On 14 March 2016 at 17:05, James Sewell <james.sew...@lisasoft.com> wrote: > > Hi again, > > I've been playing around with inheritance combined with this patch. Currently > it looks like you are taking max(parallel_degree) from all the child tables > and using that for the number of workers. > > For large machines it makes much more sense to use sum(parallel_degree) - but > I've just seen this comment in the code: > > /* > * Decide what parallel degree to request for this append path. For > * now, we just use the maximum parallel degree of any member. It > * might be useful to use a higher number if the Append node were > * smart enough to spread out the workers, but it currently isn't. > */ > > Does this mean that even though we are aggregating in parallel, we are only > operating on one child table at a time currently?
There is nothing in the planner yet, or any patch that I know of to push the Partial Aggregate node to below an Append node. That will most likely come in 9.7. -- 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
