On 12 February 2016 at 04:55, Robert Haas <robertmh...@gmail.com> wrote: > On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs <si...@2ndquadrant.com> wrote: >> Is it slower if you request N workers, yet only 1 is available? > > I sure hope so. There may be some cases where more workers are slower > than fewer workers, but those cases are defects that we should try to > fix.
It would only take anything but the CPU to be a bottleneck for this to be highly likely the case. If a non-parallel query is bound on I/O, then adding workers is most likely going to slow it down further. I've seen this when testing parallel aggregates. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
