Received: from magus.postgresql.org ([87.238.57.229]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1T22bi-0007C3-UQ for pgsql-performance@postgresql.org; Thu, 16 Aug 2012 16:07:38 +0000 Received: from mail.anarazel.de ([217.115.131.40]) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1T22bg-0002C4-Vv for pgsql-performance@postgresql.org; Thu, 16 Aug 2012 16:07:38 +0000 Received: from [10.139.184.120] (unknown [89.204.137.120]) (Authenticated sender: andres@anarazel.de) by mail.anarazel.de (Postfix) with ESMTPSA id 2DF52448005; Thu, 16 Aug 2012 18:07:35 +0200 (CEST) References: <502C6AD5.4070407@oneit.com.au> <20120816145321.GA8359@momjian.us> User-Agent: K-9 Mail for Android In-Reply-To: <20120816145321.GA8359@momjian.us> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Subject: Re: High Disk write and space taken by PostgreSQL From: "anarazel@anarazel.de" Date: Thu, 16 Aug 2012 18:07:26 +0200 To: Bruce Momjian , =?UTF-8?Q?Ondrej_Ivani=C4=8D?= CC: J Ramesh Kumar ,pgsql-performance@postgresql.org Message-ID: Content-Transfer-Encoding: quoted-printable X-Pg-Spam-Score: -1.8 (-) X-Archive-Number: 201208/106 X-Sequence-Number: 47644 Bruce Momjian schrieb: >On Thu, Aug 16, 2012 at 03:48:57PM +1000, Ondrej Ivani=C4=8D wrote: >> Hi, >>=20 >> On 16 August 2012 15:40, J Ramesh Kumar >wrote: >> > As you said, MySQL with MyISAM is better choice for my app. Because >I don't >> > need transaction/backup. May be I'll try with InnoDB and find the >disk >> > write/space difference. Is there any similar methods available in >postgresql >> > like MyISAM engine ? >>=20 >> You can try unlogged tables: >> http://www.postgresql.org/docs/9.1/static/sql-createtable.html >>=20 >> If specified, the table is created as an unlogged table. Data written >> to unlogged tables is not written to the write-ahead log (see Chapter >> 29), which makes them considerably faster than ordinary tables. >> However, they are not crash-safe: an unlogged table is automatically >> truncated after a crash or unclean shutdown. The contents of an >> unlogged table are also not replicated to standby servers. Any >indexes >> created on an unlogged table are automatically unlogged as well; >> however, unlogged GiST indexes are currently not supported and cannot >> be created on an unlogged table. > >I would set full_page_writes =3D off too. Why? There shouldn't be any such writes on unlogged tables. Andres Please excuse the brevity and formatting - I am writing this on my mobile= phone.