I’m on a project where I was asked to take a quick peek at some reporting SQL (in a SQL Server 2K5 environment) and was surprised at what I found: 4 to 5 levels of subquerys, distinct clauses, unions, and NoLock hints (which were needed because the SQL was running so long it was blocking standard processing) – all in the same set!.
Because I (foolishly 🙂 mentioned that I thought the SQL was inefficient I’ve been labeled the “expert” and have been tasked with creating a test for a couple of interviewees to do that will assess their SQL optimizing abilities. I’m hoping someone can point me to some URLS, or maybe provide a list that I can use to help weed out the good from the bad.
Since you mentioned the SQL Server 2005 environment:
More SQL Server interview questions than you possibly could have imagined:
The classic set. Most interviewees will probably have studied these…maybe a good way to gauge who has prepared.
Another classic
Questions from one of the original Stack Overflow DBAs
Another link for best SQL questions and answers