Re: what are keys and surrogates?

From: David BL <davidbl_at_iinet.net.au>
Date: Sun, 13 Jan 2008 18:26:00 -0800 (PST)
Message-ID: <50f28da0-2759-4c8b-965d-1e0fe29e9237_at_p69g2000hsa.googlegroups.com>


On Jan 14, 6:41 am, "David Cressey" <cresse..._at_verizon.net> wrote:
> "David BL" <davi..._at_iinet.net.au> wrote in message
>
> news:b05f3396-4c1f-4710-8d27-d4940b7e689f_at_e10g2000prf.googlegroups.com...
>
> > This however doesn't change the fact that most authors define a
> > (mathematical) relation as a set of ordered tuples, which means a
> > function is not a relation (assuming, as most do, that a function has
> > a defined domain and codomain).
>
> I don't understand how the conclusion follow from the premise.

Please read my response to mAsterdam. Received on Mon Jan 14 2008 - 03:26:00 CET

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