Hello Henners,

I was also unaware until recently, and am not sure how much it is used by the optimizer (the only thing I can think of that this would allow would be to determine if a relationship is one to one that a seek could stop after a single record is found). I just found it to be an iteresting fact. It also seems that changing the options on replication doesn't work as advertised because regardless of what I do, I can't turn on the subscriber without the foreign keys getting set to NOT FOR REPLICATION. This is regardless of how replication is set up.

Thanks for your reply. I am thinking that recreating the foreign keys is my only option. It just seems that this should be unnecessary since the foreign keys are valid until replication is activated and then they are all marked as not trusted.

Does anybody have any idea of how how optimization is performed on foreign keys? It seems to me that maybe it doesn't really matter enough to really care about it. If simply replicating a database caused a significant performance hit, that would seem to make replication useless.