Received: from localhost (unknown [200.46.204.184]) by developer.postgresql.org (Postfix) with ESMTP id 7F3502E005C for ; Sat, 26 Apr 2008 15:21:10 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 30563-03 for ; Sat, 26 Apr 2008 15:21:03 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from vms040pub.verizon.net (vms040pub.verizon.net [206.46.252.40]) by developer.postgresql.org (Postfix) with ESMTP id F090C2E0056 for ; Sat, 26 Apr 2008 15:21:05 -0300 (ADT) Received: from new-host.home ([72.81.136.83]) by vms040.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0JZY005W635GRIZ0@vms040.mailsrvcs.net> for pgsql-performance@postgresql.org; Sat, 26 Apr 2008 13:24:53 -0500 (CDT) Date: Sat, 26 Apr 2008 14:20:15 -0400 From: Robert Treat Subject: Re: Re: [HACKERS] [COMMITTERS] pgsql: Fix TransactionIdIsCurrentTransactionId() to use binary search In-reply-to: <13180.1209230804@sss.pgh.pa.us> To: Tom Lane Cc: pgsql-performance@postgresql.org, Alvaro Herrera Message-id: <200804261420.16064.xzilla@users.sourceforge.net> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-15 Content-transfer-encoding: 7bit Content-disposition: inline References: <20080317021856.0D2D37558DC@cvs.postgresql.org> <200804260910.55203.xzilla@users.sourceforge.net> <13180.1209230804@sss.pgh.pa.us> User-Agent: KMail/1.9.1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200804/377 X-Sequence-Number: 29870 On Saturday 26 April 2008 13:26, Tom Lane wrote: > Robert Treat writes: > > On Friday 25 April 2008 17:32, Tom Lane wrote: > >> Robert Treat writes: > >>> Oddly some dtrace profiling gave me this, which is pretty different, > >>> but certainly doesn't have concerns about > >>> TransactionIdIsCurrentTransactionId > >> > >> .... which seems to pretty much destroy your thesis, no? > > > > How so? Before the patch we bog down for hours, spending 99% of our time > > in TransactionIdIsCurrentTransactionId, after the patch everything > > performs well (really better than before) and we spend so little time in > > TransactionIdIsCurrentTransactionId it barely shows up on the radar. > > Oh, you failed to state that the dtrace output was post-patch. You need > to show *pre* patch dtrace output if you want us to think it relevant. > Please read up-thread. -- Robert Treat Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL