Re: Normalization and DBMS
From: Leandro Guimarães Faria Corsetti Dutra <leandro_at_dutra.fastmail.fm>
Date: Wed, 12 May 2004 00:46:00 -0300
Message-ID: <pan.2004.05.12.03.46.00.535494_at_dutra.fastmail.fm>
>
> What problems are caused by this? I suspect there are some, but then
> there are tradeoffs.
Date: Wed, 12 May 2004 00:46:00 -0300
Message-ID: <pan.2004.05.12.03.46.00.535494_at_dutra.fastmail.fm>
Em Tue, 11 May 2004 22:40:10 -0500, Dawn M. Wolthuis escreveu:
> "Leandro Guimarães Faria Corsetti Dutra" <leandro_at_dutra.fastmail.fm>
>> Em Tue, 11 May 2004 20:10:10 -0500, Dawn M. Wolthuis escreveu: >> >> > it seems to have a direct correlation to the flexibility of a system >> > to withstand years of requirements changes >> >> Quite to the contrary. With nested tables, the only way to ever reach >> the subtable is thru the supertable.
>
> What problems are caused by this? I suspect there are some, but then
> there are tradeoffs.
See how you want to have it both ways. You want to 'withstand [...] requirement changes', but also a less powerful, more complex, less flexible structure.
> One thing that works well is the integrity -- when
> the parent goes away, so does the child table and there is no chance that
> a child will be born without a parent.
This is trivial. Even SQL does it right.
-- 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 12 2004 - 05:46:00 CEST