On Tue, May 31, 2016 at 11:22 AM, Josh berkus <j...@agliodbs.com> wrote: >> I think we can hope that developers are going to be less confused about >> that than users. > > Makes sense.
Maybe EXPLAIN doesn't have to use the term parallel worker at all. It can instead use a slightly broader terminology, possibly including the term "core". > One more consistency question: what's the effect of running out of > max_parallel_workers? > > That is, say max_parallel_workers is set to 10, and 8 are already > allocated. If I ask for max_parallel_X = 4, how many cores to I use? Well, it depends on the planner, of course. But when constrained only by the availability of worker processes, then your example could use 3 cores -- the 2 remaining parallel workers, plus the leader itself. > Presumably the leader isn't counted towards max_parallel_workers? Exactly. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers