The collection changes in the fix defect FOG-6928 of the 6.1.0.11 MySQL PI cartridge caused the query to become more expensive as the history table becomes larger and more expensive to run. In testing it was found that
- when
performance_schema.events_waits_history
table has 50000 rows query executions is about 15-20 sec. - when the table is larger than 100000 rows then query takes more than 90 sec and times out
It appears that the size of performance_schema.events_waits_history has an impact on the query that the PI engine collects data. In databases that have a large number of rows (e.g. 100,000) in the table, it causes a long time to return results.
Users can run this query to obtain the total number of rows from the table.
select COUNT(1) from performance_schema.events_waits_history;