Re: Len Silverston's Universal Data Models sanity
Date: Tue, 04 May 2004 23:46:30 -0300
Message-ID: <pan.2004.05.05.02.46.29.91031_at_dutra.fastmail.fm>
Em Tue, 04 May 2004 17:15:45 -0700, Alfredo Novoa escreveu:
> It is not so easy. There are different accounting cultures. American
> accounting data models are strange to me.
Agreed. So let's say 'universal' it was a bit too much optimistic.
> On the other hand what I miss more in such books is that the designs
> don't represent the vast majority of the business rules like
> integrity constraints and derived data
I see, and in fact I expected that. But I do think they could yet do good in guiding early stages of modelling and enabling easier data exchange. XML done better in a way.
> and they are highly redundant.
Do you mean, not normalised?
> For instance the stock of an article could be derived from the
> inputs and the outputs of the article.
Yes, but there are performance considerations there. For example, how do you keep the system from degrading after some years of highly movemented goods?
> In wich sectors do you work?
Retail: supermarkets, fidelity programs.
We're considering entering also financial systems (accounting, controlling, credit cards), and perhaps act also as a software factory. Hopefully only after we decide on a better, relational tool like Alphora Dataphor or yours.
> I have several designs I could post, but I have to translate them
> first.
No need to translate, Brazilians can understand Spanish quite well... it would be nice to set somethink like a wiki for that. Problem would become maintaining it, and settling on a preferred format. I would say Tutorial D would be quite nice for that, D4 good enough, ANSI SQL acceptable and other SQL flavours a minor evil. ER and UML diagrams bad, bad bad as there isn't even a standard format for them. Any other suggestions?
-- Leandro Guimarães Faria Corsetti Dutra +55 (11) 5685 2219 Av Sgto Geraldo Santana, 1100 6/71 +55 (11) 5686 9607 04.674-000 São Paulo, SP BRASIL http://br.geocities.com./lgcdutra/Received on Wed May 05 2004 - 04:46:30 CEST