[AccessD] OT: The Great Primary Debate

On 4 Jun 2004 at 15:46, Ken Ismert wrote:

> On the other hand, the Autonumber is supposed to be a 'meaningless' unique
> ID. But, consider an auto-generated date dimension table, with consecutive
> date records. Think an Autonumber key is meaningless in this situation?
> Think again - it really represents the number of days since Day Zero (the
> earliest date record in your table). 

Does it? What if you:

1.  Delete records and rebuild the table without compacting the database.
2.  Create records with an algorithm that generates records counting backwards 
from an end date
3. Extend your table by adding earlier dates after you build your first date 
range.
4.  etc

If you rely on the ANPK to be meaningful and use it in calcuations base on your 
assumption, you can get into trouble very quickly.




 
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