Home > Database > Mysql Tutorial > mysql优化之路----hash索引优化

mysql优化之路----hash索引优化

WBOY
Release: 2016-06-07 16:28:35
Original
1169 people have browsed it

创建表 CREATE TABLE `t1` (`id` int(11) NOT NULL AUTO_INCREMENT,`msg` varchar(20) NOT NULL DEFAULT '',`crcmsg` int(15) NOT NULL DEFAULT '0',PRIMARY KEY (`id`)) ENGINE=MyISAM AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 //插入数据 insert into t1 (m

创建表

CREATE TABLE `t1` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`msg` varchar(20) NOT NULL DEFAULT '',
`crcmsg` int(15) NOT NULL DEFAULT '0',
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=3 DEFAULT CHARSET=utf8

Copy after login

//插入数据

insert into t1 (msg) values('www.baidu.com'),('www.sina.com');

Copy after login

分别给msg, crcmsg 字段添加索引

alter table t1 add index msg(msg(5));

update t1 set crcmsg=crc32(msg);

Copy after login

alter table t1 add index crcmsg(crcmsg);

Copy after login

开始做测试

最后数据表结构

根据key_len的长度的大小从而给数据库查询提高速度。

自己做的小测试,希望能够给您带来收获,祝您工作愉快。

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template