MDEV-10139 Support for SEQUENCE objects

Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
    [ INCREMENT [ BY | = ] increment ]
    [ MINVALUE [=] minvalue | NO MINVALUE ]
    [ MAXVALUE [=] maxvalue | NO MAXVALUE ]
    [ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
    ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);

SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE  [IF EXISTS] sequence_names

Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
  not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
  already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
  - Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
  be better if we would have a separate list for sequence tables so that
  select doesn't know about them, except if refereed to with FROM.

Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
  use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
  that want's to support sequences
- Added handler calls:
 - engine_name(), to simplify getting engine name for partition and sequences
 - update_first_row(), to be able to do efficient sequence implementations.
 - Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
  changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
  deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
  the table is a sequence. Needed by DROP SQUENCE to not drop a table.

1 files changed, 12 insertions, 7 deletions

diff --git a/sql/datadict.h b/sql/datadict.h
index 9b180a882f9..46dac394f07 100644
--- a/sql/datadict.h
+++ b/sql/datadict.h
@@ -1,6 +1,7 @@
 #ifndef DATADICT_INCLUDED
 #define DATADICT_INCLUDED
-/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2010, Oracle and/or its affiliates.
+   Copyright (c) 2017 MariaDB corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -21,11 +22,12 @@
   Data dictionary API.
 */
 
-enum frm_type_enum
+enum Table_type
 {
-  FRMTYPE_ERROR= 0,
-  FRMTYPE_TABLE,
-  FRMTYPE_VIEW
+  TABLE_TYPE_UNKNOWN,
+  TABLE_TYPE_NORMAL,                            /* Normal table */
+  TABLE_TYPE_SEQUENCE,
+  TABLE_TYPE_VIEW
 };
 
 /*
@@ -35,11 +37,14 @@ enum frm_type_enum
   Prefer to use ha_table_exists() instead.
   To check whether it's an frm of a view, use dd_frm_is_view().
 */
-frm_type_enum dd_frm_type(THD *thd, char *path, LEX_STRING *engine_name);
+
+enum Table_type dd_frm_type(THD *thd, char *path, LEX_STRING *engine_name,
+                            bool *is_sequence);
 
 static inline bool dd_frm_is_view(THD *thd, char *path)
 {
-  return dd_frm_type(thd, path, NULL) == FRMTYPE_VIEW;
+  bool not_used2;
+  return dd_frm_type(thd, path, NULL, &not_used2) == TABLE_TYPE_VIEW;
 }
 
 bool dd_recreate_table(THD *thd, const char *db, const char *table_name,