(2019/03/11 14:14), Tom Lane wrote:
Etsuro Fujita<fujita.ets...@lab.ntt.co.jp> writes:
(2019/03/11 13:06), Tom Lane wrote:
Is that the only possible outcome? Per Robert's summary quoted above,
it seems like it might be possible for the code to decide that the final
scan/join target to be parallel safe when it is not, leading to outright
wrong answers or query failures.
Maybe I'm missing something, but I think that if the final scan/join
target is not parallel-safe, then the grouping target would not be
parallel-safe either, by the construction of the two targets, so I don't
think that we have such a correctness issue.
Seems to me it's the other way around: the final target would include
all functions invoked in the grouping target plus maybe some more.
So a non-parallel-safe grouping target implies a non-parallel-safe
final target, but not vice versa.
I mean the final *scan/join* target, not the final target.
Best regards,
Etsuro Fujita
