Josh, I agree to treat this case as a (1) convinence. But it is still very cpecific, more than just simplifying FKs And you have said about general GUID problem. Let we disscuss this problem ? I hope to here good ideas from you again.
Now I solve the GUID problem, with one sequence of IDs on the main server. The clients ask the server to lease some IDs via special (application-layer) protocol. Server remembers who and when and what IDs have took. (in terms of segments [a..b],[c..d]... etc) ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster