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

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

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

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 >

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

2017-10-17 Thread Thomas Munro
Hi hackers, 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. If you set it to off, Gather and Gather Merge