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Cc: Karsten Hilbert <Karsten.Hilbert@gmx.net>,
	pgsql-sql@postgresql.org
From: Michael Glaesemann <grzm@myrealbox.com>
Subject: Re: surrogate key or not?
Date: Fri, 23 Jul 2004 18:59:33 +0900
To: Kenneth Gonsalves <lawgon@thenilgiris.com>


On Jul 23, 2004, at 4:57 PM, Kenneth Gonsalves wrote:

> On Friday 23 July 2004 12:27 pm, Karsten Hilbert wrote:
>
>> BTW, our full schema is here:
>>
>> http://www.hherb.com/gnumed/schema/
>
> i was looking at your schema. i'm not a database pro, but in master 
> tables i
> see you have made the serial id as the primary key. i do it this way:
>
> id	serial unique
> name	varchar(25) not null
> primary key is name - after all, you are going to search this on name 
> arent
> you? or is there some advantage in doing it your way?

Kenneth,

You appear to be misunderstanding the purpose of a primary key. A 
primary key is used to ensure there is a way to identify each row 
uniquely. It is quite independent of which columns you may or may not 
want to search on. If name is not going to be necessarily unique in the 
table, it isn't a primary key.

Michael Glaesemann
grzm myrealbox com