Mysql 优化器之派生条件回移Derived Condition Pushdown详解 派生条件回移优化概述 Mysql 8.0.22之后的版本支持派生条件回移(Derived Condition Pushdown)优化。该优化可以减少派生表处理的行数从而提高查询执行的效率。比方说有如下查询： SELECT * FROM (SELECT i, j FROM t1) AS dt WHER