Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id C4762632DD5 for ; Fri, 13 Mar 2009 23:37:40 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 59164-10 for ; Fri, 13 Mar 2009 23:37:31 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.251]) by mail.postgresql.org (Postfix) with ESMTP id C411D632718 for ; Fri, 13 Mar 2009 23:37:38 -0300 (ADT) Received: by an-out-0708.google.com with SMTP id c3so1244180ana.28 for ; Fri, 13 Mar 2009 19:37:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=A5kooQN2PivsGHzhPjcSbaIMjtzOZfCE+BZ7LYaP4D0=; b=iAlm3yNVYkRPtqz3K1QOxcmf5QzIbzjRcf4vX5UoOZ/TIgR/Ixs2pq2CsQ0ZTns3aX 2KI+wmaNpmhbIHBI+aYHIIhD0ZyOb7H/pcm0oCrDA1ehifIFfyDJcCMaVR8OCGD/cixK uBOIROTxTAkDWcsRIljPnBCjCB16rvL1PkwOk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=TZbb7rZbLKjS2zg0HGeruxStt1rvNUywbZGycboghaoz4DvpDg7u4qrHTep2uo8XkH KIobG8q8xJxFgQwN7e4Z8WB7libGLWp9F8bh1MaTMXoTPpUxDi5frwapYepxCIzsUiy7 /YLjgJq6l+VRQa61/SfrHQD5IGc2EXqbMrae4= MIME-Version: 1.0 Received: by 10.100.197.3 with SMTP id u3mr1357624anf.62.1236998257105; Fri, 13 Mar 2009 19:37:37 -0700 (PDT) In-Reply-To: <26666.1236996376@sss.pgh.pa.us> References: <49B922C0.6050700@sun.com> <49BA5537.8060002@sun.com> <87prgl4jbh.fsf@oxford.xeocode.com> <49BA79A4.9030208@rentec.com> <12431.1236965004@sss.pgh.pa.us> <87d4ck50h1.fsf@oxford.xeocode.com> <26666.1236996376@sss.pgh.pa.us> Date: Fri, 13 Mar 2009 22:37:37 -0400 Message-ID: <603c8f070903131937t1c33fa97k29e7d8d07fa2e83@mail.gmail.com> Subject: Re: 8.4 Performance improvements: was Re: Proposal of tunable fix for scalability of 8.4 From: Robert Haas To: Tom Lane Cc: Gregory Stark , Alan Stange , "Jignesh K. Shah" , Greg Smith , "pgsql-performance@postgresql.org" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.238 tagged_above=0 required=5 tests=AWL=0.238 X-Spam-Level: X-Archive-Number: 200903/183 X-Sequence-Number: 33105 On Fri, Mar 13, 2009 at 10:06 PM, Tom Lane wrote: > Gregory Stark writes: >> Tom Lane writes: >>> Ugh. =A0So apparently, we actually need to special-case Solaris to not >>> believe that posix_fadvise works, or we'll waste cycles uselessly >>> calling a do-nothing function. =A0Thanks, Sun. > >> Do we? Or do we just document that setting effective_cache_size on Solar= is >> won't help? > > I assume you meant effective_io_concurrency. =A0We'd still need a special > case because the default is currently hard-wired at 1, not 0, if > configure thinks the function exists. =A0Also there's a posix_fadvise cal= l > in xlog.c that that parameter doesn't control anyhow. I think 1 should mean no prefetching, rather than 0. If the number of concurrent I/O requests was 0, that would mean you couldn't perform any I/O at all. ...Robert