Subject: Re: Selects query stats?
From: Simon Riggs <simon@2ndquadrant.com>
To: Dan Gorman <dgorman@hi5.com>
Cc: mischa@ca.sophos.com, pgsql-performance@postgresql.org
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	<127D68F6-7620-4A62-8D1A-9B475E7571CD@hi5.com>
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Date: Tue, 23 May 2006 19:51:12 +0100
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On Tue, 2006-05-23 at 11:33 -0700, Dan Gorman wrote:
> In any other DB (oracle, mysql) I know how many queries (selects) per
> second the database is executing. How do I get this 
> number out of postgres?
> 
> 
> I have a perl script that can test this, but no way the db tells me
> how fast it's going.
> 
> 
> (e.g. in oracle: select sum(executions) from v$sqlarea;)

The Oracle query you show doesn't do that either. It tells you how many
statements have been executed since startup, not per second.

The main problem with what you ask is it only seems to have value. If
the value dips for some reason, you have no way of knowing whether that
occurred because the arrival rate dropped off, there is a system problem
or whether statements just happened to access more data over that time
period. You can collect information that would allow you to understand
what is happening on your system and summarise that as you choose.

-- 
  Simon Riggs
  EnterpriseDB          http://www.enterprisedb.com