Database Performance Testing

Abstract

Knowing how to identify performance issues and how to fix them is a great skill to have. The problem, though, is that you need to be able to demonstrate that the improvements you make are real improvements. While you can, and should, capture the performance metrics before and after you tune a query or add an index, the best way to be sure that you’re looking at real improvement is to put the changes youmake to work. Testing means more than simply running a query a few times and then putting it into your production system with your fingers crossed. You need to have a systematic way to validate performance improvements using the full panoply of queries that are run against your system in a realistic manner. SQL Server 2012 provides such a mechanism through its new Distributed Replay tool.