Re: Surrogate Keys: an Implementation Issue

From: paul c <toledobythesea_at_oohay.ac>
Date: Sun, 30 Jul 2006 15:47:42 GMT
Message-ID: <yw4zg.281148$IK3.258613@pd7tw1no>

Brian Selzer wrote:
> "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.

No, it doesn't depend on 'circumstances'. Assuming variables, as you are, the truth of a statement depends on the value of the relation that is assigned to a variable.

p Received on Sun Jul 30 2006 - 10:47:42 CDT