distinct和group by 的效率比较? 不是区别哈,是效率,说说为什么distinct或者group by效率就高啊,不是很明白。。。。。。。。
分享到: ------解决方案-------------------- distinct 和 group by 是不同的机制,分别使用在不同的场景
所以不能做效率对比
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