Re: What predicates the following relation represents

From: Mikito Harakiri <mikharakiri_at_iahu.com>
Date: Thu, 6 May 2004 13:19:41 -0700
Message-ID: <Wfxmc.1$Oy4.110_at_news.oracle.com>


"Paul" <paul_at_test.com> wrote in message news:cEwmc.563$wI4.53161_at_wards.force9.net...
> robert wrote:
> This is really just standard set theory: duplicates aren't wrong,
> they're just meaningless. I can define a set as {1, 2, 2, 2, 3}. It just
> happens to be identical to the set {1, 2, 3}. I can add the number 3 to
> this set, it just so happens that the result is the set {1, 2, 3} again.
>
> If I tell a computer to remember the set {1, 2, 2, 2, 2, 3} I expect it
> to tell me {1, 2, 3} when I ask it to regurgitate the set.
>
> Adding the number 3 to the set is really just doing {3} U {1, 2, 3}
> (where U is set union). I can add it as many times as I want: the answer
> is still {3} U {3} U {3} U .... U {3} U {1, 2, 3} = {1, 2, 3}

No, duplicates are meaningless only within relatively narrow scope of predicate logic. Other branches of math thrive on duplicates (combinatorics, for instance). Of course, it remains to see a sucessfull query theory expanded into these areas, but anti cat food arguments aren't always suffice. Received on Thu May 06 2004 - 22:19:41 CEST

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