MySQL 5.7 Release Notes
The events_waits_history table
contains the N most recent wait
events that have ended per thread. Wait events are not added
to the table until they have ended. When the table contains
the maximum number of rows for a given thread, the oldest
thread row is discarded when a new row for that thread is
added. When a thread ends, all its rows are discarded.
The Performance Schema autosizes the value of
N during server startup. To set the
number of rows per thread explicitly, set the
performance_schema_events_waits_history_size
system variable at server startup.
The events_waits_history table
has the same columns as
events_waits_current. See
Section 25.12.4.1, “The events_waits_current Table”.
TRUNCATE TABLE is permitted for
the events_waits_history table.
It removes the rows.
For more information about the relationship between the three wait event tables, see Section 25.9, “Performance Schema Tables for Current and Historical Events”.
For information about configuring whether to collect wait events, see Section 25.12.4, “Performance Schema Wait Event Tables”.