Normalization of an already normalized relation
Created by: Piiit
Is the following assumption correct?
/*
* Create a subquery to handle temporal normalization, if not done
* already by the GROUP BY PERIOD transformation above. Normalization
* of a already normalized relation has no effect, if the same bounds
* and non-temporal attributes are used.
* PEMOSER Check if this is always the case if period group by and
* distinct period are both set.
*/