cardinality of 1
From: pc <magoo_at_pssstoff.org>
Date: Fri, 26 Nov 2004 22:52:40 GMT
Message-ID: <YsOpd.8772$VL6.500_at_clgrps13>
In another thread, Bob Badour said: "Relation-valued attributes already allow us to represent optional data as a constrained set where we can enforce a maximum cardinality of 1 by specifying a nullary key."
Date: Fri, 26 Nov 2004 22:52:40 GMT
Message-ID: <YsOpd.8772$VL6.500_at_clgrps13>
In another thread, Bob Badour said: "Relation-valued attributes already allow us to represent optional data as a constrained set where we can enforce a maximum cardinality of 1 by specifying a nullary key."
I'm intrigued by this quote, but I just don't get it. Have looked elsewhere (thethirdmanifesto.com among other places). My motive doesn't have to do with "missing information", but rather finding out whether cardinality in any amount can be determined for an arbitrary table (as opposed to DEE or DUM) in a way that is intrinsic.
Would appreciate any clues or pointers.
pc Received on Fri Nov 26 2004 - 23:52:40 CET