Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 3C2D364FCDA for ; Thu, 1 Jan 2009 14:23:01 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 77886-04 for ; Thu, 1 Jan 2009 14:22:58 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.156]) by mail.postgresql.org (Postfix) with ESMTP id 2623564FC83 for ; Thu, 1 Jan 2009 14:22:57 -0400 (AST) Received: by fg-out-1718.google.com with SMTP id 16so2052850fgg.23 for ; Thu, 01 Jan 2009 10:22:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=WXvzS/j4wRn07LtMae8kxGMU0hWKn0zsALFukA2BXz0=; b=e1cB93lLR2BFNP1vj1/heRQka1TyuOd97Agf4ivbBhWWd4EZuF8gjOMvYWnFaC5X0c 5Wcra+KidFXELdN7a7N0spmgyCOTIo7ll0ue3pWeHUfgDDOjimOu7eAIoo+nkQ29vCWt JK/x4UbmDd08hKOEK0aVkxq8vxMyQ1AGo0Cgc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Ifc6TjZUpcbMwNKJvpm98Bi9CviVKiASCdesXSze8VBBcBBRt3Qb2yFvIXcv8iAgV2 eI2AMQHuoZAQZ24KfayPxMDjr/ayiI8Sa56+eq+N2841nqE4vrDoEJWXmwesn40F6rSX SfuVYm9KPISu3Bcxtc+FXGmqJMjKzLMZ75rIA= Received: by 10.86.94.11 with SMTP id r11mr10067639fgb.11.1230834176738; Thu, 01 Jan 2009 10:22:56 -0800 (PST) Received: by 10.86.78.15 with HTTP; Thu, 1 Jan 2009 10:22:56 -0800 (PST) Message-ID: <1d4e0c10901011022v4a1d5eeaidc2692a7729e79df@mail.gmail.com> Date: Thu, 1 Jan 2009 19:22:56 +0100 From: "Guillaume Smet" To: "Alvaro Herrera" Subject: Re: Poor plan choice in prepared statement Cc: "Tom Lane" , "Scott Carey" , bricklen , "Scott Marlowe" , "Merlin Moncure" , "pgsql-performance@postgresql.org" In-Reply-To: <20081231160118.GE3809@alvh.no-ip.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <33b743250812301059u31ce82faw3d72a38280b37402@mail.gmail.com> <2796.1230678149@sss.pgh.pa.us> <20081231160118.GE3809@alvh.no-ip.org> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200901/2 X-Sequence-Number: 32281 On Wed, Dec 31, 2008 at 5:01 PM, Alvaro Herrera wrote: > I think it has been shown enough times that the performance drop caused > by a worse plan can be orders of magnitudes worse than what's gained by > producing the plan only once. It does not seem a bad idea to provide a > way to carry out only the parse phase, and postpone planning until the > parameters have been received. It's already done in 8.3 for unnamed plans, isn't it? -- Guillaume