我有一个覆盖lat/lon字段的索引,当我只选择lat/lon时它很快(毫秒级响应)。但是,当我选择表中的其他字段时,速度变得非常慢,需要5-8秒。
我使用myisam来利用全文搜索。其他索引表现良好(例如,从Listing中选择* where slug ='xxxxx')。
如何优化查询、表或索引以加快速度?
我的模式是:
CREATE TABLE `Listing` (
`id` int(10) unsigned NOT NULL auto_increment,
`name` varchar(125) collate utf8_unicode_ci default NULL,
`phone` varchar(18) collate utf8_unicode_ci default NULL,
`fax` varchar(18) collate utf8_unicode_ci default NULL,
`email` varchar(55) collate utf8_unicode_ci default NULL,
`photourl` varchar(55) collate utf8_unicode_ci default NULL,
`thumburl` varchar(5) collate utf8_unicode_ci default NULL,
`website` varchar(85) collate utf8_unicode_ci default NULL,
`categoryid` int(10) unsigned default NULL,
`addressid` int(10) unsigned default NULL,
`deleted` tinyint(1) default NULL,
`status` int(10) unsigned default '2',
`parentid` int(10) unsigned default NULL,
`organizationid` int(10) unsigned default NULL,
`listinginfoid` int(10) unsigned default NULL,
`createuserid` int(10) unsigned default NULL,
`createdate` datetime default NULL,
`lasteditdate` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
`lastedituserid` int(10) unsigned default NULL,
`slug` varchar(155) collate utf8_unicode_ci default NULL,
`aclid` int(10) unsigned default NULL,
`alt_address` varchar(80) collate utf8_unicode_ci default NULL,
`alt_website` varchar(80) collate utf8_unicode_ci default NULL,
`lat` decimal(10,7) default NULL,
`lon` decimal(10,7) default NULL,
`city` varchar(80) collate utf8_unicode_ci default NULL,
`state` varchar(10) collate utf8_unicode_ci default NULL,
PRIMARY KEY (`id`),
KEY `idx_fetch` USING BTREE (`slug`,`deleted`),
KEY `idx_loc` (`state`,`city`),
KEY `idx_org` (`organizationid`,`status`,`deleted`),
KEY `idx_geo_latlon` USING BTREE (`status`,`lat`,`lon`),
FULLTEXT KEY `idx_name` (`name`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci ROW_FORMAT=DYNAMIC;
我需要查询:
SELECT Listing.name, Listing.categoryid, Listing.lat, Listing.lon
, 3956 * 2 * ASIN(SQRT( POWER(SIN((Listing.lat - 37.369195) * pi()/180 / 2), 2) + COS(Listing.lat * pi()/180) * COS(37.369195 * pi()/180) * POWER(SIN((Listing.lon --122.036849) * pi()/180 / 2), 2) )) rawgeosearchdistance
FROM Listing
WHERE
Listing.status = '2'
AND ( Listing.lon between -122.10913433498 and -121.96456366502 )
AND ( Listing.lat between 37.296909665016 and 37.441480334984)
HAVING rawgeosearchdistance < 5
ORDER BY rawgeosearchdistance ASC;
没有geosearch的执行计划:
+----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len |ref | rows | Extra | +----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-------------+ | 1 | SIMPLE | Listing | range | idx_geo_latlon | idx_geo_latlon | 19 | NULL | 453 | 使用where条件 | +----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-------------+
有geosearch的执行计划:
+----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-----------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-----------------------------+ | 1 | SIMPLE | Listing | range | idx_geo_latlon | idx_geo_latlon | 19 | NULL | 453 | 使用where条件; 使用文件排序 | +----+-------------+------------+-------+-----------------+-----------------+---------+------+------+-----------------------------+
这是使用覆盖索引的执行计划。正确顺序的列有很大的区别:
+----+-------------+--------+-------+---------------+---------------+---------+------+--------+------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------+-------+---------------+---------------+---------+------+--------+------------------------------------------+ | 1 | SIMPLE | Listing | range | idx_geo_cover | idx_geo_cover | 12 | NULL | 453 | 使用where条件; 使用索引; 使用文件排序 | +----+-------------+--------+-------+---------------+---------------+---------+------+--------+------------------------------------------+
谢谢!