Re: Another view on analysis and ER
Date: Tue, 18 Dec 2007 08:06:31 -0400
David Cressey wrote:
> "rpost" <rpost_at_pcwin518.campus.tue.nl> wrote in message
>>David Cressey wrote: >> >>[...] >> >>>The question of whether it's "the same entity" or "a different entity "
>>>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 - 13:06:31 CET