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Message-ID: <46008747.30206@modgraph-usa.com>
Date: Tue, 20 Mar 2007 17:15:51 -0800
From: "Craig A. James" <cjames@modgraph-usa.com>
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To: Dan Harris <fbsd@drivefaster.net>
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Subject: Re: Determining server load from client
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Dan Harris wrote:
> I've found that it would be helpful to be able to tell how busy my 
> dedicated PG server is ...
> 
> I have seen some other nice back-end things exposed through PG functions 
> ( e.g. database size on disk ) and wondered if there was anything 
> applicable to this.

I'd write a simple pg-perl function to do this.  You can access operating-system calls to find out the system's load.  But notice that you need "Untrusted Perl" to do this, so you can only do it on a system where you trust every application that connects to your database.  Something like this:

create or replace function get_stats()
  returns text as '
  open(STAT, "</proc/stat");
  my @stats = <STAT>;
  close STAT;
  return join("", @stats);
' language plperlu;

See http://www.postgresql.org/docs/8.1/interactive/plperl-trusted.html

Craig