Re: On view updating

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: 21 Sep 2004 04:12:57 -0700
Message-ID: <e4330f45.0409210312.3b1ec70b@posting.google.com>

"Peter Koch Larsen" <pklspam_at_mailme.dk> wrote in message news:<Vmb3d.50270$Vf.2438722_at_news000.worldonline.dk>...

> I do not agree. Remove the "AND ONLY IF", and we can talk.

Jan and Hegner say that this is the most common approach.

> Yes - the rules for view updates in the third maniphesto are downright
> awful.

They are not in the manifesto.

> Now I do not know what rules you are talking about.

About Date & McGoveran rules.

> A sensible DBMS should
> have no problem with the above deduction.

But a DBMS that uses that rules can not make the above deduction.

> Why not read some "real" database theory?

Because it does not solve the problem, and the Date & McGoveran's approach only needs some little adjustements to be very useful IMO.

> something about updates of views. You could also check the work of Stephen
> Hegner (http://www.cs.umu.se/~hegner/Publications/db.html).

I don't think that I can implement view updates with that.

Regards Received on Tue Sep 21 2004 - 06:12:57 CDT