Re: [RFC] Change the default of update_process_title to off

On Wed, Aug 24, 2016 at 2:35 PM, Tsunakawa, Takayuki
<tsunakawa.takay@jp.fujitsu.com> wrote:
> From: Peter Geoghegan [mailto:pg@heroku.com]
>> On Tue, Aug 23, 2016 at 1:44 PM, Bruce Momjian <bruce@momjian.us> wrote:
>> >> [Windows]
>> >> #clients  on    off
>> >> 12     29793  38169
>> >> 24     31587 87237
>> >> 48     32588 83335
>> >> 96     34261  67668
>> >
>> > This ranges from a 28% to a 97% speed improvement on Windows!  Those
>> > are not typos!  This is a game-changer for use of Postgres on Windows
>> > for certain workloads!
>>
>> While I don't care all that much about performance on windows, it is a little
>> sad that it took this long to fix something so simple. Consider this exchange,
>> as a further example of our lack of concern here:
>>
>> https://www.postgresql.org/message-id/30619.1428157653@sss.pgh.pa.us
>
> Probably, the useful Windows Performance Toolkit, which is a counterpart of perf on Linux, was not available before.
Maybewe can dig deeper into performance problems with it now.
 
>
> As a similar topic, I wonder whether the following still holds true, after many improvements on shared buffer lock
contention.
>
> https://www.postgresql.org/docs/devel/static/runtime-config-resource.html
>
>         "The useful range for shared_buffers on Windows systems is generally from 64MB to 512MB."

I don't use Windows, but I have heard recently that this is still true
from someone who was testing with pgbench.  He reported a dip in the
curve above 512MB.

Another database vendor recommends granting SeLockMemoryPrivilege so
that it can use large pages on Windows when using several GB of buffer
pool.  I wonder if that might help Postgres on Windows.  This could be
useful as a starting point to test that theory:

https://www.postgresql.org/message-id/CAEepm%3D075-bgHi_VDt4SCAmt%2Bo_%2B1XaRap2zh7XwfZvT294oHA%40mail.gmail.com

-- 
Thomas Munro
http://www.enterprisedb.com