Add a missing DaemonLogEvent key for garbage collection
Summary: See PHI176. This is issued periodically by the garbage collector. Normally this table is relatively small-ish so this missing key isn't hugely noticeable.
Test Plan:
Ran ./bin/garbage collect --collector daemon.processes --trace to get the query the GC runs.
Ran DELETE FROM `daemon_logevent` WHERE epoch < 1508443504 LIMIT 100 before and after the key, saw a much better query plan afterward:
Before:
mysql> explain DELETE FROM `daemon_logevent` WHERE epoch < 1508443504 LIMIT 100; +----+-------------+-----------------+------+---------------+------+---------+------+-------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-----------------+------+---------------+------+---------+------+-------+-------------+ | 1 | SIMPLE | daemon_logevent | ALL | NULL | NULL | NULL | NULL | 19325 | Using where | +----+-------------+-----------------+------+---------------+------+---------+------+-------+-------------+ 1 row in set (0.00 sec)
After:
mysql> explain DELETE FROM `daemon_logevent` WHERE epoch < 1508443504 LIMIT 100; +----+-------------+-----------------+-------+---------------+-----------+---------+-------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-----------------+-------+---------------+-----------+---------+-------+------+-------------+ | 1 | SIMPLE | daemon_logevent | range | key_epoch | key_epoch | 4 | const | 1 | Using where | +----+-------------+-----------------+-------+---------------+-----------+---------+-------+------+-------------+ 1 row in set (0.00 sec)
Reviewers: amckinley
Reviewed By: amckinley
Differential Revision: https://secure.phabricator.com/D18733