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

On Tue, Aug 16, 2016 at 11:53:25AM +0200, Magnus Hagander wrote:
> On Fri, Aug 5, 2016 at 12:25 PM, Tsunakawa, Takayuki <
> tsunakawa.takay@jp.fujitsu.com> wrote:
> 
>     > From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
>     > Yeah, I think I agree.  It would be bad to disable it by default on Unix,
>     > because ps(1) is a very standard tool there, but the same argument
>     doesn't
>     > hold for Windows.
> 
>     It seems that we could reach a consensus.  The patch is attached.  I'll add
>     this to the next CommitFest.
>    
>     > Another route to a solution would be to find a cheaper way to update the
>     > process title on Windows ... has anyone looked for alternatives?
> 
>     I couldn't find an alternative solution after asking some Windows support
>     staff.
> 
> 
> FWIW, I remember this from back in the days when this was written. We kind of
> expected this would be slow already back then, but couldn't find a better way
> at the time either. And back then, I guess there were just enough *other*
> things that were slow with pg-on-windows that it didn't become as obvious.
> 
> So - +1 for changing the defaults as suggested.

I am shocked at how much a speedup we get by turning off the process
title on Windows:

> From Tsunakawa, Takayuki
> 
> C:\> pgbench -h <db_server> -T 30 -c #clients -j 12 -S benchdb
> 
> [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!

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com

+ As you are, so once was I. As I am, so you will be. +
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