Performance Schema events_waits_history Table

The events_waits_history table by default contains the ten most recent completed wait events per thread. This number can be adjusted by setting the performance_schema_events_waits_history_size system variable when the server starts up.

The table structure is identical to the events_waits_current table structure, and contains the following columns:

Column	Description
`THREAD_ID`	Thread associated with the event. Together with `EVENT_ID` uniquely identifies the row.
`EVENT_ID`	Thread's current event number at the start of the event. Together with `THREAD_ID` uniquely identifies the row.
`END_EVENT_ID`	`NULL` when the event starts, set to the thread's current event number at the end of the event.
`EVENT_NAME`	Event instrument name and a `NAME` from the `setup_instruments` table
`SOURCE`	Name and line number of the source file containing the instrumented code that produced the event.
`TIMER_START`	Value in picoseconds when the event timing started or `NULL` if timing is not collected.
`TIMER_END`	Value in picoseconds when the event timing ended, or `NULL` if timing is not collected.
`TIMER_WAIT`	Value in picoseconds of the event's duration or `NULL` if timing is not collected.
`SPINS`	Number of spin rounds for a mutex, or `NULL` if spin rounds are not used, or spinning is not instrumented.
`OBJECT_SCHEMA`	Name of the schema that contains the table for table I/O objects, otherwise `NULL` for file I/O and synchronization objects.
`OBJECT_NAME`	File name for file I/O objects, table name for table I/O objects, the socket's `IP:PORT` value for a socket object or `NULL` for a synchronization object.
`INDEX NAME`	Name of the index, `PRIMARY` for the primary key, or `NULL` for no index used.
`OBJECT_TYPE`	FILE for a file object, `TABLE` or `TEMPORARY TABLE` for a table object, or `NULL` for a synchronization object.
`OBJECT_INSTANCE_BEGIN`	Address in memory of the object.
`NESTING_EVENT_ID`	EVENT_ID of event within which this event nests.
`NESTING_EVENT_TYPE`	Nesting event type. Either `statement`, `stage` or `wait`.
`OPERATION`	Operation type, for example read, write or lock
`NUMBER_OF_BYTES`	Number of bytes that the operation read or wrote, or `NULL` for table I/O waits.
`FLAGS`	Reserved for use in the future.

It is possible to empty this table with a TRUNCATE TABLE statement.

events_waits_current and events_waits_history_long are related tables.

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https://mariadb.com/kb/en/performance-schema-events_waits_history-table/