Re: A simple notation, again
Date: Thu, 19 Jul 2007 00:48:31 -0700
Message-ID: <1184831311.154363.226930_at_z28g2000prd.googlegroups.com>
On Jul 17, 2:57 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> Cimode wrote:
> > On Jul 16, 7:05 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
>
> >>"David Cressey" <cresse..._at_verizon.net> wrote in message
>
> ...
>
> >>How about something like this
> >>{(Last, First, Num) :
> >>("David", "Cressey", 1),
> >>("Marshall", "Spight", 2),
> >>("Bob", "Badour", 3),
> >>("Jan", "Hidders", 4)}
>
> > You imply order (adjacency) when relation attributes should not be
> > subjected to any....
>
> When Codd wrote of eliminating order dependency, he wasn't talking about
> language notations or grammars, in fact he used ordering to describe his
> idea!
I know but thank you for reminding. Order however in grammar is
imposed by header not body. Never felt comfortable with that. In
other words, why would sets unordered nature not be reflected on the
grammar that expresses them?
> p
Received on Thu Jul 19 2007 - 09:48:31 CEST