Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id D2746B5DBBE for ; Fri, 24 Jun 2011 05:40:25 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 39458-06 for ; Fri, 24 Jun 2011 08:40:18 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from exprod7og119.obsmtp.com (exprod7og119.obsmtp.com [64.18.2.16]) by mail.postgresql.org (Postfix) with ESMTP id EF466B5DBC9 for ; Fri, 24 Jun 2011 05:40:17 -0300 (ADT) Received: from mail-ey0-f177.google.com ([209.85.215.177]) (using TLSv1) by exprod7ob119.postini.com ([64.18.6.12]) with SMTP ID DSNKTgRNcOtB0XXKG207p88ZEPj/fo6jLdUt@postini.com; Fri, 24 Jun 2011 01:40:18 PDT Received: by eyh6 with SMTP id 6so970816eyh.36 for ; Fri, 24 Jun 2011 01:40:15 -0700 (PDT) Received: by 10.14.95.76 with SMTP id o52mr2111920eef.152.1308904815336; Fri, 24 Jun 2011 01:40:15 -0700 (PDT) Received: from [90.190.247.247] (247.247.190.90.dyn.estpak.ee [90.190.247.247]) by mx.google.com with ESMTPS id z14sm1875845eef.27.2011.06.24.01.40.13 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 24 Jun 2011 01:40:14 -0700 (PDT) Message-ID: <4E044D68.5070605@enterprisedb.com> Date: Fri, 24 Jun 2011 11:40:08 +0300 From: Heikki Linnakangas User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; fi-FI; rv:1.9.2.17) Gecko/20110606 Icedove/3.1.10 MIME-Version: 1.0 To: Alexander Korotkov CC: pgsql-hackers Subject: Re: WIP: Fast GiST index build References: <4DEC84D7.7040602@enterprisedb.com> <4DECB141.2040707@enterprisedb.com> <4DF8676F.9040801@enterprisedb.com> <4DFA4AE5.1010806@enterprisedb.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=-5 required=5 tests=BAYES_00=-1.9 X-Spam-Level: X-Archive-Number: 201106/1964 X-Sequence-Number: 190677 On 21.06.2011 13:08, Alexander Korotkov wrote: > I've created section about testing in project wiki page: > http://wiki.postgresql.org/wiki/Fast_GiST_index_build_GSoC_2011#Testing_results > Do you have any notes about table structure? It would be nice to have links to the datasets and scripts used, so that others can reproduce the tests. It's surprising that the search time differs so much between the point_ops tests with uniformly random data with 100M and 10M rows. Just to be sure I'm reading it correctly: a small search time is good, right? You might want to spell that out explicitly. > As you can see I found that CPU usage might be much higher > with gist_trgm_ops. Yeah, that is a bit worrysome. 6 minutes without the patch and 18 minutes with it. > I believe it's due to relatively expensive penalty > method in that opclass. Hmm, I wonder if it could be optimized. I did a quick test, creating a gist_trgm_ops index on a list of English words from /usr/share/dict/words. oprofile shows that with the patch, 60% of the CPU time is spent in the makesign() function. > But, probably index build can be still faster when > index doesn't fit cache even for gist_trgm_ops. Yep. > Also with that opclass index > quality is slightly worse but the difference is not dramatic. 5-10% difference should be acceptable -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com