Re: Another view on analysis and ER
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 06 Dec 2007 09:57:37 -0400
Message-ID: <4757ffd2$0$5257$9a566e8b_at_news.aliant.net>
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> Minor point: Is designation of primary keys really at the logical level?
Date: Thu, 06 Dec 2007 09:57:37 -0400
Message-ID: <4757ffd2$0$5257$9a566e8b_at_news.aliant.net>
>>David Cressey wrote: >> >>>This could have consequences for performance, ease of >>>programming, "natural joins" etc. etc. >> >>Performance is independent of choices at the logical level of discourse >>where one identifies candidate keys or designates primary keys.
>
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> Minor point: Is designation of primary keys really at the logical level?
Yes.
> Are there any substantial logical consequences?
The preponderance of foreign key references will refer to the primary key when one designates a primary key. Received on Thu Dec 06 2007 - 14:57:37 CET