Re: design question

DA Morgan wrote:
> vnr1995_at_gmail.com wrote:
> > I have a table: questions(question_id, content)
> >
> > I am in the process of creating another table, titled as test, which
> > should map a unique test id to multiple questions.
> >
> > There are two possibilities to create this table:
> >
> > 1. test(test_id, a set of question_ids); the set of questions is stored
> > as a nested table.
> >
> > 2. test(surrogate_key, test_id, question_id)
> >
> > Which alternative is better? Or is there any other alternative that is
> > better than the above two?
> >
> > Thanks
>
> Think vertically: Not horizontally. And stay away from nested tables.
> --
> Daniel A. Morgan
> University of Washington
> damorgan_at_x.washington.edu
> (replace x with u to respond)
> Puget Sound Oracle Users Group
> www.psoug.org

I recently played with the idea of creating a nested table. I do not know about the extra overhead on the DBMS but from a design standpoint can a table be normalized if it has them? According to my manual 1NF says that all column values must be atomic. It seems that this is moving away from that definition. Received on Wed Dec 13 2006 - 14:42:23 CST