Horton

Re: expose parallel leader in CSV and log_line_prefix

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Justin Pryzby <pryzby@telsasoft.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-07-21T04:38:21Z
Lists: pgsql-hackers 
On Fri, Jul 17, 2020 at 07:34:54AM +0200, Julien Rouhaud wrote:
> I had the same concern and was thinking about this approach too.
> Another argument is that IIUC any log emitted due to
> log_min_duration_statement wouldn't see the backend as executing a
> parallel query, since the workers would already have been shut down.

Not sure that it is worth bothering about this case.  You could also
have a backend killed by log_min_duration_statement on a query that
did not involve parallel query, where you would still report the PID
if it got involved at least once in parallel query for a query before
that.
--
Michael

Commits

  1. Add %P to log_line_prefix for parallel group leader

  2. Tweak behavior of pg_stat_activity.leader_pid

  3. Add leader_pid to pg_stat_activity