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Message-ID: <20060706183920.46008.qmail@web33314.mail.mud.yahoo.com>
Date: Thu, 6 Jul 2006 11:39:20 -0700 (PDT)
From: <operationsengineer1@yahoo.com>
Subject: Re: Alternative to serial primary key
To: Aaron Bono <postgresql@aranya.com>
Cc: pgsql-sql@postgresql.org
In-Reply-To: <bf05e51c0607060902vdd8d993u470c128abf127d3d@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
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> On 7/6/06, David Clarke <pigwin32@gmail.com> wrote:
> >
> > I posted a couple of weeks back a question
> regarding the use of a 100
> > char column as a primary key and the responses
> uniformily advised the
> > use of a serial column. My concern is that the key
> is effectively
> > abstract and I want to use the column as a foreign
> key in other
> > tables.
> 
> 
> I have a simple question... why do you want to use
> the column as a foreign
> key in other tables?  If you use the serial column
> then all you need is a
> simple join to get the 100 char column out in your
> query.  If you need to
> make things simpler, just create a view that does
> the join for you.
> 
> Either there is some requirement here that I am not
> aware of or it sounds
> like you may be trying to use a sledge hammer on a
> nail.
> 
> -Aaron

i agree.  all my primary keys are abstract - even
though some don't have to be.  iow, i'm comfortable
using serials as my primary key even when i don't
absolutely need to.

in any case, the primary key is typically used as a
unique identifer *and that's it*.  the uniqueness
makes it ideal for another table to use it to link
related data.

it sounds like you want a unique identifier *plus
something else*.  i'd argue that the "plus something
else" belongs in a separate column.

imho, your database life will be much easier and more
consistent.

good luck.

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