Re: Increasing CPU usage of PostgreSQL

On 25.10.2013 19:04, Scott Marlowe wrote:
> On Fri, Oct 25, 2013 at 8:29 AM, Rahila Syed <rahilasyed90(at)gmail(dot)com> wrote:
>>
>> Configurations of my machine is:
>>
>> Processors: Xeon E5-2650 Processor Kit
>> Intel® Xeon ® Processor E5-2650 (2 GHz, 8C/16T,
>> 20 MB) * 2 nos
>>
>>
>> RAM : 32GB DDR3-1600 REG Memory Kit
>> 8x 4GB Registered ECC DIMM, DDR3L-1600(PC3L-12800)
>>
>> HDD: 450GB 10K Hot Plug 2.5-inch SAS HDD * 8 nos
>> 1 x 450 GB SAS HDD, 2.5-inch, 6Gb/s
>>
>> Disk Speed : 10,000 RPM
>>
>> RAID Controller (512MB, RAID 0/1)
>
> My guess is that you're maxing out your IO subsystem long before
> you're maxing out CPU. What does
>
> iostat -xd 10
>
> have to say about it?

Right, that's my guess too. The problem is most likely the "sync" at the
end of the transaction.

Rahila, if you want to saturate the CPU and don't care about the
particular benchmark, try to use read-only transactions. Either just add
"-S" at the pgbench command line, or write something SELECT-only on your
own. Anyway, use '-j' in such cases.

Tomas