"*Really* big sites don't ever have referential integrity. Or if the few spots they do (like with financial transactions) it's implemented on the application level (via, say, optimistic locking), never the database level."
Some large sites don't even use data types! http://www.thestar.com/News/article/189175 "in some cases the field for the social insurance number was instead filled in with a birth date." (search the archives for "OT: Canadian Tax Database") Cheers, Stuart. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
