Async stats update causing blocking
An index rebuild quietly blocked an async stats update, and the whole server started timing out. Here is the lock-partitioning repro and the SQL Server 2022 fix.
Performance
8 posts
Scary Scalar Functions - Part Four: Your Environment
You've learned why Scalar UDFs are slow and how to remove them. The last question: where do you even start? Here's how I triage them across a whole environment.
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.
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.
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.
KEEP PLAN Demystified
Ever wondered what the KEEP PLAN hint actually does? The docs are vague, so I tested it against every recompilation threshold to find out.
Query Store default settings
Query Store comes with default settings - but are they what the documentation says? Let's find out using a simple Extended Events session.
Generate XML documents efficiently
Believe it or not, there is a wrong and correct way when it comes to generating XML documents in SQL.