MySQL stuck on "using filesort" when doing an "order by"
- by noko
I can't seem to get my query to stop using filesort.
This is my query:
SELECT s.`pilot`, p.`name`, s.`sector`, s.`hull`
FROM `pilots` p
LEFT JOIN `ships` s ON ( (s.`game` = p.`game`)
AND (s.`pilot` = p.`id`) )
WHERE p.`game` = 1
AND p.`id` <> 2
AND s.`sector` = 43
AND s.`hull` > 0
ORDER BY p.`last_move` DESC
Table structures:
CREATE TABLE IF NOT EXISTS `pilots` (
`id` mediumint(5) unsigned NOT NULL AUTO_INCREMENT,
`game` tinyint(3) unsigned NOT NULL DEFAULT '0',
`last_move` int(10) NOT NULL DEFAULT '0',
UNIQUE KEY `id` (`id`),
KEY `last_move` (`last_move`),
KEY `game_id_lastmove` (`game`,`id`,`last_move`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=8 ;
CREATE TABLE IF NOT EXISTS `ships` (
`id` mediumint(5) unsigned NOT NULL AUTO_INCREMENT,
`game` tinyint(3) unsigned NOT NULL DEFAULT '0',
`pilot` mediumint(5) unsigned NOT NULL DEFAULT '0',
`sector` smallint(5) unsigned NOT NULL DEFAULT '0',
`hull` smallint(4) unsigned NOT NULL DEFAULT '50',
UNIQUE KEY `id` (`id`),
KEY `game` (`game`),
KEY `pilot` (`pilot`),
KEY `sector` (`sector`),
KEY `hull` (`hull`),
KEY `game_2` (`game`,`pilot`,`sector`,`hull`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=8 ;
The explain:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE p ref id,game_id_lastmove game_id_lastmove 1 const 7 Using where; Using filesort
1 SIMPLE s ref game,pilot,sector... game_2 6 const,fightclub_alpha.p.id,const 1 Using where; Using index
edit: I cut some of the unnecessary pieces out of my queries/table structure.
Anybody have any ideas?
