Path: newssvr20.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!prodigy.com!rip!news.webusenet.com!feed2.newsreader.com!newsreader.com!news-out.visi.com!petbe.visi.com!newsfeeder1.randori.com!news.sanjose1.Level3.net!Level3.net!news.oracle.com!not-for-mail From: "Mikito Harakiri" Newsgroups: comp.databases.theory References: <3567017.1068124091@dbforums.com> <1b0b566c.0311070332.54a041e@posting.google.com> <64ea97cf.0311090213.38942cc@posting.google.com> <_%7sb.173236$Fm2.151658@attbi_s04> Subject: Re: Is relational theory irrelevant? (was Re: Dreaming About Redesigning SQL) Lines: 22 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Message-ID: Date: Tue, 11 Nov 2003 10:45:34 -0800 NNTP-Posting-Host: 130.35.179.109 X-Trace: news.oracle.com 1068576942 130.35.179.109 (Tue, 11 Nov 2003 10:55:42 PST) NNTP-Posting-Date: Tue, 11 Nov 2003 10:55:42 PST Xref: newssvr20.news.prodigy.com comp.databases.theory:22630 "Bob Badour" wrote in message news:xaadncLRvLrBjCyiRVn-gw@golden.net... > Relations have no order. The ordered operand implies some conversion to a > different type that is ordered, which then changes the logical model from a > "relational model" to a "relational and something else model". ...changes the model from a "relational model" to a "mathematical model". Some think separating logic from the rest of the math is a good idea, while some don't. > Sorting is physical when dealing with an unordered logical structure and may > not even be required. Ordering is legitimate mathematical construct. It is a question, though, if one can have a simple algebra/calculus that would include ordering too.