Well the short answer is that they just don’t have enough information to give a definitive answer. You will notice that “it depends” is almost always followed by a series of questions. This is very similar to the Chaos theory that as I understand it basically says that if you knew everything you could predict anything.

Simple example. “Why is the query plan for my query changing between one day and the next?” The number of possibilities here are staggering. Your data could be changing, your statistics could have been updated, your query could have been compiled with different parameters than last time. Heck, you could have added more memory to the server. You can see how no one could possibly give a good answer without asking a lot of questions.

On top of that DBAs are trained (generally by themselves unless they are very lucky) to try to help find and fix the problem, which is not necessarily the answer to the question. “How do I stop my instance from using up all of the memory on my server?” This at face value is fairly simple. Change your max memory settings .. or add more memory. But WHY are you using up so much memory? The answer may be that you just need more memory for your workload. On the other hand you may be using it inefficiently and a couple of indexes could dramatically reduce the amount of memory that SQL needs.

So next time you hear “It depends” don’t think “The DBA is being flip again.” Think “What else can I tell the DBA so they can give me a well thought out, intelligent answer.” Now DBAs being DBAs he/she may very well be trying to obnoxious.. but probably not.