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发布时间:2025-01-22 09:09:36
索引是有序存储的,查询最左或最右就可以查询最小,最大值,这是一种非常快的操作,因为min.max索引前导列,只需要从最左或最右侧
扫描到第一个非NULL值即可。
pg和mysql支持索引列min.max写在一起,会快速定位,而oracle不行,oracle可以拆分成两个标量子查询实现。
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吻的感觉适2025-07-18 23:11
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