Re: Multiple specification of constraints
From: Eric Kaun <ekaun_at_yahoo.com>
Date: Wed, 03 Mar 2004 16:16:36 GMT
Message-ID: <Exn1c.20851$mK4.3170_at_newssvr31.news.prodigy.com>
> > > can do that too just as well. But those things can't do data
management.
> > > [...]
> > > The idea that databases are primarily about persistence is toxic myth.
> > > You can have persistence without data management, and you can
> > > have data management without persistence.
>
> A database is a set of facts. It might persist, and it might not.
Date: Wed, 03 Mar 2004 16:16:36 GMT
Message-ID: <Exn1c.20851$mK4.3170_at_newssvr31.news.prodigy.com>
"Bob Badour" <bbadour_at_golden.net> wrote in message
news:FcydneB9COOek9ndRVn-ug_at_golden.net...> > > implement persistence as a service, but there are other things that
> > "Marshall Spight" <mspight_at_dnai.com> wrote in message
> > news:%kJ0c.94816$4o.117703_at_attbi_s52...
> > > Ack! That's not a good definition! RDBMSs are primarily about data
> > > management, not persistence. They happen to be a good place to
> > > can do that too just as well. But those things can't do data
management.
> > > [...]
> > > The idea that databases are primarily about persistence is toxic myth.
> > > You can have persistence without data management, and you can
> > > have data management without persistence.
>
> A database is a set of facts. It might persist, and it might not.
Agreed. And if we had languages that supported relations for all processing, we wouldn't be in the O-O mess we're in now. It would be just amazingly useful to be able to perform relational operations on data in memory... and then, at the end when satisfied, persist it.
(ben wrote)
> > Constraints are requirements of the 'user', or the 'one' who is defining
> > the system.
>
> Nope. They are limitations imposed on the user to keep the fallible from
> doing what they do best.
I'd say both, actually. Certainly they prevent errors, but they also serve to communicate (to developers and DBAs and such). And they document (in executable form!) the meaning of the system's data.
- Eric