Received: from localhost (unknown [200.46.204.184]) by developer.postgresql.org (Postfix) with ESMTP id 9F9FC2E006B for ; Sat, 26 Apr 2008 14:26:49 -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 18133-01 for ; Sat, 26 Apr 2008 14:26:45 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by developer.postgresql.org (Postfix) with ESMTP id B99262E006A for ; Sat, 26 Apr 2008 14:26:46 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id m3QHQis2013181; Sat, 26 Apr 2008 13:26:44 -0400 (EDT) To: Robert Treat cc: pgsql-performance@postgresql.org, Alvaro Herrera Subject: Re: Re: [HACKERS] [COMMITTERS] pgsql: Fix TransactionIdIsCurrentTransactionId() to use binary search In-reply-to: <200804260910.55203.xzilla@users.sourceforge.net> References: <20080317021856.0D2D37558DC@cvs.postgresql.org> <200804251724.48705.xzilla@users.sourceforge.net> <865.1209159179@sss.pgh.pa.us> <200804260910.55203.xzilla@users.sourceforge.net> Comments: In-reply-to Robert Treat message dated "Sat, 26 Apr 2008 09:10:53 -0400" Date: Sat, 26 Apr 2008 13:26:44 -0400 Message-ID: <13180.1209230804@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200804/376 X-Sequence-Number: 29869 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. regards, tom lane