Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 5D9DC64FD08 for ; Mon, 22 Dec 2008 14:07:30 -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 83503-01 for ; Mon, 22 Dec 2008 14:07:26 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.181]) by mail.postgresql.org (Postfix) with ESMTP id 5C7A264FC9D for ; Mon, 22 Dec 2008 14:07:26 -0400 (AST) Received: by wa-out-1112.google.com with SMTP id j4so1290762wah.19 for ; Mon, 22 Dec 2008 10:07:25 -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=m8ldlYn0N5N+LKUbGkde3iu/E9eJVuJcrfc/T9HifGo=; b=Zwi50dyhnRU0cFqF/Aeci3rXP0tZ3Y4XcBnybT8XLUzcXnop9LQAB1HMLoW6fiJEQH b1kigbkuajjDozDn1RIfrreyXmRQzdUHLmrDTZqCDpy5NLvXjyLkArELDBdPUSdLSOvD jEUEb3PJIkWR3XugW5UE4hJewFYp6xPzZz3Cc= 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=ECWPYkMxNz2nbYtNwYX+pNejKPIzZSDdC+qxt95giIrkjI7JF3EFt9E5LmSkDmR3MV PsvW5M78A2x4Psuv0NX2y/92pCbNCmVUYU5vZvu+kihMLGfzS6hGePKmYGgPDU66ocT5 Feb/IIVrkSaBUy79PudfLnBMqXF/R0Zw7e898= Received: by 10.114.130.1 with SMTP id c1mr4187596wad.73.1229969244994; Mon, 22 Dec 2008 10:07:24 -0800 (PST) Received: by 10.114.132.17 with HTTP; Mon, 22 Dec 2008 10:07:24 -0800 (PST) Message-ID: Date: Mon, 22 Dec 2008 11:07:24 -0700 From: "Scott Marlowe" To: "Marc Mamin" Subject: Re: temp_tablespaces and RAID Cc: pgsql-performance@postgresql.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: 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: 200812/196 X-Sequence-Number: 32232 On Mon, Dec 22, 2008 at 7:40 AM, Marc Mamin wrote: > > Hello, > > To improve performances, I would like to try moving the temp_tablespaces > locations outside of our RAID system. > Is it a good practice ? Maybe yes, maybe no. If you move it to a single slow drive, then it could well slow things down a fair bit when the system needs temp space. OTOH, if the queries that would need temp space are few and far between, and they're slowing down the rest of the system in weird ways, it might be the right thing to do. I'm afraid we don't have enough information to say if it's the right thing to do right now, but there are reasons to do it (and not).