Re: Postgress is taking lot of CPU on our embedded hardware.

Hi,

I downloaded the source code and cross compiled it into a relocatable package and copied it to the device.
LTIB was the cross-compile tool chain that was used. Controller is coldfire MCF54418 CPU.
Here is the configure options I used.

./configure CC=/opt/freescale/usr/local/gcc-4.4.54-eglibc-2.10.54/m68k-linux/bin/m68k-linux-gnu-gcc CFLAGS='-fmessage-length=0 -fpack-struct -mcpu=54418 -msoft-float' --host=i686-pc-linux-gnu --target=m68k-linux-gnu --prefix=/home/jayashankar/databases/Postgre_8.4.9_relocatable/

Any other special flags that could be of help to us?

Thanks and Regards
Jayashankar

-----Original Message-----
From: Claudio Freire [mailto:klaussfreire(at)gmail(dot)com]
Sent: Saturday, January 28, 2012 7:54 AM
To: Heikki Linnakangas
Cc: Jayashankar K B; Andy Colson; pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] Postgress is taking lot of CPU on our embedded hardware.

On Fri, Jan 27, 2012 at 4:56 PM, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> I don't think there's anything particular in postgres that would make
> it a poor choice on a small system, as far as CPU usage is concerned
> anyway. But inserting rows in a database is certainly slower than,
> say, writing them into a flat file.

How did you install postgres?
Did you build it?
Which configure flags did you use?
Exactly which m68k cpu is it? (it does matter)

For instance...

wiki: "However, a significant difference is that the 68060 FPU is not pipelined and is therefore up to three times slower than the Pentium in floating point applications"

This means, if you don't configure the build correctly, you will get really sub-optimal code. Modern versions are optimized for modern cpus.
Of utmost importance, I would imagine, is the binary format chosen for pg data types (floating types especially, if you use them).

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