MYSQL - 按索引列排序

Question

我的这张表有500,000行

CREATE TABLE IF NOT EXISTS `listings` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `source_id` int(10) unsigned NOT NULL,
  `cat_id` mediumint(5) NOT NULL,
  `title` mediumtext NOT NULL,
  `views_point` int(10) unsigned NOT NULL DEFAULT '0',
  `publishedon_hourly` int(10) unsigned NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  KEY `views_point` (`views_point`),
  KEY `listings` (`publishedon_hourly`,`published`,`cat_id`,`source_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 ROW_FORMAT=FIXED AUTO_INCREMENT=365513 ;

我想像这样进行查询

SELECT *
FROM listings
WHERE (
`publishedon_hourly`
BETWEEN UNIX_TIMESTAMP( '2015-09-5 12:00:00' )AND UNIX_TIMESTAMP( '2015-10-5 12:00:00' ) ) AND ( published =1 ) AND cat_id
IN ( 1, 2, 3, 4, 5 )
ORDER BY views_point DESC
LIMIT 10 

这个查询一段时间工作正如我想要的那样（see this），但经过一些意见，这是不正确的，我在网上搜索解决方案，我找到了

这：http://venublog.com/2007/11/29/mysql-how-to-avoid-filesort/ 而这：http://www.getsymphony.com/discuss/issues/view/657/ 然后我在views_point添加索引然后尝试了这个查询

select t1.* 
from  listings t1 
left outer join  listings t2 on (t1.views_point=t2.views_point) 
order by t1.views_point 
limit 10

这个解释

但我无法添加此条件

`publishedon_hourly` BETWEEN UNIX_TIMESTAMP( '2015-09-5 12:00:00' ) AND UNIX_TIMESTAMP( '2015-09-5 12:00:00' ) ) AND ( published =1 ) AND cat_id = 5

我不知道，我应该指定哪一个（t1或t2）？

另一方面怎么样呢

SELECT *
FROM listings
WHERE (
`publishedon_hourly` BETWEEN UNIX_TIMESTAMP( '2015-09-5 00:00:00' ) AND UNIX_TIMESTAMP( '2015-09-5 23:00:00' ))
AND (published =1)
and views_point is not null
ORDER BY views_point DESC limit 20

如果任何一个人不好，任何人都可以告诉我大博客如何通过点击获得帖子？

Answer 1

您应该将listings索引拆分为单独的索引。

除此之外，鉴于您按t1排序，几乎可以肯定您应为所有条件指定t1。

编辑： 使用条件为

`t1`.`publishedon_hourly` BETWEEN UNIX_TIMESTAMP( '2015-09-5 12:00:00' ) AND UNIX_TIMESTAMP( '2015-09-5 12:00:00' ) ) AND ( `t1`.`published` = 1 ) AND `t1`.`cat_id` = 5