[MySQL] Innodb's MVCC working principle of MySQL

【Series Articles】

1. [MySQL] MySQL transaction
2. [MySQL] MySQL lock mechanism
3. [MySQL] MySQL Index
4. [MySQL] MySQL log

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1. What is MVCC

MVCC, The full name Multi-Version Concurrency Control, that is, multi-version concurrency control. MVCC is a method of concurrency control, generally in a database management system, to achieve concurrent access to the database, and to achieve transactional memory in a programming language.

The implementation of MVCC in MySQL InnoDB is mainly to improve the concurrency performance of the database, and to deal with read-write conflicts in a better way, so that even when there is a read-write conflict, it can be read without locking and non-blocking concurrent reads.

1.1  What are current read and snapshot read?

Before learning MVCC multi-version concurrency control, we must first understand, what is the 当前读sum under MySQL InnoDB 快照读?

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