| From: | Peter Geoghegan <pg(at)bowt(dot)ie> |
|---|---|
| To: | Bruce Momjian <bruce(at)momjian(dot)us> |
| Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Rename max_parallel_degree? |
| Date: | 2016-04-24 06:00:51 |
| Message-ID: | CAH2-WzmUNrKcEaYELuROksx=8QAnoQk7nvkAHj4_8rHgjyPU3g@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Sat, Apr 23, 2016 at 8:58 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> Why is the parallelism variable called "max_parallel_degree"? Is that a
> descriptive name? What does "degree" mean? Why is it not called
> "max_parallel_workers"?
I also think that "max_parallel_workers" works better.
While certain other systems have a concept of a "maximum parallel
degree", it is not the same. Those other systems disable parallelism
altogether when "max parallel degree" is 1, whereas Postgres uses 1
parallel worker along with a leader process. And so, parallelism
*will* still be used on Postgres. That's a pretty significant
difference.
--
Peter Geoghegan
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