* Davi Arnaut <davi@stripped> [07/09/11 08:56]:
> diff -Nrup a/sql/sql_insert.cc b/sql/sql_insert.cc
> --- a/sql/sql_insert.cc 2007-09-10 06:42:13 -03:00
> +++ b/sql/sql_insert.cc 2007-09-11 01:29:29 -03:00
> @@ -3265,7 +3265,7 @@ static TABLE *create_table_from_items(TH
> TABLE_LIST *create_table,
> Alter_info *alter_info,
> List<Item> *items,
> - MYSQL_LOCK **lock,
> + MYSQL_LOCK **extra_lock,
> TABLEOP_HOOKS *hooks)
> {
> TABLE tmp_table; // Used during 'Create_field()'
> @@ -3277,6 +3277,7 @@ static TABLE *create_table_from_items(TH
> Item *item;
> Field *tmp_field;
> bool not_used;
> + MYSQL_LOCK *lock;
> DBUG_ENTER("create_table_from_items");
>
> DBUG_EXECUTE_IF("sleep_create_select_before_check_if_exists",
> my_sleep(6000000););
> @@ -3406,20 +3407,27 @@ static TABLE *create_table_from_items(TH
>
> table->reginfo.lock_type=TL_WRITE;
> hooks->prelock(&table, 1); // Call prelock hooks
> - if (! ((*lock)= mysql_lock_tables(thd, &table, 1,
> - MYSQL_LOCK_IGNORE_FLUSH, ¬_used)) ||
> + if (! (lock= mysql_lock_tables(thd, &table, 1,
> + MYSQL_LOCK_IGNORE_FLUSH, ¬_used)) ||
> hooks->postlock(&table, 1))
> {
> - if (*lock)
> + if (lock)
> {
> - mysql_unlock_tables(thd, *lock);
> - *lock= 0;
> + mysql_unlock_tables(thd, lock);
> + if (! (create_info->options & HA_LEX_CREATE_TMP_TABLE))
> + *extra_lock= 0;
> }
>
> if (!create_info->table_existed)
> drop_open_table(thd, table, create_table->db,
> create_table->table_name);
> DBUG_RETURN(0);
> }
> +
> + if (create_info->options & HA_LEX_CREATE_TMP_TABLE)
> + mysql_unlock_tables(thd, lock);
> + else
> + *extra_lock= lock;
> +
You're on track, but I think we can't unlock prematurely even a
temporary table - it's a violation of the storage engine protocol,
which demands that write_row() is called under a lock, even for
temporary tables.
We need to rethink implementation of extra_lock, perhaps. And
maybe it's not a #runtime but #replication problem, since
extra_lock is used only to write table map events.
Perhaps you could talk to Mats from replication team to see if
thd->extra_lock could be removed altogether and a member of
create_select class used instead?
Thanks.
--
-- Konstantin Osipov Software Developer, Moscow, Russia
-- MySQL AB, www.mysql.com The best DATABASE COMPANY in the GALAXY
