Re: Mixing OO and DB

From: David Cressey <cressey73_at_verizon.net>
Date: Sat, 09 Feb 2008 17:40:04 GMT
Message-ID: <Uzlrj.110$%q3.99_at_trndny07>


"Daniel T." <daniel_t_at_earthlink.net> wrote in message news:daniel_t-2CAF35.10321309022008_at_earthlink.vsrv-sjc.supernews.net...
> mAsterdam <mAsterdam_at_vrijdag.org> wrote:
>
> > Any ideas except 'the other guys are so stupid'?
>
> I've been on comp.object a long time, never visited
> comp.databases.theory. David Cressey admitted to having "not seen much"
> of OO theory, so I will have to admit to having not seen much of
> database theory, and even less of SQL.
>
> I bring up SQL because Mr. Cressey says that, "A lot of us mere
> practicioners [sic] treat the SQL model and the relational model as
> variations on the same theme." If SQL is the exemplar of the relational
> model, then let me propose that SmallTalk be used as the exemplar of the
> OO model (some in comp.object will strongly disagree, primarily because
> SmallTalk cannot handle multi-dispatching, but I'm willing to settle.)
>
> Now I grant that I know very little of SQL, in fact I may know less of
> SQL than Mr. Cressey knows of SmallTalk, :-) but it seems to me that
> comparing the two languages, as exemplars, is fundamentally unfair to
> SQL simply because as I understand it, SQL is *not* turing complete,
> whereas SmallTalk is.

Turing completeness is not, IMO, as important in a data sublanguage as it is in a programming language. A Turing complete extension of SQL could be made.

BTW, SQL is, strictly speaking, not in line with the relational model. The differences were important to Ed Codd. They are also important to some of the c.d.t. regulars. Smalltalk is closer to being mainstream in OOP than SQL is to being mainstream in RM.

>
> Since "mAsterdam" brought up the ship metaphor... Imagine two companies,
> one makes engines, while the other makes whole boats (engine included.)
> Even if the first company's engines are superior to the engines made by
> the second company, is it really fair to compare which of the companies'
> products are the best for going out to sea? I think not.
>

Database theory and practice does not cover the same ground that programming theory and practice does.

> In response to mAsterdam's call for a civilized discussion of the pros
> and cons of both theories, I can't say much because I only know one side
> of the argument. But I will be following the thread in the hopes of
> learning something.

If the past is any guide, the discussion will generate more heat than light. Received on Sat Feb 09 2008 - 18:40:04 CET

Original text of this message