From 7ffc9da093bf34cf0f524fcf39be9af2a149ce19 Mon Sep 17 00:00:00 2001 From: Michael Widenius Date: Wed, 29 Jan 2014 15:37:17 +0200 Subject: Implementation of MDEV-5491: CREATE OR REPLACE TABLE Using CREATE OR REPLACE TABLE is be identical to DROP TABLE IF EXISTS table_name; CREATE TABLE ...; Except that: * CREATE OR REPLACE is be atomic (now one can create the same table between drop and create). * Temporary tables will not shadow the table name for the DROP as the CREATE TABLE tells us already if we are using a temporary table or not. * If the table was locked with LOCK TABLES, the new table will be locked with the same lock after it's created. Implementation details: - We don't anymore open the to-be-created table during CREATE TABLE, which the original code did. - There is no need to open a table we are planning to create. It's enough to check if the table exists or not. - Removed some of duplicated code for CREATE IF NOT EXISTS. - Give an error when using CREATE OR REPLACE with IF NOT EXISTS (conflicting options). - As a side effect of the code changes, we don't anymore have to internally re-prepare prepared statements with CREATE TABLE if the table exists. - Made one code path for all testing if log table are in use. - Better error message if one tries to create/drop/alter a log table in use - Added back disabled rpl_row_create_table test as it now seams to work and includes a lot of interesting tests. - Added HA_LEX_CREATE_REPLACE to mark if we are using CREATE OR REPLACE - Aligned CREATE OR REPLACE parsing code in sql_yacc.yy for TABLE and VIEW - Changed interface for drop_temporary_table() to make it more reusable - Changed Locked_tables_list::init_locked_tables() to work on the table object instead of the table list object. Before this it used a mix of both, which was not good. - Locked_tables_list::unlock_locked_tables(THD *thd) now requires a valid thd argument. Old usage of calling this with 0 i changed to instead call Locked_tables_list::reset() - Added functions Locked_tables_list:restore_lock() and Locked_tables_list::add_back_last_deleted_lock() to be able to easily add back a locked table to the lock list. - Added restart_trans_for_tables() to be able to restart a transaction. - DROP_ACL is required if one uses CREATE TABLE OR REPLACE. - Added drop of normal and temporary tables in create_table_imp() if CREATE OR REPLACE was used. - Added reacquiring of table locks in mysql_create_table() and mysql_create_like_table() mysql-test/include/commit.inc: With new code we get fewer status increments mysql-test/r/commit_1innodb.result: With new code we get fewer status increments mysql-test/r/create.result: Added testing of create or replace with timeout mysql-test/r/create_or_replace.result: Basic testing of CREATE OR REPLACE TABLE mysql-test/r/partition_exchange.result: New error message mysql-test/r/ps_ddl.result: Fewer reprepares with new code mysql-test/suite/archive/discover.result: Don't rediscover archive tables if the .frm file exists (Sergei will look at this if there is a better way...) mysql-test/suite/archive/discover.test: Don't rediscover archive tables if the .frm file exists (Sergei will look at this if there is a better way...) mysql-test/suite/funcs_1/r/innodb_views.result: New error message mysql-test/suite/funcs_1/r/memory_views.result: New error message mysql-test/suite/rpl/disabled.def: rpl_row_create_table should now be safe to use mysql-test/suite/rpl/r/rpl_row_create_table.result: Updated results after adding back disabled test mysql-test/suite/rpl/t/rpl_create_if_not_exists.test: Added comment mysql-test/suite/rpl/t/rpl_row_create_table.test: Added CREATE OR REPLACE TABLE test mysql-test/t/create.test: Added CREATE OR REPLACE TABLE test mysql-test/t/create_or_replace-master.opt: Create logs mysql-test/t/create_or_replace.test: Basic testing of CREATE OR REPLACE TABLE mysql-test/t/partition_exchange.test: Error number changed as we are now using same code for all log table change issues mysql-test/t/ps_ddl.test: Fewer reprepares with new code sql/handler.h: Moved things around a bit in a structure to get better alignment. Added HA_LEX_CREATE_REPLACE to mark if we are using CREATE OR REPLACE Added 3 elements to end of HA_CREATE_INFO to be able to store state to add backs locks in case of LOCK TABLES. sql/log.cc: Reimplemented check_if_log_table(): - Simpler and faster usage - Can give error messages This gives us one code path for allmost all error messages if log tables are in use sql/log.h: New interface for check_if_log_table() sql/slave.cc: More logging sql/sql_alter.cc: New interface for check_if_log_table() sql/sql_base.cc: More documentation Changed interface for drop_temporary_table() to make it more reusable Changed Locked_tables_list::init_locked_tables() to work on the table object instead of the table list object. Before this it used a mix of both, which was not good. Locked_tables_list::unlock_locked_tables(THD *thd) now requires a valid thd argument. Old usage of calling this with 0 i changed to instead call Locked_tables_list::reset() Added functions Locked_tables_list:restore_lock() and Locked_tables_list::add_back_last_deleted_lock() to be able to easily add back a locked table to the lock list. Check for command number instead of open_strategy of CREATE TABLE was used. Added restart_trans_for_tables() to be able to restart a transaction. This was needed in "create or replace ... select" between the drop table and the select. sql/sql_base.h: Added and updated function prototypes sql/sql_class.h: Added new prototypes to Locked_tables_list class Added extra argument to select_create to avoid double call to eof() or send_error() - I needed this in some edge case where the table was not created against expections. sql/sql_db.cc: New interface for check_if_log_table() sql/sql_insert.cc: Remember position to lock information so that we can reaquire table lock for LOCK TABLES + CREATE OR REPLACE TABLE SELECT. Later add back the lock by calling restore_lock(). Removed one not needed indentation level in create_table_from_items() Ensure we don't call send_eof() or abort_result_set() twice. sql/sql_lex.h: Removed variable that I temporarly added in an earlier changeset sql/sql_parse.cc: Removed old test code (marked with QQ) Ensure that we have open_strategy set as TABLE_LIST::OPEN_STUB in CREATE TABLE Removed some IF NOT EXISTS code as this is now handled in create_table_table_impl(). Set OPTION_KEEP_LOGS later. This code had to be moved as the test for IF EXISTS has changed place. DROP_ACL is required if one uses CREATE TABLE OR REPLACE. sql/sql_partition_admin.cc: New interface for check_if_log_table() sql/sql_rename.cc: New interface for check_if_log_table() sql/sql_table.cc: New interface for check_if_log_table() Moved some code in mysql_rm_table() under a common test. - Safe as temporary tables doesn't have statistics. - !is_temporary_table(table) test was moved out from drop_temporary_table() and merged with upper level code. - Added drop of normal and temporary tables in create_table_imp() if CREATE OR REPLACE was used. - Added reacquiring of table locks in mysql_create_table() and mysql_create_like_table() - In mysql_create_like_table(), restore table->open_strategy() if it was changed. - Re-test if table was a view after opening it. sql/sql_table.h: New prototype for mysql_create_table_no_lock() sql/sql_yacc.yy: Added syntax for CREATE OR REPLACE TABLE Reuse new code for CREATE OR REPLACE VIEW sql/table.h: Added name for enum type sql/table_cache.cc: More DBUG --- sql/sql_insert.cc | 165 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 105 insertions(+), 60 deletions(-) (limited to 'sql/sql_insert.cc') diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc index 8e3826eff48..719e0bae4ff 100644 --- a/sql/sql_insert.cc +++ b/sql/sql_insert.cc @@ -3916,6 +3916,16 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info, DEBUG_SYNC(thd,"create_table_select_before_create"); + /* Check if LOCK TABLES + CREATE OR REPLACE of existing normal table*/ + if (thd->locked_tables_mode && create_table->table && + !create_info->tmp_table()) + { + /* Remember information about the locked table */ + create_info->pos_in_locked_tables= + create_table->table->pos_in_locked_tables; + create_info->mdl_ticket= create_table->table->mdl_ticket; + } + /* Create and lock table. @@ -3932,52 +3942,63 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info, TABLE, which is a wrong order. So we keep binary logging disabled when we open_table(). */ + + if (!mysql_create_table_no_lock(thd, create_table->db, + create_table->table_name, + create_info, alter_info, NULL, + select_field_count)) { - if (!mysql_create_table_no_lock(thd, create_table->db, - create_table->table_name, - create_info, alter_info, NULL, - select_field_count)) + DEBUG_SYNC(thd,"create_table_select_before_open"); + + /* + If we had a temporary table or a table used with LOCK TABLES, + it was closed by mysql_create() + */ + create_table->table= 0; + + if (!create_info->tmp_table()) { - DEBUG_SYNC(thd,"create_table_select_before_open"); + Open_table_context ot_ctx(thd, MYSQL_OPEN_REOPEN); + TABLE_LIST::enum_open_strategy save_open_strategy; - if (!create_info->tmp_table()) - { - Open_table_context ot_ctx(thd, MYSQL_OPEN_REOPEN); - /* - Here we open the destination table, on which we already have - an exclusive metadata lock. - */ - if (open_table(thd, create_table, thd->mem_root, &ot_ctx)) - { - quick_rm_table(thd, create_info->db_type, create_table->db, - table_case_name(create_info, create_table->table_name), - 0); - } - else - table= create_table->table; - } - else + /* Force the newly created table to be opened */ + save_open_strategy= create_table->open_strategy; + create_table->open_strategy= TABLE_LIST::OPEN_NORMAL; + /* + Here we open the destination table, on which we already have + an exclusive metadata lock. + */ + if (open_table(thd, create_table, thd->mem_root, &ot_ctx)) { - if (open_temporary_table(thd, create_table)) - { - /* - This shouldn't happen as creation of temporary table should make - it preparable for open. Anyway we can't drop temporary table if - we are unable to find it. - */ - DBUG_ASSERT(0); - } - else - table= create_table->table; + quick_rm_table(thd, create_info->db_type, create_table->db, + table_case_name(create_info, create_table->table_name), + 0); } + /* Restore */ + create_table->open_strategy= save_open_strategy; } - if (!table) // open failed + else { - if (!thd->is_error()) // CREATE ... IF NOT EXISTS - my_ok(thd); // succeed, but did nothing - DBUG_RETURN(0); + if (open_temporary_table(thd, create_table)) + { + /* + This shouldn't happen as creation of temporary table should make + it preparable for open. Anyway we can't drop temporary table if + we are unable to find it. + */ + DBUG_ASSERT(0); + } } } + else + create_table->table= 0; // Create failed + + if (!(table= create_table->table)) + { + if (!thd->is_error()) // CREATE ... IF NOT EXISTS + my_ok(thd); // succeed, but did nothing + DBUG_RETURN(0); + } DEBUG_SYNC(thd,"create_table_select_before_lock"); @@ -3994,7 +4015,7 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info, /* purecov: begin tested */ /* This can happen in innodb when you get a deadlock when using same table - in insert and select + in insert and select or when you run out of memory. */ my_error(ER_CANT_LOCK, MYF(0), my_errno); if (*lock) @@ -4092,8 +4113,6 @@ select_create::prepare(List &values, SELECT_LEX_UNIT *u) thd->binlog_start_trans_and_stmt(); } - DBUG_ASSERT(create_table->table == NULL); - DEBUG_SYNC(thd,"create_table_select_before_check_if_exists"); if (!(table= create_table_from_items(thd, create_info, create_table, @@ -4236,32 +4255,53 @@ void select_create::send_error(uint errcode,const char *err) bool select_create::send_eof() { - bool tmp=select_insert::send_eof(); - if (tmp) + if (select_insert::send_eof()) + { abort_result_set(); - else + return 1; + } + + exit_done= 1; // Avoid double calls + /* + Do an implicit commit at end of statement for non-temporary + tables. This can fail, but we should unlock the table + nevertheless. + */ + if (!table->s->tmp_table) { - /* - Do an implicit commit at end of statement for non-temporary - tables. This can fail, but we should unlock the table - nevertheless. - */ - if (!table->s->tmp_table) - { - trans_commit_stmt(thd); - trans_commit_implicit(thd); - } + trans_commit_stmt(thd); + trans_commit_implicit(thd); + } - table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY); - table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE); - if (m_plock) + table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY); + table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE); + + if (m_plock) + { + MYSQL_LOCK *lock= *m_plock; + *m_plock= NULL; + m_plock= NULL; + + if (create_info->pos_in_locked_tables) { - mysql_unlock_tables(thd, *m_plock); - *m_plock= NULL; - m_plock= NULL; + /* + If we are under lock tables, we have created a table that was + originally locked. We should add back the lock to ensure that + all tables in the thd->open_list are locked! + */ + table->mdl_ticket= create_info->mdl_ticket; + + /* The following should never fail, except if out of memory */ + if (!thd->locked_tables_list.restore_lock(thd, + create_info-> + pos_in_locked_tables, + table, lock)) + return 0; // ok + /* Fail. Continue without locking the table */ } + mysql_unlock_tables(thd, lock); } - return tmp; + return 0; } @@ -4269,6 +4309,11 @@ void select_create::abort_result_set() { DBUG_ENTER("select_create::abort_result_set"); + /* Avoid double calls, could happen in case of out of memory on cleanup */ + if (exit_done) + DBUG_VOID_RETURN; + exit_done= 1; + /* In select_insert::abort_result_set() we roll back the statement, including truncating the transaction cache of the binary log. To do this, we -- cgit v1.2.1