<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[Better_YZQ的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/yangmolulu</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; yangmolulu]]></copyright><item><title><![CDATA[分布式事务]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/135420072</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/135420072</guid><author>yangmolulu</author><pubDate>Sat, 06 Jan 2024 00:01:15 +0800</pubDate><description><![CDATA[分布式事务]]></description><category></category></item><item><title><![CDATA[java 日期时区转换类]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131938481</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131938481</guid><author>yangmolulu</author><pubDate>Wed, 26 Jul 2023 14:27:57 +0800</pubDate><description><![CDATA[【代码】java 日期时区转换类。]]></description><category></category></item><item><title><![CDATA[24 | MySQL是怎么保证主备一致的？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131650022</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131650022</guid><author>yangmolulu</author><pubDate>Mon, 10 Jul 2023 23:02:44 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》 https://time.geekbang.org/column/article/76446。]]></description><category></category></item><item><title><![CDATA[23 | MySQL是怎么保证数据不丢的？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131625480</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131625480</guid><author>yangmolulu</author><pubDate>Sun, 09 Jul 2023 17:55:28 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[21 | 为什么我只改一行的语句，锁这么多？ MySQL 加锁规则和实战分析]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131587285</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131587285</guid><author>yangmolulu</author><pubDate>Thu, 06 Jul 2023 23:32:32 +0800</pubDate><description><![CDATA[可重复读隔离级别遵守两阶段锁协议，所有加锁的资源，都是在事务提交或者回滚的时候才释放的。在最后的案例中，知道 next-key lock 实际上是由间隙锁加行锁实现的。如果切换到读提交隔离级别 (read-committed) 的话，就只剩下行锁的部分。其实读提交隔离级别在外键场景下还是有间隙锁，在读提交隔离级别语句执行过程中加上的行锁，在语句执行完成后，就要把“不满足条件的行”上的行锁直接释放了，不需要等到事务提交。]]></description><category></category></item><item><title><![CDATA[19 | 为什么我只查一行的语句，也执行这么慢？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131585736</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131585736</guid><author>yangmolulu</author><pubDate>Thu, 06 Jul 2023 21:38:01 +0800</pubDate><description><![CDATA[以下内容出自 《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[18 | 为什么这些SQL语句逻辑相同，性能却差异巨大？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131503854</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131503854</guid><author>yangmolulu</author><pubDate>Sun, 02 Jul 2023 18:44:46 +0800</pubDate><description><![CDATA[在这个例子里，放弃了树搜索功能，优化器可以选择遍历主键索引，也可以选择遍历索引 t_modified，优化器对比索引大小后发现，索引 t_modified 更小，遍历这个索引比遍历主键索引来得更快。交易编号 tradeid 这个字段上，本来就有索引，但是 explain 的结果却显示，这条语句需要走全表扫描。这是因为，tradeid 的字段类型是 varchar(32)，而输入的参数却是整型，所以需要做类型转换。MySQL 中，字符串和数字做比较的话，是将字符串转换成数字。上面的语句实际上相当于。]]></description><category></category></item><item><title><![CDATA[16 | “order by”是怎么工作的？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131503628</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131503628</guid><author>yangmolulu</author><pubDate>Sun, 02 Jul 2023 18:20:13 +0800</pubDate><description><![CDATA[MySQL 会给每个线程分配一块内存用于排序，称为 sort_buffer。排序时可能在内存中完成，也可能需要使用外部排序，这取决于排序所需的内存和参数 sort_buffer_size。sort_buffer_size，就是 MySQL 为排序开辟的内存（sort_buffer）的大小。如果要排序的数据量小于 sort_buffer_size，排序就在内存中完成。但如果排序数据量太大，内存放不下，则不得不利用磁盘临时文件辅助排序。]]></description><category></category></item><item><title><![CDATA[14 | count(*)这么慢，我该怎么办？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131499639</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131499639</guid><author>yangmolulu</author><pubDate>Sun, 02 Jul 2023 12:17:50 +0800</pubDate><description><![CDATA[一下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[13 | 为什么表数据删掉一半，表文件大小不变？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131491234</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131491234</guid><author>yangmolulu</author><pubDate>Sat, 01 Jul 2023 15:36:37 +0800</pubDate><description><![CDATA[以下内容出自 《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[12 | 为什么我的MySQL会“抖”一下？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131465725</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131465725</guid><author>yangmolulu</author><pubDate>Thu, 29 Jun 2023 22:33:11 +0800</pubDate><description><![CDATA[一下内容出自 《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[11 | 怎么给字符串字段加索引？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131447349</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131447349</guid><author>yangmolulu</author><pubDate>Thu, 29 Jun 2023 00:20:14 +0800</pubDate><description><![CDATA[以下出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[10 | MySQL为什么有时候会选错索引？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131447016</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131447016</guid><author>yangmolulu</author><pubDate>Wed, 28 Jun 2023 23:37:18 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[09 | 普通索引和唯一索引，应该怎么选择？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131427406</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131427406</guid><author>yangmolulu</author><pubDate>Tue, 27 Jun 2023 23:58:23 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[08 | 事务到底是隔离的还是不隔离的？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131427000</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131427000</guid><author>yangmolulu</author><pubDate>Tue, 27 Jun 2023 23:15:22 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[PHP 基础知识]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131408969</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131408969</guid><author>yangmolulu</author><pubDate>Mon, 26 Jun 2023 23:30:00 +0800</pubDate><description><![CDATA[目录PHP基础	2PHP代码标记	2PHP注释	2PHP语句分隔符	2PHP变量	3常量	3数据类型	4流程控制	6文件	7函数	9闭包	11常用系统函数	12错误处理	13错误显示设置	15字符串类型	17字符串相关函数	19数组	21遍历数组	22数组的相关函数	25PHP基础PHP是一种运行在服务器端的脚本语言，可以嵌入到HTML中。 PHP代码标记在PHP历史中，可以使用多种标记来区分P...]]></description><category></category></item><item><title><![CDATA[06、07 | 全局锁、表锁和行锁]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131407178</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131407178</guid><author>yangmolulu</author><pubDate>Mon, 26 Jun 2023 23:15:46 +0800</pubDate><description><![CDATA[以下内容出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[MySQL EXPLAIN]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131387394</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131387394</guid><author>yangmolulu</author><pubDate>Sun, 25 Jun 2023 22:40:43 +0800</pubDate><description><![CDATA[EXPLAIN命令是查看查询优化器如何决定执行查询的主要方法。]]></description><category></category></item><item><title><![CDATA[04 | 05 深入浅出索引]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131386972</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131386972</guid><author>yangmolulu</author><pubDate>Sun, 25 Jun 2023 22:05:13 +0800</pubDate><description><![CDATA[以下出自《MySQL 实战 45 讲》]]></description><category></category></item><item><title><![CDATA[03 | 事务隔离：为什么你改了我还看不见？]]></title><link>https://blog.youkuaiyun.com/yangmolulu/article/details/131385617</link><guid>https://blog.youkuaiyun.com/yangmolulu/article/details/131385617</guid><author>yangmolulu</author><pubDate>Sun, 25 Jun 2023 20:40:06 +0800</pubDate><description><![CDATA[以下出自 《MySQL 实战 45 讲》]]></description><category></category></item></channel></rss>