The events_stages_history_long table, along with many other new Performance Schema tables, was added in MariaDB 10.0
The events_stages_history_long table by default contains the ten thousand most recent completed stage events. This number can be adjusted by setting the performance_schema_events_stages_history_long_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. |
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. |
NESTING_EVENT_ID |
EVENT_ID of event within which this event nests. |
NESTING_EVENT_TYPE |
Nesting event type. Either statement, stage or wait. |
It is possible to empty this table with a TRUNCATE TABLE statement.
events_stages_current and events_stages_history are related tables.
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Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/performance-schema-events_stages_history_long-table/