What are some examples of transaction isolation levels?

What are some examples of transaction isolation levels?

Transaction isolation levels define how transaction integrity is visible to other transactions. Common examples include Read Uncommitted, Read Committed, Repeatable Read, and Serializable.

Can you explain Read Committed with an example?

Sure! In Read Committed, a transaction can only read data that has been committed. For example, if Transaction A is updating a record, Transaction B cannot read that record until Transaction A is complete.

What about Serializable? How does it differ?

Serializable is the strictest isolation level. It ensures complete isolation from other transactions, meaning no other transactions can read or write data until the current transaction is finished. This prevents phenomena like phantom reads.

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 balance isolation with performance needs.