Re: Possible problems with Date & McGoveran View Updating
Date: Mon, 8 Sep 2003 19:17:56 -0700
Message-ID: <OTa7b.30$741.269_at_news.oracle.com>
"Bob Badour" <bbadour_at_golden.net> wrote in message
news:N3b7b.732$%Q.69880903_at_mantis.golden.net...
> > Not general enough.
>
> Not general enough for what?
Clarified in different thread.
> > Constraints are one possibility. Extending views (aka adding more
> equations)
> > like in the "union" example above is more general approach.
>
> The view is what it is. Extending the view would alter the logical view of
> some user or application.
No, I'm not suggesting to arbitrarily extend the view.
The system must just reject any attempt updating ambiguous system of views.
The user can correct the error by supplying view update effect on additional
views (which is analogous to adding more equations). If you agree that
V*x=y
and many constraints like this
VC*x=DUM
Next, I can hope handling equations involving views with a uniform method, while Date et.al. needs to a special rules involving constraints. Received on Tue Sep 09 2003 - 04:17:56 CEST