Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id D7DF6133798F for ; Wed, 27 Oct 2010 15:42:32 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 43681-05 for ; Wed, 27 Oct 2010 18:42:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from shrek.krogh.cc (2605ds1-ynoe.0.fullrate.dk [90.184.12.24]) by mail.postgresql.org (Postfix) with ESMTP id 8B43C133655C for ; Wed, 27 Oct 2010 15:42:25 -0300 (ADT) Received: from localhost (localhost [127.0.0.1]) by shrek.krogh.cc (Postfix) with ESMTP id C80C6434E; Wed, 27 Oct 2010 20:42:23 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at shrek.krogh.cc Received: from shrek.krogh.cc ([127.0.0.1]) by localhost (shrek.krogh.cc [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eN21VatCbU1s; Wed, 27 Oct 2010 20:42:20 +0200 (CEST) Received: from [90.184.13.151] (2605ds1-ynoe.2.fullrate.dk [90.184.13.151]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: jesper@krogh.cc) by shrek.krogh.cc (Postfix) with ESMTPSA id 333811E35; Wed, 27 Oct 2010 20:42:20 +0200 (CEST) Message-ID: <4CC8728B.9050205@krogh.cc> Date: Wed, 27 Oct 2010 20:42:19 +0200 From: Jesper Krogh User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100915 Thunderbird/3.0.8 MIME-Version: 1.0 To: Merlin Moncure CC: Divakar Singh , Robert Haas , Mladen Gogala , pgsql-performance@postgresql.org Subject: Re: Postgres insert performance and storage requirement compared to Oracle References: <402913.53404.qm@web65405.mail.ac4.yahoo.com> <208728.42197.qm@web65409.mail.ac4.yahoo.com> <770715.39613.qm@web29003.mail.ird.yahoo.com> <4CC741FF.8050709@vmsinfo.com> <4CC74E31.6060307@vmsinfo.com> <252538.42200.qm@web65405.mail.ac4.yahoo.com> <173298.80592.qm@web65406.mail.ac4.yahoo.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.9 tagged_above=-10 required=5 tests=BAYES_00=-1.9 X-Spam-Level: X-Archive-Number: 201010/495 X-Sequence-Number: 40913 On 2010-10-27 20:28, Merlin Moncure wrote: > Postgres indexes are pretty compact, and oracle (internals I am not > familiar with) also has to do MVCC type management, so I am suspecting > your measurement is off (aka, operator error) or oracle is cheating > somehow by optimizing away storage requirements somehow via some sort > of tradeoff. However you still fail to explain why storage size is a > problem. Are planning to port oracle to postgres on a volume that is > 50% full? :-) > Pretty ignorant comment.. sorry .. But when your database approaches something that is not mainly fitting in memory, space directly translates into speed and a more compact table utillizes the OS-page cache better. This is both true for index and table page caching. And the more compact your table the later you hit the stage where you cant fit into memory anymore. .. but if above isn't issues, then your statements are true. -- Jesper