Re: Who conceptualized physical data independence before E.F. Codd, Chris Date and Michael Stonebreaker?
From: David BL <davidbl_at_iinet.net.au>
Date: Tue, 25 Jan 2011 03:19:57 -0800 (PST)
Message-ID: <22458a62-8519-4c6c-9c1c-e68dd2909306_at_i25g2000prd.googlegroups.com>
Date: Tue, 25 Jan 2011 03:19:57 -0800 (PST)
Message-ID: <22458a62-8519-4c6c-9c1c-e68dd2909306_at_i25g2000prd.googlegroups.com>
On Jan 25, 11:04 am, paul c <anonym..._at_not-for-mail.invalid> wrote:
> On 24/01/2011 11:57 AM, knorth wrote:
>
> > Who conceptualized physical data independence before E.F. #Codd, Chris
> > #Date and Michael #Stonebreaker?
>
> >http://bit.ly/gibPP9
>
> What is this question about? No doubt Codd knew about Childs' work but
> what direct comparison can apply? Codd showed a possible connection
> between classical set ops and predicate logic. He didn't prescribe any
> particular data structure (nor any particular domains for that matter).
> The word 'physical' doesn't appear in his 1970 paper as far as I know.