Received: from localhost (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 39EB24766FB for ; Fri, 6 Dec 2002 12:41:49 -0500 (EST) Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251]) by postgresql.org (Postfix) with ESMTP id B876D475EE2 for ; Fri, 6 Dec 2002 12:41:17 -0500 (EST) Received: (from pgman@localhost) by candle.pha.pa.us (8.11.6/8.10.1) id gB6Hf7121431; Fri, 6 Dec 2002 12:41:07 -0500 (EST) From: Bruce Momjian Message-Id: <200212061741.gB6Hf7121431@candle.pha.pa.us> Subject: Re: Rules/Trigges Trade-offs In-Reply-To: <3DF0DEA7.14D89064@nsd.ca> To: Jean-Luc Lachance Date: Fri, 6 Dec 2002 12:41:07 -0500 (EST) Cc: Richard Huxton , pgsql-sql X-Mailer: ELM [version 2.4ME+ PL99 (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Virus-Scanned: by AMaViS new-20020517 X-Archive-Number: 200212/76 X-Sequence-Number: 10664 No, the rule will affect all the rows using one query. --------------------------------------------------------------------------- Jean-Luc Lachance wrote: > Thanks for the info. > > Do you mean that if an update affects more than one row I should use > triggers because the rules will be executed only once? > > JLL > > > Richard Huxton wrote: > > > > On Friday 06 Dec 2002 4:03 pm, Jean-Luc Lachance wrote: > > > Hi all! > > > > > > Is there a guideline on the use of rules compared to triggers when both > > > can be use to achieve the same result? > > > > If I can use rules I do. Rules rewrite the query so are processed once, > > whereas triggers get processed for every row. > > -- > > Richard Huxton > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073