Re: Surrogate Keys: an Implementation Issue
Date: Sun, 30 Jul 2006 04:53:41 GMT
Message-ID: <pXWyg.137638$dW3.94230_at_newssvr21.news.prodigy.com>
"paul c" <toledobythesea_at_oohay.ac> wrote in message
news:zTOyg.269253$IK3.233927_at_pd7tw1no...
> Brian Selzer wrote:
>> "paul c" <toledobythesea_at_oohay.ac> wrote in message >> news:g9Nyg.263082$iF6.250988_at_pd7tw2no... >>> Brian Selzer wrote: >>>> What's the point of a database if it doesn't reflect some aspect of >>>> reality. ... >>> To talk precisely about whatever we want to talk about. Nothing more. >>> Doesn't need to be real. >>> >> >> Agreed. But even a conceived universe subsumes certain absolutes, such >> as time. >> >
> In that case, the statements in the database should talk about time, ie.,
> aspects of time. These are different from statements about the time it
> takes the database to say something.
>
There can be no discussion without time. Relational assignment cannot exist without the concepts of before and after. And the truth of a statement belonging to the database state that existed before an assignment depend on the circumstances that obtain before the assignment, which may no longer remain after. Thus each database state is separate and distinct and disjoint. The truth of the statements in each database state depend only on the circumstances that existed when it came into being; therefore, without some means to tie them together, that is, to correlate the constituent statements, the argument that a key value in one database state means the same thing in another is fallacious.
> p
Received on Sun Jul 30 2006 - 06:53:41 CEST