The INNODB_LOCK_WAITS table contains one or
more rows for each blocked InnoDB transaction,
indicating the lock it has requested and any locks that are
blocking that request.
Table 21.14 INNODB_LOCK_WAITS Columns
| Column name | Description |
|---|---|
REQUESTING_TRX_ID | ID of the requesting (blocked) transaction. |
REQUESTED_LOCK_ID | ID of the lock for which a transaction is waiting. To obtain details
about the lock, join this column with the
LOCK_ID column of the
INNODB_LOCKS table. |
BLOCKING_TRX_ID | ID of the blocking transaction. |
BLOCKING_LOCK_ID | ID of a lock held by a transaction blocking another transaction from
proceeding. To obtain details about the lock, join this
column with the LOCK_ID column of the
INNODB_LOCKS table. |
Example:
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS\G
*************************** 1. row ***************************
requesting_trx_id: 3396
requested_lock_id: 3396:91:3:2
blocking_trx_id: 3395
blocking_lock_id: 3395:91:3:2
Notes:
Use this table to help diagnose performance problems that occur during times of heavy concurrent load. Its contents are updated as described in Section 14.15.2.3, “Persistence and Consistency of InnoDB Transaction and Locking Information”.
Use DESCRIBE or
SHOW COLUMNS to view additional
information about the columns of this table including data
types and default values.
You must have the PROCESS
privilege to query this table.
For usage information, see Section 14.15.2.1, “Using InnoDB Transaction and Locking Information”.