Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!wns14feed!worldnet.att.net!207.35.177.252!nf3.bellglobal.com!ursa-nb00s0.nbnet.nb.ca!53ab2750!not-for-mail From: Bob Badour User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.databases.theory Subject: Re: Storing derived and derivable data References: <1145622076.958951.174100@t31g2000cwb.googlegroups.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Lines: 29 Message-ID: Date: Fri, 05 May 2006 01:05:46 GMT NNTP-Posting-Host: 142.176.115.36 X-Complaints-To: abuse@aliant.net X-Trace: ursa-nb00s0.nbnet.nb.ca 1146791146 142.176.115.36 (Thu, 04 May 2006 22:05:46 ADT) NNTP-Posting-Date: Thu, 04 May 2006 22:05:46 ADT Organization: Sympatico-Subscriber Xref: dp-news.maxwell.syr.edu comp.databases.theory:39192 Kenneth Downs wrote: > dawn wrote: > >> Is there database theory that includes identification of >> >> 1. the fact that values for an attribute either were or could have been >> derived? >> 2. how values for an attribute were derived? >> 3. how values for an attribute could have been derived? >> > > Dawn, hello! Long time no see. > > I saw your post and decided it was time to end my long exile, you have > asked the questions that are at the heart of my company and project. > > In order to even begin to deal with this question, you have to deal with > the 800lb gorilla called "Normalization", which forbids derived data. I > wrote an essay on that some months ago, which is here: > > http://docs.secdat.com/index.php?gppn=Normalization+and+Automation > > The states basically that derived data is part of life, and since > normalization can't deal with it, normalization is not enough to guide > serious application development. But you also can't throw it away, > because it gives good things. Yikes! Another self-aggrandizing ignorant! Plonk.