X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 65ACA9FB351 for ; Thu, 17 Aug 2006 01:57:51 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 80882-03 for ; Thu, 17 Aug 2006 01:57:40 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from noel.decibel.org (noel.decibel.org [67.100.216.10]) by postgresql.org (Postfix) with ESMTP id 2A34E9FB2F2 for ; Thu, 17 Aug 2006 01:57:40 -0300 (ADT) Received: by noel.decibel.org (Postfix, from userid 1001) id 3378256427; Wed, 16 Aug 2006 23:57:24 -0500 (CDT) Received: (hashcash-sendmail, from uid 1001); Wed, 16 Aug 2006 23:57:23 -0500 Date: Wed, 16 Aug 2006 23:57:23 -0500 From: "Jim C. Nasby" To: Carl Youngblood Cc: pgsql-performance@postgresql.org Subject: Re: Beginner optimization questions, esp. regarding Tsearch2 Message-ID: <20060817045723.GY21363@pervasive.com> References: <44DAFB2B.4070307@archonet.com> <20060815150529.GO27928@pervasive.com> <20060815192145.GI21363@pervasive.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: FreeBSD 6.0-RELEASE-p4 amd64 X-Distributed: Join the Effort! http://www.distributed.net User-Agent: Mutt/1.5.11 X-Hashcash: 1:20:060817:carl@youngbloods.org::1FZ7YWPS10gYwzXT:00000000000000000 0000000000000000000000002Ka1 X-Hashcash: 1:20:060817:pgsql-performance@postgresql.org::PzakyVG+oMV41gI4:00000 0000000000000000000000001Jjx X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.1 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200608/275 X-Sequence-Number: 20460 On Wed, Aug 16, 2006 at 09:34:24AM -0600, Carl Youngblood wrote: > The relevant portion of my sysctl.conf file looks like this: > > kernel.shmall = 2097152 > kernel.shmmax = 2147483648 > kernel.shmmni = 4096 > kernel.sem = 250 32000 100 128 > fs.file-max = 65536 > > I understood it was a good idea to set shmmax to half of available > memory (2GB in this case). I assume that I need to set shared_buffers I don't see any reason to do that, so long as you have control over what's being run on the system. Just set it to 3000000000 or so. > slightly lower than 2GB for postgresql to start successfully. > > Carl > > On 8/15/06, Jim C. Nasby wrote: > >On Tue, Aug 15, 2006 at 12:47:54PM -0600, Carl Youngblood wrote: > >> I tried setting it to 2GB and postgres wouldn't start. Didn't > >> investigate in much greater detail as to why it wouldn't start, but > >> after switching it back to 1GB it started fine. > > > >Most likely because you didn't set the kernel's shared memory settings > >high enough. > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match > -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461