The IN() operator is not a performance problem in MySQL but the equivalent OR is
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http://forums.devshed.com/mysql-help-4/inefficiency-of-in-clause-631109.html 阅读全文
posted @ 2009-08-27 21:57 cy163 阅读(180) 评论(0) 推荐(0)
posted @ 2009-08-27 21:57 cy163 阅读(180) 评论(0) 推荐(0)