From: Justin Pryzby <pryzby@telsasoft.com>
To: Philip Semanchuk <philip@americanefficient.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: increased max_parallel_workers_per_gather results in fewer workers?
Date: Wed, 3 Jun 2020 16:15:26 -0500
Message-ID: <20200603211526.GU30144@telsasoft.com> (raw)
In-Reply-To: <B2C0B20E-4562-4F0B-A876-922EA4AC22A8@americanefficient.com>
References: <B2C0B20E-4562-4F0B-A876-922EA4AC22A8@americanefficient.com>
On Wed, Jun 03, 2020 at 04:04:13PM -0400, Philip Semanchuk wrote:
> Can anyone help me understand why this happens, or where I might look for clues?
What version postgres ?
Can you reproduce if you do:
ALTER SYSTEM SET max_parallel_workers_per_gather=0; SELECT pg_reload_conf();
.. and then within the session do: SET max_parallel_workers_per_gather=12;
I guess you should show an explain analyze, specifically "Workers
Planned/Launched", maybe by linking to explain.depesz.com
--
Justin
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To: pgsql-performance@postgresql.org
Cc: pryzby@telsasoft.com, philip@americanefficient.com, pgsql-performance@lists.postgresql.org
Subject: Re: increased max_parallel_workers_per_gather results in fewer workers?
In-Reply-To: <20200603211526.GU30144@telsasoft.com>
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