Principal of view equality?
From: paul c <toledobysea_at_ac.ooyah>
Date: Wed, 04 Jun 2008 02:53:39 GMT
Message-ID: <Tsn1k.4999$C12.2720_at_pd7urf3no>
I was just looking at Codd's RM 2 book again (the rather short chapter on views from acm.org) and it seemed to me that what he wrote took it as essential that a view must always equal the expression that defines the view. If so, does this in effect constitute a kind of indirect constraint on any base relations involved?
Date: Wed, 04 Jun 2008 02:53:39 GMT
Message-ID: <Tsn1k.4999$C12.2720_at_pd7urf3no>
I was just looking at Codd's RM 2 book again (the rather short chapter on views from acm.org) and it seemed to me that what he wrote took it as essential that a view must always equal the expression that defines the view. If so, does this in effect constitute a kind of indirect constraint on any base relations involved?
(Assuming that all relations a dbms stores are to be considered 'true') Received on Wed Jun 04 2008 - 04:53:39 CEST