MySQL Concurrency: Locking and Transactions for MySQL Developers and DBAs

© Jesper Wisborg Krogh 2021

J. W. KroghMySQL Concurrencyhttps://doi.org/10.1007/978-1-4842-6652-6_12

12. Transaction Isolation Levels

Jesper Wisborg Krogh¹  

(1)

Hornsby, NSW, Australia

 

In the previous chapter, you learned that isolation is an important property of transactions. As it turns out, it is not so straightforward to answer whether two transactions are isolated as the answer depends on what degree of isolation is required. The degree of isolation is defined through the transaction isolation levels.

InnoDB supports the four transaction isolation levels defined by the SQL:1992 standard¹, and they are in descending degree of isolation: SERIALIZABLE, REPEATABLE READ, READ COMMITTED, and READ UNCOMMITTED. The repeatable read transaction isolation ...