Re: Cascade updates on primary keys..

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From: Samuel R. Neff (blinex_at_newsgroup.nospam)
Date: 12/17/04 

Date: Fri, 17 Dec 2004 14:33:05 -0500

When the primary key is used as a foreign key in another table, then
the use of a compound primary key is both wasteful and
non-normalized--it duplicates data unnecessarily.

Sam

On Fri, 17 Dec 2004 13:20:12 -0600, "David Browne" <davidbaxterbrowne
no potted meat@hotmail.com> wrote:

>
>"Samuel R. Neff" <blinex@newsgroup.nospam> wrote in message
>news:fc76s0ltjsfq6g9hdl15gq4v356mm5j2ke@4ax.com...
>>
>> You shouldn't link tables on multiple fields--it's a non-normalized
>> and waisteful design. Define a single primary key field such as an
>> int identity field and use that as the fk to the other table.
>
>1) There's nothing "non-normalized" about a compound primary key.
>
>2) There's nothing "wasteful" about a compound primary key.
>
>But,
>
>3) Primary keys should be immutable, and should never use cascade updates.
>
>So if you must update a compound key, you will need to introduce a surrogate
>primary key (eg int identity primary key).
>
>
>David
>

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