Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 7803A1337BD8 for ; Thu, 31 Mar 2011 15:13:04 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 45862-01-8 for ; Thu, 31 Mar 2011 18:12:42 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from midnight-anchovy.ambulatoryclam.net (unknown [18.141.0.210]) by mail.postgresql.org (Postfix) with ESMTP id 532B31337999 for ; Thu, 31 Mar 2011 15:12:17 -0300 (ADT) Received: by midnight-anchovy.ambulatoryclam.net (Postfix, from userid 1001) id 83FF84AC1F; Thu, 31 Mar 2011 14:12:16 -0400 (EDT) Date: Thu, 31 Mar 2011 14:12:16 -0400 From: Dan Ports To: Kevin Grittner Cc: Heikki Linnakangas , YAMAMOTO Takashi , pgsql-hackers@postgresql.org Subject: Re: SSI bug? Message-ID: <20110331181216.GF81592@csail.mit.edu> References: <4D8F54E6020000250003BD16@gw.wicourts.gov> <4D8F54E6020000250003BD16@gw.wicourts.gov> <20110328031616.CDAA719CEDF@mail.netbsd.org> <4D943BEC020000250003BFDA@gw.wicourts.gov> <4D94A2BB.3090605@enterprisedb.com> <4D946036020000250003BFFC@gw.wicourts.gov> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D946036020000250003BFFC@gw.wicourts.gov> User-Agent: Mutt/1.5.21 (2010-09-15) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.107 tagged_above=-5 required=5 tests=BAYES_00=-1.9, RDNS_NONE=0.793 X-Spam-Level: X-Archive-Number: 201103/1908 X-Sequence-Number: 185158 On Thu, Mar 31, 2011 at 11:06:30AM -0500, Kevin Grittner wrote: > The only thing I've been on the fence about is whether it > makes more sense to allocate it all up front or to continue to allow > incremental allocation but set a hard limit on the number of entries > allocated for each shared memory HTAB. Is there a performance- > related reason to choose one path or the other? Seems like it would be marginally better to allocate it up front -- then you don't have the cost of having to split buckets later as it grows. Dan -- Dan R. K. Ports MIT CSAIL http://drkp.net/