Message-ID: <4CC90676.4080503@agliodbs.com>
Date: Wed, 27 Oct 2010 22:13:26 -0700
From: Josh Berkus <josh@agliodbs.com>
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To: Robert Haas <robertmhaas@gmail.com>
CC: Simon Riggs <simon@2ndQuadrant.com>, Greg Stark <gsstark@mit.edu>,
	Bruce Momjian <bruce@momjian.us>, pgsql-hackers@postgresql.org
Subject: Re: Simplifying replication
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> I sort of agree with you that the current checkpoint_segments
> parameter is a bit hard to tune, at least if your goal is to control
> the amount of disk space that will be used by WAL files.  But I'm not
> sure your proposal is better.  Instead of having a complicated formula
> for predicting how much disk space would get used by a given value for
> checkpoint_segments, we'd have a complicated formula for the amount of
> WAL that would force a checkpoint based on max_wal_size.

Yes, but the complicated formula would then be *in our code* instead of 
being inflicted on the user, as it now is.

-- 
                                   -- Josh Berkus
                                      PostgreSQL Experts Inc.
                                      http://www.pgexperts.com