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Date: Tue, 28 Feb 2006 12:07:21 -0700
From: Michael Fuhr <mike@fuhr.org>
To: Eugene Prokopiev <prokopiev@stc.donpac.ru>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: Python psycopg transaction isolation level
Message-ID: <20060228190721.GA6495@winnie.fuhr.org>
References: <44049611.8050300@stc.donpac.ru>
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On Tue, Feb 28, 2006 at 09:27:29PM +0300, Eugene Prokopiev wrote:
> connection = psycopg.connect("host="+server+" dbname="+database+" 
> user="+login+" password="+password)
> cursor_modify = connection.cursor()
> cursor_modify.execute("update messages set flag=1 where flag=0")
> connection.commit()
> 
> On running it sometimes I got:
> 
> psycopg.ProgrammingError: ERROR:  could not serialize access due to 
> concurrent update

psycopg's default isolation level is SERIALIZABLE.  I think the way
to set the isolation level to READ COMMITTED is:

connection = psycopg.connect(...)
connection.set_isolation_level(1)

You'll find more psycopg expertise on the psycopg mailing list:

http://lists.initd.org/mailman/listinfo/psycopg

-- 
Michael Fuhr