Re: Gather performance analysis

Tomas Vondra <tomas.vondra@enterprisedb.com>

From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-09-24T20:44:32Z
Lists: pgsql-hackers
On 9/24/21 1:43 AM, Robert Haas wrote:
> On Thu, Sep 23, 2021 at 5:36 PM Tomas Vondra
> <tomas.vondra@enterprisedb.com> wrote:
>> (c) This can't explain the slowdown for cases without any Gather nodes
>> (and it's ~17%, so unlikely due to binary layout).
> 
> Yeah, but none of the modified code would even execute in those cases,
> so it's either binary layout, something wrong in your test
> environment, or gremlins.
> 

I'm not going to the office all that often these days, but I think I'm 
sure I'd notice a bunch of gremlins running around ... so it's probably 
the binary layout thing. But still, strange.

regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



Commits

  1. shm_mq: Update mq_bytes_written less often.