Oracle Database MySQL 5.6 Developer — Question 13

You have a transaction that queries a table at the beginning of the transaction and performs the same query later.
Which two transaction isolation levels guarantee that you get the same results both times?

Answer options

• A. Repeatable read
• B. Read committed
• C. Read uncommitted
• D. Single user
• E. serializable

Correct answer: A, E

Explanation

The Repeatable Read and Serializable isolation levels both ensure that the results of a query remain consistent throughout the duration of the transaction. Read Committed and Read Uncommitted do not provide this guarantee, as they allow changes made by other transactions to be visible, which can lead to different results on repeated queries.