Domains, types, and application engineering ....
Date: 9 Jan 2007 10:52:38 -0800
Message-ID: <1168368757.898108.24190_at_k58g2000hse.googlegroups.com>
Adding a note (and yes, I am still puzzling about the definition of Plus, so relax!) ...
To drag this whole discussion out into the machine shop, pin it down with a set of vice clamps, and go at it hard with the drill press and arc-welding gear, the POINT of a relational DBMS is to accurately model some real world problem domain.
So what "ought" the behavior of the domains in your relation schema be?
Precisely the interesting behavior of the real world phenomenon we're modeling. Not something some standard dreamed up (though that's probably going to be useful in a lot of cases, and re-use will doubtless improve your the quality of your information system and the productivity of your engineers).If your application calls for you to organize instances of a concept like '10 mandarins', then you need first, to document and nail down how these things behave, and then second, implement software to encapsulate (*gasp*) that behavior.
The function of the DBMS is to take this implementation and to present you with a body of relational machinery that can be used to organize and reason about instances of this domain, according to the behavior you've defined for it. Received on Tue Jan 09 2007 - 19:52:38 CET