mysql 优化问题-groupby orderby 对主键分组和排序很慢

[oldtwobill]

explain SELECT `Member`.`imei`, `Member`.`time`, `Member`.`id`, `Member`.`version` FROM `members` AS `Member` inner JOIN
`member_time_orders` AS `MemberTimeOrder` ON (`MemberTimeOrder`.`member_id` = `Member`.`id`) WHERE
`Member`.`time` >= 1394553600 AND `Member`.`time` <= 1397231999 AND `MemberTimeOrder`.`datetime` >= 1394553600 AND
`MemberTimeOrder`.`datetime` <= 1397231999 GROUP BY `Member`.`id` ORDER BY `Member`.`id` DESC LIMIT 20

1 SIMPLE MemberTimeOrder range datetime_channel datetime_channel 4 282802 Using where; Using temporary; Using filesort
1 SIMPLE Member eq_ref PRIMARY,time PRIMARY 4 ebook.MemberTimeOrder.member_id 1 Using where
这个语句要5秒钟 请问要怎么优化 我奇怪的是 我对主键排序分组怎么这么慢 我这个主键是有索引的 我发现我对单表主键分组排序的时候还是很快的 但是对联表主键排序 就很慢 我把 GROUP BY `Member`.`id` ORDER BY `Member`.`id` DESC 去掉就很快

[oldtwobill]

d

[benluobo]

执行 show index from Member 贴出结果

[benluobo]

你可以试试将查询语句中的inner join 改成 straight join