What is the impact of isolation levels on performance?

Can you explain what isolation levels are in databases?

Isolation levels define how transaction integrity is visible to other transactions. They control the visibility of changes made by one transaction to others.

What are the different types of isolation levels?

The main isolation levels are Read Uncommitted, Read Committed, Repeatable Read, and Serializable. Each has different trade-offs.

How do these isolation levels affect performance?

Higher isolation levels like Serializable can lead to more locking and blocking, which may decrease performance. Lower levels can improve performance but may risk data anomalies.

Can you give an example of when to use a specific isolation level?

Use Read Committed for most applications to balance performance and data integrity. Serializable is best for critical transactions where accuracy is paramount.