I am a database developer, and I have a great working relationship with the DBAs at my company. I think the DBAs and I respect each other because I have learned quite a bit about the challenges of administering and maintaining enterprise-scale databases and am always learning more. I can anticipate many of their concerns about my code and know when it's important to get their input on a project *before* development begins. They know that I'll understand and accept their explanations of the technical and policy concerns that govern their decisions and actions.

My role as a *database* developer gives me more time and reason to dig into the internal workings of SQL Server than most application developers, but I think even application developers can improve their working relationships with DBAs by learning more about the DBAs' responsibilities. One needn't know how to do the DBAs' job, only understand why they do the things they do. A good first step here is to *ask* them in a manner that demonstrates your interest in learning (*not* a combative tone that demands they justify themselves)!