What are the different database isolation levels and their examples?

Can you explain the different database isolation levels and provide examples?

Sure! The main database isolation levels are Read Uncommitted, Read Committed, Repeatable Read, and Serializable. Would you like examples for each?

Yes, please provide examples for each isolation level.

1. Read Uncommitted: A transaction can read data that is not yet committed. For example, if Transaction A is updating a record, Transaction B can read the uncommitted changes.
2. Read Committed: A transaction can only read committed data. For instance, if Transaction A is updating a record, Transaction B will only see the data after Transaction A commits.
3. Repeatable Read: A transaction can read the same row multiple times and get the same result. If Transaction A reads a record, Transaction B cannot change it until Transaction A is complete.
4. Serializable: This is the strictest level, where transactions are completely isolated from one another. It ensures that transactions are executed in a way that they appear to be serial.

What are the trade-offs of using higher isolation levels?

Higher isolation levels can lead to increased data integrity but may also cause more locking and reduced concurrency, which can impact performance.