设计一:
设计一增加了自增 ID,数据量占用磁盘空间会稍大些,索引战胜小些;
100 万条数据磁盘占用:45.00 MB 索引占用:49.70 MB
设计二:
没有自增 ID,数据量占用磁盘空间稍小些,但索引占用会大些;
100 万条数据磁盘占用:33.00 MB 索引占用:73.10 MB
这个表以后可能会有好几 G 的大小,如果是你,你们会选择那种?
查询速度测试差异不大;
设计一
CREATE TABLE `follow` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`uid` bigint(20) unsigned NOT NULL DEFAULT '0',
`aid` bigint(20) unsigned NOT NULL DEFAULT '0',
`cid` tinyint(3) unsigned NOT NULL DEFAULT '0',
`time` int(10) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`id`),
KEY `uid` (`uid`,`time`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
设计二
CREATE TABLE `follow` (
`uid` bigint(20) unsigned NOT NULL DEFAULT '0',
`aid` bigint(20) unsigned NOT NULL DEFAULT '0',
`cid` tinyint(3) unsigned NOT NULL DEFAULT '0',
`time` int(10) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`uid`,`aid`),
KEY `uid` (`uid`,`time`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
设计一增加了自增 ID,数据量占用磁盘空间会稍大些,索引战胜小些;
100 万条数据磁盘占用:45.00 MB 索引占用:49.70 MB
设计二:
没有自增 ID,数据量占用磁盘空间稍小些,但索引占用会大些;
100 万条数据磁盘占用:33.00 MB 索引占用:73.10 MB
这个表以后可能会有好几 G 的大小,如果是你,你们会选择那种?
查询速度测试差异不大;
设计一
CREATE TABLE `follow` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`uid` bigint(20) unsigned NOT NULL DEFAULT '0',
`aid` bigint(20) unsigned NOT NULL DEFAULT '0',
`cid` tinyint(3) unsigned NOT NULL DEFAULT '0',
`time` int(10) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`id`),
KEY `uid` (`uid`,`time`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
设计二
CREATE TABLE `follow` (
`uid` bigint(20) unsigned NOT NULL DEFAULT '0',
`aid` bigint(20) unsigned NOT NULL DEFAULT '0',
`cid` tinyint(3) unsigned NOT NULL DEFAULT '0',
`time` int(10) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`uid`,`aid`),
KEY `uid` (`uid`,`time`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;