Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!border1.nntp.dca.giganews.com!nntp.giganews.com!local1.nntp.dca.giganews.com!nntp.comcast.com!news.comcast.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 15 Oct 2004 15:24:11 -0500 Reply-To: "Laconic2" From: "Laconic2" Newsgroups: comp.databases.theory References: <042dnV7g9uRc3cncRVn-hg@comcast.com> <_PSdneE0efWEH_3cRVn-hg@comcast.com> <60e3m0l1q69rp04b5o5iasso8d5pnuc525@4ax.com> <4163d4ef.5438328@news.wanadoo.es> <1y39d.4927$eq1.3778@trnddc08> <3e68f717.0410141738.5a248ae2@posting.google.com> <3e68f717.0410151209.59904d7@posting.google.com> Subject: Re: Dawn doesn't like 1NF Date: Fri, 15 Oct 2004 16:23:57 -0400 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: Lines: 42 NNTP-Posting-Host: 24.60.68.134 X-Trace: sv3-X1aWQEoHuDCPiJC6JIDCF6bpwe6p6N+EpsZalJNxhVM/qDX7t4GDSw58WBd3n9z+Wpvb0f306oUAqgl!G2tE5FNuTibOYVDVxhB9ehOiHXPsCpnYxeI6nEVwnauxd0lRccCj9qir+sgD X-Complaints-To: abuse@comcast.net X-DMCA-Complaints-To: dmca@comcast.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.20 Xref: dp-news.maxwell.syr.edu comp.databases.theory:26905 "Dan" wrote in message news:3e68f717.0410151209.59904d7@posting.google.com... > I don't doubt that introductory textbooks begin with simple examples. > Even more than useful or powerful properties, however, one needs a > mathematical/logical model that is consistent and complete. I'm > simply asking for someone to show me this more powerful and useful > model in mathematics that is also as consistent and complete as the > "basic" definition of a relation. Sho' me the money. > > It shouldn't be that hard to produce an example or "proof" to > demonstrate one's assertion, right? I'll leave that one to the mathematicians. > > > I've read Date's ideas on this, and I respect them immensely, but I am > not entirely convinced that all the fundamental issues have been > addressed, such as how calculii and algebra are affected by his model. You and me both. I noticed recently that in a discussion of UDT in here, they were mentioning some system (maybe prolog?) that allows users to define types, but require the user to supply the function that test for equality. There's more here than meets the eye. Testing two of a UDT for equality is a whole lot more subtle than comparing the bits, bit by bit. I'm not convinced that two values drawn from the same complex domain can be easily tested for equality. Is {1, 2, 3} equal to {2, 3, 1} ? Is 3.21E3 equal to 32.1E2 ?