+  int *piEndOffset,                   /* OUT: Ending offset of token */
+  int *piPosition                     /* OUT: Position integer of token */
+){
+  simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
+  simple_tokenizer *t = (simple_tokenizer *) pCursor->pTokenizer;
+  unsigned char *p = (unsigned char *)c->pInput;
+
+  while( c->iOffsetnBytes ){
+    int iStartOffset;
+
+    /* Scan past delimiter characters */
+    while( c->iOffsetnBytes && simpleDelim(t, p[c->iOffset]) ){
+      c->iOffset++;
+    }
+
+    /* Count non-delimiter characters. */
+    iStartOffset = c->iOffset;
+    while( c->iOffsetnBytes && !simpleDelim(t, p[c->iOffset]) ){
+      c->iOffset++;
+    }
+
+    if( c->iOffset>iStartOffset ){
+      int i, n = c->iOffset-iStartOffset;
+      if( n>c->nTokenAllocated ){
+        char *pNew;
+        c->nTokenAllocated = n+20;
+        pNew = sqlite3_realloc(c->pToken, c->nTokenAllocated);
+        if( !pNew ) return SQLITE_NOMEM;
+        c->pToken = pNew;
+      }
+      for(i=0; ipToken[i] = (char)((ch>='A' && ch<='Z') ? ch-'A'+'a' : ch);
+      }
+      *ppToken = c->pToken;
+      *pnBytes = n;
+      *piStartOffset = iStartOffset;
+      *piEndOffset = c->iOffset;
+      *piPosition = c->iToken++;
+
+      return SQLITE_OK;
+    }
+  }
+  return SQLITE_DONE;
+}
+
+/*
+** The set of routines that implement the simple tokenizer
+*/
+static const sqlite3_tokenizer_module simpleTokenizerModule = {
+  0,
+  simpleCreate,
+  simpleDestroy,
+  simpleOpen,
+  simpleClose,
+  simpleNext,
+  0,
+};
+
+/*
+** Allocate a new simple tokenizer.  Return a pointer to the new
+** tokenizer in *ppModule
+*/
+SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(
+  sqlite3_tokenizer_module const**ppModule
+){
+  *ppModule = &simpleTokenizerModule;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_tokenizer1.c *************************************/
+/************** Begin file fts3_tokenize_vtab.c ******************************/
+/*
+** 2013 Apr 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code for the "fts3tokenize" virtual table module.
+** An fts3tokenize virtual table is created as follows:
+**
+**   CREATE VIRTUAL TABLE  USING fts3tokenize(
+**       , , ...
+**   );
+**
+** The table created has the following schema:
+**
+**   CREATE TABLE (input, token, start, end, position)
+**
+** When queried, the query must include a WHERE clause of type:
+**
+**   input = 
+**
+** The virtual table module tokenizes this , using the FTS3 
+** tokenizer specified by the arguments to the CREATE VIRTUAL TABLE 
+** statement and returns one row for each token in the result. With
+** fields set as follows:
+**
+**   input:   Always set to a copy of 
+**   token:   A token from the input.
+**   start:   Byte offset of the token within the input .
+**   end:     Byte offset of the byte immediately following the end of the
+**            token within the input string.
+**   pos:     Token offset of token within input.
+**
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+
+typedef struct Fts3tokTable Fts3tokTable;
+typedef struct Fts3tokCursor Fts3tokCursor;
+
+/*
+** Virtual table structure.
+*/
+struct Fts3tokTable {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  const sqlite3_tokenizer_module *pMod;
+  sqlite3_tokenizer *pTok;
+};
+
+/*
+** Virtual table cursor structure.
+*/
+struct Fts3tokCursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  char *zInput;                   /* Input string */
+  sqlite3_tokenizer_cursor *pCsr; /* Cursor to iterate through zInput */
+  int iRowid;                     /* Current 'rowid' value */
+  const char *zToken;             /* Current 'token' value */
+  int nToken;                     /* Size of zToken in bytes */
+  int iStart;                     /* Current 'start' value */
+  int iEnd;                       /* Current 'end' value */
+  int iPos;                       /* Current 'pos' value */
+};
+
+/*
+** Query FTS for the tokenizer implementation named zName.
+*/
+static int fts3tokQueryTokenizer(
+  Fts3Hash *pHash,
+  const char *zName,
+  const sqlite3_tokenizer_module **pp,
+  char **pzErr
+){
+  sqlite3_tokenizer_module *p;
+  int nName = (int)strlen(zName);
+
+  p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
+  if( !p ){
+    sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", zName);
+    return SQLITE_ERROR;
+  }
+
+  *pp = p;
+  return SQLITE_OK;
+}
+
+/*
+** The second argument, argv[], is an array of pointers to nul-terminated
+** strings. This function makes a copy of the array and strings into a 
+** single block of memory. It then dequotes any of the strings that appear
+** to be quoted.
+**
+** If successful, output parameter *pazDequote is set to point at the
+** array of dequoted strings and SQLITE_OK is returned. The caller is
+** responsible for eventually calling sqlite3_free() to free the array
+** in this case. Or, if an error occurs, an SQLite error code is returned.
+** The final value of *pazDequote is undefined in this case.
+*/
+static int fts3tokDequoteArray(
+  int argc,                       /* Number of elements in argv[] */
+  const char * const *argv,       /* Input array */
+  char ***pazDequote              /* Output array */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( argc==0 ){
+    *pazDequote = 0;
+  }else{
+    int i;
+    int nByte = 0;
+    char **azDequote;
+
+    for(i=0; ixCreate((nDequote>1 ? nDequote-1 : 0), azArg, &pTok);
+  }
+
+  if( rc==SQLITE_OK ){
+    pTab = (Fts3tokTable *)sqlite3_malloc(sizeof(Fts3tokTable));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    memset(pTab, 0, sizeof(Fts3tokTable));
+    pTab->pMod = pMod;
+    pTab->pTok = pTok;
+    *ppVtab = &pTab->base;
+  }else{
+    if( pTok ){
+      pMod->xDestroy(pTok);
+    }
+  }
+
+  sqlite3_free(azDequote);
+  return rc;
+}
+
+/*
+** This function does the work for both the xDisconnect and xDestroy methods.
+** These tables have no persistent representation of their own, so xDisconnect
+** and xDestroy are identical operations.
+*/
+static int fts3tokDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts3tokTable *pTab = (Fts3tokTable *)pVtab;
+
+  pTab->pMod->xDestroy(pTab->pTok);
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex - Analyze a WHERE and ORDER BY clause.
+*/
+static int fts3tokBestIndexMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_index_info *pInfo
+){
+  int i;
+  UNUSED_PARAMETER(pVTab);
+
+  for(i=0; inConstraint; i++){
+    if( pInfo->aConstraint[i].usable 
+     && pInfo->aConstraint[i].iColumn==0 
+     && pInfo->aConstraint[i].op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
+      pInfo->idxNum = 1;
+      pInfo->aConstraintUsage[i].argvIndex = 1;
+      pInfo->aConstraintUsage[i].omit = 1;
+      pInfo->estimatedCost = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  pInfo->idxNum = 0;
+  assert( pInfo->estimatedCost>1000000.0 );
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen - Open a cursor.
+*/
+static int fts3tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts3tokCursor *pCsr;
+  UNUSED_PARAMETER(pVTab);
+
+  pCsr = (Fts3tokCursor *)sqlite3_malloc(sizeof(Fts3tokCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(Fts3tokCursor));
+
+  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** Reset the tokenizer cursor passed as the only argument. As if it had
+** just been returned by fts3tokOpenMethod().
+*/
+static void fts3tokResetCursor(Fts3tokCursor *pCsr){
+  if( pCsr->pCsr ){
+    Fts3tokTable *pTab = (Fts3tokTable *)(pCsr->base.pVtab);
+    pTab->pMod->xClose(pCsr->pCsr);
+    pCsr->pCsr = 0;
+  }
+  sqlite3_free(pCsr->zInput);
+  pCsr->zInput = 0;
+  pCsr->zToken = 0;
+  pCsr->nToken = 0;
+  pCsr->iStart = 0;
+  pCsr->iEnd = 0;
+  pCsr->iPos = 0;
+  pCsr->iRowid = 0;
+}
+
+/*
+** xClose - Close a cursor.
+*/
+static int fts3tokCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  fts3tokResetCursor(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** xNext - Advance the cursor to the next row, if any.
+*/
+static int fts3tokNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  int rc;                         /* Return code */
+
+  pCsr->iRowid++;
+  rc = pTab->pMod->xNext(pCsr->pCsr,
+      &pCsr->zToken, &pCsr->nToken,
+      &pCsr->iStart, &pCsr->iEnd, &pCsr->iPos
+  );
+
+  if( rc!=SQLITE_OK ){
+    fts3tokResetCursor(pCsr);
+    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  }
+
+  return rc;
+}
+
+/*
+** xFilter - Initialize a cursor to point at the start of its data.
+*/
+static int fts3tokFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  int rc = SQLITE_ERROR;
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  UNUSED_PARAMETER(idxStr);
+  UNUSED_PARAMETER(nVal);
+
+  fts3tokResetCursor(pCsr);
+  if( idxNum==1 ){
+    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
+    int nByte = sqlite3_value_bytes(apVal[0]);
+    pCsr->zInput = sqlite3_malloc(nByte+1);
+    if( pCsr->zInput==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memcpy(pCsr->zInput, zByte, nByte);
+      pCsr->zInput[nByte] = 0;
+      rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);
+      if( rc==SQLITE_OK ){
+        pCsr->pCsr->pTokenizer = pTab->pTok;
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ) return rc;
+  return fts3tokNextMethod(pCursor);
+}
+
+/*
+** xEof - Return true if the cursor is at EOF, or false otherwise.
+*/
+static int fts3tokEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  return (pCsr->zToken==0);
+}
+
+/*
+** xColumn - Return a column value.
+*/
+static int fts3tokColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  /* CREATE TABLE x(input, token, start, end, position) */
+  switch( iCol ){
+    case 0:
+      sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);
+      break;
+    case 1:
+      sqlite3_result_text(pCtx, pCsr->zToken, pCsr->nToken, SQLITE_TRANSIENT);
+      break;
+    case 2:
+      sqlite3_result_int(pCtx, pCsr->iStart);
+      break;
+    case 3:
+      sqlite3_result_int(pCtx, pCsr->iEnd);
+      break;
+    default:
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, pCsr->iPos);
+      break;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** xRowid - Return the current rowid for the cursor.
+*/
+static int fts3tokRowidMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite_int64 *pRowid            /* OUT: Rowid value */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  *pRowid = (sqlite3_int64)pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** Register the fts3tok module with database connection db. Return SQLITE_OK
+** if successful or an error code if sqlite3_create_module() fails.
+*/
+SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3 *db, Fts3Hash *pHash){
+  static const sqlite3_module fts3tok_module = {
+     0,                           /* iVersion      */
+     fts3tokConnectMethod,        /* xCreate       */
+     fts3tokConnectMethod,        /* xConnect      */
+     fts3tokBestIndexMethod,      /* xBestIndex    */
+     fts3tokDisconnectMethod,     /* xDisconnect   */
+     fts3tokDisconnectMethod,     /* xDestroy      */
+     fts3tokOpenMethod,           /* xOpen         */
+     fts3tokCloseMethod,          /* xClose        */
+     fts3tokFilterMethod,         /* xFilter       */
+     fts3tokNextMethod,           /* xNext         */
+     fts3tokEofMethod,            /* xEof          */
+     fts3tokColumnMethod,         /* xColumn       */
+     fts3tokRowidMethod,          /* xRowid        */
+     0,                           /* xUpdate       */
+     0,                           /* xBegin        */
+     0,                           /* xSync         */
+     0,                           /* xCommit       */
+     0,                           /* xRollback     */
+     0,                           /* xFindFunction */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
+  };
+  int rc;                         /* Return code */
+
+  rc = sqlite3_create_module(db, "fts3tokenize", &fts3tok_module, (void*)pHash);
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_tokenize_vtab.c **********************************/
+/************** Begin file fts3_write.c **************************************/
+/*
+** 2009 Oct 23
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file is part of the SQLite FTS3 extension module. Specifically,
+** this file contains code to insert, update and delete rows from FTS3
+** tables. It also contains code to merge FTS3 b-tree segments. Some
+** of the sub-routines used to merge segments are also used by the query 
+** code in fts3.c.
+*/
+
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+/* #include  */
+
+
+#define FTS_MAX_APPENDABLE_HEIGHT 16
+
+/*
+** When full-text index nodes are loaded from disk, the buffer that they
+** are loaded into has the following number of bytes of padding at the end 
+** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer
+** of 920 bytes is allocated for it.
+**
+** This means that if we have a pointer into a buffer containing node data,
+** it is always safe to read up to two varints from it without risking an
+** overread, even if the node data is corrupted.
+*/
+#define FTS3_NODE_PADDING (FTS3_VARINT_MAX*2)
+
+/*
+** Under certain circumstances, b-tree nodes (doclists) can be loaded into
+** memory incrementally instead of all at once. This can be a big performance
+** win (reduced IO and CPU) if SQLite stops calling the virtual table xNext()
+** method before retrieving all query results (as may happen, for example,
+** if a query has a LIMIT clause).
+**
+** Incremental loading is used for b-tree nodes FTS3_NODE_CHUNK_THRESHOLD 
+** bytes and larger. Nodes are loaded in chunks of FTS3_NODE_CHUNKSIZE bytes.
+** The code is written so that the hard lower-limit for each of these values 
+** is 1. Clearly such small values would be inefficient, but can be useful 
+** for testing purposes.
+**
+** If this module is built with SQLITE_TEST defined, these constants may
+** be overridden at runtime for testing purposes. File fts3_test.c contains
+** a Tcl interface to read and write the values.
+*/
+#ifdef SQLITE_TEST
+int test_fts3_node_chunksize = (4*1024);
+int test_fts3_node_chunk_threshold = (4*1024)*4;
+# define FTS3_NODE_CHUNKSIZE       test_fts3_node_chunksize
+# define FTS3_NODE_CHUNK_THRESHOLD test_fts3_node_chunk_threshold
+#else
+# define FTS3_NODE_CHUNKSIZE (4*1024) 
+# define FTS3_NODE_CHUNK_THRESHOLD (FTS3_NODE_CHUNKSIZE*4)
+#endif
+
+/*
+** The two values that may be meaningfully bound to the :1 parameter in
+** statements SQL_REPLACE_STAT and SQL_SELECT_STAT.
+*/
+#define FTS_STAT_DOCTOTAL      0
+#define FTS_STAT_INCRMERGEHINT 1
+#define FTS_STAT_AUTOINCRMERGE 2
+
+/*
+** If FTS_LOG_MERGES is defined, call sqlite3_log() to report each automatic
+** and incremental merge operation that takes place. This is used for 
+** debugging FTS only, it should not usually be turned on in production
+** systems.
+*/
+#ifdef FTS3_LOG_MERGES
+static void fts3LogMerge(int nMerge, sqlite3_int64 iAbsLevel){
+  sqlite3_log(SQLITE_OK, "%d-way merge from level %d", nMerge, (int)iAbsLevel);
+}
+#else
+#define fts3LogMerge(x, y)
+#endif
+
+
+typedef struct PendingList PendingList;
+typedef struct SegmentNode SegmentNode;
+typedef struct SegmentWriter SegmentWriter;
+
+/*
+** An instance of the following data structure is used to build doclists
+** incrementally. See function fts3PendingListAppend() for details.
+*/
+struct PendingList {
+  int nData;
+  char *aData;
+  int nSpace;
+  sqlite3_int64 iLastDocid;
+  sqlite3_int64 iLastCol;
+  sqlite3_int64 iLastPos;
+};
+
+
+/*
+** Each cursor has a (possibly empty) linked list of the following objects.
+*/
+struct Fts3DeferredToken {
+  Fts3PhraseToken *pToken;        /* Pointer to corresponding expr token */
+  int iCol;                       /* Column token must occur in */
+  Fts3DeferredToken *pNext;       /* Next in list of deferred tokens */
+  PendingList *pList;             /* Doclist is assembled here */
+};
+
+/*
+** An instance of this structure is used to iterate through the terms on
+** a contiguous set of segment b-tree leaf nodes. Although the details of
+** this structure are only manipulated by code in this file, opaque handles
+** of type Fts3SegReader* are also used by code in fts3.c to iterate through
+** terms when querying the full-text index. See functions:
+**
+**   sqlite3Fts3SegReaderNew()
+**   sqlite3Fts3SegReaderFree()
+**   sqlite3Fts3SegReaderIterate()
+**
+** Methods used to manipulate Fts3SegReader structures:
+**
+**   fts3SegReaderNext()
+**   fts3SegReaderFirstDocid()
+**   fts3SegReaderNextDocid()
+*/
+struct Fts3SegReader {
+  int iIdx;                       /* Index within level, or 0x7FFFFFFF for PT */
+  u8 bLookup;                     /* True for a lookup only */
+  u8 rootOnly;                    /* True for a root-only reader */
+
+  sqlite3_int64 iStartBlock;      /* Rowid of first leaf block to traverse */
+  sqlite3_int64 iLeafEndBlock;    /* Rowid of final leaf block to traverse */
+  sqlite3_int64 iEndBlock;        /* Rowid of final block in segment (or 0) */
+  sqlite3_int64 iCurrentBlock;    /* Current leaf block (or 0) */
+
+  char *aNode;                    /* Pointer to node data (or NULL) */
+  int nNode;                      /* Size of buffer at aNode (or 0) */
+  int nPopulate;                  /* If >0, bytes of buffer aNode[] loaded */
+  sqlite3_blob *pBlob;            /* If not NULL, blob handle to read node */
+
+  Fts3HashElem **ppNextElem;
+
+  /* Variables set by fts3SegReaderNext(). These may be read directly
+  ** by the caller. They are valid from the time SegmentReaderNew() returns
+  ** until SegmentReaderNext() returns something other than SQLITE_OK
+  ** (i.e. SQLITE_DONE).
+  */
+  int nTerm;                      /* Number of bytes in current term */
+  char *zTerm;                    /* Pointer to current term */
+  int nTermAlloc;                 /* Allocated size of zTerm buffer */
+  char *aDoclist;                 /* Pointer to doclist of current entry */
+  int nDoclist;                   /* Size of doclist in current entry */
+
+  /* The following variables are used by fts3SegReaderNextDocid() to iterate 
+  ** through the current doclist (aDoclist/nDoclist).
+  */
+  char *pOffsetList;
+  int nOffsetList;                /* For descending pending seg-readers only */
+  sqlite3_int64 iDocid;
+};
+
+#define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0)
+#define fts3SegReaderIsRootOnly(p) ((p)->rootOnly!=0)
+
+/*
+** An instance of this structure is used to create a segment b-tree in the
+** database. The internal details of this type are only accessed by the
+** following functions:
+**
+**   fts3SegWriterAdd()
+**   fts3SegWriterFlush()
+**   fts3SegWriterFree()
+*/
+struct SegmentWriter {
+  SegmentNode *pTree;             /* Pointer to interior tree structure */
+  sqlite3_int64 iFirst;           /* First slot in %_segments written */
+  sqlite3_int64 iFree;            /* Next free slot in %_segments */
+  char *zTerm;                    /* Pointer to previous term buffer */
+  int nTerm;                      /* Number of bytes in zTerm */
+  int nMalloc;                    /* Size of malloc'd buffer at zMalloc */
+  char *zMalloc;                  /* Malloc'd space (possibly) used for zTerm */
+  int nSize;                      /* Size of allocation at aData */
+  int nData;                      /* Bytes of data in aData */
+  char *aData;                    /* Pointer to block from malloc() */
+  i64 nLeafData;                  /* Number of bytes of leaf data written */
+};
+
+/*
+** Type SegmentNode is used by the following three functions to create
+** the interior part of the segment b+-tree structures (everything except
+** the leaf nodes). These functions and type are only ever used by code
+** within the fts3SegWriterXXX() family of functions described above.
+**
+**   fts3NodeAddTerm()
+**   fts3NodeWrite()
+**   fts3NodeFree()
+**
+** When a b+tree is written to the database (either as a result of a merge
+** or the pending-terms table being flushed), leaves are written into the 
+** database file as soon as they are completely populated. The interior of
+** the tree is assembled in memory and written out only once all leaves have
+** been populated and stored. This is Ok, as the b+-tree fanout is usually
+** very large, meaning that the interior of the tree consumes relatively 
+** little memory.
+*/
+struct SegmentNode {
+  SegmentNode *pParent;           /* Parent node (or NULL for root node) */
+  SegmentNode *pRight;            /* Pointer to right-sibling */
+  SegmentNode *pLeftmost;         /* Pointer to left-most node of this depth */
+  int nEntry;                     /* Number of terms written to node so far */
+  char *zTerm;                    /* Pointer to previous term buffer */
+  int nTerm;                      /* Number of bytes in zTerm */
+  int nMalloc;                    /* Size of malloc'd buffer at zMalloc */
+  char *zMalloc;                  /* Malloc'd space (possibly) used for zTerm */
+  int nData;                      /* Bytes of valid data so far */
+  char *aData;                    /* Node data */
+};
+
+/*
+** Valid values for the second argument to fts3SqlStmt().
+*/
+#define SQL_DELETE_CONTENT             0
+#define SQL_IS_EMPTY                   1
+#define SQL_DELETE_ALL_CONTENT         2 
+#define SQL_DELETE_ALL_SEGMENTS        3
+#define SQL_DELETE_ALL_SEGDIR          4
+#define SQL_DELETE_ALL_DOCSIZE         5
+#define SQL_DELETE_ALL_STAT            6
+#define SQL_SELECT_CONTENT_BY_ROWID    7
+#define SQL_NEXT_SEGMENT_INDEX         8
+#define SQL_INSERT_SEGMENTS            9
+#define SQL_NEXT_SEGMENTS_ID          10
+#define SQL_INSERT_SEGDIR             11
+#define SQL_SELECT_LEVEL              12
+#define SQL_SELECT_LEVEL_RANGE        13
+#define SQL_SELECT_LEVEL_COUNT        14
+#define SQL_SELECT_SEGDIR_MAX_LEVEL   15
+#define SQL_DELETE_SEGDIR_LEVEL       16
+#define SQL_DELETE_SEGMENTS_RANGE     17
+#define SQL_CONTENT_INSERT            18
+#define SQL_DELETE_DOCSIZE            19
+#define SQL_REPLACE_DOCSIZE           20
+#define SQL_SELECT_DOCSIZE            21
+#define SQL_SELECT_STAT               22
+#define SQL_REPLACE_STAT              23
+
+#define SQL_SELECT_ALL_PREFIX_LEVEL   24
+#define SQL_DELETE_ALL_TERMS_SEGDIR   25
+#define SQL_DELETE_SEGDIR_RANGE       26
+#define SQL_SELECT_ALL_LANGID         27
+#define SQL_FIND_MERGE_LEVEL          28
+#define SQL_MAX_LEAF_NODE_ESTIMATE    29
+#define SQL_DELETE_SEGDIR_ENTRY       30
+#define SQL_SHIFT_SEGDIR_ENTRY        31
+#define SQL_SELECT_SEGDIR             32
+#define SQL_CHOMP_SEGDIR              33
+#define SQL_SEGMENT_IS_APPENDABLE     34
+#define SQL_SELECT_INDEXES            35
+#define SQL_SELECT_MXLEVEL            36
+
+#define SQL_SELECT_LEVEL_RANGE2       37
+#define SQL_UPDATE_LEVEL_IDX          38
+#define SQL_UPDATE_LEVEL              39
+
+/*
+** This function is used to obtain an SQLite prepared statement handle
+** for the statement identified by the second argument. If successful,
+** *pp is set to the requested statement handle and SQLITE_OK returned.
+** Otherwise, an SQLite error code is returned and *pp is set to 0.
+**
+** If argument apVal is not NULL, then it must point to an array with
+** at least as many entries as the requested statement has bound 
+** parameters. The values are bound to the statements parameters before
+** returning.
+*/
+static int fts3SqlStmt(
+  Fts3Table *p,                   /* Virtual table handle */
+  int eStmt,                      /* One of the SQL_XXX constants above */
+  sqlite3_stmt **pp,              /* OUT: Statement handle */
+  sqlite3_value **apVal           /* Values to bind to statement */
+){
+  const char *azSql[] = {
+/* 0  */  "DELETE FROM %Q.'%q_content' WHERE rowid = ?",
+/* 1  */  "SELECT NOT EXISTS(SELECT docid FROM %Q.'%q_content' WHERE rowid!=?)",
+/* 2  */  "DELETE FROM %Q.'%q_content'",
+/* 3  */  "DELETE FROM %Q.'%q_segments'",
+/* 4  */  "DELETE FROM %Q.'%q_segdir'",
+/* 5  */  "DELETE FROM %Q.'%q_docsize'",
+/* 6  */  "DELETE FROM %Q.'%q_stat'",
+/* 7  */  "SELECT %s WHERE rowid=?",
+/* 8  */  "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1",
+/* 9  */  "REPLACE INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)",
+/* 10 */  "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)",
+/* 11 */  "REPLACE INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)",
+
+          /* Return segments in order from oldest to newest.*/ 
+/* 12 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
+            "FROM %Q.'%q_segdir' WHERE level = ? ORDER BY idx ASC",
+/* 13 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
+            "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?"
+            "ORDER BY level DESC, idx ASC",
+
+/* 14 */  "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?",
+/* 15 */  "SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",
+
+/* 16 */  "DELETE FROM %Q.'%q_segdir' WHERE level = ?",
+/* 17 */  "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?",
+/* 18 */  "INSERT INTO %Q.'%q_content' VALUES(%s)",
+/* 19 */  "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
+/* 20 */  "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
+/* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
+/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=?",
+/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(?,?)",
+/* 24 */  "",
+/* 25 */  "",
+
+/* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",
+/* 27 */ "SELECT ? UNION SELECT level / (1024 * ?) FROM %Q.'%q_segdir'",
+
+/* This statement is used to determine which level to read the input from
+** when performing an incremental merge. It returns the absolute level number
+** of the oldest level in the db that contains at least ? segments. Or,
+** if no level in the FTS index contains more than ? segments, the statement
+** returns zero rows.  */
+/* 28 */ "SELECT level, count(*) AS cnt FROM %Q.'%q_segdir' "
+         "  GROUP BY level HAVING cnt>=?"
+         "  ORDER BY (level %% 1024) ASC LIMIT 1",
+
+/* Estimate the upper limit on the number of leaf nodes in a new segment
+** created by merging the oldest :2 segments from absolute level :1. See 
+** function sqlite3Fts3Incrmerge() for details.  */
+/* 29 */ "SELECT 2 * total(1 + leaves_end_block - start_block) "
+         "  FROM %Q.'%q_segdir' WHERE level = ? AND idx < ?",
+
+/* SQL_DELETE_SEGDIR_ENTRY
+**   Delete the %_segdir entry on absolute level :1 with index :2.  */
+/* 30 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",
+
+/* SQL_SHIFT_SEGDIR_ENTRY
+**   Modify the idx value for the segment with idx=:3 on absolute level :2
+**   to :1.  */
+/* 31 */ "UPDATE %Q.'%q_segdir' SET idx = ? WHERE level=? AND idx=?",
+
+/* SQL_SELECT_SEGDIR
+**   Read a single entry from the %_segdir table. The entry from absolute 
+**   level :1 with index value :2.  */
+/* 32 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
+            "FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",
+
+/* SQL_CHOMP_SEGDIR
+**   Update the start_block (:1) and root (:2) fields of the %_segdir
+**   entry located on absolute level :3 with index :4.  */
+/* 33 */  "UPDATE %Q.'%q_segdir' SET start_block = ?, root = ?"
+            "WHERE level = ? AND idx = ?",
+
+/* SQL_SEGMENT_IS_APPENDABLE
+**   Return a single row if the segment with end_block=? is appendable. Or
+**   no rows otherwise.  */
+/* 34 */  "SELECT 1 FROM %Q.'%q_segments' WHERE blockid=? AND block IS NULL",
+
+/* SQL_SELECT_INDEXES
+**   Return the list of valid segment indexes for absolute level ?  */
+/* 35 */  "SELECT idx FROM %Q.'%q_segdir' WHERE level=? ORDER BY 1 ASC",
+
+/* SQL_SELECT_MXLEVEL
+**   Return the largest relative level in the FTS index or indexes.  */
+/* 36 */  "SELECT max( level %% 1024 ) FROM %Q.'%q_segdir'",
+
+          /* Return segments in order from oldest to newest.*/ 
+/* 37 */  "SELECT level, idx, end_block "
+            "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ? "
+            "ORDER BY level DESC, idx ASC",
+
+          /* Update statements used while promoting segments */
+/* 38 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=-1,idx=? "
+            "WHERE level=? AND idx=?",
+/* 39 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=? WHERE level=-1"
+
+  };
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pStmt;
+
+  assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );
+  assert( eStmt=0 );
+  
+  pStmt = p->aStmt[eStmt];
+  if( !pStmt ){
+    char *zSql;
+    if( eStmt==SQL_CONTENT_INSERT ){
+      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist);
+    }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){
+      zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist);
+    }else{
+      zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName);
+    }
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v3(p->db, zSql, -1, SQLITE_PREPARE_PERSISTENT,
+                              &pStmt, NULL);
+      sqlite3_free(zSql);
+      assert( rc==SQLITE_OK || pStmt==0 );
+      p->aStmt[eStmt] = pStmt;
+    }
+  }
+  if( apVal ){
+    int i;
+    int nParam = sqlite3_bind_parameter_count(pStmt);
+    for(i=0; rc==SQLITE_OK && inPendingData==0 ){
+    sqlite3_stmt *pStmt;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_null(pStmt, 1);
+      sqlite3_step(pStmt);
+      rc = sqlite3_reset(pStmt);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** FTS maintains a separate indexes for each language-id (a 32-bit integer).
+** Within each language id, a separate index is maintained to store the
+** document terms, and each configured prefix size (configured the FTS 
+** "prefix=" option). And each index consists of multiple levels ("relative
+** levels").
+**
+** All three of these values (the language id, the specific index and the
+** level within the index) are encoded in 64-bit integer values stored
+** in the %_segdir table on disk. This function is used to convert three
+** separate component values into the single 64-bit integer value that
+** can be used to query the %_segdir table.
+**
+** Specifically, each language-id/index combination is allocated 1024 
+** 64-bit integer level values ("absolute levels"). The main terms index
+** for language-id 0 is allocate values 0-1023. The first prefix index
+** (if any) for language-id 0 is allocated values 1024-2047. And so on.
+** Language 1 indexes are allocated immediately following language 0.
+**
+** So, for a system with nPrefix prefix indexes configured, the block of
+** absolute levels that corresponds to language-id iLangid and index 
+** iIndex starts at absolute level ((iLangid * (nPrefix+1) + iIndex) * 1024).
+*/
+static sqlite3_int64 getAbsoluteLevel(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id */
+  int iIndex,                     /* Index in p->aIndex[] */
+  int iLevel                      /* Level of segments */
+){
+  sqlite3_int64 iBase;            /* First absolute level for iLangid/iIndex */
+  assert( iLangid>=0 );
+  assert( p->nIndex>0 );
+  assert( iIndex>=0 && iIndexnIndex );
+
+  iBase = ((sqlite3_int64)iLangid * p->nIndex + iIndex) * FTS3_SEGDIR_MAXLEVEL;
+  return iBase + iLevel;
+}
+
+/*
+** Set *ppStmt to a statement handle that may be used to iterate through
+** all rows in the %_segdir table, from oldest to newest. If successful,
+** return SQLITE_OK. If an error occurs while preparing the statement, 
+** return an SQLite error code.
+**
+** There is only ever one instance of this SQL statement compiled for
+** each FTS3 table.
+**
+** The statement returns the following columns from the %_segdir table:
+**
+**   0: idx
+**   1: start_block
+**   2: leaves_end_block
+**   3: end_block
+**   4: root
+*/
+SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(
+  Fts3Table *p,                   /* FTS3 table */
+  int iLangid,                    /* Language being queried */
+  int iIndex,                     /* Index for p->aIndex[] */
+  int iLevel,                     /* Level to select (relative level) */
+  sqlite3_stmt **ppStmt           /* OUT: Compiled statement */
+){
+  int rc;
+  sqlite3_stmt *pStmt = 0;
+
+  assert( iLevel==FTS3_SEGCURSOR_ALL || iLevel>=0 );
+  assert( iLevel=0 && iIndexnIndex );
+
+  if( iLevel<0 ){
+    /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */
+    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0);
+    if( rc==SQLITE_OK ){ 
+      sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+      sqlite3_bind_int64(pStmt, 2, 
+          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+      );
+    }
+  }else{
+    /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */
+    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
+    if( rc==SQLITE_OK ){ 
+      sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex,iLevel));
+    }
+  }
+  *ppStmt = pStmt;
+  return rc;
+}
+
+
+/*
+** Append a single varint to a PendingList buffer. SQLITE_OK is returned
+** if successful, or an SQLite error code otherwise.
+**
+** This function also serves to allocate the PendingList structure itself.
+** For example, to create a new PendingList structure containing two
+** varints:
+**
+**   PendingList *p = 0;
+**   fts3PendingListAppendVarint(&p, 1);
+**   fts3PendingListAppendVarint(&p, 2);
+*/
+static int fts3PendingListAppendVarint(
+  PendingList **pp,               /* IN/OUT: Pointer to PendingList struct */
+  sqlite3_int64 i                 /* Value to append to data */
+){
+  PendingList *p = *pp;
+
+  /* Allocate or grow the PendingList as required. */
+  if( !p ){
+    p = sqlite3_malloc(sizeof(*p) + 100);
+    if( !p ){
+      return SQLITE_NOMEM;
+    }
+    p->nSpace = 100;
+    p->aData = (char *)&p[1];
+    p->nData = 0;
+  }
+  else if( p->nData+FTS3_VARINT_MAX+1>p->nSpace ){
+    int nNew = p->nSpace * 2;
+    p = sqlite3_realloc(p, sizeof(*p) + nNew);
+    if( !p ){
+      sqlite3_free(*pp);
+      *pp = 0;
+      return SQLITE_NOMEM;
+    }
+    p->nSpace = nNew;
+    p->aData = (char *)&p[1];
+  }
+
+  /* Append the new serialized varint to the end of the list. */
+  p->nData += sqlite3Fts3PutVarint(&p->aData[p->nData], i);
+  p->aData[p->nData] = '\0';
+  *pp = p;
+  return SQLITE_OK;
+}
+
+/*
+** Add a docid/column/position entry to a PendingList structure. Non-zero
+** is returned if the structure is sqlite3_realloced as part of adding
+** the entry. Otherwise, zero.
+**
+** If an OOM error occurs, *pRc is set to SQLITE_NOMEM before returning.
+** Zero is always returned in this case. Otherwise, if no OOM error occurs,
+** it is set to SQLITE_OK.
+*/
+static int fts3PendingListAppend(
+  PendingList **pp,               /* IN/OUT: PendingList structure */
+  sqlite3_int64 iDocid,           /* Docid for entry to add */
+  sqlite3_int64 iCol,             /* Column for entry to add */
+  sqlite3_int64 iPos,             /* Position of term for entry to add */
+  int *pRc                        /* OUT: Return code */
+){
+  PendingList *p = *pp;
+  int rc = SQLITE_OK;
+
+  assert( !p || p->iLastDocid<=iDocid );
+
+  if( !p || p->iLastDocid!=iDocid ){
+    sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0);
+    if( p ){
+      assert( p->nDatanSpace );
+      assert( p->aData[p->nData]==0 );
+      p->nData++;
+    }
+    if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iDelta)) ){
+      goto pendinglistappend_out;
+    }
+    p->iLastCol = -1;
+    p->iLastPos = 0;
+    p->iLastDocid = iDocid;
+  }
+  if( iCol>0 && p->iLastCol!=iCol ){
+    if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, 1))
+     || SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iCol))
+    ){
+      goto pendinglistappend_out;
+    }
+    p->iLastCol = iCol;
+    p->iLastPos = 0;
+  }
+  if( iCol>=0 ){
+    assert( iPos>p->iLastPos || (iPos==0 && p->iLastPos==0) );
+    rc = fts3PendingListAppendVarint(&p, 2+iPos-p->iLastPos);
+    if( rc==SQLITE_OK ){
+      p->iLastPos = iPos;
+    }
+  }
+
+ pendinglistappend_out:
+  *pRc = rc;
+  if( p!=*pp ){
+    *pp = p;
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Free a PendingList object allocated by fts3PendingListAppend().
+*/
+static void fts3PendingListDelete(PendingList *pList){
+  sqlite3_free(pList);
+}
+
+/*
+** Add an entry to one of the pending-terms hash tables.
+*/
+static int fts3PendingTermsAddOne(
+  Fts3Table *p,
+  int iCol,
+  int iPos,
+  Fts3Hash *pHash,                /* Pending terms hash table to add entry to */
+  const char *zToken,
+  int nToken
+){
+  PendingList *pList;
+  int rc = SQLITE_OK;
+
+  pList = (PendingList *)fts3HashFind(pHash, zToken, nToken);
+  if( pList ){
+    p->nPendingData -= (pList->nData + nToken + sizeof(Fts3HashElem));
+  }
+  if( fts3PendingListAppend(&pList, p->iPrevDocid, iCol, iPos, &rc) ){
+    if( pList==fts3HashInsert(pHash, zToken, nToken, pList) ){
+      /* Malloc failed while inserting the new entry. This can only 
+      ** happen if there was no previous entry for this token.
+      */
+      assert( 0==fts3HashFind(pHash, zToken, nToken) );
+      sqlite3_free(pList);
+      rc = SQLITE_NOMEM;
+    }
+  }
+  if( rc==SQLITE_OK ){
+    p->nPendingData += (pList->nData + nToken + sizeof(Fts3HashElem));
+  }
+  return rc;
+}
+
+/*
+** Tokenize the nul-terminated string zText and add all tokens to the
+** pending-terms hash-table. The docid used is that currently stored in
+** p->iPrevDocid, and the column is specified by argument iCol.
+**
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
+*/
+static int fts3PendingTermsAdd(
+  Fts3Table *p,                   /* Table into which text will be inserted */
+  int iLangid,                    /* Language id to use */
+  const char *zText,              /* Text of document to be inserted */
+  int iCol,                       /* Column into which text is being inserted */
+  u32 *pnWord                     /* IN/OUT: Incr. by number tokens inserted */
+){
+  int rc;
+  int iStart = 0;
+  int iEnd = 0;
+  int iPos = 0;
+  int nWord = 0;
+
+  char const *zToken;
+  int nToken = 0;
+
+  sqlite3_tokenizer *pTokenizer = p->pTokenizer;
+  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
+  sqlite3_tokenizer_cursor *pCsr;
+  int (*xNext)(sqlite3_tokenizer_cursor *pCursor,
+      const char**,int*,int*,int*,int*);
+
+  assert( pTokenizer && pModule );
+
+  /* If the user has inserted a NULL value, this function may be called with
+  ** zText==0. In this case, add zero token entries to the hash table and 
+  ** return early. */
+  if( zText==0 ){
+    *pnWord = 0;
+    return SQLITE_OK;
+  }
+
+  rc = sqlite3Fts3OpenTokenizer(pTokenizer, iLangid, zText, -1, &pCsr);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  xNext = pModule->xNext;
+  while( SQLITE_OK==rc
+      && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos))
+  ){
+    int i;
+    if( iPos>=nWord ) nWord = iPos+1;
+
+    /* Positions cannot be negative; we use -1 as a terminator internally.
+    ** Tokens must have a non-zero length.
+    */
+    if( iPos<0 || !zToken || nToken<=0 ){
+      rc = SQLITE_ERROR;
+      break;
+    }
+
+    /* Add the term to the terms index */
+    rc = fts3PendingTermsAddOne(
+        p, iCol, iPos, &p->aIndex[0].hPending, zToken, nToken
+    );
+    
+    /* Add the term to each of the prefix indexes that it is not too 
+    ** short for. */
+    for(i=1; rc==SQLITE_OK && inIndex; i++){
+      struct Fts3Index *pIndex = &p->aIndex[i];
+      if( nTokennPrefix ) continue;
+      rc = fts3PendingTermsAddOne(
+          p, iCol, iPos, &pIndex->hPending, zToken, pIndex->nPrefix
+      );
+    }
+  }
+
+  pModule->xClose(pCsr);
+  *pnWord += nWord;
+  return (rc==SQLITE_DONE ? SQLITE_OK : rc);
+}
+
+/* 
+** Calling this function indicates that subsequent calls to 
+** fts3PendingTermsAdd() are to add term/position-list pairs for the
+** contents of the document with docid iDocid.
+*/
+static int fts3PendingTermsDocid(
+  Fts3Table *p,                   /* Full-text table handle */
+  int bDelete,                    /* True if this op is a delete */
+  int iLangid,                    /* Language id of row being written */
+  sqlite_int64 iDocid             /* Docid of row being written */
+){
+  assert( iLangid>=0 );
+  assert( bDelete==1 || bDelete==0 );
+
+  /* TODO(shess) Explore whether partially flushing the buffer on
+  ** forced-flush would provide better performance.  I suspect that if
+  ** we ordered the doclists by size and flushed the largest until the
+  ** buffer was half empty, that would let the less frequent terms
+  ** generate longer doclists.
+  */
+  if( iDocidiPrevDocid 
+   || (iDocid==p->iPrevDocid && p->bPrevDelete==0)
+   || p->iPrevLangid!=iLangid
+   || p->nPendingData>p->nMaxPendingData 
+  ){
+    int rc = sqlite3Fts3PendingTermsFlush(p);
+    if( rc!=SQLITE_OK ) return rc;
+  }
+  p->iPrevDocid = iDocid;
+  p->iPrevLangid = iLangid;
+  p->bPrevDelete = bDelete;
+  return SQLITE_OK;
+}
+
+/*
+** Discard the contents of the pending-terms hash tables. 
+*/
+SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *p){
+  int i;
+  for(i=0; inIndex; i++){
+    Fts3HashElem *pElem;
+    Fts3Hash *pHash = &p->aIndex[i].hPending;
+    for(pElem=fts3HashFirst(pHash); pElem; pElem=fts3HashNext(pElem)){
+      PendingList *pList = (PendingList *)fts3HashData(pElem);
+      fts3PendingListDelete(pList);
+    }
+    fts3HashClear(pHash);
+  }
+  p->nPendingData = 0;
+}
+
+/*
+** This function is called by the xUpdate() method as part of an INSERT
+** operation. It adds entries for each term in the new record to the
+** pendingTerms hash table.
+**
+** Argument apVal is the same as the similarly named argument passed to
+** fts3InsertData(). Parameter iDocid is the docid of the new row.
+*/
+static int fts3InsertTerms(
+  Fts3Table *p, 
+  int iLangid, 
+  sqlite3_value **apVal, 
+  u32 *aSz
+){
+  int i;                          /* Iterator variable */
+  for(i=2; inColumn+2; i++){
+    int iCol = i-2;
+    if( p->abNotindexed[iCol]==0 ){
+      const char *zText = (const char *)sqlite3_value_text(apVal[i]);
+      int rc = fts3PendingTermsAdd(p, iLangid, zText, iCol, &aSz[iCol]);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** This function is called by the xUpdate() method for an INSERT operation.
+** The apVal parameter is passed a copy of the apVal argument passed by
+** SQLite to the xUpdate() method. i.e:
+**
+**   apVal[0]                Not used for INSERT.
+**   apVal[1]                rowid
+**   apVal[2]                Left-most user-defined column
+**   ...
+**   apVal[p->nColumn+1]     Right-most user-defined column
+**   apVal[p->nColumn+2]     Hidden column with same name as table
+**   apVal[p->nColumn+3]     Hidden "docid" column (alias for rowid)
+**   apVal[p->nColumn+4]     Hidden languageid column
+*/
+static int fts3InsertData(
+  Fts3Table *p,                   /* Full-text table */
+  sqlite3_value **apVal,          /* Array of values to insert */
+  sqlite3_int64 *piDocid          /* OUT: Docid for row just inserted */
+){
+  int rc;                         /* Return code */
+  sqlite3_stmt *pContentInsert;   /* INSERT INTO %_content VALUES(...) */
+
+  if( p->zContentTbl ){
+    sqlite3_value *pRowid = apVal[p->nColumn+3];
+    if( sqlite3_value_type(pRowid)==SQLITE_NULL ){
+      pRowid = apVal[1];
+    }
+    if( sqlite3_value_type(pRowid)!=SQLITE_INTEGER ){
+      return SQLITE_CONSTRAINT;
+    }
+    *piDocid = sqlite3_value_int64(pRowid);
+    return SQLITE_OK;
+  }
+
+  /* Locate the statement handle used to insert data into the %_content
+  ** table. The SQL for this statement is:
+  **
+  **   INSERT INTO %_content VALUES(?, ?, ?, ...)
+  **
+  ** The statement features N '?' variables, where N is the number of user
+  ** defined columns in the FTS3 table, plus one for the docid field.
+  */
+  rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]);
+  if( rc==SQLITE_OK && p->zLanguageid ){
+    rc = sqlite3_bind_int(
+        pContentInsert, p->nColumn+2, 
+        sqlite3_value_int(apVal[p->nColumn+4])
+    );
+  }
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* There is a quirk here. The users INSERT statement may have specified
+  ** a value for the "rowid" field, for the "docid" field, or for both.
+  ** Which is a problem, since "rowid" and "docid" are aliases for the
+  ** same value. For example:
+  **
+  **   INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2);
+  **
+  ** In FTS3, this is an error. It is an error to specify non-NULL values
+  ** for both docid and some other rowid alias.
+  */
+  if( SQLITE_NULL!=sqlite3_value_type(apVal[3+p->nColumn]) ){
+    if( SQLITE_NULL==sqlite3_value_type(apVal[0])
+     && SQLITE_NULL!=sqlite3_value_type(apVal[1])
+    ){
+      /* A rowid/docid conflict. */
+      return SQLITE_ERROR;
+    }
+    rc = sqlite3_bind_value(pContentInsert, 1, apVal[3+p->nColumn]);
+    if( rc!=SQLITE_OK ) return rc;
+  }
+
+  /* Execute the statement to insert the record. Set *piDocid to the 
+  ** new docid value. 
+  */
+  sqlite3_step(pContentInsert);
+  rc = sqlite3_reset(pContentInsert);
+
+  *piDocid = sqlite3_last_insert_rowid(p->db);
+  return rc;
+}
+
+
+
+/*
+** Remove all data from the FTS3 table. Clear the hash table containing
+** pending terms.
+*/
+static int fts3DeleteAll(Fts3Table *p, int bContent){
+  int rc = SQLITE_OK;             /* Return code */
+
+  /* Discard the contents of the pending-terms hash table. */
+  sqlite3Fts3PendingTermsClear(p);
+
+  /* Delete everything from the shadow tables. Except, leave %_content as
+  ** is if bContent is false.  */
+  assert( p->zContentTbl==0 || bContent==0 );
+  if( bContent ) fts3SqlExec(&rc, p, SQL_DELETE_ALL_CONTENT, 0);
+  fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGMENTS, 0);
+  fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0);
+  if( p->bHasDocsize ){
+    fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0);
+  }
+  if( p->bHasStat ){
+    fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0);
+  }
+  return rc;
+}
+
+/*
+**
+*/
+static int langidFromSelect(Fts3Table *p, sqlite3_stmt *pSelect){
+  int iLangid = 0;
+  if( p->zLanguageid ) iLangid = sqlite3_column_int(pSelect, p->nColumn+1);
+  return iLangid;
+}
+
+/*
+** The first element in the apVal[] array is assumed to contain the docid
+** (an integer) of a row about to be deleted. Remove all terms from the
+** full-text index.
+*/
+static void fts3DeleteTerms( 
+  int *pRC,               /* Result code */
+  Fts3Table *p,           /* The FTS table to delete from */
+  sqlite3_value *pRowid,  /* The docid to be deleted */
+  u32 *aSz,               /* Sizes of deleted document written here */
+  int *pbFound            /* OUT: Set to true if row really does exist */
+){
+  int rc;
+  sqlite3_stmt *pSelect;
+
+  assert( *pbFound==0 );
+  if( *pRC ) return;
+  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pSelect) ){
+      int i;
+      int iLangid = langidFromSelect(p, pSelect);
+      i64 iDocid = sqlite3_column_int64(pSelect, 0);
+      rc = fts3PendingTermsDocid(p, 1, iLangid, iDocid);
+      for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
+        int iCol = i-1;
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
+          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
+        }
+      }
+      if( rc!=SQLITE_OK ){
+        sqlite3_reset(pSelect);
+        *pRC = rc;
+        return;
+      }
+      *pbFound = 1;
+    }
+    rc = sqlite3_reset(pSelect);
+  }else{
+    sqlite3_reset(pSelect);
+  }
+  *pRC = rc;
+}
+
+/*
+** Forward declaration to account for the circular dependency between
+** functions fts3SegmentMerge() and fts3AllocateSegdirIdx().
+*/
+static int fts3SegmentMerge(Fts3Table *, int, int, int);
+
+/* 
+** This function allocates a new level iLevel index in the segdir table.
+** Usually, indexes are allocated within a level sequentially starting
+** with 0, so the allocated index is one greater than the value returned
+** by:
+**
+**   SELECT max(idx) FROM %_segdir WHERE level = :iLevel
+**
+** However, if there are already FTS3_MERGE_COUNT indexes at the requested
+** level, they are merged into a single level (iLevel+1) segment and the 
+** allocated index is 0.
+**
+** If successful, *piIdx is set to the allocated index slot and SQLITE_OK
+** returned. Otherwise, an SQLite error code is returned.
+*/
+static int fts3AllocateSegdirIdx(
+  Fts3Table *p, 
+  int iLangid,                    /* Language id */
+  int iIndex,                     /* Index for p->aIndex */
+  int iLevel, 
+  int *piIdx
+){
+  int rc;                         /* Return Code */
+  sqlite3_stmt *pNextIdx;         /* Query for next idx at level iLevel */
+  int iNext = 0;                  /* Result of query pNextIdx */
+
+  assert( iLangid>=0 );
+  assert( p->nIndex>=1 );
+
+  /* Set variable iNext to the next available segdir index at level iLevel. */
+  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(
+        pNextIdx, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)
+    );
+    if( SQLITE_ROW==sqlite3_step(pNextIdx) ){
+      iNext = sqlite3_column_int(pNextIdx, 0);
+    }
+    rc = sqlite3_reset(pNextIdx);
+  }
+
+  if( rc==SQLITE_OK ){
+    /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already
+    ** full, merge all segments in level iLevel into a single iLevel+1
+    ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise,
+    ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.
+    */
+    if( iNext>=FTS3_MERGE_COUNT ){
+      fts3LogMerge(16, getAbsoluteLevel(p, iLangid, iIndex, iLevel));
+      rc = fts3SegmentMerge(p, iLangid, iIndex, iLevel);
+      *piIdx = 0;
+    }else{
+      *piIdx = iNext;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** The %_segments table is declared as follows:
+**
+**   CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB)
+**
+** This function reads data from a single row of the %_segments table. The
+** specific row is identified by the iBlockid parameter. If paBlob is not
+** NULL, then a buffer is allocated using sqlite3_malloc() and populated
+** with the contents of the blob stored in the "block" column of the 
+** identified table row is. Whether or not paBlob is NULL, *pnBlob is set
+** to the size of the blob in bytes before returning.
+**
+** If an error occurs, or the table does not contain the specified row,
+** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If
+** paBlob is non-NULL, then it is the responsibility of the caller to
+** eventually free the returned buffer.
+**
+** This function may leave an open sqlite3_blob* handle in the
+** Fts3Table.pSegments variable. This handle is reused by subsequent calls
+** to this function. The handle may be closed by calling the
+** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy
+** performance improvement, but the blob handle should always be closed
+** before control is returned to the user (to prevent a lock being held
+** on the database file for longer than necessary). Thus, any virtual table
+** method (xFilter etc.) that may directly or indirectly call this function
+** must call sqlite3Fts3SegmentsClose() before returning.
+*/
+SQLITE_PRIVATE int sqlite3Fts3ReadBlock(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iBlockid,         /* Access the row with blockid=$iBlockid */
+  char **paBlob,                  /* OUT: Blob data in malloc'd buffer */
+  int *pnBlob,                    /* OUT: Size of blob data */
+  int *pnLoad                     /* OUT: Bytes actually loaded */
+){
+  int rc;                         /* Return code */
+
+  /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */
+  assert( pnBlob );
+
+  if( p->pSegments ){
+    rc = sqlite3_blob_reopen(p->pSegments, iBlockid);
+  }else{
+    if( 0==p->zSegmentsTbl ){
+      p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName);
+      if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM;
+    }
+    rc = sqlite3_blob_open(
+       p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments
+    );
+  }
+
+  if( rc==SQLITE_OK ){
+    int nByte = sqlite3_blob_bytes(p->pSegments);
+    *pnBlob = nByte;
+    if( paBlob ){
+      char *aByte = sqlite3_malloc(nByte + FTS3_NODE_PADDING);
+      if( !aByte ){
+        rc = SQLITE_NOMEM;
+      }else{
+        if( pnLoad && nByte>(FTS3_NODE_CHUNK_THRESHOLD) ){
+          nByte = FTS3_NODE_CHUNKSIZE;
+          *pnLoad = nByte;
+        }
+        rc = sqlite3_blob_read(p->pSegments, aByte, nByte, 0);
+        memset(&aByte[nByte], 0, FTS3_NODE_PADDING);
+        if( rc!=SQLITE_OK ){
+          sqlite3_free(aByte);
+          aByte = 0;
+        }
+      }
+      *paBlob = aByte;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Close the blob handle at p->pSegments, if it is open. See comments above
+** the sqlite3Fts3ReadBlock() function for details.
+*/
+SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *p){
+  sqlite3_blob_close(p->pSegments);
+  p->pSegments = 0;
+}
+    
+static int fts3SegReaderIncrRead(Fts3SegReader *pReader){
+  int nRead;                      /* Number of bytes to read */
+  int rc;                         /* Return code */
+
+  nRead = MIN(pReader->nNode - pReader->nPopulate, FTS3_NODE_CHUNKSIZE);
+  rc = sqlite3_blob_read(
+      pReader->pBlob, 
+      &pReader->aNode[pReader->nPopulate],
+      nRead,
+      pReader->nPopulate
+  );
+
+  if( rc==SQLITE_OK ){
+    pReader->nPopulate += nRead;
+    memset(&pReader->aNode[pReader->nPopulate], 0, FTS3_NODE_PADDING);
+    if( pReader->nPopulate==pReader->nNode ){
+      sqlite3_blob_close(pReader->pBlob);
+      pReader->pBlob = 0;
+      pReader->nPopulate = 0;
+    }
+  }
+  return rc;
+}
+
+static int fts3SegReaderRequire(Fts3SegReader *pReader, char *pFrom, int nByte){
+  int rc = SQLITE_OK;
+  assert( !pReader->pBlob 
+       || (pFrom>=pReader->aNode && pFrom<&pReader->aNode[pReader->nNode])
+  );
+  while( pReader->pBlob && rc==SQLITE_OK 
+     &&  (pFrom - pReader->aNode + nByte)>pReader->nPopulate
+  ){
+    rc = fts3SegReaderIncrRead(pReader);
+  }
+  return rc;
+}
+
+/*
+** Set an Fts3SegReader cursor to point at EOF.
+*/
+static void fts3SegReaderSetEof(Fts3SegReader *pSeg){
+  if( !fts3SegReaderIsRootOnly(pSeg) ){
+    sqlite3_free(pSeg->aNode);
+    sqlite3_blob_close(pSeg->pBlob);
+    pSeg->pBlob = 0;
+  }
+  pSeg->aNode = 0;
+}
+
+/*
+** Move the iterator passed as the first argument to the next term in the
+** segment. If successful, SQLITE_OK is returned. If there is no next term,
+** SQLITE_DONE. Otherwise, an SQLite error code.
+*/
+static int fts3SegReaderNext(
+  Fts3Table *p, 
+  Fts3SegReader *pReader,
+  int bIncr
+){
+  int rc;                         /* Return code of various sub-routines */
+  char *pNext;                    /* Cursor variable */
+  int nPrefix;                    /* Number of bytes in term prefix */
+  int nSuffix;                    /* Number of bytes in term suffix */
+
+  if( !pReader->aDoclist ){
+    pNext = pReader->aNode;
+  }else{
+    pNext = &pReader->aDoclist[pReader->nDoclist];
+  }
+
+  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){
+
+    if( fts3SegReaderIsPending(pReader) ){
+      Fts3HashElem *pElem = *(pReader->ppNextElem);
+      sqlite3_free(pReader->aNode);
+      pReader->aNode = 0;
+      if( pElem ){
+        char *aCopy;
+        PendingList *pList = (PendingList *)fts3HashData(pElem);
+        int nCopy = pList->nData+1;
+        pReader->zTerm = (char *)fts3HashKey(pElem);
+        pReader->nTerm = fts3HashKeysize(pElem);
+        aCopy = (char*)sqlite3_malloc(nCopy);
+        if( !aCopy ) return SQLITE_NOMEM;
+        memcpy(aCopy, pList->aData, nCopy);
+        pReader->nNode = pReader->nDoclist = nCopy;
+        pReader->aNode = pReader->aDoclist = aCopy;
+        pReader->ppNextElem++;
+        assert( pReader->aNode );
+      }
+      return SQLITE_OK;
+    }
+
+    fts3SegReaderSetEof(pReader);
+
+    /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf 
+    ** blocks have already been traversed.  */
+    assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock );
+    if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){
+      return SQLITE_OK;
+    }
+
+    rc = sqlite3Fts3ReadBlock(
+        p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode, 
+        (bIncr ? &pReader->nPopulate : 0)
+    );
+    if( rc!=SQLITE_OK ) return rc;
+    assert( pReader->pBlob==0 );
+    if( bIncr && pReader->nPopulatenNode ){
+      pReader->pBlob = p->pSegments;
+      p->pSegments = 0;
+    }
+    pNext = pReader->aNode;
+  }
+
+  assert( !fts3SegReaderIsPending(pReader) );
+
+  rc = fts3SegReaderRequire(pReader, pNext, FTS3_VARINT_MAX*2);
+  if( rc!=SQLITE_OK ) return rc;
+  
+  /* Because of the FTS3_NODE_PADDING bytes of padding, the following is 
+  ** safe (no risk of overread) even if the node data is corrupted. */
+  pNext += fts3GetVarint32(pNext, &nPrefix);
+  pNext += fts3GetVarint32(pNext, &nSuffix);
+  if( nPrefix<0 || nSuffix<=0 
+   || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] 
+  ){
+    return FTS_CORRUPT_VTAB;
+  }
+
+  if( nPrefix+nSuffix>pReader->nTermAlloc ){
+    int nNew = (nPrefix+nSuffix)*2;
+    char *zNew = sqlite3_realloc(pReader->zTerm, nNew);
+    if( !zNew ){
+      return SQLITE_NOMEM;
+    }
+    pReader->zTerm = zNew;
+    pReader->nTermAlloc = nNew;
+  }
+
+  rc = fts3SegReaderRequire(pReader, pNext, nSuffix+FTS3_VARINT_MAX);
+  if( rc!=SQLITE_OK ) return rc;
+
+  memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);
+  pReader->nTerm = nPrefix+nSuffix;
+  pNext += nSuffix;
+  pNext += fts3GetVarint32(pNext, &pReader->nDoclist);
+  pReader->aDoclist = pNext;
+  pReader->pOffsetList = 0;
+
+  /* Check that the doclist does not appear to extend past the end of the
+  ** b-tree node. And that the final byte of the doclist is 0x00. If either 
+  ** of these statements is untrue, then the data structure is corrupt.
+  */
+  if( &pReader->aDoclist[pReader->nDoclist]>&pReader->aNode[pReader->nNode] 
+   || (pReader->nPopulate==0 && pReader->aDoclist[pReader->nDoclist-1])
+  ){
+    return FTS_CORRUPT_VTAB;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Set the SegReader to point to the first docid in the doclist associated
+** with the current term.
+*/
+static int fts3SegReaderFirstDocid(Fts3Table *pTab, Fts3SegReader *pReader){
+  int rc = SQLITE_OK;
+  assert( pReader->aDoclist );
+  assert( !pReader->pOffsetList );
+  if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){
+    u8 bEof = 0;
+    pReader->iDocid = 0;
+    pReader->nOffsetList = 0;
+    sqlite3Fts3DoclistPrev(0,
+        pReader->aDoclist, pReader->nDoclist, &pReader->pOffsetList, 
+        &pReader->iDocid, &pReader->nOffsetList, &bEof
+    );
+  }else{
+    rc = fts3SegReaderRequire(pReader, pReader->aDoclist, FTS3_VARINT_MAX);
+    if( rc==SQLITE_OK ){
+      int n = sqlite3Fts3GetVarint(pReader->aDoclist, &pReader->iDocid);
+      pReader->pOffsetList = &pReader->aDoclist[n];
+    }
+  }
+  return rc;
+}
+
+/*
+** Advance the SegReader to point to the next docid in the doclist
+** associated with the current term.
+** 
+** If arguments ppOffsetList and pnOffsetList are not NULL, then 
+** *ppOffsetList is set to point to the first column-offset list
+** in the doclist entry (i.e. immediately past the docid varint).
+** *pnOffsetList is set to the length of the set of column-offset
+** lists, not including the nul-terminator byte. For example:
+*/
+static int fts3SegReaderNextDocid(
+  Fts3Table *pTab,
+  Fts3SegReader *pReader,         /* Reader to advance to next docid */
+  char **ppOffsetList,            /* OUT: Pointer to current position-list */
+  int *pnOffsetList               /* OUT: Length of *ppOffsetList in bytes */
+){
+  int rc = SQLITE_OK;
+  char *p = pReader->pOffsetList;
+  char c = 0;
+
+  assert( p );
+
+  if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){
+    /* A pending-terms seg-reader for an FTS4 table that uses order=desc.
+    ** Pending-terms doclists are always built up in ascending order, so
+    ** we have to iterate through them backwards here. */
+    u8 bEof = 0;
+    if( ppOffsetList ){
+      *ppOffsetList = pReader->pOffsetList;
+      *pnOffsetList = pReader->nOffsetList - 1;
+    }
+    sqlite3Fts3DoclistPrev(0,
+        pReader->aDoclist, pReader->nDoclist, &p, &pReader->iDocid,
+        &pReader->nOffsetList, &bEof
+    );
+    if( bEof ){
+      pReader->pOffsetList = 0;
+    }else{
+      pReader->pOffsetList = p;
+    }
+  }else{
+    char *pEnd = &pReader->aDoclist[pReader->nDoclist];
+
+    /* Pointer p currently points at the first byte of an offset list. The
+    ** following block advances it to point one byte past the end of
+    ** the same offset list. */
+    while( 1 ){
+  
+      /* The following line of code (and the "p++" below the while() loop) is
+      ** normally all that is required to move pointer p to the desired 
+      ** position. The exception is if this node is being loaded from disk
+      ** incrementally and pointer "p" now points to the first byte past
+      ** the populated part of pReader->aNode[].
+      */
+      while( *p | c ) c = *p++ & 0x80;
+      assert( *p==0 );
+  
+      if( pReader->pBlob==0 || p<&pReader->aNode[pReader->nPopulate] ) break;
+      rc = fts3SegReaderIncrRead(pReader);
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    p++;
+  
+    /* If required, populate the output variables with a pointer to and the
+    ** size of the previous offset-list.
+    */
+    if( ppOffsetList ){
+      *ppOffsetList = pReader->pOffsetList;
+      *pnOffsetList = (int)(p - pReader->pOffsetList - 1);
+    }
+
+    /* List may have been edited in place by fts3EvalNearTrim() */
+    while( p=pEnd ){
+      pReader->pOffsetList = 0;
+    }else{
+      rc = fts3SegReaderRequire(pReader, p, FTS3_VARINT_MAX);
+      if( rc==SQLITE_OK ){
+        sqlite3_int64 iDelta;
+        pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta);
+        if( pTab->bDescIdx ){
+          pReader->iDocid -= iDelta;
+        }else{
+          pReader->iDocid += iDelta;
+        }
+      }
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+
+SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(
+  Fts3Cursor *pCsr, 
+  Fts3MultiSegReader *pMsr,
+  int *pnOvfl
+){
+  Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;
+  int nOvfl = 0;
+  int ii;
+  int rc = SQLITE_OK;
+  int pgsz = p->nPgsz;
+
+  assert( p->bFts4 );
+  assert( pgsz>0 );
+
+  for(ii=0; rc==SQLITE_OK && iinSegment; ii++){
+    Fts3SegReader *pReader = pMsr->apSegment[ii];
+    if( !fts3SegReaderIsPending(pReader) 
+     && !fts3SegReaderIsRootOnly(pReader) 
+    ){
+      sqlite3_int64 jj;
+      for(jj=pReader->iStartBlock; jj<=pReader->iLeafEndBlock; jj++){
+        int nBlob;
+        rc = sqlite3Fts3ReadBlock(p, jj, 0, &nBlob, 0);
+        if( rc!=SQLITE_OK ) break;
+        if( (nBlob+35)>pgsz ){
+          nOvfl += (nBlob + 34)/pgsz;
+        }
+      }
+    }
+  }
+  *pnOvfl = nOvfl;
+  return rc;
+}
+
+/*
+** Free all allocations associated with the iterator passed as the 
+** second argument.
+*/
+SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){
+  if( pReader ){
+    if( !fts3SegReaderIsPending(pReader) ){
+      sqlite3_free(pReader->zTerm);
+    }
+    if( !fts3SegReaderIsRootOnly(pReader) ){
+      sqlite3_free(pReader->aNode);
+    }
+    sqlite3_blob_close(pReader->pBlob);
+  }
+  sqlite3_free(pReader);
+}
+
+/*
+** Allocate a new SegReader object.
+*/
+SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
+  int iAge,                       /* Segment "age". */
+  int bLookup,                    /* True for a lookup only */
+  sqlite3_int64 iStartLeaf,       /* First leaf to traverse */
+  sqlite3_int64 iEndLeaf,         /* Final leaf to traverse */
+  sqlite3_int64 iEndBlock,        /* Final block of segment */
+  const char *zRoot,              /* Buffer containing root node */
+  int nRoot,                      /* Size of buffer containing root node */
+  Fts3SegReader **ppReader        /* OUT: Allocated Fts3SegReader */
+){
+  Fts3SegReader *pReader;         /* Newly allocated SegReader object */
+  int nExtra = 0;                 /* Bytes to allocate segment root node */
+
+  assert( iStartLeaf<=iEndLeaf );
+  if( iStartLeaf==0 ){
+    nExtra = nRoot + FTS3_NODE_PADDING;
+  }
+
+  pReader = (Fts3SegReader *)sqlite3_malloc(sizeof(Fts3SegReader) + nExtra);
+  if( !pReader ){
+    return SQLITE_NOMEM;
+  }
+  memset(pReader, 0, sizeof(Fts3SegReader));
+  pReader->iIdx = iAge;
+  pReader->bLookup = bLookup!=0;
+  pReader->iStartBlock = iStartLeaf;
+  pReader->iLeafEndBlock = iEndLeaf;
+  pReader->iEndBlock = iEndBlock;
+
+  if( nExtra ){
+    /* The entire segment is stored in the root node. */
+    pReader->aNode = (char *)&pReader[1];
+    pReader->rootOnly = 1;
+    pReader->nNode = nRoot;
+    memcpy(pReader->aNode, zRoot, nRoot);
+    memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING);
+  }else{
+    pReader->iCurrentBlock = iStartLeaf-1;
+  }
+  *ppReader = pReader;
+  return SQLITE_OK;
+}
+
+/*
+** This is a comparison function used as a qsort() callback when sorting
+** an array of pending terms by term. This occurs as part of flushing
+** the contents of the pending-terms hash table to the database.
+*/
+static int SQLITE_CDECL fts3CompareElemByTerm(
+  const void *lhs,
+  const void *rhs
+){
+  char *z1 = fts3HashKey(*(Fts3HashElem **)lhs);
+  char *z2 = fts3HashKey(*(Fts3HashElem **)rhs);
+  int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs);
+  int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs);
+
+  int n = (n1aIndex */
+  const char *zTerm,              /* Term to search for */
+  int nTerm,                      /* Size of buffer zTerm */
+  int bPrefix,                    /* True for a prefix iterator */
+  Fts3SegReader **ppReader        /* OUT: SegReader for pending-terms */
+){
+  Fts3SegReader *pReader = 0;     /* Fts3SegReader object to return */
+  Fts3HashElem *pE;               /* Iterator variable */
+  Fts3HashElem **aElem = 0;       /* Array of term hash entries to scan */
+  int nElem = 0;                  /* Size of array at aElem */
+  int rc = SQLITE_OK;             /* Return Code */
+  Fts3Hash *pHash;
+
+  pHash = &p->aIndex[iIndex].hPending;
+  if( bPrefix ){
+    int nAlloc = 0;               /* Size of allocated array at aElem */
+
+    for(pE=fts3HashFirst(pHash); pE; pE=fts3HashNext(pE)){
+      char *zKey = (char *)fts3HashKey(pE);
+      int nKey = fts3HashKeysize(pE);
+      if( nTerm==0 || (nKey>=nTerm && 0==memcmp(zKey, zTerm, nTerm)) ){
+        if( nElem==nAlloc ){
+          Fts3HashElem **aElem2;
+          nAlloc += 16;
+          aElem2 = (Fts3HashElem **)sqlite3_realloc(
+              aElem, nAlloc*sizeof(Fts3HashElem *)
+          );
+          if( !aElem2 ){
+            rc = SQLITE_NOMEM;
+            nElem = 0;
+            break;
+          }
+          aElem = aElem2;
+        }
+
+        aElem[nElem++] = pE;
+      }
+    }
+
+    /* If more than one term matches the prefix, sort the Fts3HashElem
+    ** objects in term order using qsort(). This uses the same comparison
+    ** callback as is used when flushing terms to disk.
+    */
+    if( nElem>1 ){
+      qsort(aElem, nElem, sizeof(Fts3HashElem *), fts3CompareElemByTerm);
+    }
+
+  }else{
+    /* The query is a simple term lookup that matches at most one term in
+    ** the index. All that is required is a straight hash-lookup. 
+    **
+    ** Because the stack address of pE may be accessed via the aElem pointer
+    ** below, the "Fts3HashElem *pE" must be declared so that it is valid
+    ** within this entire function, not just this "else{...}" block.
+    */
+    pE = fts3HashFindElem(pHash, zTerm, nTerm);
+    if( pE ){
+      aElem = &pE;
+      nElem = 1;
+    }
+  }
+
+  if( nElem>0 ){
+    int nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *);
+    pReader = (Fts3SegReader *)sqlite3_malloc(nByte);
+    if( !pReader ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pReader, 0, nByte);
+      pReader->iIdx = 0x7FFFFFFF;
+      pReader->ppNextElem = (Fts3HashElem **)&pReader[1];
+      memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *));
+    }
+  }
+
+  if( bPrefix ){
+    sqlite3_free(aElem);
+  }
+  *ppReader = pReader;
+  return rc;
+}
+
+/*
+** Compare the entries pointed to by two Fts3SegReader structures. 
+** Comparison is as follows:
+**
+**   1) EOF is greater than not EOF.
+**
+**   2) The current terms (if any) are compared using memcmp(). If one
+**      term is a prefix of another, the longer term is considered the
+**      larger.
+**
+**   3) By segment age. An older segment is considered larger.
+*/
+static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){
+  int rc;
+  if( pLhs->aNode && pRhs->aNode ){
+    int rc2 = pLhs->nTerm - pRhs->nTerm;
+    if( rc2<0 ){
+      rc = memcmp(pLhs->zTerm, pRhs->zTerm, pLhs->nTerm);
+    }else{
+      rc = memcmp(pLhs->zTerm, pRhs->zTerm, pRhs->nTerm);
+    }
+    if( rc==0 ){
+      rc = rc2;
+    }
+  }else{
+    rc = (pLhs->aNode==0) - (pRhs->aNode==0);
+  }
+  if( rc==0 ){
+    rc = pRhs->iIdx - pLhs->iIdx;
+  }
+  assert( rc!=0 );
+  return rc;
+}
+
+/*
+** A different comparison function for SegReader structures. In this
+** version, it is assumed that each SegReader points to an entry in
+** a doclist for identical terms. Comparison is made as follows:
+**
+**   1) EOF (end of doclist in this case) is greater than not EOF.
+**
+**   2) By current docid.
+**
+**   3) By segment age. An older segment is considered larger.
+*/
+static int fts3SegReaderDoclistCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){
+  int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0);
+  if( rc==0 ){
+    if( pLhs->iDocid==pRhs->iDocid ){
+      rc = pRhs->iIdx - pLhs->iIdx;
+    }else{
+      rc = (pLhs->iDocid > pRhs->iDocid) ? 1 : -1;
+    }
+  }
+  assert( pLhs->aNode && pRhs->aNode );
+  return rc;
+}
+static int fts3SegReaderDoclistCmpRev(Fts3SegReader *pLhs, Fts3SegReader *pRhs){
+  int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0);
+  if( rc==0 ){
+    if( pLhs->iDocid==pRhs->iDocid ){
+      rc = pRhs->iIdx - pLhs->iIdx;
+    }else{
+      rc = (pLhs->iDocid < pRhs->iDocid) ? 1 : -1;
+    }
+  }
+  assert( pLhs->aNode && pRhs->aNode );
+  return rc;
+}
+
+/*
+** Compare the term that the Fts3SegReader object passed as the first argument
+** points to with the term specified by arguments zTerm and nTerm. 
+**
+** If the pSeg iterator is already at EOF, return 0. Otherwise, return
+** -ve if the pSeg term is less than zTerm/nTerm, 0 if the two terms are
+** equal, or +ve if the pSeg term is greater than zTerm/nTerm.
+*/
+static int fts3SegReaderTermCmp(
+  Fts3SegReader *pSeg,            /* Segment reader object */
+  const char *zTerm,              /* Term to compare to */
+  int nTerm                       /* Size of term zTerm in bytes */
+){
+  int res = 0;
+  if( pSeg->aNode ){
+    if( pSeg->nTerm>nTerm ){
+      res = memcmp(pSeg->zTerm, zTerm, nTerm);
+    }else{
+      res = memcmp(pSeg->zTerm, zTerm, pSeg->nTerm);
+    }
+    if( res==0 ){
+      res = pSeg->nTerm-nTerm;
+    }
+  }
+  return res;
+}
+
+/*
+** Argument apSegment is an array of nSegment elements. It is known that
+** the final (nSegment-nSuspect) members are already in sorted order
+** (according to the comparison function provided). This function shuffles
+** the array around until all entries are in sorted order.
+*/
+static void fts3SegReaderSort(
+  Fts3SegReader **apSegment,                     /* Array to sort entries of */
+  int nSegment,                                  /* Size of apSegment array */
+  int nSuspect,                                  /* Unsorted entry count */
+  int (*xCmp)(Fts3SegReader *, Fts3SegReader *)  /* Comparison function */
+){
+  int i;                          /* Iterator variable */
+
+  assert( nSuspect<=nSegment );
+
+  if( nSuspect==nSegment ) nSuspect--;
+  for(i=nSuspect-1; i>=0; i--){
+    int j;
+    for(j=i; j<(nSegment-1); j++){
+      Fts3SegReader *pTmp;
+      if( xCmp(apSegment[j], apSegment[j+1])<0 ) break;
+      pTmp = apSegment[j+1];
+      apSegment[j+1] = apSegment[j];
+      apSegment[j] = pTmp;
+    }
+  }
+
+#ifndef NDEBUG
+  /* Check that the list really is sorted now. */
+  for(i=0; i<(nSuspect-1); i++){
+    assert( xCmp(apSegment[i], apSegment[i+1])<0 );
+  }
+#endif
+}
+
+/* 
+** Insert a record into the %_segments table.
+*/
+static int fts3WriteSegment(
+  Fts3Table *p,                   /* Virtual table handle */
+  sqlite3_int64 iBlock,           /* Block id for new block */
+  char *z,                        /* Pointer to buffer containing block data */
+  int n                           /* Size of buffer z in bytes */
+){
+  sqlite3_stmt *pStmt;
+  int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pStmt, 1, iBlock);
+    sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);
+    sqlite3_step(pStmt);
+    rc = sqlite3_reset(pStmt);
+  }
+  return rc;
+}
+
+/*
+** Find the largest relative level number in the table. If successful, set
+** *pnMax to this value and return SQLITE_OK. Otherwise, if an error occurs,
+** set *pnMax to zero and return an SQLite error code.
+*/
+SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *p, int *pnMax){
+  int rc;
+  int mxLevel = 0;
+  sqlite3_stmt *pStmt = 0;
+
+  rc = fts3SqlStmt(p, SQL_SELECT_MXLEVEL, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pStmt) ){
+      mxLevel = sqlite3_column_int(pStmt, 0);
+    }
+    rc = sqlite3_reset(pStmt);
+  }
+  *pnMax = mxLevel;
+  return rc;
+}
+
+/* 
+** Insert a record into the %_segdir table.
+*/
+static int fts3WriteSegdir(
+  Fts3Table *p,                   /* Virtual table handle */
+  sqlite3_int64 iLevel,           /* Value for "level" field (absolute level) */
+  int iIdx,                       /* Value for "idx" field */
+  sqlite3_int64 iStartBlock,      /* Value for "start_block" field */
+  sqlite3_int64 iLeafEndBlock,    /* Value for "leaves_end_block" field */
+  sqlite3_int64 iEndBlock,        /* Value for "end_block" field */
+  sqlite3_int64 nLeafData,        /* Bytes of leaf data in segment */
+  char *zRoot,                    /* Blob value for "root" field */
+  int nRoot                       /* Number of bytes in buffer zRoot */
+){
+  sqlite3_stmt *pStmt;
+  int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pStmt, 1, iLevel);
+    sqlite3_bind_int(pStmt, 2, iIdx);
+    sqlite3_bind_int64(pStmt, 3, iStartBlock);
+    sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);
+    if( nLeafData==0 ){
+      sqlite3_bind_int64(pStmt, 5, iEndBlock);
+    }else{
+      char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);
+      if( !zEnd ) return SQLITE_NOMEM;
+      sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);
+    }
+    sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
+    sqlite3_step(pStmt);
+    rc = sqlite3_reset(pStmt);
+  }
+  return rc;
+}
+
+/*
+** Return the size of the common prefix (if any) shared by zPrev and
+** zNext, in bytes. For example, 
+**
+**   fts3PrefixCompress("abc", 3, "abcdef", 6)   // returns 3
+**   fts3PrefixCompress("abX", 3, "abcdef", 6)   // returns 2
+**   fts3PrefixCompress("abX", 3, "Xbcdef", 6)   // returns 0
+*/
+static int fts3PrefixCompress(
+  const char *zPrev,              /* Buffer containing previous term */
+  int nPrev,                      /* Size of buffer zPrev in bytes */
+  const char *zNext,              /* Buffer containing next term */
+  int nNext                       /* Size of buffer zNext in bytes */
+){
+  int n;
+  UNUSED_PARAMETER(nNext);
+  for(n=0; nnData;     /* Current size of node in bytes */
+    int nReq = nData;             /* Required space after adding zTerm */
+    int nPrefix;                  /* Number of bytes of prefix compression */
+    int nSuffix;                  /* Suffix length */
+
+    nPrefix = fts3PrefixCompress(pTree->zTerm, pTree->nTerm, zTerm, nTerm);
+    nSuffix = nTerm-nPrefix;
+
+    nReq += sqlite3Fts3VarintLen(nPrefix)+sqlite3Fts3VarintLen(nSuffix)+nSuffix;
+    if( nReq<=p->nNodeSize || !pTree->zTerm ){
+
+      if( nReq>p->nNodeSize ){
+        /* An unusual case: this is the first term to be added to the node
+        ** and the static node buffer (p->nNodeSize bytes) is not large
+        ** enough. Use a separately malloced buffer instead This wastes
+        ** p->nNodeSize bytes, but since this scenario only comes about when
+        ** the database contain two terms that share a prefix of almost 2KB, 
+        ** this is not expected to be a serious problem. 
+        */
+        assert( pTree->aData==(char *)&pTree[1] );
+        pTree->aData = (char *)sqlite3_malloc(nReq);
+        if( !pTree->aData ){
+          return SQLITE_NOMEM;
+        }
+      }
+
+      if( pTree->zTerm ){
+        /* There is no prefix-length field for first term in a node */
+        nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nPrefix);
+      }
+
+      nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nSuffix);
+      memcpy(&pTree->aData[nData], &zTerm[nPrefix], nSuffix);
+      pTree->nData = nData + nSuffix;
+      pTree->nEntry++;
+
+      if( isCopyTerm ){
+        if( pTree->nMalloczMalloc, nTerm*2);
+          if( !zNew ){
+            return SQLITE_NOMEM;
+          }
+          pTree->nMalloc = nTerm*2;
+          pTree->zMalloc = zNew;
+        }
+        pTree->zTerm = pTree->zMalloc;
+        memcpy(pTree->zTerm, zTerm, nTerm);
+        pTree->nTerm = nTerm;
+      }else{
+        pTree->zTerm = (char *)zTerm;
+        pTree->nTerm = nTerm;
+      }
+      return SQLITE_OK;
+    }
+  }
 
-      assert( (pStart->wtFlags & TERM_VNULL)==0 );
-      testcase( pStart->wtFlags & TERM_VIRTUAL );
-      pX = pStart->pExpr;
-      assert( pX!=0 );
-      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
-      r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
-      sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
-      VdbeComment((v, "pk"));
-      VdbeCoverageIf(v, pX->op==TK_GT);
-      VdbeCoverageIf(v, pX->op==TK_LE);
-      VdbeCoverageIf(v, pX->op==TK_LT);
-      VdbeCoverageIf(v, pX->op==TK_GE);
-      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
-      sqlite3ReleaseTempReg(pParse, rTemp);
-      disableTerm(pLevel, pStart);
-    }else{
-      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
-      VdbeCoverageIf(v, bRev==0);
-      VdbeCoverageIf(v, bRev!=0);
+  /* If control flows to here, it was not possible to append zTerm to the
+  ** current node. Create a new node (a right-sibling of the current node).
+  ** If this is the first node in the tree, the term is added to it.
+  **
+  ** Otherwise, the term is not added to the new node, it is left empty for
+  ** now. Instead, the term is inserted into the parent of pTree. If pTree 
+  ** has no parent, one is created here.
+  */
+  pNew = (SegmentNode *)sqlite3_malloc(sizeof(SegmentNode) + p->nNodeSize);
+  if( !pNew ){
+    return SQLITE_NOMEM;
+  }
+  memset(pNew, 0, sizeof(SegmentNode));
+  pNew->nData = 1 + FTS3_VARINT_MAX;
+  pNew->aData = (char *)&pNew[1];
+
+  if( pTree ){
+    SegmentNode *pParent = pTree->pParent;
+    rc = fts3NodeAddTerm(p, &pParent, isCopyTerm, zTerm, nTerm);
+    if( pTree->pParent==0 ){
+      pTree->pParent = pParent;
     }
-    if( pEnd ){
-      Expr *pX;
-      pX = pEnd->pExpr;
-      assert( pX!=0 );
-      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
-      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
-      testcase( pEnd->wtFlags & TERM_VIRTUAL );
-      memEndValue = ++pParse->nMem;
-      sqlite3ExprCode(pParse, pX->pRight, memEndValue);
-      if( pX->op==TK_LT || pX->op==TK_GT ){
-        testOp = bRev ? OP_Le : OP_Ge;
-      }else{
-        testOp = bRev ? OP_Lt : OP_Gt;
+    pTree->pRight = pNew;
+    pNew->pLeftmost = pTree->pLeftmost;
+    pNew->pParent = pParent;
+    pNew->zMalloc = pTree->zMalloc;
+    pNew->nMalloc = pTree->nMalloc;
+    pTree->zMalloc = 0;
+  }else{
+    pNew->pLeftmost = pNew;
+    rc = fts3NodeAddTerm(p, &pNew, isCopyTerm, zTerm, nTerm); 
+  }
+
+  *ppTree = pNew;
+  return rc;
+}
+
+/*
+** Helper function for fts3NodeWrite().
+*/
+static int fts3TreeFinishNode(
+  SegmentNode *pTree, 
+  int iHeight, 
+  sqlite3_int64 iLeftChild
+){
+  int nStart;
+  assert( iHeight>=1 && iHeight<128 );
+  nStart = FTS3_VARINT_MAX - sqlite3Fts3VarintLen(iLeftChild);
+  pTree->aData[nStart] = (char)iHeight;
+  sqlite3Fts3PutVarint(&pTree->aData[nStart+1], iLeftChild);
+  return nStart;
+}
+
+/*
+** Write the buffer for the segment node pTree and all of its peers to the
+** database. Then call this function recursively to write the parent of 
+** pTree and its peers to the database. 
+**
+** Except, if pTree is a root node, do not write it to the database. Instead,
+** set output variables *paRoot and *pnRoot to contain the root node.
+**
+** If successful, SQLITE_OK is returned and output variable *piLast is
+** set to the largest blockid written to the database (or zero if no
+** blocks were written to the db). Otherwise, an SQLite error code is 
+** returned.
+*/
+static int fts3NodeWrite(
+  Fts3Table *p,                   /* Virtual table handle */
+  SegmentNode *pTree,             /* SegmentNode handle */
+  int iHeight,                    /* Height of this node in tree */
+  sqlite3_int64 iLeaf,            /* Block id of first leaf node */
+  sqlite3_int64 iFree,            /* Block id of next free slot in %_segments */
+  sqlite3_int64 *piLast,          /* OUT: Block id of last entry written */
+  char **paRoot,                  /* OUT: Data for root node */
+  int *pnRoot                     /* OUT: Size of root node in bytes */
+){
+  int rc = SQLITE_OK;
+
+  if( !pTree->pParent ){
+    /* Root node of the tree. */
+    int nStart = fts3TreeFinishNode(pTree, iHeight, iLeaf);
+    *piLast = iFree-1;
+    *pnRoot = pTree->nData - nStart;
+    *paRoot = &pTree->aData[nStart];
+  }else{
+    SegmentNode *pIter;
+    sqlite3_int64 iNextFree = iFree;
+    sqlite3_int64 iNextLeaf = iLeaf;
+    for(pIter=pTree->pLeftmost; pIter && rc==SQLITE_OK; pIter=pIter->pRight){
+      int nStart = fts3TreeFinishNode(pIter, iHeight, iNextLeaf);
+      int nWrite = pIter->nData - nStart;
+  
+      rc = fts3WriteSegment(p, iNextFree, &pIter->aData[nStart], nWrite);
+      iNextFree++;
+      iNextLeaf += (pIter->nEntry+1);
+    }
+    if( rc==SQLITE_OK ){
+      assert( iNextLeaf==iFree );
+      rc = fts3NodeWrite(
+          p, pTree->pParent, iHeight+1, iFree, iNextFree, piLast, paRoot, pnRoot
+      );
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Free all memory allocations associated with the tree pTree.
+*/
+static void fts3NodeFree(SegmentNode *pTree){
+  if( pTree ){
+    SegmentNode *p = pTree->pLeftmost;
+    fts3NodeFree(p->pParent);
+    while( p ){
+      SegmentNode *pRight = p->pRight;
+      if( p->aData!=(char *)&p[1] ){
+        sqlite3_free(p->aData);
       }
-      disableTerm(pLevel, pEnd);
+      assert( pRight==0 || p->zMalloc==0 );
+      sqlite3_free(p->zMalloc);
+      sqlite3_free(p);
+      p = pRight;
     }
-    start = sqlite3VdbeCurrentAddr(v);
-    pLevel->op = bRev ? OP_Prev : OP_Next;
-    pLevel->p1 = iCur;
-    pLevel->p2 = start;
-    assert( pLevel->p5==0 );
-    if( testOp!=OP_Noop ){
-      iRowidReg = ++pParse->nMem;
-      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
-      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
-      VdbeCoverageIf(v, testOp==OP_Le);
-      VdbeCoverageIf(v, testOp==OP_Lt);
-      VdbeCoverageIf(v, testOp==OP_Ge);
-      VdbeCoverageIf(v, testOp==OP_Gt);
-      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+  }
+}
+
+/*
+** Add a term to the segment being constructed by the SegmentWriter object
+** *ppWriter. When adding the first term to a segment, *ppWriter should
+** be passed NULL. This function will allocate a new SegmentWriter object
+** and return it via the input/output variable *ppWriter in this case.
+**
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
+*/
+static int fts3SegWriterAdd(
+  Fts3Table *p,                   /* Virtual table handle */
+  SegmentWriter **ppWriter,       /* IN/OUT: SegmentWriter handle */ 
+  int isCopyTerm,                 /* True if buffer zTerm must be copied */
+  const char *zTerm,              /* Pointer to buffer containing term */
+  int nTerm,                      /* Size of term in bytes */
+  const char *aDoclist,           /* Pointer to buffer containing doclist */
+  int nDoclist                    /* Size of doclist in bytes */
+){
+  int nPrefix;                    /* Size of term prefix in bytes */
+  int nSuffix;                    /* Size of term suffix in bytes */
+  int nReq;                       /* Number of bytes required on leaf page */
+  int nData;
+  SegmentWriter *pWriter = *ppWriter;
+
+  if( !pWriter ){
+    int rc;
+    sqlite3_stmt *pStmt;
+
+    /* Allocate the SegmentWriter structure */
+    pWriter = (SegmentWriter *)sqlite3_malloc(sizeof(SegmentWriter));
+    if( !pWriter ) return SQLITE_NOMEM;
+    memset(pWriter, 0, sizeof(SegmentWriter));
+    *ppWriter = pWriter;
+
+    /* Allocate a buffer in which to accumulate data */
+    pWriter->aData = (char *)sqlite3_malloc(p->nNodeSize);
+    if( !pWriter->aData ) return SQLITE_NOMEM;
+    pWriter->nSize = p->nNodeSize;
+
+    /* Find the next free blockid in the %_segments table */
+    rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pStmt, 0);
+    if( rc!=SQLITE_OK ) return rc;
+    if( SQLITE_ROW==sqlite3_step(pStmt) ){
+      pWriter->iFree = sqlite3_column_int64(pStmt, 0);
+      pWriter->iFirst = pWriter->iFree;
     }
-  }else if( pLoop->wsFlags & WHERE_INDEXED ){
-    /* Case 4: A scan using an index.
-    **
-    **         The WHERE clause may contain zero or more equality 
-    **         terms ("==" or "IN" operators) that refer to the N
-    **         left-most columns of the index. It may also contain
-    **         inequality constraints (>, <, >= or <=) on the indexed
-    **         column that immediately follows the N equalities. Only 
-    **         the right-most column can be an inequality - the rest must
-    **         use the "==" and "IN" operators. For example, if the 
-    **         index is on (x,y,z), then the following clauses are all 
-    **         optimized:
-    **
-    **            x=5
-    **            x=5 AND y=10
-    **            x=5 AND y<10
-    **            x=5 AND y>5 AND y<10
-    **            x=5 AND y=5 AND z<=10
+    rc = sqlite3_reset(pStmt);
+    if( rc!=SQLITE_OK ) return rc;
+  }
+  nData = pWriter->nData;
+
+  nPrefix = fts3PrefixCompress(pWriter->zTerm, pWriter->nTerm, zTerm, nTerm);
+  nSuffix = nTerm-nPrefix;
+
+  /* Figure out how many bytes are required by this new entry */
+  nReq = sqlite3Fts3VarintLen(nPrefix) +    /* varint containing prefix size */
+    sqlite3Fts3VarintLen(nSuffix) +         /* varint containing suffix size */
+    nSuffix +                               /* Term suffix */
+    sqlite3Fts3VarintLen(nDoclist) +        /* Size of doclist */
+    nDoclist;                               /* Doclist data */
+
+  if( nData>0 && nData+nReq>p->nNodeSize ){
+    int rc;
+
+    /* The current leaf node is full. Write it out to the database. */
+    rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData);
+    if( rc!=SQLITE_OK ) return rc;
+    p->nLeafAdd++;
+
+    /* Add the current term to the interior node tree. The term added to
+    ** the interior tree must:
     **
-    **         The z<10 term of the following cannot be used, only
-    **         the x=5 term:
+    **   a) be greater than the largest term on the leaf node just written
+    **      to the database (still available in pWriter->zTerm), and
     **
-    **            x=5 AND z<10
+    **   b) be less than or equal to the term about to be added to the new
+    **      leaf node (zTerm/nTerm).
     **
-    **         N may be zero if there are inequality constraints.
-    **         If there are no inequality constraints, then N is at
-    **         least one.
+    ** In other words, it must be the prefix of zTerm 1 byte longer than
+    ** the common prefix (if any) of zTerm and pWriter->zTerm.
+    */
+    assert( nPrefixpTree, isCopyTerm, zTerm, nPrefix+1);
+    if( rc!=SQLITE_OK ) return rc;
+
+    nData = 0;
+    pWriter->nTerm = 0;
+
+    nPrefix = 0;
+    nSuffix = nTerm;
+    nReq = 1 +                              /* varint containing prefix size */
+      sqlite3Fts3VarintLen(nTerm) +         /* varint containing suffix size */
+      nTerm +                               /* Term suffix */
+      sqlite3Fts3VarintLen(nDoclist) +      /* Size of doclist */
+      nDoclist;                             /* Doclist data */
+  }
+
+  /* Increase the total number of bytes written to account for the new entry. */
+  pWriter->nLeafData += nReq;
+
+  /* If the buffer currently allocated is too small for this entry, realloc
+  ** the buffer to make it large enough.
+  */
+  if( nReq>pWriter->nSize ){
+    char *aNew = sqlite3_realloc(pWriter->aData, nReq);
+    if( !aNew ) return SQLITE_NOMEM;
+    pWriter->aData = aNew;
+    pWriter->nSize = nReq;
+  }
+  assert( nData+nReq<=pWriter->nSize );
+
+  /* Append the prefix-compressed term and doclist to the buffer. */
+  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nPrefix);
+  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nSuffix);
+  memcpy(&pWriter->aData[nData], &zTerm[nPrefix], nSuffix);
+  nData += nSuffix;
+  nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nDoclist);
+  memcpy(&pWriter->aData[nData], aDoclist, nDoclist);
+  pWriter->nData = nData + nDoclist;
+
+  /* Save the current term so that it can be used to prefix-compress the next.
+  ** If the isCopyTerm parameter is true, then the buffer pointed to by
+  ** zTerm is transient, so take a copy of the term data. Otherwise, just
+  ** store a copy of the pointer.
+  */
+  if( isCopyTerm ){
+    if( nTerm>pWriter->nMalloc ){
+      char *zNew = sqlite3_realloc(pWriter->zMalloc, nTerm*2);
+      if( !zNew ){
+        return SQLITE_NOMEM;
+      }
+      pWriter->nMalloc = nTerm*2;
+      pWriter->zMalloc = zNew;
+      pWriter->zTerm = zNew;
+    }
+    assert( pWriter->zTerm==pWriter->zMalloc );
+    memcpy(pWriter->zTerm, zTerm, nTerm);
+  }else{
+    pWriter->zTerm = (char *)zTerm;
+  }
+  pWriter->nTerm = nTerm;
+
+  return SQLITE_OK;
+}
+
+/*
+** Flush all data associated with the SegmentWriter object pWriter to the
+** database. This function must be called after all terms have been added
+** to the segment using fts3SegWriterAdd(). If successful, SQLITE_OK is
+** returned. Otherwise, an SQLite error code.
+*/
+static int fts3SegWriterFlush(
+  Fts3Table *p,                   /* Virtual table handle */
+  SegmentWriter *pWriter,         /* SegmentWriter to flush to the db */
+  sqlite3_int64 iLevel,           /* Value for 'level' column of %_segdir */
+  int iIdx                        /* Value for 'idx' column of %_segdir */
+){
+  int rc;                         /* Return code */
+  if( pWriter->pTree ){
+    sqlite3_int64 iLast = 0;      /* Largest block id written to database */
+    sqlite3_int64 iLastLeaf;      /* Largest leaf block id written to db */
+    char *zRoot = NULL;           /* Pointer to buffer containing root node */
+    int nRoot = 0;                /* Size of buffer zRoot */
+
+    iLastLeaf = pWriter->iFree;
+    rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, pWriter->nData);
+    if( rc==SQLITE_OK ){
+      rc = fts3NodeWrite(p, pWriter->pTree, 1,
+          pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot);
+    }
+    if( rc==SQLITE_OK ){
+      rc = fts3WriteSegdir(p, iLevel, iIdx, 
+          pWriter->iFirst, iLastLeaf, iLast, pWriter->nLeafData, zRoot, nRoot);
+    }
+  }else{
+    /* The entire tree fits on the root node. Write it to the segdir table. */
+    rc = fts3WriteSegdir(p, iLevel, iIdx, 
+        0, 0, 0, pWriter->nLeafData, pWriter->aData, pWriter->nData);
+  }
+  p->nLeafAdd++;
+  return rc;
+}
+
+/*
+** Release all memory held by the SegmentWriter object passed as the 
+** first argument.
+*/
+static void fts3SegWriterFree(SegmentWriter *pWriter){
+  if( pWriter ){
+    sqlite3_free(pWriter->aData);
+    sqlite3_free(pWriter->zMalloc);
+    fts3NodeFree(pWriter->pTree);
+    sqlite3_free(pWriter);
+  }
+}
+
+/*
+** The first value in the apVal[] array is assumed to contain an integer.
+** This function tests if there exist any documents with docid values that
+** are different from that integer. i.e. if deleting the document with docid
+** pRowid would mean the FTS3 table were empty.
+**
+** If successful, *pisEmpty is set to true if the table is empty except for
+** document pRowid, or false otherwise, and SQLITE_OK is returned. If an
+** error occurs, an SQLite error code is returned.
+*/
+static int fts3IsEmpty(Fts3Table *p, sqlite3_value *pRowid, int *pisEmpty){
+  sqlite3_stmt *pStmt;
+  int rc;
+  if( p->zContentTbl ){
+    /* If using the content=xxx option, assume the table is never empty */
+    *pisEmpty = 0;
+    rc = SQLITE_OK;
+  }else{
+    rc = fts3SqlStmt(p, SQL_IS_EMPTY, &pStmt, &pRowid);
+    if( rc==SQLITE_OK ){
+      if( SQLITE_ROW==sqlite3_step(pStmt) ){
+        *pisEmpty = sqlite3_column_int(pStmt, 0);
+      }
+      rc = sqlite3_reset(pStmt);
+    }
+  }
+  return rc;
+}
+
+/*
+** Set *pnMax to the largest segment level in the database for the index
+** iIndex.
+**
+** Segment levels are stored in the 'level' column of the %_segdir table.
+**
+** Return SQLITE_OK if successful, or an SQLite error code if not.
+*/
+static int fts3SegmentMaxLevel(
+  Fts3Table *p, 
+  int iLangid,
+  int iIndex, 
+  sqlite3_int64 *pnMax
+){
+  sqlite3_stmt *pStmt;
+  int rc;
+  assert( iIndex>=0 && iIndexnIndex );
+
+  /* Set pStmt to the compiled version of:
+  **
+  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
+  **
+  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
+  */
+  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+  sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+  sqlite3_bind_int64(pStmt, 2, 
+      getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+  );
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    *pnMax = sqlite3_column_int64(pStmt, 0);
+  }
+  return sqlite3_reset(pStmt);
+}
+
+/*
+** iAbsLevel is an absolute level that may be assumed to exist within
+** the database. This function checks if it is the largest level number
+** within its index. Assuming no error occurs, *pbMax is set to 1 if
+** iAbsLevel is indeed the largest level, or 0 otherwise, and SQLITE_OK
+** is returned. If an error occurs, an error code is returned and the
+** final value of *pbMax is undefined.
+*/
+static int fts3SegmentIsMaxLevel(Fts3Table *p, i64 iAbsLevel, int *pbMax){
+
+  /* Set pStmt to the compiled version of:
+  **
+  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
+  **
+  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
+  */
+  sqlite3_stmt *pStmt;
+  int rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+  sqlite3_bind_int64(pStmt, 1, iAbsLevel+1);
+  sqlite3_bind_int64(pStmt, 2, 
+      ((iAbsLevel/FTS3_SEGDIR_MAXLEVEL)+1) * FTS3_SEGDIR_MAXLEVEL
+  );
+
+  *pbMax = 0;
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    *pbMax = sqlite3_column_type(pStmt, 0)==SQLITE_NULL;
+  }
+  return sqlite3_reset(pStmt);
+}
+
+/*
+** Delete all entries in the %_segments table associated with the segment
+** opened with seg-reader pSeg. This function does not affect the contents
+** of the %_segdir table.
+*/
+static int fts3DeleteSegment(
+  Fts3Table *p,                   /* FTS table handle */
+  Fts3SegReader *pSeg             /* Segment to delete */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( pSeg->iStartBlock ){
+    sqlite3_stmt *pDelete;        /* SQL statement to delete rows */
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDelete, 1, pSeg->iStartBlock);
+      sqlite3_bind_int64(pDelete, 2, pSeg->iEndBlock);
+      sqlite3_step(pDelete);
+      rc = sqlite3_reset(pDelete);
+    }
+  }
+  return rc;
+}
+
+/*
+** This function is used after merging multiple segments into a single large
+** segment to delete the old, now redundant, segment b-trees. Specifically,
+** it:
+** 
+**   1) Deletes all %_segments entries for the segments associated with 
+**      each of the SegReader objects in the array passed as the third 
+**      argument, and
+**
+**   2) deletes all %_segdir entries with level iLevel, or all %_segdir
+**      entries regardless of level if (iLevel<0).
+**
+** SQLITE_OK is returned if successful, otherwise an SQLite error code.
+*/
+static int fts3DeleteSegdir(
+  Fts3Table *p,                   /* Virtual table handle */
+  int iLangid,                    /* Language id */
+  int iIndex,                     /* Index for p->aIndex */
+  int iLevel,                     /* Level of %_segdir entries to delete */
+  Fts3SegReader **apSegment,      /* Array of SegReader objects */
+  int nReader                     /* Size of array apSegment */
+){
+  int rc = SQLITE_OK;             /* Return Code */
+  int i;                          /* Iterator variable */
+  sqlite3_stmt *pDelete = 0;      /* SQL statement to delete rows */
+
+  for(i=0; rc==SQLITE_OK && i=0 || iLevel==FTS3_SEGCURSOR_ALL );
+  if( iLevel==FTS3_SEGCURSOR_ALL ){
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+      sqlite3_bind_int64(pDelete, 2, 
+          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+      );
+    }
+  }else{
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(
+          pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)
+      );
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    sqlite3_step(pDelete);
+    rc = sqlite3_reset(pDelete);
+  }
+
+  return rc;
+}
+
+/*
+** When this function is called, buffer *ppList (size *pnList bytes) contains 
+** a position list that may (or may not) feature multiple columns. This
+** function adjusts the pointer *ppList and the length *pnList so that they
+** identify the subset of the position list that corresponds to column iCol.
+**
+** If there are no entries in the input position list for column iCol, then
+** *pnList is set to zero before returning.
+**
+** If parameter bZero is non-zero, then any part of the input list following
+** the end of the output list is zeroed before returning.
+*/
+static void fts3ColumnFilter(
+  int iCol,                       /* Column to filter on */
+  int bZero,                      /* Zero out anything following *ppList */
+  char **ppList,                  /* IN/OUT: Pointer to position list */
+  int *pnList                     /* IN/OUT: Size of buffer *ppList in bytes */
+){
+  char *pList = *ppList;
+  int nList = *pnList;
+  char *pEnd = &pList[nList];
+  int iCurrent = 0;
+  char *p = pList;
+
+  assert( iCol>=0 );
+  while( 1 ){
+    char c = 0;
+    while( ppMsr->nBuffer ){
+    char *pNew;
+    pMsr->nBuffer = nList*2;
+    pNew = (char *)sqlite3_realloc(pMsr->aBuffer, pMsr->nBuffer);
+    if( !pNew ) return SQLITE_NOMEM;
+    pMsr->aBuffer = pNew;
+  }
+
+  memcpy(pMsr->aBuffer, pList, nList);
+  return SQLITE_OK;
+}
+
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3MultiSegReader *pMsr,       /* Multi-segment-reader handle */
+  sqlite3_int64 *piDocid,         /* OUT: Docid value */
+  char **paPoslist,               /* OUT: Pointer to position list */
+  int *pnPoslist                  /* OUT: Size of position list in bytes */
+){
+  int nMerge = pMsr->nAdvance;
+  Fts3SegReader **apSegment = pMsr->apSegment;
+  int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (
+    p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp
+  );
+
+  if( nMerge==0 ){
+    *paPoslist = 0;
+    return SQLITE_OK;
+  }
+
+  while( 1 ){
+    Fts3SegReader *pSeg;
+    pSeg = pMsr->apSegment[0];
+
+    if( pSeg->pOffsetList==0 ){
+      *paPoslist = 0;
+      break;
+    }else{
+      int rc;
+      char *pList;
+      int nList;
+      int j;
+      sqlite3_int64 iDocid = apSegment[0]->iDocid;
+
+      rc = fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);
+      j = 1;
+      while( rc==SQLITE_OK 
+        && jpOffsetList
+        && apSegment[j]->iDocid==iDocid
+      ){
+        rc = fts3SegReaderNextDocid(p, apSegment[j], 0, 0);
+        j++;
+      }
+      if( rc!=SQLITE_OK ) return rc;
+      fts3SegReaderSort(pMsr->apSegment, nMerge, j, xCmp);
+
+      if( nList>0 && fts3SegReaderIsPending(apSegment[0]) ){
+        rc = fts3MsrBufferData(pMsr, pList, nList+1);
+        if( rc!=SQLITE_OK ) return rc;
+        assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );
+        pList = pMsr->aBuffer;
+      }
+
+      if( pMsr->iColFilter>=0 ){
+        fts3ColumnFilter(pMsr->iColFilter, 1, &pList, &nList);
+      }
+
+      if( nList>0 ){
+        *paPoslist = pList;
+        *piDocid = iDocid;
+        *pnPoslist = nList;
+        break;
+      }
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+static int fts3SegReaderStart(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3MultiSegReader *pCsr,       /* Cursor object */
+  const char *zTerm,              /* Term searched for (or NULL) */
+  int nTerm                       /* Length of zTerm in bytes */
+){
+  int i;
+  int nSeg = pCsr->nSegment;
+
+  /* If the Fts3SegFilter defines a specific term (or term prefix) to search 
+  ** for, then advance each segment iterator until it points to a term of
+  ** equal or greater value than the specified term. This prevents many
+  ** unnecessary merge/sort operations for the case where single segment
+  ** b-tree leaf nodes contain more than one term.
+  */
+  for(i=0; pCsr->bRestart==0 && inSegment; i++){
+    int res = 0;
+    Fts3SegReader *pSeg = pCsr->apSegment[i];
+    do {
+      int rc = fts3SegReaderNext(p, pSeg, 0);
+      if( rc!=SQLITE_OK ) return rc;
+    }while( zTerm && (res = fts3SegReaderTermCmp(pSeg, zTerm, nTerm))<0 );
+
+    if( pSeg->bLookup && res!=0 ){
+      fts3SegReaderSetEof(pSeg);
+    }
+  }
+  fts3SegReaderSort(pCsr->apSegment, nSeg, nSeg, fts3SegReaderCmp);
+
+  return SQLITE_OK;
+}
+
+SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3MultiSegReader *pCsr,       /* Cursor object */
+  Fts3SegFilter *pFilter          /* Restrictions on range of iteration */
+){
+  pCsr->pFilter = pFilter;
+  return fts3SegReaderStart(p, pCsr, pFilter->zTerm, pFilter->nTerm);
+}
+
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3MultiSegReader *pCsr,       /* Cursor object */
+  int iCol,                       /* Column to match on. */
+  const char *zTerm,              /* Term to iterate through a doclist for */
+  int nTerm                       /* Number of bytes in zTerm */
+){
+  int i;
+  int rc;
+  int nSegment = pCsr->nSegment;
+  int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (
+    p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp
+  );
+
+  assert( pCsr->pFilter==0 );
+  assert( zTerm && nTerm>0 );
+
+  /* Advance each segment iterator until it points to the term zTerm/nTerm. */
+  rc = fts3SegReaderStart(p, pCsr, zTerm, nTerm);
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* Determine how many of the segments actually point to zTerm/nTerm. */
+  for(i=0; iapSegment[i];
+    if( !pSeg->aNode || fts3SegReaderTermCmp(pSeg, zTerm, nTerm) ){
+      break;
+    }
+  }
+  pCsr->nAdvance = i;
+
+  /* Advance each of the segments to point to the first docid. */
+  for(i=0; inAdvance; i++){
+    rc = fts3SegReaderFirstDocid(p, pCsr->apSegment[i]);
+    if( rc!=SQLITE_OK ) return rc;
+  }
+  fts3SegReaderSort(pCsr->apSegment, i, i, xCmp);
+
+  assert( iCol<0 || iColnColumn );
+  pCsr->iColFilter = iCol;
+
+  return SQLITE_OK;
+}
+
+/*
+** This function is called on a MultiSegReader that has been started using
+** sqlite3Fts3MsrIncrStart(). One or more calls to MsrIncrNext() may also
+** have been made. Calling this function puts the MultiSegReader in such
+** a state that if the next two calls are:
+**
+**   sqlite3Fts3SegReaderStart()
+**   sqlite3Fts3SegReaderStep()
+**
+** then the entire doclist for the term is available in 
+** MultiSegReader.aDoclist/nDoclist.
+*/
+SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr){
+  int i;                          /* Used to iterate through segment-readers */
+
+  assert( pCsr->zTerm==0 );
+  assert( pCsr->nTerm==0 );
+  assert( pCsr->aDoclist==0 );
+  assert( pCsr->nDoclist==0 );
+
+  pCsr->nAdvance = 0;
+  pCsr->bRestart = 1;
+  for(i=0; inSegment; i++){
+    pCsr->apSegment[i]->pOffsetList = 0;
+    pCsr->apSegment[i]->nOffsetList = 0;
+    pCsr->apSegment[i]->iDocid = 0;
+  }
+
+  return SQLITE_OK;
+}
+
+
+SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(
+  Fts3Table *p,                   /* Virtual table handle */
+  Fts3MultiSegReader *pCsr        /* Cursor object */
+){
+  int rc = SQLITE_OK;
+
+  int isIgnoreEmpty =  (pCsr->pFilter->flags & FTS3_SEGMENT_IGNORE_EMPTY);
+  int isRequirePos =   (pCsr->pFilter->flags & FTS3_SEGMENT_REQUIRE_POS);
+  int isColFilter =    (pCsr->pFilter->flags & FTS3_SEGMENT_COLUMN_FILTER);
+  int isPrefix =       (pCsr->pFilter->flags & FTS3_SEGMENT_PREFIX);
+  int isScan =         (pCsr->pFilter->flags & FTS3_SEGMENT_SCAN);
+  int isFirst =        (pCsr->pFilter->flags & FTS3_SEGMENT_FIRST);
+
+  Fts3SegReader **apSegment = pCsr->apSegment;
+  int nSegment = pCsr->nSegment;
+  Fts3SegFilter *pFilter = pCsr->pFilter;
+  int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (
+    p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp
+  );
+
+  if( pCsr->nSegment==0 ) return SQLITE_OK;
+
+  do {
+    int nMerge;
+    int i;
+  
+    /* Advance the first pCsr->nAdvance entries in the apSegment[] array
+    ** forward. Then sort the list in order of current term again.  
+    */
+    for(i=0; inAdvance; i++){
+      Fts3SegReader *pSeg = apSegment[i];
+      if( pSeg->bLookup ){
+        fts3SegReaderSetEof(pSeg);
+      }else{
+        rc = fts3SegReaderNext(p, pSeg, 0);
+      }
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp);
+    pCsr->nAdvance = 0;
+
+    /* If all the seg-readers are at EOF, we're finished. return SQLITE_OK. */
+    assert( rc==SQLITE_OK );
+    if( apSegment[0]->aNode==0 ) break;
+
+    pCsr->nTerm = apSegment[0]->nTerm;
+    pCsr->zTerm = apSegment[0]->zTerm;
+
+    /* If this is a prefix-search, and if the term that apSegment[0] points
+    ** to does not share a suffix with pFilter->zTerm/nTerm, then all 
+    ** required callbacks have been made. In this case exit early.
     **
-    **         This case is also used when there are no WHERE clause
-    **         constraints but an index is selected anyway, in order
-    **         to force the output order to conform to an ORDER BY.
-    */  
-    static const u8 aStartOp[] = {
-      0,
-      0,
-      OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
-      OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
-      OP_SeekGT,           /* 4: (start_constraints  && !startEq && !bRev) */
-      OP_SeekLT,           /* 5: (start_constraints  && !startEq &&  bRev) */
-      OP_SeekGE,           /* 6: (start_constraints  &&  startEq && !bRev) */
-      OP_SeekLE            /* 7: (start_constraints  &&  startEq &&  bRev) */
-    };
-    static const u8 aEndOp[] = {
-      OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */
-      OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */
-      OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */
-      OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */
-    };
-    u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */
-    int regBase;                 /* Base register holding constraint values */
-    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
-    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
-    int startEq;                 /* True if range start uses ==, >= or <= */
-    int endEq;                   /* True if range end uses ==, >= or <= */
-    int start_constraints;       /* Start of range is constrained */
-    int nConstraint;             /* Number of constraint terms */
-    Index *pIdx;                 /* The index we will be using */
-    int iIdxCur;                 /* The VDBE cursor for the index */
-    int nExtraReg = 0;           /* Number of extra registers needed */
-    int op;                      /* Instruction opcode */
-    char *zStartAff;             /* Affinity for start of range constraint */
-    char cEndAff = 0;            /* Affinity for end of range constraint */
-    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
-    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */
+    ** Similarly, if this is a search for an exact match, and the first term
+    ** of segment apSegment[0] is not a match, exit early.
+    */
+    if( pFilter->zTerm && !isScan ){
+      if( pCsr->nTermnTerm 
+       || (!isPrefix && pCsr->nTerm>pFilter->nTerm)
+       || memcmp(pCsr->zTerm, pFilter->zTerm, pFilter->nTerm) 
+      ){
+        break;
+      }
+    }
+
+    nMerge = 1;
+    while( nMergeaNode
+        && apSegment[nMerge]->nTerm==pCsr->nTerm 
+        && 0==memcmp(pCsr->zTerm, apSegment[nMerge]->zTerm, pCsr->nTerm)
+    ){
+      nMerge++;
+    }
+
+    assert( isIgnoreEmpty || (isRequirePos && !isColFilter) );
+    if( nMerge==1 
+     && !isIgnoreEmpty 
+     && !isFirst 
+     && (p->bDescIdx==0 || fts3SegReaderIsPending(apSegment[0])==0)
+    ){
+      pCsr->nDoclist = apSegment[0]->nDoclist;
+      if( fts3SegReaderIsPending(apSegment[0]) ){
+        rc = fts3MsrBufferData(pCsr, apSegment[0]->aDoclist, pCsr->nDoclist);
+        pCsr->aDoclist = pCsr->aBuffer;
+      }else{
+        pCsr->aDoclist = apSegment[0]->aDoclist;
+      }
+      if( rc==SQLITE_OK ) rc = SQLITE_ROW;
+    }else{
+      int nDoclist = 0;           /* Size of doclist */
+      sqlite3_int64 iPrev = 0;    /* Previous docid stored in doclist */
+
+      /* The current term of the first nMerge entries in the array
+      ** of Fts3SegReader objects is the same. The doclists must be merged
+      ** and a single term returned with the merged doclist.
+      */
+      for(i=0; ipOffsetList ){
+        int j;                    /* Number of segments that share a docid */
+        char *pList = 0;
+        int nList = 0;
+        int nByte;
+        sqlite3_int64 iDocid = apSegment[0]->iDocid;
+        fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);
+        j = 1;
+        while( jpOffsetList
+            && apSegment[j]->iDocid==iDocid
+        ){
+          fts3SegReaderNextDocid(p, apSegment[j], 0, 0);
+          j++;
+        }
+
+        if( isColFilter ){
+          fts3ColumnFilter(pFilter->iCol, 0, &pList, &nList);
+        }
+
+        if( !isIgnoreEmpty || nList>0 ){
+
+          /* Calculate the 'docid' delta value to write into the merged 
+          ** doclist. */
+          sqlite3_int64 iDelta;
+          if( p->bDescIdx && nDoclist>0 ){
+            iDelta = iPrev - iDocid;
+          }else{
+            iDelta = iDocid - iPrev;
+          }
+          assert( iDelta>0 || (nDoclist==0 && iDelta==iDocid) );
+          assert( nDoclist>0 || iDelta==iDocid );
+
+          nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0);
+          if( nDoclist+nByte>pCsr->nBuffer ){
+            char *aNew;
+            pCsr->nBuffer = (nDoclist+nByte)*2;
+            aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);
+            if( !aNew ){
+              return SQLITE_NOMEM;
+            }
+            pCsr->aBuffer = aNew;
+          }
+
+          if( isFirst ){
+            char *a = &pCsr->aBuffer[nDoclist];
+            int nWrite;
+           
+            nWrite = sqlite3Fts3FirstFilter(iDelta, pList, nList, a);
+            if( nWrite ){
+              iPrev = iDocid;
+              nDoclist += nWrite;
+            }
+          }else{
+            nDoclist += sqlite3Fts3PutVarint(&pCsr->aBuffer[nDoclist], iDelta);
+            iPrev = iDocid;
+            if( isRequirePos ){
+              memcpy(&pCsr->aBuffer[nDoclist], pList, nList);
+              nDoclist += nList;
+              pCsr->aBuffer[nDoclist++] = '\0';
+            }
+          }
+        }
 
-    pIdx = pLoop->u.btree.pIndex;
-    iIdxCur = pLevel->iIdxCur;
-    assert( nEq>=pLoop->nSkip );
+        fts3SegReaderSort(apSegment, nMerge, j, xCmp);
+      }
+      if( nDoclist>0 ){
+        pCsr->aDoclist = pCsr->aBuffer;
+        pCsr->nDoclist = nDoclist;
+        rc = SQLITE_ROW;
+      }
+    }
+    pCsr->nAdvance = nMerge;
+  }while( rc==SQLITE_OK );
 
-    /* If this loop satisfies a sort order (pOrderBy) request that 
-    ** was passed to this function to implement a "SELECT min(x) ..." 
-    ** query, then the caller will only allow the loop to run for
-    ** a single iteration. This means that the first row returned
-    ** should not have a NULL value stored in 'x'. If column 'x' is
-    ** the first one after the nEq equality constraints in the index,
-    ** this requires some special handling.
-    */
-    assert( pWInfo->pOrderBy==0
-         || pWInfo->pOrderBy->nExpr==1
-         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
-    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
-     && pWInfo->nOBSat>0
-     && (pIdx->nKeyCol>nEq)
-    ){
-      assert( pLoop->nSkip==0 );
-      bSeekPastNull = 1;
-      nExtraReg = 1;
+  return rc;
+}
+
+
+SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(
+  Fts3MultiSegReader *pCsr       /* Cursor object */
+){
+  if( pCsr ){
+    int i;
+    for(i=0; inSegment; i++){
+      sqlite3Fts3SegReaderFree(pCsr->apSegment[i]);
     }
+    sqlite3_free(pCsr->apSegment);
+    sqlite3_free(pCsr->aBuffer);
 
-    /* Find any inequality constraint terms for the start and end 
-    ** of the range. 
-    */
-    j = nEq;
-    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
-      pRangeStart = pLoop->aLTerm[j++];
-      nExtraReg = 1;
+    pCsr->nSegment = 0;
+    pCsr->apSegment = 0;
+    pCsr->aBuffer = 0;
+  }
+}
+
+/*
+** Decode the "end_block" field, selected by column iCol of the SELECT 
+** statement passed as the first argument. 
+**
+** The "end_block" field may contain either an integer, or a text field
+** containing the text representation of two non-negative integers separated 
+** by one or more space (0x20) characters. In the first case, set *piEndBlock 
+** to the integer value and *pnByte to zero before returning. In the second, 
+** set *piEndBlock to the first value and *pnByte to the second.
+*/
+static void fts3ReadEndBlockField(
+  sqlite3_stmt *pStmt, 
+  int iCol, 
+  i64 *piEndBlock,
+  i64 *pnByte
+){
+  const unsigned char *zText = sqlite3_column_text(pStmt, iCol);
+  if( zText ){
+    int i;
+    int iMul = 1;
+    i64 iVal = 0;
+    for(i=0; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
     }
-    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
-      pRangeEnd = pLoop->aLTerm[j++];
-      nExtraReg = 1;
-      if( pRangeStart==0
-       && (j = pIdx->aiColumn[nEq])>=0 
-       && pIdx->pTable->aCol[j].notNull==0
-      ){
-        bSeekPastNull = 1;
-      }
+    *piEndBlock = iVal;
+    while( zText[i]==' ' ) i++;
+    iVal = 0;
+    if( zText[i]=='-' ){
+      i++;
+      iMul = -1;
     }
-    assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
+    for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
+    }
+    *pnByte = (iVal * (i64)iMul);
+  }
+}
 
-    /* Generate code to evaluate all constraint terms using == or IN
-    ** and store the values of those terms in an array of registers
-    ** starting at regBase.
-    */
-    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
-    assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
-    if( zStartAff ) cEndAff = zStartAff[nEq];
-    addrNxt = pLevel->addrNxt;
 
-    /* If we are doing a reverse order scan on an ascending index, or
-    ** a forward order scan on a descending index, interchange the 
-    ** start and end terms (pRangeStart and pRangeEnd).
-    */
-    if( (nEqnKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
-     || (bRev && pIdx->nKeyCol==nEq)
-    ){
-      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
-      SWAP(u8, bSeekPastNull, bStopAtNull);
-    }
+/*
+** A segment of size nByte bytes has just been written to absolute level
+** iAbsLevel. Promote any segments that should be promoted as a result.
+*/
+static int fts3PromoteSegments(
+  Fts3Table *p,                   /* FTS table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level just updated */
+  sqlite3_int64 nByte             /* Size of new segment at iAbsLevel */
+){
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pRange;
 
-    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
-    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
-    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
-    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
-    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
-    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
-    start_constraints = pRangeStart || nEq>0;
+  rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE2, &pRange, 0);
 
-    /* Seek the index cursor to the start of the range. */
-    nConstraint = nEq;
-    if( pRangeStart ){
-      Expr *pRight = pRangeStart->pExpr->pRight;
-      sqlite3ExprCode(pParse, pRight, regBase+nEq);
-      if( (pRangeStart->wtFlags & TERM_VNULL)==0
-       && sqlite3ExprCanBeNull(pRight)
-      ){
-        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
-        VdbeCoverage(v);
+  if( rc==SQLITE_OK ){
+    int bOk = 0;
+    i64 iLast = (iAbsLevel/FTS3_SEGDIR_MAXLEVEL + 1) * FTS3_SEGDIR_MAXLEVEL - 1;
+    i64 nLimit = (nByte*3)/2;
+
+    /* Loop through all entries in the %_segdir table corresponding to 
+    ** segments in this index on levels greater than iAbsLevel. If there is
+    ** at least one such segment, and it is possible to determine that all 
+    ** such segments are smaller than nLimit bytes in size, they will be 
+    ** promoted to level iAbsLevel.  */
+    sqlite3_bind_int64(pRange, 1, iAbsLevel+1);
+    sqlite3_bind_int64(pRange, 2, iLast);
+    while( SQLITE_ROW==sqlite3_step(pRange) ){
+      i64 nSize = 0, dummy;
+      fts3ReadEndBlockField(pRange, 2, &dummy, &nSize);
+      if( nSize<=0 || nSize>nLimit ){
+        /* If nSize==0, then the %_segdir.end_block field does not not 
+        ** contain a size value. This happens if it was written by an
+        ** old version of FTS. In this case it is not possible to determine
+        ** the size of the segment, and so segment promotion does not
+        ** take place.  */
+        bOk = 0;
+        break;
       }
-      if( zStartAff ){
-        if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_NONE){
-          /* Since the comparison is to be performed with no conversions
-          ** applied to the operands, set the affinity to apply to pRight to 
-          ** SQLITE_AFF_NONE.  */
-          zStartAff[nEq] = SQLITE_AFF_NONE;
-        }
-        if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
-          zStartAff[nEq] = SQLITE_AFF_NONE;
-        }
-      }  
-      nConstraint++;
-      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
-    }else if( bSeekPastNull ){
-      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
-      nConstraint++;
-      startEq = 0;
-      start_constraints = 1;
+      bOk = 1;
     }
-    codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
-    op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
-    assert( op!=0 );
-    sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
-    VdbeCoverage(v);
-    VdbeCoverageIf(v, op==OP_Rewind);  testcase( op==OP_Rewind );
-    VdbeCoverageIf(v, op==OP_Last);    testcase( op==OP_Last );
-    VdbeCoverageIf(v, op==OP_SeekGT);  testcase( op==OP_SeekGT );
-    VdbeCoverageIf(v, op==OP_SeekGE);  testcase( op==OP_SeekGE );
-    VdbeCoverageIf(v, op==OP_SeekLE);  testcase( op==OP_SeekLE );
-    VdbeCoverageIf(v, op==OP_SeekLT);  testcase( op==OP_SeekLT );
+    rc = sqlite3_reset(pRange);
 
-    /* Load the value for the inequality constraint at the end of the
-    ** range (if any).
-    */
-    nConstraint = nEq;
-    if( pRangeEnd ){
-      Expr *pRight = pRangeEnd->pExpr->pRight;
-      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
-      sqlite3ExprCode(pParse, pRight, regBase+nEq);
-      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
-       && sqlite3ExprCanBeNull(pRight)
-      ){
-        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
-        VdbeCoverage(v);
+    if( bOk ){
+      int iIdx = 0;
+      sqlite3_stmt *pUpdate1 = 0;
+      sqlite3_stmt *pUpdate2 = 0;
+
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL_IDX, &pUpdate1, 0);
       }
-      if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_NONE
-       && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
-      ){
-        codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL, &pUpdate2, 0);
       }
-      nConstraint++;
-      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
-    }else if( bStopAtNull ){
-      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
-      endEq = 0;
-      nConstraint++;
-    }
-    sqlite3DbFree(db, zStartAff);
 
-    /* Top of the loop body */
-    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+      if( rc==SQLITE_OK ){
 
-    /* Check if the index cursor is past the end of the range. */
-    if( nConstraint ){
-      op = aEndOp[bRev*2 + endEq];
-      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
-      testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );
-      testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
-      testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
-      testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
-    }
+        /* Loop through all %_segdir entries for segments in this index with
+        ** levels equal to or greater than iAbsLevel. As each entry is visited,
+        ** updated it to set (level = -1) and (idx = N), where N is 0 for the
+        ** oldest segment in the range, 1 for the next oldest, and so on.
+        **
+        ** In other words, move all segments being promoted to level -1,
+        ** setting the "idx" fields as appropriate to keep them in the same
+        ** order. The contents of level -1 (which is never used, except
+        ** transiently here), will be moved back to level iAbsLevel below.  */
+        sqlite3_bind_int64(pRange, 1, iAbsLevel);
+        while( SQLITE_ROW==sqlite3_step(pRange) ){
+          sqlite3_bind_int(pUpdate1, 1, iIdx++);
+          sqlite3_bind_int(pUpdate1, 2, sqlite3_column_int(pRange, 0));
+          sqlite3_bind_int(pUpdate1, 3, sqlite3_column_int(pRange, 1));
+          sqlite3_step(pUpdate1);
+          rc = sqlite3_reset(pUpdate1);
+          if( rc!=SQLITE_OK ){
+            sqlite3_reset(pRange);
+            break;
+          }
+        }
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3_reset(pRange);
+      }
 
-    /* Seek the table cursor, if required */
-    disableTerm(pLevel, pRangeStart);
-    disableTerm(pLevel, pRangeEnd);
-    if( omitTable ){
-      /* pIdx is a covering index.  No need to access the main table. */
-    }else if( HasRowid(pIdx->pTable) ){
-      iRowidReg = ++pParse->nMem;
-      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
-      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-      sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
-    }else if( iCur!=iIdxCur ){
-      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
-      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
-      for(j=0; jnKeyCol; j++){
-        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
-        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
+      /* Move level -1 to level iAbsLevel */
+      if( rc==SQLITE_OK ){
+        sqlite3_bind_int64(pUpdate2, 1, iAbsLevel);
+        sqlite3_step(pUpdate2);
+        rc = sqlite3_reset(pUpdate2);
       }
-      sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
-                           iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
     }
+  }
 
-    /* Record the instruction used to terminate the loop. Disable 
-    ** WHERE clause terms made redundant by the index range scan.
-    */
-    if( pLoop->wsFlags & WHERE_ONEROW ){
-      pLevel->op = OP_Noop;
-    }else if( bRev ){
-      pLevel->op = OP_Prev;
-    }else{
-      pLevel->op = OP_Next;
-    }
-    pLevel->p1 = iIdxCur;
-    pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
-    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
-      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
-    }else{
-      assert( pLevel->p5==0 );
-    }
-  }else
 
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
-  if( pLoop->wsFlags & WHERE_MULTI_OR ){
-    /* Case 5:  Two or more separately indexed terms connected by OR
-    **
-    ** Example:
-    **
-    **   CREATE TABLE t1(a,b,c,d);
-    **   CREATE INDEX i1 ON t1(a);
-    **   CREATE INDEX i2 ON t1(b);
-    **   CREATE INDEX i3 ON t1(c);
-    **
-    **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
-    **
-    ** In the example, there are three indexed terms connected by OR.
-    ** The top of the loop looks like this:
-    **
-    **          Null       1                # Zero the rowset in reg 1
-    **
-    ** Then, for each indexed term, the following. The arguments to
-    ** RowSetTest are such that the rowid of the current row is inserted
-    ** into the RowSet. If it is already present, control skips the
-    ** Gosub opcode and jumps straight to the code generated by WhereEnd().
-    **
-    **        sqlite3WhereBegin()
-    **          RowSetTest                  # Insert rowid into rowset
-    **          Gosub      2 A
-    **        sqlite3WhereEnd()
-    **
-    ** Following the above, code to terminate the loop. Label A, the target
-    ** of the Gosub above, jumps to the instruction right after the Goto.
-    **
-    **          Null       1                # Zero the rowset in reg 1
-    **          Goto       B                # The loop is finished.
-    **
-    **       A:                  # Return data, whatever.
-    **
-    **          Return     2                # Jump back to the Gosub
-    **
-    **       B: 
-    **
-    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
-    ** use an ephemeral index instead of a RowSet to record the primary
-    ** keys of the rows we have already seen.
-    **
-    */
-    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
-    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
-    Index *pCov = 0;             /* Potential covering index (or NULL) */
-    int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */
+  return rc;
+}
 
-    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
-    int regRowset = 0;                        /* Register for RowSet object */
-    int regRowid = 0;                         /* Register holding rowid */
-    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
-    int iRetInit;                             /* Address of regReturn init */
-    int untestedTerms = 0;             /* Some terms not completely tested */
-    int ii;                            /* Loop counter */
-    u16 wctrlFlags;                    /* Flags for sub-WHERE clause */
-    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
-    Table *pTab = pTabItem->pTab;
-   
-    pTerm = pLoop->aLTerm[0];
-    assert( pTerm!=0 );
-    assert( pTerm->eOperator & WO_OR );
-    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
-    pOrWc = &pTerm->u.pOrInfo->wc;
-    pLevel->op = OP_Return;
-    pLevel->p1 = regReturn;
+/*
+** Merge all level iLevel segments in the database into a single 
+** iLevel+1 segment. Or, if iLevel<0, merge all segments into a
+** single segment with a level equal to the numerically largest level 
+** currently present in the database.
+**
+** If this function is called with iLevel<0, but there is only one
+** segment in the database, SQLITE_DONE is returned immediately. 
+** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
+** an SQLite error code is returned.
+*/
+static int fts3SegmentMerge(
+  Fts3Table *p, 
+  int iLangid,                    /* Language id to merge */
+  int iIndex,                     /* Index in p->aIndex[] to merge */
+  int iLevel                      /* Level to merge */
+){
+  int rc;                         /* Return code */
+  int iIdx = 0;                   /* Index of new segment */
+  sqlite3_int64 iNewLevel = 0;    /* Level/index to create new segment at */
+  SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */
+  Fts3SegFilter filter;           /* Segment term filter condition */
+  Fts3MultiSegReader csr;         /* Cursor to iterate through level(s) */
+  int bIgnoreEmpty = 0;           /* True to ignore empty segments */
+  i64 iMaxLevel = 0;              /* Max level number for this index/langid */
 
-    /* Set up a new SrcList in pOrTab containing the table being scanned
-    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
-    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
-    */
-    if( pWInfo->nLevel>1 ){
-      int nNotReady;                 /* The number of notReady tables */
-      struct SrcList_item *origSrc;     /* Original list of tables */
-      nNotReady = pWInfo->nLevel - iLevel - 1;
-      pOrTab = sqlite3StackAllocRaw(db,
-                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
-      if( pOrTab==0 ) return notReady;
-      pOrTab->nAlloc = (u8)(nNotReady + 1);
-      pOrTab->nSrc = pOrTab->nAlloc;
-      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
-      origSrc = pWInfo->pTabList->a;
-      for(k=1; k<=nNotReady; k++){
-        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
-      }
-    }else{
-      pOrTab = pWInfo->pTabList;
+  assert( iLevel==FTS3_SEGCURSOR_ALL
+       || iLevel==FTS3_SEGCURSOR_PENDING
+       || iLevel>=0
+  );
+  assert( iLevel=0 && iIndexnIndex );
+
+  rc = sqlite3Fts3SegReaderCursor(p, iLangid, iIndex, iLevel, 0, 0, 1, 0, &csr);
+  if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;
+
+  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
+    rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iMaxLevel);
+    if( rc!=SQLITE_OK ) goto finished;
+  }
+
+  if( iLevel==FTS3_SEGCURSOR_ALL ){
+    /* This call is to merge all segments in the database to a single
+    ** segment. The level of the new segment is equal to the numerically
+    ** greatest segment level currently present in the database for this
+    ** index. The idx of the new segment is always 0.  */
+    if( csr.nSegment==1 && 0==fts3SegReaderIsPending(csr.apSegment[0]) ){
+      rc = SQLITE_DONE;
+      goto finished;
     }
+    iNewLevel = iMaxLevel;
+    bIgnoreEmpty = 1;
 
-    /* Initialize the rowset register to contain NULL. An SQL NULL is 
-    ** equivalent to an empty rowset.  Or, create an ephemeral index
-    ** capable of holding primary keys in the case of a WITHOUT ROWID.
-    **
-    ** Also initialize regReturn to contain the address of the instruction 
-    ** immediately following the OP_Return at the bottom of the loop. This
-    ** is required in a few obscure LEFT JOIN cases where control jumps
-    ** over the top of the loop into the body of it. In this case the 
-    ** correct response for the end-of-loop code (the OP_Return) is to 
-    ** fall through to the next instruction, just as an OP_Next does if
-    ** called on an uninitialized cursor.
-    */
-    if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
-      if( HasRowid(pTab) ){
-        regRowset = ++pParse->nMem;
-        sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
-      }else{
-        Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-        regRowset = pParse->nTab++;
-        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
-        sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+  }else{
+    /* This call is to merge all segments at level iLevel. find the next
+    ** available segment index at level iLevel+1. The call to
+    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
+    ** a single iLevel+2 segment if necessary.  */
+    assert( FTS3_SEGCURSOR_PENDING==-1 );
+    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);
+    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
+    bIgnoreEmpty = (iLevel!=FTS3_SEGCURSOR_PENDING) && (iNewLevel>iMaxLevel);
+  }
+  if( rc!=SQLITE_OK ) goto finished;
+
+  assert( csr.nSegment>0 );
+  assert( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
+  assert( iNewLevelnLeafData);
       }
-      regRowid = ++pParse->nMem;
     }
-    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
+  }
 
-    /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y
-    ** Then for every term xN, evaluate as the subexpression: xN AND z
-    ** That way, terms in y that are factored into the disjunction will
-    ** be picked up by the recursive calls to sqlite3WhereBegin() below.
-    **
-    ** Actually, each subexpression is converted to "xN AND w" where w is
-    ** the "interesting" terms of z - terms that did not originate in the
-    ** ON or USING clause of a LEFT JOIN, and terms that are usable as 
-    ** indices.
-    **
-    ** This optimization also only applies if the (x1 OR x2 OR ...) term
-    ** is not contained in the ON clause of a LEFT JOIN.
-    ** See ticket http://www.sqlite.org/src/info/f2369304e4
-    */
-    if( pWC->nTerm>1 ){
-      int iTerm;
-      for(iTerm=0; iTermnTerm; iTerm++){
-        Expr *pExpr = pWC->a[iTerm].pExpr;
-        if( &pWC->a[iTerm] == pTerm ) continue;
-        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
-        if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;
-        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
-        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
-        pExpr = sqlite3ExprDup(db, pExpr, 0);
-        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
-      }
-      if( pAndExpr ){
-        pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
+ finished:
+  fts3SegWriterFree(pWriter);
+  sqlite3Fts3SegReaderFinish(&csr);
+  return rc;
+}
+
+
+/* 
+** Flush the contents of pendingTerms to level 0 segments. 
+*/
+SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
+  int rc = SQLITE_OK;
+  int i;
+        
+  for(i=0; rc==SQLITE_OK && inIndex; i++){
+    rc = fts3SegmentMerge(p, p->iPrevLangid, i, FTS3_SEGCURSOR_PENDING);
+    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  }
+  sqlite3Fts3PendingTermsClear(p);
+
+  /* Determine the auto-incr-merge setting if unknown.  If enabled,
+  ** estimate the number of leaf blocks of content to be written
+  */
+  if( rc==SQLITE_OK && p->bHasStat
+   && p->nAutoincrmerge==0xff && p->nLeafAdd>0
+  ){
+    sqlite3_stmt *pStmt = 0;
+    rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
+      rc = sqlite3_step(pStmt);
+      if( rc==SQLITE_ROW ){
+        p->nAutoincrmerge = sqlite3_column_int(pStmt, 0);
+        if( p->nAutoincrmerge==1 ) p->nAutoincrmerge = 8;
+      }else if( rc==SQLITE_DONE ){
+        p->nAutoincrmerge = 0;
       }
+      rc = sqlite3_reset(pStmt);
     }
+  }
+  return rc;
+}
 
-    /* Run a separate WHERE clause for each term of the OR clause.  After
-    ** eliminating duplicates from other WHERE clauses, the action for each
-    ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
-    */
-    wctrlFlags =  WHERE_OMIT_OPEN_CLOSE
-                | WHERE_FORCE_TABLE
-                | WHERE_ONETABLE_ONLY;
-    for(ii=0; iinTerm; ii++){
-      WhereTerm *pOrTerm = &pOrWc->a[ii];
-      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
-        WhereInfo *pSubWInfo;           /* Info for single OR-term scan */
-        Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
-        int j1 = 0;                     /* Address of jump operation */
-        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
-          pAndExpr->pLeft = pOrExpr;
-          pOrExpr = pAndExpr;
-        }
-        /* Loop through table entries that match term pOrTerm. */
-        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
-        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
-                                      wctrlFlags, iCovCur);
-        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
-        if( pSubWInfo ){
-          WhereLoop *pSubLoop;
-          int addrExplain = explainOneScan(
-              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
-          );
-          addScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
-
-          /* This is the sub-WHERE clause body.  First skip over
-          ** duplicate rows from prior sub-WHERE clauses, and record the
-          ** rowid (or PRIMARY KEY) for the current row so that the same
-          ** row will be skipped in subsequent sub-WHERE clauses.
-          */
-          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
-            int r;
-            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
-            if( HasRowid(pTab) ){
-              r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
-              j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet);
-              VdbeCoverage(v);
-            }else{
-              Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-              int nPk = pPk->nKeyCol;
-              int iPk;
+/*
+** Encode N integers as varints into a blob.
+*/
+static void fts3EncodeIntArray(
+  int N,             /* The number of integers to encode */
+  u32 *a,            /* The integer values */
+  char *zBuf,        /* Write the BLOB here */
+  int *pNBuf         /* Write number of bytes if zBuf[] used here */
+){
+  int i, j;
+  for(i=j=0; iaiColumn[iPk];
-                sqlite3ExprCodeGetColumn(pParse, pTab, iCol, iCur, r+iPk, 0);
-              }
+/*
+** Decode a blob of varints into N integers
+*/
+static void fts3DecodeIntArray(
+  int N,             /* The number of integers to decode */
+  u32 *a,            /* Write the integer values */
+  const char *zBuf,  /* The BLOB containing the varints */
+  int nBuf           /* size of the BLOB */
+){
+  int i, j;
+  UNUSED_PARAMETER(nBuf);
+  for(i=j=0; i=0 ){
-                sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
-                sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0);
-                if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-              }
+/*
+** Insert the sizes (in tokens) for each column of the document
+** with docid equal to p->iPrevDocid.  The sizes are encoded as
+** a blob of varints.
+*/
+static void fts3InsertDocsize(
+  int *pRC,                       /* Result code */
+  Fts3Table *p,                   /* Table into which to insert */
+  u32 *aSz                        /* Sizes of each column, in tokens */
+){
+  char *pBlob;             /* The BLOB encoding of the document size */
+  int nBlob;               /* Number of bytes in the BLOB */
+  sqlite3_stmt *pStmt;     /* Statement used to insert the encoding */
+  int rc;                  /* Result code from subfunctions */
 
-              /* Release the array of temp registers */
-              sqlite3ReleaseTempRange(pParse, r, nPk);
-            }
-          }
+  if( *pRC ) return;
+  pBlob = sqlite3_malloc( 10*p->nColumn );
+  if( pBlob==0 ){
+    *pRC = SQLITE_NOMEM;
+    return;
+  }
+  fts3EncodeIntArray(p->nColumn, aSz, pBlob, &nBlob);
+  rc = fts3SqlStmt(p, SQL_REPLACE_DOCSIZE, &pStmt, 0);
+  if( rc ){
+    sqlite3_free(pBlob);
+    *pRC = rc;
+    return;
+  }
+  sqlite3_bind_int64(pStmt, 1, p->iPrevDocid);
+  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, sqlite3_free);
+  sqlite3_step(pStmt);
+  *pRC = sqlite3_reset(pStmt);
+}
 
-          /* Invoke the main loop body as a subroutine */
-          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+/*
+** Record 0 of the %_stat table contains a blob consisting of N varints,
+** where N is the number of user defined columns in the fts3 table plus
+** two. If nCol is the number of user defined columns, then values of the 
+** varints are set as follows:
+**
+**   Varint 0:       Total number of rows in the table.
+**
+**   Varint 1..nCol: For each column, the total number of tokens stored in
+**                   the column for all rows of the table.
+**
+**   Varint 1+nCol:  The total size, in bytes, of all text values in all
+**                   columns of all rows of the table.
+**
+*/
+static void fts3UpdateDocTotals(
+  int *pRC,                       /* The result code */
+  Fts3Table *p,                   /* Table being updated */
+  u32 *aSzIns,                    /* Size increases */
+  u32 *aSzDel,                    /* Size decreases */
+  int nChng                       /* Change in the number of documents */
+){
+  char *pBlob;             /* Storage for BLOB written into %_stat */
+  int nBlob;               /* Size of BLOB written into %_stat */
+  u32 *a;                  /* Array of integers that becomes the BLOB */
+  sqlite3_stmt *pStmt;     /* Statement for reading and writing */
+  int i;                   /* Loop counter */
+  int rc;                  /* Result code from subfunctions */
 
-          /* Jump here (skipping the main loop body subroutine) if the
-          ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
-          if( j1 ) sqlite3VdbeJumpHere(v, j1);
+  const int nStat = p->nColumn+2;
 
-          /* The pSubWInfo->untestedTerms flag means that this OR term
-          ** contained one or more AND term from a notReady table.  The
-          ** terms from the notReady table could not be tested and will
-          ** need to be tested later.
-          */
-          if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+  if( *pRC ) return;
+  a = sqlite3_malloc( (sizeof(u32)+10)*nStat );
+  if( a==0 ){
+    *pRC = SQLITE_NOMEM;
+    return;
+  }
+  pBlob = (char*)&a[nStat];
+  rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
+  if( rc ){
+    sqlite3_free(a);
+    *pRC = rc;
+    return;
+  }
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
+  if( sqlite3_step(pStmt)==SQLITE_ROW ){
+    fts3DecodeIntArray(nStat, a,
+         sqlite3_column_blob(pStmt, 0),
+         sqlite3_column_bytes(pStmt, 0));
+  }else{
+    memset(a, 0, sizeof(u32)*(nStat) );
+  }
+  rc = sqlite3_reset(pStmt);
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(a);
+    *pRC = rc;
+    return;
+  }
+  if( nChng<0 && a[0]<(u32)(-nChng) ){
+    a[0] = 0;
+  }else{
+    a[0] += nChng;
+  }
+  for(i=0; inColumn+1; i++){
+    u32 x = a[i+1];
+    if( x+aSzIns[i] < aSzDel[i] ){
+      x = 0;
+    }else{
+      x = x + aSzIns[i] - aSzDel[i];
+    }
+    a[i+1] = x;
+  }
+  fts3EncodeIntArray(nStat, a, pBlob, &nBlob);
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
+  if( rc ){
+    sqlite3_free(a);
+    *pRC = rc;
+    return;
+  }
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
+  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, SQLITE_STATIC);
+  sqlite3_step(pStmt);
+  *pRC = sqlite3_reset(pStmt);
+  sqlite3_free(a);
+}
 
-          /* If all of the OR-connected terms are optimized using the same
-          ** index, and the index is opened using the same cursor number
-          ** by each call to sqlite3WhereBegin() made by this loop, it may
-          ** be possible to use that index as a covering index.
-          **
-          ** If the call to sqlite3WhereBegin() above resulted in a scan that
-          ** uses an index, and this is either the first OR-connected term
-          ** processed or the index is the same as that used by all previous
-          ** terms, set pCov to the candidate covering index. Otherwise, set 
-          ** pCov to NULL to indicate that no candidate covering index will 
-          ** be available.
-          */
-          pSubLoop = pSubWInfo->a[0].pWLoop;
-          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
-          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
-           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
-           && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
-          ){
-            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
-            pCov = pSubLoop->u.btree.pIndex;
-            wctrlFlags |= WHERE_REOPEN_IDX;
-          }else{
-            pCov = 0;
-          }
+/*
+** Merge the entire database so that there is one segment for each 
+** iIndex/iLangid combination.
+*/
+static int fts3DoOptimize(Fts3Table *p, int bReturnDone){
+  int bSeenDone = 0;
+  int rc;
+  sqlite3_stmt *pAllLangid = 0;
 
-          /* Finish the loop through table entries that match term pOrTerm. */
-          sqlite3WhereEnd(pSubWInfo);
+  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);
+    sqlite3_bind_int(pAllLangid, 2, p->nIndex);
+    while( sqlite3_step(pAllLangid)==SQLITE_ROW ){
+      int i;
+      int iLangid = sqlite3_column_int(pAllLangid, 0);
+      for(i=0; rc==SQLITE_OK && inIndex; i++){
+        rc = fts3SegmentMerge(p, iLangid, i, FTS3_SEGCURSOR_ALL);
+        if( rc==SQLITE_DONE ){
+          bSeenDone = 1;
+          rc = SQLITE_OK;
         }
       }
     }
-    pLevel->u.pCovidx = pCov;
-    if( pCov ) pLevel->iIdxCur = iCovCur;
-    if( pAndExpr ){
-      pAndExpr->pLeft = 0;
-      sqlite3ExprDelete(db, pAndExpr);
-    }
-    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
-    sqlite3VdbeResolveLabel(v, iLoopBody);
+    rc2 = sqlite3_reset(pAllLangid);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
 
-    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
-    if( !untestedTerms ) disableTerm(pLevel, pTerm);
-  }else
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+  sqlite3Fts3SegmentsClose(p);
+  sqlite3Fts3PendingTermsClear(p);
 
-  {
-    /* Case 6:  There is no usable index.  We must do a complete
-    **          scan of the entire table.
-    */
-    static const u8 aStep[] = { OP_Next, OP_Prev };
-    static const u8 aStart[] = { OP_Rewind, OP_Last };
-    assert( bRev==0 || bRev==1 );
-    if( pTabItem->isRecursive ){
-      /* Tables marked isRecursive have only a single row that is stored in
-      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
-      pLevel->op = OP_Noop;
+  return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc;
+}
+
+/*
+** This function is called when the user executes the following statement:
+**
+**     INSERT INTO () VALUES('rebuild');
+**
+** The entire FTS index is discarded and rebuilt. If the table is one 
+** created using the content=xxx option, then the new index is based on
+** the current contents of the xxx table. Otherwise, it is rebuilt based
+** on the contents of the %_content table.
+*/
+static int fts3DoRebuild(Fts3Table *p){
+  int rc;                         /* Return Code */
+
+  rc = fts3DeleteAll(p, 0);
+  if( rc==SQLITE_OK ){
+    u32 *aSz = 0;
+    u32 *aSzIns = 0;
+    u32 *aSzDel = 0;
+    sqlite3_stmt *pStmt = 0;
+    int nEntry = 0;
+
+    /* Compose and prepare an SQL statement to loop through the content table */
+    char *zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist);
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
     }else{
-      pLevel->op = aStep[bRev];
-      pLevel->p1 = iCur;
-      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
-      VdbeCoverageIf(v, bRev==0);
-      VdbeCoverageIf(v, bRev!=0);
-      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      sqlite3_free(zSql);
     }
-  }
 
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-  pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
-#endif
+    if( rc==SQLITE_OK ){
+      int nByte = sizeof(u32) * (p->nColumn+1)*3;
+      aSz = (u32 *)sqlite3_malloc(nByte);
+      if( aSz==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(aSz, 0, nByte);
+        aSzIns = &aSz[p->nColumn+1];
+        aSzDel = &aSzIns[p->nColumn+1];
+      }
+    }
 
-  /* Insert code to test every subexpression that can be completely
-  ** computed using the current set of tables.
-  */
-  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE;
-    testcase( pTerm->wtFlags & TERM_VIRTUAL );
-    testcase( pTerm->wtFlags & TERM_CODED );
-    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
-      testcase( pWInfo->untestedTerms==0
-               && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
-      pWInfo->untestedTerms = 1;
-      continue;
+    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      int iCol;
+      int iLangid = langidFromSelect(p, pStmt);
+      rc = fts3PendingTermsDocid(p, 0, iLangid, sqlite3_column_int64(pStmt, 0));
+      memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
+      for(iCol=0; rc==SQLITE_OK && iColnColumn; iCol++){
+        if( p->abNotindexed[iCol]==0 ){
+          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
+          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        }
+      }
+      if( p->bHasDocsize ){
+        fts3InsertDocsize(&rc, p, aSz);
+      }
+      if( rc!=SQLITE_OK ){
+        sqlite3_finalize(pStmt);
+        pStmt = 0;
+      }else{
+        nEntry++;
+        for(iCol=0; iCol<=p->nColumn; iCol++){
+          aSzIns[iCol] += aSz[iCol];
+        }
+      }
     }
-    pE = pTerm->pExpr;
-    assert( pE!=0 );
-    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
-      continue;
+    if( p->bFts4 ){
+      fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nEntry);
     }
-    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
-    pTerm->wtFlags |= TERM_CODED;
-  }
+    sqlite3_free(aSz);
 
-  /* Insert code to test for implied constraints based on transitivity
-  ** of the "==" operator.
-  **
-  ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
-  ** and we are coding the t1 loop and the t2 loop has not yet coded,
-  ** then we cannot use the "t1.a=t2.b" constraint, but we can code
-  ** the implied "t1.a=123" constraint.
-  */
-  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE, *pEAlt;
-    WhereTerm *pAlt;
-    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue;
-    if( pTerm->leftCursor!=iCur ) continue;
-    if( pLevel->iLeftJoin ) continue;
-    pE = pTerm->pExpr;
-    assert( !ExprHasProperty(pE, EP_FromJoin) );
-    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
-    pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
-    if( pAlt==0 ) continue;
-    if( pAlt->wtFlags & (TERM_CODED) ) continue;
-    testcase( pAlt->eOperator & WO_EQ );
-    testcase( pAlt->eOperator & WO_IN );
-    VdbeModuleComment((v, "begin transitive constraint"));
-    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
-    if( pEAlt ){
-      *pEAlt = *pAlt->pExpr;
-      pEAlt->pLeft = pE->pLeft;
-      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
-      sqlite3StackFree(db, pEAlt);
+    if( pStmt ){
+      int rc2 = sqlite3_finalize(pStmt);
+      if( rc==SQLITE_OK ){
+        rc = rc2;
+      }
     }
   }
 
-  /* For a LEFT OUTER JOIN, generate code that will record the fact that
-  ** at least one row of the right table has matched the left table.  
-  */
-  if( pLevel->iLeftJoin ){
-    pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
-    VdbeComment((v, "record LEFT JOIN hit"));
-    sqlite3ExprCacheClear(pParse);
-    for(pTerm=pWC->a, j=0; jnTerm; j++, pTerm++){
-      testcase( pTerm->wtFlags & TERM_VIRTUAL );
-      testcase( pTerm->wtFlags & TERM_CODED );
-      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
-        assert( pWInfo->untestedTerms );
-        continue;
-      }
-      assert( pTerm->pExpr );
-      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
-      pTerm->wtFlags |= TERM_CODED;
+  return rc;
+}
+
+
+/*
+** This function opens a cursor used to read the input data for an 
+** incremental merge operation. Specifically, it opens a cursor to scan
+** the oldest nSeg segments (idx=0 through idx=(nSeg-1)) in absolute 
+** level iAbsLevel.
+*/
+static int fts3IncrmergeCsr(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level to open */
+  int nSeg,                       /* Number of segments to merge */
+  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
+){
+  int rc;                         /* Return Code */
+  sqlite3_stmt *pStmt = 0;        /* Statement used to read %_segdir entry */  
+  int nByte;                      /* Bytes allocated at pCsr->apSegment[] */
+
+  /* Allocate space for the Fts3MultiSegReader.aCsr[] array */
+  memset(pCsr, 0, sizeof(*pCsr));
+  nByte = sizeof(Fts3SegReader *) * nSeg;
+  pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc(nByte);
+
+  if( pCsr->apSegment==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    memset(pCsr->apSegment, 0, nByte);
+    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
+  }
+  if( rc==SQLITE_OK ){
+    int i;
+    int rc2;
+    sqlite3_bind_int64(pStmt, 1, iAbsLevel);
+    assert( pCsr->nSegment==0 );
+    for(i=0; rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW && iapSegment[i]
+      );
+      pCsr->nSegment++;
     }
+    rc2 = sqlite3_reset(pStmt);
+    if( rc==SQLITE_OK ) rc = rc2;
   }
 
-  return pLevel->notReady;
+  return rc;
 }
 
-#ifdef WHERETRACE_ENABLED
+typedef struct IncrmergeWriter IncrmergeWriter;
+typedef struct NodeWriter NodeWriter;
+typedef struct Blob Blob;
+typedef struct NodeReader NodeReader;
+
 /*
-** Print the content of a WhereTerm object
+** An instance of the following structure is used as a dynamic buffer
+** to build up nodes or other blobs of data in.
+**
+** The function blobGrowBuffer() is used to extend the allocation.
 */
-static void whereTermPrint(WhereTerm *pTerm, int iTerm){
-  if( pTerm==0 ){
-    sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
-  }else{
-    char zType[4];
-    memcpy(zType, "...", 4);
-    if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
-    if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';
-    if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
-    sqlite3DebugPrintf("TERM-%-3d %p %s cursor=%-3d prob=%-3d op=0x%03x\n",
-                       iTerm, pTerm, zType, pTerm->leftCursor, pTerm->truthProb,
-                       pTerm->eOperator);
-    sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
-  }
-}
-#endif
+struct Blob {
+  char *a;                        /* Pointer to allocation */
+  int n;                          /* Number of valid bytes of data in a[] */
+  int nAlloc;                     /* Allocated size of a[] (nAlloc>=n) */
+};
 
-#ifdef WHERETRACE_ENABLED
 /*
-** Print a WhereLoop object for debugging purposes
+** This structure is used to build up buffers containing segment b-tree 
+** nodes (blocks).
 */
-static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
-  WhereInfo *pWInfo = pWC->pWInfo;
-  int nb = 1+(pWInfo->pTabList->nSrc+7)/8;
-  struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
-  Table *pTab = pItem->pTab;
-  sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
-                     p->iTab, nb, p->maskSelf, nb, p->prereq);
-  sqlite3DebugPrintf(" %12s",
-                     pItem->zAlias ? pItem->zAlias : pTab->zName);
-  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
-    const char *zName;
-    if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
-      if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
-        int i = sqlite3Strlen30(zName) - 1;
-        while( zName[i]!='_' ) i--;
-        zName += i;
-      }
-      sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
-    }else{
-      sqlite3DebugPrintf("%20s","");
-    }
-  }else{
-    char *z;
-    if( p->u.vtab.idxStr ){
-      z = sqlite3_mprintf("(%d,\"%s\",%x)",
-                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+struct NodeWriter {
+  sqlite3_int64 iBlock;           /* Current block id */
+  Blob key;                       /* Last key written to the current block */
+  Blob block;                     /* Current block image */
+};
+
+/*
+** An object of this type contains the state required to create or append
+** to an appendable b-tree segment.
+*/
+struct IncrmergeWriter {
+  int nLeafEst;                   /* Space allocated for leaf blocks */
+  int nWork;                      /* Number of leaf pages flushed */
+  sqlite3_int64 iAbsLevel;        /* Absolute level of input segments */
+  int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */
+  sqlite3_int64 iStart;           /* Block number of first allocated block */
+  sqlite3_int64 iEnd;             /* Block number of last allocated block */
+  sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */
+  u8 bNoLeafData;                 /* If true, store 0 for segment size */
+  NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];
+};
+
+/*
+** An object of the following type is used to read data from a single
+** FTS segment node. See the following functions:
+**
+**     nodeReaderInit()
+**     nodeReaderNext()
+**     nodeReaderRelease()
+*/
+struct NodeReader {
+  const char *aNode;
+  int nNode;
+  int iOff;                       /* Current offset within aNode[] */
+
+  /* Output variables. Containing the current node entry. */
+  sqlite3_int64 iChild;           /* Pointer to child node */
+  Blob term;                      /* Current term */
+  const char *aDoclist;           /* Pointer to doclist */
+  int nDoclist;                   /* Size of doclist in bytes */
+};
+
+/*
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, if the allocation at pBlob->a is not already at least nMin
+** bytes in size, extend (realloc) it to be so.
+**
+** If an OOM error occurs, set *pRc to SQLITE_NOMEM and leave pBlob->a
+** unmodified. Otherwise, if the allocation succeeds, update pBlob->nAlloc
+** to reflect the new size of the pBlob->a[] buffer.
+*/
+static void blobGrowBuffer(Blob *pBlob, int nMin, int *pRc){
+  if( *pRc==SQLITE_OK && nMin>pBlob->nAlloc ){
+    int nAlloc = nMin;
+    char *a = (char *)sqlite3_realloc(pBlob->a, nAlloc);
+    if( a ){
+      pBlob->nAlloc = nAlloc;
+      pBlob->a = a;
     }else{
-      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
+      *pRc = SQLITE_NOMEM;
     }
-    sqlite3DebugPrintf(" %-19s", z);
-    sqlite3_free(z);
   }
-  if( p->wsFlags & WHERE_SKIPSCAN ){
-    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
+}
+
+/*
+** Attempt to advance the node-reader object passed as the first argument to
+** the next entry on the node. 
+**
+** Return an error code if an error occurs (SQLITE_NOMEM is possible). 
+** Otherwise return SQLITE_OK. If there is no next entry on the node
+** (e.g. because the current entry is the last) set NodeReader->aNode to
+** NULL to indicate EOF. Otherwise, populate the NodeReader structure output 
+** variables for the new entry.
+*/
+static int nodeReaderNext(NodeReader *p){
+  int bFirst = (p->term.n==0);    /* True for first term on the node */
+  int nPrefix = 0;                /* Bytes to copy from previous term */
+  int nSuffix = 0;                /* Bytes to append to the prefix */
+  int rc = SQLITE_OK;             /* Return code */
+
+  assert( p->aNode );
+  if( p->iChild && bFirst==0 ) p->iChild++;
+  if( p->iOff>=p->nNode ){
+    /* EOF */
+    p->aNode = 0;
   }else{
-    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
-  }
-  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
-  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
-    int i;
-    for(i=0; inLTerm; i++){
-      whereTermPrint(p->aLTerm[i], i);
+    if( bFirst==0 ){
+      p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);
+    }
+    p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);
+
+    blobGrowBuffer(&p->term, nPrefix+nSuffix, &rc);
+    if( rc==SQLITE_OK ){
+      memcpy(&p->term.a[nPrefix], &p->aNode[p->iOff], nSuffix);
+      p->term.n = nPrefix+nSuffix;
+      p->iOff += nSuffix;
+      if( p->iChild==0 ){
+        p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);
+        p->aDoclist = &p->aNode[p->iOff];
+        p->iOff += p->nDoclist;
+      }
     }
   }
+
+  assert( p->iOff<=p->nNode );
+
+  return rc;
 }
-#endif
 
 /*
-** Convert bulk memory into a valid WhereLoop that can be passed
-** to whereLoopClear harmlessly.
+** Release all dynamic resources held by node-reader object *p.
 */
-static void whereLoopInit(WhereLoop *p){
-  p->aLTerm = p->aLTermSpace;
-  p->nLTerm = 0;
-  p->nLSlot = ArraySize(p->aLTermSpace);
-  p->wsFlags = 0;
+static void nodeReaderRelease(NodeReader *p){
+  sqlite3_free(p->term.a);
 }
 
 /*
-** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.
+** Initialize a node-reader object to read the node in buffer aNode/nNode.
+**
+** If successful, SQLITE_OK is returned and the NodeReader object set to 
+** point to the first entry on the node (if any). Otherwise, an SQLite
+** error code is returned.
 */
-static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
-  if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
-    if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
-      sqlite3_free(p->u.vtab.idxStr);
-      p->u.vtab.needFree = 0;
-      p->u.vtab.idxStr = 0;
-    }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
-      sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
-      sqlite3DbFree(db, p->u.btree.pIndex);
-      p->u.btree.pIndex = 0;
-    }
+static int nodeReaderInit(NodeReader *p, const char *aNode, int nNode){
+  memset(p, 0, sizeof(NodeReader));
+  p->aNode = aNode;
+  p->nNode = nNode;
+
+  /* Figure out if this is a leaf or an internal node. */
+  if( p->aNode[0] ){
+    /* An internal node. */
+    p->iOff = 1 + sqlite3Fts3GetVarint(&p->aNode[1], &p->iChild);
+  }else{
+    p->iOff = 1;
   }
-}
 
-/*
-** Deallocate internal memory used by a WhereLoop object
-*/
-static void whereLoopClear(sqlite3 *db, WhereLoop *p){
-  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
-  whereLoopClearUnion(db, p);
-  whereLoopInit(p);
+  return nodeReaderNext(p);
 }
 
 /*
-** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+** This function is called while writing an FTS segment each time a leaf o
+** node is finished and written to disk. The key (zTerm/nTerm) is guaranteed
+** to be greater than the largest key on the node just written, but smaller
+** than or equal to the first key that will be written to the next leaf
+** node.
+**
+** The block id of the leaf node just written to disk may be found in
+** (pWriter->aNodeWriter[0].iBlock) when this function is called.
 */
-static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
-  WhereTerm **paNew;
-  if( p->nLSlot>=n ) return SQLITE_OK;
-  n = (n+7)&~7;
-  paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n);
-  if( paNew==0 ) return SQLITE_NOMEM;
-  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
-  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
-  p->aLTerm = paNew;
-  p->nLSlot = n;
-  return SQLITE_OK;
+static int fts3IncrmergePush(
+  Fts3Table *p,                   /* Fts3 table handle */
+  IncrmergeWriter *pWriter,       /* Writer object */
+  const char *zTerm,              /* Term to write to internal node */
+  int nTerm                       /* Bytes at zTerm */
+){
+  sqlite3_int64 iPtr = pWriter->aNodeWriter[0].iBlock;
+  int iLayer;
+
+  assert( nTerm>0 );
+  for(iLayer=1; ALWAYS(iLayeraNodeWriter[iLayer];
+    int rc = SQLITE_OK;
+    int nPrefix;
+    int nSuffix;
+    int nSpace;
+
+    /* Figure out how much space the key will consume if it is written to
+    ** the current node of layer iLayer. Due to the prefix compression, 
+    ** the space required changes depending on which node the key is to
+    ** be added to.  */
+    nPrefix = fts3PrefixCompress(pNode->key.a, pNode->key.n, zTerm, nTerm);
+    nSuffix = nTerm - nPrefix;
+    nSpace  = sqlite3Fts3VarintLen(nPrefix);
+    nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+
+    if( pNode->key.n==0 || (pNode->block.n + nSpace)<=p->nNodeSize ){ 
+      /* If the current node of layer iLayer contains zero keys, or if adding
+      ** the key to it will not cause it to grow to larger than nNodeSize 
+      ** bytes in size, write the key here.  */
+
+      Blob *pBlk = &pNode->block;
+      if( pBlk->n==0 ){
+        blobGrowBuffer(pBlk, p->nNodeSize, &rc);
+        if( rc==SQLITE_OK ){
+          pBlk->a[0] = (char)iLayer;
+          pBlk->n = 1 + sqlite3Fts3PutVarint(&pBlk->a[1], iPtr);
+        }
+      }
+      blobGrowBuffer(pBlk, pBlk->n + nSpace, &rc);
+      blobGrowBuffer(&pNode->key, nTerm, &rc);
+
+      if( rc==SQLITE_OK ){
+        if( pNode->key.n ){
+          pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nPrefix);
+        }
+        pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nSuffix);
+        memcpy(&pBlk->a[pBlk->n], &zTerm[nPrefix], nSuffix);
+        pBlk->n += nSuffix;
+
+        memcpy(pNode->key.a, zTerm, nTerm);
+        pNode->key.n = nTerm;
+      }
+    }else{
+      /* Otherwise, flush the current node of layer iLayer to disk.
+      ** Then allocate a new, empty sibling node. The key will be written
+      ** into the parent of this node. */
+      rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);
+
+      assert( pNode->block.nAlloc>=p->nNodeSize );
+      pNode->block.a[0] = (char)iLayer;
+      pNode->block.n = 1 + sqlite3Fts3PutVarint(&pNode->block.a[1], iPtr+1);
+
+      iNextPtr = pNode->iBlock;
+      pNode->iBlock++;
+      pNode->key.n = 0;
+    }
+
+    if( rc!=SQLITE_OK || iNextPtr==0 ) return rc;
+    iPtr = iNextPtr;
+  }
+
+  assert( 0 );
+  return 0;
 }
 
 /*
-** Transfer content from the second pLoop into the first.
+** Append a term and (optionally) doclist to the FTS segment node currently
+** stored in blob *pNode. The node need not contain any terms, but the
+** header must be written before this function is called.
+**
+** A node header is a single 0x00 byte for a leaf node, or a height varint
+** followed by the left-hand-child varint for an internal node.
+**
+** The term to be appended is passed via arguments zTerm/nTerm. For a 
+** leaf node, the doclist is passed as aDoclist/nDoclist. For an internal
+** node, both aDoclist and nDoclist must be passed 0.
+**
+** If the size of the value in blob pPrev is zero, then this is the first
+** term written to the node. Otherwise, pPrev contains a copy of the 
+** previous term. Before this function returns, it is updated to contain a
+** copy of zTerm/nTerm.
+**
+** It is assumed that the buffer associated with pNode is already large
+** enough to accommodate the new entry. The buffer associated with pPrev
+** is extended by this function if requrired.
+**
+** If an error (i.e. OOM condition) occurs, an SQLite error code is
+** returned. Otherwise, SQLITE_OK.
 */
-static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
-  whereLoopClearUnion(db, pTo);
-  if( whereLoopResize(db, pTo, pFrom->nLTerm) ){
-    memset(&pTo->u, 0, sizeof(pTo->u));
-    return SQLITE_NOMEM;
+static int fts3AppendToNode(
+  Blob *pNode,                    /* Current node image to append to */
+  Blob *pPrev,                    /* Buffer containing previous term written */
+  const char *zTerm,              /* New term to write */
+  int nTerm,                      /* Size of zTerm in bytes */
+  const char *aDoclist,           /* Doclist (or NULL) to write */
+  int nDoclist                    /* Size of aDoclist in bytes */ 
+){
+  int rc = SQLITE_OK;             /* Return code */
+  int bFirst = (pPrev->n==0);     /* True if this is the first term written */
+  int nPrefix;                    /* Size of term prefix in bytes */
+  int nSuffix;                    /* Size of term suffix in bytes */
+
+  /* Node must have already been started. There must be a doclist for a
+  ** leaf node, and there must not be a doclist for an internal node.  */
+  assert( pNode->n>0 );
+  assert( (pNode->a[0]=='\0')==(aDoclist!=0) );
+
+  blobGrowBuffer(pPrev, nTerm, &rc);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nPrefix = fts3PrefixCompress(pPrev->a, pPrev->n, zTerm, nTerm);
+  nSuffix = nTerm - nPrefix;
+  memcpy(pPrev->a, zTerm, nTerm);
+  pPrev->n = nTerm;
+
+  if( bFirst==0 ){
+    pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nPrefix);
   }
-  memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
-  memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
-  if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
-    pFrom->u.vtab.needFree = 0;
-  }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
-    pFrom->u.btree.pIndex = 0;
+  pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nSuffix);
+  memcpy(&pNode->a[pNode->n], &zTerm[nPrefix], nSuffix);
+  pNode->n += nSuffix;
+
+  if( aDoclist ){
+    pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nDoclist);
+    memcpy(&pNode->a[pNode->n], aDoclist, nDoclist);
+    pNode->n += nDoclist;
   }
+
+  assert( pNode->n<=pNode->nAlloc );
+
   return SQLITE_OK;
 }
 
 /*
-** Delete a WhereLoop object
+** Append the current term and doclist pointed to by cursor pCsr to the
+** appendable b-tree segment opened for writing by pWriter.
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise.
 */
-static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
-  whereLoopClear(db, p);
-  sqlite3DbFree(db, p);
-}
+static int fts3IncrmergeAppend(
+  Fts3Table *p,                   /* Fts3 table handle */
+  IncrmergeWriter *pWriter,       /* Writer object */
+  Fts3MultiSegReader *pCsr        /* Cursor containing term and doclist */
+){
+  const char *zTerm = pCsr->zTerm;
+  int nTerm = pCsr->nTerm;
+  const char *aDoclist = pCsr->aDoclist;
+  int nDoclist = pCsr->nDoclist;
+  int rc = SQLITE_OK;           /* Return code */
+  int nSpace;                   /* Total space in bytes required on leaf */
+  int nPrefix;                  /* Size of prefix shared with previous term */
+  int nSuffix;                  /* Size of suffix (nTerm - nPrefix) */
+  NodeWriter *pLeaf;            /* Object used to write leaf nodes */
 
-/*
-** Free a WhereInfo structure
-*/
-static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
-  if( ALWAYS(pWInfo) ){
-    whereClauseClear(&pWInfo->sWC);
-    while( pWInfo->pLoops ){
-      WhereLoop *p = pWInfo->pLoops;
-      pWInfo->pLoops = p->pNextLoop;
-      whereLoopDelete(db, p);
+  pLeaf = &pWriter->aNodeWriter[0];
+  nPrefix = fts3PrefixCompress(pLeaf->key.a, pLeaf->key.n, zTerm, nTerm);
+  nSuffix = nTerm - nPrefix;
+
+  nSpace  = sqlite3Fts3VarintLen(nPrefix);
+  nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+  nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;
+
+  /* If the current block is not empty, and if adding this term/doclist
+  ** to the current block would make it larger than Fts3Table.nNodeSize
+  ** bytes, write this block out to the database. */
+  if( pLeaf->block.n>0 && (pLeaf->block.n + nSpace)>p->nNodeSize ){
+    rc = fts3WriteSegment(p, pLeaf->iBlock, pLeaf->block.a, pLeaf->block.n);
+    pWriter->nWork++;
+
+    /* Add the current term to the parent node. The term added to the 
+    ** parent must:
+    **
+    **   a) be greater than the largest term on the leaf node just written
+    **      to the database (still available in pLeaf->key), and
+    **
+    **   b) be less than or equal to the term about to be added to the new
+    **      leaf node (zTerm/nTerm).
+    **
+    ** In other words, it must be the prefix of zTerm 1 byte longer than
+    ** the common prefix (if any) of zTerm and pWriter->zTerm.
+    */
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergePush(p, pWriter, zTerm, nPrefix+1);
     }
-    sqlite3DbFree(db, pWInfo);
+
+    /* Advance to the next output block */
+    pLeaf->iBlock++;
+    pLeaf->key.n = 0;
+    pLeaf->block.n = 0;
+
+    nSuffix = nTerm;
+    nSpace  = 1;
+    nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+    nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;
+  }
+
+  pWriter->nLeafData += nSpace;
+  blobGrowBuffer(&pLeaf->block, pLeaf->block.n + nSpace, &rc);
+  if( rc==SQLITE_OK ){
+    if( pLeaf->block.n==0 ){
+      pLeaf->block.n = 1;
+      pLeaf->block.a[0] = '\0';
+    }
+    rc = fts3AppendToNode(
+        &pLeaf->block, &pLeaf->key, zTerm, nTerm, aDoclist, nDoclist
+    );
   }
+
+  return rc;
 }
 
 /*
-** Return TRUE if all of the following are true:
-**
-**   (1)  X has the same or lower cost that Y
-**   (2)  X is a proper subset of Y
-**   (3)  X skips at least as many columns as Y
+** This function is called to release all dynamic resources held by the
+** merge-writer object pWriter, and if no error has occurred, to flush
+** all outstanding node buffers held by pWriter to disk.
 **
-** By "proper subset" we mean that X uses fewer WHERE clause terms
-** than Y and that every WHERE clause term used by X is also used
-** by Y.
+** If *pRc is not SQLITE_OK when this function is called, then no attempt
+** is made to write any data to disk. Instead, this function serves only
+** to release outstanding resources.
 **
-** If X is a proper subset of Y then Y is a better choice and ought
-** to have a lower cost.  This routine returns TRUE when that cost 
-** relationship is inverted and needs to be adjusted.  The third rule
-** was added because if X uses skip-scan less than Y it still might
-** deserve a lower cost even if it is a proper subset of Y.
+** Otherwise, if *pRc is initially SQLITE_OK and an error occurs while
+** flushing buffers to disk, *pRc is set to an SQLite error code before
+** returning.
 */
-static int whereLoopCheaperProperSubset(
-  const WhereLoop *pX,       /* First WhereLoop to compare */
-  const WhereLoop *pY        /* Compare against this WhereLoop */
+static void fts3IncrmergeRelease(
+  Fts3Table *p,                   /* FTS3 table handle */
+  IncrmergeWriter *pWriter,       /* Merge-writer object */
+  int *pRc                        /* IN/OUT: Error code */
 ){
-  int i, j;
-  if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
-    return 0; /* X is not a subset of Y */
+  int i;                          /* Used to iterate through non-root layers */
+  int iRoot;                      /* Index of root in pWriter->aNodeWriter */
+  NodeWriter *pRoot;              /* NodeWriter for root node */
+  int rc = *pRc;                  /* Error code */
+
+  /* Set iRoot to the index in pWriter->aNodeWriter[] of the output segment 
+  ** root node. If the segment fits entirely on a single leaf node, iRoot
+  ** will be set to 0. If the root node is the parent of the leaves, iRoot
+  ** will be 1. And so on.  */
+  for(iRoot=FTS_MAX_APPENDABLE_HEIGHT-1; iRoot>=0; iRoot--){
+    NodeWriter *pNode = &pWriter->aNodeWriter[iRoot];
+    if( pNode->block.n>0 ) break;
+    assert( *pRc || pNode->block.nAlloc==0 );
+    assert( *pRc || pNode->key.nAlloc==0 );
+    sqlite3_free(pNode->block.a);
+    sqlite3_free(pNode->key.a);
   }
-  if( pY->nSkip > pX->nSkip ) return 0;
-  if( pX->rRun >= pY->rRun ){
-    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
-    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
+
+  /* Empty output segment. This is a no-op. */
+  if( iRoot<0 ) return;
+
+  /* The entire output segment fits on a single node. Normally, this means
+  ** the node would be stored as a blob in the "root" column of the %_segdir
+  ** table. However, this is not permitted in this case. The problem is that 
+  ** space has already been reserved in the %_segments table, and so the 
+  ** start_block and end_block fields of the %_segdir table must be populated. 
+  ** And, by design or by accident, released versions of FTS cannot handle 
+  ** segments that fit entirely on the root node with start_block!=0.
+  **
+  ** Instead, create a synthetic root node that contains nothing but a 
+  ** pointer to the single content node. So that the segment consists of a
+  ** single leaf and a single interior (root) node.
+  **
+  ** Todo: Better might be to defer allocating space in the %_segments 
+  ** table until we are sure it is needed.
+  */
+  if( iRoot==0 ){
+    Blob *pBlock = &pWriter->aNodeWriter[1].block;
+    blobGrowBuffer(pBlock, 1 + FTS3_VARINT_MAX, &rc);
+    if( rc==SQLITE_OK ){
+      pBlock->a[0] = 0x01;
+      pBlock->n = 1 + sqlite3Fts3PutVarint(
+          &pBlock->a[1], pWriter->aNodeWriter[0].iBlock
+      );
+    }
+    iRoot = 1;
   }
-  for(i=pX->nLTerm-1; i>=0; i--){
-    if( pX->aLTerm[i]==0 ) continue;
-    for(j=pY->nLTerm-1; j>=0; j--){
-      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
+  pRoot = &pWriter->aNodeWriter[iRoot];
+
+  /* Flush all currently outstanding nodes to disk. */
+  for(i=0; iaNodeWriter[i];
+    if( pNode->block.n>0 && rc==SQLITE_OK ){
+      rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);
     }
-    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
+    sqlite3_free(pNode->block.a);
+    sqlite3_free(pNode->key.a);
   }
-  return 1;  /* All conditions meet */
+
+  /* Write the %_segdir record. */
+  if( rc==SQLITE_OK ){
+    rc = fts3WriteSegdir(p, 
+        pWriter->iAbsLevel+1,               /* level */
+        pWriter->iIdx,                      /* idx */
+        pWriter->iStart,                    /* start_block */
+        pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */
+        pWriter->iEnd,                      /* end_block */
+        (pWriter->bNoLeafData==0 ? pWriter->nLeafData : 0),   /* end_block */
+        pRoot->block.a, pRoot->block.n      /* root */
+    );
+  }
+  sqlite3_free(pRoot->block.a);
+  sqlite3_free(pRoot->key.a);
+
+  *pRc = rc;
 }
 
 /*
-** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so
-** that:
+** Compare the term in buffer zLhs (size in bytes nLhs) with that in
+** zRhs (size in bytes nRhs) using memcmp. If one term is a prefix of
+** the other, it is considered to be smaller than the other.
 **
-**   (1) pTemplate costs less than any other WhereLoops that are a proper
-**       subset of pTemplate
+** Return -ve if zLhs is smaller than zRhs, 0 if it is equal, or +ve
+** if it is greater.
+*/
+static int fts3TermCmp(
+  const char *zLhs, int nLhs,     /* LHS of comparison */
+  const char *zRhs, int nRhs      /* RHS of comparison */
+){
+  int nCmp = MIN(nLhs, nRhs);
+  int res;
+
+  res = memcmp(zLhs, zRhs, nCmp);
+  if( res==0 ) res = nLhs - nRhs;
+
+  return res;
+}
+
+
+/*
+** Query to see if the entry in the %_segments table with blockid iEnd is 
+** NULL. If no error occurs and the entry is NULL, set *pbRes 1 before
+** returning. Otherwise, set *pbRes to 0. 
 **
-**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
-**       is a proper subset.
+** Or, if an error occurs while querying the database, return an SQLite 
+** error code. The final value of *pbRes is undefined in this case.
 **
-** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
-** WHERE clause terms than Y and that every WHERE clause term used by X is
-** also used by Y.
+** This is used to test if a segment is an "appendable" segment. If it
+** is, then a NULL entry has been inserted into the %_segments table
+** with blockid %_segdir.end_block.
 */
-static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
-  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
-  for(; p; p=p->pNextLoop){
-    if( p->iTab!=pTemplate->iTab ) continue;
-    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
-    if( whereLoopCheaperProperSubset(p, pTemplate) ){
-      /* Adjust pTemplate cost downward so that it is cheaper than its 
-      ** subset p. */
-      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
-                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
-      pTemplate->rRun = p->rRun;
-      pTemplate->nOut = p->nOut - 1;
-    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
-      /* Adjust pTemplate cost upward so that it is costlier than p since
-      ** pTemplate is a proper subset of p */
-      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
-                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
-      pTemplate->rRun = p->rRun;
-      pTemplate->nOut = p->nOut + 1;
-    }
+static int fts3IsAppendable(Fts3Table *p, sqlite3_int64 iEnd, int *pbRes){
+  int bRes = 0;                   /* Result to set *pbRes to */
+  sqlite3_stmt *pCheck = 0;       /* Statement to query database with */
+  int rc;                         /* Return code */
+
+  rc = fts3SqlStmt(p, SQL_SEGMENT_IS_APPENDABLE, &pCheck, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pCheck, 1, iEnd);
+    if( SQLITE_ROW==sqlite3_step(pCheck) ) bRes = 1;
+    rc = sqlite3_reset(pCheck);
   }
+  
+  *pbRes = bRes;
+  return rc;
 }
 
 /*
-** Search the list of WhereLoops in *ppPrev looking for one that can be
-** supplanted by pTemplate.
+** This function is called when initializing an incremental-merge operation.
+** It checks if the existing segment with index value iIdx at absolute level 
+** (iAbsLevel+1) can be appended to by the incremental merge. If it can, the
+** merge-writer object *pWriter is initialized to write to it.
 **
-** Return NULL if the WhereLoop list contains an entry that can supplant
-** pTemplate, in other words if pTemplate does not belong on the list.
+** An existing segment can be appended to by an incremental merge if:
 **
-** If pX is a WhereLoop that pTemplate can supplant, then return the
-** link that points to pX.
+**   * It was initially created as an appendable segment (with all required
+**     space pre-allocated), and
 **
-** If pTemplate cannot supplant any existing element of the list but needs
-** to be added to the list, then return a pointer to the tail of the list.
+**   * The first key read from the input (arguments zKey and nKey) is 
+**     greater than the largest key currently stored in the potential
+**     output segment.
 */
-static WhereLoop **whereLoopFindLesser(
-  WhereLoop **ppPrev,
-  const WhereLoop *pTemplate
+static int fts3IncrmergeLoad(
+  Fts3Table *p,                   /* Fts3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */
+  int iIdx,                       /* Index of candidate output segment */
+  const char *zKey,               /* First key to write */
+  int nKey,                       /* Number of bytes in nKey */
+  IncrmergeWriter *pWriter        /* Populate this object */
 ){
-  WhereLoop *p;
-  for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
-    if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
-      /* If either the iTab or iSortIdx values for two WhereLoop are different
-      ** then those WhereLoops need to be considered separately.  Neither is
-      ** a candidate to replace the other. */
-      continue;
-    }
-    /* In the current implementation, the rSetup value is either zero
-    ** or the cost of building an automatic index (NlogN) and the NlogN
-    ** is the same for compatible WhereLoops. */
-    assert( p->rSetup==0 || pTemplate->rSetup==0 
-                 || p->rSetup==pTemplate->rSetup );
+  int rc;                         /* Return code */
+  sqlite3_stmt *pSelect = 0;      /* SELECT to read %_segdir entry */
 
-    /* whereLoopAddBtree() always generates and inserts the automatic index
-    ** case first.  Hence compatible candidate WhereLoops never have a larger
-    ** rSetup. Call this SETUP-INVARIANT */
-    assert( p->rSetup>=pTemplate->rSetup );
+  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pSelect, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_int64 iStart = 0;     /* Value of %_segdir.start_block */
+    sqlite3_int64 iLeafEnd = 0;   /* Value of %_segdir.leaves_end_block */
+    sqlite3_int64 iEnd = 0;       /* Value of %_segdir.end_block */
+    const char *aRoot = 0;        /* Pointer to %_segdir.root buffer */
+    int nRoot = 0;                /* Size of aRoot[] in bytes */
+    int rc2;                      /* Return code from sqlite3_reset() */
+    int bAppendable = 0;          /* Set to true if segment is appendable */
 
-    /* Any loop using an appliation-defined index (or PRIMARY KEY or
-    ** UNIQUE constraint) with one or more == constraints is better
-    ** than an automatic index. Unless it is a skip-scan. */
-    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
-     && (pTemplate->nSkip)==0
-     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
-     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
-     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
-    ){
-      break;
+    /* Read the %_segdir entry for index iIdx absolute level (iAbsLevel+1) */
+    sqlite3_bind_int64(pSelect, 1, iAbsLevel+1);
+    sqlite3_bind_int(pSelect, 2, iIdx);
+    if( sqlite3_step(pSelect)==SQLITE_ROW ){
+      iStart = sqlite3_column_int64(pSelect, 1);
+      iLeafEnd = sqlite3_column_int64(pSelect, 2);
+      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
+      if( pWriter->nLeafData<0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
+      pWriter->bNoLeafData = (pWriter->nLeafData==0);
+      nRoot = sqlite3_column_bytes(pSelect, 4);
+      aRoot = sqlite3_column_blob(pSelect, 4);
+    }else{
+      return sqlite3_reset(pSelect);
     }
 
-    /* If existing WhereLoop p is better than pTemplate, pTemplate can be
-    ** discarded.  WhereLoop p is better if:
-    **   (1)  p has no more dependencies than pTemplate, and
-    **   (2)  p has an equal or lower cost than pTemplate
-    */
-    if( (p->prereq & pTemplate->prereq)==p->prereq    /* (1)  */
-     && p->rSetup<=pTemplate->rSetup                  /* (2a) */
-     && p->rRun<=pTemplate->rRun                      /* (2b) */
-     && p->nOut<=pTemplate->nOut                      /* (2c) */
-    ){
-      return 0;  /* Discard pTemplate */
+    /* Check for the zero-length marker in the %_segments table */
+    rc = fts3IsAppendable(p, iEnd, &bAppendable);
+
+    /* Check that zKey/nKey is larger than the largest key the candidate */
+    if( rc==SQLITE_OK && bAppendable ){
+      char *aLeaf = 0;
+      int nLeaf = 0;
+
+      rc = sqlite3Fts3ReadBlock(p, iLeafEnd, &aLeaf, &nLeaf, 0);
+      if( rc==SQLITE_OK ){
+        NodeReader reader;
+        for(rc = nodeReaderInit(&reader, aLeaf, nLeaf);
+            rc==SQLITE_OK && reader.aNode;
+            rc = nodeReaderNext(&reader)
+        ){
+          assert( reader.aNode );
+        }
+        if( fts3TermCmp(zKey, nKey, reader.term.a, reader.term.n)<=0 ){
+          bAppendable = 0;
+        }
+        nodeReaderRelease(&reader);
+      }
+      sqlite3_free(aLeaf);
     }
 
-    /* If pTemplate is always better than p, then cause p to be overwritten
-    ** with pTemplate.  pTemplate is better than p if:
-    **   (1)  pTemplate has no more dependences than p, and
-    **   (2)  pTemplate has an equal or lower cost than p.
-    */
-    if( (p->prereq & pTemplate->prereq)==pTemplate->prereq   /* (1)  */
-     && p->rRun>=pTemplate->rRun                             /* (2a) */
-     && p->nOut>=pTemplate->nOut                             /* (2b) */
-    ){
-      assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
-      break;   /* Cause p to be overwritten by pTemplate */
+    if( rc==SQLITE_OK && bAppendable ){
+      /* It is possible to append to this segment. Set up the IncrmergeWriter
+      ** object to do so.  */
+      int i;
+      int nHeight = (int)aRoot[0];
+      NodeWriter *pNode;
+
+      pWriter->nLeafEst = (int)((iEnd - iStart) + 1)/FTS_MAX_APPENDABLE_HEIGHT;
+      pWriter->iStart = iStart;
+      pWriter->iEnd = iEnd;
+      pWriter->iAbsLevel = iAbsLevel;
+      pWriter->iIdx = iIdx;
+
+      for(i=nHeight+1; iaNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
+      }
+
+      pNode = &pWriter->aNodeWriter[nHeight];
+      pNode->iBlock = pWriter->iStart + pWriter->nLeafEst*nHeight;
+      blobGrowBuffer(&pNode->block, MAX(nRoot, p->nNodeSize), &rc);
+      if( rc==SQLITE_OK ){
+        memcpy(pNode->block.a, aRoot, nRoot);
+        pNode->block.n = nRoot;
+      }
+
+      for(i=nHeight; i>=0 && rc==SQLITE_OK; i--){
+        NodeReader reader;
+        pNode = &pWriter->aNodeWriter[i];
+
+        rc = nodeReaderInit(&reader, pNode->block.a, pNode->block.n);
+        while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);
+        blobGrowBuffer(&pNode->key, reader.term.n, &rc);
+        if( rc==SQLITE_OK ){
+          memcpy(pNode->key.a, reader.term.a, reader.term.n);
+          pNode->key.n = reader.term.n;
+          if( i>0 ){
+            char *aBlock = 0;
+            int nBlock = 0;
+            pNode = &pWriter->aNodeWriter[i-1];
+            pNode->iBlock = reader.iChild;
+            rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
+            blobGrowBuffer(&pNode->block, MAX(nBlock, p->nNodeSize), &rc);
+            if( rc==SQLITE_OK ){
+              memcpy(pNode->block.a, aBlock, nBlock);
+              pNode->block.n = nBlock;
+            }
+            sqlite3_free(aBlock);
+          }
+        }
+        nodeReaderRelease(&reader);
+      }
     }
+
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
   }
-  return ppPrev;
+
+  return rc;
 }
 
 /*
-** Insert or replace a WhereLoop entry using the template supplied.
+** Determine the largest segment index value that exists within absolute
+** level iAbsLevel+1. If no error occurs, set *piIdx to this value plus
+** one before returning SQLITE_OK. Or, if there are no segments at all 
+** within level iAbsLevel, set *piIdx to zero.
 **
-** An existing WhereLoop entry might be overwritten if the new template
-** is better and has fewer dependencies.  Or the template will be ignored
-** and no insert will occur if an existing WhereLoop is faster and has
-** fewer dependencies than the template.  Otherwise a new WhereLoop is
-** added based on the template.
+** If an error occurs, return an SQLite error code. The final value of
+** *piIdx is undefined in this case.
+*/
+static int fts3IncrmergeOutputIdx( 
+  Fts3Table *p,                   /* FTS Table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute index of input segments */
+  int *piIdx                      /* OUT: Next free index at iAbsLevel+1 */
+){
+  int rc;
+  sqlite3_stmt *pOutputIdx = 0;   /* SQL used to find output index */
+
+  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pOutputIdx, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pOutputIdx, 1, iAbsLevel+1);
+    sqlite3_step(pOutputIdx);
+    *piIdx = sqlite3_column_int(pOutputIdx, 0);
+    rc = sqlite3_reset(pOutputIdx);
+  }
+
+  return rc;
+}
+
+/* 
+** Allocate an appendable output segment on absolute level iAbsLevel+1
+** with idx value iIdx.
 **
-** If pBuilder->pOrSet is not NULL then we care about only the
-** prerequisites and rRun and nOut costs of the N best loops.  That
-** information is gathered in the pBuilder->pOrSet object.  This special
-** processing mode is used only for OR clause processing.
+** In the %_segdir table, a segment is defined by the values in three
+** columns:
 **
-** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
-** still might overwrite similar loops with the new template if the
-** new template is better.  Loops may be overwritten if the following 
-** conditions are met:
+**     start_block
+**     leaves_end_block
+**     end_block
 **
-**    (1)  They have the same iTab.
-**    (2)  They have the same iSortIdx.
-**    (3)  The template has same or fewer dependencies than the current loop
-**    (4)  The template has the same or lower cost than the current loop
+** When an appendable segment is allocated, it is estimated that the
+** maximum number of leaf blocks that may be required is the sum of the
+** number of leaf blocks consumed by the input segments, plus the number
+** of input segments, multiplied by two. This value is stored in stack 
+** variable nLeafEst.
+**
+** A total of 16*nLeafEst blocks are allocated when an appendable segment
+** is created ((1 + end_block - start_block)==16*nLeafEst). The contiguous
+** array of leaf nodes starts at the first block allocated. The array
+** of interior nodes that are parents of the leaf nodes start at block
+** (start_block + (1 + end_block - start_block) / 16). And so on.
+**
+** In the actual code below, the value "16" is replaced with the 
+** pre-processor macro FTS_MAX_APPENDABLE_HEIGHT.
 */
-static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
-  WhereLoop **ppPrev, *p;
-  WhereInfo *pWInfo = pBuilder->pWInfo;
-  sqlite3 *db = pWInfo->pParse->db;
+static int fts3IncrmergeWriter( 
+  Fts3Table *p,                   /* Fts3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */
+  int iIdx,                       /* Index of new output segment */
+  Fts3MultiSegReader *pCsr,       /* Cursor that data will be read from */
+  IncrmergeWriter *pWriter        /* Populate this object */
+){
+  int rc;                         /* Return Code */
+  int i;                          /* Iterator variable */
+  int nLeafEst = 0;               /* Blocks allocated for leaf nodes */
+  sqlite3_stmt *pLeafEst = 0;     /* SQL used to determine nLeafEst */
+  sqlite3_stmt *pFirstBlock = 0;  /* SQL used to determine first block */
 
-  /* If pBuilder->pOrSet is defined, then only keep track of the costs
-  ** and prereqs.
-  */
-  if( pBuilder->pOrSet!=0 ){
-#if WHERETRACE_ENABLED
-    u16 n = pBuilder->pOrSet->n;
-    int x =
-#endif
-    whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
-                                    pTemplate->nOut);
-#if WHERETRACE_ENABLED /* 0x8 */
-    if( sqlite3WhereTrace & 0x8 ){
-      sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
-      whereLoopPrint(pTemplate, pBuilder->pWC);
+  /* Calculate nLeafEst. */
+  rc = fts3SqlStmt(p, SQL_MAX_LEAF_NODE_ESTIMATE, &pLeafEst, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pLeafEst, 1, iAbsLevel);
+    sqlite3_bind_int64(pLeafEst, 2, pCsr->nSegment);
+    if( SQLITE_ROW==sqlite3_step(pLeafEst) ){
+      nLeafEst = sqlite3_column_int(pLeafEst, 0);
     }
-#endif
-    return SQLITE_OK;
+    rc = sqlite3_reset(pLeafEst);
   }
+  if( rc!=SQLITE_OK ) return rc;
 
-  /* Look for an existing WhereLoop to replace with pTemplate
-  */
-  whereLoopAdjustCost(pWInfo->pLoops, pTemplate);
-  ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
-
-  if( ppPrev==0 ){
-    /* There already exists a WhereLoop on the list that is better
-    ** than pTemplate, so just ignore pTemplate */
-#if WHERETRACE_ENABLED /* 0x8 */
-    if( sqlite3WhereTrace & 0x8 ){
-      sqlite3DebugPrintf("   skip: ");
-      whereLoopPrint(pTemplate, pBuilder->pWC);
+  /* Calculate the first block to use in the output segment */
+  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pFirstBlock, 0);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pFirstBlock) ){
+      pWriter->iStart = sqlite3_column_int64(pFirstBlock, 0);
+      pWriter->iEnd = pWriter->iStart - 1;
+      pWriter->iEnd += nLeafEst * FTS_MAX_APPENDABLE_HEIGHT;
     }
-#endif
-    return SQLITE_OK;  
-  }else{
-    p = *ppPrev;
+    rc = sqlite3_reset(pFirstBlock);
   }
+  if( rc!=SQLITE_OK ) return rc;
 
-  /* If we reach this point it means that either p[] should be overwritten
-  ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
-  ** WhereLoop and insert it.
-  */
-#if WHERETRACE_ENABLED /* 0x8 */
-  if( sqlite3WhereTrace & 0x8 ){
-    if( p!=0 ){
-      sqlite3DebugPrintf("replace: ");
-      whereLoopPrint(p, pBuilder->pWC);
-    }
-    sqlite3DebugPrintf("    add: ");
-    whereLoopPrint(pTemplate, pBuilder->pWC);
-  }
-#endif
-  if( p==0 ){
-    /* Allocate a new WhereLoop to add to the end of the list */
-    *ppPrev = p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
-    if( p==0 ) return SQLITE_NOMEM;
-    whereLoopInit(p);
-    p->pNextLoop = 0;
-  }else{
-    /* We will be overwriting WhereLoop p[].  But before we do, first
-    ** go through the rest of the list and delete any other entries besides
-    ** p[] that are also supplated by pTemplate */
-    WhereLoop **ppTail = &p->pNextLoop;
-    WhereLoop *pToDel;
-    while( *ppTail ){
-      ppTail = whereLoopFindLesser(ppTail, pTemplate);
-      if( ppTail==0 ) break;
-      pToDel = *ppTail;
-      if( pToDel==0 ) break;
-      *ppTail = pToDel->pNextLoop;
-#if WHERETRACE_ENABLED /* 0x8 */
-      if( sqlite3WhereTrace & 0x8 ){
-        sqlite3DebugPrintf(" delete: ");
-        whereLoopPrint(pToDel, pBuilder->pWC);
-      }
-#endif
-      whereLoopDelete(db, pToDel);
-    }
+  /* Insert the marker in the %_segments table to make sure nobody tries
+  ** to steal the space just allocated. This is also used to identify 
+  ** appendable segments.  */
+  rc = fts3WriteSegment(p, pWriter->iEnd, 0, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  pWriter->iAbsLevel = iAbsLevel;
+  pWriter->nLeafEst = nLeafEst;
+  pWriter->iIdx = iIdx;
+
+  /* Set up the array of NodeWriter objects */
+  for(i=0; iaNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
   }
-  whereLoopXfer(db, p, pTemplate);
-  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
-    Index *pIndex = p->u.btree.pIndex;
-    if( pIndex && pIndex->tnum==0 ){
-      p->u.btree.pIndex = 0;
-    }
+  return SQLITE_OK;
+}
+
+/*
+** Remove an entry from the %_segdir table. This involves running the 
+** following two statements:
+**
+**   DELETE FROM %_segdir WHERE level = :iAbsLevel AND idx = :iIdx
+**   UPDATE %_segdir SET idx = idx - 1 WHERE level = :iAbsLevel AND idx > :iIdx
+**
+** The DELETE statement removes the specific %_segdir level. The UPDATE 
+** statement ensures that the remaining segments have contiguously allocated
+** idx values.
+*/
+static int fts3RemoveSegdirEntry(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level to delete from */
+  int iIdx                        /* Index of %_segdir entry to delete */
+){
+  int rc;                         /* Return code */
+  sqlite3_stmt *pDelete = 0;      /* DELETE statement */
+
+  rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_ENTRY, &pDelete, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pDelete, 1, iAbsLevel);
+    sqlite3_bind_int(pDelete, 2, iIdx);
+    sqlite3_step(pDelete);
+    rc = sqlite3_reset(pDelete);
   }
-  return SQLITE_OK;
+
+  return rc;
 }
 
 /*
-** Adjust the WhereLoop.nOut value downward to account for terms of the
-** WHERE clause that reference the loop but which are not used by an
-** index.
-*
-** For every WHERE clause term that is not used by the index
-** and which has a truth probability assigned by one of the likelihood(),
-** likely(), or unlikely() SQL functions, reduce the estimated number
-** of output rows by the probability specified.
-**
-** TUNING:  For every WHERE clause term that is not used by the index
-** and which does not have an assigned truth probability, heuristics
-** described below are used to try to estimate the truth probability.
-** TODO --> Perhaps this is something that could be improved by better
-** table statistics.
-**
-** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%
-** value corresponds to -1 in LogEst notation, so this means decrement
-** the WhereLoop.nOut field for every such WHERE clause term.
-**
-** Heuristic 2:  If there exists one or more WHERE clause terms of the
-** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
-** final output row estimate is no greater than 1/4 of the total number
-** of rows in the table.  In other words, assume that x==EXPR will filter
-** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the
-** "x" column is boolean or else -1 or 0 or 1 is a common default value
-** on the "x" column and so in that case only cap the output row estimate
-** at 1/2 instead of 1/4.
+** One or more segments have just been removed from absolute level iAbsLevel.
+** Update the 'idx' values of the remaining segments in the level so that
+** the idx values are a contiguous sequence starting from 0.
 */
-static void whereLoopOutputAdjust(
-  WhereClause *pWC,      /* The WHERE clause */
-  WhereLoop *pLoop,      /* The loop to adjust downward */
-  LogEst nRow            /* Number of rows in the entire table */
+static int fts3RepackSegdirLevel(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel         /* Absolute level to repack */
 ){
-  WhereTerm *pTerm, *pX;
-  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
-  int i, j, k;
-  LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */
+  int rc;                         /* Return code */
+  int *aIdx = 0;                  /* Array of remaining idx values */
+  int nIdx = 0;                   /* Valid entries in aIdx[] */
+  int nAlloc = 0;                 /* Allocated size of aIdx[] */
+  int i;                          /* Iterator variable */
+  sqlite3_stmt *pSelect = 0;      /* Select statement to read idx values */
+  sqlite3_stmt *pUpdate = 0;      /* Update statement to modify idx values */
 
-  assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
-  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
-    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
-    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
-    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
-    for(j=pLoop->nLTerm-1; j>=0; j--){
-      pX = pLoop->aLTerm[j];
-      if( pX==0 ) continue;
-      if( pX==pTerm ) break;
-      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
-    }
-    if( j<0 ){
-      if( pTerm->truthProb<=0 ){
-        /* If a truth probability is specified using the likelihood() hints,
-        ** then use the probability provided by the application. */
-        pLoop->nOut += pTerm->truthProb;
-      }else{
-        /* In the absence of explicit truth probabilities, use heuristics to
-        ** guess a reasonable truth probability. */
-        pLoop->nOut--;
-        if( pTerm->eOperator&WO_EQ ){
-          Expr *pRight = pTerm->pExpr->pRight;
-          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
-            k = 10;
-          }else{
-            k = 20;
-          }
-          if( iReduce=nAlloc ){
+        int *aNew;
+        nAlloc += 16;
+        aNew = sqlite3_realloc(aIdx, nAlloc*sizeof(int));
+        if( !aNew ){
+          rc = SQLITE_NOMEM;
+          break;
         }
+        aIdx = aNew;
       }
+      aIdx[nIdx++] = sqlite3_column_int(pSelect, 0);
     }
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
   }
-  if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
+
+  if( rc==SQLITE_OK ){
+    rc = fts3SqlStmt(p, SQL_SHIFT_SEGDIR_ENTRY, &pUpdate, 0);
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pUpdate, 2, iAbsLevel);
+  }
+
+  assert( p->bIgnoreSavepoint==0 );
+  p->bIgnoreSavepoint = 1;
+  for(i=0; rc==SQLITE_OK && ibIgnoreSavepoint = 0;
+
+  sqlite3_free(aIdx);
+  return rc;
 }
 
-/*
-** Adjust the cost C by the costMult facter T.  This only occurs if
-** compiled with -DSQLITE_ENABLE_COSTMULT
-*/
-#ifdef SQLITE_ENABLE_COSTMULT
-# define ApplyCostMultiplier(C,T)  C += T
-#else
-# define ApplyCostMultiplier(C,T)
-#endif
+static void fts3StartNode(Blob *pNode, int iHeight, sqlite3_int64 iChild){
+  pNode->a[0] = (char)iHeight;
+  if( iChild ){
+    assert( pNode->nAlloc>=1+sqlite3Fts3VarintLen(iChild) );
+    pNode->n = 1 + sqlite3Fts3PutVarint(&pNode->a[1], iChild);
+  }else{
+    assert( pNode->nAlloc>=1 );
+    pNode->n = 1;
+  }
+}
 
 /*
-** We have so far matched pBuilder->pNew->u.btree.nEq terms of the 
-** index pIndex. Try to match one more.
-**
-** When this function is called, pBuilder->pNew->nOut contains the 
-** number of rows expected to be visited by filtering using the nEq 
-** terms only. If it is modified, this value is restored before this 
-** function returns.
+** The first two arguments are a pointer to and the size of a segment b-tree
+** node. The node may be a leaf or an internal node.
 **
-** If pProbe->tnum==0, that means pIndex is a fake index used for the
-** INTEGER PRIMARY KEY.
+** This function creates a new node image in blob object *pNew by copying
+** all terms that are greater than or equal to zTerm/nTerm (for leaf nodes)
+** or greater than zTerm/nTerm (for internal nodes) from aNode/nNode.
 */
-static int whereLoopAddBtreeIndex(
-  WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */
-  struct SrcList_item *pSrc,      /* FROM clause term being analyzed */
-  Index *pProbe,                  /* An index on pSrc */
-  LogEst nInMul                   /* log(Number of iterations due to IN) */
+static int fts3TruncateNode(
+  const char *aNode,              /* Current node image */
+  int nNode,                      /* Size of aNode in bytes */
+  Blob *pNew,                     /* OUT: Write new node image here */
+  const char *zTerm,              /* Omit all terms smaller than this */
+  int nTerm,                      /* Size of zTerm in bytes */
+  sqlite3_int64 *piBlock          /* OUT: Block number in next layer down */
 ){
-  WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */
-  Parse *pParse = pWInfo->pParse;        /* Parsing context */
-  sqlite3 *db = pParse->db;       /* Database connection malloc context */
-  WhereLoop *pNew;                /* Template WhereLoop under construction */
-  WhereTerm *pTerm;               /* A WhereTerm under consideration */
-  int opMask;                     /* Valid operators for constraints */
-  WhereScan scan;                 /* Iterator for WHERE terms */
-  Bitmask saved_prereq;           /* Original value of pNew->prereq */
-  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
-  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
-  u16 saved_nSkip;                /* Original value of pNew->nSkip */
-  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
-  LogEst saved_nOut;              /* Original value of pNew->nOut */
-  int iCol;                       /* Index of the column in the table */
+  NodeReader reader;              /* Reader object */
+  Blob prev = {0, 0, 0};          /* Previous term written to new node */
   int rc = SQLITE_OK;             /* Return code */
-  LogEst rSize;                   /* Number of rows in the table */
-  LogEst rLogSize;                /* Logarithm of table size */
-  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
-
-  pNew = pBuilder->pNew;
-  if( db->mallocFailed ) return SQLITE_NOMEM;
-
-  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
-  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
-  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
-    opMask = WO_LT|WO_LE;
-  }else if( pProbe->tnum<=0 || (pSrc->jointype & JT_LEFT)!=0 ){
-    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
-  }else{
-    opMask = WO_EQ|WO_IN|WO_ISNULL|WO_GT|WO_GE|WO_LT|WO_LE;
-  }
-  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+  int bLeaf = aNode[0]=='\0';     /* True for a leaf node */
 
-  assert( pNew->u.btree.nEqnColumn );
-  iCol = pProbe->aiColumn[pNew->u.btree.nEq];
+  /* Allocate required output space */
+  blobGrowBuffer(pNew, nNode, &rc);
+  if( rc!=SQLITE_OK ) return rc;
+  pNew->n = 0;
 
-  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
-                        opMask, pProbe);
-  saved_nEq = pNew->u.btree.nEq;
-  saved_nSkip = pNew->nSkip;
-  saved_nLTerm = pNew->nLTerm;
-  saved_wsFlags = pNew->wsFlags;
-  saved_prereq = pNew->prereq;
-  saved_nOut = pNew->nOut;
-  pNew->rSetup = 0;
-  rSize = pProbe->aiRowLogEst[0];
-  rLogSize = estLog(rSize);
-  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
-    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
-    LogEst rCostIdx;
-    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
-    int nIn = 0;
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-    int nRecValid = pBuilder->nRecValid;
-#endif
-    if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
-     && (iCol<0 || pSrc->pTab->aCol[iCol].notNull)
-    ){
-      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
+  /* Populate new node buffer */
+  for(rc = nodeReaderInit(&reader, aNode, nNode); 
+      rc==SQLITE_OK && reader.aNode; 
+      rc = nodeReaderNext(&reader)
+  ){
+    if( pNew->n==0 ){
+      int res = fts3TermCmp(reader.term.a, reader.term.n, zTerm, nTerm);
+      if( res<0 || (bLeaf==0 && res==0) ) continue;
+      fts3StartNode(pNew, (int)aNode[0], reader.iChild);
+      *piBlock = reader.iChild;
     }
-    if( pTerm->prereqRight & pNew->maskSelf ) continue;
-
-    pNew->wsFlags = saved_wsFlags;
-    pNew->u.btree.nEq = saved_nEq;
-    pNew->nLTerm = saved_nLTerm;
-    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
-    pNew->aLTerm[pNew->nLTerm++] = pTerm;
-    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
-
-    assert( nInMul==0
-        || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 
-        || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 
-        || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 
+    rc = fts3AppendToNode(
+        pNew, &prev, reader.term.a, reader.term.n,
+        reader.aDoclist, reader.nDoclist
     );
+    if( rc!=SQLITE_OK ) break;
+  }
+  if( pNew->n==0 ){
+    fts3StartNode(pNew, (int)aNode[0], reader.iChild);
+    *piBlock = reader.iChild;
+  }
+  assert( pNew->n<=pNew->nAlloc );
 
-    if( eOp & WO_IN ){
-      Expr *pExpr = pTerm->pExpr;
-      pNew->wsFlags |= WHERE_COLUMN_IN;
-      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
-        nIn = 46;  assert( 46==sqlite3LogEst(25) );
-      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
-        /* "x IN (value, value, ...)" */
-        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
-      }
-      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
-                        ** changes "x IN (?)" into "x=?". */
-
-    }else if( eOp & (WO_EQ) ){
-      pNew->wsFlags |= WHERE_COLUMN_EQ;
-      if( iCol<0 || (nInMul==0 && pNew->u.btree.nEq==pProbe->nKeyCol-1) ){
-        if( iCol>=0 && !IsUniqueIndex(pProbe) ){
-          pNew->wsFlags |= WHERE_UNQ_WANTED;
-        }else{
-          pNew->wsFlags |= WHERE_ONEROW;
-        }
-      }
-    }else if( eOp & WO_ISNULL ){
-      pNew->wsFlags |= WHERE_COLUMN_NULL;
-    }else if( eOp & (WO_GT|WO_GE) ){
-      testcase( eOp & WO_GT );
-      testcase( eOp & WO_GE );
-      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
-      pBtm = pTerm;
-      pTop = 0;
-    }else{
-      assert( eOp & (WO_LT|WO_LE) );
-      testcase( eOp & WO_LT );
-      testcase( eOp & WO_LE );
-      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
-      pTop = pTerm;
-      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
-                     pNew->aLTerm[pNew->nLTerm-2] : 0;
-    }
-
-    /* At this point pNew->nOut is set to the number of rows expected to
-    ** be visited by the index scan before considering term pTerm, or the
-    ** values of nIn and nInMul. In other words, assuming that all 
-    ** "x IN(...)" terms are replaced with "x = ?". This block updates
-    ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul).  */
-    assert( pNew->nOut==saved_nOut );
-    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
-      /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4
-      ** data, using some other estimate.  */
-      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
-    }else{
-      int nEq = ++pNew->u.btree.nEq;
-      assert( eOp & (WO_ISNULL|WO_EQ|WO_IN) );
+  nodeReaderRelease(&reader);
+  sqlite3_free(prev.a);
+  return rc;
+}
 
-      assert( pNew->nOut==saved_nOut );
-      if( pTerm->truthProb<=0 && iCol>=0 ){
-        assert( (eOp & WO_IN) || nIn==0 );
-        testcase( eOp & WO_IN );
-        pNew->nOut += pTerm->truthProb;
-        pNew->nOut -= nIn;
-      }else{
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-        tRowcnt nOut = 0;
-        if( nInMul==0 
-         && pProbe->nSample 
-         && pNew->u.btree.nEq<=pProbe->nSampleCol
-         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
-        ){
-          Expr *pExpr = pTerm->pExpr;
-          if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){
-            testcase( eOp & WO_EQ );
-            testcase( eOp & WO_ISNULL );
-            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
-          }else{
-            rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
-          }
-          if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
-          if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */
-          if( nOut ){
-            pNew->nOut = sqlite3LogEst(nOut);
-            if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;
-            pNew->nOut -= nIn;
-          }
-        }
-        if( nOut==0 )
-#endif
-        {
-          pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);
-          if( eOp & WO_ISNULL ){
-            /* TUNING: If there is no likelihood() value, assume that a 
-            ** "col IS NULL" expression matches twice as many rows 
-            ** as (col=?). */
-            pNew->nOut += 10;
-          }
-        }
-      }
-    }
+/*
+** Remove all terms smaller than zTerm/nTerm from segment iIdx in absolute 
+** level iAbsLevel. This may involve deleting entries from the %_segments
+** table, and modifying existing entries in both the %_segments and %_segdir
+** tables.
+**
+** SQLITE_OK is returned if the segment is updated successfully. Or an
+** SQLite error code otherwise.
+*/
+static int fts3TruncateSegment(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of segment to modify */
+  int iIdx,                       /* Index within level of segment to modify */
+  const char *zTerm,              /* Remove terms smaller than this */
+  int nTerm                      /* Number of bytes in buffer zTerm */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Blob root = {0,0,0};            /* New root page image */
+  Blob block = {0,0,0};           /* Buffer used for any other block */
+  sqlite3_int64 iBlock = 0;       /* Block id */
+  sqlite3_int64 iNewStart = 0;    /* New value for iStartBlock */
+  sqlite3_int64 iOldStart = 0;    /* Old value for iStartBlock */
+  sqlite3_stmt *pFetch = 0;       /* Statement used to fetch segdir */
 
-    /* Set rCostIdx to the cost of visiting selected rows in index. Add
-    ** it to pNew->rRun, which is currently set to the cost of the index
-    ** seek only. Then, if this is a non-covering index, add the cost of
-    ** visiting the rows in the main table.  */
-    rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
-    pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
-    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
-      pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
+  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pFetch, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;                      /* sqlite3_reset() return code */
+    sqlite3_bind_int64(pFetch, 1, iAbsLevel);
+    sqlite3_bind_int(pFetch, 2, iIdx);
+    if( SQLITE_ROW==sqlite3_step(pFetch) ){
+      const char *aRoot = sqlite3_column_blob(pFetch, 4);
+      int nRoot = sqlite3_column_bytes(pFetch, 4);
+      iOldStart = sqlite3_column_int64(pFetch, 1);
+      rc = fts3TruncateNode(aRoot, nRoot, &root, zTerm, nTerm, &iBlock);
     }
-    ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
+    rc2 = sqlite3_reset(pFetch);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
 
-    nOutUnadjusted = pNew->nOut;
-    pNew->rRun += nInMul + nIn;
-    pNew->nOut += nInMul + nIn;
-    whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
-    rc = whereLoopInsert(pBuilder, pNew);
+  while( rc==SQLITE_OK && iBlock ){
+    char *aBlock = 0;
+    int nBlock = 0;
+    iNewStart = iBlock;
 
-    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
-      pNew->nOut = saved_nOut;
-    }else{
-      pNew->nOut = nOutUnadjusted;
+    rc = sqlite3Fts3ReadBlock(p, iBlock, &aBlock, &nBlock, 0);
+    if( rc==SQLITE_OK ){
+      rc = fts3TruncateNode(aBlock, nBlock, &block, zTerm, nTerm, &iBlock);
+    }
+    if( rc==SQLITE_OK ){
+      rc = fts3WriteSegment(p, iNewStart, block.a, block.n);
     }
+    sqlite3_free(aBlock);
+  }
 
-    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
-     && pNew->u.btree.nEqnColumn
-    ){
-      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
+  /* Variable iNewStart now contains the first valid leaf node. */
+  if( rc==SQLITE_OK && iNewStart ){
+    sqlite3_stmt *pDel = 0;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDel, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDel, 1, iOldStart);
+      sqlite3_bind_int64(pDel, 2, iNewStart-1);
+      sqlite3_step(pDel);
+      rc = sqlite3_reset(pDel);
     }
-    pNew->nOut = saved_nOut;
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-    pBuilder->nRecValid = nRecValid;
-#endif
   }
-  pNew->prereq = saved_prereq;
-  pNew->u.btree.nEq = saved_nEq;
-  pNew->nSkip = saved_nSkip;
-  pNew->wsFlags = saved_wsFlags;
-  pNew->nOut = saved_nOut;
-  pNew->nLTerm = saved_nLTerm;
 
-  /* Consider using a skip-scan if there are no WHERE clause constraints
-  ** available for the left-most terms of the index, and if the average
-  ** number of repeats in the left-most terms is at least 18. 
-  **
-  ** The magic number 18 is selected on the basis that scanning 17 rows
-  ** is almost always quicker than an index seek (even though if the index
-  ** contains fewer than 2^17 rows we assume otherwise in other parts of
-  ** the code). And, even if it is not, it should not be too much slower. 
-  ** On the other hand, the extra seeks could end up being significantly
-  ** more expensive.  */
-  assert( 42==sqlite3LogEst(18) );
-  if( saved_nEq==saved_nSkip
-   && saved_nEq+1nKeyCol
-   && pProbe->noSkipScan==0
-   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
-   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
-  ){
-    LogEst nIter;
-    pNew->u.btree.nEq++;
-    pNew->nSkip++;
-    pNew->aLTerm[pNew->nLTerm++] = 0;
-    pNew->wsFlags |= WHERE_SKIPSCAN;
-    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
-    pNew->nOut -= nIter;
-    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
-    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
-    nIter += 5;
-    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
-    pNew->nOut = saved_nOut;
-    pNew->u.btree.nEq = saved_nEq;
-    pNew->nSkip = saved_nSkip;
-    pNew->wsFlags = saved_wsFlags;
+  if( rc==SQLITE_OK ){
+    sqlite3_stmt *pChomp = 0;
+    rc = fts3SqlStmt(p, SQL_CHOMP_SEGDIR, &pChomp, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pChomp, 1, iNewStart);
+      sqlite3_bind_blob(pChomp, 2, root.a, root.n, SQLITE_STATIC);
+      sqlite3_bind_int64(pChomp, 3, iAbsLevel);
+      sqlite3_bind_int(pChomp, 4, iIdx);
+      sqlite3_step(pChomp);
+      rc = sqlite3_reset(pChomp);
+    }
   }
 
+  sqlite3_free(root.a);
+  sqlite3_free(block.a);
   return rc;
 }
 
 /*
-** Return True if it is possible that pIndex might be useful in
-** implementing the ORDER BY clause in pBuilder.
+** This function is called after an incrmental-merge operation has run to
+** merge (or partially merge) two or more segments from absolute level
+** iAbsLevel.
 **
-** Return False if pBuilder does not contain an ORDER BY clause or
-** if there is no way for pIndex to be useful in implementing that
-** ORDER BY clause.
+** Each input segment is either removed from the db completely (if all of
+** its data was copied to the output segment by the incrmerge operation)
+** or modified in place so that it no longer contains those entries that
+** have been duplicated in the output segment.
 */
-static int indexMightHelpWithOrderBy(
-  WhereLoopBuilder *pBuilder,
-  Index *pIndex,
-  int iCursor
+static int fts3IncrmergeChomp(
+  Fts3Table *p,                   /* FTS table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level containing segments */
+  Fts3MultiSegReader *pCsr,       /* Chomp all segments opened by this cursor */
+  int *pnRem                      /* Number of segments not deleted */
 ){
-  ExprList *pOB;
-  int ii, jj;
+  int i;
+  int nRem = 0;
+  int rc = SQLITE_OK;
 
-  if( pIndex->bUnordered ) return 0;
-  if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
-  for(ii=0; iinExpr; ii++){
-    Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
-    if( pExpr->op!=TK_COLUMN ) return 0;
-    if( pExpr->iTable==iCursor ){
-      if( pExpr->iColumn<0 ) return 1;
-      for(jj=0; jjnKeyCol; jj++){
-        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
+  for(i=pCsr->nSegment-1; i>=0 && rc==SQLITE_OK; i--){
+    Fts3SegReader *pSeg = 0;
+    int j;
+
+    /* Find the Fts3SegReader object with Fts3SegReader.iIdx==i. It is hiding
+    ** somewhere in the pCsr->apSegment[] array.  */
+    for(j=0; ALWAYS(jnSegment); j++){
+      pSeg = pCsr->apSegment[j];
+      if( pSeg->iIdx==i ) break;
+    }
+    assert( jnSegment && pSeg->iIdx==i );
+
+    if( pSeg->aNode==0 ){
+      /* Seg-reader is at EOF. Remove the entire input segment. */
+      rc = fts3DeleteSegment(p, pSeg);
+      if( rc==SQLITE_OK ){
+        rc = fts3RemoveSegdirEntry(p, iAbsLevel, pSeg->iIdx);
       }
+      *pnRem = 0;
+    }else{
+      /* The incremental merge did not copy all the data from this 
+      ** segment to the upper level. The segment is modified in place
+      ** so that it contains no keys smaller than zTerm/nTerm. */ 
+      const char *zTerm = pSeg->zTerm;
+      int nTerm = pSeg->nTerm;
+      rc = fts3TruncateSegment(p, iAbsLevel, pSeg->iIdx, zTerm, nTerm);
+      nRem++;
     }
   }
-  return 0;
-}
 
-/*
-** Return a bitmask where 1s indicate that the corresponding column of
-** the table is used by an index.  Only the first 63 columns are considered.
-*/
-static Bitmask columnsInIndex(Index *pIdx){
-  Bitmask m = 0;
-  int j;
-  for(j=pIdx->nColumn-1; j>=0; j--){
-    int x = pIdx->aiColumn[j];
-    if( x>=0 ){
-      testcase( x==BMS-1 );
-      testcase( x==BMS-2 );
-      if( xnSegment ){
+    rc = fts3RepackSegdirLevel(p, iAbsLevel);
   }
-  return m;
+
+  *pnRem = nRem;
+  return rc;
 }
 
-/* Check to see if a partial index with pPartIndexWhere can be used
-** in the current query.  Return true if it can be and false if not.
+/*
+** Store an incr-merge hint in the database.
 */
-static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
-  int i;
-  WhereTerm *pTerm;
-  for(i=0, pTerm=pWC->a; inTerm; i++, pTerm++){
-    if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab) ) return 1;
+static int fts3IncrmergeHintStore(Fts3Table *p, Blob *pHint){
+  sqlite3_stmt *pReplace = 0;
+  int rc;                         /* Return code */
+
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pReplace, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int(pReplace, 1, FTS_STAT_INCRMERGEHINT);
+    sqlite3_bind_blob(pReplace, 2, pHint->a, pHint->n, SQLITE_STATIC);
+    sqlite3_step(pReplace);
+    rc = sqlite3_reset(pReplace);
   }
-  return 0;
+
+  return rc;
 }
 
 /*
-** Add all WhereLoop objects for a single table of the join where the table
-** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be
-** a b-tree table, not a virtual table.
-**
-** The costs (WhereLoop.rRun) of the b-tree loops added by this function
-** are calculated as follows:
-**
-** For a full scan, assuming the table (or index) contains nRow rows:
-**
-**     cost = nRow * 3.0                    // full-table scan
-**     cost = nRow * K                      // scan of covering index
-**     cost = nRow * (K+3.0)                // scan of non-covering index
-**
-** where K is a value between 1.1 and 3.0 set based on the relative 
-** estimated average size of the index and table records.
-**
-** For an index scan, where nVisit is the number of index rows visited
-** by the scan, and nSeek is the number of seek operations required on 
-** the index b-tree:
-**
-**     cost = nSeek * (log(nRow) + K * nVisit)          // covering index
-**     cost = nSeek * (log(nRow) + (K+3.0) * nVisit)    // non-covering index
-**
-** Normally, nSeek is 1. nSeek values greater than 1 come about if the 
-** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when 
-** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.
+** Load an incr-merge hint from the database. The incr-merge hint, if one 
+** exists, is stored in the rowid==1 row of the %_stat table.
 **
-** The estimated values (nRow, nVisit, nSeek) often contain a large amount
-** of uncertainty.  For this reason, scoring is designed to pick plans that
-** "do the least harm" if the estimates are inaccurate.  For example, a
-** log(nRow) factor is omitted from a non-covering index scan in order to
-** bias the scoring in favor of using an index, since the worst-case
-** performance of using an index is far better than the worst-case performance
-** of a full table scan.
+** If successful, populate blob *pHint with the value read from the %_stat
+** table and return SQLITE_OK. Otherwise, if an error occurs, return an
+** SQLite error code.
 */
-static int whereLoopAddBtree(
-  WhereLoopBuilder *pBuilder, /* WHERE clause information */
-  Bitmask mExtra              /* Extra prerequesites for using this table */
-){
-  WhereInfo *pWInfo;          /* WHERE analysis context */
-  Index *pProbe;              /* An index we are evaluating */
-  Index sPk;                  /* A fake index object for the primary key */
-  LogEst aiRowEstPk[2];       /* The aiRowLogEst[] value for the sPk index */
-  i16 aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
-  SrcList *pTabList;          /* The FROM clause */
-  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
-  WhereLoop *pNew;            /* Template WhereLoop object */
-  int rc = SQLITE_OK;         /* Return code */
-  int iSortIdx = 1;           /* Index number */
-  int b;                      /* A boolean value */
-  LogEst rSize;               /* number of rows in the table */
-  LogEst rLogSize;            /* Logarithm of the number of rows in the table */
-  WhereClause *pWC;           /* The parsed WHERE clause */
-  Table *pTab;                /* Table being queried */
-  
-  pNew = pBuilder->pNew;
-  pWInfo = pBuilder->pWInfo;
-  pTabList = pWInfo->pTabList;
-  pSrc = pTabList->a + pNew->iTab;
-  pTab = pSrc->pTab;
-  pWC = pBuilder->pWC;
-  assert( !IsVirtual(pSrc->pTab) );
-
-  if( pSrc->pIndex ){
-    /* An INDEXED BY clause specifies a particular index to use */
-    pProbe = pSrc->pIndex;
-  }else if( !HasRowid(pTab) ){
-    pProbe = pTab->pIndex;
-  }else{
-    /* There is no INDEXED BY clause.  Create a fake Index object in local
-    ** variable sPk to represent the rowid primary key index.  Make this
-    ** fake index the first in a chain of Index objects with all of the real
-    ** indices to follow */
-    Index *pFirst;                  /* First of real indices on the table */
-    memset(&sPk, 0, sizeof(Index));
-    sPk.nKeyCol = 1;
-    sPk.nColumn = 1;
-    sPk.aiColumn = &aiColumnPk;
-    sPk.aiRowLogEst = aiRowEstPk;
-    sPk.onError = OE_Replace;
-    sPk.pTable = pTab;
-    sPk.szIdxRow = pTab->szTabRow;
-    aiRowEstPk[0] = pTab->nRowLogEst;
-    aiRowEstPk[1] = 0;
-    pFirst = pSrc->pTab->pIndex;
-    if( pSrc->notIndexed==0 ){
-      /* The real indices of the table are only considered if the
-      ** NOT INDEXED qualifier is omitted from the FROM clause */
-      sPk.pNext = pFirst;
-    }
-    pProbe = &sPk;
-  }
-  rSize = pTab->nRowLogEst;
-  rLogSize = estLog(rSize);
+static int fts3IncrmergeHintLoad(Fts3Table *p, Blob *pHint){
+  sqlite3_stmt *pSelect = 0;
+  int rc;
 
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-  /* Automatic indexes */
-  if( !pBuilder->pOrSet
-   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
-   && pSrc->pIndex==0
-   && !pSrc->viaCoroutine
-   && !pSrc->notIndexed
-   && HasRowid(pTab)
-   && !pSrc->isCorrelated
-   && !pSrc->isRecursive
-  ){
-    /* Generate auto-index WhereLoops */
-    WhereTerm *pTerm;
-    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
-    for(pTerm=pWC->a; rc==SQLITE_OK && pTermprereqRight & pNew->maskSelf ) continue;
-      if( termCanDriveIndex(pTerm, pSrc, 0) ){
-        pNew->u.btree.nEq = 1;
-        pNew->nSkip = 0;
-        pNew->u.btree.pIndex = 0;
-        pNew->nLTerm = 1;
-        pNew->aLTerm[0] = pTerm;
-        /* TUNING: One-time cost for computing the automatic index is
-        ** estimated to be X*N*log2(N) where N is the number of rows in
-        ** the table being indexed and where X is 7 (LogEst=28) for normal
-        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
-        ** of X is smaller for views and subqueries so that the query planner
-        ** will be more aggressive about generating automatic indexes for
-        ** those objects, since there is no opportunity to add schema
-        ** indexes on subqueries and views. */
-        pNew->rSetup = rLogSize + rSize + 4;
-        if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){
-          pNew->rSetup += 24;
+  pHint->n = 0;
+  rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pSelect, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pSelect, 1, FTS_STAT_INCRMERGEHINT);
+    if( SQLITE_ROW==sqlite3_step(pSelect) ){
+      const char *aHint = sqlite3_column_blob(pSelect, 0);
+      int nHint = sqlite3_column_bytes(pSelect, 0);
+      if( aHint ){
+        blobGrowBuffer(pHint, nHint, &rc);
+        if( rc==SQLITE_OK ){
+          memcpy(pHint->a, aHint, nHint);
+          pHint->n = nHint;
         }
-        ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
-        /* TUNING: Each index lookup yields 20 rows in the table.  This
-        ** is more than the usual guess of 10 rows, since we have no way
-        ** of knowing how selective the index will ultimately be.  It would
-        ** not be unreasonable to make this value much larger. */
-        pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );
-        pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
-        pNew->wsFlags = WHERE_AUTO_INDEX;
-        pNew->prereq = mExtra | pTerm->prereqRight;
-        rc = whereLoopInsert(pBuilder, pNew);
       }
     }
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
   }
-#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
 
-  /* Loop over all indices
-  */
-  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
-    if( pProbe->pPartIdxWhere!=0
-     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
-      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
-      continue;  /* Partial index inappropriate for this query */
-    }
-    rSize = pProbe->aiRowLogEst[0];
-    pNew->u.btree.nEq = 0;
-    pNew->nSkip = 0;
-    pNew->nLTerm = 0;
-    pNew->iSortIdx = 0;
-    pNew->rSetup = 0;
-    pNew->prereq = mExtra;
-    pNew->nOut = rSize;
-    pNew->u.btree.pIndex = pProbe;
-    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
-    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
-    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
-    if( pProbe->tnum<=0 ){
-      /* Integer primary key index */
-      pNew->wsFlags = WHERE_IPK;
+  return rc;
+}
 
-      /* Full table scan */
-      pNew->iSortIdx = b ? iSortIdx : 0;
-      /* TUNING: Cost of full table scan is (N*3.0). */
-      pNew->rRun = rSize + 16;
-      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
-      whereLoopOutputAdjust(pWC, pNew, rSize);
-      rc = whereLoopInsert(pBuilder, pNew);
-      pNew->nOut = rSize;
-      if( rc ) break;
-    }else{
-      Bitmask m;
-      if( pProbe->isCovering ){
-        pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
-        m = 0;
-      }else{
-        m = pSrc->colUsed & ~columnsInIndex(pProbe);
-        pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
-      }
+/*
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, append an entry to the hint stored in blob *pHint. Each entry
+** consists of two varints, the absolute level number of the input segments 
+** and the number of input segments.
+**
+** If successful, leave *pRc set to SQLITE_OK and return. If an error occurs,
+** set *pRc to an SQLite error code before returning.
+*/
+static void fts3IncrmergeHintPush(
+  Blob *pHint,                    /* Hint blob to append to */
+  i64 iAbsLevel,                  /* First varint to store in hint */
+  int nInput,                     /* Second varint to store in hint */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  blobGrowBuffer(pHint, pHint->n + 2*FTS3_VARINT_MAX, pRc);
+  if( *pRc==SQLITE_OK ){
+    pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], iAbsLevel);
+    pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], (i64)nInput);
+  }
+}
 
-      /* Full scan via index */
-      if( b
-       || !HasRowid(pTab)
-       || ( m==0
-         && pProbe->bUnordered==0
-         && (pProbe->szIdxRowszTabRow)
-         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
-         && sqlite3GlobalConfig.bUseCis
-         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
-          )
-      ){
-        pNew->iSortIdx = b ? iSortIdx : 0;
+/*
+** Read the last entry (most recently pushed) from the hint blob *pHint
+** and then remove the entry. Write the two values read to *piAbsLevel and 
+** *pnInput before returning.
+**
+** If no error occurs, return SQLITE_OK. If the hint blob in *pHint does
+** not contain at least two valid varints, return SQLITE_CORRUPT_VTAB.
+*/
+static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){
+  const int nHint = pHint->n;
+  int i;
 
-        /* The cost of visiting the index rows is N*K, where K is
-        ** between 1.1 and 3.0, depending on the relative sizes of the
-        ** index and table rows. If this is a non-covering index scan,
-        ** also add the cost of visiting table rows (N*3.0).  */
-        pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
-        if( m!=0 ){
-          pNew->rRun = sqlite3LogEstAdd(pNew->rRun, rSize+16);
-        }
-        ApplyCostMultiplier(pNew->rRun, pTab->costMult);
-        whereLoopOutputAdjust(pWC, pNew, rSize);
-        rc = whereLoopInsert(pBuilder, pNew);
-        pNew->nOut = rSize;
-        if( rc ) break;
-      }
-    }
+  i = pHint->n-2;
+  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;
+  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;
 
-    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
-    sqlite3Stat4ProbeFree(pBuilder->pRec);
-    pBuilder->nRecValid = 0;
-    pBuilder->pRec = 0;
-#endif
+  pHint->n = i;
+  i += sqlite3Fts3GetVarint(&pHint->a[i], piAbsLevel);
+  i += fts3GetVarint32(&pHint->a[i], pnInput);
+  if( i!=nHint ) return FTS_CORRUPT_VTAB;
 
-    /* If there was an INDEXED BY clause, then only that one index is
-    ** considered. */
-    if( pSrc->pIndex ) break;
-  }
-  return rc;
+  return SQLITE_OK;
 }
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
+
 /*
-** Add all WhereLoop objects for a table of the join identified by
-** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
+** Attempt an incremental merge that writes nMerge leaf blocks.
+**
+** Incremental merges happen nMin segments at a time. The segments 
+** to be merged are the nMin oldest segments (the ones with the smallest 
+** values for the _segdir.idx field) in the highest level that contains 
+** at least nMin segments. Multiple merges might occur in an attempt to 
+** write the quota of nMerge leaf blocks.
 */
-static int whereLoopAddVirtual(
-  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
-  Bitmask mExtra
-){
-  WhereInfo *pWInfo;           /* WHERE analysis context */
-  Parse *pParse;               /* The parsing context */
-  WhereClause *pWC;            /* The WHERE clause */
-  struct SrcList_item *pSrc;   /* The FROM clause term to search */
-  Table *pTab;
-  sqlite3 *db;
-  sqlite3_index_info *pIdxInfo;
-  struct sqlite3_index_constraint *pIdxCons;
-  struct sqlite3_index_constraint_usage *pUsage;
-  WhereTerm *pTerm;
-  int i, j;
-  int iTerm, mxTerm;
-  int nConstraint;
-  int seenIn = 0;              /* True if an IN operator is seen */
-  int seenVar = 0;             /* True if a non-constant constraint is seen */
-  int iPhase;                  /* 0: const w/o IN, 1: const, 2: no IN,  2: IN */
-  WhereLoop *pNew;
-  int rc = SQLITE_OK;
+SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
+  int rc;                         /* Return code */
+  int nRem = nMerge;              /* Number of leaf pages yet to  be written */
+  Fts3MultiSegReader *pCsr;       /* Cursor used to read input data */
+  Fts3SegFilter *pFilter;         /* Filter used with cursor pCsr */
+  IncrmergeWriter *pWriter;       /* Writer object */
+  int nSeg = 0;                   /* Number of input segments */
+  sqlite3_int64 iAbsLevel = 0;    /* Absolute level number to work on */
+  Blob hint = {0, 0, 0};          /* Hint read from %_stat table */
+  int bDirtyHint = 0;             /* True if blob 'hint' has been modified */
 
-  pWInfo = pBuilder->pWInfo;
-  pParse = pWInfo->pParse;
-  db = pParse->db;
-  pWC = pBuilder->pWC;
-  pNew = pBuilder->pNew;
-  pSrc = &pWInfo->pTabList->a[pNew->iTab];
-  pTab = pSrc->pTab;
-  assert( IsVirtual(pTab) );
-  pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy);
-  if( pIdxInfo==0 ) return SQLITE_NOMEM;
-  pNew->prereq = 0;
-  pNew->rSetup = 0;
-  pNew->wsFlags = WHERE_VIRTUALTABLE;
-  pNew->nLTerm = 0;
-  pNew->u.vtab.needFree = 0;
-  pUsage = pIdxInfo->aConstraintUsage;
-  nConstraint = pIdxInfo->nConstraint;
-  if( whereLoopResize(db, pNew, nConstraint) ){
-    sqlite3DbFree(db, pIdxInfo);
-    return SQLITE_NOMEM;
-  }
+  /* Allocate space for the cursor, filter and writer objects */
+  const int nAlloc = sizeof(*pCsr) + sizeof(*pFilter) + sizeof(*pWriter);
+  pWriter = (IncrmergeWriter *)sqlite3_malloc(nAlloc);
+  if( !pWriter ) return SQLITE_NOMEM;
+  pFilter = (Fts3SegFilter *)&pWriter[1];
+  pCsr = (Fts3MultiSegReader *)&pFilter[1];
 
-  for(iPhase=0; iPhase<=3; iPhase++){
-    if( !seenIn && (iPhase&1)!=0 ){
-      iPhase++;
-      if( iPhase>3 ) break;
-    }
-    if( !seenVar && iPhase>1 ) break;
-    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-    for(i=0; inConstraint; i++, pIdxCons++){
-      j = pIdxCons->iTermOffset;
-      pTerm = &pWC->a[j];
-      switch( iPhase ){
-        case 0:    /* Constants without IN operator */
-          pIdxCons->usable = 0;
-          if( (pTerm->eOperator & WO_IN)!=0 ){
-            seenIn = 1;
-          }
-          if( pTerm->prereqRight!=0 ){
-            seenVar = 1;
-          }else if( (pTerm->eOperator & WO_IN)==0 ){
-            pIdxCons->usable = 1;
-          }
-          break;
-        case 1:    /* Constants with IN operators */
-          assert( seenIn );
-          pIdxCons->usable = (pTerm->prereqRight==0);
-          break;
-        case 2:    /* Variables without IN */
-          assert( seenVar );
-          pIdxCons->usable = (pTerm->eOperator & WO_IN)==0;
-          break;
-        default:   /* Variables with IN */
-          assert( seenVar && seenIn );
-          pIdxCons->usable = 1;
-          break;
-      }
+  rc = fts3IncrmergeHintLoad(p, &hint);
+  while( rc==SQLITE_OK && nRem>0 ){
+    const i64 nMod = FTS3_SEGDIR_MAXLEVEL * p->nIndex;
+    sqlite3_stmt *pFindLevel = 0; /* SQL used to determine iAbsLevel */
+    int bUseHint = 0;             /* True if attempting to append */
+    int iIdx = 0;                 /* Largest idx in level (iAbsLevel+1) */
+
+    /* Search the %_segdir table for the absolute level with the smallest
+    ** relative level number that contains at least nMin segments, if any.
+    ** If one is found, set iAbsLevel to the absolute level number and
+    ** nSeg to nMin. If no level with at least nMin segments can be found, 
+    ** set nSeg to -1.
+    */
+    rc = fts3SqlStmt(p, SQL_FIND_MERGE_LEVEL, &pFindLevel, 0);
+    sqlite3_bind_int(pFindLevel, 1, MAX(2, nMin));
+    if( sqlite3_step(pFindLevel)==SQLITE_ROW ){
+      iAbsLevel = sqlite3_column_int64(pFindLevel, 0);
+      nSeg = sqlite3_column_int(pFindLevel, 1);
+      assert( nSeg>=2 );
+    }else{
+      nSeg = -1;
     }
-    memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
-    if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
-    pIdxInfo->idxStr = 0;
-    pIdxInfo->idxNum = 0;
-    pIdxInfo->needToFreeIdxStr = 0;
-    pIdxInfo->orderByConsumed = 0;
-    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
-    pIdxInfo->estimatedRows = 25;
-    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
-    if( rc ) goto whereLoopAddVtab_exit;
-    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-    pNew->prereq = mExtra;
-    mxTerm = -1;
-    assert( pNew->nLSlot>=nConstraint );
-    for(i=0; iaLTerm[i] = 0;
-    pNew->u.vtab.omitMask = 0;
-    for(i=0; i=0 ){
-        j = pIdxCons->iTermOffset;
-        if( iTerm>=nConstraint
-         || j<0
-         || j>=pWC->nTerm
-         || pNew->aLTerm[iTerm]!=0
-        ){
-          rc = SQLITE_ERROR;
-          sqlite3ErrorMsg(pParse, "%s.xBestIndex() malfunction", pTab->zName);
-          goto whereLoopAddVtab_exit;
-        }
-        testcase( iTerm==nConstraint-1 );
-        testcase( j==0 );
-        testcase( j==pWC->nTerm-1 );
-        pTerm = &pWC->a[j];
-        pNew->prereq |= pTerm->prereqRight;
-        assert( iTermnLSlot );
-        pNew->aLTerm[iTerm] = pTerm;
-        if( iTerm>mxTerm ) mxTerm = iTerm;
-        testcase( iTerm==15 );
-        testcase( iTerm==16 );
-        if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<eOperator & WO_IN)!=0 ){
-          if( pUsage[i].omit==0 ){
-            /* Do not attempt to use an IN constraint if the virtual table
-            ** says that the equivalent EQ constraint cannot be safely omitted.
-            ** If we do attempt to use such a constraint, some rows might be
-            ** repeated in the output. */
-            break;
-          }
-          /* A virtual table that is constrained by an IN clause may not
-          ** consume the ORDER BY clause because (1) the order of IN terms
-          ** is not necessarily related to the order of output terms and
-          ** (2) Multiple outputs from a single IN value will not merge
-          ** together.  */
-          pIdxInfo->orderByConsumed = 0;
-        }
-      }
-    }
-    if( i>=nConstraint ){
-      pNew->nLTerm = mxTerm+1;
-      assert( pNew->nLTerm<=pNew->nLSlot );
-      pNew->u.vtab.idxNum = pIdxInfo->idxNum;
-      pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
-      pIdxInfo->needToFreeIdxStr = 0;
-      pNew->u.vtab.idxStr = pIdxInfo->idxStr;
-      pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
-                                      pIdxInfo->nOrderBy : 0);
-      pNew->rSetup = 0;
-      pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
-      pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);
-      whereLoopInsert(pBuilder, pNew);
-      if( pNew->u.vtab.needFree ){
-        sqlite3_free(pNew->u.vtab.idxStr);
-        pNew->u.vtab.needFree = 0;
+    rc = sqlite3_reset(pFindLevel);
+
+    /* If the hint read from the %_stat table is not empty, check if the
+    ** last entry in it specifies a relative level smaller than or equal
+    ** to the level identified by the block above (if any). If so, this 
+    ** iteration of the loop will work on merging at the hinted level.
+    */
+    if( rc==SQLITE_OK && hint.n ){
+      int nHint = hint.n;
+      sqlite3_int64 iHintAbsLevel = 0;      /* Hint level */
+      int nHintSeg = 0;                     /* Hint number of segments */
+
+      rc = fts3IncrmergeHintPop(&hint, &iHintAbsLevel, &nHintSeg);
+      if( nSeg<0 || (iAbsLevel % nMod) >= (iHintAbsLevel % nMod) ){
+        iAbsLevel = iHintAbsLevel;
+        nSeg = nHintSeg;
+        bUseHint = 1;
+        bDirtyHint = 1;
+      }else{
+        /* This undoes the effect of the HintPop() above - so that no entry
+        ** is removed from the hint blob.  */
+        hint.n = nHint;
       }
     }
-  }  
 
-whereLoopAddVtab_exit:
-  if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
-  sqlite3DbFree(db, pIdxInfo);
-  return rc;
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
+    /* If nSeg is less that zero, then there is no level with at least
+    ** nMin segments and no hint in the %_stat table. No work to do.
+    ** Exit early in this case.  */
+    if( nSeg<0 ) break;
 
-/*
-** Add WhereLoop entries to handle OR terms.  This works for either
-** btrees or virtual tables.
-*/
-static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
-  WhereInfo *pWInfo = pBuilder->pWInfo;
-  WhereClause *pWC;
-  WhereLoop *pNew;
-  WhereTerm *pTerm, *pWCEnd;
-  int rc = SQLITE_OK;
-  int iCur;
-  WhereClause tempWC;
-  WhereLoopBuilder sSubBuild;
-  WhereOrSet sSum, sCur;
-  struct SrcList_item *pItem;
-  
-  pWC = pBuilder->pWC;
-  pWCEnd = pWC->a + pWC->nTerm;
-  pNew = pBuilder->pNew;
-  memset(&sSum, 0, sizeof(sSum));
-  pItem = pWInfo->pTabList->a + pNew->iTab;
-  iCur = pItem->iCursor;
+    /* Open a cursor to iterate through the contents of the oldest nSeg 
+    ** indexes of absolute level iAbsLevel. If this cursor is opened using 
+    ** the 'hint' parameters, it is possible that there are less than nSeg
+    ** segments available in level iAbsLevel. In this case, no work is
+    ** done on iAbsLevel - fall through to the next iteration of the loop 
+    ** to start work on some other level.  */
+    memset(pWriter, 0, nAlloc);
+    pFilter->flags = FTS3_SEGMENT_REQUIRE_POS;
 
-  for(pTerm=pWC->a; pTermeOperator & WO_OR)!=0
-     && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);
+      assert( bUseHint==1 || bUseHint==0 );
+      if( iIdx==0 || (bUseHint && iIdx==1) ){
+        int bIgnore = 0;
+        rc = fts3SegmentIsMaxLevel(p, iAbsLevel+1, &bIgnore);
+        if( bIgnore ){
+          pFilter->flags |= FTS3_SEGMENT_IGNORE_EMPTY;
+        }
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergeCsr(p, iAbsLevel, nSeg, pCsr);
+    }
+    if( SQLITE_OK==rc && pCsr->nSegment==nSeg
+     && SQLITE_OK==(rc = sqlite3Fts3SegReaderStart(p, pCsr, pFilter))
+     && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pCsr))
     ){
-      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
-      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
-      WhereTerm *pOrTerm;
-      int once = 1;
-      int i, j;
-    
-      sSubBuild = *pBuilder;
-      sSubBuild.pOrderBy = 0;
-      sSubBuild.pOrSet = &sCur;
+      if( bUseHint && iIdx>0 ){
+        const char *zKey = pCsr->zTerm;
+        int nKey = pCsr->nTerm;
+        rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);
+      }else{
+        rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);
+      }
 
-      WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));
-      for(pOrTerm=pOrWC->a; pOrTermeOperator & WO_AND)!=0 ){
-          sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
-        }else if( pOrTerm->leftCursor==iCur ){
-          tempWC.pWInfo = pWC->pWInfo;
-          tempWC.pOuter = pWC;
-          tempWC.op = TK_AND;
-          tempWC.nTerm = 1;
-          tempWC.a = pOrTerm;
-          sSubBuild.pWC = &tempWC;
-        }else{
-          continue;
-        }
-        sCur.n = 0;
-#ifdef WHERETRACE_ENABLED
-        WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n", 
-                   (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
-        if( sqlite3WhereTrace & 0x400 ){
-          for(i=0; inTerm; i++){
-            whereTermPrint(&sSubBuild.pWC->a[i], i);
-          }
-        }
-#endif
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-        if( IsVirtual(pItem->pTab) ){
-          rc = whereLoopAddVirtual(&sSubBuild, mExtra);
-        }else
-#endif
-        {
-          rc = whereLoopAddBtree(&sSubBuild, mExtra);
-        }
+      if( rc==SQLITE_OK && pWriter->nLeafEst ){
+        fts3LogMerge(nSeg, iAbsLevel);
+        do {
+          rc = fts3IncrmergeAppend(p, pWriter, pCsr);
+          if( rc==SQLITE_OK ) rc = sqlite3Fts3SegReaderStep(p, pCsr);
+          if( pWriter->nWork>=nRem && rc==SQLITE_ROW ) rc = SQLITE_OK;
+        }while( rc==SQLITE_ROW );
+
+        /* Update or delete the input segments */
         if( rc==SQLITE_OK ){
-          rc = whereLoopAddOr(&sSubBuild, mExtra);
-        }
-        assert( rc==SQLITE_OK || sCur.n==0 );
-        if( sCur.n==0 ){
-          sSum.n = 0;
-          break;
-        }else if( once ){
-          whereOrMove(&sSum, &sCur);
-          once = 0;
-        }else{
-          WhereOrSet sPrev;
-          whereOrMove(&sPrev, &sSum);
-          sSum.n = 0;
-          for(i=0; inWork);
+          rc = fts3IncrmergeChomp(p, iAbsLevel, pCsr, &nSeg);
+          if( nSeg!=0 ){
+            bDirtyHint = 1;
+            fts3IncrmergeHintPush(&hint, iAbsLevel, nSeg, &rc);
           }
         }
       }
-      pNew->nLTerm = 1;
-      pNew->aLTerm[0] = pTerm;
-      pNew->wsFlags = WHERE_MULTI_OR;
-      pNew->rSetup = 0;
-      pNew->iSortIdx = 0;
-      memset(&pNew->u, 0, sizeof(pNew->u));
-      for(i=0; rc==SQLITE_OK && irRun = sSum.a[i].rRun + 1;
-        pNew->nOut = sSum.a[i].nOut;
-        pNew->prereq = sSum.a[i].prereq;
-        rc = whereLoopInsert(pBuilder, pNew);
+
+      if( nSeg!=0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
+      fts3IncrmergeRelease(p, pWriter, &rc);
+      if( nSeg==0 && pWriter->bNoLeafData==0 ){
+        fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);
       }
-      WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));
     }
+
+    sqlite3Fts3SegReaderFinish(pCsr);
+  }
+
+  /* Write the hint values into the %_stat table for the next incr-merger */
+  if( bDirtyHint && rc==SQLITE_OK ){
+    rc = fts3IncrmergeHintStore(p, &hint);
   }
+
+  sqlite3_free(pWriter);
+  sqlite3_free(hint.a);
   return rc;
 }
 
 /*
-** Add all WhereLoop objects for all tables 
+** Convert the text beginning at *pz into an integer and return
+** its value.  Advance *pz to point to the first character past
+** the integer.
+**
+** This function used for parameters to merge= and incrmerge=
+** commands. 
 */
-static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
-  WhereInfo *pWInfo = pBuilder->pWInfo;
-  Bitmask mExtra = 0;
-  Bitmask mPrior = 0;
-  int iTab;
-  SrcList *pTabList = pWInfo->pTabList;
-  struct SrcList_item *pItem;
-  sqlite3 *db = pWInfo->pParse->db;
-  int nTabList = pWInfo->nLevel;
-  int rc = SQLITE_OK;
-  u8 priorJoinType = 0;
-  WhereLoop *pNew;
+static int fts3Getint(const char **pz){
+  const char *z = *pz;
+  int i = 0;
+  while( (*z)>='0' && (*z)<='9' && i<214748363 ) i = 10*i + *(z++) - '0';
+  *pz = z;
+  return i;
+}
 
-  /* Loop over the tables in the join, from left to right */
-  pNew = pBuilder->pNew;
-  whereLoopInit(pNew);
-  for(iTab=0, pItem=pTabList->a; iTabiTab = iTab;
-    pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
-    if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
-      mExtra = mPrior;
-    }
-    priorJoinType = pItem->jointype;
-    if( IsVirtual(pItem->pTab) ){
-      rc = whereLoopAddVirtual(pBuilder, mExtra);
-    }else{
-      rc = whereLoopAddBtree(pBuilder, mExtra);
+/*
+** Process statements of the form:
+**
+**    INSERT INTO table(table) VALUES('merge=A,B');
+**
+** A and B are integers that decode to be the number of leaf pages
+** written for the merge, and the minimum number of segments on a level
+** before it will be selected for a merge, respectively.
+*/
+static int fts3DoIncrmerge(
+  Fts3Table *p,                   /* FTS3 table handle */
+  const char *zParam              /* Nul-terminated string containing "A,B" */
+){
+  int rc;
+  int nMin = (FTS3_MERGE_COUNT / 2);
+  int nMerge = 0;
+  const char *z = zParam;
+
+  /* Read the first integer value */
+  nMerge = fts3Getint(&z);
+
+  /* If the first integer value is followed by a ',',  read the second
+  ** integer value. */
+  if( z[0]==',' && z[1]!='\0' ){
+    z++;
+    nMin = fts3Getint(&z);
+  }
+
+  if( z[0]!='\0' || nMin<2 ){
+    rc = SQLITE_ERROR;
+  }else{
+    rc = SQLITE_OK;
+    if( !p->bHasStat ){
+      assert( p->bFts4==0 );
+      sqlite3Fts3CreateStatTable(&rc, p);
     }
     if( rc==SQLITE_OK ){
-      rc = whereLoopAddOr(pBuilder, mExtra);
+      rc = sqlite3Fts3Incrmerge(p, nMerge, nMin);
     }
-    mPrior |= pNew->maskSelf;
-    if( rc || db->mallocFailed ) break;
+    sqlite3Fts3SegmentsClose(p);
   }
-  whereLoopClear(db, pNew);
   return rc;
 }
 
 /*
-** Examine a WherePath (with the addition of the extra WhereLoop of the 5th
-** parameters) to see if it outputs rows in the requested ORDER BY
-** (or GROUP BY) without requiring a separate sort operation.  Return N:
-** 
-**   N>0:   N terms of the ORDER BY clause are satisfied
-**   N==0:  No terms of the ORDER BY clause are satisfied
-**   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   
+** Process statements of the form:
 **
-** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
-** strict.  With GROUP BY and DISTINCT the only requirement is that
-** equivalent rows appear immediately adjacent to one another.  GROUP BY
-** and DISTINCT do not require rows to appear in any particular order as long
-** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT
-** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
-** pOrderBy terms must be matched in strict left-to-right order.
+**    INSERT INTO table(table) VALUES('automerge=X');
+**
+** where X is an integer.  X==0 means to turn automerge off.  X!=0 means
+** turn it on.  The setting is persistent.
 */
-static i8 wherePathSatisfiesOrderBy(
-  WhereInfo *pWInfo,    /* The WHERE clause */
-  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
-  WherePath *pPath,     /* The WherePath to check */
-  u16 wctrlFlags,       /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */
-  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
-  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
-  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
+static int fts3DoAutoincrmerge(
+  Fts3Table *p,                   /* FTS3 table handle */
+  const char *zParam              /* Nul-terminated string containing boolean */
 ){
-  u8 revSet;            /* True if rev is known */
-  u8 rev;               /* Composite sort order */
-  u8 revIdx;            /* Index sort order */
-  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
-  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
-  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
-  u16 nKeyCol;          /* Number of key columns in pIndex */
-  u16 nColumn;          /* Total number of ordered columns in the index */
-  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
-  int iLoop;            /* Index of WhereLoop in pPath being processed */
-  int i, j;             /* Loop counters */
-  int iCur;             /* Cursor number for current WhereLoop */
-  int iColumn;          /* A column number within table iCur */
-  WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
-  WhereTerm *pTerm;     /* A single term of the WHERE clause */
-  Expr *pOBExpr;        /* An expression from the ORDER BY clause */
-  CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */
-  Index *pIndex;        /* The index associated with pLoop */
-  sqlite3 *db = pWInfo->pParse->db;  /* Database connection */
-  Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */
-  Bitmask obDone;       /* Mask of all ORDER BY terms */
-  Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */
-  Bitmask ready;              /* Mask of inner loops */
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pStmt = 0;
+  p->nAutoincrmerge = fts3Getint(&zParam);
+  if( p->nAutoincrmerge==1 || p->nAutoincrmerge>FTS3_MERGE_COUNT ){
+    p->nAutoincrmerge = 8;
+  }
+  if( !p->bHasStat ){
+    assert( p->bFts4==0 );
+    sqlite3Fts3CreateStatTable(&rc, p);
+    if( rc ) return rc;
+  }
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
+  if( rc ) return rc;
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
+  sqlite3_bind_int(pStmt, 2, p->nAutoincrmerge);
+  sqlite3_step(pStmt);
+  rc = sqlite3_reset(pStmt);
+  return rc;
+}
 
-  /*
-  ** We say the WhereLoop is "one-row" if it generates no more than one
-  ** row of output.  A WhereLoop is one-row if all of the following are true:
-  **  (a) All index columns match with WHERE_COLUMN_EQ.
-  **  (b) The index is unique
-  ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
-  ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
-  **
-  ** We say the WhereLoop is "order-distinct" if the set of columns from
-  ** that WhereLoop that are in the ORDER BY clause are different for every
-  ** row of the WhereLoop.  Every one-row WhereLoop is automatically
-  ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause
-  ** is not order-distinct. To be order-distinct is not quite the same as being
-  ** UNIQUE since a UNIQUE column or index can have multiple rows that 
-  ** are NULL and NULL values are equivalent for the purpose of order-distinct.
-  ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
-  **
-  ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
-  ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
-  ** automatically order-distinct.
-  */
+/*
+** Return a 64-bit checksum for the FTS index entry specified by the
+** arguments to this function.
+*/
+static u64 fts3ChecksumEntry(
+  const char *zTerm,              /* Pointer to buffer containing term */
+  int nTerm,                      /* Size of zTerm in bytes */
+  int iLangid,                    /* Language id for current row */
+  int iIndex,                     /* Index (0..Fts3Table.nIndex-1) */
+  i64 iDocid,                     /* Docid for current row. */
+  int iCol,                       /* Column number */
+  int iPos                        /* Position */
+){
+  int i;
+  u64 ret = (u64)iDocid;
 
-  assert( pOrderBy!=0 );
-  if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+  ret += (ret<<3) + iLangid;
+  ret += (ret<<3) + iIndex;
+  ret += (ret<<3) + iCol;
+  ret += (ret<<3) + iPos;
+  for(i=0; inExpr;
-  testcase( nOrderBy==BMS-1 );
-  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
-  isOrderDistinct = 1;
-  obDone = MASKBIT(nOrderBy)-1;
-  orderDistinctMask = 0;
-  ready = 0;
-  for(iLoop=0; isOrderDistinct && obSat0 ) ready |= pLoop->maskSelf;
-    pLoop = iLoopaLoop[iLoop] : pLast;
-    if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
-      if( pLoop->u.vtab.isOrdered ) obSat = obDone;
-      break;
-    }
-    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
+  return ret;
+}
 
-    /* Mark off any ORDER BY term X that is a column in the table of
-    ** the current loop for which there is term in the WHERE
-    ** clause of the form X IS NULL or X=? that reference only outer
-    ** loops.
-    */
-    for(i=0; ia[i].pExpr);
-      if( pOBExpr->op!=TK_COLUMN ) continue;
-      if( pOBExpr->iTable!=iCur ) continue;
-      pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
-                       ~ready, WO_EQ|WO_ISNULL, 0);
-      if( pTerm==0 ) continue;
-      if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){
-        const char *z1, *z2;
-        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
-        if( !pColl ) pColl = db->pDfltColl;
-        z1 = pColl->zName;
-        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
-        if( !pColl ) pColl = db->pDfltColl;
-        z2 = pColl->zName;
-        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
-      }
-      obSat |= MASKBIT(i);
-    }
+/*
+** Return a checksum of all entries in the FTS index that correspond to
+** language id iLangid. The checksum is calculated by XORing the checksums
+** of each individual entry (see fts3ChecksumEntry()) together.
+**
+** If successful, the checksum value is returned and *pRc set to SQLITE_OK.
+** Otherwise, if an error occurs, *pRc is set to an SQLite error code. The
+** return value is undefined in this case.
+*/
+static u64 fts3ChecksumIndex(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id to return cksum for */
+  int iIndex,                     /* Index to cksum (0..p->nIndex-1) */
+  int *pRc                        /* OUT: Return code */
+){
+  Fts3SegFilter filter;
+  Fts3MultiSegReader csr;
+  int rc;
+  u64 cksum = 0;
 
-    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
-      if( pLoop->wsFlags & WHERE_IPK ){
-        pIndex = 0;
-        nKeyCol = 0;
-        nColumn = 1;
-      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
-        return 0;
-      }else{
-        nKeyCol = pIndex->nKeyCol;
-        nColumn = pIndex->nColumn;
-        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
-        assert( pIndex->aiColumn[nColumn-1]==(-1) || !HasRowid(pIndex->pTable));
-        isOrderDistinct = IsUniqueIndex(pIndex);
-      }
+  assert( *pRc==SQLITE_OK );
 
-      /* Loop through all columns of the index and deal with the ones
-      ** that are not constrained by == or IN.
-      */
-      rev = revSet = 0;
-      distinctColumns = 0;
-      for(j=0; ju.btree.nEq
-         && pLoop->nSkip==0
-         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
-        ){
-          if( i & WO_ISNULL ){
-            testcase( isOrderDistinct );
-            isOrderDistinct = 0;
-          }
-          continue;  
-        }
+  rc = sqlite3Fts3SegReaderCursor(
+      p, iLangid, iIndex, FTS3_SEGCURSOR_ALL, 0, 0, 0, 1,&csr
+  );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);
+  }
 
-        /* Get the column number in the table (iColumn) and sort order
-        ** (revIdx) for the j-th column of the index.
-        */
-        if( pIndex ){
-          iColumn = pIndex->aiColumn[j];
-          revIdx = pIndex->aSortOrder[j];
-          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
-        }else{
-          iColumn = -1;
-          revIdx = 0;
-        }
+  if( rc==SQLITE_OK ){
+    while( SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, &csr)) ){
+      char *pCsr = csr.aDoclist;
+      char *pEnd = &pCsr[csr.nDoclist];
 
-        /* An unconstrained column that might be NULL means that this
-        ** WhereLoop is not well-ordered
-        */
-        if( isOrderDistinct
-         && iColumn>=0
-         && j>=pLoop->u.btree.nEq
-         && pIndex->pTable->aCol[iColumn].notNull==0
-        ){
-          isOrderDistinct = 0;
-        }
+      i64 iDocid = 0;
+      i64 iCol = 0;
+      i64 iPos = 0;
 
-        /* Find the ORDER BY term that corresponds to the j-th column
-        ** of the index and mark that ORDER BY term off 
-        */
-        bOnce = 1;
-        isMatch = 0;
-        for(i=0; bOnce && ia[i].pExpr);
-          testcase( wctrlFlags & WHERE_GROUPBY );
-          testcase( wctrlFlags & WHERE_DISTINCTBY );
-          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
-          if( pOBExpr->op!=TK_COLUMN ) continue;
-          if( pOBExpr->iTable!=iCur ) continue;
-          if( pOBExpr->iColumn!=iColumn ) continue;
-          if( iColumn>=0 ){
-            pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
-            if( !pColl ) pColl = db->pDfltColl;
-            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
-          }
-          isMatch = 1;
-          break;
-        }
-        if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
-          /* Make sure the sort order is compatible in an ORDER BY clause.
-          ** Sort order is irrelevant for a GROUP BY clause. */
-          if( revSet ){
-            if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0;
+      pCsr += sqlite3Fts3GetVarint(pCsr, &iDocid);
+      while( pCsra[i].sortOrder;
-            if( rev ) *pRevMask |= MASKBIT(iLoop);
-            revSet = 1;
-          }
-        }
-        if( isMatch ){
-          if( iColumn<0 ){
-            testcase( distinctColumns==0 );
-            distinctColumns = 1;
-          }
-          obSat |= MASKBIT(i);
-        }else{
-          /* No match found */
-          if( j==0 || jmaskSelf;
-      for(i=0; ia[i].pExpr;
-        mTerm = exprTableUsage(&pWInfo->sMaskSet,p);
-        if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
-        if( (mTerm&~orderDistinctMask)==0 ){
-          obSat |= MASKBIT(i);
-        }
+  *pRc = rc;
+  return cksum;
+}
+
+/*
+** Check if the contents of the FTS index match the current contents of the
+** content table. If no error occurs and the contents do match, set *pbOk
+** to true and return SQLITE_OK. Or if the contents do not match, set *pbOk
+** to false before returning.
+**
+** If an error occurs (e.g. an OOM or IO error), return an SQLite error 
+** code. The final value of *pbOk is undefined in this case.
+*/
+static int fts3IntegrityCheck(Fts3Table *p, int *pbOk){
+  int rc = SQLITE_OK;             /* Return code */
+  u64 cksum1 = 0;                 /* Checksum based on FTS index contents */
+  u64 cksum2 = 0;                 /* Checksum based on %_content contents */
+  sqlite3_stmt *pAllLangid = 0;   /* Statement to return all language-ids */
+
+  /* This block calculates the checksum according to the FTS index. */
+  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);
+    sqlite3_bind_int(pAllLangid, 2, p->nIndex);
+    while( rc==SQLITE_OK && sqlite3_step(pAllLangid)==SQLITE_ROW ){
+      int iLangid = sqlite3_column_int(pAllLangid, 0);
+      int i;
+      for(i=0; inIndex; i++){
+        cksum1 = cksum1 ^ fts3ChecksumIndex(p, iLangid, i, &rc);
       }
     }
-  } /* End the loop over all WhereLoops from outer-most down to inner-most */
-  if( obSat==obDone ) return (i8)nOrderBy;
-  if( !isOrderDistinct ){
-    for(i=nOrderBy-1; i>0; i--){
-      Bitmask m = MASKBIT(i) - 1;
-      if( (obSat&m)==m ) return i;
+    rc2 = sqlite3_reset(pAllLangid);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  /* This block calculates the checksum according to the %_content table */
+  if( rc==SQLITE_OK ){
+    sqlite3_tokenizer_module const *pModule = p->pTokenizer->pModule;
+    sqlite3_stmt *pStmt = 0;
+    char *zSql;
+   
+    zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist);
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      sqlite3_free(zSql);
     }
-    return 0;
+
+    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      i64 iDocid = sqlite3_column_int64(pStmt, 0);
+      int iLang = langidFromSelect(p, pStmt);
+      int iCol;
+
+      for(iCol=0; rc==SQLITE_OK && iColnColumn; iCol++){
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
+          int nText = sqlite3_column_bytes(pStmt, iCol+1);
+          sqlite3_tokenizer_cursor *pT = 0;
+
+          rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);
+          while( rc==SQLITE_OK ){
+            char const *zToken;       /* Buffer containing token */
+            int nToken = 0;           /* Number of bytes in token */
+            int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+            int iPos = 0;             /* Position of token in zText */
+
+            rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+            if( rc==SQLITE_OK ){
+              int i;
+              cksum2 = cksum2 ^ fts3ChecksumEntry(
+                  zToken, nToken, iLang, 0, iDocid, iCol, iPos
+              );
+              for(i=1; inIndex; i++){
+                if( p->aIndex[i].nPrefix<=nToken ){
+                  cksum2 = cksum2 ^ fts3ChecksumEntry(
+                      zToken, p->aIndex[i].nPrefix, iLang, i, iDocid, iCol, iPos
+                  );
+                }
+              }
+            }
+          }
+          if( pT ) pModule->xClose(pT);
+          if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+        }
+      }
+    }
+
+    sqlite3_finalize(pStmt);
   }
-  return -1;
-}
 
+  *pbOk = (cksum1==cksum2);
+  return rc;
+}
 
 /*
-** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),
-** the planner assumes that the specified pOrderBy list is actually a GROUP
-** BY clause - and so any order that groups rows as required satisfies the
-** request.
+** Run the integrity-check. If no error occurs and the current contents of
+** the FTS index are correct, return SQLITE_OK. Or, if the contents of the
+** FTS index are incorrect, return SQLITE_CORRUPT_VTAB.
 **
-** Normally, in this case it is not possible for the caller to determine
-** whether or not the rows are really being delivered in sorted order, or
-** just in some other order that provides the required grouping. However,
-** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then
-** this function may be called on the returned WhereInfo object. It returns
-** true if the rows really will be sorted in the specified order, or false
-** otherwise.
+** Or, if an error (e.g. an OOM or IO error) occurs, return an SQLite 
+** error code.
 **
-** For example, assuming:
+** The integrity-check works as follows. For each token and indexed token
+** prefix in the document set, a 64-bit checksum is calculated (by code
+** in fts3ChecksumEntry()) based on the following:
 **
-**   CREATE INDEX i1 ON t1(x, Y);
+**     + The index number (0 for the main index, 1 for the first prefix
+**       index etc.),
+**     + The token (or token prefix) text itself, 
+**     + The language-id of the row it appears in,
+**     + The docid of the row it appears in,
+**     + The column it appears in, and
+**     + The tokens position within that column.
 **
-** then
+** The checksums for all entries in the index are XORed together to create
+** a single checksum for the entire index.
 **
-**   SELECT * FROM t1 GROUP BY x,y ORDER BY x,y;   -- IsSorted()==1
-**   SELECT * FROM t1 GROUP BY y,x ORDER BY y,x;   -- IsSorted()==0
-*/
-SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){
-  assert( pWInfo->wctrlFlags & WHERE_GROUPBY );
-  assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );
-  return pWInfo->sorted;
-}
-
-#ifdef WHERETRACE_ENABLED
-/* For debugging use only: */
-static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
-  static char zName[65];
-  int i;
-  for(i=0; iaLoop[i]->cId; }
-  if( pLast ) zName[i++] = pLast->cId;
-  zName[i] = 0;
-  return zName;
-}
-#endif
-
-/*
-** Return the cost of sorting nRow rows, assuming that the keys have 
-** nOrderby columns and that the first nSorted columns are already in
-** order.
+** The integrity-check code calculates the same checksum in two ways:
+**
+**     1. By scanning the contents of the FTS index, and 
+**     2. By scanning and tokenizing the content table.
+**
+** If the two checksums are identical, the integrity-check is deemed to have
+** passed.
 */
-static LogEst whereSortingCost(
-  WhereInfo *pWInfo,
-  LogEst nRow,
-  int nOrderBy,
-  int nSorted
+static int fts3DoIntegrityCheck(
+  Fts3Table *p                    /* FTS3 table handle */
 ){
-  /* TUNING: Estimated cost of a full external sort, where N is 
-  ** the number of rows to sort is:
-  **
-  **   cost = (3.0 * N * log(N)).
-  ** 
-  ** Or, if the order-by clause has X terms but only the last Y 
-  ** terms are out of order, then block-sorting will reduce the 
-  ** sorting cost to:
-  **
-  **   cost = (3.0 * N * log(N)) * (Y/X)
-  **
-  ** The (Y/X) term is implemented using stack variable rScale
-  ** below.  */
-  LogEst rScale, rSortCost;
-  assert( nOrderBy>0 && 66==sqlite3LogEst(100) );
-  rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;
-  rSortCost = nRow + estLog(nRow) + rScale + 16;
-
-  /* TUNING: The cost of implementing DISTINCT using a B-TREE is
-  ** similar but with a larger constant of proportionality. 
-  ** Multiply by an additional factor of 3.0.  */
-  if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
-    rSortCost += 16;
-  }
-
-  return rSortCost;
+  int rc;
+  int bOk = 0;
+  rc = fts3IntegrityCheck(p, &bOk);
+  if( rc==SQLITE_OK && bOk==0 ) rc = FTS_CORRUPT_VTAB;
+  return rc;
 }
 
 /*
-** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
-** attempts to find the lowest cost path that visits each WhereLoop
-** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
+** Handle a 'special' INSERT of the form:
 **
-** Assume that the total number of output rows that will need to be sorted
-** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting
-** costs if nRowEst==0.
+**   "INSERT INTO tbl(tbl) VALUES()"
 **
-** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
-** error occurs.
+** Argument pVal contains the result of . Currently the only 
+** meaningful value to insert is the text 'optimize'.
 */
-static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
-  int mxChoice;             /* Maximum number of simultaneous paths tracked */
-  int nLoop;                /* Number of terms in the join */
-  Parse *pParse;            /* Parsing context */
-  sqlite3 *db;              /* The database connection */
-  int iLoop;                /* Loop counter over the terms of the join */
-  int ii, jj;               /* Loop counters */
-  int mxI = 0;              /* Index of next entry to replace */
-  int nOrderBy;             /* Number of ORDER BY clause terms */
-  LogEst mxCost = 0;        /* Maximum cost of a set of paths */
-  LogEst mxUnsorted = 0;    /* Maximum unsorted cost of a set of path */
-  int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
-  WherePath *aFrom;         /* All nFrom paths at the previous level */
-  WherePath *aTo;           /* The nTo best paths at the current level */
-  WherePath *pFrom;         /* An element of aFrom[] that we are working on */
-  WherePath *pTo;           /* An element of aTo[] that we are working on */
-  WhereLoop *pWLoop;        /* One of the WhereLoop objects */
-  WhereLoop **pX;           /* Used to divy up the pSpace memory */
-  LogEst *aSortCost = 0;    /* Sorting and partial sorting costs */
-  char *pSpace;             /* Temporary memory used by this routine */
-  int nSpace;               /* Bytes of space allocated at pSpace */
-
-  pParse = pWInfo->pParse;
-  db = pParse->db;
-  nLoop = pWInfo->nLevel;
-  /* TUNING: For simple queries, only the best path is tracked.
-  ** For 2-way joins, the 5 best paths are followed.
-  ** For joins of 3 or more tables, track the 10 best paths */
-  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);
-  assert( nLoop<=pWInfo->pTabList->nSrc );
-  WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d)\n", nRowEst));
+static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
+  int rc;                         /* Return Code */
+  const char *zVal = (const char *)sqlite3_value_text(pVal);
+  int nVal = sqlite3_value_bytes(pVal);
 
-  /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this
-  ** case the purpose of this call is to estimate the number of rows returned
-  ** by the overall query. Once this estimate has been obtained, the caller
-  ** will invoke this function a second time, passing the estimate as the
-  ** nRowEst parameter.  */
-  if( pWInfo->pOrderBy==0 || nRowEst==0 ){
-    nOrderBy = 0;
+  if( !zVal ){
+    return SQLITE_NOMEM;
+  }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){
+    rc = fts3DoOptimize(p, 0);
+  }else if( nVal==7 && 0==sqlite3_strnicmp(zVal, "rebuild", 7) ){
+    rc = fts3DoRebuild(p);
+  }else if( nVal==15 && 0==sqlite3_strnicmp(zVal, "integrity-check", 15) ){
+    rc = fts3DoIntegrityCheck(p);
+  }else if( nVal>6 && 0==sqlite3_strnicmp(zVal, "merge=", 6) ){
+    rc = fts3DoIncrmerge(p, &zVal[6]);
+  }else if( nVal>10 && 0==sqlite3_strnicmp(zVal, "automerge=", 10) ){
+    rc = fts3DoAutoincrmerge(p, &zVal[10]);
+#ifdef SQLITE_TEST
+  }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
+    p->nNodeSize = atoi(&zVal[9]);
+    rc = SQLITE_OK;
+  }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
+    p->nMaxPendingData = atoi(&zVal[11]);
+    rc = SQLITE_OK;
+  }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){
+    p->bNoIncrDoclist = atoi(&zVal[21]);
+    rc = SQLITE_OK;
+#endif
   }else{
-    nOrderBy = pWInfo->pOrderBy->nExpr;
+    rc = SQLITE_ERROR;
   }
 
-  /* Allocate and initialize space for aTo, aFrom and aSortCost[] */
-  nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
-  nSpace += sizeof(LogEst) * nOrderBy;
-  pSpace = sqlite3DbMallocRaw(db, nSpace);
-  if( pSpace==0 ) return SQLITE_NOMEM;
-  aTo = (WherePath*)pSpace;
-  aFrom = aTo+mxChoice;
-  memset(aFrom, 0, sizeof(aFrom[0]));
-  pX = (WhereLoop**)(aFrom+mxChoice);
-  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
-    pFrom->aLoop = pX;
-  }
-  if( nOrderBy ){
-    /* If there is an ORDER BY clause and it is not being ignored, set up
-    ** space for the aSortCost[] array. Each element of the aSortCost array
-    ** is either zero - meaning it has not yet been initialized - or the
-    ** cost of sorting nRowEst rows of data where the first X terms of
-    ** the ORDER BY clause are already in order, where X is the array 
-    ** index.  */
-    aSortCost = (LogEst*)pX;
-    memset(aSortCost, 0, sizeof(LogEst) * nOrderBy);
-  }
-  assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] );
-  assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX );
+  return rc;
+}
 
-  /* Seed the search with a single WherePath containing zero WhereLoops.
-  **
-  ** TUNING: Do not let the number of iterations go above 25.  If the cost
-  ** of computing an automatic index is not paid back within the first 25
-  ** rows, then do not use the automatic index. */
-  aFrom[0].nRow = MIN(pParse->nQueryLoop, 46);  assert( 46==sqlite3LogEst(25) );
-  nFrom = 1;
-  assert( aFrom[0].isOrdered==0 );
-  if( nOrderBy ){
-    /* If nLoop is zero, then there are no FROM terms in the query. Since
-    ** in this case the query may return a maximum of one row, the results
-    ** are already in the requested order. Set isOrdered to nOrderBy to
-    ** indicate this. Or, if nLoop is greater than zero, set isOrdered to
-    ** -1, indicating that the result set may or may not be ordered, 
-    ** depending on the loops added to the current plan.  */
-    aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy;
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+/*
+** Delete all cached deferred doclists. Deferred doclists are cached
+** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function.
+*/
+SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *pCsr){
+  Fts3DeferredToken *pDef;
+  for(pDef=pCsr->pDeferred; pDef; pDef=pDef->pNext){
+    fts3PendingListDelete(pDef->pList);
+    pDef->pList = 0;
   }
+}
 
-  /* Compute successively longer WherePaths using the previous generation
-  ** of WherePaths as the basis for the next.  Keep track of the mxChoice
-  ** best paths at each generation */
-  for(iLoop=0; iLooppLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
-        LogEst nOut;                      /* Rows visited by (pFrom+pWLoop) */
-        LogEst rCost;                     /* Cost of path (pFrom+pWLoop) */
-        LogEst rUnsorted;                 /* Unsorted cost of (pFrom+pWLoop) */
-        i8 isOrdered = pFrom->isOrdered;  /* isOrdered for (pFrom+pWLoop) */
-        Bitmask maskNew;                  /* Mask of src visited by (..) */
-        Bitmask revMask = 0;              /* Mask of rev-order loops for (..) */
-
-        if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
-        if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
-        /* At this point, pWLoop is a candidate to be the next loop. 
-        ** Compute its cost */
-        rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
-        rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted);
-        nOut = pFrom->nRow + pWLoop->nOut;
-        maskNew = pFrom->maskLoop | pWLoop->maskSelf;
-        if( isOrdered<0 ){
-          isOrdered = wherePathSatisfiesOrderBy(pWInfo,
-                       pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
-                       iLoop, pWLoop, &revMask);
-        }else{
-          revMask = pFrom->revLoop;
-        }
-        if( isOrdered>=0 && isOrderedpDeffered list. Entries are added to 
+** this list using sqlite3Fts3DeferToken().
+*/
+SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *pCsr){
+  Fts3DeferredToken *pDef;
+  Fts3DeferredToken *pNext;
+  for(pDef=pCsr->pDeferred; pDef; pDef=pNext){
+    pNext = pDef->pNext;
+    fts3PendingListDelete(pDef->pList);
+    sqlite3_free(pDef);
+  }
+  pCsr->pDeferred = 0;
+}
 
-          WHERETRACE(0x002,
-              ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n",
-               aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, 
-               rUnsorted, rCost));
-        }else{
-          rCost = rUnsorted;
-        }
+/*
+** Generate deferred-doclists for all tokens in the pCsr->pDeferred list
+** based on the row that pCsr currently points to.
+**
+** A deferred-doclist is like any other doclist with position information
+** included, except that it only contains entries for a single row of the
+** table, not for all rows.
+*/
+SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){
+  int rc = SQLITE_OK;             /* Return code */
+  if( pCsr->pDeferred ){
+    int i;                        /* Used to iterate through table columns */
+    sqlite3_int64 iDocid;         /* Docid of the row pCsr points to */
+    Fts3DeferredToken *pDef;      /* Used to iterate through deferred tokens */
+  
+    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+    sqlite3_tokenizer *pT = p->pTokenizer;
+    sqlite3_tokenizer_module const *pModule = pT->pModule;
+   
+    assert( pCsr->isRequireSeek==0 );
+    iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
+  
+    for(i=0; inColumn && rc==SQLITE_OK; i++){
+      if( p->abNotindexed[i]==0 ){
+        const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
+        sqlite3_tokenizer_cursor *pTC = 0;
 
-        /* Check to see if pWLoop should be added to the set of
-        ** mxChoice best-so-far paths.
-        **
-        ** First look for an existing path among best-so-far paths
-        ** that covers the same set of loops and has the same isOrdered
-        ** setting as the current path candidate.
-        **
-        ** The term "((pTo->isOrdered^isOrdered)&0x80)==0" is equivalent
-        ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range
-        ** of legal values for isOrdered, -1..64.
-        */
-        for(jj=0, pTo=aTo; jjmaskLoop==maskNew
-           && ((pTo->isOrdered^isOrdered)&0x80)==0
-          ){
-            testcase( jj==nTo-1 );
-            break;
-          }
-        }
-        if( jj>=nTo ){
-          /* None of the existing best-so-far paths match the candidate. */
-          if( nTo>=mxChoice
-           && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted))
-          ){
-            /* The current candidate is no better than any of the mxChoice
-            ** paths currently in the best-so-far buffer.  So discard
-            ** this candidate as not viable. */
-#ifdef WHERETRACE_ENABLED /* 0x4 */
-            if( sqlite3WhereTrace&0x4 ){
-              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
-                  isOrdered>=0 ? isOrdered+'0' : '?');
-            }
-#endif
-            continue;
-          }
-          /* If we reach this points it means that the new candidate path
-          ** needs to be added to the set of best-so-far paths. */
-          if( nTo=0 ? isOrdered+'0' : '?');
-          }
-#endif
-        }else{
-          /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
-          ** same set of loops and has the sam isOrdered setting as the
-          ** candidate path.  Check to see if the candidate should replace
-          ** pTo or if the candidate should be skipped */
-          if( pTo->rCostrCost==rCost && pTo->nRow<=nOut) ){
-#ifdef WHERETRACE_ENABLED /* 0x4 */
-            if( sqlite3WhereTrace&0x4 ){
-              sqlite3DebugPrintf(
-                  "Skip   %s cost=%-3d,%3d order=%c",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
-                  isOrdered>=0 ? isOrdered+'0' : '?');
-              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
-                  wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                  pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
-            }
-#endif
-            /* Discard the candidate path from further consideration */
-            testcase( pTo->rCost==rCost );
-            continue;
-          }
-          testcase( pTo->rCost==rCost+1 );
-          /* Control reaches here if the candidate path is better than the
-          ** pTo path.  Replace pTo with the candidate. */
-#ifdef WHERETRACE_ENABLED /* 0x4 */
-          if( sqlite3WhereTrace&0x4 ){
-            sqlite3DebugPrintf(
-                "Update %s cost=%-3d,%3d order=%c",
-                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
-                isOrdered>=0 ? isOrdered+'0' : '?');
-            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
-                wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
-          }
-#endif
-        }
-        /* pWLoop is a winner.  Add it to the set of best so far */
-        pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
-        pTo->revLoop = revMask;
-        pTo->nRow = nOut;
-        pTo->rCost = rCost;
-        pTo->rUnsorted = rUnsorted;
-        pTo->isOrdered = isOrdered;
-        memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
-        pTo->aLoop[iLoop] = pWLoop;
-        if( nTo>=mxChoice ){
-          mxI = 0;
-          mxCost = aTo[0].rCost;
-          mxUnsorted = aTo[0].nRow;
-          for(jj=1, pTo=&aTo[1]; jjrCost>mxCost 
-             || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) 
-            ){
-              mxCost = pTo->rCost;
-              mxUnsorted = pTo->rUnsorted;
-              mxI = jj;
-            }
-          }
-        }
-      }
-    }
+        rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
+        while( rc==SQLITE_OK ){
+          char const *zToken;       /* Buffer containing token */
+          int nToken = 0;           /* Number of bytes in token */
+          int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+          int iPos = 0;             /* Position of token in zText */
 
-#ifdef WHERETRACE_ENABLED  /* >=2 */
-    if( sqlite3WhereTrace & 0x02 ){
-      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
-      for(ii=0, pTo=aTo; iirCost, pTo->nRow,
-           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
-        if( pTo->isOrdered>0 ){
-          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
-        }else{
-          sqlite3DebugPrintf("\n");
+          rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+          for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
+            Fts3PhraseToken *pPT = pDef->pToken;
+            if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
+                && (pPT->bFirst==0 || iPos==0)
+                && (pPT->n==nToken || (pPT->isPrefix && pPT->nz, pPT->n))
+              ){
+              fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+            }
+          }
         }
+        if( pTC ) pModule->xClose(pTC);
+        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
       }
     }
-#endif
 
-    /* Swap the roles of aFrom and aTo for the next generation */
-    pFrom = aTo;
-    aTo = aFrom;
-    aFrom = pFrom;
-    nFrom = nTo;
+    for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
+      if( pDef->pList ){
+        rc = fts3PendingListAppendVarint(&pDef->pList, 0);
+      }
+    }
   }
 
-  if( nFrom==0 ){
-    sqlite3ErrorMsg(pParse, "no query solution");
-    sqlite3DbFree(db, pSpace);
-    return SQLITE_ERROR;
+  return rc;
+}
+
+SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(
+  Fts3DeferredToken *p, 
+  char **ppData, 
+  int *pnData
+){
+  char *pRet;
+  int nSkip;
+  sqlite3_int64 dummy;
+
+  *ppData = 0;
+  *pnData = 0;
+
+  if( p->pList==0 ){
+    return SQLITE_OK;
   }
+
+  pRet = (char *)sqlite3_malloc(p->pList->nData);
+  if( !pRet ) return SQLITE_NOMEM;
+
+  nSkip = sqlite3Fts3GetVarint(p->pList->aData, &dummy);
+  *pnData = p->pList->nData - nSkip;
+  *ppData = pRet;
   
-  /* Find the lowest cost path.  pFrom will be left pointing to that path */
-  pFrom = aFrom;
-  for(ii=1; iirCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
-  }
-  assert( pWInfo->nLevel==nLoop );
-  /* Load the lowest cost path into pWInfo */
-  for(iLoop=0; iLoopa + iLoop;
-    pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
-    pLevel->iFrom = pWLoop->iTab;
-    pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
-  }
-  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
-   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
-   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
-   && nRowEst
-  ){
-    Bitmask notUsed;
-    int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,
-                 WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], ¬Used);
-    if( rc==pWInfo->pResultSet->nExpr ){
-      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
-    }
-  }
-  if( pWInfo->pOrderBy ){
-    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
-      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
-        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
-      }
-    }else{
-      pWInfo->nOBSat = pFrom->isOrdered;
-      if( pWInfo->nOBSat<0 ) pWInfo->nOBSat = 0;
-      pWInfo->revMask = pFrom->revLoop;
-    }
-    if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
-        && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr
-    ){
-      Bitmask revMask = 0;
-      int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 
-          pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask
-      );
-      assert( pWInfo->sorted==0 );
-      if( nOrder==pWInfo->pOrderBy->nExpr ){
-        pWInfo->sorted = 1;
-        pWInfo->revMask = revMask;
-      }
-    }
-  }
+  memcpy(pRet, &p->pList->aData[nSkip], *pnData);
+  return SQLITE_OK;
+}
 
+/*
+** Add an entry for token pToken to the pCsr->pDeferred list.
+*/
+SQLITE_PRIVATE int sqlite3Fts3DeferToken(
+  Fts3Cursor *pCsr,               /* Fts3 table cursor */
+  Fts3PhraseToken *pToken,        /* Token to defer */
+  int iCol                        /* Column that token must appear in (or -1) */
+){
+  Fts3DeferredToken *pDeferred;
+  pDeferred = sqlite3_malloc(sizeof(*pDeferred));
+  if( !pDeferred ){
+    return SQLITE_NOMEM;
+  }
+  memset(pDeferred, 0, sizeof(*pDeferred));
+  pDeferred->pToken = pToken;
+  pDeferred->pNext = pCsr->pDeferred; 
+  pDeferred->iCol = iCol;
+  pCsr->pDeferred = pDeferred;
 
-  pWInfo->nRowOut = pFrom->nRow;
+  assert( pToken->pDeferred==0 );
+  pToken->pDeferred = pDeferred;
 
-  /* Free temporary memory and return success */
-  sqlite3DbFree(db, pSpace);
   return SQLITE_OK;
 }
+#endif
 
 /*
-** Most queries use only a single table (they are not joins) and have
-** simple == constraints against indexed fields.  This routine attempts
-** to plan those simple cases using much less ceremony than the
-** general-purpose query planner, and thereby yield faster sqlite3_prepare()
-** times for the common case.
-**
-** Return non-zero on success, if this query can be handled by this
-** no-frills query planner.  Return zero if this query needs the 
-** general-purpose query planner.
+** SQLite value pRowid contains the rowid of a row that may or may not be
+** present in the FTS3 table. If it is, delete it and adjust the contents
+** of subsiduary data structures accordingly.
 */
-static int whereShortCut(WhereLoopBuilder *pBuilder){
-  WhereInfo *pWInfo;
-  struct SrcList_item *pItem;
-  WhereClause *pWC;
-  WhereTerm *pTerm;
-  WhereLoop *pLoop;
-  int iCur;
-  int j;
-  Table *pTab;
-  Index *pIdx;
-  
-  pWInfo = pBuilder->pWInfo;
-  if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0;
-  assert( pWInfo->pTabList->nSrc>=1 );
-  pItem = pWInfo->pTabList->a;
-  pTab = pItem->pTab;
-  if( IsVirtual(pTab) ) return 0;
-  if( pItem->zIndex ) return 0;
-  iCur = pItem->iCursor;
-  pWC = &pWInfo->sWC;
-  pLoop = pBuilder->pNew;
-  pLoop->wsFlags = 0;
-  pLoop->nSkip = 0;
-  pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0);
-  if( pTerm ){
-    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
-    pLoop->aLTerm[0] = pTerm;
-    pLoop->nLTerm = 1;
-    pLoop->u.btree.nEq = 1;
-    /* TUNING: Cost of a rowid lookup is 10 */
-    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
-  }else{
-    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-      assert( pLoop->aLTermSpace==pLoop->aLTerm );
-      if( !IsUniqueIndex(pIdx)
-       || pIdx->pPartIdxWhere!=0 
-       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
-      ) continue;
-      for(j=0; jnKeyCol; j++){
-        pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
-        if( pTerm==0 ) break;
-        pLoop->aLTerm[j] = pTerm;
-      }
-      if( j!=pIdx->nKeyCol ) continue;
-      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
-      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
-        pLoop->wsFlags |= WHERE_IDX_ONLY;
+static int fts3DeleteByRowid(
+  Fts3Table *p, 
+  sqlite3_value *pRowid, 
+  int *pnChng,                    /* IN/OUT: Decrement if row is deleted */
+  u32 *aSzDel
+){
+  int rc = SQLITE_OK;             /* Return code */
+  int bFound = 0;                 /* True if *pRowid really is in the table */
+
+  fts3DeleteTerms(&rc, p, pRowid, aSzDel, &bFound);
+  if( bFound && rc==SQLITE_OK ){
+    int isEmpty = 0;              /* Deleting *pRowid leaves the table empty */
+    rc = fts3IsEmpty(p, pRowid, &isEmpty);
+    if( rc==SQLITE_OK ){
+      if( isEmpty ){
+        /* Deleting this row means the whole table is empty. In this case
+        ** delete the contents of all three tables and throw away any
+        ** data in the pendingTerms hash table.  */
+        rc = fts3DeleteAll(p, 1);
+        *pnChng = 0;
+        memset(aSzDel, 0, sizeof(u32) * (p->nColumn+1) * 2);
+      }else{
+        *pnChng = *pnChng - 1;
+        if( p->zContentTbl==0 ){
+          fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
+        }
+        if( p->bHasDocsize ){
+          fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);
+        }
       }
-      pLoop->nLTerm = j;
-      pLoop->u.btree.nEq = j;
-      pLoop->u.btree.pIndex = pIdx;
-      /* TUNING: Cost of a unique index lookup is 15 */
-      pLoop->rRun = 39;  /* 39==sqlite3LogEst(15) */
-      break;
-    }
-  }
-  if( pLoop->wsFlags ){
-    pLoop->nOut = (LogEst)1;
-    pWInfo->a[0].pWLoop = pLoop;
-    pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur);
-    pWInfo->a[0].iTabCur = iCur;
-    pWInfo->nRowOut = 1;
-    if( pWInfo->pOrderBy ) pWInfo->nOBSat =  pWInfo->pOrderBy->nExpr;
-    if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
-      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
     }
-#ifdef SQLITE_DEBUG
-    pLoop->cId = '0';
-#endif
-    return 1;
   }
-  return 0;
+
+  return rc;
 }
 
 /*
-** Generate the beginning of the loop used for WHERE clause processing.
-** The return value is a pointer to an opaque structure that contains
-** information needed to terminate the loop.  Later, the calling routine
-** should invoke sqlite3WhereEnd() with the return value of this function
-** in order to complete the WHERE clause processing.
-**
-** If an error occurs, this routine returns NULL.
-**
-** The basic idea is to do a nested loop, one loop for each table in
-** the FROM clause of a select.  (INSERT and UPDATE statements are the
-** same as a SELECT with only a single table in the FROM clause.)  For
-** example, if the SQL is this:
-**
-**       SELECT * FROM t1, t2, t3 WHERE ...;
-**
-** Then the code generated is conceptually like the following:
-**
-**      foreach row1 in t1 do       \    Code generated
-**        foreach row2 in t2 do      |-- by sqlite3WhereBegin()
-**          foreach row3 in t3 do   /
-**            ...
-**          end                     \    Code generated
-**        end                        |-- by sqlite3WhereEnd()
-**      end                         /
-**
-** Note that the loops might not be nested in the order in which they
-** appear in the FROM clause if a different order is better able to make
-** use of indices.  Note also that when the IN operator appears in
-** the WHERE clause, it might result in additional nested loops for
-** scanning through all values on the right-hand side of the IN.
-**
-** There are Btree cursors associated with each table.  t1 uses cursor
-** number pTabList->a[0].iCursor.  t2 uses the cursor pTabList->a[1].iCursor.
-** And so forth.  This routine generates code to open those VDBE cursors
-** and sqlite3WhereEnd() generates the code to close them.
-**
-** The code that sqlite3WhereBegin() generates leaves the cursors named
-** in pTabList pointing at their appropriate entries.  The [...] code
-** can use OP_Column and OP_Rowid opcodes on these cursors to extract
-** data from the various tables of the loop.
-**
-** If the WHERE clause is empty, the foreach loops must each scan their
-** entire tables.  Thus a three-way join is an O(N^3) operation.  But if
-** the tables have indices and there are terms in the WHERE clause that
-** refer to those indices, a complete table scan can be avoided and the
-** code will run much faster.  Most of the work of this routine is checking
-** to see if there are indices that can be used to speed up the loop.
-**
-** Terms of the WHERE clause are also used to limit which rows actually
-** make it to the "..." in the middle of the loop.  After each "foreach",
-** terms of the WHERE clause that use only terms in that loop and outer
-** loops are evaluated and if false a jump is made around all subsequent
-** inner loops (or around the "..." if the test occurs within the inner-
-** most loop)
-**
-** OUTER JOINS
-**
-** An outer join of tables t1 and t2 is conceptally coded as follows:
-**
-**    foreach row1 in t1 do
-**      flag = 0
-**      foreach row2 in t2 do
-**        start:
-**          ...
-**          flag = 1
-**      end
-**      if flag==0 then
-**        move the row2 cursor to a null row
-**        goto start
-**      fi
-**    end
-**
-** ORDER BY CLAUSE PROCESSING
+** This function does the work for the xUpdate method of FTS3 virtual
+** tables. The schema of the virtual table being:
 **
-** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
-** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
-** if there is one.  If there is no ORDER BY clause or if this routine
-** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
+**     CREATE TABLE 
    ( 
+**       ,
+**       
     HIDDEN, 
+**       docid HIDDEN, 
+**        HIDDEN
+**     );
 **
-** The iIdxCur parameter is the cursor number of an index.  If 
-** WHERE_ONETABLE_ONLY is set, iIdxCur is the cursor number of an index
-** to use for OR clause processing.  The WHERE clause should use this
-** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
-** the first cursor in an array of cursors for all indices.  iIdxCur should
-** be used to compute the appropriate cursor depending on which index is
-** used.
+** 
 */
-SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
-  Parse *pParse,        /* The parser context */
-  SrcList *pTabList,    /* FROM clause: A list of all tables to be scanned */
-  Expr *pWhere,         /* The WHERE clause */
-  ExprList *pOrderBy,   /* An ORDER BY (or GROUP BY) clause, or NULL */
-  ExprList *pResultSet, /* Result set of the query */
-  u16 wctrlFlags,       /* One of the WHERE_* flags defined in sqliteInt.h */
-  int iIdxCur           /* If WHERE_ONETABLE_ONLY is set, index cursor number */
+SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
+  sqlite3_vtab *pVtab,            /* FTS3 vtab object */
+  int nArg,                       /* Size of argument array */
+  sqlite3_value **apVal,          /* Array of arguments */
+  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
 ){
-  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
-  int nTabList;              /* Number of elements in pTabList */
-  WhereInfo *pWInfo;         /* Will become the return value of this function */
-  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
-  Bitmask notReady;          /* Cursors that are not yet positioned */
-  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
-  WhereMaskSet *pMaskSet;    /* The expression mask set */
-  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
-  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
-  int ii;                    /* Loop counter */
-  sqlite3 *db;               /* Database connection */
-  int rc;                    /* Return code */
-
-
-  /* Variable initialization */
-  db = pParse->db;
-  memset(&sWLB, 0, sizeof(sWLB));
+  Fts3Table *p = (Fts3Table *)pVtab;
+  int rc = SQLITE_OK;             /* Return Code */
+  int isRemove = 0;               /* True for an UPDATE or DELETE */
+  u32 *aSzIns = 0;                /* Sizes of inserted documents */
+  u32 *aSzDel = 0;                /* Sizes of deleted documents */
+  int nChng = 0;                  /* Net change in number of documents */
+  int bInsertDone = 0;
 
-  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
-  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
-  if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0;
-  sWLB.pOrderBy = pOrderBy;
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  assert( p->bHasStat==0 || p->bHasStat==1 );
 
-  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
-  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
-  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
-    wctrlFlags &= ~WHERE_WANT_DISTINCT;
-  }
+  assert( p->pSegments==0 );
+  assert( 
+      nArg==1                     /* DELETE operations */
+   || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */
+  );
 
-  /* The number of tables in the FROM clause is limited by the number of
-  ** bits in a Bitmask 
+  /* Check for a "special" INSERT operation. One of the form:
+  **
+  **   INSERT INTO xyz(xyz) VALUES('command');
   */
-  testcase( pTabList->nSrc==BMS );
-  if( pTabList->nSrc>BMS ){
-    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
-    return 0;
+  if( nArg>1 
+   && sqlite3_value_type(apVal[0])==SQLITE_NULL 
+   && sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL 
+  ){
+    rc = fts3SpecialInsert(p, apVal[p->nColumn+2]);
+    goto update_out;
   }
 
-  /* This function normally generates a nested loop for all tables in 
-  ** pTabList.  But if the WHERE_ONETABLE_ONLY flag is set, then we should
-  ** only generate code for the first table in pTabList and assume that
-  ** any cursors associated with subsequent tables are uninitialized.
-  */
-  nTabList = (wctrlFlags & WHERE_ONETABLE_ONLY) ? 1 : pTabList->nSrc;
+  if( nArg>1 && sqlite3_value_int(apVal[2 + p->nColumn + 2])<0 ){
+    rc = SQLITE_CONSTRAINT;
+    goto update_out;
+  }
 
-  /* Allocate and initialize the WhereInfo structure that will become the
-  ** return value. A single allocation is used to store the WhereInfo
-  ** struct, the contents of WhereInfo.a[], the WhereClause structure
-  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
-  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
-  ** some architectures. Hence the ROUND8() below.
-  */
-  nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
-  pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
-  if( db->mallocFailed ){
-    sqlite3DbFree(db, pWInfo);
-    pWInfo = 0;
-    goto whereBeginError;
+  /* Allocate space to hold the change in document sizes */
+  aSzDel = sqlite3_malloc( sizeof(aSzDel[0])*(p->nColumn+1)*2 );
+  if( aSzDel==0 ){
+    rc = SQLITE_NOMEM;
+    goto update_out;
   }
-  pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;
-  pWInfo->nLevel = nTabList;
-  pWInfo->pParse = pParse;
-  pWInfo->pTabList = pTabList;
-  pWInfo->pOrderBy = pOrderBy;
-  pWInfo->pResultSet = pResultSet;
-  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
-  pWInfo->wctrlFlags = wctrlFlags;
-  pWInfo->savedNQueryLoop = pParse->nQueryLoop;
-  pMaskSet = &pWInfo->sMaskSet;
-  sWLB.pWInfo = pWInfo;
-  sWLB.pWC = &pWInfo->sWC;
-  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
-  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
-  whereLoopInit(sWLB.pNew);
-#ifdef SQLITE_DEBUG
-  sWLB.pNew->cId = '*';
-#endif
+  aSzIns = &aSzDel[p->nColumn+1];
+  memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);
 
-  /* Split the WHERE clause into separate subexpressions where each
-  ** subexpression is separated by an AND operator.
-  */
-  initMaskSet(pMaskSet);
-  whereClauseInit(&pWInfo->sWC, pWInfo);
-  whereSplit(&pWInfo->sWC, pWhere, TK_AND);
-    
-  /* Special case: a WHERE clause that is constant.  Evaluate the
-  ** expression and either jump over all of the code or fall thru.
+  rc = fts3Writelock(p);
+  if( rc!=SQLITE_OK ) goto update_out;
+
+  /* If this is an INSERT operation, or an UPDATE that modifies the rowid
+  ** value, then this operation requires constraint handling.
+  **
+  ** If the on-conflict mode is REPLACE, this means that the existing row
+  ** should be deleted from the database before inserting the new row. Or,
+  ** if the on-conflict mode is other than REPLACE, then this method must
+  ** detect the conflict and return SQLITE_CONSTRAINT before beginning to
+  ** modify the database file.
   */
-  for(ii=0; iinTerm; ii++){
-    if( nTabList==0 || sqlite3ExprIsConstantNotJoin(sWLB.pWC->a[ii].pExpr) ){
-      sqlite3ExprIfFalse(pParse, sWLB.pWC->a[ii].pExpr, pWInfo->iBreak,
-                         SQLITE_JUMPIFNULL);
-      sWLB.pWC->a[ii].wtFlags |= TERM_CODED;
+  if( nArg>1 && p->zContentTbl==0 ){
+    /* Find the value object that holds the new rowid value. */
+    sqlite3_value *pNewRowid = apVal[3+p->nColumn];
+    if( sqlite3_value_type(pNewRowid)==SQLITE_NULL ){
+      pNewRowid = apVal[1];
     }
-  }
 
-  /* Special case: No FROM clause
-  */
-  if( nTabList==0 ){
-    if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
-    if( wctrlFlags & WHERE_WANT_DISTINCT ){
-      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    if( sqlite3_value_type(pNewRowid)!=SQLITE_NULL && ( 
+        sqlite3_value_type(apVal[0])==SQLITE_NULL
+     || sqlite3_value_int64(apVal[0])!=sqlite3_value_int64(pNewRowid)
+    )){
+      /* The new rowid is not NULL (in this case the rowid will be
+      ** automatically assigned and there is no chance of a conflict), and 
+      ** the statement is either an INSERT or an UPDATE that modifies the
+      ** rowid column. So if the conflict mode is REPLACE, then delete any
+      ** existing row with rowid=pNewRowid. 
+      **
+      ** Or, if the conflict mode is not REPLACE, insert the new record into 
+      ** the %_content table. If we hit the duplicate rowid constraint (or any
+      ** other error) while doing so, return immediately.
+      **
+      ** This branch may also run if pNewRowid contains a value that cannot
+      ** be losslessly converted to an integer. In this case, the eventual 
+      ** call to fts3InsertData() (either just below or further on in this
+      ** function) will return SQLITE_MISMATCH. If fts3DeleteByRowid is 
+      ** invoked, it will delete zero rows (since no row will have
+      ** docid=$pNewRowid if $pNewRowid is not an integer value).
+      */
+      if( sqlite3_vtab_on_conflict(p->db)==SQLITE_REPLACE ){
+        rc = fts3DeleteByRowid(p, pNewRowid, &nChng, aSzDel);
+      }else{
+        rc = fts3InsertData(p, apVal, pRowid);
+        bInsertDone = 1;
+      }
     }
   }
+  if( rc!=SQLITE_OK ){
+    goto update_out;
+  }
 
-  /* Assign a bit from the bitmask to every term in the FROM clause.
-  **
-  ** When assigning bitmask values to FROM clause cursors, it must be
-  ** the case that if X is the bitmask for the N-th FROM clause term then
-  ** the bitmask for all FROM clause terms to the left of the N-th term
-  ** is (X-1).   An expression from the ON clause of a LEFT JOIN can use
-  ** its Expr.iRightJoinTable value to find the bitmask of the right table
-  ** of the join.  Subtracting one from the right table bitmask gives a
-  ** bitmask for all tables to the left of the join.  Knowing the bitmask
-  ** for all tables to the left of a left join is important.  Ticket #3015.
-  **
-  ** Note that bitmasks are created for all pTabList->nSrc tables in
-  ** pTabList, not just the first nTabList tables.  nTabList is normally
-  ** equal to pTabList->nSrc but might be shortened to 1 if the
-  ** WHERE_ONETABLE_ONLY flag is set.
-  */
-  for(ii=0; iinSrc; ii++){
-    createMask(pMaskSet, pTabList->a[ii].iCursor);
+  /* If this is a DELETE or UPDATE operation, remove the old record. */
+  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
+    assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );
+    rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);
+    isRemove = 1;
   }
-#ifndef NDEBUG
-  {
-    Bitmask toTheLeft = 0;
-    for(ii=0; iinSrc; ii++){
-      Bitmask m = getMask(pMaskSet, pTabList->a[ii].iCursor);
-      assert( (m-1)==toTheLeft );
-      toTheLeft |= m;
+  
+  /* If this is an INSERT or UPDATE operation, insert the new record. */
+  if( nArg>1 && rc==SQLITE_OK ){
+    int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);
+    if( bInsertDone==0 ){
+      rc = fts3InsertData(p, apVal, pRowid);
+      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
+        rc = FTS_CORRUPT_VTAB;
+      }
+    }
+    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
+      rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);
+    }
+    if( rc==SQLITE_OK ){
+      assert( p->iPrevDocid==*pRowid );
+      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
+    }
+    if( p->bHasDocsize ){
+      fts3InsertDocsize(&rc, p, aSzIns);
     }
+    nChng++;
   }
-#endif
 
-  /* Analyze all of the subexpressions.  Note that exprAnalyze() might
-  ** add new virtual terms onto the end of the WHERE clause.  We do not
-  ** want to analyze these virtual terms, so start analyzing at the end
-  ** and work forward so that the added virtual terms are never processed.
-  */
-  exprAnalyzeAll(pTabList, &pWInfo->sWC);
-  if( db->mallocFailed ){
-    goto whereBeginError;
+  if( p->bFts4 ){
+    fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng);
   }
 
-  if( wctrlFlags & WHERE_WANT_DISTINCT ){
-    if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
-      /* The DISTINCT marking is pointless.  Ignore it. */
-      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
-    }else if( pOrderBy==0 ){
-      /* Try to ORDER BY the result set to make distinct processing easier */
-      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
-      pWInfo->pOrderBy = pResultSet;
-    }
-  }
+ update_out:
+  sqlite3_free(aSzDel);
+  sqlite3Fts3SegmentsClose(p);
+  return rc;
+}
 
-  /* Construct the WhereLoop objects */
-  WHERETRACE(0xffff,("*** Optimizer Start ***\n"));
-#if defined(WHERETRACE_ENABLED)
-  /* Display all terms of the WHERE clause */
-  if( sqlite3WhereTrace & 0x100 ){
-    int i;
-    for(i=0; inTerm; i++){
-      whereTermPrint(&sWLB.pWC->a[i], i);
+/* 
+** Flush any data in the pending-terms hash table to disk. If successful,
+** merge all segments in the database (including the new segment, if 
+** there was any data to flush) into a single segment. 
+*/
+SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *p){
+  int rc;
+  rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = fts3DoOptimize(p, 1);
+    if( rc==SQLITE_OK || rc==SQLITE_DONE ){
+      int rc2 = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
+      if( rc2!=SQLITE_OK ) rc = rc2;
+    }else{
+      sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0);
+      sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
     }
   }
-#endif
+  sqlite3Fts3SegmentsClose(p);
+  return rc;
+}
 
-  if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
-    rc = whereLoopAddAll(&sWLB);
-    if( rc ) goto whereBeginError;
-  
-    /* Display all of the WhereLoop objects if wheretrace is enabled */
-#ifdef WHERETRACE_ENABLED /* !=0 */
-    if( sqlite3WhereTrace ){
-      WhereLoop *p;
-      int i;
-      static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
-                                       "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
-      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
-        p->cId = zLabel[i%sizeof(zLabel)];
-        whereLoopPrint(p, sWLB.pWC);
-      }
-    }
 #endif
-  
-    wherePathSolver(pWInfo, 0);
-    if( db->mallocFailed ) goto whereBeginError;
-    if( pWInfo->pOrderBy ){
-       wherePathSolver(pWInfo, pWInfo->nRowOut+1);
-       if( db->mallocFailed ) goto whereBeginError;
-    }
+
+/************** End of fts3_write.c ******************************************/
+/************** Begin file fts3_snippet.c ************************************/
+/*
+** 2009 Oct 23
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
+/* #include  */
+
+/*
+** Characters that may appear in the second argument to matchinfo().
+*/
+#define FTS3_MATCHINFO_NPHRASE   'p'        /* 1 value */
+#define FTS3_MATCHINFO_NCOL      'c'        /* 1 value */
+#define FTS3_MATCHINFO_NDOC      'n'        /* 1 value */
+#define FTS3_MATCHINFO_AVGLENGTH 'a'        /* nCol values */
+#define FTS3_MATCHINFO_LENGTH    'l'        /* nCol values */
+#define FTS3_MATCHINFO_LCS       's'        /* nCol values */
+#define FTS3_MATCHINFO_HITS      'x'        /* 3*nCol*nPhrase values */
+#define FTS3_MATCHINFO_LHITS     'y'        /* nCol*nPhrase values */
+#define FTS3_MATCHINFO_LHITS_BM  'b'        /* nCol*nPhrase values */
+
+/*
+** The default value for the second argument to matchinfo(). 
+*/
+#define FTS3_MATCHINFO_DEFAULT   "pcx"
+
+
+/*
+** Used as an fts3ExprIterate() context when loading phrase doclists to
+** Fts3Expr.aDoclist[]/nDoclist.
+*/
+typedef struct LoadDoclistCtx LoadDoclistCtx;
+struct LoadDoclistCtx {
+  Fts3Cursor *pCsr;               /* FTS3 Cursor */
+  int nPhrase;                    /* Number of phrases seen so far */
+  int nToken;                     /* Number of tokens seen so far */
+};
+
+/*
+** The following types are used as part of the implementation of the 
+** fts3BestSnippet() routine.
+*/
+typedef struct SnippetIter SnippetIter;
+typedef struct SnippetPhrase SnippetPhrase;
+typedef struct SnippetFragment SnippetFragment;
+
+struct SnippetIter {
+  Fts3Cursor *pCsr;               /* Cursor snippet is being generated from */
+  int iCol;                       /* Extract snippet from this column */
+  int nSnippet;                   /* Requested snippet length (in tokens) */
+  int nPhrase;                    /* Number of phrases in query */
+  SnippetPhrase *aPhrase;         /* Array of size nPhrase */
+  int iCurrent;                   /* First token of current snippet */
+};
+
+struct SnippetPhrase {
+  int nToken;                     /* Number of tokens in phrase */
+  char *pList;                    /* Pointer to start of phrase position list */
+  int iHead;                      /* Next value in position list */
+  char *pHead;                    /* Position list data following iHead */
+  int iTail;                      /* Next value in trailing position list */
+  char *pTail;                    /* Position list data following iTail */
+};
+
+struct SnippetFragment {
+  int iCol;                       /* Column snippet is extracted from */
+  int iPos;                       /* Index of first token in snippet */
+  u64 covered;                    /* Mask of query phrases covered */
+  u64 hlmask;                     /* Mask of snippet terms to highlight */
+};
+
+/*
+** This type is used as an fts3ExprIterate() context object while 
+** accumulating the data returned by the matchinfo() function.
+*/
+typedef struct MatchInfo MatchInfo;
+struct MatchInfo {
+  Fts3Cursor *pCursor;            /* FTS3 Cursor */
+  int nCol;                       /* Number of columns in table */
+  int nPhrase;                    /* Number of matchable phrases in query */
+  sqlite3_int64 nDoc;             /* Number of docs in database */
+  char flag;
+  u32 *aMatchinfo;                /* Pre-allocated buffer */
+};
+
+/*
+** An instance of this structure is used to manage a pair of buffers, each
+** (nElem * sizeof(u32)) bytes in size. See the MatchinfoBuffer code below
+** for details.
+*/
+struct MatchinfoBuffer {
+  u8 aRef[3];
+  int nElem;
+  int bGlobal;                    /* Set if global data is loaded */
+  char *zMatchinfo;
+  u32 aMatchinfo[1];
+};
+
+
+/*
+** The snippet() and offsets() functions both return text values. An instance
+** of the following structure is used to accumulate those values while the
+** functions are running. See fts3StringAppend() for details.
+*/
+typedef struct StrBuffer StrBuffer;
+struct StrBuffer {
+  char *z;                        /* Pointer to buffer containing string */
+  int n;                          /* Length of z in bytes (excl. nul-term) */
+  int nAlloc;                     /* Allocated size of buffer z in bytes */
+};
+
+
+/*************************************************************************
+** Start of MatchinfoBuffer code.
+*/
+
+/*
+** Allocate a two-slot MatchinfoBuffer object.
+*/
+static MatchinfoBuffer *fts3MIBufferNew(int nElem, const char *zMatchinfo){
+  MatchinfoBuffer *pRet;
+  int nByte = sizeof(u32) * (2*nElem + 1) + sizeof(MatchinfoBuffer);
+  int nStr = (int)strlen(zMatchinfo);
+
+  pRet = sqlite3_malloc(nByte + nStr+1);
+  if( pRet ){
+    memset(pRet, 0, nByte);
+    pRet->aMatchinfo[0] = (u8*)(&pRet->aMatchinfo[1]) - (u8*)pRet;
+    pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0] + sizeof(u32)*(nElem+1);
+    pRet->nElem = nElem;
+    pRet->zMatchinfo = ((char*)pRet) + nByte;
+    memcpy(pRet->zMatchinfo, zMatchinfo, nStr+1);
+    pRet->aRef[0] = 1;
   }
-  if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
-     pWInfo->revMask = (Bitmask)(-1);
+
+  return pRet;
+}
+
+static void fts3MIBufferFree(void *p){
+  MatchinfoBuffer *pBuf = (MatchinfoBuffer*)((u8*)p - ((u32*)p)[-1]);
+
+  assert( (u32*)p==&pBuf->aMatchinfo[1] 
+       || (u32*)p==&pBuf->aMatchinfo[pBuf->nElem+2] 
+  );
+  if( (u32*)p==&pBuf->aMatchinfo[1] ){
+    pBuf->aRef[1] = 0;
+  }else{
+    pBuf->aRef[2] = 0;
   }
-  if( pParse->nErr || NEVER(db->mallocFailed) ){
-    goto whereBeginError;
+
+  if( pBuf->aRef[0]==0 && pBuf->aRef[1]==0 && pBuf->aRef[2]==0 ){
+    sqlite3_free(pBuf);
   }
-#ifdef WHERETRACE_ENABLED /* !=0 */
-  if( sqlite3WhereTrace ){
-    int ii;
-    sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
-    if( pWInfo->nOBSat>0 ){
-      sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);
-    }
-    switch( pWInfo->eDistinct ){
-      case WHERE_DISTINCT_UNIQUE: {
-        sqlite3DebugPrintf("  DISTINCT=unique");
-        break;
-      }
-      case WHERE_DISTINCT_ORDERED: {
-        sqlite3DebugPrintf("  DISTINCT=ordered");
-        break;
-      }
-      case WHERE_DISTINCT_UNORDERED: {
-        sqlite3DebugPrintf("  DISTINCT=unordered");
-        break;
-      }
-    }
-    sqlite3DebugPrintf("\n");
-    for(ii=0; iinLevel; ii++){
-      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
-    }
+}
+
+static void (*fts3MIBufferAlloc(MatchinfoBuffer *p, u32 **paOut))(void*){
+  void (*xRet)(void*) = 0;
+  u32 *aOut = 0;
+
+  if( p->aRef[1]==0 ){
+    p->aRef[1] = 1;
+    aOut = &p->aMatchinfo[1];
+    xRet = fts3MIBufferFree;
   }
-#endif
-  /* Attempt to omit tables from the join that do not effect the result */
-  if( pWInfo->nLevel>=2
-   && pResultSet!=0
-   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
-  ){
-    Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
-    if( sWLB.pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, sWLB.pOrderBy);
-    while( pWInfo->nLevel>=2 ){
-      WhereTerm *pTerm, *pEnd;
-      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
-      if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break;
-      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
-       && (pLoop->wsFlags & WHERE_ONEROW)==0
-      ){
-        break;
-      }
-      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
-      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
-      for(pTerm=sWLB.pWC->a; pTermprereqAll & pLoop->maskSelf)!=0
-         && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
-        ){
-          break;
-        }
-      }
-      if( pTerm drop loop %c not used\n", pLoop->cId));
-      pWInfo->nLevel--;
-      nTabList--;
+  else if( p->aRef[2]==0 ){
+    p->aRef[2] = 1;
+    aOut = &p->aMatchinfo[p->nElem+2];
+    xRet = fts3MIBufferFree;
+  }else{
+    aOut = (u32*)sqlite3_malloc(p->nElem * sizeof(u32));
+    if( aOut ){
+      xRet = sqlite3_free;
+      if( p->bGlobal ) memcpy(aOut, &p->aMatchinfo[1], p->nElem*sizeof(u32));
     }
   }
-  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
-  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
 
-  /* If the caller is an UPDATE or DELETE statement that is requesting
-  ** to use a one-pass algorithm, determine if this is appropriate.
-  ** The one-pass algorithm only works if the WHERE clause constrains
-  ** the statement to update a single row.
-  */
-  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
-  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
-   && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){
-    pWInfo->okOnePass = 1;
-    if( HasRowid(pTabList->a[0].pTab) ){
-      pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;
-    }
-  }
+  *paOut = aOut;
+  return xRet;
+}
 
-  /* Open all tables in the pTabList and any indices selected for
-  ** searching those tables.
-  */
-  notReady = ~(Bitmask)0;
-  for(ii=0, pLevel=pWInfo->a; iibGlobal = 1;
+  memcpy(&p->aMatchinfo[2+p->nElem], &p->aMatchinfo[1], p->nElem*sizeof(u32));
+}
 
-    pTabItem = &pTabList->a[pLevel->iFrom];
-    pTab = pTabItem->pTab;
-    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-    pLoop = pLevel->pWLoop;
-    if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
-      /* Do nothing */
-    }else
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
-      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
-      int iCur = pTabItem->iCursor;
-      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
-    }else if( IsVirtual(pTab) ){
-      /* noop */
-    }else
-#endif
-    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
-         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
-      int op = OP_OpenRead;
-      if( pWInfo->okOnePass ){
-        op = OP_OpenWrite;
-        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
-      };
-      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
-      assert( pTabItem->iCursor==pLevel->iTabCur );
-      testcase( !pWInfo->okOnePass && pTab->nCol==BMS-1 );
-      testcase( !pWInfo->okOnePass && pTab->nCol==BMS );
-      if( !pWInfo->okOnePass && pTab->nColcolUsed;
-        int n = 0;
-        for(; b; b=b>>1, n++){}
-        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
-                            SQLITE_INT_TO_PTR(n), P4_INT32);
-        assert( n<=pTab->nCol );
-      }
-    }else{
-      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
-    }
-    if( pLoop->wsFlags & WHERE_INDEXED ){
-      Index *pIx = pLoop->u.btree.pIndex;
-      int iIndexCur;
-      int op = OP_OpenRead;
-      /* iIdxCur is always set if to a positive value if ONEPASS is possible */
-      assert( iIdxCur!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );
-      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
-       && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0
-      ){
-        /* This is one term of an OR-optimization using the PRIMARY KEY of a
-        ** WITHOUT ROWID table.  No need for a separate index */
-        iIndexCur = pLevel->iTabCur;
-        op = 0;
-      }else if( pWInfo->okOnePass ){
-        Index *pJ = pTabItem->pTab->pIndex;
-        iIndexCur = iIdxCur;
-        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
-        while( ALWAYS(pJ) && pJ!=pIx ){
-          iIndexCur++;
-          pJ = pJ->pNext;
-        }
-        op = OP_OpenWrite;
-        pWInfo->aiCurOnePass[1] = iIndexCur;
-      }else if( iIdxCur && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0 ){
-        iIndexCur = iIdxCur;
-        if( wctrlFlags & WHERE_REOPEN_IDX ) op = OP_ReopenIdx;
-      }else{
-        iIndexCur = pParse->nTab++;
-      }
-      pLevel->iIdxCur = iIndexCur;
-      assert( pIx->pSchema==pTab->pSchema );
-      assert( iIndexCur>=0 );
-      if( op ){
-        sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb);
-        sqlite3VdbeSetP4KeyInfo(pParse, pIx);
-        VdbeComment((v, "%s", pIx->zName));
-      }
+/*
+** Free a MatchinfoBuffer object allocated using fts3MIBufferNew()
+*/
+SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p){
+  if( p ){
+    assert( p->aRef[0]==1 );
+    p->aRef[0] = 0;
+    if( p->aRef[0]==0 && p->aRef[1]==0 && p->aRef[2]==0 ){
+      sqlite3_free(p);
     }
-    if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);
-    notReady &= ~getMask(&pWInfo->sMaskSet, pTabItem->iCursor);
   }
-  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
-  if( db->mallocFailed ) goto whereBeginError;
+}
 
-  /* Generate the code to do the search.  Each iteration of the for
-  ** loop below generates code for a single nested loop of the VM
-  ** program.
-  */
-  notReady = ~(Bitmask)0;
-  for(ii=0; iia[ii];
-    wsFlags = pLevel->pWLoop->wsFlags;
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
-      constructAutomaticIndex(pParse, &pWInfo->sWC,
-                &pTabList->a[pLevel->iFrom], notReady, pLevel);
-      if( db->mallocFailed ) goto whereBeginError;
-    }
-#endif
-    addrExplain = explainOneScan(
-        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
-    );
-    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
-    notReady = codeOneLoopStart(pWInfo, ii, notReady);
-    pWInfo->iContinue = pLevel->addrCont;
-    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_ONETABLE_ONLY)==0 ){
-      addScanStatus(v, pTabList, pLevel, addrExplain);
+/* 
+** End of MatchinfoBuffer code.
+*************************************************************************/
+
+
+/*
+** This function is used to help iterate through a position-list. A position
+** list is a list of unique integers, sorted from smallest to largest. Each
+** element of the list is represented by an FTS3 varint that takes the value
+** of the difference between the current element and the previous one plus
+** two. For example, to store the position-list:
+**
+**     4 9 113
+**
+** the three varints:
+**
+**     6 7 106
+**
+** are encoded.
+**
+** When this function is called, *pp points to the start of an element of
+** the list. *piPos contains the value of the previous entry in the list.
+** After it returns, *piPos contains the value of the next element of the
+** list and *pp is advanced to the following varint.
+*/
+static void fts3GetDeltaPosition(char **pp, int *piPos){
+  int iVal;
+  *pp += fts3GetVarint32(*pp, &iVal);
+  *piPos += (iVal-2);
+}
+
+/*
+** Helper function for fts3ExprIterate() (see below).
+*/
+static int fts3ExprIterate2(
+  Fts3Expr *pExpr,                /* Expression to iterate phrases of */
+  int *piPhrase,                  /* Pointer to phrase counter */
+  int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */
+  void *pCtx                      /* Second argument to pass to callback */
+){
+  int rc;                         /* Return code */
+  int eType = pExpr->eType;     /* Type of expression node pExpr */
+
+  if( eType!=FTSQUERY_PHRASE ){
+    assert( pExpr->pLeft && pExpr->pRight );
+    rc = fts3ExprIterate2(pExpr->pLeft, piPhrase, x, pCtx);
+    if( rc==SQLITE_OK && eType!=FTSQUERY_NOT ){
+      rc = fts3ExprIterate2(pExpr->pRight, piPhrase, x, pCtx);
     }
+  }else{
+    rc = x(pExpr, *piPhrase, pCtx);
+    (*piPhrase)++;
   }
+  return rc;
+}
 
-  /* Done. */
-  VdbeModuleComment((v, "Begin WHERE-core"));
-  return pWInfo;
+/*
+** Iterate through all phrase nodes in an FTS3 query, except those that
+** are part of a sub-tree that is the right-hand-side of a NOT operator.
+** For each phrase node found, the supplied callback function is invoked.
+**
+** If the callback function returns anything other than SQLITE_OK, 
+** the iteration is abandoned and the error code returned immediately.
+** Otherwise, SQLITE_OK is returned after a callback has been made for
+** all eligible phrase nodes.
+*/
+static int fts3ExprIterate(
+  Fts3Expr *pExpr,                /* Expression to iterate phrases of */
+  int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */
+  void *pCtx                      /* Second argument to pass to callback */
+){
+  int iPhrase = 0;                /* Variable used as the phrase counter */
+  return fts3ExprIterate2(pExpr, &iPhrase, x, pCtx);
+}
 
-  /* Jump here if malloc fails */
-whereBeginError:
-  if( pWInfo ){
-    pParse->nQueryLoop = pWInfo->savedNQueryLoop;
-    whereInfoFree(db, pWInfo);
+
+/*
+** This is an fts3ExprIterate() callback used while loading the doclists
+** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also
+** fts3ExprLoadDoclists().
+*/
+static int fts3ExprLoadDoclistsCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
+  int rc = SQLITE_OK;
+  Fts3Phrase *pPhrase = pExpr->pPhrase;
+  LoadDoclistCtx *p = (LoadDoclistCtx *)ctx;
+
+  UNUSED_PARAMETER(iPhrase);
+
+  p->nPhrase++;
+  p->nToken += pPhrase->nToken;
+
+  return rc;
+}
+
+/*
+** Load the doclists for each phrase in the query associated with FTS3 cursor
+** pCsr. 
+**
+** If pnPhrase is not NULL, then *pnPhrase is set to the number of matchable 
+** phrases in the expression (all phrases except those directly or 
+** indirectly descended from the right-hand-side of a NOT operator). If 
+** pnToken is not NULL, then it is set to the number of tokens in all
+** matchable phrases of the expression.
+*/
+static int fts3ExprLoadDoclists(
+  Fts3Cursor *pCsr,               /* Fts3 cursor for current query */
+  int *pnPhrase,                  /* OUT: Number of phrases in query */
+  int *pnToken                    /* OUT: Number of tokens in query */
+){
+  int rc;                         /* Return Code */
+  LoadDoclistCtx sCtx = {0,0,0};  /* Context for fts3ExprIterate() */
+  sCtx.pCsr = pCsr;
+  rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb, (void *)&sCtx);
+  if( pnPhrase ) *pnPhrase = sCtx.nPhrase;
+  if( pnToken ) *pnToken = sCtx.nToken;
+  return rc;
+}
+
+static int fts3ExprPhraseCountCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
+  (*(int *)ctx)++;
+  pExpr->iPhrase = iPhrase;
+  return SQLITE_OK;
+}
+static int fts3ExprPhraseCount(Fts3Expr *pExpr){
+  int nPhrase = 0;
+  (void)fts3ExprIterate(pExpr, fts3ExprPhraseCountCb, (void *)&nPhrase);
+  return nPhrase;
+}
+
+/*
+** Advance the position list iterator specified by the first two 
+** arguments so that it points to the first element with a value greater
+** than or equal to parameter iNext.
+*/
+static void fts3SnippetAdvance(char **ppIter, int *piIter, int iNext){
+  char *pIter = *ppIter;
+  if( pIter ){
+    int iIter = *piIter;
+
+    while( iIterpParse;
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  WhereLevel *pLevel;
-  WhereLoop *pLoop;
-  SrcList *pTabList = pWInfo->pTabList;
-  sqlite3 *db = pParse->db;
+static int fts3SnippetNextCandidate(SnippetIter *pIter){
+  int i;                          /* Loop counter */
 
-  /* Generate loop termination code.
-  */
-  VdbeModuleComment((v, "End WHERE-core"));
-  sqlite3ExprCacheClear(pParse);
-  for(i=pWInfo->nLevel-1; i>=0; i--){
-    int addr;
-    pLevel = &pWInfo->a[i];
-    pLoop = pLevel->pWLoop;
-    sqlite3VdbeResolveLabel(v, pLevel->addrCont);
-    if( pLevel->op!=OP_Noop ){
-      sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);
-      sqlite3VdbeChangeP5(v, pLevel->p5);
-      VdbeCoverage(v);
-      VdbeCoverageIf(v, pLevel->op==OP_Next);
-      VdbeCoverageIf(v, pLevel->op==OP_Prev);
-      VdbeCoverageIf(v, pLevel->op==OP_VNext);
+  if( pIter->iCurrent<0 ){
+    /* The SnippetIter object has just been initialized. The first snippet
+    ** candidate always starts at offset 0 (even if this candidate has a
+    ** score of 0.0).
+    */
+    pIter->iCurrent = 0;
+
+    /* Advance the 'head' iterator of each phrase to the first offset that
+    ** is greater than or equal to (iNext+nSnippet).
+    */
+    for(i=0; inPhrase; i++){
+      SnippetPhrase *pPhrase = &pIter->aPhrase[i];
+      fts3SnippetAdvance(&pPhrase->pHead, &pPhrase->iHead, pIter->nSnippet);
     }
-    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
-      struct InLoop *pIn;
-      int j;
-      sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
-      for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
-        sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
-        sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
-        VdbeCoverage(v);
-        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
-        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
-        sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
+  }else{
+    int iStart;
+    int iEnd = 0x7FFFFFFF;
+
+    for(i=0; inPhrase; i++){
+      SnippetPhrase *pPhrase = &pIter->aPhrase[i];
+      if( pPhrase->pHead && pPhrase->iHeadiHead;
       }
-      sqlite3DbFree(db, pLevel->u.in.aInLoop);
     }
-    sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
-    if( pLevel->addrSkip ){
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrSkip);
-      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
-      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
-      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
+    if( iEnd==0x7FFFFFFF ){
+      return 1;
     }
-    if( pLevel->iLeftJoin ){
-      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
-      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
-           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
-      if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
-        sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
-      }
-      if( pLoop->wsFlags & WHERE_INDEXED ){
-        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
-      }
-      if( pLevel->op==OP_Return ){
-        sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
-      }else{
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrFirst);
-      }
-      sqlite3VdbeJumpHere(v, addr);
+
+    pIter->iCurrent = iStart = iEnd - pIter->nSnippet + 1;
+    for(i=0; inPhrase; i++){
+      SnippetPhrase *pPhrase = &pIter->aPhrase[i];
+      fts3SnippetAdvance(&pPhrase->pHead, &pPhrase->iHead, iEnd+1);
+      fts3SnippetAdvance(&pPhrase->pTail, &pPhrase->iTail, iStart);
     }
-    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
-                     pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));
   }
 
-  /* The "break" point is here, just past the end of the outer loop.
-  ** Set it.
-  */
-  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);
+  return 0;
+}
 
-  assert( pWInfo->nLevel<=pTabList->nSrc );
-  for(i=0, pLevel=pWInfo->a; inLevel; i++, pLevel++){
-    int k, last;
-    VdbeOp *pOp;
-    Index *pIdx = 0;
-    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
-    Table *pTab = pTabItem->pTab;
-    assert( pTab!=0 );
-    pLoop = pLevel->pWLoop;
+/*
+** Retrieve information about the current candidate snippet of snippet 
+** iterator pIter.
+*/
+static void fts3SnippetDetails(
+  SnippetIter *pIter,             /* Snippet iterator */
+  u64 mCovered,                   /* Bitmask of phrases already covered */
+  int *piToken,                   /* OUT: First token of proposed snippet */
+  int *piScore,                   /* OUT: "Score" for this snippet */
+  u64 *pmCover,                   /* OUT: Bitmask of phrases covered */
+  u64 *pmHighlight                /* OUT: Bitmask of terms to highlight */
+){
+  int iStart = pIter->iCurrent;   /* First token of snippet */
+  int iScore = 0;                 /* Score of this snippet */
+  int i;                          /* Loop counter */
+  u64 mCover = 0;                 /* Mask of phrases covered by this snippet */
+  u64 mHighlight = 0;             /* Mask of tokens to highlight in snippet */
 
-    /* For a co-routine, change all OP_Column references to the table of
-    ** the co-routine into OP_SCopy of result contained in a register.
-    ** OP_Rowid becomes OP_Null.
-    */
-    if( pTabItem->viaCoroutine && !db->mallocFailed ){
-      last = sqlite3VdbeCurrentAddr(v);
-      k = pLevel->addrBody;
-      pOp = sqlite3VdbeGetOp(v, k);
-      for(; kp1!=pLevel->iTabCur ) continue;
-        if( pOp->opcode==OP_Column ){
-          pOp->opcode = OP_Copy;
-          pOp->p1 = pOp->p2 + pTabItem->regResult;
-          pOp->p2 = pOp->p3;
-          pOp->p3 = 0;
-        }else if( pOp->opcode==OP_Rowid ){
-          pOp->opcode = OP_Null;
-          pOp->p1 = 0;
-          pOp->p3 = 0;
-        }
-      }
-      continue;
-    }
+  for(i=0; inPhrase; i++){
+    SnippetPhrase *pPhrase = &pIter->aPhrase[i];
+    if( pPhrase->pTail ){
+      char *pCsr = pPhrase->pTail;
+      int iCsr = pPhrase->iTail;
 
-    /* Close all of the cursors that were opened by sqlite3WhereBegin.
-    ** Except, do not close cursors that will be reused by the OR optimization
-    ** (WHERE_OMIT_OPEN_CLOSE).  And do not close the OP_OpenWrite cursors
-    ** created for the ONEPASS optimization.
-    */
-    if( (pTab->tabFlags & TF_Ephemeral)==0
-     && pTab->pSelect==0
-     && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
-    ){
-      int ws = pLoop->wsFlags;
-      if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
-        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
-      }
-      if( (ws & WHERE_INDEXED)!=0
-       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
-       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
-      ){
-        sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
-      }
-    }
+      while( iCsr<(iStart+pIter->nSnippet) ){
+        int j;
+        u64 mPhrase = (u64)1 << i;
+        u64 mPos = (u64)1 << (iCsr - iStart);
+        assert( iCsr>=iStart );
+        if( (mCover|mCovered)&mPhrase ){
+          iScore++;
+        }else{
+          iScore += 1000;
+        }
+        mCover |= mPhrase;
 
-    /* If this scan uses an index, make VDBE code substitutions to read data
-    ** from the index instead of from the table where possible.  In some cases
-    ** this optimization prevents the table from ever being read, which can
-    ** yield a significant performance boost.
-    ** 
-    ** Calls to the code generator in between sqlite3WhereBegin and
-    ** sqlite3WhereEnd will have created code that references the table
-    ** directly.  This loop scans all that code looking for opcodes
-    ** that reference the table and converts them into opcodes that
-    ** reference the index.
-    */
-    if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
-      pIdx = pLoop->u.btree.pIndex;
-    }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
-      pIdx = pLevel->u.pCovidx;
-    }
-    if( pIdx && !db->mallocFailed ){
-      last = sqlite3VdbeCurrentAddr(v);
-      k = pLevel->addrBody;
-      pOp = sqlite3VdbeGetOp(v, k);
-      for(; kp1!=pLevel->iTabCur ) continue;
-        if( pOp->opcode==OP_Column ){
-          int x = pOp->p2;
-          assert( pIdx->pTable==pTab );
-          if( !HasRowid(pTab) ){
-            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-            x = pPk->aiColumn[x];
-          }
-          x = sqlite3ColumnOfIndex(pIdx, x);
-          if( x>=0 ){
-            pOp->p2 = x;
-            pOp->p1 = pLevel->iIdxCur;
-          }
-          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 );
-        }else if( pOp->opcode==OP_Rowid ){
-          pOp->p1 = pLevel->iIdxCur;
-          pOp->opcode = OP_IdxRowid;
+        for(j=0; jnToken; j++){
+          mHighlight |= (mPos>>j);
         }
+
+        if( 0==(*pCsr & 0x0FE) ) break;
+        fts3GetDeltaPosition(&pCsr, &iCsr);
       }
     }
   }
 
-  /* Final cleanup
-  */
-  pParse->nQueryLoop = pWInfo->savedNQueryLoop;
-  whereInfoFree(db, pWInfo);
-  return;
+  /* Set the output variables before returning. */
+  *piToken = iStart;
+  *piScore = iScore;
+  *pmCover = mCover;
+  *pmHighlight = mHighlight;
 }
 
-/************** End of where.c ***********************************************/
-/************** Begin file parse.c *******************************************/
-/* Driver template for the LEMON parser generator.
-** The author disclaims copyright to this source code.
-**
-** This version of "lempar.c" is modified, slightly, for use by SQLite.
-** The only modifications are the addition of a couple of NEVER()
-** macros to disable tests that are needed in the case of a general
-** LALR(1) grammar but which are always false in the
-** specific grammar used by SQLite.
-*/
-/* First off, code is included that follows the "include" declaration
-** in the input grammar file. */
-/* #include  */
-
-
-/*
-** Disable all error recovery processing in the parser push-down
-** automaton.
-*/
-#define YYNOERRORRECOVERY 1
-
 /*
-** Make yytestcase() the same as testcase()
+** This function is an fts3ExprIterate() callback used by fts3BestSnippet().
+** Each invocation populates an element of the SnippetIter.aPhrase[] array.
 */
-#define yytestcase(X) testcase(X)
+static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){
+  SnippetIter *p = (SnippetIter *)ctx;
+  SnippetPhrase *pPhrase = &p->aPhrase[iPhrase];
+  char *pCsr;
+  int rc;
 
-/*
-** An instance of this structure holds information about the
-** LIMIT clause of a SELECT statement.
-*/
-struct LimitVal {
-  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
-  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
-};
+  pPhrase->nToken = pExpr->pPhrase->nToken;
+  rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pCsr);
+  assert( rc==SQLITE_OK || pCsr==0 );
+  if( pCsr ){
+    int iFirst = 0;
+    pPhrase->pList = pCsr;
+    fts3GetDeltaPosition(&pCsr, &iFirst);
+    assert( iFirst>=0 );
+    pPhrase->pHead = pCsr;
+    pPhrase->pTail = pCsr;
+    pPhrase->iHead = iFirst;
+    pPhrase->iTail = iFirst;
+  }else{
+    assert( rc!=SQLITE_OK || (
+       pPhrase->pList==0 && pPhrase->pHead==0 && pPhrase->pTail==0 
+    ));
+  }
 
-/*
-** An instance of this structure is used to store the LIKE,
-** GLOB, NOT LIKE, and NOT GLOB operators.
-*/
-struct LikeOp {
-  Token eOperator;  /* "like" or "glob" or "regexp" */
-  int bNot;         /* True if the NOT keyword is present */
-};
+  return rc;
+}
 
 /*
-** An instance of the following structure describes the event of a
-** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
-** TK_DELETE, or TK_INSTEAD.  If the event is of the form
+** Select the fragment of text consisting of nFragment contiguous tokens 
+** from column iCol that represent the "best" snippet. The best snippet
+** is the snippet with the highest score, where scores are calculated
+** by adding:
 **
-**      UPDATE ON (a,b,c)
+**   (a) +1 point for each occurrence of a matchable phrase in the snippet.
 **
-** Then the "b" IdList records the list "a,b,c".
-*/
-struct TrigEvent { int a; IdList * b; };
-
-/*
-** An instance of this structure holds the ATTACH key and the key type.
+**   (b) +1000 points for the first occurrence of each matchable phrase in 
+**       the snippet for which the corresponding mCovered bit is not set.
+**
+** The selected snippet parameters are stored in structure *pFragment before
+** returning. The score of the selected snippet is stored in *piScore
+** before returning.
 */
-struct AttachKey { int type;  Token key; };
+static int fts3BestSnippet(
+  int nSnippet,                   /* Desired snippet length */
+  Fts3Cursor *pCsr,               /* Cursor to create snippet for */
+  int iCol,                       /* Index of column to create snippet from */
+  u64 mCovered,                   /* Mask of phrases already covered */
+  u64 *pmSeen,                    /* IN/OUT: Mask of phrases seen */
+  SnippetFragment *pFragment,     /* OUT: Best snippet found */
+  int *piScore                    /* OUT: Score of snippet pFragment */
+){
+  int rc;                         /* Return Code */
+  int nList;                      /* Number of phrases in expression */
+  SnippetIter sIter;              /* Iterates through snippet candidates */
+  int nByte;                      /* Number of bytes of space to allocate */
+  int iBestScore = -1;            /* Best snippet score found so far */
+  int i;                          /* Loop counter */
 
+  memset(&sIter, 0, sizeof(sIter));
 
-  /* This is a utility routine used to set the ExprSpan.zStart and
-  ** ExprSpan.zEnd values of pOut so that the span covers the complete
-  ** range of text beginning with pStart and going to the end of pEnd.
+  /* Iterate through the phrases in the expression to count them. The same
+  ** callback makes sure the doclists are loaded for each phrase.
   */
-  static void spanSet(ExprSpan *pOut, Token *pStart, Token *pEnd){
-    pOut->zStart = pStart->z;
-    pOut->zEnd = &pEnd->z[pEnd->n];
+  rc = fts3ExprLoadDoclists(pCsr, &nList, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
   }
 
-  /* Construct a new Expr object from a single identifier.  Use the
-  ** new Expr to populate pOut.  Set the span of pOut to be the identifier
-  ** that created the expression.
+  /* Now that it is known how many phrases there are, allocate and zero
+  ** the required space using malloc().
   */
-  static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token *pValue){
-    pOut->pExpr = sqlite3PExpr(pParse, op, 0, 0, pValue);
-    pOut->zStart = pValue->z;
-    pOut->zEnd = &pValue->z[pValue->n];
+  nByte = sizeof(SnippetPhrase) * nList;
+  sIter.aPhrase = (SnippetPhrase *)sqlite3_malloc(nByte);
+  if( !sIter.aPhrase ){
+    return SQLITE_NOMEM;
   }
+  memset(sIter.aPhrase, 0, nByte);
 
-  /* This routine constructs a binary expression node out of two ExprSpan
-  ** objects and uses the result to populate a new ExprSpan object.
+  /* Initialize the contents of the SnippetIter object. Then iterate through
+  ** the set of phrases in the expression to populate the aPhrase[] array.
   */
-  static void spanBinaryExpr(
-    ExprSpan *pOut,     /* Write the result here */
-    Parse *pParse,      /* The parsing context.  Errors accumulate here */
-    int op,             /* The binary operation */
-    ExprSpan *pLeft,    /* The left operand */
-    ExprSpan *pRight    /* The right operand */
-  ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pLeft->pExpr, pRight->pExpr, 0);
-    pOut->zStart = pLeft->zStart;
-    pOut->zEnd = pRight->zEnd;
-  }
+  sIter.pCsr = pCsr;
+  sIter.iCol = iCol;
+  sIter.nSnippet = nSnippet;
+  sIter.nPhrase = nList;
+  sIter.iCurrent = -1;
+  rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void*)&sIter);
+  if( rc==SQLITE_OK ){
 
-  /* Construct an expression node for a unary postfix operator
-  */
-  static void spanUnaryPostfix(
-    ExprSpan *pOut,        /* Write the new expression node here */
-    Parse *pParse,         /* Parsing context to record errors */
-    int op,                /* The operator */
-    ExprSpan *pOperand,    /* The operand */
-    Token *pPostOp         /* The operand token for setting the span */
-  ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
-    pOut->zStart = pOperand->zStart;
-    pOut->zEnd = &pPostOp->z[pPostOp->n];
-  }                           
+    /* Set the *pmSeen output variable. */
+    for(i=0; idb;
-    if( pY && pA && pY->op==TK_NULL ){
-      pA->op = (u8)op;
-      sqlite3ExprDelete(db, pA->pRight);
-      pA->pRight = 0;
+    /* Loop through all candidate snippets. Store the best snippet in 
+     ** *pFragment. Store its associated 'score' in iBestScore.
+     */
+    pFragment->iCol = iCol;
+    while( !fts3SnippetNextCandidate(&sIter) ){
+      int iPos;
+      int iScore;
+      u64 mCover;
+      u64 mHighlite;
+      fts3SnippetDetails(&sIter, mCovered, &iPos, &iScore, &mCover,&mHighlite);
+      assert( iScore>=0 );
+      if( iScore>iBestScore ){
+        pFragment->iPos = iPos;
+        pFragment->hlmask = mHighlite;
+        pFragment->covered = mCover;
+        iBestScore = iScore;
+      }
     }
-  }
 
-  /* Construct an expression node for a unary prefix operator
-  */
-  static void spanUnaryPrefix(
-    ExprSpan *pOut,        /* Write the new expression node here */
-    Parse *pParse,         /* Parsing context to record errors */
-    int op,                /* The operator */
-    ExprSpan *pOperand,    /* The operand */
-    Token *pPreOp         /* The operand token for setting the span */
-  ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
-    pOut->zStart = pPreOp->z;
-    pOut->zEnd = pOperand->zEnd;
+    *piScore = iBestScore;
   }
-/* Next is all token values, in a form suitable for use by makeheaders.
-** This section will be null unless lemon is run with the -m switch.
-*/
-/* 
-** These constants (all generated automatically by the parser generator)
-** specify the various kinds of tokens (terminals) that the parser
-** understands. 
-**
-** Each symbol here is a terminal symbol in the grammar.
-*/
-/* Make sure the INTERFACE macro is defined.
-*/
-#ifndef INTERFACE
-# define INTERFACE 1
-#endif
-/* The next thing included is series of defines which control
-** various aspects of the generated parser.
-**    YYCODETYPE         is the data type used for storing terminal
-**                       and nonterminal numbers.  "unsigned char" is
-**                       used if there are fewer than 250 terminals
-**                       and nonterminals.  "int" is used otherwise.
-**    YYNOCODE           is a number of type YYCODETYPE which corresponds
-**                       to no legal terminal or nonterminal number.  This
-**                       number is used to fill in empty slots of the hash 
-**                       table.
-**    YYFALLBACK         If defined, this indicates that one or more tokens
-**                       have fall-back values which should be used if the
-**                       original value of the token will not parse.
-**    YYACTIONTYPE       is the data type used for storing terminal
-**                       and nonterminal numbers.  "unsigned char" is
-**                       used if there are fewer than 250 rules and
-**                       states combined.  "int" is used otherwise.
-**    sqlite3ParserTOKENTYPE     is the data type used for minor tokens given 
-**                       directly to the parser from the tokenizer.
-**    YYMINORTYPE        is the data type used for all minor tokens.
-**                       This is typically a union of many types, one of
-**                       which is sqlite3ParserTOKENTYPE.  The entry in the union
-**                       for base tokens is called "yy0".
-**    YYSTACKDEPTH       is the maximum depth of the parser's stack.  If
-**                       zero the stack is dynamically sized using realloc()
-**    sqlite3ParserARG_SDECL     A static variable declaration for the %extra_argument
-**    sqlite3ParserARG_PDECL     A parameter declaration for the %extra_argument
-**    sqlite3ParserARG_STORE     Code to store %extra_argument into yypParser
-**    sqlite3ParserARG_FETCH     Code to extract %extra_argument from yypParser
-**    YYNSTATE           the combined number of states.
-**    YYNRULE            the number of rules in the grammar
-**    YYERRORSYMBOL      is the code number of the error symbol.  If not
-**                       defined, then do no error processing.
-*/
-#define YYCODETYPE unsigned char
-#define YYNOCODE 254
-#define YYACTIONTYPE unsigned short int
-#define YYWILDCARD 70
-#define sqlite3ParserTOKENTYPE Token
-typedef union {
-  int yyinit;
-  sqlite3ParserTOKENTYPE yy0;
-  Select* yy3;
-  ExprList* yy14;
-  With* yy59;
-  SrcList* yy65;
-  struct LikeOp yy96;
-  Expr* yy132;
-  u8 yy186;
-  int yy328;
-  ExprSpan yy346;
-  struct TrigEvent yy378;
-  u16 yy381;
-  IdList* yy408;
-  struct {int value; int mask;} yy429;
-  TriggerStep* yy473;
-  struct LimitVal yy476;
-} YYMINORTYPE;
-#ifndef YYSTACKDEPTH
-#define YYSTACKDEPTH 100
-#endif
-#define sqlite3ParserARG_SDECL Parse *pParse;
-#define sqlite3ParserARG_PDECL ,Parse *pParse
-#define sqlite3ParserARG_FETCH Parse *pParse = yypParser->pParse
-#define sqlite3ParserARG_STORE yypParser->pParse = pParse
-#define YYNSTATE 642
-#define YYNRULE 327
-#define YYFALLBACK 1
-#define YY_NO_ACTION      (YYNSTATE+YYNRULE+2)
-#define YY_ACCEPT_ACTION  (YYNSTATE+YYNRULE+1)
-#define YY_ERROR_ACTION   (YYNSTATE+YYNRULE)
+  sqlite3_free(sIter.aPhrase);
+  return rc;
+}
 
-/* The yyzerominor constant is used to initialize instances of
-** YYMINORTYPE objects to zero. */
-static const YYMINORTYPE yyzerominor = { 0 };
 
-/* Define the yytestcase() macro to be a no-op if is not already defined
-** otherwise.
+/*
+** Append a string to the string-buffer passed as the first argument.
 **
-** Applications can choose to define yytestcase() in the %include section
-** to a macro that can assist in verifying code coverage.  For production
-** code the yytestcase() macro should be turned off.  But it is useful
-** for testing.
+** If nAppend is negative, then the length of the string zAppend is
+** determined using strlen().
 */
-#ifndef yytestcase
-# define yytestcase(X)
-#endif
+static int fts3StringAppend(
+  StrBuffer *pStr,                /* Buffer to append to */
+  const char *zAppend,            /* Pointer to data to append to buffer */
+  int nAppend                     /* Size of zAppend in bytes (or -1) */
+){
+  if( nAppend<0 ){
+    nAppend = (int)strlen(zAppend);
+  }
 
+  /* If there is insufficient space allocated at StrBuffer.z, use realloc()
+  ** to grow the buffer until so that it is big enough to accomadate the
+  ** appended data.
+  */
+  if( pStr->n+nAppend+1>=pStr->nAlloc ){
+    int nAlloc = pStr->nAlloc+nAppend+100;
+    char *zNew = sqlite3_realloc(pStr->z, nAlloc);
+    if( !zNew ){
+      return SQLITE_NOMEM;
+    }
+    pStr->z = zNew;
+    pStr->nAlloc = nAlloc;
+  }
+  assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );
 
-/* Next are the tables used to determine what action to take based on the
-** current state and lookahead token.  These tables are used to implement
-** functions that take a state number and lookahead value and return an
-** action integer.  
-**
-** Suppose the action integer is N.  Then the action is determined as
-** follows
-**
-**   0 <= N < YYNSTATE                  Shift N.  That is, push the lookahead
-**                                      token onto the stack and goto state N.
-**
-**   YYNSTATE <= N < YYNSTATE+YYNRULE   Reduce by rule N-YYNSTATE.
-**
-**   N == YYNSTATE+YYNRULE              A syntax error has occurred.
-**
-**   N == YYNSTATE+YYNRULE+1            The parser accepts its input.
-**
-**   N == YYNSTATE+YYNRULE+2            No such action.  Denotes unused
-**                                      slots in the yy_action[] table.
-**
-** The action table is constructed as a single large table named yy_action[].
-** Given state S and lookahead X, the action is computed as
-**
-**      yy_action[ yy_shift_ofst[S] + X ]
+  /* Append the data to the string buffer. */
+  memcpy(&pStr->z[pStr->n], zAppend, nAppend);
+  pStr->n += nAppend;
+  pStr->z[pStr->n] = '\0';
+
+  return SQLITE_OK;
+}
+
+/*
+** The fts3BestSnippet() function often selects snippets that end with a
+** query term. That is, the final term of the snippet is always a term
+** that requires highlighting. For example, if 'X' is a highlighted term
+** and '.' is a non-highlighted term, BestSnippet() may select:
 **
-** If the index value yy_shift_ofst[S]+X is out of range or if the value
-** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X or if yy_shift_ofst[S]
-** is equal to YY_SHIFT_USE_DFLT, it means that the action is not in the table
-** and that yy_default[S] should be used instead.  
+**     ........X.....X
 **
-** The formula above is for computing the action when the lookahead is
-** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
-** a reduce action) then the yy_reduce_ofst[] array is used in place of
-** the yy_shift_ofst[] array and YY_REDUCE_USE_DFLT is used in place of
-** YY_SHIFT_USE_DFLT.
+** This function "shifts" the beginning of the snippet forward in the 
+** document so that there are approximately the same number of 
+** non-highlighted terms to the right of the final highlighted term as there
+** are to the left of the first highlighted term. For example, to this:
 **
-** The following are the tables generated in this section:
+**     ....X.....X....
 **
-**  yy_action[]        A single table containing all actions.
-**  yy_lookahead[]     A table containing the lookahead for each entry in
-**                     yy_action.  Used to detect hash collisions.
-**  yy_shift_ofst[]    For each state, the offset into yy_action for
-**                     shifting terminals.
-**  yy_reduce_ofst[]   For each state, the offset into yy_action for
-**                     shifting non-terminals after a reduce.
-**  yy_default[]       Default action for each state.
+** This is done as part of extracting the snippet text, not when selecting
+** the snippet. Snippet selection is done based on doclists only, so there
+** is no way for fts3BestSnippet() to know whether or not the document 
+** actually contains terms that follow the final highlighted term. 
 */
-#define YY_ACTTAB_COUNT (1497)
-static const YYACTIONTYPE yy_action[] = {
- /*     0 */   306,  212,  432,  955,  639,  191,  955,  295,  559,   88,
- /*    10 */    88,   88,   88,   81,   86,   86,   86,   86,   85,   85,
- /*    20 */    84,   84,   84,   83,  330,  185,  184,  183,  635,  635,
- /*    30 */   292,  606,  606,   88,   88,   88,   88,  683,   86,   86,
- /*    40 */    86,   86,   85,   85,   84,   84,   84,   83,  330,   16,
- /*    50 */   436,  597,   89,   90,   80,  600,  599,  601,  601,   87,
- /*    60 */    87,   88,   88,   88,   88,  684,   86,   86,   86,   86,
- /*    70 */    85,   85,   84,   84,   84,   83,  330,  306,  559,   84,
- /*    80 */    84,   84,   83,  330,   65,   86,   86,   86,   86,   85,
- /*    90 */    85,   84,   84,   84,   83,  330,  635,  635,  634,  633,
- /*   100 */   182,  682,  550,  379,  376,  375,   17,  322,  606,  606,
- /*   110 */   371,  198,  479,   91,  374,   82,   79,  165,   85,   85,
- /*   120 */    84,   84,   84,   83,  330,  598,  635,  635,  107,   89,
- /*   130 */    90,   80,  600,  599,  601,  601,   87,   87,   88,   88,
- /*   140 */    88,   88,  186,   86,   86,   86,   86,   85,   85,   84,
- /*   150 */    84,   84,   83,  330,  306,  594,  594,  142,  328,  327,
- /*   160 */   484,  249,  344,  238,  635,  635,  634,  633,  585,  448,
- /*   170 */   526,  525,  229,  388,    1,  394,  450,  584,  449,  635,
- /*   180 */   635,  635,  635,  319,  395,  606,  606,  199,  157,  273,
- /*   190 */   382,  268,  381,  187,  635,  635,  634,  633,  311,  555,
- /*   200 */   266,  593,  593,  266,  347,  588,   89,   90,   80,  600,
- /*   210 */   599,  601,  601,   87,   87,   88,   88,   88,   88,  478,
- /*   220 */    86,   86,   86,   86,   85,   85,   84,   84,   84,   83,
- /*   230 */   330,  306,  272,  536,  634,  633,  146,  610,  197,  310,
- /*   240 */   575,  182,  482,  271,  379,  376,  375,  506,   21,  634,
- /*   250 */   633,  634,  633,  635,  635,  374,  611,  574,  548,  440,
- /*   260 */   111,  563,  606,  606,  634,  633,  324,  479,  608,  608,
- /*   270 */   608,  300,  435,  573,  119,  407,  210,  162,  562,  883,
- /*   280 */   592,  592,  306,   89,   90,   80,  600,  599,  601,  601,
- /*   290 */    87,   87,   88,   88,   88,   88,  506,   86,   86,   86,
- /*   300 */    86,   85,   85,   84,   84,   84,   83,  330,  620,  111,
- /*   310 */   635,  635,  361,  606,  606,  358,  249,  349,  248,  433,
- /*   320 */   243,  479,  586,  634,  633,  195,  611,   93,  119,  221,
- /*   330 */   575,  497,  534,  534,   89,   90,   80,  600,  599,  601,
- /*   340 */   601,   87,   87,   88,   88,   88,   88,  574,   86,   86,
- /*   350 */    86,   86,   85,   85,   84,   84,   84,   83,  330,  306,
- /*   360 */    77,  429,  638,  573,  589,  530,  240,  230,  242,  105,
- /*   370 */   249,  349,  248,  515,  588,  208,  460,  529,  564,  173,
- /*   380 */   634,  633,  970,  144,  430,    2,  424,  228,  380,  557,
- /*   390 */   606,  606,  190,  153,  159,  158,  514,   51,  632,  631,
- /*   400 */   630,   71,  536,  432,  954,  196,  610,  954,  614,   45,
- /*   410 */    18,   89,   90,   80,  600,  599,  601,  601,   87,   87,
- /*   420 */    88,   88,   88,   88,  261,   86,   86,   86,   86,   85,
- /*   430 */    85,   84,   84,   84,   83,  330,  306,  608,  608,  608,
- /*   440 */   542,  424,  402,  385,  241,  506,  451,  320,  211,  543,
- /*   450 */   164,  436,  386,  293,  451,  587,  108,  496,  111,  334,
- /*   460 */   391,  591,  424,  614,   27,  452,  453,  606,  606,   72,
- /*   470 */   257,   70,  259,  452,  339,  342,  564,  582,   68,  415,
- /*   480 */   469,  328,  327,   62,  614,   45,  110,  393,   89,   90,
- /*   490 */    80,  600,  599,  601,  601,   87,   87,   88,   88,   88,
- /*   500 */    88,  152,   86,   86,   86,   86,   85,   85,   84,   84,
- /*   510 */    84,   83,  330,  306,  110,  499,  520,  538,  402,  389,
- /*   520 */   424,  110,  566,  500,  593,  593,  454,   82,   79,  165,
- /*   530 */   424,  591,  384,  564,  340,  615,  188,  162,  424,  350,
- /*   540 */   616,  424,  614,   44,  606,  606,  445,  582,  300,  434,
- /*   550 */   151,   19,  614,    9,  568,  580,  348,  615,  469,  567,
- /*   560 */   614,   26,  616,  614,   45,   89,   90,   80,  600,  599,
- /*   570 */   601,  601,   87,   87,   88,   88,   88,   88,  411,   86,
- /*   580 */    86,   86,   86,   85,   85,   84,   84,   84,   83,  330,
- /*   590 */   306,  579,  110,  578,  521,  282,  433,  398,  400,  255,
- /*   600 */   486,   82,   79,  165,  487,  164,   82,   79,  165,  488,
- /*   610 */   488,  364,  387,  424,  544,  544,  509,  350,  362,  155,
- /*   620 */   191,  606,  606,  559,  642,  640,  333,   82,   79,  165,
- /*   630 */   305,  564,  507,  312,  357,  614,   45,  329,  596,  595,
- /*   640 */   194,  337,   89,   90,   80,  600,  599,  601,  601,   87,
- /*   650 */    87,   88,   88,   88,   88,  424,   86,   86,   86,   86,
- /*   660 */    85,   85,   84,   84,   84,   83,  330,  306,   20,  323,
- /*   670 */   150,  263,  211,  543,  421,  596,  595,  614,   22,  424,
- /*   680 */   193,  424,  284,  424,  391,  424,  509,  424,  577,  424,
- /*   690 */   186,  335,  424,  559,  424,  313,  120,  546,  606,  606,
- /*   700 */    67,  614,   47,  614,   50,  614,   48,  614,  100,  614,
- /*   710 */    99,  614,  101,  576,  614,  102,  614,  109,  326,   89,
- /*   720 */    90,   80,  600,  599,  601,  601,   87,   87,   88,   88,
- /*   730 */    88,   88,  424,   86,   86,   86,   86,   85,   85,   84,
- /*   740 */    84,   84,   83,  330,  306,  424,  311,  424,  585,   54,
- /*   750 */   424,  516,  517,  590,  614,  112,  424,  584,  424,  572,
- /*   760 */   424,  195,  424,  571,  424,   67,  424,  614,   94,  614,
- /*   770 */    98,  424,  614,   97,  264,  606,  606,  195,  614,   46,
- /*   780 */   614,   96,  614,   30,  614,   49,  614,  115,  614,  114,
- /*   790 */   418,  229,  388,  614,  113,  306,   89,   90,   80,  600,
- /*   800 */   599,  601,  601,   87,   87,   88,   88,   88,   88,  424,
- /*   810 */    86,   86,   86,   86,   85,   85,   84,   84,   84,   83,
- /*   820 */   330,  119,  424,  590,  110,  372,  606,  606,  195,   53,
- /*   830 */   250,  614,   29,  195,  472,  438,  729,  190,  302,  498,
- /*   840 */    14,  523,  641,    2,  614,   43,  306,   89,   90,   80,
- /*   850 */   600,  599,  601,  601,   87,   87,   88,   88,   88,   88,
- /*   860 */   424,   86,   86,   86,   86,   85,   85,   84,   84,   84,
- /*   870 */    83,  330,  424,  613,  964,  964,  354,  606,  606,  420,
- /*   880 */   312,   64,  614,   42,  391,  355,  283,  437,  301,  255,
- /*   890 */   414,  410,  495,  492,  614,   28,  471,  306,   89,   90,
- /*   900 */    80,  600,  599,  601,  601,   87,   87,   88,   88,   88,
- /*   910 */    88,  424,   86,   86,   86,   86,   85,   85,   84,   84,
- /*   920 */    84,   83,  330,  424,  110,  110,  110,  110,  606,  606,
- /*   930 */   110,  254,   13,  614,   41,  532,  531,  283,  481,  531,
- /*   940 */   457,  284,  119,  561,  356,  614,   40,  284,  306,   89,
- /*   950 */    78,   80,  600,  599,  601,  601,   87,   87,   88,   88,
- /*   960 */    88,   88,  424,   86,   86,   86,   86,   85,   85,   84,
- /*   970 */    84,   84,   83,  330,  110,  424,  341,  220,  555,  606,
- /*   980 */   606,  351,  555,  318,  614,   95,  413,  255,   83,  330,
- /*   990 */   284,  284,  255,  640,  333,  356,  255,  614,   39,  306,
- /*  1000 */   356,   90,   80,  600,  599,  601,  601,   87,   87,   88,
- /*  1010 */    88,   88,   88,  424,   86,   86,   86,   86,   85,   85,
- /*  1020 */    84,   84,   84,   83,  330,  424,  317,  316,  141,  465,
- /*  1030 */   606,  606,  219,  619,  463,  614,   10,  417,  462,  255,
- /*  1040 */   189,  510,  553,  351,  207,  363,  161,  614,   38,  315,
- /*  1050 */   218,  255,  255,   80,  600,  599,  601,  601,   87,   87,
- /*  1060 */    88,   88,   88,   88,  424,   86,   86,   86,   86,   85,
- /*  1070 */    85,   84,   84,   84,   83,  330,   76,  419,  255,    3,
- /*  1080 */   878,  461,  424,  247,  331,  331,  614,   37,  217,   76,
- /*  1090 */   419,  390,    3,  216,  215,  422,    4,  331,  331,  424,
- /*  1100 */   547,   12,  424,  545,  614,   36,  424,  541,  422,  424,
- /*  1110 */   540,  424,  214,  424,  408,  424,  539,  403,  605,  605,
- /*  1120 */   237,  614,   25,  119,  614,   24,  588,  408,  614,   45,
- /*  1130 */   118,  614,   35,  614,   34,  614,   33,  614,   23,  588,
- /*  1140 */    60,  223,  603,  602,  513,  378,   73,   74,  140,  139,
- /*  1150 */   424,  110,  265,   75,  426,  425,   59,  424,  610,   73,
- /*  1160 */    74,  549,  402,  404,  424,  373,   75,  426,  425,  604,
- /*  1170 */   138,  610,  614,   11,  392,   76,  419,  181,    3,  614,
- /*  1180 */    32,  271,  369,  331,  331,  493,  614,   31,  149,  608,
- /*  1190 */   608,  608,  607,   15,  422,  365,  614,    8,  137,  489,
- /*  1200 */   136,  190,  608,  608,  608,  607,   15,  485,  176,  135,
- /*  1210 */     7,  252,  477,  408,  174,  133,  175,  474,   57,   56,
- /*  1220 */   132,  130,  119,   76,  419,  588,    3,  468,  245,  464,
- /*  1230 */   171,  331,  331,  125,  123,  456,  447,  122,  446,  104,
- /*  1240 */   336,  231,  422,  166,  154,   73,   74,  332,  116,  431,
- /*  1250 */   121,  309,   75,  426,  425,  222,  106,  610,  308,  637,
- /*  1260 */   204,  408,  629,  627,  628,    6,  200,  428,  427,  290,
- /*  1270 */   203,  622,  201,  588,   62,   63,  289,   66,  419,  399,
- /*  1280 */     3,  401,  288,   92,  143,  331,  331,  287,  608,  608,
- /*  1290 */   608,  607,   15,   73,   74,  227,  422,  325,   69,  416,
- /*  1300 */    75,  426,  425,  612,  412,  610,  192,   61,  569,  209,
- /*  1310 */   396,  226,  278,  225,  383,  408,  527,  558,  276,  533,
- /*  1320 */   552,  528,  321,  523,  370,  508,  180,  588,  494,  179,
- /*  1330 */   366,  117,  253,  269,  522,  503,  608,  608,  608,  607,
- /*  1340 */    15,  551,  502,   58,  274,  524,  178,   73,   74,  304,
- /*  1350 */   501,  368,  303,  206,   75,  426,  425,  491,  360,  610,
- /*  1360 */   213,  177,  483,  131,  345,  298,  297,  296,  202,  294,
- /*  1370 */   480,  490,  466,  134,  172,  129,  444,  346,  470,  128,
- /*  1380 */   314,  459,  103,  127,  126,  148,  124,  167,  443,  235,
- /*  1390 */   608,  608,  608,  607,   15,  442,  439,  623,  234,  299,
- /*  1400 */   145,  583,  291,  377,  581,  160,  119,  156,  270,  636,
- /*  1410 */   971,  169,  279,  626,  520,  625,  473,  624,  170,  621,
- /*  1420 */   618,  119,  168,   55,  409,  423,  537,  609,  286,  285,
- /*  1430 */   405,  570,  560,  556,    5,   52,  458,  554,  147,  267,
- /*  1440 */   519,  504,  518,  406,  262,  239,  260,  512,  343,  511,
- /*  1450 */   258,  353,  565,  256,  224,  251,  359,  277,  275,  476,
- /*  1460 */   475,  246,  352,  244,  467,  455,  236,  233,  232,  307,
- /*  1470 */   441,  281,  205,  163,  397,  280,  535,  505,  330,  617,
- /*  1480 */   971,  971,  971,  971,  367,  971,  971,  971,  971,  971,
- /*  1490 */   971,  971,  971,  971,  971,  971,  338,
-};
-static const YYCODETYPE yy_lookahead[] = {
- /*     0 */    19,   22,   22,   23,    1,   24,   26,   15,   27,   80,
- /*    10 */    81,   82,   83,   84,   85,   86,   87,   88,   89,   90,
- /*    20 */    91,   92,   93,   94,   95,  108,  109,  110,   27,   28,
- /*    30 */    23,   50,   51,   80,   81,   82,   83,  122,   85,   86,
- /*    40 */    87,   88,   89,   90,   91,   92,   93,   94,   95,   22,
- /*    50 */    70,   23,   71,   72,   73,   74,   75,   76,   77,   78,
- /*    60 */    79,   80,   81,   82,   83,  122,   85,   86,   87,   88,
- /*    70 */    89,   90,   91,   92,   93,   94,   95,   19,   97,   91,
- /*    80 */    92,   93,   94,   95,   26,   85,   86,   87,   88,   89,
- /*    90 */    90,   91,   92,   93,   94,   95,   27,   28,   97,   98,
- /*   100 */    99,  122,  211,  102,  103,  104,   79,   19,   50,   51,
- /*   110 */    19,  122,   59,   55,  113,  224,  225,  226,   89,   90,
- /*   120 */    91,   92,   93,   94,   95,   23,   27,   28,   26,   71,
- /*   130 */    72,   73,   74,   75,   76,   77,   78,   79,   80,   81,
- /*   140 */    82,   83,   51,   85,   86,   87,   88,   89,   90,   91,
- /*   150 */    92,   93,   94,   95,   19,  132,  133,   58,   89,   90,
- /*   160 */    21,  108,  109,  110,   27,   28,   97,   98,   33,  100,
- /*   170 */     7,    8,  119,  120,   22,   19,  107,   42,  109,   27,
- /*   180 */    28,   27,   28,   95,   28,   50,   51,   99,  100,  101,
- /*   190 */   102,  103,  104,  105,   27,   28,   97,   98,  107,  152,
- /*   200 */   112,  132,  133,  112,   65,   69,   71,   72,   73,   74,
- /*   210 */    75,   76,   77,   78,   79,   80,   81,   82,   83,   11,
- /*   220 */    85,   86,   87,   88,   89,   90,   91,   92,   93,   94,
- /*   230 */    95,   19,  101,   97,   97,   98,   24,  101,  122,  157,
- /*   240 */    12,   99,  103,  112,  102,  103,  104,  152,   22,   97,
- /*   250 */    98,   97,   98,   27,   28,  113,   27,   29,   91,  164,
- /*   260 */   165,  124,   50,   51,   97,   98,  219,   59,  132,  133,
- /*   270 */   134,   22,   23,   45,   66,   47,  212,  213,  124,  140,
- /*   280 */   132,  133,   19,   71,   72,   73,   74,   75,   76,   77,
- /*   290 */    78,   79,   80,   81,   82,   83,  152,   85,   86,   87,
- /*   300 */    88,   89,   90,   91,   92,   93,   94,   95,  164,  165,
- /*   310 */    27,   28,  230,   50,   51,  233,  108,  109,  110,   70,
- /*   320 */    16,   59,   23,   97,   98,   26,   97,   22,   66,  185,
- /*   330 */    12,  187,   27,   28,   71,   72,   73,   74,   75,   76,
- /*   340 */    77,   78,   79,   80,   81,   82,   83,   29,   85,   86,
- /*   350 */    87,   88,   89,   90,   91,   92,   93,   94,   95,   19,
- /*   360 */    22,  148,  149,   45,   23,   47,   62,  154,   64,  156,
- /*   370 */   108,  109,  110,   37,   69,   23,  163,   59,   26,   26,
- /*   380 */    97,   98,  144,  145,  146,  147,  152,  200,   52,   23,
- /*   390 */    50,   51,   26,   22,   89,   90,   60,  210,    7,    8,
- /*   400 */     9,  138,   97,   22,   23,   26,  101,   26,  174,  175,
- /*   410 */   197,   71,   72,   73,   74,   75,   76,   77,   78,   79,
- /*   420 */    80,   81,   82,   83,   16,   85,   86,   87,   88,   89,
- /*   430 */    90,   91,   92,   93,   94,   95,   19,  132,  133,  134,
- /*   440 */    23,  152,  208,  209,  140,  152,  152,  111,  195,  196,
- /*   450 */    98,   70,  163,  160,  152,   23,   22,  164,  165,  246,
- /*   460 */   207,   27,  152,  174,  175,  171,  172,   50,   51,  137,
- /*   470 */    62,  139,   64,  171,  172,  222,  124,   27,  138,   24,
- /*   480 */   163,   89,   90,  130,  174,  175,  197,  163,   71,   72,
- /*   490 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
- /*   500 */    83,   22,   85,   86,   87,   88,   89,   90,   91,   92,
- /*   510 */    93,   94,   95,   19,  197,  181,  182,   23,  208,  209,
- /*   520 */   152,  197,   26,  189,  132,  133,  232,  224,  225,  226,
- /*   530 */   152,   97,   91,   26,  232,  116,  212,  213,  152,  222,
- /*   540 */   121,  152,  174,  175,   50,   51,  243,   97,   22,   23,
- /*   550 */    22,  234,  174,  175,  177,   23,  239,  116,  163,  177,
- /*   560 */   174,  175,  121,  174,  175,   71,   72,   73,   74,   75,
- /*   570 */    76,   77,   78,   79,   80,   81,   82,   83,   24,   85,
- /*   580 */    86,   87,   88,   89,   90,   91,   92,   93,   94,   95,
- /*   590 */    19,   23,  197,   11,   23,  227,   70,  208,  220,  152,
- /*   600 */    31,  224,  225,  226,   35,   98,  224,  225,  226,  108,
- /*   610 */   109,  110,  115,  152,  117,  118,   27,  222,   49,  123,
- /*   620 */    24,   50,   51,   27,    0,    1,    2,  224,  225,  226,
- /*   630 */   166,  124,  168,  169,  239,  174,  175,  170,  171,  172,
- /*   640 */    22,  194,   71,   72,   73,   74,   75,   76,   77,   78,
- /*   650 */    79,   80,   81,   82,   83,  152,   85,   86,   87,   88,
- /*   660 */    89,   90,   91,   92,   93,   94,   95,   19,   22,  208,
- /*   670 */    24,   23,  195,  196,  170,  171,  172,  174,  175,  152,
- /*   680 */    26,  152,  152,  152,  207,  152,   97,  152,   23,  152,
- /*   690 */    51,  244,  152,   97,  152,  247,  248,   23,   50,   51,
- /*   700 */    26,  174,  175,  174,  175,  174,  175,  174,  175,  174,
- /*   710 */   175,  174,  175,   23,  174,  175,  174,  175,  188,   71,
- /*   720 */    72,   73,   74,   75,   76,   77,   78,   79,   80,   81,
- /*   730 */    82,   83,  152,   85,   86,   87,   88,   89,   90,   91,
- /*   740 */    92,   93,   94,   95,   19,  152,  107,  152,   33,   24,
- /*   750 */   152,  100,  101,   27,  174,  175,  152,   42,  152,   23,
- /*   760 */   152,   26,  152,   23,  152,   26,  152,  174,  175,  174,
- /*   770 */   175,  152,  174,  175,   23,   50,   51,   26,  174,  175,
- /*   780 */   174,  175,  174,  175,  174,  175,  174,  175,  174,  175,
- /*   790 */   163,  119,  120,  174,  175,   19,   71,   72,   73,   74,
- /*   800 */    75,   76,   77,   78,   79,   80,   81,   82,   83,  152,
- /*   810 */    85,   86,   87,   88,   89,   90,   91,   92,   93,   94,
- /*   820 */    95,   66,  152,   97,  197,   23,   50,   51,   26,   53,
- /*   830 */    23,  174,  175,   26,   23,   23,   23,   26,   26,   26,
- /*   840 */    36,  106,  146,  147,  174,  175,   19,   71,   72,   73,
- /*   850 */    74,   75,   76,   77,   78,   79,   80,   81,   82,   83,
- /*   860 */   152,   85,   86,   87,   88,   89,   90,   91,   92,   93,
- /*   870 */    94,   95,  152,  196,  119,  120,   19,   50,   51,  168,
- /*   880 */   169,   26,  174,  175,  207,   28,  152,  249,  250,  152,
- /*   890 */   163,  163,  163,  163,  174,  175,  163,   19,   71,   72,
- /*   900 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
- /*   910 */    83,  152,   85,   86,   87,   88,   89,   90,   91,   92,
- /*   920 */    93,   94,   95,  152,  197,  197,  197,  197,   50,   51,
- /*   930 */   197,  194,   36,  174,  175,  191,  192,  152,  191,  192,
- /*   940 */   163,  152,   66,  124,  152,  174,  175,  152,   19,   71,
- /*   950 */    72,   73,   74,   75,   76,   77,   78,   79,   80,   81,
- /*   960 */    82,   83,  152,   85,   86,   87,   88,   89,   90,   91,
- /*   970 */    92,   93,   94,   95,  197,  152,  100,  188,  152,   50,
- /*   980 */    51,  152,  152,  188,  174,  175,  252,  152,   94,   95,
- /*   990 */   152,  152,  152,    1,    2,  152,  152,  174,  175,   19,
- /*  1000 */   152,   72,   73,   74,   75,   76,   77,   78,   79,   80,
- /*  1010 */    81,   82,   83,  152,   85,   86,   87,   88,   89,   90,
- /*  1020 */    91,   92,   93,   94,   95,  152,  188,  188,   22,  194,
- /*  1030 */    50,   51,  240,  173,  194,  174,  175,  252,  194,  152,
- /*  1040 */    36,  181,   28,  152,   23,  219,  122,  174,  175,  219,
- /*  1050 */   221,  152,  152,   73,   74,   75,   76,   77,   78,   79,
- /*  1060 */    80,   81,   82,   83,  152,   85,   86,   87,   88,   89,
- /*  1070 */    90,   91,   92,   93,   94,   95,   19,   20,  152,   22,
- /*  1080 */    23,  194,  152,  240,   27,   28,  174,  175,  240,   19,
- /*  1090 */    20,   26,   22,  194,  194,   38,   22,   27,   28,  152,
- /*  1100 */    23,   22,  152,  116,  174,  175,  152,   23,   38,  152,
- /*  1110 */    23,  152,  221,  152,   57,  152,   23,  163,   50,   51,
- /*  1120 */   194,  174,  175,   66,  174,  175,   69,   57,  174,  175,
- /*  1130 */    40,  174,  175,  174,  175,  174,  175,  174,  175,   69,
- /*  1140 */    22,   53,   74,   75,   30,   53,   89,   90,   22,   22,
- /*  1150 */   152,  197,   23,   96,   97,   98,   22,  152,  101,   89,
- /*  1160 */    90,   91,  208,  209,  152,   53,   96,   97,   98,  101,
- /*  1170 */    22,  101,  174,  175,  152,   19,   20,  105,   22,  174,
- /*  1180 */   175,  112,   19,   27,   28,   20,  174,  175,   24,  132,
- /*  1190 */   133,  134,  135,  136,   38,   44,  174,  175,  107,   61,
- /*  1200 */    54,   26,  132,  133,  134,  135,  136,   54,  107,   22,
- /*  1210 */     5,  140,    1,   57,   36,  111,  122,   28,   79,   79,
- /*  1220 */   131,  123,   66,   19,   20,   69,   22,    1,   16,   20,
- /*  1230 */   125,   27,   28,  123,  111,  120,   23,  131,   23,   16,
- /*  1240 */    68,  142,   38,   15,   22,   89,   90,    3,  167,    4,
- /*  1250 */   248,  251,   96,   97,   98,  180,  180,  101,  251,  151,
- /*  1260 */     6,   57,  151,   13,  151,   26,   25,  151,  161,  202,
- /*  1270 */   153,  162,  153,   69,  130,  128,  203,   19,   20,  127,
- /*  1280 */    22,  126,  204,  129,   22,   27,   28,  205,  132,  133,
- /*  1290 */   134,  135,  136,   89,   90,  231,   38,   95,  137,  179,
- /*  1300 */    96,   97,   98,  206,  179,  101,  122,  107,  159,  159,
- /*  1310 */   125,  231,  216,  228,  107,   57,  184,  217,  216,  176,
- /*  1320 */   217,  176,   48,  106,   18,  184,  158,   69,  159,  158,
- /*  1330 */    46,   71,  237,  176,  176,  176,  132,  133,  134,  135,
- /*  1340 */   136,  217,  176,  137,  216,  178,  158,   89,   90,  179,
- /*  1350 */   176,  159,  179,  159,   96,   97,   98,  159,  159,  101,
- /*  1360 */     5,  158,  202,   22,   18,   10,   11,   12,   13,   14,
- /*  1370 */   190,  238,   17,  190,  158,  193,   41,  159,  202,  193,
- /*  1380 */   159,  202,  245,  193,  193,  223,  190,   32,  159,   34,
- /*  1390 */   132,  133,  134,  135,  136,  159,   39,  155,   43,  150,
- /*  1400 */   223,  177,  201,  178,  177,  186,   66,  199,  177,  152,
- /*  1410 */   253,   56,  215,  152,  182,  152,  202,  152,   63,  152,
- /*  1420 */   152,   66,   67,  242,  229,  152,  174,  152,  152,  152,
- /*  1430 */   152,  152,  152,  152,  199,  242,  202,  152,  198,  152,
- /*  1440 */   152,  152,  183,  192,  152,  215,  152,  183,  215,  183,
- /*  1450 */   152,  241,  214,  152,  211,  152,  152,  211,  211,  152,
- /*  1460 */   152,  241,  152,  152,  152,  152,  152,  152,  152,  114,
- /*  1470 */   152,  152,  235,  152,  152,  152,  174,  187,   95,  174,
- /*  1480 */   253,  253,  253,  253,  236,  253,  253,  253,  253,  253,
- /*  1490 */   253,  253,  253,  253,  253,  253,  141,
-};
-#define YY_SHIFT_USE_DFLT (-86)
-#define YY_SHIFT_COUNT (429)
-#define YY_SHIFT_MIN   (-85)
-#define YY_SHIFT_MAX   (1383)
-static const short yy_shift_ofst[] = {
- /*     0 */   992, 1057, 1355, 1156, 1204, 1204,    1,  262,  -19,  135,
- /*    10 */   135,  776, 1204, 1204, 1204, 1204,   69,   69,   53,  208,
- /*    20 */   283,  755,   58,  725,  648,  571,  494,  417,  340,  263,
- /*    30 */   212,  827,  827,  827,  827,  827,  827,  827,  827,  827,
- /*    40 */   827,  827,  827,  827,  827,  827,  878,  827,  929,  980,
- /*    50 */   980, 1070, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
- /*    60 */  1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
- /*    70 */  1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
- /*    80 */  1258, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
- /*    90 */  1204, 1204, 1204, 1204,  -71,  -47,  -47,  -47,  -47,  -47,
- /*   100 */     0,   29,  -12,  283,  283,  139,   91,  392,  392,  894,
- /*   110 */   672,  726, 1383,  -86,  -86,  -86,   88,  318,  318,   99,
- /*   120 */   381,  -20,  283,  283,  283,  283,  283,  283,  283,  283,
- /*   130 */   283,  283,  283,  283,  283,  283,  283,  283,  283,  283,
- /*   140 */   283,  283,  283,  283,  624,  876,  726,  672, 1340, 1340,
- /*   150 */  1340, 1340, 1340, 1340,  -86,  -86,  -86,  305,  136,  136,
- /*   160 */   142,  167,  226,  154,  137,  152,  283,  283,  283,  283,
- /*   170 */   283,  283,  283,  283,  283,  283,  283,  283,  283,  283,
- /*   180 */   283,  283,  283,  336,  336,  336,  283,  283,  352,  283,
- /*   190 */   283,  283,  283,  283,  228,  283,  283,  283,  283,  283,
- /*   200 */   283,  283,  283,  283,  283,  501,  569,  596,  596,  596,
- /*   210 */   507,  497,  441,  391,  353,  156,  156,  857,  353,  857,
- /*   220 */   735,  813,  639,  715,  156,  332,  715,  715,  496,  419,
- /*   230 */   646, 1357, 1184, 1184, 1335, 1335, 1184, 1341, 1260, 1144,
- /*   240 */  1346, 1346, 1346, 1346, 1184, 1306, 1144, 1341, 1260, 1260,
- /*   250 */  1144, 1184, 1306, 1206, 1284, 1184, 1184, 1306, 1184, 1306,
- /*   260 */  1184, 1306, 1262, 1207, 1207, 1207, 1274, 1262, 1207, 1217,
- /*   270 */  1207, 1274, 1207, 1207, 1185, 1200, 1185, 1200, 1185, 1200,
- /*   280 */  1184, 1184, 1161, 1262, 1202, 1202, 1262, 1154, 1155, 1147,
- /*   290 */  1152, 1144, 1241, 1239, 1250, 1250, 1254, 1254, 1254, 1254,
- /*   300 */   -86,  -86,  -86,  -86,  -86,  -86, 1068,  304,  526,  249,
- /*   310 */   408,  -83,  434,  812,   27,  811,  807,  802,  751,  589,
- /*   320 */   651,  163,  131,  674,  366,  450,  299,  148,   23,  102,
- /*   330 */   229,  -21, 1245, 1244, 1222, 1099, 1228, 1172, 1223, 1215,
- /*   340 */  1213, 1115, 1106, 1123, 1110, 1209, 1105, 1212, 1226, 1098,
- /*   350 */  1089, 1140, 1139, 1104, 1189, 1178, 1094, 1211, 1205, 1187,
- /*   360 */  1101, 1071, 1153, 1175, 1146, 1138, 1151, 1091, 1164, 1165,
- /*   370 */  1163, 1069, 1072, 1148, 1112, 1134, 1127, 1129, 1126, 1092,
- /*   380 */  1114, 1118, 1088, 1090, 1093, 1087, 1084,  987, 1079, 1077,
- /*   390 */  1074, 1065,  924, 1021, 1014, 1004, 1006,  819,  739,  896,
- /*   400 */   855,  804,  739,  740,  736,  690,  654,  665,  618,  582,
- /*   410 */   568,  528,  554,  379,  532,  479,  455,  379,  432,  371,
- /*   420 */   341,   28,  338,  116,  -11,  -57,  -85,    7,   -8,    3,
-};
-#define YY_REDUCE_USE_DFLT (-110)
-#define YY_REDUCE_COUNT (305)
-#define YY_REDUCE_MIN   (-109)
-#define YY_REDUCE_MAX   (1323)
-static const short yy_reduce_ofst[] = {
- /*     0 */   238,  954,  213,  289,  310,  234,  144,  317, -109,  382,
- /*    10 */   377,  303,  461,  389,  378,  368,  302,  294,  253,  395,
- /*    20 */   293,  324,  403,  403,  403,  403,  403,  403,  403,  403,
- /*    30 */   403,  403,  403,  403,  403,  403,  403,  403,  403,  403,
- /*    40 */   403,  403,  403,  403,  403,  403,  403,  403,  403,  403,
- /*    50 */   403, 1022, 1012, 1005,  998,  963,  961,  959,  957,  950,
- /*    60 */   947,  930,  912,  873,  861,  823,  810,  771,  759,  720,
- /*    70 */   708,  670,  657,  619,  614,  612,  610,  608,  606,  604,
- /*    80 */   598,  595,  593,  580,  542,  540,  537,  535,  533,  531,
- /*    90 */   529,  527,  503,  386,  403,  403,  403,  403,  403,  403,
- /*   100 */   403,  403,  403,   95,  447,   82,  334,  504,  467,  403,
- /*   110 */   477,  464,  403,  403,  403,  403,  860,  747,  744,  785,
- /*   120 */   638,  638,  926,  891,  900,  899,  887,  844,  840,  835,
- /*   130 */   848,  830,  843,  829,  792,  839,  826,  737,  838,  795,
- /*   140 */   789,   47,  734,  530,  696,  777,  711,  677,  733,  730,
- /*   150 */   729,  728,  727,  627,  448,   64,  187, 1305, 1302, 1252,
- /*   160 */  1290, 1273, 1323, 1322, 1321, 1319, 1318, 1316, 1315, 1314,
- /*   170 */  1313, 1312, 1311, 1310, 1308, 1307, 1304, 1303, 1301, 1298,
- /*   180 */  1294, 1292, 1289, 1266, 1264, 1259, 1288, 1287, 1238, 1285,
- /*   190 */  1281, 1280, 1279, 1278, 1251, 1277, 1276, 1275, 1273, 1268,
- /*   200 */  1267, 1265, 1263, 1261, 1257, 1248, 1237, 1247, 1246, 1243,
- /*   210 */  1238, 1240, 1235, 1249, 1234, 1233, 1230, 1220, 1214, 1210,
- /*   220 */  1225, 1219, 1232, 1231, 1197, 1195, 1227, 1224, 1201, 1208,
- /*   230 */  1242, 1137, 1236, 1229, 1193, 1181, 1221, 1177, 1196, 1179,
- /*   240 */  1191, 1190, 1186, 1182, 1218, 1216, 1176, 1162, 1183, 1180,
- /*   250 */  1160, 1199, 1203, 1133, 1095, 1198, 1194, 1188, 1192, 1171,
- /*   260 */  1169, 1168, 1173, 1174, 1166, 1159, 1141, 1170, 1158, 1167,
- /*   270 */  1157, 1132, 1145, 1143, 1124, 1128, 1103, 1102, 1100, 1096,
- /*   280 */  1150, 1149, 1085, 1125, 1080, 1064, 1120, 1097, 1082, 1078,
- /*   290 */  1073, 1067, 1109, 1107, 1119, 1117, 1116, 1113, 1111, 1108,
- /*   300 */  1007, 1000, 1002, 1076, 1075, 1081,
-};
-static const YYACTIONTYPE yy_default[] = {
- /*     0 */   647,  964,  964,  964,  878,  878,  969,  964,  774,  802,
- /*    10 */   802,  938,  969,  969,  969,  876,  969,  969,  969,  964,
- /*    20 */   969,  778,  808,  969,  969,  969,  969,  969,  969,  969,
- /*    30 */   969,  937,  939,  816,  815,  918,  789,  813,  806,  810,
- /*    40 */   879,  872,  873,  871,  875,  880,  969,  809,  841,  856,
- /*    50 */   840,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*    60 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*    70 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*    80 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*    90 */   969,  969,  969,  969,  850,  855,  862,  854,  851,  843,
- /*   100 */   842,  844,  845,  969,  969,  673,  739,  969,  969,  846,
- /*   110 */   969,  685,  847,  859,  858,  857,  680,  969,  969,  969,
- /*   120 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   130 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   140 */   969,  969,  969,  969,  647,  964,  969,  969,  964,  964,
- /*   150 */   964,  964,  964,  964,  956,  778,  768,  969,  969,  969,
- /*   160 */   969,  969,  969,  969,  969,  969,  969,  944,  942,  969,
- /*   170 */   891,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   180 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   190 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   200 */   969,  969,  969,  969,  653,  969,  911,  774,  774,  774,
- /*   210 */   776,  754,  766,  655,  812,  791,  791,  923,  812,  923,
- /*   220 */   710,  733,  707,  802,  791,  874,  802,  802,  775,  766,
- /*   230 */   969,  949,  782,  782,  941,  941,  782,  821,  743,  812,
- /*   240 */   750,  750,  750,  750,  782,  670,  812,  821,  743,  743,
- /*   250 */   812,  782,  670,  917,  915,  782,  782,  670,  782,  670,
- /*   260 */   782,  670,  884,  741,  741,  741,  725,  884,  741,  710,
- /*   270 */   741,  725,  741,  741,  795,  790,  795,  790,  795,  790,
- /*   280 */   782,  782,  969,  884,  888,  888,  884,  807,  796,  805,
- /*   290 */   803,  812,  676,  728,  663,  663,  652,  652,  652,  652,
- /*   300 */   961,  961,  956,  712,  712,  695,  969,  969,  969,  969,
- /*   310 */   969,  969,  687,  969,  893,  969,  969,  969,  969,  969,
- /*   320 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   330 */   969,  828,  969,  648,  951,  969,  969,  948,  969,  969,
- /*   340 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   350 */   969,  969,  969,  969,  969,  969,  921,  969,  969,  969,
- /*   360 */   969,  969,  969,  914,  913,  969,  969,  969,  969,  969,
- /*   370 */   969,  969,  969,  969,  969,  969,  969,  969,  969,  969,
- /*   380 */   969,  969,  969,  969,  969,  969,  969,  757,  969,  969,
- /*   390 */   969,  761,  969,  969,  969,  969,  969,  969,  804,  969,
- /*   400 */   797,  969,  877,  969,  969,  969,  969,  969,  969,  969,
- /*   410 */   969,  969,  969,  966,  969,  969,  969,  965,  969,  969,
- /*   420 */   969,  969,  969,  830,  969,  829,  833,  969,  661,  969,
- /*   430 */   644,  649,  960,  963,  962,  959,  958,  957,  952,  950,
- /*   440 */   947,  946,  945,  943,  940,  936,  897,  895,  902,  901,
- /*   450 */   900,  899,  898,  896,  894,  892,  818,  817,  814,  811,
- /*   460 */   753,  935,  890,  752,  749,  748,  669,  953,  920,  929,
- /*   470 */   928,  927,  822,  926,  925,  924,  922,  919,  906,  820,
- /*   480 */   819,  744,  882,  881,  672,  910,  909,  908,  912,  916,
- /*   490 */   907,  784,  751,  671,  668,  675,  679,  731,  732,  740,
- /*   500 */   738,  737,  736,  735,  734,  730,  681,  686,  724,  709,
- /*   510 */   708,  717,  716,  722,  721,  720,  719,  718,  715,  714,
- /*   520 */   713,  706,  705,  711,  704,  727,  726,  723,  703,  747,
- /*   530 */   746,  745,  742,  702,  701,  700,  833,  699,  698,  838,
- /*   540 */   837,  866,  826,  755,  759,  758,  762,  763,  771,  770,
- /*   550 */   769,  780,  781,  793,  792,  824,  823,  794,  779,  773,
- /*   560 */   772,  788,  787,  786,  785,  777,  767,  799,  798,  868,
- /*   570 */   783,  867,  865,  934,  933,  932,  931,  930,  870,  967,
- /*   580 */   968,  887,  889,  886,  801,  800,  885,  869,  839,  836,
- /*   590 */   690,  691,  905,  904,  903,  693,  692,  689,  688,  863,
- /*   600 */   860,  852,  864,  861,  853,  849,  848,  834,  832,  831,
- /*   610 */   827,  835,  760,  756,  825,  765,  764,  697,  696,  694,
- /*   620 */   678,  677,  674,  667,  665,  664,  666,  662,  660,  659,
- /*   630 */   658,  657,  656,  684,  683,  682,  654,  651,  650,  646,
- /*   640 */   645,  643,
-};
+static int fts3SnippetShift(
+  Fts3Table *pTab,                /* FTS3 table snippet comes from */
+  int iLangid,                    /* Language id to use in tokenizing */
+  int nSnippet,                   /* Number of tokens desired for snippet */
+  const char *zDoc,               /* Document text to extract snippet from */
+  int nDoc,                       /* Size of buffer zDoc in bytes */
+  int *piPos,                     /* IN/OUT: First token of snippet */
+  u64 *pHlmask                    /* IN/OUT: Mask of tokens to highlight */
+){
+  u64 hlmask = *pHlmask;          /* Local copy of initial highlight-mask */
 
-/* The next table maps tokens into fallback tokens.  If a construct
-** like the following:
-** 
-**      %fallback ID X Y Z.
-**
-** appears in the grammar, then ID becomes a fallback token for X, Y,
-** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
-** but it does not parse, the type of the token is changed to ID and
-** the parse is retried before an error is thrown.
-*/
-#ifdef YYFALLBACK
-static const YYCODETYPE yyFallback[] = {
-    0,  /*          $ => nothing */
-    0,  /*       SEMI => nothing */
-   27,  /*    EXPLAIN => ID */
-   27,  /*      QUERY => ID */
-   27,  /*       PLAN => ID */
-   27,  /*      BEGIN => ID */
-    0,  /* TRANSACTION => nothing */
-   27,  /*   DEFERRED => ID */
-   27,  /*  IMMEDIATE => ID */
-   27,  /*  EXCLUSIVE => ID */
-    0,  /*     COMMIT => nothing */
-   27,  /*        END => ID */
-   27,  /*   ROLLBACK => ID */
-   27,  /*  SAVEPOINT => ID */
-   27,  /*    RELEASE => ID */
-    0,  /*         TO => nothing */
-    0,  /*      TABLE => nothing */
-    0,  /*     CREATE => nothing */
-   27,  /*         IF => ID */
-    0,  /*        NOT => nothing */
-    0,  /*     EXISTS => nothing */
-   27,  /*       TEMP => ID */
-    0,  /*         LP => nothing */
-    0,  /*         RP => nothing */
-    0,  /*         AS => nothing */
-   27,  /*    WITHOUT => ID */
-    0,  /*      COMMA => nothing */
-    0,  /*         ID => nothing */
-    0,  /*    INDEXED => nothing */
-   27,  /*      ABORT => ID */
-   27,  /*     ACTION => ID */
-   27,  /*      AFTER => ID */
-   27,  /*    ANALYZE => ID */
-   27,  /*        ASC => ID */
-   27,  /*     ATTACH => ID */
-   27,  /*     BEFORE => ID */
-   27,  /*         BY => ID */
-   27,  /*    CASCADE => ID */
-   27,  /*       CAST => ID */
-   27,  /*   COLUMNKW => ID */
-   27,  /*   CONFLICT => ID */
-   27,  /*   DATABASE => ID */
-   27,  /*       DESC => ID */
-   27,  /*     DETACH => ID */
-   27,  /*       EACH => ID */
-   27,  /*       FAIL => ID */
-   27,  /*        FOR => ID */
-   27,  /*     IGNORE => ID */
-   27,  /*  INITIALLY => ID */
-   27,  /*    INSTEAD => ID */
-   27,  /*    LIKE_KW => ID */
-   27,  /*      MATCH => ID */
-   27,  /*         NO => ID */
-   27,  /*        KEY => ID */
-   27,  /*         OF => ID */
-   27,  /*     OFFSET => ID */
-   27,  /*     PRAGMA => ID */
-   27,  /*      RAISE => ID */
-   27,  /*  RECURSIVE => ID */
-   27,  /*    REPLACE => ID */
-   27,  /*   RESTRICT => ID */
-   27,  /*        ROW => ID */
-   27,  /*    TRIGGER => ID */
-   27,  /*     VACUUM => ID */
-   27,  /*       VIEW => ID */
-   27,  /*    VIRTUAL => ID */
-   27,  /*       WITH => ID */
-   27,  /*    REINDEX => ID */
-   27,  /*     RENAME => ID */
-   27,  /*   CTIME_KW => ID */
-};
-#endif /* YYFALLBACK */
+  if( hlmask ){
+    int nLeft;                    /* Tokens to the left of first highlight */
+    int nRight;                   /* Tokens to the right of last highlight */
+    int nDesired;                 /* Ideal number of tokens to shift forward */
 
-/* The following structure represents a single element of the
-** parser's stack.  Information stored includes:
-**
-**   +  The state number for the parser at this level of the stack.
-**
-**   +  The value of the token stored at this level of the stack.
-**      (In other words, the "major" token.)
-**
-**   +  The semantic value stored at this level of the stack.  This is
-**      the information used by the action routines in the grammar.
-**      It is sometimes called the "minor" token.
-*/
-struct yyStackEntry {
-  YYACTIONTYPE stateno;  /* The state-number */
-  YYCODETYPE major;      /* The major token value.  This is the code
-                         ** number for the token at this stack level */
-  YYMINORTYPE minor;     /* The user-supplied minor token value.  This
-                         ** is the value of the token  */
-};
-typedef struct yyStackEntry yyStackEntry;
+    for(nLeft=0; !(hlmask & ((u64)1 << nLeft)); nLeft++);
+    for(nRight=0; !(hlmask & ((u64)1 << (nSnippet-1-nRight))); nRight++);
+    nDesired = (nLeft-nRight)/2;
 
-/* The state of the parser is completely contained in an instance of
-** the following structure */
-struct yyParser {
-  int yyidx;                    /* Index of top element in stack */
-#ifdef YYTRACKMAXSTACKDEPTH
-  int yyidxMax;                 /* Maximum value of yyidx */
-#endif
-  int yyerrcnt;                 /* Shifts left before out of the error */
-  sqlite3ParserARG_SDECL                /* A place to hold %extra_argument */
-#if YYSTACKDEPTH<=0
-  int yystksz;                  /* Current side of the stack */
-  yyStackEntry *yystack;        /* The parser's stack */
-#else
-  yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */
-#endif
-};
-typedef struct yyParser yyParser;
+    /* Ideally, the start of the snippet should be pushed forward in the
+    ** document nDesired tokens. This block checks if there are actually
+    ** nDesired tokens to the right of the snippet. If so, *piPos and
+    ** *pHlMask are updated to shift the snippet nDesired tokens to the
+    ** right. Otherwise, the snippet is shifted by the number of tokens
+    ** available.
+    */
+    if( nDesired>0 ){
+      int nShift;                 /* Number of tokens to shift snippet by */
+      int iCurrent = 0;           /* Token counter */
+      int rc;                     /* Return Code */
+      sqlite3_tokenizer_module *pMod;
+      sqlite3_tokenizer_cursor *pC;
+      pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
 
-#ifndef NDEBUG
-/* #include  */
-static FILE *yyTraceFILE = 0;
-static char *yyTracePrompt = 0;
-#endif /* NDEBUG */
+      /* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)
+      ** or more tokens in zDoc/nDoc.
+      */
+      rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, iLangid, zDoc, nDoc, &pC);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){
+        const char *ZDUMMY; int DUMMY1 = 0, DUMMY2 = 0, DUMMY3 = 0;
+        rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);
+      }
+      pMod->xClose(pC);
+      if( rc!=SQLITE_OK && rc!=SQLITE_DONE ){ return rc; }
 
-#ifndef NDEBUG
-/* 
-** Turn parser tracing on by giving a stream to which to write the trace
-** and a prompt to preface each trace message.  Tracing is turned off
-** by making either argument NULL 
-**
-** Inputs:
-** 
      
-** 
    •  A FILE* to which trace output should be written.
-**      If NULL, then tracing is turned off.
-** 
    •  A prefix string written at the beginning of every
-**      line of trace output.  If NULL, then tracing is
-**      turned off.
-** 
    
-**
-** Outputs:
-** None.
+      nShift = (rc==SQLITE_DONE)+iCurrent-nSnippet;
+      assert( nShift<=nDesired );
+      if( nShift>0 ){
+        *piPos += nShift;
+        *pHlmask = hlmask >> nShift;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Extract the snippet text for fragment pFragment from cursor pCsr and
+** append it to string buffer pOut.
 */
-SQLITE_PRIVATE void sqlite3ParserTrace(FILE *TraceFILE, char *zTracePrompt){
-  yyTraceFILE = TraceFILE;
-  yyTracePrompt = zTracePrompt;
-  if( yyTraceFILE==0 ) yyTracePrompt = 0;
-  else if( yyTracePrompt==0 ) yyTraceFILE = 0;
+static int fts3SnippetText(
+  Fts3Cursor *pCsr,               /* FTS3 Cursor */
+  SnippetFragment *pFragment,     /* Snippet to extract */
+  int iFragment,                  /* Fragment number */
+  int isLast,                     /* True for final fragment in snippet */
+  int nSnippet,                   /* Number of tokens in extracted snippet */
+  const char *zOpen,              /* String inserted before highlighted term */
+  const char *zClose,             /* String inserted after highlighted term */
+  const char *zEllipsis,          /* String inserted between snippets */
+  StrBuffer *pOut                 /* Write output here */
+){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc;                         /* Return code */
+  const char *zDoc;               /* Document text to extract snippet from */
+  int nDoc;                       /* Size of zDoc in bytes */
+  int iCurrent = 0;               /* Current token number of document */
+  int iEnd = 0;                   /* Byte offset of end of current token */
+  int isShiftDone = 0;            /* True after snippet is shifted */
+  int iPos = pFragment->iPos;     /* First token of snippet */
+  u64 hlmask = pFragment->hlmask; /* Highlight-mask for snippet */
+  int iCol = pFragment->iCol+1;   /* Query column to extract text from */
+  sqlite3_tokenizer_module *pMod; /* Tokenizer module methods object */
+  sqlite3_tokenizer_cursor *pC;   /* Tokenizer cursor open on zDoc/nDoc */
+  
+  zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol);
+  if( zDoc==0 ){
+    if( sqlite3_column_type(pCsr->pStmt, iCol)!=SQLITE_NULL ){
+      return SQLITE_NOMEM;
+    }
+    return SQLITE_OK;
+  }
+  nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol);
+
+  /* Open a token cursor on the document. */
+  pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
+  rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid, zDoc,nDoc,&pC);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  while( rc==SQLITE_OK ){
+    const char *ZDUMMY;           /* Dummy argument used with tokenizer */
+    int DUMMY1 = -1;              /* Dummy argument used with tokenizer */
+    int iBegin = 0;               /* Offset in zDoc of start of token */
+    int iFin = 0;                 /* Offset in zDoc of end of token */
+    int isHighlight = 0;          /* True for highlighted terms */
+
+    /* Variable DUMMY1 is initialized to a negative value above. Elsewhere
+    ** in the FTS code the variable that the third argument to xNext points to
+    ** is initialized to zero before the first (*but not necessarily
+    ** subsequent*) call to xNext(). This is done for a particular application
+    ** that needs to know whether or not the tokenizer is being used for
+    ** snippet generation or for some other purpose.
+    **
+    ** Extreme care is required when writing code to depend on this
+    ** initialization. It is not a documented part of the tokenizer interface.
+    ** If a tokenizer is used directly by any code outside of FTS, this
+    ** convention might not be respected.  */
+    rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &iBegin, &iFin, &iCurrent);
+    if( rc!=SQLITE_OK ){
+      if( rc==SQLITE_DONE ){
+        /* Special case - the last token of the snippet is also the last token
+        ** of the column. Append any punctuation that occurred between the end
+        ** of the previous token and the end of the document to the output. 
+        ** Then break out of the loop. */
+        rc = fts3StringAppend(pOut, &zDoc[iEnd], -1);
+      }
+      break;
+    }
+    if( iCurrentiLangid, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask
+      );
+      isShiftDone = 1;
+
+      /* Now that the shift has been done, check if the initial "..." are
+      ** required. They are required if (a) this is not the first fragment,
+      ** or (b) this fragment does not begin at position 0 of its column. 
+      */
+      if( rc==SQLITE_OK ){
+        if( iPos>0 || iFragment>0 ){
+          rc = fts3StringAppend(pOut, zEllipsis, -1);
+        }else if( iBegin ){
+          rc = fts3StringAppend(pOut, zDoc, iBegin);
+        }
+      }
+      if( rc!=SQLITE_OK || iCurrent=(iPos+nSnippet) ){
+      if( isLast ){
+        rc = fts3StringAppend(pOut, zEllipsis, -1);
+      }
+      break;
+    }
+
+    /* Set isHighlight to true if this term should be highlighted. */
+    isHighlight = (hlmask & ((u64)1 << (iCurrent-iPos)))!=0;
+
+    if( iCurrent>iPos ) rc = fts3StringAppend(pOut, &zDoc[iEnd], iBegin-iEnd);
+    if( rc==SQLITE_OK && isHighlight ) rc = fts3StringAppend(pOut, zOpen, -1);
+    if( rc==SQLITE_OK ) rc = fts3StringAppend(pOut, &zDoc[iBegin], iFin-iBegin);
+    if( rc==SQLITE_OK && isHighlight ) rc = fts3StringAppend(pOut, zClose, -1);
+
+    iEnd = iFin;
+  }
+
+  pMod->xClose(pC);
+  return rc;
 }
-#endif /* NDEBUG */
 
-#ifndef NDEBUG
-/* For tracing shifts, the names of all terminals and nonterminals
-** are required.  The following table supplies these names */
-static const char *const yyTokenName[] = { 
-  "$",             "SEMI",          "EXPLAIN",       "QUERY",       
-  "PLAN",          "BEGIN",         "TRANSACTION",   "DEFERRED",    
-  "IMMEDIATE",     "EXCLUSIVE",     "COMMIT",        "END",         
-  "ROLLBACK",      "SAVEPOINT",     "RELEASE",       "TO",          
-  "TABLE",         "CREATE",        "IF",            "NOT",         
-  "EXISTS",        "TEMP",          "LP",            "RP",          
-  "AS",            "WITHOUT",       "COMMA",         "ID",          
-  "INDEXED",       "ABORT",         "ACTION",        "AFTER",       
-  "ANALYZE",       "ASC",           "ATTACH",        "BEFORE",      
-  "BY",            "CASCADE",       "CAST",          "COLUMNKW",    
-  "CONFLICT",      "DATABASE",      "DESC",          "DETACH",      
-  "EACH",          "FAIL",          "FOR",           "IGNORE",      
-  "INITIALLY",     "INSTEAD",       "LIKE_KW",       "MATCH",       
-  "NO",            "KEY",           "OF",            "OFFSET",      
-  "PRAGMA",        "RAISE",         "RECURSIVE",     "REPLACE",     
-  "RESTRICT",      "ROW",           "TRIGGER",       "VACUUM",      
-  "VIEW",          "VIRTUAL",       "WITH",          "REINDEX",     
-  "RENAME",        "CTIME_KW",      "ANY",           "OR",          
-  "AND",           "IS",            "BETWEEN",       "IN",          
-  "ISNULL",        "NOTNULL",       "NE",            "EQ",          
-  "GT",            "LE",            "LT",            "GE",          
-  "ESCAPE",        "BITAND",        "BITOR",         "LSHIFT",      
-  "RSHIFT",        "PLUS",          "MINUS",         "STAR",        
-  "SLASH",         "REM",           "CONCAT",        "COLLATE",     
-  "BITNOT",        "STRING",        "JOIN_KW",       "CONSTRAINT",  
-  "DEFAULT",       "NULL",          "PRIMARY",       "UNIQUE",      
-  "CHECK",         "REFERENCES",    "AUTOINCR",      "ON",          
-  "INSERT",        "DELETE",        "UPDATE",        "SET",         
-  "DEFERRABLE",    "FOREIGN",       "DROP",          "UNION",       
-  "ALL",           "EXCEPT",        "INTERSECT",     "SELECT",      
-  "VALUES",        "DISTINCT",      "DOT",           "FROM",        
-  "JOIN",          "USING",         "ORDER",         "GROUP",       
-  "HAVING",        "LIMIT",         "WHERE",         "INTO",        
-  "INTEGER",       "FLOAT",         "BLOB",          "VARIABLE",    
-  "CASE",          "WHEN",          "THEN",          "ELSE",        
-  "INDEX",         "ALTER",         "ADD",           "error",       
-  "input",         "cmdlist",       "ecmd",          "explain",     
-  "cmdx",          "cmd",           "transtype",     "trans_opt",   
-  "nm",            "savepoint_opt",  "create_table",  "create_table_args",
-  "createkw",      "temp",          "ifnotexists",   "dbnm",        
-  "columnlist",    "conslist_opt",  "table_options",  "select",      
-  "column",        "columnid",      "type",          "carglist",    
-  "typetoken",     "typename",      "signed",        "plus_num",    
-  "minus_num",     "ccons",         "term",          "expr",        
-  "onconf",        "sortorder",     "autoinc",       "idxlist_opt", 
-  "refargs",       "defer_subclause",  "refarg",        "refact",      
-  "init_deferred_pred_opt",  "conslist",      "tconscomma",    "tcons",       
-  "idxlist",       "defer_subclause_opt",  "orconf",        "resolvetype", 
-  "raisetype",     "ifexists",      "fullname",      "selectnowith",
-  "oneselect",     "with",          "multiselect_op",  "distinct",    
-  "selcollist",    "from",          "where_opt",     "groupby_opt", 
-  "having_opt",    "orderby_opt",   "limit_opt",     "values",      
-  "nexprlist",     "exprlist",      "sclp",          "as",          
-  "seltablist",    "stl_prefix",    "joinop",        "indexed_opt", 
-  "on_opt",        "using_opt",     "joinop2",       "idlist",      
-  "sortlist",      "setlist",       "insert_cmd",    "inscollist_opt",
-  "likeop",        "between_op",    "in_op",         "case_operand",
-  "case_exprlist",  "case_else",     "uniqueflag",    "collate",     
-  "nmnum",         "trigger_decl",  "trigger_cmd_list",  "trigger_time",
-  "trigger_event",  "foreach_clause",  "when_clause",   "trigger_cmd", 
-  "trnm",          "tridxby",       "database_kw_opt",  "key_opt",     
-  "add_column_fullname",  "kwcolumn_opt",  "create_vtab",   "vtabarglist", 
-  "vtabarg",       "vtabargtoken",  "lp",            "anylist",     
-  "wqlist",      
-};
-#endif /* NDEBUG */
 
-#ifndef NDEBUG
-/* For tracing reduce actions, the names of all rules are required.
+/*
+** This function is used to count the entries in a column-list (a 
+** delta-encoded list of term offsets within a single column of a single 
+** row). When this function is called, *ppCollist should point to the
+** beginning of the first varint in the column-list (the varint that
+** contains the position of the first matching term in the column data).
+** Before returning, *ppCollist is set to point to the first byte after
+** the last varint in the column-list (either the 0x00 signifying the end
+** of the position-list, or the 0x01 that precedes the column number of
+** the next column in the position-list).
+**
+** The number of elements in the column-list is returned.
 */
-static const char *const yyRuleName[] = {
- /*   0 */ "input ::= cmdlist",
- /*   1 */ "cmdlist ::= cmdlist ecmd",
- /*   2 */ "cmdlist ::= ecmd",
- /*   3 */ "ecmd ::= SEMI",
- /*   4 */ "ecmd ::= explain cmdx SEMI",
- /*   5 */ "explain ::=",
- /*   6 */ "explain ::= EXPLAIN",
- /*   7 */ "explain ::= EXPLAIN QUERY PLAN",
- /*   8 */ "cmdx ::= cmd",
- /*   9 */ "cmd ::= BEGIN transtype trans_opt",
- /*  10 */ "trans_opt ::=",
- /*  11 */ "trans_opt ::= TRANSACTION",
- /*  12 */ "trans_opt ::= TRANSACTION nm",
- /*  13 */ "transtype ::=",
- /*  14 */ "transtype ::= DEFERRED",
- /*  15 */ "transtype ::= IMMEDIATE",
- /*  16 */ "transtype ::= EXCLUSIVE",
- /*  17 */ "cmd ::= COMMIT trans_opt",
- /*  18 */ "cmd ::= END trans_opt",
- /*  19 */ "cmd ::= ROLLBACK trans_opt",
- /*  20 */ "savepoint_opt ::= SAVEPOINT",
- /*  21 */ "savepoint_opt ::=",
- /*  22 */ "cmd ::= SAVEPOINT nm",
- /*  23 */ "cmd ::= RELEASE savepoint_opt nm",
- /*  24 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",
- /*  25 */ "cmd ::= create_table create_table_args",
- /*  26 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",
- /*  27 */ "createkw ::= CREATE",
- /*  28 */ "ifnotexists ::=",
- /*  29 */ "ifnotexists ::= IF NOT EXISTS",
- /*  30 */ "temp ::= TEMP",
- /*  31 */ "temp ::=",
- /*  32 */ "create_table_args ::= LP columnlist conslist_opt RP table_options",
- /*  33 */ "create_table_args ::= AS select",
- /*  34 */ "table_options ::=",
- /*  35 */ "table_options ::= WITHOUT nm",
- /*  36 */ "columnlist ::= columnlist COMMA column",
- /*  37 */ "columnlist ::= column",
- /*  38 */ "column ::= columnid type carglist",
- /*  39 */ "columnid ::= nm",
- /*  40 */ "nm ::= ID|INDEXED",
- /*  41 */ "nm ::= STRING",
- /*  42 */ "nm ::= JOIN_KW",
- /*  43 */ "type ::=",
- /*  44 */ "type ::= typetoken",
- /*  45 */ "typetoken ::= typename",
- /*  46 */ "typetoken ::= typename LP signed RP",
- /*  47 */ "typetoken ::= typename LP signed COMMA signed RP",
- /*  48 */ "typename ::= ID|STRING",
- /*  49 */ "typename ::= typename ID|STRING",
- /*  50 */ "signed ::= plus_num",
- /*  51 */ "signed ::= minus_num",
- /*  52 */ "carglist ::= carglist ccons",
- /*  53 */ "carglist ::=",
- /*  54 */ "ccons ::= CONSTRAINT nm",
- /*  55 */ "ccons ::= DEFAULT term",
- /*  56 */ "ccons ::= DEFAULT LP expr RP",
- /*  57 */ "ccons ::= DEFAULT PLUS term",
- /*  58 */ "ccons ::= DEFAULT MINUS term",
- /*  59 */ "ccons ::= DEFAULT ID|INDEXED",
- /*  60 */ "ccons ::= NULL onconf",
- /*  61 */ "ccons ::= NOT NULL onconf",
- /*  62 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",
- /*  63 */ "ccons ::= UNIQUE onconf",
- /*  64 */ "ccons ::= CHECK LP expr RP",
- /*  65 */ "ccons ::= REFERENCES nm idxlist_opt refargs",
- /*  66 */ "ccons ::= defer_subclause",
- /*  67 */ "ccons ::= COLLATE ID|STRING",
- /*  68 */ "autoinc ::=",
- /*  69 */ "autoinc ::= AUTOINCR",
- /*  70 */ "refargs ::=",
- /*  71 */ "refargs ::= refargs refarg",
- /*  72 */ "refarg ::= MATCH nm",
- /*  73 */ "refarg ::= ON INSERT refact",
- /*  74 */ "refarg ::= ON DELETE refact",
- /*  75 */ "refarg ::= ON UPDATE refact",
- /*  76 */ "refact ::= SET NULL",
- /*  77 */ "refact ::= SET DEFAULT",
- /*  78 */ "refact ::= CASCADE",
- /*  79 */ "refact ::= RESTRICT",
- /*  80 */ "refact ::= NO ACTION",
- /*  81 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",
- /*  82 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",
- /*  83 */ "init_deferred_pred_opt ::=",
- /*  84 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",
- /*  85 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",
- /*  86 */ "conslist_opt ::=",
- /*  87 */ "conslist_opt ::= COMMA conslist",
- /*  88 */ "conslist ::= conslist tconscomma tcons",
- /*  89 */ "conslist ::= tcons",
- /*  90 */ "tconscomma ::= COMMA",
- /*  91 */ "tconscomma ::=",
- /*  92 */ "tcons ::= CONSTRAINT nm",
- /*  93 */ "tcons ::= PRIMARY KEY LP idxlist autoinc RP onconf",
- /*  94 */ "tcons ::= UNIQUE LP idxlist RP onconf",
- /*  95 */ "tcons ::= CHECK LP expr RP onconf",
- /*  96 */ "tcons ::= FOREIGN KEY LP idxlist RP REFERENCES nm idxlist_opt refargs defer_subclause_opt",
- /*  97 */ "defer_subclause_opt ::=",
- /*  98 */ "defer_subclause_opt ::= defer_subclause",
- /*  99 */ "onconf ::=",
- /* 100 */ "onconf ::= ON CONFLICT resolvetype",
- /* 101 */ "orconf ::=",
- /* 102 */ "orconf ::= OR resolvetype",
- /* 103 */ "resolvetype ::= raisetype",
- /* 104 */ "resolvetype ::= IGNORE",
- /* 105 */ "resolvetype ::= REPLACE",
- /* 106 */ "cmd ::= DROP TABLE ifexists fullname",
- /* 107 */ "ifexists ::= IF EXISTS",
- /* 108 */ "ifexists ::=",
- /* 109 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm AS select",
- /* 110 */ "cmd ::= DROP VIEW ifexists fullname",
- /* 111 */ "cmd ::= select",
- /* 112 */ "select ::= with selectnowith",
- /* 113 */ "selectnowith ::= oneselect",
- /* 114 */ "selectnowith ::= selectnowith multiselect_op oneselect",
- /* 115 */ "multiselect_op ::= UNION",
- /* 116 */ "multiselect_op ::= UNION ALL",
- /* 117 */ "multiselect_op ::= EXCEPT|INTERSECT",
- /* 118 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",
- /* 119 */ "oneselect ::= values",
- /* 120 */ "values ::= VALUES LP nexprlist RP",
- /* 121 */ "values ::= values COMMA LP exprlist RP",
- /* 122 */ "distinct ::= DISTINCT",
- /* 123 */ "distinct ::= ALL",
- /* 124 */ "distinct ::=",
- /* 125 */ "sclp ::= selcollist COMMA",
- /* 126 */ "sclp ::=",
- /* 127 */ "selcollist ::= sclp expr as",
- /* 128 */ "selcollist ::= sclp STAR",
- /* 129 */ "selcollist ::= sclp nm DOT STAR",
- /* 130 */ "as ::= AS nm",
- /* 131 */ "as ::= ID|STRING",
- /* 132 */ "as ::=",
- /* 133 */ "from ::=",
- /* 134 */ "from ::= FROM seltablist",
- /* 135 */ "stl_prefix ::= seltablist joinop",
- /* 136 */ "stl_prefix ::=",
- /* 137 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",
- /* 138 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",
- /* 139 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",
- /* 140 */ "dbnm ::=",
- /* 141 */ "dbnm ::= DOT nm",
- /* 142 */ "fullname ::= nm dbnm",
- /* 143 */ "joinop ::= COMMA|JOIN",
- /* 144 */ "joinop ::= JOIN_KW JOIN",
- /* 145 */ "joinop ::= JOIN_KW nm JOIN",
- /* 146 */ "joinop ::= JOIN_KW nm nm JOIN",
- /* 147 */ "on_opt ::= ON expr",
- /* 148 */ "on_opt ::=",
- /* 149 */ "indexed_opt ::=",
- /* 150 */ "indexed_opt ::= INDEXED BY nm",
- /* 151 */ "indexed_opt ::= NOT INDEXED",
- /* 152 */ "using_opt ::= USING LP idlist RP",
- /* 153 */ "using_opt ::=",
- /* 154 */ "orderby_opt ::=",
- /* 155 */ "orderby_opt ::= ORDER BY sortlist",
- /* 156 */ "sortlist ::= sortlist COMMA expr sortorder",
- /* 157 */ "sortlist ::= expr sortorder",
- /* 158 */ "sortorder ::= ASC",
- /* 159 */ "sortorder ::= DESC",
- /* 160 */ "sortorder ::=",
- /* 161 */ "groupby_opt ::=",
- /* 162 */ "groupby_opt ::= GROUP BY nexprlist",
- /* 163 */ "having_opt ::=",
- /* 164 */ "having_opt ::= HAVING expr",
- /* 165 */ "limit_opt ::=",
- /* 166 */ "limit_opt ::= LIMIT expr",
- /* 167 */ "limit_opt ::= LIMIT expr OFFSET expr",
- /* 168 */ "limit_opt ::= LIMIT expr COMMA expr",
- /* 169 */ "cmd ::= with DELETE FROM fullname indexed_opt where_opt",
- /* 170 */ "where_opt ::=",
- /* 171 */ "where_opt ::= WHERE expr",
- /* 172 */ "cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt",
- /* 173 */ "setlist ::= setlist COMMA nm EQ expr",
- /* 174 */ "setlist ::= nm EQ expr",
- /* 175 */ "cmd ::= with insert_cmd INTO fullname inscollist_opt select",
- /* 176 */ "cmd ::= with insert_cmd INTO fullname inscollist_opt DEFAULT VALUES",
- /* 177 */ "insert_cmd ::= INSERT orconf",
- /* 178 */ "insert_cmd ::= REPLACE",
- /* 179 */ "inscollist_opt ::=",
- /* 180 */ "inscollist_opt ::= LP idlist RP",
- /* 181 */ "idlist ::= idlist COMMA nm",
- /* 182 */ "idlist ::= nm",
- /* 183 */ "expr ::= term",
- /* 184 */ "expr ::= LP expr RP",
- /* 185 */ "term ::= NULL",
- /* 186 */ "expr ::= ID|INDEXED",
- /* 187 */ "expr ::= JOIN_KW",
- /* 188 */ "expr ::= nm DOT nm",
- /* 189 */ "expr ::= nm DOT nm DOT nm",
- /* 190 */ "term ::= INTEGER|FLOAT|BLOB",
- /* 191 */ "term ::= STRING",
- /* 192 */ "expr ::= VARIABLE",
- /* 193 */ "expr ::= expr COLLATE ID|STRING",
- /* 194 */ "expr ::= CAST LP expr AS typetoken RP",
- /* 195 */ "expr ::= ID|INDEXED LP distinct exprlist RP",
- /* 196 */ "expr ::= ID|INDEXED LP STAR RP",
- /* 197 */ "term ::= CTIME_KW",
- /* 198 */ "expr ::= expr AND expr",
- /* 199 */ "expr ::= expr OR expr",
- /* 200 */ "expr ::= expr LT|GT|GE|LE expr",
- /* 201 */ "expr ::= expr EQ|NE expr",
- /* 202 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",
- /* 203 */ "expr ::= expr PLUS|MINUS expr",
- /* 204 */ "expr ::= expr STAR|SLASH|REM expr",
- /* 205 */ "expr ::= expr CONCAT expr",
- /* 206 */ "likeop ::= LIKE_KW|MATCH",
- /* 207 */ "likeop ::= NOT LIKE_KW|MATCH",
- /* 208 */ "expr ::= expr likeop expr",
- /* 209 */ "expr ::= expr likeop expr ESCAPE expr",
- /* 210 */ "expr ::= expr ISNULL|NOTNULL",
- /* 211 */ "expr ::= expr NOT NULL",
- /* 212 */ "expr ::= expr IS expr",
- /* 213 */ "expr ::= expr IS NOT expr",
- /* 214 */ "expr ::= NOT expr",
- /* 215 */ "expr ::= BITNOT expr",
- /* 216 */ "expr ::= MINUS expr",
- /* 217 */ "expr ::= PLUS expr",
- /* 218 */ "between_op ::= BETWEEN",
- /* 219 */ "between_op ::= NOT BETWEEN",
- /* 220 */ "expr ::= expr between_op expr AND expr",
- /* 221 */ "in_op ::= IN",
- /* 222 */ "in_op ::= NOT IN",
- /* 223 */ "expr ::= expr in_op LP exprlist RP",
- /* 224 */ "expr ::= LP select RP",
- /* 225 */ "expr ::= expr in_op LP select RP",
- /* 226 */ "expr ::= expr in_op nm dbnm",
- /* 227 */ "expr ::= EXISTS LP select RP",
- /* 228 */ "expr ::= CASE case_operand case_exprlist case_else END",
- /* 229 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",
- /* 230 */ "case_exprlist ::= WHEN expr THEN expr",
- /* 231 */ "case_else ::= ELSE expr",
- /* 232 */ "case_else ::=",
- /* 233 */ "case_operand ::= expr",
- /* 234 */ "case_operand ::=",
- /* 235 */ "exprlist ::= nexprlist",
- /* 236 */ "exprlist ::=",
- /* 237 */ "nexprlist ::= nexprlist COMMA expr",
- /* 238 */ "nexprlist ::= expr",
- /* 239 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP idxlist RP where_opt",
- /* 240 */ "uniqueflag ::= UNIQUE",
- /* 241 */ "uniqueflag ::=",
- /* 242 */ "idxlist_opt ::=",
- /* 243 */ "idxlist_opt ::= LP idxlist RP",
- /* 244 */ "idxlist ::= idxlist COMMA nm collate sortorder",
- /* 245 */ "idxlist ::= nm collate sortorder",
- /* 246 */ "collate ::=",
- /* 247 */ "collate ::= COLLATE ID|STRING",
- /* 248 */ "cmd ::= DROP INDEX ifexists fullname",
- /* 249 */ "cmd ::= VACUUM",
- /* 250 */ "cmd ::= VACUUM nm",
- /* 251 */ "cmd ::= PRAGMA nm dbnm",
- /* 252 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",
- /* 253 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",
- /* 254 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",
- /* 255 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",
- /* 256 */ "nmnum ::= plus_num",
- /* 257 */ "nmnum ::= nm",
- /* 258 */ "nmnum ::= ON",
- /* 259 */ "nmnum ::= DELETE",
- /* 260 */ "nmnum ::= DEFAULT",
- /* 261 */ "plus_num ::= PLUS INTEGER|FLOAT",
- /* 262 */ "plus_num ::= INTEGER|FLOAT",
- /* 263 */ "minus_num ::= MINUS INTEGER|FLOAT",
- /* 264 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",
- /* 265 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",
- /* 266 */ "trigger_time ::= BEFORE",
- /* 267 */ "trigger_time ::= AFTER",
- /* 268 */ "trigger_time ::= INSTEAD OF",
- /* 269 */ "trigger_time ::=",
- /* 270 */ "trigger_event ::= DELETE|INSERT",
- /* 271 */ "trigger_event ::= UPDATE",
- /* 272 */ "trigger_event ::= UPDATE OF idlist",
- /* 273 */ "foreach_clause ::=",
- /* 274 */ "foreach_clause ::= FOR EACH ROW",
- /* 275 */ "when_clause ::=",
- /* 276 */ "when_clause ::= WHEN expr",
- /* 277 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",
- /* 278 */ "trigger_cmd_list ::= trigger_cmd SEMI",
- /* 279 */ "trnm ::= nm",
- /* 280 */ "trnm ::= nm DOT nm",
- /* 281 */ "tridxby ::=",
- /* 282 */ "tridxby ::= INDEXED BY nm",
- /* 283 */ "tridxby ::= NOT INDEXED",
- /* 284 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt",
- /* 285 */ "trigger_cmd ::= insert_cmd INTO trnm inscollist_opt select",
- /* 286 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt",
- /* 287 */ "trigger_cmd ::= select",
- /* 288 */ "expr ::= RAISE LP IGNORE RP",
- /* 289 */ "expr ::= RAISE LP raisetype COMMA nm RP",
- /* 290 */ "raisetype ::= ROLLBACK",
- /* 291 */ "raisetype ::= ABORT",
- /* 292 */ "raisetype ::= FAIL",
- /* 293 */ "cmd ::= DROP TRIGGER ifexists fullname",
- /* 294 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",
- /* 295 */ "cmd ::= DETACH database_kw_opt expr",
- /* 296 */ "key_opt ::=",
- /* 297 */ "key_opt ::= KEY expr",
- /* 298 */ "database_kw_opt ::= DATABASE",
- /* 299 */ "database_kw_opt ::=",
- /* 300 */ "cmd ::= REINDEX",
- /* 301 */ "cmd ::= REINDEX nm dbnm",
- /* 302 */ "cmd ::= ANALYZE",
- /* 303 */ "cmd ::= ANALYZE nm dbnm",
- /* 304 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",
- /* 305 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column",
- /* 306 */ "add_column_fullname ::= fullname",
- /* 307 */ "kwcolumn_opt ::=",
- /* 308 */ "kwcolumn_opt ::= COLUMNKW",
- /* 309 */ "cmd ::= create_vtab",
- /* 310 */ "cmd ::= create_vtab LP vtabarglist RP",
- /* 311 */ "create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm",
- /* 312 */ "vtabarglist ::= vtabarg",
- /* 313 */ "vtabarglist ::= vtabarglist COMMA vtabarg",
- /* 314 */ "vtabarg ::=",
- /* 315 */ "vtabarg ::= vtabarg vtabargtoken",
- /* 316 */ "vtabargtoken ::= ANY",
- /* 317 */ "vtabargtoken ::= lp anylist RP",
- /* 318 */ "lp ::= LP",
- /* 319 */ "anylist ::=",
- /* 320 */ "anylist ::= anylist LP anylist RP",
- /* 321 */ "anylist ::= anylist ANY",
- /* 322 */ "with ::=",
- /* 323 */ "with ::= WITH wqlist",
- /* 324 */ "with ::= WITH RECURSIVE wqlist",
- /* 325 */ "wqlist ::= nm idxlist_opt AS LP select RP",
- /* 326 */ "wqlist ::= wqlist COMMA nm idxlist_opt AS LP select RP",
-};
-#endif /* NDEBUG */
+static int fts3ColumnlistCount(char **ppCollist){
+  char *pEnd = *ppCollist;
+  char c = 0;
+  int nEntry = 0;
 
+  /* A column-list is terminated by either a 0x01 or 0x00. */
+  while( 0xFE & (*pEnd | c) ){
+    c = *pEnd++ & 0x80;
+    if( !c ) nEntry++;
+  }
+
+  *ppCollist = pEnd;
+  return nEntry;
+}
 
-#if YYSTACKDEPTH<=0
 /*
-** Try to increase the size of the parser stack.
+** This function gathers 'y' or 'b' data for a single phrase.
 */
-static void yyGrowStack(yyParser *p){
-  int newSize;
-  yyStackEntry *pNew;
+static void fts3ExprLHits(
+  Fts3Expr *pExpr,                /* Phrase expression node */
+  MatchInfo *p                    /* Matchinfo context */
+){
+  Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;
+  int iStart;
+  Fts3Phrase *pPhrase = pExpr->pPhrase;
+  char *pIter = pPhrase->doclist.pList;
+  int iCol = 0;
 
-  newSize = p->yystksz*2 + 100;
-  pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));
-  if( pNew ){
-    p->yystack = pNew;
-    p->yystksz = newSize;
-#ifndef NDEBUG
-    if( yyTraceFILE ){
-      fprintf(yyTraceFILE,"%sStack grows to %d entries!\n",
-              yyTracePrompt, p->yystksz);
+  assert( p->flag==FTS3_MATCHINFO_LHITS_BM || p->flag==FTS3_MATCHINFO_LHITS );
+  if( p->flag==FTS3_MATCHINFO_LHITS ){
+    iStart = pExpr->iPhrase * p->nCol;
+  }else{
+    iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);
+  }
+
+  while( 1 ){
+    int nHit = fts3ColumnlistCount(&pIter);
+    if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
+      if( p->flag==FTS3_MATCHINFO_LHITS ){
+        p->aMatchinfo[iStart + iCol] = (u32)nHit;
+      }else if( nHit ){
+        p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));
+      }
     }
-#endif
+    assert( *pIter==0x00 || *pIter==0x01 );
+    if( *pIter!=0x01 ) break;
+    pIter++;
+    pIter += fts3GetVarint32(pIter, &iCol);
   }
 }
-#endif
 
-/* 
-** This function allocates a new parser.
-** The only argument is a pointer to a function which works like
-** malloc.
-**
-** Inputs:
-** A pointer to the function used to allocate memory.
-**
-** Outputs:
-** A pointer to a parser.  This pointer is used in subsequent calls
-** to sqlite3Parser and sqlite3ParserFree.
+/*
+** Gather the results for matchinfo directives 'y' and 'b'.
 */
-SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(u64)){
-  yyParser *pParser;
-  pParser = (yyParser*)(*mallocProc)( (u64)sizeof(yyParser) );
-  if( pParser ){
-    pParser->yyidx = -1;
-#ifdef YYTRACKMAXSTACKDEPTH
-    pParser->yyidxMax = 0;
-#endif
-#if YYSTACKDEPTH<=0
-    pParser->yystack = NULL;
-    pParser->yystksz = 0;
-    yyGrowStack(pParser);
-#endif
+static void fts3ExprLHitGather(
+  Fts3Expr *pExpr,
+  MatchInfo *p
+){
+  assert( (pExpr->pLeft==0)==(pExpr->pRight==0) );
+  if( pExpr->bEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){
+    if( pExpr->pLeft ){
+      fts3ExprLHitGather(pExpr->pLeft, p);
+      fts3ExprLHitGather(pExpr->pRight, p);
+    }else{
+      fts3ExprLHits(pExpr, p);
+    }
   }
-  return pParser;
 }
 
-/* The following function deletes the value associated with a
-** symbol.  The symbol can be either a terminal or nonterminal.
-** "yymajor" is the symbol code, and "yypminor" is a pointer to
-** the value.
+/*
+** fts3ExprIterate() callback used to collect the "global" matchinfo stats
+** for a single query. 
+**
+** fts3ExprIterate() callback to load the 'global' elements of a
+** FTS3_MATCHINFO_HITS matchinfo array. The global stats are those elements 
+** of the matchinfo array that are constant for all rows returned by the 
+** current query.
+**
+** Argument pCtx is actually a pointer to a struct of type MatchInfo. This
+** function populates Matchinfo.aMatchinfo[] as follows:
+**
+**   for(iCol=0; iColdb, (yypminor->yy3));
-}
-      break;
-    case 174: /* term */
-    case 175: /* expr */
-{
-sqlite3ExprDelete(pParse->db, (yypminor->yy346).pExpr);
-}
-      break;
-    case 179: /* idxlist_opt */
-    case 188: /* idxlist */
-    case 200: /* selcollist */
-    case 203: /* groupby_opt */
-    case 205: /* orderby_opt */
-    case 208: /* nexprlist */
-    case 209: /* exprlist */
-    case 210: /* sclp */
-    case 220: /* sortlist */
-    case 221: /* setlist */
-    case 228: /* case_exprlist */
-{
-sqlite3ExprListDelete(pParse->db, (yypminor->yy14));
+  MatchInfo *p = (MatchInfo *)pCtx;
+  return sqlite3Fts3EvalPhraseStats(
+      p->pCursor, pExpr, &p->aMatchinfo[3*iPhrase*p->nCol]
+  );
 }
-      break;
-    case 194: /* fullname */
-    case 201: /* from */
-    case 212: /* seltablist */
-    case 213: /* stl_prefix */
-{
-sqlite3SrcListDelete(pParse->db, (yypminor->yy65));
+
+/*
+** fts3ExprIterate() callback used to collect the "local" part of the
+** FTS3_MATCHINFO_HITS array. The local stats are those elements of the 
+** array that are different for each row returned by the query.
+*/
+static int fts3ExprLocalHitsCb(
+  Fts3Expr *pExpr,                /* Phrase expression node */
+  int iPhrase,                    /* Phrase number */
+  void *pCtx                      /* Pointer to MatchInfo structure */
+){
+  int rc = SQLITE_OK;
+  MatchInfo *p = (MatchInfo *)pCtx;
+  int iStart = iPhrase * p->nCol * 3;
+  int i;
+
+  for(i=0; inCol && rc==SQLITE_OK; i++){
+    char *pCsr;
+    rc = sqlite3Fts3EvalPhrasePoslist(p->pCursor, pExpr, i, &pCsr);
+    if( pCsr ){
+      p->aMatchinfo[iStart+i*3] = fts3ColumnlistCount(&pCsr);
+    }else{
+      p->aMatchinfo[iStart+i*3] = 0;
+    }
+  }
+
+  return rc;
 }
-      break;
-    case 197: /* with */
-    case 252: /* wqlist */
-{
-sqlite3WithDelete(pParse->db, (yypminor->yy59));
+
+static int fts3MatchinfoCheck(
+  Fts3Table *pTab, 
+  char cArg,
+  char **pzErr
+){
+  if( (cArg==FTS3_MATCHINFO_NPHRASE)
+   || (cArg==FTS3_MATCHINFO_NCOL)
+   || (cArg==FTS3_MATCHINFO_NDOC && pTab->bFts4)
+   || (cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bFts4)
+   || (cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize)
+   || (cArg==FTS3_MATCHINFO_LCS)
+   || (cArg==FTS3_MATCHINFO_HITS)
+   || (cArg==FTS3_MATCHINFO_LHITS)
+   || (cArg==FTS3_MATCHINFO_LHITS_BM)
+  ){
+    return SQLITE_OK;
+  }
+  sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);
+  return SQLITE_ERROR;
 }
+
+static int fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
+  int nVal;                       /* Number of integers output by cArg */
+
+  switch( cArg ){
+    case FTS3_MATCHINFO_NDOC:
+    case FTS3_MATCHINFO_NPHRASE: 
+    case FTS3_MATCHINFO_NCOL: 
+      nVal = 1;
       break;
-    case 202: /* where_opt */
-    case 204: /* having_opt */
-    case 216: /* on_opt */
-    case 227: /* case_operand */
-    case 229: /* case_else */
-    case 238: /* when_clause */
-    case 243: /* key_opt */
-{
-sqlite3ExprDelete(pParse->db, (yypminor->yy132));
-}
+
+    case FTS3_MATCHINFO_AVGLENGTH:
+    case FTS3_MATCHINFO_LENGTH:
+    case FTS3_MATCHINFO_LCS:
+      nVal = pInfo->nCol;
       break;
-    case 217: /* using_opt */
-    case 219: /* idlist */
-    case 223: /* inscollist_opt */
-{
-sqlite3IdListDelete(pParse->db, (yypminor->yy408));
-}
+
+    case FTS3_MATCHINFO_LHITS:
+      nVal = pInfo->nCol * pInfo->nPhrase;
       break;
-    case 234: /* trigger_cmd_list */
-    case 239: /* trigger_cmd */
-{
-sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy473));
-}
+
+    case FTS3_MATCHINFO_LHITS_BM:
+      nVal = pInfo->nPhrase * ((pInfo->nCol + 31) / 32);
       break;
-    case 236: /* trigger_event */
-{
-sqlite3IdListDelete(pParse->db, (yypminor->yy378).b);
-}
+
+    default:
+      assert( cArg==FTS3_MATCHINFO_HITS );
+      nVal = pInfo->nCol * pInfo->nPhrase * 3;
       break;
-    default:  break;   /* If no destructor action specified: do nothing */
   }
+
+  return nVal;
 }
 
-/*
-** Pop the parser's stack once.
-**
-** If there is a destructor routine associated with the token which
-** is popped from the stack, then call it.
-**
-** Return the major token number for the symbol popped.
-*/
-static int yy_pop_parser_stack(yyParser *pParser){
-  YYCODETYPE yymajor;
-  yyStackEntry *yytos = &pParser->yystack[pParser->yyidx];
+static int fts3MatchinfoSelectDoctotal(
+  Fts3Table *pTab,
+  sqlite3_stmt **ppStmt,
+  sqlite3_int64 *pnDoc,
+  const char **paLen
+){
+  sqlite3_stmt *pStmt;
+  const char *a;
+  sqlite3_int64 nDoc;
 
-  /* There is no mechanism by which the parser stack can be popped below
-  ** empty in SQLite.  */
-  if( NEVER(pParser->yyidx<0) ) return 0;
-#ifndef NDEBUG
-  if( yyTraceFILE && pParser->yyidx>=0 ){
-    fprintf(yyTraceFILE,"%sPopping %s\n",
-      yyTracePrompt,
-      yyTokenName[yytos->major]);
+  if( !*ppStmt ){
+    int rc = sqlite3Fts3SelectDoctotal(pTab, ppStmt);
+    if( rc!=SQLITE_OK ) return rc;
   }
-#endif
-  yymajor = yytos->major;
-  yy_destructor(pParser, yymajor, &yytos->minor);
-  pParser->yyidx--;
-  return yymajor;
+  pStmt = *ppStmt;
+  assert( sqlite3_data_count(pStmt)==1 );
+
+  a = sqlite3_column_blob(pStmt, 0);
+  a += sqlite3Fts3GetVarint(a, &nDoc);
+  if( nDoc==0 ) return FTS_CORRUPT_VTAB;
+  *pnDoc = (u32)nDoc;
+
+  if( paLen ) *paLen = a;
+  return SQLITE_OK;
 }
 
+/*
+** An instance of the following structure is used to store state while 
+** iterating through a multi-column position-list corresponding to the
+** hits for a single phrase on a single row in order to calculate the
+** values for a matchinfo() FTS3_MATCHINFO_LCS request.
+*/
+typedef struct LcsIterator LcsIterator;
+struct LcsIterator {
+  Fts3Expr *pExpr;                /* Pointer to phrase expression */
+  int iPosOffset;                 /* Tokens count up to end of this phrase */
+  char *pRead;                    /* Cursor used to iterate through aDoclist */
+  int iPos;                       /* Current position */
+};
+
 /* 
-** Deallocate and destroy a parser.  Destructors are all called for
-** all stack elements before shutting the parser down.
-**
-** Inputs:
-** 
      
-** 
    •   A pointer to the parser.  This should be a pointer
-**       obtained from sqlite3ParserAlloc.
-** 
    •   A pointer to a function used to reclaim memory obtained
-**       from malloc.
-** 
    
+** If LcsIterator.iCol is set to the following value, the iterator has
+** finished iterating through all offsets for all columns.
 */
-SQLITE_PRIVATE void sqlite3ParserFree(
-  void *p,                    /* The parser to be deleted */
-  void (*freeProc)(void*)     /* Function used to reclaim memory */
+#define LCS_ITERATOR_FINISHED 0x7FFFFFFF;
+
+static int fts3MatchinfoLcsCb(
+  Fts3Expr *pExpr,                /* Phrase expression node */
+  int iPhrase,                    /* Phrase number (numbered from zero) */
+  void *pCtx                      /* Pointer to MatchInfo structure */
 ){
-  yyParser *pParser = (yyParser*)p;
-  /* In SQLite, we never try to destroy a parser that was not successfully
-  ** created in the first place. */
-  if( NEVER(pParser==0) ) return;
-  while( pParser->yyidx>=0 ) yy_pop_parser_stack(pParser);
-#if YYSTACKDEPTH<=0
-  free(pParser->yystack);
-#endif
-  (*freeProc)((void*)pParser);
+  LcsIterator *aIter = (LcsIterator *)pCtx;
+  aIter[iPhrase].pExpr = pExpr;
+  return SQLITE_OK;
 }
 
 /*
-** Return the peak depth of the stack for a parser.
+** Advance the iterator passed as an argument to the next position. Return
+** 1 if the iterator is at EOF or if it now points to the start of the
+** position list for the next column.
 */
-#ifdef YYTRACKMAXSTACKDEPTH
-SQLITE_PRIVATE int sqlite3ParserStackPeak(void *p){
-  yyParser *pParser = (yyParser*)p;
-  return pParser->yyidxMax;
-}
-#endif
+static int fts3LcsIteratorAdvance(LcsIterator *pIter){
+  char *pRead = pIter->pRead;
+  sqlite3_int64 iRead;
+  int rc = 0;
+
+  pRead += sqlite3Fts3GetVarint(pRead, &iRead);
+  if( iRead==0 || iRead==1 ){
+    pRead = 0;
+    rc = 1;
+  }else{
+    pIter->iPos += (int)(iRead-2);
+  }
 
+  pIter->pRead = pRead;
+  return rc;
+}
+  
 /*
-** Find the appropriate action for a parser given the terminal
-** look-ahead token iLookAhead.
+** This function implements the FTS3_MATCHINFO_LCS matchinfo() flag. 
 **
-** If the look-ahead token is YYNOCODE, then check to see if the action is
-** independent of the look-ahead.  If it is, return the action, otherwise
-** return YY_NO_ACTION.
+** If the call is successful, the longest-common-substring lengths for each
+** column are written into the first nCol elements of the pInfo->aMatchinfo[] 
+** array before returning. SQLITE_OK is returned in this case.
+**
+** Otherwise, if an error occurs, an SQLite error code is returned and the
+** data written to the first nCol elements of pInfo->aMatchinfo[] is 
+** undefined.
 */
-static int yy_find_shift_action(
-  yyParser *pParser,        /* The parser */
-  YYCODETYPE iLookAhead     /* The look-ahead token */
-){
+static int fts3MatchinfoLcs(Fts3Cursor *pCsr, MatchInfo *pInfo){
+  LcsIterator *aIter;
   int i;
-  int stateno = pParser->yystack[pParser->yyidx].stateno;
- 
-  if( stateno>YY_SHIFT_COUNT
-   || (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){
-    return yy_default[stateno];
+  int iCol;
+  int nToken = 0;
+
+  /* Allocate and populate the array of LcsIterator objects. The array
+  ** contains one element for each matchable phrase in the query.
+  **/
+  aIter = sqlite3_malloc(sizeof(LcsIterator) * pCsr->nPhrase);
+  if( !aIter ) return SQLITE_NOMEM;
+  memset(aIter, 0, sizeof(LcsIterator) * pCsr->nPhrase);
+  (void)fts3ExprIterate(pCsr->pExpr, fts3MatchinfoLcsCb, (void*)aIter);
+
+  for(i=0; inPhrase; i++){
+    LcsIterator *pIter = &aIter[i];
+    nToken -= pIter->pExpr->pPhrase->nToken;
+    pIter->iPosOffset = nToken;
   }
-  assert( iLookAhead!=YYNOCODE );
-  i += iLookAhead;
-  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
-    if( iLookAhead>0 ){
-#ifdef YYFALLBACK
-      YYCODETYPE iFallback;            /* Fallback token */
-      if( iLookAhead %s\n",
-             yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);
-        }
-#endif
-        return yy_find_shift_action(pParser, iFallback);
+
+  for(iCol=0; iColnCol; iCol++){
+    int nLcs = 0;                 /* LCS value for this column */
+    int nLive = 0;                /* Number of iterators in aIter not at EOF */
+
+    for(i=0; inPhrase; i++){
+      int rc;
+      LcsIterator *pIt = &aIter[i];
+      rc = sqlite3Fts3EvalPhrasePoslist(pCsr, pIt->pExpr, iCol, &pIt->pRead);
+      if( rc!=SQLITE_OK ) return rc;
+      if( pIt->pRead ){
+        pIt->iPos = pIt->iPosOffset;
+        fts3LcsIteratorAdvance(&aIter[i]);
+        nLive++;
       }
-#endif
-#ifdef YYWILDCARD
-      {
-        int j = i - iLookAhead + YYWILDCARD;
-        if( 
-#if YY_SHIFT_MIN+YYWILDCARD<0
-          j>=0 &&
-#endif
-#if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT
-          j %s\n",
-               yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[YYWILDCARD]);
+    }
+
+    while( nLive>0 ){
+      LcsIterator *pAdv = 0;      /* The iterator to advance by one position */
+      int nThisLcs = 0;           /* LCS for the current iterator positions */
+
+      for(i=0; inPhrase; i++){
+        LcsIterator *pIter = &aIter[i];
+        if( pIter->pRead==0 ){
+          /* This iterator is already at EOF for this column. */
+          nThisLcs = 0;
+        }else{
+          if( pAdv==0 || pIter->iPosiPos ){
+            pAdv = pIter;
           }
-#endif /* NDEBUG */
-          return yy_action[j];
+          if( nThisLcs==0 || pIter->iPos==pIter[-1].iPos ){
+            nThisLcs++;
+          }else{
+            nThisLcs = 1;
+          }
+          if( nThisLcs>nLcs ) nLcs = nThisLcs;
         }
       }
-#endif /* YYWILDCARD */
+      if( fts3LcsIteratorAdvance(pAdv) ) nLive--;
     }
-    return yy_default[stateno];
-  }else{
-    return yy_action[i];
+
+    pInfo->aMatchinfo[iCol] = nLcs;
   }
+
+  sqlite3_free(aIter);
+  return SQLITE_OK;
 }
 
 /*
-** Find the appropriate action for a parser given the non-terminal
-** look-ahead token iLookAhead.
+** Populate the buffer pInfo->aMatchinfo[] with an array of integers to
+** be returned by the matchinfo() function. Argument zArg contains the 
+** format string passed as the second argument to matchinfo (or the
+** default value "pcx" if no second argument was specified). The format
+** string has already been validated and the pInfo->aMatchinfo[] array
+** is guaranteed to be large enough for the output.
+**
+** If bGlobal is true, then populate all fields of the matchinfo() output.
+** If it is false, then assume that those fields that do not change between
+** rows (i.e. FTS3_MATCHINFO_NPHRASE, NCOL, NDOC, AVGLENGTH and part of HITS)
+** have already been populated.
 **
-** If the look-ahead token is YYNOCODE, then check to see if the action is
-** independent of the look-ahead.  If it is, return the action, otherwise
-** return YY_NO_ACTION.
+** Return SQLITE_OK if successful, or an SQLite error code if an error 
+** occurs. If a value other than SQLITE_OK is returned, the state the
+** pInfo->aMatchinfo[] buffer is left in is undefined.
 */
-static int yy_find_reduce_action(
-  int stateno,              /* Current state number */
-  YYCODETYPE iLookAhead     /* The look-ahead token */
+static int fts3MatchinfoValues(
+  Fts3Cursor *pCsr,               /* FTS3 cursor object */
+  int bGlobal,                    /* True to grab the global stats */
+  MatchInfo *pInfo,               /* Matchinfo context object */
+  const char *zArg                /* Matchinfo format string */
 ){
+  int rc = SQLITE_OK;
   int i;
-#ifdef YYERRORSYMBOL
-  if( stateno>YY_REDUCE_COUNT ){
-    return yy_default[stateno];
-  }
-#else
-  assert( stateno<=YY_REDUCE_COUNT );
-#endif
-  i = yy_reduce_ofst[stateno];
-  assert( i!=YY_REDUCE_USE_DFLT );
-  assert( iLookAhead!=YYNOCODE );
-  i += iLookAhead;
-#ifdef YYERRORSYMBOL
-  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
-    return yy_default[stateno];
-  }
-#else
-  assert( i>=0 && ibase.pVtab;
+  sqlite3_stmt *pSelect = 0;
 
-/*
-** The following routine is called if the stack overflows.
-*/
-static void yyStackOverflow(yyParser *yypParser, YYMINORTYPE *yypMinor){
-   sqlite3ParserARG_FETCH;
-   yypParser->yyidx--;
-#ifndef NDEBUG
-   if( yyTraceFILE ){
-     fprintf(yyTraceFILE,"%sStack Overflow!\n",yyTracePrompt);
-   }
-#endif
-   while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
-   /* Here code is inserted which will execute if the parser
-   ** stack every overflows */
+  for(i=0; rc==SQLITE_OK && zArg[i]; i++){
+    pInfo->flag = zArg[i];
+    switch( zArg[i] ){
+      case FTS3_MATCHINFO_NPHRASE:
+        if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nPhrase;
+        break;
 
-  UNUSED_PARAMETER(yypMinor); /* Silence some compiler warnings */
-  sqlite3ErrorMsg(pParse, "parser stack overflow");
-   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
-}
+      case FTS3_MATCHINFO_NCOL:
+        if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nCol;
+        break;
+        
+      case FTS3_MATCHINFO_NDOC:
+        if( bGlobal ){
+          sqlite3_int64 nDoc = 0;
+          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0);
+          pInfo->aMatchinfo[0] = (u32)nDoc;
+        }
+        break;
 
-/*
-** Perform a shift action.
-*/
-static void yy_shift(
-  yyParser *yypParser,          /* The parser to be shifted */
-  int yyNewState,               /* The new state to shift in */
-  int yyMajor,                  /* The major token to shift in */
-  YYMINORTYPE *yypMinor         /* Pointer to the minor token to shift in */
-){
-  yyStackEntry *yytos;
-  yypParser->yyidx++;
-#ifdef YYTRACKMAXSTACKDEPTH
-  if( yypParser->yyidx>yypParser->yyidxMax ){
-    yypParser->yyidxMax = yypParser->yyidx;
-  }
-#endif
-#if YYSTACKDEPTH>0 
-  if( yypParser->yyidx>=YYSTACKDEPTH ){
-    yyStackOverflow(yypParser, yypMinor);
-    return;
-  }
-#else
-  if( yypParser->yyidx>=yypParser->yystksz ){
-    yyGrowStack(yypParser);
-    if( yypParser->yyidx>=yypParser->yystksz ){
-      yyStackOverflow(yypParser, yypMinor);
-      return;
+      case FTS3_MATCHINFO_AVGLENGTH: 
+        if( bGlobal ){
+          sqlite3_int64 nDoc;     /* Number of rows in table */
+          const char *a;          /* Aggregate column length array */
+
+          rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);
+          if( rc==SQLITE_OK ){
+            int iCol;
+            for(iCol=0; iColnCol; iCol++){
+              u32 iVal;
+              sqlite3_int64 nToken;
+              a += sqlite3Fts3GetVarint(a, &nToken);
+              iVal = (u32)(((u32)(nToken&0xffffffff)+nDoc/2)/nDoc);
+              pInfo->aMatchinfo[iCol] = iVal;
+            }
+          }
+        }
+        break;
+
+      case FTS3_MATCHINFO_LENGTH: {
+        sqlite3_stmt *pSelectDocsize = 0;
+        rc = sqlite3Fts3SelectDocsize(pTab, pCsr->iPrevId, &pSelectDocsize);
+        if( rc==SQLITE_OK ){
+          int iCol;
+          const char *a = sqlite3_column_blob(pSelectDocsize, 0);
+          for(iCol=0; iColnCol; iCol++){
+            sqlite3_int64 nToken;
+            a += sqlite3Fts3GetVarint(a, &nToken);
+            pInfo->aMatchinfo[iCol] = (u32)nToken;
+          }
+        }
+        sqlite3_reset(pSelectDocsize);
+        break;
+      }
+
+      case FTS3_MATCHINFO_LCS:
+        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
+        if( rc==SQLITE_OK ){
+          rc = fts3MatchinfoLcs(pCsr, pInfo);
+        }
+        break;
+
+      case FTS3_MATCHINFO_LHITS_BM:
+      case FTS3_MATCHINFO_LHITS: {
+        int nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);
+        memset(pInfo->aMatchinfo, 0, nZero);
+        fts3ExprLHitGather(pCsr->pExpr, pInfo);
+        break;
+      }
+
+      default: {
+        Fts3Expr *pExpr;
+        assert( zArg[i]==FTS3_MATCHINFO_HITS );
+        pExpr = pCsr->pExpr;
+        rc = fts3ExprLoadDoclists(pCsr, 0, 0);
+        if( rc!=SQLITE_OK ) break;
+        if( bGlobal ){
+          if( pCsr->pDeferred ){
+            rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);
+            if( rc!=SQLITE_OK ) break;
+          }
+          rc = fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
+          sqlite3Fts3EvalTestDeferred(pCsr, &rc);
+          if( rc!=SQLITE_OK ) break;
+        }
+        (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);
+        break;
+      }
     }
+
+    pInfo->aMatchinfo += fts3MatchinfoSize(pInfo, zArg[i]);
   }
-#endif
-  yytos = &yypParser->yystack[yypParser->yyidx];
-  yytos->stateno = (YYACTIONTYPE)yyNewState;
-  yytos->major = (YYCODETYPE)yyMajor;
-  yytos->minor = *yypMinor;
-#ifndef NDEBUG
-  if( yyTraceFILE && yypParser->yyidx>0 ){
-    int i;
-    fprintf(yyTraceFILE,"%sShift %d\n",yyTracePrompt,yyNewState);
-    fprintf(yyTraceFILE,"%sStack:",yyTracePrompt);
-    for(i=1; i<=yypParser->yyidx; i++)
-      fprintf(yyTraceFILE," %s",yyTokenName[yypParser->yystack[i].major]);
-    fprintf(yyTraceFILE,"\n");
-  }
-#endif
-}
 
-/* The following table contains information about every rule that
-** is used during the reduce.
-*/
-static const struct {
-  YYCODETYPE lhs;         /* Symbol on the left-hand side of the rule */
-  unsigned char nrhs;     /* Number of right-hand side symbols in the rule */
-} yyRuleInfo[] = {
-  { 144, 1 },
-  { 145, 2 },
-  { 145, 1 },
-  { 146, 1 },
-  { 146, 3 },
-  { 147, 0 },
-  { 147, 1 },
-  { 147, 3 },
-  { 148, 1 },
-  { 149, 3 },
-  { 151, 0 },
-  { 151, 1 },
-  { 151, 2 },
-  { 150, 0 },
-  { 150, 1 },
-  { 150, 1 },
-  { 150, 1 },
-  { 149, 2 },
-  { 149, 2 },
-  { 149, 2 },
-  { 153, 1 },
-  { 153, 0 },
-  { 149, 2 },
-  { 149, 3 },
-  { 149, 5 },
-  { 149, 2 },
-  { 154, 6 },
-  { 156, 1 },
-  { 158, 0 },
-  { 158, 3 },
-  { 157, 1 },
-  { 157, 0 },
-  { 155, 5 },
-  { 155, 2 },
-  { 162, 0 },
-  { 162, 2 },
-  { 160, 3 },
-  { 160, 1 },
-  { 164, 3 },
-  { 165, 1 },
-  { 152, 1 },
-  { 152, 1 },
-  { 152, 1 },
-  { 166, 0 },
-  { 166, 1 },
-  { 168, 1 },
-  { 168, 4 },
-  { 168, 6 },
-  { 169, 1 },
-  { 169, 2 },
-  { 170, 1 },
-  { 170, 1 },
-  { 167, 2 },
-  { 167, 0 },
-  { 173, 2 },
-  { 173, 2 },
-  { 173, 4 },
-  { 173, 3 },
-  { 173, 3 },
-  { 173, 2 },
-  { 173, 2 },
-  { 173, 3 },
-  { 173, 5 },
-  { 173, 2 },
-  { 173, 4 },
-  { 173, 4 },
-  { 173, 1 },
-  { 173, 2 },
-  { 178, 0 },
-  { 178, 1 },
-  { 180, 0 },
-  { 180, 2 },
-  { 182, 2 },
-  { 182, 3 },
-  { 182, 3 },
-  { 182, 3 },
-  { 183, 2 },
-  { 183, 2 },
-  { 183, 1 },
-  { 183, 1 },
-  { 183, 2 },
-  { 181, 3 },
-  { 181, 2 },
-  { 184, 0 },
-  { 184, 2 },
-  { 184, 2 },
-  { 161, 0 },
-  { 161, 2 },
-  { 185, 3 },
-  { 185, 1 },
-  { 186, 1 },
-  { 186, 0 },
-  { 187, 2 },
-  { 187, 7 },
-  { 187, 5 },
-  { 187, 5 },
-  { 187, 10 },
-  { 189, 0 },
-  { 189, 1 },
-  { 176, 0 },
-  { 176, 3 },
-  { 190, 0 },
-  { 190, 2 },
-  { 191, 1 },
-  { 191, 1 },
-  { 191, 1 },
-  { 149, 4 },
-  { 193, 2 },
-  { 193, 0 },
-  { 149, 8 },
-  { 149, 4 },
-  { 149, 1 },
-  { 163, 2 },
-  { 195, 1 },
-  { 195, 3 },
-  { 198, 1 },
-  { 198, 2 },
-  { 198, 1 },
-  { 196, 9 },
-  { 196, 1 },
-  { 207, 4 },
-  { 207, 5 },
-  { 199, 1 },
-  { 199, 1 },
-  { 199, 0 },
-  { 210, 2 },
-  { 210, 0 },
-  { 200, 3 },
-  { 200, 2 },
-  { 200, 4 },
-  { 211, 2 },
-  { 211, 1 },
-  { 211, 0 },
-  { 201, 0 },
-  { 201, 2 },
-  { 213, 2 },
-  { 213, 0 },
-  { 212, 7 },
-  { 212, 7 },
-  { 212, 7 },
-  { 159, 0 },
-  { 159, 2 },
-  { 194, 2 },
-  { 214, 1 },
-  { 214, 2 },
-  { 214, 3 },
-  { 214, 4 },
-  { 216, 2 },
-  { 216, 0 },
-  { 215, 0 },
-  { 215, 3 },
-  { 215, 2 },
-  { 217, 4 },
-  { 217, 0 },
-  { 205, 0 },
-  { 205, 3 },
-  { 220, 4 },
-  { 220, 2 },
-  { 177, 1 },
-  { 177, 1 },
-  { 177, 0 },
-  { 203, 0 },
-  { 203, 3 },
-  { 204, 0 },
-  { 204, 2 },
-  { 206, 0 },
-  { 206, 2 },
-  { 206, 4 },
-  { 206, 4 },
-  { 149, 6 },
-  { 202, 0 },
-  { 202, 2 },
-  { 149, 8 },
-  { 221, 5 },
-  { 221, 3 },
-  { 149, 6 },
-  { 149, 7 },
-  { 222, 2 },
-  { 222, 1 },
-  { 223, 0 },
-  { 223, 3 },
-  { 219, 3 },
-  { 219, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 174, 1 },
-  { 175, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 175, 5 },
-  { 174, 1 },
-  { 174, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 175, 6 },
-  { 175, 5 },
-  { 175, 4 },
-  { 174, 1 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 224, 1 },
-  { 224, 2 },
-  { 175, 3 },
-  { 175, 5 },
-  { 175, 2 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 4 },
-  { 175, 2 },
-  { 175, 2 },
-  { 175, 2 },
-  { 175, 2 },
-  { 225, 1 },
-  { 225, 2 },
-  { 175, 5 },
-  { 226, 1 },
-  { 226, 2 },
-  { 175, 5 },
-  { 175, 3 },
-  { 175, 5 },
-  { 175, 4 },
-  { 175, 4 },
-  { 175, 5 },
-  { 228, 5 },
-  { 228, 4 },
-  { 229, 2 },
-  { 229, 0 },
-  { 227, 1 },
-  { 227, 0 },
-  { 209, 1 },
-  { 209, 0 },
-  { 208, 3 },
-  { 208, 1 },
-  { 149, 12 },
-  { 230, 1 },
-  { 230, 0 },
-  { 179, 0 },
-  { 179, 3 },
-  { 188, 5 },
-  { 188, 3 },
-  { 231, 0 },
-  { 231, 2 },
-  { 149, 4 },
-  { 149, 1 },
-  { 149, 2 },
-  { 149, 3 },
-  { 149, 5 },
-  { 149, 6 },
-  { 149, 5 },
-  { 149, 6 },
-  { 232, 1 },
-  { 232, 1 },
-  { 232, 1 },
-  { 232, 1 },
-  { 232, 1 },
-  { 171, 2 },
-  { 171, 1 },
-  { 172, 2 },
-  { 149, 5 },
-  { 233, 11 },
-  { 235, 1 },
-  { 235, 1 },
-  { 235, 2 },
-  { 235, 0 },
-  { 236, 1 },
-  { 236, 1 },
-  { 236, 3 },
-  { 237, 0 },
-  { 237, 3 },
-  { 238, 0 },
-  { 238, 2 },
-  { 234, 3 },
-  { 234, 2 },
-  { 240, 1 },
-  { 240, 3 },
-  { 241, 0 },
-  { 241, 3 },
-  { 241, 2 },
-  { 239, 7 },
-  { 239, 5 },
-  { 239, 5 },
-  { 239, 1 },
-  { 175, 4 },
-  { 175, 6 },
-  { 192, 1 },
-  { 192, 1 },
-  { 192, 1 },
-  { 149, 4 },
-  { 149, 6 },
-  { 149, 3 },
-  { 243, 0 },
-  { 243, 2 },
-  { 242, 1 },
-  { 242, 0 },
-  { 149, 1 },
-  { 149, 3 },
-  { 149, 1 },
-  { 149, 3 },
-  { 149, 6 },
-  { 149, 6 },
-  { 244, 1 },
-  { 245, 0 },
-  { 245, 1 },
-  { 149, 1 },
-  { 149, 4 },
-  { 246, 8 },
-  { 247, 1 },
-  { 247, 3 },
-  { 248, 0 },
-  { 248, 2 },
-  { 249, 1 },
-  { 249, 3 },
-  { 250, 1 },
-  { 251, 0 },
-  { 251, 4 },
-  { 251, 2 },
-  { 197, 0 },
-  { 197, 2 },
-  { 197, 3 },
-  { 252, 6 },
-  { 252, 8 },
-};
+  sqlite3_reset(pSelect);
+  return rc;
+}
 
-static void yy_accept(yyParser*);  /* Forward Declaration */
 
 /*
-** Perform a reduce action and the shift that must immediately
-** follow the reduce.
+** Populate pCsr->aMatchinfo[] with data for the current row. The 
+** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).
 */
-static void yy_reduce(
-  yyParser *yypParser,         /* The parser */
-  int yyruleno                 /* Number of the rule by which to reduce */
+static void fts3GetMatchinfo(
+  sqlite3_context *pCtx,        /* Return results here */
+  Fts3Cursor *pCsr,               /* FTS3 Cursor object */
+  const char *zArg                /* Second argument to matchinfo() function */
 ){
-  int yygoto;                     /* The next state */
-  int yyact;                      /* The next action */
-  YYMINORTYPE yygotominor;        /* The LHS of the rule reduced */
-  yyStackEntry *yymsp;            /* The top of the parser's stack */
-  int yysize;                     /* Amount to pop the stack */
-  sqlite3ParserARG_FETCH;
-  yymsp = &yypParser->yystack[yypParser->yyidx];
-#ifndef NDEBUG
-  if( yyTraceFILE && yyruleno>=0 
-        && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
-    fprintf(yyTraceFILE, "%sReduce [%s].\n", yyTracePrompt,
-      yyRuleName[yyruleno]);
-  }
-#endif /* NDEBUG */
+  MatchInfo sInfo;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;
+  int bGlobal = 0;                /* Collect 'global' stats as well as local */
 
-  /* Silence complaints from purify about yygotominor being uninitialized
-  ** in some cases when it is copied into the stack after the following
-  ** switch.  yygotominor is uninitialized when a rule reduces that does
-  ** not set the value of its left-hand side nonterminal.  Leaving the
-  ** value of the nonterminal uninitialized is utterly harmless as long
-  ** as the value is never used.  So really the only thing this code
-  ** accomplishes is to quieten purify.  
-  **
-  ** 2007-01-16:  The wireshark project (www.wireshark.org) reports that
-  ** without this code, their parser segfaults.  I'm not sure what there
-  ** parser is doing to make this happen.  This is the second bug report
-  ** from wireshark this week.  Clearly they are stressing Lemon in ways
-  ** that it has not been previously stressed...  (SQLite ticket #2172)
-  */
-  /*memset(&yygotominor, 0, sizeof(yygotominor));*/
-  yygotominor = yyzerominor;
+  u32 *aOut = 0;
+  void (*xDestroyOut)(void*) = 0;
 
+  memset(&sInfo, 0, sizeof(MatchInfo));
+  sInfo.pCursor = pCsr;
+  sInfo.nCol = pTab->nColumn;
 
-  switch( yyruleno ){
-  /* Beginning here are the reduction cases.  A typical example
-  ** follows:
-  **   case 0:
-  **  #line  
-  **     { ... }           // User supplied code
-  **  #line  
-  **     break;
-  */
-      case 5: /* explain ::= */
-{ sqlite3BeginParse(pParse, 0); }
-        break;
-      case 6: /* explain ::= EXPLAIN */
-{ sqlite3BeginParse(pParse, 1); }
-        break;
-      case 7: /* explain ::= EXPLAIN QUERY PLAN */
-{ sqlite3BeginParse(pParse, 2); }
-        break;
-      case 8: /* cmdx ::= cmd */
-{ sqlite3FinishCoding(pParse); }
-        break;
-      case 9: /* cmd ::= BEGIN transtype trans_opt */
-{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy328);}
-        break;
-      case 13: /* transtype ::= */
-{yygotominor.yy328 = TK_DEFERRED;}
-        break;
-      case 14: /* transtype ::= DEFERRED */
-      case 15: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==15);
-      case 16: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==16);
-      case 115: /* multiselect_op ::= UNION */ yytestcase(yyruleno==115);
-      case 117: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==117);
-{yygotominor.yy328 = yymsp[0].major;}
-        break;
-      case 17: /* cmd ::= COMMIT trans_opt */
-      case 18: /* cmd ::= END trans_opt */ yytestcase(yyruleno==18);
-{sqlite3CommitTransaction(pParse);}
-        break;
-      case 19: /* cmd ::= ROLLBACK trans_opt */
-{sqlite3RollbackTransaction(pParse);}
-        break;
-      case 22: /* cmd ::= SAVEPOINT nm */
-{
-  sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &yymsp[0].minor.yy0);
-}
-        break;
-      case 23: /* cmd ::= RELEASE savepoint_opt nm */
-{
-  sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &yymsp[0].minor.yy0);
-}
-        break;
-      case 24: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */
-{
-  sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &yymsp[0].minor.yy0);
-}
-        break;
-      case 26: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
-{
-   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy328,0,0,yymsp[-2].minor.yy328);
-}
-        break;
-      case 27: /* createkw ::= CREATE */
-{
-  pParse->db->lookaside.bEnabled = 0;
-  yygotominor.yy0 = yymsp[0].minor.yy0;
-}
-        break;
-      case 28: /* ifnotexists ::= */
-      case 31: /* temp ::= */ yytestcase(yyruleno==31);
-      case 68: /* autoinc ::= */ yytestcase(yyruleno==68);
-      case 81: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */ yytestcase(yyruleno==81);
-      case 83: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==83);
-      case 85: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */ yytestcase(yyruleno==85);
-      case 97: /* defer_subclause_opt ::= */ yytestcase(yyruleno==97);
-      case 108: /* ifexists ::= */ yytestcase(yyruleno==108);
-      case 218: /* between_op ::= BETWEEN */ yytestcase(yyruleno==218);
-      case 221: /* in_op ::= IN */ yytestcase(yyruleno==221);
-{yygotominor.yy328 = 0;}
-        break;
-      case 29: /* ifnotexists ::= IF NOT EXISTS */
-      case 30: /* temp ::= TEMP */ yytestcase(yyruleno==30);
-      case 69: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==69);
-      case 84: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */ yytestcase(yyruleno==84);
-      case 107: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==107);
-      case 219: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==219);
-      case 222: /* in_op ::= NOT IN */ yytestcase(yyruleno==222);
-{yygotominor.yy328 = 1;}
-        break;
-      case 32: /* create_table_args ::= LP columnlist conslist_opt RP table_options */
-{
-  sqlite3EndTable(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,yymsp[0].minor.yy186,0);
-}
-        break;
-      case 33: /* create_table_args ::= AS select */
-{
-  sqlite3EndTable(pParse,0,0,0,yymsp[0].minor.yy3);
-  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy3);
-}
-        break;
-      case 34: /* table_options ::= */
-{yygotominor.yy186 = 0;}
-        break;
-      case 35: /* table_options ::= WITHOUT nm */
-{
-  if( yymsp[0].minor.yy0.n==5 && sqlite3_strnicmp(yymsp[0].minor.yy0.z,"rowid",5)==0 ){
-    yygotominor.yy186 = TF_WithoutRowid;
-  }else{
-    yygotominor.yy186 = 0;
-    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", yymsp[0].minor.yy0.n, yymsp[0].minor.yy0.z);
-  }
-}
-        break;
-      case 38: /* column ::= columnid type carglist */
-{
-  yygotominor.yy0.z = yymsp[-2].minor.yy0.z;
-  yygotominor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-2].minor.yy0.z) + pParse->sLastToken.n;
-}
-        break;
-      case 39: /* columnid ::= nm */
-{
-  sqlite3AddColumn(pParse,&yymsp[0].minor.yy0);
-  yygotominor.yy0 = yymsp[0].minor.yy0;
-  pParse->constraintName.n = 0;
-}
-        break;
-      case 40: /* nm ::= ID|INDEXED */
-      case 41: /* nm ::= STRING */ yytestcase(yyruleno==41);
-      case 42: /* nm ::= JOIN_KW */ yytestcase(yyruleno==42);
-      case 45: /* typetoken ::= typename */ yytestcase(yyruleno==45);
-      case 48: /* typename ::= ID|STRING */ yytestcase(yyruleno==48);
-      case 130: /* as ::= AS nm */ yytestcase(yyruleno==130);
-      case 131: /* as ::= ID|STRING */ yytestcase(yyruleno==131);
-      case 141: /* dbnm ::= DOT nm */ yytestcase(yyruleno==141);
-      case 150: /* indexed_opt ::= INDEXED BY nm */ yytestcase(yyruleno==150);
-      case 247: /* collate ::= COLLATE ID|STRING */ yytestcase(yyruleno==247);
-      case 256: /* nmnum ::= plus_num */ yytestcase(yyruleno==256);
-      case 257: /* nmnum ::= nm */ yytestcase(yyruleno==257);
-      case 258: /* nmnum ::= ON */ yytestcase(yyruleno==258);
-      case 259: /* nmnum ::= DELETE */ yytestcase(yyruleno==259);
-      case 260: /* nmnum ::= DEFAULT */ yytestcase(yyruleno==260);
-      case 261: /* plus_num ::= PLUS INTEGER|FLOAT */ yytestcase(yyruleno==261);
-      case 262: /* plus_num ::= INTEGER|FLOAT */ yytestcase(yyruleno==262);
-      case 263: /* minus_num ::= MINUS INTEGER|FLOAT */ yytestcase(yyruleno==263);
-      case 279: /* trnm ::= nm */ yytestcase(yyruleno==279);
-{yygotominor.yy0 = yymsp[0].minor.yy0;}
-        break;
-      case 44: /* type ::= typetoken */
-{sqlite3AddColumnType(pParse,&yymsp[0].minor.yy0);}
-        break;
-      case 46: /* typetoken ::= typename LP signed RP */
-{
-  yygotominor.yy0.z = yymsp[-3].minor.yy0.z;
-  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);
-}
-        break;
-      case 47: /* typetoken ::= typename LP signed COMMA signed RP */
-{
-  yygotominor.yy0.z = yymsp[-5].minor.yy0.z;
-  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);
-}
-        break;
-      case 49: /* typename ::= typename ID|STRING */
-{yygotominor.yy0.z=yymsp[-1].minor.yy0.z; yygotominor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}
-        break;
-      case 54: /* ccons ::= CONSTRAINT nm */
-      case 92: /* tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==92);
-{pParse->constraintName = yymsp[0].minor.yy0;}
-        break;
-      case 55: /* ccons ::= DEFAULT term */
-      case 57: /* ccons ::= DEFAULT PLUS term */ yytestcase(yyruleno==57);
-{sqlite3AddDefaultValue(pParse,&yymsp[0].minor.yy346);}
-        break;
-      case 56: /* ccons ::= DEFAULT LP expr RP */
-{sqlite3AddDefaultValue(pParse,&yymsp[-1].minor.yy346);}
-        break;
-      case 58: /* ccons ::= DEFAULT MINUS term */
-{
-  ExprSpan v;
-  v.pExpr = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy346.pExpr, 0, 0);
-  v.zStart = yymsp[-1].minor.yy0.z;
-  v.zEnd = yymsp[0].minor.yy346.zEnd;
-  sqlite3AddDefaultValue(pParse,&v);
-}
-        break;
-      case 59: /* ccons ::= DEFAULT ID|INDEXED */
-{
-  ExprSpan v;
-  spanExpr(&v, pParse, TK_STRING, &yymsp[0].minor.yy0);
-  sqlite3AddDefaultValue(pParse,&v);
-}
-        break;
-      case 61: /* ccons ::= NOT NULL onconf */
-{sqlite3AddNotNull(pParse, yymsp[0].minor.yy328);}
-        break;
-      case 62: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */
-{sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy328,yymsp[0].minor.yy328,yymsp[-2].minor.yy328);}
-        break;
-      case 63: /* ccons ::= UNIQUE onconf */
-{sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy328,0,0,0,0);}
-        break;
-      case 64: /* ccons ::= CHECK LP expr RP */
-{sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy346.pExpr);}
-        break;
-      case 65: /* ccons ::= REFERENCES nm idxlist_opt refargs */
-{sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy14,yymsp[0].minor.yy328);}
-        break;
-      case 66: /* ccons ::= defer_subclause */
-{sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy328);}
-        break;
-      case 67: /* ccons ::= COLLATE ID|STRING */
-{sqlite3AddCollateType(pParse, &yymsp[0].minor.yy0);}
-        break;
-      case 70: /* refargs ::= */
-{ yygotominor.yy328 = OE_None*0x0101; /* EV: R-19803-45884 */}
-        break;
-      case 71: /* refargs ::= refargs refarg */
-{ yygotominor.yy328 = (yymsp[-1].minor.yy328 & ~yymsp[0].minor.yy429.mask) | yymsp[0].minor.yy429.value; }
-        break;
-      case 72: /* refarg ::= MATCH nm */
-      case 73: /* refarg ::= ON INSERT refact */ yytestcase(yyruleno==73);
-{ yygotominor.yy429.value = 0;     yygotominor.yy429.mask = 0x000000; }
-        break;
-      case 74: /* refarg ::= ON DELETE refact */
-{ yygotominor.yy429.value = yymsp[0].minor.yy328;     yygotominor.yy429.mask = 0x0000ff; }
-        break;
-      case 75: /* refarg ::= ON UPDATE refact */
-{ yygotominor.yy429.value = yymsp[0].minor.yy328<<8;  yygotominor.yy429.mask = 0x00ff00; }
-        break;
-      case 76: /* refact ::= SET NULL */
-{ yygotominor.yy328 = OE_SetNull;  /* EV: R-33326-45252 */}
-        break;
-      case 77: /* refact ::= SET DEFAULT */
-{ yygotominor.yy328 = OE_SetDflt;  /* EV: R-33326-45252 */}
-        break;
-      case 78: /* refact ::= CASCADE */
-{ yygotominor.yy328 = OE_Cascade;  /* EV: R-33326-45252 */}
-        break;
-      case 79: /* refact ::= RESTRICT */
-{ yygotominor.yy328 = OE_Restrict; /* EV: R-33326-45252 */}
-        break;
-      case 80: /* refact ::= NO ACTION */
-{ yygotominor.yy328 = OE_None;     /* EV: R-33326-45252 */}
-        break;
-      case 82: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */
-      case 98: /* defer_subclause_opt ::= defer_subclause */ yytestcase(yyruleno==98);
-      case 100: /* onconf ::= ON CONFLICT resolvetype */ yytestcase(yyruleno==100);
-      case 103: /* resolvetype ::= raisetype */ yytestcase(yyruleno==103);
-{yygotominor.yy328 = yymsp[0].minor.yy328;}
-        break;
-      case 86: /* conslist_opt ::= */
-{yygotominor.yy0.n = 0; yygotominor.yy0.z = 0;}
-        break;
-      case 87: /* conslist_opt ::= COMMA conslist */
-{yygotominor.yy0 = yymsp[-1].minor.yy0;}
-        break;
-      case 90: /* tconscomma ::= COMMA */
-{pParse->constraintName.n = 0;}
-        break;
-      case 93: /* tcons ::= PRIMARY KEY LP idxlist autoinc RP onconf */
-{sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy14,yymsp[0].minor.yy328,yymsp[-2].minor.yy328,0);}
-        break;
-      case 94: /* tcons ::= UNIQUE LP idxlist RP onconf */
-{sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy14,yymsp[0].minor.yy328,0,0,0,0);}
-        break;
-      case 95: /* tcons ::= CHECK LP expr RP onconf */
-{sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy346.pExpr);}
-        break;
-      case 96: /* tcons ::= FOREIGN KEY LP idxlist RP REFERENCES nm idxlist_opt refargs defer_subclause_opt */
-{
-    sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy14, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy14, yymsp[-1].minor.yy328);
-    sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy328);
-}
-        break;
-      case 99: /* onconf ::= */
-{yygotominor.yy328 = OE_Default;}
-        break;
-      case 101: /* orconf ::= */
-{yygotominor.yy186 = OE_Default;}
-        break;
-      case 102: /* orconf ::= OR resolvetype */
-{yygotominor.yy186 = (u8)yymsp[0].minor.yy328;}
-        break;
-      case 104: /* resolvetype ::= IGNORE */
-{yygotominor.yy328 = OE_Ignore;}
-        break;
-      case 105: /* resolvetype ::= REPLACE */
-{yygotominor.yy328 = OE_Replace;}
-        break;
-      case 106: /* cmd ::= DROP TABLE ifexists fullname */
-{
-  sqlite3DropTable(pParse, yymsp[0].minor.yy65, 0, yymsp[-1].minor.yy328);
-}
-        break;
-      case 109: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm AS select */
-{
-  sqlite3CreateView(pParse, &yymsp[-7].minor.yy0, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, yymsp[0].minor.yy3, yymsp[-6].minor.yy328, yymsp[-4].minor.yy328);
-}
-        break;
-      case 110: /* cmd ::= DROP VIEW ifexists fullname */
-{
-  sqlite3DropTable(pParse, yymsp[0].minor.yy65, 1, yymsp[-1].minor.yy328);
-}
-        break;
-      case 111: /* cmd ::= select */
-{
-  SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};
-  sqlite3Select(pParse, yymsp[0].minor.yy3, &dest);
-  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy3);
-}
-        break;
-      case 112: /* select ::= with selectnowith */
-{
-  Select *p = yymsp[0].minor.yy3, *pNext, *pLoop;
-  if( p ){
-    int cnt = 0, mxSelect;
-    p->pWith = yymsp[-1].minor.yy59;
-    if( p->pPrior ){
-      u16 allValues = SF_Values;
-      pNext = 0;
-      for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){
-        pLoop->pNext = pNext;
-        pLoop->selFlags |= SF_Compound;
-        allValues &= pLoop->selFlags;
-      }
-      if( allValues ){
-        p->selFlags |= SF_AllValues;
-      }else if(
-        (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0
-        && cnt>mxSelect
-      ){
-        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
-      }
-    }
-  }else{
-    sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy59);
-  }
-  yygotominor.yy3 = p;
-}
-        break;
-      case 113: /* selectnowith ::= oneselect */
-      case 119: /* oneselect ::= values */ yytestcase(yyruleno==119);
-{yygotominor.yy3 = yymsp[0].minor.yy3;}
-        break;
-      case 114: /* selectnowith ::= selectnowith multiselect_op oneselect */
-{
-  Select *pRhs = yymsp[0].minor.yy3;
-  if( pRhs && pRhs->pPrior ){
-    SrcList *pFrom;
-    Token x;
-    x.n = 0;
-    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
-    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0,0);
-  }
-  if( pRhs ){
-    pRhs->op = (u8)yymsp[-1].minor.yy328;
-    pRhs->pPrior = yymsp[-2].minor.yy3;
-    if( yymsp[-1].minor.yy328!=TK_ALL ) pParse->hasCompound = 1;
-  }else{
-    sqlite3SelectDelete(pParse->db, yymsp[-2].minor.yy3);
+  /* If there is cached matchinfo() data, but the format string for the 
+  ** cache does not match the format string for this request, discard 
+  ** the cached data. */
+  if( pCsr->pMIBuffer && strcmp(pCsr->pMIBuffer->zMatchinfo, zArg) ){
+    sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
+    pCsr->pMIBuffer = 0;
   }
-  yygotominor.yy3 = pRhs;
-}
-        break;
-      case 116: /* multiselect_op ::= UNION ALL */
-{yygotominor.yy328 = TK_ALL;}
-        break;
-      case 118: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */
-{
-  yygotominor.yy3 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy14,yymsp[-5].minor.yy65,yymsp[-4].minor.yy132,yymsp[-3].minor.yy14,yymsp[-2].minor.yy132,yymsp[-1].minor.yy14,yymsp[-7].minor.yy381,yymsp[0].minor.yy476.pLimit,yymsp[0].minor.yy476.pOffset);
-#if SELECTTRACE_ENABLED
-  /* Populate the Select.zSelName[] string that is used to help with
-  ** query planner debugging, to differentiate between multiple Select
-  ** objects in a complex query.
-  **
-  ** If the SELECT keyword is immediately followed by a C-style comment
-  ** then extract the first few alphanumeric characters from within that
-  ** comment to be the zSelName value.  Otherwise, the label is #N where
-  ** is an integer that is incremented with each SELECT statement seen.
+
+  /* If Fts3Cursor.pMIBuffer is NULL, then this is the first time the
+  ** matchinfo function has been called for this query. In this case 
+  ** allocate the array used to accumulate the matchinfo data and
+  ** initialize those elements that are constant for every row.
   */
-  if( yygotominor.yy3!=0 ){
-    const char *z = yymsp[-8].minor.yy0.z+6;
-    int i;
-    sqlite3_snprintf(sizeof(yygotominor.yy3->zSelName), yygotominor.yy3->zSelName, "#%d",
-                     ++pParse->nSelect);
-    while( z[0]==' ' ) z++;
-    if( z[0]=='/' && z[1]=='*' ){
-      z += 2;
-      while( z[0]==' ' ) z++;
-      for(i=0; sqlite3Isalnum(z[i]); i++){}
-      sqlite3_snprintf(sizeof(yygotominor.yy3->zSelName), yygotominor.yy3->zSelName, "%.*s", i, z);
-    }
-  }
-#endif /* SELECTRACE_ENABLED */
-}
-        break;
-      case 120: /* values ::= VALUES LP nexprlist RP */
-{
-  yygotominor.yy3 = sqlite3SelectNew(pParse,yymsp[-1].minor.yy14,0,0,0,0,0,SF_Values,0,0);
-}
-        break;
-      case 121: /* values ::= values COMMA LP exprlist RP */
-{
-  Select *pRight = sqlite3SelectNew(pParse,yymsp[-1].minor.yy14,0,0,0,0,0,SF_Values,0,0);
-  if( pRight ){
-    pRight->op = TK_ALL;
-    pRight->pPrior = yymsp[-4].minor.yy3;
-    yygotominor.yy3 = pRight;
-  }else{
-    yygotominor.yy3 = yymsp[-4].minor.yy3;
-  }
-}
-        break;
-      case 122: /* distinct ::= DISTINCT */
-{yygotominor.yy381 = SF_Distinct;}
-        break;
-      case 123: /* distinct ::= ALL */
-      case 124: /* distinct ::= */ yytestcase(yyruleno==124);
-{yygotominor.yy381 = 0;}
-        break;
-      case 125: /* sclp ::= selcollist COMMA */
-      case 243: /* idxlist_opt ::= LP idxlist RP */ yytestcase(yyruleno==243);
-{yygotominor.yy14 = yymsp[-1].minor.yy14;}
-        break;
-      case 126: /* sclp ::= */
-      case 154: /* orderby_opt ::= */ yytestcase(yyruleno==154);
-      case 161: /* groupby_opt ::= */ yytestcase(yyruleno==161);
-      case 236: /* exprlist ::= */ yytestcase(yyruleno==236);
-      case 242: /* idxlist_opt ::= */ yytestcase(yyruleno==242);
-{yygotominor.yy14 = 0;}
-        break;
-      case 127: /* selcollist ::= sclp expr as */
-{
-   yygotominor.yy14 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy14, yymsp[-1].minor.yy346.pExpr);
-   if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yygotominor.yy14, &yymsp[0].minor.yy0, 1);
-   sqlite3ExprListSetSpan(pParse,yygotominor.yy14,&yymsp[-1].minor.yy346);
-}
-        break;
-      case 128: /* selcollist ::= sclp STAR */
-{
-  Expr *p = sqlite3Expr(pParse->db, TK_ALL, 0);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse, yymsp[-1].minor.yy14, p);
-}
-        break;
-      case 129: /* selcollist ::= sclp nm DOT STAR */
-{
-  Expr *pRight = sqlite3PExpr(pParse, TK_ALL, 0, 0, &yymsp[0].minor.yy0);
-  Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
-  Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy14, pDot);
-}
-        break;
-      case 132: /* as ::= */
-{yygotominor.yy0.n = 0;}
-        break;
-      case 133: /* from ::= */
-{yygotominor.yy65 = sqlite3DbMallocZero(pParse->db, sizeof(*yygotominor.yy65));}
-        break;
-      case 134: /* from ::= FROM seltablist */
-{
-  yygotominor.yy65 = yymsp[0].minor.yy65;
-  sqlite3SrcListShiftJoinType(yygotominor.yy65);
-}
-        break;
-      case 135: /* stl_prefix ::= seltablist joinop */
-{
-   yygotominor.yy65 = yymsp[-1].minor.yy65;
-   if( ALWAYS(yygotominor.yy65 && yygotominor.yy65->nSrc>0) ) yygotominor.yy65->a[yygotominor.yy65->nSrc-1].jointype = (u8)yymsp[0].minor.yy328;
-}
-        break;
-      case 136: /* stl_prefix ::= */
-{yygotominor.yy65 = 0;}
-        break;
-      case 137: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */
-{
-  yygotominor.yy65 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy65,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy132,yymsp[0].minor.yy408);
-  sqlite3SrcListIndexedBy(pParse, yygotominor.yy65, &yymsp[-2].minor.yy0);
-}
-        break;
-      case 138: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */
-{
-    yygotominor.yy65 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy65,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy3,yymsp[-1].minor.yy132,yymsp[0].minor.yy408);
-  }
-        break;
-      case 139: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */
-{
-    if( yymsp[-6].minor.yy65==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy132==0 && yymsp[0].minor.yy408==0 ){
-      yygotominor.yy65 = yymsp[-4].minor.yy65;
-    }else if( yymsp[-4].minor.yy65->nSrc==1 ){
-      yygotominor.yy65 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy65,0,0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy132,yymsp[0].minor.yy408);
-      if( yygotominor.yy65 ){
-        struct SrcList_item *pNew = &yygotominor.yy65->a[yygotominor.yy65->nSrc-1];
-        struct SrcList_item *pOld = yymsp[-4].minor.yy65->a;
-        pNew->zName = pOld->zName;
-        pNew->zDatabase = pOld->zDatabase;
-        pNew->pSelect = pOld->pSelect;
-        pOld->zName = pOld->zDatabase = 0;
-        pOld->pSelect = 0;
-      }
-      sqlite3SrcListDelete(pParse->db, yymsp[-4].minor.yy65);
-    }else{
-      Select *pSubquery;
-      sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy65);
-      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy65,0,0,0,0,SF_NestedFrom,0,0);
-      yygotominor.yy65 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy65,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy132,yymsp[0].minor.yy408);
-    }
-  }
-        break;
-      case 140: /* dbnm ::= */
-      case 149: /* indexed_opt ::= */ yytestcase(yyruleno==149);
-{yygotominor.yy0.z=0; yygotominor.yy0.n=0;}
-        break;
-      case 142: /* fullname ::= nm dbnm */
-{yygotominor.yy65 = sqlite3SrcListAppend(pParse->db,0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}
-        break;
-      case 143: /* joinop ::= COMMA|JOIN */
-{ yygotominor.yy328 = JT_INNER; }
-        break;
-      case 144: /* joinop ::= JOIN_KW JOIN */
-{ yygotominor.yy328 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0); }
-        break;
-      case 145: /* joinop ::= JOIN_KW nm JOIN */
-{ yygotominor.yy328 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); }
-        break;
-      case 146: /* joinop ::= JOIN_KW nm nm JOIN */
-{ yygotominor.yy328 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0); }
-        break;
-      case 147: /* on_opt ::= ON expr */
-      case 164: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==164);
-      case 171: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==171);
-      case 231: /* case_else ::= ELSE expr */ yytestcase(yyruleno==231);
-      case 233: /* case_operand ::= expr */ yytestcase(yyruleno==233);
-{yygotominor.yy132 = yymsp[0].minor.yy346.pExpr;}
-        break;
-      case 148: /* on_opt ::= */
-      case 163: /* having_opt ::= */ yytestcase(yyruleno==163);
-      case 170: /* where_opt ::= */ yytestcase(yyruleno==170);
-      case 232: /* case_else ::= */ yytestcase(yyruleno==232);
-      case 234: /* case_operand ::= */ yytestcase(yyruleno==234);
-{yygotominor.yy132 = 0;}
-        break;
-      case 151: /* indexed_opt ::= NOT INDEXED */
-{yygotominor.yy0.z=0; yygotominor.yy0.n=1;}
-        break;
-      case 152: /* using_opt ::= USING LP idlist RP */
-      case 180: /* inscollist_opt ::= LP idlist RP */ yytestcase(yyruleno==180);
-{yygotominor.yy408 = yymsp[-1].minor.yy408;}
-        break;
-      case 153: /* using_opt ::= */
-      case 179: /* inscollist_opt ::= */ yytestcase(yyruleno==179);
-{yygotominor.yy408 = 0;}
-        break;
-      case 155: /* orderby_opt ::= ORDER BY sortlist */
-      case 162: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==162);
-      case 235: /* exprlist ::= nexprlist */ yytestcase(yyruleno==235);
-{yygotominor.yy14 = yymsp[0].minor.yy14;}
-        break;
-      case 156: /* sortlist ::= sortlist COMMA expr sortorder */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy14,yymsp[-1].minor.yy346.pExpr);
-  if( yygotominor.yy14 ) yygotominor.yy14->a[yygotominor.yy14->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy328;
-}
-        break;
-      case 157: /* sortlist ::= expr sortorder */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy346.pExpr);
-  if( yygotominor.yy14 && ALWAYS(yygotominor.yy14->a) ) yygotominor.yy14->a[0].sortOrder = (u8)yymsp[0].minor.yy328;
-}
-        break;
-      case 158: /* sortorder ::= ASC */
-      case 160: /* sortorder ::= */ yytestcase(yyruleno==160);
-{yygotominor.yy328 = SQLITE_SO_ASC;}
-        break;
-      case 159: /* sortorder ::= DESC */
-{yygotominor.yy328 = SQLITE_SO_DESC;}
-        break;
-      case 165: /* limit_opt ::= */
-{yygotominor.yy476.pLimit = 0; yygotominor.yy476.pOffset = 0;}
-        break;
-      case 166: /* limit_opt ::= LIMIT expr */
-{yygotominor.yy476.pLimit = yymsp[0].minor.yy346.pExpr; yygotominor.yy476.pOffset = 0;}
-        break;
-      case 167: /* limit_opt ::= LIMIT expr OFFSET expr */
-{yygotominor.yy476.pLimit = yymsp[-2].minor.yy346.pExpr; yygotominor.yy476.pOffset = yymsp[0].minor.yy346.pExpr;}
-        break;
-      case 168: /* limit_opt ::= LIMIT expr COMMA expr */
-{yygotominor.yy476.pOffset = yymsp[-2].minor.yy346.pExpr; yygotominor.yy476.pLimit = yymsp[0].minor.yy346.pExpr;}
-        break;
-      case 169: /* cmd ::= with DELETE FROM fullname indexed_opt where_opt */
-{
-  sqlite3WithPush(pParse, yymsp[-5].minor.yy59, 1);
-  sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy65, &yymsp[-1].minor.yy0);
-  sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy65,yymsp[0].minor.yy132);
-}
-        break;
-      case 172: /* cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt */
-{
-  sqlite3WithPush(pParse, yymsp[-7].minor.yy59, 1);
-  sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy65, &yymsp[-3].minor.yy0);
-  sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy14,"set list"); 
-  sqlite3Update(pParse,yymsp[-4].minor.yy65,yymsp[-1].minor.yy14,yymsp[0].minor.yy132,yymsp[-5].minor.yy186);
-}
-        break;
-      case 173: /* setlist ::= setlist COMMA nm EQ expr */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy14, yymsp[0].minor.yy346.pExpr);
-  sqlite3ExprListSetName(pParse, yygotominor.yy14, &yymsp[-2].minor.yy0, 1);
-}
-        break;
-      case 174: /* setlist ::= nm EQ expr */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy346.pExpr);
-  sqlite3ExprListSetName(pParse, yygotominor.yy14, &yymsp[-2].minor.yy0, 1);
-}
-        break;
-      case 175: /* cmd ::= with insert_cmd INTO fullname inscollist_opt select */
-{
-  sqlite3WithPush(pParse, yymsp[-5].minor.yy59, 1);
-  sqlite3Insert(pParse, yymsp[-2].minor.yy65, yymsp[0].minor.yy3, yymsp[-1].minor.yy408, yymsp[-4].minor.yy186);
-}
-        break;
-      case 176: /* cmd ::= with insert_cmd INTO fullname inscollist_opt DEFAULT VALUES */
-{
-  sqlite3WithPush(pParse, yymsp[-6].minor.yy59, 1);
-  sqlite3Insert(pParse, yymsp[-3].minor.yy65, 0, yymsp[-2].minor.yy408, yymsp[-5].minor.yy186);
-}
-        break;
-      case 177: /* insert_cmd ::= INSERT orconf */
-{yygotominor.yy186 = yymsp[0].minor.yy186;}
-        break;
-      case 178: /* insert_cmd ::= REPLACE */
-{yygotominor.yy186 = OE_Replace;}
-        break;
-      case 181: /* idlist ::= idlist COMMA nm */
-{yygotominor.yy408 = sqlite3IdListAppend(pParse->db,yymsp[-2].minor.yy408,&yymsp[0].minor.yy0);}
-        break;
-      case 182: /* idlist ::= nm */
-{yygotominor.yy408 = sqlite3IdListAppend(pParse->db,0,&yymsp[0].minor.yy0);}
-        break;
-      case 183: /* expr ::= term */
-{yygotominor.yy346 = yymsp[0].minor.yy346;}
-        break;
-      case 184: /* expr ::= LP expr RP */
-{yygotominor.yy346.pExpr = yymsp[-1].minor.yy346.pExpr; spanSet(&yygotominor.yy346,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);}
-        break;
-      case 185: /* term ::= NULL */
-      case 190: /* term ::= INTEGER|FLOAT|BLOB */ yytestcase(yyruleno==190);
-      case 191: /* term ::= STRING */ yytestcase(yyruleno==191);
-{spanExpr(&yygotominor.yy346, pParse, yymsp[0].major, &yymsp[0].minor.yy0);}
-        break;
-      case 186: /* expr ::= ID|INDEXED */
-      case 187: /* expr ::= JOIN_KW */ yytestcase(yyruleno==187);
-{spanExpr(&yygotominor.yy346, pParse, TK_ID, &yymsp[0].minor.yy0);}
-        break;
-      case 188: /* expr ::= nm DOT nm */
-{
-  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
-  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp2, 0);
-  spanSet(&yygotominor.yy346,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);
-}
-        break;
-      case 189: /* expr ::= nm DOT nm DOT nm */
-{
-  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-4].minor.yy0);
-  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
-  Expr *temp3 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
-  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0);
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
-  spanSet(&yygotominor.yy346,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
-}
-        break;
-      case 192: /* expr ::= VARIABLE */
-{
-  if( yymsp[0].minor.yy0.n>=2 && yymsp[0].minor.yy0.z[0]=='#' && sqlite3Isdigit(yymsp[0].minor.yy0.z[1]) ){
-    /* When doing a nested parse, one can include terms in an expression
-    ** that look like this:   #1 #2 ...  These terms refer to registers
-    ** in the virtual machine.  #N is the N-th register. */
-    if( pParse->nested==0 ){
-      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &yymsp[0].minor.yy0);
-      yygotominor.yy346.pExpr = 0;
-    }else{
-      yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, &yymsp[0].minor.yy0);
-      if( yygotominor.yy346.pExpr ) sqlite3GetInt32(&yymsp[0].minor.yy0.z[1], &yygotominor.yy346.pExpr->iTable);
-    }
-  }else{
-    spanExpr(&yygotominor.yy346, pParse, TK_VARIABLE, &yymsp[0].minor.yy0);
-    sqlite3ExprAssignVarNumber(pParse, yygotominor.yy346.pExpr);
-  }
-  spanSet(&yygotominor.yy346, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
-}
-        break;
-      case 193: /* expr ::= expr COLLATE ID|STRING */
-{
-  yygotominor.yy346.pExpr = sqlite3ExprAddCollateToken(pParse, yymsp[-2].minor.yy346.pExpr, &yymsp[0].minor.yy0);
-  yygotominor.yy346.zStart = yymsp[-2].minor.yy346.zStart;
-  yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-}
-        break;
-      case 194: /* expr ::= CAST LP expr AS typetoken RP */
-{
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_CAST, yymsp[-3].minor.yy346.pExpr, 0, &yymsp[-1].minor.yy0);
-  spanSet(&yygotominor.yy346,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0);
-}
-        break;
-      case 195: /* expr ::= ID|INDEXED LP distinct exprlist RP */
-{
-  if( yymsp[-1].minor.yy14 && yymsp[-1].minor.yy14->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
-    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &yymsp[-4].minor.yy0);
-  }
-  yygotominor.yy346.pExpr = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy14, &yymsp[-4].minor.yy0);
-  spanSet(&yygotominor.yy346,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
-  if( yymsp[-2].minor.yy381 && yygotominor.yy346.pExpr ){
-    yygotominor.yy346.pExpr->flags |= EP_Distinct;
-  }
-}
-        break;
-      case 196: /* expr ::= ID|INDEXED LP STAR RP */
-{
-  yygotominor.yy346.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0);
-  spanSet(&yygotominor.yy346,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);
-}
-        break;
-      case 197: /* term ::= CTIME_KW */
-{
-  yygotominor.yy346.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[0].minor.yy0);
-  spanSet(&yygotominor.yy346, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
-}
-        break;
-      case 198: /* expr ::= expr AND expr */
-      case 199: /* expr ::= expr OR expr */ yytestcase(yyruleno==199);
-      case 200: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==200);
-      case 201: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==201);
-      case 202: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==202);
-      case 203: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==203);
-      case 204: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==204);
-      case 205: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==205);
-{spanBinaryExpr(&yygotominor.yy346,pParse,yymsp[-1].major,&yymsp[-2].minor.yy346,&yymsp[0].minor.yy346);}
-        break;
-      case 206: /* likeop ::= LIKE_KW|MATCH */
-{yygotominor.yy96.eOperator = yymsp[0].minor.yy0; yygotominor.yy96.bNot = 0;}
-        break;
-      case 207: /* likeop ::= NOT LIKE_KW|MATCH */
-{yygotominor.yy96.eOperator = yymsp[0].minor.yy0; yygotominor.yy96.bNot = 1;}
-        break;
-      case 208: /* expr ::= expr likeop expr */
-{
-  ExprList *pList;
-  pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy346.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy346.pExpr);
-  yygotominor.yy346.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy96.eOperator);
-  if( yymsp[-1].minor.yy96.bNot ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-  yygotominor.yy346.zStart = yymsp[-2].minor.yy346.zStart;
-  yygotominor.yy346.zEnd = yymsp[0].minor.yy346.zEnd;
-  if( yygotominor.yy346.pExpr ) yygotominor.yy346.pExpr->flags |= EP_InfixFunc;
-}
-        break;
-      case 209: /* expr ::= expr likeop expr ESCAPE expr */
-{
-  ExprList *pList;
-  pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy346.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy346.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy346.pExpr);
-  yygotominor.yy346.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy96.eOperator);
-  if( yymsp[-3].minor.yy96.bNot ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-  yygotominor.yy346.zStart = yymsp[-4].minor.yy346.zStart;
-  yygotominor.yy346.zEnd = yymsp[0].minor.yy346.zEnd;
-  if( yygotominor.yy346.pExpr ) yygotominor.yy346.pExpr->flags |= EP_InfixFunc;
-}
-        break;
-      case 210: /* expr ::= expr ISNULL|NOTNULL */
-{spanUnaryPostfix(&yygotominor.yy346,pParse,yymsp[0].major,&yymsp[-1].minor.yy346,&yymsp[0].minor.yy0);}
-        break;
-      case 211: /* expr ::= expr NOT NULL */
-{spanUnaryPostfix(&yygotominor.yy346,pParse,TK_NOTNULL,&yymsp[-2].minor.yy346,&yymsp[0].minor.yy0);}
-        break;
-      case 212: /* expr ::= expr IS expr */
-{
-  spanBinaryExpr(&yygotominor.yy346,pParse,TK_IS,&yymsp[-2].minor.yy346,&yymsp[0].minor.yy346);
-  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy346.pExpr, yygotominor.yy346.pExpr, TK_ISNULL);
-}
-        break;
-      case 213: /* expr ::= expr IS NOT expr */
-{
-  spanBinaryExpr(&yygotominor.yy346,pParse,TK_ISNOT,&yymsp[-3].minor.yy346,&yymsp[0].minor.yy346);
-  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy346.pExpr, yygotominor.yy346.pExpr, TK_NOTNULL);
-}
-        break;
-      case 214: /* expr ::= NOT expr */
-      case 215: /* expr ::= BITNOT expr */ yytestcase(yyruleno==215);
-{spanUnaryPrefix(&yygotominor.yy346,pParse,yymsp[-1].major,&yymsp[0].minor.yy346,&yymsp[-1].minor.yy0);}
-        break;
-      case 216: /* expr ::= MINUS expr */
-{spanUnaryPrefix(&yygotominor.yy346,pParse,TK_UMINUS,&yymsp[0].minor.yy346,&yymsp[-1].minor.yy0);}
-        break;
-      case 217: /* expr ::= PLUS expr */
-{spanUnaryPrefix(&yygotominor.yy346,pParse,TK_UPLUS,&yymsp[0].minor.yy346,&yymsp[-1].minor.yy0);}
-        break;
-      case 220: /* expr ::= expr between_op expr AND expr */
-{
-  ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy346.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy346.pExpr);
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy346.pExpr, 0, 0);
-  if( yygotominor.yy346.pExpr ){
-    yygotominor.yy346.pExpr->x.pList = pList;
-  }else{
-    sqlite3ExprListDelete(pParse->db, pList);
-  } 
-  if( yymsp[-3].minor.yy328 ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-  yygotominor.yy346.zStart = yymsp[-4].minor.yy346.zStart;
-  yygotominor.yy346.zEnd = yymsp[0].minor.yy346.zEnd;
-}
-        break;
-      case 223: /* expr ::= expr in_op LP exprlist RP */
-{
-    if( yymsp[-1].minor.yy14==0 ){
-      /* Expressions of the form
-      **
-      **      expr1 IN ()
-      **      expr1 NOT IN ()
-      **
-      ** simplify to constants 0 (false) and 1 (true), respectively,
-      ** regardless of the value of expr1.
-      */
-      yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &sqlite3IntTokens[yymsp[-3].minor.yy328]);
-      sqlite3ExprDelete(pParse->db, yymsp[-4].minor.yy346.pExpr);
-    }else if( yymsp[-1].minor.yy14->nExpr==1 ){
-      /* Expressions of the form:
-      **
-      **      expr1 IN (?1)
-      **      expr1 NOT IN (?2)
-      **
-      ** with exactly one value on the RHS can be simplified to something
-      ** like this:
-      **
-      **      expr1 == ?1
-      **      expr1 <> ?2
-      **
-      ** But, the RHS of the == or <> is marked with the EP_Generic flag
-      ** so that it may not contribute to the computation of comparison
-      ** affinity or the collating sequence to use for comparison.  Otherwise,
-      ** the semantics would be subtly different from IN or NOT IN.
-      */
-      Expr *pRHS = yymsp[-1].minor.yy14->a[0].pExpr;
-      yymsp[-1].minor.yy14->a[0].pExpr = 0;
-      sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy14);
-      /* pRHS cannot be NULL because a malloc error would have been detected
-      ** before now and control would have never reached this point */
-      if( ALWAYS(pRHS) ){
-        pRHS->flags &= ~EP_Collate;
-        pRHS->flags |= EP_Generic;
-      }
-      yygotominor.yy346.pExpr = sqlite3PExpr(pParse, yymsp[-3].minor.yy328 ? TK_NE : TK_EQ, yymsp[-4].minor.yy346.pExpr, pRHS, 0);
-    }else{
-      yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy346.pExpr, 0, 0);
-      if( yygotominor.yy346.pExpr ){
-        yygotominor.yy346.pExpr->x.pList = yymsp[-1].minor.yy14;
-        sqlite3ExprSetHeight(pParse, yygotominor.yy346.pExpr);
-      }else{
-        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy14);
+  if( pCsr->pMIBuffer==0 ){
+    int nMatchinfo = 0;           /* Number of u32 elements in match-info */
+    int i;                        /* Used to iterate through zArg */
+
+    /* Determine the number of phrases in the query */
+    pCsr->nPhrase = fts3ExprPhraseCount(pCsr->pExpr);
+    sInfo.nPhrase = pCsr->nPhrase;
+
+    /* Determine the number of integers in the buffer returned by this call. */
+    for(i=0; zArg[i]; i++){
+      char *zErr = 0;
+      if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
+        sqlite3_result_error(pCtx, zErr, -1);
+        sqlite3_free(zErr);
+        return;
       }
-      if( yymsp[-3].minor.yy328 ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-    }
-    yygotominor.yy346.zStart = yymsp[-4].minor.yy346.zStart;
-    yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-  }
-        break;
-      case 224: /* expr ::= LP select RP */
-{
-    yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
-    if( yygotominor.yy346.pExpr ){
-      yygotominor.yy346.pExpr->x.pSelect = yymsp[-1].minor.yy3;
-      ExprSetProperty(yygotominor.yy346.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy346.pExpr);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy3);
-    }
-    yygotominor.yy346.zStart = yymsp[-2].minor.yy0.z;
-    yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-  }
-        break;
-      case 225: /* expr ::= expr in_op LP select RP */
-{
-    yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy346.pExpr, 0, 0);
-    if( yygotominor.yy346.pExpr ){
-      yygotominor.yy346.pExpr->x.pSelect = yymsp[-1].minor.yy3;
-      ExprSetProperty(yygotominor.yy346.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy346.pExpr);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy3);
-    }
-    if( yymsp[-3].minor.yy328 ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-    yygotominor.yy346.zStart = yymsp[-4].minor.yy346.zStart;
-    yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-  }
-        break;
-      case 226: /* expr ::= expr in_op nm dbnm */
-{
-    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);
-    yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-3].minor.yy346.pExpr, 0, 0);
-    if( yygotominor.yy346.pExpr ){
-      yygotominor.yy346.pExpr->x.pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
-      ExprSetProperty(yygotominor.yy346.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy346.pExpr);
-    }else{
-      sqlite3SrcListDelete(pParse->db, pSrc);
-    }
-    if( yymsp[-2].minor.yy328 ) yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy346.pExpr, 0, 0);
-    yygotominor.yy346.zStart = yymsp[-3].minor.yy346.zStart;
-    yygotominor.yy346.zEnd = yymsp[0].minor.yy0.z ? &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] : &yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n];
-  }
-        break;
-      case 227: /* expr ::= EXISTS LP select RP */
-{
-    Expr *p = yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
-    if( p ){
-      p->x.pSelect = yymsp[-1].minor.yy3;
-      ExprSetProperty(p, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, p);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy3);
+      nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);
     }
-    yygotominor.yy346.zStart = yymsp[-3].minor.yy0.z;
-    yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-  }
-        break;
-      case 228: /* expr ::= CASE case_operand case_exprlist case_else END */
-{
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy132, 0, 0);
-  if( yygotominor.yy346.pExpr ){
-    yygotominor.yy346.pExpr->x.pList = yymsp[-1].minor.yy132 ? sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy14,yymsp[-1].minor.yy132) : yymsp[-2].minor.yy14;
-    sqlite3ExprSetHeight(pParse, yygotominor.yy346.pExpr);
-  }else{
-    sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy14);
-    sqlite3ExprDelete(pParse->db, yymsp[-1].minor.yy132);
-  }
-  yygotominor.yy346.zStart = yymsp[-4].minor.yy0.z;
-  yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-}
-        break;
-      case 229: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy14, yymsp[-2].minor.yy346.pExpr);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yygotominor.yy14, yymsp[0].minor.yy346.pExpr);
-}
-        break;
-      case 230: /* case_exprlist ::= WHEN expr THEN expr */
-{
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy346.pExpr);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yygotominor.yy14, yymsp[0].minor.yy346.pExpr);
-}
-        break;
-      case 237: /* nexprlist ::= nexprlist COMMA expr */
-{yygotominor.yy14 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy14,yymsp[0].minor.yy346.pExpr);}
-        break;
-      case 238: /* nexprlist ::= expr */
-{yygotominor.yy14 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy346.pExpr);}
-        break;
-      case 239: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP idxlist RP where_opt */
-{
-  sqlite3CreateIndex(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, 
-                     sqlite3SrcListAppend(pParse->db,0,&yymsp[-4].minor.yy0,0), yymsp[-2].minor.yy14, yymsp[-10].minor.yy328,
-                      &yymsp[-11].minor.yy0, yymsp[0].minor.yy132, SQLITE_SO_ASC, yymsp[-8].minor.yy328);
-}
-        break;
-      case 240: /* uniqueflag ::= UNIQUE */
-      case 291: /* raisetype ::= ABORT */ yytestcase(yyruleno==291);
-{yygotominor.yy328 = OE_Abort;}
-        break;
-      case 241: /* uniqueflag ::= */
-{yygotominor.yy328 = OE_None;}
-        break;
-      case 244: /* idxlist ::= idxlist COMMA nm collate sortorder */
-{
-  Expr *p = sqlite3ExprAddCollateToken(pParse, 0, &yymsp[-1].minor.yy0);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy14, p);
-  sqlite3ExprListSetName(pParse,yygotominor.yy14,&yymsp[-2].minor.yy0,1);
-  sqlite3ExprListCheckLength(pParse, yygotominor.yy14, "index");
-  if( yygotominor.yy14 ) yygotominor.yy14->a[yygotominor.yy14->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy328;
-}
-        break;
-      case 245: /* idxlist ::= nm collate sortorder */
-{
-  Expr *p = sqlite3ExprAddCollateToken(pParse, 0, &yymsp[-1].minor.yy0);
-  yygotominor.yy14 = sqlite3ExprListAppend(pParse,0, p);
-  sqlite3ExprListSetName(pParse, yygotominor.yy14, &yymsp[-2].minor.yy0, 1);
-  sqlite3ExprListCheckLength(pParse, yygotominor.yy14, "index");
-  if( yygotominor.yy14 ) yygotominor.yy14->a[yygotominor.yy14->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy328;
-}
-        break;
-      case 246: /* collate ::= */
-{yygotominor.yy0.z = 0; yygotominor.yy0.n = 0;}
-        break;
-      case 248: /* cmd ::= DROP INDEX ifexists fullname */
-{sqlite3DropIndex(pParse, yymsp[0].minor.yy65, yymsp[-1].minor.yy328);}
-        break;
-      case 249: /* cmd ::= VACUUM */
-      case 250: /* cmd ::= VACUUM nm */ yytestcase(yyruleno==250);
-{sqlite3Vacuum(pParse);}
-        break;
-      case 251: /* cmd ::= PRAGMA nm dbnm */
-{sqlite3Pragma(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0,0);}
-        break;
-      case 252: /* cmd ::= PRAGMA nm dbnm EQ nmnum */
-{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,0);}
-        break;
-      case 253: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */
-{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,0);}
-        break;
-      case 254: /* cmd ::= PRAGMA nm dbnm EQ minus_num */
-{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,1);}
-        break;
-      case 255: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */
-{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,1);}
-        break;
-      case 264: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */
-{
-  Token all;
-  all.z = yymsp[-3].minor.yy0.z;
-  all.n = (int)(yymsp[0].minor.yy0.z - yymsp[-3].minor.yy0.z) + yymsp[0].minor.yy0.n;
-  sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy473, &all);
-}
-        break;
-      case 265: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */
-{
-  sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy328, yymsp[-4].minor.yy378.a, yymsp[-4].minor.yy378.b, yymsp[-2].minor.yy65, yymsp[0].minor.yy132, yymsp[-10].minor.yy328, yymsp[-8].minor.yy328);
-  yygotominor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0);
-}
-        break;
-      case 266: /* trigger_time ::= BEFORE */
-      case 269: /* trigger_time ::= */ yytestcase(yyruleno==269);
-{ yygotominor.yy328 = TK_BEFORE; }
-        break;
-      case 267: /* trigger_time ::= AFTER */
-{ yygotominor.yy328 = TK_AFTER;  }
-        break;
-      case 268: /* trigger_time ::= INSTEAD OF */
-{ yygotominor.yy328 = TK_INSTEAD;}
-        break;
-      case 270: /* trigger_event ::= DELETE|INSERT */
-      case 271: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==271);
-{yygotominor.yy378.a = yymsp[0].major; yygotominor.yy378.b = 0;}
-        break;
-      case 272: /* trigger_event ::= UPDATE OF idlist */
-{yygotominor.yy378.a = TK_UPDATE; yygotominor.yy378.b = yymsp[0].minor.yy408;}
-        break;
-      case 275: /* when_clause ::= */
-      case 296: /* key_opt ::= */ yytestcase(yyruleno==296);
-{ yygotominor.yy132 = 0; }
-        break;
-      case 276: /* when_clause ::= WHEN expr */
-      case 297: /* key_opt ::= KEY expr */ yytestcase(yyruleno==297);
-{ yygotominor.yy132 = yymsp[0].minor.yy346.pExpr; }
-        break;
-      case 277: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */
-{
-  assert( yymsp[-2].minor.yy473!=0 );
-  yymsp[-2].minor.yy473->pLast->pNext = yymsp[-1].minor.yy473;
-  yymsp[-2].minor.yy473->pLast = yymsp[-1].minor.yy473;
-  yygotominor.yy473 = yymsp[-2].minor.yy473;
-}
-        break;
-      case 278: /* trigger_cmd_list ::= trigger_cmd SEMI */
-{ 
-  assert( yymsp[-1].minor.yy473!=0 );
-  yymsp[-1].minor.yy473->pLast = yymsp[-1].minor.yy473;
-  yygotominor.yy473 = yymsp[-1].minor.yy473;
-}
-        break;
-      case 280: /* trnm ::= nm DOT nm */
-{
-  yygotominor.yy0 = yymsp[0].minor.yy0;
-  sqlite3ErrorMsg(pParse, 
-        "qualified table names are not allowed on INSERT, UPDATE, and DELETE "
-        "statements within triggers");
-}
-        break;
-      case 282: /* tridxby ::= INDEXED BY nm */
-{
-  sqlite3ErrorMsg(pParse,
-        "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "
-        "within triggers");
-}
-        break;
-      case 283: /* tridxby ::= NOT INDEXED */
-{
-  sqlite3ErrorMsg(pParse,
-        "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "
-        "within triggers");
-}
-        break;
-      case 284: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt */
-{ yygotominor.yy473 = sqlite3TriggerUpdateStep(pParse->db, &yymsp[-4].minor.yy0, yymsp[-1].minor.yy14, yymsp[0].minor.yy132, yymsp[-5].minor.yy186); }
-        break;
-      case 285: /* trigger_cmd ::= insert_cmd INTO trnm inscollist_opt select */
-{yygotominor.yy473 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy408, yymsp[0].minor.yy3, yymsp[-4].minor.yy186);}
-        break;
-      case 286: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt */
-{yygotominor.yy473 = sqlite3TriggerDeleteStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[0].minor.yy132);}
-        break;
-      case 287: /* trigger_cmd ::= select */
-{yygotominor.yy473 = sqlite3TriggerSelectStep(pParse->db, yymsp[0].minor.yy3); }
-        break;
-      case 288: /* expr ::= RAISE LP IGNORE RP */
-{
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, 0); 
-  if( yygotominor.yy346.pExpr ){
-    yygotominor.yy346.pExpr->affinity = OE_Ignore;
-  }
-  yygotominor.yy346.zStart = yymsp[-3].minor.yy0.z;
-  yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-}
-        break;
-      case 289: /* expr ::= RAISE LP raisetype COMMA nm RP */
-{
-  yygotominor.yy346.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, &yymsp[-1].minor.yy0); 
-  if( yygotominor.yy346.pExpr ) {
-    yygotominor.yy346.pExpr->affinity = (char)yymsp[-3].minor.yy328;
-  }
-  yygotominor.yy346.zStart = yymsp[-5].minor.yy0.z;
-  yygotominor.yy346.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
-}
-        break;
-      case 290: /* raisetype ::= ROLLBACK */
-{yygotominor.yy328 = OE_Rollback;}
-        break;
-      case 292: /* raisetype ::= FAIL */
-{yygotominor.yy328 = OE_Fail;}
-        break;
-      case 293: /* cmd ::= DROP TRIGGER ifexists fullname */
-{
-  sqlite3DropTrigger(pParse,yymsp[0].minor.yy65,yymsp[-1].minor.yy328);
-}
-        break;
-      case 294: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */
-{
-  sqlite3Attach(pParse, yymsp[-3].minor.yy346.pExpr, yymsp[-1].minor.yy346.pExpr, yymsp[0].minor.yy132);
-}
-        break;
-      case 295: /* cmd ::= DETACH database_kw_opt expr */
-{
-  sqlite3Detach(pParse, yymsp[0].minor.yy346.pExpr);
-}
-        break;
-      case 300: /* cmd ::= REINDEX */
-{sqlite3Reindex(pParse, 0, 0);}
-        break;
-      case 301: /* cmd ::= REINDEX nm dbnm */
-{sqlite3Reindex(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
-        break;
-      case 302: /* cmd ::= ANALYZE */
-{sqlite3Analyze(pParse, 0, 0);}
-        break;
-      case 303: /* cmd ::= ANALYZE nm dbnm */
-{sqlite3Analyze(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
-        break;
-      case 304: /* cmd ::= ALTER TABLE fullname RENAME TO nm */
-{
-  sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy65,&yymsp[0].minor.yy0);
-}
-        break;
-      case 305: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column */
-{
-  sqlite3AlterFinishAddColumn(pParse, &yymsp[0].minor.yy0);
-}
-        break;
-      case 306: /* add_column_fullname ::= fullname */
-{
-  pParse->db->lookaside.bEnabled = 0;
-  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy65);
-}
-        break;
-      case 309: /* cmd ::= create_vtab */
-{sqlite3VtabFinishParse(pParse,0);}
-        break;
-      case 310: /* cmd ::= create_vtab LP vtabarglist RP */
-{sqlite3VtabFinishParse(pParse,&yymsp[0].minor.yy0);}
-        break;
-      case 311: /* create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */
-{
-    sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0, yymsp[-4].minor.yy328);
-}
-        break;
-      case 314: /* vtabarg ::= */
-{sqlite3VtabArgInit(pParse);}
-        break;
-      case 316: /* vtabargtoken ::= ANY */
-      case 317: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==317);
-      case 318: /* lp ::= LP */ yytestcase(yyruleno==318);
-{sqlite3VtabArgExtend(pParse,&yymsp[0].minor.yy0);}
-        break;
-      case 322: /* with ::= */
-{yygotominor.yy59 = 0;}
-        break;
-      case 323: /* with ::= WITH wqlist */
-      case 324: /* with ::= WITH RECURSIVE wqlist */ yytestcase(yyruleno==324);
-{ yygotominor.yy59 = yymsp[0].minor.yy59; }
-        break;
-      case 325: /* wqlist ::= nm idxlist_opt AS LP select RP */
-{
-  yygotominor.yy59 = sqlite3WithAdd(pParse, 0, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy14, yymsp[-1].minor.yy3);
-}
-        break;
-      case 326: /* wqlist ::= wqlist COMMA nm idxlist_opt AS LP select RP */
-{
-  yygotominor.yy59 = sqlite3WithAdd(pParse, yymsp[-7].minor.yy59, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy14, yymsp[-1].minor.yy3);
-}
-        break;
-      default:
-      /* (0) input ::= cmdlist */ yytestcase(yyruleno==0);
-      /* (1) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==1);
-      /* (2) cmdlist ::= ecmd */ yytestcase(yyruleno==2);
-      /* (3) ecmd ::= SEMI */ yytestcase(yyruleno==3);
-      /* (4) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==4);
-      /* (10) trans_opt ::= */ yytestcase(yyruleno==10);
-      /* (11) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==11);
-      /* (12) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==12);
-      /* (20) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==20);
-      /* (21) savepoint_opt ::= */ yytestcase(yyruleno==21);
-      /* (25) cmd ::= create_table create_table_args */ yytestcase(yyruleno==25);
-      /* (36) columnlist ::= columnlist COMMA column */ yytestcase(yyruleno==36);
-      /* (37) columnlist ::= column */ yytestcase(yyruleno==37);
-      /* (43) type ::= */ yytestcase(yyruleno==43);
-      /* (50) signed ::= plus_num */ yytestcase(yyruleno==50);
-      /* (51) signed ::= minus_num */ yytestcase(yyruleno==51);
-      /* (52) carglist ::= carglist ccons */ yytestcase(yyruleno==52);
-      /* (53) carglist ::= */ yytestcase(yyruleno==53);
-      /* (60) ccons ::= NULL onconf */ yytestcase(yyruleno==60);
-      /* (88) conslist ::= conslist tconscomma tcons */ yytestcase(yyruleno==88);
-      /* (89) conslist ::= tcons */ yytestcase(yyruleno==89);
-      /* (91) tconscomma ::= */ yytestcase(yyruleno==91);
-      /* (273) foreach_clause ::= */ yytestcase(yyruleno==273);
-      /* (274) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==274);
-      /* (281) tridxby ::= */ yytestcase(yyruleno==281);
-      /* (298) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==298);
-      /* (299) database_kw_opt ::= */ yytestcase(yyruleno==299);
-      /* (307) kwcolumn_opt ::= */ yytestcase(yyruleno==307);
-      /* (308) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==308);
-      /* (312) vtabarglist ::= vtabarg */ yytestcase(yyruleno==312);
-      /* (313) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==313);
-      /* (315) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==315);
-      /* (319) anylist ::= */ yytestcase(yyruleno==319);
-      /* (320) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==320);
-      /* (321) anylist ::= anylist ANY */ yytestcase(yyruleno==321);
-        break;
-  };
-  assert( yyruleno>=0 && yyrulenoyyidx -= yysize;
-  yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto);
-  if( yyact < YYNSTATE ){
-#ifdef NDEBUG
-    /* If we are not debugging and the reduce action popped at least
-    ** one element off the stack, then we can push the new element back
-    ** onto the stack here, and skip the stack overflow test in yy_shift().
-    ** That gives a significant speed improvement. */
-    if( yysize ){
-      yypParser->yyidx++;
-      yymsp -= yysize-1;
-      yymsp->stateno = (YYACTIONTYPE)yyact;
-      yymsp->major = (YYCODETYPE)yygoto;
-      yymsp->minor = yygotominor;
-    }else
-#endif
-    {
-      yy_shift(yypParser,yyact,yygoto,&yygotominor);
+
+    /* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */
+    pCsr->pMIBuffer = fts3MIBufferNew(nMatchinfo, zArg);
+    if( !pCsr->pMIBuffer ) rc = SQLITE_NOMEM;
+
+    pCsr->isMatchinfoNeeded = 1;
+    bGlobal = 1;
+  }
+
+  if( rc==SQLITE_OK ){
+    xDestroyOut = fts3MIBufferAlloc(pCsr->pMIBuffer, &aOut);
+    if( xDestroyOut==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    sInfo.aMatchinfo = aOut;
+    sInfo.nPhrase = pCsr->nPhrase;
+    rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);
+    if( bGlobal ){
+      fts3MIBufferSetGlobal(pCsr->pMIBuffer);
     }
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx, rc);
+    if( xDestroyOut ) xDestroyOut(aOut);
   }else{
-    assert( yyact == YYNSTATE + YYNRULE + 1 );
-    yy_accept(yypParser);
+    int n = pCsr->pMIBuffer->nElem * sizeof(u32);
+    sqlite3_result_blob(pCtx, aOut, n, xDestroyOut);
   }
 }
 
 /*
-** The following code executes when the parse fails
+** Implementation of snippet() function.
 */
-#ifndef YYNOERRORRECOVERY
-static void yy_parse_failed(
-  yyParser *yypParser           /* The parser */
+SQLITE_PRIVATE void sqlite3Fts3Snippet(
+  sqlite3_context *pCtx,          /* SQLite function call context */
+  Fts3Cursor *pCsr,               /* Cursor object */
+  const char *zStart,             /* Snippet start text - "" */
+  const char *zEnd,               /* Snippet end text - "" */
+  const char *zEllipsis,          /* Snippet ellipsis text - "..." */
+  int iCol,                       /* Extract snippet from this column */
+  int nToken                      /* Approximate number of tokens in snippet */
 ){
-  sqlite3ParserARG_FETCH;
-#ifndef NDEBUG
-  if( yyTraceFILE ){
-    fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt);
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;
+  int i;
+  StrBuffer res = {0, 0, 0};
+
+  /* The returned text includes up to four fragments of text extracted from
+  ** the data in the current row. The first iteration of the for(...) loop
+  ** below attempts to locate a single fragment of text nToken tokens in 
+  ** size that contains at least one instance of all phrases in the query
+  ** expression that appear in the current row. If such a fragment of text
+  ** cannot be found, the second iteration of the loop attempts to locate
+  ** a pair of fragments, and so on.
+  */
+  int nSnippet = 0;               /* Number of fragments in this snippet */
+  SnippetFragment aSnippet[4];    /* Maximum of 4 fragments per snippet */
+  int nFToken = -1;               /* Number of tokens in each fragment */
+
+  if( !pCsr->pExpr ){
+    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
+    return;
   }
-#endif
-  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
-  /* Here code is inserted which will be executed whenever the
-  ** parser fails */
-  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
-}
-#endif /* YYNOERRORRECOVERY */
 
-/*
-** The following code executes when a syntax error first occurs.
-*/
-static void yy_syntax_error(
-  yyParser *yypParser,           /* The parser */
-  int yymajor,                   /* The major type of the error token */
-  YYMINORTYPE yyminor            /* The minor type of the error token */
-){
-  sqlite3ParserARG_FETCH;
-#define TOKEN (yyminor.yy0)
+  for(nSnippet=1; 1; nSnippet++){
 
-  UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */
-  assert( TOKEN.z[0] );  /* The tokenizer always gives us a token */
-  sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
-  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+    int iSnip;                    /* Loop counter 0..nSnippet-1 */
+    u64 mCovered = 0;             /* Bitmask of phrases covered by snippet */
+    u64 mSeen = 0;                /* Bitmask of phrases seen by BestSnippet() */
+
+    if( nToken>=0 ){
+      nFToken = (nToken+nSnippet-1) / nSnippet;
+    }else{
+      nFToken = -1 * nToken;
+    }
+
+    for(iSnip=0; iSnipnColumn; iRead++){
+        SnippetFragment sF = {0, 0, 0, 0};
+        int iS = 0;
+        if( iCol>=0 && iRead!=iCol ) continue;
+
+        /* Find the best snippet of nFToken tokens in column iRead. */
+        rc = fts3BestSnippet(nFToken, pCsr, iRead, mCovered, &mSeen, &sF, &iS);
+        if( rc!=SQLITE_OK ){
+          goto snippet_out;
+        }
+        if( iS>iBestScore ){
+          *pFragment = sF;
+          iBestScore = iS;
+        }
+      }
+
+      mCovered |= pFragment->covered;
+    }
+
+    /* If all query phrases seen by fts3BestSnippet() are present in at least
+    ** one of the nSnippet snippet fragments, break out of the loop.
+    */
+    assert( (mCovered&mSeen)==mCovered );
+    if( mSeen==mCovered || nSnippet==SizeofArray(aSnippet) ) break;
+  }
+
+  assert( nFToken>0 );
+
+  for(i=0; ipCsr, pExpr, p->iCol, &pList);
+  nTerm = pExpr->pPhrase->nToken;
+  if( pList ){
+    fts3GetDeltaPosition(&pList, &iPos);
+    assert( iPos>=0 );
   }
-#endif
-  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
-  /* Here code is inserted which will be executed whenever the
-  ** parser accepts */
-  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+
+  for(iTerm=0; iTermaTerm[p->iTerm++];
+    pT->iOff = nTerm-iTerm-1;
+    pT->pList = pList;
+    pT->iPos = iPos;
+  }
+
+  return rc;
 }
 
-/* The main parser program.
-** The first argument is a pointer to a structure obtained from
-** "sqlite3ParserAlloc" which describes the current state of the parser.
-** The second argument is the major token number.  The third is
-** the minor token.  The fourth optional argument is whatever the
-** user wants (and specified in the grammar) and is available for
-** use by the action routines.
-**
-** Inputs:
-** 
      
-** 
    •  A pointer to the parser (an opaque structure.)
-** 
    •  The major token number.
-** 
    •  The minor token number.
-** 
    •  An option argument of a grammar-specified type.
-** 
    
-**
-** Outputs:
-** None.
+/*
+** Implementation of offsets() function.
 */
-SQLITE_PRIVATE void sqlite3Parser(
-  void *yyp,                   /* The parser */
-  int yymajor,                 /* The major token code number */
-  sqlite3ParserTOKENTYPE yyminor       /* The value for the token */
-  sqlite3ParserARG_PDECL               /* Optional %extra_argument parameter */
+SQLITE_PRIVATE void sqlite3Fts3Offsets(
+  sqlite3_context *pCtx,          /* SQLite function call context */
+  Fts3Cursor *pCsr                /* Cursor object */
 ){
-  YYMINORTYPE yyminorunion;
-  int yyact;            /* The parser action. */
-#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
-  int yyendofinput;     /* True if we are at the end of input */
-#endif
-#ifdef YYERRORSYMBOL
-  int yyerrorhit = 0;   /* True if yymajor has invoked an error */
-#endif
-  yyParser *yypParser;  /* The parser */
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  sqlite3_tokenizer_module const *pMod = pTab->pTokenizer->pModule;
+  int rc;                         /* Return Code */
+  int nToken;                     /* Number of tokens in query */
+  int iCol;                       /* Column currently being processed */
+  StrBuffer res = {0, 0, 0};      /* Result string */
+  TermOffsetCtx sCtx;             /* Context for fts3ExprTermOffsetInit() */
 
-  /* (re)initialize the parser, if necessary */
-  yypParser = (yyParser*)yyp;
-  if( yypParser->yyidx<0 ){
-#if YYSTACKDEPTH<=0
-    if( yypParser->yystksz <=0 ){
-      /*memset(&yyminorunion, 0, sizeof(yyminorunion));*/
-      yyminorunion = yyzerominor;
-      yyStackOverflow(yypParser, &yyminorunion);
-      return;
-    }
-#endif
-    yypParser->yyidx = 0;
-    yypParser->yyerrcnt = -1;
-    yypParser->yystack[0].stateno = 0;
-    yypParser->yystack[0].major = 0;
+  if( !pCsr->pExpr ){
+    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
+    return;
   }
-  yyminorunion.yy0 = yyminor;
-#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
-  yyendofinput = (yymajor==0);
-#endif
-  sqlite3ParserARG_STORE;
 
-#ifndef NDEBUG
-  if( yyTraceFILE ){
-    fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]);
+  memset(&sCtx, 0, sizeof(sCtx));
+  assert( pCsr->isRequireSeek==0 );
+
+  /* Count the number of terms in the query */
+  rc = fts3ExprLoadDoclists(pCsr, 0, &nToken);
+  if( rc!=SQLITE_OK ) goto offsets_out;
+
+  /* Allocate the array of TermOffset iterators. */
+  sCtx.aTerm = (TermOffset *)sqlite3_malloc(sizeof(TermOffset)*nToken);
+  if( 0==sCtx.aTerm ){
+    rc = SQLITE_NOMEM;
+    goto offsets_out;
   }
-#endif
+  sCtx.iDocid = pCsr->iPrevId;
+  sCtx.pCsr = pCsr;
 
-  do{
-    yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
-    if( yyactyyerrcnt--;
-      yymajor = YYNOCODE;
-    }else if( yyact < YYNSTATE + YYNRULE ){
-      yy_reduce(yypParser,yyact-YYNSTATE);
-    }else{
-      assert( yyact == YY_ERROR_ACTION );
-#ifdef YYERRORSYMBOL
-      int yymx;
-#endif
-#ifndef NDEBUG
-      if( yyTraceFILE ){
-        fprintf(yyTraceFILE,"%sSyntax Error!\n",yyTracePrompt);
-      }
-#endif
-#ifdef YYERRORSYMBOL
-      /* A syntax error has occurred.
-      ** The response to an error depends upon whether or not the
-      ** grammar defines an error token "ERROR".  
-      **
-      ** This is what we do if the grammar does define ERROR:
-      **
-      **  * Call the %syntax_error function.
-      **
-      **  * Begin popping the stack until we enter a state where
-      **    it is legal to shift the error symbol, then shift
-      **    the error symbol.
-      **
-      **  * Set the error count to three.
-      **
-      **  * Begin accepting and shifting new tokens.  No new error
-      **    processing will occur until three tokens have been
-      **    shifted successfully.
-      **
-      */
-      if( yypParser->yyerrcnt<0 ){
-        yy_syntax_error(yypParser,yymajor,yyminorunion);
+  /* Loop through the table columns, appending offset information to 
+  ** string-buffer res for each column.
+  */
+  for(iCol=0; iColnColumn; iCol++){
+    sqlite3_tokenizer_cursor *pC; /* Tokenizer cursor */
+    const char *ZDUMMY;           /* Dummy argument used with xNext() */
+    int NDUMMY = 0;               /* Dummy argument used with xNext() */
+    int iStart = 0;
+    int iEnd = 0;
+    int iCurrent = 0;
+    const char *zDoc;
+    int nDoc;
+
+    /* Initialize the contents of sCtx.aTerm[] for column iCol. There is 
+    ** no way that this operation can fail, so the return code from
+    ** fts3ExprIterate() can be discarded.
+    */
+    sCtx.iCol = iCol;
+    sCtx.iTerm = 0;
+    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void*)&sCtx);
+
+    /* Retreive the text stored in column iCol. If an SQL NULL is stored 
+    ** in column iCol, jump immediately to the next iteration of the loop.
+    ** If an OOM occurs while retrieving the data (this can happen if SQLite
+    ** needs to transform the data from utf-16 to utf-8), return SQLITE_NOMEM 
+    ** to the caller. 
+    */
+    zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol+1);
+    nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol+1);
+    if( zDoc==0 ){
+      if( sqlite3_column_type(pCsr->pStmt, iCol+1)==SQLITE_NULL ){
+        continue;
       }
-      yymx = yypParser->yystack[yypParser->yyidx].major;
-      if( yymx==YYERRORSYMBOL || yyerrorhit ){
-#ifndef NDEBUG
-        if( yyTraceFILE ){
-          fprintf(yyTraceFILE,"%sDiscard input token %s\n",
-             yyTracePrompt,yyTokenName[yymajor]);
+      rc = SQLITE_NOMEM;
+      goto offsets_out;
+    }
+
+    /* Initialize a tokenizer iterator to iterate through column iCol. */
+    rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid,
+        zDoc, nDoc, &pC
+    );
+    if( rc!=SQLITE_OK ) goto offsets_out;
+
+    rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
+    while( rc==SQLITE_OK ){
+      int i;                      /* Used to loop through terms */
+      int iMinPos = 0x7FFFFFFF;   /* Position of next token */
+      TermOffset *pTerm = 0;      /* TermOffset associated with next token */
+
+      for(i=0; ipList && (pT->iPos-pT->iOff)iPos-pT->iOff;
+          pTerm = pT;
         }
-#endif
-        yy_destructor(yypParser, (YYCODETYPE)yymajor,&yyminorunion);
-        yymajor = YYNOCODE;
+      }
+
+      if( !pTerm ){
+        /* All offsets for this column have been gathered. */
+        rc = SQLITE_DONE;
       }else{
-         while(
-          yypParser->yyidx >= 0 &&
-          yymx != YYERRORSYMBOL &&
-          (yyact = yy_find_reduce_action(
-                        yypParser->yystack[yypParser->yyidx].stateno,
-                        YYERRORSYMBOL)) >= YYNSTATE
-        ){
-          yy_pop_parser_stack(yypParser);
+        assert( iCurrent<=iMinPos );
+        if( 0==(0xFE&*pTerm->pList) ){
+          pTerm->pList = 0;
+        }else{
+          fts3GetDeltaPosition(&pTerm->pList, &pTerm->iPos);
         }
-        if( yypParser->yyidx < 0 || yymajor==0 ){
-          yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
-          yy_parse_failed(yypParser);
-          yymajor = YYNOCODE;
-        }else if( yymx!=YYERRORSYMBOL ){
-          YYMINORTYPE u2;
-          u2.YYERRSYMDT = 0;
-          yy_shift(yypParser,yyact,YYERRORSYMBOL,&u2);
+        while( rc==SQLITE_OK && iCurrentxNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
+        }
+        if( rc==SQLITE_OK ){
+          char aBuffer[64];
+          sqlite3_snprintf(sizeof(aBuffer), aBuffer, 
+              "%d %d %d %d ", iCol, pTerm-sCtx.aTerm, iStart, iEnd-iStart
+          );
+          rc = fts3StringAppend(&res, aBuffer, -1);
+        }else if( rc==SQLITE_DONE && pTab->zContentTbl==0 ){
+          rc = FTS_CORRUPT_VTAB;
         }
       }
-      yypParser->yyerrcnt = 3;
-      yyerrorhit = 1;
-#elif defined(YYNOERRORRECOVERY)
-      /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to
-      ** do any kind of error recovery.  Instead, simply invoke the syntax
-      ** error routine and continue going as if nothing had happened.
-      **
-      ** Applications can set this macro (for example inside %include) if
-      ** they intend to abandon the parse upon the first syntax error seen.
-      */
-      yy_syntax_error(yypParser,yymajor,yyminorunion);
-      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
-      yymajor = YYNOCODE;
-      
-#else  /* YYERRORSYMBOL is not defined */
-      /* This is what we do if the grammar does not define ERROR:
-      **
-      **  * Report an error message, and throw away the input token.
-      **
-      **  * If the input token is $, then fail the parse.
-      **
-      ** As before, subsequent error messages are suppressed until
-      ** three input tokens have been successfully shifted.
-      */
-      if( yypParser->yyerrcnt<=0 ){
-        yy_syntax_error(yypParser,yymajor,yyminorunion);
-      }
-      yypParser->yyerrcnt = 3;
-      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
-      if( yyendofinput ){
-        yy_parse_failed(yypParser);
-      }
-      yymajor = YYNOCODE;
-#endif
     }
-  }while( yymajor!=YYNOCODE && yypParser->yyidx>=0 );
+    if( rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
+    }
+
+    pMod->xClose(pC);
+    if( rc!=SQLITE_OK ) goto offsets_out;
+  }
+
+ offsets_out:
+  sqlite3_free(sCtx.aTerm);
+  assert( rc!=SQLITE_DONE );
+  sqlite3Fts3SegmentsClose(pTab);
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx,  rc);
+    sqlite3_free(res.z);
+  }else{
+    sqlite3_result_text(pCtx, res.z, res.n-1, sqlite3_free);
+  }
   return;
 }
 
-/************** End of parse.c ***********************************************/
-/************** Begin file tokenize.c ****************************************/
 /*
-** 2001 September 15
+** Implementation of matchinfo() function.
+*/
+SQLITE_PRIVATE void sqlite3Fts3Matchinfo(
+  sqlite3_context *pContext,      /* Function call context */
+  Fts3Cursor *pCsr,               /* FTS3 table cursor */
+  const char *zArg                /* Second arg to matchinfo() function */
+){
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  const char *zFormat;
+
+  if( zArg ){
+    zFormat = zArg;
+  }else{
+    zFormat = FTS3_MATCHINFO_DEFAULT;
+  }
+
+  if( !pCsr->pExpr ){
+    sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
+    return;
+  }else{
+    /* Retrieve matchinfo() data. */
+    fts3GetMatchinfo(pContext, pCsr, zFormat);
+    sqlite3Fts3SegmentsClose(pTab);
+  }
+}
+
+#endif
+
+/************** End of fts3_snippet.c ****************************************/
+/************** Begin file fts3_unicode.c ************************************/
+/*
+** 2012 May 24
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -125227,803 +164502,394 @@ SQLITE_PRIVATE void sqlite3Parser(
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
-*************************************************************************
-** An tokenizer for SQL
+******************************************************************************
 **
-** This file contains C code that splits an SQL input string up into
-** individual tokens and sends those tokens one-by-one over to the
-** parser for analysis.
+** Implementation of the "unicode" full-text-search tokenizer.
 */
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include  */
 /* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "fts3_tokenizer.h" */
 
 /*
-** The charMap() macro maps alphabetic characters into their
-** lower-case ASCII equivalent.  On ASCII machines, this is just
-** an upper-to-lower case map.  On EBCDIC machines we also need
-** to adjust the encoding.  Only alphabetic characters and underscores
-** need to be translated.
+** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied
+** from the sqlite3 source file utf.c. If this file is compiled as part
+** of the amalgamation, they are not required.
 */
-#ifdef SQLITE_ASCII
-# define charMap(X) sqlite3UpperToLower[(unsigned char)X]
-#endif
-#ifdef SQLITE_EBCDIC
-# define charMap(X) ebcdicToAscii[(unsigned char)X]
-const unsigned char ebcdicToAscii[] = {
-/* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */
-   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */
-   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */
-   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */
-   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */
-   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */
-   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */
-   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */
+#ifndef SQLITE_AMALGAMATION
+
+static const unsigned char sqlite3Utf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
 };
-#endif
 
-/*
-** The sqlite3KeywordCode function looks up an identifier to determine if
-** it is a keyword.  If it is a keyword, the token code of that keyword is 
-** returned.  If the input is not a keyword, TK_ID is returned.
-**
-** The implementation of this routine was generated by a program,
-** mkkeywordhash.h, located in the tool subdirectory of the distribution.
-** The output of the mkkeywordhash.c program is written into a file
-** named keywordhash.h and then included into this source file by
-** the #include below.
-*/
-/************** Include keywordhash.h in the middle of tokenize.c ************/
-/************** Begin file keywordhash.h *************************************/
-/***** This file contains automatically generated code ******
-**
-** The code in this file has been automatically generated by
-**
-**   sqlite/tool/mkkeywordhash.c
-**
-** The code in this file implements a function that determines whether
-** or not a given identifier is really an SQL keyword.  The same thing
-** might be implemented more directly using a hand-written hash table.
-** But by using this automatically generated code, the size of the code
-** is substantially reduced.  This is important for embedded applications
-** on platforms with limited memory.
-*/
-/* Hash score: 182 */
-static int keywordCode(const char *z, int n){
-  /* zText[] encodes 834 bytes of keywords in 554 bytes */
-  /*   REINDEXEDESCAPEACHECKEYBEFOREIGNOREGEXPLAINSTEADDATABASELECT       */
-  /*   ABLEFTHENDEFERRABLELSEXCEPTRANSACTIONATURALTERAISEXCLUSIVE         */
-  /*   XISTSAVEPOINTERSECTRIGGEREFERENCESCONSTRAINTOFFSETEMPORARY         */
-  /*   UNIQUERYWITHOUTERELEASEATTACHAVINGROUPDATEBEGINNERECURSIVE         */
-  /*   BETWEENOTNULLIKECASCADELETECASECOLLATECREATECURRENT_DATEDETACH     */
-  /*   IMMEDIATEJOINSERTMATCHPLANALYZEPRAGMABORTVALUESVIRTUALIMITWHEN     */
-  /*   WHERENAMEAFTEREPLACEANDEFAULTAUTOINCREMENTCASTCOLUMNCOMMIT         */
-  /*   CONFLICTCROSSCURRENT_TIMESTAMPRIMARYDEFERREDISTINCTDROPFAIL        */
-  /*   FROMFULLGLOBYIFISNULLORDERESTRICTRIGHTROLLBACKROWUNIONUSING        */
-  /*   VACUUMVIEWINITIALLY                                                */
-  static const char zText[553] = {
-    'R','E','I','N','D','E','X','E','D','E','S','C','A','P','E','A','C','H',
-    'E','C','K','E','Y','B','E','F','O','R','E','I','G','N','O','R','E','G',
-    'E','X','P','L','A','I','N','S','T','E','A','D','D','A','T','A','B','A',
-    'S','E','L','E','C','T','A','B','L','E','F','T','H','E','N','D','E','F',
-    'E','R','R','A','B','L','E','L','S','E','X','C','E','P','T','R','A','N',
-    'S','A','C','T','I','O','N','A','T','U','R','A','L','T','E','R','A','I',
-    'S','E','X','C','L','U','S','I','V','E','X','I','S','T','S','A','V','E',
-    'P','O','I','N','T','E','R','S','E','C','T','R','I','G','G','E','R','E',
-    'F','E','R','E','N','C','E','S','C','O','N','S','T','R','A','I','N','T',
-    'O','F','F','S','E','T','E','M','P','O','R','A','R','Y','U','N','I','Q',
-    'U','E','R','Y','W','I','T','H','O','U','T','E','R','E','L','E','A','S',
-    'E','A','T','T','A','C','H','A','V','I','N','G','R','O','U','P','D','A',
-    'T','E','B','E','G','I','N','N','E','R','E','C','U','R','S','I','V','E',
-    'B','E','T','W','E','E','N','O','T','N','U','L','L','I','K','E','C','A',
-    'S','C','A','D','E','L','E','T','E','C','A','S','E','C','O','L','L','A',
-    'T','E','C','R','E','A','T','E','C','U','R','R','E','N','T','_','D','A',
-    'T','E','D','E','T','A','C','H','I','M','M','E','D','I','A','T','E','J',
-    'O','I','N','S','E','R','T','M','A','T','C','H','P','L','A','N','A','L',
-    'Y','Z','E','P','R','A','G','M','A','B','O','R','T','V','A','L','U','E',
-    'S','V','I','R','T','U','A','L','I','M','I','T','W','H','E','N','W','H',
-    'E','R','E','N','A','M','E','A','F','T','E','R','E','P','L','A','C','E',
-    'A','N','D','E','F','A','U','L','T','A','U','T','O','I','N','C','R','E',
-    'M','E','N','T','C','A','S','T','C','O','L','U','M','N','C','O','M','M',
-    'I','T','C','O','N','F','L','I','C','T','C','R','O','S','S','C','U','R',
-    'R','E','N','T','_','T','I','M','E','S','T','A','M','P','R','I','M','A',
-    'R','Y','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T','D',
-    'R','O','P','F','A','I','L','F','R','O','M','F','U','L','L','G','L','O',
-    'B','Y','I','F','I','S','N','U','L','L','O','R','D','E','R','E','S','T',
-    'R','I','C','T','R','I','G','H','T','R','O','L','L','B','A','C','K','R',
-    'O','W','U','N','I','O','N','U','S','I','N','G','V','A','C','U','U','M',
-    'V','I','E','W','I','N','I','T','I','A','L','L','Y',
-  };
-  static const unsigned char aHash[127] = {
-      76, 105, 117,  74,   0,  45,   0,   0,  82,   0,  77,   0,   0,
-      42,  12,  78,  15,   0, 116,  85,  54, 112,   0,  19,   0,   0,
-     121,   0, 119, 115,   0,  22,  93,   0,   9,   0,   0,  70,  71,
-       0,  69,   6,   0,  48,  90, 102,   0, 118, 101,   0,   0,  44,
-       0, 103,  24,   0,  17,   0, 122,  53,  23,   0,   5, 110,  25,
-      96,   0,   0, 124, 106,  60, 123,  57,  28,  55,   0,  91,   0,
-     100,  26,   0,  99,   0,   0,   0,  95,  92,  97,  88, 109,  14,
-      39, 108,   0,  81,   0,  18,  89, 111,  32,   0, 120,  80, 113,
-      62,  46,  84,   0,   0,  94,  40,  59, 114,   0,  36,   0,   0,
-      29,   0,  86,  63,  64,   0,  20,  61,   0,  56,
-  };
-  static const unsigned char aNext[124] = {
-       0,   0,   0,   0,   4,   0,   0,   0,   0,   0,   0,   0,   0,
-       0,   2,   0,   0,   0,   0,   0,   0,  13,   0,   0,   0,   0,
-       0,   7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-       0,   0,   0,   0,  33,   0,  21,   0,   0,   0,   0,   0,  50,
-       0,  43,   3,  47,   0,   0,   0,   0,  30,   0,  58,   0,  38,
-       0,   0,   0,   1,  66,   0,   0,  67,   0,  41,   0,   0,   0,
-       0,   0,   0,  49,  65,   0,   0,   0,   0,  31,  52,  16,  34,
-      10,   0,   0,   0,   0,   0,   0,   0,  11,  72,  79,   0,   8,
-       0, 104,  98,   0, 107,   0,  87,   0,  75,  51,   0,  27,  37,
-      73,  83,   0,  35,  68,   0,   0,
-  };
-  static const unsigned char aLen[124] = {
-       7,   7,   5,   4,   6,   4,   5,   3,   6,   7,   3,   6,   6,
-       7,   7,   3,   8,   2,   6,   5,   4,   4,   3,  10,   4,   6,
-      11,   6,   2,   7,   5,   5,   9,   6,   9,   9,   7,  10,  10,
-       4,   6,   2,   3,   9,   4,   2,   6,   5,   7,   4,   5,   7,
-       6,   6,   5,   6,   5,   5,   9,   7,   7,   3,   2,   4,   4,
-       7,   3,   6,   4,   7,   6,  12,   6,   9,   4,   6,   5,   4,
-       7,   6,   5,   6,   7,   5,   4,   5,   6,   5,   7,   3,   7,
-      13,   2,   2,   4,   6,   6,   8,   5,  17,  12,   7,   8,   8,
-       2,   4,   4,   4,   4,   4,   2,   2,   6,   5,   8,   5,   8,
-       3,   5,   5,   6,   4,   9,   3,
-  };
-  static const unsigned short int aOffset[124] = {
-       0,   2,   2,   8,   9,  14,  16,  20,  23,  25,  25,  29,  33,
-      36,  41,  46,  48,  53,  54,  59,  62,  65,  67,  69,  78,  81,
-      86,  91,  95,  96, 101, 105, 109, 117, 122, 128, 136, 142, 152,
-     159, 162, 162, 165, 167, 167, 171, 176, 179, 184, 184, 188, 192,
-     199, 204, 209, 212, 218, 221, 225, 234, 240, 240, 240, 243, 246,
-     250, 251, 255, 261, 265, 272, 278, 290, 296, 305, 307, 313, 318,
-     320, 327, 332, 337, 343, 349, 354, 358, 361, 367, 371, 378, 380,
-     387, 389, 391, 400, 404, 410, 416, 424, 429, 429, 445, 452, 459,
-     460, 467, 471, 475, 479, 483, 486, 488, 490, 496, 500, 508, 513,
-     521, 524, 529, 534, 540, 544, 549,
-  };
-  static const unsigned char aCode[124] = {
-    TK_REINDEX,    TK_INDEXED,    TK_INDEX,      TK_DESC,       TK_ESCAPE,     
-    TK_EACH,       TK_CHECK,      TK_KEY,        TK_BEFORE,     TK_FOREIGN,    
-    TK_FOR,        TK_IGNORE,     TK_LIKE_KW,    TK_EXPLAIN,    TK_INSTEAD,    
-    TK_ADD,        TK_DATABASE,   TK_AS,         TK_SELECT,     TK_TABLE,      
-    TK_JOIN_KW,    TK_THEN,       TK_END,        TK_DEFERRABLE, TK_ELSE,       
-    TK_EXCEPT,     TK_TRANSACTION,TK_ACTION,     TK_ON,         TK_JOIN_KW,    
-    TK_ALTER,      TK_RAISE,      TK_EXCLUSIVE,  TK_EXISTS,     TK_SAVEPOINT,  
-    TK_INTERSECT,  TK_TRIGGER,    TK_REFERENCES, TK_CONSTRAINT, TK_INTO,       
-    TK_OFFSET,     TK_OF,         TK_SET,        TK_TEMP,       TK_TEMP,       
-    TK_OR,         TK_UNIQUE,     TK_QUERY,      TK_WITHOUT,    TK_WITH,       
-    TK_JOIN_KW,    TK_RELEASE,    TK_ATTACH,     TK_HAVING,     TK_GROUP,      
-    TK_UPDATE,     TK_BEGIN,      TK_JOIN_KW,    TK_RECURSIVE,  TK_BETWEEN,    
-    TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       TK_LIKE_KW,    
-    TK_CASCADE,    TK_ASC,        TK_DELETE,     TK_CASE,       TK_COLLATE,    
-    TK_CREATE,     TK_CTIME_KW,   TK_DETACH,     TK_IMMEDIATE,  TK_JOIN,       
-    TK_INSERT,     TK_MATCH,      TK_PLAN,       TK_ANALYZE,    TK_PRAGMA,     
-    TK_ABORT,      TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      TK_WHEN,       
-    TK_WHERE,      TK_RENAME,     TK_AFTER,      TK_REPLACE,    TK_AND,        
-    TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         TK_CAST,       
-    TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   
-    TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   TK_IS,         
-    TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    TK_LIKE_KW,    
-    TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   
-    TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        TK_UNION,      TK_USING,      
-    TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  TK_ALL,        
-  };
-  int h, i;
-  if( n<2 ) return TK_ID;
-  h = ((charMap(z[0])*4) ^
-      (charMap(z[n-1])*3) ^
-      n) % 127;
-  for(i=((int)aHash[h])-1; i>=0; i=((int)aNext[i])-1){
-    if( aLen[i]==n && sqlite3StrNICmp(&zText[aOffset[i]],z,n)==0 ){
-      testcase( i==0 ); /* REINDEX */
-      testcase( i==1 ); /* INDEXED */
-      testcase( i==2 ); /* INDEX */
-      testcase( i==3 ); /* DESC */
-      testcase( i==4 ); /* ESCAPE */
-      testcase( i==5 ); /* EACH */
-      testcase( i==6 ); /* CHECK */
-      testcase( i==7 ); /* KEY */
-      testcase( i==8 ); /* BEFORE */
-      testcase( i==9 ); /* FOREIGN */
-      testcase( i==10 ); /* FOR */
-      testcase( i==11 ); /* IGNORE */
-      testcase( i==12 ); /* REGEXP */
-      testcase( i==13 ); /* EXPLAIN */
-      testcase( i==14 ); /* INSTEAD */
-      testcase( i==15 ); /* ADD */
-      testcase( i==16 ); /* DATABASE */
-      testcase( i==17 ); /* AS */
-      testcase( i==18 ); /* SELECT */
-      testcase( i==19 ); /* TABLE */
-      testcase( i==20 ); /* LEFT */
-      testcase( i==21 ); /* THEN */
-      testcase( i==22 ); /* END */
-      testcase( i==23 ); /* DEFERRABLE */
-      testcase( i==24 ); /* ELSE */
-      testcase( i==25 ); /* EXCEPT */
-      testcase( i==26 ); /* TRANSACTION */
-      testcase( i==27 ); /* ACTION */
-      testcase( i==28 ); /* ON */
-      testcase( i==29 ); /* NATURAL */
-      testcase( i==30 ); /* ALTER */
-      testcase( i==31 ); /* RAISE */
-      testcase( i==32 ); /* EXCLUSIVE */
-      testcase( i==33 ); /* EXISTS */
-      testcase( i==34 ); /* SAVEPOINT */
-      testcase( i==35 ); /* INTERSECT */
-      testcase( i==36 ); /* TRIGGER */
-      testcase( i==37 ); /* REFERENCES */
-      testcase( i==38 ); /* CONSTRAINT */
-      testcase( i==39 ); /* INTO */
-      testcase( i==40 ); /* OFFSET */
-      testcase( i==41 ); /* OF */
-      testcase( i==42 ); /* SET */
-      testcase( i==43 ); /* TEMPORARY */
-      testcase( i==44 ); /* TEMP */
-      testcase( i==45 ); /* OR */
-      testcase( i==46 ); /* UNIQUE */
-      testcase( i==47 ); /* QUERY */
-      testcase( i==48 ); /* WITHOUT */
-      testcase( i==49 ); /* WITH */
-      testcase( i==50 ); /* OUTER */
-      testcase( i==51 ); /* RELEASE */
-      testcase( i==52 ); /* ATTACH */
-      testcase( i==53 ); /* HAVING */
-      testcase( i==54 ); /* GROUP */
-      testcase( i==55 ); /* UPDATE */
-      testcase( i==56 ); /* BEGIN */
-      testcase( i==57 ); /* INNER */
-      testcase( i==58 ); /* RECURSIVE */
-      testcase( i==59 ); /* BETWEEN */
-      testcase( i==60 ); /* NOTNULL */
-      testcase( i==61 ); /* NOT */
-      testcase( i==62 ); /* NO */
-      testcase( i==63 ); /* NULL */
-      testcase( i==64 ); /* LIKE */
-      testcase( i==65 ); /* CASCADE */
-      testcase( i==66 ); /* ASC */
-      testcase( i==67 ); /* DELETE */
-      testcase( i==68 ); /* CASE */
-      testcase( i==69 ); /* COLLATE */
-      testcase( i==70 ); /* CREATE */
-      testcase( i==71 ); /* CURRENT_DATE */
-      testcase( i==72 ); /* DETACH */
-      testcase( i==73 ); /* IMMEDIATE */
-      testcase( i==74 ); /* JOIN */
-      testcase( i==75 ); /* INSERT */
-      testcase( i==76 ); /* MATCH */
-      testcase( i==77 ); /* PLAN */
-      testcase( i==78 ); /* ANALYZE */
-      testcase( i==79 ); /* PRAGMA */
-      testcase( i==80 ); /* ABORT */
-      testcase( i==81 ); /* VALUES */
-      testcase( i==82 ); /* VIRTUAL */
-      testcase( i==83 ); /* LIMIT */
-      testcase( i==84 ); /* WHEN */
-      testcase( i==85 ); /* WHERE */
-      testcase( i==86 ); /* RENAME */
-      testcase( i==87 ); /* AFTER */
-      testcase( i==88 ); /* REPLACE */
-      testcase( i==89 ); /* AND */
-      testcase( i==90 ); /* DEFAULT */
-      testcase( i==91 ); /* AUTOINCREMENT */
-      testcase( i==92 ); /* TO */
-      testcase( i==93 ); /* IN */
-      testcase( i==94 ); /* CAST */
-      testcase( i==95 ); /* COLUMN */
-      testcase( i==96 ); /* COMMIT */
-      testcase( i==97 ); /* CONFLICT */
-      testcase( i==98 ); /* CROSS */
-      testcase( i==99 ); /* CURRENT_TIMESTAMP */
-      testcase( i==100 ); /* CURRENT_TIME */
-      testcase( i==101 ); /* PRIMARY */
-      testcase( i==102 ); /* DEFERRED */
-      testcase( i==103 ); /* DISTINCT */
-      testcase( i==104 ); /* IS */
-      testcase( i==105 ); /* DROP */
-      testcase( i==106 ); /* FAIL */
-      testcase( i==107 ); /* FROM */
-      testcase( i==108 ); /* FULL */
-      testcase( i==109 ); /* GLOB */
-      testcase( i==110 ); /* BY */
-      testcase( i==111 ); /* IF */
-      testcase( i==112 ); /* ISNULL */
-      testcase( i==113 ); /* ORDER */
-      testcase( i==114 ); /* RESTRICT */
-      testcase( i==115 ); /* RIGHT */
-      testcase( i==116 ); /* ROLLBACK */
-      testcase( i==117 ); /* ROW */
-      testcase( i==118 ); /* UNION */
-      testcase( i==119 ); /* USING */
-      testcase( i==120 ); /* VACUUM */
-      testcase( i==121 ); /* VIEW */
-      testcase( i==122 ); /* INITIALLY */
-      testcase( i==123 ); /* ALL */
-      return aCode[i];
-    }
+#define READ_UTF8(zIn, zTerm, c)                           \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = sqlite3Utf8Trans1[c-0xc0];                         \
+    while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+    if( c<0x80                                             \
+        || (c&0xFFFFF800)==0xD800                          \
+        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
   }
-  return TK_ID;
-}
-SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){
-  return keywordCode((char*)z, n);
+
+#define WRITE_UTF8(zOut, c) {                          \
+  if( c<0x00080 ){                                     \
+    *zOut++ = (u8)(c&0xFF);                            \
+  }                                                    \
+  else if( c<0x00800 ){                                \
+    *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);                \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }                                                    \
+  else if( c<0x10000 ){                                \
+    *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);               \
+    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }else{                                               \
+    *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);             \
+    *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);             \
+    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }                                                    \
 }
-#define SQLITE_N_KEYWORD 124
 
-/************** End of keywordhash.h *****************************************/
-/************** Continuing where we left off in tokenize.c *******************/
+#endif /* ifndef SQLITE_AMALGAMATION */
 
+typedef struct unicode_tokenizer unicode_tokenizer;
+typedef struct unicode_cursor unicode_cursor;
 
-/*
-** If X is a character that can be used in an identifier then
-** IdChar(X) will be true.  Otherwise it is false.
-**
-** For ASCII, any character with the high-order bit set is
-** allowed in an identifier.  For 7-bit characters, 
-** sqlite3IsIdChar[X] must be 1.
-**
-** For EBCDIC, the rules are more complex but have the same
-** end result.
-**
-** Ticket #1066.  the SQL standard does not allow '$' in the
-** middle of identifiers.  But many SQL implementations do. 
-** SQLite will allow '$' in identifiers for compatibility.
-** But the feature is undocumented.
-*/
-#ifdef SQLITE_ASCII
-#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
-#endif
-#ifdef SQLITE_EBCDIC
-SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[] = {
-/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
-    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 4x */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0,  /* 5x */
-    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0,  /* 6x */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,  /* 7x */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0,  /* 8x */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,  /* 9x */
-    1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,  /* Ax */
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* Bx */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Cx */
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Dx */
-    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Ex */
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,  /* Fx */
+struct unicode_tokenizer {
+  sqlite3_tokenizer base;
+  int bRemoveDiacritic;
+  int nException;
+  int *aiException;
+};
+
+struct unicode_cursor {
+  sqlite3_tokenizer_cursor base;
+  const unsigned char *aInput;    /* Input text being tokenized */
+  int nInput;                     /* Size of aInput[] in bytes */
+  int iOff;                       /* Current offset within aInput[] */
+  int iToken;                     /* Index of next token to be returned */
+  char *zToken;                   /* storage for current token */
+  int nAlloc;                     /* space allocated at zToken */
 };
-#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
-#endif
-SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }
 
 
 /*
-** Return the length of the token that begins at z[0]. 
-** Store the token type in *tokenType before returning.
+** Destroy a tokenizer allocated by unicodeCreate().
 */
-SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
-  int i, c;
-  switch( *z ){
-    case ' ': case '\t': case '\n': case '\f': case '\r': {
-      testcase( z[0]==' ' );
-      testcase( z[0]=='\t' );
-      testcase( z[0]=='\n' );
-      testcase( z[0]=='\f' );
-      testcase( z[0]=='\r' );
-      for(i=1; sqlite3Isspace(z[i]); i++){}
-      *tokenType = TK_SPACE;
-      return i;
-    }
-    case '-': {
-      if( z[1]=='-' ){
-        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
-        *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
-        return i;
-      }
-      *tokenType = TK_MINUS;
-      return 1;
-    }
-    case '(': {
-      *tokenType = TK_LP;
-      return 1;
-    }
-    case ')': {
-      *tokenType = TK_RP;
-      return 1;
-    }
-    case ';': {
-      *tokenType = TK_SEMI;
-      return 1;
-    }
-    case '+': {
-      *tokenType = TK_PLUS;
-      return 1;
-    }
-    case '*': {
-      *tokenType = TK_STAR;
-      return 1;
-    }
-    case '/': {
-      if( z[1]!='*' || z[2]==0 ){
-        *tokenType = TK_SLASH;
-        return 1;
-      }
-      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
-      if( c ) i++;
-      *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
-      return i;
-    }
-    case '%': {
-      *tokenType = TK_REM;
-      return 1;
-    }
-    case '=': {
-      *tokenType = TK_EQ;
-      return 1 + (z[1]=='=');
-    }
-    case '<': {
-      if( (c=z[1])=='=' ){
-        *tokenType = TK_LE;
-        return 2;
-      }else if( c=='>' ){
-        *tokenType = TK_NE;
-        return 2;
-      }else if( c=='<' ){
-        *tokenType = TK_LSHIFT;
-        return 2;
-      }else{
-        *tokenType = TK_LT;
-        return 1;
-      }
-    }
-    case '>': {
-      if( (c=z[1])=='=' ){
-        *tokenType = TK_GE;
-        return 2;
-      }else if( c=='>' ){
-        *tokenType = TK_RSHIFT;
-        return 2;
-      }else{
-        *tokenType = TK_GT;
-        return 1;
-      }
-    }
-    case '!': {
-      if( z[1]!='=' ){
-        *tokenType = TK_ILLEGAL;
-        return 2;
-      }else{
-        *tokenType = TK_NE;
-        return 2;
-      }
-    }
-    case '|': {
-      if( z[1]!='|' ){
-        *tokenType = TK_BITOR;
-        return 1;
-      }else{
-        *tokenType = TK_CONCAT;
-        return 2;
-      }
-    }
-    case ',': {
-      *tokenType = TK_COMMA;
-      return 1;
-    }
-    case '&': {
-      *tokenType = TK_BITAND;
-      return 1;
-    }
-    case '~': {
-      *tokenType = TK_BITNOT;
-      return 1;
-    }
-    case '`':
-    case '\'':
-    case '"': {
-      int delim = z[0];
-      testcase( delim=='`' );
-      testcase( delim=='\'' );
-      testcase( delim=='"' );
-      for(i=1; (c=z[i])!=0; i++){
-        if( c==delim ){
-          if( z[i+1]==delim ){
-            i++;
-          }else{
-            break;
-          }
-        }
-      }
-      if( c=='\'' ){
-        *tokenType = TK_STRING;
-        return i+1;
-      }else if( c!=0 ){
-        *tokenType = TK_ID;
-        return i+1;
-      }else{
-        *tokenType = TK_ILLEGAL;
-        return i;
-      }
-    }
-    case '.': {
-#ifndef SQLITE_OMIT_FLOATING_POINT
-      if( !sqlite3Isdigit(z[1]) )
-#endif
-      {
-        *tokenType = TK_DOT;
-        return 1;
-      }
-      /* If the next character is a digit, this is a floating point
-      ** number that begins with ".".  Fall thru into the next case */
-    }
-    case '0': case '1': case '2': case '3': case '4':
-    case '5': case '6': case '7': case '8': case '9': {
-      testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
-      testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
-      testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
-      testcase( z[0]=='9' );
-      *tokenType = TK_INTEGER;
-#ifndef SQLITE_OMIT_HEX_INTEGER
-      if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
-        for(i=3; sqlite3Isxdigit(z[i]); i++){}
-        return i;
-      }
-#endif
-      for(i=0; sqlite3Isdigit(z[i]); i++){}
-#ifndef SQLITE_OMIT_FLOATING_POINT
-      if( z[i]=='.' ){
-        i++;
-        while( sqlite3Isdigit(z[i]) ){ i++; }
-        *tokenType = TK_FLOAT;
-      }
-      if( (z[i]=='e' || z[i]=='E') &&
-           ( sqlite3Isdigit(z[i+1]) 
-            || ((z[i+1]=='+' || z[i+1]=='-') && sqlite3Isdigit(z[i+2]))
-           )
-      ){
-        i += 2;
-        while( sqlite3Isdigit(z[i]) ){ i++; }
-        *tokenType = TK_FLOAT;
-      }
-#endif
-      while( IdChar(z[i]) ){
-        *tokenType = TK_ILLEGAL;
-        i++;
-      }
-      return i;
-    }
-    case '[': {
-      for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
-      *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
-      return i;
-    }
-    case '?': {
-      *tokenType = TK_VARIABLE;
-      for(i=1; sqlite3Isdigit(z[i]); i++){}
-      return i;
-    }
-#ifndef SQLITE_OMIT_TCL_VARIABLE
-    case '$':
-#endif
-    case '@':  /* For compatibility with MS SQL Server */
-    case '#':
-    case ':': {
-      int n = 0;
-      testcase( z[0]=='$' );  testcase( z[0]=='@' );
-      testcase( z[0]==':' );  testcase( z[0]=='#' );
-      *tokenType = TK_VARIABLE;
-      for(i=1; (c=z[i])!=0; i++){
-        if( IdChar(c) ){
-          n++;
-#ifndef SQLITE_OMIT_TCL_VARIABLE
-        }else if( c=='(' && n>0 ){
-          do{
-            i++;
-          }while( (c=z[i])!=0 && !sqlite3Isspace(c) && c!=')' );
-          if( c==')' ){
-            i++;
-          }else{
-            *tokenType = TK_ILLEGAL;
-          }
-          break;
-        }else if( c==':' && z[i+1]==':' ){
-          i++;
-#endif
-        }else{
-          break;
-        }
-      }
-      if( n==0 ) *tokenType = TK_ILLEGAL;
-      return i;
-    }
-#ifndef SQLITE_OMIT_BLOB_LITERAL
-    case 'x': case 'X': {
-      testcase( z[0]=='x' ); testcase( z[0]=='X' );
-      if( z[1]=='\'' ){
-        *tokenType = TK_BLOB;
-        for(i=2; sqlite3Isxdigit(z[i]); i++){}
-        if( z[i]!='\'' || i%2 ){
-          *tokenType = TK_ILLEGAL;
-          while( z[i] && z[i]!='\'' ){ i++; }
-        }
-        if( z[i] ) i++;
-        return i;
+static int unicodeDestroy(sqlite3_tokenizer *pTokenizer){
+  if( pTokenizer ){
+    unicode_tokenizer *p = (unicode_tokenizer *)pTokenizer;
+    sqlite3_free(p->aiException);
+    sqlite3_free(p);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** As part of a tokenchars= or separators= option, the CREATE VIRTUAL TABLE
+** statement has specified that the tokenizer for this table shall consider
+** all characters in string zIn/nIn to be separators (if bAlnum==0) or
+** token characters (if bAlnum==1).
+**
+** For each codepoint in the zIn/nIn string, this function checks if the
+** sqlite3FtsUnicodeIsalnum() function already returns the desired result.
+** If so, no action is taken. Otherwise, the codepoint is added to the 
+** unicode_tokenizer.aiException[] array. For the purposes of tokenization,
+** the return value of sqlite3FtsUnicodeIsalnum() is inverted for all
+** codepoints in the aiException[] array.
+**
+** If a standalone diacritic mark (one that sqlite3FtsUnicodeIsdiacritic()
+** identifies as a diacritic) occurs in the zIn/nIn string it is ignored.
+** It is not possible to change the behavior of the tokenizer with respect
+** to these codepoints.
+*/
+static int unicodeAddExceptions(
+  unicode_tokenizer *p,           /* Tokenizer to add exceptions to */
+  int bAlnum,                     /* Replace Isalnum() return value with this */
+  const char *zIn,                /* Array of characters to make exceptions */
+  int nIn                         /* Length of z in bytes */
+){
+  const unsigned char *z = (const unsigned char *)zIn;
+  const unsigned char *zTerm = &z[nIn];
+  unsigned int iCode;
+  int nEntry = 0;
+
+  assert( bAlnum==0 || bAlnum==1 );
+
+  while( zaiException, (p->nException+nEntry)*sizeof(int));
+    if( aNew==0 ) return SQLITE_NOMEM;
+    nNew = p->nException;
+
+    z = (const unsigned char *)zIn;
+    while( zi; j--) aNew[j] = aNew[j-1];
+        aNew[i] = (int)iCode;
+        nNew++;
       }
-      /* Otherwise fall through to the next case */
     }
-#endif
-    default: {
-      if( !IdChar(*z) ){
-        break;
+    p->aiException = aNew;
+    p->nException = nNew;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Return true if the p->aiException[] array contains the value iCode.
+*/
+static int unicodeIsException(unicode_tokenizer *p, int iCode){
+  if( p->nException>0 ){
+    int *a = p->aiException;
+    int iLo = 0;
+    int iHi = p->nException-1;
+
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( iCode==a[iTest] ){
+        return 1;
+      }else if( iCode>a[iTest] ){
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
       }
-      for(i=1; IdChar(z[i]); i++){}
-      *tokenType = keywordCode((char*)z, i);
-      return i;
     }
   }
-  *tokenType = TK_ILLEGAL;
-  return 1;
+
+  return 0;
 }
 
 /*
-** Run the parser on the given SQL string.  The parser structure is
-** passed in.  An SQLITE_ status code is returned.  If an error occurs
-** then an and attempt is made to write an error message into 
-** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
-** error message.
+** Return true if, for the purposes of tokenization, codepoint iCode is
+** considered a token character (not a separator).
 */
-SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
-  int nErr = 0;                   /* Number of errors encountered */
-  int i;                          /* Loop counter */
-  void *pEngine;                  /* The LEMON-generated LALR(1) parser */
-  int tokenType;                  /* type of the next token */
-  int lastTokenParsed = -1;       /* type of the previous token */
-  u8 enableLookaside;             /* Saved value of db->lookaside.bEnabled */
-  sqlite3 *db = pParse->db;       /* The database connection */
-  int mxSqlLen;                   /* Max length of an SQL string */
+static int unicodeIsAlnum(unicode_tokenizer *p, int iCode){
+  assert( (sqlite3FtsUnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
+  return sqlite3FtsUnicodeIsalnum(iCode) ^ unicodeIsException(p, iCode);
+}
 
+/*
+** Create a new tokenizer instance.
+*/
+static int unicodeCreate(
+  int nArg,                       /* Size of array argv[] */
+  const char * const *azArg,      /* Tokenizer creation arguments */
+  sqlite3_tokenizer **pp          /* OUT: New tokenizer handle */
+){
+  unicode_tokenizer *pNew;        /* New tokenizer object */
+  int i;
+  int rc = SQLITE_OK;
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( zSql==0 || pzErrMsg==0 ) return SQLITE_MISUSE_BKPT;
-#endif
-  mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
-  if( db->nVdbeActive==0 ){
-    db->u1.isInterrupted = 0;
-  }
-  pParse->rc = SQLITE_OK;
-  pParse->zTail = zSql;
-  i = 0;
-  assert( pzErrMsg!=0 );
-  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
-  if( pEngine==0 ){
-    db->mallocFailed = 1;
-    return SQLITE_NOMEM;
-  }
-  assert( pParse->pNewTable==0 );
-  assert( pParse->pNewTrigger==0 );
-  assert( pParse->nVar==0 );
-  assert( pParse->nzVar==0 );
-  assert( pParse->azVar==0 );
-  enableLookaside = db->lookaside.bEnabled;
-  if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
-  while( !db->mallocFailed && zSql[i]!=0 ){
-    assert( i>=0 );
-    pParse->sLastToken.z = &zSql[i];
-    pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
-    i += pParse->sLastToken.n;
-    if( i>mxSqlLen ){
-      pParse->rc = SQLITE_TOOBIG;
-      break;
+  pNew = (unicode_tokenizer *) sqlite3_malloc(sizeof(unicode_tokenizer));
+  if( pNew==NULL ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(unicode_tokenizer));
+  pNew->bRemoveDiacritic = 1;
+
+  for(i=0; rc==SQLITE_OK && ibRemoveDiacritic = 1;
     }
-    switch( tokenType ){
-      case TK_SPACE: {
-        if( db->u1.isInterrupted ){
-          sqlite3ErrorMsg(pParse, "interrupt");
-          pParse->rc = SQLITE_INTERRUPT;
-          goto abort_parse;
-        }
-        break;
-      }
-      case TK_ILLEGAL: {
-        sqlite3DbFree(db, *pzErrMsg);
-        *pzErrMsg = sqlite3MPrintf(db, "unrecognized token: \"%T\"",
-                        &pParse->sLastToken);
-        nErr++;
-        goto abort_parse;
-      }
-      case TK_SEMI: {
-        pParse->zTail = &zSql[i];
-        /* Fall thru into the default case */
-      }
-      default: {
-        sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
-        lastTokenParsed = tokenType;
-        if( pParse->rc!=SQLITE_OK ){
-          goto abort_parse;
-        }
-        break;
-      }
+    else if( n==19 && memcmp("remove_diacritics=0", z, 19)==0 ){
+      pNew->bRemoveDiacritic = 0;
     }
-  }
-abort_parse:
-  if( zSql[i]==0 && nErr==0 && pParse->rc==SQLITE_OK ){
-    if( lastTokenParsed!=TK_SEMI ){
-      sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
-      pParse->zTail = &zSql[i];
+    else if( n>=11 && memcmp("tokenchars=", z, 11)==0 ){
+      rc = unicodeAddExceptions(pNew, 1, &z[11], n-11);
+    }
+    else if( n>=11 && memcmp("separators=", z, 11)==0 ){
+      rc = unicodeAddExceptions(pNew, 0, &z[11], n-11);
+    }
+    else{
+      /* Unrecognized argument */
+      rc  = SQLITE_ERROR;
     }
-    sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
-  }
-#ifdef YYTRACKMAXSTACKDEPTH
-  sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
-      sqlite3ParserStackPeak(pEngine)
-  );
-#endif /* YYDEBUG */
-  sqlite3ParserFree(pEngine, sqlite3_free);
-  db->lookaside.bEnabled = enableLookaside;
-  if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
-  }
-  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
-    sqlite3SetString(&pParse->zErrMsg, db, "%s", sqlite3ErrStr(pParse->rc));
-  }
-  assert( pzErrMsg!=0 );
-  if( pParse->zErrMsg ){
-    *pzErrMsg = pParse->zErrMsg;
-    sqlite3_log(pParse->rc, "%s", *pzErrMsg);
-    pParse->zErrMsg = 0;
-    nErr++;
-  }
-  if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
-    sqlite3VdbeDelete(pParse->pVdbe);
-    pParse->pVdbe = 0;
-  }
-#ifndef SQLITE_OMIT_SHARED_CACHE
-  if( pParse->nested==0 ){
-    sqlite3DbFree(db, pParse->aTableLock);
-    pParse->aTableLock = 0;
-    pParse->nTableLock = 0;
   }
-#endif
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  sqlite3_free(pParse->apVtabLock);
-#endif
 
-  if( !IN_DECLARE_VTAB ){
-    /* If the pParse->declareVtab flag is set, do not delete any table 
-    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
-    ** will take responsibility for freeing the Table structure.
-    */
-    sqlite3DeleteTable(db, pParse->pNewTable);
+  if( rc!=SQLITE_OK ){
+    unicodeDestroy((sqlite3_tokenizer *)pNew);
+    pNew = 0;
   }
+  *pp = (sqlite3_tokenizer *)pNew;
+  return rc;
+}
 
-  if( pParse->bFreeWith ) sqlite3WithDelete(db, pParse->pWith);
-  sqlite3DeleteTrigger(db, pParse->pNewTrigger);
-  for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
-  sqlite3DbFree(db, pParse->azVar);
-  while( pParse->pAinc ){
-    AutoincInfo *p = pParse->pAinc;
-    pParse->pAinc = p->pNext;
-    sqlite3DbFree(db, p);
+/*
+** Prepare to begin tokenizing a particular string.  The input
+** string to be tokenized is pInput[0..nBytes-1].  A cursor
+** used to incrementally tokenize this string is returned in 
+** *ppCursor.
+*/
+static int unicodeOpen(
+  sqlite3_tokenizer *p,           /* The tokenizer */
+  const char *aInput,             /* Input string */
+  int nInput,                     /* Size of string aInput in bytes */
+  sqlite3_tokenizer_cursor **pp   /* OUT: New cursor object */
+){
+  unicode_cursor *pCsr;
+
+  pCsr = (unicode_cursor *)sqlite3_malloc(sizeof(unicode_cursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
   }
-  while( pParse->pZombieTab ){
-    Table *p = pParse->pZombieTab;
-    pParse->pZombieTab = p->pNextZombie;
-    sqlite3DeleteTable(db, p);
+  memset(pCsr, 0, sizeof(unicode_cursor));
+
+  pCsr->aInput = (const unsigned char *)aInput;
+  if( aInput==0 ){
+    pCsr->nInput = 0;
+  }else if( nInput<0 ){
+    pCsr->nInput = (int)strlen(aInput);
+  }else{
+    pCsr->nInput = nInput;
   }
-  if( nErr>0 && pParse->rc==SQLITE_OK ){
-    pParse->rc = SQLITE_ERROR;
+
+  *pp = &pCsr->base;
+  UNUSED_PARAMETER(p);
+  return SQLITE_OK;
+}
+
+/*
+** Close a tokenization cursor previously opened by a call to
+** simpleOpen() above.
+*/
+static int unicodeClose(sqlite3_tokenizer_cursor *pCursor){
+  unicode_cursor *pCsr = (unicode_cursor *) pCursor;
+  sqlite3_free(pCsr->zToken);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** Extract the next token from a tokenization cursor.  The cursor must
+** have been opened by a prior call to simpleOpen().
+*/
+static int unicodeNext(
+  sqlite3_tokenizer_cursor *pC,   /* Cursor returned by simpleOpen */
+  const char **paToken,           /* OUT: Token text */
+  int *pnToken,                   /* OUT: Number of bytes at *paToken */
+  int *piStart,                   /* OUT: Starting offset of token */
+  int *piEnd,                     /* OUT: Ending offset of token */
+  int *piPos                      /* OUT: Position integer of token */
+){
+  unicode_cursor *pCsr = (unicode_cursor *)pC;
+  unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);
+  unsigned int iCode = 0;
+  char *zOut;
+  const unsigned char *z = &pCsr->aInput[pCsr->iOff];
+  const unsigned char *zStart = z;
+  const unsigned char *zEnd;
+  const unsigned char *zTerm = &pCsr->aInput[pCsr->nInput];
+
+  /* Scan past any delimiter characters before the start of the next token.
+  ** Return SQLITE_DONE early if this takes us all the way to the end of 
+  ** the input.  */
+  while( z=zTerm ) return SQLITE_DONE;
+
+  zOut = pCsr->zToken;
+  do {
+    int iOut;
+
+    /* Grow the output buffer if required. */
+    if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){
+      char *zNew = sqlite3_realloc(pCsr->zToken, pCsr->nAlloc+64);
+      if( !zNew ) return SQLITE_NOMEM;
+      zOut = &zNew[zOut - pCsr->zToken];
+      pCsr->zToken = zNew;
+      pCsr->nAlloc += 64;
+    }
+
+    /* Write the folded case of the last character read to the output */
+    zEnd = z;
+    iOut = sqlite3FtsUnicodeFold((int)iCode, p->bRemoveDiacritic);
+    if( iOut ){
+      WRITE_UTF8(zOut, iOut);
+    }
+
+    /* If the cursor is not at EOF, read the next character */
+    if( z>=zTerm ) break;
+    READ_UTF8(z, zTerm, iCode);
+  }while( unicodeIsAlnum(p, (int)iCode) 
+       || sqlite3FtsUnicodeIsdiacritic((int)iCode)
+  );
+
+  /* Set the output variables and return. */
+  pCsr->iOff = (int)(z - pCsr->aInput);
+  *paToken = pCsr->zToken;
+  *pnToken = (int)(zOut - pCsr->zToken);
+  *piStart = (int)(zStart - pCsr->aInput);
+  *piEnd = (int)(zEnd - pCsr->aInput);
+  *piPos = pCsr->iToken++;
+  return SQLITE_OK;
 }
 
-/************** End of tokenize.c ********************************************/
-/************** Begin file complete.c ****************************************/
 /*
-** 2001 September 15
+** Set *ppModule to a pointer to the sqlite3_tokenizer_module 
+** structure for the unicode tokenizer.
+*/
+SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const **ppModule){
+  static const sqlite3_tokenizer_module module = {
+    0,
+    unicodeCreate,
+    unicodeDestroy,
+    unicodeOpen,
+    unicodeClose,
+    unicodeNext,
+    0,
+  };
+  *ppModule = &module;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+#endif /* ifndef SQLITE_DISABLE_FTS3_UNICODE */
+
+/************** End of fts3_unicode.c ****************************************/
+/************** Begin file fts3_unicode2.c ***********************************/
+/*
+** 2012 May 25
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -126032,342 +164898,365 @@ abort_parse:
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
-*************************************************************************
-** An tokenizer for SQL
-**
-** This file contains C code that implements the sqlite3_complete() API.
-** This code used to be part of the tokenizer.c source file.  But by
-** separating it out, the code will be automatically omitted from
-** static links that do not use it.
+******************************************************************************
 */
-#ifndef SQLITE_OMIT_COMPLETE
 
 /*
-** This is defined in tokenize.c.  We just have to import the definition.
+** DO NOT EDIT THIS MACHINE GENERATED FILE.
 */
-#ifndef SQLITE_AMALGAMATION
-#ifdef SQLITE_ASCII
-#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
-#endif
-#ifdef SQLITE_EBCDIC
-SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
-#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
-#endif
-#endif /* SQLITE_AMALGAMATION */
 
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
 
-/*
-** Token types used by the sqlite3_complete() routine.  See the header
-** comments on that procedure for additional information.
-*/
-#define tkSEMI    0
-#define tkWS      1
-#define tkOTHER   2
-#ifndef SQLITE_OMIT_TRIGGER
-#define tkEXPLAIN 3
-#define tkCREATE  4
-#define tkTEMP    5
-#define tkTRIGGER 6
-#define tkEND     7
-#endif
+/* #include  */
 
 /*
-** Return TRUE if the given SQL string ends in a semicolon.
-**
-** Special handling is require for CREATE TRIGGER statements.
-** Whenever the CREATE TRIGGER keywords are seen, the statement
-** must end with ";END;".
-**
-** This implementation uses a state machine with 8 states:
-**
-**   (0) INVALID   We have not yet seen a non-whitespace character.
-**
-**   (1) START     At the beginning or end of an SQL statement.  This routine
-**                 returns 1 if it ends in the START state and 0 if it ends
-**                 in any other state.
-**
-**   (2) NORMAL    We are in the middle of statement which ends with a single
-**                 semicolon.
-**
-**   (3) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 
-**                 a statement.
-**
-**   (4) CREATE    The keyword CREATE has been seen at the beginning of a
-**                 statement, possibly preceded by EXPLAIN and/or followed by
-**                 TEMP or TEMPORARY
-**
-**   (5) TRIGGER   We are in the middle of a trigger definition that must be
-**                 ended by a semicolon, the keyword END, and another semicolon.
-**
-**   (6) SEMI      We've seen the first semicolon in the ";END;" that occurs at
-**                 the end of a trigger definition.
-**
-**   (7) END       We've seen the ";END" of the ";END;" that occurs at the end
-**                 of a trigger definition.
-**
-** Transitions between states above are determined by tokens extracted
-** from the input.  The following tokens are significant:
-**
-**   (0) tkSEMI      A semicolon.
-**   (1) tkWS        Whitespace.
-**   (2) tkOTHER     Any other SQL token.
-**   (3) tkEXPLAIN   The "explain" keyword.
-**   (4) tkCREATE    The "create" keyword.
-**   (5) tkTEMP      The "temp" or "temporary" keyword.
-**   (6) tkTRIGGER   The "trigger" keyword.
-**   (7) tkEND       The "end" keyword.
-**
-** Whitespace never causes a state transition and is always ignored.
-** This means that a SQL string of all whitespace is invalid.
+** Return true if the argument corresponds to a unicode codepoint
+** classified as either a letter or a number. Otherwise false.
 **
-** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
-** to recognize the end of a trigger can be omitted.  All we have to do
-** is look for a semicolon that is not part of an string or comment.
+** The results are undefined if the value passed to this function
+** is less than zero.
 */
-SQLITE_API int sqlite3_complete(const char *zSql){
-  u8 state = 0;   /* Current state, using numbers defined in header comment */
-  u8 token;       /* Value of the next token */
-
-#ifndef SQLITE_OMIT_TRIGGER
-  /* A complex statement machine used to detect the end of a CREATE TRIGGER
-  ** statement.  This is the normal case.
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int c){
+  /* Each unsigned integer in the following array corresponds to a contiguous
+  ** range of unicode codepoints that are not either letters or numbers (i.e.
+  ** codepoints for which this function should return 0).
+  **
+  ** The most significant 22 bits in each 32-bit value contain the first 
+  ** codepoint in the range. The least significant 10 bits are used to store
+  ** the size of the range (always at least 1). In other words, the value 
+  ** ((C<<22) + N) represents a range of N codepoints starting with codepoint 
+  ** C. It is not possible to represent a range larger than 1023 codepoints 
+  ** using this format.
   */
-  static const u8 trans[8][8] = {
-                     /* Token:                                                */
-     /* State:       **  SEMI  WS  OTHER  EXPLAIN  CREATE  TEMP  TRIGGER  END */
-     /* 0 INVALID: */ {    1,  0,     2,       3,      4,    2,       2,   2, },
-     /* 1   START: */ {    1,  1,     2,       3,      4,    2,       2,   2, },
-     /* 2  NORMAL: */ {    1,  2,     2,       2,      2,    2,       2,   2, },
-     /* 3 EXPLAIN: */ {    1,  3,     3,       2,      4,    2,       2,   2, },
-     /* 4  CREATE: */ {    1,  4,     2,       2,      2,    4,       5,   2, },
-     /* 5 TRIGGER: */ {    6,  5,     5,       5,      5,    5,       5,   5, },
-     /* 6    SEMI: */ {    6,  6,     5,       5,      5,    5,       5,   7, },
-     /* 7     END: */ {    1,  7,     5,       5,      5,    5,       5,   5, },
+  static const unsigned int aEntry[] = {
+    0x00000030, 0x0000E807, 0x00016C06, 0x0001EC2F, 0x0002AC07,
+    0x0002D001, 0x0002D803, 0x0002EC01, 0x0002FC01, 0x00035C01,
+    0x0003DC01, 0x000B0804, 0x000B480E, 0x000B9407, 0x000BB401,
+    0x000BBC81, 0x000DD401, 0x000DF801, 0x000E1002, 0x000E1C01,
+    0x000FD801, 0x00120808, 0x00156806, 0x00162402, 0x00163C01,
+    0x00164437, 0x0017CC02, 0x00180005, 0x00181816, 0x00187802,
+    0x00192C15, 0x0019A804, 0x0019C001, 0x001B5001, 0x001B580F,
+    0x001B9C07, 0x001BF402, 0x001C000E, 0x001C3C01, 0x001C4401,
+    0x001CC01B, 0x001E980B, 0x001FAC09, 0x001FD804, 0x00205804,
+    0x00206C09, 0x00209403, 0x0020A405, 0x0020C00F, 0x00216403,
+    0x00217801, 0x0023901B, 0x00240004, 0x0024E803, 0x0024F812,
+    0x00254407, 0x00258804, 0x0025C001, 0x00260403, 0x0026F001,
+    0x0026F807, 0x00271C02, 0x00272C03, 0x00275C01, 0x00278802,
+    0x0027C802, 0x0027E802, 0x00280403, 0x0028F001, 0x0028F805,
+    0x00291C02, 0x00292C03, 0x00294401, 0x0029C002, 0x0029D401,
+    0x002A0403, 0x002AF001, 0x002AF808, 0x002B1C03, 0x002B2C03,
+    0x002B8802, 0x002BC002, 0x002C0403, 0x002CF001, 0x002CF807,
+    0x002D1C02, 0x002D2C03, 0x002D5802, 0x002D8802, 0x002DC001,
+    0x002E0801, 0x002EF805, 0x002F1803, 0x002F2804, 0x002F5C01,
+    0x002FCC08, 0x00300403, 0x0030F807, 0x00311803, 0x00312804,
+    0x00315402, 0x00318802, 0x0031FC01, 0x00320802, 0x0032F001,
+    0x0032F807, 0x00331803, 0x00332804, 0x00335402, 0x00338802,
+    0x00340802, 0x0034F807, 0x00351803, 0x00352804, 0x00355C01,
+    0x00358802, 0x0035E401, 0x00360802, 0x00372801, 0x00373C06,
+    0x00375801, 0x00376008, 0x0037C803, 0x0038C401, 0x0038D007,
+    0x0038FC01, 0x00391C09, 0x00396802, 0x003AC401, 0x003AD006,
+    0x003AEC02, 0x003B2006, 0x003C041F, 0x003CD00C, 0x003DC417,
+    0x003E340B, 0x003E6424, 0x003EF80F, 0x003F380D, 0x0040AC14,
+    0x00412806, 0x00415804, 0x00417803, 0x00418803, 0x00419C07,
+    0x0041C404, 0x0042080C, 0x00423C01, 0x00426806, 0x0043EC01,
+    0x004D740C, 0x004E400A, 0x00500001, 0x0059B402, 0x005A0001,
+    0x005A6C02, 0x005BAC03, 0x005C4803, 0x005CC805, 0x005D4802,
+    0x005DC802, 0x005ED023, 0x005F6004, 0x005F7401, 0x0060000F,
+    0x0062A401, 0x0064800C, 0x0064C00C, 0x00650001, 0x00651002,
+    0x0066C011, 0x00672002, 0x00677822, 0x00685C05, 0x00687802,
+    0x0069540A, 0x0069801D, 0x0069FC01, 0x006A8007, 0x006AA006,
+    0x006C0005, 0x006CD011, 0x006D6823, 0x006E0003, 0x006E840D,
+    0x006F980E, 0x006FF004, 0x00709014, 0x0070EC05, 0x0071F802,
+    0x00730008, 0x00734019, 0x0073B401, 0x0073C803, 0x00770027,
+    0x0077F004, 0x007EF401, 0x007EFC03, 0x007F3403, 0x007F7403,
+    0x007FB403, 0x007FF402, 0x00800065, 0x0081A806, 0x0081E805,
+    0x00822805, 0x0082801A, 0x00834021, 0x00840002, 0x00840C04,
+    0x00842002, 0x00845001, 0x00845803, 0x00847806, 0x00849401,
+    0x00849C01, 0x0084A401, 0x0084B801, 0x0084E802, 0x00850005,
+    0x00852804, 0x00853C01, 0x00864264, 0x00900027, 0x0091000B,
+    0x0092704E, 0x00940200, 0x009C0475, 0x009E53B9, 0x00AD400A,
+    0x00B39406, 0x00B3BC03, 0x00B3E404, 0x00B3F802, 0x00B5C001,
+    0x00B5FC01, 0x00B7804F, 0x00B8C00C, 0x00BA001A, 0x00BA6C59,
+    0x00BC00D6, 0x00BFC00C, 0x00C00005, 0x00C02019, 0x00C0A807,
+    0x00C0D802, 0x00C0F403, 0x00C26404, 0x00C28001, 0x00C3EC01,
+    0x00C64002, 0x00C6580A, 0x00C70024, 0x00C8001F, 0x00C8A81E,
+    0x00C94001, 0x00C98020, 0x00CA2827, 0x00CB003F, 0x00CC0100,
+    0x01370040, 0x02924037, 0x0293F802, 0x02983403, 0x0299BC10,
+    0x029A7C01, 0x029BC008, 0x029C0017, 0x029C8002, 0x029E2402,
+    0x02A00801, 0x02A01801, 0x02A02C01, 0x02A08C09, 0x02A0D804,
+    0x02A1D004, 0x02A20002, 0x02A2D011, 0x02A33802, 0x02A38012,
+    0x02A3E003, 0x02A4980A, 0x02A51C0D, 0x02A57C01, 0x02A60004,
+    0x02A6CC1B, 0x02A77802, 0x02A8A40E, 0x02A90C01, 0x02A93002,
+    0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,
+    0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,
+    0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,
+    0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,
+    0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,
+    0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,
+    0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,
+    0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,
+    0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,
+    0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,
+    0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,
+    0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,
+    0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,
+    0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,
+    0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,
+    0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,
+    0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,
+    0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,
+    0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,
+    0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,
+    0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,
+    0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,
+    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
+    0x380400F0,
   };
-#else
-  /* If triggers are not supported by this compile then the statement machine
-  ** used to detect the end of a statement is much simpler
-  */
-  static const u8 trans[3][3] = {
-                     /* Token:           */
-     /* State:       **  SEMI  WS  OTHER */
-     /* 0 INVALID: */ {    1,  0,     2, },
-     /* 1   START: */ {    1,  1,     2, },
-     /* 2  NORMAL: */ {    1,  2,     2, },
+  static const unsigned int aAscii[4] = {
+    0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
   };
-#endif /* SQLITE_OMIT_TRIGGER */
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( zSql==0 ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
-#endif
 
-  while( *zSql ){
-    switch( *zSql ){
-      case ';': {  /* A semicolon */
-        token = tkSEMI;
-        break;
-      }
-      case ' ':
-      case '\r':
-      case '\t':
-      case '\n':
-      case '\f': {  /* White space is ignored */
-        token = tkWS;
-        break;
-      }
-      case '/': {   /* C-style comments */
-        if( zSql[1]!='*' ){
-          token = tkOTHER;
-          break;
-        }
-        zSql += 2;
-        while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
-        if( zSql[0]==0 ) return 0;
-        zSql++;
-        token = tkWS;
-        break;
-      }
-      case '-': {   /* SQL-style comments from "--" to end of line */
-        if( zSql[1]!='-' ){
-          token = tkOTHER;
-          break;
-        }
-        while( *zSql && *zSql!='\n' ){ zSql++; }
-        if( *zSql==0 ) return state==1;
-        token = tkWS;
-        break;
-      }
-      case '[': {   /* Microsoft-style identifiers in [...] */
-        zSql++;
-        while( *zSql && *zSql!=']' ){ zSql++; }
-        if( *zSql==0 ) return 0;
-        token = tkOTHER;
-        break;
-      }
-      case '`':     /* Grave-accent quoted symbols used by MySQL */
-      case '"':     /* single- and double-quoted strings */
-      case '\'': {
-        int c = *zSql;
-        zSql++;
-        while( *zSql && *zSql!=c ){ zSql++; }
-        if( *zSql==0 ) return 0;
-        token = tkOTHER;
-        break;
-      }
-      default: {
-#ifdef SQLITE_EBCDIC
-        unsigned char c;
-#endif
-        if( IdChar((u8)*zSql) ){
-          /* Keywords and unquoted identifiers */
-          int nId;
-          for(nId=1; IdChar(zSql[nId]); nId++){}
-#ifdef SQLITE_OMIT_TRIGGER
-          token = tkOTHER;
-#else
-          switch( *zSql ){
-            case 'c': case 'C': {
-              if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
-                token = tkCREATE;
-              }else{
-                token = tkOTHER;
-              }
-              break;
-            }
-            case 't': case 'T': {
-              if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
-                token = tkTRIGGER;
-              }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
-                token = tkTEMP;
-              }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
-                token = tkTEMP;
-              }else{
-                token = tkOTHER;
-              }
-              break;
-            }
-            case 'e':  case 'E': {
-              if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
-                token = tkEND;
-              }else
-#ifndef SQLITE_OMIT_EXPLAIN
-              if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
-                token = tkEXPLAIN;
-              }else
-#endif
-              {
-                token = tkOTHER;
-              }
-              break;
-            }
-            default: {
-              token = tkOTHER;
-              break;
-            }
-          }
-#endif /* SQLITE_OMIT_TRIGGER */
-          zSql += nId-1;
-        }else{
-          /* Operators and special symbols */
-          token = tkOTHER;
-        }
-        break;
+  if( (unsigned int)c<128 ){
+    return ( (aAscii[c >> 5] & ((unsigned int)1 << (c & 0x001F)))==0 );
+  }else if( (unsigned int)c<(1<<22) ){
+    unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
+    int iRes = 0;
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( key >= aEntry[iTest] ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
       }
     }
-    state = trans[state][token];
-    zSql++;
+    assert( aEntry[0]=aEntry[iRes] );
+    return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
   }
-  return state==1;
+  return 1;
 }
 
-#ifndef SQLITE_OMIT_UTF16
+
 /*
-** This routine is the same as the sqlite3_complete() routine described
-** above, except that the parameter is required to be UTF-16 encoded, not
-** UTF-8.
+** If the argument is a codepoint corresponding to a lowercase letter
+** in the ASCII range with a diacritic added, return the codepoint
+** of the ASCII letter only. For example, if passed 235 - "LATIN
+** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER
+** E"). The resuls of passing a codepoint that corresponds to an
+** uppercase letter are undefined.
 */
-SQLITE_API int sqlite3_complete16(const void *zSql){
-  sqlite3_value *pVal;
-  char const *zSql8;
-  int rc = SQLITE_NOMEM;
+static int remove_diacritic(int c){
+  unsigned short aDia[] = {
+        0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 
+     2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 
+     2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 
+     2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 
+     3456,  3696,  3712,  3728,  3744,  3896,  3912,  3928, 
+     3968,  4008,  4040,  4106,  4138,  4170,  4202,  4234, 
+     4266,  4296,  4312,  4344,  4408,  4424,  4472,  4504, 
+     6148,  6198,  6264,  6280,  6360,  6429,  6505,  6529, 
+    61448, 61468, 61534, 61592, 61642, 61688, 61704, 61726, 
+    61784, 61800, 61836, 61880, 61914, 61948, 61998, 62122, 
+    62154, 62200, 62218, 62302, 62364, 62442, 62478, 62536, 
+    62554, 62584, 62604, 62640, 62648, 62656, 62664, 62730, 
+    62924, 63050, 63082, 63274, 63390, 
+  };
+  char aChar[] = {
+    '\0', 'a',  'c',  'e',  'i',  'n',  'o',  'u',  'y',  'y',  'a',  'c',  
+    'd',  'e',  'e',  'g',  'h',  'i',  'j',  'k',  'l',  'n',  'o',  'r',  
+    's',  't',  'u',  'u',  'w',  'y',  'z',  'o',  'u',  'a',  'i',  'o',  
+    'u',  'g',  'k',  'o',  'j',  'g',  'n',  'a',  'e',  'i',  'o',  'r',  
+    'u',  's',  't',  'h',  'a',  'e',  'o',  'y',  '\0', '\0', '\0', '\0', 
+    '\0', '\0', '\0', '\0', 'a',  'b',  'd',  'd',  'e',  'f',  'g',  'h',  
+    'h',  'i',  'k',  'l',  'l',  'm',  'n',  'p',  'r',  'r',  's',  't',  
+    'u',  'v',  'w',  'w',  'x',  'y',  'z',  'h',  't',  'w',  'y',  'a',  
+    'e',  'i',  'o',  'u',  'y',  
+  };
 
-#ifndef SQLITE_OMIT_AUTOINIT
-  rc = sqlite3_initialize();
-  if( rc ) return rc;
-#endif
-  pVal = sqlite3ValueNew(0);
-  sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
-  zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
-  if( zSql8 ){
-    rc = sqlite3_complete(zSql8);
-  }else{
-    rc = SQLITE_NOMEM;
+  unsigned int key = (((unsigned int)c)<<3) | 0x00000007;
+  int iRes = 0;
+  int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;
+  int iLo = 0;
+  while( iHi>=iLo ){
+    int iTest = (iHi + iLo) / 2;
+    if( key >= aDia[iTest] ){
+      iRes = iTest;
+      iLo = iTest+1;
+    }else{
+      iHi = iTest-1;
+    }
   }
-  sqlite3ValueFree(pVal);
-  return sqlite3ApiExit(0, rc);
+  assert( key>=aDia[iRes] );
+  return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);
 }
-#endif /* SQLITE_OMIT_UTF16 */
-#endif /* SQLITE_OMIT_COMPLETE */
 
-/************** End of complete.c ********************************************/
-/************** Begin file main.c ********************************************/
+
 /*
-** 2001 September 15
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-** Main file for the SQLite library.  The routines in this file
-** implement the programmer interface to the library.  Routines in
-** other files are for internal use by SQLite and should not be
-** accessed by users of the library.
+** Return true if the argument interpreted as a unicode codepoint
+** is a diacritical modifier character.
 */
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int c){
+  unsigned int mask0 = 0x08029FDF;
+  unsigned int mask1 = 0x000361F8;
+  if( c<768 || c>817 ) return 0;
+  return (c < 768+32) ?
+      (mask0 & (1 << (c-768))) :
+      (mask1 & (1 << (c-768-32)));
+}
+
 
-#ifdef SQLITE_ENABLE_FTS3
-/************** Include fts3.h in the middle of main.c ***********************/
-/************** Begin file fts3.h ********************************************/
 /*
-** 2006 Oct 10
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-******************************************************************************
+** Interpret the argument as a unicode codepoint. If the codepoint
+** is an upper case character that has a lower case equivalent,
+** return the codepoint corresponding to the lower case version.
+** Otherwise, return a copy of the argument.
 **
-** This header file is used by programs that want to link against the
-** FTS3 library.  All it does is declare the sqlite3Fts3Init() interface.
+** The results are undefined if the value passed to this function
+** is less than zero.
 */
+SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int c, int bRemoveDiacritic){
+  /* Each entry in the following array defines a rule for folding a range
+  ** of codepoints to lower case. The rule applies to a range of nRange
+  ** codepoints starting at codepoint iCode.
+  **
+  ** If the least significant bit in flags is clear, then the rule applies
+  ** to all nRange codepoints (i.e. all nRange codepoints are upper case and
+  ** need to be folded). Or, if it is set, then the rule only applies to
+  ** every second codepoint in the range, starting with codepoint C.
+  **
+  ** The 7 most significant bits in flags are an index into the aiOff[]
+  ** array. If a specific codepoint C does require folding, then its lower
+  ** case equivalent is ((C + aiOff[flags>>1]) & 0xFFFF).
+  **
+  ** The contents of this array are generated by parsing the CaseFolding.txt
+  ** file distributed as part of the "Unicode Character Database". See
+  ** http://www.unicode.org for details.
+  */
+  static const struct TableEntry {
+    unsigned short iCode;
+    unsigned char flags;
+    unsigned char nRange;
+  } aEntry[] = {
+    {65, 14, 26},          {181, 64, 1},          {192, 14, 23},
+    {216, 14, 7},          {256, 1, 48},          {306, 1, 6},
+    {313, 1, 16},          {330, 1, 46},          {376, 116, 1},
+    {377, 1, 6},           {383, 104, 1},         {385, 50, 1},
+    {386, 1, 4},           {390, 44, 1},          {391, 0, 1},
+    {393, 42, 2},          {395, 0, 1},           {398, 32, 1},
+    {399, 38, 1},          {400, 40, 1},          {401, 0, 1},
+    {403, 42, 1},          {404, 46, 1},          {406, 52, 1},
+    {407, 48, 1},          {408, 0, 1},           {412, 52, 1},
+    {413, 54, 1},          {415, 56, 1},          {416, 1, 6},
+    {422, 60, 1},          {423, 0, 1},           {425, 60, 1},
+    {428, 0, 1},           {430, 60, 1},          {431, 0, 1},
+    {433, 58, 2},          {435, 1, 4},           {439, 62, 1},
+    {440, 0, 1},           {444, 0, 1},           {452, 2, 1},
+    {453, 0, 1},           {455, 2, 1},           {456, 0, 1},
+    {458, 2, 1},           {459, 1, 18},          {478, 1, 18},
+    {497, 2, 1},           {498, 1, 4},           {502, 122, 1},
+    {503, 134, 1},         {504, 1, 40},          {544, 110, 1},
+    {546, 1, 18},          {570, 70, 1},          {571, 0, 1},
+    {573, 108, 1},         {574, 68, 1},          {577, 0, 1},
+    {579, 106, 1},         {580, 28, 1},          {581, 30, 1},
+    {582, 1, 10},          {837, 36, 1},          {880, 1, 4},
+    {886, 0, 1},           {902, 18, 1},          {904, 16, 3},
+    {908, 26, 1},          {910, 24, 2},          {913, 14, 17},
+    {931, 14, 9},          {962, 0, 1},           {975, 4, 1},
+    {976, 140, 1},         {977, 142, 1},         {981, 146, 1},
+    {982, 144, 1},         {984, 1, 24},          {1008, 136, 1},
+    {1009, 138, 1},        {1012, 130, 1},        {1013, 128, 1},
+    {1015, 0, 1},          {1017, 152, 1},        {1018, 0, 1},
+    {1021, 110, 3},        {1024, 34, 16},        {1040, 14, 32},
+    {1120, 1, 34},         {1162, 1, 54},         {1216, 6, 1},
+    {1217, 1, 14},         {1232, 1, 88},         {1329, 22, 38},
+    {4256, 66, 38},        {4295, 66, 1},         {4301, 66, 1},
+    {7680, 1, 150},        {7835, 132, 1},        {7838, 96, 1},
+    {7840, 1, 96},         {7944, 150, 8},        {7960, 150, 6},
+    {7976, 150, 8},        {7992, 150, 8},        {8008, 150, 6},
+    {8025, 151, 8},        {8040, 150, 8},        {8072, 150, 8},
+    {8088, 150, 8},        {8104, 150, 8},        {8120, 150, 2},
+    {8122, 126, 2},        {8124, 148, 1},        {8126, 100, 1},
+    {8136, 124, 4},        {8140, 148, 1},        {8152, 150, 2},
+    {8154, 120, 2},        {8168, 150, 2},        {8170, 118, 2},
+    {8172, 152, 1},        {8184, 112, 2},        {8186, 114, 2},
+    {8188, 148, 1},        {8486, 98, 1},         {8490, 92, 1},
+    {8491, 94, 1},         {8498, 12, 1},         {8544, 8, 16},
+    {8579, 0, 1},          {9398, 10, 26},        {11264, 22, 47},
+    {11360, 0, 1},         {11362, 88, 1},        {11363, 102, 1},
+    {11364, 90, 1},        {11367, 1, 6},         {11373, 84, 1},
+    {11374, 86, 1},        {11375, 80, 1},        {11376, 82, 1},
+    {11378, 0, 1},         {11381, 0, 1},         {11390, 78, 2},
+    {11392, 1, 100},       {11499, 1, 4},         {11506, 0, 1},
+    {42560, 1, 46},        {42624, 1, 24},        {42786, 1, 14},
+    {42802, 1, 62},        {42873, 1, 4},         {42877, 76, 1},
+    {42878, 1, 10},        {42891, 0, 1},         {42893, 74, 1},
+    {42896, 1, 4},         {42912, 1, 10},        {42922, 72, 1},
+    {65313, 14, 26},       
+  };
+  static const unsigned short aiOff[] = {
+   1,     2,     8,     15,    16,    26,    28,    32,    
+   37,    38,    40,    48,    63,    64,    69,    71,    
+   79,    80,    116,   202,   203,   205,   206,   207,   
+   209,   210,   211,   213,   214,   217,   218,   219,   
+   775,   7264,  10792, 10795, 23228, 23256, 30204, 54721, 
+   54753, 54754, 54756, 54787, 54793, 54809, 57153, 57274, 
+   57921, 58019, 58363, 61722, 65268, 65341, 65373, 65406, 
+   65408, 65410, 65415, 65424, 65436, 65439, 65450, 65462, 
+   65472, 65476, 65478, 65480, 65482, 65488, 65506, 65511, 
+   65514, 65521, 65527, 65528, 65529, 
+  };
 
-#if 0
-extern "C" {
-#endif  /* __cplusplus */
+  int ret = c;
 
-SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);
+  assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );
 
-#if 0
-}  /* extern "C" */
-#endif  /* __cplusplus */
+  if( c<128 ){
+    if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');
+  }else if( c<65536 ){
+    const struct TableEntry *p;
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    int iRes = -1;
 
-/************** End of fts3.h ************************************************/
-/************** Continuing where we left off in main.c ***********************/
-#endif
-#ifdef SQLITE_ENABLE_RTREE
-/************** Include rtree.h in the middle of main.c **********************/
-/************** Begin file rtree.h *******************************************/
+    assert( c>aEntry[0].iCode );
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      int cmp = (c - aEntry[iTest].iCode);
+      if( cmp>=0 ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+
+    assert( iRes>=0 && c>=aEntry[iRes].iCode );
+    p = &aEntry[iRes];
+    if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){
+      ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;
+      assert( ret>0 );
+    }
+
+    if( bRemoveDiacritic ) ret = remove_diacritic(ret);
+  }
+  
+  else if( c>=66560 && c<66600 ){
+    ret = c + 40;
+  }
+
+  return ret;
+}
+#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */
+#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */
+
+/************** End of fts3_unicode2.c ***************************************/
+/************** Begin file rtree.c *******************************************/
 /*
-** 2008 May 26
+** 2001 September 15
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -126376,12967 +165265,18369 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
-******************************************************************************
-**
-** This header file is used by programs that want to link against the
-** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.
+*************************************************************************
+** This file contains code for implementations of the r-tree and r*-tree
+** algorithms packaged as an SQLite virtual table module.
 */
 
-#if 0
-extern "C" {
-#endif  /* __cplusplus */
-
-SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db);
-
-#if 0
-}  /* extern "C" */
-#endif  /* __cplusplus */
-
-/************** End of rtree.h ***********************************************/
-/************** Continuing where we left off in main.c ***********************/
-#endif
-#ifdef SQLITE_ENABLE_ICU
-/************** Include sqliteicu.h in the middle of main.c ******************/
-/************** Begin file sqliteicu.h ***************************************/
 /*
-** 2008 May 26
+** Database Format of R-Tree Tables
+** --------------------------------
 **
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
+** The data structure for a single virtual r-tree table is stored in three 
+** native SQLite tables declared as follows. In each case, the '%' character
+** in the table name is replaced with the user-supplied name of the r-tree
+** table.
 **
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
+**   CREATE TABLE %_node(nodeno INTEGER PRIMARY KEY, data BLOB)
+**   CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)
+**   CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER)
 **
-******************************************************************************
+** The data for each node of the r-tree structure is stored in the %_node
+** table. For each node that is not the root node of the r-tree, there is
+** an entry in the %_parent table associating the node with its parent.
+** And for each row of data in the table, there is an entry in the %_rowid
+** table that maps from the entries rowid to the id of the node that it
+** is stored on.
 **
-** This header file is used by programs that want to link against the
-** ICU extension.  All it does is declare the sqlite3IcuInit() interface.
+** The root node of an r-tree always exists, even if the r-tree table is
+** empty. The nodeno of the root node is always 1. All other nodes in the
+** table must be the same size as the root node. The content of each node
+** is formatted as follows:
+**
+**   1. If the node is the root node (node 1), then the first 2 bytes
+**      of the node contain the tree depth as a big-endian integer.
+**      For non-root nodes, the first 2 bytes are left unused.
+**
+**   2. The next 2 bytes contain the number of entries currently 
+**      stored in the node.
+**
+**   3. The remainder of the node contains the node entries. Each entry
+**      consists of a single 8-byte integer followed by an even number
+**      of 4-byte coordinates. For leaf nodes the integer is the rowid
+**      of a record. For internal nodes it is the node number of a
+**      child page.
 */
 
-#if 0
-extern "C" {
-#endif  /* __cplusplus */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RTREE)
 
-SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);
+#ifndef SQLITE_CORE
+/*   #include "sqlite3ext.h" */
+  SQLITE_EXTENSION_INIT1
+#else
+/*   #include "sqlite3.h" */
+#endif
 
-#if 0
-}  /* extern "C" */
-#endif  /* __cplusplus */
+/* #include  */
+/* #include  */
+/* #include  */
+
+#ifndef SQLITE_AMALGAMATION
+#include "sqlite3rtree.h"
+typedef sqlite3_int64 i64;
+typedef sqlite3_uint64 u64;
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+#endif
+
+/*  The following macro is used to suppress compiler warnings.
+*/
+#ifndef UNUSED_PARAMETER
+# define UNUSED_PARAMETER(x) (void)(x)
+#endif
 
+typedef struct Rtree Rtree;
+typedef struct RtreeCursor RtreeCursor;
+typedef struct RtreeNode RtreeNode;
+typedef struct RtreeCell RtreeCell;
+typedef struct RtreeConstraint RtreeConstraint;
+typedef struct RtreeMatchArg RtreeMatchArg;
+typedef struct RtreeGeomCallback RtreeGeomCallback;
+typedef union RtreeCoord RtreeCoord;
+typedef struct RtreeSearchPoint RtreeSearchPoint;
 
-/************** End of sqliteicu.h *******************************************/
-/************** Continuing where we left off in main.c ***********************/
-#endif
+/* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
+#define RTREE_MAX_DIMENSIONS 5
 
-#ifndef SQLITE_AMALGAMATION
-/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
-** contains the text of SQLITE_VERSION macro. 
+/* Size of hash table Rtree.aHash. This hash table is not expected to
+** ever contain very many entries, so a fixed number of buckets is 
+** used.
 */
-SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
-#endif
+#define HASHSIZE 97
 
-/* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
-** a pointer to the to the sqlite3_version[] string constant. 
+/* The xBestIndex method of this virtual table requires an estimate of
+** the number of rows in the virtual table to calculate the costs of
+** various strategies. If possible, this estimate is loaded from the
+** sqlite_stat1 table (with RTREE_MIN_ROWEST as a hard-coded minimum).
+** Otherwise, if no sqlite_stat1 entry is available, use 
+** RTREE_DEFAULT_ROWEST.
 */
-SQLITE_API const char *sqlite3_libversion(void){ return sqlite3_version; }
+#define RTREE_DEFAULT_ROWEST 1048576
+#define RTREE_MIN_ROWEST         100
 
-/* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
-** pointer to a string constant whose value is the same as the
-** SQLITE_SOURCE_ID C preprocessor macro. 
+/* 
+** An rtree virtual-table object.
 */
-SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
+struct Rtree {
+  sqlite3_vtab base;          /* Base class.  Must be first */
+  sqlite3 *db;                /* Host database connection */
+  int iNodeSize;              /* Size in bytes of each node in the node table */
+  u8 nDim;                    /* Number of dimensions */
+  u8 nDim2;                   /* Twice the number of dimensions */
+  u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */
+  u8 nBytesPerCell;           /* Bytes consumed per cell */
+  u8 inWrTrans;               /* True if inside write transaction */
+  int iDepth;                 /* Current depth of the r-tree structure */
+  char *zDb;                  /* Name of database containing r-tree table */
+  char *zName;                /* Name of r-tree table */ 
+  u32 nBusy;                  /* Current number of users of this structure */
+  i64 nRowEst;                /* Estimated number of rows in this table */
+  u32 nCursor;                /* Number of open cursors */
 
-/* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
-** returns an integer equal to SQLITE_VERSION_NUMBER.
-*/
-SQLITE_API int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
+  /* List of nodes removed during a CondenseTree operation. List is
+  ** linked together via the pointer normally used for hash chains -
+  ** RtreeNode.pNext. RtreeNode.iNode stores the depth of the sub-tree 
+  ** headed by the node (leaf nodes have RtreeNode.iNode==0).
+  */
+  RtreeNode *pDeleted;
+  int iReinsertHeight;        /* Height of sub-trees Reinsert() has run on */
 
-/* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
-** zero if and only if SQLite was compiled with mutexing code omitted due to
-** the SQLITE_THREADSAFE compile-time option being set to 0.
-*/
-SQLITE_API int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+  /* Blob I/O on xxx_node */
+  sqlite3_blob *pNodeBlob;
+
+  /* Statements to read/write/delete a record from xxx_node */
+  sqlite3_stmt *pWriteNode;
+  sqlite3_stmt *pDeleteNode;
+
+  /* Statements to read/write/delete a record from xxx_rowid */
+  sqlite3_stmt *pReadRowid;
+  sqlite3_stmt *pWriteRowid;
+  sqlite3_stmt *pDeleteRowid;
+
+  /* Statements to read/write/delete a record from xxx_parent */
+  sqlite3_stmt *pReadParent;
+  sqlite3_stmt *pWriteParent;
+  sqlite3_stmt *pDeleteParent;
+
+  RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 
+};
+
+/* Possible values for Rtree.eCoordType: */
+#define RTREE_COORD_REAL32 0
+#define RTREE_COORD_INT32  1
 
-#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
 /*
-** If the following function pointer is not NULL and if
-** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
-** I/O active are written using this function.  These messages
-** are intended for debugging activity only.
+** If SQLITE_RTREE_INT_ONLY is defined, then this virtual table will
+** only deal with integer coordinates.  No floating point operations
+** will be done.
 */
-/* not-private */ void (*sqlite3IoTrace)(const char*, ...) = 0;
+#ifdef SQLITE_RTREE_INT_ONLY
+  typedef sqlite3_int64 RtreeDValue;       /* High accuracy coordinate */
+  typedef int RtreeValue;                  /* Low accuracy coordinate */
+# define RTREE_ZERO 0
+#else
+  typedef double RtreeDValue;              /* High accuracy coordinate */
+  typedef float RtreeValue;                /* Low accuracy coordinate */
+# define RTREE_ZERO 0.0
 #endif
 
 /*
-** If the following global variable points to a string which is the
-** name of a directory, then that directory will be used to store
-** temporary files.
+** When doing a search of an r-tree, instances of the following structure
+** record intermediate results from the tree walk.
 **
-** See also the "PRAGMA temp_store_directory" SQL command.
+** The id is always a node-id.  For iLevel>=1 the id is the node-id of
+** the node that the RtreeSearchPoint represents.  When iLevel==0, however,
+** the id is of the parent node and the cell that RtreeSearchPoint
+** represents is the iCell-th entry in the parent node.
 */
-SQLITE_API char *sqlite3_temp_directory = 0;
+struct RtreeSearchPoint {
+  RtreeDValue rScore;    /* The score for this node.  Smallest goes first. */
+  sqlite3_int64 id;      /* Node ID */
+  u8 iLevel;             /* 0=entries.  1=leaf node.  2+ for higher */
+  u8 eWithin;            /* PARTLY_WITHIN or FULLY_WITHIN */
+  u8 iCell;              /* Cell index within the node */
+};
 
 /*
-** If the following global variable points to a string which is the
-** name of a directory, then that directory will be used to store
-** all database files specified with a relative pathname.
+** The minimum number of cells allowed for a node is a third of the 
+** maximum. In Gutman's notation:
 **
-** See also the "PRAGMA data_store_directory" SQL command.
+**     m = M/3
+**
+** If an R*-tree "Reinsert" operation is required, the same number of
+** cells are removed from the overfull node and reinserted into the tree.
 */
-SQLITE_API char *sqlite3_data_directory = 0;
+#define RTREE_MINCELLS(p) ((((p)->iNodeSize-4)/(p)->nBytesPerCell)/3)
+#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
+#define RTREE_MAXCELLS 51
 
 /*
-** Initialize SQLite.  
-**
-** This routine must be called to initialize the memory allocation,
-** VFS, and mutex subsystems prior to doing any serious work with
-** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
-** this routine will be called automatically by key routines such as
-** sqlite3_open().  
-**
-** This routine is a no-op except on its very first call for the process,
-** or for the first call after a call to sqlite3_shutdown.
-**
-** The first thread to call this routine runs the initialization to
-** completion.  If subsequent threads call this routine before the first
-** thread has finished the initialization process, then the subsequent
-** threads must block until the first thread finishes with the initialization.
-**
-** The first thread might call this routine recursively.  Recursive
-** calls to this routine should not block, of course.  Otherwise the
-** initialization process would never complete.
-**
-** Let X be the first thread to enter this routine.  Let Y be some other
-** thread.  Then while the initial invocation of this routine by X is
-** incomplete, it is required that:
-**
-**    *  Calls to this routine from Y must block until the outer-most
-**       call by X completes.
-**
-**    *  Recursive calls to this routine from thread X return immediately
-**       without blocking.
+** The smallest possible node-size is (512-64)==448 bytes. And the largest
+** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
+** Therefore all non-root nodes must contain at least 3 entries. Since 
+** 2^40 is greater than 2^64, an r-tree structure always has a depth of
+** 40 or less.
 */
-SQLITE_API int sqlite3_initialize(void){
-  MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
-  int rc;                                      /* Result code */
-#ifdef SQLITE_EXTRA_INIT
-  int bRunExtraInit = 0;                       /* Extra initialization needed */
-#endif
+#define RTREE_MAX_DEPTH 40
 
-#ifdef SQLITE_OMIT_WSD
-  rc = sqlite3_wsd_init(4096, 24);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-#endif
 
-  /* If SQLite is already completely initialized, then this call
-  ** to sqlite3_initialize() should be a no-op.  But the initialization
-  ** must be complete.  So isInit must not be set until the very end
-  ** of this routine.
-  */
-  if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
+/*
+** Number of entries in the cursor RtreeNode cache.  The first entry is
+** used to cache the RtreeNode for RtreeCursor.sPoint.  The remaining
+** entries cache the RtreeNode for the first elements of the priority queue.
+*/
+#define RTREE_CACHE_SZ  5
 
-  /* Make sure the mutex subsystem is initialized.  If unable to 
-  ** initialize the mutex subsystem, return early with the error.
-  ** If the system is so sick that we are unable to allocate a mutex,
-  ** there is not much SQLite is going to be able to do.
-  **
-  ** The mutex subsystem must take care of serializing its own
-  ** initialization.
-  */
-  rc = sqlite3MutexInit();
-  if( rc ) return rc;
+/* 
+** An rtree cursor object.
+*/
+struct RtreeCursor {
+  sqlite3_vtab_cursor base;         /* Base class.  Must be first */
+  u8 atEOF;                         /* True if at end of search */
+  u8 bPoint;                        /* True if sPoint is valid */
+  int iStrategy;                    /* Copy of idxNum search parameter */
+  int nConstraint;                  /* Number of entries in aConstraint */
+  RtreeConstraint *aConstraint;     /* Search constraints. */
+  int nPointAlloc;                  /* Number of slots allocated for aPoint[] */
+  int nPoint;                       /* Number of slots used in aPoint[] */
+  int mxLevel;                      /* iLevel value for root of the tree */
+  RtreeSearchPoint *aPoint;         /* Priority queue for search points */
+  RtreeSearchPoint sPoint;          /* Cached next search point */
+  RtreeNode *aNode[RTREE_CACHE_SZ]; /* Rtree node cache */
+  u32 anQueue[RTREE_MAX_DEPTH+1];   /* Number of queued entries by iLevel */
+};
 
-  /* Initialize the malloc() system and the recursive pInitMutex mutex.
-  ** This operation is protected by the STATIC_MASTER mutex.  Note that
-  ** MutexAlloc() is called for a static mutex prior to initializing the
-  ** malloc subsystem - this implies that the allocation of a static
-  ** mutex must not require support from the malloc subsystem.
-  */
-  MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
-  sqlite3_mutex_enter(pMaster);
-  sqlite3GlobalConfig.isMutexInit = 1;
-  if( !sqlite3GlobalConfig.isMallocInit ){
-    rc = sqlite3MallocInit();
-  }
-  if( rc==SQLITE_OK ){
-    sqlite3GlobalConfig.isMallocInit = 1;
-    if( !sqlite3GlobalConfig.pInitMutex ){
-      sqlite3GlobalConfig.pInitMutex =
-           sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
-      if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
-        rc = SQLITE_NOMEM;
-      }
-    }
-  }
-  if( rc==SQLITE_OK ){
-    sqlite3GlobalConfig.nRefInitMutex++;
-  }
-  sqlite3_mutex_leave(pMaster);
+/* Return the Rtree of a RtreeCursor */
+#define RTREE_OF_CURSOR(X)   ((Rtree*)((X)->base.pVtab))
 
-  /* If rc is not SQLITE_OK at this point, then either the malloc
-  ** subsystem could not be initialized or the system failed to allocate
-  ** the pInitMutex mutex. Return an error in either case.  */
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
+/*
+** A coordinate can be either a floating point number or a integer.  All
+** coordinates within a single R-Tree are always of the same time.
+*/
+union RtreeCoord {
+  RtreeValue f;      /* Floating point value */
+  int i;             /* Integer value */
+  u32 u;             /* Unsigned for byte-order conversions */
+};
 
-  /* Do the rest of the initialization under the recursive mutex so
-  ** that we will be able to handle recursive calls into
-  ** sqlite3_initialize().  The recursive calls normally come through
-  ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
-  ** recursive calls might also be possible.
-  **
-  ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
-  ** to the xInit method, so the xInit method need not be threadsafe.
-  **
-  ** The following mutex is what serializes access to the appdef pcache xInit
-  ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
-  ** call to sqlite3PcacheInitialize().
-  */
-  sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
-  if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
-    FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-    sqlite3GlobalConfig.inProgress = 1;
-    memset(pHash, 0, sizeof(sqlite3GlobalFunctions));
-    sqlite3RegisterGlobalFunctions();
-    if( sqlite3GlobalConfig.isPCacheInit==0 ){
-      rc = sqlite3PcacheInitialize();
-    }
-    if( rc==SQLITE_OK ){
-      sqlite3GlobalConfig.isPCacheInit = 1;
-      rc = sqlite3OsInit();
-    }
-    if( rc==SQLITE_OK ){
-      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
-          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
-      sqlite3GlobalConfig.isInit = 1;
-#ifdef SQLITE_EXTRA_INIT
-      bRunExtraInit = 1;
+/*
+** The argument is an RtreeCoord. Return the value stored within the RtreeCoord
+** formatted as a RtreeDValue (double or int64). This macro assumes that local
+** variable pRtree points to the Rtree structure associated with the
+** RtreeCoord.
+*/
+#ifdef SQLITE_RTREE_INT_ONLY
+# define DCOORD(coord) ((RtreeDValue)coord.i)
+#else
+# define DCOORD(coord) (                           \
+    (pRtree->eCoordType==RTREE_COORD_REAL32) ?      \
+      ((double)coord.f) :                           \
+      ((double)coord.i)                             \
+  )
 #endif
-    }
-    sqlite3GlobalConfig.inProgress = 0;
-  }
-  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
-
-  /* Go back under the static mutex and clean up the recursive
-  ** mutex to prevent a resource leak.
-  */
-  sqlite3_mutex_enter(pMaster);
-  sqlite3GlobalConfig.nRefInitMutex--;
-  if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
-    assert( sqlite3GlobalConfig.nRefInitMutex==0 );
-    sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
-    sqlite3GlobalConfig.pInitMutex = 0;
-  }
-  sqlite3_mutex_leave(pMaster);
 
-  /* The following is just a sanity check to make sure SQLite has
-  ** been compiled correctly.  It is important to run this code, but
-  ** we don't want to run it too often and soak up CPU cycles for no
-  ** reason.  So we run it once during initialization.
-  */
-#ifndef NDEBUG
-#ifndef SQLITE_OMIT_FLOATING_POINT
-  /* This section of code's only "output" is via assert() statements. */
-  if ( rc==SQLITE_OK ){
-    u64 x = (((u64)1)<<63)-1;
-    double y;
-    assert(sizeof(x)==8);
-    assert(sizeof(x)==sizeof(y));
-    memcpy(&y, &x, 8);
-    assert( sqlite3IsNaN(y) );
-  }
-#endif
-#endif
+/*
+** A search constraint.
+*/
+struct RtreeConstraint {
+  int iCoord;                     /* Index of constrained coordinate */
+  int op;                         /* Constraining operation */
+  union {
+    RtreeDValue rValue;             /* Constraint value. */
+    int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*);
+    int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  } u;
+  sqlite3_rtree_query_info *pInfo;  /* xGeom and xQueryFunc argument */
+};
 
-  /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
-  ** compile-time option.
-  */
-#ifdef SQLITE_EXTRA_INIT
-  if( bRunExtraInit ){
-    int SQLITE_EXTRA_INIT(const char*);
-    rc = SQLITE_EXTRA_INIT(0);
-  }
-#endif
+/* Possible values for RtreeConstraint.op */
+#define RTREE_EQ    0x41  /* A */
+#define RTREE_LE    0x42  /* B */
+#define RTREE_LT    0x43  /* C */
+#define RTREE_GE    0x44  /* D */
+#define RTREE_GT    0x45  /* E */
+#define RTREE_MATCH 0x46  /* F: Old-style sqlite3_rtree_geometry_callback() */
+#define RTREE_QUERY 0x47  /* G: New-style sqlite3_rtree_query_callback() */
 
-  return rc;
-}
 
-/*
-** Undo the effects of sqlite3_initialize().  Must not be called while
-** there are outstanding database connections or memory allocations or
-** while any part of SQLite is otherwise in use in any thread.  This
-** routine is not threadsafe.  But it is safe to invoke this routine
-** on when SQLite is already shut down.  If SQLite is already shut down
-** when this routine is invoked, then this routine is a harmless no-op.
+/* 
+** An rtree structure node.
 */
-SQLITE_API int sqlite3_shutdown(void){
-#ifdef SQLITE_OMIT_WSD
-  int rc = sqlite3_wsd_init(4096, 24);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-#endif
+struct RtreeNode {
+  RtreeNode *pParent;         /* Parent node */
+  i64 iNode;                  /* The node number */
+  int nRef;                   /* Number of references to this node */
+  int isDirty;                /* True if the node needs to be written to disk */
+  u8 *zData;                  /* Content of the node, as should be on disk */
+  RtreeNode *pNext;           /* Next node in this hash collision chain */
+};
 
-  if( sqlite3GlobalConfig.isInit ){
-#ifdef SQLITE_EXTRA_SHUTDOWN
-    void SQLITE_EXTRA_SHUTDOWN(void);
-    SQLITE_EXTRA_SHUTDOWN();
-#endif
-    sqlite3_os_end();
-    sqlite3_reset_auto_extension();
-    sqlite3GlobalConfig.isInit = 0;
-  }
-  if( sqlite3GlobalConfig.isPCacheInit ){
-    sqlite3PcacheShutdown();
-    sqlite3GlobalConfig.isPCacheInit = 0;
-  }
-  if( sqlite3GlobalConfig.isMallocInit ){
-    sqlite3MallocEnd();
-    sqlite3GlobalConfig.isMallocInit = 0;
+/* Return the number of cells in a node  */
+#define NCELL(pNode) readInt16(&(pNode)->zData[2])
 
-#ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
-    /* The heap subsystem has now been shutdown and these values are supposed
-    ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
-    ** which would rely on that heap subsystem; therefore, make sure these
-    ** values cannot refer to heap memory that was just invalidated when the
-    ** heap subsystem was shutdown.  This is only done if the current call to
-    ** this function resulted in the heap subsystem actually being shutdown.
-    */
-    sqlite3_data_directory = 0;
-    sqlite3_temp_directory = 0;
-#endif
-  }
-  if( sqlite3GlobalConfig.isMutexInit ){
-    sqlite3MutexEnd();
-    sqlite3GlobalConfig.isMutexInit = 0;
-  }
+/* 
+** A single cell from a node, deserialized
+*/
+struct RtreeCell {
+  i64 iRowid;                                 /* Node or entry ID */
+  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];  /* Bounding box coordinates */
+};
 
-  return SQLITE_OK;
-}
 
 /*
-** This API allows applications to modify the global configuration of
-** the SQLite library at run-time.
+** This object becomes the sqlite3_user_data() for the SQL functions
+** that are created by sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() and which appear on the right of MATCH
+** operators in order to constrain a search.
 **
-** This routine should only be called when there are no outstanding
-** database connections or memory allocations.  This routine is not
-** threadsafe.  Failure to heed these warnings can lead to unpredictable
-** behavior.
+** xGeom and xQueryFunc are the callback functions.  Exactly one of 
+** xGeom and xQueryFunc fields is non-NULL, depending on whether the
+** SQL function was created using sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback().
+** 
+** This object is deleted automatically by the destructor mechanism in
+** sqlite3_create_function_v2().
 */
-SQLITE_API int sqlite3_config(int op, ...){
-  va_list ap;
-  int rc = SQLITE_OK;
-
-  /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
-  ** the SQLite library is in use. */
-  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
+struct RtreeGeomCallback {
+  int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
+  int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  void (*xDestructor)(void*);
+  void *pContext;
+};
 
-  va_start(ap, op);
-  switch( op ){
+/*
+** An instance of this structure (in the form of a BLOB) is returned by
+** the SQL functions that sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() create, and is read as the right-hand
+** operand to the MATCH operator of an R-Tree.
+*/
+struct RtreeMatchArg {
+  u32 iSize;                  /* Size of this object */
+  RtreeGeomCallback cb;       /* Info about the callback functions */
+  int nParam;                 /* Number of parameters to the SQL function */
+  sqlite3_value **apSqlParam; /* Original SQL parameter values */
+  RtreeDValue aParam[1];      /* Values for parameters to the SQL function */
+};
 
-    /* Mutex configuration options are only available in a threadsafe
-    ** compile.
-    */
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
-    case SQLITE_CONFIG_SINGLETHREAD: {
-      /* Disable all mutexing */
-      sqlite3GlobalConfig.bCoreMutex = 0;
-      sqlite3GlobalConfig.bFullMutex = 0;
-      break;
-    }
-#endif
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
-    case SQLITE_CONFIG_MULTITHREAD: {
-      /* Disable mutexing of database connections */
-      /* Enable mutexing of core data structures */
-      sqlite3GlobalConfig.bCoreMutex = 1;
-      sqlite3GlobalConfig.bFullMutex = 0;
-      break;
-    }
-#endif
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
-    case SQLITE_CONFIG_SERIALIZED: {
-      /* Enable all mutexing */
-      sqlite3GlobalConfig.bCoreMutex = 1;
-      sqlite3GlobalConfig.bFullMutex = 1;
-      break;
-    }
-#endif
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
-    case SQLITE_CONFIG_MUTEX: {
-      /* Specify an alternative mutex implementation */
-      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
-      break;
-    }
+#ifndef MAX
+# define MAX(x,y) ((x) < (y) ? (y) : (x))
 #endif
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
-    case SQLITE_CONFIG_GETMUTEX: {
-      /* Retrieve the current mutex implementation */
-      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
-      break;
-    }
+#ifndef MIN
+# define MIN(x,y) ((x) > (y) ? (y) : (x))
 #endif
 
-    case SQLITE_CONFIG_MALLOC: {
-      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
-      ** single argument which is a pointer to an instance of the
-      ** sqlite3_mem_methods structure. The argument specifies alternative
-      ** low-level memory allocation routines to be used in place of the memory
-      ** allocation routines built into SQLite. */
-      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
-      break;
-    }
-    case SQLITE_CONFIG_GETMALLOC: {
-      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
-      ** single argument which is a pointer to an instance of the
-      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
-      ** filled with the currently defined memory allocation routines. */
-      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
-      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
-      break;
-    }
-    case SQLITE_CONFIG_MEMSTATUS: {
-      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
-      ** single argument of type int, interpreted as a boolean, which enables
-      ** or disables the collection of memory allocation statistics. */
-      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
-      break;
-    }
-    case SQLITE_CONFIG_SCRATCH: {
-      /* EVIDENCE-OF: R-08404-60887 There are three arguments to
-      ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
-      ** which the scratch allocations will be drawn, the size of each scratch
-      ** allocation (sz), and the maximum number of scratch allocations (N). */
-      sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
-      sqlite3GlobalConfig.szScratch = va_arg(ap, int);
-      sqlite3GlobalConfig.nScratch = va_arg(ap, int);
-      break;
-    }
-    case SQLITE_CONFIG_PAGECACHE: {
-      /* EVIDENCE-OF: R-31408-40510 There are three arguments to
-      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory, the size
-      ** of each page buffer (sz), and the number of pages (N). */
-      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
-      sqlite3GlobalConfig.szPage = va_arg(ap, int);
-      sqlite3GlobalConfig.nPage = va_arg(ap, int);
-      break;
-    }
-    case SQLITE_CONFIG_PCACHE_HDRSZ: {
-      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
-      ** a single parameter which is a pointer to an integer and writes into
-      ** that integer the number of extra bytes per page required for each page
-      ** in SQLITE_CONFIG_PAGECACHE. */
-      *va_arg(ap, int*) = 
-          sqlite3HeaderSizeBtree() +
-          sqlite3HeaderSizePcache() +
-          sqlite3HeaderSizePcache1();
-      break;
-    }
-
-    case SQLITE_CONFIG_PCACHE: {
-      /* no-op */
-      break;
-    }
-    case SQLITE_CONFIG_GETPCACHE: {
-      /* now an error */
-      rc = SQLITE_ERROR;
-      break;
-    }
-
-    case SQLITE_CONFIG_PCACHE2: {
-      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
-      ** single argument which is a pointer to an sqlite3_pcache_methods2
-      ** object. This object specifies the interface to a custom page cache
-      ** implementation. */
-      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
-      break;
-    }
-    case SQLITE_CONFIG_GETPCACHE2: {
-      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
-      ** single argument which is a pointer to an sqlite3_pcache_methods2
-      ** object. SQLite copies of the current page cache implementation into
-      ** that object. */
-      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
-        sqlite3PCacheSetDefault();
-      }
-      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
-      break;
-    }
-
-/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
-** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
-** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
-#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
-    case SQLITE_CONFIG_HEAP: {
-      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
-      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
-      ** number of bytes in the memory buffer, and the minimum allocation size. */
-      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
-      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
-      sqlite3GlobalConfig.mnReq = va_arg(ap, int);
-
-      if( sqlite3GlobalConfig.mnReq<1 ){
-        sqlite3GlobalConfig.mnReq = 1;
-      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
-        /* cap min request size at 2^12 */
-        sqlite3GlobalConfig.mnReq = (1<<12);
-      }
-
-      if( sqlite3GlobalConfig.pHeap==0 ){
-        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
-        ** is NULL, then SQLite reverts to using its default memory allocator
-        ** (the system malloc() implementation), undoing any prior invocation of
-        ** SQLITE_CONFIG_MALLOC.
-        **
-        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
-        ** revert to its default implementation when sqlite3_initialize() is run
-        */
-        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
-      }else{
-        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
-        ** alternative memory allocator is engaged to handle all of SQLites
-        ** memory allocation needs. */
-#ifdef SQLITE_ENABLE_MEMSYS3
-        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
-#endif
-#ifdef SQLITE_ENABLE_MEMSYS5
-        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
-#endif
-      }
-      break;
-    }
+/* What version of GCC is being used.  0 means GCC is not being used .
+** Note that the GCC_VERSION macro will also be set correctly when using
+** clang, since clang works hard to be gcc compatible.  So the gcc
+** optimizations will also work when compiling with clang.
+*/
+#ifndef GCC_VERSION
+#if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)
+# define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)
+#else
+# define GCC_VERSION 0
 #endif
-
-    case SQLITE_CONFIG_LOOKASIDE: {
-      sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
-      sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
-      break;
-    }
-    
-    /* Record a pointer to the logger function and its first argument.
-    ** The default is NULL.  Logging is disabled if the function pointer is
-    ** NULL.
-    */
-    case SQLITE_CONFIG_LOG: {
-      /* MSVC is picky about pulling func ptrs from va lists.
-      ** http://support.microsoft.com/kb/47961
-      ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
-      */
-      typedef void(*LOGFUNC_t)(void*,int,const char*);
-      sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
-      sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
-      break;
-    }
-
-    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
-    ** can be changed at start-time using the
-    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
-    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
-    */
-    case SQLITE_CONFIG_URI: {
-      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
-      ** argument of type int. If non-zero, then URI handling is globally
-      ** enabled. If the parameter is zero, then URI handling is globally
-      ** disabled. */
-      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
-      break;
-    }
-
-    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
-      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
-      ** option takes a single integer argument which is interpreted as a
-      ** boolean in order to enable or disable the use of covering indices for
-      ** full table scans in the query optimizer. */
-      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
-      break;
-    }
-
-#ifdef SQLITE_ENABLE_SQLLOG
-    case SQLITE_CONFIG_SQLLOG: {
-      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
-      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
-      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
-      break;
-    }
 #endif
 
-    case SQLITE_CONFIG_MMAP_SIZE: {
-      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
-      ** integer (sqlite3_int64) values that are the default mmap size limit
-      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
-      ** mmap size limit. */
-      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
-      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
-      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
-      ** negative, then that argument is changed to its compile-time default.
-      **
-      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
-      ** silently truncated if necessary so that it does not exceed the
-      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
-      ** compile-time option.
-      */
-      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ) mxMmap = SQLITE_MAX_MMAP_SIZE;
-      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
-      if( szMmap>mxMmap) szMmap = mxMmap;
-      sqlite3GlobalConfig.mxMmap = mxMmap;
-      sqlite3GlobalConfig.szMmap = szMmap;
-      break;
-    }
-
-#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
-    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
-      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
-      ** unsigned integer value that specifies the maximum size of the created
-      ** heap. */
-      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
-      break;
-    }
+/* The testcase() macro should already be defined in the amalgamation.  If
+** it is not, make it a no-op.
+*/
+#ifndef SQLITE_AMALGAMATION
+# define testcase(X)
 #endif
 
-    case SQLITE_CONFIG_PMASZ: {
-      sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
-      break;
-    }
-
-    default: {
-      rc = SQLITE_ERROR;
-      break;
-    }
-  }
-  va_end(ap);
-  return rc;
-}
-
 /*
-** Set up the lookaside buffers for a database connection.
-** Return SQLITE_OK on success.  
-** If lookaside is already active, return SQLITE_BUSY.
+** Macros to determine whether the machine is big or little endian,
+** and whether or not that determination is run-time or compile-time.
 **
-** The sz parameter is the number of bytes in each lookaside slot.
-** The cnt parameter is the number of slots.  If pStart is NULL the
-** space for the lookaside memory is obtained from sqlite3_malloc().
-** If pStart is not NULL then it is sz*cnt bytes of memory to use for
-** the lookaside memory.
-*/
-static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
-  void *pStart;
-  if( db->lookaside.nOut ){
-    return SQLITE_BUSY;
-  }
-  /* Free any existing lookaside buffer for this handle before
-  ** allocating a new one so we don't have to have space for 
-  ** both at the same time.
-  */
-  if( db->lookaside.bMalloced ){
-    sqlite3_free(db->lookaside.pStart);
-  }
-  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
-  ** than a pointer to be useful.
-  */
-  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
-  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
-  if( cnt<0 ) cnt = 0;
-  if( sz==0 || cnt==0 ){
-    sz = 0;
-    pStart = 0;
-  }else if( pBuf==0 ){
-    sqlite3BeginBenignMalloc();
-    pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
-    sqlite3EndBenignMalloc();
-    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
-  }else{
-    pStart = pBuf;
-  }
-  db->lookaside.pStart = pStart;
-  db->lookaside.pFree = 0;
-  db->lookaside.sz = (u16)sz;
-  if( pStart ){
-    int i;
-    LookasideSlot *p;
-    assert( sz > (int)sizeof(LookasideSlot*) );
-    p = (LookasideSlot*)pStart;
-    for(i=cnt-1; i>=0; i--){
-      p->pNext = db->lookaside.pFree;
-      db->lookaside.pFree = p;
-      p = (LookasideSlot*)&((u8*)p)[sz];
-    }
-    db->lookaside.pEnd = p;
-    db->lookaside.bEnabled = 1;
-    db->lookaside.bMalloced = pBuf==0 ?1:0;
-  }else{
-    db->lookaside.pStart = db;
-    db->lookaside.pEnd = db;
-    db->lookaside.bEnabled = 0;
-    db->lookaside.bMalloced = 0;
-  }
-  return SQLITE_OK;
-}
-
-/*
-** Return the mutex associated with a database connection.
+** For best performance, an attempt is made to guess at the byte-order
+** using C-preprocessor macros.  If that is unsuccessful, or if
+** -DSQLITE_RUNTIME_BYTEORDER=1 is set, then byte-order is determined
+** at run-time.
 */
-SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
+#ifndef SQLITE_BYTEORDER
+#if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
+    defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
+    defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
+    defined(__arm__)
+# define SQLITE_BYTEORDER    1234
+#elif defined(sparc)    || defined(__ppc__)
+# define SQLITE_BYTEORDER    4321
+#else
+# define SQLITE_BYTEORDER    0     /* 0 means "unknown at compile-time" */
+#endif
 #endif
-  return db->mutex;
-}
 
-/*
-** Free up as much memory as we can from the given database
-** connection.
-*/
-SQLITE_API int sqlite3_db_release_memory(sqlite3 *db){
-  int i;
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+/* What version of MSVC is being used.  0 means MSVC is not being used */
+#ifndef MSVC_VERSION
+#if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC)
+# define MSVC_VERSION _MSC_VER
+#else
+# define MSVC_VERSION 0
+#endif
 #endif
-  sqlite3_mutex_enter(db->mutex);
-  sqlite3BtreeEnterAll(db);
-  for(i=0; inDb; i++){
-    Btree *pBt = db->aDb[i].pBt;
-    if( pBt ){
-      Pager *pPager = sqlite3BtreePager(pBt);
-      sqlite3PagerShrink(pPager);
-    }
-  }
-  sqlite3BtreeLeaveAll(db);
-  sqlite3_mutex_leave(db->mutex);
-  return SQLITE_OK;
-}
 
 /*
-** Configuration settings for an individual database connection
+** Functions to deserialize a 16 bit integer, 32 bit real number and
+** 64 bit integer. The deserialized value is returned.
 */
-SQLITE_API int sqlite3_db_config(sqlite3 *db, int op, ...){
-  va_list ap;
-  int rc;
-  va_start(ap, op);
-  switch( op ){
-    case SQLITE_DBCONFIG_LOOKASIDE: {
-      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
-      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
-      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
-      rc = setupLookaside(db, pBuf, sz, cnt);
-      break;
-    }
-    default: {
-      static const struct {
-        int op;      /* The opcode */
-        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
-      } aFlagOp[] = {
-        { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
-        { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
-      };
-      unsigned int i;
-      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
-      for(i=0; iflags;
-          if( onoff>0 ){
-            db->flags |= aFlagOp[i].mask;
-          }else if( onoff==0 ){
-            db->flags &= ~aFlagOp[i].mask;
-          }
-          if( oldFlags!=db->flags ){
-            sqlite3ExpirePreparedStatements(db);
-          }
-          if( pRes ){
-            *pRes = (db->flags & aFlagOp[i].mask)!=0;
-          }
-          rc = SQLITE_OK;
-          break;
-        }
-      }
-      break;
-    }
-  }
-  va_end(ap);
-  return rc;
+static int readInt16(u8 *p){
+  return (p[0]<<8) + p[1];
 }
-
-
-/*
-** Return true if the buffer z[0..n-1] contains all spaces.
-*/
-static int allSpaces(const char *z, int n){
-  while( n>0 && z[n-1]==' ' ){ n--; }
-  return n==0;
+static void readCoord(u8 *p, RtreeCoord *pCoord){
+  assert( ((((char*)p) - (char*)0)&3)==0 );  /* p is always 4-byte aligned */
+#if SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+  pCoord->u = _byteswap_ulong(*(u32*)p);
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  pCoord->u = __builtin_bswap32(*(u32*)p);
+#elif SQLITE_BYTEORDER==4321
+  pCoord->u = *(u32*)p;
+#else
+  pCoord->u = (
+    (((u32)p[0]) << 24) + 
+    (((u32)p[1]) << 16) + 
+    (((u32)p[2]) <<  8) + 
+    (((u32)p[3]) <<  0)
+  );
+#endif
 }
-
-/*
-** This is the default collating function named "BINARY" which is always
-** available.
-**
-** If the padFlag argument is not NULL then space padding at the end
-** of strings is ignored.  This implements the RTRIM collation.
-*/
-static int binCollFunc(
-  void *padFlag,
-  int nKey1, const void *pKey1,
-  int nKey2, const void *pKey2
-){
-  int rc, n;
-  n = nKey1=1300
+  u64 x;
+  memcpy(&x, p, 8);
+  return (i64)_byteswap_uint64(x);
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  u64 x;
+  memcpy(&x, p, 8);
+  return (i64)__builtin_bswap64(x);
+#elif SQLITE_BYTEORDER==4321
+  i64 x;
+  memcpy(&x, p, 8);
+  return x;
+#else
+  return (i64)(
+    (((u64)p[0]) << 56) + 
+    (((u64)p[1]) << 48) + 
+    (((u64)p[2]) << 40) + 
+    (((u64)p[3]) << 32) + 
+    (((u64)p[4]) << 24) + 
+    (((u64)p[5]) << 16) + 
+    (((u64)p[6]) <<  8) + 
+    (((u64)p[7]) <<  0)
+  );
+#endif
 }
 
 /*
-** Another built-in collating sequence: NOCASE. 
-**
-** This collating sequence is intended to be used for "case independent
-** comparison". SQLite's knowledge of upper and lower case equivalents
-** extends only to the 26 characters used in the English language.
-**
-** At the moment there is only a UTF-8 implementation.
+** Functions to serialize a 16 bit integer, 32 bit real number and
+** 64 bit integer. The value returned is the number of bytes written
+** to the argument buffer (always 2, 4 and 8 respectively).
 */
-static int nocaseCollatingFunc(
-  void *NotUsed,
-  int nKey1, const void *pKey1,
-  int nKey2, const void *pKey2
-){
-  int r = sqlite3StrNICmp(
-      (const char *)pKey1, (const char *)pKey2, (nKey1> 8)&0xFF;
+  p[1] = (i>> 0)&0xFF;
 }
-
-/*
-** Return the ROWID of the most recent insert
-*/
-SQLITE_API sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
+static int writeCoord(u8 *p, RtreeCoord *pCoord){
+  u32 i;
+  assert( ((((char*)p) - (char*)0)&3)==0 );  /* p is always 4-byte aligned */
+  assert( sizeof(RtreeCoord)==4 );
+  assert( sizeof(u32)==4 );
+#if SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  i = __builtin_bswap32(pCoord->u);
+  memcpy(p, &i, 4);
+#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+  i = _byteswap_ulong(pCoord->u);
+  memcpy(p, &i, 4);
+#elif SQLITE_BYTEORDER==4321
+  i = pCoord->u;
+  memcpy(p, &i, 4);
+#else
+  i = pCoord->u;
+  p[0] = (i>>24)&0xFF;
+  p[1] = (i>>16)&0xFF;
+  p[2] = (i>> 8)&0xFF;
+  p[3] = (i>> 0)&0xFF;
 #endif
-  return db->lastRowid;
+  return 4;
 }
-
-/*
-** Return the number of changes in the most recent call to sqlite3_exec().
-*/
-SQLITE_API int sqlite3_changes(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
+static int writeInt64(u8 *p, i64 i){
+#if SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+  i = (i64)__builtin_bswap64((u64)i);
+  memcpy(p, &i, 8);
+#elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+  i = (i64)_byteswap_uint64((u64)i);
+  memcpy(p, &i, 8);
+#elif SQLITE_BYTEORDER==4321
+  memcpy(p, &i, 8);
+#else
+  p[0] = (i>>56)&0xFF;
+  p[1] = (i>>48)&0xFF;
+  p[2] = (i>>40)&0xFF;
+  p[3] = (i>>32)&0xFF;
+  p[4] = (i>>24)&0xFF;
+  p[5] = (i>>16)&0xFF;
+  p[6] = (i>> 8)&0xFF;
+  p[7] = (i>> 0)&0xFF;
 #endif
-  return db->nChange;
+  return 8;
 }
 
 /*
-** Return the number of changes since the database handle was opened.
+** Increment the reference count of node p.
 */
-SQLITE_API int sqlite3_total_changes(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+static void nodeReference(RtreeNode *p){
+  if( p ){
+    p->nRef++;
   }
-#endif
-  return db->nTotalChange;
 }
 
 /*
-** Close all open savepoints. This function only manipulates fields of the
-** database handle object, it does not close any savepoints that may be open
-** at the b-tree/pager level.
+** Clear the content of node p (set all bytes to 0x00).
 */
-SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *db){
-  while( db->pSavepoint ){
-    Savepoint *pTmp = db->pSavepoint;
-    db->pSavepoint = pTmp->pNext;
-    sqlite3DbFree(db, pTmp);
-  }
-  db->nSavepoint = 0;
-  db->nStatement = 0;
-  db->isTransactionSavepoint = 0;
+static void nodeZero(Rtree *pRtree, RtreeNode *p){
+  memset(&p->zData[2], 0, pRtree->iNodeSize-2);
+  p->isDirty = 1;
 }
 
 /*
-** Invoke the destructor function associated with FuncDef p, if any. Except,
-** if this is not the last copy of the function, do not invoke it. Multiple
-** copies of a single function are created when create_function() is called
-** with SQLITE_ANY as the encoding.
+** Given a node number iNode, return the corresponding key to use
+** in the Rtree.aHash table.
 */
-static void functionDestroy(sqlite3 *db, FuncDef *p){
-  FuncDestructor *pDestructor = p->pDestructor;
-  if( pDestructor ){
-    pDestructor->nRef--;
-    if( pDestructor->nRef==0 ){
-      pDestructor->xDestroy(pDestructor->pUserData);
-      sqlite3DbFree(db, pDestructor);
-    }
-  }
+static int nodeHash(i64 iNode){
+  return iNode % HASHSIZE;
 }
 
 /*
-** Disconnect all sqlite3_vtab objects that belong to database connection
-** db. This is called when db is being closed.
+** Search the node hash table for node iNode. If found, return a pointer
+** to it. Otherwise, return 0.
 */
-static void disconnectAllVtab(sqlite3 *db){
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  int i;
-  sqlite3BtreeEnterAll(db);
-  for(i=0; inDb; i++){
-    Schema *pSchema = db->aDb[i].pSchema;
-    if( db->aDb[i].pSchema ){
-      HashElem *p;
-      for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
-        Table *pTab = (Table *)sqliteHashData(p);
-        if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
-      }
-    }
-  }
-  sqlite3VtabUnlockList(db);
-  sqlite3BtreeLeaveAll(db);
-#else
-  UNUSED_PARAMETER(db);
-#endif
+static RtreeNode *nodeHashLookup(Rtree *pRtree, i64 iNode){
+  RtreeNode *p;
+  for(p=pRtree->aHash[nodeHash(iNode)]; p && p->iNode!=iNode; p=p->pNext);
+  return p;
 }
 
 /*
-** Return TRUE if database connection db has unfinalized prepared
-** statements or unfinished sqlite3_backup objects.  
+** Add node pNode to the node hash table.
 */
-static int connectionIsBusy(sqlite3 *db){
-  int j;
-  assert( sqlite3_mutex_held(db->mutex) );
-  if( db->pVdbe ) return 1;
-  for(j=0; jnDb; j++){
-    Btree *pBt = db->aDb[j].pBt;
-    if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
-  }
-  return 0;
+static void nodeHashInsert(Rtree *pRtree, RtreeNode *pNode){
+  int iHash;
+  assert( pNode->pNext==0 );
+  iHash = nodeHash(pNode->iNode);
+  pNode->pNext = pRtree->aHash[iHash];
+  pRtree->aHash[iHash] = pNode;
 }
 
 /*
-** Close an existing SQLite database
+** Remove node pNode from the node hash table.
 */
-static int sqlite3Close(sqlite3 *db, int forceZombie){
-  if( !db ){
-    /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
-    ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
-    return SQLITE_OK;
-  }
-  if( !sqlite3SafetyCheckSickOrOk(db) ){
-    return SQLITE_MISUSE_BKPT;
-  }
-  sqlite3_mutex_enter(db->mutex);
-
-  /* Force xDisconnect calls on all virtual tables */
-  disconnectAllVtab(db);
-
-  /* If a transaction is open, the disconnectAllVtab() call above
-  ** will not have called the xDisconnect() method on any virtual
-  ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
-  ** call will do so. We need to do this before the check for active
-  ** SQL statements below, as the v-table implementation may be storing
-  ** some prepared statements internally.
-  */
-  sqlite3VtabRollback(db);
-
-  /* Legacy behavior (sqlite3_close() behavior) is to return
-  ** SQLITE_BUSY if the connection can not be closed immediately.
-  */
-  if( !forceZombie && connectionIsBusy(db) ){
-    sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
-       "statements or unfinished backups");
-    sqlite3_mutex_leave(db->mutex);
-    return SQLITE_BUSY;
+static void nodeHashDelete(Rtree *pRtree, RtreeNode *pNode){
+  RtreeNode **pp;
+  if( pNode->iNode!=0 ){
+    pp = &pRtree->aHash[nodeHash(pNode->iNode)];
+    for( ; (*pp)!=pNode; pp = &(*pp)->pNext){ assert(*pp); }
+    *pp = pNode->pNext;
+    pNode->pNext = 0;
   }
+}
 
-#ifdef SQLITE_ENABLE_SQLLOG
-  if( sqlite3GlobalConfig.xSqllog ){
-    /* Closing the handle. Fourth parameter is passed the value 2. */
-    sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
+/*
+** Allocate and return new r-tree node. Initially, (RtreeNode.iNode==0),
+** indicating that node has not yet been assigned a node number. It is
+** assigned a node number when nodeWrite() is called to write the
+** node contents out to the database.
+*/
+static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
+  RtreeNode *pNode;
+  pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode) + pRtree->iNodeSize);
+  if( pNode ){
+    memset(pNode, 0, sizeof(RtreeNode) + pRtree->iNodeSize);
+    pNode->zData = (u8 *)&pNode[1];
+    pNode->nRef = 1;
+    pNode->pParent = pParent;
+    pNode->isDirty = 1;
+    nodeReference(pParent);
   }
-#endif
-
-  /* Convert the connection into a zombie and then close it.
-  */
-  db->magic = SQLITE_MAGIC_ZOMBIE;
-  sqlite3LeaveMutexAndCloseZombie(db);
-  return SQLITE_OK;
+  return pNode;
 }
 
 /*
-** Two variations on the public interface for closing a database
-** connection. The sqlite3_close() version returns SQLITE_BUSY and
-** leaves the connection option if there are unfinalized prepared
-** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
-** version forces the connection to become a zombie if there are
-** unclosed resources, and arranges for deallocation when the last
-** prepare statement or sqlite3_backup closes.
+** Clear the Rtree.pNodeBlob object
 */
-SQLITE_API int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
-SQLITE_API int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
-
+static void nodeBlobReset(Rtree *pRtree){
+  if( pRtree->pNodeBlob && pRtree->inWrTrans==0 && pRtree->nCursor==0 ){
+    sqlite3_blob *pBlob = pRtree->pNodeBlob;
+    pRtree->pNodeBlob = 0;
+    sqlite3_blob_close(pBlob);
+  }
+}
 
 /*
-** Close the mutex on database connection db.
-**
-** Furthermore, if database connection db is a zombie (meaning that there
-** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
-** every sqlite3_stmt has now been finalized and every sqlite3_backup has
-** finished, then free all resources.
+** Obtain a reference to an r-tree node.
 */
-SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
-  HashElem *i;                    /* Hash table iterator */
-  int j;
-
-  /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
-  ** or if the connection has not yet been closed by sqlite3_close_v2(),
-  ** then just leave the mutex and return.
-  */
-  if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
-    sqlite3_mutex_leave(db->mutex);
-    return;
-  }
+static int nodeAcquire(
+  Rtree *pRtree,             /* R-tree structure */
+  i64 iNode,                 /* Node number to load */
+  RtreeNode *pParent,        /* Either the parent node or NULL */
+  RtreeNode **ppNode         /* OUT: Acquired node */
+){
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = 0;
 
-  /* If we reach this point, it means that the database connection has
-  ** closed all sqlite3_stmt and sqlite3_backup objects and has been
-  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
-  ** go ahead and free all resources.
+  /* Check if the requested node is already in the hash table. If so,
+  ** increase its reference count and return it.
   */
-
-  /* If a transaction is open, roll it back. This also ensures that if
-  ** any database schemas have been modified by an uncommitted transaction
-  ** they are reset. And that the required b-tree mutex is held to make
-  ** the pager rollback and schema reset an atomic operation. */
-  sqlite3RollbackAll(db, SQLITE_OK);
-
-  /* Free any outstanding Savepoint structures. */
-  sqlite3CloseSavepoints(db);
-
-  /* Close all database connections */
-  for(j=0; jnDb; j++){
-    struct Db *pDb = &db->aDb[j];
-    if( pDb->pBt ){
-      sqlite3BtreeClose(pDb->pBt);
-      pDb->pBt = 0;
-      if( j!=1 ){
-        pDb->pSchema = 0;
-      }
+  if( (pNode = nodeHashLookup(pRtree, iNode)) ){
+    assert( !pParent || !pNode->pParent || pNode->pParent==pParent );
+    if( pParent && !pNode->pParent ){
+      nodeReference(pParent);
+      pNode->pParent = pParent;
     }
+    pNode->nRef++;
+    *ppNode = pNode;
+    return SQLITE_OK;
   }
-  /* Clear the TEMP schema separately and last */
-  if( db->aDb[1].pSchema ){
-    sqlite3SchemaClear(db->aDb[1].pSchema);
-  }
-  sqlite3VtabUnlockList(db);
-
-  /* Free up the array of auxiliary databases */
-  sqlite3CollapseDatabaseArray(db);
-  assert( db->nDb<=2 );
-  assert( db->aDb==db->aDbStatic );
 
-  /* Tell the code in notify.c that the connection no longer holds any
-  ** locks and does not require any further unlock-notify callbacks.
-  */
-  sqlite3ConnectionClosed(db);
-
-  for(j=0; jaFunc.a); j++){
-    FuncDef *pNext, *pHash, *p;
-    for(p=db->aFunc.a[j]; p; p=pHash){
-      pHash = p->pHash;
-      while( p ){
-        functionDestroy(db, p);
-        pNext = p->pNext;
-        sqlite3DbFree(db, p);
-        p = pNext;
-      }
+  if( pRtree->pNodeBlob ){
+    sqlite3_blob *pBlob = pRtree->pNodeBlob;
+    pRtree->pNodeBlob = 0;
+    rc = sqlite3_blob_reopen(pBlob, iNode);
+    pRtree->pNodeBlob = pBlob;
+    if( rc ){
+      nodeBlobReset(pRtree);
+      if( rc==SQLITE_NOMEM ) return SQLITE_NOMEM;
     }
   }
-  for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
-    CollSeq *pColl = (CollSeq *)sqliteHashData(i);
-    /* Invoke any destructors registered for collation sequence user data. */
-    for(j=0; j<3; j++){
-      if( pColl[j].xDel ){
-        pColl[j].xDel(pColl[j].pUser);
-      }
-    }
-    sqlite3DbFree(db, pColl);
+  if( pRtree->pNodeBlob==0 ){
+    char *zTab = sqlite3_mprintf("%s_node", pRtree->zName);
+    if( zTab==0 ) return SQLITE_NOMEM;
+    rc = sqlite3_blob_open(pRtree->db, pRtree->zDb, zTab, "data", iNode, 0,
+                           &pRtree->pNodeBlob);
+    sqlite3_free(zTab);
   }
-  sqlite3HashClear(&db->aCollSeq);
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
-    Module *pMod = (Module *)sqliteHashData(i);
-    if( pMod->xDestroy ){
-      pMod->xDestroy(pMod->pAux);
+  if( rc ){
+    nodeBlobReset(pRtree);
+    *ppNode = 0;
+    /* If unable to open an sqlite3_blob on the desired row, that can only
+    ** be because the shadow tables hold erroneous data. */
+    if( rc==SQLITE_ERROR ) rc = SQLITE_CORRUPT_VTAB;
+  }else if( pRtree->iNodeSize==sqlite3_blob_bytes(pRtree->pNodeBlob) ){
+    pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
+    if( !pNode ){
+      rc = SQLITE_NOMEM;
+    }else{
+      pNode->pParent = pParent;
+      pNode->zData = (u8 *)&pNode[1];
+      pNode->nRef = 1;
+      pNode->iNode = iNode;
+      pNode->isDirty = 0;
+      pNode->pNext = 0;
+      rc = sqlite3_blob_read(pRtree->pNodeBlob, pNode->zData,
+                             pRtree->iNodeSize, 0);
+      nodeReference(pParent);
     }
-    sqlite3DbFree(db, pMod);
   }
-  sqlite3HashClear(&db->aModule);
-#endif
-
-  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
-  sqlite3ValueFree(db->pErr);
-  sqlite3CloseExtensions(db);
-#if SQLITE_USER_AUTHENTICATION
-  sqlite3_free(db->auth.zAuthUser);
-  sqlite3_free(db->auth.zAuthPW);
-#endif
-
-  db->magic = SQLITE_MAGIC_ERROR;
 
-  /* The temp-database schema is allocated differently from the other schema
-  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
-  ** So it needs to be freed here. Todo: Why not roll the temp schema into
-  ** the same sqliteMalloc() as the one that allocates the database 
-  ** structure?
+  /* If the root node was just loaded, set pRtree->iDepth to the height
+  ** of the r-tree structure. A height of zero means all data is stored on
+  ** the root node. A height of one means the children of the root node
+  ** are the leaves, and so on. If the depth as specified on the root node
+  ** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.
   */
-  sqlite3DbFree(db, db->aDb[1].pSchema);
-  sqlite3_mutex_leave(db->mutex);
-  db->magic = SQLITE_MAGIC_CLOSED;
-  sqlite3_mutex_free(db->mutex);
-  assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
-  if( db->lookaside.bMalloced ){
-    sqlite3_free(db->lookaside.pStart);
+  if( pNode && iNode==1 ){
+    pRtree->iDepth = readInt16(pNode->zData);
+    if( pRtree->iDepth>RTREE_MAX_DEPTH ){
+      rc = SQLITE_CORRUPT_VTAB;
+    }
   }
-  sqlite3_free(db);
-}
-
-/*
-** Rollback all database files.  If tripCode is not SQLITE_OK, then
-** any write cursors are invalidated ("tripped" - as in "tripping a circuit
-** breaker") and made to return tripCode if there are any further
-** attempts to use that cursor.  Read cursors remain open and valid
-** but are "saved" in case the table pages are moved around.
-*/
-SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){
-  int i;
-  int inTrans = 0;
-  int schemaChange;
-  assert( sqlite3_mutex_held(db->mutex) );
-  sqlite3BeginBenignMalloc();
-
-  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
-  ** This is important in case the transaction being rolled back has
-  ** modified the database schema. If the b-tree mutexes are not taken
-  ** here, then another shared-cache connection might sneak in between
-  ** the database rollback and schema reset, which can cause false
-  ** corruption reports in some cases.  */
-  sqlite3BtreeEnterAll(db);
-  schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
 
-  for(i=0; inDb; i++){
-    Btree *p = db->aDb[i].pBt;
-    if( p ){
-      if( sqlite3BtreeIsInTrans(p) ){
-        inTrans = 1;
-      }
-      sqlite3BtreeRollback(p, tripCode, !schemaChange);
+  /* If no error has occurred so far, check if the "number of entries"
+  ** field on the node is too large. If so, set the return code to 
+  ** SQLITE_CORRUPT_VTAB.
+  */
+  if( pNode && rc==SQLITE_OK ){
+    if( NCELL(pNode)>((pRtree->iNodeSize-4)/pRtree->nBytesPerCell) ){
+      rc = SQLITE_CORRUPT_VTAB;
     }
   }
-  sqlite3VtabRollback(db);
-  sqlite3EndBenignMalloc();
 
-  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
-    sqlite3ExpirePreparedStatements(db);
-    sqlite3ResetAllSchemasOfConnection(db);
+  if( rc==SQLITE_OK ){
+    if( pNode!=0 ){
+      nodeHashInsert(pRtree, pNode);
+    }else{
+      rc = SQLITE_CORRUPT_VTAB;
+    }
+    *ppNode = pNode;
+  }else{
+    sqlite3_free(pNode);
+    *ppNode = 0;
   }
-  sqlite3BtreeLeaveAll(db);
-
-  /* Any deferred constraint violations have now been resolved. */
-  db->nDeferredCons = 0;
-  db->nDeferredImmCons = 0;
-  db->flags &= ~SQLITE_DeferFKs;
 
-  /* If one has been configured, invoke the rollback-hook callback */
-  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
-    db->xRollbackCallback(db->pRollbackArg);
-  }
+  return rc;
 }
 
 /*
-** Return a static string containing the name corresponding to the error code
-** specified in the argument.
+** Overwrite cell iCell of node pNode with the contents of pCell.
 */
-#if (defined(SQLITE_DEBUG) && SQLITE_OS_WIN) || defined(SQLITE_TEST)
-SQLITE_PRIVATE const char *sqlite3ErrName(int rc){
-  const char *zName = 0;
-  int i, origRc = rc;
-  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
-    switch( rc ){
-      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
-      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
-      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
-      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
-      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
-      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
-      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
-      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
-      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
-      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
-      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
-      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
-      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
-      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
-      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
-      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
-      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
-      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
-      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
-      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
-      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
-      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
-      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
-      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
-      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
-      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
-      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
-      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
-      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
-      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
-      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
-      case SQLITE_IOERR_CHECKRESERVEDLOCK:
-                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
-      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
-      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
-      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
-      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
-      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
-      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
-      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
-      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
-      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
-      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
-      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
-      case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
-      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
-      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
-      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
-      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
-      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
-      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
-      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
-      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
-      case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
-      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
-      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
-      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
-      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
-      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
-      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
-      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
-      case SQLITE_CONSTRAINT_FOREIGNKEY:
-                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
-      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
-      case SQLITE_CONSTRAINT_PRIMARYKEY:
-                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
-      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
-      case SQLITE_CONSTRAINT_COMMITHOOK:
-                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
-      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
-      case SQLITE_CONSTRAINT_FUNCTION:
-                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
-      case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
-      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
-      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
-      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
-      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
-      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
-      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
-      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
-      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
-      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
-      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
-      case SQLITE_NOTICE_RECOVER_ROLLBACK:
-                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
-      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
-      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
-      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
-    }
-  }
-  if( zName==0 ){
-    static char zBuf[50];
-    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
-    zName = zBuf;
+static void nodeOverwriteCell(
+  Rtree *pRtree,             /* The overall R-Tree */
+  RtreeNode *pNode,          /* The node into which the cell is to be written */
+  RtreeCell *pCell,          /* The cell to write */
+  int iCell                  /* Index into pNode into which pCell is written */
+){
+  int ii;
+  u8 *p = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
+  p += writeInt64(p, pCell->iRowid);
+  for(ii=0; iinDim2; ii++){
+    p += writeCoord(p, &pCell->aCoord[ii]);
   }
-  return zName;
+  pNode->isDirty = 1;
 }
-#endif
 
 /*
-** Return a static string that describes the kind of error specified in the
-** argument.
+** Remove the cell with index iCell from node pNode.
 */
-SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){
-  static const char* const aMsg[] = {
-    /* SQLITE_OK          */ "not an error",
-    /* SQLITE_ERROR       */ "SQL logic error or missing database",
-    /* SQLITE_INTERNAL    */ 0,
-    /* SQLITE_PERM        */ "access permission denied",
-    /* SQLITE_ABORT       */ "callback requested query abort",
-    /* SQLITE_BUSY        */ "database is locked",
-    /* SQLITE_LOCKED      */ "database table is locked",
-    /* SQLITE_NOMEM       */ "out of memory",
-    /* SQLITE_READONLY    */ "attempt to write a readonly database",
-    /* SQLITE_INTERRUPT   */ "interrupted",
-    /* SQLITE_IOERR       */ "disk I/O error",
-    /* SQLITE_CORRUPT     */ "database disk image is malformed",
-    /* SQLITE_NOTFOUND    */ "unknown operation",
-    /* SQLITE_FULL        */ "database or disk is full",
-    /* SQLITE_CANTOPEN    */ "unable to open database file",
-    /* SQLITE_PROTOCOL    */ "locking protocol",
-    /* SQLITE_EMPTY       */ "table contains no data",
-    /* SQLITE_SCHEMA      */ "database schema has changed",
-    /* SQLITE_TOOBIG      */ "string or blob too big",
-    /* SQLITE_CONSTRAINT  */ "constraint failed",
-    /* SQLITE_MISMATCH    */ "datatype mismatch",
-    /* SQLITE_MISUSE      */ "library routine called out of sequence",
-    /* SQLITE_NOLFS       */ "large file support is disabled",
-    /* SQLITE_AUTH        */ "authorization denied",
-    /* SQLITE_FORMAT      */ "auxiliary database format error",
-    /* SQLITE_RANGE       */ "bind or column index out of range",
-    /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
-  };
-  const char *zErr = "unknown error";
-  switch( rc ){
-    case SQLITE_ABORT_ROLLBACK: {
-      zErr = "abort due to ROLLBACK";
-      break;
-    }
-    default: {
-      rc &= 0xff;
-      if( ALWAYS(rc>=0) && rczData[4 + pRtree->nBytesPerCell*iCell];
+  u8 *pSrc = &pDst[pRtree->nBytesPerCell];
+  int nByte = (NCELL(pNode) - iCell - 1) * pRtree->nBytesPerCell;
+  memmove(pDst, pSrc, nByte);
+  writeInt16(&pNode->zData[2], NCELL(pNode)-1);
+  pNode->isDirty = 1;
 }
 
 /*
-** This routine implements a busy callback that sleeps and tries
-** again until a timeout value is reached.  The timeout value is
-** an integer number of milliseconds passed in as the first
-** argument.
+** Insert the contents of cell pCell into node pNode. If the insert
+** is successful, return SQLITE_OK.
+**
+** If there is not enough free space in pNode, return SQLITE_FULL.
 */
-static int sqliteDefaultBusyCallback(
- void *ptr,               /* Database connection */
- int count                /* Number of times table has been busy */
+static int nodeInsertCell(
+  Rtree *pRtree,                /* The overall R-Tree */
+  RtreeNode *pNode,             /* Write new cell into this node */
+  RtreeCell *pCell              /* The cell to be inserted */
 ){
-#if SQLITE_OS_WIN || HAVE_USLEEP
-  static const u8 delays[] =
-     { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
-  static const u8 totals[] =
-     { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
-# define NDELAY ArraySize(delays)
-  sqlite3 *db = (sqlite3 *)ptr;
-  int timeout = db->busyTimeout;
-  int delay, prior;
+  int nCell;                    /* Current number of cells in pNode */
+  int nMaxCell;                 /* Maximum number of cells for pNode */
 
-  assert( count>=0 );
-  if( count < NDELAY ){
-    delay = delays[count];
-    prior = totals[count];
-  }else{
-    delay = delays[NDELAY-1];
-    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
-  }
-  if( prior + delay > timeout ){
-    delay = timeout - prior;
-    if( delay<=0 ) return 0;
-  }
-  sqlite3OsSleep(db->pVfs, delay*1000);
-  return 1;
-#else
-  sqlite3 *db = (sqlite3 *)ptr;
-  int timeout = ((sqlite3 *)ptr)->busyTimeout;
-  if( (count+1)*1000 > timeout ){
-    return 0;
-  }
-  sqlite3OsSleep(db->pVfs, 1000000);
-  return 1;
-#endif
-}
+  nMaxCell = (pRtree->iNodeSize-4)/pRtree->nBytesPerCell;
+  nCell = NCELL(pNode);
 
-/*
-** Invoke the given busy handler.
-**
-** This routine is called when an operation failed with a lock.
-** If this routine returns non-zero, the lock is retried.  If it
-** returns 0, the operation aborts with an SQLITE_BUSY error.
-*/
-SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler *p){
-  int rc;
-  if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
-  rc = p->xFunc(p->pArg, p->nBusy);
-  if( rc==0 ){
-    p->nBusy = -1;
-  }else{
-    p->nBusy++;
+  assert( nCell<=nMaxCell );
+  if( nCellzData[2], nCell+1);
+    pNode->isDirty = 1;
   }
-  return rc; 
-}
 
-/*
-** This routine sets the busy callback for an Sqlite database to the
-** given callback function with the given argument.
-*/
-SQLITE_API int sqlite3_busy_handler(
-  sqlite3 *db,
-  int (*xBusy)(void*,int),
-  void *pArg
-){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  db->busyHandler.xFunc = xBusy;
-  db->busyHandler.pArg = pArg;
-  db->busyHandler.nBusy = 0;
-  db->busyTimeout = 0;
-  sqlite3_mutex_leave(db->mutex);
-  return SQLITE_OK;
+  return (nCell==nMaxCell);
 }
 
-#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
 /*
-** This routine sets the progress callback for an Sqlite database to the
-** given callback function with the given argument. The progress callback will
-** be invoked every nOps opcodes.
+** If the node is dirty, write it out to the database.
 */
-SQLITE_API void sqlite3_progress_handler(
-  sqlite3 *db, 
-  int nOps,
-  int (*xProgress)(void*), 
-  void *pArg
-){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return;
-  }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  if( nOps>0 ){
-    db->xProgress = xProgress;
-    db->nProgressOps = (unsigned)nOps;
-    db->pProgressArg = pArg;
-  }else{
-    db->xProgress = 0;
-    db->nProgressOps = 0;
-    db->pProgressArg = 0;
+static int nodeWrite(Rtree *pRtree, RtreeNode *pNode){
+  int rc = SQLITE_OK;
+  if( pNode->isDirty ){
+    sqlite3_stmt *p = pRtree->pWriteNode;
+    if( pNode->iNode ){
+      sqlite3_bind_int64(p, 1, pNode->iNode);
+    }else{
+      sqlite3_bind_null(p, 1);
+    }
+    sqlite3_bind_blob(p, 2, pNode->zData, pRtree->iNodeSize, SQLITE_STATIC);
+    sqlite3_step(p);
+    pNode->isDirty = 0;
+    rc = sqlite3_reset(p);
+    if( pNode->iNode==0 && rc==SQLITE_OK ){
+      pNode->iNode = sqlite3_last_insert_rowid(pRtree->db);
+      nodeHashInsert(pRtree, pNode);
+    }
   }
-  sqlite3_mutex_leave(db->mutex);
+  return rc;
 }
-#endif
-
 
 /*
-** This routine installs a default busy handler that waits for the
-** specified number of milliseconds before returning 0.
+** Release a reference to a node. If the node is dirty and the reference
+** count drops to zero, the node data is written to the database.
 */
-SQLITE_API int sqlite3_busy_timeout(sqlite3 *db, int ms){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
-  if( ms>0 ){
-    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
-    db->busyTimeout = ms;
-  }else{
-    sqlite3_busy_handler(db, 0, 0);
+static int nodeRelease(Rtree *pRtree, RtreeNode *pNode){
+  int rc = SQLITE_OK;
+  if( pNode ){
+    assert( pNode->nRef>0 );
+    pNode->nRef--;
+    if( pNode->nRef==0 ){
+      if( pNode->iNode==1 ){
+        pRtree->iDepth = -1;
+      }
+      if( pNode->pParent ){
+        rc = nodeRelease(pRtree, pNode->pParent);
+      }
+      if( rc==SQLITE_OK ){
+        rc = nodeWrite(pRtree, pNode);
+      }
+      nodeHashDelete(pRtree, pNode);
+      sqlite3_free(pNode);
+    }
   }
-  return SQLITE_OK;
+  return rc;
 }
 
 /*
-** Cause any pending operation to stop at its earliest opportunity.
+** Return the 64-bit integer value associated with cell iCell of
+** node pNode. If pNode is a leaf node, this is a rowid. If it is
+** an internal node, then the 64-bit integer is a child page number.
 */
-SQLITE_API void sqlite3_interrupt(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return;
-  }
-#endif
-  db->u1.isInterrupted = 1;
+static i64 nodeGetRowid(
+  Rtree *pRtree,       /* The overall R-Tree */
+  RtreeNode *pNode,    /* The node from which to extract the ID */
+  int iCell            /* The cell index from which to extract the ID */
+){
+  assert( iCellzData[4 + pRtree->nBytesPerCell*iCell]);
 }
 
-
 /*
-** This function is exactly the same as sqlite3_create_function(), except
-** that it is designed to be called by internal code. The difference is
-** that if a malloc() fails in sqlite3_create_function(), an error code
-** is returned and the mallocFailed flag cleared. 
+** Return coordinate iCoord from cell iCell in node pNode.
 */
-SQLITE_PRIVATE int sqlite3CreateFunc(
-  sqlite3 *db,
-  const char *zFunctionName,
-  int nArg,
-  int enc,
-  void *pUserData,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
-  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
-  void (*xFinal)(sqlite3_context*),
-  FuncDestructor *pDestructor
+static void nodeGetCoord(
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node from which to extract a coordinate */
+  int iCell,                   /* The index of the cell within the node */
+  int iCoord,                  /* Which coordinate to extract */
+  RtreeCoord *pCoord           /* OUT: Space to write result to */
 ){
-  FuncDef *p;
-  int nName;
-  int extraFlags;
-
-  assert( sqlite3_mutex_held(db->mutex) );
-  if( zFunctionName==0 ||
-      (xFunc && (xFinal || xStep)) || 
-      (!xFunc && (xFinal && !xStep)) ||
-      (!xFunc && (!xFinal && xStep)) ||
-      (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
-      (255<(nName = sqlite3Strlen30( zFunctionName))) ){
-    return SQLITE_MISUSE_BKPT;
-  }
-
-  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
-  extraFlags = enc &  SQLITE_DETERMINISTIC;
-  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
-  
-#ifndef SQLITE_OMIT_UTF16
-  /* If SQLITE_UTF16 is specified as the encoding type, transform this
-  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
-  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
-  **
-  ** If SQLITE_ANY is specified, add three versions of the function
-  ** to the hash table.
-  */
-  if( enc==SQLITE_UTF16 ){
-    enc = SQLITE_UTF16NATIVE;
-  }else if( enc==SQLITE_ANY ){
-    int rc;
-    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
-         pUserData, xFunc, xStep, xFinal, pDestructor);
-    if( rc==SQLITE_OK ){
-      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
-          pUserData, xFunc, xStep, xFinal, pDestructor);
-    }
-    if( rc!=SQLITE_OK ){
-      return rc;
-    }
-    enc = SQLITE_UTF16BE;
-  }
-#else
-  enc = SQLITE_UTF8;
-#endif
-  
-  /* Check if an existing function is being overridden or deleted. If so,
-  ** and there are active VMs, then return SQLITE_BUSY. If a function
-  ** is being overridden/deleted but there are no active VMs, allow the
-  ** operation to continue but invalidate all precompiled statements.
-  */
-  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
-  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
-    if( db->nVdbeActive ){
-      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
-        "unable to delete/modify user-function due to active statements");
-      assert( !db->mallocFailed );
-      return SQLITE_BUSY;
-    }else{
-      sqlite3ExpirePreparedStatements(db);
-    }
-  }
-
-  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 1);
-  assert(p || db->mallocFailed);
-  if( !p ){
-    return SQLITE_NOMEM;
-  }
-
-  /* If an older version of the function with a configured destructor is
-  ** being replaced invoke the destructor function here. */
-  functionDestroy(db, p);
-
-  if( pDestructor ){
-    pDestructor->nRef++;
-  }
-  p->pDestructor = pDestructor;
-  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
-  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
-  p->xFunc = xFunc;
-  p->xStep = xStep;
-  p->xFinalize = xFinal;
-  p->pUserData = pUserData;
-  p->nArg = (u16)nArg;
-  return SQLITE_OK;
+  readCoord(&pNode->zData[12 + pRtree->nBytesPerCell*iCell + 4*iCoord], pCoord);
 }
 
 /*
-** Create new user functions.
+** Deserialize cell iCell of node pNode. Populate the structure pointed
+** to by pCell with the results.
 */
-SQLITE_API int sqlite3_create_function(
-  sqlite3 *db,
-  const char *zFunc,
-  int nArg,
-  int enc,
-  void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
-  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
-  void (*xFinal)(sqlite3_context*)
+static void nodeGetCell(
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node containing the cell to be read */
+  int iCell,                   /* Index of the cell within the node */
+  RtreeCell *pCell             /* OUT: Write the cell contents here */
 ){
-  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
-                                    xFinal, 0);
+  u8 *pData;
+  RtreeCoord *pCoord;
+  int ii = 0;
+  pCell->iRowid = nodeGetRowid(pRtree, pNode, iCell);
+  pData = pNode->zData + (12 + pRtree->nBytesPerCell*iCell);
+  pCoord = pCell->aCoord;
+  do{
+    readCoord(pData, &pCoord[ii]);
+    readCoord(pData+4, &pCoord[ii+1]);
+    pData += 8;
+    ii += 2;
+  }while( iinDim2 );
 }
 
-SQLITE_API int sqlite3_create_function_v2(
-  sqlite3 *db,
-  const char *zFunc,
-  int nArg,
-  int enc,
-  void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
-  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
-  void (*xFinal)(sqlite3_context*),
-  void (*xDestroy)(void *)
-){
-  int rc = SQLITE_ERROR;
-  FuncDestructor *pArg = 0;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    return SQLITE_MISUSE_BKPT;
-  }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  if( xDestroy ){
-    pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
-    if( !pArg ){
-      xDestroy(p);
-      goto out;
-    }
-    pArg->xDestroy = xDestroy;
-    pArg->pUserData = p;
-  }
-  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
-  if( pArg && pArg->nRef==0 ){
-    assert( rc!=SQLITE_OK );
-    xDestroy(p);
-    sqlite3DbFree(db, pArg);
-  }
 
- out:
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
-}
+/* Forward declaration for the function that does the work of
+** the virtual table module xCreate() and xConnect() methods.
+*/
+static int rtreeInit(
+  sqlite3 *, void *, int, const char *const*, sqlite3_vtab **, char **, int
+);
 
-#ifndef SQLITE_OMIT_UTF16
-SQLITE_API int sqlite3_create_function16(
+/* 
+** Rtree virtual table module xCreate method.
+*/
+static int rtreeCreate(
   sqlite3 *db,
-  const void *zFunctionName,
-  int nArg,
-  int eTextRep,
-  void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
-  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
-  void (*xFinal)(sqlite3_context*)
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
 ){
-  int rc;
-  char *zFunc8;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  assert( !db->mallocFailed );
-  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
-  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
-  sqlite3DbFree(db, zFunc8);
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
+  return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 1);
 }
-#endif
 
-
-/*
-** Declare that a function has been overloaded by a virtual table.
-**
-** If the function already exists as a regular global function, then
-** this routine is a no-op.  If the function does not exist, then create
-** a new one that always throws a run-time error.  
-**
-** When virtual tables intend to provide an overloaded function, they
-** should call this routine to make sure the global function exists.
-** A global function must exist in order for name resolution to work
-** properly.
+/* 
+** Rtree virtual table module xConnect method.
 */
-SQLITE_API int sqlite3_overload_function(
+static int rtreeConnect(
   sqlite3 *db,
-  const char *zName,
-  int nArg
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
 ){
-  int nName = sqlite3Strlen30(zName);
-  int rc = SQLITE_OK;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
-    return SQLITE_MISUSE_BKPT;
-  }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
-    rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
-                           0, sqlite3InvalidFunction, 0, 0, 0);
-  }
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
+  return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 0);
 }
 
-#ifndef SQLITE_OMIT_TRACE
 /*
-** Register a trace function.  The pArg from the previously registered trace
-** is returned.  
-**
-** A NULL trace function means that no tracing is executes.  A non-NULL
-** trace is a pointer to a function that is invoked at the start of each
-** SQL statement.
+** Increment the r-tree reference count.
 */
-SQLITE_API void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
-  void *pOld;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pOld = db->pTraceArg;
-  db->xTrace = xTrace;
-  db->pTraceArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pOld;
+static void rtreeReference(Rtree *pRtree){
+  pRtree->nBusy++;
 }
+
 /*
-** Register a profile function.  The pArg from the previously registered 
-** profile function is returned.  
-**
-** A NULL profile function means that no profiling is executes.  A non-NULL
-** profile is a pointer to a function that is invoked at the conclusion of
-** each SQL statement that is run.
+** Decrement the r-tree reference count. When the reference count reaches
+** zero the structure is deleted.
 */
-SQLITE_API void *sqlite3_profile(
-  sqlite3 *db,
-  void (*xProfile)(void*,const char*,sqlite_uint64),
-  void *pArg
-){
-  void *pOld;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+static void rtreeRelease(Rtree *pRtree){
+  pRtree->nBusy--;
+  if( pRtree->nBusy==0 ){
+    pRtree->inWrTrans = 0;
+    pRtree->nCursor = 0;
+    nodeBlobReset(pRtree);
+    sqlite3_finalize(pRtree->pWriteNode);
+    sqlite3_finalize(pRtree->pDeleteNode);
+    sqlite3_finalize(pRtree->pReadRowid);
+    sqlite3_finalize(pRtree->pWriteRowid);
+    sqlite3_finalize(pRtree->pDeleteRowid);
+    sqlite3_finalize(pRtree->pReadParent);
+    sqlite3_finalize(pRtree->pWriteParent);
+    sqlite3_finalize(pRtree->pDeleteParent);
+    sqlite3_free(pRtree);
   }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pOld = db->pProfileArg;
-  db->xProfile = xProfile;
-  db->pProfileArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pOld;
 }
-#endif /* SQLITE_OMIT_TRACE */
 
-/*
-** Register a function to be invoked when a transaction commits.
-** If the invoked function returns non-zero, then the commit becomes a
-** rollback.
+/* 
+** Rtree virtual table module xDisconnect method.
 */
-SQLITE_API void *sqlite3_commit_hook(
-  sqlite3 *db,              /* Attach the hook to this database */
-  int (*xCallback)(void*),  /* Function to invoke on each commit */
-  void *pArg                /* Argument to the function */
-){
-  void *pOld;
+static int rtreeDisconnect(sqlite3_vtab *pVtab){
+  rtreeRelease((Rtree *)pVtab);
+  return SQLITE_OK;
+}
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+/* 
+** Rtree virtual table module xDestroy method.
+*/
+static int rtreeDestroy(sqlite3_vtab *pVtab){
+  Rtree *pRtree = (Rtree *)pVtab;
+  int rc;
+  char *zCreate = sqlite3_mprintf(
+    "DROP TABLE '%q'.'%q_node';"
+    "DROP TABLE '%q'.'%q_rowid';"
+    "DROP TABLE '%q'.'%q_parent';",
+    pRtree->zDb, pRtree->zName, 
+    pRtree->zDb, pRtree->zName,
+    pRtree->zDb, pRtree->zName
+  );
+  if( !zCreate ){
+    rc = SQLITE_NOMEM;
+  }else{
+    nodeBlobReset(pRtree);
+    rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);
+    sqlite3_free(zCreate);
   }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pOld = db->pCommitArg;
-  db->xCommitCallback = xCallback;
-  db->pCommitArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pOld;
+  if( rc==SQLITE_OK ){
+    rtreeRelease(pRtree);
+  }
+
+  return rc;
 }
 
-/*
-** Register a callback to be invoked each time a row is updated,
-** inserted or deleted using this database connection.
+/* 
+** Rtree virtual table module xOpen method.
 */
-SQLITE_API void *sqlite3_update_hook(
-  sqlite3 *db,              /* Attach the hook to this database */
-  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
-  void *pArg                /* Argument to the function */
-){
-  void *pRet;
+static int rtreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  int rc = SQLITE_NOMEM;
+  Rtree *pRtree = (Rtree *)pVTab;
+  RtreeCursor *pCsr;
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+  pCsr = (RtreeCursor *)sqlite3_malloc(sizeof(RtreeCursor));
+  if( pCsr ){
+    memset(pCsr, 0, sizeof(RtreeCursor));
+    pCsr->base.pVtab = pVTab;
+    rc = SQLITE_OK;
+    pRtree->nCursor++;
   }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pRet = db->pUpdateArg;
-  db->xUpdateCallback = xCallback;
-  db->pUpdateArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pRet;
+  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
+
+  return rc;
 }
 
+
 /*
-** Register a callback to be invoked each time a transaction is rolled
-** back by this database connection.
+** Free the RtreeCursor.aConstraint[] array and its contents.
 */
-SQLITE_API void *sqlite3_rollback_hook(
-  sqlite3 *db,              /* Attach the hook to this database */
-  void (*xCallback)(void*), /* Callback function */
-  void *pArg                /* Argument to the function */
-){
-  void *pRet;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+static void freeCursorConstraints(RtreeCursor *pCsr){
+  if( pCsr->aConstraint ){
+    int i;                        /* Used to iterate through constraint array */
+    for(i=0; inConstraint; i++){
+      sqlite3_rtree_query_info *pInfo = pCsr->aConstraint[i].pInfo;
+      if( pInfo ){
+        if( pInfo->xDelUser ) pInfo->xDelUser(pInfo->pUser);
+        sqlite3_free(pInfo);
+      }
+    }
+    sqlite3_free(pCsr->aConstraint);
+    pCsr->aConstraint = 0;
   }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pRet = db->pRollbackArg;
-  db->xRollbackCallback = xCallback;
-  db->pRollbackArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pRet;
 }
 
-#ifndef SQLITE_OMIT_WAL
-/*
-** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
-** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
-** is greater than sqlite3.pWalArg cast to an integer (the value configured by
-** wal_autocheckpoint()).
-*/ 
-SQLITE_PRIVATE int sqlite3WalDefaultHook(
-  void *pClientData,     /* Argument */
-  sqlite3 *db,           /* Connection */
-  const char *zDb,       /* Database */
-  int nFrame             /* Size of WAL */
-){
-  if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
-    sqlite3BeginBenignMalloc();
-    sqlite3_wal_checkpoint(db, zDb);
-    sqlite3EndBenignMalloc();
-  }
+/* 
+** Rtree virtual table module xClose method.
+*/
+static int rtreeClose(sqlite3_vtab_cursor *cur){
+  Rtree *pRtree = (Rtree *)(cur->pVtab);
+  int ii;
+  RtreeCursor *pCsr = (RtreeCursor *)cur;
+  assert( pRtree->nCursor>0 );
+  freeCursorConstraints(pCsr);
+  sqlite3_free(pCsr->aPoint);
+  for(ii=0; iiaNode[ii]);
+  sqlite3_free(pCsr);
+  pRtree->nCursor--;
+  nodeBlobReset(pRtree);
   return SQLITE_OK;
 }
-#endif /* SQLITE_OMIT_WAL */
 
 /*
-** Configure an sqlite3_wal_hook() callback to automatically checkpoint
-** a database after committing a transaction if there are nFrame or
-** more frames in the log file. Passing zero or a negative value as the
-** nFrame parameter disables automatic checkpoints entirely.
+** Rtree virtual table module xEof method.
 **
-** The callback registered by this function replaces any existing callback
-** registered using sqlite3_wal_hook(). Likewise, registering a callback
-** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
-** configured by this function.
+** Return non-zero if the cursor does not currently point to a valid 
+** record (i.e if the scan has finished), or zero otherwise.
 */
-SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
-#ifdef SQLITE_OMIT_WAL
-  UNUSED_PARAMETER(db);
-  UNUSED_PARAMETER(nFrame);
-#else
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
-  if( nFrame>0 ){
-    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
-  }else{
-    sqlite3_wal_hook(db, 0, 0);
-  }
-#endif
-  return SQLITE_OK;
+static int rtreeEof(sqlite3_vtab_cursor *cur){
+  RtreeCursor *pCsr = (RtreeCursor *)cur;
+  return pCsr->atEOF;
 }
 
 /*
-** Register a callback to be invoked each time a transaction is written
-** into the write-ahead-log by this database connection.
+** Convert raw bits from the on-disk RTree record into a coordinate value.
+** The on-disk format is big-endian and needs to be converted for little-
+** endian platforms.  The on-disk record stores integer coordinates if
+** eInt is true and it stores 32-bit floating point records if eInt is
+** false.  a[] is the four bytes of the on-disk record to be decoded.
+** Store the results in "r".
+**
+** There are five versions of this macro.  The last one is generic.  The
+** other four are various architectures-specific optimizations.
 */
-SQLITE_API void *sqlite3_wal_hook(
-  sqlite3 *db,                    /* Attach the hook to this db handle */
-  int(*xCallback)(void *, sqlite3*, const char*, int),
-  void *pArg                      /* First argument passed to xCallback() */
-){
-#ifndef SQLITE_OMIT_WAL
-  void *pRet;
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pRet = db->pWalArg;
-  db->xWalCallback = xCallback;
-  db->pWalArg = pArg;
-  sqlite3_mutex_leave(db->mutex);
-  return pRet;
+#if SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    c.u = _byteswap_ulong(*(u32*)a);                            \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    c.u = __builtin_bswap32(*(u32*)a);                          \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#elif SQLITE_BYTEORDER==1234
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    c.u = ((c.u>>24)&0xff)|((c.u>>8)&0xff00)|                   \
+          ((c.u&0xff)<<24)|((c.u&0xff00)<<8);                   \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#elif SQLITE_BYTEORDER==4321
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
 #else
-  return 0;
-#endif
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    c.u = ((u32)a[0]<<24) + ((u32)a[1]<<16)                     \
+           +((u32)a[2]<<8) + a[3];                              \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
 }
+#endif
 
 /*
-** Checkpoint database zDb.
+** Check the RTree node or entry given by pCellData and p against the MATCH
+** constraint pConstraint.  
 */
-SQLITE_API int sqlite3_wal_checkpoint_v2(
-  sqlite3 *db,                    /* Database handle */
-  const char *zDb,                /* Name of attached database (or NULL) */
-  int eMode,                      /* SQLITE_CHECKPOINT_* value */
-  int *pnLog,                     /* OUT: Size of WAL log in frames */
-  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
+static int rtreeCallbackConstraint(
+  RtreeConstraint *pConstraint,  /* The constraint to test */
+  int eInt,                      /* True if RTree holding integer coordinates */
+  u8 *pCellData,                 /* Raw cell content */
+  RtreeSearchPoint *pSearch,     /* Container of this cell */
+  sqlite3_rtree_dbl *prScore,    /* OUT: score for the cell */
+  int *peWithin                  /* OUT: visibility of the cell */
 ){
-#ifdef SQLITE_OMIT_WAL
-  return SQLITE_OK;
-#else
-  int rc;                         /* Return code */
-  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
+  sqlite3_rtree_query_info *pInfo = pConstraint->pInfo; /* Callback info */
+  int nCoord = pInfo->nCoord;                           /* No. of coordinates */
+  int rc;                                             /* Callback return code */
+  RtreeCoord c;                                       /* Translator union */
+  sqlite3_rtree_dbl aCoord[RTREE_MAX_DIMENSIONS*2];   /* Decoded coordinates */
 
-  /* Initialize the output variables to -1 in case an error occurs. */
-  if( pnLog ) *pnLog = -1;
-  if( pnCkpt ) *pnCkpt = -1;
+  assert( pConstraint->op==RTREE_MATCH || pConstraint->op==RTREE_QUERY );
+  assert( nCoord==2 || nCoord==4 || nCoord==6 || nCoord==8 || nCoord==10 );
 
-  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
-  assert( SQLITE_CHECKPOINT_FULL==1 );
-  assert( SQLITE_CHECKPOINT_RESTART==2 );
-  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
-  if( eModeSQLITE_CHECKPOINT_TRUNCATE ){
-    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
-    ** mode: */
-    return SQLITE_MISUSE;
+  if( pConstraint->op==RTREE_QUERY && pSearch->iLevel==1 ){
+    pInfo->iRowid = readInt64(pCellData);
   }
-
-  sqlite3_mutex_enter(db->mutex);
-  if( zDb && zDb[0] ){
-    iDb = sqlite3FindDbName(db, zDb);
+  pCellData += 8;
+#ifndef SQLITE_RTREE_INT_ONLY
+  if( eInt==0 ){
+    switch( nCoord ){
+      case 10:  readCoord(pCellData+36, &c); aCoord[9] = c.f;
+                readCoord(pCellData+32, &c); aCoord[8] = c.f;
+      case 8:   readCoord(pCellData+28, &c); aCoord[7] = c.f;
+                readCoord(pCellData+24, &c); aCoord[6] = c.f;
+      case 6:   readCoord(pCellData+20, &c); aCoord[5] = c.f;
+                readCoord(pCellData+16, &c); aCoord[4] = c.f;
+      case 4:   readCoord(pCellData+12, &c); aCoord[3] = c.f;
+                readCoord(pCellData+8,  &c); aCoord[2] = c.f;
+      default:  readCoord(pCellData+4,  &c); aCoord[1] = c.f;
+                readCoord(pCellData,    &c); aCoord[0] = c.f;
+    }
+  }else
+#endif
+  {
+    switch( nCoord ){
+      case 10:  readCoord(pCellData+36, &c); aCoord[9] = c.i;
+                readCoord(pCellData+32, &c); aCoord[8] = c.i;
+      case 8:   readCoord(pCellData+28, &c); aCoord[7] = c.i;
+                readCoord(pCellData+24, &c); aCoord[6] = c.i;
+      case 6:   readCoord(pCellData+20, &c); aCoord[5] = c.i;
+                readCoord(pCellData+16, &c); aCoord[4] = c.i;
+      case 4:   readCoord(pCellData+12, &c); aCoord[3] = c.i;
+                readCoord(pCellData+8,  &c); aCoord[2] = c.i;
+      default:  readCoord(pCellData+4,  &c); aCoord[1] = c.i;
+                readCoord(pCellData,    &c); aCoord[0] = c.i;
+    }
   }
-  if( iDb<0 ){
-    rc = SQLITE_ERROR;
-    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
+  if( pConstraint->op==RTREE_MATCH ){
+    int eWithin = 0;
+    rc = pConstraint->u.xGeom((sqlite3_rtree_geometry*)pInfo,
+                              nCoord, aCoord, &eWithin);
+    if( eWithin==0 ) *peWithin = NOT_WITHIN;
+    *prScore = RTREE_ZERO;
   }else{
-    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
-    sqlite3Error(db, rc);
+    pInfo->aCoord = aCoord;
+    pInfo->iLevel = pSearch->iLevel - 1;
+    pInfo->rScore = pInfo->rParentScore = pSearch->rScore;
+    pInfo->eWithin = pInfo->eParentWithin = pSearch->eWithin;
+    rc = pConstraint->u.xQueryFunc(pInfo);
+    if( pInfo->eWithin<*peWithin ) *peWithin = pInfo->eWithin;
+    if( pInfo->rScore<*prScore || *prScorerScore;
+    }
   }
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
   return rc;
-#endif
 }
 
-
-/*
-** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
-** to contains a zero-length string, all attached databases are 
-** checkpointed.
+/* 
+** Check the internal RTree node given by pCellData against constraint p.
+** If this constraint cannot be satisfied by any child within the node,
+** set *peWithin to NOT_WITHIN.
 */
-SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
-  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
-  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
-  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
-}
+static void rtreeNonleafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
+){
+  sqlite3_rtree_dbl val;     /* Coordinate value convert to a double */
 
-#ifndef SQLITE_OMIT_WAL
-/*
-** Run a checkpoint on database iDb. This is a no-op if database iDb is
-** not currently open in WAL mode.
-**
-** If a transaction is open on the database being checkpointed, this 
-** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
-** an error occurs while running the checkpoint, an SQLite error code is 
-** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
-**
-** The mutex on database handle db should be held by the caller. The mutex
-** associated with the specific b-tree being checkpointed is taken by
-** this function while the checkpoint is running.
-**
-** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
-** checkpointed. If an error is encountered it is returned immediately -
-** no attempt is made to checkpoint any remaining databases.
-**
-** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
-*/
-SQLITE_PRIVATE int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
-  int rc = SQLITE_OK;             /* Return code */
-  int i;                          /* Used to iterate through attached dbs */
-  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
+  /* p->iCoord might point to either a lower or upper bound coordinate
+  ** in a coordinate pair.  But make pCellData point to the lower bound.
+  */
+  pCellData += 8 + 4*(p->iCoord&0xfe);
 
-  assert( sqlite3_mutex_held(db->mutex) );
-  assert( !pnLog || *pnLog==-1 );
-  assert( !pnCkpt || *pnCkpt==-1 );
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  assert( ((((char*)pCellData) - (char*)0)&3)==0 );  /* 4-byte aligned */
+  switch( p->op ){
+    case RTREE_LE:
+    case RTREE_LT:
+    case RTREE_EQ:
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the lower bound of the coordinate pair */
+      if( p->u.rValue>=val ) return;
+      if( p->op!=RTREE_EQ ) break;  /* RTREE_LE and RTREE_LT end here */
+      /* Fall through for the RTREE_EQ case */
 
-  for(i=0; inDb && rc==SQLITE_OK; i++){
-    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
-      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
-      pnLog = 0;
-      pnCkpt = 0;
-      if( rc==SQLITE_BUSY ){
-        bBusy = 1;
-        rc = SQLITE_OK;
-      }
-    }
+    default: /* RTREE_GT or RTREE_GE,  or fallthrough of RTREE_EQ */
+      pCellData += 4;
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the upper bound of the coordinate pair */
+      if( p->u.rValue<=val ) return;
   }
-
-  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
+  *peWithin = NOT_WITHIN;
 }
-#endif /* SQLITE_OMIT_WAL */
 
 /*
-** This function returns true if main-memory should be used instead of
-** a temporary file for transient pager files and statement journals.
-** The value returned depends on the value of db->temp_store (runtime
-** parameter) and the compile time value of SQLITE_TEMP_STORE. The
-** following table describes the relationship between these two values
-** and this functions return value.
+** Check the leaf RTree cell given by pCellData against constraint p.
+** If this constraint is not satisfied, set *peWithin to NOT_WITHIN.
+** If the constraint is satisfied, leave *peWithin unchanged.
 **
-**   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
-**   -----------------     --------------     ------------------------------
-**   0                     any                file      (return 0)
-**   1                     1                  file      (return 0)
-**   1                     2                  memory    (return 1)
-**   1                     0                  file      (return 0)
-**   2                     1                  file      (return 0)
-**   2                     2                  memory    (return 1)
-**   2                     0                  memory    (return 1)
-**   3                     any                memory    (return 1)
+** The constraint is of the form:  xN op $val
+**
+** The op is given by p->op.  The xN is p->iCoord-th coordinate in
+** pCellData.  $val is given by p->u.rValue.
 */
-SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){
-#if SQLITE_TEMP_STORE==1
-  return ( db->temp_store==2 );
-#endif
-#if SQLITE_TEMP_STORE==2
-  return ( db->temp_store!=1 );
-#endif
-#if SQLITE_TEMP_STORE==3
-  return 1;
-#endif
-#if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
-  return 0;
-#endif
-}
+static void rtreeLeafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
+){
+  RtreeDValue xN;      /* Coordinate value converted to a double */
 
-/*
-** Return UTF-8 encoded English language explanation of the most recent
-** error.
-*/
-SQLITE_API const char *sqlite3_errmsg(sqlite3 *db){
-  const char *z;
-  if( !db ){
-    return sqlite3ErrStr(SQLITE_NOMEM);
-  }
-  if( !sqlite3SafetyCheckSickOrOk(db) ){
-    return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
-  }
-  sqlite3_mutex_enter(db->mutex);
-  if( db->mallocFailed ){
-    z = sqlite3ErrStr(SQLITE_NOMEM);
-  }else{
-    testcase( db->pErr==0 );
-    z = (char*)sqlite3_value_text(db->pErr);
-    assert( !db->mallocFailed );
-    if( z==0 ){
-      z = sqlite3ErrStr(db->errCode);
-    }
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  pCellData += 8 + p->iCoord*4;
+  assert( ((((char*)pCellData) - (char*)0)&3)==0 );  /* 4-byte aligned */
+  RTREE_DECODE_COORD(eInt, pCellData, xN);
+  switch( p->op ){
+    case RTREE_LE: if( xN <= p->u.rValue ) return;  break;
+    case RTREE_LT: if( xN <  p->u.rValue ) return;  break;
+    case RTREE_GE: if( xN >= p->u.rValue ) return;  break;
+    case RTREE_GT: if( xN >  p->u.rValue ) return;  break;
+    default:       if( xN == p->u.rValue ) return;  break;
   }
-  sqlite3_mutex_leave(db->mutex);
-  return z;
+  *peWithin = NOT_WITHIN;
 }
 
-#ifndef SQLITE_OMIT_UTF16
 /*
-** Return UTF-16 encoded English language explanation of the most recent
-** error.
+** One of the cells in node pNode is guaranteed to have a 64-bit 
+** integer value equal to iRowid. Return the index of this cell.
 */
-SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
-  static const u16 outOfMem[] = {
-    'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
-  };
-  static const u16 misuse[] = {
-    'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ', 
-    'r', 'o', 'u', 't', 'i', 'n', 'e', ' ', 
-    'c', 'a', 'l', 'l', 'e', 'd', ' ', 
-    'o', 'u', 't', ' ', 
-    'o', 'f', ' ', 
-    's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
-  };
-
-  const void *z;
-  if( !db ){
-    return (void *)outOfMem;
-  }
-  if( !sqlite3SafetyCheckSickOrOk(db) ){
-    return (void *)misuse;
-  }
-  sqlite3_mutex_enter(db->mutex);
-  if( db->mallocFailed ){
-    z = (void *)outOfMem;
-  }else{
-    z = sqlite3_value_text16(db->pErr);
-    if( z==0 ){
-      sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
-      z = sqlite3_value_text16(db->pErr);
+static int nodeRowidIndex(
+  Rtree *pRtree, 
+  RtreeNode *pNode, 
+  i64 iRowid,
+  int *piIndex
+){
+  int ii;
+  int nCell = NCELL(pNode);
+  assert( nCell<200 );
+  for(ii=0; iimallocFailed flag needs to
-    ** be cleared before returning. Do this directly, instead of via
-    ** sqlite3ApiExit(), to avoid setting the database handle error message.
-    */
-    db->mallocFailed = 0;
   }
-  sqlite3_mutex_leave(db->mutex);
-  return z;
+  return SQLITE_CORRUPT_VTAB;
 }
-#endif /* SQLITE_OMIT_UTF16 */
 
 /*
-** Return the most recent error code generated by an SQLite routine. If NULL is
-** passed to this function, we assume a malloc() failed during sqlite3_open().
+** Return the index of the cell containing a pointer to node pNode
+** in its parent. If pNode is the root node, return -1.
 */
-SQLITE_API int sqlite3_errcode(sqlite3 *db){
-  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
-    return SQLITE_MISUSE_BKPT;
-  }
-  if( !db || db->mallocFailed ){
-    return SQLITE_NOMEM;
-  }
-  return db->errCode & db->errMask;
-}
-SQLITE_API int sqlite3_extended_errcode(sqlite3 *db){
-  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
-    return SQLITE_MISUSE_BKPT;
-  }
-  if( !db || db->mallocFailed ){
-    return SQLITE_NOMEM;
+static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){
+  RtreeNode *pParent = pNode->pParent;
+  if( pParent ){
+    return nodeRowidIndex(pRtree, pParent, pNode->iNode, piIndex);
   }
-  return db->errCode;
+  *piIndex = -1;
+  return SQLITE_OK;
 }
 
 /*
-** Return a string that describes the kind of error specified in the
-** argument.  For now, this simply calls the internal sqlite3ErrStr()
-** function.
+** Compare two search points.  Return negative, zero, or positive if the first
+** is less than, equal to, or greater than the second.
+**
+** The rScore is the primary key.  Smaller rScore values come first.
+** If the rScore is a tie, then use iLevel as the tie breaker with smaller
+** iLevel values coming first.  In this way, if rScore is the same for all
+** SearchPoints, then iLevel becomes the deciding factor and the result
+** is a depth-first search, which is the desired default behavior.
 */
-SQLITE_API const char *sqlite3_errstr(int rc){
-  return sqlite3ErrStr(rc);
+static int rtreeSearchPointCompare(
+  const RtreeSearchPoint *pA,
+  const RtreeSearchPoint *pB
+){
+  if( pA->rScorerScore ) return -1;
+  if( pA->rScore>pB->rScore ) return +1;
+  if( pA->iLeveliLevel ) return -1;
+  if( pA->iLevel>pB->iLevel ) return +1;
+  return 0;
 }
 
 /*
-** Create a new collating function for database "db".  The name is zName
-** and the encoding is enc.
+** Interchange two search points in a cursor.
 */
-static int createCollation(
-  sqlite3* db,
-  const char *zName, 
-  u8 enc,
-  void* pCtx,
-  int(*xCompare)(void*,int,const void*,int,const void*),
-  void(*xDel)(void*)
-){
-  CollSeq *pColl;
-  int enc2;
-  
-  assert( sqlite3_mutex_held(db->mutex) );
-
-  /* If SQLITE_UTF16 is specified as the encoding type, transform this
-  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
-  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
-  */
-  enc2 = enc;
-  testcase( enc2==SQLITE_UTF16 );
-  testcase( enc2==SQLITE_UTF16_ALIGNED );
-  if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
-    enc2 = SQLITE_UTF16NATIVE;
-  }
-  if( enc2SQLITE_UTF16BE ){
-    return SQLITE_MISUSE_BKPT;
-  }
-
-  /* Check if this call is removing or replacing an existing collation 
-  ** sequence. If so, and there are active VMs, return busy. If there
-  ** are no active VMs, invalidate any pre-compiled statements.
-  */
-  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
-  if( pColl && pColl->xCmp ){
-    if( db->nVdbeActive ){
-      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
-        "unable to delete/modify collation sequence due to active statements");
-      return SQLITE_BUSY;
-    }
-    sqlite3ExpirePreparedStatements(db);
-
-    /* If collation sequence pColl was created directly by a call to
-    ** sqlite3_create_collation, and not generated by synthCollSeq(),
-    ** then any copies made by synthCollSeq() need to be invalidated.
-    ** Also, collation destructor - CollSeq.xDel() - function may need
-    ** to be called.
-    */ 
-    if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
-      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
-      int j;
-      for(j=0; j<3; j++){
-        CollSeq *p = &aColl[j];
-        if( p->enc==pColl->enc ){
-          if( p->xDel ){
-            p->xDel(p->pUser);
-          }
-          p->xCmp = 0;
-        }
-      }
+static void rtreeSearchPointSwap(RtreeCursor *p, int i, int j){
+  RtreeSearchPoint t = p->aPoint[i];
+  assert( iaPoint[i] = p->aPoint[j];
+  p->aPoint[j] = t;
+  i++; j++;
+  if( i=RTREE_CACHE_SZ ){
+      nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+      p->aNode[i] = 0;
+    }else{
+      RtreeNode *pTemp = p->aNode[i];
+      p->aNode[i] = p->aNode[j];
+      p->aNode[j] = pTemp;
     }
   }
-
-  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
-  if( pColl==0 ) return SQLITE_NOMEM;
-  pColl->xCmp = xCompare;
-  pColl->pUser = pCtx;
-  pColl->xDel = xDel;
-  pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
-  sqlite3Error(db, SQLITE_OK);
-  return SQLITE_OK;
 }
 
-
 /*
-** This array defines hard upper bounds on limit values.  The
-** initializer must be kept in sync with the SQLITE_LIMIT_*
-** #defines in sqlite3.h.
+** Return the search point with the lowest current score.
 */
-static const int aHardLimit[] = {
-  SQLITE_MAX_LENGTH,
-  SQLITE_MAX_SQL_LENGTH,
-  SQLITE_MAX_COLUMN,
-  SQLITE_MAX_EXPR_DEPTH,
-  SQLITE_MAX_COMPOUND_SELECT,
-  SQLITE_MAX_VDBE_OP,
-  SQLITE_MAX_FUNCTION_ARG,
-  SQLITE_MAX_ATTACHED,
-  SQLITE_MAX_LIKE_PATTERN_LENGTH,
-  SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
-  SQLITE_MAX_TRIGGER_DEPTH,
-  SQLITE_MAX_WORKER_THREADS,
-};
+static RtreeSearchPoint *rtreeSearchPointFirst(RtreeCursor *pCur){
+  return pCur->bPoint ? &pCur->sPoint : pCur->nPoint ? pCur->aPoint : 0;
+}
 
 /*
-** Make sure the hard limits are set to reasonable values
+** Get the RtreeNode for the search point with the lowest score.
 */
-#if SQLITE_MAX_LENGTH<100
-# error SQLITE_MAX_LENGTH must be at least 100
-#endif
-#if SQLITE_MAX_SQL_LENGTH<100
-# error SQLITE_MAX_SQL_LENGTH must be at least 100
-#endif
-#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
-# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
-#endif
-#if SQLITE_MAX_COMPOUND_SELECT<2
-# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
-#endif
-#if SQLITE_MAX_VDBE_OP<40
-# error SQLITE_MAX_VDBE_OP must be at least 40
-#endif
-#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
-# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
-#endif
-#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
-# error SQLITE_MAX_ATTACHED must be between 0 and 125
-#endif
-#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
-# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
-#endif
-#if SQLITE_MAX_COLUMN>32767
-# error SQLITE_MAX_COLUMN must not exceed 32767
-#endif
-#if SQLITE_MAX_TRIGGER_DEPTH<1
-# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
-#endif
-#if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
-# error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
-#endif
-
+static RtreeNode *rtreeNodeOfFirstSearchPoint(RtreeCursor *pCur, int *pRC){
+  sqlite3_int64 id;
+  int ii = 1 - pCur->bPoint;
+  assert( ii==0 || ii==1 );
+  assert( pCur->bPoint || pCur->nPoint );
+  if( pCur->aNode[ii]==0 ){
+    assert( pRC!=0 );
+    id = ii ? pCur->aPoint[0].id : pCur->sPoint.id;
+    *pRC = nodeAcquire(RTREE_OF_CURSOR(pCur), id, 0, &pCur->aNode[ii]);
+  }
+  return pCur->aNode[ii];
+}
 
 /*
-** Change the value of a limit.  Report the old value.
-** If an invalid limit index is supplied, report -1.
-** Make no changes but still report the old value if the
-** new limit is negative.
-**
-** A new lower limit does not shrink existing constructs.
-** It merely prevents new constructs that exceed the limit
-** from forming.
+** Push a new element onto the priority queue
 */
-SQLITE_API int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
-  int oldLimit;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return -1;
-  }
-#endif
-
-  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
-  ** there is a hard upper bound set at compile-time by a C preprocessor
-  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
-  ** "_MAX_".)
-  */
-  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
-  assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
-  assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
-  assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
-  assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
-  assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
-  assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
-  assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
-  assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
-                                               SQLITE_MAX_LIKE_PATTERN_LENGTH );
-  assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
-  assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
-  assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
-  assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
-
-
-  if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
-    return -1;
+static RtreeSearchPoint *rtreeEnqueue(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
+){
+  int i, j;
+  RtreeSearchPoint *pNew;
+  if( pCur->nPoint>=pCur->nPointAlloc ){
+    int nNew = pCur->nPointAlloc*2 + 8;
+    pNew = sqlite3_realloc(pCur->aPoint, nNew*sizeof(pCur->aPoint[0]));
+    if( pNew==0 ) return 0;
+    pCur->aPoint = pNew;
+    pCur->nPointAlloc = nNew;
   }
-  oldLimit = db->aLimit[limitId];
-  if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
-    if( newLimit>aHardLimit[limitId] ){
-      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
-    }
-    db->aLimit[limitId] = newLimit;
+  i = pCur->nPoint++;
+  pNew = pCur->aPoint + i;
+  pNew->rScore = rScore;
+  pNew->iLevel = iLevel;
+  assert( iLevel<=RTREE_MAX_DEPTH );
+  while( i>0 ){
+    RtreeSearchPoint *pParent;
+    j = (i-1)/2;
+    pParent = pCur->aPoint + j;
+    if( rtreeSearchPointCompare(pNew, pParent)>=0 ) break;
+    rtreeSearchPointSwap(pCur, j, i);
+    i = j;
+    pNew = pParent;
   }
-  return oldLimit;                     /* IMP: R-53341-35419 */
+  return pNew;
 }
 
 /*
-** This function is used to parse both URIs and non-URI filenames passed by the
-** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
-** URIs specified as part of ATTACH statements.
-**
-** The first argument to this function is the name of the VFS to use (or
-** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
-** query parameter. The second argument contains the URI (or non-URI filename)
-** itself. When this function is called the *pFlags variable should contain
-** the default flags to open the database handle with. The value stored in
-** *pFlags may be updated before returning if the URI filename contains 
-** "cache=xxx" or "mode=xxx" query parameters.
-**
-** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
-** the VFS that should be used to open the database file. *pzFile is set to
-** point to a buffer containing the name of the file to open. It is the 
-** responsibility of the caller to eventually call sqlite3_free() to release
-** this buffer.
-**
-** If an error occurs, then an SQLite error code is returned and *pzErrMsg
-** may be set to point to a buffer containing an English language error 
-** message. It is the responsibility of the caller to eventually release
-** this buffer by calling sqlite3_free().
+** Allocate a new RtreeSearchPoint and return a pointer to it.  Return
+** NULL if malloc fails.
 */
-SQLITE_PRIVATE int sqlite3ParseUri(
-  const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
-  const char *zUri,               /* Nul-terminated URI to parse */
-  unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
-  sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
-  char **pzFile,                  /* OUT: Filename component of URI */
-  char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
+static RtreeSearchPoint *rtreeSearchPointNew(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
 ){
-  int rc = SQLITE_OK;
-  unsigned int flags = *pFlags;
-  const char *zVfs = zDefaultVfs;
-  char *zFile;
-  char c;
-  int nUri = sqlite3Strlen30(zUri);
-
-  assert( *pzErrMsg==0 );
-
-  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
-            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
-   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
+  RtreeSearchPoint *pNew, *pFirst;
+  pFirst = rtreeSearchPointFirst(pCur);
+  pCur->anQueue[iLevel]++;
+  if( pFirst==0
+   || pFirst->rScore>rScore 
+   || (pFirst->rScore==rScore && pFirst->iLevel>iLevel)
   ){
-    char *zOpt;
-    int eState;                   /* Parser state when parsing URI */
-    int iIn;                      /* Input character index */
-    int iOut = 0;                 /* Output character index */
-    int nByte = nUri+2;           /* Bytes of space to allocate */
-
-    /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
-    ** method that there may be extra parameters following the file-name.  */
-    flags |= SQLITE_OPEN_URI;
-
-    for(iIn=0; iInbPoint ){
+      int ii;
+      pNew = rtreeEnqueue(pCur, rScore, iLevel);
+      if( pNew==0 ) return 0;
+      ii = (int)(pNew - pCur->aPoint) + 1;
+      if( iiaNode[ii]==0 );
+        pCur->aNode[ii] = pCur->aNode[0];
+       }else{
+        nodeRelease(RTREE_OF_CURSOR(pCur), pCur->aNode[0]);
       }
+      pCur->aNode[0] = 0;
+      *pNew = pCur->sPoint;
     }
-#endif
+    pCur->sPoint.rScore = rScore;
+    pCur->sPoint.iLevel = iLevel;
+    pCur->bPoint = 1;
+    return &pCur->sPoint;
+  }else{
+    return rtreeEnqueue(pCur, rScore, iLevel);
+  }
+}
 
-    /* Copy the filename and any query parameters into the zFile buffer. 
-    ** Decode %HH escape codes along the way. 
-    **
-    ** Within this loop, variable eState may be set to 0, 1 or 2, depending
-    ** on the parsing context. As follows:
-    **
-    **   0: Parsing file-name.
-    **   1: Parsing name section of a name=value query parameter.
-    **   2: Parsing value section of a name=value query parameter.
-    */
-    eState = 0;
-    while( (c = zUri[iIn])!=0 && c!='#' ){
-      iIn++;
-      if( c=='%' 
-       && sqlite3Isxdigit(zUri[iIn]) 
-       && sqlite3Isxdigit(zUri[iIn+1]) 
-      ){
-        int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
-        octet += sqlite3HexToInt(zUri[iIn++]);
+#if 0
+/* Tracing routines for the RtreeSearchPoint queue */
+static void tracePoint(RtreeSearchPoint *p, int idx, RtreeCursor *pCur){
+  if( idx<0 ){ printf(" s"); }else{ printf("%2d", idx); }
+  printf(" %d.%05lld.%02d %g %d",
+    p->iLevel, p->id, p->iCell, p->rScore, p->eWithin
+  );
+  idx++;
+  if( idxaNode[idx]);
+  }else{
+    printf("\n");
+  }
+}
+static void traceQueue(RtreeCursor *pCur, const char *zPrefix){
+  int ii;
+  printf("=== %9s ", zPrefix);
+  if( pCur->bPoint ){
+    tracePoint(&pCur->sPoint, -1, pCur);
+  }
+  for(ii=0; iinPoint; ii++){
+    if( ii>0 || pCur->bPoint ) printf("              ");
+    tracePoint(&pCur->aPoint[ii], ii, pCur);
+  }
+}
+# define RTREE_QUEUE_TRACE(A,B) traceQueue(A,B)
+#else
+# define RTREE_QUEUE_TRACE(A,B)   /* no-op */
+#endif
 
-        assert( octet>=0 && octet<256 );
-        if( octet==0 ){
-          /* This branch is taken when "%00" appears within the URI. In this
-          ** case we ignore all text in the remainder of the path, name or
-          ** value currently being parsed. So ignore the current character
-          ** and skip to the next "?", "=" or "&", as appropriate. */
-          while( (c = zUri[iIn])!=0 && c!='#' 
-              && (eState!=0 || c!='?')
-              && (eState!=1 || (c!='=' && c!='&'))
-              && (eState!=2 || c!='&')
-          ){
-            iIn++;
-          }
-          continue;
-        }
-        c = octet;
-      }else if( eState==1 && (c=='&' || c=='=') ){
-        if( zFile[iOut-1]==0 ){
-          /* An empty option name. Ignore this option altogether. */
-          while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
-          continue;
-        }
-        if( c=='&' ){
-          zFile[iOut++] = '\0';
-        }else{
-          eState = 2;
-        }
-        c = 0;
-      }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
-        c = 0;
-        eState = 1;
-      }
-      zFile[iOut++] = c;
+/* Remove the search point with the lowest current score.
+*/
+static void rtreeSearchPointPop(RtreeCursor *p){
+  int i, j, k, n;
+  i = 1 - p->bPoint;
+  assert( i==0 || i==1 );
+  if( p->aNode[i] ){
+    nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+    p->aNode[i] = 0;
+  }
+  if( p->bPoint ){
+    p->anQueue[p->sPoint.iLevel]--;
+    p->bPoint = 0;
+  }else if( p->nPoint ){
+    p->anQueue[p->aPoint[0].iLevel]--;
+    n = --p->nPoint;
+    p->aPoint[0] = p->aPoint[n];
+    if( naNode[1] = p->aNode[n+1];
+      p->aNode[n+1] = 0;
     }
-    if( eState==1 ) zFile[iOut++] = '\0';
-    zFile[iOut++] = '\0';
-    zFile[iOut++] = '\0';
-
-    /* Check if there were any options specified that should be interpreted 
-    ** here. Options that are interpreted here include "vfs" and those that
-    ** correspond to flags that may be passed to the sqlite3_open_v2()
-    ** method. */
-    zOpt = &zFile[sqlite3Strlen30(zFile)+1];
-    while( zOpt[0] ){
-      int nOpt = sqlite3Strlen30(zOpt);
-      char *zVal = &zOpt[nOpt+1];
-      int nVal = sqlite3Strlen30(zVal);
-
-      if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
-        zVfs = zVal;
-      }else{
-        struct OpenMode {
-          const char *z;
-          int mode;
-        } *aMode = 0;
-        char *zModeType = 0;
-        int mask = 0;
-        int limit = 0;
-
-        if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
-          static struct OpenMode aCacheMode[] = {
-            { "shared",  SQLITE_OPEN_SHAREDCACHE },
-            { "private", SQLITE_OPEN_PRIVATECACHE },
-            { 0, 0 }
-          };
-
-          mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
-          aMode = aCacheMode;
-          limit = mask;
-          zModeType = "cache";
+    i = 0;
+    while( (j = i*2+1)aPoint[k], &p->aPoint[j])<0 ){
+        if( rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, k);
+          i = k;
+        }else{
+          break;
         }
-        if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
-          static struct OpenMode aOpenMode[] = {
-            { "ro",  SQLITE_OPEN_READONLY },
-            { "rw",  SQLITE_OPEN_READWRITE }, 
-            { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
-            { "memory", SQLITE_OPEN_MEMORY },
-            { 0, 0 }
-          };
-
-          mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
-                   | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
-          aMode = aOpenMode;
-          limit = mask & flags;
-          zModeType = "access";
+      }else{
+        if( rtreeSearchPointCompare(&p->aPoint[j], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, j);
+          i = j;
+        }else{
+          break;
         }
+      }
+    }
+  }
+}
 
-        if( aMode ){
-          int i;
-          int mode = 0;
-          for(i=0; aMode[i].z; i++){
-            const char *z = aMode[i].z;
-            if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
-              mode = aMode[i].mode;
-              break;
-            }
-          }
-          if( mode==0 ){
-            *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
-            rc = SQLITE_ERROR;
-            goto parse_uri_out;
-          }
-          if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
-            *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
-                                        zModeType, zVal);
-            rc = SQLITE_PERM;
-            goto parse_uri_out;
-          }
-          flags = (flags & ~mask) | mode;
+
+/*
+** Continue the search on cursor pCur until the front of the queue
+** contains an entry suitable for returning as a result-set row,
+** or until the RtreeSearchPoint queue is empty, indicating that the
+** query has completed.
+*/
+static int rtreeStepToLeaf(RtreeCursor *pCur){
+  RtreeSearchPoint *p;
+  Rtree *pRtree = RTREE_OF_CURSOR(pCur);
+  RtreeNode *pNode;
+  int eWithin;
+  int rc = SQLITE_OK;
+  int nCell;
+  int nConstraint = pCur->nConstraint;
+  int ii;
+  int eInt;
+  RtreeSearchPoint x;
+
+  eInt = pRtree->eCoordType==RTREE_COORD_INT32;
+  while( (p = rtreeSearchPointFirst(pCur))!=0 && p->iLevel>0 ){
+    pNode = rtreeNodeOfFirstSearchPoint(pCur, &rc);
+    if( rc ) return rc;
+    nCell = NCELL(pNode);
+    assert( nCell<200 );
+    while( p->iCellzData + (4+pRtree->nBytesPerCell*p->iCell);
+      eWithin = FULLY_WITHIN;
+      for(ii=0; iiaConstraint + ii;
+        if( pConstraint->op>=RTREE_MATCH ){
+          rc = rtreeCallbackConstraint(pConstraint, eInt, pCellData, p,
+                                       &rScore, &eWithin);
+          if( rc ) return rc;
+        }else if( p->iLevel==1 ){
+          rtreeLeafConstraint(pConstraint, eInt, pCellData, &eWithin);
+        }else{
+          rtreeNonleafConstraint(pConstraint, eInt, pCellData, &eWithin);
         }
+        if( eWithin==NOT_WITHIN ) break;
       }
-
-      zOpt = &zVal[nVal+1];
+      p->iCell++;
+      if( eWithin==NOT_WITHIN ) continue;
+      x.iLevel = p->iLevel - 1;
+      if( x.iLevel ){
+        x.id = readInt64(pCellData);
+        x.iCell = 0;
+      }else{
+        x.id = p->id;
+        x.iCell = p->iCell - 1;
+      }
+      if( p->iCell>=nCell ){
+        RTREE_QUEUE_TRACE(pCur, "POP-S:");
+        rtreeSearchPointPop(pCur);
+      }
+      if( rScoreeWithin = (u8)eWithin;
+      p->id = x.id;
+      p->iCell = x.iCell;
+      RTREE_QUEUE_TRACE(pCur, "PUSH-S:");
+      break;
+    }
+    if( p->iCell>=nCell ){
+      RTREE_QUEUE_TRACE(pCur, "POP-Se:");
+      rtreeSearchPointPop(pCur);
     }
-
-  }else{
-    zFile = sqlite3_malloc(nUri+2);
-    if( !zFile ) return SQLITE_NOMEM;
-    memcpy(zFile, zUri, nUri);
-    zFile[nUri] = '\0';
-    zFile[nUri+1] = '\0';
-    flags &= ~SQLITE_OPEN_URI;
   }
+  pCur->atEOF = p==0;
+  return SQLITE_OK;
+}
 
-  *ppVfs = sqlite3_vfs_find(zVfs);
-  if( *ppVfs==0 ){
-    *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
-    rc = SQLITE_ERROR;
-  }
- parse_uri_out:
-  if( rc!=SQLITE_OK ){
-    sqlite3_free(zFile);
-    zFile = 0;
-  }
-  *pFlags = flags;
-  *pzFile = zFile;
+/* 
+** Rtree virtual table module xNext method.
+*/
+static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
+  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
+  int rc = SQLITE_OK;
+
+  /* Move to the next entry that matches the configured constraints. */
+  RTREE_QUEUE_TRACE(pCsr, "POP-Nx:");
+  rtreeSearchPointPop(pCsr);
+  rc = rtreeStepToLeaf(pCsr);
   return rc;
 }
 
+/* 
+** Rtree virtual table module xRowid method.
+*/
+static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
+  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
+  if( rc==SQLITE_OK && p ){
+    *pRowid = nodeGetRowid(RTREE_OF_CURSOR(pCsr), pNode, p->iCell);
+  }
+  return rc;
+}
 
-/*
-** This routine does the work of opening a database on behalf of
-** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
-** is UTF-8 encoded.
+/* 
+** Rtree virtual table module xColumn method.
 */
-static int openDatabase(
-  const char *zFilename, /* Database filename UTF-8 encoded */
-  sqlite3 **ppDb,        /* OUT: Returned database handle */
-  unsigned int flags,    /* Operational flags */
-  const char *zVfs       /* Name of the VFS to use */
-){
-  sqlite3 *db;                    /* Store allocated handle here */
-  int rc;                         /* Return code */
-  int isThreadsafe;               /* True for threadsafe connections */
-  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
-  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
+static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  Rtree *pRtree = (Rtree *)cur->pVtab;
+  RtreeCursor *pCsr = (RtreeCursor *)cur;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  RtreeCoord c;
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
-#endif
-  *ppDb = 0;
-#ifndef SQLITE_OMIT_AUTOINIT
-  rc = sqlite3_initialize();
   if( rc ) return rc;
+  if( p==0 ) return SQLITE_OK;
+  if( i==0 ){
+    sqlite3_result_int64(ctx, nodeGetRowid(pRtree, pNode, p->iCell));
+  }else{
+    nodeGetCoord(pRtree, pNode, p->iCell, i-1, &c);
+#ifndef SQLITE_RTREE_INT_ONLY
+    if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
+      sqlite3_result_double(ctx, c.f);
+    }else
 #endif
-
-  /* Only allow sensible combinations of bits in the flags argument.  
-  ** Throw an error if any non-sense combination is used.  If we
-  ** do not block illegal combinations here, it could trigger
-  ** assert() statements in deeper layers.  Sensible combinations
-  ** are:
-  **
-  **  1:  SQLITE_OPEN_READONLY
-  **  2:  SQLITE_OPEN_READWRITE
-  **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
-  */
-  assert( SQLITE_OPEN_READONLY  == 0x01 );
-  assert( SQLITE_OPEN_READWRITE == 0x02 );
-  assert( SQLITE_OPEN_CREATE    == 0x04 );
-  testcase( (1<<(flags&7))==0x02 ); /* READONLY */
-  testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
-  testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
-  if( ((1<<(flags&7)) & 0x46)==0 ){
-    return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
+    {
+      assert( pRtree->eCoordType==RTREE_COORD_INT32 );
+      sqlite3_result_int(ctx, c.i);
+    }
   }
+  return SQLITE_OK;
+}
 
-  if( sqlite3GlobalConfig.bCoreMutex==0 ){
-    isThreadsafe = 0;
-  }else if( flags & SQLITE_OPEN_NOMUTEX ){
-    isThreadsafe = 0;
-  }else if( flags & SQLITE_OPEN_FULLMUTEX ){
-    isThreadsafe = 1;
+/* 
+** Use nodeAcquire() to obtain the leaf node containing the record with 
+** rowid iRowid. If successful, set *ppLeaf to point to the node and
+** return SQLITE_OK. If there is no such record in the table, set
+** *ppLeaf to 0 and return SQLITE_OK. If an error occurs, set *ppLeaf
+** to zero and return an SQLite error code.
+*/
+static int findLeafNode(
+  Rtree *pRtree,              /* RTree to search */
+  i64 iRowid,                 /* The rowid searching for */
+  RtreeNode **ppLeaf,         /* Write the node here */
+  sqlite3_int64 *piNode       /* Write the node-id here */
+){
+  int rc;
+  *ppLeaf = 0;
+  sqlite3_bind_int64(pRtree->pReadRowid, 1, iRowid);
+  if( sqlite3_step(pRtree->pReadRowid)==SQLITE_ROW ){
+    i64 iNode = sqlite3_column_int64(pRtree->pReadRowid, 0);
+    if( piNode ) *piNode = iNode;
+    rc = nodeAcquire(pRtree, iNode, 0, ppLeaf);
+    sqlite3_reset(pRtree->pReadRowid);
   }else{
-    isThreadsafe = sqlite3GlobalConfig.bFullMutex;
-  }
-  if( flags & SQLITE_OPEN_PRIVATECACHE ){
-    flags &= ~SQLITE_OPEN_SHAREDCACHE;
-  }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
-    flags |= SQLITE_OPEN_SHAREDCACHE;
+    rc = sqlite3_reset(pRtree->pReadRowid);
   }
+  return rc;
+}
 
-  /* Remove harmful bits from the flags parameter
-  **
-  ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
-  ** dealt with in the previous code block.  Besides these, the only
-  ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
-  ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
-  ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
-  ** off all other flags.
-  */
-  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
-               SQLITE_OPEN_EXCLUSIVE |
-               SQLITE_OPEN_MAIN_DB |
-               SQLITE_OPEN_TEMP_DB | 
-               SQLITE_OPEN_TRANSIENT_DB | 
-               SQLITE_OPEN_MAIN_JOURNAL | 
-               SQLITE_OPEN_TEMP_JOURNAL | 
-               SQLITE_OPEN_SUBJOURNAL | 
-               SQLITE_OPEN_MASTER_JOURNAL |
-               SQLITE_OPEN_NOMUTEX |
-               SQLITE_OPEN_FULLMUTEX |
-               SQLITE_OPEN_WAL
-             );
+/*
+** This function is called to configure the RtreeConstraint object passed
+** as the second argument for a MATCH constraint. The value passed as the
+** first argument to this function is the right-hand operand to the MATCH
+** operator.
+*/
+static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
+  RtreeMatchArg *pBlob, *pSrc;       /* BLOB returned by geometry function */
+  sqlite3_rtree_query_info *pInfo;   /* Callback information */
 
-  /* Allocate the sqlite data structure */
-  db = sqlite3MallocZero( sizeof(sqlite3) );
-  if( db==0 ) goto opendb_out;
-  if( isThreadsafe ){
-    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
-    if( db->mutex==0 ){
-      sqlite3_free(db);
-      db = 0;
-      goto opendb_out;
-    }
+  pSrc = sqlite3_value_pointer(pValue, "RtreeMatchArg");
+  if( pSrc==0 ) return SQLITE_ERROR;
+  pInfo = (sqlite3_rtree_query_info*)
+                sqlite3_malloc64( sizeof(*pInfo)+pSrc->iSize );
+  if( !pInfo ) return SQLITE_NOMEM;
+  memset(pInfo, 0, sizeof(*pInfo));
+  pBlob = (RtreeMatchArg*)&pInfo[1];
+  memcpy(pBlob, pSrc, pSrc->iSize);
+  pInfo->pContext = pBlob->cb.pContext;
+  pInfo->nParam = pBlob->nParam;
+  pInfo->aParam = pBlob->aParam;
+  pInfo->apSqlParam = pBlob->apSqlParam;
+
+  if( pBlob->cb.xGeom ){
+    pCons->u.xGeom = pBlob->cb.xGeom;
+  }else{
+    pCons->op = RTREE_QUERY;
+    pCons->u.xQueryFunc = pBlob->cb.xQueryFunc;
   }
-  sqlite3_mutex_enter(db->mutex);
-  db->errMask = 0xff;
-  db->nDb = 2;
-  db->magic = SQLITE_MAGIC_BUSY;
-  db->aDb = db->aDbStatic;
+  pCons->pInfo = pInfo;
+  return SQLITE_OK;
+}
 
-  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
-  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
-  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
-  db->autoCommit = 1;
-  db->nextAutovac = -1;
-  db->szMmap = sqlite3GlobalConfig.szMmap;
-  db->nextPagesize = 0;
-  db->nMaxSorterMmap = 0x7FFFFFFF;
-  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
-#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
-                 | SQLITE_AutoIndex
-#endif
-#if SQLITE_DEFAULT_FILE_FORMAT<4
-                 | SQLITE_LegacyFileFmt
-#endif
-#ifdef SQLITE_ENABLE_LOAD_EXTENSION
-                 | SQLITE_LoadExtension
-#endif
-#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
-                 | SQLITE_RecTriggers
-#endif
-#if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
-                 | SQLITE_ForeignKeys
-#endif
-#if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
-                 | SQLITE_ReverseOrder
-#endif
-      ;
-  sqlite3HashInit(&db->aCollSeq);
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  sqlite3HashInit(&db->aModule);
-#endif
+/* 
+** Rtree virtual table module xFilter method.
+*/
+static int rtreeFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
+  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
+  RtreeNode *pRoot = 0;
+  int ii;
+  int rc = SQLITE_OK;
+  int iCell = 0;
 
-  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
-  ** and UTF-16, so add a version for each to avoid any unnecessary
-  ** conversions. The only error that can occur here is a malloc() failure.
-  **
-  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
-  ** functions:
-  */
-  createCollation(db, "BINARY", SQLITE_UTF8, 0, binCollFunc, 0);
-  createCollation(db, "BINARY", SQLITE_UTF16BE, 0, binCollFunc, 0);
-  createCollation(db, "BINARY", SQLITE_UTF16LE, 0, binCollFunc, 0);
-  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
-  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
-  if( db->mallocFailed ){
-    goto opendb_out;
-  }
-  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
-  ** strings is BINARY. 
-  */
-  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
-  assert( db->pDfltColl!=0 );
+  rtreeReference(pRtree);
 
-  /* Parse the filename/URI argument. */
-  db->openFlags = flags;
-  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
-  if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
-    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
-    sqlite3_free(zErrMsg);
-    goto opendb_out;
-  }
+  /* Reset the cursor to the same state as rtreeOpen() leaves it in. */
+  freeCursorConstraints(pCsr);
+  sqlite3_free(pCsr->aPoint);
+  memset(pCsr, 0, sizeof(RtreeCursor));
+  pCsr->base.pVtab = (sqlite3_vtab*)pRtree;
 
-  /* Open the backend database driver */
-  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
-                        flags | SQLITE_OPEN_MAIN_DB);
-  if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_IOERR_NOMEM ){
-      rc = SQLITE_NOMEM;
+  pCsr->iStrategy = idxNum;
+  if( idxNum==1 ){
+    /* Special case - lookup by rowid. */
+    RtreeNode *pLeaf;        /* Leaf on which the required cell resides */
+    RtreeSearchPoint *p;     /* Search point for the leaf */
+    i64 iRowid = sqlite3_value_int64(argv[0]);
+    i64 iNode = 0;
+    rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);
+    if( rc==SQLITE_OK && pLeaf!=0 ){
+      p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);
+      assert( p!=0 );  /* Always returns pCsr->sPoint */
+      pCsr->aNode[0] = pLeaf;
+      p->id = iNode;
+      p->eWithin = PARTLY_WITHIN;
+      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);
+      p->iCell = (u8)iCell;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");
+    }else{
+      pCsr->atEOF = 1;
+    }
+  }else{
+    /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 
+    ** with the configured constraints. 
+    */
+    rc = nodeAcquire(pRtree, 1, 0, &pRoot);
+    if( rc==SQLITE_OK && argc>0 ){
+      pCsr->aConstraint = sqlite3_malloc(sizeof(RtreeConstraint)*argc);
+      pCsr->nConstraint = argc;
+      if( !pCsr->aConstraint ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);
+        memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));
+        assert( (idxStr==0 && argc==0)
+                || (idxStr && (int)strlen(idxStr)==argc*2) );
+        for(ii=0; iiaConstraint[ii];
+          p->op = idxStr[ii*2];
+          p->iCoord = idxStr[ii*2+1]-'0';
+          if( p->op>=RTREE_MATCH ){
+            /* A MATCH operator. The right-hand-side must be a blob that
+            ** can be cast into an RtreeMatchArg object. One created using
+            ** an sqlite3_rtree_geometry_callback() SQL user function.
+            */
+            rc = deserializeGeometry(argv[ii], p);
+            if( rc!=SQLITE_OK ){
+              break;
+            }
+            p->pInfo->nCoord = pRtree->nDim2;
+            p->pInfo->anQueue = pCsr->anQueue;
+            p->pInfo->mxLevel = pRtree->iDepth + 1;
+          }else{
+#ifdef SQLITE_RTREE_INT_ONLY
+            p->u.rValue = sqlite3_value_int64(argv[ii]);
+#else
+            p->u.rValue = sqlite3_value_double(argv[ii]);
+#endif
+          }
+        }
+      }
+    }
+    if( rc==SQLITE_OK ){
+      RtreeSearchPoint *pNew;
+      pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, (u8)(pRtree->iDepth+1));
+      if( pNew==0 ) return SQLITE_NOMEM;
+      pNew->id = 1;
+      pNew->iCell = 0;
+      pNew->eWithin = PARTLY_WITHIN;
+      assert( pCsr->bPoint==1 );
+      pCsr->aNode[0] = pRoot;
+      pRoot = 0;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");
+      rc = rtreeStepToLeaf(pCsr);
     }
-    sqlite3Error(db, rc);
-    goto opendb_out;
   }
-  sqlite3BtreeEnter(db->aDb[0].pBt);
-  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
-  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
-  sqlite3BtreeLeave(db->aDb[0].pBt);
-  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
 
-  /* The default safety_level for the main database is 'full'; for the temp
-  ** database it is 'NONE'. This matches the pager layer defaults.  
-  */
-  db->aDb[0].zName = "main";
-  db->aDb[0].safety_level = 3;
-  db->aDb[1].zName = "temp";
-  db->aDb[1].safety_level = 1;
+  nodeRelease(pRtree, pRoot);
+  rtreeRelease(pRtree);
+  return rc;
+}
 
-  db->magic = SQLITE_MAGIC_OPEN;
-  if( db->mallocFailed ){
-    goto opendb_out;
-  }
+/*
+** Rtree virtual table module xBestIndex method. There are three
+** table scan strategies to choose from (in order from most to 
+** least desirable):
+**
+**   idxNum     idxStr        Strategy
+**   ------------------------------------------------
+**     1        Unused        Direct lookup by rowid.
+**     2        See below     R-tree query or full-table scan.
+**   ------------------------------------------------
+**
+** If strategy 1 is used, then idxStr is not meaningful. If strategy
+** 2 is used, idxStr is formatted to contain 2 bytes for each 
+** constraint used. The first two bytes of idxStr correspond to 
+** the constraint in sqlite3_index_info.aConstraintUsage[] with
+** (argvIndex==1) etc.
+**
+** The first of each pair of bytes in idxStr identifies the constraint
+** operator as follows:
+**
+**   Operator    Byte Value
+**   ----------------------
+**      =        0x41 ('A')
+**     <=        0x42 ('B')
+**      <        0x43 ('C')
+**     >=        0x44 ('D')
+**      >        0x45 ('E')
+**   MATCH       0x46 ('F')
+**   ----------------------
+**
+** The second of each pair of bytes identifies the coordinate column
+** to which the constraint applies. The leftmost coordinate column
+** is 'a', the second from the left 'b' etc.
+*/
+static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  Rtree *pRtree = (Rtree*)tab;
+  int rc = SQLITE_OK;
+  int ii;
+  int bMatch = 0;                 /* True if there exists a MATCH constraint */
+  i64 nRow;                       /* Estimated rows returned by this scan */
 
-  /* Register all built-in functions, but do not attempt to read the
-  ** database schema yet. This is delayed until the first time the database
-  ** is accessed.
-  */
-  sqlite3Error(db, SQLITE_OK);
-  sqlite3RegisterBuiltinFunctions(db);
+  int iIdx = 0;
+  char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
+  memset(zIdxStr, 0, sizeof(zIdxStr));
 
-  /* Load automatic extensions - extensions that have been registered
-  ** using the sqlite3_automatic_extension() API.
-  */
-  rc = sqlite3_errcode(db);
-  if( rc==SQLITE_OK ){
-    sqlite3AutoLoadExtensions(db);
-    rc = sqlite3_errcode(db);
-    if( rc!=SQLITE_OK ){
-      goto opendb_out;
+  /* Check if there exists a MATCH constraint - even an unusable one. If there
+  ** is, do not consider the lookup-by-rowid plan as using such a plan would
+  ** require the VDBE to evaluate the MATCH constraint, which is not currently
+  ** possible. */
+  for(ii=0; iinConstraint; ii++){
+    if( pIdxInfo->aConstraint[ii].op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+      bMatch = 1;
     }
   }
 
-#ifdef SQLITE_ENABLE_FTS1
-  if( !db->mallocFailed ){
-    extern int sqlite3Fts1Init(sqlite3*);
-    rc = sqlite3Fts1Init(db);
-  }
-#endif
+  assert( pIdxInfo->idxStr==0 );
+  for(ii=0; iinConstraint && iIdx<(int)(sizeof(zIdxStr)-1); ii++){
+    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];
 
-#ifdef SQLITE_ENABLE_FTS2
-  if( !db->mallocFailed && rc==SQLITE_OK ){
-    extern int sqlite3Fts2Init(sqlite3*);
-    rc = sqlite3Fts2Init(db);
-  }
-#endif
+    if( bMatch==0 && p->usable 
+     && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
+      /* We have an equality constraint on the rowid. Use strategy 1. */
+      int jj;
+      for(jj=0; jjaConstraintUsage[jj].argvIndex = 0;
+        pIdxInfo->aConstraintUsage[jj].omit = 0;
+      }
+      pIdxInfo->idxNum = 1;
+      pIdxInfo->aConstraintUsage[ii].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[jj].omit = 1;
 
-#ifdef SQLITE_ENABLE_FTS3
-  if( !db->mallocFailed && rc==SQLITE_OK ){
-    rc = sqlite3Fts3Init(db);
-  }
-#endif
+      /* This strategy involves a two rowid lookups on an B-Tree structures
+      ** and then a linear search of an R-Tree node. This should be 
+      ** considered almost as quick as a direct rowid lookup (for which 
+      ** sqlite uses an internal cost of 0.0). It is expected to return
+      ** a single row.
+      */ 
+      pIdxInfo->estimatedCost = 30.0;
+      pIdxInfo->estimatedRows = 1;
+      return SQLITE_OK;
+    }
 
-#ifdef SQLITE_ENABLE_ICU
-  if( !db->mallocFailed && rc==SQLITE_OK ){
-    rc = sqlite3IcuInit(db);
+    if( p->usable && (p->iColumn>0 || p->op==SQLITE_INDEX_CONSTRAINT_MATCH) ){
+      u8 op;
+      switch( p->op ){
+        case SQLITE_INDEX_CONSTRAINT_EQ: op = RTREE_EQ; break;
+        case SQLITE_INDEX_CONSTRAINT_GT: op = RTREE_GT; break;
+        case SQLITE_INDEX_CONSTRAINT_LE: op = RTREE_LE; break;
+        case SQLITE_INDEX_CONSTRAINT_LT: op = RTREE_LT; break;
+        case SQLITE_INDEX_CONSTRAINT_GE: op = RTREE_GE; break;
+        default:
+          assert( p->op==SQLITE_INDEX_CONSTRAINT_MATCH );
+          op = RTREE_MATCH; 
+          break;
+      }
+      zIdxStr[iIdx++] = op;
+      zIdxStr[iIdx++] = (char)(p->iColumn - 1 + '0');
+      pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);
+      pIdxInfo->aConstraintUsage[ii].omit = 1;
+    }
   }
-#endif
 
-#ifdef SQLITE_ENABLE_RTREE
-  if( !db->mallocFailed && rc==SQLITE_OK){
-    rc = sqlite3RtreeInit(db);
+  pIdxInfo->idxNum = 2;
+  pIdxInfo->needToFreeIdxStr = 1;
+  if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){
+    return SQLITE_NOMEM;
   }
-#endif
-
-  /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
-  ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
-  ** mode.  Doing nothing at all also makes NORMAL the default.
-  */
-#ifdef SQLITE_DEFAULT_LOCKING_MODE
-  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
-  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
-                          SQLITE_DEFAULT_LOCKING_MODE);
-#endif
-
-  if( rc ) sqlite3Error(db, rc);
 
-  /* Enable the lookaside-malloc subsystem */
-  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
-                        sqlite3GlobalConfig.nLookaside);
+  nRow = pRtree->nRowEst >> (iIdx/2);
+  pIdxInfo->estimatedCost = (double)6.0 * (double)nRow;
+  pIdxInfo->estimatedRows = nRow;
 
-  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
+  return rc;
+}
 
-opendb_out:
-  sqlite3_free(zOpen);
-  if( db ){
-    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3GlobalConfig.bFullMutex==0 );
-    sqlite3_mutex_leave(db->mutex);
-  }
-  rc = sqlite3_errcode(db);
-  assert( db!=0 || rc==SQLITE_NOMEM );
-  if( rc==SQLITE_NOMEM ){
-    sqlite3_close(db);
-    db = 0;
-  }else if( rc!=SQLITE_OK ){
-    db->magic = SQLITE_MAGIC_SICK;
-  }
-  *ppDb = db;
-#ifdef SQLITE_ENABLE_SQLLOG
-  if( sqlite3GlobalConfig.xSqllog ){
-    /* Opening a db handle. Fourth parameter is passed 0. */
-    void *pArg = sqlite3GlobalConfig.pSqllogArg;
-    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
-  }
+/*
+** Return the N-dimensional volumn of the cell stored in *p.
+*/
+static RtreeDValue cellArea(Rtree *pRtree, RtreeCell *p){
+  RtreeDValue area = (RtreeDValue)1;
+  assert( pRtree->nDim>=1 && pRtree->nDim<=5 );
+#ifndef SQLITE_RTREE_INT_ONLY
+  if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
+    switch( pRtree->nDim ){
+      case 5:  area  = p->aCoord[9].f - p->aCoord[8].f;
+      case 4:  area *= p->aCoord[7].f - p->aCoord[6].f;
+      case 3:  area *= p->aCoord[5].f - p->aCoord[4].f;
+      case 2:  area *= p->aCoord[3].f - p->aCoord[2].f;
+      default: area *= p->aCoord[1].f - p->aCoord[0].f;
+    }
+  }else
 #endif
-  return sqlite3ApiExit(0, rc);
+  {
+    switch( pRtree->nDim ){
+      case 5:  area  = p->aCoord[9].i - p->aCoord[8].i;
+      case 4:  area *= p->aCoord[7].i - p->aCoord[6].i;
+      case 3:  area *= p->aCoord[5].i - p->aCoord[4].i;
+      case 2:  area *= p->aCoord[3].i - p->aCoord[2].i;
+      default: area *= p->aCoord[1].i - p->aCoord[0].i;
+    }
+  }
+  return area;
 }
 
 /*
-** Open a new database handle.
+** Return the margin length of cell p. The margin length is the sum
+** of the objects size in each dimension.
 */
-SQLITE_API int sqlite3_open(
-  const char *zFilename, 
-  sqlite3 **ppDb 
-){
-  return openDatabase(zFilename, ppDb,
-                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
-}
-SQLITE_API int sqlite3_open_v2(
-  const char *filename,   /* Database filename (UTF-8) */
-  sqlite3 **ppDb,         /* OUT: SQLite db handle */
-  int flags,              /* Flags */
-  const char *zVfs        /* Name of VFS module to use */
-){
-  return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
+static RtreeDValue cellMargin(Rtree *pRtree, RtreeCell *p){
+  RtreeDValue margin = 0;
+  int ii = pRtree->nDim2 - 2;
+  do{
+    margin += (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));
+    ii -= 2;
+  }while( ii>=0 );
+  return margin;
 }
 
-#ifndef SQLITE_OMIT_UTF16
 /*
-** Open a new database handle.
+** Store the union of cells p1 and p2 in p1.
 */
-SQLITE_API int sqlite3_open16(
-  const void *zFilename, 
-  sqlite3 **ppDb
-){
-  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
-  sqlite3_value *pVal;
-  int rc;
-
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
-#endif
-  *ppDb = 0;
-#ifndef SQLITE_OMIT_AUTOINIT
-  rc = sqlite3_initialize();
-  if( rc ) return rc;
-#endif
-  if( zFilename==0 ) zFilename = "\000\000";
-  pVal = sqlite3ValueNew(0);
-  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
-  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
-  if( zFilename8 ){
-    rc = openDatabase(zFilename8, ppDb,
-                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
-    assert( *ppDb || rc==SQLITE_NOMEM );
-    if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
-      SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
-    }
+static void cellUnion(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){
+  int ii = 0;
+  if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
+    do{
+      p1->aCoord[ii].f = MIN(p1->aCoord[ii].f, p2->aCoord[ii].f);
+      p1->aCoord[ii+1].f = MAX(p1->aCoord[ii+1].f, p2->aCoord[ii+1].f);
+      ii += 2;
+    }while( iinDim2 );
   }else{
-    rc = SQLITE_NOMEM;
+    do{
+      p1->aCoord[ii].i = MIN(p1->aCoord[ii].i, p2->aCoord[ii].i);
+      p1->aCoord[ii+1].i = MAX(p1->aCoord[ii+1].i, p2->aCoord[ii+1].i);
+      ii += 2;
+    }while( iinDim2 );
   }
-  sqlite3ValueFree(pVal);
-
-  return sqlite3ApiExit(0, rc);
 }
-#endif /* SQLITE_OMIT_UTF16 */
 
 /*
-** Register a new collation sequence with the database handle db.
+** Return true if the area covered by p2 is a subset of the area covered
+** by p1. False otherwise.
 */
-SQLITE_API int sqlite3_create_collation(
-  sqlite3* db, 
-  const char *zName, 
-  int enc, 
-  void* pCtx,
-  int(*xCompare)(void*,int,const void*,int,const void*)
-){
-  return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
+static int cellContains(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){
+  int ii;
+  int isInt = (pRtree->eCoordType==RTREE_COORD_INT32);
+  for(ii=0; iinDim2; ii+=2){
+    RtreeCoord *a1 = &p1->aCoord[ii];
+    RtreeCoord *a2 = &p2->aCoord[ii];
+    if( (!isInt && (a2[0].fa1[1].f)) 
+     || ( isInt && (a2[0].ia1[1].i)) 
+    ){
+      return 0;
+    }
+  }
+  return 1;
 }
 
 /*
-** Register a new collation sequence with the database handle db.
+** Return the amount cell p would grow by if it were unioned with pCell.
 */
-SQLITE_API int sqlite3_create_collation_v2(
-  sqlite3* db, 
-  const char *zName, 
-  int enc, 
-  void* pCtx,
-  int(*xCompare)(void*,int,const void*,int,const void*),
-  void(*xDel)(void*)
-){
-  int rc;
+static RtreeDValue cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
+  RtreeDValue area;
+  RtreeCell cell;
+  memcpy(&cell, p, sizeof(RtreeCell));
+  area = cellArea(pRtree, &cell);
+  cellUnion(pRtree, &cell, pCell);
+  return (cellArea(pRtree, &cell)-area);
+}
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  assert( !db->mallocFailed );
-  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
+static RtreeDValue cellOverlap(
+  Rtree *pRtree, 
+  RtreeCell *p, 
+  RtreeCell *aCell, 
+  int nCell
+){
+  int ii;
+  RtreeDValue overlap = RTREE_ZERO;
+  for(ii=0; iinDim2; jj+=2){
+      RtreeDValue x1, x2;
+      x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
+      x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
+      if( x2mutex);
-  assert( !db->mallocFailed );
-  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
-  if( zName8 ){
-    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
-    sqlite3DbFree(db, zName8);
+  for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){
+    int iCell;
+    sqlite3_int64 iBest = 0;
+
+    RtreeDValue fMinGrowth = RTREE_ZERO;
+    RtreeDValue fMinArea = RTREE_ZERO;
+
+    int nCell = NCELL(pNode);
+    RtreeCell cell;
+    RtreeNode *pChild;
+
+    RtreeCell *aCell = 0;
+
+    /* Select the child node which will be enlarged the least if pCell
+    ** is inserted into it. Resolve ties by choosing the entry with
+    ** the smallest area.
+    */
+    for(iCell=0; iCellmutex);
+
+  *ppLeaf = pNode;
   return rc;
 }
-#endif /* SQLITE_OMIT_UTF16 */
 
 /*
-** Register a collation sequence factory callback with the database handle
-** db. Replace any previously installed collation sequence factory.
+** A cell with the same content as pCell has just been inserted into
+** the node pNode. This function updates the bounding box cells in
+** all ancestor elements.
 */
-SQLITE_API int sqlite3_collation_needed(
-  sqlite3 *db, 
-  void *pCollNeededArg, 
-  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
+static int AdjustTree(
+  Rtree *pRtree,                    /* Rtree table */
+  RtreeNode *pNode,                 /* Adjust ancestry of this node. */
+  RtreeCell *pCell                  /* This cell was just inserted */
 ){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  db->xCollNeeded = xCollNeeded;
-  db->xCollNeeded16 = 0;
-  db->pCollNeededArg = pCollNeededArg;
-  sqlite3_mutex_leave(db->mutex);
+  RtreeNode *p = pNode;
+  while( p->pParent ){
+    RtreeNode *pParent = p->pParent;
+    RtreeCell cell;
+    int iCell;
+
+    if( nodeParentIndex(pRtree, p, &iCell) ){
+      return SQLITE_CORRUPT_VTAB;
+    }
+
+    nodeGetCell(pRtree, pParent, iCell, &cell);
+    if( !cellContains(pRtree, &cell, pCell) ){
+      cellUnion(pRtree, &cell, pCell);
+      nodeOverwriteCell(pRtree, pParent, &cell, iCell);
+    }
+ 
+    p = pParent;
+  }
   return SQLITE_OK;
 }
 
-#ifndef SQLITE_OMIT_UTF16
 /*
-** Register a collation sequence factory callback with the database handle
-** db. Replace any previously installed collation sequence factory.
+** Write mapping (iRowid->iNode) to the _rowid table.
 */
-SQLITE_API int sqlite3_collation_needed16(
-  sqlite3 *db, 
-  void *pCollNeededArg, 
-  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
-){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  db->xCollNeeded = 0;
-  db->xCollNeeded16 = xCollNeeded16;
-  db->pCollNeededArg = pCollNeededArg;
-  sqlite3_mutex_leave(db->mutex);
-  return SQLITE_OK;
+static int rowidWrite(Rtree *pRtree, sqlite3_int64 iRowid, sqlite3_int64 iNode){
+  sqlite3_bind_int64(pRtree->pWriteRowid, 1, iRowid);
+  sqlite3_bind_int64(pRtree->pWriteRowid, 2, iNode);
+  sqlite3_step(pRtree->pWriteRowid);
+  return sqlite3_reset(pRtree->pWriteRowid);
 }
-#endif /* SQLITE_OMIT_UTF16 */
 
-#ifndef SQLITE_OMIT_DEPRECATED
 /*
-** This function is now an anachronism. It used to be used to recover from a
-** malloc() failure, but SQLite now does this automatically.
+** Write mapping (iNode->iPar) to the _parent table.
 */
-SQLITE_API int sqlite3_global_recover(void){
-  return SQLITE_OK;
+static int parentWrite(Rtree *pRtree, sqlite3_int64 iNode, sqlite3_int64 iPar){
+  sqlite3_bind_int64(pRtree->pWriteParent, 1, iNode);
+  sqlite3_bind_int64(pRtree->pWriteParent, 2, iPar);
+  sqlite3_step(pRtree->pWriteParent);
+  return sqlite3_reset(pRtree->pWriteParent);
 }
-#endif
+
+static int rtreeInsertCell(Rtree *, RtreeNode *, RtreeCell *, int);
+
 
 /*
-** Test to see whether or not the database connection is in autocommit
-** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
-** by default.  Autocommit is disabled by a BEGIN statement and reenabled
-** by the next COMMIT or ROLLBACK.
+** Arguments aIdx, aDistance and aSpare all point to arrays of size
+** nIdx. The aIdx array contains the set of integers from 0 to 
+** (nIdx-1) in no particular order. This function sorts the values
+** in aIdx according to the indexed values in aDistance. For
+** example, assuming the inputs:
+**
+**   aIdx      = { 0,   1,   2,   3 }
+**   aDistance = { 5.0, 2.0, 7.0, 6.0 }
+**
+** this function sets the aIdx array to contain:
+**
+**   aIdx      = { 0,   1,   2,   3 }
+**
+** The aSpare array is used as temporary working space by the
+** sorting algorithm.
 */
-SQLITE_API int sqlite3_get_autocommit(sqlite3 *db){
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
-  }
+static void SortByDistance(
+  int *aIdx, 
+  int nIdx, 
+  RtreeDValue *aDistance, 
+  int *aSpare
+){
+  if( nIdx>1 ){
+    int iLeft = 0;
+    int iRight = 0;
+
+    int nLeft = nIdx/2;
+    int nRight = nIdx-nLeft;
+    int *aLeft = aIdx;
+    int *aRight = &aIdx[nLeft];
+
+    SortByDistance(aLeft, nLeft, aDistance, aSpare);
+    SortByDistance(aRight, nRight, aDistance, aSpare);
+
+    memcpy(aSpare, aLeft, sizeof(int)*nLeft);
+    aLeft = aSpare;
+
+    while( iLeftautoCommit;
+  }
 }
 
 /*
-** The following routines are substitutes for constants SQLITE_CORRUPT,
-** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
-** constants.  They serve two purposes:
-**
-**   1.  Serve as a convenient place to set a breakpoint in a debugger
-**       to detect when version error conditions occurs.
+** Arguments aIdx, aCell and aSpare all point to arrays of size
+** nIdx. The aIdx array contains the set of integers from 0 to 
+** (nIdx-1) in no particular order. This function sorts the values
+** in aIdx according to dimension iDim of the cells in aCell. The
+** minimum value of dimension iDim is considered first, the
+** maximum used to break ties.
 **
-**   2.  Invoke sqlite3_log() to provide the source code location where
-**       a low-level error is first detected.
+** The aSpare array is used as temporary working space by the
+** sorting algorithm.
 */
-SQLITE_PRIVATE int sqlite3CorruptError(int lineno){
-  testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_CORRUPT,
-              "database corruption at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_CORRUPT;
-}
-SQLITE_PRIVATE int sqlite3MisuseError(int lineno){
-  testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_MISUSE, 
-              "misuse at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_MISUSE;
-}
-SQLITE_PRIVATE int sqlite3CantopenError(int lineno){
-  testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_CANTOPEN, 
-              "cannot open file at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_CANTOPEN;
-}
+static void SortByDimension(
+  Rtree *pRtree,
+  int *aIdx, 
+  int nIdx, 
+  int iDim, 
+  RtreeCell *aCell, 
+  int *aSpare
+){
+  if( nIdx>1 ){
 
+    int iLeft = 0;
+    int iRight = 0;
 
-#ifndef SQLITE_OMIT_DEPRECATED
-/*
-** This is a convenience routine that makes sure that all thread-specific
-** data for this thread has been deallocated.
-**
-** SQLite no longer uses thread-specific data so this routine is now a
-** no-op.  It is retained for historical compatibility.
-*/
-SQLITE_API void sqlite3_thread_cleanup(void){
-}
+    int nLeft = nIdx/2;
+    int nRight = nIdx-nLeft;
+    int *aLeft = aIdx;
+    int *aRight = &aIdx[nLeft];
+
+    SortByDimension(pRtree, aLeft, nLeft, iDim, aCell, aSpare);
+    SortByDimension(pRtree, aRight, nRight, iDim, aCell, aSpare);
+
+    memcpy(aSpare, aLeft, sizeof(int)*nLeft);
+    aLeft = aSpare;
+    while( iLeftmutex);
-  sqlite3BtreeEnterAll(db);
-  rc = sqlite3Init(db, &zErrMsg);
-  if( SQLITE_OK!=rc ){
-    goto error_out;
-  }
+  int nByte = (pRtree->nDim+1)*(sizeof(int*)+nCell*sizeof(int));
 
-  /* Locate the table in question */
-  pTab = sqlite3FindTable(db, zTableName, zDbName);
-  if( !pTab || pTab->pSelect ){
-    pTab = 0;
-    goto error_out;
+  aaSorted = (int **)sqlite3_malloc(nByte);
+  if( !aaSorted ){
+    return SQLITE_NOMEM;
   }
 
-  /* Find the column for which info is requested */
-  if( zColumnName==0 ){
-    /* Query for existance of table only */
-  }else{
-    for(iCol=0; iColnCol; iCol++){
-      pCol = &pTab->aCol[iCol];
-      if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
-        break;
-      }
-    }
-    if( iCol==pTab->nCol ){
-      if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
-        iCol = pTab->iPKey;
-        pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
-      }else{
-        pTab = 0;
-        goto error_out;
-      }
+  aSpare = &((int *)&aaSorted[pRtree->nDim])[pRtree->nDim*nCell];
+  memset(aaSorted, 0, nByte);
+  for(ii=0; iinDim; ii++){
+    int jj;
+    aaSorted[ii] = &((int *)&aaSorted[pRtree->nDim])[ii*nCell];
+    for(jj=0; jjzType;
-    zCollSeq = pCol->zColl;
-    notnull = pCol->notNull!=0;
-    primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
-    autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
-  }else{
-    zDataType = "INTEGER";
-    primarykey = 1;
-  }
-  if( !zCollSeq ){
-    zCollSeq = "BINARY";
-  }
+  for(ii=0; iinDim; ii++){
+    RtreeDValue margin = RTREE_ZERO;
+    RtreeDValue fBestOverlap = RTREE_ZERO;
+    RtreeDValue fBestArea = RTREE_ZERO;
+    int iBestLeft = 0;
+    int nLeft;
 
-error_out:
-  sqlite3BtreeLeaveAll(db);
+    for(
+      nLeft=RTREE_MINCELLS(pRtree); 
+      nLeft<=(nCell-RTREE_MINCELLS(pRtree)); 
+      nLeft++
+    ){
+      RtreeCell left;
+      RtreeCell right;
+      int kk;
+      RtreeDValue overlap;
+      RtreeDValue area;
 
-  /* Whether the function call succeeded or failed, set the output parameters
-  ** to whatever their local counterparts contain. If an error did occur,
-  ** this has the effect of zeroing all output parameters.
-  */
-  if( pzDataType ) *pzDataType = zDataType;
-  if( pzCollSeq ) *pzCollSeq = zCollSeq;
-  if( pNotNull ) *pNotNull = notnull;
-  if( pPrimaryKey ) *pPrimaryKey = primarykey;
-  if( pAutoinc ) *pAutoinc = autoinc;
+      memcpy(&left, &aCell[aaSorted[ii][0]], sizeof(RtreeCell));
+      memcpy(&right, &aCell[aaSorted[ii][nCell-1]], sizeof(RtreeCell));
+      for(kk=1; kk<(nCell-1); kk++){
+        if( kkmutex);
-  return rc;
-}
-
-/*
-** Sleep for a little while.  Return the amount of time slept.
-*/
-SQLITE_API int sqlite3_sleep(int ms){
-  sqlite3_vfs *pVfs;
-  int rc;
-  pVfs = sqlite3_vfs_find(0);
-  if( pVfs==0 ) return 0;
 
-  /* This function works in milliseconds, but the underlying OsSleep() 
-  ** API uses microseconds. Hence the 1000's.
-  */
-  rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
-  return rc;
-}
+  memcpy(pBboxLeft, &aCell[aaSorted[iBestDim][0]], sizeof(RtreeCell));
+  memcpy(pBboxRight, &aCell[aaSorted[iBestDim][iBestSplit]], sizeof(RtreeCell));
+  for(ii=0; iimutex);
-  db->errMask = onoff ? 0xffffffff : 0xff;
-  sqlite3_mutex_leave(db->mutex);
+  sqlite3_free(aaSorted);
   return SQLITE_OK;
 }
 
-/*
-** Invoke the xFileControl method on a particular database.
-*/
-SQLITE_API int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
-  int rc = SQLITE_ERROR;
-  Btree *pBtree;
 
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
-#endif
-  sqlite3_mutex_enter(db->mutex);
-  pBtree = sqlite3DbNameToBtree(db, zDbName);
-  if( pBtree ){
-    Pager *pPager;
-    sqlite3_file *fd;
-    sqlite3BtreeEnter(pBtree);
-    pPager = sqlite3BtreePager(pBtree);
-    assert( pPager!=0 );
-    fd = sqlite3PagerFile(pPager);
-    assert( fd!=0 );
-    if( op==SQLITE_FCNTL_FILE_POINTER ){
-      *(sqlite3_file**)pArg = fd;
-      rc = SQLITE_OK;
-    }else if( fd->pMethods ){
-      rc = sqlite3OsFileControl(fd, op, pArg);
-    }else{
-      rc = SQLITE_NOTFOUND;
+static int updateMapping(
+  Rtree *pRtree, 
+  i64 iRowid, 
+  RtreeNode *pNode, 
+  int iHeight
+){
+  int (*xSetMapping)(Rtree *, sqlite3_int64, sqlite3_int64);
+  xSetMapping = ((iHeight==0)?rowidWrite:parentWrite);
+  if( iHeight>0 ){
+    RtreeNode *pChild = nodeHashLookup(pRtree, iRowid);
+    if( pChild ){
+      nodeRelease(pRtree, pChild->pParent);
+      nodeReference(pNode);
+      pChild->pParent = pNode;
     }
-    sqlite3BtreeLeave(pBtree);
   }
-  sqlite3_mutex_leave(db->mutex);
-  return rc;   
+  return xSetMapping(pRtree, iRowid, pNode->iNode);
 }
 
-/*
-** Interface to the testing logic.
-*/
-SQLITE_API int sqlite3_test_control(int op, ...){
-  int rc = 0;
-#ifndef SQLITE_OMIT_BUILTIN_TEST
-  va_list ap;
-  va_start(ap, op);
-  switch( op ){
-
-    /*
-    ** Save the current state of the PRNG.
-    */
-    case SQLITE_TESTCTRL_PRNG_SAVE: {
-      sqlite3PrngSaveState();
-      break;
-    }
-
-    /*
-    ** Restore the state of the PRNG to the last state saved using
-    ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
-    ** this verb acts like PRNG_RESET.
-    */
-    case SQLITE_TESTCTRL_PRNG_RESTORE: {
-      sqlite3PrngRestoreState();
-      break;
-    }
-
-    /*
-    ** Reset the PRNG back to its uninitialized state.  The next call
-    ** to sqlite3_randomness() will reseed the PRNG using a single call
-    ** to the xRandomness method of the default VFS.
-    */
-    case SQLITE_TESTCTRL_PRNG_RESET: {
-      sqlite3_randomness(0,0);
-      break;
-    }
+static int SplitNode(
+  Rtree *pRtree,
+  RtreeNode *pNode,
+  RtreeCell *pCell,
+  int iHeight
+){
+  int i;
+  int newCellIsRight = 0;
 
-    /*
-    **  sqlite3_test_control(BITVEC_TEST, size, program)
-    **
-    ** Run a test against a Bitvec object of size.  The program argument
-    ** is an array of integers that defines the test.  Return -1 on a
-    ** memory allocation error, 0 on success, or non-zero for an error.
-    ** See the sqlite3BitvecBuiltinTest() for additional information.
-    */
-    case SQLITE_TESTCTRL_BITVEC_TEST: {
-      int sz = va_arg(ap, int);
-      int *aProg = va_arg(ap, int*);
-      rc = sqlite3BitvecBuiltinTest(sz, aProg);
-      break;
-    }
+  int rc = SQLITE_OK;
+  int nCell = NCELL(pNode);
+  RtreeCell *aCell;
+  int *aiUsed;
 
-    /*
-    **  sqlite3_test_control(FAULT_INSTALL, xCallback)
-    **
-    ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
-    ** if xCallback is not NULL.
-    **
-    ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
-    ** is called immediately after installing the new callback and the return
-    ** value from sqlite3FaultSim(0) becomes the return from
-    ** sqlite3_test_control().
-    */
-    case SQLITE_TESTCTRL_FAULT_INSTALL: {
-      /* MSVC is picky about pulling func ptrs from va lists.
-      ** http://support.microsoft.com/kb/47961
-      ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
-      */
-      typedef int(*TESTCALLBACKFUNC_t)(int);
-      sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
-      rc = sqlite3FaultSim(0);
-      break;
-    }
+  RtreeNode *pLeft = 0;
+  RtreeNode *pRight = 0;
 
-    /*
-    **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
-    **
-    ** Register hooks to call to indicate which malloc() failures 
-    ** are benign.
-    */
-    case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
-      typedef void (*void_function)(void);
-      void_function xBenignBegin;
-      void_function xBenignEnd;
-      xBenignBegin = va_arg(ap, void_function);
-      xBenignEnd = va_arg(ap, void_function);
-      sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
-      break;
-    }
+  RtreeCell leftbbox;
+  RtreeCell rightbbox;
 
-    /*
-    **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
-    **
-    ** Set the PENDING byte to the value in the argument, if X>0.
-    ** Make no changes if X==0.  Return the value of the pending byte
-    ** as it existing before this routine was called.
-    **
-    ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
-    ** an incompatible database file format.  Changing the PENDING byte
-    ** while any database connection is open results in undefined and
-    ** deleterious behavior.
-    */
-    case SQLITE_TESTCTRL_PENDING_BYTE: {
-      rc = PENDING_BYTE;
-#ifndef SQLITE_OMIT_WSD
-      {
-        unsigned int newVal = va_arg(ap, unsigned int);
-        if( newVal ) sqlite3PendingByte = newVal;
-      }
-#endif
-      break;
-    }
+  /* Allocate an array and populate it with a copy of pCell and 
+  ** all cells from node pLeft. Then zero the original node.
+  */
+  aCell = sqlite3_malloc((sizeof(RtreeCell)+sizeof(int))*(nCell+1));
+  if( !aCell ){
+    rc = SQLITE_NOMEM;
+    goto splitnode_out;
+  }
+  aiUsed = (int *)&aCell[nCell+1];
+  memset(aiUsed, 0, sizeof(int)*(nCell+1));
+  for(i=0; iiNode==1 ){
+    pRight = nodeNew(pRtree, pNode);
+    pLeft = nodeNew(pRtree, pNode);
+    pRtree->iDepth++;
+    pNode->isDirty = 1;
+    writeInt16(pNode->zData, pRtree->iDepth);
+  }else{
+    pLeft = pNode;
+    pRight = nodeNew(pRtree, pLeft->pParent);
+    nodeReference(pLeft);
+  }
 
+  if( !pLeft || !pRight ){
+    rc = SQLITE_NOMEM;
+    goto splitnode_out;
+  }
 
-    /*
-    **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
-    **
-    ** This action provides a run-time test to see how the ALWAYS and
-    ** NEVER macros were defined at compile-time.
-    **
-    ** The return value is ALWAYS(X).  
-    **
-    ** The recommended test is X==2.  If the return value is 2, that means
-    ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
-    ** default setting.  If the return value is 1, then ALWAYS() is either
-    ** hard-coded to true or else it asserts if its argument is false.
-    ** The first behavior (hard-coded to true) is the case if
-    ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
-    ** behavior (assert if the argument to ALWAYS() is false) is the case if
-    ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
-    **
-    ** The run-time test procedure might look something like this:
-    **
-    **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
-    **      // ALWAYS() and NEVER() are no-op pass-through macros
-    **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
-    **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
-    **    }else{
-    **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
-    **    }
-    */
-    case SQLITE_TESTCTRL_ALWAYS: {
-      int x = va_arg(ap,int);
-      rc = ALWAYS(x);
-      break;
-    }
+  memset(pLeft->zData, 0, pRtree->iNodeSize);
+  memset(pRight->zData, 0, pRtree->iNodeSize);
 
-    /*
-    **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
-    **
-    ** The integer returned reveals the byte-order of the computer on which
-    ** SQLite is running:
-    **
-    **       1     big-endian,    determined at run-time
-    **      10     little-endian, determined at run-time
-    **  432101     big-endian,    determined at compile-time
-    **  123410     little-endian, determined at compile-time
-    */ 
-    case SQLITE_TESTCTRL_BYTEORDER: {
-      rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
-      break;
-    }
+  rc = splitNodeStartree(pRtree, aCell, nCell, pLeft, pRight,
+                         &leftbbox, &rightbbox);
+  if( rc!=SQLITE_OK ){
+    goto splitnode_out;
+  }
 
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
-    **
-    ** Set the nReserve size to N for the main database on the database
-    ** connection db.
-    */
-    case SQLITE_TESTCTRL_RESERVE: {
-      sqlite3 *db = va_arg(ap, sqlite3*);
-      int x = va_arg(ap,int);
-      sqlite3_mutex_enter(db->mutex);
-      sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
-      sqlite3_mutex_leave(db->mutex);
-      break;
-    }
+  /* Ensure both child nodes have node numbers assigned to them by calling
+  ** nodeWrite(). Node pRight always needs a node number, as it was created
+  ** by nodeNew() above. But node pLeft sometimes already has a node number.
+  ** In this case avoid the all to nodeWrite().
+  */
+  if( SQLITE_OK!=(rc = nodeWrite(pRtree, pRight))
+   || (0==pLeft->iNode && SQLITE_OK!=(rc = nodeWrite(pRtree, pLeft)))
+  ){
+    goto splitnode_out;
+  }
 
-    /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
-    **
-    ** Enable or disable various optimizations for testing purposes.  The 
-    ** argument N is a bitmask of optimizations to be disabled.  For normal
-    ** operation N should be 0.  The idea is that a test program (like the
-    ** SQL Logic Test or SLT test module) can run the same SQL multiple times
-    ** with various optimizations disabled to verify that the same answer
-    ** is obtained in every case.
-    */
-    case SQLITE_TESTCTRL_OPTIMIZATIONS: {
-      sqlite3 *db = va_arg(ap, sqlite3*);
-      db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
-      break;
-    }
+  rightbbox.iRowid = pRight->iNode;
+  leftbbox.iRowid = pLeft->iNode;
 
-#ifdef SQLITE_N_KEYWORD
-    /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
-    **
-    ** If zWord is a keyword recognized by the parser, then return the
-    ** number of keywords.  Or if zWord is not a keyword, return 0.
-    ** 
-    ** This test feature is only available in the amalgamation since
-    ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
-    ** is built using separate source files.
-    */
-    case SQLITE_TESTCTRL_ISKEYWORD: {
-      const char *zWord = va_arg(ap, const char*);
-      int n = sqlite3Strlen30(zWord);
-      rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
-      break;
+  if( pNode->iNode==1 ){
+    rc = rtreeInsertCell(pRtree, pLeft->pParent, &leftbbox, iHeight+1);
+    if( rc!=SQLITE_OK ){
+      goto splitnode_out;
     }
-#endif 
-
-    /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
-    **
-    ** Pass pFree into sqlite3ScratchFree(). 
-    ** If sz>0 then allocate a scratch buffer into pNew.  
-    */
-    case SQLITE_TESTCTRL_SCRATCHMALLOC: {
-      void *pFree, **ppNew;
-      int sz;
-      sz = va_arg(ap, int);
-      ppNew = va_arg(ap, void**);
-      pFree = va_arg(ap, void*);
-      if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
-      sqlite3ScratchFree(pFree);
-      break;
+  }else{
+    RtreeNode *pParent = pLeft->pParent;
+    int iCell;
+    rc = nodeParentIndex(pRtree, pLeft, &iCell);
+    if( rc==SQLITE_OK ){
+      nodeOverwriteCell(pRtree, pParent, &leftbbox, iCell);
+      rc = AdjustTree(pRtree, pParent, &leftbbox);
     }
-
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
-    **
-    ** If parameter onoff is non-zero, configure the wrappers so that all
-    ** subsequent calls to localtime() and variants fail. If onoff is zero,
-    ** undo this setting.
-    */
-    case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
-      sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
-      break;
+    if( rc!=SQLITE_OK ){
+      goto splitnode_out;
     }
+  }
+  if( (rc = rtreeInsertCell(pRtree, pRight->pParent, &rightbbox, iHeight+1)) ){
+    goto splitnode_out;
+  }
 
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
-    **
-    ** Set or clear a flag that indicates that the database file is always well-
-    ** formed and never corrupt.  This flag is clear by default, indicating that
-    ** database files might have arbitrary corruption.  Setting the flag during
-    ** testing causes certain assert() statements in the code to be activated
-    ** that demonstrat invariants on well-formed database files.
-    */
-    case SQLITE_TESTCTRL_NEVER_CORRUPT: {
-      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
-      break;
+  for(i=0; iiRowid ){
+      newCellIsRight = 1;
     }
-
-
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
-    **
-    ** Set the VDBE coverage callback function to xCallback with context 
-    ** pointer ptr.
-    */
-    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
-#ifdef SQLITE_VDBE_COVERAGE
-      typedef void (*branch_callback)(void*,int,u8,u8);
-      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
-      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
-#endif
-      break;
+    if( rc!=SQLITE_OK ){
+      goto splitnode_out;
     }
-
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
-    case SQLITE_TESTCTRL_SORTER_MMAP: {
-      sqlite3 *db = va_arg(ap, sqlite3*);
-      db->nMaxSorterMmap = va_arg(ap, int);
-      break;
+  }
+  if( pNode->iNode==1 ){
+    for(i=0; iiRowid, pLeft, iHeight);
+  }
 
-    /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
-    **
-    ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
-    ** not.
-    */
-    case SQLITE_TESTCTRL_ISINIT: {
-      if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
-      break;
-    }
+  if( rc==SQLITE_OK ){
+    rc = nodeRelease(pRtree, pRight);
+    pRight = 0;
   }
-  va_end(ap);
-#endif /* SQLITE_OMIT_BUILTIN_TEST */
+  if( rc==SQLITE_OK ){
+    rc = nodeRelease(pRtree, pLeft);
+    pLeft = 0;
+  }
+
+splitnode_out:
+  nodeRelease(pRtree, pRight);
+  nodeRelease(pRtree, pLeft);
+  sqlite3_free(aCell);
   return rc;
 }
 
 /*
-** This is a utility routine, useful to VFS implementations, that checks
-** to see if a database file was a URI that contained a specific query 
-** parameter, and if so obtains the value of the query parameter.
+** If node pLeaf is not the root of the r-tree and its pParent pointer is 
+** still NULL, load all ancestor nodes of pLeaf into memory and populate
+** the pLeaf->pParent chain all the way up to the root node.
 **
-** The zFilename argument is the filename pointer passed into the xOpen()
-** method of a VFS implementation.  The zParam argument is the name of the
-** query parameter we seek.  This routine returns the value of the zParam
-** parameter if it exists.  If the parameter does not exist, this routine
-** returns a NULL pointer.
+** This operation is required when a row is deleted (or updated - an update
+** is implemented as a delete followed by an insert). SQLite provides the
+** rowid of the row to delete, which can be used to find the leaf on which
+** the entry resides (argument pLeaf). Once the leaf is located, this 
+** function is called to determine its ancestry.
 */
-SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
-  if( zFilename==0 || zParam==0 ) return 0;
-  zFilename += sqlite3Strlen30(zFilename) + 1;
-  while( zFilename[0] ){
-    int x = strcmp(zFilename, zParam);
-    zFilename += sqlite3Strlen30(zFilename) + 1;
-    if( x==0 ) return zFilename;
-    zFilename += sqlite3Strlen30(zFilename) + 1;
+static int fixLeafParent(Rtree *pRtree, RtreeNode *pLeaf){
+  int rc = SQLITE_OK;
+  RtreeNode *pChild = pLeaf;
+  while( rc==SQLITE_OK && pChild->iNode!=1 && pChild->pParent==0 ){
+    int rc2 = SQLITE_OK;          /* sqlite3_reset() return code */
+    sqlite3_bind_int64(pRtree->pReadParent, 1, pChild->iNode);
+    rc = sqlite3_step(pRtree->pReadParent);
+    if( rc==SQLITE_ROW ){
+      RtreeNode *pTest;           /* Used to test for reference loops */
+      i64 iNode;                  /* Node number of parent node */
+
+      /* Before setting pChild->pParent, test that we are not creating a
+      ** loop of references (as we would if, say, pChild==pParent). We don't
+      ** want to do this as it leads to a memory leak when trying to delete
+      ** the referenced counted node structures.
+      */
+      iNode = sqlite3_column_int64(pRtree->pReadParent, 0);
+      for(pTest=pLeaf; pTest && pTest->iNode!=iNode; pTest=pTest->pParent);
+      if( !pTest ){
+        rc2 = nodeAcquire(pRtree, iNode, 0, &pChild->pParent);
+      }
+    }
+    rc = sqlite3_reset(pRtree->pReadParent);
+    if( rc==SQLITE_OK ) rc = rc2;
+    if( rc==SQLITE_OK && !pChild->pParent ) rc = SQLITE_CORRUPT_VTAB;
+    pChild = pChild->pParent;
   }
-  return 0;
+  return rc;
 }
 
-/*
-** Return a boolean value for a query parameter.
-*/
-SQLITE_API int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
-  const char *z = sqlite3_uri_parameter(zFilename, zParam);
-  bDflt = bDflt!=0;
-  return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
-}
+static int deleteCell(Rtree *, RtreeNode *, int, int);
 
-/*
-** Return a 64-bit integer value for a query parameter.
-*/
-SQLITE_API sqlite3_int64 sqlite3_uri_int64(
-  const char *zFilename,    /* Filename as passed to xOpen */
-  const char *zParam,       /* URI parameter sought */
-  sqlite3_int64 bDflt       /* return if parameter is missing */
-){
-  const char *z = sqlite3_uri_parameter(zFilename, zParam);
-  sqlite3_int64 v;
-  if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
-    bDflt = v;
+static int removeNode(Rtree *pRtree, RtreeNode *pNode, int iHeight){
+  int rc;
+  int rc2;
+  RtreeNode *pParent = 0;
+  int iCell;
+
+  assert( pNode->nRef==1 );
+
+  /* Remove the entry in the parent cell. */
+  rc = nodeParentIndex(pRtree, pNode, &iCell);
+  if( rc==SQLITE_OK ){
+    pParent = pNode->pParent;
+    pNode->pParent = 0;
+    rc = deleteCell(pRtree, pParent, iCell, iHeight+1);
+  }
+  rc2 = nodeRelease(pRtree, pParent);
+  if( rc==SQLITE_OK ){
+    rc = rc2;
+  }
+  if( rc!=SQLITE_OK ){
+    return rc;
   }
-  return bDflt;
-}
 
-/*
-** Return the Btree pointer identified by zDbName.  Return NULL if not found.
-*/
-SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
-  int i;
-  for(i=0; inDb; i++){
-    if( db->aDb[i].pBt
-     && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zName)==0)
-    ){
-      return db->aDb[i].pBt;
-    }
+  /* Remove the xxx_node entry. */
+  sqlite3_bind_int64(pRtree->pDeleteNode, 1, pNode->iNode);
+  sqlite3_step(pRtree->pDeleteNode);
+  if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteNode)) ){
+    return rc;
   }
-  return 0;
-}
 
-/*
-** Return the filename of the database associated with a database
-** connection.
-*/
-SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
-  Btree *pBt;
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return 0;
+  /* Remove the xxx_parent entry. */
+  sqlite3_bind_int64(pRtree->pDeleteParent, 1, pNode->iNode);
+  sqlite3_step(pRtree->pDeleteParent);
+  if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteParent)) ){
+    return rc;
   }
-#endif
-  pBt = sqlite3DbNameToBtree(db, zDbName);
-  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
+  
+  /* Remove the node from the in-memory hash table and link it into
+  ** the Rtree.pDeleted list. Its contents will be re-inserted later on.
+  */
+  nodeHashDelete(pRtree, pNode);
+  pNode->iNode = iHeight;
+  pNode->pNext = pRtree->pDeleted;
+  pNode->nRef++;
+  pRtree->pDeleted = pNode;
+
+  return SQLITE_OK;
 }
 
-/*
-** Return 1 if database is read-only or 0 if read/write.  Return -1 if
-** no such database exists.
-*/
-SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
-  Btree *pBt;
-#ifdef SQLITE_ENABLE_API_ARMOR
-  if( !sqlite3SafetyCheckOk(db) ){
-    (void)SQLITE_MISUSE_BKPT;
-    return -1;
+static int fixBoundingBox(Rtree *pRtree, RtreeNode *pNode){
+  RtreeNode *pParent = pNode->pParent;
+  int rc = SQLITE_OK; 
+  if( pParent ){
+    int ii; 
+    int nCell = NCELL(pNode);
+    RtreeCell box;                            /* Bounding box for pNode */
+    nodeGetCell(pRtree, pNode, 0, &box);
+    for(ii=1; iiiNode;
+    rc = nodeParentIndex(pRtree, pNode, &ii);
+    if( rc==SQLITE_OK ){
+      nodeOverwriteCell(pRtree, pParent, &box, ii);
+      rc = fixBoundingBox(pRtree, pParent);
+    }
   }
-#endif
-  pBt = sqlite3DbNameToBtree(db, zDbName);
-  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
+  return rc;
 }
 
-/************** End of main.c ************************************************/
-/************** Begin file notify.c ******************************************/
 /*
-** 2009 March 3
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-**
-** This file contains the implementation of the sqlite3_unlock_notify()
-** API method and its associated functionality.
+** Delete the cell at index iCell of node pNode. After removing the
+** cell, adjust the r-tree data structure if required.
 */
+static int deleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell, int iHeight){
+  RtreeNode *pParent;
+  int rc;
 
-/* Omit this entire file if SQLITE_ENABLE_UNLOCK_NOTIFY is not defined. */
-#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
+  if( SQLITE_OK!=(rc = fixLeafParent(pRtree, pNode)) ){
+    return rc;
+  }
 
-/*
-** Public interfaces:
-**
-**   sqlite3ConnectionBlocked()
-**   sqlite3ConnectionUnlocked()
-**   sqlite3ConnectionClosed()
-**   sqlite3_unlock_notify()
-*/
+  /* Remove the cell from the node. This call just moves bytes around
+  ** the in-memory node image, so it cannot fail.
+  */
+  nodeDeleteCell(pRtree, pNode, iCell);
 
-#define assertMutexHeld() \
-  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) )
+  /* If the node is not the tree root and now has less than the minimum
+  ** number of cells, remove it from the tree. Otherwise, update the
+  ** cell in the parent node so that it tightly contains the updated
+  ** node.
+  */
+  pParent = pNode->pParent;
+  assert( pParent || pNode->iNode==1 );
+  if( pParent ){
+    if( NCELL(pNode)pNextBlocked){
-    int seen = 0;
-    sqlite3 *p2;
+static int Reinsert(
+  Rtree *pRtree, 
+  RtreeNode *pNode, 
+  RtreeCell *pCell, 
+  int iHeight
+){
+  int *aOrder;
+  int *aSpare;
+  RtreeCell *aCell;
+  RtreeDValue *aDistance;
+  int nCell;
+  RtreeDValue aCenterCoord[RTREE_MAX_DIMENSIONS];
+  int iDim;
+  int ii;
+  int rc = SQLITE_OK;
+  int n;
 
-    /* Verify property (1) */
-    assert( p->pUnlockConnection || p->pBlockingConnection );
+  memset(aCenterCoord, 0, sizeof(RtreeDValue)*RTREE_MAX_DIMENSIONS);
+
+  nCell = NCELL(pNode)+1;
+  n = (nCell+1)&(~1);
+
+  /* Allocate the buffers used by this operation. The allocation is
+  ** relinquished before this function returns.
+  */
+  aCell = (RtreeCell *)sqlite3_malloc(n * (
+    sizeof(RtreeCell)     +         /* aCell array */
+    sizeof(int)           +         /* aOrder array */
+    sizeof(int)           +         /* aSpare array */
+    sizeof(RtreeDValue)             /* aDistance array */
+  ));
+  if( !aCell ){
+    return SQLITE_NOMEM;
+  }
+  aOrder    = (int *)&aCell[n];
+  aSpare    = (int *)&aOrder[n];
+  aDistance = (RtreeDValue *)&aSpare[n];
 
-    /* Verify property (2) */
-    for(p2=sqlite3BlockedList; p2!=p; p2=p2->pNextBlocked){
-      if( p2->xUnlockNotify==p->xUnlockNotify ) seen = 1;
-      assert( p2->xUnlockNotify==p->xUnlockNotify || !seen );
-      assert( db==0 || p->pUnlockConnection!=db );
-      assert( db==0 || p->pBlockingConnection!=db );
+  for(ii=0; iinDim; iDim++){
+      aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2]);
+      aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2+1]);
     }
   }
-}
-#else
-# define checkListProperties(x)
-#endif
+  for(iDim=0; iDimnDim; iDim++){
+    aCenterCoord[iDim] = (aCenterCoord[iDim]/(nCell*(RtreeDValue)2));
+  }
 
-/*
-** Remove connection db from the blocked connections list. If connection
-** db is not currently a part of the list, this function is a no-op.
-*/
-static void removeFromBlockedList(sqlite3 *db){
-  sqlite3 **pp;
-  assertMutexHeld();
-  for(pp=&sqlite3BlockedList; *pp; pp = &(*pp)->pNextBlocked){
-    if( *pp==db ){
-      *pp = (*pp)->pNextBlocked;
-      break;
+  for(ii=0; iinDim; iDim++){
+      RtreeDValue coord = (DCOORD(aCell[ii].aCoord[iDim*2+1]) - 
+                               DCOORD(aCell[ii].aCoord[iDim*2]));
+      aDistance[ii] += (coord-aCenterCoord[iDim])*(coord-aCenterCoord[iDim]);
     }
   }
-}
 
-/*
-** Add connection db to the blocked connections list. It is assumed
-** that it is not already a part of the list.
-*/
-static void addToBlockedList(sqlite3 *db){
-  sqlite3 **pp;
-  assertMutexHeld();
-  for(
-    pp=&sqlite3BlockedList; 
-    *pp && (*pp)->xUnlockNotify!=db->xUnlockNotify; 
-    pp=&(*pp)->pNextBlocked
-  );
-  db->pNextBlocked = *pp;
-  *pp = db;
-}
+  SortByDistance(aOrder, nCell, aDistance, aSpare);
+  nodeZero(pRtree, pNode);
 
-/*
-** Obtain the STATIC_MASTER mutex.
-*/
-static void enterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
-  checkListProperties(0);
-}
+  for(ii=0; rc==SQLITE_OK && ii<(nCell-(RTREE_MINCELLS(pRtree)+1)); ii++){
+    RtreeCell *p = &aCell[aOrder[ii]];
+    nodeInsertCell(pRtree, pNode, p);
+    if( p->iRowid==pCell->iRowid ){
+      if( iHeight==0 ){
+        rc = rowidWrite(pRtree, p->iRowid, pNode->iNode);
+      }else{
+        rc = parentWrite(pRtree, p->iRowid, pNode->iNode);
+      }
+    }
+  }
+  if( rc==SQLITE_OK ){
+    rc = fixBoundingBox(pRtree, pNode);
+  }
+  for(; rc==SQLITE_OK && iiiNode currently contains
+    ** the height of the sub-tree headed by the cell.
+    */
+    RtreeNode *pInsert;
+    RtreeCell *p = &aCell[aOrder[ii]];
+    rc = ChooseLeaf(pRtree, p, iHeight, &pInsert);
+    if( rc==SQLITE_OK ){
+      int rc2;
+      rc = rtreeInsertCell(pRtree, pInsert, p, iHeight);
+      rc2 = nodeRelease(pRtree, pInsert);
+      if( rc==SQLITE_OK ){
+        rc = rc2;
+      }
+    }
+  }
 
-/*
-** Release the STATIC_MASTER mutex.
-*/
-static void leaveMutex(void){
-  assertMutexHeld();
-  checkListProperties(0);
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_free(aCell);
+  return rc;
 }
 
 /*
-** Register an unlock-notify callback.
-**
-** This is called after connection "db" has attempted some operation
-** but has received an SQLITE_LOCKED error because another connection
-** (call it pOther) in the same process was busy using the same shared
-** cache.  pOther is found by looking at db->pBlockingConnection.
-**
-** If there is no blocking connection, the callback is invoked immediately,
-** before this routine returns.
-**
-** If pOther is already blocked on db, then report SQLITE_LOCKED, to indicate
-** a deadlock.
-**
-** Otherwise, make arrangements to invoke xNotify when pOther drops
-** its locks.
-**
-** Each call to this routine overrides any prior callbacks registered
-** on the same "db".  If xNotify==0 then any prior callbacks are immediately
-** cancelled.
+** Insert cell pCell into node pNode. Node pNode is the head of a 
+** subtree iHeight high (leaf nodes have iHeight==0).
 */
-SQLITE_API int sqlite3_unlock_notify(
-  sqlite3 *db,
-  void (*xNotify)(void **, int),
-  void *pArg
+static int rtreeInsertCell(
+  Rtree *pRtree,
+  RtreeNode *pNode,
+  RtreeCell *pCell,
+  int iHeight
 ){
   int rc = SQLITE_OK;
+  if( iHeight>0 ){
+    RtreeNode *pChild = nodeHashLookup(pRtree, pCell->iRowid);
+    if( pChild ){
+      nodeRelease(pRtree, pChild->pParent);
+      nodeReference(pNode);
+      pChild->pParent = pNode;
+    }
+  }
+  if( nodeInsertCell(pRtree, pNode, pCell) ){
+    if( iHeight<=pRtree->iReinsertHeight || pNode->iNode==1){
+      rc = SplitNode(pRtree, pNode, pCell, iHeight);
+    }else{
+      pRtree->iReinsertHeight = iHeight;
+      rc = Reinsert(pRtree, pNode, pCell, iHeight);
+    }
+  }else{
+    rc = AdjustTree(pRtree, pNode, pCell);
+    if( rc==SQLITE_OK ){
+      if( iHeight==0 ){
+        rc = rowidWrite(pRtree, pCell->iRowid, pNode->iNode);
+      }else{
+        rc = parentWrite(pRtree, pCell->iRowid, pNode->iNode);
+      }
+    }
+  }
+  return rc;
+}
 
-  sqlite3_mutex_enter(db->mutex);
-  enterMutex();
+static int reinsertNodeContent(Rtree *pRtree, RtreeNode *pNode){
+  int ii;
+  int rc = SQLITE_OK;
+  int nCell = NCELL(pNode);
 
-  if( xNotify==0 ){
-    removeFromBlockedList(db);
-    db->pBlockingConnection = 0;
-    db->pUnlockConnection = 0;
-    db->xUnlockNotify = 0;
-    db->pUnlockArg = 0;
-  }else if( 0==db->pBlockingConnection ){
-    /* The blocking transaction has been concluded. Or there never was a 
-    ** blocking transaction. In either case, invoke the notify callback
-    ** immediately. 
-    */
-    xNotify(&pArg, 1);
-  }else{
-    sqlite3 *p;
+  for(ii=0; rc==SQLITE_OK && iipBlockingConnection; p && p!=db; p=p->pUnlockConnection){}
-    if( p ){
-      rc = SQLITE_LOCKED;              /* Deadlock detected. */
-    }else{
-      db->pUnlockConnection = db->pBlockingConnection;
-      db->xUnlockNotify = xNotify;
-      db->pUnlockArg = pArg;
-      removeFromBlockedList(db);
-      addToBlockedList(db);
+    /* Find a node to store this cell in. pNode->iNode currently contains
+    ** the height of the sub-tree headed by the cell.
+    */
+    rc = ChooseLeaf(pRtree, &cell, (int)pNode->iNode, &pInsert);
+    if( rc==SQLITE_OK ){
+      int rc2;
+      rc = rtreeInsertCell(pRtree, pInsert, &cell, (int)pNode->iNode);
+      rc2 = nodeRelease(pRtree, pInsert);
+      if( rc==SQLITE_OK ){
+        rc = rc2;
+      }
     }
   }
-
-  leaveMutex();
-  assert( !db->mallocFailed );
-  sqlite3ErrorWithMsg(db, rc, (rc?"database is deadlocked":0));
-  sqlite3_mutex_leave(db->mutex);
   return rc;
 }
 
 /*
-** This function is called while stepping or preparing a statement 
-** associated with connection db. The operation will return SQLITE_LOCKED
-** to the user because it requires a lock that will not be available
-** until connection pBlocker concludes its current transaction.
+** Select a currently unused rowid for a new r-tree record.
 */
-SQLITE_PRIVATE void sqlite3ConnectionBlocked(sqlite3 *db, sqlite3 *pBlocker){
-  enterMutex();
-  if( db->pBlockingConnection==0 && db->pUnlockConnection==0 ){
-    addToBlockedList(db);
-  }
-  db->pBlockingConnection = pBlocker;
-  leaveMutex();
+static int newRowid(Rtree *pRtree, i64 *piRowid){
+  int rc;
+  sqlite3_bind_null(pRtree->pWriteRowid, 1);
+  sqlite3_bind_null(pRtree->pWriteRowid, 2);
+  sqlite3_step(pRtree->pWriteRowid);
+  rc = sqlite3_reset(pRtree->pWriteRowid);
+  *piRowid = sqlite3_last_insert_rowid(pRtree->db);
+  return rc;
 }
 
 /*
-** This function is called when
-** the transaction opened by database db has just finished. Locks held 
-** by database connection db have been released.
-**
-** This function loops through each entry in the blocked connections
-** list and does the following:
-**
-**   1) If the sqlite3.pBlockingConnection member of a list entry is
-**      set to db, then set pBlockingConnection=0.
-**
-**   2) If the sqlite3.pUnlockConnection member of a list entry is
-**      set to db, then invoke the configured unlock-notify callback and
-**      set pUnlockConnection=0.
-**
-**   3) If the two steps above mean that pBlockingConnection==0 and
-**      pUnlockConnection==0, remove the entry from the blocked connections
-**      list.
+** Remove the entry with rowid=iDelete from the r-tree structure.
 */
-SQLITE_PRIVATE void sqlite3ConnectionUnlocked(sqlite3 *db){
-  void (*xUnlockNotify)(void **, int) = 0; /* Unlock-notify cb to invoke */
-  int nArg = 0;                            /* Number of entries in aArg[] */
-  sqlite3 **pp;                            /* Iterator variable */
-  void **aArg;               /* Arguments to the unlock callback */
-  void **aDyn = 0;           /* Dynamically allocated space for aArg[] */
-  void *aStatic[16];         /* Starter space for aArg[].  No malloc required */
+static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
+  int rc;                         /* Return code */
+  RtreeNode *pLeaf = 0;           /* Leaf node containing record iDelete */
+  int iCell;                      /* Index of iDelete cell in pLeaf */
+  RtreeNode *pRoot;               /* Root node of rtree structure */
 
-  aArg = aStatic;
-  enterMutex();         /* Enter STATIC_MASTER mutex */
 
-  /* This loop runs once for each entry in the blocked-connections list. */
-  for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){
-    sqlite3 *p = *pp;
+  /* Obtain a reference to the root node to initialize Rtree.iDepth */
+  rc = nodeAcquire(pRtree, 1, 0, &pRoot);
 
-    /* Step 1. */
-    if( p->pBlockingConnection==db ){
-      p->pBlockingConnection = 0;
-    }
+  /* Obtain a reference to the leaf node that contains the entry 
+  ** about to be deleted. 
+  */
+  if( rc==SQLITE_OK ){
+    rc = findLeafNode(pRtree, iDelete, &pLeaf, 0);
+  }
 
-    /* Step 2. */
-    if( p->pUnlockConnection==db ){
-      assert( p->xUnlockNotify );
-      if( p->xUnlockNotify!=xUnlockNotify && nArg!=0 ){
-        xUnlockNotify(aArg, nArg);
-        nArg = 0;
-      }
+  /* Delete the cell in question from the leaf node. */
+  if( rc==SQLITE_OK ){
+    int rc2;
+    rc = nodeRowidIndex(pRtree, pLeaf, iDelete, &iCell);
+    if( rc==SQLITE_OK ){
+      rc = deleteCell(pRtree, pLeaf, iCell, 0);
+    }
+    rc2 = nodeRelease(pRtree, pLeaf);
+    if( rc==SQLITE_OK ){
+      rc = rc2;
+    }
+  }
 
-      sqlite3BeginBenignMalloc();
-      assert( aArg==aDyn || (aDyn==0 && aArg==aStatic) );
-      assert( nArg<=(int)ArraySize(aStatic) || aArg==aDyn );
-      if( (!aDyn && nArg==(int)ArraySize(aStatic))
-       || (aDyn && nArg==(int)(sqlite3MallocSize(aDyn)/sizeof(void*)))
-      ){
-        /* The aArg[] array needs to grow. */
-        void **pNew = (void **)sqlite3Malloc(nArg*sizeof(void *)*2);
-        if( pNew ){
-          memcpy(pNew, aArg, nArg*sizeof(void *));
-          sqlite3_free(aDyn);
-          aDyn = aArg = pNew;
-        }else{
-          /* This occurs when the array of context pointers that need to
-          ** be passed to the unlock-notify callback is larger than the
-          ** aStatic[] array allocated on the stack and the attempt to 
-          ** allocate a larger array from the heap has failed.
-          **
-          ** This is a difficult situation to handle. Returning an error
-          ** code to the caller is insufficient, as even if an error code
-          ** is returned the transaction on connection db will still be
-          ** closed and the unlock-notify callbacks on blocked connections
-          ** will go unissued. This might cause the application to wait
-          ** indefinitely for an unlock-notify callback that will never 
-          ** arrive.
-          **
-          ** Instead, invoke the unlock-notify callback with the context
-          ** array already accumulated. We can then clear the array and
-          ** begin accumulating any further context pointers without 
-          ** requiring any dynamic allocation. This is sub-optimal because
-          ** it means that instead of one callback with a large array of
-          ** context pointers the application will receive two or more
-          ** callbacks with smaller arrays of context pointers, which will
-          ** reduce the applications ability to prioritize multiple 
-          ** connections. But it is the best that can be done under the
-          ** circumstances.
-          */
-          xUnlockNotify(aArg, nArg);
-          nArg = 0;
-        }
-      }
-      sqlite3EndBenignMalloc();
+  /* Delete the corresponding entry in the _rowid table. */
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pRtree->pDeleteRowid, 1, iDelete);
+    sqlite3_step(pRtree->pDeleteRowid);
+    rc = sqlite3_reset(pRtree->pDeleteRowid);
+  }
 
-      aArg[nArg++] = p->pUnlockArg;
-      xUnlockNotify = p->xUnlockNotify;
-      p->pUnlockConnection = 0;
-      p->xUnlockNotify = 0;
-      p->pUnlockArg = 0;
+  /* Check if the root node now has exactly one child. If so, remove
+  ** it, schedule the contents of the child for reinsertion and 
+  ** reduce the tree height by one.
+  **
+  ** This is equivalent to copying the contents of the child into
+  ** the root node (the operation that Gutman's paper says to perform 
+  ** in this scenario).
+  */
+  if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){
+    int rc2;
+    RtreeNode *pChild;
+    i64 iChild = nodeGetRowid(pRtree, pRoot, 0);
+    rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);
+    if( rc==SQLITE_OK ){
+      rc = removeNode(pRtree, pChild, pRtree->iDepth-1);
+    }
+    rc2 = nodeRelease(pRtree, pChild);
+    if( rc==SQLITE_OK ) rc = rc2;
+    if( rc==SQLITE_OK ){
+      pRtree->iDepth--;
+      writeInt16(pRoot->zData, pRtree->iDepth);
+      pRoot->isDirty = 1;
     }
+  }
 
-    /* Step 3. */
-    if( p->pBlockingConnection==0 && p->pUnlockConnection==0 ){
-      /* Remove connection p from the blocked connections list. */
-      *pp = p->pNextBlocked;
-      p->pNextBlocked = 0;
-    }else{
-      pp = &p->pNextBlocked;
+  /* Re-insert the contents of any underfull nodes removed from the tree. */
+  for(pLeaf=pRtree->pDeleted; pLeaf; pLeaf=pRtree->pDeleted){
+    if( rc==SQLITE_OK ){
+      rc = reinsertNodeContent(pRtree, pLeaf);
     }
+    pRtree->pDeleted = pLeaf->pNext;
+    sqlite3_free(pLeaf);
   }
 
-  if( nArg!=0 ){
-    xUnlockNotify(aArg, nArg);
+  /* Release the reference to the root node. */
+  if( rc==SQLITE_OK ){
+    rc = nodeRelease(pRtree, pRoot);
+  }else{
+    nodeRelease(pRtree, pRoot);
   }
-  sqlite3_free(aDyn);
-  leaveMutex();         /* Leave STATIC_MASTER mutex */
-}
 
-/*
-** This is called when the database connection passed as an argument is 
-** being closed. The connection is removed from the blocked list.
-*/
-SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
-  sqlite3ConnectionUnlocked(db);
-  enterMutex();
-  removeFromBlockedList(db);
-  checkListProperties(db);
-  leaveMutex();
+  return rc;
 }
-#endif
 
-/************** End of notify.c **********************************************/
-/************** Begin file fts3.c ********************************************/
 /*
-** 2006 Oct 10
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-******************************************************************************
-**
-** This is an SQLite module implementing full-text search.
+** Rounding constants for float->double conversion.
 */
+#define RNDTOWARDS  (1.0 - 1.0/8388608.0)  /* Round towards zero */
+#define RNDAWAY     (1.0 + 1.0/8388608.0)  /* Round away from zero */
 
+#if !defined(SQLITE_RTREE_INT_ONLY)
 /*
-** The code in this file is only compiled if:
-**
-**     * The FTS3 module is being built as an extension
-**       (in which case SQLITE_CORE is not defined), or
-**
-**     * The FTS3 module is being built into the core of
-**       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
-*/
-
-/* The full-text index is stored in a series of b+tree (-like)
-** structures called segments which map terms to doclists.  The
-** structures are like b+trees in layout, but are constructed from the
-** bottom up in optimal fashion and are not updatable.  Since trees
-** are built from the bottom up, things will be described from the
-** bottom up.
-**
-**
-**** Varints ****
-** The basic unit of encoding is a variable-length integer called a
-** varint.  We encode variable-length integers in little-endian order
-** using seven bits * per byte as follows:
-**
-** KEY:
-**         A = 0xxxxxxx    7 bits of data and one flag bit
-**         B = 1xxxxxxx    7 bits of data and one flag bit
-**
-**  7 bits - A
-** 14 bits - BA
-** 21 bits - BBA
-** and so on.
-**
-** This is similar in concept to how sqlite encodes "varints" but
-** the encoding is not the same.  SQLite varints are big-endian
-** are are limited to 9 bytes in length whereas FTS3 varints are
-** little-endian and can be up to 10 bytes in length (in theory).
-**
-** Example encodings:
-**
-**     1:    0x01
-**   127:    0x7f
-**   128:    0x81 0x00
-**
-**
-**** Document lists ****
-** A doclist (document list) holds a docid-sorted list of hits for a
-** given term.  Doclists hold docids and associated token positions.
-** A docid is the unique integer identifier for a single document.
-** A position is the index of a word within the document.  The first 
-** word of the document has a position of 0.
-**
-** FTS3 used to optionally store character offsets using a compile-time
-** option.  But that functionality is no longer supported.
-**
-** A doclist is stored like this:
-**
-** array {
-**   varint docid;          (delta from previous doclist)
-**   array {                (position list for column 0)
-**     varint position;     (2 more than the delta from previous position)
-**   }
-**   array {
-**     varint POS_COLUMN;   (marks start of position list for new column)
-**     varint column;       (index of new column)
-**     array {
-**       varint position;   (2 more than the delta from previous position)
-**     }
-**   }
-**   varint POS_END;        (marks end of positions for this document.
-** }
-**
-** Here, array { X } means zero or more occurrences of X, adjacent in
-** memory.  A "position" is an index of a token in the token stream
-** generated by the tokenizer. Note that POS_END and POS_COLUMN occur 
-** in the same logical place as the position element, and act as sentinals
-** ending a position list array.  POS_END is 0.  POS_COLUMN is 1.
-** The positions numbers are not stored literally but rather as two more
-** than the difference from the prior position, or the just the position plus
-** 2 for the first position.  Example:
-**
-**   label:       A B C D E  F  G H   I  J K
-**   value:     123 5 9 1 1 14 35 0 234 72 0
-**
-** The 123 value is the first docid.  For column zero in this document
-** there are two matches at positions 3 and 10 (5-2 and 9-2+3).  The 1
-** at D signals the start of a new column; the 1 at E indicates that the
-** new column is column number 1.  There are two positions at 12 and 45
-** (14-2 and 35-2+12).  The 0 at H indicate the end-of-document.  The
-** 234 at I is the delta to next docid (357).  It has one position 70
-** (72-2) and then terminates with the 0 at K.
-**
-** A "position-list" is the list of positions for multiple columns for
-** a single docid.  A "column-list" is the set of positions for a single
-** column.  Hence, a position-list consists of one or more column-lists,
-** a document record consists of a docid followed by a position-list and
-** a doclist consists of one or more document records.
-**
-** A bare doclist omits the position information, becoming an 
-** array of varint-encoded docids.
-**
-**** Segment leaf nodes ****
-** Segment leaf nodes store terms and doclists, ordered by term.  Leaf
-** nodes are written using LeafWriter, and read using LeafReader (to
-** iterate through a single leaf node's data) and LeavesReader (to
-** iterate through a segment's entire leaf layer).  Leaf nodes have
-** the format:
-**
-** varint iHeight;             (height from leaf level, always 0)
-** varint nTerm;               (length of first term)
-** char pTerm[nTerm];          (content of first term)
-** varint nDoclist;            (length of term's associated doclist)
-** char pDoclist[nDoclist];    (content of doclist)
-** array {
-**                             (further terms are delta-encoded)
-**   varint nPrefix;           (length of prefix shared with previous term)
-**   varint nSuffix;           (length of unshared suffix)
-**   char pTermSuffix[nSuffix];(unshared suffix of next term)
-**   varint nDoclist;          (length of term's associated doclist)
-**   char pDoclist[nDoclist];  (content of doclist)
-** }
-**
-** Here, array { X } means zero or more occurrences of X, adjacent in
-** memory.
-**
-** Leaf nodes are broken into blocks which are stored contiguously in
-** the %_segments table in sorted order.  This means that when the end
-** of a node is reached, the next term is in the node with the next
-** greater node id.
-**
-** New data is spilled to a new leaf node when the current node
-** exceeds LEAF_MAX bytes (default 2048).  New data which itself is
-** larger than STANDALONE_MIN (default 1024) is placed in a standalone
-** node (a leaf node with a single term and doclist).  The goal of
-** these settings is to pack together groups of small doclists while
-** making it efficient to directly access large doclists.  The
-** assumption is that large doclists represent terms which are more
-** likely to be query targets.
-**
-** TODO(shess) It may be useful for blocking decisions to be more
-** dynamic.  For instance, it may make more sense to have a 2.5k leaf
-** node rather than splitting into 2k and .5k nodes.  My intuition is
-** that this might extend through 2x or 4x the pagesize.
-**
-**
-**** Segment interior nodes ****
-** Segment interior nodes store blockids for subtree nodes and terms
-** to describe what data is stored by the each subtree.  Interior
-** nodes are written using InteriorWriter, and read using
-** InteriorReader.  InteriorWriters are created as needed when
-** SegmentWriter creates new leaf nodes, or when an interior node
-** itself grows too big and must be split.  The format of interior
-** nodes:
-**
-** varint iHeight;           (height from leaf level, always >0)
-** varint iBlockid;          (block id of node's leftmost subtree)
-** optional {
-**   varint nTerm;           (length of first term)
-**   char pTerm[nTerm];      (content of first term)
-**   array {
-**                                (further terms are delta-encoded)
-**     varint nPrefix;            (length of shared prefix with previous term)
-**     varint nSuffix;            (length of unshared suffix)
-**     char pTermSuffix[nSuffix]; (unshared suffix of next term)
-**   }
-** }
-**
-** Here, optional { X } means an optional element, while array { X }
-** means zero or more occurrences of X, adjacent in memory.
-**
-** An interior node encodes n terms separating n+1 subtrees.  The
-** subtree blocks are contiguous, so only the first subtree's blockid
-** is encoded.  The subtree at iBlockid will contain all terms less
-** than the first term encoded (or all terms if no term is encoded).
-** Otherwise, for terms greater than or equal to pTerm[i] but less
-** than pTerm[i+1], the subtree for that term will be rooted at
-** iBlockid+i.  Interior nodes only store enough term data to
-** distinguish adjacent children (if the rightmost term of the left
-** child is "something", and the leftmost term of the right child is
-** "wicked", only "w" is stored).
-**
-** New data is spilled to a new interior node at the same height when
-** the current node exceeds INTERIOR_MAX bytes (default 2048).
-** INTERIOR_MIN_TERMS (default 7) keeps large terms from monopolizing
-** interior nodes and making the tree too skinny.  The interior nodes
-** at a given height are naturally tracked by interior nodes at
-** height+1, and so on.
-**
-**
-**** Segment directory ****
-** The segment directory in table %_segdir stores meta-information for
-** merging and deleting segments, and also the root node of the
-** segment's tree.
-**
-** The root node is the top node of the segment's tree after encoding
-** the entire segment, restricted to ROOT_MAX bytes (default 1024).
-** This could be either a leaf node or an interior node.  If the top
-** node requires more than ROOT_MAX bytes, it is flushed to %_segments
-** and a new root interior node is generated (which should always fit
-** within ROOT_MAX because it only needs space for 2 varints, the
-** height and the blockid of the previous root).
-**
-** The meta-information in the segment directory is:
-**   level               - segment level (see below)
-**   idx                 - index within level
-**                       - (level,idx uniquely identify a segment)
-**   start_block         - first leaf node
-**   leaves_end_block    - last leaf node
-**   end_block           - last block (including interior nodes)
-**   root                - contents of root node
-**
-** If the root node is a leaf node, then start_block,
-** leaves_end_block, and end_block are all 0.
-**
-**
-**** Segment merging ****
-** To amortize update costs, segments are grouped into levels and
-** merged in batches.  Each increase in level represents exponentially
-** more documents.
-**
-** New documents (actually, document updates) are tokenized and
-** written individually (using LeafWriter) to a level 0 segment, with
-** incrementing idx.  When idx reaches MERGE_COUNT (default 16), all
-** level 0 segments are merged into a single level 1 segment.  Level 1
-** is populated like level 0, and eventually MERGE_COUNT level 1
-** segments are merged to a single level 2 segment (representing
-** MERGE_COUNT^2 updates), and so on.
-**
-** A segment merge traverses all segments at a given level in
-** parallel, performing a straightforward sorted merge.  Since segment
-** leaf nodes are written in to the %_segments table in order, this
-** merge traverses the underlying sqlite disk structures efficiently.
-** After the merge, all segment blocks from the merged level are
-** deleted.
-**
-** MERGE_COUNT controls how often we merge segments.  16 seems to be
-** somewhat of a sweet spot for insertion performance.  32 and 64 show
-** very similar performance numbers to 16 on insertion, though they're
-** a tiny bit slower (perhaps due to more overhead in merge-time
-** sorting).  8 is about 20% slower than 16, 4 about 50% slower than
-** 16, 2 about 66% slower than 16.
-**
-** At query time, high MERGE_COUNT increases the number of segments
-** which need to be scanned and merged.  For instance, with 100k docs
-** inserted:
-**
-**    MERGE_COUNT   segments
-**       16           25
-**        8           12
-**        4           10
-**        2            6
-**
-** This appears to have only a moderate impact on queries for very
-** frequent terms (which are somewhat dominated by segment merge
-** costs), and infrequent and non-existent terms still seem to be fast
-** even with many segments.
-**
-** TODO(shess) That said, it would be nice to have a better query-side
-** argument for MERGE_COUNT of 16.  Also, it is possible/likely that
-** optimizations to things like doclist merging will swing the sweet
-** spot around.
-**
-**
-**
-**** Handling of deletions and updates ****
-** Since we're using a segmented structure, with no docid-oriented
-** index into the term index, we clearly cannot simply update the term
-** index when a document is deleted or updated.  For deletions, we
-** write an empty doclist (varint(docid) varint(POS_END)), for updates
-** we simply write the new doclist.  Segment merges overwrite older
-** data for a particular docid with newer data, so deletes or updates
-** will eventually overtake the earlier data and knock it out.  The
-** query logic likewise merges doclists so that newer data knocks out
-** older data.
+** Convert an sqlite3_value into an RtreeValue (presumably a float)
+** while taking care to round toward negative or positive, respectively.
 */
+static RtreeValue rtreeValueDown(sqlite3_value *v){
+  double d = sqlite3_value_double(v);
+  float f = (float)d;
+  if( f>d ){
+    f = (float)(d*(d<0 ? RNDAWAY : RNDTOWARDS));
+  }
+  return f;
+}
+static RtreeValue rtreeValueUp(sqlite3_value *v){
+  double d = sqlite3_value_double(v);
+  float f = (float)d;
+  if( fbase.zErrMsg) to an appropriate value and returns
+** SQLITE_CONSTRAINT.
 **
-******************************************************************************
+** Parameter iCol is the index of the leftmost column involved in the
+** constraint failure. If it is 0, then the constraint that failed is
+** the unique constraint on the id column. Otherwise, it is the rtree
+** (c1<=c2) constraint on columns iCol and iCol+1 that has failed.
 **
+** If an OOM occurs, SQLITE_NOMEM is returned instead of SQLITE_CONSTRAINT.
 */
-#ifndef _FTSINT_H
-#define _FTSINT_H
-
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
-# define NDEBUG 1
-#endif
+static int rtreeConstraintError(Rtree *pRtree, int iCol){
+  sqlite3_stmt *pStmt = 0;
+  char *zSql; 
+  int rc;
 
-/*
-** FTS4 is really an extension for FTS3.  It is enabled using the
-** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
-** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
-*/
-#if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
-# define SQLITE_ENABLE_FTS3
-#endif
+  assert( iCol==0 || iCol%2 );
+  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", pRtree->zDb, pRtree->zName);
+  if( zSql ){
+    rc = sqlite3_prepare_v2(pRtree->db, zSql, -1, &pStmt, 0);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3_free(zSql);
 
-#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+  if( rc==SQLITE_OK ){
+    if( iCol==0 ){
+      const char *zCol = sqlite3_column_name(pStmt, 0);
+      pRtree->base.zErrMsg = sqlite3_mprintf(
+          "UNIQUE constraint failed: %s.%s", pRtree->zName, zCol
+      );
+    }else{
+      const char *zCol1 = sqlite3_column_name(pStmt, iCol);
+      const char *zCol2 = sqlite3_column_name(pStmt, iCol+1);
+      pRtree->base.zErrMsg = sqlite3_mprintf(
+          "rtree constraint failed: %s.(%s<=%s)", pRtree->zName, zCol1, zCol2
+      );
+    }
+  }
 
-/* If not building as part of the core, include sqlite3ext.h. */
-#ifndef SQLITE_CORE
-SQLITE_EXTENSION_INIT3
-#endif
+  sqlite3_finalize(pStmt);
+  return (rc==SQLITE_OK ? SQLITE_CONSTRAINT : rc);
+}
 
-/************** Include fts3_tokenizer.h in the middle of fts3Int.h **********/
-/************** Begin file fts3_tokenizer.h **********************************/
-/*
-** 2006 July 10
-**
-** The author disclaims copyright to this source code.
-**
-*************************************************************************
-** Defines the interface to tokenizers used by fulltext-search.  There
-** are three basic components:
-**
-** sqlite3_tokenizer_module is a singleton defining the tokenizer
-** interface functions.  This is essentially the class structure for
-** tokenizers.
-**
-** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
-** including customization information defined at creation time.
-**
-** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
-** tokens from a particular input.
-*/
-#ifndef _FTS3_TOKENIZER_H_
-#define _FTS3_TOKENIZER_H_
 
-/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
-** If tokenizers are to be allowed to call sqlite3_*() functions, then
-** we will need a way to register the API consistently.
-*/
 
 /*
-** Structures used by the tokenizer interface. When a new tokenizer
-** implementation is registered, the caller provides a pointer to
-** an sqlite3_tokenizer_module containing pointers to the callback
-** functions that make up an implementation.
-**
-** When an fts3 table is created, it passes any arguments passed to
-** the tokenizer clause of the CREATE VIRTUAL TABLE statement to the
-** sqlite3_tokenizer_module.xCreate() function of the requested tokenizer
-** implementation. The xCreate() function in turn returns an 
-** sqlite3_tokenizer structure representing the specific tokenizer to
-** be used for the fts3 table (customized by the tokenizer clause arguments).
-**
-** To tokenize an input buffer, the sqlite3_tokenizer_module.xOpen()
-** method is called. It returns an sqlite3_tokenizer_cursor object
-** that may be used to tokenize a specific input buffer based on
-** the tokenization rules supplied by a specific sqlite3_tokenizer
-** object.
+** The xUpdate method for rtree module virtual tables.
 */
-typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
-typedef struct sqlite3_tokenizer sqlite3_tokenizer;
-typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
+static int rtreeUpdate(
+  sqlite3_vtab *pVtab, 
+  int nData, 
+  sqlite3_value **azData, 
+  sqlite_int64 *pRowid
+){
+  Rtree *pRtree = (Rtree *)pVtab;
+  int rc = SQLITE_OK;
+  RtreeCell cell;                 /* New cell to insert if nData>1 */
+  int bHaveRowid = 0;             /* Set to 1 after new rowid is determined */
 
-struct sqlite3_tokenizer_module {
+  rtreeReference(pRtree);
+  assert(nData>=1);
 
-  /*
-  ** Structure version. Should always be set to 0 or 1.
-  */
-  int iVersion;
+  cell.iRowid = 0;  /* Used only to suppress a compiler warning */
 
-  /*
-  ** Create a new tokenizer. The values in the argv[] array are the
-  ** arguments passed to the "tokenizer" clause of the CREATE VIRTUAL
-  ** TABLE statement that created the fts3 table. For example, if
-  ** the following SQL is executed:
-  **
-  **   CREATE .. USING fts3( ... , tokenizer  arg1 arg2)
+  /* Constraint handling. A write operation on an r-tree table may return
+  ** SQLITE_CONSTRAINT for two reasons:
   **
-  ** then argc is set to 2, and the argv[] array contains pointers
-  ** to the strings "arg1" and "arg2".
+  **   1. A duplicate rowid value, or
+  **   2. The supplied data violates the "x2>=x1" constraint.
   **
-  ** This method should return either SQLITE_OK (0), or an SQLite error 
-  ** code. If SQLITE_OK is returned, then *ppTokenizer should be set
-  ** to point at the newly created tokenizer structure. The generic
-  ** sqlite3_tokenizer.pModule variable should not be initialized by
-  ** this callback. The caller will do so.
-  */
-  int (*xCreate)(
-    int argc,                           /* Size of argv array */
-    const char *const*argv,             /* Tokenizer argument strings */
-    sqlite3_tokenizer **ppTokenizer     /* OUT: Created tokenizer */
-  );
-
-  /*
-  ** Destroy an existing tokenizer. The fts3 module calls this method
-  ** exactly once for each successful call to xCreate().
-  */
-  int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
-
-  /*
-  ** Create a tokenizer cursor to tokenize an input buffer. The caller
-  ** is responsible for ensuring that the input buffer remains valid
-  ** until the cursor is closed (using the xClose() method). 
+  ** In the first case, if the conflict-handling mode is REPLACE, then
+  ** the conflicting row can be removed before proceeding. In the second
+  ** case, SQLITE_CONSTRAINT must be returned regardless of the
+  ** conflict-handling mode specified by the user.
   */
-  int (*xOpen)(
-    sqlite3_tokenizer *pTokenizer,       /* Tokenizer object */
-    const char *pInput, int nBytes,      /* Input buffer */
-    sqlite3_tokenizer_cursor **ppCursor  /* OUT: Created tokenizer cursor */
-  );
+  if( nData>1 ){
+    int ii;
 
-  /*
-  ** Destroy an existing tokenizer cursor. The fts3 module calls this 
-  ** method exactly once for each successful call to xOpen().
-  */
-  int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
+    /* Populate the cell.aCoord[] array. The first coordinate is azData[3].
+    **
+    ** NB: nData can only be less than nDim*2+3 if the rtree is mis-declared
+    ** with "column" that are interpreted as table constraints.
+    ** Example:  CREATE VIRTUAL TABLE bad USING rtree(x,y,CHECK(y>5));
+    ** This problem was discovered after years of use, so we silently ignore
+    ** these kinds of misdeclared tables to avoid breaking any legacy.
+    */
+    assert( nData<=(pRtree->nDim2 + 3) );
 
-  /*
-  ** Retrieve the next token from the tokenizer cursor pCursor. This
-  ** method should either return SQLITE_OK and set the values of the
-  ** "OUT" variables identified below, or SQLITE_DONE to indicate that
-  ** the end of the buffer has been reached, or an SQLite error code.
-  **
-  ** *ppToken should be set to point at a buffer containing the 
-  ** normalized version of the token (i.e. after any case-folding and/or
-  ** stemming has been performed). *pnBytes should be set to the length
-  ** of this buffer in bytes. The input text that generated the token is
-  ** identified by the byte offsets returned in *piStartOffset and
-  ** *piEndOffset. *piStartOffset should be set to the index of the first
-  ** byte of the token in the input buffer. *piEndOffset should be set
-  ** to the index of the first byte just past the end of the token in
-  ** the input buffer.
-  **
-  ** The buffer *ppToken is set to point at is managed by the tokenizer
-  ** implementation. It is only required to be valid until the next call
-  ** to xNext() or xClose(). 
-  */
-  /* TODO(shess) current implementation requires pInput to be
-  ** nul-terminated.  This should either be fixed, or pInput/nBytes
-  ** should be converted to zInput.
-  */
-  int (*xNext)(
-    sqlite3_tokenizer_cursor *pCursor,   /* Tokenizer cursor */
-    const char **ppToken, int *pnBytes,  /* OUT: Normalized text for token */
-    int *piStartOffset,  /* OUT: Byte offset of token in input buffer */
-    int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */
-    int *piPosition      /* OUT: Number of tokens returned before this one */
-  );
+#ifndef SQLITE_RTREE_INT_ONLY
+    if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
+      for(ii=0; iicell.aCoord[ii+1].f ){
+          rc = rtreeConstraintError(pRtree, ii+1);
+          goto constraint;
+        }
+      }
+    }else
+#endif
+    {
+      for(ii=0; iicell.aCoord[ii+1].i ){
+          rc = rtreeConstraintError(pRtree, ii+1);
+          goto constraint;
+        }
+      }
+    }
 
-  /***********************************************************************
-  ** Methods below this point are only available if iVersion>=1.
-  */
+    /* If a rowid value was supplied, check if it is already present in 
+    ** the table. If so, the constraint has failed. */
+    if( sqlite3_value_type(azData[2])!=SQLITE_NULL ){
+      cell.iRowid = sqlite3_value_int64(azData[2]);
+      if( sqlite3_value_type(azData[0])==SQLITE_NULL
+       || sqlite3_value_int64(azData[0])!=cell.iRowid
+      ){
+        int steprc;
+        sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);
+        steprc = sqlite3_step(pRtree->pReadRowid);
+        rc = sqlite3_reset(pRtree->pReadRowid);
+        if( SQLITE_ROW==steprc ){
+          if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){
+            rc = rtreeDeleteRowid(pRtree, cell.iRowid);
+          }else{
+            rc = rtreeConstraintError(pRtree, 0);
+            goto constraint;
+          }
+        }
+      }
+      bHaveRowid = 1;
+    }
+  }
 
-  /* 
-  ** Configure the language id of a tokenizer cursor.
+  /* If azData[0] is not an SQL NULL value, it is the rowid of a
+  ** record to delete from the r-tree table. The following block does
+  ** just that.
   */
-  int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
-};
-
-struct sqlite3_tokenizer {
-  const sqlite3_tokenizer_module *pModule;  /* The module for this tokenizer */
-  /* Tokenizer implementations will typically add additional fields */
-};
-
-struct sqlite3_tokenizer_cursor {
-  sqlite3_tokenizer *pTokenizer;       /* Tokenizer for this cursor. */
-  /* Tokenizer implementations will typically add additional fields */
-};
-
-int fts3_global_term_cnt(int iTerm, int iCol);
-int fts3_term_cnt(int iTerm, int iCol);
-
-
-#endif /* _FTS3_TOKENIZER_H_ */
-
-/************** End of fts3_tokenizer.h **************************************/
-/************** Continuing where we left off in fts3Int.h ********************/
-/************** Include fts3_hash.h in the middle of fts3Int.h ***************/
-/************** Begin file fts3_hash.h ***************************************/
-/*
-** 2001 September 22
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This is the header file for the generic hash-table implementation
-** used in SQLite.  We've modified it slightly to serve as a standalone
-** hash table implementation for the full-text indexing module.
-**
-*/
-#ifndef _FTS3_HASH_H_
-#define _FTS3_HASH_H_
-
-/* Forward declarations of structures. */
-typedef struct Fts3Hash Fts3Hash;
-typedef struct Fts3HashElem Fts3HashElem;
-
-/* A complete hash table is an instance of the following structure.
-** The internals of this structure are intended to be opaque -- client
-** code should not attempt to access or modify the fields of this structure
-** directly.  Change this structure only by using the routines below.
-** However, many of the "procedures" and "functions" for modifying and
-** accessing this structure are really macros, so we can't really make
-** this structure opaque.
-*/
-struct Fts3Hash {
-  char keyClass;          /* HASH_INT, _POINTER, _STRING, _BINARY */
-  char copyKey;           /* True if copy of key made on insert */
-  int count;              /* Number of entries in this table */
-  Fts3HashElem *first;    /* The first element of the array */
-  int htsize;             /* Number of buckets in the hash table */
-  struct _fts3ht {        /* the hash table */
-    int count;               /* Number of entries with this hash */
-    Fts3HashElem *chain;     /* Pointer to first entry with this hash */
-  } *ht;
-};
+  if( sqlite3_value_type(azData[0])!=SQLITE_NULL ){
+    rc = rtreeDeleteRowid(pRtree, sqlite3_value_int64(azData[0]));
+  }
 
-/* Each element in the hash table is an instance of the following 
-** structure.  All elements are stored on a single doubly-linked list.
-**
-** Again, this structure is intended to be opaque, but it can't really
-** be opaque because it is used by macros.
-*/
-struct Fts3HashElem {
-  Fts3HashElem *next, *prev; /* Next and previous elements in the table */
-  void *data;                /* Data associated with this element */
-  void *pKey; int nKey;      /* Key associated with this element */
-};
+  /* If the azData[] array contains more than one element, elements
+  ** (azData[2]..azData[argc-1]) contain a new record to insert into
+  ** the r-tree structure.
+  */
+  if( rc==SQLITE_OK && nData>1 ){
+    /* Insert the new record into the r-tree */
+    RtreeNode *pLeaf = 0;
+
+    /* Figure out the rowid of the new row. */
+    if( bHaveRowid==0 ){
+      rc = newRowid(pRtree, &cell.iRowid);
+    }
+    *pRowid = cell.iRowid;
+
+    if( rc==SQLITE_OK ){
+      rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);
+    }
+    if( rc==SQLITE_OK ){
+      int rc2;
+      pRtree->iReinsertHeight = -1;
+      rc = rtreeInsertCell(pRtree, pLeaf, &cell, 0);
+      rc2 = nodeRelease(pRtree, pLeaf);
+      if( rc==SQLITE_OK ){
+        rc = rc2;
+      }
+    }
+  }
+
+constraint:
+  rtreeRelease(pRtree);
+  return rc;
+}
 
 /*
-** There are 2 different modes of operation for a hash table:
-**
-**   FTS3_HASH_STRING        pKey points to a string that is nKey bytes long
-**                           (including the null-terminator, if any).  Case
-**                           is respected in comparisons.
-**
-**   FTS3_HASH_BINARY        pKey points to binary data nKey bytes long. 
-**                           memcmp() is used to compare keys.
-**
-** A copy of the key is made if the copyKey parameter to fts3HashInit is 1.  
+** Called when a transaction starts.
 */
-#define FTS3_HASH_STRING    1
-#define FTS3_HASH_BINARY    2
+static int rtreeBeginTransaction(sqlite3_vtab *pVtab){
+  Rtree *pRtree = (Rtree *)pVtab;
+  assert( pRtree->inWrTrans==0 );
+  pRtree->inWrTrans++;
+  return SQLITE_OK;
+}
 
 /*
-** Access routines.  To delete, insert a NULL pointer.
+** Called when a transaction completes (either by COMMIT or ROLLBACK).
+** The sqlite3_blob object should be released at this point.
 */
-SQLITE_PRIVATE void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey);
-SQLITE_PRIVATE void *sqlite3Fts3HashInsert(Fts3Hash*, const void *pKey, int nKey, void *pData);
-SQLITE_PRIVATE void *sqlite3Fts3HashFind(const Fts3Hash*, const void *pKey, int nKey);
-SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash*);
-SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const void *, int);
+static int rtreeEndTransaction(sqlite3_vtab *pVtab){
+  Rtree *pRtree = (Rtree *)pVtab;
+  pRtree->inWrTrans = 0;
+  nodeBlobReset(pRtree);
+  return SQLITE_OK;
+}
 
 /*
-** Shorthand for the functions above
+** The xRename method for rtree module virtual tables.
 */
-#define fts3HashInit     sqlite3Fts3HashInit
-#define fts3HashInsert   sqlite3Fts3HashInsert
-#define fts3HashFind     sqlite3Fts3HashFind
-#define fts3HashClear    sqlite3Fts3HashClear
-#define fts3HashFindElem sqlite3Fts3HashFindElem
+static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
+  Rtree *pRtree = (Rtree *)pVtab;
+  int rc = SQLITE_NOMEM;
+  char *zSql = sqlite3_mprintf(
+    "ALTER TABLE %Q.'%q_node'   RENAME TO \"%w_node\";"
+    "ALTER TABLE %Q.'%q_parent' RENAME TO \"%w_parent\";"
+    "ALTER TABLE %Q.'%q_rowid'  RENAME TO \"%w_rowid\";"
+    , pRtree->zDb, pRtree->zName, zNewName 
+    , pRtree->zDb, pRtree->zName, zNewName 
+    , pRtree->zDb, pRtree->zName, zNewName
+  );
+  if( zSql ){
+    nodeBlobReset(pRtree);
+    rc = sqlite3_exec(pRtree->db, zSql, 0, 0, 0);
+    sqlite3_free(zSql);
+  }
+  return rc;
+}
 
 /*
-** Macros for looping over all elements of a hash table.  The idiom is
-** like this:
+** The xSavepoint method.
 **
-**   Fts3Hash h;
-**   Fts3HashElem *p;
-**   ...
-**   for(p=fts3HashFirst(&h); p; p=fts3HashNext(p)){
-**     SomeStructure *pData = fts3HashData(p);
-**     // do something with pData
-**   }
+** This module does not need to do anything to support savepoints. However,
+** it uses this hook to close any open blob handle. This is done because a 
+** DROP TABLE command - which fortunately always opens a savepoint - cannot 
+** succeed if there are any open blob handles. i.e. if the blob handle were
+** not closed here, the following would fail:
+**
+**   BEGIN;
+**     INSERT INTO rtree...
+**     DROP TABLE ;    -- Would fail with SQLITE_LOCKED
+**   COMMIT;
 */
-#define fts3HashFirst(H)  ((H)->first)
-#define fts3HashNext(E)   ((E)->next)
-#define fts3HashData(E)   ((E)->data)
-#define fts3HashKey(E)    ((E)->pKey)
-#define fts3HashKeysize(E) ((E)->nKey)
+static int rtreeSavepoint(sqlite3_vtab *pVtab, int iSavepoint){
+  Rtree *pRtree = (Rtree *)pVtab;
+  int iwt = pRtree->inWrTrans;
+  UNUSED_PARAMETER(iSavepoint);
+  pRtree->inWrTrans = 0;
+  nodeBlobReset(pRtree);
+  pRtree->inWrTrans = iwt;
+  return SQLITE_OK;
+}
 
 /*
-** Number of entries in a hash table
+** This function populates the pRtree->nRowEst variable with an estimate
+** of the number of rows in the virtual table. If possible, this is based
+** on sqlite_stat1 data. Otherwise, use RTREE_DEFAULT_ROWEST.
 */
-#define fts3HashCount(H)  ((H)->count)
+static int rtreeQueryStat1(sqlite3 *db, Rtree *pRtree){
+  const char *zFmt = "SELECT stat FROM %Q.sqlite_stat1 WHERE tbl = '%q_rowid'";
+  char *zSql;
+  sqlite3_stmt *p;
+  int rc;
+  i64 nRow = 0;
 
-#endif /* _FTS3_HASH_H_ */
+  rc = sqlite3_table_column_metadata(
+      db, pRtree->zDb, "sqlite_stat1",0,0,0,0,0,0
+  );
+  if( rc!=SQLITE_OK ){
+    pRtree->nRowEst = RTREE_DEFAULT_ROWEST;
+    return rc==SQLITE_ERROR ? SQLITE_OK : rc;
+  }
+  zSql = sqlite3_mprintf(zFmt, pRtree->zDb, pRtree->zName);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare_v2(db, zSql, -1, &p, 0);
+    if( rc==SQLITE_OK ){
+      if( sqlite3_step(p)==SQLITE_ROW ) nRow = sqlite3_column_int64(p, 0);
+      rc = sqlite3_finalize(p);
+    }else if( rc!=SQLITE_NOMEM ){
+      rc = SQLITE_OK;
+    }
 
-/************** End of fts3_hash.h *******************************************/
-/************** Continuing where we left off in fts3Int.h ********************/
+    if( rc==SQLITE_OK ){
+      if( nRow==0 ){
+        pRtree->nRowEst = RTREE_DEFAULT_ROWEST;
+      }else{
+        pRtree->nRowEst = MAX(nRow, RTREE_MIN_ROWEST);
+      }
+    }
+    sqlite3_free(zSql);
+  }
 
-/*
-** This constant determines the maximum depth of an FTS expression tree
-** that the library will create and use. FTS uses recursion to perform 
-** various operations on the query tree, so the disadvantage of a large
-** limit is that it may allow very large queries to use large amounts
-** of stack space (perhaps causing a stack overflow).
-*/
-#ifndef SQLITE_FTS3_MAX_EXPR_DEPTH
-# define SQLITE_FTS3_MAX_EXPR_DEPTH 12
-#endif
+  return rc;
+}
 
+static sqlite3_module rtreeModule = {
+  2,                          /* iVersion */
+  rtreeCreate,                /* xCreate - create a table */
+  rtreeConnect,               /* xConnect - connect to an existing table */
+  rtreeBestIndex,             /* xBestIndex - Determine search strategy */
+  rtreeDisconnect,            /* xDisconnect - Disconnect from a table */
+  rtreeDestroy,               /* xDestroy - Drop a table */
+  rtreeOpen,                  /* xOpen - open a cursor */
+  rtreeClose,                 /* xClose - close a cursor */
+  rtreeFilter,                /* xFilter - configure scan constraints */
+  rtreeNext,                  /* xNext - advance a cursor */
+  rtreeEof,                   /* xEof */
+  rtreeColumn,                /* xColumn - read data */
+  rtreeRowid,                 /* xRowid - read data */
+  rtreeUpdate,                /* xUpdate - write data */
+  rtreeBeginTransaction,      /* xBegin - begin transaction */
+  rtreeEndTransaction,        /* xSync - sync transaction */
+  rtreeEndTransaction,        /* xCommit - commit transaction */
+  rtreeEndTransaction,        /* xRollback - rollback transaction */
+  0,                          /* xFindFunction - function overloading */
+  rtreeRename,                /* xRename - rename the table */
+  rtreeSavepoint,             /* xSavepoint */
+  0,                          /* xRelease */
+  0,                          /* xRollbackTo */
+};
 
-/*
-** This constant controls how often segments are merged. Once there are
-** FTS3_MERGE_COUNT segments of level N, they are merged into a single
-** segment of level N+1.
-*/
-#define FTS3_MERGE_COUNT 16
+static int rtreeSqlInit(
+  Rtree *pRtree, 
+  sqlite3 *db, 
+  const char *zDb, 
+  const char *zPrefix, 
+  int isCreate
+){
+  int rc = SQLITE_OK;
 
-/*
-** This is the maximum amount of data (in bytes) to store in the 
-** Fts3Table.pendingTerms hash table. Normally, the hash table is
-** populated as documents are inserted/updated/deleted in a transaction
-** and used to create a new segment when the transaction is committed.
-** However if this limit is reached midway through a transaction, a new 
-** segment is created and the hash table cleared immediately.
-*/
-#define FTS3_MAX_PENDING_DATA (1*1024*1024)
+  #define N_STATEMENT 8
+  static const char *azSql[N_STATEMENT] = {
+    /* Write the xxx_node table */
+    "INSERT OR REPLACE INTO '%q'.'%q_node' VALUES(:1, :2)",
+    "DELETE FROM '%q'.'%q_node' WHERE nodeno = :1",
 
-/*
-** Macro to return the number of elements in an array. SQLite has a
-** similar macro called ArraySize(). Use a different name to avoid
-** a collision when building an amalgamation with built-in FTS3.
-*/
-#define SizeofArray(X) ((int)(sizeof(X)/sizeof(X[0])))
+    /* Read and write the xxx_rowid table */
+    "SELECT nodeno FROM '%q'.'%q_rowid' WHERE rowid = :1",
+    "INSERT OR REPLACE INTO '%q'.'%q_rowid' VALUES(:1, :2)",
+    "DELETE FROM '%q'.'%q_rowid' WHERE rowid = :1",
 
+    /* Read and write the xxx_parent table */
+    "SELECT parentnode FROM '%q'.'%q_parent' WHERE nodeno = :1",
+    "INSERT OR REPLACE INTO '%q'.'%q_parent' VALUES(:1, :2)",
+    "DELETE FROM '%q'.'%q_parent' WHERE nodeno = :1"
+  };
+  sqlite3_stmt **appStmt[N_STATEMENT];
+  int i;
 
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-#ifndef MAX
-# define MAX(x,y) ((x)>(y)?(x):(y))
-#endif
+  pRtree->db = db;
+
+  if( isCreate ){
+    char *zCreate = sqlite3_mprintf(
+"CREATE TABLE \"%w\".\"%w_node\"(nodeno INTEGER PRIMARY KEY, data BLOB);"
+"CREATE TABLE \"%w\".\"%w_rowid\"(rowid INTEGER PRIMARY KEY, nodeno INTEGER);"
+"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY,"
+                                  " parentnode INTEGER);"
+"INSERT INTO '%q'.'%q_node' VALUES(1, zeroblob(%d))",
+      zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, pRtree->iNodeSize
+    );
+    if( !zCreate ){
+      return SQLITE_NOMEM;
+    }
+    rc = sqlite3_exec(db, zCreate, 0, 0, 0);
+    sqlite3_free(zCreate);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+  }
+
+  appStmt[0] = &pRtree->pWriteNode;
+  appStmt[1] = &pRtree->pDeleteNode;
+  appStmt[2] = &pRtree->pReadRowid;
+  appStmt[3] = &pRtree->pWriteRowid;
+  appStmt[4] = &pRtree->pDeleteRowid;
+  appStmt[5] = &pRtree->pReadParent;
+  appStmt[6] = &pRtree->pWriteParent;
+  appStmt[7] = &pRtree->pDeleteParent;
+
+  rc = rtreeQueryStat1(db, pRtree);
+  for(i=0; iiNodeSize is populated and SQLITE_OK returned.
+** Otherwise, an SQLite error code is returned.
 **
-** It is possible to determine which index a b+-tree belongs to based on the
-** value stored in the "%_segdir.level" column. Given this value L, the index
-** that the b+-tree belongs to is (L<<10). In other words, all b+-trees with
-** level values between 0 and 1023 (inclusive) belong to index 0, all levels
-** between 1024 and 2047 to index 1, and so on.
+** If this function is being called as part of an xConnect(), then the rtree
+** table already exists. In this case the node-size is determined by inspecting
+** the root node of the tree.
 **
-** It is considered impossible for an index to use more than 1024 levels. In 
-** theory though this may happen, but only after at least 
-** (FTS3_MERGE_COUNT^1024) separate flushes of the pending-terms tables.
+** Otherwise, for an xCreate(), use 64 bytes less than the database page-size. 
+** This ensures that each node is stored on a single database page. If the 
+** database page-size is so large that more than RTREE_MAXCELLS entries 
+** would fit in a single node, use a smaller node-size.
 */
-#define FTS3_SEGDIR_MAXLEVEL      1024
-#define FTS3_SEGDIR_MAXLEVEL_STR "1024"
+static int getNodeSize(
+  sqlite3 *db,                    /* Database handle */
+  Rtree *pRtree,                  /* Rtree handle */
+  int isCreate,                   /* True for xCreate, false for xConnect */
+  char **pzErr                    /* OUT: Error message, if any */
+){
+  int rc;
+  char *zSql;
+  if( isCreate ){
+    int iPageSize = 0;
+    zSql = sqlite3_mprintf("PRAGMA %Q.page_size", pRtree->zDb);
+    rc = getIntFromStmt(db, zSql, &iPageSize);
+    if( rc==SQLITE_OK ){
+      pRtree->iNodeSize = iPageSize-64;
+      if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)iNodeSize ){
+        pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;
+      }
+    }else{
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    }
+  }else{
+    zSql = sqlite3_mprintf(
+        "SELECT length(data) FROM '%q'.'%q_node' WHERE nodeno = 1",
+        pRtree->zDb, pRtree->zName
+    );
+    rc = getIntFromStmt(db, zSql, &pRtree->iNodeSize);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    }else if( pRtree->iNodeSize<(512-64) ){
+      rc = SQLITE_CORRUPT;
+      *pzErr = sqlite3_mprintf("undersize RTree blobs in \"%q_node\"",
+                               pRtree->zName);
+    }
+  }
 
-/*
-** The testcase() macro is only used by the amalgamation.  If undefined,
-** make it a no-op.
-*/
-#ifndef testcase
-# define testcase(X)
-#endif
+  sqlite3_free(zSql);
+  return rc;
+}
 
-/*
-** Terminator values for position-lists and column-lists.
+/* 
+** This function is the implementation of both the xConnect and xCreate
+** methods of the r-tree virtual table.
+**
+**   argv[0]   -> module name
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[...] -> column names...
 */
-#define POS_COLUMN  (1)     /* Column-list terminator */
-#define POS_END     (0)     /* Position-list terminator */ 
+static int rtreeInit(
+  sqlite3 *db,                        /* Database connection */
+  void *pAux,                         /* One of the RTREE_COORD_* constants */
+  int argc, const char *const*argv,   /* Parameters to CREATE TABLE statement */
+  sqlite3_vtab **ppVtab,              /* OUT: New virtual table */
+  char **pzErr,                       /* OUT: Error message, if any */
+  int isCreate                        /* True for xCreate, false for xConnect */
+){
+  int rc = SQLITE_OK;
+  Rtree *pRtree;
+  int nDb;              /* Length of string argv[1] */
+  int nName;            /* Length of string argv[2] */
+  int eCoordType = (pAux ? RTREE_COORD_INT32 : RTREE_COORD_REAL32);
 
-/*
-** This section provides definitions to allow the
-** FTS3 extension to be compiled outside of the 
-** amalgamation.
-*/
-#ifndef SQLITE_AMALGAMATION
-/*
-** Macros indicating that conditional expressions are always true or
-** false.
-*/
-#ifdef SQLITE_COVERAGE_TEST
-# define ALWAYS(x) (1)
-# define NEVER(X)  (0)
-#else
-# define ALWAYS(x) (x)
-# define NEVER(x)  (x)
-#endif
+  const char *aErrMsg[] = {
+    0,                                                    /* 0 */
+    "Wrong number of columns for an rtree table",         /* 1 */
+    "Too few columns for an rtree table",                 /* 2 */
+    "Too many columns for an rtree table"                 /* 3 */
+  };
 
-/*
-** Internal types used by SQLite.
-*/
-typedef unsigned char u8;         /* 1-byte (or larger) unsigned integer */
-typedef short int i16;            /* 2-byte (or larger) signed integer */
-typedef unsigned int u32;         /* 4-byte unsigned integer */
-typedef sqlite3_uint64 u64;       /* 8-byte unsigned integer */
-typedef sqlite3_int64 i64;        /* 8-byte signed integer */
+  int iErr = (argc<6) ? 2 : argc>(RTREE_MAX_DIMENSIONS*2+4) ? 3 : argc%2;
+  if( aErrMsg[iErr] ){
+    *pzErr = sqlite3_mprintf("%s", aErrMsg[iErr]);
+    return SQLITE_ERROR;
+  }
 
-/*
-** Macro used to suppress compiler warnings for unused parameters.
-*/
-#define UNUSED_PARAMETER(x) (void)(x)
+  sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
+
+  /* Allocate the sqlite3_vtab structure */
+  nDb = (int)strlen(argv[1]);
+  nName = (int)strlen(argv[2]);
+  pRtree = (Rtree *)sqlite3_malloc(sizeof(Rtree)+nDb+nName+2);
+  if( !pRtree ){
+    return SQLITE_NOMEM;
+  }
+  memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);
+  pRtree->nBusy = 1;
+  pRtree->base.pModule = &rtreeModule;
+  pRtree->zDb = (char *)&pRtree[1];
+  pRtree->zName = &pRtree->zDb[nDb+1];
+  pRtree->nDim = (u8)((argc-4)/2);
+  pRtree->nDim2 = pRtree->nDim*2;
+  pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;
+  pRtree->eCoordType = (u8)eCoordType;
+  memcpy(pRtree->zDb, argv[1], nDb);
+  memcpy(pRtree->zName, argv[2], nName);
+
+  /* Figure out the node size to use. */
+  rc = getNodeSize(db, pRtree, isCreate, pzErr);
+
+  /* Create/Connect to the underlying relational database schema. If
+  ** that is successful, call sqlite3_declare_vtab() to configure
+  ** the r-tree table schema.
+  */
+  if( rc==SQLITE_OK ){
+    if( (rc = rtreeSqlInit(pRtree, db, argv[1], argv[2], isCreate)) ){
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    }else{
+      char *zSql = sqlite3_mprintf("CREATE TABLE x(%s", argv[3]);
+      char *zTmp;
+      int ii;
+      for(ii=4; zSql && iinBusy==1 );
+    rtreeRelease(pRtree);
+  }
+  return rc;
+}
 
-/*
-** Activate assert() only if SQLITE_TEST is enabled.
-*/
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
-# define NDEBUG 1
-#endif
 
 /*
-** The TESTONLY macro is used to enclose variable declarations or
-** other bits of code that are needed to support the arguments
-** within testcase() and assert() macros.
+** Implementation of a scalar function that decodes r-tree nodes to
+** human readable strings. This can be used for debugging and analysis.
+**
+** The scalar function takes two arguments: (1) the number of dimensions
+** to the rtree (between 1 and 5, inclusive) and (2) a blob of data containing
+** an r-tree node.  For a two-dimensional r-tree structure called "rt", to
+** deserialize all nodes, a statement like:
+**
+**   SELECT rtreenode(2, data) FROM rt_node;
+**
+** The human readable string takes the form of a Tcl list with one
+** entry for each cell in the r-tree node. Each entry is itself a
+** list, containing the 8-byte rowid/pageno followed by the 
+** *2 coordinates.
 */
-#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
-# define TESTONLY(X)  X
-#else
-# define TESTONLY(X)
-#endif
+static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
+  char *zText = 0;
+  RtreeNode node;
+  Rtree tree;
+  int ii;
 
-#endif /* SQLITE_AMALGAMATION */
+  UNUSED_PARAMETER(nArg);
+  memset(&node, 0, sizeof(RtreeNode));
+  memset(&tree, 0, sizeof(Rtree));
+  tree.nDim = (u8)sqlite3_value_int(apArg[0]);
+  tree.nDim2 = tree.nDim*2;
+  tree.nBytesPerCell = 8 + 8 * tree.nDim;
+  node.zData = (u8 *)sqlite3_value_blob(apArg[1]);
 
-#ifdef SQLITE_DEBUG
-SQLITE_PRIVATE int sqlite3Fts3Corrupt(void);
-# define FTS_CORRUPT_VTAB sqlite3Fts3Corrupt()
+  for(ii=0; iixDestructor ) pInfo->xDestructor(pInfo->pContext);
+  sqlite3_free(p);
+}
 
-#define FTS3_EVAL_FILTER    0
-#define FTS3_EVAL_NEXT      1
-#define FTS3_EVAL_MATCHINFO 2
+/*
+** This routine frees the BLOB that is returned by geomCallback().
+*/
+static void rtreeMatchArgFree(void *pArg){
+  int i;
+  RtreeMatchArg *p = (RtreeMatchArg*)pArg;
+  for(i=0; inParam; i++){
+    sqlite3_value_free(p->apSqlParam[i]);
+  }
+  sqlite3_free(p);
+}
 
 /*
-** The Fts3Cursor.eSearch member is always set to one of the following.
-** Actualy, Fts3Cursor.eSearch can be greater than or equal to
-** FTS3_FULLTEXT_SEARCH.  If so, then Fts3Cursor.eSearch - 2 is the index
-** of the column to be searched.  For example, in
+** Each call to sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback() creates an ordinary SQLite
+** scalar function that is implemented by this routine.
 **
-**     CREATE VIRTUAL TABLE ex1 USING fts3(a,b,c,d);
-**     SELECT docid FROM ex1 WHERE b MATCH 'one two three';
-** 
-** Because the LHS of the MATCH operator is 2nd column "b",
-** Fts3Cursor.eSearch will be set to FTS3_FULLTEXT_SEARCH+1.  (+0 for a,
-** +1 for b, +2 for c, +3 for d.)  If the LHS of MATCH were "ex1" 
-** indicating that all columns should be searched,
-** then eSearch would be set to FTS3_FULLTEXT_SEARCH+4.
+** All this function does is construct an RtreeMatchArg object that
+** contains the geometry-checking callback routines and a list of
+** parameters to this function, then return that RtreeMatchArg object
+** as a BLOB.
+**
+** The R-Tree MATCH operator will read the returned BLOB, deserialize
+** the RtreeMatchArg object, and use the RtreeMatchArg object to figure
+** out which elements of the R-Tree should be returned by the query.
 */
-#define FTS3_FULLSCAN_SEARCH 0    /* Linear scan of %_content table */
-#define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
-#define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */
+static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
+  RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);
+  RtreeMatchArg *pBlob;
+  int nBlob;
+  int memErr = 0;
+
+  nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(RtreeDValue)
+           + nArg*sizeof(sqlite3_value*);
+  pBlob = (RtreeMatchArg *)sqlite3_malloc(nBlob);
+  if( !pBlob ){
+    sqlite3_result_error_nomem(ctx);
+  }else{
+    int i;
+    pBlob->iSize = nBlob;
+    pBlob->cb = pGeomCtx[0];
+    pBlob->apSqlParam = (sqlite3_value**)&pBlob->aParam[nArg];
+    pBlob->nParam = nArg;
+    for(i=0; iapSqlParam[i] = sqlite3_value_dup(aArg[i]);
+      if( pBlob->apSqlParam[i]==0 ) memErr = 1;
+#ifdef SQLITE_RTREE_INT_ONLY
+      pBlob->aParam[i] = sqlite3_value_int64(aArg[i]);
+#else
+      pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
+#endif
+    }
+    if( memErr ){
+      sqlite3_result_error_nomem(ctx);
+      rtreeMatchArgFree(pBlob);
+    }else{
+      sqlite3_result_pointer(ctx, pBlob, "RtreeMatchArg", rtreeMatchArgFree);
+    }
+  }
+}
 
 /*
-** The lower 16-bits of the sqlite3_index_info.idxNum value set by
-** the xBestIndex() method contains the Fts3Cursor.eSearch value described
-** above. The upper 16-bits contain a combination of the following
-** bits, used to describe extra constraints on full-text searches.
+** Register a new geometry function for use with the r-tree MATCH operator.
 */
-#define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */
-#define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */
-#define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */
-
-struct Fts3Doclist {
-  char *aAll;                    /* Array containing doclist (or NULL) */
-  int nAll;                      /* Size of a[] in bytes */
-  char *pNextDocid;              /* Pointer to next docid */
+SQLITE_API int sqlite3_rtree_geometry_callback(
+  sqlite3 *db,                  /* Register SQL function on this connection */
+  const char *zGeom,            /* Name of the new SQL function */
+  int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*), /* Callback */
+  void *pContext                /* Extra data associated with the callback */
+){
+  RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
 
-  sqlite3_int64 iDocid;          /* Current docid (if pList!=0) */
-  int bFreeList;                 /* True if pList should be sqlite3_free()d */
-  char *pList;                   /* Pointer to position list following iDocid */
-  int nList;                     /* Length of position list */
-};
+  /* Allocate and populate the context object. */
+  pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
+  if( !pGeomCtx ) return SQLITE_NOMEM;
+  pGeomCtx->xGeom = xGeom;
+  pGeomCtx->xQueryFunc = 0;
+  pGeomCtx->xDestructor = 0;
+  pGeomCtx->pContext = pContext;
+  return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY, 
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
+  );
+}
 
 /*
-** A "phrase" is a sequence of one or more tokens that must match in
-** sequence.  A single token is the base case and the most common case.
-** For a sequence of tokens contained in double-quotes (i.e. "one two three")
-** nToken will be the number of tokens in the string.
+** Register a new 2nd-generation geometry function for use with the
+** r-tree MATCH operator.
 */
-struct Fts3PhraseToken {
-  char *z;                        /* Text of the token */
-  int n;                          /* Number of bytes in buffer z */
-  int isPrefix;                   /* True if token ends with a "*" character */
-  int bFirst;                     /* True if token must appear at position 0 */
+SQLITE_API int sqlite3_rtree_query_callback(
+  sqlite3 *db,                 /* Register SQL function on this connection */
+  const char *zQueryFunc,      /* Name of new SQL function */
+  int (*xQueryFunc)(sqlite3_rtree_query_info*), /* Callback */
+  void *pContext,              /* Extra data passed into the callback */
+  void (*xDestructor)(void*)   /* Destructor for the extra data */
+){
+  RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
 
-  /* Variables above this point are populated when the expression is
-  ** parsed (by code in fts3_expr.c). Below this point the variables are
-  ** used when evaluating the expression. */
-  Fts3DeferredToken *pDeferred;   /* Deferred token object for this token */
-  Fts3MultiSegReader *pSegcsr;    /* Segment-reader for this token */
-};
+  /* Allocate and populate the context object. */
+  pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
+  if( !pGeomCtx ) return SQLITE_NOMEM;
+  pGeomCtx->xGeom = 0;
+  pGeomCtx->xQueryFunc = xQueryFunc;
+  pGeomCtx->xDestructor = xDestructor;
+  pGeomCtx->pContext = pContext;
+  return sqlite3_create_function_v2(db, zQueryFunc, -1, SQLITE_ANY, 
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
+  );
+}
 
-struct Fts3Phrase {
-  /* Cache of doclist for this phrase. */
-  Fts3Doclist doclist;
-  int bIncr;                 /* True if doclist is loaded incrementally */
-  int iDoclistToken;
+#if !SQLITE_CORE
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int sqlite3_rtree_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi)
+  return sqlite3RtreeInit(db);
+}
+#endif
 
-  /* Variables below this point are populated by fts3_expr.c when parsing 
-  ** a MATCH expression. Everything above is part of the evaluation phase. 
-  */
-  int nToken;                /* Number of tokens in the phrase */
-  int iColumn;               /* Index of column this phrase must match */
-  Fts3PhraseToken aToken[1]; /* One entry for each token in the phrase */
-};
+#endif
 
+/************** End of rtree.c ***********************************************/
+/************** Begin file icu.c *********************************************/
 /*
-** A tree of these objects forms the RHS of a MATCH operator.
+** 2007 May 6
 **
-** If Fts3Expr.eType is FTSQUERY_PHRASE and isLoaded is true, then aDoclist 
-** points to a malloced buffer, size nDoclist bytes, containing the results 
-** of this phrase query in FTS3 doclist format. As usual, the initial 
-** "Length" field found in doclists stored on disk is omitted from this 
-** buffer.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
 **
-** Variable aMI is used only for FTSQUERY_NEAR nodes to store the global
-** matchinfo data. If it is not NULL, it points to an array of size nCol*3,
-** where nCol is the number of columns in the queried FTS table. The array
-** is populated as follows:
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
 **
-**   aMI[iCol*3 + 0] = Undefined
-**   aMI[iCol*3 + 1] = Number of occurrences
-**   aMI[iCol*3 + 2] = Number of rows containing at least one instance
+*************************************************************************
+** $Id: icu.c,v 1.7 2007/12/13 21:54:11 drh Exp $
 **
-** The aMI array is allocated using sqlite3_malloc(). It should be freed 
-** when the expression node is.
-*/
-struct Fts3Expr {
-  int eType;                 /* One of the FTSQUERY_XXX values defined below */
-  int nNear;                 /* Valid if eType==FTSQUERY_NEAR */
-  Fts3Expr *pParent;         /* pParent->pLeft==this or pParent->pRight==this */
-  Fts3Expr *pLeft;           /* Left operand */
-  Fts3Expr *pRight;          /* Right operand */
-  Fts3Phrase *pPhrase;       /* Valid if eType==FTSQUERY_PHRASE */
-
-  /* The following are used by the fts3_eval.c module. */
-  sqlite3_int64 iDocid;      /* Current docid */
-  u8 bEof;                   /* True this expression is at EOF already */
-  u8 bStart;                 /* True if iDocid is valid */
-  u8 bDeferred;              /* True if this expression is entirely deferred */
-
-  u32 *aMI;
-};
-
-/*
-** Candidate values for Fts3Query.eType. Note that the order of the first
-** four values is in order of precedence when parsing expressions. For 
-** example, the following:
+** This file implements an integration between the ICU library 
+** ("International Components for Unicode", an open-source library 
+** for handling unicode data) and SQLite. The integration uses 
+** ICU to provide the following to SQLite:
 **
-**   "a OR b AND c NOT d NEAR e"
+**   * An implementation of the SQL regexp() function (and hence REGEXP
+**     operator) using the ICU uregex_XX() APIs.
 **
-** is equivalent to:
+**   * Implementations of the SQL scalar upper() and lower() functions
+**     for case mapping.
 **
-**   "a OR (b AND (c NOT (d NEAR e)))"
+**   * Integration of ICU and SQLite collation sequences.
+**
+**   * An implementation of the LIKE operator that uses ICU to 
+**     provide case-independent matching.
 */
-#define FTSQUERY_NEAR   1
-#define FTSQUERY_NOT    2
-#define FTSQUERY_AND    3
-#define FTSQUERY_OR     4
-#define FTSQUERY_PHRASE 5
 
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)
 
-/* fts3_write.c */
-SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
-SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *);
-SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *);
-SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *);
-SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,
-  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
-SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
-  Fts3Table*,int,const char*,int,int,Fts3SegReader**);
-SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *);
-SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
-SQLITE_PRIVATE int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);
+/* Include ICU headers */
+#include 
+#include 
+#include 
+#include 
 
-SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
-SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);
+/* #include  */
 
-#ifndef SQLITE_DISABLE_FTS4_DEFERRED
-SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
-SQLITE_PRIVATE int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
-SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
-SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
-SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, int *);
+#ifndef SQLITE_CORE
+/*   #include "sqlite3ext.h" */
+  SQLITE_EXTENSION_INIT1
 #else
-# define sqlite3Fts3FreeDeferredTokens(x)
-# define sqlite3Fts3DeferToken(x,y,z) SQLITE_OK
-# define sqlite3Fts3CacheDeferredDoclists(x) SQLITE_OK
-# define sqlite3Fts3FreeDeferredDoclists(x)
-# define sqlite3Fts3DeferredTokenList(x,y,z) SQLITE_OK
+/*   #include "sqlite3.h" */
 #endif
 
-SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *);
-SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *, int *);
-
-/* Special values interpreted by sqlite3SegReaderCursor() */
-#define FTS3_SEGCURSOR_PENDING        -1
-#define FTS3_SEGCURSOR_ALL            -2
-
-SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Fts3SegFilter*);
-SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);
-SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);
-
-SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(Fts3Table *, 
-    int, int, int, const char *, int, int, int, Fts3MultiSegReader *);
-
-/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
-#define FTS3_SEGMENT_REQUIRE_POS   0x00000001
-#define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002
-#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
-#define FTS3_SEGMENT_PREFIX        0x00000008
-#define FTS3_SEGMENT_SCAN          0x00000010
-#define FTS3_SEGMENT_FIRST         0x00000020
-
-/* Type passed as 4th argument to SegmentReaderIterate() */
-struct Fts3SegFilter {
-  const char *zTerm;
-  int nTerm;
-  int iCol;
-  int flags;
-};
+/*
+** Maximum length (in bytes) of the pattern in a LIKE or GLOB
+** operator.
+*/
+#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
+# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
+#endif
 
-struct Fts3MultiSegReader {
-  /* Used internally by sqlite3Fts3SegReaderXXX() calls */
-  Fts3SegReader **apSegment;      /* Array of Fts3SegReader objects */
-  int nSegment;                   /* Size of apSegment array */
-  int nAdvance;                   /* How many seg-readers to advance */
-  Fts3SegFilter *pFilter;         /* Pointer to filter object */
-  char *aBuffer;                  /* Buffer to merge doclists in */
-  int nBuffer;                    /* Allocated size of aBuffer[] in bytes */
+/*
+** Version of sqlite3_free() that is always a function, never a macro.
+*/
+static void xFree(void *p){
+  sqlite3_free(p);
+}
 
-  int iColFilter;                 /* If >=0, filter for this column */
-  int bRestart;
+/*
+** This lookup table is used to help decode the first byte of
+** a multi-byte UTF8 character. It is copied here from SQLite source
+** code file utf8.c.
+*/
+static const unsigned char icuUtf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
 
-  /* Used by fts3.c only. */
-  int nCost;                      /* Cost of running iterator */
-  int bLookup;                    /* True if a lookup of a single entry. */
+#define SQLITE_ICU_READ_UTF8(zIn, c)                       \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = icuUtf8Trans1[c-0xc0];                             \
+    while( (*zIn & 0xc0)==0x80 ){                          \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+  }
 
-  /* Output values. Valid only after Fts3SegReaderStep() returns SQLITE_ROW. */
-  char *zTerm;                    /* Pointer to term buffer */
-  int nTerm;                      /* Size of zTerm in bytes */
-  char *aDoclist;                 /* Pointer to doclist buffer */
-  int nDoclist;                   /* Size of aDoclist[] in bytes */
-};
+#define SQLITE_ICU_SKIP_UTF8(zIn)                          \
+  assert( *zIn );                                          \
+  if( *(zIn++)>=0xc0 ){                                    \
+    while( (*zIn & 0xc0)==0x80 ){zIn++;}                   \
+  }
 
-SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table*,int,int);
 
-#define fts3GetVarint32(p, piVal) (                                           \
-  (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \
-)
+/*
+** Compare two UTF-8 strings for equality where the first string is
+** a "LIKE" expression. Return true (1) if they are the same and 
+** false (0) if they are different.
+*/
+static int icuLikeCompare(
+  const uint8_t *zPattern,   /* LIKE pattern */
+  const uint8_t *zString,    /* The UTF-8 string to compare against */
+  const UChar32 uEsc         /* The escape character */
+){
+  static const int MATCH_ONE = (UChar32)'_';
+  static const int MATCH_ALL = (UChar32)'%';
 
-/* fts3.c */
-SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *, sqlite3_int64);
-SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
-SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *, int *);
-SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64);
-SQLITE_PRIVATE void sqlite3Fts3Dequote(char *);
-SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
-SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
-SQLITE_PRIVATE int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
-SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
+  int prevEscape = 0;     /* True if the previous character was uEsc */
 
-/* fts3_tokenizer.c */
-SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *, int *);
-SQLITE_PRIVATE int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
-SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
-    sqlite3_tokenizer **, char **
-);
-SQLITE_PRIVATE int sqlite3Fts3IsIdChar(char);
+  while( 1 ){
 
-/* fts3_snippet.c */
-SQLITE_PRIVATE void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
-SQLITE_PRIVATE void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
-  const char *, const char *, int, int
-);
-SQLITE_PRIVATE void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);
+    /* Read (and consume) the next character from the input pattern. */
+    UChar32 uPattern;
+    SQLITE_ICU_READ_UTF8(zPattern, uPattern);
+    if( uPattern==0 ) break;
 
-/* fts3_expr.c */
-SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
-  char **, int, int, int, const char *, int, Fts3Expr **, char **
-);
-SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *);
-#ifdef SQLITE_TEST
-SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
-SQLITE_PRIVATE int sqlite3Fts3InitTerm(sqlite3 *db);
-#endif
+    /* There are now 4 possibilities:
+    **
+    **     1. uPattern is an unescaped match-all character "%",
+    **     2. uPattern is an unescaped match-one character "_",
+    **     3. uPattern is an unescaped escape character, or
+    **     4. uPattern is to be handled as an ordinary character
+    */
+    if( !prevEscape && uPattern==MATCH_ALL ){
+      /* Case 1. */
+      uint8_t c;
 
-SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
-  sqlite3_tokenizer_cursor **
-);
+      /* Skip any MATCH_ALL or MATCH_ONE characters that follow a
+      ** MATCH_ALL. For each MATCH_ONE, skip one character in the 
+      ** test string.
+      */
+      while( (c=*zPattern) == MATCH_ALL || c == MATCH_ONE ){
+        if( c==MATCH_ONE ){
+          if( *zString==0 ) return 0;
+          SQLITE_ICU_SKIP_UTF8(zString);
+        }
+        zPattern++;
+      }
 
-/* fts3_aux.c */
-SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db);
+      if( *zPattern==0 ) return 1;
 
-SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);
+      while( *zString ){
+        if( icuLikeCompare(zPattern, zString, uEsc) ){
+          return 1;
+        }
+        SQLITE_ICU_SKIP_UTF8(zString);
+      }
+      return 0;
 
-SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(
-    Fts3Table*, Fts3MultiSegReader*, int, const char*, int);
-SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
-    Fts3Table *, Fts3MultiSegReader *, sqlite3_int64 *, char **, int *);
-SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol, char **); 
-SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(Fts3Cursor *, Fts3MultiSegReader *, int *);
-SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);
+    }else if( !prevEscape && uPattern==MATCH_ONE ){
+      /* Case 2. */
+      if( *zString==0 ) return 0;
+      SQLITE_ICU_SKIP_UTF8(zString);
 
-/* fts3_tokenize_vtab.c */
-SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);
+    }else if( !prevEscape && uPattern==uEsc){
+      /* Case 3. */
+      prevEscape = 1;
 
-/* fts3_unicode2.c (functions generated by parsing unicode text files) */
-#ifndef SQLITE_DISABLE_FTS3_UNICODE
-SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int, int);
-SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int);
-SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int);
-#endif
+    }else{
+      /* Case 4. */
+      UChar32 uString;
+      SQLITE_ICU_READ_UTF8(zString, uString);
+      uString = u_foldCase(uString, U_FOLD_CASE_DEFAULT);
+      uPattern = u_foldCase(uPattern, U_FOLD_CASE_DEFAULT);
+      if( uString!=uPattern ){
+        return 0;
+      }
+      prevEscape = 0;
+    }
+  }
 
-#endif /* !SQLITE_CORE || SQLITE_ENABLE_FTS3 */
-#endif /* _FTSINT_H */
+  return *zString==0;
+}
 
-/************** End of fts3Int.h *********************************************/
-/************** Continuing where we left off in fts3.c ***********************/
-#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+/*
+** Implementation of the like() SQL function.  This function implements
+** the build-in LIKE operator.  The first argument to the function is the
+** pattern and the second argument is the string.  So, the SQL statements:
+**
+**       A LIKE B
+**
+** is implemented as like(B, A). If there is an escape character E, 
+**
+**       A LIKE B ESCAPE E
+**
+** is mapped to like(B, A, E).
+*/
+static void icuLikeFunc(
+  sqlite3_context *context, 
+  int argc, 
+  sqlite3_value **argv
+){
+  const unsigned char *zA = sqlite3_value_text(argv[0]);
+  const unsigned char *zB = sqlite3_value_text(argv[1]);
+  UChar32 uEsc = 0;
 
-#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
-# define SQLITE_CORE 1
-#endif
+  /* Limit the length of the LIKE or GLOB pattern to avoid problems
+  ** of deep recursion and N*N behavior in patternCompare().
+  */
+  if( sqlite3_value_bytes(argv[0])>SQLITE_MAX_LIKE_PATTERN_LENGTH ){
+    sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
+    return;
+  }
 
-/* #include  */
-/* #include  */
-/* #include  */
-/* #include  */
-/* #include  */
-/* #include  */
 
-#ifndef SQLITE_CORE 
-  SQLITE_EXTENSION_INIT1
-#endif
+  if( argc==3 ){
+    /* The escape character string must consist of a single UTF-8 character.
+    ** Otherwise, return an error.
+    */
+    int nE= sqlite3_value_bytes(argv[2]);
+    const unsigned char *zE = sqlite3_value_text(argv[2]);
+    int i = 0;
+    if( zE==0 ) return;
+    U8_NEXT(zE, i, nE, uEsc);
+    if( i!=nE){
+      sqlite3_result_error(context, 
+          "ESCAPE expression must be a single character", -1);
+      return;
+    }
+  }
 
-static int fts3EvalNext(Fts3Cursor *pCsr);
-static int fts3EvalStart(Fts3Cursor *pCsr);
-static int fts3TermSegReaderCursor(
-    Fts3Cursor *, const char *, int, int, Fts3MultiSegReader **);
+  if( zA && zB ){
+    sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));
+  }
+}
 
-/* 
-** Write a 64-bit variable-length integer to memory starting at p[0].
-** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
-** The number of bytes written is returned.
+/*
+** This function is called when an ICU function called from within
+** the implementation of an SQL scalar function returns an error.
+**
+** The scalar function context passed as the first argument is 
+** loaded with an error message based on the following two args.
 */
-SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
-  unsigned char *q = (unsigned char *) p;
-  sqlite_uint64 vu = v;
-  do{
-    *q++ = (unsigned char) ((vu & 0x7f) | 0x80);
-    vu >>= 7;
-  }while( vu!=0 );
-  q[-1] &= 0x7f;  /* turn off high bit in final byte */
-  assert( q - (unsigned char *)p <= FTS3_VARINT_MAX );
-  return (int) (q - (unsigned char *)p);
+static void icuFunctionError(
+  sqlite3_context *pCtx,       /* SQLite scalar function context */
+  const char *zName,           /* Name of ICU function that failed */
+  UErrorCode e                 /* Error code returned by ICU function */
+){
+  char zBuf[128];
+  sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));
+  zBuf[127] = '\0';
+  sqlite3_result_error(pCtx, zBuf, -1);
 }
 
-#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
-  v = (v & mask1) | ( (*ptr++) << shift );                    \
-  if( (v & mask2)==0 ){ var = v; return ret; }
-#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
-  v = (*ptr++);                                               \
-  if( (v & mask2)==0 ){ var = v; return ret; }
+/*
+** Function to delete compiled regexp objects. Registered as
+** a destructor function with sqlite3_set_auxdata().
+*/
+static void icuRegexpDelete(void *p){
+  URegularExpression *pExpr = (URegularExpression *)p;
+  uregex_close(pExpr);
+}
 
-/* 
-** Read a 64-bit variable-length integer from memory starting at p[0].
-** Return the number of bytes read, or 0 on error.
-** The value is stored in *v.
+/*
+** Implementation of SQLite REGEXP operator. This scalar function takes
+** two arguments. The first is a regular expression pattern to compile
+** the second is a string to match against that pattern. If either 
+** argument is an SQL NULL, then NULL Is returned. Otherwise, the result
+** is 1 if the string matches the pattern, or 0 otherwise.
+**
+** SQLite maps the regexp() function to the regexp() operator such
+** that the following two are equivalent:
+**
+**     zString REGEXP zPattern
+**     regexp(zPattern, zString)
+**
+** Uses the following ICU regexp APIs:
+**
+**     uregex_open()
+**     uregex_matches()
+**     uregex_close()
 */
-SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
-  const char *pStart = p;
-  u32 a;
-  u64 b;
-  int shift;
+static void icuRegexpFunc(sqlite3_context *p, int nArg, sqlite3_value **apArg){
+  UErrorCode status = U_ZERO_ERROR;
+  URegularExpression *pExpr;
+  UBool res;
+  const UChar *zString = sqlite3_value_text16(apArg[1]);
 
-  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
-  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
-  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
-  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
-  b = (a & 0x0FFFFFFF );
+  (void)nArg;  /* Unused parameter */
 
-  for(shift=28; shift<=63; shift+=7){
-    u64 c = *p++;
-    b += (c&0x7F) << shift;
-    if( (c & 0x80)==0 ) break;
+  /* If the left hand side of the regexp operator is NULL, 
+  ** then the result is also NULL. 
+  */
+  if( !zString ){
+    return;
   }
-  *v = b;
-  return (int)(p - pStart);
-}
 
-/*
-** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to a
-** 32-bit integer before it is returned.
-*/
-SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *p, int *pi){
-  u32 a;
+  pExpr = sqlite3_get_auxdata(p, 0);
+  if( !pExpr ){
+    const UChar *zPattern = sqlite3_value_text16(apArg[0]);
+    if( !zPattern ){
+      return;
+    }
+    pExpr = uregex_open(zPattern, -1, 0, 0, &status);
 
-#ifndef fts3GetVarint32
-  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
-#else
-  a = (*p++);
-  assert( a & 0x80 );
-#endif
+    if( U_SUCCESS(status) ){
+      sqlite3_set_auxdata(p, 0, pExpr, icuRegexpDelete);
+    }else{
+      assert(!pExpr);
+      icuFunctionError(p, "uregex_open", status);
+      return;
+    }
+  }
 
-  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *pi, 2);
-  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *pi, 3);
-  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *pi, 4);
-  a = (a & 0x0FFFFFFF );
-  *pi = (int)(a | ((u32)(*p & 0x0F) << 28));
-  return 5;
-}
+  /* Configure the text that the regular expression operates on. */
+  uregex_setText(pExpr, zString, -1, &status);
+  if( !U_SUCCESS(status) ){
+    icuFunctionError(p, "uregex_setText", status);
+    return;
+  }
 
-/*
-** Return the number of bytes required to encode v as a varint
-*/
-SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64 v){
-  int i = 0;
-  do{
-    i++;
-    v >>= 7;
-  }while( v!=0 );
-  return i;
+  /* Attempt the match */
+  res = uregex_matches(pExpr, 0, &status);
+  if( !U_SUCCESS(status) ){
+    icuFunctionError(p, "uregex_matches", status);
+    return;
+  }
+
+  /* Set the text that the regular expression operates on to a NULL
+  ** pointer. This is not really necessary, but it is tidier than 
+  ** leaving the regular expression object configured with an invalid
+  ** pointer after this function returns.
+  */
+  uregex_setText(pExpr, 0, 0, &status);
+
+  /* Return 1 or 0. */
+  sqlite3_result_int(p, res ? 1 : 0);
 }
 
 /*
-** Convert an SQL-style quoted string into a normal string by removing
-** the quote characters.  The conversion is done in-place.  If the
-** input does not begin with a quote character, then this routine
-** is a no-op.
+** Implementations of scalar functions for case mapping - upper() and 
+** lower(). Function upper() converts its input to upper-case (ABC).
+** Function lower() converts to lower-case (abc).
 **
-** Examples:
+** ICU provides two types of case mapping, "general" case mapping and
+** "language specific". Refer to ICU documentation for the differences
+** between the two.
 **
-**     "abc"   becomes   abc
-**     'xyz'   becomes   xyz
-**     [pqr]   becomes   pqr
-**     `mno`   becomes   mno
+** To utilise "general" case mapping, the upper() or lower() scalar 
+** functions are invoked with one argument:
+**
+**     upper('ABC') -> 'abc'
+**     lower('abc') -> 'ABC'
+**
+** To access ICU "language specific" case mapping, upper() or lower()
+** should be invoked with two arguments. The second argument is the name
+** of the locale to use. Passing an empty string ("") or SQL NULL value
+** as the second argument is the same as invoking the 1 argument version
+** of upper() or lower().
+**
+**     lower('I', 'en_us') -> 'i'
+**     lower('I', 'tr_tr') -> '\u131' (small dotless i)
 **
+** http://www.icu-project.org/userguide/posix.html#case_mappings
 */
-SQLITE_PRIVATE void sqlite3Fts3Dequote(char *z){
-  char quote;                     /* Quote character (if any ) */
+static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
+  const UChar *zInput;            /* Pointer to input string */
+  UChar *zOutput = 0;             /* Pointer to output buffer */
+  int nInput;                     /* Size of utf-16 input string in bytes */
+  int nOut;                       /* Size of output buffer in bytes */
+  int cnt;
+  int bToUpper;                   /* True for toupper(), false for tolower() */
+  UErrorCode status;
+  const char *zLocale = 0;
 
-  quote = z[0];
-  if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
-    int iIn = 1;                  /* Index of next byte to read from input */
-    int iOut = 0;                 /* Index of next byte to write to output */
+  assert(nArg==1 || nArg==2);
+  bToUpper = (sqlite3_user_data(p)!=0);
+  if( nArg==2 ){
+    zLocale = (const char *)sqlite3_value_text(apArg[1]);
+  }
 
-    /* If the first byte was a '[', then the close-quote character is a ']' */
-    if( quote=='[' ) quote = ']';  
+  zInput = sqlite3_value_text16(apArg[0]);
+  if( !zInput ){
+    return;
+  }
+  nOut = nInput = sqlite3_value_bytes16(apArg[0]);
+  if( nOut==0 ){
+    sqlite3_result_text16(p, "", 0, SQLITE_STATIC);
+    return;
+  }
 
-    while( ALWAYS(z[iIn]) ){
-      if( z[iIn]==quote ){
-        if( z[iIn+1]!=quote ) break;
-        z[iOut++] = quote;
-        iIn += 2;
-      }else{
-        z[iOut++] = z[iIn++];
-      }
+  for(cnt=0; cnt<2; cnt++){
+    UChar *zNew = sqlite3_realloc(zOutput, nOut);
+    if( zNew==0 ){
+      sqlite3_free(zOutput);
+      sqlite3_result_error_nomem(p);
+      return;
     }
-    z[iOut] = '\0';
+    zOutput = zNew;
+    status = U_ZERO_ERROR;
+    if( bToUpper ){
+      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }else{
+      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }
+
+    if( U_SUCCESS(status) ){
+      sqlite3_result_text16(p, zOutput, nOut, xFree);
+    }else if( status==U_BUFFER_OVERFLOW_ERROR ){
+      assert( cnt==0 );
+      continue;
+    }else{
+      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
+    }
+    return;
   }
+  assert( 0 );     /* Unreachable */
 }
 
 /*
-** Read a single varint from the doclist at *pp and advance *pp to point
-** to the first byte past the end of the varint.  Add the value of the varint
-** to *pVal.
+** Collation sequence destructor function. The pCtx argument points to
+** a UCollator structure previously allocated using ucol_open().
 */
-static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
-  sqlite3_int64 iVal;
-  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
-  *pVal += iVal;
+static void icuCollationDel(void *pCtx){
+  UCollator *p = (UCollator *)pCtx;
+  ucol_close(p);
 }
 
 /*
-** When this function is called, *pp points to the first byte following a
-** varint that is part of a doclist (or position-list, or any other list
-** of varints). This function moves *pp to point to the start of that varint,
-** and sets *pVal by the varint value.
+** Collation sequence comparison function. The pCtx argument points to
+** a UCollator structure previously allocated using ucol_open().
+*/
+static int icuCollationColl(
+  void *pCtx,
+  int nLeft,
+  const void *zLeft,
+  int nRight,
+  const void *zRight
+){
+  UCollationResult res;
+  UCollator *p = (UCollator *)pCtx;
+  res = ucol_strcoll(p, (UChar *)zLeft, nLeft/2, (UChar *)zRight, nRight/2);
+  switch( res ){
+    case UCOL_LESS:    return -1;
+    case UCOL_GREATER: return +1;
+    case UCOL_EQUAL:   return 0;
+  }
+  assert(!"Unexpected return value from ucol_strcoll()");
+  return 0;
+}
+
+/*
+** Implementation of the scalar function icu_load_collation().
 **
-** Argument pStart points to the first byte of the doclist that the
-** varint is part of.
+** This scalar function is used to add ICU collation based collation 
+** types to an SQLite database connection. It is intended to be called
+** as follows:
+**
+**     SELECT icu_load_collation(, );
+**
+** Where  is a string containing an ICU locale identifier (i.e.
+** "en_AU", "tr_TR" etc.) and  is the name of the
+** collation sequence to create.
 */
-static void fts3GetReverseVarint(
-  char **pp, 
-  char *pStart, 
-  sqlite3_int64 *pVal
+static void icuLoadCollation(
+  sqlite3_context *p, 
+  int nArg, 
+  sqlite3_value **apArg
 ){
-  sqlite3_int64 iVal;
-  char *p;
+  sqlite3 *db = (sqlite3 *)sqlite3_user_data(p);
+  UErrorCode status = U_ZERO_ERROR;
+  const char *zLocale;      /* Locale identifier - (eg. "jp_JP") */
+  const char *zName;        /* SQL Collation sequence name (eg. "japanese") */
+  UCollator *pUCollator;    /* ICU library collation object */
+  int rc;                   /* Return code from sqlite3_create_collation_x() */
 
-  /* Pointer p now points at the first byte past the varint we are 
-  ** interested in. So, unless the doclist is corrupt, the 0x80 bit is
-  ** clear on character p[-1]. */
-  for(p = (*pp)-2; p>=pStart && *p&0x80; p--);
-  p++;
-  *pp = p;
+  assert(nArg==2);
+  (void)nArg; /* Unused parameter */
+  zLocale = (const char *)sqlite3_value_text(apArg[0]);
+  zName = (const char *)sqlite3_value_text(apArg[1]);
 
-  sqlite3Fts3GetVarint(p, &iVal);
-  *pVal = iVal;
+  if( !zLocale || !zName ){
+    return;
+  }
+
+  pUCollator = ucol_open(zLocale, &status);
+  if( !U_SUCCESS(status) ){
+    icuFunctionError(p, "ucol_open", status);
+    return;
+  }
+  assert(p);
+
+  rc = sqlite3_create_collation_v2(db, zName, SQLITE_UTF16, (void *)pUCollator, 
+      icuCollationColl, icuCollationDel
+  );
+  if( rc!=SQLITE_OK ){
+    ucol_close(pUCollator);
+    sqlite3_result_error(p, "Error registering collation function", -1);
+  }
 }
 
 /*
-** The xDisconnect() virtual table method.
+** Register the ICU extension functions with database db.
 */
-static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
-  Fts3Table *p = (Fts3Table *)pVtab;
+SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db){
+  static const struct IcuScalar {
+    const char *zName;                        /* Function name */
+    unsigned char nArg;                       /* Number of arguments */
+    unsigned short enc;                       /* Optimal text encoding */
+    unsigned char iContext;                   /* sqlite3_user_data() context */
+    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } scalars[] = {
+    {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},
+    {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},
+    {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
+    {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},
+    {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
+    {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},
+    {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
+    {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},
+    {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
+    {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},
+    {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
+    {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},
+  };
+  int rc = SQLITE_OK;
   int i;
 
-  assert( p->nPendingData==0 );
-  assert( p->pSegments==0 );
-
-  /* Free any prepared statements held */
-  for(i=0; iaStmt); i++){
-    sqlite3_finalize(p->aStmt[i]);
+  
+  for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){
+    const struct IcuScalar *p = &scalars[i];
+    rc = sqlite3_create_function(
+        db, p->zName, p->nArg, p->enc, 
+        p->iContext ? (void*)db : (void*)0,
+        p->xFunc, 0, 0
+    );
   }
-  sqlite3_free(p->zSegmentsTbl);
-  sqlite3_free(p->zReadExprlist);
-  sqlite3_free(p->zWriteExprlist);
-  sqlite3_free(p->zContentTbl);
-  sqlite3_free(p->zLanguageid);
 
-  /* Invoke the tokenizer destructor to free the tokenizer. */
-  p->pTokenizer->pModule->xDestroy(p->pTokenizer);
+  return rc;
+}
 
-  sqlite3_free(p);
-  return SQLITE_OK;
+#if !SQLITE_CORE
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int sqlite3_icu_init(
+  sqlite3 *db, 
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi)
+  return sqlite3IcuInit(db);
 }
+#endif
+
+#endif
 
+/************** End of icu.c *************************************************/
+/************** Begin file fts3_icu.c ****************************************/
 /*
-** Construct one or more SQL statements from the format string given
-** and then evaluate those statements. The success code is written
-** into *pRc.
+** 2007 June 22
 **
-** If *pRc is initially non-zero then this routine is a no-op.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file implements a tokenizer for fts3 based on the ICU library.
 */
-static void fts3DbExec(
-  int *pRc,              /* Success code */
-  sqlite3 *db,           /* Database in which to run SQL */
-  const char *zFormat,   /* Format string for SQL */
-  ...                    /* Arguments to the format string */
-){
-  va_list ap;
-  char *zSql;
-  if( *pRc ) return;
-  va_start(ap, zFormat);
-  zSql = sqlite3_vmprintf(zFormat, ap);
-  va_end(ap);
-  if( zSql==0 ){
-    *pRc = SQLITE_NOMEM;
-  }else{
-    *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
-    sqlite3_free(zSql);
-  }
-}
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+#ifdef SQLITE_ENABLE_ICU
+
+/* #include  */
+/* #include  */
+/* #include "fts3_tokenizer.h" */
+
+#include 
+/* #include  */
+/* #include  */
+#include 
+
+typedef struct IcuTokenizer IcuTokenizer;
+typedef struct IcuCursor IcuCursor;
+
+struct IcuTokenizer {
+  sqlite3_tokenizer base;
+  char *zLocale;
+};
+
+struct IcuCursor {
+  sqlite3_tokenizer_cursor base;
+
+  UBreakIterator *pIter;      /* ICU break-iterator object */
+  int nChar;                  /* Number of UChar elements in pInput */
+  UChar *aChar;               /* Copy of input using utf-16 encoding */
+  int *aOffset;               /* Offsets of each character in utf-8 input */
+
+  int nBuffer;
+  char *zBuffer;
+
+  int iToken;
+};
 
 /*
-** The xDestroy() virtual table method.
+** Create a new tokenizer instance.
 */
-static int fts3DestroyMethod(sqlite3_vtab *pVtab){
-  Fts3Table *p = (Fts3Table *)pVtab;
-  int rc = SQLITE_OK;              /* Return code */
-  const char *zDb = p->zDb;        /* Name of database (e.g. "main", "temp") */
-  sqlite3 *db = p->db;             /* Database handle */
+static int icuCreate(
+  int argc,                            /* Number of entries in argv[] */
+  const char * const *argv,            /* Tokenizer creation arguments */
+  sqlite3_tokenizer **ppTokenizer      /* OUT: Created tokenizer */
+){
+  IcuTokenizer *p;
+  int n = 0;
 
-  /* Drop the shadow tables */
-  if( p->zContentTbl==0 ){
-    fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_content'", zDb, p->zName);
+  if( argc>0 ){
+    n = strlen(argv[0])+1;
   }
-  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segments'", zDb,p->zName);
-  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_segdir'", zDb, p->zName);
-  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_docsize'", zDb, p->zName);
-  fts3DbExec(&rc, db, "DROP TABLE IF EXISTS %Q.'%q_stat'", zDb, p->zName);
+  p = (IcuTokenizer *)sqlite3_malloc(sizeof(IcuTokenizer)+n);
+  if( !p ){
+    return SQLITE_NOMEM;
+  }
+  memset(p, 0, sizeof(IcuTokenizer));
 
-  /* If everything has worked, invoke fts3DisconnectMethod() to free the
-  ** memory associated with the Fts3Table structure and return SQLITE_OK.
-  ** Otherwise, return an SQLite error code.
-  */
-  return (rc==SQLITE_OK ? fts3DisconnectMethod(pVtab) : rc);
+  if( n ){
+    p->zLocale = (char *)&p[1];
+    memcpy(p->zLocale, argv[0], n);
+  }
+
+  *ppTokenizer = (sqlite3_tokenizer *)p;
+
+  return SQLITE_OK;
 }
 
+/*
+** Destroy a tokenizer
+*/
+static int icuDestroy(sqlite3_tokenizer *pTokenizer){
+  IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
+  sqlite3_free(p);
+  return SQLITE_OK;
+}
 
 /*
-** Invoke sqlite3_declare_vtab() to declare the schema for the FTS3 table
-** passed as the first argument. This is done as part of the xConnect()
-** and xCreate() methods.
-**
-** If *pRc is non-zero when this function is called, it is a no-op. 
-** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
-** before returning.
+** Prepare to begin tokenizing a particular string.  The input
+** string to be tokenized is pInput[0..nBytes-1].  A cursor
+** used to incrementally tokenize this string is returned in 
+** *ppCursor.
 */
-static void fts3DeclareVtab(int *pRc, Fts3Table *p){
-  if( *pRc==SQLITE_OK ){
-    int i;                        /* Iterator variable */
-    int rc;                       /* Return code */
-    char *zSql;                   /* SQL statement passed to declare_vtab() */
-    char *zCols;                  /* List of user defined columns */
-    const char *zLanguageid;
+static int icuOpen(
+  sqlite3_tokenizer *pTokenizer,         /* The tokenizer */
+  const char *zInput,                    /* Input string */
+  int nInput,                            /* Length of zInput in bytes */
+  sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */
+){
+  IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
+  IcuCursor *pCsr;
 
-    zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");
-    sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
+  const int32_t opt = U_FOLD_CASE_DEFAULT;
+  UErrorCode status = U_ZERO_ERROR;
+  int nChar;
 
-    /* Create a list of user columns for the virtual table */
-    zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
-    for(i=1; zCols && inColumn; i++){
-      zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
+  UChar32 c;
+  int iInput = 0;
+  int iOut = 0;
+
+  *ppCursor = 0;
+
+  if( zInput==0 ){
+    nInput = 0;
+    zInput = "";
+  }else if( nInput<0 ){
+    nInput = strlen(zInput);
+  }
+  nChar = nInput+1;
+  pCsr = (IcuCursor *)sqlite3_malloc(
+      sizeof(IcuCursor) +                /* IcuCursor */
+      ((nChar+3)&~3) * sizeof(UChar) +   /* IcuCursor.aChar[] */
+      (nChar+1) * sizeof(int)            /* IcuCursor.aOffset[] */
+  );
+  if( !pCsr ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(IcuCursor));
+  pCsr->aChar = (UChar *)&pCsr[1];
+  pCsr->aOffset = (int *)&pCsr->aChar[(nChar+3)&~3];
+
+  pCsr->aOffset[iOut] = iInput;
+  U8_NEXT(zInput, iInput, nInput, c); 
+  while( c>0 ){
+    int isError = 0;
+    c = u_foldCase(c, opt);
+    U16_APPEND(pCsr->aChar, iOut, nChar, c, isError);
+    if( isError ){
+      sqlite3_free(pCsr);
+      return SQLITE_ERROR;
     }
+    pCsr->aOffset[iOut] = iInput;
 
-    /* Create the whole "CREATE TABLE" statement to pass to SQLite */
-    zSql = sqlite3_mprintf(
-        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)", 
-        zCols, p->zName, zLanguageid
-    );
-    if( !zCols || !zSql ){
-      rc = SQLITE_NOMEM;
+    if( iInputdb, zSql);
+      c = 0;
     }
+  }
 
-    sqlite3_free(zSql);
-    sqlite3_free(zCols);
-    *pRc = rc;
+  pCsr->pIter = ubrk_open(UBRK_WORD, p->zLocale, pCsr->aChar, iOut, &status);
+  if( !U_SUCCESS(status) ){
+    sqlite3_free(pCsr);
+    return SQLITE_ERROR;
   }
+  pCsr->nChar = iOut;
+
+  ubrk_first(pCsr->pIter);
+  *ppCursor = (sqlite3_tokenizer_cursor *)pCsr;
+  return SQLITE_OK;
 }
 
 /*
-** Create the %_stat table if it does not already exist.
+** Close a tokenization cursor previously opened by a call to icuOpen().
 */
-SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int *pRc, Fts3Table *p){
-  fts3DbExec(pRc, p->db, 
-      "CREATE TABLE IF NOT EXISTS %Q.'%q_stat'"
-          "(id INTEGER PRIMARY KEY, value BLOB);",
-      p->zDb, p->zName
-  );
-  if( (*pRc)==SQLITE_OK ) p->bHasStat = 1;
+static int icuClose(sqlite3_tokenizer_cursor *pCursor){
+  IcuCursor *pCsr = (IcuCursor *)pCursor;
+  ubrk_close(pCsr->pIter);
+  sqlite3_free(pCsr->zBuffer);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
 }
 
 /*
-** Create the backing store tables (%_content, %_segments and %_segdir)
-** required by the FTS3 table passed as the only argument. This is done
-** as part of the vtab xCreate() method.
-**
-** If the p->bHasDocsize boolean is true (indicating that this is an
-** FTS4 table, not an FTS3 table) then also create the %_docsize and
-** %_stat tables required by FTS4.
+** Extract the next token from a tokenization cursor.
 */
-static int fts3CreateTables(Fts3Table *p){
-  int rc = SQLITE_OK;             /* Return code */
-  int i;                          /* Iterator variable */
-  sqlite3 *db = p->db;            /* The database connection */
+static int icuNext(
+  sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by simpleOpen */
+  const char **ppToken,               /* OUT: *ppToken is the token text */
+  int *pnBytes,                       /* OUT: Number of bytes in token */
+  int *piStartOffset,                 /* OUT: Starting offset of token */
+  int *piEndOffset,                   /* OUT: Ending offset of token */
+  int *piPosition                     /* OUT: Position integer of token */
+){
+  IcuCursor *pCsr = (IcuCursor *)pCursor;
 
-  if( p->zContentTbl==0 ){
-    const char *zLanguageid = p->zLanguageid;
-    char *zContentCols;           /* Columns of %_content table */
+  int iStart = 0;
+  int iEnd = 0;
+  int nByte = 0;
 
-    /* Create a list of user columns for the content table */
-    zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
-    for(i=0; zContentCols && inColumn; i++){
-      char *z = p->azColumn[i];
-      zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
+  while( iStart==iEnd ){
+    UChar32 c;
+
+    iStart = ubrk_current(pCsr->pIter);
+    iEnd = ubrk_next(pCsr->pIter);
+    if( iEnd==UBRK_DONE ){
+      return SQLITE_DONE;
     }
-    if( zLanguageid && zContentCols ){
-      zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);
+
+    while( iStartaChar, iWhite, pCsr->nChar, c);
+      if( u_isspace(c) ){
+        iStart = iWhite;
+      }else{
+        break;
+      }
     }
-    if( zContentCols==0 ) rc = SQLITE_NOMEM;
-  
-    /* Create the content table */
-    fts3DbExec(&rc, db, 
-       "CREATE TABLE %Q.'%q_content'(%s)",
-       p->zDb, p->zName, zContentCols
-    );
-    sqlite3_free(zContentCols);
+    assert(iStart<=iEnd);
   }
 
-  /* Create other tables */
-  fts3DbExec(&rc, db, 
-      "CREATE TABLE %Q.'%q_segments'(blockid INTEGER PRIMARY KEY, block BLOB);",
-      p->zDb, p->zName
-  );
-  fts3DbExec(&rc, db, 
-      "CREATE TABLE %Q.'%q_segdir'("
-        "level INTEGER,"
-        "idx INTEGER,"
-        "start_block INTEGER,"
-        "leaves_end_block INTEGER,"
-        "end_block INTEGER,"
-        "root BLOB,"
-        "PRIMARY KEY(level, idx)"
-      ");",
-      p->zDb, p->zName
-  );
-  if( p->bHasDocsize ){
-    fts3DbExec(&rc, db, 
-        "CREATE TABLE %Q.'%q_docsize'(docid INTEGER PRIMARY KEY, size BLOB);",
-        p->zDb, p->zName
+  do {
+    UErrorCode status = U_ZERO_ERROR;
+    if( nByte ){
+      char *zNew = sqlite3_realloc(pCsr->zBuffer, nByte);
+      if( !zNew ){
+        return SQLITE_NOMEM;
+      }
+      pCsr->zBuffer = zNew;
+      pCsr->nBuffer = nByte;
+    }
+
+    u_strToUTF8(
+        pCsr->zBuffer, pCsr->nBuffer, &nByte,    /* Output vars */
+        &pCsr->aChar[iStart], iEnd-iStart,       /* Input vars */
+        &status                                  /* Output success/failure */
     );
-  }
-  assert( p->bHasStat==p->bFts4 );
-  if( p->bHasStat ){
-    sqlite3Fts3CreateStatTable(&rc, p);
-  }
-  return rc;
+  } while( nByte>pCsr->nBuffer );
+
+  *ppToken = pCsr->zBuffer;
+  *pnBytes = nByte;
+  *piStartOffset = pCsr->aOffset[iStart];
+  *piEndOffset = pCsr->aOffset[iEnd];
+  *piPosition = pCsr->iToken++;
+
+  return SQLITE_OK;
 }
 
 /*
-** Store the current database page-size in bytes in p->nPgsz.
-**
-** If *pRc is non-zero when this function is called, it is a no-op. 
-** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
-** before returning.
+** The set of routines that implement the simple tokenizer
 */
-static void fts3DatabasePageSize(int *pRc, Fts3Table *p){
-  if( *pRc==SQLITE_OK ){
-    int rc;                       /* Return code */
-    char *zSql;                   /* SQL text "PRAGMA %Q.page_size" */
-    sqlite3_stmt *pStmt;          /* Compiled "PRAGMA %Q.page_size" statement */
-  
-    zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);
-    if( !zSql ){
-      rc = SQLITE_NOMEM;
-    }else{
-      rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
-      if( rc==SQLITE_OK ){
-        sqlite3_step(pStmt);
-        p->nPgsz = sqlite3_column_int(pStmt, 0);
-        rc = sqlite3_finalize(pStmt);
-      }else if( rc==SQLITE_AUTH ){
-        p->nPgsz = 1024;
-        rc = SQLITE_OK;
-      }
-    }
-    assert( p->nPgsz>0 || rc!=SQLITE_OK );
-    sqlite3_free(zSql);
-    *pRc = rc;
-  }
+static const sqlite3_tokenizer_module icuTokenizerModule = {
+  0,                           /* iVersion    */
+  icuCreate,                   /* xCreate     */
+  icuDestroy,                  /* xCreate     */
+  icuOpen,                     /* xOpen       */
+  icuClose,                    /* xClose      */
+  icuNext,                     /* xNext       */
+  0,                           /* xLanguageid */
+};
+
+/*
+** Set *ppModule to point at the implementation of the ICU tokenizer.
+*/
+SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(
+  sqlite3_tokenizer_module const**ppModule
+){
+  *ppModule = &icuTokenizerModule;
 }
 
+#endif /* defined(SQLITE_ENABLE_ICU) */
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_icu.c ********************************************/
+/************** Begin file sqlite3rbu.c **************************************/
 /*
-** "Special" FTS4 arguments are column specifications of the following form:
+** 2014 August 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+**
+** OVERVIEW 
+**
+**  The RBU extension requires that the RBU update be packaged as an
+**  SQLite database. The tables it expects to find are described in
+**  sqlite3rbu.h.  Essentially, for each table xyz in the target database
+**  that the user wishes to write to, a corresponding data_xyz table is
+**  created in the RBU database and populated with one row for each row to
+**  update, insert or delete from the target table.
+** 
+**  The update proceeds in three stages:
+** 
+**  1) The database is updated. The modified database pages are written
+**     to a *-oal file. A *-oal file is just like a *-wal file, except
+**     that it is named "-oal" instead of "-wal".
+**     Because regular SQLite clients do not look for file named
+**     "-oal", they go on using the original database in
+**     rollback mode while the *-oal file is being generated.
+** 
+**     During this stage RBU does not update the database by writing
+**     directly to the target tables. Instead it creates "imposter"
+**     tables using the SQLITE_TESTCTRL_IMPOSTER interface that it uses
+**     to update each b-tree individually. All updates required by each
+**     b-tree are completed before moving on to the next, and all
+**     updates are done in sorted key order.
+** 
+**  2) The "-oal" file is moved to the equivalent "-wal"
+**     location using a call to rename(2). Before doing this the RBU
+**     module takes an EXCLUSIVE lock on the database file, ensuring
+**     that there are no other active readers.
+** 
+**     Once the EXCLUSIVE lock is released, any other database readers
+**     detect the new *-wal file and read the database in wal mode. At
+**     this point they see the new version of the database - including
+**     the updates made as part of the RBU update.
+** 
+**  3) The new *-wal file is checkpointed. This proceeds in the same way 
+**     as a regular database checkpoint, except that a single frame is
+**     checkpointed each time sqlite3rbu_step() is called. If the RBU
+**     handle is closed before the entire *-wal file is checkpointed,
+**     the checkpoint progress is saved in the RBU database and the
+**     checkpoint can be resumed by another RBU client at some point in
+**     the future.
+**
+** POTENTIAL PROBLEMS
+** 
+**  The rename() call might not be portable. And RBU is not currently
+**  syncing the directory after renaming the file.
+**
+**  When state is saved, any commit to the *-oal file and the commit to
+**  the RBU update database are not atomic. So if the power fails at the
+**  wrong moment they might get out of sync. As the main database will be
+**  committed before the RBU update database this will likely either just
+**  pass unnoticed, or result in SQLITE_CONSTRAINT errors (due to UNIQUE
+**  constraint violations).
+**
+**  If some client does modify the target database mid RBU update, or some
+**  other error occurs, the RBU extension will keep throwing errors. It's
+**  not really clear how to get out of this state. The system could just
+**  by delete the RBU update database and *-oal file and have the device
+**  download the update again and start over.
+**
+**  At present, for an UPDATE, both the new.* and old.* records are
+**  collected in the rbu_xyz table. And for both UPDATEs and DELETEs all
+**  fields are collected.  This means we're probably writing a lot more
+**  data to disk when saving the state of an ongoing update to the RBU
+**  update database than is strictly necessary.
+** 
+*/
+
+/* #include  */
+/* #include  */
+/* #include  */
+
+/* #include "sqlite3.h" */
+
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU)
+/************** Include sqlite3rbu.h in the middle of sqlite3rbu.c ***********/
+/************** Begin file sqlite3rbu.h **************************************/
+/*
+** 2014 August 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the public interface for the RBU extension. 
+*/
+
+/*
+** SUMMARY
+**
+** Writing a transaction containing a large number of operations on 
+** b-tree indexes that are collectively larger than the available cache
+** memory can be very inefficient. 
+**
+** The problem is that in order to update a b-tree, the leaf page (at least)
+** containing the entry being inserted or deleted must be modified. If the
+** working set of leaves is larger than the available cache memory, then a 
+** single leaf that is modified more than once as part of the transaction 
+** may be loaded from or written to the persistent media multiple times.
+** Additionally, because the index updates are likely to be applied in
+** random order, access to pages within the database is also likely to be in 
+** random order, which is itself quite inefficient.
+**
+** One way to improve the situation is to sort the operations on each index
+** by index key before applying them to the b-tree. This leads to an IO
+** pattern that resembles a single linear scan through the index b-tree,
+** and all but guarantees each modified leaf page is loaded and stored 
+** exactly once. SQLite uses this trick to improve the performance of
+** CREATE INDEX commands. This extension allows it to be used to improve
+** the performance of large transactions on existing databases.
+**
+** Additionally, this extension allows the work involved in writing the 
+** large transaction to be broken down into sub-transactions performed 
+** sequentially by separate processes. This is useful if the system cannot 
+** guarantee that a single update process will run for long enough to apply 
+** the entire update, for example because the update is being applied on a 
+** mobile device that is frequently rebooted. Even after the writer process 
+** has committed one or more sub-transactions, other database clients continue
+** to read from the original database snapshot. In other words, partially 
+** applied transactions are not visible to other clients. 
+**
+** "RBU" stands for "Resumable Bulk Update". As in a large database update
+** transmitted via a wireless network to a mobile device. A transaction
+** applied using this extension is hence refered to as an "RBU update".
+**
+**
+** LIMITATIONS
+**
+** An "RBU update" transaction is subject to the following limitations:
+**
+**   * The transaction must consist of INSERT, UPDATE and DELETE operations
+**     only.
+**
+**   * INSERT statements may not use any default values.
+**
+**   * UPDATE and DELETE statements must identify their target rows by 
+**     non-NULL PRIMARY KEY values. Rows with NULL values stored in PRIMARY
+**     KEY fields may not be updated or deleted. If the table being written 
+**     has no PRIMARY KEY, affected rows must be identified by rowid.
+**
+**   * UPDATE statements may not modify PRIMARY KEY columns.
+**
+**   * No triggers will be fired.
+**
+**   * No foreign key violations are detected or reported.
+**
+**   * CHECK constraints are not enforced.
+**
+**   * No constraint handling mode except for "OR ROLLBACK" is supported.
+**
+**
+** PREPARATION
+**
+** An "RBU update" is stored as a separate SQLite database. A database
+** containing an RBU update is an "RBU database". For each table in the 
+** target database to be updated, the RBU database should contain a table
+** named "data_" containing the same set of columns as the
+** target table, and one more - "rbu_control". The data_% table should 
+** have no PRIMARY KEY or UNIQUE constraints, but each column should have
+** the same type as the corresponding column in the target database.
+** The "rbu_control" column should have no type at all. For example, if
+** the target database contains:
+**
+**   CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT, c UNIQUE);
+**
+** Then the RBU database should contain:
+**
+**   CREATE TABLE data_t1(a INTEGER, b TEXT, c, rbu_control);
+**
+** The order of the columns in the data_% table does not matter.
+**
+** Instead of a regular table, the RBU database may also contain virtual
+** tables or view named using the data_ naming scheme. 
+**
+** Instead of the plain data_ naming scheme, RBU database tables 
+** may also be named data_, where  is any sequence
+** of zero or more numeric characters (0-9). This can be significant because
+** tables within the RBU database are always processed in order sorted by 
+** name. By judicious selection of the  portion of the names
+** of the RBU tables the user can therefore control the order in which they
+** are processed. This can be useful, for example, to ensure that "external
+** content" FTS4 tables are updated before their underlying content tables.
+**
+** If the target database table is a virtual table or a table that has no
+** PRIMARY KEY declaration, the data_% table must also contain a column 
+** named "rbu_rowid". This column is mapped to the tables implicit primary 
+** key column - "rowid". Virtual tables for which the "rowid" column does 
+** not function like a primary key value cannot be updated using RBU. For 
+** example, if the target db contains either of the following:
+**
+**   CREATE VIRTUAL TABLE x1 USING fts3(a, b);
+**   CREATE TABLE x1(a, b)
+**
+** then the RBU database should contain:
+**
+**   CREATE TABLE data_x1(a, b, rbu_rowid, rbu_control);
+**
+** All non-hidden columns (i.e. all columns matched by "SELECT *") of the
+** target table must be present in the input table. For virtual tables,
+** hidden columns are optional - they are updated by RBU if present in
+** the input table, or not otherwise. For example, to write to an fts4
+** table with a hidden languageid column such as:
+**
+**   CREATE VIRTUAL TABLE ft1 USING fts4(a, b, languageid='langid');
+**
+** Either of the following input table schemas may be used:
+**
+**   CREATE TABLE data_ft1(a, b, langid, rbu_rowid, rbu_control);
+**   CREATE TABLE data_ft1(a, b, rbu_rowid, rbu_control);
+**
+** For each row to INSERT into the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain integer value 0. The
+** other columns should be set to the values that make up the new record 
+** to insert. 
+**
+** If the target database table has an INTEGER PRIMARY KEY, it is not 
+** possible to insert a NULL value into the IPK column. Attempting to 
+** do so results in an SQLITE_MISMATCH error.
+**
+** For each row to DELETE from the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain integer value 1. The
+** real primary key values of the row to delete should be stored in the
+** corresponding columns of the data_% table. The values stored in the
+** other columns are not used.
+**
+** For each row to UPDATE from the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain a value of type text.
+** The real primary key values identifying the row to update should be 
+** stored in the corresponding columns of the data_% table row, as should
+** the new values of all columns being update. The text value in the 
+** "rbu_control" column must contain the same number of characters as
+** there are columns in the target database table, and must consist entirely
+** of 'x' and '.' characters (or in some special cases 'd' - see below). For 
+** each column that is being updated, the corresponding character is set to
+** 'x'. For those that remain as they are, the corresponding character of the
+** rbu_control value should be set to '.'. For example, given the tables 
+** above, the update statement:
+**
+**   UPDATE t1 SET c = 'usa' WHERE a = 4;
+**
+** is represented by the data_t1 row created by:
+**
+**   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..x');
+**
+** Instead of an 'x' character, characters of the rbu_control value specified
+** for UPDATEs may also be set to 'd'. In this case, instead of updating the
+** target table with the value stored in the corresponding data_% column, the
+** user-defined SQL function "rbu_delta()" is invoked and the result stored in
+** the target table column. rbu_delta() is invoked with two arguments - the
+** original value currently stored in the target table column and the 
+** value specified in the data_xxx table.
+**
+** For example, this row:
+**
+**   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..d');
+**
+** is similar to an UPDATE statement such as: 
+**
+**   UPDATE t1 SET c = rbu_delta(c, 'usa') WHERE a = 4;
 **
-**    = 
+** Finally, if an 'f' character appears in place of a 'd' or 's' in an 
+** ota_control string, the contents of the data_xxx table column is assumed
+** to be a "fossil delta" - a patch to be applied to a blob value in the
+** format used by the fossil source-code management system. In this case
+** the existing value within the target database table must be of type BLOB. 
+** It is replaced by the result of applying the specified fossil delta to
+** itself.
 **
-** There may not be whitespace surrounding the "=" character. The  
-** term may be quoted, but the  may not.
+** If the target database table is a virtual table or a table with no PRIMARY
+** KEY, the rbu_control value should not include a character corresponding 
+** to the rbu_rowid value. For example, this:
+**
+**   INSERT INTO data_ft1(a, b, rbu_rowid, rbu_control) 
+**       VALUES(NULL, 'usa', 12, '.x');
+**
+** causes a result similar to:
+**
+**   UPDATE ft1 SET b = 'usa' WHERE rowid = 12;
+**
+** The data_xxx tables themselves should have no PRIMARY KEY declarations.
+** However, RBU is more efficient if reading the rows in from each data_xxx
+** table in "rowid" order is roughly the same as reading them sorted by
+** the PRIMARY KEY of the corresponding target database table. In other 
+** words, rows should be sorted using the destination table PRIMARY KEY 
+** fields before they are inserted into the data_xxx tables.
+**
+** USAGE
+**
+** The API declared below allows an application to apply an RBU update 
+** stored on disk to an existing target database. Essentially, the 
+** application:
+**
+**     1) Opens an RBU handle using the sqlite3rbu_open() function.
+**
+**     2) Registers any required virtual table modules with the database
+**        handle returned by sqlite3rbu_db(). Also, if required, register
+**        the rbu_delta() implementation.
+**
+**     3) Calls the sqlite3rbu_step() function one or more times on
+**        the new handle. Each call to sqlite3rbu_step() performs a single
+**        b-tree operation, so thousands of calls may be required to apply 
+**        a complete update.
+**
+**     4) Calls sqlite3rbu_close() to close the RBU update handle. If
+**        sqlite3rbu_step() has been called enough times to completely
+**        apply the update to the target database, then the RBU database
+**        is marked as fully applied. Otherwise, the state of the RBU 
+**        update application is saved in the RBU database for later 
+**        resumption.
+**
+** See comments below for more detail on APIs.
+**
+** If an update is only partially applied to the target database by the
+** time sqlite3rbu_close() is called, various state information is saved 
+** within the RBU database. This allows subsequent processes to automatically
+** resume the RBU update from where it left off.
+**
+** To remove all RBU extension state information, returning an RBU database 
+** to its original contents, it is sufficient to drop all tables that begin
+** with the prefix "rbu_"
+**
+** DATABASE LOCKING
+**
+** An RBU update may not be applied to a database in WAL mode. Attempting
+** to do so is an error (SQLITE_ERROR).
+**
+** While an RBU handle is open, a SHARED lock may be held on the target
+** database file. This means it is possible for other clients to read the
+** database, but not to write it.
+**
+** If an RBU update is started and then suspended before it is completed,
+** then an external client writes to the database, then attempting to resume
+** the suspended RBU update is also an error (SQLITE_BUSY).
 */
-static int fts3IsSpecialColumn(
-  const char *z, 
-  int *pnKey,
-  char **pzValue
-){
-  char *zValue;
-  const char *zCsr = z;
 
-  while( *zCsr!='=' ){
-    if( *zCsr=='\0' ) return 0;
-    zCsr++;
-  }
+#ifndef _SQLITE3RBU_H
+#define _SQLITE3RBU_H
 
-  *pnKey = (int)(zCsr-z);
-  zValue = sqlite3_mprintf("%s", &zCsr[1]);
-  if( zValue ){
-    sqlite3Fts3Dequote(zValue);
-  }
-  *pzValue = zValue;
-  return 1;
-}
+/* #include "sqlite3.h"              ** Required for error code definitions ** */
 
-/*
-** Append the output of a printf() style formatting to an existing string.
-*/
-static void fts3Appendf(
-  int *pRc,                       /* IN/OUT: Error code */
-  char **pz,                      /* IN/OUT: Pointer to string buffer */
-  const char *zFormat,            /* Printf format string to append */
-  ...                             /* Arguments for printf format string */
-){
-  if( *pRc==SQLITE_OK ){
-    va_list ap;
-    char *z;
-    va_start(ap, zFormat);
-    z = sqlite3_vmprintf(zFormat, ap);
-    va_end(ap);
-    if( z && *pz ){
-      char *z2 = sqlite3_mprintf("%s%s", *pz, z);
-      sqlite3_free(z);
-      z = z2;
-    }
-    if( z==0 ) *pRc = SQLITE_NOMEM;
-    sqlite3_free(*pz);
-    *pz = z;
-  }
-}
+#if 0
+extern "C" {
+#endif
+
+typedef struct sqlite3rbu sqlite3rbu;
 
 /*
-** Return a copy of input string zInput enclosed in double-quotes (") and
-** with all double quote characters escaped. For example:
+** Open an RBU handle.
 **
-**     fts3QuoteId("un \"zip\"")   ->    "un \"\"zip\"\""
+** Argument zTarget is the path to the target database. Argument zRbu is
+** the path to the RBU database. Each call to this function must be matched
+** by a call to sqlite3rbu_close(). When opening the databases, RBU passes
+** the SQLITE_CONFIG_URI flag to sqlite3_open_v2(). So if either zTarget
+** or zRbu begin with "file:", it will be interpreted as an SQLite 
+** database URI, not a regular file name.
 **
-** The pointer returned points to memory obtained from sqlite3_malloc(). It
-** is the callers responsibility to call sqlite3_free() to release this
-** memory.
+** If the zState argument is passed a NULL value, the RBU extension stores 
+** the current state of the update (how many rows have been updated, which 
+** indexes are yet to be updated etc.) within the RBU database itself. This
+** can be convenient, as it means that the RBU application does not need to
+** organize removing a separate state file after the update is concluded. 
+** Or, if zState is non-NULL, it must be a path to a database file in which 
+** the RBU extension can store the state of the update.
+**
+** When resuming an RBU update, the zState argument must be passed the same
+** value as when the RBU update was started.
+**
+** Once the RBU update is finished, the RBU extension does not 
+** automatically remove any zState database file, even if it created it.
+**
+** By default, RBU uses the default VFS to access the files on disk. To
+** use a VFS other than the default, an SQLite "file:" URI containing a
+** "vfs=..." option may be passed as the zTarget option.
+**
+** IMPORTANT NOTE FOR ZIPVFS USERS: The RBU extension works with all of
+** SQLite's built-in VFSs, including the multiplexor VFS. However it does
+** not work out of the box with zipvfs. Refer to the comment describing
+** the zipvfs_create_vfs() API below for details on using RBU with zipvfs.
 */
-static char *fts3QuoteId(char const *zInput){
-  int nRet;
-  char *zRet;
-  nRet = 2 + (int)strlen(zInput)*2 + 1;
-  zRet = sqlite3_malloc(nRet);
-  if( zRet ){
-    int i;
-    char *z = zRet;
-    *(z++) = '"';
-    for(i=0; zInput[i]; i++){
-      if( zInput[i]=='"' ) *(z++) = '"';
-      *(z++) = zInput[i];
-    }
-    *(z++) = '"';
-    *(z++) = '\0';
-  }
-  return zRet;
-}
+SQLITE_API sqlite3rbu *sqlite3rbu_open(
+  const char *zTarget, 
+  const char *zRbu,
+  const char *zState
+);
 
 /*
-** Return a list of comma separated SQL expressions and a FROM clause that 
-** could be used in a SELECT statement such as the following:
+** Open an RBU handle to perform an RBU vacuum on database file zTarget.
+** An RBU vacuum is similar to SQLite's built-in VACUUM command, except
+** that it can be suspended and resumed like an RBU update.
+**
+** The second argument to this function identifies a database in which 
+** to store the state of the RBU vacuum operation if it is suspended. The 
+** first time sqlite3rbu_vacuum() is called, to start an RBU vacuum
+** operation, the state database should either not exist or be empty
+** (contain no tables). If an RBU vacuum is suspended by calling 
+** sqlite3rbu_close() on the RBU handle before sqlite3rbu_step() has
+** returned SQLITE_DONE, the vacuum state is stored in the state database. 
+** The vacuum can be resumed by calling this function to open a new RBU
+** handle specifying the same target and state databases.
+**
+** If the second argument passed to this function is NULL, then the
+** name of the state database is "-vacuum", where 
+** is the name of the target database file. In this case, on UNIX, if the
+** state database is not already present in the file-system, it is created
+** with the same permissions as the target db is made.
+**
+** This function does not delete the state database after an RBU vacuum
+** is completed, even if it created it. However, if the call to
+** sqlite3rbu_close() returns any value other than SQLITE_OK, the contents
+** of the state tables within the state database are zeroed. This way,
+** the next call to sqlite3rbu_vacuum() opens a handle that starts a 
+** new RBU vacuum operation.
+**
+** As with sqlite3rbu_open(), Zipvfs users should rever to the comment
+** describing the sqlite3rbu_create_vfs() API function below for 
+** a description of the complications associated with using RBU with 
+** zipvfs databases.
+*/
+SQLITE_API sqlite3rbu *sqlite3rbu_vacuum(
+  const char *zTarget, 
+  const char *zState
+);
+
+/*
+** Internally, each RBU connection uses a separate SQLite database 
+** connection to access the target and rbu update databases. This
+** API allows the application direct access to these database handles.
 **
-**     SELECT  FROM %_content AS x ...
+** The first argument passed to this function must be a valid, open, RBU
+** handle. The second argument should be passed zero to access the target
+** database handle, or non-zero to access the rbu update database handle.
+** Accessing the underlying database handles may be useful in the
+** following scenarios:
 **
-** to return the docid, followed by each column of text data in order
-** from left to write. If parameter zFunc is not NULL, then instead of
-** being returned directly each column of text data is passed to an SQL
-** function named zFunc first. For example, if zFunc is "unzip" and the
-** table has the three user-defined columns "a", "b", and "c", the following
-** string is returned:
+**   * If any target tables are virtual tables, it may be necessary to
+**     call sqlite3_create_module() on the target database handle to 
+**     register the required virtual table implementations.
 **
-**     "docid, unzip(x.'a'), unzip(x.'b'), unzip(x.'c') FROM %_content AS x"
+**   * If the data_xxx tables in the RBU source database are virtual 
+**     tables, the application may need to call sqlite3_create_module() on
+**     the rbu update db handle to any required virtual table
+**     implementations.
 **
-** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
-** is the responsibility of the caller to eventually free it.
+**   * If the application uses the "rbu_delta()" feature described above,
+**     it must use sqlite3_create_function() or similar to register the
+**     rbu_delta() implementation with the target database handle.
 **
-** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
-** a NULL pointer is returned). Otherwise, if an OOM error is encountered
-** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
-** no error occurs, *pRc is left unmodified.
+** If an error has occurred, either while opening or stepping the RBU object,
+** this function may return NULL. The error code and message may be collected
+** when sqlite3rbu_close() is called.
+**
+** Database handles returned by this function remain valid until the next
+** call to any sqlite3rbu_xxx() function other than sqlite3rbu_db().
 */
-static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){
-  char *zRet = 0;
-  char *zFree = 0;
-  char *zFunction;
-  int i;
-
-  if( p->zContentTbl==0 ){
-    if( !zFunc ){
-      zFunction = "";
-    }else{
-      zFree = zFunction = fts3QuoteId(zFunc);
-    }
-    fts3Appendf(pRc, &zRet, "docid");
-    for(i=0; inColumn; i++){
-      fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
-    }
-    if( p->zLanguageid ){
-      fts3Appendf(pRc, &zRet, ", x.%Q", "langid");
-    }
-    sqlite3_free(zFree);
-  }else{
-    fts3Appendf(pRc, &zRet, "rowid");
-    for(i=0; inColumn; i++){
-      fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
-    }
-    if( p->zLanguageid ){
-      fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);
-    }
-  }
-  fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x", 
-      p->zDb,
-      (p->zContentTbl ? p->zContentTbl : p->zName),
-      (p->zContentTbl ? "" : "_content")
-  );
-  return zRet;
-}
+SQLITE_API sqlite3 *sqlite3rbu_db(sqlite3rbu*, int bRbu);
 
 /*
-** Return a list of N comma separated question marks, where N is the number
-** of columns in the %_content table (one for the docid plus one for each
-** user-defined text column).
+** Do some work towards applying the RBU update to the target db. 
 **
-** If argument zFunc is not NULL, then all but the first question mark
-** is preceded by zFunc and an open bracket, and followed by a closed
-** bracket. For example, if zFunc is "zip" and the FTS3 table has three 
-** user-defined text columns, the following string is returned:
+** Return SQLITE_DONE if the update has been completely applied, or 
+** SQLITE_OK if no error occurs but there remains work to do to apply
+** the RBU update. If an error does occur, some other error code is 
+** returned. 
 **
-**     "?, zip(?), zip(?), zip(?)"
+** Once a call to sqlite3rbu_step() has returned a value other than
+** SQLITE_OK, all subsequent calls on the same RBU handle are no-ops
+** that immediately return the same value.
+*/
+SQLITE_API int sqlite3rbu_step(sqlite3rbu *pRbu);
+
+/*
+** Force RBU to save its state to disk.
 **
-** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
-** is the responsibility of the caller to eventually free it.
+** If a power failure or application crash occurs during an update, following
+** system recovery RBU may resume the update from the point at which the state
+** was last saved. In other words, from the most recent successful call to 
+** sqlite3rbu_close() or this function.
 **
-** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
-** a NULL pointer is returned). Otherwise, if an OOM error is encountered
-** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
-** no error occurs, *pRc is left unmodified.
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
 */
-static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
-  char *zRet = 0;
-  char *zFree = 0;
-  char *zFunction;
-  int i;
-
-  if( !zFunc ){
-    zFunction = "";
-  }else{
-    zFree = zFunction = fts3QuoteId(zFunc);
-  }
-  fts3Appendf(pRc, &zRet, "?");
-  for(i=0; inColumn; i++){
-    fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
-  }
-  if( p->zLanguageid ){
-    fts3Appendf(pRc, &zRet, ", ?");
-  }
-  sqlite3_free(zFree);
-  return zRet;
-}
+SQLITE_API int sqlite3rbu_savestate(sqlite3rbu *pRbu);
 
 /*
-** This function interprets the string at (*pp) as a non-negative integer
-** value. It reads the integer and sets *pnOut to the value read, then 
-** sets *pp to point to the byte immediately following the last byte of
-** the integer value.
+** Close an RBU handle. 
 **
-** Only decimal digits ('0'..'9') may be part of an integer value. 
+** If the RBU update has been completely applied, mark the RBU database
+** as fully applied. Otherwise, assuming no error has occurred, save the
+** current state of the RBU update appliation to the RBU database.
 **
-** If *pp does not being with a decimal digit SQLITE_ERROR is returned and
-** the output value undefined. Otherwise SQLITE_OK is returned.
+** If an error has already occurred as part of an sqlite3rbu_step()
+** or sqlite3rbu_open() call, or if one occurs within this function, an
+** SQLite error code is returned. Additionally, if pzErrmsg is not NULL,
+** *pzErrmsg may be set to point to a buffer containing a utf-8 formatted
+** English language error message. It is the responsibility of the caller to
+** eventually free any such buffer using sqlite3_free().
 **
-** This function is used when parsing the "prefix=" FTS4 parameter.
+** Otherwise, if no error occurs, this function returns SQLITE_OK if the
+** update has been partially applied, or SQLITE_DONE if it has been 
+** completely applied.
 */
-static int fts3GobbleInt(const char **pp, int *pnOut){
-  const char *p;                  /* Iterator pointer */
-  int nInt = 0;                   /* Output value */
+SQLITE_API int sqlite3rbu_close(sqlite3rbu *pRbu, char **pzErrmsg);
 
-  for(p=*pp; p[0]>='0' && p[0]<='9'; p++){
-    nInt = nInt * 10 + (p[0] - '0');
-  }
-  if( p==*pp ) return SQLITE_ERROR;
-  *pnOut = nInt;
-  *pp = p;
-  return SQLITE_OK;
-}
+/*
+** Return the total number of key-value operations (inserts, deletes or 
+** updates) that have been performed on the target database since the
+** current RBU update was started.
+*/
+SQLITE_API sqlite3_int64 sqlite3rbu_progress(sqlite3rbu *pRbu);
 
 /*
-** This function is called to allocate an array of Fts3Index structures
-** representing the indexes maintained by the current FTS table. FTS tables
-** always maintain the main "terms" index, but may also maintain one or
-** more "prefix" indexes, depending on the value of the "prefix=" parameter
-** (if any) specified as part of the CREATE VIRTUAL TABLE statement.
+** Obtain permyriadage (permyriadage is to 10000 as percentage is to 100) 
+** progress indications for the two stages of an RBU update. This API may
+** be useful for driving GUI progress indicators and similar.
 **
-** Argument zParam is passed the value of the "prefix=" option if one was
-** specified, or NULL otherwise.
+** An RBU update is divided into two stages:
 **
-** If no error occurs, SQLITE_OK is returned and *apIndex set to point to
-** the allocated array. *pnIndex is set to the number of elements in the
-** array. If an error does occur, an SQLite error code is returned.
+**   * Stage 1, in which changes are accumulated in an oal/wal file, and
+**   * Stage 2, in which the contents of the wal file are copied into the
+**     main database.
 **
-** Regardless of whether or not an error is returned, it is the responsibility
-** of the caller to call sqlite3_free() on the output array to free it.
+** The update is visible to non-RBU clients during stage 2. During stage 1
+** non-RBU reader clients may see the original database.
+**
+** If this API is called during stage 2 of the update, output variable 
+** (*pnOne) is set to 10000 to indicate that stage 1 has finished and (*pnTwo)
+** to a value between 0 and 10000 to indicate the permyriadage progress of
+** stage 2. A value of 5000 indicates that stage 2 is half finished, 
+** 9000 indicates that it is 90% finished, and so on.
+**
+** If this API is called during stage 1 of the update, output variable 
+** (*pnTwo) is set to 0 to indicate that stage 2 has not yet started. The
+** value to which (*pnOne) is set depends on whether or not the RBU 
+** database contains an "rbu_count" table. The rbu_count table, if it 
+** exists, must contain the same columns as the following:
+**
+**   CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID;
+**
+** There must be one row in the table for each source (data_xxx) table within
+** the RBU database. The 'tbl' column should contain the name of the source
+** table. The 'cnt' column should contain the number of rows within the
+** source table.
+**
+** If the rbu_count table is present and populated correctly and this
+** API is called during stage 1, the *pnOne output variable is set to the
+** permyriadage progress of the same stage. If the rbu_count table does
+** not exist, then (*pnOne) is set to -1 during stage 1. If the rbu_count
+** table exists but is not correctly populated, the value of the *pnOne
+** output variable during stage 1 is undefined.
 */
-static int fts3PrefixParameter(
-  const char *zParam,             /* ABC in prefix=ABC parameter to parse */
-  int *pnIndex,                   /* OUT: size of *apIndex[] array */
-  struct Fts3Index **apIndex      /* OUT: Array of indexes for this table */
-){
-  struct Fts3Index *aIndex;       /* Allocated array */
-  int nIndex = 1;                 /* Number of entries in array */
-
-  if( zParam && zParam[0] ){
-    const char *p;
-    nIndex++;
-    for(p=zParam; *p; p++){
-      if( *p==',' ) nIndex++;
-    }
-  }
-
-  aIndex = sqlite3_malloc(sizeof(struct Fts3Index) * nIndex);
-  *apIndex = aIndex;
-  *pnIndex = nIndex;
-  if( !aIndex ){
-    return SQLITE_NOMEM;
-  }
+SQLITE_API void sqlite3rbu_bp_progress(sqlite3rbu *pRbu, int *pnOne, int *pnTwo);
 
-  memset(aIndex, 0, sizeof(struct Fts3Index) * nIndex);
-  if( zParam ){
-    const char *p = zParam;
-    int i;
-    for(i=1; i module name  ("fts3" or "fts4")
-**   argv[1]   -> database name
-**   argv[2]   -> table name
-**   argv[...] -> "column name" and other module argument fields.
+** abIndexed:
+**   If the table has no indexes on it, abIndexed is set to NULL. Otherwise,
+**   it points to an array of flags nTblCol elements in size. The flag is
+**   set for each column that is either a part of the PK or a part of an
+**   index. Or clear otherwise.
+**   
 */
-static int fts3InitVtab(
-  int isCreate,                   /* True for xCreate, false for xConnect */
-  sqlite3 *db,                    /* The SQLite database connection */
-  void *pAux,                     /* Hash table containing tokenizers */
-  int argc,                       /* Number of elements in argv array */
-  const char * const *argv,       /* xCreate/xConnect argument array */
-  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
-  char **pzErr                    /* Write any error message here */
-){
-  Fts3Hash *pHash = (Fts3Hash *)pAux;
-  Fts3Table *p = 0;               /* Pointer to allocated vtab */
-  int rc = SQLITE_OK;             /* Return code */
-  int i;                          /* Iterator variable */
-  int nByte;                      /* Size of allocation used for *p */
-  int iCol;                       /* Column index */
-  int nString = 0;                /* Bytes required to hold all column names */
-  int nCol = 0;                   /* Number of columns in the FTS table */
-  char *zCsr;                     /* Space for holding column names */
-  int nDb;                        /* Bytes required to hold database name */
-  int nName;                      /* Bytes required to hold table name */
-  int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */
-  const char **aCol;              /* Array of column names */
-  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */
+struct RbuObjIter {
+  sqlite3_stmt *pTblIter;         /* Iterate through tables */
+  sqlite3_stmt *pIdxIter;         /* Index iterator */
+  int nTblCol;                    /* Size of azTblCol[] array */
+  char **azTblCol;                /* Array of unquoted target column names */
+  char **azTblType;               /* Array of target column types */
+  int *aiSrcOrder;                /* src table col -> target table col */
+  u8 *abTblPk;                    /* Array of flags, set on target PK columns */
+  u8 *abNotNull;                  /* Array of flags, set on NOT NULL columns */
+  u8 *abIndexed;                  /* Array of flags, set on indexed & PK cols */
+  int eType;                      /* Table type - an RBU_PK_XXX value */
+
+  /* Output variables. zTbl==0 implies EOF. */
+  int bCleanup;                   /* True in "cleanup" state */
+  const char *zTbl;               /* Name of target db table */
+  const char *zDataTbl;           /* Name of rbu db table (or null) */
+  const char *zIdx;               /* Name of target db index (or null) */
+  int iTnum;                      /* Root page of current object */
+  int iPkTnum;                    /* If eType==EXTERNAL, root of PK index */
+  int bUnique;                    /* Current index is unique */
+  int nIndex;                     /* Number of aux. indexes on table zTbl */
+
+  /* Statements created by rbuObjIterPrepareAll() */
+  int nCol;                       /* Number of columns in current object */
+  sqlite3_stmt *pSelect;          /* Source data */
+  sqlite3_stmt *pInsert;          /* Statement for INSERT operations */
+  sqlite3_stmt *pDelete;          /* Statement for DELETE ops */
+  sqlite3_stmt *pTmpInsert;       /* Insert into rbu_tmp_$zDataTbl */
+
+  /* Last UPDATE used (for PK b-tree updates only), or NULL. */
+  RbuUpdateStmt *pRbuUpdate;
+};
 
-  int nIndex;                     /* Size of aIndex[] array */
-  struct Fts3Index *aIndex = 0;   /* Array of indexes for this table */
+/*
+** Values for RbuObjIter.eType
+**
+**     0: Table does not exist (error)
+**     1: Table has an implicit rowid.
+**     2: Table has an explicit IPK column.
+**     3: Table has an external PK index.
+**     4: Table is WITHOUT ROWID.
+**     5: Table is a virtual table.
+*/
+#define RBU_PK_NOTABLE        0
+#define RBU_PK_NONE           1
+#define RBU_PK_IPK            2
+#define RBU_PK_EXTERNAL       3
+#define RBU_PK_WITHOUT_ROWID  4
+#define RBU_PK_VTAB           5
 
-  /* The results of parsing supported FTS4 key=value options: */
-  int bNoDocsize = 0;             /* True to omit %_docsize table */
-  int bDescIdx = 0;               /* True to store descending indexes */
-  char *zPrefix = 0;              /* Prefix parameter value (or NULL) */
-  char *zCompress = 0;            /* compress=? parameter (or NULL) */
-  char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
-  char *zContent = 0;             /* content=? parameter (or NULL) */
-  char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */
-  char **azNotindexed = 0;        /* The set of notindexed= columns */
-  int nNotindexed = 0;            /* Size of azNotindexed[] array */
 
-  assert( strlen(argv[0])==4 );
-  assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
-       || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
-  );
+/*
+** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs
+** one of the following operations.
+*/
+#define RBU_INSERT     1          /* Insert on a main table b-tree */
+#define RBU_DELETE     2          /* Delete a row from a main table b-tree */
+#define RBU_REPLACE    3          /* Delete and then insert a row */
+#define RBU_IDX_DELETE 4          /* Delete a row from an aux. index b-tree */
+#define RBU_IDX_INSERT 5          /* Insert on an aux. index b-tree */
 
-  nDb = (int)strlen(argv[1]) + 1;
-  nName = (int)strlen(argv[2]) + 1;
+#define RBU_UPDATE     6          /* Update a row in a main table b-tree */
 
-  nByte = sizeof(const char *) * (argc-2);
-  aCol = (const char **)sqlite3_malloc(nByte);
-  if( aCol ){
-    memset((void*)aCol, 0, nByte);
-    azNotindexed = (char **)sqlite3_malloc(nByte);
-  }
-  if( azNotindexed ){
-    memset(azNotindexed, 0, nByte);
-  }
-  if( !aCol || !azNotindexed ){
-    rc = SQLITE_NOMEM;
-    goto fts3_init_out;
-  }
+/*
+** A single step of an incremental checkpoint - frame iWalFrame of the wal
+** file should be copied to page iDbPage of the database file.
+*/
+struct RbuFrame {
+  u32 iDbPage;
+  u32 iWalFrame;
+};
 
-  /* Loop through all of the arguments passed by the user to the FTS3/4
-  ** module (i.e. all the column names and special arguments). This loop
-  ** does the following:
-  **
-  **   + Figures out the number of columns the FTSX table will have, and
-  **     the number of bytes of space that must be allocated to store copies
-  **     of the column names.
-  **
-  **   + If there is a tokenizer specification included in the arguments,
-  **     initializes the tokenizer pTokenizer.
-  */
-  for(i=3; rc==SQLITE_OK && i8
-     && 0==sqlite3_strnicmp(z, "tokenize", 8) 
-     && 0==sqlite3Fts3IsIdChar(z[8])
-    ){
-      rc = sqlite3Fts3InitTokenizer(pHash, &z[9], &pTokenizer, pzErr);
-    }
+/*
+** An rbu VFS is implemented using an instance of this structure.
+*/
+struct rbu_vfs {
+  sqlite3_vfs base;               /* rbu VFS shim methods */
+  sqlite3_vfs *pRealVfs;          /* Underlying VFS */
+  sqlite3_mutex *mutex;           /* Mutex to protect pMain */
+  rbu_file *pMain;                /* Linked list of main db files */
+};
 
-    /* Check if it is an FTS4 special argument. */
-    else if( isFts4 && fts3IsSpecialColumn(z, &nKey, &zVal) ){
-      struct Fts4Option {
-        const char *zOpt;
-        int nOpt;
-      } aFts4Opt[] = {
-        { "matchinfo",   9 },     /* 0 -> MATCHINFO */
-        { "prefix",      6 },     /* 1 -> PREFIX */
-        { "compress",    8 },     /* 2 -> COMPRESS */
-        { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
-        { "order",       5 },     /* 4 -> ORDER */
-        { "content",     7 },     /* 5 -> CONTENT */
-        { "languageid", 10 },     /* 6 -> LANGUAGEID */
-        { "notindexed", 10 }      /* 7 -> NOTINDEXED */
-      };
+/*
+** Each file opened by an rbu VFS is represented by an instance of
+** the following structure.
+*/
+struct rbu_file {
+  sqlite3_file base;              /* sqlite3_file methods */
+  sqlite3_file *pReal;            /* Underlying file handle */
+  rbu_vfs *pRbuVfs;               /* Pointer to the rbu_vfs object */
+  sqlite3rbu *pRbu;               /* Pointer to rbu object (rbu target only) */
 
-      int iOpt;
-      if( !zVal ){
-        rc = SQLITE_NOMEM;
-      }else{
-        for(iOpt=0; iOptnOpt && !sqlite3_strnicmp(z, pOp->zOpt, pOp->nOpt) ){
-            break;
-          }
-        }
-        if( iOpt==SizeofArray(aFts4Opt) ){
-          *pzErr = sqlite3_mprintf("unrecognized parameter: %s", z);
-          rc = SQLITE_ERROR;
-        }else{
-          switch( iOpt ){
-            case 0:               /* MATCHINFO */
-              if( strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "fts3", 4) ){
-                *pzErr = sqlite3_mprintf("unrecognized matchinfo: %s", zVal);
-                rc = SQLITE_ERROR;
-              }
-              bNoDocsize = 1;
-              break;
+  int openFlags;                  /* Flags this file was opened with */
+  u32 iCookie;                    /* Cookie value for main db files */
+  u8 iWriteVer;                   /* "write-version" value for main db files */
+  u8 bNolock;                     /* True to fail EXCLUSIVE locks */
 
-            case 1:               /* PREFIX */
-              sqlite3_free(zPrefix);
-              zPrefix = zVal;
-              zVal = 0;
-              break;
+  int nShm;                       /* Number of entries in apShm[] array */
+  char **apShm;                   /* Array of mmap'd *-shm regions */
+  char *zDel;                     /* Delete this when closing file */
 
-            case 2:               /* COMPRESS */
-              sqlite3_free(zCompress);
-              zCompress = zVal;
-              zVal = 0;
-              break;
+  const char *zWal;               /* Wal filename for this main db file */
+  rbu_file *pWalFd;               /* Wal file descriptor for this main db */
+  rbu_file *pMainNext;            /* Next MAIN_DB file */
+};
 
-            case 3:               /* UNCOMPRESS */
-              sqlite3_free(zUncompress);
-              zUncompress = zVal;
-              zVal = 0;
-              break;
+/*
+** True for an RBU vacuum handle, or false otherwise.
+*/
+#define rbuIsVacuum(p) ((p)->zTarget==0)
 
-            case 4:               /* ORDER */
-              if( (strlen(zVal)!=3 || sqlite3_strnicmp(zVal, "asc", 3)) 
-               && (strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "desc", 4)) 
-              ){
-                *pzErr = sqlite3_mprintf("unrecognized order: %s", zVal);
-                rc = SQLITE_ERROR;
-              }
-              bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
-              break;
 
-            case 5:              /* CONTENT */
-              sqlite3_free(zContent);
-              zContent = zVal;
-              zVal = 0;
-              break;
+/*************************************************************************
+** The following three functions, found below:
+**
+**   rbuDeltaGetInt()
+**   rbuDeltaChecksum()
+**   rbuDeltaApply()
+**
+** are lifted from the fossil source code (http://fossil-scm.org). They
+** are used to implement the scalar SQL function rbu_fossil_delta().
+*/
 
-            case 6:              /* LANGUAGEID */
-              assert( iOpt==6 );
-              sqlite3_free(zLanguageid);
-              zLanguageid = zVal;
-              zVal = 0;
-              break;
+/*
+** Read bytes from *pz and convert them into a positive integer.  When
+** finished, leave *pz pointing to the first character past the end of
+** the integer.  The *pLen parameter holds the length of the string
+** in *pz and is decremented once for each character in the integer.
+*/
+static unsigned int rbuDeltaGetInt(const char **pz, int *pLen){
+  static const signed char zValue[] = {
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+     0,  1,  2,  3,  4,  5,  6,  7,    8,  9, -1, -1, -1, -1, -1, -1,
+    -1, 10, 11, 12, 13, 14, 15, 16,   17, 18, 19, 20, 21, 22, 23, 24,
+    25, 26, 27, 28, 29, 30, 31, 32,   33, 34, 35, -1, -1, -1, -1, 36,
+    -1, 37, 38, 39, 40, 41, 42, 43,   44, 45, 46, 47, 48, 49, 50, 51,
+    52, 53, 54, 55, 56, 57, 58, 59,   60, 61, 62, -1, -1, -1, 63, -1,
+  };
+  unsigned int v = 0;
+  int c;
+  unsigned char *z = (unsigned char*)*pz;
+  unsigned char *zStart = z;
+  while( (c = zValue[0x7f&*(z++)])>=0 ){
+     v = (v<<6) + c;
+  }
+  z--;
+  *pLen -= z - zStart;
+  *pz = (char*)z;
+  return v;
+}
 
-            case 7:              /* NOTINDEXED */
-              azNotindexed[nNotindexed++] = zVal;
-              zVal = 0;
-              break;
-          }
+/*
+** Compute a 32-bit checksum on the N-byte buffer.  Return the result.
+*/
+static unsigned int rbuDeltaChecksum(const char *zIn, size_t N){
+  const unsigned char *z = (const unsigned char *)zIn;
+  unsigned sum0 = 0;
+  unsigned sum1 = 0;
+  unsigned sum2 = 0;
+  unsigned sum3 = 0;
+  while(N >= 16){
+    sum0 += ((unsigned)z[0] + z[4] + z[8] + z[12]);
+    sum1 += ((unsigned)z[1] + z[5] + z[9] + z[13]);
+    sum2 += ((unsigned)z[2] + z[6] + z[10]+ z[14]);
+    sum3 += ((unsigned)z[3] + z[7] + z[11]+ z[15]);
+    z += 16;
+    N -= 16;
+  }
+  while(N >= 4){
+    sum0 += z[0];
+    sum1 += z[1];
+    sum2 += z[2];
+    sum3 += z[3];
+    z += 4;
+    N -= 4;
+  }
+  sum3 += (sum2 << 8) + (sum1 << 16) + (sum0 << 24);
+  switch(N){
+    case 3:   sum3 += (z[2] << 8);
+    case 2:   sum3 += (z[1] << 16);
+    case 1:   sum3 += (z[0] << 24);
+    default:  ;
+  }
+  return sum3;
+}
+
+/*
+** Apply a delta.
+**
+** The output buffer should be big enough to hold the whole output
+** file and a NUL terminator at the end.  The delta_output_size()
+** routine will determine this size for you.
+**
+** The delta string should be null-terminated.  But the delta string
+** may contain embedded NUL characters (if the input and output are
+** binary files) so we also have to pass in the length of the delta in
+** the lenDelta parameter.
+**
+** This function returns the size of the output file in bytes (excluding
+** the final NUL terminator character).  Except, if the delta string is
+** malformed or intended for use with a source file other than zSrc,
+** then this routine returns -1.
+**
+** Refer to the delta_create() documentation above for a description
+** of the delta file format.
+*/
+static int rbuDeltaApply(
+  const char *zSrc,      /* The source or pattern file */
+  int lenSrc,            /* Length of the source file */
+  const char *zDelta,    /* Delta to apply to the pattern */
+  int lenDelta,          /* Length of the delta */
+  char *zOut             /* Write the output into this preallocated buffer */
+){
+  unsigned int limit;
+  unsigned int total = 0;
+#ifndef FOSSIL_OMIT_DELTA_CKSUM_TEST
+  char *zOrigOut = zOut;
+#endif
+
+  limit = rbuDeltaGetInt(&zDelta, &lenDelta);
+  if( *zDelta!='\n' ){
+    /* ERROR: size integer not terminated by "\n" */
+    return -1;
+  }
+  zDelta++; lenDelta--;
+  while( *zDelta && lenDelta>0 ){
+    unsigned int cnt, ofst;
+    cnt = rbuDeltaGetInt(&zDelta, &lenDelta);
+    switch( zDelta[0] ){
+      case '@': {
+        zDelta++; lenDelta--;
+        ofst = rbuDeltaGetInt(&zDelta, &lenDelta);
+        if( lenDelta>0 && zDelta[0]!=',' ){
+          /* ERROR: copy command not terminated by ',' */
+          return -1;
+        }
+        zDelta++; lenDelta--;
+        total += cnt;
+        if( total>limit ){
+          /* ERROR: copy exceeds output file size */
+          return -1;
+        }
+        if( (int)(ofst+cnt) > lenSrc ){
+          /* ERROR: copy extends past end of input */
+          return -1;
+        }
+        memcpy(zOut, &zSrc[ofst], cnt);
+        zOut += cnt;
+        break;
+      }
+      case ':': {
+        zDelta++; lenDelta--;
+        total += cnt;
+        if( total>limit ){
+          /* ERROR:  insert command gives an output larger than predicted */
+          return -1;
+        }
+        if( (int)cnt>lenDelta ){
+          /* ERROR: insert count exceeds size of delta */
+          return -1;
+        }
+        memcpy(zOut, zDelta, cnt);
+        zOut += cnt;
+        zDelta += cnt;
+        lenDelta -= cnt;
+        break;
+      }
+      case ';': {
+        zDelta++; lenDelta--;
+        zOut[0] = 0;
+#ifndef FOSSIL_OMIT_DELTA_CKSUM_TEST
+        if( cnt!=rbuDeltaChecksum(zOrigOut, total) ){
+          /* ERROR:  bad checksum */
+          return -1;
         }
-        sqlite3_free(zVal);
+#endif
+        if( total!=limit ){
+          /* ERROR: generated size does not match predicted size */
+          return -1;
+        }
+        return total;
+      }
+      default: {
+        /* ERROR: unknown delta operator */
+        return -1;
       }
     }
+  }
+  /* ERROR: unterminated delta */
+  return -1;
+}
 
-    /* Otherwise, the argument is a column name. */
-    else {
-      nString += (int)(strlen(z) + 1);
-      aCol[nCol++] = z;
-    }
+static int rbuDeltaOutputSize(const char *zDelta, int lenDelta){
+  int size;
+  size = rbuDeltaGetInt(&zDelta, &lenDelta);
+  if( *zDelta!='\n' ){
+    /* ERROR: size integer not terminated by "\n" */
+    return -1;
   }
+  return size;
+}
 
-  /* If a content=xxx option was specified, the following:
-  **
-  **   1. Ignore any compress= and uncompress= options.
-  **
-  **   2. If no column names were specified as part of the CREATE VIRTUAL
-  **      TABLE statement, use all columns from the content table.
-  */
-  if( rc==SQLITE_OK && zContent ){
-    sqlite3_free(zCompress); 
-    sqlite3_free(zUncompress); 
-    zCompress = 0;
-    zUncompress = 0;
-    if( nCol==0 ){
-      sqlite3_free((void*)aCol); 
-      aCol = 0;
-      rc = fts3ContentColumns(db, argv[1], zContent, &aCol, &nCol, &nString);
+/*
+** End of code taken from fossil.
+*************************************************************************/
 
-      /* If a languageid= option was specified, remove the language id
-      ** column from the aCol[] array. */ 
-      if( rc==SQLITE_OK && zLanguageid ){
-        int j;
-        for(j=0; jdb = db;
-  p->nColumn = nCol;
-  p->nPendingData = 0;
-  p->azColumn = (char **)&p[1];
-  p->pTokenizer = pTokenizer;
-  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
-  p->bHasDocsize = (isFts4 && bNoDocsize==0);
-  p->bHasStat = isFts4;
-  p->bFts4 = isFts4;
-  p->bDescIdx = bDescIdx;
-  p->nAutoincrmerge = 0xff;   /* 0xff means setting unknown */
-  p->zContentTbl = zContent;
-  p->zLanguageid = zLanguageid;
-  zContent = 0;
-  zLanguageid = 0;
-  TESTONLY( p->inTransaction = -1 );
-  TESTONLY( p->mxSavepoint = -1 );
+  return rc;
+}
 
-  p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];
-  memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);
-  p->nIndex = nIndex;
-  for(i=0; iaIndex[i].hPending, FTS3_HASH_STRING, 1);
+/*
+** Free the RbuObjIter.azTblCol[] and RbuObjIter.abTblPk[] arrays allocated
+** by an earlier call to rbuObjIterCacheTableInfo().
+*/
+static void rbuObjIterFreeCols(RbuObjIter *pIter){
+  int i;
+  for(i=0; inTblCol; i++){
+    sqlite3_free(pIter->azTblCol[i]);
+    sqlite3_free(pIter->azTblType[i]);
+  }
+  sqlite3_free(pIter->azTblCol);
+  pIter->azTblCol = 0;
+  pIter->azTblType = 0;
+  pIter->aiSrcOrder = 0;
+  pIter->abTblPk = 0;
+  pIter->abNotNull = 0;
+  pIter->nTblCol = 0;
+  pIter->eType = 0;               /* Invalid value */
+}
+
+/*
+** Finalize all statements and free all allocations that are specific to
+** the current object (table/index pair).
+*/
+static void rbuObjIterClearStatements(RbuObjIter *pIter){
+  RbuUpdateStmt *pUp;
+
+  sqlite3_finalize(pIter->pSelect);
+  sqlite3_finalize(pIter->pInsert);
+  sqlite3_finalize(pIter->pDelete);
+  sqlite3_finalize(pIter->pTmpInsert);
+  pUp = pIter->pRbuUpdate;
+  while( pUp ){
+    RbuUpdateStmt *pTmp = pUp->pNext;
+    sqlite3_finalize(pUp->pUpdate);
+    sqlite3_free(pUp);
+    pUp = pTmp;
   }
-  p->abNotindexed = (u8 *)&p->aIndex[nIndex];
+  
+  pIter->pSelect = 0;
+  pIter->pInsert = 0;
+  pIter->pDelete = 0;
+  pIter->pRbuUpdate = 0;
+  pIter->pTmpInsert = 0;
+  pIter->nCol = 0;
+}
 
-  /* Fill in the zName and zDb fields of the vtab structure. */
-  zCsr = (char *)&p->abNotindexed[nCol];
-  p->zName = zCsr;
-  memcpy(zCsr, argv[2], nName);
-  zCsr += nName;
-  p->zDb = zCsr;
-  memcpy(zCsr, argv[1], nDb);
-  zCsr += nDb;
+/*
+** Clean up any resources allocated as part of the iterator object passed
+** as the only argument.
+*/
+static void rbuObjIterFinalize(RbuObjIter *pIter){
+  rbuObjIterClearStatements(pIter);
+  sqlite3_finalize(pIter->pTblIter);
+  sqlite3_finalize(pIter->pIdxIter);
+  rbuObjIterFreeCols(pIter);
+  memset(pIter, 0, sizeof(RbuObjIter));
+}
 
-  /* Fill in the azColumn array */
-  for(iCol=0; iColazColumn[iCol] = zCsr;
-    zCsr += n+1;
-    assert( zCsr <= &((char *)p)[nByte] );
-  }
+/*
+** Advance the iterator to the next position.
+**
+** If no error occurs, SQLITE_OK is returned and the iterator is left 
+** pointing to the next entry. Otherwise, an error code and message is 
+** left in the RBU handle passed as the first argument. A copy of the 
+** error code is returned.
+*/
+static int rbuObjIterNext(sqlite3rbu *p, RbuObjIter *pIter){
+  int rc = p->rc;
+  if( rc==SQLITE_OK ){
 
-  /* Fill in the abNotindexed array */
-  for(iCol=0; iColazColumn[iCol]);
-    for(i=0; iazColumn[iCol], zNot, n) 
-      ){
-        p->abNotindexed[iCol] = 1;
-        sqlite3_free(zNot);
-        azNotindexed[i] = 0;
-      }
+    /* Free any SQLite statements used while processing the previous object */ 
+    rbuObjIterClearStatements(pIter);
+    if( pIter->zIdx==0 ){
+      rc = sqlite3_exec(p->dbMain,
+          "DROP TRIGGER IF EXISTS temp.rbu_insert_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_update1_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_update2_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_delete_tr;"
+          , 0, 0, &p->zErrmsg
+      );
     }
-  }
-  for(i=0; ibCleanup ){
+        rbuObjIterFreeCols(pIter);
+        pIter->bCleanup = 0;
+        rc = sqlite3_step(pIter->pTblIter);
+        if( rc!=SQLITE_ROW ){
+          rc = resetAndCollectError(pIter->pTblIter, &p->zErrmsg);
+          pIter->zTbl = 0;
+        }else{
+          pIter->zTbl = (const char*)sqlite3_column_text(pIter->pTblIter, 0);
+          pIter->zDataTbl = (const char*)sqlite3_column_text(pIter->pTblIter,1);
+          rc = (pIter->zDataTbl && pIter->zTbl) ? SQLITE_OK : SQLITE_NOMEM;
+        }
+      }else{
+        if( pIter->zIdx==0 ){
+          sqlite3_stmt *pIdx = pIter->pIdxIter;
+          rc = sqlite3_bind_text(pIdx, 1, pIter->zTbl, -1, SQLITE_STATIC);
+        }
+        if( rc==SQLITE_OK ){
+          rc = sqlite3_step(pIter->pIdxIter);
+          if( rc!=SQLITE_ROW ){
+            rc = resetAndCollectError(pIter->pIdxIter, &p->zErrmsg);
+            pIter->bCleanup = 1;
+            pIter->zIdx = 0;
+          }else{
+            pIter->zIdx = (const char*)sqlite3_column_text(pIter->pIdxIter, 0);
+            pIter->iTnum = sqlite3_column_int(pIter->pIdxIter, 1);
+            pIter->bUnique = sqlite3_column_int(pIter->pIdxIter, 2);
+            rc = pIter->zIdx ? SQLITE_OK : SQLITE_NOMEM;
+          }
+        }
+      }
     }
   }
 
-  if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){
-    char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
-    rc = SQLITE_ERROR;
-    *pzErr = sqlite3_mprintf("missing %s parameter in fts4 constructor", zMiss);
+  if( rc!=SQLITE_OK ){
+    rbuObjIterFinalize(pIter);
+    p->rc = rc;
   }
-  p->zReadExprlist = fts3ReadExprList(p, zUncompress, &rc);
-  p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);
-  if( rc!=SQLITE_OK ) goto fts3_init_out;
+  return rc;
+}
 
-  /* If this is an xCreate call, create the underlying tables in the 
-  ** database. TODO: For xConnect(), it could verify that said tables exist.
-  */
-  if( isCreate ){
-    rc = fts3CreateTables(p);
-  }
 
-  /* Check to see if a legacy fts3 table has been "upgraded" by the
-  ** addition of a %_stat table so that it can use incremental merge.
-  */
-  if( !isFts4 && !isCreate ){
-    p->bHasStat = 2;
+/*
+** The implementation of the rbu_target_name() SQL function. This function
+** accepts one or two arguments. The first argument is the name of a table -
+** the name of a table in the RBU database.  The second, if it is present, is 1
+** for a view or 0 for a table. 
+**
+** For a non-vacuum RBU handle, if the table name matches the pattern:
+**
+**     data[0-9]_
+**
+** where  is any sequence of 1 or more characters,  is returned.
+** Otherwise, if the only argument does not match the above pattern, an SQL
+** NULL is returned.
+**
+**     "data_t1"     -> "t1"
+**     "data0123_t2" -> "t2"
+**     "dataAB_t3"   -> NULL
+**
+** For an rbu vacuum handle, a copy of the first argument is returned if
+** the second argument is either missing or 0 (not a view).
+*/
+static void rbuTargetNameFunc(
+  sqlite3_context *pCtx,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3rbu *p = sqlite3_user_data(pCtx);
+  const char *zIn;
+  assert( argc==1 || argc==2 );
+
+  zIn = (const char*)sqlite3_value_text(argv[0]);
+  if( zIn ){
+    if( rbuIsVacuum(p) ){
+      if( argc==1 || 0==sqlite3_value_int(argv[1]) ){
+        sqlite3_result_text(pCtx, zIn, -1, SQLITE_STATIC);
+      }
+    }else{
+      if( strlen(zIn)>4 && memcmp("data", zIn, 4)==0 ){
+        int i;
+        for(i=4; zIn[i]>='0' && zIn[i]<='9'; i++);
+        if( zIn[i]=='_' && zIn[i+1] ){
+          sqlite3_result_text(pCtx, &zIn[i+1], -1, SQLITE_STATIC);
+        }
+      }
+    }
   }
+}
 
-  /* Figure out the page-size for the database. This is required in order to
-  ** estimate the cost of loading large doclists from the database.  */
-  fts3DatabasePageSize(&rc, p);
-  p->nNodeSize = p->nPgsz-35;
+/*
+** Initialize the iterator structure passed as the second argument.
+**
+** If no error occurs, SQLITE_OK is returned and the iterator is left 
+** pointing to the first entry. Otherwise, an error code and message is 
+** left in the RBU handle passed as the first argument. A copy of the 
+** error code is returned.
+*/
+static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){
+  int rc;
+  memset(pIter, 0, sizeof(RbuObjIter));
 
-  /* Declare the table schema to SQLite. */
-  fts3DeclareVtab(&rc, p);
+  rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, 
+    sqlite3_mprintf(
+      "SELECT rbu_target_name(name, type='view') AS target, name "
+      "FROM sqlite_master "
+      "WHERE type IN ('table', 'view') AND target IS NOT NULL "
+      " %s "
+      "ORDER BY name"
+  , rbuIsVacuum(p) ? "AND rootpage!=0 AND rootpage IS NOT NULL" : ""));
 
-fts3_init_out:
-  sqlite3_free(zPrefix);
-  sqlite3_free(aIndex);
-  sqlite3_free(zCompress);
-  sqlite3_free(zUncompress);
-  sqlite3_free(zContent);
-  sqlite3_free(zLanguageid);
-  for(i=0; ipModule->xDestroy(pTokenizer);
-    }
+  if( rc==SQLITE_OK ){
+    rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg,
+        "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' "
+        "  FROM main.sqlite_master "
+        "  WHERE type='index' AND tbl_name = ?"
+    );
+  }
+
+  pIter->bCleanup = 1;
+  p->rc = rc;
+  return rbuObjIterNext(p, pIter);
+}
+
+/*
+** This is a wrapper around "sqlite3_mprintf(zFmt, ...)". If an OOM occurs,
+** an error code is stored in the RBU handle passed as the first argument.
+**
+** If an error has already occurred (p->rc is already set to something other
+** than SQLITE_OK), then this function returns NULL without modifying the
+** stored error code. In this case it still calls sqlite3_free() on any 
+** printf() parameters associated with %z conversions.
+*/
+static char *rbuMPrintf(sqlite3rbu *p, const char *zFmt, ...){
+  char *zSql = 0;
+  va_list ap;
+  va_start(ap, zFmt);
+  zSql = sqlite3_vmprintf(zFmt, ap);
+  if( p->rc==SQLITE_OK ){
+    if( zSql==0 ) p->rc = SQLITE_NOMEM;
   }else{
-    assert( p->pSegments==0 );
-    *ppVTab = &p->base;
+    sqlite3_free(zSql);
+    zSql = 0;
   }
-  return rc;
+  va_end(ap);
+  return zSql;
 }
 
 /*
-** The xConnect() and xCreate() methods for the virtual table. All the
-** work is done in function fts3InitVtab().
+** Argument zFmt is a sqlite3_mprintf() style format string. The trailing
+** arguments are the usual subsitution values. This function performs
+** the printf() style substitutions and executes the result as an SQL
+** statement on the RBU handles database.
+**
+** If an error occurs, an error code and error message is stored in the
+** RBU handle. If an error has already occurred when this function is
+** called, it is a no-op.
 */
-static int fts3ConnectMethod(
-  sqlite3 *db,                    /* Database connection */
-  void *pAux,                     /* Pointer to tokenizer hash table */
-  int argc,                       /* Number of elements in argv array */
-  const char * const *argv,       /* xCreate/xConnect argument array */
-  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
-  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
-){
-  return fts3InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);
+static int rbuMPrintfExec(sqlite3rbu *p, sqlite3 *db, const char *zFmt, ...){
+  va_list ap;
+  char *zSql;
+  va_start(ap, zFmt);
+  zSql = sqlite3_vmprintf(zFmt, ap);
+  if( p->rc==SQLITE_OK ){
+    if( zSql==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      p->rc = sqlite3_exec(db, zSql, 0, 0, &p->zErrmsg);
+    }
+  }
+  sqlite3_free(zSql);
+  va_end(ap);
+  return p->rc;
 }
-static int fts3CreateMethod(
-  sqlite3 *db,                    /* Database connection */
-  void *pAux,                     /* Pointer to tokenizer hash table */
-  int argc,                       /* Number of elements in argv array */
-  const char * const *argv,       /* xCreate/xConnect argument array */
-  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
-  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
-){
-  return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
+
+/*
+** Attempt to allocate and return a pointer to a zeroed block of nByte 
+** bytes. 
+**
+** If an error (i.e. an OOM condition) occurs, return NULL and leave an 
+** error code in the rbu handle passed as the first argument. Or, if an 
+** error has already occurred when this function is called, return NULL 
+** immediately without attempting the allocation or modifying the stored
+** error code.
+*/
+static void *rbuMalloc(sqlite3rbu *p, int nByte){
+  void *pRet = 0;
+  if( p->rc==SQLITE_OK ){
+    assert( nByte>0 );
+    pRet = sqlite3_malloc64(nByte);
+    if( pRet==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      memset(pRet, 0, nByte);
+    }
+  }
+  return pRet;
 }
 
+
 /*
-** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
-** extension is currently being used by a version of SQLite too old to
-** support estimatedRows. In that case this function is a no-op.
+** Allocate and zero the pIter->azTblCol[] and abTblPk[] arrays so that
+** there is room for at least nCol elements. If an OOM occurs, store an
+** error code in the RBU handle passed as the first argument.
 */
-static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
-#if SQLITE_VERSION_NUMBER>=3008002
-  if( sqlite3_libversion_number()>=3008002 ){
-    pIdxInfo->estimatedRows = nRow;
+static void rbuAllocateIterArrays(sqlite3rbu *p, RbuObjIter *pIter, int nCol){
+  int nByte = (2*sizeof(char*) + sizeof(int) + 3*sizeof(u8)) * nCol;
+  char **azNew;
+
+  azNew = (char**)rbuMalloc(p, nByte);
+  if( azNew ){
+    pIter->azTblCol = azNew;
+    pIter->azTblType = &azNew[nCol];
+    pIter->aiSrcOrder = (int*)&pIter->azTblType[nCol];
+    pIter->abTblPk = (u8*)&pIter->aiSrcOrder[nCol];
+    pIter->abNotNull = (u8*)&pIter->abTblPk[nCol];
+    pIter->abIndexed = (u8*)&pIter->abNotNull[nCol];
   }
-#endif
 }
 
-/* 
-** Implementation of the xBestIndex method for FTS3 tables. There
-** are three possible strategies, in order of preference:
+/*
+** The first argument must be a nul-terminated string. This function
+** returns a copy of the string in memory obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free this memory
+** using sqlite3_free().
 **
-**   1. Direct lookup by rowid or docid. 
-**   2. Full-text search using a MATCH operator on a non-docid column.
-**   3. Linear scan of %_content table.
+** If an OOM condition is encountered when attempting to allocate memory,
+** output variable (*pRc) is set to SQLITE_NOMEM before returning. Otherwise,
+** if the allocation succeeds, (*pRc) is left unchanged.
 */
-static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
-  Fts3Table *p = (Fts3Table *)pVTab;
-  int i;                          /* Iterator variable */
-  int iCons = -1;                 /* Index of constraint to use */
-
-  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
-  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
-  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
-  int iIdx;
+static char *rbuStrndup(const char *zStr, int *pRc){
+  char *zRet = 0;
 
-  /* By default use a full table scan. This is an expensive option,
-  ** so search through the constraints to see if a more efficient 
-  ** strategy is possible.
-  */
-  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
-  pInfo->estimatedCost = 5000000;
-  for(i=0; inConstraint; i++){
-    int bDocid;                 /* True if this constraint is on docid */
-    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
-    if( pCons->usable==0 ){
-      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
-        /* There exists an unusable MATCH constraint. This means that if
-        ** the planner does elect to use the results of this call as part
-        ** of the overall query plan the user will see an "unable to use
-        ** function MATCH in the requested context" error. To discourage
-        ** this, return a very high cost here.  */
-        pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
-        pInfo->estimatedCost = 1e50;
-        fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
-        return SQLITE_OK;
-      }
-      continue;
+  assert( *pRc==SQLITE_OK );
+  if( zStr ){
+    size_t nCopy = strlen(zStr) + 1;
+    zRet = (char*)sqlite3_malloc64(nCopy);
+    if( zRet ){
+      memcpy(zRet, zStr, nCopy);
+    }else{
+      *pRc = SQLITE_NOMEM;
     }
+  }
 
-    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);
+  return zRet;
+}
 
-    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
-    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
-      pInfo->idxNum = FTS3_DOCID_SEARCH;
-      pInfo->estimatedCost = 1.0;
-      iCons = i;
+/*
+** Finalize the statement passed as the second argument.
+**
+** If the sqlite3_finalize() call indicates that an error occurs, and the
+** rbu handle error code is not already set, set the error code and error
+** message accordingly.
+*/
+static void rbuFinalize(sqlite3rbu *p, sqlite3_stmt *pStmt){
+  sqlite3 *db = sqlite3_db_handle(pStmt);
+  int rc = sqlite3_finalize(pStmt);
+  if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){
+    p->rc = rc;
+    p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+  }
+}
+
+/* Determine the type of a table.
+**
+**   peType is of type (int*), a pointer to an output parameter of type
+**   (int). This call sets the output parameter as follows, depending
+**   on the type of the table specified by parameters dbName and zTbl.
+**
+**     RBU_PK_NOTABLE:       No such table.
+**     RBU_PK_NONE:          Table has an implicit rowid.
+**     RBU_PK_IPK:           Table has an explicit IPK column.
+**     RBU_PK_EXTERNAL:      Table has an external PK index.
+**     RBU_PK_WITHOUT_ROWID: Table is WITHOUT ROWID.
+**     RBU_PK_VTAB:          Table is a virtual table.
+**
+**   Argument *piPk is also of type (int*), and also points to an output
+**   parameter. Unless the table has an external primary key index 
+**   (i.e. unless *peType is set to 3), then *piPk is set to zero. Or,
+**   if the table does have an external primary key index, then *piPk
+**   is set to the root page number of the primary key index before
+**   returning.
+**
+** ALGORITHM:
+**
+**   if( no entry exists in sqlite_master ){
+**     return RBU_PK_NOTABLE
+**   }else if( sql for the entry starts with "CREATE VIRTUAL" ){
+**     return RBU_PK_VTAB
+**   }else if( "PRAGMA index_list()" for the table contains a "pk" index ){
+**     if( the index that is the pk exists in sqlite_master ){
+**       *piPK = rootpage of that index.
+**       return RBU_PK_EXTERNAL
+**     }else{
+**       return RBU_PK_WITHOUT_ROWID
+**     }
+**   }else if( "PRAGMA table_info()" lists one or more "pk" columns ){
+**     return RBU_PK_IPK
+**   }else{
+**     return RBU_PK_NONE
+**   }
+*/
+static void rbuTableType(
+  sqlite3rbu *p,
+  const char *zTab,
+  int *peType,
+  int *piTnum,
+  int *piPk
+){
+  /*
+  ** 0) SELECT count(*) FROM sqlite_master where name=%Q AND IsVirtual(%Q)
+  ** 1) PRAGMA index_list = ?
+  ** 2) SELECT count(*) FROM sqlite_master where name=%Q 
+  ** 3) PRAGMA table_info = ?
+  */
+  sqlite3_stmt *aStmt[4] = {0, 0, 0, 0};
+
+  *peType = RBU_PK_NOTABLE;
+  *piPk = 0;
+
+  assert( p->rc==SQLITE_OK );
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, 
+    sqlite3_mprintf(
+          "SELECT (sql LIKE 'create virtual%%'), rootpage"
+          "  FROM sqlite_master"
+          " WHERE name=%Q", zTab
+  ));
+  if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){
+    /* Either an error, or no such table. */
+    goto rbuTableType_end;
+  }
+  if( sqlite3_column_int(aStmt[0], 0) ){
+    *peType = RBU_PK_VTAB;                     /* virtual table */
+    goto rbuTableType_end;
+  }
+  *piTnum = sqlite3_column_int(aStmt[0], 1);
+
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[1], &p->zErrmsg, 
+    sqlite3_mprintf("PRAGMA index_list=%Q",zTab)
+  );
+  if( p->rc ) goto rbuTableType_end;
+  while( sqlite3_step(aStmt[1])==SQLITE_ROW ){
+    const u8 *zOrig = sqlite3_column_text(aStmt[1], 3);
+    const u8 *zIdx = sqlite3_column_text(aStmt[1], 1);
+    if( zOrig && zIdx && zOrig[0]=='p' ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, 
+          sqlite3_mprintf(
+            "SELECT rootpage FROM sqlite_master WHERE name = %Q", zIdx
+      ));
+      if( p->rc==SQLITE_OK ){
+        if( sqlite3_step(aStmt[2])==SQLITE_ROW ){
+          *piPk = sqlite3_column_int(aStmt[2], 0);
+          *peType = RBU_PK_EXTERNAL;
+        }else{
+          *peType = RBU_PK_WITHOUT_ROWID;
+        }
+      }
+      goto rbuTableType_end;
     }
+  }
 
-    /* A MATCH constraint. Use a full-text search.
-    **
-    ** If there is more than one MATCH constraint available, use the first
-    ** one encountered. If there is both a MATCH constraint and a direct
-    ** rowid/docid lookup, prefer the MATCH strategy. This is done even 
-    ** though the rowid/docid lookup is faster than a MATCH query, selecting
-    ** it would lead to an "unable to use function MATCH in the requested 
-    ** context" error.
-    */
-    if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
-     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
-    ){
-      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
-      pInfo->estimatedCost = 2.0;
-      iCons = i;
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[3], &p->zErrmsg, 
+    sqlite3_mprintf("PRAGMA table_info=%Q",zTab)
+  );
+  if( p->rc==SQLITE_OK ){
+    while( sqlite3_step(aStmt[3])==SQLITE_ROW ){
+      if( sqlite3_column_int(aStmt[3],5)>0 ){
+        *peType = RBU_PK_IPK;                /* explicit IPK column */
+        goto rbuTableType_end;
+      }
     }
+    *peType = RBU_PK_NONE;
+  }
 
-    /* Equality constraint on the langid column */
-    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
-     && pCons->iColumn==p->nColumn + 2
-    ){
-      iLangidCons = i;
+rbuTableType_end: {
+    unsigned int i;
+    for(i=0; iop ){
-        case SQLITE_INDEX_CONSTRAINT_GE:
-        case SQLITE_INDEX_CONSTRAINT_GT:
-          iDocidGe = i;
-          break;
+/*
+** This is a helper function for rbuObjIterCacheTableInfo(). It populates
+** the pIter->abIndexed[] array.
+*/
+static void rbuObjIterCacheIndexedCols(sqlite3rbu *p, RbuObjIter *pIter){
+  sqlite3_stmt *pList = 0;
+  int bIndex = 0;
 
-        case SQLITE_INDEX_CONSTRAINT_LE:
-        case SQLITE_INDEX_CONSTRAINT_LT:
-          iDocidLe = i;
-          break;
-      }
+  if( p->rc==SQLITE_OK ){
+    memcpy(pIter->abIndexed, pIter->abTblPk, sizeof(u8)*pIter->nTblCol);
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pList, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)
+    );
+  }
+
+  pIter->nIndex = 0;
+  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pList) ){
+    const char *zIdx = (const char*)sqlite3_column_text(pList, 1);
+    sqlite3_stmt *pXInfo = 0;
+    if( zIdx==0 ) break;
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+    );
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      int iCid = sqlite3_column_int(pXInfo, 1);
+      if( iCid>=0 ) pIter->abIndexed[iCid] = 1;
     }
+    rbuFinalize(p, pXInfo);
+    bIndex = 1;
+    pIter->nIndex++;
   }
 
-  iIdx = 1;
-  if( iCons>=0 ){
-    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
-    pInfo->aConstraintUsage[iCons].omit = 1;
-  } 
-  if( iLangidCons>=0 ){
-    pInfo->idxNum |= FTS3_HAVE_LANGID;
-    pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
-  } 
-  if( iDocidGe>=0 ){
-    pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
-    pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
-  } 
-  if( iDocidLe>=0 ){
-    pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
-    pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
-  } 
+  if( pIter->eType==RBU_PK_WITHOUT_ROWID ){
+    /* "PRAGMA index_list" includes the main PK b-tree */
+    pIter->nIndex--;
+  }
 
-  /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
-  ** docid) order. Both ascending and descending are possible. 
-  */
-  if( pInfo->nOrderBy==1 ){
-    struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];
-    if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){
-      if( pOrder->desc ){
-        pInfo->idxStr = "DESC";
-      }else{
-        pInfo->idxStr = "ASC";
+  rbuFinalize(p, pList);
+  if( bIndex==0 ) pIter->abIndexed = 0;
+}
+
+
+/*
+** If they are not already populated, populate the pIter->azTblCol[],
+** pIter->abTblPk[], pIter->nTblCol and pIter->bRowid variables according to
+** the table (not index) that the iterator currently points to.
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise. If
+** an error does occur, an error code and error message are also left in 
+** the RBU handle.
+*/
+static int rbuObjIterCacheTableInfo(sqlite3rbu *p, RbuObjIter *pIter){
+  if( pIter->azTblCol==0 ){
+    sqlite3_stmt *pStmt = 0;
+    int nCol = 0;
+    int i;                        /* for() loop iterator variable */
+    int bRbuRowid = 0;            /* If input table has column "rbu_rowid" */
+    int iOrder = 0;
+    int iTnum = 0;
+
+    /* Figure out the type of table this step will deal with. */
+    assert( pIter->eType==0 );
+    rbuTableType(p, pIter->zTbl, &pIter->eType, &iTnum, &pIter->iPkTnum);
+    if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_NOTABLE ){
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf("no such table: %s", pIter->zTbl);
+    }
+    if( p->rc ) return p->rc;
+    if( pIter->zIdx==0 ) pIter->iTnum = iTnum;
+
+    assert( pIter->eType==RBU_PK_NONE || pIter->eType==RBU_PK_IPK 
+         || pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_WITHOUT_ROWID
+         || pIter->eType==RBU_PK_VTAB
+    );
+
+    /* Populate the azTblCol[] and nTblCol variables based on the columns
+    ** of the input table. Ignore any input table columns that begin with
+    ** "rbu_".  */
+    p->rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 
+        sqlite3_mprintf("SELECT * FROM '%q'", pIter->zDataTbl)
+    );
+    if( p->rc==SQLITE_OK ){
+      nCol = sqlite3_column_count(pStmt);
+      rbuAllocateIterArrays(p, pIter, nCol);
+    }
+    for(i=0; p->rc==SQLITE_OK && irc);
+        pIter->aiSrcOrder[pIter->nTblCol] = pIter->nTblCol;
+        pIter->azTblCol[pIter->nTblCol++] = zCopy;
+      }
+      else if( 0==sqlite3_stricmp("rbu_rowid", zName) ){
+        bRbuRowid = 1;
       }
-      pInfo->orderByConsumed = 1;
     }
-  }
+    sqlite3_finalize(pStmt);
+    pStmt = 0;
 
-  assert( p->pSegments==0 );
-  return SQLITE_OK;
-}
+    if( p->rc==SQLITE_OK
+     && rbuIsVacuum(p)==0
+     && bRbuRowid!=(pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE)
+    ){
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf(
+          "table %q %s rbu_rowid column", pIter->zDataTbl,
+          (bRbuRowid ? "may not have" : "requires")
+      );
+    }
 
-/*
-** Implementation of xOpen method.
-*/
-static int fts3OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
-  sqlite3_vtab_cursor *pCsr;               /* Allocated cursor */
+    /* Check that all non-HIDDEN columns in the destination table are also
+    ** present in the input table. Populate the abTblPk[], azTblType[] and
+    ** aiTblOrder[] arrays at the same time.  */
+    if( p->rc==SQLITE_OK ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &p->zErrmsg, 
+          sqlite3_mprintf("PRAGMA table_info(%Q)", pIter->zTbl)
+      );
+    }
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      const char *zName = (const char*)sqlite3_column_text(pStmt, 1);
+      if( zName==0 ) break;  /* An OOM - finalize() below returns S_NOMEM */
+      for(i=iOrder; inTblCol; i++){
+        if( 0==strcmp(zName, pIter->azTblCol[i]) ) break;
+      }
+      if( i==pIter->nTblCol ){
+        p->rc = SQLITE_ERROR;
+        p->zErrmsg = sqlite3_mprintf("column missing from %q: %s",
+            pIter->zDataTbl, zName
+        );
+      }else{
+        int iPk = sqlite3_column_int(pStmt, 5);
+        int bNotNull = sqlite3_column_int(pStmt, 3);
+        const char *zType = (const char*)sqlite3_column_text(pStmt, 2);
 
-  UNUSED_PARAMETER(pVTab);
+        if( i!=iOrder ){
+          SWAP(int, pIter->aiSrcOrder[i], pIter->aiSrcOrder[iOrder]);
+          SWAP(char*, pIter->azTblCol[i], pIter->azTblCol[iOrder]);
+        }
 
-  /* Allocate a buffer large enough for an Fts3Cursor structure. If the
-  ** allocation succeeds, zero it and return SQLITE_OK. Otherwise, 
-  ** if the allocation fails, return SQLITE_NOMEM.
-  */
-  *ppCsr = pCsr = (sqlite3_vtab_cursor *)sqlite3_malloc(sizeof(Fts3Cursor));
-  if( !pCsr ){
-    return SQLITE_NOMEM;
+        pIter->azTblType[iOrder] = rbuStrndup(zType, &p->rc);
+        pIter->abTblPk[iOrder] = (iPk!=0);
+        pIter->abNotNull[iOrder] = (u8)bNotNull || (iPk!=0);
+        iOrder++;
+      }
+    }
+
+    rbuFinalize(p, pStmt);
+    rbuObjIterCacheIndexedCols(p, pIter);
+    assert( pIter->eType!=RBU_PK_VTAB || pIter->abIndexed==0 );
+    assert( pIter->eType!=RBU_PK_VTAB || pIter->nIndex==0 );
   }
-  memset(pCsr, 0, sizeof(Fts3Cursor));
-  return SQLITE_OK;
+
+  return p->rc;
 }
 
 /*
-** Close the cursor.  For additional information see the documentation
-** on the xClose method of the virtual table interface.
+** This function constructs and returns a pointer to a nul-terminated 
+** string containing some SQL clause or list based on one or more of the 
+** column names currently stored in the pIter->azTblCol[] array.
 */
-static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
-  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
-  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
-  sqlite3_finalize(pCsr->pStmt);
-  sqlite3Fts3ExprFree(pCsr->pExpr);
-  sqlite3Fts3FreeDeferredTokens(pCsr);
-  sqlite3_free(pCsr->aDoclist);
-  sqlite3_free(pCsr->aMatchinfo);
-  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
-  sqlite3_free(pCsr);
-  return SQLITE_OK;
+static char *rbuObjIterGetCollist(
+  sqlite3rbu *p,                  /* RBU object */
+  RbuObjIter *pIter               /* Object iterator for column names */
+){
+  char *zList = 0;
+  const char *zSep = "";
+  int i;
+  for(i=0; inTblCol; i++){
+    const char *z = pIter->azTblCol[i];
+    zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z);
+    zSep = ", ";
+  }
+  return zList;
 }
 
 /*
-** If pCsr->pStmt has not been prepared (i.e. if pCsr->pStmt==0), then
-** compose and prepare an SQL statement of the form:
+** This function is used to create a SELECT list (the list of SQL 
+** expressions that follows a SELECT keyword) for a SELECT statement 
+** used to read from an data_xxx or rbu_tmp_xxx table while updating the 
+** index object currently indicated by the iterator object passed as the 
+** second argument. A "PRAGMA index_xinfo = " statement is used 
+** to obtain the required information.
 **
-**    "SELECT  FROM %_content WHERE rowid = ?"
+** If the index is of the following form:
 **
-** (or the equivalent for a content=xxx table) and set pCsr->pStmt to
-** it. If an error occurs, return an SQLite error code.
+**   CREATE INDEX i1 ON t1(c, b COLLATE nocase);
+**
+** and "t1" is a table with an explicit INTEGER PRIMARY KEY column 
+** "ipk", the returned string is:
 **
-** Otherwise, set *ppStmt to point to pCsr->pStmt and return SQLITE_OK.
+**   "`c` COLLATE 'BINARY', `b` COLLATE 'NOCASE', `ipk` COLLATE 'BINARY'"
+**
+** As well as the returned string, three other malloc'd strings are 
+** returned via output parameters. As follows:
+**
+**   pzImposterCols: ...
+**   pzImposterPk: ...
+**   pzWhere: ...
 */
-static int fts3CursorSeekStmt(Fts3Cursor *pCsr, sqlite3_stmt **ppStmt){
-  int rc = SQLITE_OK;
-  if( pCsr->pStmt==0 ){
-    Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
-    char *zSql;
-    zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);
-    if( !zSql ) return SQLITE_NOMEM;
-    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pCsr->pStmt, 0);
-    sqlite3_free(zSql);
+static char *rbuObjIterGetIndexCols(
+  sqlite3rbu *p,                  /* RBU object */
+  RbuObjIter *pIter,              /* Object iterator for column names */
+  char **pzImposterCols,          /* OUT: Columns for imposter table */
+  char **pzImposterPk,            /* OUT: Imposter PK clause */
+  char **pzWhere,                 /* OUT: WHERE clause */
+  int *pnBind                     /* OUT: Trbul number of columns */
+){
+  int rc = p->rc;                 /* Error code */
+  int rc2;                        /* sqlite3_finalize() return code */
+  char *zRet = 0;                 /* String to return */
+  char *zImpCols = 0;             /* String to return via *pzImposterCols */
+  char *zImpPK = 0;               /* String to return via *pzImposterPK */
+  char *zWhere = 0;               /* String to return via *pzWhere */
+  int nBind = 0;                  /* Value to return via *pnBind */
+  const char *zCom = "";          /* Set to ", " later on */
+  const char *zAnd = "";          /* Set to " AND " later on */
+  sqlite3_stmt *pXInfo = 0;       /* PRAGMA index_xinfo = ? */
+
+  if( rc==SQLITE_OK ){
+    assert( p->zErrmsg==0 );
+    rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx)
+    );
   }
-  *ppStmt = pCsr->pStmt;
-  return rc;
-}
 
-/*
-** Position the pCsr->pStmt statement so that it is on the row
-** of the %_content table that contains the last match.  Return
-** SQLITE_OK on success.  
-*/
-static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
-  int rc = SQLITE_OK;
-  if( pCsr->isRequireSeek ){
-    sqlite3_stmt *pStmt = 0;
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+    int iCid = sqlite3_column_int(pXInfo, 1);
+    int bDesc = sqlite3_column_int(pXInfo, 3);
+    const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);
+    const char *zCol;
+    const char *zType;
 
-    rc = fts3CursorSeekStmt(pCsr, &pStmt);
-    if( rc==SQLITE_OK ){
-      sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
-      pCsr->isRequireSeek = 0;
-      if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
-        return SQLITE_OK;
+    if( iCid<0 ){
+      /* An integer primary key. If the table has an explicit IPK, use
+      ** its name. Otherwise, use "rbu_rowid".  */
+      if( pIter->eType==RBU_PK_IPK ){
+        int i;
+        for(i=0; pIter->abTblPk[i]==0; i++);
+        assert( inTblCol );
+        zCol = pIter->azTblCol[i];
+      }else if( rbuIsVacuum(p) ){
+        zCol = "_rowid_";
       }else{
-        rc = sqlite3_reset(pCsr->pStmt);
-        if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
-          /* If no row was found and no error has occurred, then the %_content
-          ** table is missing a row that is present in the full-text index.
-          ** The data structures are corrupt.  */
-          rc = FTS_CORRUPT_VTAB;
-          pCsr->isEof = 1;
-        }
+        zCol = "rbu_rowid";
       }
+      zType = "INTEGER";
+    }else{
+      zCol = pIter->azTblCol[iCid];
+      zType = pIter->azTblType[iCid];
+    }
+
+    zRet = sqlite3_mprintf("%z%s\"%w\" COLLATE %Q", zRet, zCom, zCol, zCollate);
+    if( pIter->bUnique==0 || sqlite3_column_int(pXInfo, 5) ){
+      const char *zOrder = (bDesc ? " DESC" : "");
+      zImpPK = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\"%s", 
+          zImpPK, zCom, nBind, zCol, zOrder
+      );
     }
+    zImpCols = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\" %s COLLATE %Q", 
+        zImpCols, zCom, nBind, zCol, zType, zCollate
+    );
+    zWhere = sqlite3_mprintf(
+        "%z%s\"rbu_imp_%d%w\" IS ?", zWhere, zAnd, nBind, zCol
+    );
+    if( zRet==0 || zImpPK==0 || zImpCols==0 || zWhere==0 ) rc = SQLITE_NOMEM;
+    zCom = ", ";
+    zAnd = " AND ";
+    nBind++;
   }
 
-  if( rc!=SQLITE_OK && pContext ){
-    sqlite3_result_error_code(pContext, rc);
+  rc2 = sqlite3_finalize(pXInfo);
+  if( rc==SQLITE_OK ) rc = rc2;
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(zRet);
+    sqlite3_free(zImpCols);
+    sqlite3_free(zImpPK);
+    sqlite3_free(zWhere);
+    zRet = 0;
+    zImpCols = 0;
+    zImpPK = 0;
+    zWhere = 0;
+    p->rc = rc;
   }
-  return rc;
+
+  *pzImposterCols = zImpCols;
+  *pzImposterPk = zImpPK;
+  *pzWhere = zWhere;
+  *pnBind = nBind;
+  return zRet;
 }
 
 /*
-** This function is used to process a single interior node when searching
-** a b-tree for a term or term prefix. The node data is passed to this 
-** function via the zNode/nNode parameters. The term to search for is
-** passed in zTerm/nTerm.
+** Assuming the current table columns are "a", "b" and "c", and the zObj
+** paramter is passed "old", return a string of the form:
 **
-** If piFirst is not NULL, then this function sets *piFirst to the blockid
-** of the child node that heads the sub-tree that may contain the term.
+**     "old.a, old.b, old.b"
 **
-** If piLast is not NULL, then *piLast is set to the right-most child node
-** that heads a sub-tree that may contain a term for which zTerm/nTerm is
-** a prefix.
+** With the column names escaped.
 **
-** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
+** For tables with implicit rowids - RBU_PK_EXTERNAL and RBU_PK_NONE, append
+** the text ", old._rowid_" to the returned value.
 */
-static int fts3ScanInteriorNode(
-  const char *zTerm,              /* Term to select leaves for */
-  int nTerm,                      /* Size of term zTerm in bytes */
-  const char *zNode,              /* Buffer containing segment interior node */
-  int nNode,                      /* Size of buffer at zNode */
-  sqlite3_int64 *piFirst,         /* OUT: Selected child node */
-  sqlite3_int64 *piLast           /* OUT: Selected child node */
+static char *rbuObjIterGetOldlist(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  const char *zObj
 ){
-  int rc = SQLITE_OK;             /* Return code */
-  const char *zCsr = zNode;       /* Cursor to iterate through node */
-  const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
-  char *zBuffer = 0;              /* Buffer to load terms into */
-  int nAlloc = 0;                 /* Size of allocated buffer */
-  int isFirstTerm = 1;            /* True when processing first term on page */
-  sqlite3_int64 iChild;           /* Block id of child node to descend to */
-
-  /* Skip over the 'height' varint that occurs at the start of every 
-  ** interior node. Then load the blockid of the left-child of the b-tree
-  ** node into variable iChild.  
-  **
-  ** Even if the data structure on disk is corrupted, this (reading two
-  ** varints from the buffer) does not risk an overread. If zNode is a
-  ** root node, then the buffer comes from a SELECT statement. SQLite does
-  ** not make this guarantee explicitly, but in practice there are always
-  ** either more than 20 bytes of allocated space following the nNode bytes of
-  ** contents, or two zero bytes. Or, if the node is read from the %_segments
-  ** table, then there are always 20 bytes of zeroed padding following the
-  ** nNode bytes of content (see sqlite3Fts3ReadBlock() for details).
-  */
-  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
-  zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
-  if( zCsr>zEnd ){
-    return FTS_CORRUPT_VTAB;
-  }
-  
-  while( zCsrzEnd ){
-      rc = FTS_CORRUPT_VTAB;
-      goto finish_scan;
-    }
-    if( nPrefix+nSuffix>nAlloc ){
-      char *zNew;
-      nAlloc = (nPrefix+nSuffix) * 2;
-      zNew = (char *)sqlite3_realloc(zBuffer, nAlloc);
-      if( !zNew ){
-        rc = SQLITE_NOMEM;
-        goto finish_scan;
+  char *zList = 0;
+  if( p->rc==SQLITE_OK && pIter->abIndexed ){
+    const char *zS = "";
+    int i;
+    for(i=0; inTblCol; i++){
+      if( pIter->abIndexed[i] ){
+        const char *zCol = pIter->azTblCol[i];
+        zList = sqlite3_mprintf("%z%s%s.\"%w\"", zList, zS, zObj, zCol);
+      }else{
+        zList = sqlite3_mprintf("%z%sNULL", zList, zS);
+      }
+      zS = ", ";
+      if( zList==0 ){
+        p->rc = SQLITE_NOMEM;
+        break;
       }
-      zBuffer = zNew;
     }
-    assert( zBuffer );
-    memcpy(&zBuffer[nPrefix], zCsr, nSuffix);
-    nBuffer = nPrefix + nSuffix;
-    zCsr += nSuffix;
 
-    /* Compare the term we are searching for with the term just loaded from
-    ** the interior node. If the specified term is greater than or equal
-    ** to the term from the interior node, then all terms on the sub-tree 
-    ** headed by node iChild are smaller than zTerm. No need to search 
-    ** iChild.
-    **
-    ** If the interior node term is larger than the specified term, then
-    ** the tree headed by iChild may contain the specified term.
-    */
-    cmp = memcmp(zTerm, zBuffer, (nBuffer>nTerm ? nTerm : nBuffer));
-    if( piFirst && (cmp<0 || (cmp==0 && nBuffer>nTerm)) ){
-      *piFirst = iChild;
-      piFirst = 0;
+    /* For a table with implicit rowids, append "old._rowid_" to the list. */
+    if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+      zList = rbuMPrintf(p, "%z, %s._rowid_", zList, zObj);
     }
+  }
+  return zList;
+}
 
-    if( piLast && cmp<0 ){
-      *piLast = iChild;
-      piLast = 0;
+/*
+** Return an expression that can be used in a WHERE clause to match the
+** primary key of the current table. For example, if the table is:
+**
+**   CREATE TABLE t1(a, b, c, PRIMARY KEY(b, c));
+**
+** Return the string:
+**
+**   "b = ?1 AND c = ?2"
+*/
+static char *rbuObjIterGetWhere(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter
+){
+  char *zList = 0;
+  if( pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE ){
+    zList = rbuMPrintf(p, "_rowid_ = ?%d", pIter->nTblCol+1);
+  }else if( pIter->eType==RBU_PK_EXTERNAL ){
+    const char *zSep = "";
+    int i;
+    for(i=0; inTblCol; i++){
+      if( pIter->abTblPk[i] ){
+        zList = rbuMPrintf(p, "%z%sc%d=?%d", zList, zSep, i, i+1);
+        zSep = " AND ";
+      }
     }
+    zList = rbuMPrintf(p, 
+        "_rowid_ = (SELECT id FROM rbu_imposter2 WHERE %z)", zList
+    );
 
-    iChild++;
-  };
-
-  if( piFirst ) *piFirst = iChild;
-  if( piLast ) *piLast = iChild;
+  }else{
+    const char *zSep = "";
+    int i;
+    for(i=0; inTblCol; i++){
+      if( pIter->abTblPk[i] ){
+        const char *zCol = pIter->azTblCol[i];
+        zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", zList, zSep, zCol, i+1);
+        zSep = " AND ";
+      }
+    }
+  }
+  return zList;
+}
 
- finish_scan:
-  sqlite3_free(zBuffer);
-  return rc;
+/*
+** The SELECT statement iterating through the keys for the current object
+** (p->objiter.pSelect) currently points to a valid row. However, there
+** is something wrong with the rbu_control value in the rbu_control value
+** stored in the (p->nCol+1)'th column. Set the error code and error message
+** of the RBU handle to something reflecting this.
+*/
+static void rbuBadControlError(sqlite3rbu *p){
+  p->rc = SQLITE_ERROR;
+  p->zErrmsg = sqlite3_mprintf("invalid rbu_control value");
 }
 
 
 /*
-** The buffer pointed to by argument zNode (size nNode bytes) contains an
-** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)
-** contains a term. This function searches the sub-tree headed by the zNode
-** node for the range of leaf nodes that may contain the specified term
-** or terms for which the specified term is a prefix.
-**
-** If piLeaf is not NULL, then *piLeaf is set to the blockid of the 
-** left-most leaf node in the tree that may contain the specified term.
-** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the
-** right-most leaf node that may contain a term for which the specified
-** term is a prefix.
+** Return a nul-terminated string containing the comma separated list of
+** assignments that should be included following the "SET" keyword of
+** an UPDATE statement used to update the table object that the iterator
+** passed as the second argument currently points to if the rbu_control
+** column of the data_xxx table entry is set to zMask.
 **
-** It is possible that the range of returned leaf nodes does not contain 
-** the specified term or any terms for which it is a prefix. However, if the 
-** segment does contain any such terms, they are stored within the identified
-** range. Because this function only inspects interior segment nodes (and
-** never loads leaf nodes into memory), it is not possible to be sure.
+** The memory for the returned string is obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free it using
+** sqlite3_free(). 
 **
-** If an error occurs, an error code other than SQLITE_OK is returned.
-*/ 
-static int fts3SelectLeaf(
-  Fts3Table *p,                   /* Virtual table handle */
-  const char *zTerm,              /* Term to select leaves for */
-  int nTerm,                      /* Size of term zTerm in bytes */
-  const char *zNode,              /* Buffer containing segment interior node */
-  int nNode,                      /* Size of buffer at zNode */
-  sqlite3_int64 *piLeaf,          /* Selected leaf node */
-  sqlite3_int64 *piLeaf2          /* Selected leaf node */
+** If an OOM error is encountered when allocating space for the new
+** string, an error code is left in the rbu handle passed as the first
+** argument and NULL is returned. Or, if an error has already occurred
+** when this function is called, NULL is returned immediately, without
+** attempting the allocation or modifying the stored error code.
+*/
+static char *rbuObjIterGetSetlist(
+  sqlite3rbu *p,
+  RbuObjIter *pIter,
+  const char *zMask
 ){
-  int rc = SQLITE_OK;             /* Return code */
-  int iHeight;                    /* Height of this node in tree */
-
-  assert( piLeaf || piLeaf2 );
-
-  fts3GetVarint32(zNode, &iHeight);
-  rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
-  assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
-
-  if( rc==SQLITE_OK && iHeight>1 ){
-    char *zBlob = 0;              /* Blob read from %_segments table */
-    int nBlob = 0;                /* Size of zBlob in bytes */
+  char *zList = 0;
+  if( p->rc==SQLITE_OK ){
+    int i;
 
-    if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
-      rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);
-      if( rc==SQLITE_OK ){
-        rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);
+    if( (int)strlen(zMask)!=pIter->nTblCol ){
+      rbuBadControlError(p);
+    }else{
+      const char *zSep = "";
+      for(i=0; inTblCol; i++){
+        char c = zMask[pIter->aiSrcOrder[i]];
+        if( c=='x' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", 
+              zList, zSep, pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
+        else if( c=='d' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_delta(\"%w\", ?%d)", 
+              zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
+        else if( c=='f' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_fossil_delta(\"%w\", ?%d)", 
+              zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
       }
-      sqlite3_free(zBlob);
-      piLeaf = 0;
-      zBlob = 0;
     }
+  }
+  return zList;
+}
 
-    if( rc==SQLITE_OK ){
-      rc = sqlite3Fts3ReadBlock(p, piLeaf?*piLeaf:*piLeaf2, &zBlob, &nBlob, 0);
-    }
-    if( rc==SQLITE_OK ){
-      rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
+/*
+** Return a nul-terminated string consisting of nByte comma separated
+** "?" expressions. For example, if nByte is 3, return a pointer to
+** a buffer containing the string "?,?,?".
+**
+** The memory for the returned string is obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free it using
+** sqlite3_free(). 
+**
+** If an OOM error is encountered when allocating space for the new
+** string, an error code is left in the rbu handle passed as the first
+** argument and NULL is returned. Or, if an error has already occurred
+** when this function is called, NULL is returned immediately, without
+** attempting the allocation or modifying the stored error code.
+*/
+static char *rbuObjIterGetBindlist(sqlite3rbu *p, int nBind){
+  char *zRet = 0;
+  int nByte = nBind*2 + 1;
+
+  zRet = (char*)rbuMalloc(p, nByte);
+  if( zRet ){
+    int i;
+    for(i=0; i 0 || (*piPrev==0 && iVal==0) );
-  *pp += sqlite3Fts3PutVarint(*pp, iVal-*piPrev);
-  *piPrev = iVal;
+static char *rbuWithoutRowidPK(sqlite3rbu *p, RbuObjIter *pIter){
+  char *z = 0;
+  assert( pIter->zIdx==0 );
+  if( p->rc==SQLITE_OK ){
+    const char *zSep = "PRIMARY KEY(";
+    sqlite3_stmt *pXList = 0;     /* PRAGMA index_list = (pIter->zTbl) */
+    sqlite3_stmt *pXInfo = 0;     /* PRAGMA index_xinfo =  */
+   
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pXList, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)
+    );
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXList) ){
+      const char *zOrig = (const char*)sqlite3_column_text(pXList,3);
+      if( zOrig && strcmp(zOrig, "pk")==0 ){
+        const char *zIdx = (const char*)sqlite3_column_text(pXList,1);
+        if( zIdx ){
+          p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+              sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+          );
+        }
+        break;
+      }
+    }
+    rbuFinalize(p, pXList);
+
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      if( sqlite3_column_int(pXInfo, 5) ){
+        /* int iCid = sqlite3_column_int(pXInfo, 0); */
+        const char *zCol = (const char*)sqlite3_column_text(pXInfo, 2);
+        const char *zDesc = sqlite3_column_int(pXInfo, 3) ? " DESC" : "";
+        z = rbuMPrintf(p, "%z%s\"%w\"%s", z, zSep, zCol, zDesc);
+        zSep = ", ";
+      }
+    }
+    z = rbuMPrintf(p, "%z)", z);
+    rbuFinalize(p, pXInfo);
+  }
+  return z;
 }
 
 /*
-** When this function is called, *ppPoslist is assumed to point to the 
-** start of a position-list. After it returns, *ppPoslist points to the
-** first byte after the position-list.
+** This function creates the second imposter table used when writing to
+** a table b-tree where the table has an external primary key. If the
+** iterator passed as the second argument does not currently point to
+** a table (not index) with an external primary key, this function is a
+** no-op. 
 **
-** A position list is list of positions (delta encoded) and columns for 
-** a single document record of a doclist.  So, in other words, this
-** routine advances *ppPoslist so that it points to the next docid in
-** the doclist, or to the first byte past the end of the doclist.
+** Assuming the iterator does point to a table with an external PK, this
+** function creates a WITHOUT ROWID imposter table named "rbu_imposter2"
+** used to access that PK index. For example, if the target table is
+** declared as follows:
+**
+**   CREATE TABLE t1(a, b TEXT, c REAL, PRIMARY KEY(b, c));
+**
+** then the imposter table schema is:
+**
+**   CREATE TABLE rbu_imposter2(c1 TEXT, c2 REAL, id INTEGER) WITHOUT ROWID;
 **
-** If pp is not NULL, then the contents of the position list are copied
-** to *pp. *pp is set to point to the first byte past the last byte copied
-** before this function returns.
 */
-static void fts3PoslistCopy(char **pp, char **ppPoslist){
-  char *pEnd = *ppPoslist;
-  char c = 0;
+static void rbuCreateImposterTable2(sqlite3rbu *p, RbuObjIter *pIter){
+  if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_EXTERNAL ){
+    int tnum = pIter->iPkTnum;    /* Root page of PK index */
+    sqlite3_stmt *pQuery = 0;     /* SELECT name ... WHERE rootpage = $tnum */
+    const char *zIdx = 0;         /* Name of PK index */
+    sqlite3_stmt *pXInfo = 0;     /* PRAGMA main.index_xinfo = $zIdx */
+    const char *zComma = "";
+    char *zCols = 0;              /* Used to build up list of table cols */
+    char *zPk = 0;                /* Used to build up table PK declaration */
 
-  /* The end of a position list is marked by a zero encoded as an FTS3 
-  ** varint. A single POS_END (0) byte. Except, if the 0 byte is preceded by
-  ** a byte with the 0x80 bit set, then it is not a varint 0, but the tail
-  ** of some other, multi-byte, value.
-  **
-  ** The following while-loop moves pEnd to point to the first byte that is not 
-  ** immediately preceded by a byte with the 0x80 bit set. Then increments
-  ** pEnd once more so that it points to the byte immediately following the
-  ** last byte in the position-list.
-  */
-  while( *pEnd | c ){
-    c = *pEnd++ & 0x80;
-    testcase( c!=0 && (*pEnd)==0 );
-  }
-  pEnd++;  /* Advance past the POS_END terminator byte */
+    /* Figure out the name of the primary key index for the current table.
+    ** This is needed for the argument to "PRAGMA index_xinfo". Set
+    ** zIdx to point to a nul-terminated string containing this name. */
+    p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, 
+        "SELECT name FROM sqlite_master WHERE rootpage = ?"
+    );
+    if( p->rc==SQLITE_OK ){
+      sqlite3_bind_int(pQuery, 1, tnum);
+      if( SQLITE_ROW==sqlite3_step(pQuery) ){
+        zIdx = (const char*)sqlite3_column_text(pQuery, 0);
+      }
+    }
+    if( zIdx ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+          sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+      );
+    }
+    rbuFinalize(p, pQuery);
 
-  if( pp ){
-    int n = (int)(pEnd - *ppPoslist);
-    char *p = *pp;
-    memcpy(p, *ppPoslist, n);
-    p += n;
-    *pp = p;
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      int bKey = sqlite3_column_int(pXInfo, 5);
+      if( bKey ){
+        int iCid = sqlite3_column_int(pXInfo, 1);
+        int bDesc = sqlite3_column_int(pXInfo, 3);
+        const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);
+        zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %s", zCols, zComma, 
+            iCid, pIter->azTblType[iCid], zCollate
+        );
+        zPk = rbuMPrintf(p, "%z%sc%d%s", zPk, zComma, iCid, bDesc?" DESC":"");
+        zComma = ", ";
+      }
+    }
+    zCols = rbuMPrintf(p, "%z, id INTEGER", zCols);
+    rbuFinalize(p, pXInfo);
+
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);
+    rbuMPrintfExec(p, p->dbMain,
+        "CREATE TABLE rbu_imposter2(%z, PRIMARY KEY(%z)) WITHOUT ROWID", 
+        zCols, zPk
+    );
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
   }
-  *ppPoslist = pEnd;
 }
 
 /*
-** When this function is called, *ppPoslist is assumed to point to the 
-** start of a column-list. After it returns, *ppPoslist points to the
-** to the terminator (POS_COLUMN or POS_END) byte of the column-list.
+** If an error has already occurred when this function is called, it 
+** immediately returns zero (without doing any work). Or, if an error
+** occurs during the execution of this function, it sets the error code
+** in the sqlite3rbu object indicated by the first argument and returns
+** zero.
 **
-** A column-list is list of delta-encoded positions for a single column
-** within a single document within a doclist.
+** The iterator passed as the second argument is guaranteed to point to
+** a table (not an index) when this function is called. This function
+** attempts to create any imposter table required to write to the main
+** table b-tree of the table before returning. Non-zero is returned if
+** an imposter table are created, or zero otherwise.
+**
+** An imposter table is required in all cases except RBU_PK_VTAB. Only
+** virtual tables are written to directly. The imposter table has the 
+** same schema as the actual target table (less any UNIQUE constraints). 
+** More precisely, the "same schema" means the same columns, types, 
+** collation sequences. For tables that do not have an external PRIMARY
+** KEY, it also means the same PRIMARY KEY declaration.
+*/
+static void rbuCreateImposterTable(sqlite3rbu *p, RbuObjIter *pIter){
+  if( p->rc==SQLITE_OK && pIter->eType!=RBU_PK_VTAB ){
+    int tnum = pIter->iTnum;
+    const char *zComma = "";
+    char *zSql = 0;
+    int iCol;
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);
+
+    for(iCol=0; p->rc==SQLITE_OK && iColnTblCol; iCol++){
+      const char *zPk = "";
+      const char *zCol = pIter->azTblCol[iCol];
+      const char *zColl = 0;
+
+      p->rc = sqlite3_table_column_metadata(
+          p->dbMain, "main", pIter->zTbl, zCol, 0, &zColl, 0, 0, 0
+      );
+
+      if( pIter->eType==RBU_PK_IPK && pIter->abTblPk[iCol] ){
+        /* If the target table column is an "INTEGER PRIMARY KEY", add
+        ** "PRIMARY KEY" to the imposter table column declaration. */
+        zPk = "PRIMARY KEY ";
+      }
+      zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %s%s", 
+          zSql, zComma, zCol, pIter->azTblType[iCol], zPk, zColl,
+          (pIter->abNotNull[iCol] ? " NOT NULL" : "")
+      );
+      zComma = ", ";
+    }
+
+    if( pIter->eType==RBU_PK_WITHOUT_ROWID ){
+      char *zPk = rbuWithoutRowidPK(p, pIter);
+      if( zPk ){
+        zSql = rbuMPrintf(p, "%z, %z", zSql, zPk);
+      }
+    }
+
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);
+    rbuMPrintfExec(p, p->dbMain, "CREATE TABLE \"rbu_imp_%w\"(%z)%s", 
+        pIter->zTbl, zSql, 
+        (pIter->eType==RBU_PK_WITHOUT_ROWID ? " WITHOUT ROWID" : "")
+    );
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
+  }
+}
+
+/*
+** Prepare a statement used to insert rows into the "rbu_tmp_xxx" table.
+** Specifically a statement of the form:
 **
-** The column-list is terminated either by a POS_COLUMN varint (1) or
-** a POS_END varint (0).  This routine leaves *ppPoslist pointing to
-** the POS_COLUMN or POS_END that terminates the column-list.
+**     INSERT INTO rbu_tmp_xxx VALUES(?, ?, ? ...);
 **
-** If pp is not NULL, then the contents of the column-list are copied
-** to *pp. *pp is set to point to the first byte past the last byte copied
-** before this function returns.  The POS_COLUMN or POS_END terminator
-** is not copied into *pp.
+** The number of bound variables is equal to the number of columns in
+** the target table, plus one (for the rbu_control column), plus one more 
+** (for the rbu_rowid column) if the target table is an implicit IPK or 
+** virtual table.
 */
-static void fts3ColumnlistCopy(char **pp, char **ppPoslist){
-  char *pEnd = *ppPoslist;
-  char c = 0;
+static void rbuObjIterPrepareTmpInsert(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  const char *zCollist,
+  const char *zRbuRowid
+){
+  int bRbuRowid = (pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE);
+  char *zBind = rbuObjIterGetBindlist(p, pIter->nTblCol + 1 + bRbuRowid);
+  if( zBind ){
+    assert( pIter->pTmpInsert==0 );
+    p->rc = prepareFreeAndCollectError(
+        p->dbRbu, &pIter->pTmpInsert, &p->zErrmsg, sqlite3_mprintf(
+          "INSERT INTO %s.'rbu_tmp_%q'(rbu_control,%s%s) VALUES(%z)", 
+          p->zStateDb, pIter->zDataTbl, zCollist, zRbuRowid, zBind
+    ));
+  }
+}
 
-  /* A column-list is terminated by either a 0x01 or 0x00 byte that is
-  ** not part of a multi-byte varint.
-  */
-  while( 0xFE & (*pEnd | c) ){
-    c = *pEnd++ & 0x80;
-    testcase( c!=0 && ((*pEnd)&0xfe)==0 );
+static void rbuTmpInsertFunc(
+  sqlite3_context *pCtx, 
+  int nVal,
+  sqlite3_value **apVal
+){
+  sqlite3rbu *p = sqlite3_user_data(pCtx);
+  int rc = SQLITE_OK;
+  int i;
+
+  assert( sqlite3_value_int(apVal[0])!=0
+      || p->objiter.eType==RBU_PK_EXTERNAL 
+      || p->objiter.eType==RBU_PK_NONE 
+  );
+  if( sqlite3_value_int(apVal[0])!=0 ){
+    p->nPhaseOneStep += p->objiter.nIndex;
   }
-  if( pp ){
-    int n = (int)(pEnd - *ppPoslist);
-    char *p = *pp;
-    memcpy(p, *ppPoslist, n);
-    p += n;
-    *pp = p;
+
+  for(i=0; rc==SQLITE_OK && iobjiter.pTmpInsert, i+1, apVal[i]);
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3_step(p->objiter.pTmpInsert);
+    rc = sqlite3_reset(p->objiter.pTmpInsert);
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx, rc);
   }
-  *ppPoslist = pEnd;
 }
 
 /*
-** Value used to signify the end of an position-list. This is safe because
-** it is not possible to have a document with 2^31 terms.
+** Ensure that the SQLite statement handles required to update the 
+** target database object currently indicated by the iterator passed 
+** as the second argument are available.
 */
-#define POSITION_LIST_END 0x7fffffff
+static int rbuObjIterPrepareAll(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  int nOffset                     /* Add "LIMIT -1 OFFSET $nOffset" to SELECT */
+){
+  assert( pIter->bCleanup==0 );
+  if( pIter->pSelect==0 && rbuObjIterCacheTableInfo(p, pIter)==SQLITE_OK ){
+    const int tnum = pIter->iTnum;
+    char *zCollist = 0;           /* List of indexed columns */
+    char **pz = &p->zErrmsg;
+    const char *zIdx = pIter->zIdx;
+    char *zLimit = 0;
+
+    if( nOffset ){
+      zLimit = sqlite3_mprintf(" LIMIT -1 OFFSET %d", nOffset);
+      if( !zLimit ) p->rc = SQLITE_NOMEM;
+    }
+
+    if( zIdx ){
+      const char *zTbl = pIter->zTbl;
+      char *zImposterCols = 0;    /* Columns for imposter table */
+      char *zImposterPK = 0;      /* Primary key declaration for imposter */
+      char *zWhere = 0;           /* WHERE clause on PK columns */
+      char *zBind = 0;
+      int nBind = 0;
+
+      assert( pIter->eType!=RBU_PK_VTAB );
+      zCollist = rbuObjIterGetIndexCols(
+          p, pIter, &zImposterCols, &zImposterPK, &zWhere, &nBind
+      );
+      zBind = rbuObjIterGetBindlist(p, nBind);
+
+      /* Create the imposter table used to write to this index. */
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1,tnum);
+      rbuMPrintfExec(p, p->dbMain,
+          "CREATE TABLE \"rbu_imp_%w\"( %s, PRIMARY KEY( %s ) ) WITHOUT ROWID",
+          zTbl, zImposterCols, zImposterPK
+      );
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
+
+      /* Create the statement to insert index entries */
+      pIter->nCol = nBind;
+      if( p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(
+            p->dbMain, &pIter->pInsert, &p->zErrmsg,
+          sqlite3_mprintf("INSERT INTO \"rbu_imp_%w\" VALUES(%s)", zTbl, zBind)
+        );
+      }
+
+      /* And to delete index entries */
+      if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(
+            p->dbMain, &pIter->pDelete, &p->zErrmsg,
+          sqlite3_mprintf("DELETE FROM \"rbu_imp_%w\" WHERE %s", zTbl, zWhere)
+        );
+      }
+
+      /* Create the SELECT statement to read keys in sorted order */
+      if( p->rc==SQLITE_OK ){
+        char *zSql;
+        if( rbuIsVacuum(p) ){
+          zSql = sqlite3_mprintf(
+              "SELECT %s, 0 AS rbu_control FROM '%q' ORDER BY %s%s",
+              zCollist, 
+              pIter->zDataTbl,
+              zCollist, zLimit
+          );
+        }else
+
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          zSql = sqlite3_mprintf(
+              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' ORDER BY %s%s",
+              zCollist, p->zStateDb, pIter->zDataTbl,
+              zCollist, zLimit
+          );
+        }else{
+          zSql = sqlite3_mprintf(
+              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' "
+              "UNION ALL "
+              "SELECT %s, rbu_control FROM '%q' "
+              "WHERE typeof(rbu_control)='integer' AND rbu_control!=1 "
+              "ORDER BY %s%s",
+              zCollist, p->zStateDb, pIter->zDataTbl, 
+              zCollist, pIter->zDataTbl, 
+              zCollist, zLimit
+          );
+        }
+        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, zSql);
+      }
+
+      sqlite3_free(zImposterCols);
+      sqlite3_free(zImposterPK);
+      sqlite3_free(zWhere);
+      sqlite3_free(zBind);
+    }else{
+      int bRbuRowid = (pIter->eType==RBU_PK_VTAB)
+                    ||(pIter->eType==RBU_PK_NONE)
+                    ||(pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p));
+      const char *zTbl = pIter->zTbl;       /* Table this step applies to */
+      const char *zWrite;                   /* Imposter table name */
+
+      char *zBindings = rbuObjIterGetBindlist(p, pIter->nTblCol + bRbuRowid);
+      char *zWhere = rbuObjIterGetWhere(p, pIter);
+      char *zOldlist = rbuObjIterGetOldlist(p, pIter, "old");
+      char *zNewlist = rbuObjIterGetOldlist(p, pIter, "new");
+
+      zCollist = rbuObjIterGetCollist(p, pIter);
+      pIter->nCol = pIter->nTblCol;
+
+      /* Create the imposter table or tables (if required). */
+      rbuCreateImposterTable(p, pIter);
+      rbuCreateImposterTable2(p, pIter);
+      zWrite = (pIter->eType==RBU_PK_VTAB ? "" : "rbu_imp_");
+
+      /* Create the INSERT statement to write to the target PK b-tree */
+      if( p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pInsert, pz,
+            sqlite3_mprintf(
+              "INSERT INTO \"%s%w\"(%s%s) VALUES(%s)", 
+              zWrite, zTbl, zCollist, (bRbuRowid ? ", _rowid_" : ""), zBindings
+            )
+        );
+      }
+
+      /* Create the DELETE statement to write to the target PK b-tree.
+      ** Because it only performs INSERT operations, this is not required for
+      ** an rbu vacuum handle.  */
+      if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pDelete, pz,
+            sqlite3_mprintf(
+              "DELETE FROM \"%s%w\" WHERE %s", zWrite, zTbl, zWhere
+            )
+        );
+      }
+
+      if( rbuIsVacuum(p)==0 && pIter->abIndexed ){
+        const char *zRbuRowid = "";
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          zRbuRowid = ", rbu_rowid";
+        }
+
+        /* Create the rbu_tmp_xxx table and the triggers to populate it. */
+        rbuMPrintfExec(p, p->dbRbu,
+            "CREATE TABLE IF NOT EXISTS %s.'rbu_tmp_%q' AS "
+            "SELECT *%s FROM '%q' WHERE 0;"
+            , p->zStateDb, pIter->zDataTbl
+            , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "")
+            , pIter->zDataTbl
+        );
+
+        rbuMPrintfExec(p, p->dbMain,
+            "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(3, %s);"
+            "END;"
+
+            "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(3, %s);"
+            "END;"
+
+            "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(4, %s);"
+            "END;",
+            zWrite, zTbl, zOldlist,
+            zWrite, zTbl, zOldlist,
+            zWrite, zTbl, zNewlist
+        );
+
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          rbuMPrintfExec(p, p->dbMain,
+              "CREATE TEMP TRIGGER rbu_insert_tr AFTER INSERT ON \"%s%w\" "
+              "BEGIN "
+              "  SELECT rbu_tmp_insert(0, %s);"
+              "END;",
+              zWrite, zTbl, zNewlist
+          );
+        }
+
+        rbuObjIterPrepareTmpInsert(p, pIter, zCollist, zRbuRowid);
+      }
+
+      /* Create the SELECT statement to read keys from data_xxx */
+      if( p->rc==SQLITE_OK ){
+        const char *zRbuRowid = "";
+        if( bRbuRowid ){
+          zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid";
+        }
+        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz,
+            sqlite3_mprintf(
+              "SELECT %s,%s rbu_control%s FROM '%q'%s", 
+              zCollist, 
+              (rbuIsVacuum(p) ? "0 AS " : ""),
+              zRbuRowid,
+              pIter->zDataTbl, zLimit
+            )
+        );
+      }
+
+      sqlite3_free(zWhere);
+      sqlite3_free(zOldlist);
+      sqlite3_free(zNewlist);
+      sqlite3_free(zBindings);
+    }
+    sqlite3_free(zCollist);
+    sqlite3_free(zLimit);
+  }
+  
+  return p->rc;
+}
 
 /*
-** This function is used to help parse position-lists. When this function is
-** called, *pp may point to the start of the next varint in the position-list
-** being parsed, or it may point to 1 byte past the end of the position-list
-** (in which case **pp will be a terminator bytes POS_END (0) or
-** (1)).
-**
-** If *pp points past the end of the current position-list, set *pi to 
-** POSITION_LIST_END and return. Otherwise, read the next varint from *pp,
-** increment the current value of *pi by the value read, and set *pp to
-** point to the next value before returning.
-**
-** Before calling this routine *pi must be initialized to the value of
-** the previous position, or zero if we are reading the first position
-** in the position-list.  Because positions are delta-encoded, the value
-** of the previous position is needed in order to compute the value of
-** the next position.
+** Set output variable *ppStmt to point to an UPDATE statement that may
+** be used to update the imposter table for the main table b-tree of the
+** table object that pIter currently points to, assuming that the 
+** rbu_control column of the data_xyz table contains zMask.
+** 
+** If the zMask string does not specify any columns to update, then this
+** is not an error. Output variable *ppStmt is set to NULL in this case.
 */
-static void fts3ReadNextPos(
-  char **pp,                    /* IN/OUT: Pointer into position-list buffer */
-  sqlite3_int64 *pi             /* IN/OUT: Value read from position-list */
+static int rbuGetUpdateStmt(
+  sqlite3rbu *p,                  /* RBU handle */
+  RbuObjIter *pIter,              /* Object iterator */
+  const char *zMask,              /* rbu_control value ('x.x.') */
+  sqlite3_stmt **ppStmt           /* OUT: UPDATE statement handle */
 ){
-  if( (**pp)&0xFE ){
-    fts3GetDeltaVarint(pp, pi);
-    *pi -= 2;
+  RbuUpdateStmt **pp;
+  RbuUpdateStmt *pUp = 0;
+  int nUp = 0;
+
+  /* In case an error occurs */
+  *ppStmt = 0;
+
+  /* Search for an existing statement. If one is found, shift it to the front
+  ** of the LRU queue and return immediately. Otherwise, leave nUp pointing
+  ** to the number of statements currently in the cache and pUp to the
+  ** last object in the list.  */
+  for(pp=&pIter->pRbuUpdate; *pp; pp=&((*pp)->pNext)){
+    pUp = *pp;
+    if( strcmp(pUp->zMask, zMask)==0 ){
+      *pp = pUp->pNext;
+      pUp->pNext = pIter->pRbuUpdate;
+      pIter->pRbuUpdate = pUp;
+      *ppStmt = pUp->pUpdate; 
+      return SQLITE_OK;
+    }
+    nUp++;
+  }
+  assert( pUp==0 || pUp->pNext==0 );
+
+  if( nUp>=SQLITE_RBU_UPDATE_CACHESIZE ){
+    for(pp=&pIter->pRbuUpdate; *pp!=pUp; pp=&((*pp)->pNext));
+    *pp = 0;
+    sqlite3_finalize(pUp->pUpdate);
+    pUp->pUpdate = 0;
   }else{
-    *pi = POSITION_LIST_END;
+    pUp = (RbuUpdateStmt*)rbuMalloc(p, sizeof(RbuUpdateStmt)+pIter->nTblCol+1);
+  }
+
+  if( pUp ){
+    char *zWhere = rbuObjIterGetWhere(p, pIter);
+    char *zSet = rbuObjIterGetSetlist(p, pIter, zMask);
+    char *zUpdate = 0;
+
+    pUp->zMask = (char*)&pUp[1];
+    memcpy(pUp->zMask, zMask, pIter->nTblCol);
+    pUp->pNext = pIter->pRbuUpdate;
+    pIter->pRbuUpdate = pUp;
+
+    if( zSet ){
+      const char *zPrefix = "";
+
+      if( pIter->eType!=RBU_PK_VTAB ) zPrefix = "rbu_imp_";
+      zUpdate = sqlite3_mprintf("UPDATE \"%s%w\" SET %s WHERE %s", 
+          zPrefix, pIter->zTbl, zSet, zWhere
+      );
+      p->rc = prepareFreeAndCollectError(
+          p->dbMain, &pUp->pUpdate, &p->zErrmsg, zUpdate
+      );
+      *ppStmt = pUp->pUpdate;
+    }
+    sqlite3_free(zWhere);
+    sqlite3_free(zSet);
+  }
+
+  return p->rc;
+}
+
+static sqlite3 *rbuOpenDbhandle(
+  sqlite3rbu *p, 
+  const char *zName, 
+  int bUseVfs
+){
+  sqlite3 *db = 0;
+  if( p->rc==SQLITE_OK ){
+    const int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_URI;
+    p->rc = sqlite3_open_v2(zName, &db, flags, bUseVfs ? p->zVfsName : 0);
+    if( p->rc ){
+      p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+      sqlite3_close(db);
+      db = 0;
+    }
   }
+  return db;
 }
 
 /*
-** If parameter iCol is not 0, write an POS_COLUMN (1) byte followed by
-** the value of iCol encoded as a varint to *pp.   This will start a new
-** column list.
-**
-** Set *pp to point to the byte just after the last byte written before 
-** returning (do not modify it if iCol==0). Return the total number of bytes
-** written (0 if iCol==0).
+** Free an RbuState object allocated by rbuLoadState().
 */
-static int fts3PutColNumber(char **pp, int iCol){
-  int n = 0;                      /* Number of bytes written */
-  if( iCol ){
-    char *p = *pp;                /* Output pointer */
-    n = 1 + sqlite3Fts3PutVarint(&p[1], iCol);
-    *p = 0x01;
-    *pp = &p[n];
+static void rbuFreeState(RbuState *p){
+  if( p ){
+    sqlite3_free(p->zTbl);
+    sqlite3_free(p->zIdx);
+    sqlite3_free(p);
   }
-  return n;
 }
 
 /*
-** Compute the union of two position lists.  The output written
-** into *pp contains all positions of both *pp1 and *pp2 in sorted
-** order and with any duplicates removed.  All pointers are
-** updated appropriately.   The caller is responsible for insuring
-** that there is enough space in *pp to hold the complete output.
+** Allocate an RbuState object and load the contents of the rbu_state 
+** table into it. Return a pointer to the new object. It is the 
+** responsibility of the caller to eventually free the object using
+** sqlite3_free().
+**
+** If an error occurs, leave an error code and message in the rbu handle
+** and return NULL.
 */
-static void fts3PoslistMerge(
-  char **pp,                      /* Output buffer */
-  char **pp1,                     /* Left input list */
-  char **pp2                      /* Right input list */
-){
-  char *p = *pp;
-  char *p1 = *pp1;
-  char *p2 = *pp2;
+static RbuState *rbuLoadState(sqlite3rbu *p){
+  RbuState *pRet = 0;
+  sqlite3_stmt *pStmt = 0;
+  int rc;
+  int rc2;
 
-  while( *p1 || *p2 ){
-    int iCol1;         /* The current column index in pp1 */
-    int iCol2;         /* The current column index in pp2 */
+  pRet = (RbuState*)rbuMalloc(p, sizeof(RbuState));
+  if( pRet==0 ) return 0;
 
-    if( *p1==POS_COLUMN ) fts3GetVarint32(&p1[1], &iCol1);
-    else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;
-    else iCol1 = 0;
+  rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 
+      sqlite3_mprintf("SELECT k, v FROM %s.rbu_state", p->zStateDb)
+  );
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+    switch( sqlite3_column_int(pStmt, 0) ){
+      case RBU_STATE_STAGE:
+        pRet->eStage = sqlite3_column_int(pStmt, 1);
+        if( pRet->eStage!=RBU_STAGE_OAL
+         && pRet->eStage!=RBU_STAGE_MOVE
+         && pRet->eStage!=RBU_STAGE_CKPT
+        ){
+          p->rc = SQLITE_CORRUPT;
+        }
+        break;
 
-    if( *p2==POS_COLUMN ) fts3GetVarint32(&p2[1], &iCol2);
-    else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;
-    else iCol2 = 0;
+      case RBU_STATE_TBL:
+        pRet->zTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);
+        break;
 
-    if( iCol1==iCol2 ){
-      sqlite3_int64 i1 = 0;       /* Last position from pp1 */
-      sqlite3_int64 i2 = 0;       /* Last position from pp2 */
-      sqlite3_int64 iPrev = 0;
-      int n = fts3PutColNumber(&p, iCol1);
-      p1 += n;
-      p2 += n;
+      case RBU_STATE_IDX:
+        pRet->zIdx = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);
+        break;
 
-      /* At this point, both p1 and p2 point to the start of column-lists
-      ** for the same column (the column with index iCol1 and iCol2).
-      ** A column-list is a list of non-negative delta-encoded varints, each 
-      ** incremented by 2 before being stored. Each list is terminated by a
-      ** POS_END (0) or POS_COLUMN (1). The following block merges the two lists
-      ** and writes the results to buffer p. p is left pointing to the byte
-      ** after the list written. No terminator (POS_END or POS_COLUMN) is
-      ** written to the output.
-      */
-      fts3GetDeltaVarint(&p1, &i1);
-      fts3GetDeltaVarint(&p2, &i2);
-      do {
-        fts3PutDeltaVarint(&p, &iPrev, (i1nRow = sqlite3_column_int(pStmt, 1);
+        break;
+
+      case RBU_STATE_PROGRESS:
+        pRet->nProgress = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_CKPT:
+        pRet->iWalCksum = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_COOKIE:
+        pRet->iCookie = (u32)sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_OALSZ:
+        pRet->iOalSz = (u32)sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_PHASEONESTEP:
+        pRet->nPhaseOneStep = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      default:
+        rc = SQLITE_CORRUPT;
+        break;
     }
   }
+  rc2 = sqlite3_finalize(pStmt);
+  if( rc==SQLITE_OK ) rc = rc2;
 
-  *p++ = POS_END;
-  *pp = p;
-  *pp1 = p1 + 1;
-  *pp2 = p2 + 1;
+  p->rc = rc;
+  return pRet;
 }
 
+
 /*
-** This function is used to merge two position lists into one. When it is
-** called, *pp1 and *pp2 must both point to position lists. A position-list is
-** the part of a doclist that follows each document id. For example, if a row
-** contains:
-**
-**     'a b c'|'x y z'|'a b b a'
-**
-** Then the position list for this row for token 'b' would consist of:
-**
-**     0x02 0x01 0x02 0x03 0x03 0x00
-**
-** When this function returns, both *pp1 and *pp2 are left pointing to the
-** byte following the 0x00 terminator of their respective position lists.
-**
-** If isSaveLeft is 0, an entry is added to the output position list for 
-** each position in *pp2 for which there exists one or more positions in
-** *pp1 so that (pos(*pp2)>pos(*pp1) && pos(*pp2)-pos(*pp1)<=nToken). i.e.
-** when the *pp1 token appears before the *pp2 token, but not more than nToken
-** slots before it.
-**
-** e.g. nToken==1 searches for adjacent positions.
+** Open the database handle and attach the RBU database as "rbu". If an
+** error occurs, leave an error code and message in the RBU handle.
 */
-static int fts3PoslistPhraseMerge(
-  char **pp,                      /* IN/OUT: Preallocated output buffer */
-  int nToken,                     /* Maximum difference in token positions */
-  int isSaveLeft,                 /* Save the left position */
-  int isExact,                    /* If *pp1 is exactly nTokens before *pp2 */
-  char **pp1,                     /* IN/OUT: Left input list */
-  char **pp2                      /* IN/OUT: Right input list */
-){
-  char *p = *pp;
-  char *p1 = *pp1;
-  char *p2 = *pp2;
-  int iCol1 = 0;
-  int iCol2 = 0;
+static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){
+  assert( p->rc || (p->dbMain==0 && p->dbRbu==0) );
+  assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 );
 
-  /* Never set both isSaveLeft and isExact for the same invocation. */
-  assert( isSaveLeft==0 || isExact==0 );
+  /* Open the RBU database */
+  p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1);
 
-  assert( p!=0 && *p1!=0 && *p2!=0 );
-  if( *p1==POS_COLUMN ){ 
-    p1++;
-    p1 += fts3GetVarint32(p1, &iCol1);
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);
+    if( p->zState==0 ){
+      const char *zFile = sqlite3_db_filename(p->dbRbu, "main");
+      p->zState = rbuMPrintf(p, "file://%s-vacuum?modeof=%s", zFile, zFile);
+    }
   }
-  if( *p2==POS_COLUMN ){ 
-    p2++;
-    p2 += fts3GetVarint32(p2, &iCol2);
+
+  /* If using separate RBU and state databases, attach the state database to
+  ** the RBU db handle now.  */
+  if( p->zState ){
+    rbuMPrintfExec(p, p->dbRbu, "ATTACH %Q AS stat", p->zState);
+    memcpy(p->zStateDb, "stat", 4);
+  }else{
+    memcpy(p->zStateDb, "main", 4);
   }
 
-  while( 1 ){
-    if( iCol1==iCol2 ){
-      char *pSave = p;
-      sqlite3_int64 iPrev = 0;
-      sqlite3_int64 iPos1 = 0;
-      sqlite3_int64 iPos2 = 0;
+#if 0
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, 0);
+  }
+#endif
 
-      if( iCol1 ){
-        *p++ = POS_COLUMN;
-        p += sqlite3Fts3PutVarint(p, iCol1);
+  /* If it has not already been created, create the rbu_state table */
+  rbuMPrintfExec(p, p->dbRbu, RBU_CREATE_STATE, p->zStateDb);
+
+#if 0
+  if( rbuIsVacuum(p) ){
+    if( p->rc==SQLITE_OK ){
+      int rc2;
+      int bOk = 0;
+      sqlite3_stmt *pCnt = 0;
+      p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg,
+          "SELECT count(*) FROM stat.sqlite_master"
+      );
+      if( p->rc==SQLITE_OK 
+       && sqlite3_step(pCnt)==SQLITE_ROW
+       && 1==sqlite3_column_int(pCnt, 0)
+      ){
+        bOk = 1;
       }
+      rc2 = sqlite3_finalize(pCnt);
+      if( p->rc==SQLITE_OK ) p->rc = rc2;
 
-      assert( *p1!=POS_END && *p1!=POS_COLUMN );
-      assert( *p2!=POS_END && *p2!=POS_COLUMN );
-      fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
-      fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
+      if( p->rc==SQLITE_OK && bOk==0 ){
+        p->rc = SQLITE_ERROR;
+        p->zErrmsg = sqlite3_mprintf("invalid state database");
+      }
+    
+      if( p->rc==SQLITE_OK ){
+        p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0);
+      }
+    }
+  }
+#endif
 
-      while( 1 ){
-        if( iPos2==iPos1+nToken 
-         || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken) 
-        ){
-          sqlite3_int64 iSave;
-          iSave = isSaveLeft ? iPos1 : iPos2;
-          fts3PutDeltaVarint(&p, &iPrev, iSave+2); iPrev -= 2;
-          pSave = 0;
-          assert( p );
-        }
-        if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){
-          if( (*p2&0xFE)==0 ) break;
-          fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
-        }else{
-          if( (*p1&0xFE)==0 ) break;
-          fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    int bOpen = 0;
+    int rc;
+    p->nRbu = 0;
+    p->pRbuFd = 0;
+    rc = sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);
+    if( rc!=SQLITE_NOTFOUND ) p->rc = rc;
+    if( p->eStage>=RBU_STAGE_MOVE ){
+      bOpen = 1;
+    }else{
+      RbuState *pState = rbuLoadState(p);
+      if( pState ){
+        bOpen = (pState->eStage>=RBU_STAGE_MOVE);
+        rbuFreeState(pState);
+      }
+    }
+    if( bOpen ) p->dbMain = rbuOpenDbhandle(p, p->zRbu, p->nRbu<=1);
+  }
+
+  p->eStage = 0;
+  if( p->rc==SQLITE_OK && p->dbMain==0 ){
+    if( !rbuIsVacuum(p) ){
+      p->dbMain = rbuOpenDbhandle(p, p->zTarget, 1);
+    }else if( p->pRbuFd->pWalFd ){
+      if( pbRetry ){
+        p->pRbuFd->bNolock = 0;
+        sqlite3_close(p->dbRbu);
+        sqlite3_close(p->dbMain);
+        p->dbMain = 0;
+        p->dbRbu = 0;
+        *pbRetry = 1;
+        return;
+      }
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf("cannot vacuum wal mode database");
+    }else{
+      char *zTarget;
+      char *zExtra = 0;
+      if( strlen(p->zRbu)>=5 && 0==memcmp("file:", p->zRbu, 5) ){
+        zExtra = &p->zRbu[5];
+        while( *zExtra ){
+          if( *zExtra++=='?' ) break;
         }
+        if( *zExtra=='\0' ) zExtra = 0;
       }
 
-      if( pSave ){
-        assert( pp && p );
-        p = pSave;
+      zTarget = sqlite3_mprintf("file:%s-vacuum?rbu_memory=1%s%s", 
+          sqlite3_db_filename(p->dbRbu, "main"),
+          (zExtra==0 ? "" : "&"), (zExtra==0 ? "" : zExtra)
+      );
+
+      if( zTarget==0 ){
+        p->rc = SQLITE_NOMEM;
+        return;
       }
+      p->dbMain = rbuOpenDbhandle(p, zTarget, p->nRbu<=1);
+      sqlite3_free(zTarget);
+    }
+  }
 
-      fts3ColumnlistCopy(0, &p1);
-      fts3ColumnlistCopy(0, &p2);
-      assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );
-      if( 0==*p1 || 0==*p2 ) break;
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbMain, 
+        "rbu_tmp_insert", -1, SQLITE_UTF8, (void*)p, rbuTmpInsertFunc, 0, 0
+    );
+  }
 
-      p1++;
-      p1 += fts3GetVarint32(p1, &iCol1);
-      p2++;
-      p2 += fts3GetVarint32(p2, &iCol2);
-    }
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbMain, 
+        "rbu_fossil_delta", 2, SQLITE_UTF8, 0, rbuFossilDeltaFunc, 0, 0
+    );
+  }
 
-    /* Advance pointer p1 or p2 (whichever corresponds to the smaller of
-    ** iCol1 and iCol2) so that it points to either the 0x00 that marks the
-    ** end of the position list, or the 0x01 that precedes the next 
-    ** column-number in the position list. 
-    */
-    else if( iCol1rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbRbu, 
+        "rbu_target_name", -1, SQLITE_UTF8, (void*)p, rbuTargetNameFunc, 0, 0
+    );
   }
 
-  fts3PoslistCopy(0, &p2);
-  fts3PoslistCopy(0, &p1);
-  *pp1 = p1;
-  *pp2 = p2;
-  if( *pp==p ){
-    return 0;
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
+  }
+  rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_master");
+
+  /* Mark the database file just opened as an RBU target database. If 
+  ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use.
+  ** This is an error.  */
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
+  }
+
+  if( p->rc==SQLITE_NOTFOUND ){
+    p->rc = SQLITE_ERROR;
+    p->zErrmsg = sqlite3_mprintf("rbu vfs not found");
   }
-  *p++ = 0x00;
-  *pp = p;
-  return 1;
 }
 
 /*
-** Merge two position-lists as required by the NEAR operator. The argument
-** position lists correspond to the left and right phrases of an expression 
-** like:
+** This routine is a copy of the sqlite3FileSuffix3() routine from the core.
+** It is a no-op unless SQLITE_ENABLE_8_3_NAMES is defined.
 **
-**     "phrase 1" NEAR "phrase number 2"
+** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database
+** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and
+** if filename in z[] has a suffix (a.k.a. "extension") that is longer than
+** three characters, then shorten the suffix on z[] to be the last three
+** characters of the original suffix.
 **
-** Position list *pp1 corresponds to the left-hand side of the NEAR 
-** expression and *pp2 to the right. As usual, the indexes in the position 
-** lists are the offsets of the last token in each phrase (tokens "1" and "2" 
-** in the example above).
+** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always
+** do the suffix shortening regardless of URI parameter.
 **
-** The output position list - written to *pp - is a copy of *pp2 with those
-** entries that are not sufficiently NEAR entries in *pp1 removed.
+** Examples:
+**
+**     test.db-journal    =>   test.nal
+**     test.db-wal        =>   test.wal
+**     test.db-shm        =>   test.shm
+**     test.db-mj7f3319fa =>   test.9fa
 */
-static int fts3PoslistNearMerge(
-  char **pp,                      /* Output buffer */
-  char *aTmp,                     /* Temporary buffer space */
-  int nRight,                     /* Maximum difference in token positions */
-  int nLeft,                      /* Maximum difference in token positions */
-  char **pp1,                     /* IN/OUT: Left input list */
-  char **pp2                      /* IN/OUT: Right input list */
-){
-  char *p1 = *pp1;
-  char *p2 = *pp2;
+static void rbuFileSuffix3(const char *zBase, char *z){
+#ifdef SQLITE_ENABLE_8_3_NAMES
+#if SQLITE_ENABLE_8_3_NAMES<2
+  if( sqlite3_uri_boolean(zBase, "8_3_names", 0) )
+#endif
+  {
+    int i, sz;
+    sz = (int)strlen(z)&0xffffff;
+    for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
+    if( z[i]=='.' && sz>i+4 ) memmove(&z[i+1], &z[sz-3], 4);
+  }
+#endif
+}
 
-  char *pTmp1 = aTmp;
-  char *pTmp2;
-  char *aTmp2;
-  int res = 1;
+/*
+** Return the current wal-index header checksum for the target database 
+** as a 64-bit integer.
+**
+** The checksum is store in the first page of xShmMap memory as an 8-byte 
+** blob starting at byte offset 40.
+*/
+static i64 rbuShmChecksum(sqlite3rbu *p){
+  i64 iRet = 0;
+  if( p->rc==SQLITE_OK ){
+    sqlite3_file *pDb = p->pTargetFd->pReal;
+    u32 volatile *ptr;
+    p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, (void volatile**)&ptr);
+    if( p->rc==SQLITE_OK ){
+      iRet = ((i64)ptr[10] << 32) + ptr[11];
+    }
+  }
+  return iRet;
+}
 
-  fts3PoslistPhraseMerge(&pTmp1, nRight, 0, 0, pp1, pp2);
-  aTmp2 = pTmp2 = pTmp1;
-  *pp1 = p1;
-  *pp2 = p2;
-  fts3PoslistPhraseMerge(&pTmp2, nLeft, 1, 0, pp2, pp1);
-  if( pTmp1!=aTmp && pTmp2!=aTmp2 ){
-    fts3PoslistMerge(pp, &aTmp, &aTmp2);
-  }else if( pTmp1!=aTmp ){
-    fts3PoslistCopy(pp, &aTmp);
-  }else if( pTmp2!=aTmp2 ){
-    fts3PoslistCopy(pp, &aTmp2);
-  }else{
-    res = 0;
+/*
+** This function is called as part of initializing or reinitializing an
+** incremental checkpoint. 
+**
+** It populates the sqlite3rbu.aFrame[] array with the set of 
+** (wal frame -> db page) copy operations required to checkpoint the 
+** current wal file, and obtains the set of shm locks required to safely 
+** perform the copy operations directly on the file-system.
+**
+** If argument pState is not NULL, then the incremental checkpoint is
+** being resumed. In this case, if the checksum of the wal-index-header
+** following recovery is not the same as the checksum saved in the RbuState
+** object, then the rbu handle is set to DONE state. This occurs if some
+** other client appends a transaction to the wal file in the middle of
+** an incremental checkpoint.
+*/
+static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){
+
+  /* If pState is NULL, then the wal file may not have been opened and
+  ** recovered. Running a read-statement here to ensure that doing so
+  ** does not interfere with the "capture" process below.  */
+  if( pState==0 ){
+    p->eStage = 0;
+    if( p->rc==SQLITE_OK ){
+      p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_master", 0, 0, 0);
+    }
   }
 
-  return res;
+  /* Assuming no error has occurred, run a "restart" checkpoint with the
+  ** sqlite3rbu.eStage variable set to CAPTURE. This turns on the following
+  ** special behaviour in the rbu VFS:
+  **
+  **   * If the exclusive shm WRITER or READ0 lock cannot be obtained,
+  **     the checkpoint fails with SQLITE_BUSY (normally SQLite would
+  **     proceed with running a passive checkpoint instead of failing).
+  **
+  **   * Attempts to read from the *-wal file or write to the database file
+  **     do not perform any IO. Instead, the frame/page combinations that
+  **     would be read/written are recorded in the sqlite3rbu.aFrame[]
+  **     array.
+  **
+  **   * Calls to xShmLock(UNLOCK) to release the exclusive shm WRITER, 
+  **     READ0 and CHECKPOINT locks taken as part of the checkpoint are
+  **     no-ops. These locks will not be released until the connection
+  **     is closed.
+  **
+  **   * Attempting to xSync() the database file causes an SQLITE_INTERNAL 
+  **     error.
+  **
+  ** As a result, unless an error (i.e. OOM or SQLITE_BUSY) occurs, the
+  ** checkpoint below fails with SQLITE_INTERNAL, and leaves the aFrame[]
+  ** array populated with a set of (frame -> page) mappings. Because the 
+  ** WRITER, CHECKPOINT and READ0 locks are still held, it is safe to copy 
+  ** data from the wal file into the database file according to the 
+  ** contents of aFrame[].
+  */
+  if( p->rc==SQLITE_OK ){
+    int rc2;
+    p->eStage = RBU_STAGE_CAPTURE;
+    rc2 = sqlite3_exec(p->dbMain, "PRAGMA main.wal_checkpoint=restart", 0, 0,0);
+    if( rc2!=SQLITE_INTERNAL ) p->rc = rc2;
+  }
+
+  if( p->rc==SQLITE_OK && p->nFrame>0 ){
+    p->eStage = RBU_STAGE_CKPT;
+    p->nStep = (pState ? pState->nRow : 0);
+    p->aBuf = rbuMalloc(p, p->pgsz);
+    p->iWalCksum = rbuShmChecksum(p);
+  }
+
+  if( p->rc==SQLITE_OK ){
+    if( p->nFrame==0 || (pState && pState->iWalCksum!=p->iWalCksum) ){
+      p->rc = SQLITE_DONE;
+      p->eStage = RBU_STAGE_DONE;
+    }else{
+      int nSectorSize;
+      sqlite3_file *pDb = p->pTargetFd->pReal;
+      sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal;
+      assert( p->nPagePerSector==0 );
+      nSectorSize = pDb->pMethods->xSectorSize(pDb);
+      if( nSectorSize>p->pgsz ){
+        p->nPagePerSector = nSectorSize / p->pgsz;
+      }else{
+        p->nPagePerSector = 1;
+      }
+
+      /* Call xSync() on the wal file. This causes SQLite to sync the 
+      ** directory in which the target database and the wal file reside, in 
+      ** case it has not been synced since the rename() call in 
+      ** rbuMoveOalFile(). */
+      p->rc = pWal->pMethods->xSync(pWal, SQLITE_SYNC_NORMAL);
+    }
+  }
 }
 
-/* 
-** An instance of this function is used to merge together the (potentially
-** large number of) doclists for each term that matches a prefix query.
-** See function fts3TermSelectMerge() for details.
+/*
+** Called when iAmt bytes are read from offset iOff of the wal file while
+** the rbu object is in capture mode. Record the frame number of the frame
+** being read in the aFrame[] array.
 */
-typedef struct TermSelect TermSelect;
-struct TermSelect {
-  char *aaOutput[16];             /* Malloc'd output buffers */
-  int anOutput[16];               /* Size each output buffer in bytes */
-};
+static int rbuCaptureWalRead(sqlite3rbu *pRbu, i64 iOff, int iAmt){
+  const u32 mReq = (1<mLock!=mReq ){
+    pRbu->rc = SQLITE_BUSY;
+    return SQLITE_INTERNAL;
+  }
+
+  pRbu->pgsz = iAmt;
+  if( pRbu->nFrame==pRbu->nFrameAlloc ){
+    int nNew = (pRbu->nFrameAlloc ? pRbu->nFrameAlloc : 64) * 2;
+    RbuFrame *aNew;
+    aNew = (RbuFrame*)sqlite3_realloc64(pRbu->aFrame, nNew * sizeof(RbuFrame));
+    if( aNew==0 ) return SQLITE_NOMEM;
+    pRbu->aFrame = aNew;
+    pRbu->nFrameAlloc = nNew;
+  }
+
+  iFrame = (u32)((iOff-32) / (i64)(iAmt+24)) + 1;
+  if( pRbu->iMaxFrame