Re: design question

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 13 Dec 2006 22:03:03 -0000
Message-ID: <Q-WdnVSHu8wO5R3YnZ2dnUVZ8sWhnZ2d@bt.com>

"Bruman" <uv_katastrophe_at_yahoo.com> wrote in message news:1166042543.456028.182860_at_16g2000cwy.googlegroups.com...
>
> 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.
>

I don't think there is anything in Codd's original definition that precludes the use of table or array types as data types, provided you treat them as atomic types. In other words, you cannot 'peek inside' the structure of a value of a complex type to use the algebra on components of that type.

In other words you can only say things like:

where X = Y
if X and Y are values of the complex data type, they may not be values of the sub-components of the complex data type.

-- 
Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

Received on Wed Dec 13 2006 - 16:03:03 CST