Message-Id: <5.0.2.1.0.20010207214024.009ee160@mail.retep.org.uk>
Date: Wed, 07 Feb 2001 21:41:43 +0000
To: Bruce Momjian <pgman@candle.pha.pa.us>,
	"Thies C. Arntzen" <thies@digicol.de>
From: Peter Mount <peter@retep.org.uk>
Subject: Re: PostgreSQL and PHP persistent connections
Cc: pgsql-jdbc@postgresql.org,
	PostgreSQL-interfaces <pgsql-interfaces@postgresql.org>
In-Reply-To: <200102071912.OAA27530@candle.pha.pa.us>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 14:12 07/02/01 -0500, Bruce Momjian wrote:
>Thies, we talked at LinuxWorld about improving the reliability of
>persistent PostgreSQL connections in PHP.
>
>I believe the problem is that persistent connections sometime do not
>pass clean sessions because of open transactions and SET changes to the
>session.
>
>We discussed using 'ROLLBACK' before passing a connection to a new user,
>but the problem was that ROLLBACK with no open transaction causes a
>server log error message.  We discussed adding 'ROLLBACK SILENT' to fix
>this, but I believe a better, more portable solution is a simple "BEGIN
>WORK;ROLLBACK".  This will do nothing if there is no open transaction,
>and will ROLLBACK any open transaction.  I propose this be sent by PHP
>as the first query when passing persistent connections.
>
>As far as SET changes, does anyone on the PostgreSQL interfaces list
>have a suggestion on how to RESET all session parameters?  Seems we may
>need to add this feature in to the backend.

Some Java apps utilise connection pools so they would possibly benefit. I 
could add the BEGIN WORK;ROLLBACK; to JDBC.

Peter