Path: news.cambrium.nl!textnews.cambrium.nl!feeder2.cambriumusenet.nl!feed.tweaknews.nl!193.141.40.65.MISMATCH!npeer.de.kpn-eurorings.net!npeer-ng0.de.kpn-eurorings.net!news.glorb.com!Xl.tags.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.megapath.net!news.megapath.net.POSTED!not-for-mail NNTP-Posting-Date: Sun, 01 Feb 2015 17:49:57 -0600 Date: Sun, 1 Feb 2015 18:49:57 -0500 From: "James K. Lowden" Newsgroups: comp.databases.theory Subject: Re: Hierarchical Model and its Relevance in the Relational Model Message-Id: <20150201184957.7a34fedb.jklowden@speakeasy.net> References: <20150128210905.8a136636.jklowden@speakeasy.net> <0fedf4f7-adc9-4ea2-90c0-4fa9321704ce@googlegroups.com> X-Newsreader: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64--netbsd) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Lines: 27 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 209.166.36.60 X-Trace: sv3-hsMoNsrmt3wKC/9A8WO6vNCqxM+rSOoG/Ppwm6aQtcijBvgKoTl+EVfHiB19JFbW8PCst5IuG+ySpXe!7gDLrigdj/l8kC4L62URNGMhD9/bR4YBkWa33WviXDoLmJHj55mOho4D6UYc3W7UbPzAtEPI71GP!ukpvEdPrSD3NayS2xwgRy2sZ4f3cDAB6 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: 1.3.40 X-Original-Bytes: 2461 Xref: news.cambrium.nl On Sat, 31 Jan 2015 18:38:26 -0800 (PST) Derek Asirvadem wrote: > > It would seem that once you introduce the average programmer to > > a hierarchical filesystem, you can never wean him of the notion that > > that's the "natural" structure for data. > > Could you please give an example of what one of those guys did, that > you consider to be incorrect In two cases that I had direct contact with, the database design reflected some form of object orientation. It used the table structure to implement an elaborated version of the entity-attribute-value table, and self-joins to construct what you or I would have designed as tables. Naturally, the design was, er, designed to be "flexible". The resulting databases were impossible to understand, comprised solely abstract nouns, and defeated the system's ability to enforce integrity constraints. Queries were tedious to read and executed poorly. When I was approached for ways to make it faster (because speed is the only thing that every application programmer and his manager understands), they were nonplussed when I suggested a Dumpster, a clean slate, and class in database design, not necessarily in that order. --jkl