Evil Kraig F (2/5/2014)
DTA is... um... I'll find a polite word for it in a moment, hang on.....
DTA is a best effort guess from an app to try to help you figure out good methods for approaching your data from a single point of view. It's really, really bad at it though. It's not horrible for OLAP systems which are typically write once/read 3 billion times, but OLTP systems that implement all the recommendations would bog down.
And it's better than the missing query DMV/hints in query plans
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability