>So Jim,
>
>>I would say that the chief reasons for de-normalizing would be speed and convenience.
>
>Are you saying that if I store all the computed fields, the design IS normalized, and if I compute them on the fly, it's not normalized?
>
Jill,

The quote you used is not from me. Storing computed values is a violation of the third normal form so tables with computed values in them are not normalized to the 3rd NF.

3rd NF says all fields in a table are dependant for their value on the Primary Key only and not on any other fields that are not alternate keys. Computed fields are dependant on the values that enter into the computation which are not alternate keys nor are they the PK, therefore a table that stores a computed value is not in 3rd NF.