To: Kevin Johnson <Kevin.Johnson@noaa.gov>
cc: pgsql-admin@postgresql.org
Subject: Re: pg_subtrans 
In-reply-to: <4B7EA146.5060501@noaa.gov> 
References: <4B7EA146.5060501@noaa.gov>
Comments: In-reply-to Kevin Johnson <Kevin.Johnson@noaa.gov>
	message dated "Fri, 19 Feb 2010 09:33:42 -0500"
Date: Fri, 19 Feb 2010 09:40:12 -0500
Message-ID: <2640.1266590412@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Kevin Johnson <Kevin.Johnson@noaa.gov> writes:
> I am attempting to get information on the pg_subtrans directory.  I 
> found this morning that one had a large number of files queued in it.  
> It filled the disk partition on which pgdata resides.  After moving, 
> linking and restarting as a temporary solution, the engine properly 
> worked off these files.  So, I'm trying now to get to the root cause of 
> why it filled in the first place -- however I'm not sure when postgres 
> engine uses this directory.  I've searched the documentation and mailing 
> list archive, but can't find much.  Can anyone give me a link or some 
> more information?

I don't recall the exact horizon for pg_subtrans offhand, but I'm pretty
sure that it's determined by your oldest open transaction.  Look around
for idle-in-transaction sessions.

			regards, tom lane