May 2012 - Posts

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

  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... Posted Saturday, May 26, 2012 5:56 PM by Hugo Kornelis | 1 Comments Filed under: T-SQL, UDF

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

  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... Posted Sunday, May 20, 2012 5:08 PM by Hugo Kornelis | 23 Comments Filed under: Personal, T-SQL, UDF

• Principles of Modeling: Avoid Redundancy

  In 1994, I learned a method for data modeling that is based on three principles. I immediately knew that these principles should embraced by anyone who does any data modeling or process modeling. Or almost any other job, for that matter. I have described Read More... Posted Saturday, May 05, 2012 10:31 PM by Hugo Kornelis | 1 Comments

• The Curious Case of the Optimizer that doesn’t

  The optimizer is the part of SQL Server that takes your query and reorders and rearranges your query to find the optimal execution plan. In theory. In practice, that doesn’t always work out well. Often, the optimizer manages to come up with brilliant Read More... Posted Friday, May 04, 2012 1:13 AM by Hugo Kornelis | 7 Comments Filed under: Performance, SQL Server 2008, SQL Server 2012, T-SQL