Re: Rename max_parallel_degree?

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: Josh berkus <josh@agliodbs.com>

Cc: Peter Geoghegan <pg@heroku.com>, Robert Haas <robertmhaas@gmail.com>, Noah Misch <noah@leadboat.com>, David Rowley <david.rowley@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Magnus Hagander <magnus@hagander.net>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2016-05-31T17:30:36Z

Lists: pgsql-hackers

Josh berkus <josh@agliodbs.com> writes:
> On 05/31/2016 10:16 AM, Peter Geoghegan wrote:
>> But the distinction between parallel workers and backends that can
>> participate in parallel query does need to be user-visible. Worker
>> processes are a commodity (i.e. the user must consider
>> max_worker_processes).

> It's still WAY simpler to understand "max_parallel is the number of
> parallel workers I requested".

> Any system where you set it to 2 and get only 1 worker on an idle system
> is going to cause endless queries on the mailing lists.

I really think that a GUC named "max_parallel_workers", which in fact
limits the number of workers and not something else, is the way to go.

			regards, tom lane