From: anarazel@anarazel.de <andres@anarazel.de>
To: Bruce Momjian <bruce@momjian.us>
To: Ondrej Ivanič <ondrej.ivanic@gmail.com>
Cc: J Ramesh Kumar <rameshj1977@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: High Disk write and space taken by PostgreSQL
Date: Thu, 16 Aug 2012 18:07:26 +0200
Message-ID: <d541296c-ddb4-44d6-b546-8dec81ae1fb8@email.android.com> (raw)
In-Reply-To: <20120816145321.GA8359@momjian.us>
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<20120816145321.GA8359@momjian.us>
Bruce Momjian <bruce@momjian.us> schrieb:
>On Thu, Aug 16, 2012 at 03:48:57PM +1000, Ondrej Ivanič wrote:
>> Hi,
>>
>> On 16 August 2012 15:40, J Ramesh Kumar <rameshj1977@gmail.com>
>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 ?
>>
>> You can try unlogged tables:
>> http://www.postgresql.org/docs/9.1/static/sql-createtable.html
>>
>> 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 = 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.
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To: pgsql-performance@postgresql.org
Cc: andres@anarazel.de, bruce@momjian.us, ondrej.ivanic@gmail.com, rameshj1977@gmail.com
Subject: Re: High Disk write and space taken by PostgreSQL
In-Reply-To: <d541296c-ddb4-44d6-b546-8dec81ae1fb8@email.android.com>
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