Re: Remove the comment on the countereffectiveness of large shared_buffers on Windows

On Fri, Nov 11, 2016 at 3:01 PM, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>> > Based on this optimization we might want to keep the text that says
>> > large
>> > shared buffers on Windows aren't as effective perhaps,

Sounds sensible or may add a line to say why it isn't as effective as on Linux.

> and just remove
>> > the
>> > sentence that explicitly says don't go over 512MB?
>>

Have we done any windows specific optimization since it was originally
mentioned as 512MB which indicates that we can remove it? Are you
telling it based on results in this thread, if so, I think it is
better to do few more tests before changing it.

>> Just removing the reference to the size would make users ask a question
>> "What size is the effective upper limit?"
>
>
> True, but that's a question for other platforms as well, isn't it?
>

Right, but for other platforms, the recommendation seems to be 25% of
RAM, can we safely say that for Windows as well? As per test results
in this thread, it seems the read-write performance degrades when
shared buffers have increased from 12.5 to 25%. I think as the test
is done for a short duration so that degradation could be just a run
to run to run variation, that's why I suggested doing few more tests.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com