High Quality Content by WIKIPEDIA articles! In databases, and transaction processing (transaction management), snapshot isolation is a guarantee that all reads made in a transaction will see a consistent snapshot of the database, and the transaction itself will successfully commit only if no updates it has made conflict with any concurrent updates made since that snapshot. Snapshot isolation has been adopted by several major database management systems, such as SQL Anywhere, InterBase, Firebird, Oracle, PostgreSQL and Microsoft SQL Server (2005 and later). The main reason for its adoption is that it allows better performance than serializability, yet still avoids the kind of concurrency anomalies that cannot easily be worked around. Snapshot isolation is closely connected to multiversion concurrency control (MVCC), as it is very easy to implement the former given the latter.