Re: object algebra
From: Christopher Browne <cbbrowne_at_acm.org>
Date: 24 Feb 2004 19:08:10 GMT
Message-ID: <c1g7eq$1ia96o$3_at_ID-125932.news.uni-berlin.de>
Date: 24 Feb 2004 19:08:10 GMT
Message-ID: <c1g7eq$1ia96o$3_at_ID-125932.news.uni-berlin.de>
Oops! "Eric Kaun" <ekaun_at_yahoo.com> was seen spray-painting on a wall:
> Tables are not relations, and neither of them are "rectangular." You can
> display, for example, a 4-dimensional tessaract (hypercube) as a table if
> you like - that doesn't mean it's rectangular.
You have to be prepared to forgive people at least a little for making this mistaken assumption.
After all:
- xBase was often described as a "relational database" despite the fact that it certainly wasn't;
- I haven't seen much evidence of commercial SQL system vendors having produced systems that are convenient to use with data that isn't shaped pretty blindly like a "table."
Perhaps a relational data representation _should_ be analagous to Lisp structures or Prolog facts, and therefore be able to be of pretty much any shape. But in the absence of conspicuous implementations of such, it shouldn't be surprising for people to make the "table" mistake...
-- wm(X,Y):-write(X),write('_at_'),write(Y). wm('cbbrowne','ntlug.org'). http://www3.sympatico.ca/cbbrowne/multiplexor.html :FATAL ERROR -- YOU ARE OUT OF VECTOR SPACEReceived on Tue Feb 24 2004 - 20:08:10 CET