Performance Schema events_stages_history Table

This table records the ten most recent completed stage events per thread, useful for analyzing recent thread activity.

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

The table structure is identical to the events_stage_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. Relative to the server start, not to the epoch, so cannot directly be converted to a timestamp.
TIMER_END	Value in picoseconds when the event timing ended, or NULL if timing is not collected. Relative to the server start, not to the epoch, so cannot directly be converted to a timestamp.
TIMER_WAIT	Value in picoseconds of the event's duration or NULL if timing is not collected.
NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
NESTING_EVENT_TYPE	Nesting event type. One of transaction, statement, stage or wait.

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

events_stages_current and events_stages_history_long are related tables.

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