从mysql删除数据的最快方法

问题描述

我正在这样做:

delete from calibration_2009 where rowid in
(SELECT rowid FROM `qcvalues`.`batchinfo_2009` where reporttime like "%2010%");

我需要删除大约 25 万行.

i need to have about 250k rows deleted.

为什么需要这么长时间?有没有更快的方法来做到这一点?

why does it take such a long time? is there a quicker way to do this?

推荐答案

DELETE  c
FROM    `qcvalues`.`batchinfo_2009` b
JOIN    calibration_2009 c
ON      c.rowid = b.rowid
WHERE   b.reporttime LIKE '%2010%';

您应该在 calibration_2009 (rowid) 上有一个索引，以便快速工作.

You should have an index on calibration_2009 (rowid) for this to work fast.

我认为它是一个 PRIMARY KEY 无论如何，但你最好检查一下.

I assume it's a PRIMARY KEY anyway, but you better check.

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