functions

Last week, I presented on the topic of TSQL User Defined Functions (UDFs) in SQL Server at the PASS Summit.

User defined functions are fairly simple to create in SQL Server, but figuring out exactly how they are being used can take a little time - even in a simple execution plan. This is because the functions can be tucked away into lots of different operators in the plan, even join operators.

The good news: once you learn what to look for, it’s not terribly complicated. There are some fancy terms involved, but the definitions are pretty simple.

It’s tough to keep track of which features work in each version of SQL Server, and which Editions support them.

My memory told me that the new Adaptive Joins feature in SQL Server 2017 was Enterprise Edition only…  and that’s correct, but I didn’t realize that the fancy new feature to make Multi-Statement TVFs smarter has much wider licensing.

It’s time to write a blog post, so I can save time when I go searching for this in a couple years!