Re: Stored fields ordered left to right

Mike Preece wrote:
> [...various non-illuminating diatribes omitted...]
 > If I'm following this discussion correctly, you're saying the word
> "relational", in the generally accepted context of "relational
> databases", has a different meaning when used in a strictly
> mathematical context.
>
> The difference has something to do with "ordering". I don't
> understand. Sorry.
>
> Is it important? and if so, why?

Possibly the simplest thing to do is look at the original paper, which is available online at:

http://www.acm.org/classics/nov95/toc.html

As I pointed out earlier in one of these threads (possibly even this one), there is a section in this about the difference between ordered mathematical relations and unordered 'relationships' used in RDBMS, and why that is important. My take on it is that the primary issue is usability - people have a harder time using numbers to identify columns than using names.

-- 
Jonathan Leffler                   #include <disclaimer.h>
Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com
Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/