Date: Thu, 27 Jul 2006 15:35:20 -0400
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Mark Lewis <mark.lewis@mir3.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Savepoint performance
Message-ID: <20060727193520.GG18774@surnet.cl>
Mail-Followup-To: Mark Lewis <mark.lewis@mir3.com>,
	pgsql-performance@postgresql.org
References: <1154020755.1634.509.camel@archimedes>
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Mark Lewis wrote:

> So my question is, how expensive is setting a savepoint in PG?  If it's
> not too expensive, I'm wondering if it would be feasible to add a config
> parameter to psql or other client interfaces (thinking specifically of
> jdbc here) to do it automatically.  Doing so would make it a little
> easier to work with PG in a multi-db environment.

It is moderately expensive.  It's cheaper than starting/committing a
transaction, but certainly much more expensive than not setting a
savepoint.

In psql you can do what you want using \set ON_ERROR_ROLLBACK on.  This
is clearly a client-only issue, so the server does not provide any
special support for it (just like autocommit mode).

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support