MySQL Forums
Forum List  »  Optimizer & Parser

Close to a million records & query too slow
Posted by: sabelo simelane
Date: March 03, 2010 01:49PM

Could you please assist; in one of my tables I have close to a million records and still growing. The query is too slow as I am doing a 3 table join. Here are the details:

DROP TABLE IF EXISTS `charts`.`artist`;
CREATE TABLE `charts`.`artist` (
`artistId` smallint(5) unsigned NOT NULL,
`name` varchar(150) NOT NULL,
`gender` varchar(10) DEFAULT NULL,
`isLocal` tinyint(1) unsigned DEFAULT NULL,
`picture` mediumblob NOT NULL,
PRIMARY KEY (`artistId`),
KEY `isLocal` (`isLocal`,`artistId`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

DROP TABLE IF EXISTS `charts`.`play`;
CREATE TABLE `charts`.`play` (
`playId` mediumint(8) unsigned NOT NULL,
`dateAndTime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`stationId` tinyint(3) unsigned NOT NULL,
`songId` smallint(5) unsigned NOT NULL,
PRIMARY KEY (`playId`),
UNIQUE KEY `dateAndTime` (`dateAndTime`,`stationId`,`songId`),
KEY `FK_stationId2` (`stationId`),
KEY `FK_songId` (`songId`),
CONSTRAINT `FK_songId` FOREIGN KEY (`songId`) REFERENCES `song` (`songId`) ON UPDATE NO ACTION,
CONSTRAINT `FK_stationId2` FOREIGN KEY (`stationId`) REFERENCES `station` (`stationId`) ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

DROP TABLE IF EXISTS `charts`.`song`;
CREATE TABLE `charts`.`song` (
`songId` smallint(5) unsigned NOT NULL,
`title` varchar(150) NOT NULL,
`artistId` smallint(5) unsigned NOT NULL,
`yesComId` mediumint(8) unsigned NOT NULL,
`coverUrl` varchar(150) DEFAULT NULL,
PRIMARY KEY (`songId`),
UNIQUE KEY `yescomId` (`yesComId`),
KEY `FK_artistId` (`artistId`),
CONSTRAINT `FK_artistId` FOREIGN KEY (`artistId`) REFERENCES `artist` (`artistId`) ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

And here's the monster query:

select song.songId, song.title, artist.name, play.dateAndTime, count(play.playId) as plays, song.coverUrl from charts.play play, charts.artist artist, charts.song song where (play.songId = song.songId) and (song.artistId = artist.artistId) and (date(play.dateAndTime) >= '2010-02-10') and (date(play.dateAndTime) <= '2010-02-11') and (artist.isLocal is true) group by song.songId order by plays desc;

Here's the explanation of the query:

table | type | possible keys | key | key_len | ref | rows | Extra
---------------------------------------------------------------------
artist|ALL | PRIMARY | null| null | null | 7393 | Using filesort..
----------------------------------------------------------------------
song | ref |PRIMARY,FK_ar..|artistId| 2 |artistId | 1 |
-----------------------------------------------------------------------
play | ref | FK_SongId |songId | 2 |songId | 17 | Using where

Options: ReplyQuote


Subject
Views
Written By
Posted
Close to a million records & query too slow
6120
March 03, 2010 01:49PM


Sorry, you can't reply to this topic. It has been closed.
This forum is currently read only. You can not log in or make any changes. This is a temporary situation.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.