To: "Burgholzer, Robert (DEQ)" <Robert.Burgholzer@deq.virginia.gov>
cc: pgsql-admin@postgresql.org
Subject: Re: proper tuning for restoring from pg_dump in 8.3.7 
In-reply-to: 
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References: 
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Comments: In-reply-to "Burgholzer,
	Robert (DEQ)" <Robert.Burgholzer@deq.virginia.gov>
	message dated "Wed, 14 Jul 2010 13:07:48 -0400"
Date: Wed, 14 Jul 2010 13:19:37 -0400
Message-ID: <8594.1279127977@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

"Burgholzer, Robert (DEQ)" <Robert.Burgholzer@deq.virginia.gov> writes:
> That said, the time to restore is explainable, but is there something in
> my tuning that is causing all of my memory to be eaten?

That's normal behavior.  A working Linux/Unix system *should* have near
zero free memory.  If it doesn't, either the filesystem cache is failing
to do its job, or you recently booted the machine and it hasn't had a
chance to fill the cache, or you bought way more RAM than your workload
has any use for.

> We seem to have some undiagnosed issue whereby opening and closing large
> files on the system leaves a lot in the cache -- I am guessing that this
> is my culprit and NOT my pg tuning?

That's called "it's working correctly".

If you want to get an accurate picture of whether the system is under
memory pressure, you need to discount filesystem cache, and also pay
attention to whether anything much has been pushed out to swap.

			regards, tom lane