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Re: Extending my question. Was: The relational model and relational algebra - why did SQL become the industry standard?

From: Bob Badour <bbadour_at_golden.net>
Date: Mon, 10 Mar 2003 10:40:45 -0500
Message-ID: <_O2ba.466$Cd4.66949231@mantis.golden.net>


"Jan Hidders" <jan.hidders_at_REMOVE.THIS.ua.ac.be> wrote in message news:3e6c88a6.0_at_news.ruca.ua.ac.be...
> Lauri Pietarinen wrote:
> >Jan Hidders wrote:
> >>Lauri Pietarinen wrote:
> >>
> >>>I can't get into all the details here but there
> >>>there is lot's of discussion on different issues relating
> >>>aggregates in
> >>>Relational Database Writings 1994-1997
> >>>(ISBN 0-201-39814-1) installments 44, 45 and 50.
> >>
> >>I'm not much impressed by those references. The whole point of our
> >>discussion was to see how well their arguments stand up to critical
> >>examination. Since you apparently don't want to go into the specific
issue
> >>that we were disussing I now get the feeling that you want to avoid that
> >>discussion.
> >>
> >>Pity.
> >
> >I was not really trying to impress you by those references. I was just
> >figuring that since we were talking about aggregates we should have some
> >reference (if not agreement) as to what an aggregate function means.
>
> Why do you think there is disagreement about that?
>
> >Regarding sets<-->bags in general I would sum up my arguments
followingly:
> >
> >1) SQL operates in two modes: "bag"-mode and "set"-mode
>
> Where do you get this idea from? There is just one mode: the bag mode.
>
> >Regarding point 5) I challenge you to give me just
> >*one* *real* *world* *example* in which duplicates
> >would actually be of use to the end user.
>
> I never said there was, and even if there was you could simulate this in a
> set-only model.
>
> So, what is your point exactly?

One could ask you the same, Jan. Received on Mon Mar 10 2003 - 09:40:45 CST

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