From: David Clarke <pigwin32@gmail.com>
To: operationsengineer1@yahoo.com <operationsengineer1@yahoo.com>
Cc: Aaron Bono <postgresql@aranya.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Alternative to serial primary key
Date: Fri, 7 Jul 2006 08:30:57 +1200
Message-ID: <12b7ac1e0607061330o34adbd6ds9bd624d3889c7fe7@mail.gmail.com> (raw)
In-Reply-To: <20060706183920.46008.qmail@web33314.mail.mud.yahoo.com>
References: <bf05e51c0607060902vdd8d993u470c128abf127d3d@mail.gmail.com>
<20060706183920.46008.qmail@web33314.mail.mud.yahoo.com>
On 7/7/06, operationsengineer1@yahoo.com <operationsengineer1@yahoo.com> wrote:
> 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.
Yes I had in fact already created my table using a serial as the
primary key but I've been reading Celko's SQL Programming Style and
the use of a hash on the address column as the primary key (and for
use in FK's) meets a number of the requirements for a good key. The
address column itself is the natural primary key but it doesn't make
for a good FK. Plus I feel I would be remiss in not exploring an
alternative to the serial key.
To recap, yes there is only a single column, yes it is varchar. I need
to do a lookup on the address column which is unique and use it as a
foreign key in other tables. Using a serial id would obviously work
and has been recommended. But having a hash function over the address
column as the primary key means I can always regenerate my primary key
from the data which is impossible with a serial key. I believe the
risk of collision using md5 is effectively zero on this data and I can
put a unique index over it.
I'm kind of new to sql so apologies if this is a naive approach.
Thanks to all for responses.
Dave
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: pigwin32@gmail.com, operationsengineer1@yahoo.com, postgresql@aranya.com
Subject: Re: Alternative to serial primary key
In-Reply-To: <12b7ac1e0607061330o34adbd6ds9bd624d3889c7fe7@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox