>>>..... In any case the "child table" appointments would still have the date.
>>
>>Why?
>
>Oh, well, an alternative is to have a foreign key to the date table.

Yes but no.

If there is a Date table and a Appointment table and both have a Day file Appointment.Day could be called a FK anyway. (And this would be the real FK)

I think mean a surrogate index that uses integers.

And even that might not be used. If the appointments are single records with a start time + duration one would use DateTime and there is a date in it. So no need to store the Date to an extra field.

Agnes