Re: Relation Schemata vs. Relation Variables

From: paul c <toledobythesea_at_oohay.ac>
Date: Mon, 21 Aug 2006 17:28:36 GMT
Message-ID: <83mGg.433655$Mn5.393293@pd7tw3no>

Brian Selzer wrote:

> "JOG" <jog_at_cs.nott.ac.uk> wrote in message 
> news:1156163752.697442.161770_at_i3g2000cwc.googlegroups.com...

>> Brian Selzer wrote:
>>> Identity beyond that provided by a candidate key (that is, a single
>>> database
>>> state) is in the eye of the beholder:
>> Identity beyond that provided by the identifying keys is a nonsense. By
>> not encoding it you have told the system it does not exist. If this is
>> not true who is at fault?
>>

>
> How do you tell the system that it does exist? ...

Closed-world assumption.

p Received on Mon Aug 21 2006 - 12:28:36 CDT