Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!news-FFM2.ecrc.net!fu-berlin.de!uni-berlin.de!not-for-mail From: Kenneth Downs Newsgroups: comp.databases.theory Subject: Re: Normalization and Derived Information Date: Sun, 10 Oct 2004 10:41:45 -0400 Lines: 33 Message-ID: <8nhbkc.5d7.ln@mercury.downsfam.net> References: <367sic.063.ln@mercury.downsfam.net> <18c7b3c2.0409221847.2c7cc2c6@posting.google.com> <18c7b3c2.0409241139.1b76e22f@posting.google.com> Reply-To: sameas@email.address Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-Trace: news.uni-berlin.de jwlszue/RtODVjLin9CuWg1EkDMpQAyhyKFqGptc7TI2m0M+rm X-Orig-Path: mercury.downsfam.net!nobody User-Agent: KNode/0.7.7 Xref: dp-news.maxwell.syr.edu comp.databases.theory:26730 Bill H wrote: > Kenneth: > > "Kenneth Downs" wrote in message > news:mtf9kc.so1.ln@mercury.downsfam.net... > > [snipped] > >> Although I still believe that pre-stored calculated values are faster >> than calc-at-read, I'm going to drop that line for now and try to pursue >> your suggestion of the history table, I want to make sure I fully >> understand what you are suggesting. > > There are some excellent reasons for storing calculated values; especially > in accounting and other money handling applications. In fact, one might > even go so far as to state it is advisable to maintain duplicate data in > order to effectuate financial error control. > Yes, my final fallback is the audit trail. Seeing each column in a chain of calculations gives the auditors the warm-fuzzies, they hate it when you tell them, "Oh, the gross profit calc is OK, trust me." If I can make the customer happy and guarantee correctness, I'll do it and leave the quetion of theory to another day. In this particular response to Mr. Celko however I am pretending that I never want to materialize anything, and trying to pursue that through to its final endpoint so that I can discover anything I've missed by materializing all these years. -- Kenneth Downs Use first initial plus last name at last name plus literal "fam.net" to email me