Deep Dive
Async stats update causing blocking
How lock partitioning causes async stats updates to block during online index rebuilds with WAIT_AT_LOW_PRIORITY - full repro and the SQL Server 2022 fix.
Notes from a TSQL trench
Database stuff,
with a side of memes.
Long-form notes on TSQL performance, Extended Events, Query Store and the tooling around them. Written from the trenches, not the slide deck.
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Latest posts
Unexpected Blocking during the Indexed View Creation
Here are the chronicles of my struggles to add a large Clustered index to a View without causing an outage.
My Toolbox - Greenshot
Print Screen and Paint never cut it for me. Greenshot did: precise region capture, a real annotation editor, obfuscation, and one-key sharing. Here's the tour.
Scary Scalar Functions - Part Three: The Cure
Nuke them from orbit, or inline them. The practical ways to neutralize Scalar UDF performance pain, from a free SCHEMABINDING win to a full ITVF rewrite.
What's in a name? (T-SQL Tuesday #152)
My T-SQL Tuesday rant: an app that connects as '.Net SqlClient Data Provider' turns debugging into a manhunt. Please, name your apps.
Scary Scalar Functions - Part Two: Performance
A Scalar function that does literally nothing still runs over 20 times slower. Here is the proof, measured four different ways.
What is causing my constraint to be untrusted?
You fix an untrusted constraint, and by morning it's back to untrusted. Here's how to catch the process responsible, using Extended Events.
Scary Scalar Functions - Part One: Parallelism
Consultants hate me for this one weird trick. Because I'll be uncovering all the mess Scalar functions can cause in a series of articles.