浅析MySQL事务隔离级别对其性能的影响
浅析MySQL事务隔离级别对其性能的影响MySQL对事务的隔离级别共分为四个级别，分别是：1.READUNCOMMITTED&nbs..
MySQL对事务的隔离级别共分为四个级别，分别是：
1. READ UNCOMMITTED 读未提交
2. READ COMMITTED 读提交
3. REPEATABLE 可重读
4. SERIALIABLE 可串读
MySQL默认工作在级别三下。我们知道事务隔离是为了避免并发操作相互影响而导数据的不一致性。所以为了保证数据的一致性，就引入了事务隔离的功能。以上四个级别的对数据的一致性保护是逐步提高的。级别4对事务的隔离效果最好，但是性能最差，一般不再生产环境中使用。
下面通过实例来检验不同级别下MySQL性能收到的影响。我的实验环境是：Redhat5.8+MySQL5.5
首先我们这里启用两个session：
1、验证级别一的特性
我们在session A上进行的操作为：
这就设串行化隔离的效果，也是为什么串行化隔离并发能力差的原因。
实验测试用的数据我已经上传。
本文出自 “张志亮” 博客，转载请与作者联系！
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