How to Identify MySQL Tables Locked by LOCK TABLE?

Identifying MySQL Tables Locked by LOCK TABLE

In MySQL, the LOCK TABLE command enables explicit locking of tables for write or read operations. Detecting such locked tables can be crucial for ensuring data integrity and resolving potential deadlocks.

Solution

To detect tables locked by the LOCK TABLE command, you can utilize the SHOW OPEN TABLES command. This command provides detailed information about all currently open tables in a MySQL instance. By filtering the results, you can identify tables that are locked by LOCK TABLE.

Use the following command template to check for locked tables in a specific database:

SHOW OPEN TABLES WHERE `Table` LIKE '%[TABLE_NAME]%' AND `Database` LIKE '[DBNAME]' AND In_use > 0;

Replace [TABLE_NAME] and [DBNAME] with the actual table name and database name, respectively.

Example

To check for locked tables in the test database, run the following command:

SHOW OPEN TABLES WHERE `Table` LIKE '%table_name%' AND `Database` LIKE 'test' AND In_use > 0;

If any tables are locked by LOCK TABLE, they will be listed in the output. This allows you to identify and address any potential deadlocks or data integrity issues.

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