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@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 "

>
> is
>

>>>also moot.
>>
>>Until you consider other relations referring to the same entity.
>>Their attributes may or may not have to be updated as well.

>
> 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 - 06:06:31 CST