Performance Schema events_waits_summary_by_thread_by_event_name Table

MariaDB starting with 10.0

The events_waits_summary_by_thread_by_event_name table, along with many other new Performance Schema tables, was added in MariaDB 10.0.

The Performance Schema events_waits_summary_by_thread_by_event_name table contains wait events summarized by thread and event name. It contains the following columns:

ColumnDescription
THREAD_IDThread associated with the event. Together with EVENT_NAME uniquely identifies the row.
EVENT_NAMEEvent name. Used together with THREAD_ID for grouping events.
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_thread_by_event_name\G
...
*************************** 6424. row ***************************
     THREAD_ID: 64
    EVENT_NAME: wait/io/socket/sql/server_unix_socket
    COUNT_STAR: 0
SUM_TIMER_WAIT: 0
MIN_TIMER_WAIT: 0
AVG_TIMER_WAIT: 0
MAX_TIMER_WAIT: 0
*************************** 6425. row ***************************
     THREAD_ID: 64
    EVENT_NAME: wait/io/socket/sql/client_connection
    COUNT_STAR: 0
SUM_TIMER_WAIT: 0
MIN_TIMER_WAIT: 0
AVG_TIMER_WAIT: 0
MAX_TIMER_WAIT: 0
*************************** 6426. row ***************************
     THREAD_ID: 64
    EVENT_NAME: idle
    COUNT_STAR: 73
SUM_TIMER_WAIT: 22005252162000000
MIN_TIMER_WAIT: 3000000
AVG_TIMER_WAIT: 301441810000000
MAX_TIMER_WAIT: 4912417573000000

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