Re: Business Rules
Date: Thu, 27 Mar 2008 08:12:05 -0700 (PDT)
On Mar 27, 6:50 am, Tegiri Nenashi <TegiriNena..._at_gmail.com> wrote:
> In practice, there is a lot of technical details to work out no matter
> what approach would you take, being that constraint enforcement via
> triggers or via ANSI SQL style assertions (implemeted as check
> constraints on materialized views).
Perhaps I can suggest some literature.
"Applied Mathematics for Database Professionals" by Lex de Haan & Toon Koppelaars covers a lot of material on constraints. Frankly, I don't see the point of their constraint classification scheme based on constraint appearance. Database wide constraint is an equation/ inequality involving more than one relation, single relation wide constraint refer to a sinle relvar. Tuple-level constraints can be identified if we operate expression on relational calculus level, but not RA?
"SQL Design Patterns: Expert Guide to SQL Programming" by Vadim
Tropashko contains a chapter on constraint enforcement via ANSI SQL
style assertions implemeted as check
constraints on materialized views.
(I picture Joe Celko reading this and feverishly starting typing a new book about constraints. BTW, "Thinking in Sets" -- nice title!) Received on Thu Mar 27 2008 - 16:12:05 CET