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mysql千万级的count统计对比_MySQL

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Jun 01, 2016 pm 01:31 PM

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mysql千万级的count统计对比

数据库：mysql 5.5

数据量：45199077 条

sql语句：

[sql] select count(1) from tbresult;  select count(id) from tbresult;

查询时间对比图：

mysql千万级的count统计对比_MySQL

总结：在统计查询的时候尽量使用count(id)，不要使用count(*)这样的；特别是数据量特别大的时候。

下面是重启后的对比图

mysql千万级的count统计对比_MySQL

重启mysql并把sql语句换位置后的结果：

mysql千万级的count统计对比_MySQL

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