SELECT Hints, Tips, Tricks FROM Hugo Kornelis WHERE RDBMS = 'SQL Server' : UDF

SQLRally Nordic 2012 – session material

Hugo Kornelis — Fri, 05 Oct 2012 16:49:00 GMT

As some of you might know, I have been to SQLRally Nordic 2012 in Copenhagen earlier this week. I was able to attend many interesting sessions, I had a great time catching up with old friends and meeting new people, and I was allowed to present a session...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 4)

Hugo Kornelis — Fri, 24 Aug 2012 21:07:00 GMT

Scalar user-defined functions are bad for performance. I already showed that for T-SQL scalar user-defined functions without and with data access, and for most CLR scalar user-defined functions without data access , and in this blog post I will show that...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 3)

Hugo Kornelis — Fri, 29 Jun 2012 18:44:00 GMT

I showed why T-SQL scalar user-defined functions are bad for performance in two previous posts. In this post, I will show that CLR scalar user-defined functions are bad as well (though not always quite as bad as T-SQL scalar user-defined functions). I...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 2)

Hugo Kornelis — Sat, 26 May 2012 14:56:00 GMT

In a previous blog post , I demonstrated just how much you can hurt your performance by encapsulating expressions and computations in a user-defined function (UDF). I focused on scalar functions that didn’t include any data access. In this post, I will...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 1)

Hugo Kornelis — Sun, 20 May 2012 14:08:00 GMT

So you thought that encapsulating code in user-defined functions for easy reuse is a good idea? Think again! SQL Server supports three types of user-defined functions. Only one of them qualifies as good. The other two – well, the title says it all, doesn’t...(read more)