Re: Who conceptualized physical data independence before E.F. Codd, Chris Date and Michael Stonebreaker?
Date: Mon, 24 Jan 2011 19:04:53 -0800
On 24/01/2011 11:57 AM, knorth wrote:
> Who conceptualized physical data independence before E.F. #Codd, Chris
> #Date and Michael #Stonebreaker?
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. Received on Mon Jan 24 2011 - 21:04:53 CST