Re: EXPLAIN ANALYZE for parallel query doesn't report the SortMethod information.

Amit Kapila <amit.kapila16@gmail.com> writes:
> On Thu, Jul 7, 2016 at 1:23 PM, Fujii Masao <masao.fujii@gmail.com> wrote:
>> I found $SUBJECT while trying to test parallel queries. Is this a bug?

Presumably the instrumentation data needed for that is not getting
returned from the worker to the leader.  I would bet there's a lot
of other plan-node-specific data that doesn't work either.

> I think this can never happen for force_parallel_mode TO off, because
> we don't generate a gather on top of sort node.  The reason why we are
> able to push Sort below gather, because it is marked as parallel_safe
> (create_sort_path).  I think we should not mark it as parallel_safe.

That seems rather ridiculous.  An oversight in managing EXPLAIN data
is not a sufficient reason to cripple parallel query.
        regards, tom lane