On 17/03/2016 11:23, Julien Rouhaud wrote: > On 17/03/2016 02:07, James Sewell wrote: >> >> On Thu, Mar 17, 2016 at 5:05 AM, Julien Rouhaud >> <julien.rouh...@dalibo.com <mailto:julien.rouh...@dalibo.com>> wrote: >> >> >> attached v3 drops the GUC part. >> >> >> This looks good good. I do think that some threshold control would be >> good in the long term - but you are right Robert it just feels strange. >> >> Maybe once the final formula is implemented in 9.7+ and this gets some >> real world use cases it can be revisited? >> >> One thing I really, really like about the way the new patch works is >> that you can set parallel_degree on an inheritance parent, then that >> will set the minimum workers for all associated children (when accessing >> from the parent). >> >> Currently this patch will not fire on small tables even >> when parallel_degree is set, can we fix this by adding a check >> for ref->parallel_degree to the table size condition? >> > > Actually, a parallel plan will be created, since in this case the > rel->reloptkind will be RELOPT_OTHER_MEMBER_REL, not RELOPT_BASEREL. >
And after re-reading your mail I see that it was what you meant, sorry :) With the current threshold, you need a table bigger than 8 MB to be able to force parallel workers. I'm not sure there'll be benefits for multiple workers on a table smaller than 8 MB, since setting up all the parallel stuff takes time. -- Julien Rouhaud http://dalibo.com - http://dalibo.org -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
