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Sep 10, 2021
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Update InnoDB对MVCC的实现.md #1378

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Update InnoDB对MVCC的实现.md
mo-nian Sep 9, 2021
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Merge pull request #1 from mo-nian/mo-nian-patch-1
mo-nian Sep 9, 2021
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4 changes: 2 additions & 2 deletions docs/database/mysql/InnoDB对MVCC的实现.md
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Expand Up @@ -149,7 +149,7 @@

- 此时最新记录的 `DB_TRX_ID` 为 102，m_up_limit_id <= 102 < m_low_limit_id，所以要在 `m_ids` 列表中查找，发现 `DB_TRX_ID` 存在列表中，那么这个记录不可见

- 根据 `DB_ROLL_PTR` 找到 `undo log` 中的上一版本记录，上一条记录的 `DB_TRX_ID` 为 101，满足 102 < m_up_limit_id，记录可见，所以在 `T6` 时间点查询到数据为 `name = 李四`，与时间 T4 查询到的结果不一致，不可重复读！
- 根据 `DB_ROLL_PTR` 找到 `undo log` 中的上一版本记录，上一条记录的 `DB_TRX_ID` 为 101，满足 101 < m_up_limit_id，记录可见，所以在 `T6` 时间点查询到数据为 `name = 李四`，与时间 T4 查询到的结果不一致，不可重复读！

3. **`时间线来到 T9 ，数据的版本链为`：**

Expand Down Expand Up @@ -212,4 +212,4 @@
- **《MySQL 技术内幕 InnoDB 存储引擎第 2 版》**

- [Innodb 中的事务隔离级别和锁的关系](https://tech.meituan.com/2014/08/20/innodb-lock.html)
- [MySQL 事务与 MVCC 如何实现的隔离级别](https://blog.csdn.net/qq_35190492/article/details/109044141)
- [MySQL 事务与 MVCC 如何实现的隔离级别](https://blog.csdn.net/qq_35190492/article/details/109044141)