Implement group join #13243
Description
Is your feature request related to a problem or challenge?
From https://www.vldb.org/pvldb/vol4/p843-moerkotte.pdf
A group join will use a single table from the hash join for executing a join followed by a group by on the same columns.
An example query from the paper introduction
select a,count(*)
from R1 left outer join R2 on R1.a = R2.b
where R1.c=5
group by a
Describe the solution you'd like
Implement group join in execution and in the (logical) planner.
Describe alternatives you've considered
No response
Additional context
No response