What are the different SQL isolation levels and their use cases?

What are the different SQL isolation levels and when should I use them?

SQL isolation levels define how transaction integrity is visible to other transactions. The main levels are Read Uncommitted, Read Committed, Repeatable Read, and Serializable. Each level balances consistency and performance differently.

Can you explain Read Committed and its use case?

Read Committed prevents dirty reads, meaning a transaction can only read committed data. It's commonly used in applications where data consistency is important but some level of concurrency is also needed.

What about Serializable? When is it necessary?

Serializable is the strictest isolation level, ensuring complete isolation from other transactions. It's necessary in scenarios where transactions must be executed in a strict sequence to maintain data integrity, like in financial applications.

Are there any performance trade-offs with higher isolation levels?

Yes, higher isolation levels like Serializable can lead to increased locking and reduced concurrency, which may impact performance. It's essential to choose the right level based on your application's needs.