Software Vendor Mistakes With SQL Server: Scalar User Defined Functions

The Very Worst Idea


Scalar UDFs answered a very good question: How do I ruin query performance so that two generations of consultants can make a living off of SQL Server?

In the videos below, which are part of my paid training, I’m going to show you how T-SQL Scalar UDFs ruin query performance, and one way of fixing them. If you’ve got lots of these little devils hanging around your codebase, you’ll wanna pay close attention, here to see how:

  • T-SQL Scalar UDFs force queries to run single threaded
  • T-SQL Scalar UDFs run once per row that they process
  • T-SQL Scalar UDFs hide all the work they actually do in query plans and other metrics

There’s a ton more available in the full paid training courses, so hit the link below to get 75% off the whole thing.

Thanks for reading!

Going Further


If this is the kind of SQL Server stuff you love learning about, you’ll love my training. I’m offering a 75% discount on to my blog readers if you click from here. I’m also available for consulting if you just don’t have time for that and need to solve performance problems quickly.