Re: Dreaming About Redesigning SQL

Originally posted by Bob Badour

> "andrewst" <member14183_at_dbforums.com> wrote in message

> news:3552095.1067851333_at_dbforums.com"]news:3552095.1067851333_at_d-
> bforums.com[/url]...

> > Yes, in the relational model if you had originally allowed for
> only one

> > phone per person by putting a phone_no column in the person
> table, and

> > now wanted multiple phones per person, you would have to move
> the

> > phone_no attribute to a separate table.

>

> A relation valued attribute need not be in a separate relvar. I
> suggest a

> little more study is in order for you.

I know that, hence my comment in my next paragraph: "So if this is a single attribute, it is actually a relation-valued attribute with columns phone_no, phone_type etc." However, I see no particular benefit in using a relation-valued attribute for phone numbers; my preference would be for the separate table. Apologies if I misled anyone.

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