https://blog.youkuaiyun.com/belongtocodezh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/belongtocode/article/details/168448699https://blog.youkuaiyun.com/belongtocode/article/details/168448699belongtocodeSat, 24 Oct 2026 13:16:53 +0800https://blog.youkuaiyun.com/belongtocode/article/details/161466792https://blog.youkuaiyun.com/belongtocode/article/details/161466792belongtocodeFri, 26 Jun 2026 10:53:27 +0800https://blog.youkuaiyun.com/belongtocode/article/details/161462646https://blog.youkuaiyun.com/belongtocode/article/details/161462646belongtocodeWed, 17 Jun 2026 16:21:40 +0800https://blog.youkuaiyun.com/belongtocode/article/details/161400430https://blog.youkuaiyun.com/belongtocode/article/details/161400430belongtocodeMon, 01 Jun 2026 22:41:52 +0800https://blog.youkuaiyun.com/belongtocode/article/details/158968848https://blog.youkuaiyun.com/belongtocode/article/details/158968848belongtocodeSun, 24 May 2026 21:25:28 +0800https://blog.youkuaiyun.com/belongtocode/article/details/161258919https://blog.youkuaiyun.com/belongtocode/article/details/161258919belongtocodeThu, 21 May 2026 17:30:58 +0800https://blog.youkuaiyun.com/belongtocode/article/details/158661168https://blog.youkuaiyun.com/belongtocode/article/details/158661168belongtocodeWed, 04 Mar 2026 20:03:30 +0800https://blog.youkuaiyun.com/belongtocode/article/details/156066158https://blog.youkuaiyun.com/belongtocode/article/details/156066158belongtocodeFri, 19 Dec 2025 09:24:48 +0800https://blog.youkuaiyun.com/belongtocode/article/details/150640873https://blog.youkuaiyun.com/belongtocode/article/details/150640873belongtocodeSun, 24 Aug 2025 23:31:46 +0800https://blog.youkuaiyun.com/belongtocode/article/details/150059664https://blog.youkuaiyun.com/belongtocode/article/details/150059664belongtocodeFri, 08 Aug 2025 11:24:10 +0800https://blog.youkuaiyun.com/belongtocode/article/details/149257965https://blog.youkuaiyun.com/belongtocode/article/details/149257965belongtocodeSun, 03 Aug 2025 13:24:58 +0800https://blog.youkuaiyun.com/belongtocode/article/details/149258244https://blog.youkuaiyun.com/belongtocode/article/details/149258244belongtocodeSun, 27 Jul 2025 19:17:26 +0800https://blog.youkuaiyun.com/belongtocode/article/details/147622286https://blog.youkuaiyun.com/belongtocode/article/details/147622286belongtocodeTue, 06 May 2025 20:39:23 +0800https://blog.youkuaiyun.com/belongtocode/article/details/147194828https://blog.youkuaiyun.com/belongtocode/article/details/147194828belongtocodeSun, 13 Apr 2025 20:43:06 +0800https://blog.youkuaiyun.com/belongtocode/article/details/146769232https://blog.youkuaiyun.com/belongtocode/article/details/146769232belongtocodeSun, 30 Mar 2025 17:22:28 +0800 全表扫描成本时，就会出现使用索引反而更慢的情况。)上，当我给查询语句加上索引条件时，查询速度反而变慢了。这个过程中，"回表"操作是非常耗时的，特别是当需要回表1500000次时。最近在进行项目数据库优化时，我遇到了一个很有趣的现象。字段建立了索引，为什么带条件的查询反而更慢？]]>https://blog.youkuaiyun.com/belongtocode/article/details/146425343https://blog.youkuaiyun.com/belongtocode/article/details/146425343belongtocodeSun, 23 Mar 2025 21:53:10 +0800https://blog.youkuaiyun.com/belongtocode/article/details/146262603https://blog.youkuaiyun.com/belongtocode/article/details/146262603belongtocodeSun, 16 Mar 2025 16:44:20 +0800https://blog.youkuaiyun.com/belongtocode/article/details/143218211https://blog.youkuaiyun.com/belongtocode/article/details/143218211belongtocodeThu, 24 Oct 2024 20:13:04 +0800https://blog.youkuaiyun.com/belongtocode/article/details/142437523https://blog.youkuaiyun.com/belongtocode/article/details/142437523belongtocodeSun, 22 Sep 2024 15:13:23 +0800https://blog.youkuaiyun.com/belongtocode/article/details/141404972https://blog.youkuaiyun.com/belongtocode/article/details/141404972belongtocodeTue, 17 Sep 2024 13:01:53 +0800