Re: How long is long enough for primary key ?

From: DA Morgan <damorgan_at_psoug.org>
Date: Sat, 07 Oct 2006 10:31:41 -0700
Message-ID: <1160242298.586067@bubbleator.drizzle.com>

David Portas wrote:
> DA Morgan wrote:

>> Niall Litchfield wrote:
>>> DA Morgan wrote:
>>>> Second Normal Form
>>>> tables do not have composite primary keys
>>> huh?
>> As in my response to Dave:
>>
>> "Second normal form (2NF) requires that data stored in a table with a
>> composite primary key must not be dependent on only part of the table's
>> primary key"
>>
>> http://en.wikipedia.org/wiki/Database_normalization#Second_normal_form
>> --
>> 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

>
> LOL. Do you normally trust what you read in Wikipedia? Maybe it is on
> the reading list at U of W? That definition is completely bogus and
> worthless. Anyway it is not the same as what you originally said.
>
> 2NF has nothing to do with whether keys are composite or not. I
> recommend you study some more reliable sources to clear up your own
> misconceptions. There is no value in attempting to understand a potted
> summary otherwise.

No. But it is rather hard to photocopy Codd's books and post them here.

Perhaps you'd prefer one of these instead:

http://www.cdf.toronto.edu/~boconnel/434/normalization.txt
http://www.devx.com/ibm/Article/20859
http://www.cs.jcu.edu.au/Subjects/cp1500/1998/Lecture_Notes/normalisation/2nf.html
http://www.utexas.edu/its/windows/database/datamodeling/rm/rm7.html

I've got a couple of hundred more if these similarly produce fits of laughter.

-- 
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

Received on Sat Oct 07 2006 - 12:31:41 CDT