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, 9 insertions, 6 deletions

diff --git a/sql/lock.cc b/sql/lock.cc
index a51c34365fa..12de6ae0616 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -261,7 +261,7 @@ static void track_table_access(THD *thd, TABLE **tables, size_t count)
 
       if (t)
         tst->add_trx_state(thd,  t->reginfo.lock_type,
-                           t->file->has_transactions());
+                           t->file->has_transaction_manager());
     }
   }
 }
@@ -439,10 +439,10 @@ void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock, bool free_lock)
   This will work even if get_lock_data fails (next unlock will free all)
 */
 
-void mysql_unlock_some_tables(THD *thd, TABLE **table,uint count)
+void mysql_unlock_some_tables(THD *thd, TABLE **table,uint count, uint flag)
 {
   MYSQL_LOCK *sql_lock=
-    get_lock_data(thd, table, count, GET_LOCK_UNLOCK | GET_LOCK_ON_THD);
+    get_lock_data(thd, table, count, GET_LOCK_UNLOCK | GET_LOCK_ON_THD | flag);
   if (sql_lock)
     mysql_unlock_tables(thd, sql_lock, 0);
 }
@@ -539,7 +539,7 @@ void mysql_lock_remove(THD *thd, MYSQL_LOCK *locked,TABLE *table)
         DBUG_ASSERT(table->lock_position == i);
 
         /* Unlock the table. */
-        mysql_unlock_some_tables(thd, &table, /* table count */ 1);
+        mysql_unlock_some_tables(thd, &table, /* table count */ 1, 0);
 
         /* Decrement table_count in advance, making below expressions easier */
         old_tables= --locked->table_count;
@@ -733,6 +733,7 @@ static int unlock_external(THD *thd, TABLE **table,uint count)
   @param flags		    One of:
            - GET_LOCK_UNLOCK      : If we should send TL_IGNORE to store lock
            - GET_LOCK_STORE_LOCKS : Store lock info in TABLE
+           - GET_LOCK_SKIP_SEQUENCES : Ignore sequences (for temporary unlock)
 */
 
 MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count, uint flags)
@@ -750,7 +751,8 @@ MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count, uint flags)
     TABLE *t= table_ptr[i];
     
     if (t->s->tmp_table != NON_TRANSACTIONAL_TMP_TABLE && 
-        t->s->tmp_table != INTERNAL_TMP_TABLE)
+        t->s->tmp_table != INTERNAL_TMP_TABLE &&
+        (!(flags & GET_LOCK_SKIP_SEQUENCES) || t->s->sequence == 0))
     {
       lock_count+= t->file->lock_count();
       table_count++;
@@ -781,7 +783,8 @@ MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count, uint flags)
     THR_LOCK_DATA **locks_start;
     table= table_ptr[i];
     if (table->s->tmp_table == NON_TRANSACTIONAL_TMP_TABLE ||
-        table->s->tmp_table == INTERNAL_TMP_TABLE) 
+        table->s->tmp_table == INTERNAL_TMP_TABLE ||
+        ((flags & GET_LOCK_SKIP_SEQUENCES) && table->s->sequence))
       continue;
     lock_type= table->reginfo.lock_type;
     DBUG_ASSERT(lock_type != TL_WRITE_DEFAULT && lock_type != TL_READ_DEFAULT);