Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1iB0DF-0006rg-9B for pgsql-performance@arkaria.postgresql.org; Thu, 19 Sep 2019 17:27:25 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1iB0DD-0001PT-UE for pgsql-performance@arkaria.postgresql.org; Thu, 19 Sep 2019 17:27:23 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1iB0DD-0001PG-IU for pgsql-performance@lists.postgresql.org; Thu, 19 Sep 2019 17:27:23 +0000 Received: from feynman.df7cb.de ([195.49.152.168]) by makus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iB0D6-00089v-Of for pgsql-performance@postgresql.org; Thu, 19 Sep 2019 17:27:22 +0000 Received: from msg.df7cb.de (unknown [IPv6:2a02:908:1473:f520:76e5:bff:fef3:7e00]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by feynman.df7cb.de (Postfix) with ESMTPSA id 46Z3gj6qd8z3Dx6; Thu, 19 Sep 2019 19:27:13 +0200 (CEST) Date: Thu, 19 Sep 2019 19:27:13 +0200 From: Christoph Berg To: Joao Junior Cc: pgsql-performance@postgresql.org Subject: Re: Delete huge Table under XFS Message-ID: <20190919172713.GA6865@msg.df7cb.de> Mail-Followup-To: Christoph Berg , Joao Junior , pgsql-performance@postgresql.org References: <357e7bd3-1b40-180c-14ce-7911229b5efb@a-kretschmer.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Re: Joao Junior 2019-09-19 > A table with 800 gb means 800 files of 1 gb. When I use truncate or drop > table, xfs that is a log based filesystem, will write lots of data in its > log and this is the problem. The problem is not postgres, it is the way > that xfs works with big files , or being more clear, the way that it > handles lots of files. Why is the runtime of a DROP TABLE command important? Is anything waiting for it? Christoph