In what cases would you raise the isolation level? When to use Serializable?

Transaction isolation levels are increased when it is necessary to guarantee data integrity and avoid anomalies such as phantom reads, non-repeatable reads, or dirty reads. The Serializable level is the strictest, providing full transaction isolation as if they were executed sequentially.

Using Serializable is advisable in cases where absolute data consistency is crucial, such as in financial transactions, resource booking, or other critical business processes where errors due to concurrent access are unacceptable. However, this level reduces concurrency and can lead to locking, so it is only used where it is truly necessary.