Re: Rename max_parallel_degree?

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Josh berkus <josh@agliodbs.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Peter Geoghegan <pg@heroku.com>, Noah Misch <noah@leadboat.com>, David Rowley <david.rowley@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, Magnus Hagander <magnus@hagander.net>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2016-05-31T20:04:41Z
Lists: pgsql-hackers
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Robert Haas wrote:
>> So I think in the long run we should have three limits:
>> 
>> 1. Cluster-wide limit on number of worker processes for all purposes
>> (currently, max_worker_processes).
>> 
>> 2. Cluster-wide limit on number of worker processes for parallelism
>> (don't have this yet).
>> 
>> 3. Per-operation limit on number of worker processes for parallelism
>> (currently, max_parallel_degree).
>> 
>> Whatever we rename, there needs to be enough semantic space between #1
>> and #3 to allow for the possibility - I think the very likely
>> possibility - that we will eventually also want #2.

> max_background_workers sounds fine to me for #1, and I propose to add #2
> in 9.6 rather than wait.

+1 to both points.

> max_total_parallel_query_workers ?

The name should be closely related to what we use for #3.  I could go for
max_total_parallel_workers for #2 and max_parallel_workers for #3.
Or maybe max_parallel_workers_total?

			regards, tom lane