Re: On view updating

On Mon, 20 Sep 2004 15:12:23 -0700, Alfredo Novoa wrote:
> Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be> wrote in message
> news:<pan.2004.09.18.21.34.55.114875_at_REMOVETHIS.pandora.be>...

>> > ---
>> > I therefore have come to believe that "view updateability" should be
>> > allowed to happen IF AND ONLY IF the system has PRECISELY ONE WAY to
>> > "resolve" the user's request.
>> > ---
>> 
>> It depends of course on what you mean by "resolve"

Yes. Agreed. But not everybody agrees on what the right translation is and that sometimes matters.

>> but for most
>> reasonable interpretations that I can think of the ONLY IF part is
>> widely accepted by almost everybody who has done any serious research
>> on the view update problem. The IF part is an entirely other matter and
>> certainly not obvious, as you may remember from the discussions with
>> Jens Lechtenboerger.

?? Surely you don't mean to say that you think that "P if Q" (Q -> P) is the same as "P if and only if Q" (P <-> Q)?

> It is the "uniqueness criterion" of the slides that you posted a link
> some time ago.

That's only the ONLY IF part. Btw. I didn't post that link, I only said I liked it very much and that doesn't count. :-)

• Jan Hidders