Re: Enabling parallelism for queries coming from SQL or other PL functions

On Fri, Feb 24, 2017 at 10:06 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> We have a below check in standard_planner() (!IsParallelWorker())
> which should prohibit generating parallel plan inside worker, if that
> is what you are seeing, then we might need a similar check at other
> places.
>
> if ((cursorOptions & CURSOR_OPT_PARALLEL_OK) != 0 &&
> IsUnderPostmaster &&
> dynamic_shared_memory_type != DSM_IMPL_NONE &&
> parse->commandType == CMD_SELECT &&
> !parse->hasModifyingCTE &&
> max_parallel_workers_per_gather > 0 &&
> !IsParallelWorker() &&
> !IsolationIsSerializable())
> {
> /* all the cheap tests pass, so scan the query tree */
> glob->maxParallelHazard = max_parallel_hazard(parse);
> glob->parallelModeOK = (glob->maxParallelHazard != PROPARALLEL_UNSAFE);
> }

Ok, I see. But, the problem with PL functions is that plan might have
already generated in previous execution of the function and during
that time outer query might not be running in parallel. So I think we
may need some check during execution time as well?

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com