From: Peter Eisentraut <peter_e@gmx.net>
To: pgsql-sql@postgresql.org
Subject: Re: Bitfields always atomic? Other way to store attributes?
Date: Mon, 27 Mar 2006 21:13:17 +0200
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Cc: Bryce Nesbitt <bryce1@obviously.com>
References: <44270BF6.6080109@obviously.com>
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Bryce Nesbitt wrote:
> If I have two threads modifying the same "bit" field:
>     thread1=> update table set bf=bf | '01000'
>     thread2=> update table set bf=bf | '10000'
> Will this operation always be safe (e.g. result in bf='11000')?  Or
> must I wrap things in
> explicit transactions?

Each of these commands will be its own transaction if you don't 
explicitly start one.

> My application is to give attributes to an address table.  But maybe
> there is a better way?

Create 5 boolean fields.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/