SELECT sum(val) as all,`type` FROM `v4_finance_history` WHERE `name` = 'c' AND `edit_time` BETWEEN '1469808000' AND '1469894399' GROUP BY type
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mysql 查询优化中遇到的疑惑
mysql加索引不一定比加索引更快,但在已使用了索引情况下查询rows 条目更少的情况下,sql语句既然更慢? 图一使用索引 查询时间0.2秒 图二没使用索引0.1秒 sql语句 SELECT sum(val) as all,`type` FROM `v4_finance_history` WHERE `name` = 'c' AND `edit_time` BETWEEN '1469808000' AND '1469894399' GROUP BY type