Microsoft recently gave us a more lightweight way to trace data related to execution plan performance. As of SQL Server 2014 SP2, you can trace the query_thread_profile Extended Event.
They say, “never read the comments” on the internet, but I’m lucky to get lots of interesting points and questions in my comments.
SQL Server has more than one way to pull pages in from disk for your queries. SQL Server can do a physical read of an 8KB page, or an extent of 8 of those 8KB pages.
Perfmon counters are an excellent tool for monitoring and sometimes troubleshooting Microsoft SQL Server. But some counters can get you into trouble, because they don’t mean what many people think. Learn what to look out for in the world of widely-used perfmon counters.
Collecting perfmon counters from SQL Server databases where you are using database mirroring is a little tricky
The counters won’t behave “normally” until after you set up mirroring for a database.
You’ve got some troubling wait stats in SQL Server. How can you tell which queries are causing those waits?
Learn the pros and cons of different techniques to track down the cause of both common and tricky waits in SQL Server, including CXPACKET, PAGEIOLATCH, LCK, RESOURCE_SEMAPHORE, and THREADPOOL waits.
Nonclustered indexes are awesome in SQL Server: they can get you huge performance gains.
But we can’t always create the perfect index for every query. And sometimes when SQL Server finds an index that isn’t quite perfect and decides to use it, it might make your query slower instead of faster.
Copyright (c) 2025, Catalyze SQL, LLC; all rights reserved. Opinions expressed on this site are solely those of Kendra Little of Catalyze SQL, LLC. Content policy: Short excerpts of blog posts (3 sentences) may be republished, but longer excerpts and artwork cannot be shared without explicit permission.