Microsoft® SQL Server 2012 Unleashed

Summary

Locking is critical in a multiuser environment for providing transaction isolation. SQL Server supports all ANSI-defined transaction isolation levels, including the Snapshot Isolation level for applications that can benefit from optimistic concurrency. The Lock Manager in SQL Server automatically locks data at the row level or higher, as necessary, to provide the appropriate isolation while balancing the locking overhead with concurrent access to the data. It is important to understand how locking works and what its effect is on application performance to develop efficient queries and applications.

SQL Server provides a number of tools for monitoring and identifying locking problems and behavior. In addition, SQL Server provides a number ...