Re: Another view on analysis and ER
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 06 Dec 2007 10:31:15 -0400
Message-ID: <475807b4$0$5262$9a566e8b_at_news.aliant.net>
>
> Oops, sorry. SQL does indeed use primary key designation, not column
> names, if you're not explicit. But SQL is well-known for mixing logical
> and physical concerns. Anyway, I don't think this is a good enough
> reason to say that key primacy is a logical issue.
Date: Thu, 06 Dec 2007 10:31:15 -0400
Message-ID: <475807b4$0$5262$9a566e8b_at_news.aliant.net>
Jon Heggland wrote:
>>Granted, but it will be explicit which key a foreign key refers to (or >>it will be implicitly given by the attribute names in the foreign key).
>
> Oops, sorry. SQL does indeed use primary key designation, not column
> names, if you're not explicit. But SQL is well-known for mixing logical
> and physical concerns. Anyway, I don't think this is a good enough
> reason to say that key primacy is a logical issue.
Keys and references are logical issues and not physical issues. Physical issues affect only performance. Received on Thu Dec 06 2007 - 15:31:15 CET