Performance Schema Summary Tables These columns aggregate internal read locks. These columns aggregate internal read locks. These columns aggregate external read locks. These columns aggregate internal write locks. These columns aggregate internal write locks. These columns aggregate internal write locks. These columns aggregate internal write locks. These columns aggregate external write locks. TRUNCATE TABLE  is permitted for table lock summary tables. It resets the summary columns to zero rather than removing rows. The  table_lock_waits_summary_by_table  table has these indexes: These socket summary tables aggregate timer and byte count information for socket operations: 27.12.20.9 Socket Summary Tables • socket_summary_by_instance : Aggregate timer and byte count statistics generated by the  wait/ io/socket/*  instruments for all socket I/O operations, per socket instance. When a connection terminates, the row in  socket_summary_by_instance  corresponding to it is deleted. • socket_summary_by_event_name : Aggregate timer and byte count statistics generated by the wait/io/socket/*  instruments for all socket I/O operations, per socket instrument. •Unique index on ( OBJECT_TYPE ,  OBJECT_SCHEMA ,  OBJECT_NAME ) • COUNT_WRITE_EXTERNAL ,  SUM_TIMER_WRITE_EXTERNAL ,  MIN_TIMER_WRITE_EXTERNAL , AVG_TIMER_WRITE_EXTERNAL ,  MAX_TIMER_WRITE_EXTERNAL • COUNT_WRITE_NORMAL ,  SUM_TIMER_WRITE_NORMAL ,  MIN_TIMER_WRITE_NORMAL , AVG_TIMER_WRITE_NORMAL ,  MAX_TIMER_WRITE_NORMAL • COUNT_WRITE_LOW_PRIORITY ,  SUM_TIMER_WRITE_LOW_PRIORITY , MIN_TIMER_WRITE_LOW_PRIORITY ,  AVG_TIMER_WRITE_LOW_PRIORITY , MAX_TIMER_WRITE_LOW_PRIORITY • COUNT_WRITE_CONCURRENT_INSERT ,  SUM_TIMER_WRITE_CONCURRENT_INSERT , MIN_TIMER_WRITE_CONCURRENT_INSERT ,  AVG_TIMER_WRITE_CONCURRENT_INSERT , MAX_TIMER_WRITE_CONCURRENT_INSERT • COUNT_WRITE_ALLOW_WRITE ,  SUM_TIMER_WRITE_ALLOW_WRITE , MIN_TIMER_WRITE_ALLOW_WRITE ,  AVG_TIMER_WRITE_ALLOW_WRITE , MAX_TIMER_WRITE_ALLOW_WRITE • COUNT_READ_EXTERNAL ,  SUM_TIMER_READ_EXTERNAL ,  MIN_TIMER_READ_EXTERNAL , AVG_TIMER_READ_EXTERNAL ,  MAX_TIMER_READ_EXTERNAL • COUNT_READ_NO_INSERT ,  SUM_TIMER_READ_NO_INSERT ,  MIN_TIMER_READ_NO_INSERT , AVG_TIMER_READ_NO_INSERT ,  MAX_TIMER_READ_NO_INSERT 5068