Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 3C93363242D for ; Sat, 10 Jan 2009 15:08:27 -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 52864-01-8 for ; Sat, 10 Jan 2009 15:08:23 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-bw0-f20.google.com (mail-bw0-f20.google.com [209.85.218.20]) by mail.postgresql.org (Postfix) with ESMTP id 941186322FD for ; Sat, 10 Jan 2009 15:07:08 -0400 (AST) Received: by bwz13 with SMTP id 13so4110358bwz.19 for ; Sat, 10 Jan 2009 11:07:06 -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=+RyBDtn1zjurbJNVifT53NSwHNyndUsz9dXiOetKEQs=; b=og9D7WyN9bAuzEIxssRtSK41J2r3kKwwio3UeZpFIG2JEojjCuwJ99gwPso4cgNY0T DSCIecrwoCzytAZMocieldkx+DXbaQ/+3uNN7bIFAO8Tx0AN+9mFNgbCZtub/zch+Iv+ xw5q+QpRmcpNhTG8Pn2omba+3ZANKrAKLZjL8= 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=dpsrE85hrllA1P9QG9LJZgJue+e2Fjm+Z5WgY2tMDFb7Ay7TmDnuMU6uqPggBVNz7X r3hcN41mts/XsLuqq8OQjjt5+kihtUlKE8OCNwe5cH8cWgkFOQsg0ejfNCp7eqvOfmnI inMI2b1bqdt7U6V7YRtYefTxbFZ3oquMN9+hI= Received: by 10.223.110.211 with SMTP id o19mr516766fap.57.1231614426586; Sat, 10 Jan 2009 11:07:06 -0800 (PST) Received: by 10.223.107.134 with HTTP; Sat, 10 Jan 2009 11:07:06 -0800 (PST) Message-ID: <603c8f070901101107m3321d2acu439cea602d6c7a1c@mail.gmail.com> Date: Sat, 10 Jan 2009 14:07:06 -0500 From: "Robert Haas" To: "Tom Lane" Subject: Re: [SPAM] Re: posix_fadvise v22 Cc: "Peter Eisentraut" , "Gregory Stark" , pgsql-hackers@postgresql.org, "Greg Stark" , "ITAGAKI Takahiro" In-Reply-To: <24021.1231613465@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <603c8f070901012011hca2c36flf527a5cd01695205@mail.gmail.com> <262184F8-1206-4E2C-B50F-9FF84E63C1B6@enterprisedb.com> <200901032342.19435.peter_e@gmx.net> <87iqowt3ba.fsf@oxford.xeocode.com> <4961C80C.6030307@gmx.net> <24021.1231613465@sss.pgh.pa.us> 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: 200901/773 X-Sequence-Number: 131417 > I think at a minimum there should be a manual configuration switch > (ie something in pg_config_manual.h) to allow the builder to disable > use of posix_fadvise, even if configure thinks it's there. Depending > on buildfarm results we may have to do more than that. This seems pretty pointless, since there is already a GUC to control the behavior, and the default is off. The only value here would be if you could demonstrate that even with effective_io_concurrency set to 1 there is a significant performance dropoff. But that would probably be an argument for rejecting the patch outright, not adding a compile-time switch. ...Robert