Re: [PERFORM] Hardware/OS recommendations for large databases (</TIT= LE> </HEAD> <BODY> Dave,= On 11/18/05 7:25 AM, "Dave Cramer" <pg@fastcrypt.com> wrote= : <BLOCKQUOTE>Luke, Interesting numbers. I'm a little concerned about the use of=A0blockdev ̵= 2;setra 16384. If I understand this correctly it assumes that the table is c= ontiguous on the disk does it not ? </BLOCKQUOTE> For optimum performance, yes it does. Remember that the poster is ask= ing about a 5TB warehouse. Decision support applications deal with lar= ge tables and sequential scans a lot, and the data is generally contiguous o= n disk. If delete gaps are there, they will generally vacuum them away= . - Luke </BODY> </HTML> --B_3215143831

X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id BDC99DBA92 for ; Fri, 18 Nov 2005 11:30:52 -0400 (AST) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 40592-03 for ; Fri, 18 Nov 2005 15:30:56 +0000 (GMT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mail.mi8.com (d01gw04.mi8.com [63.240.6.44]) by svr1.postgresql.org (Postfix) with ESMTP id F04DADBAAF for ; Fri, 18 Nov 2005 11:30:49 -0400 (AST) Received: from 172.16.1.110 by mail.mi8.com with ESMTP (- Welcome to Mi8 Corporation www.Mi8.com (D4)); Fri, 18 Nov 2005 10:30:40 -0500 X-Server-Uuid: C8FB4D43-1108-484A-A898-3CBCC7906230 Received: from MI8NYCMAIL06.Mi8.com ([172.16.1.175]) by D01SMTP01.Mi8.com with Microsoft SMTPSVC(6.0.3790.211); Fri, 18 Nov 2005 10:30:32 -0500 Received: from 69.181.100.71 ([69.181.100.71]) by MI8NYCMAIL06.Mi8.com ( [172.16.1.219]) via Exchange Front-End Server mi8owa.mi8.com ( [172.16.1.104]) with Microsoft Exchange Server HTTP-DAV ; Fri, 18 Nov 2005 10:30:31 -0500 User-Agent: Microsoft-Entourage/11.2.1.051004 Date: Fri, 18 Nov 2005 07:30:31 -0800 Subject: Re: Hardware/OS recommendations for large databases ( From: "Luke Lonergan" To: "Dave Cramer" cc: "Greg Stark" , "Joshua Marsh" , pgsql-performance@postgresql.org Message-ID: Thread-Topic: [PERFORM] Hardware/OS recommendations for large databases ( Thread-Index: AcXsVGDnQ6yoPa0qRCyzZpo4/hApJQAAKGyl In-Reply-To: MIME-Version: 1.0 X-OriginalArrivalTime: 18 Nov 2005 15:30:32.0129 (UTC) FILETIME=[03470B10:01C5EC55] X-WSS-ID: 6F632C1131S14498826-01-01 Content-Type: multipart/alternative; boundary=B_3215143831_2195651 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=1.254 required=5 tests=[AWL=-0.000, HTML_MESSAGE=0.001, RCVD_NUMERIC_HELO=1.253] X-Spam-Score: 1.254 X-Spam-Level: * X-Archive-Number: 200511/377 X-Sequence-Number: 15634 > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3215143831_2195651 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Dave, On 11/18/05 7:25 AM, "Dave Cramer" wrote: > Luke, >=20 > Interesting numbers. I'm a little concerned about the use of=A0blockdev =8Bse= tra > 16384. If I understand this correctly it assumes that the table is contig= uous > on the disk does it not ? For optimum performance, yes it does. Remember that the poster is asking about a 5TB warehouse. Decision support applications deal with large table= s and sequential scans a lot, and the data is generally contiguous on disk. If delete gaps are there, they will generally vacuum them away. - Luke --B_3215143831_2195651 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Re: [PERFORM] Hardware/OS recommendations for large databases (</TIT= LE> </HEAD> <BODY> Dave,= On 11/18/05 7:25 AM, "Dave Cramer" <pg@fastcrypt.com> wrote= : <BLOCKQUOTE>Luke, Interesting numbers. I'm a little concerned about the use of=A0blockdev ̵= 2;setra 16384. If I understand this correctly it assumes that the table is c= ontiguous on the disk does it not ? </BLOCKQUOTE> For optimum performance, yes it does. Remember that the poster is ask= ing about a 5TB warehouse. Decision support applications deal with lar= ge tables and sequential scans a lot, and the data is generally contiguous o= n disk. If delete gaps are there, they will generally vacuum them away= . - Luke </BODY> </HTML> --B_3215143831_2195651--