Message-ID: <4CC0F10D.3000201@agliodbs.com>
Date: Thu, 21 Oct 2010 19:03:57 -0700
From: Josh Berkus <josh@agliodbs.com>
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To: Robert Haas <robertmhaas@gmail.com>
CC: Bruce Momjian <bruce@momjian.us>, Greg Stark <gsstark@mit.edu>,
	pgsql-hackers@postgresql.org
Subject: Re: Simplifying replication
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> I think it's pretty well explained in the fine manual.
> 
> http://www.postgresql.org/docs/current/static/runtime-config-wal.html#GUC-WAL-KEEP-SEGMENTS

Nope.  No relationship to checkpoint_segments is explained there.  Try
again?

>> If checkpoint_segments were a hard limit, then we could let admins set
>> wal_keep_segments to -1, knowing that they'd set checkpoint_segments to
>> the max space they had available.
> 
> This assumes that more checkpoint segments is always better, which
> isn't true.  I might have 100 GB of disk space free, but not want to
> replay WAL for 4 days if I have a crash.

No, it assumes no such thing.

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