A colleague of mine, Shaun Thomas, is one of a few database administrators who manage all our company's databases by monitoring, optimizing, partitioning, building star schemas, etc. The DBAs also maintain standard operating procedures for how to name a column or how to refer to an external identifier. Most importantly, they conduct reviews of your horrid schema changes before you break stuff.
Most web frameworks (Django, Rails, etc) out there abstract away a lot of low level database details since they focus on making life easier for web developers. This is great but it's important to have a way to easily tweak the low level stuff when you need to. In fact, most frameworks kinda leave DBAs in the dust. It looks like Shaun reached his breaking point on this a few weeks ago and the result was a hilarious rant. He does have a good point. The only database abstraction layer I've used that truly keeps the DBA in mind is SQLAlchemy. It adds more complexity to the tool but not in a way that makes your life difficult.