On Fri, 15 Sept 2023 at 01:57, Stephen Flavin <stephen_flav@hotmail.com> wrote:
> I missed https://www.postgresql.org/docs/15/when-can-parallel-query-be-used.html so I guess this isn't a bug but you
sayyou're seeing
> parallel workers in the insert which confuses me more. (sorry)
Parallel workers are not the same thing as partition-wise aggregate.
Partition-wise aggregate just means that the aggregation will be
performed below the Append/MergeAppend node. In the query you've just
shown you can see that as Hash Aggregate below (before) the Append.
Parallel workers is something that is used by parallel query. A
parallel plan will have a Gather or Gather Merge node. I certainly
didn't see one of those with the INSERT.
David
