Re: Clean Object Class Design -- What is it?

Bill Cole wrote:
>
> On Wed, 25 Jul 2001 23:05:26 -0700, Lee Fesperman
> <firstsql_at_ix.netcom.com> wrote:
> >
> >OO *is* better than the previous generally used method of creating software, but it is
> >hardly a panacea. It's fine for modeling software artifacts, especially when compared to
> >what went before. However, its capability in modeling the real world is weak (see, for
> >instance, C. J. Date's article on Debunkings --
> >http://www.firstsql.com/dbdebunk/cjd8a.htm).
> >
> I read C.J. Date's article. I am at a loss how you draw the
> conclusion that the capability of OO to model the real world is weak
> from that article.
>
> The article is basically a design argument on how to factor geometric
> abstractions in an inheritance hierarchy (symmetrical/asymmetrical).
> Truth be known, graphics programmers resolved these issues over a
> decade ago. Why Date would chose this as a "Debunking" issue for
> Databases is curious. Maybe it's a navel-staring excercise on the
> theory of programming constraints or something (which is what got
> Stroustrup in an tiz).

I really didn't draw my conclusion from Date's article (it was just a 'for instance'). OO is fine for modeling programming artifacts, but I think it has problems expanding its horzions. That's fine with me. I want to use it to model programming artifacts.

> >Combining data and behavior was possible with Forth in the '60s.
>
> Agreed. (Same is true for Fortran.) Maybe the problem here is not so
> much between code and data (objects), but programming languages and
> Databases.
>
> My point being that the data in a Database is often used by *multiple*
> programs written in a variety of programming languages. Consequently
> the context of "data" in a shared repository (Database) has a
> different (and larger) set of design factors than "data" encapsulated
> in a single application object instance (program).

Agreed. I've said it before. The modeling problems of a 'shared' database are quite large, and I don't see that OO techniques have the power to be used in organizing such a database.

-- 
Lee Fesperman, FFE Software, Inc. (http://www.firstsql.com)
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