Re: SUPPORT FOR DECLARATIVE TRANSITION CONSTRAINTS
Date: Mon, 20 Sep 2010 02:56:12 -0700 (PDT)
Message-ID: <ea82a7fb-db65-46c1-b1c5-7521ece1765d_at_t3g2000vbb.googlegroups.com>
On 20 sep, 10:40, Brian <br..._at_selzer-software.com> wrote:
> Is it so difficult to grasp that two different
No, that is not difficult to grasp at all.
It seems much more difficult for you to grasp that this is completely
besides the point and completely irrelevant.
> propositions at different times can reference the same concrete
> object?
> And by extension, is it so difficult to grasp that it should
> be possible to match tuples in a relvar as it was prior to an update
> to tuples in the database as it would be if the update were to
> succeed?
That may perhaps be possible.
But once again, you seem to fail to realize that what you are advocating is precisely an update mechanism that operates at the tuplelevel, and that that is in violation of the important prescription that all updates are set-level.
You are free to disagree with any such prescription, but it is then up to you to DEFINE a better model than Date's, and present and defend that. Just a few fuzzy ramblings drawn off some particular "practical case" won't suffice for that. Received on Mon Sep 20 2010 - 11:56:12 CEST