Have you applied the Repeatable Read transaction isolation level in your projects?

The Repeatable Read transaction isolation level guarantees that within a single transaction, repeated reads of the same data will not change, preventing non-repeatable reads. In my Java projects using databases like PostgreSQL or MySQL, I have applied this isolation level to ensure data consistency during complex operations where it is important that data does not change throughout the transaction.

For example, when processing banking operations that require reading the account balance multiple times within a single transaction to avoid errors due to concurrent modifications. In Spring, you can set the isolation level using the @Transactional annotation:

@Transactional(isolation = Isolation.REPEATABLE_READ)
public void processTransaction() {
    // business logic
}

This isolation level helps prevent issues with non-repeatable reads but may lead to locking and reduced concurrency, so it should be used consciously.