RE: Data Modeling?

I totally agree with the pencil and paper route. One comment on tools doing more than just the basics.....checkout IBM's Rational Data Architect. I saw a demo and it's cool. Seriously...... for example, reverse engineer and existing database, pull the physical layout (DBA) into a logical layout (non-DBA), modify either logical or physical... and then you can compare the 2.... like doing a "diff" on unix files. Then the comparison will allow you to push changes one way or the other, or generate script to do it when you want/incorporate into whatever else you got going on. Also the "diff" functionality is useful for comparing the physical layout stored in the tool with the actual DB layout on the server.... and thereby allowing you to generate alter statements to adjust the DB on the server (you know the DB we as DBAs actually work with ;))..... So you can keep the managers and other people who care about tracking data models and stuff happy, and still get your job done ;) Don't know the cost.... Lord help me, I've been drinking the blue Kool-aid..... better blue than red ;p Norma Jean Sebastian ERP Support Administration GIS- Enterprise Technical Services -----Original Message----- From: informix-list-bounces@iiug.org [mailto:informix-list-bounces@iiug.org] On Behalf Of Double Echo Sent: Friday, December 08, 2006 7:36 AM To: informix-list@iiug.org Subject: Re: Data Modeling? Urich Ann wrote: > Is it a 'norm' that DBA's use a data model (both logical and physical) > to design a database? > or > Are data models mostly used as a 'post-design' afterthought, to document > what is physically already implemented? > > In most shops that I have worked, we never used a model. And if they did > have a data model, it was never up-to-date. > The model was an after-thought for documentation purposes... It was done > after the table was implemented in Production. > > Is there a good modeling tool for Informix 10? > Is there any one 'data modeling' design class that is better then > others? > > I think you should look at Data Modeling from two perspectives. One view is for new work, the second for existing systems. On new work, I think the best Data Modeling tool is still pencil and paper, or a white board. This is a fun time, where you can actually design the data without any restrictions other than what the business people throw into it to screw it up. On existing systems, probably best to reverse engineer the schema with some kind of software tool, but even the best I've never used to go and make changes to the database with it. PowerDesigner does a good job, even Visio is adequate for that. But I've yet to see some kind of software product actually go beyond just linking primary and foreign keys. You can write your own column cross-reference tool to see column relationships, which is basically what visual tools are going to do, unless you can link some kind of documentation in the metadata describing what each table is and how it relates to the other tables. Good luck if you find something that doesn't cost a fortune, and actually does more than just draw lines connecting primary-keys and foreign-keys together. The evaluation of current products will be interesting, you should produce a white paper of comparison products, it might be quite beneficial for the rest of us. _______________________________________________ Informix-list mailing list Informix-list@iiug.org http://www.iiug.org/mailman/listinfo/informix-list ============================================================ The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any reproduction, dissemination or distribution of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Tellabs ============================================================