On Thu, Mar 2, 2017 at 3:50 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Feb 28, 2017 at 5:25 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: >> When such a function (that contains statements which have parallel >> plans) is being executed as part of another parallel plan, it can >> allow spawning workers unboundedly. Assume a query like select * >> from t1 where c1 < func1(), this can use parallel scan for t1 and >> then in master backend, during partial scan of t1, it can again spawn >> new set of workers for queries inside func1(), this can happen >> multiple times if parallel query inside func1() again calls some other >> function func2() which has parallel query. Now, this might be okay, >> but today such a situation doesn't exist that Gather execution can >> invoke another Gather node, so it is worth to consider if we want to >> allow it. > > If we want to prohibit that, the check in standard_planner can be > changed from !IsParallelWorker() to !IsInParallelMode(), but I'm not > 100% sure whether that's an improvement or not. >
I am not sure how you can achieve that by just changing standard_planner() code, because the plans of statements inside pl can be cached in which case it will not try to regenerate the plan. > I would be inclined > to leave it alone unless we get several votes to change it. > Okay, not a problem. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
