Re: Codd's Information Principle
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 05 Nov 2009 15:59:14 -0400
Message-ID: <4af32e97$0$5334$9a566e8b_at_news.aliant.net>
>
> I thought projection is relational algebra's quantifier, are you talking
> about something else?
Date: Thu, 05 Nov 2009 15:59:14 -0400
Message-ID: <4af32e97$0$5334$9a566e8b_at_news.aliant.net>
paul c wrote:
> Cimode wrote:
>
>> ... >> I would be glad to hear how we establish a valid quantifier in >> relational algebra using only internal predicates. ...
>
> I thought projection is relational algebra's quantifier, are you talking
> about something else?
Projection is one quantifier. Equality (or containment) comparison is the other. Received on Thu Nov 05 2009 - 20:59:14 CET