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26.12.17.6 Object Wait Summary Table

The Performance Schema maintains the objects_summary_global_by_type table for aggregating object wait events.

Example object wait event summary information:

mysql> SELECT * FROM performance_schema.objects_summary_global_by_type\G
...
*************************** 3. row ***************************
   OBJECT_TYPE: TABLE
 OBJECT_SCHEMA: test
   OBJECT_NAME: t
    COUNT_STAR: 3
SUM_TIMER_WAIT: 263126976
MIN_TIMER_WAIT: 1522272
AVG_TIMER_WAIT: 87708678
MAX_TIMER_WAIT: 258428280
...
*************************** 10. row ***************************
   OBJECT_TYPE: TABLE
 OBJECT_SCHEMA: mysql
   OBJECT_NAME: user
    COUNT_STAR: 14
SUM_TIMER_WAIT: 365567592
MIN_TIMER_WAIT: 1141704
AVG_TIMER_WAIT: 26111769
MAX_TIMER_WAIT: 334783032
...

The objects_summary_global_by_type table has these grouping columns to indicate how the table aggregates events: OBJECT_TYPE, OBJECT_SCHEMA, and OBJECT_NAME. Each row summarizes events for the given object.

objects_summary_global_by_type has the same summary columns as the events_waits_summary_by_xxx tables. See Section 26.12.17.1, “Wait Event Summary Tables”.

The objects_summary_global_by_type table has these indexes:

  • Primary key on (OBJECT_TYPE, OBJECT_SCHEMA, OBJECT_NAME)

TRUNCATE TABLE is permitted for the object summary table. It resets the summary columns to zero rather than removing rows.