X-Received: by 10.70.13.161 with SMTP id i1mr18045148pdc.3.1422901088830; Mon, 02 Feb 2015 10:18:08 -0800 (PST) X-Received: by 10.50.43.196 with SMTP id y4mr171157igl.2.1422901088709; Mon, 02 Feb 2015 10:18:08 -0800 (PST) Path: news.cambrium.nl!textnews.cambrium.nl!feeder3.cambriumusenet.nl!feed.tweaknews.nl!209.85.213.216.MISMATCH!hl2no7855171igb.0!news-out.google.com!qk8ni19963igc.0!nntp.google.com!hl2no7855169igb.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.databases.theory Date: Mon, 2 Feb 2015 10:18:07 -0800 (PST) In-Reply-To: <3db26254-29be-4a55-8869-eecfa48cda12@googlegroups.com> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=2601:9:100:600:808c:1aa9:1630:bac8; posting-account=PBsn8woAAADaWofLEAjNrE17YVrUmBlm NNTP-Posting-Host: 2601:9:100:600:808c:1aa9:1630:bac8 References: <61044dae-51c9-43d4-87f9-1e12e0e3b15e@googlegroups.com> <2807ea7c-a50e-4a67-8357-2ccd0bdc9e57@googlegroups.com> <6cc9b130-6adc-494f-905a-b43a343416c5@googlegroups.com> <3db26254-29be-4a55-8869-eecfa48cda12@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <17212e15-f678-4fac-b862-b7caec276b75@googlegroups.com> Subject: Normalization Theory From: Tegiri Nenashi Injection-Date: Mon, 02 Feb 2015 18:18:08 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: news.cambrium.nl On Sunday, February 1, 2015 at 3:29:28 PM UTC-8, Derek Asirvadem wrote: > Please be advised that when I teach RDb Design, Normalisation is a major = subject, and I approach it as science. The first thing I do is excise the = abnormal "normal form" definitions which are marketed by the schizophrenics= that wrote them, retaining the three Normal Forms that undamaged human bei= ngs need. Then I teach the science, complete with exercises that use sever= al tables (frauds use single "relations" to construct their Straw Man argum= ents; papers; mathematical poofs). Then I teach the two scientific Normal = Forms that are /informally/ but scientifically (at least to those who have = their feet on the ground) defined in the Relational Model (the concrete Cod= d RM, not the 42 religious artefacts). There are 2 sides of the issue. Is database normalization theory polished e= nough to be presentable to an average undergrad? My answer is no. However, = is normalization topic a gem of database theory? Yes. Has it progressed sin= ce 1970s? Let's postpone this answer a little. > The fact that the theorists continue to define schizophrenic "normal form= s", the purpose of which is to justify Record Filing Systems that are non-r= elational, in forty five years, stands as evidence that the theorists in ou= r field understand only Record Filing systems. The fact that you are so upset by Normal form definitions indicates that yo= u pay no attention to what happens underneath. I'm little uncomfortable wit= h those voluntaristic definitions as well, but happily ignore them because = there is something more fundamental going on. In case if you are wondering = how normalization theory progressed since its early days: 1. The first foundation that was explored quite exhaustively in last couple= decades was information measure (entropy). Is entropy "not scientific" eno= ugh for you? 2. Algebraic approach was also studied quite in depth. Remarkably, the majo= r tool in algebraic approach is algebra of binary relations, and one of the= main results is that relation with multivalued dependency is formally desc= ribed by commutativity of relational composition.=20 To conclude, a typical database introductory course is quite odd. The first= half studies relational algebra, but later almost nothing from that kit is= utilized when teaching normalization theory. =20