mysql.tidb_mdl_view

This view shows the information about the metadata locks.

DESC mysql.tidb_mdl_view;

The output is as follows:

+-------------+-----------------+------+------+---------+-------+
| Field       | Type            | Null | Key  | Default | Extra |
+-------------+-----------------+------+------+---------+-------+
| job_id      | bigint          | NO   | PRI  | NULL    |       |
| db_name     | longtext        | YES  |      | NULL    |       |
| table_name  | longtext        | YES  |      | NULL    |       |
| query       | longtext        | YES  |      | NULL    |       |
| session_id  | bigint unsigned | YES  |      | NULL    |       |
| start_time  | timestamp(6)    | YES  |      | NULL    |       |
| SQL_DIGESTS | varchar(5)      | YES  |      | NULL    |       |
+-------------+-----------------+------+------+---------+-------+
7 rows in set (0.00 sec)

Fields

• job_id: The identifier of the job.
• db_name: The database name.
• table_name: The table name.
• query: The query.
• session_id: The identifier of the session.
• start_time: The start time. This column was called TxnStart in earlier versions.
• SQL_DIGESTS: The digests of the SQL statements.