table 有两个相同最大长度的字段 a,b
select a,b from table where a is null;
select a,b from table where b is not null;
这两个在性能上 是一样的吗
This topic created in 1891 days ago, the information mentioned may be changed or developed.
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rainymoring1995Sep 1, 2021
1
看一下执行计划就知道了
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is not null 会索引失效
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