https://blog.youkuaiyun.com/a415171995zh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/a415171995/article/details/141813823https://blog.youkuaiyun.com/a415171995/article/details/141813823a415171995Mon, 02 Sep 2024 21:27:24 +0800https://blog.youkuaiyun.com/a415171995/article/details/141783608https://blog.youkuaiyun.com/a415171995/article/details/141783608a415171995Sun, 01 Sep 2024 14:01:31 +0800https://blog.youkuaiyun.com/a415171995/article/details/141752718https://blog.youkuaiyun.com/a415171995/article/details/141752718a415171995Sat, 31 Aug 2024 19:54:40 +0800https://blog.youkuaiyun.com/a415171995/article/details/141729823https://blog.youkuaiyun.com/a415171995/article/details/141729823a415171995Sat, 31 Aug 2024 00:35:52 +0800https://blog.youkuaiyun.com/a415171995/article/details/141439640https://blog.youkuaiyun.com/a415171995/article/details/141439640a415171995Thu, 22 Aug 2024 22:36:30 +0800https://blog.youkuaiyun.com/a415171995/article/details/141438870https://blog.youkuaiyun.com/a415171995/article/details/141438870a415171995Thu, 22 Aug 2024 22:08:46 +0800https://blog.youkuaiyun.com/a415171995/article/details/133742891https://blog.youkuaiyun.com/a415171995/article/details/133742891a415171995Tue, 10 Oct 2023 11:17:14 +0800https://blog.youkuaiyun.com/a415171995/article/details/133742876https://blog.youkuaiyun.com/a415171995/article/details/133742876a415171995Tue, 10 Oct 2023 11:16:35 +0800https://blog.youkuaiyun.com/a415171995/article/details/133636556https://blog.youkuaiyun.com/a415171995/article/details/133636556a415171995Sat, 07 Oct 2023 12:23:15 +0800 内存 部分数据(10%)，再和驱动表 多条(100)的匹配(减少 磁盘 加载驱动表的代价)。连接查询，申请一块固定大小的内存，若干(1000条)驱动表的数据。每遍历一次被驱动表。把之前的内存清理掉，从FILE -> 内存 部分数据(10%)，再和驱动表做一次匹配。]]>https://blog.youkuaiyun.com/a415171995/article/details/133636552https://blog.youkuaiyun.com/a415171995/article/details/133636552a415171995Sat, 07 Oct 2023 12:22:30 +0800 MySQL系统库。]]>https://blog.youkuaiyun.com/a415171995/article/details/132844018https://blog.youkuaiyun.com/a415171995/article/details/132844018a415171995Wed, 13 Sep 2023 01:05:29 +0800 默认看不见索引)当前会话设置(测试的时候)：set session optimizer_switch='use_invisible_indexes=on';password_history | 0 (0:可以修改相同密码;]]>https://blog.youkuaiyun.com/a415171995/article/details/132797992https://blog.youkuaiyun.com/a415171995/article/details/132797992a415171995Mon, 11 Sep 2023 00:44:33 +0800100),B+tree定位到这条数据位置，获取X锁，该条记录彻底删除，插入一条心记录(100),100位置获取X锁。- delete：B+tree 读这条记录 取一下这条记录的 X锁 delete记录。1、要去该的记录A，（1024），所在的存储空间，修改前后没有发生变化，获取X锁。- 事务：某条记录 加 共享锁的时候，先在表的级别 一个IS锁。- 定位删除的记录 B+树的过程，获取X锁定读。- X排他锁 X-X不兼容 X-S不兼容。事务1->读取一条记录，X锁。]]>https://blog.youkuaiyun.com/a415171995/article/details/132795282https://blog.youkuaiyun.com/a415171995/article/details/132795282a415171995Sun, 10 Sep 2023 21:14:47 +0800不可重复读>幻读。]]>https://blog.youkuaiyun.com/a415171995/article/details/132768673https://blog.youkuaiyun.com/a415171995/article/details/132768673a415171995Fri, 08 Sep 2023 22:40:54 +0800覆盖索引 （不是索引）这不是一种索引，指的这种场景：“查询语句所需的列，被包含在查询条件中的索引列里面”]]>