Performance Schema table_handles Table
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:
|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.|