Detecting locked tables (locked by LOCK TABLE)

Question

Is there a way to detect locked tables in MySQL? I mean tables locked by the LOCK TABLE table WRITE/READ command.

_{(Note that readers interested in}

Answer 1

This article describes how to get information about locked MySQL resources. mysqladmin debug might also be of some use.

Answer 2

You could also get all relevant details from performance_schema:

SELECT
OBJECT_SCHEMA
,OBJECT_NAME
,GROUP_CONCAT(DISTINCT EXTERNAL_LOCK)
FROM performance_schema.table_handles 
WHERE EXTERNAL_LOCK IS NOT NULL

GROUP BY
OBJECT_SCHEMA
,OBJECT_NAME

This works similar as

show open tables WHERE In_use > 0