Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!linac!uwm.edu!zaphod.mps.ohio-state.edu!usc!petunia!news From: jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) Newsgroups: comp.databases Subject: Re: ER versus dependency normalization methods. Message-ID: <2754b792.a54@petunia.CalPoly.EDU> Date: 29 Nov 90 07:24:02 GMT References: <33445@netnews.upenn.edu> Distribution: comp Organization: Cal Poly State Univ,CSC Dept,San Luis Obispo,CA 93407 Lines: 31 In an article cimshop!davidm@uunet.UU.NET (David S. Masterson) wrote: >Have you seen the book "Conceptual Schema and Relational Database Design - A >Fact Oriented Approach" by G.M. Nijssen and T.A. Halpin. It discusses a >cookbook method (known as NIAM) for relational database design beginning by >working with real world examples and then step by step transforming them into >a list of facts showing the entities involved, roles they play, constraints on >entities in roles, types of facts and constraints in diagrammatic form. There >is also methodologies for transforming one design into another equivalent, but >more manageable form which then can be optimally normalized (the book talks >about optimal normalization being the balance between performance needs and >reduction of redundancy). Perhaps this method would seem a little less "silly >and artificial"? I read this book rather hastily last year and made a mental note that it bears further study. My impression was that their graphical visualization method is basically similar to ER diagramming such as the Consoi-ERM program gives on the Mac, but the NIAM approach puts more detaied information into the diagrams. To me, this seemed to make it more difficult to learn to use. One of the advantages of Consoi-ERM is its simplicity. I suspect that NIAM is more powerful, but until it is embodied in a simple, elegant program for a popular computer such as the PC or Mac, it will never become known and used. HINT: Does anyone feel like writing such a program? -- John Dudeck "If it's Object Oriented then by jdudeck@Polyslo.CalPoly.Edu definition it's A Good Thing". ESL: 62013975 Tel: 805-545-9549 -- D. Stearns