Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UZOw7-0000MV-Ev for pgsql-performance@arkaria.postgresql.org; Mon, 06 May 2013 17:10:52 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1UZOw6-0003be-QR for pgsql-performance@arkaria.postgresql.org; Mon, 06 May 2013 17:10:50 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UZOw6-0003bZ-16 for pgsql-performance@postgresql.org; Mon, 06 May 2013 17:10:50 +0000 Received: from plane.gmane.org ([80.91.229.3]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1UZOw2-000297-AQ for pgsql-performance@postgresql.org; Mon, 06 May 2013 17:10:49 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UZOvz-0002eV-UG for pgsql-performance@postgresql.org; Mon, 06 May 2013 19:10:43 +0200 Received: from business-188-111-100-027.static.arcor-ip.net ([188.111.100.27]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 06 May 2013 19:10:43 +0200 Received: from spam_eater by business-188-111-100-027.static.arcor-ip.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 06 May 2013 19:10:43 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: pgsql-performance@postgresql.org From: Thomas Kellerer Subject: Re: Deterioration in performance when query executed in multi threads Date: Mon, 06 May 2013 19:11:43 +0200 Lines: 34 Message-ID: References: <9A6B86D66BD3C2438AFACFA09354890F20A2DF6D@EXCH01.sp.corp.collab.net> <20130501141236.GG27807@aart.rice.edu> <9A6B86D66BD3C2438AFACFA09354890F20A2E06C@EXCH01.sp.corp.collab.net> <20130501162650.GI27807@aart.rice.edu> <9A6B86D66BD3C2438AFACFA09354890F20A2E0E2@EXCH01.sp.corp.collab.net> <9A6B86D66BD3C2438AFACFA09354890F20A2F24A@EXCH01.sp.corp.collab.net> <9A6B86D66BD3C2438AFACFA09354890F20A30B1B@EXCH01.sp.corp.collab.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: business-188-111-100-027.static.arcor-ip.net User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.23) Gecko/20090812 Thunderbird/2.0.0.23 Mnenhy/0.7.6.666 In-Reply-To: <9A6B86D66BD3C2438AFACFA09354890F20A30B1B@EXCH01.sp.corp.collab.net> X-Pg-Spam-Score: -3.1 (---) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org Anne Rosset, 06.05.2013 19:00: > Postgres version: 9.0.13 > >> Work_mem is set to 64MB >> Shared_buffer to 240MB >> Segment_size is 1GB >> Wal_buffer is 10MB > > Artifact table: 251831 rows > Field_value table: 77378 rows > Mntr_subscription: 929071 rows > Relationship: 270478 row > Folder: 280356 rows > Item: 716465 rows > Sfuser: 5733 rows > Project: 1817 rows > > 8CPUs > RAM: 8GB > With 8GB RAM you should be able to increase shared_buffer to 1GB or maybe even higher especially if this is a dedicated server. 240MB is pretty conservative for a server with that amount of RAM (unless you have many other applications running on that box) Also what are the values for cpu_tuple_cost seq_page_cost random_page_cost effective_cache_size What kind of harddisk is in the server? SSD? Regular ones (spinning disks)? -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance