Received: from mail.mobileway.com ([212.155.187.171])
	by postgresql.org (8.11.3/8.11.1) with SMTP id f35CTo821021
	for <pgsql-sql@postgresql.org>; Thu, 5 Apr 2001 08:29:50 -0400 (EDT)
	(envelope-from loic.bourgeois@mobileway.com)
Received: (qmail 3694 invoked from network); 5 Apr 2001 12:29:43 -0000
Received: from chablis.local (HELO mobileway.com) (192.168.1.65)
	by mailadmin.local with SMTP; 5 Apr 2001 12:29:43 -0000
Message-ID: <3ACC6537.9080200@mobileway.com>
Date: Thu, 05 Apr 2001 14:29:43 +0200
From: =?ISO-8859-1?Q?Lo=EFc?= Bourgeois <loic.bourgeois@mobileway.com>
Organization: MobileWay
User-Agent: Mozilla/5.0 (X11; U; Linux 2.2.12-32 i686; en-US;
	m18) Gecko/20010131 Netscape6/6.01
X-Accept-Language: en, fr
MIME-Version: 1.0
To: pgsql-sql@postgresql.org
Subject: SELECT ... FOR UPDATE
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Archive-Number: 200104/76
X-Sequence-Number: 2416

I have to create a program to use the lastest version of PostgreSQL.
Many processes of this program must run in parallele.
In a table I have to select some specific row next insert a new row with 
the same search carateristiques
and commit.

But between the select and the insert action none other proccesses 
execute the same research parameters (which must return the same lines)
before the commit of the first process. Or the result of the second 
select must contain the insert result of the precedent process.

I known I must use SELECT FOR UPDATE and or BEGIN section with lock table.
What is the lock option mode.


Thanks a lot for all the informations.

For resume I would like to do a SELECT ... FOR UPDATE with the option NOWAIT (cf. ORACLE instruction).