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 738F7D9A6C for ; Fri, 11 Nov 2005 19:02:11 -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 07080-03 for ; Fri, 11 Nov 2005 23:02:08 +0000 (GMT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id F2C2ED96AD for ; Fri, 11 Nov 2005 19:02:09 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id jABN2CDv022259; Fri, 11 Nov 2005 18:02:12 -0500 (EST) To: Kelly Burkhart cc: pgsql-performance@postgresql.org Subject: Re: 8.x index insert performance In-reply-to: <1131749305.14024.32.camel@krb06.tradebot.com> References: <6EE64EF3AB31D5448D0007DD34EEB3417DD725@Herge.rcsinc.local> <20051031193547.GA3311@mark.mielke.cc> <18647.1130790629@sss.pgh.pa.us> <1130792391.7026.55.camel@krb06.tradebot.com> <19065.1130793527@sss.pgh.pa.us> <1130852029.7026.88.camel@krb06.tradebot.com> <24845.1130852730@sss.pgh.pa.us> <1131660117.7514.57.camel@krb06.tradebot.com> <13167.1131668008@sss.pgh.pa.us> <1131749305.14024.32.camel@krb06.tradebot.com> Comments: In-reply-to Kelly Burkhart message dated "Fri, 11 Nov 2005 16:48:25 -0600" Date: Fri, 11 Nov 2005 18:02:11 -0500 Message-ID: <22258.1131750131@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.006 required=5 tests=[AWL=0.006] X-Spam-Score: 0.006 X-Spam-Level: X-Archive-Number: 200511/219 X-Sequence-Number: 15476 Kelly Burkhart writes: > On Thu, 2005-11-10 at 19:13 -0500, Tom Lane wrote: >> Kelly, could there be any patterns in the data that might be >> related? > I modified my original program to insert generated, sequential data. > The following graph shows the results to be flat: > > Thus, hardware is sufficient to handle predictably sequential data. Yeah, inserting sequentially increasing data would only ever touch the right-hand edge of the btree, so memory requirements would be pretty low and constant. > There very well could be a pattern in the data which could affect > things, however, I'm not sure how to identify it in 100K rows out of > 100M. I conjecture that the problem areas represent places where the key sequence is significantly "more random" than it is elsewhere. Hard to be more specific than that though. regards, tom lane