Re: Q: Historical primary key

Atul Ashar wrote:
>
> Barry Johnson wrote:
> >
> > Roger Wernersson (roger.wernersson_at_adra.se) wrote:
> >
> > Based on requirements as stated, just as you suggest...except I
> > might add the Customer_Valid_Date in your original draft to the
> > Customer shown above if that is still required....and I might
>
> Instead of valid_from, I think adding current address and phone number
> (any one based on its importance if more than one). This will help as you
> avoid join(s).
>

This won't do. The issue is to schedule future changes so that if I select the phone number today I get one and tomorrow I get another without changing the data.

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