[AccessD] OT: The Great Primary Debate

On 7 Jun 2004 at 13:27, Ken Ismert wrote:

> 
> 3. That's why I said auto-generated! This is where relying on a ANPK can
> cause you problems: you can't extend the table without ruining your
> calculations.
>

> For regular, sequential data (no interruptions) with a single field natural
> key, or any data where a unique key can be mathematically calculated (as
> above), you can make an argument that ANPK is redundant, and can actually
> make the data more difficult to work with. This is where intent of the data,
> and your data modeling style, plays the deciding role in your PK choice.
> 

In your data dimension table example, you are creating a meaningful field 
SequentialDateNumber (which you are calling ID) and are using it in data 
calculations.  

Thr real question in this situation is not whether you use this natural key as 
a PK, but whether you have a PK in the table at all - which comes down to the 
sub-debate about "what is a PK and what is it used for" :-)

















 
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