Why dynamic filters don't support right outer join?

[SeaRise]

from

velox/velox/exec/HashProbe.cpp

Lines 332 to 335 in ad1f393

	(isInnerJoin(joinType_) || isLeftSemiFilterJoin(joinType_) ||
	isRightSemiFilterJoin(joinType_) || isRightSemiProjectJoin(joinType_)) &&
	table_->hashMode() != BaseHashTable::HashMode::kHash && !isSpillInput() &&
	!hasMoreSpillData()) {

we can see that dynamic filters do not support right outer join.
Why is that? Semantically, right outer join and runtime filters do not seem to conflict.

[xiaodouchen]

I have the same question. Could you help to clarify this? @mbasmanova @xiaoxmeng

[mbasmanova]

@xiaodouchen That's a good question. I agree that it seems like right join could support dynamic filter pushdown since it doesn't need probe rows that do not match. Would you like to add this support?

[xiaodouchen]

@mbasmanova Thank you for your reply. I will support it.