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This article mainly introduces the differences between read committed and repeatable read locking, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to know about it.

The DML statement will lock records that cannot be locked by dml for equivalent conditions, and next key locks will be used for range or valueless dml and cannot be inserted again.

Select statements are unlocked using mvcc.

For the range select. Lock in shared mode, the former has a shared lock, and other sessions can be inserted but cannot be updated, while the latter shares the next key, which cannot be updated or inserted.

For the range select. For update, the former has a shared lock, and other sessions can be inserted but cannot be updated, while the latter shares the next key, which cannot be updated or inserted. (select... For update always puts a shared lock on the selected records, and the description here is only for records that do not exist)

So what we need to do is to optimize the logic, and most scenarios read committed will satisfy the conditions.

Thank you for reading this article carefully. I hope the article "what is the difference between read committed and repeatable read locking" shared by the editor will be helpful to you. At the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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