Performance Schema table_handles Table

The table_handles table lists all open table handles, showing which threads are currently accessing which table instances and the locks they hold.

The table_handles table is available from MariaDB 10.5.2.

The table_handles table contains table lock information. It uses the wait/lock/table/sql/handler instrument, which is enabled by default.

Information includes which table handles are open, which sessions are holding the locks, and how they are locked.

The table is read-only, and TRUNCATE TABLE cannot be performed on the table.

The maximum number of opened table objects is determined by the performance_schema_max_table_handles system variable.

The table contains the following columns:

Column	Description
OBJECT_TYPE	The table opened by a table handle.
OBJECT_SCHEMA	The schema that contains the object.
OBJECT_NAME	The name of the instrumented object.
OBJECT_INSTANCE_BEGIN	The table handle address in memory.
OWNER_THREAD_ID	The thread owning the table handle.
OWNER_EVENT_ID	The event which caused the table handle to be opened.
INTERNAL_LOCK	The table lock used at the SQL level.
EXTERNAL_LOCK	The table lock used at the storage engine level.

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