Re: How can I proove associtivity of natural in relational algebra?
From: Mikito Harakiri <mikharakiri_nospaum_at_yahoo.com>
Date: 21 Nov 2005 12:10:45 -0800
Message-ID: <1132603845.384888.67090_at_g44g2000cwa.googlegroups.com>
Date: 21 Nov 2005 12:10:45 -0800
Message-ID: <1132603845.384888.67090_at_g44g2000cwa.googlegroups.com>
Filter911 wrote:
> Can someone give me a link for a full proof or something?
Given relations A,B, and C, expand each realtion into a (possibly infinite) relations A', B', and C' with the same set of attributes (which is the union of the attribute sets for A, B, and C). Then, the join of A, B and C is the intersection of A', B', and C'. Intersection is associative. Received on Mon Nov 21 2005 - 21:10:45 CET