Re: The fable of DEMETRIUS, CONSTRAINTICUS, and AUTOMATICUS

From: Marshall Spight <mspight_at_dnai.com>
Date: Tue, 19 Oct 2004 16:13:01 GMT
Message-ID: <h2bdd.277140$D%.200426@attbi_s51>

"Tony Andrews" <andrewst_at_onetel.com> wrote in message news:1098201951.251759.85460_at_z14g2000cwz.googlegroups.com...
> Marshall Spight wrote:
> >
> > This was roughly my thought as well. The *best* way to enforce
> > a constraint is structurally, so that in the language of the
> application's
> > schema, it is *not possible to express* corrupt data.
>
> That's great when possible. But some constraints just aren't
> expressible structurally - examples given in earlier posts.

Agreed.

> For those,
> what you want is a complex declarative constraint (aka an "assertion")
> - something many DBMSs can't do, unfortunately.

Yes, that's exactly what you want!

Marshall Received on Tue Oct 19 2004 - 11:13:01 CDT