Re: Peter Chen and Charles Bachman
From: Leandro Guimarães Faria Corsetti Dutra <leandro_at_dutra.fastmail.fm>
Date: Wed, 05 May 2004 18:34:17 -0300
Message-ID: <pan.2004.05.05.21.34.17.793912_at_dutra.fastmail.fm>
> schema.
Date: Wed, 05 May 2004 18:34:17 -0300
Message-ID: <pan.2004.05.05.21.34.17.793912_at_dutra.fastmail.fm>
Em Wed, 05 May 2004 14:25:07 -0700, Gene Wirchenko escreveu:
>> An ERD is a diagram. A draft. For presentation. Nothing >>more.> something useless? If I have an ERD, I use it to develop the database
>
> Bah! You think I am going to go to the trouble of drawing
> schema.
Yet it is just a draft. Incomplete and misleading.
>> So it is not a logical model. At most a conceptual one, and >>incomplete at that.> detail. It is not the physical model though.
>
> Nope. It can be a logical model, if done to a RW amount of
Physical is totally another story.
ERDs can't represent the constraints of the logical model.
-- 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 - 23:34:17 CEST