Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1T7BbQ-0007B6-EU; Thu, 30 Aug 2012 20:44:36 +0000 Received: from momjian.us ([72.94.173.45]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1T7BbO-0006Kf-Jj; Thu, 30 Aug 2012 20:44:35 +0000 Received: from bruce by momjian.us with local (Exim 4.72) (envelope-from ) id 1T7BbN-0006mg-T1; Thu, 30 Aug 2012 16:44:33 -0400 Date: Thu, 30 Aug 2012 16:44:33 -0400 From: Bruce Momjian To: Tatsuo Ishii Cc: tgl@sss.pgh.pa.us, pgsql-performance@postgresql.org, pgsql-hackers@postgresql.org Subject: Re: pg_dump and thousands of schemas Message-ID: <20120830204433.GW8753@momjian.us> References: <20120529.185149.1127748531209576379.t-ishii@sraoss.co.jp> <12147.1338306742@sss.pgh.pa.us> <20120530.180620.600165924826262795.t-ishii@sraoss.co.jp> <20120531.092043.1953698679173443322.t-ishii@sraoss.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120531.092043.1953698679173443322.t-ishii@sraoss.co.jp> User-Agent: Mutt/1.5.20 (2009-06-14) X-Pg-Spam-Score: -2.1 (--) X-Archive-Number: 201208/194 X-Sequence-Number: 47732 On Thu, May 31, 2012 at 09:20:43AM +0900, Tatsuo Ishii wrote: > >> Yeah, Jeff's experiments indicated that the remaining bottleneck is lock > >> management in the server. What I fixed so far on the pg_dump side > >> should be enough to let partial dumps run at reasonable speed even if > >> the whole database contains many tables. But if psql is taking > >> AccessShareLock on lots of tables, there's still a problem. > > > > Ok, I modified the part of pg_dump where tremendous number of LOCK > > TABLE are issued. I replace them with single LOCK TABLE with multiple > > tables. With 100k tables LOCK statements took 13 minutes in total, now > > it only takes 3 seconds. Comments? > > Shall I commit to master and all supported branches? Was this applied? -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. +