X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 6926C52830 for ; Wed, 25 May 2005 00:01:56 -0300 (ADT) 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 58816-08 for ; Wed, 25 May 2005 03:01:47 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id ECEB4528AC for ; Wed, 25 May 2005 00:01:43 -0300 (ADT) 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 j4P31SNB007666; Tue, 24 May 2005 23:01:29 -0400 (EDT) To: Christopher Kings-Lynne Cc: SpaceBallOne , pgsql-performance@postgresql.org Subject: Re: Can anyone explain this: duplicate dbs. In-reply-to: <4293E17D.8090706@familyhealth.com.au> References: <4293E17D.8090706@familyhealth.com.au> Comments: In-reply-to Christopher Kings-Lynne message dated "Wed, 25 May 2005 10:22:53 +0800" Date: Tue, 24 May 2005 23:01:28 -0400 Message-ID: <7665.1116990088@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200505/384 X-Sequence-Number: 12548 Christopher Kings-Lynne writes: >> If I pg_dump that database then create a new database (e.g. "tempdb") >> and upload the dump file (thus making a duplicate) then the same query >> only takes 190ms !! >> Vacuum, vacuum analyse, and vacuum full analyse does not seem to have an >> impact on these times. > Damn, for some reason I didn't read that you had already tried vacuum > full. I'm thinking index bloat, and a PG version too old for vacuum full to recover any index space. But without any information about PG version or EXPLAIN ANALYZE results, we're all just guessing. regards, tom lane