Re: [HACKERS] A GUC to prevent leader processes from running subplans?

2017-11-12 Thread Thomas Munro
On Sun, Nov 12, 2017 at 8:51 PM, Amit Kapila wrote: > On Sun, Nov 12, 2017 at 9:18 AM, Thomas Munro > wrote: >> How about parallel_leader_participation = on|off? The attached >> version has it that way, and adds regression tests to exercise on, off >> and off-but-couldn't-start-any-workers for b

Re: [HACKERS] A GUC to prevent leader processes from running subplans?

2017-11-11 Thread Amit Kapila
On Sun, Nov 12, 2017 at 9:18 AM, Thomas Munro wrote: > On Sat, Oct 21, 2017 at 8:09 AM, Robert Haas wrote: >> On Tue, Oct 17, 2017 at 7:27 AM, Thomas Munro >> wrote: >> >> I don't think overloading force_parallel_mode is a good idea, but >> having some other GUC for this seems OK to me. Not sur

Re: [HACKERS] A GUC to prevent leader processes from running subplans?

2017-11-11 Thread Thomas Munro
On Sat, Oct 21, 2017 at 8:09 AM, Robert Haas wrote: > On Tue, Oct 17, 2017 at 7:27 AM, Thomas Munro > wrote: >> While testing parallelism work I've wanted to be able to prevent >> gather nodes from running the plan in the leader process, and I've >> heard others say the same. One way would be to

Re: [HACKERS] A GUC to prevent leader processes from running subplans?

2017-10-20 Thread Robert Haas
On Tue, Oct 17, 2017 at 7:27 AM, Thomas Munro wrote: > While testing parallelism work I've wanted to be able to prevent > gather nodes from running the plan in the leader process, and I've > heard others say the same. One way would be to add a GUC > "multiplex_gather", like in the attached patch.