Re: atomic
Date: Wed, 31 Oct 2007 19:57:01 -0000
Message-ID: <1193860621.614232.245860_at_q3g2000prf.googlegroups.com>
On Oct 31, 11:46 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> paul c wrote:
> > David BL wrote:
>
> >> On Oct 31, 4:31 pm, "Roy Hann" <specia..._at_processed.almost.meat>
>
> > ...
>
> >>> 1NF does not *require* that values be atomic. It asserts that values
> >>> will
> >>> be *treated as* atomic. Big difference. Essential difference.
>
> >>> Roy
>
> >> Can that be formalised? I agree with Bob that in general we have a
> >> set of operators and they can allow us to see internal structure.
> >> What does it mean for a value to be *treated* as atomic?
>
> > I think it means that relational algebra operators are not allowed to
> > decompose it.
>
> Actually, the structure is illusory and representation-dependent.
> Domains have operations that appear to reveal internal structure even
> when that internal structure may not physically exist.
Agreed.
Marshall Received on Wed Oct 31 2007 - 20:57:01 CET