Description:
Hi, guys
When I executed LOCK TABLE command, the table of PERFORMANCE_SCHEMA.metadata_locks displayed the MDL lock duration as TRANSACTION, But actually it should be EXPLICIT.
The MDL lock duration can only be changed to EXPLICIT when the RENAME TABLE command is executed after LOCK TABLE, which is fixed in Bug #96237.
How to repeat:
mysql> create table t1 (id int);
Query OK, 0 rows affected (0.01 sec)
mysql> insert into t1 values (1);
Query OK, 1 row affected (0.00 sec)
mysql> lock table t1 write;
Query OK, 0 rows affected (0.01 sec)
mysql> select * from performance_schema.metadata_locks;
+-------------+--------------------+----------------+-------------+-----------------------+----------------------+---------------+-------------+-------------------+-----------------+----------------+
| OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | COLUMN_NAME | OBJECT_INSTANCE_BEGIN | LOCK_TYPE | LOCK_DURATION | LOCK_STATUS | SOURCE | OWNER_THREAD_ID | OWNER_EVENT_ID |
+-------------+--------------------+----------------+-------------+-----------------------+----------------------+---------------+-------------+-------------------+-----------------+----------------+
| GLOBAL | NULL | NULL | NULL | 105553176921904 | INTENTION_EXCLUSIVE | STATEMENT | GRANTED | sql_base.cc:5476 | 51 | 14 |
| SCHEMA | test | NULL | NULL | 105553176920224 | INTENTION_EXCLUSIVE | TRANSACTION | GRANTED | sql_base.cc:5463 | 51 | 14 |
| TABLE | test | t1 | NULL | 105553176920304 | SHARED_NO_READ_WRITE | TRANSACTION | GRANTED | sql_parse.cc:6013 | 51 | 14 |
| TABLESPACE | NULL | test/t1 | NULL | 105553176981936 | INTENTION_EXCLUSIVE | TRANSACTION | GRANTED | lock.cc:808 | 51 | 14 |
| TABLE | performance_schema | metadata_locks | NULL | 105553176985760 | SHARED_READ | TRANSACTION | GRANTED | sql_parse.cc:6013 | 51 | 17 |
+-------------+--------------------+----------------+-------------+-----------------------+----------------------+---------------+-------------+-------------------+-----------------+----------------+
5 rows in set (0.00 sec)
mysql> alter table t1 rename t2;
Query OK, 0 rows affected (0.02 sec)
mysql> select * from performance_schema.metadata_locks;
+-------------+--------------------+----------------+-------------+-----------------------+---------------------+---------------+-------------+------------------------+-----------------+----------------+
| OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | COLUMN_NAME | OBJECT_INSTANCE_BEGIN | LOCK_TYPE | LOCK_DURATION | LOCK_STATUS | SOURCE | OWNER_THREAD_ID | OWNER_EVENT_ID |
+-------------+--------------------+----------------+-------------+-----------------------+---------------------+---------------+-------------+------------------------+-----------------+----------------+
| GLOBAL | NULL | NULL | NULL | 105553176921904 | INTENTION_EXCLUSIVE | STATEMENT | GRANTED | sql_base.cc:5476 | 51 | 14 |
| SCHEMA | test | NULL | NULL | 105553176920224 | INTENTION_EXCLUSIVE | TRANSACTION | GRANTED | sql_base.cc:5463 | 51 | 14 |
| TABLE | test | t2 | NULL | 105553176728656 | EXCLUSIVE | EXPLICIT | GRANTED | sql_alter.cc:206 | 51 | 18 |
| TABLESPACE | NULL | test/t2 | NULL | 105553176738976 | EXCLUSIVE | EXPLICIT | GRANTED | dictionary_impl.cc:471 | 51 | 19 |
| TABLE | performance_schema | metadata_locks | NULL | 105553176981936 | SHARED_READ | TRANSACTION | GRANTED | sql_parse.cc:6013 | 51 | 21 |
+-------------+--------------------+----------------+-------------+-----------------------+---------------------+---------------+-------------+------------------------+-----------------+----------------+
5 rows in set (0.00 sec)
mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.30 |
+-----------+
1 row in set (0.00 sec)
Suggested fix:
Function: MDL_ticket_store::move_all_to_explicit_duration()
