On 05/31/2016 10:16 AM, Peter Geoghegan wrote: > On Tue, May 31, 2016 at 10:10 AM, Josh berkus <j...@agliodbs.com> wrote: >> "max_parallel_degree is the amount of parallelism in the query, with the >> understanding that the original parent process counts as 1, which means >> that if you set it to 1 you get no parallelism, and if you want 4 >> parallel workers you need to set it to 5." >> >> Which one of those is going to require more explanations on -general and >> -novice? Bets? >> >> Let's not be complicated for the sake of being complicated. > > 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. -- -- Josh Berkus Red Hat OSAS (any opinions are my own) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
