Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TVkkd-00049y-Ba for pgsql-performance@postgresql.org; Tue, 06 Nov 2012 15:07:39 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TVkka-00061b-Kj for pgsql-performance@postgresql.org; Tue, 06 Nov 2012 15:07:38 +0000 Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.5/8.14.5) with ESMTP id qA6F7Y7k013006; Tue, 6 Nov 2012 10:07:35 -0500 (EST) From: Tom Lane To: Denis cc: pgsql-performance@postgresql.org Subject: Re: [HACKERS] pg_dump and thousands of schemas In-reply-to: <1352211374706-5730864.post@n5.nabble.com> 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> <20120830204433.GW8753@momjian.us> <1086.1346359916@sss.pgh.pa.us> <27683.1346383075@sss.pgh.pa.us> <1352211374706-5730864.post@n5.nabble.com> Comments: In-reply-to Denis message dated "Tue, 06 Nov 2012 06:16:14 -0800" Date: Tue, 06 Nov 2012 10:07:34 -0500 Message-ID: <13005.1352214454@sss.pgh.pa.us> X-Pg-Spam-Score: -2.3 (--) X-Archive-Number: 201211/54 X-Sequence-Number: 48420 Denis writes: > I've read all the posts in thread, and as I understood in version 9.2 some > patches were applied to improve pg_dump speed. I've just installed > PostgreSQL 9.2.1 and I still have the same problem. I have a database with > 2600 schemas in it. I try to dump each schema individually, but it takes too > much time for every schema (about 30-40 seconds per schema, no matter what > the data size is). Could you provide a test case for that? Maybe the output of pg_dump -s, anonymized as you see fit? > Also for each schema dump I have a slow query log entry, Could you provide EXPLAIN ANALYZE output for that query? regards, tom lane