Message-ID: <4F22D528.6090604@enterprisedb.com>
Date: Fri, 27 Jan 2012 18:47:36 +0200
From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20120104 Icedove/8.0
MIME-Version: 1.0
To: Jayashankar K B <Jayashankar.KB@lnties.com>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Postgress is taking lot of CPU on our embedded hardware.
References: 
 <1365276B7BDA4C40A519F0B4088230B3096F3B17@POCITMSEXMB03.LntUniverse.com>
In-Reply-To: 
 <1365276B7BDA4C40A519F0B4088230B3096F3B17@POCITMSEXMB03.LntUniverse.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

On 27.01.2012 15:34, Jayashankar K B wrote:
> Hi,
>
> We are having an embedded system with a freescale m68k architecture based micro-controller, 256MB RAM running a customized version of Slackware 12 linux.
> It's a relatively modest Hardware.

Fascinating!

> We have installed postgres 9.1 as our database engine. While testing, we found that the Postgres operations take more than 70% of CPU and the average also stays above 40%.
> This is suffocating the various other processes running on the system. Couple of them are very critical ones.
> The testing involves inserting bulk number of records (approx. 10000 records having between 10 and 20 columns).
> Please let us know how we can reduce CPU usage for the postgres.

The first step would be to figure out where all the time is spent. Are 
there unnecessary indexes you could remove? Are you using INSERT 
statements or COPY? Sending the data in binary format instead of text 
might shave some cycles.

If you can run something like oprofile on the system, that would be 
helpful to pinpoint the expensive part.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com