Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 2321A9FA603 for ; Fri, 29 Sep 2006 00:08:48 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 77747-06 for ; Fri, 29 Sep 2006 03:08:43 +0000 (UTC) X-Greylist: delayed 08:21:04.288789 by SQLgrey- Received: from adelie.ubuntu.com (adelie.ubuntu.com [82.211.81.139]) by postgresql.org (Postfix) with ESMTP id BD60E9FB2D1 for ; Fri, 29 Sep 2006 00:08:42 -0300 (ADT) Received: from hutte.ubuntu.com ([82.211.81.181]) by adelie.ubuntu.com with esmtp (Exim 4.60 #1 (Debian)) id 1GT8ju-00081G-D8; Fri, 29 Sep 2006 04:08:38 +0100 Received: from 12-216-147-124.client.mchsi.com ([12.216.147.124] helo=[192.168.1.103]) by hutte.ubuntu.com with esmtpsa (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1GT8ju-0001y1-6r; Fri, 29 Sep 2006 04:08:38 +0100 Message-ID: <451C8E35.7000906@canonical.com> Date: Thu, 28 Sep 2006 22:08:37 -0500 From: Matthew Nuzum User-Agent: Thunderbird 1.5.0.7 (X11/20060922) MIME-Version: 1.0 To: Carlo Stonebanks CC: pgsql-performance@postgresql.org Subject: Re: Performace Optimization for Dummies References: <451C18BE.8050908@canonical.com> In-Reply-To: X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests= X-Spam-Level: X-Archive-Number: 200609/413 X-Sequence-Number: 21099 Carlo Stonebanks wrote: > Lots of great info here, I will see what applies to my situation. However, I > don't see bulk inserts of the tables working, because all of the tables need > to be refreshed as values to deduplicate and match will change with every > row added. In order for this to work, i would have to write queries against > the hash tables. This is where something like MySQL's in-memory tables would > have come in handy... > > What is GDB? > > Carlo Sorry, meant GDBM (disk based hash/lookup table). With Postgres if your tables fit into RAM then they are in-memory as long as they're actively being used. Hashtables and GDBM, as far as I know, are only useful for key->value lookups. However, for this they are *fast*. If you can figure out a way to make them work I'll bet things speed up. -- Matthew Nuzum newz2000 on freenode