Re: [HACKERS] Parallel safety for extern params

2017-10-29 Thread Amit Kapila
On Sun, Oct 29, 2017 at 9:55 PM, Robert Haas wrote: > On Sat, Oct 28, 2017 at 8:02 PM, Amit Kapila wrote: >> I think we need to make changes in exec_simple_recheck_plan to make >> the behavior similar to HEAD. With the attached patch, all tests >>

Re: [HACKERS] Parallel safety for extern params

2017-10-29 Thread Robert Haas
On Sat, Oct 28, 2017 at 8:02 PM, Amit Kapila wrote: > I think we need to make changes in exec_simple_recheck_plan to make > the behavior similar to HEAD. With the attached patch, all tests > passed with force_parallel_mode. Committed to REL_10_STABLE. -- Robert Haas

Re: [HACKERS] Parallel safety for extern params

2017-10-28 Thread Amit Kapila
On Sat, Oct 28, 2017 at 2:02 AM, Robert Haas wrote: > On Mon, Oct 16, 2017 at 12:59 PM, Amit Kapila wrote: > When I tried back-porting the patch to v10 I discovered that the > plpgsql changes conflict heavily and that ripping them out all the way >

Re: [HACKERS] Parallel safety for extern params

2017-10-27 Thread Robert Haas
On Mon, Oct 16, 2017 at 12:59 PM, Amit Kapila wrote: >> I think the Param case should be mentioned after "... but" not before >> - i.e. referencing the child node's output... but setrefs.c might also >> have copied a Const or Param is-is. > > I am not sure if we can write

Re: [HACKERS] Parallel safety for extern params

2017-10-27 Thread Amit Kapila
On Mon, Oct 16, 2017 at 4:29 PM, Amit Kapila wrote: > On Sat, Oct 14, 2017 at 1:51 AM, Robert Haas wrote: > >> I think the bug is in ExecGather(Merge): it assumes that if we're in >> parallel mode, it's OK to start workers. But actually, it

Re: [HACKERS] Parallel safety for extern params

2017-10-16 Thread Amit Kapila
On Sat, Oct 14, 2017 at 1:51 AM, Robert Haas wrote: > On Fri, Oct 13, 2017 at 1:19 AM, Amit Kapila wrote: >> After fixing this problem, when I ran the regression tests with >> force_parallel_mode = regress, I saw multiple other failures. All the

Re: [HACKERS] Parallel safety for extern params

2017-10-13 Thread Robert Haas
On Fri, Oct 13, 2017 at 1:19 AM, Amit Kapila wrote: > After fixing this problem, when I ran the regression tests with > force_parallel_mode = regress, I saw multiple other failures. All the > failures boil down to two kinds of cases: > > 1. There was an assumption while

[HACKERS] Parallel safety for extern params

2017-10-12 Thread Amit Kapila
As discussed in a nearby thread [1] (parallelize queries containing initplans), it appears that there are cases where queries referring PARAM_EXTERN params are treated as parallel-restricted even though they should be parallel-safe. I have done some further investigation and found that actually