| From: | Alan Hodgson <ahodgson(at)simkin(dot)ca> | 
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org | 
| Subject: | Re: CPU Usage | 
| Date: | 2007-02-13 18:48:25 | 
| Message-ID: | 200702131048.25646@hal.simkin.ca | 
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| Lists: | pgsql-performance | 
On Tuesday 13 February 2007 10:36, "Campbell, Lance" <lance(at)uiuc(dot)edu> 
wrote:
> We have 12+ schemas in 1 database. When I do a unix "top" command I
> notice one postmaster process has 100% CPU usage.  This process just
> stays at 100% to 99% CPU usage.  There are other postmaster processes
> that pop up.  They use hardly no CPU or memory.  They also disappear
> very fast.  I am wondering, is postgres only using one processor for
> database queries?  Is there something I need to do to tell postgres
> to use more than one processor?  Or does postgres only use up to one
> processor for any particular database?
Each connection to the cluster gets a dedicated backend process, which 
can only be scheduled on one processor at a time.  So, in effect, a 
single query can only use one processor at a time, but any number of 
other backends can be simultaneously using the other CPUs.  It does not 
matter which database they are operating on.
-- 
"It is a besetting vice of democracies to substitute public opinion for
law." - James Fenimore Cooper 
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