Re: Another view on analysis and ER
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Tue, 18 Dec 2007 08:06:31 -0400
Message-ID: <4767b7c9$0$5271$9a566e8b_at_news.aliant.net>
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> is
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> Are they really "referring to the same entity"? Or are they "referring to
> data values that describe and/or identify some entity"? Can an entity be
> identified without data?
Date: Tue, 18 Dec 2007 08:06:31 -0400
Message-ID: <4767b7c9$0$5271$9a566e8b_at_news.aliant.net>
David Cressey wrote:
> "rpost" <rpost_at_pcwin518.campus.tue.nl> wrote in message
> news:c1f35$4766eca5$839b4533$16718_at_news1.tudelft.nl...
>
>>David Cressey wrote: >> >>[...] >> >>>The question of whether it's "the same entity" or "a different entity "
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> is
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>>>also moot. >> >>Until you consider other relations referring to the same entity. >>Their attributes may or may not have to be updated as well.
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> Are they really "referring to the same entity"? Or are they "referring to
> data values that describe and/or identify some entity"? Can an entity be
> identified without data?
That depends on your definition of data. Can you identify yourself if nothing about you has been represented suitably for machine processing?
I think you can. You can probably even communicate that identity to another human without representing anything suitably for machine processing. You can probably even identify Grandpa's Axe with a grunt and a gesture.
However, we cannot manage data without data, and database theory is all about managing data. Received on Tue Dec 18 2007 - 13:06:31 CET