Is there a join type that can pushdown join filter to one side's scan?

[alexwilcoxson-rel]

I was looking through the join options' code and it didn't look like this was possible. e.g.

LHS table produces small number of rows. Collect these and provide them as a filter pushed down to RHS scan to reduce files read.

[alamb]

To the best of my knowledge this is not supported today by DataFusion -- I think this type of filter pushdown is called "sideways information passing" in database literature and is a typical technique to improve the performance for column stores.

I think it has come up before in the context of improving join performance (for example, on the TPCH benchmarks -- cc @Dandandan and @mingmwang )

@alexwilcoxson-rel would you be willing to help file a feature request for this item? I can provide some additional commentary / pointers as well

[alexwilcoxson-rel]

thanks @alamb ! I also have a POC doing this that I can clean up and include. Will probably later today or early next week if I can get to it