From: Tom Lane <tgl@sss.pgh.pa.us>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org, Greg Smith <greg@2ndquadrant.com>
Subject: Re: Defaulting wal_sync_method to fdatasync on Linux for 9.1?
Date: Tue, 16 Nov 2010 18:31:34 -0500
Message-ID: <9058.1289950294@sss.pgh.pa.us> (raw)
In-Reply-To: <4CE312D9.6030503@agliodbs.com>
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<201011010010.28724.andres@anarazel.de>
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<4CE312D9.6030503@agliodbs.com>
Josh Berkus <josh@agliodbs.com> writes:
> On 11/16/10 12:39 PM, Greg Smith wrote:
>> I want to next go through and replicate some of the actual database
>> level tests before giving a full opinion on whether this data proves
>> it's worth changing the wal_sync_method detection. So far I'm torn
>> between whether that's the right approach, or if we should just increase
>> the default value for wal_buffers to something more reasonable.
> We'd love to, but wal_buffers uses sysV shmem.
Well, we're not going to increase the default to gigabytes, but we could
very probably increase it by a factor of 10 or so without anyone
squawking. It's been awhile since I heard of anyone trying to run PG in
4MB shmmax. How much would a change of that size help?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, josh@agliodbs.com, greg@2ndquadrant.com
Subject: Re: Defaulting wal_sync_method to fdatasync on Linux for 9.1?
In-Reply-To: <9058.1289950294@sss.pgh.pa.us>
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