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Re: select on 22 GB table causes "An I/O error occured while sending to the backend." exception

From: Bill Moran <wmoran(at)collaborativefusion(dot)com>
To: Greg Smith <gsmith(at)gregsmith(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: select on 22 GB table causes "An I/O error occured while sending to the backend." exception
Date: 2008-08-29 11:08:52
Message-ID: 20080829070852.0000022f.wmoran@collaborativefusion.com (view raw or flat)
Thread:
Lists: pgsql-performance
In response to Greg Smith <gsmith(at)gregsmith(dot)com>:

> On Thu, 28 Aug 2008, Bill Moran wrote:
> 
> > In linux, it's possible to tell the OOM killer never to consider
> > certain processes for the axe, using /proc magic.  See this page:
> > http://linux-mm.org/OOM_Killer
> >
> > Perhaps this should be in the PostgreSQL docs somewhere?
> 
> The fact that 
> http://www.postgresql.org/docs/current/static/kernel-resources.html#AEN22218 
> tells you to flat-out turn off overcommit is the right conservative thing 
> to be in the documentation as I see it.  Sure, it's possible to keep it on 
> but disable the worst side-effect in some kernels (looks like 2.6.11+, so 
> no RHEL4 for example).  Trying to get into all in the manual is kind of 
> pushing what's appropriate for the PostgreSQL docs I think.

I don't know, Greg.  First off, the solution of making the postmaster
immune to the OOM killer seems better than disabling overcommit to me
anyway; and secondly, I don't understand why we should avoid making
the PG documentation as comprehensive as possible, which seems to be
what you are saying: "we shouldn't make the PG documentation too
comprehensive, because then it will get very big"

-- 
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran(at)collaborativefusion(dot)com
Phone: 412-422-3463x4023

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Subject: Re: select on 22 GB table causes "An I/O error occured while sending to the backend." exception
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