Re: Microsoft and the two great blunders

"Alfredo Novoa" <alfredo_at_ncs.es> wrote in message news:e4330f45.0312281200.406f3000_at_posting.google.com...
> Costin Cozianu <c_cozianu_at_hotmail.com> wrote in message
news:<bsgq38$cmb87$1_at_ID-152540.news.uni-berlin.de>...
> > > Any operator may be a part of several types, and you can express that
> > > without problems with that template (and flawed) grammar.
> >
> > So if an operator is part of several types, you've got a problem. Are
> > operators part of the type definiton or not ?
>
> You are mixing apples with oranges. The proper question should be: Are
> operators definitions part of type definition? And IMO the answer is
> yes.
>
> But one operator may be shared by several types.

You both are confusing issues. Conceptually, a type is defined by the vast set of possible operations for the type. Any given logical design will declare only a small subset of that vast set of operations. Whether one physically and logically declares the operations proximately with the values is largely arbitrary. I suggest that separating the declarations has advantages for schema evolution. Regardless whether an operation is declared to the dbms at any given point of time, the operation is always a valid operation on values of the type. Received on Mon Dec 29 2003 - 06:35:34 CET