The Ultimate Guide to High Availability with MariaDB

Performance Schema events_waits_summary_by_instance Table

The Performance Schema events_waits_summary_by_instance table contains wait events summarized by instance. It contains the following columns:

ColumnDescription
EVENT_NAMEEvent name. Used together with OBJECT_INSTANCE_BEGIN for grouping events.
OBJECT_INSTANCE_BEGINIf an instrument creates multiple instances, each instance has a unique OBJECT_INSTANCE_BEGIN value to allow for grouping by instance.
COUNT_STARNumber of summarized events
SUM_TIMER_WAITTotal wait time of the summarized events that are timed.
MIN_TIMER_WAITMinimum wait time of the summarized events that are timed.
AVG_TIMER_WAITAverage wait time of the summarized events that are timed.
MAX_TIMER_WAITMaximum wait time of the summarized events that are timed.

The *_TIMER_WAIT columns only calculate results for timed events, as non-timed events have a NULL wait time.

Example

SELECT * FROM events_waits_summary_by_instance\G
...
*************************** 202. row ***************************
           EVENT_NAME: wait/io/file/sql/binlog
OBJECT_INSTANCE_BEGIN: 140578961969856
           COUNT_STAR: 6
       SUM_TIMER_WAIT: 90478331960
       MIN_TIMER_WAIT: 263344
       AVG_TIMER_WAIT: 15079721848
       MAX_TIMER_WAIT: 67760576376
*************************** 203. row ***************************
           EVENT_NAME: wait/io/file/sql/dbopt
OBJECT_INSTANCE_BEGIN: 140578961970560
           COUNT_STAR: 6
       SUM_TIMER_WAIT: 39891428472
       MIN_TIMER_WAIT: 387168
       AVG_TIMER_WAIT: 6648571412
       MAX_TIMER_WAIT: 24503293304
*************************** 204. row ***************************
           EVENT_NAME: wait/io/file/sql/dbopt
OBJECT_INSTANCE_BEGIN: 140578961971264
           COUNT_STAR: 6
       SUM_TIMER_WAIT: 39902495024
       MIN_TIMER_WAIT: 177888
       AVG_TIMER_WAIT: 6650415692
       MAX_TIMER_WAIT: 21026400404

Comments

Comments loading...
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.