Performance Schema Lock Tables The  data_lock_waits  table has these columns: • ENGINE The storage engine that requested the lock. The ID of the lock requested by the storage engine. To obtain details about the lock, join this column with the  ENGINE_LOCK_ID  column of the  data_locks  table. • REQUESTING_ENGINE_LOCK_ID • REQUESTING_ENGINE_TRANSACTION_ID • REQUESTING_THREAD_ID The storage engine internal ID of the transaction that requested the lock. The thread ID of the session that requested the lock. The Performance Schema event that caused the lock request in the session that requested the lock. The address in memory of the requested lock. The ID of the blocking lock. To obtain details about the lock, join this column with the  ENGINE_LOCK_ID column of the  data_locks  table. The storage engine internal ID of the transaction that holds the blocking lock. • REQUESTING_EVENT_ID • REQUESTING_OBJECT_INSTANCE_BEGIN • BLOCKING_ENGINE_LOCK_ID • BLOCKING_ENGINE_TRANSACTION_ID • BLOCKING_THREAD_ID • BLOCKING_EVENT_ID • BLOCKING_OBJECT_INSTANCE_BEGIN The thread ID of the session that holds the blocking lock. The Performance Schema event that caused the blocking lock in the session that holds it. The address in memory of the blocking lock. The  data_lock_waits  table has these indexes: •Index on ( REQUESTING_ENGINE_LOCK_ID ,  ENGINE ) •Index on ( BLOCKING_ENGINE_LOCK_ID ,  ENGINE ) •Index on ( REQUESTING_ENGINE_TRANSACTION_ID ,  ENGINE ) •Index on ( BLOCKING_ENGINE_TRANSACTION_ID ,  ENGINE ) •Index on ( REQUESTING_THREAD_ID ,  REQUESTING_EVENT_ID ) 5026