Marc-Olaf Jaschke <moj@dshare.de> writes:
> I can confirm that the patch fixes the issue (Bug #19030). The memory usage remains within the expected range of
work_mem.
> This also applies to parallel hash joins.
> The query also runs significantly faster.
> I also tested cases with multiple left joins.
> I have only observed this problem when there are many null values in the join column.
Thanks for testing!
regards, tom lane