Ebook: SQL Server Concurrency: Locking, Blocking, and Row Versioning

If you've designed your SQL code intelligently, and implemented a sensible indexing strategy, there's a good chance your queries will "fly", when tested in isolation. In the real world, however, where multiple processes can access the same data at the same time, SQL Server often has to make one process wait, sacrificing concurrency and performance, in order that in order that all can succeed, without destroying data integrity. Your application can have world-class indexes and queries, but they won't help you if you can't get your data, because another application has it locked. That's why every DBA and developer must understand SQL Server concurrency, and how to troubleshoot any issues. I hope my book helps!