Path: news.easynews.com!core-easynews!newsfeed1.easynews.com!easynews.com!easynews!feed2.news.rcn.net!feed1.news.rcn.net!rcn!kibo.news.demon.net!news.demon.co.uk!demon!thewolery.demon.co.uk!wol From: "Anthony W. Youngman" Newsgroups: comp.databases.theory Subject: Re: In an RDBMS, what does "Data" mean? Date: Fri, 4 Jun 2004 00:02:46 +0100 Organization: vinny-puch Lines: 36 Message-ID: References: <3Nrpc.40241$TT.30435@news-server.bigpond.net.au> <1tsrc.7160$NK4.722786@stones.force9.net> <40bec99c@post.usenet.com> Reply-To: "Anthony W. Youngman" NNTP-Posting-Host: thewolery.demon.co.uk Mime-Version: 1.0 Content-Type: text/plain;charset=us-ascii;format=flowed X-Trace: news.demon.co.uk 1086304076 3368 158.152.222.21 (3 Jun 2004 23:07:56 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Thu, 3 Jun 2004 23:07:56 +0000 (UTC) User-Agent: Turnpike/6.02-U () Xref: core-easynews comp.databases.theory:35585 X-Received-Date: Thu, 03 Jun 2004 16:07:18 MST (news.easynews.com) In message , Paul writes >> I'm not sure a database is a finite set of axioms. > >Why not? A databases is just a finite set of tuples from which you >derive other truths. In which case, your database is arbitrarily complex ... The whole point of axioms is that YOU DON'T WANT THEM! The aim of logicians, mathematicians, and scientists is always to simplify things. If you can derive an axiom from other axioms, it ceases to be an axiom and becomes a theorem, and makes your fundamental theory simpler. To define "axiom == tuple" is, I think, a major mistake. I can't explain why, it just feels COMPLETELY wrong. > >> And the set of facts in a database can grow arbitrary large >> (theoretically speaking). > >There's a big (though maybe subtle) difference between "infinite" and >"unbounded but finite". Even though there is no theoretical limit to >the size of a database, we do know that any given database is of finite >size. > Yep. But as any scientist will tell you, an unbounded axiom set is a crap theory. That's why it feels wrong. Cheers, Wol -- Anthony W. Youngman - wol at thewolery dot demon dot co dot uk HEX wondered how much he should tell the Wizards. He felt it would not be a good idea to burden them with too much input. Hex always thought of his reports as Lies-to-People. The Science of Discworld : (c) Terry Pratchett 1999