dave-L (1/31/2013)
Incidentally, I'm wondering about this for Foreign Keys as well. Beyond enforcing referential integrity and documentation, are there any advantages to actually declaring these constraints in the schema? It would seem that the enforcement of referential integrity would actually be a bit of a performance hit, no?
No. In fact, in many cases there can be a performance improvement. The existence of a trusted foreign key gives the optimiser additional information that can well lead to better performance than when there isn't a foreign key.
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