aurora_stat_system_waits - Amazon Aurora
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aurora_stat_system_waits

Reports wait event information for the Aurora PostgreSQL DB instance.

Syntax

aurora_stat_system_waits()

Arguments

None

Return type

SETOF record

Usage notes

This function returns the cumulative number of waits and cumulative wait time for each wait event generated by the DB instance that you're currently connected to.

The returned recordset includes the following fields:

  • type_id – The ID of the type of wait event.

  • event_id – The ID of the wait event.

  • waits – The number of times the wait event occurred.

  • wait_time – The total amount of time in microseconds spent waiting for this event.

Statistics returned by this function are reset when a DB instance restarts.

Examples

The following example shows results from calling the aurora_stat_system_waits function.

=> SELECT * FROM aurora_stat_system_waits(); type_id | event_id | waits | wait_time ---------+-----------+-----------+-------------- 1 | 16777219 | 11 | 12864 1 | 16777220 | 501 | 174473 1 | 16777270 | 53171 | 23641847 1 | 16777271 | 23 | 319668 1 | 16777274 | 60 | 12759 . . . 10 | 167772231 | 204596 | 790945212 10 | 167772232 | 2 | 47729 10 | 167772234 | 1 | 888 10 | 167772235 | 2 | 64

The following example shows how you can use this function together with aurora_stat_wait_event and aurora_stat_wait_type to produce more readable results.

=> SELECT type_name, event_name, waits, wait_time FROM aurora_stat_system_waits() NATURAL JOIN aurora_stat_wait_event() NATURAL JOIN aurora_stat_wait_type(); type_name | event_name | waits | wait_time -----------+------------------------+----------+-------------- LWLock | XidGenLock | 11 | 12864 LWLock | ProcArrayLock | 501 | 174473 LWLock | buffer_content | 53171 | 23641847 LWLock | rdsutils | 2 | 12764 Lock | tuple | 75686 | 2033956052 Lock | transactionid | 1765147 | 47267583409 Activity | AutoVacuumMain | 136868 | 56305604538 Activity | BgWriterHibernate | 7486 | 55266949471 Activity | BgWriterMain | 7487 | 1508909964 . . . IO | SLRURead | 3 | 11756 IO | WALWrite | 52544463 | 388850428 IO | XactSync | 187073 | 597041642 IO | ClogRead | 2 | 47729 IO | OutboundCtrlRead | 1 | 888 IO | OutboundCtrlWrite | 2 | 64