# Re: I think my book may be wrong about cardinality, but I'm not sure

Date: Thu, 26 Jul 2007 08:16:04 -0700

Message-ID: <1185462964.626601.174460_at_d55g2000hsg.googlegroups.com>

On 26 juil, 16:38, "Bruce C. Baker" <b..._at_undisclosedlocation.net>
wrote:

*> "Cimode" <cim..._at_hotmail.com> wrote in message
**>
*

> news:1185446387.854491.306850_at_w3g2000hsg.googlegroups.com...

*>
**> > On 26 juil, 03:13, "Bruce C. Baker" <b..._at_undisclosedlocation.net>
**> > wrote:
**>
**> <snip>
**>
**> >> Each tuple in a relation with N attributes corresponds to a point in an
**> >> N-dimensional space, with each attribute being orthogonal to all of the
**> >> others.
**> > What does that mean ? How is a single attribute orthogonal to N-1
**> > attributes part of the same relation?. What do you exactly designate
**> > as *orthogonality*? Why would a tuple necessarily be a point and not
**> > a line ofr plane in geometrical N-space?
**> > What about degree 0/1 relations? How does a degree 0 relation
**> > represent a point in space?
**>
**> The answers to all your questions can be found in any linear algebra
**> textbook.
*

Really? Would you care providing a source? Received on Thu Jul 26 2007 - 17:16:04 CEST