MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
The events_waits_history_long
table contains N the most recent
wait events that have ended globally, across all threads. Wait
events are not added to the table until they have ended. When
the table becomes full, the oldest row is discarded when a new
row is added, regardless of which thread generated either row.
The Performance Schema autosizes the value of
N during server startup. To set the
table size explicitly, set the
performance_schema_events_waits_history_long_size
system variable at server startup.
The events_waits_history_long
table has the same columns as
events_waits_current. See
Section 29.12.4.1, “The events_waits_current Table”.
Unlike events_waits_current,
events_waits_history_long has no
indexing.
TRUNCATE TABLE is permitted for
the events_waits_history_long
table. It removes the rows.
For more information about the relationship between the three wait event tables, see Section 29.9, “Performance Schema Tables for Current and Historical Events”.
For information about configuring whether to collect wait events, see Section 29.12.4, “Performance Schema Wait Event Tables”.