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Delete删除表数据时对性能的影响分析

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Release: 2016-06-07 16:44:29
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当我们用delete删除数据时,因为无法降低高水位,对表做全表扫描时会带来数据库性能问题,而truncate可以大大改善这一状况,下面

用delete删除100W行数据的大表TEST1时,产生了大量的redo(2亿多),另外还有很多一致性读(1953),读取了100多W个数据块,,814次递归调用,可以看到,用delete删除表记录,对数据库的性能消耗是很大的,尤其是当delete大量行的时候

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