Re: Possible problems with Date & McGoveran View Updating

From: Mikito Harakiri <mikharakiri_at_ywho.com>
Date: Mon, 15 Sep 2003 14:30:59 -0700
Message-ID: <Vkq9b.32$lB2.69_at_news.oracle.com>


"Costin Cozianu" <c_cozianu_at_hotmail.com> wrote in message news:bjqmkq$mburj$1_at_ID-152540.news.uni-berlin.de...
> I don't think "smallest" is good enough , it has to be unique.
>
> Maybe you can derive that the existence of smallest implies uniqueness
> (The examples that I think of where there is no unique set also implies
> there is no smallest).
>
>
> If we pick smallest (vs. unique), then we can have problems, i.e. users
> observe a derived fact, the database chooses the "smallest" update,
> however in reality a "larger" set of facts is true. Then we broke the
> close world assumption: the user might:
> select count(*) ...
> and get the wrong results.

Could you clarify the last paragraph? How can user get wrong count, for example? Received on Mon Sep 15 2003 - 23:30:59 CEST

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