Snapshot Isolation in SQL Server 2005

(Vinod Kumar) SQL Server uses isolation levels as a means to give us consistent data across multiple user accesses at the same time. There is generally a tradeoff with the fact that as we get higher up the isolation level the consistency of data is high and more is the reliability. But there is a caveat that we will be running low on the concurrency. SQL Server has had four levels prior to SQL Server 2005 namely Read Uncommitted, Read Committed, Repeatable Read and Serializable. I leave it to readers for the exact definition as these are found in SQL Server Books Online (SQL BOL). But in the next version of SQL Server 2005, we have a new Isolation Level called as “Snapshot Isolation” level. In this article we will take a preview into the how and what’s of this feature.