Performance Schema table_handles Table
MariaDB starting with 10.5.2
The table_handles
table was added in 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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