Left/full outer join incorrect for CollectLeft / broadcast

[Dandandan]

Describe the bug
See discussion here apache/datafusion#12454

The "broadcast join" (CollectLeft) is wrong for certain join types which produce results on unmatched left rows.

To Reproduce
Run a broadcast join with left / full outer on more than one node

Expected behavior

Additional context

[Dandandan]

There is a proposal in DataFusion for adding a hook to support sharing the join state apache/datafusion#12523

We tested this at Coralogix, this works very well for us.

[Dandandan]

It could be disabled as well, although that will likely hurt performance by quite a bit.

[milenkovicm]

should we take this once it gets merged in DF ?