On Tue, May 31, 2016 at 10:23 AM, Josh berkus <j...@agliodbs.com> wrote: > It's still WAY simpler to understand "max_parallel is the number of > parallel workers I requested".
(Sorry Josh, somehow hit reply, not reply-all) Yes, it is. But as long as parallel workers are not really that distinct to the leader-as-worker when executing a parallel query, then you have another consideration. Which is that you need to care about how many cores your query uses first and foremost, and not the number of parallel workers used. I don't think that having only one worker will cause too much confusion, because users will trust that we won't allow something that simply makes no sense to happen. In my parallel create index patch, the leader participates as a worker to scan and sort runs. It's identical to a worker, practically speaking, at least until time comes to merge those runs. Similarly, parallel aggregate does not really have much for the leader process to do other than act as a worker. -- 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
