Read committed Snapshot VS Snapshot Isolation Level

Question

Could some one please help me understand when to use SNAPSHOT isolation level over READ COMMITTED SNAPSHOT in SQL Server?

I understand that in most cases READ COMMITTED SNAPSHOT works, but not sure when go for SNAPSHOT isolation.

Thanks

Answer 1

READ COMMITTED SNAPSHOT does optimistic reads and pessimistic writes. In contrast, SNAPSHOT does optimistic reads and optimistic writes.

Microsoft recommends READ COMMITTED SNAPSHOT for most apps that need row versioning.

Read this excellent Microsoft article: Choosing Row Versioning-based Isolation Levels. It explains the benefits and costs of both isolation levels.

And here's a more thorough one: http://msdn.microsoft.com/en-us/library/ms345124(SQL.90).aspx