don't jump to conclusions. Just because a tuple is "all key" is no
reason to think it must be split.
As far as classes, rooms and periods and no overlap; this is clearly a
constraint. This is one of the things that always posed a problem in
the classes that I have taught. The tables/relationships/keys do not
change, what does change is the criteria for membership in one/all of
the involved tables. It's the program doing the INSERT/UPDATE that has
to implement this rule. The rule itself is not referential, it's
semantic.
Received on Sun Dec 04 2005 - 02:09:53 CST
