On 5/24/23 12:13 AM, David Rowley wrote:
> On Wed, 24 May 2023 at 15:54, Bruce Momjian <bruce@momjian.us> wrote:
>>
>> On Wed, May 24, 2023 at 08:37:45AM +1200, David Rowley wrote:
>>> On Mon, 22 May 2023 at 07:05, Jonathan S. Katz <jkatz@postgresql.org> wrote:
>>>> * Parallel execution of queries that use `FULL` and `OUTER` joins
>>>
>>> I think this should be `RIGHT` joins rather than `OUTER` joins.
>>>
>>> LEFT joins have been parallelizable I think for a long time now.
>>
>> Well, since we can swap left/right easily, why would we not have just
>> have swappted the tables and done the join in the past? I think there
>> are two things missing in my description.
>>
>> First, I need to mention parallel _hash_ join. Second, I think this
>> item is saying that the _inner_ side of a parallel hash join can be an
>> OUTER or FULL join. How about?
>>
>> Allow hash joins to be parallelized where the inner side is
>> processed as an OUTER or FULL join (Melanie Plageman, Thomas Munro)
>>
>> In this case, the inner side is the hashed side.
>
> I think Jonathan's text is safe to swap OUTER to RIGHT as it mentions
> "execution".
I made this swap in the release announcement. Thanks!
Jonathan