Daniel Janik head-fakes us a few times when looking at scalar user-defined function performance:
I’ve read a lot of things lately pointing to scalar functions as if they were the devil. In this blog I’m going to explore if that’s the case. Let’s have a look.
It’s true that in many situations a scalar function is often a performance bottleneck; but, is there a situation where they could be responsibly used?
What if you had a lookup table that almost never changed? Is it worth doing a join on the lookup to get the data you need?
Let’s examine a simple join between a customer address and a state lookup table.
Things are not always as they seem.