Hi, I am looking at the substrait protobuf for AggregateRel as well the Acero substrait consumer code:
https://github.com/apache/arrow/blob/main/cpp/src/arrow/engine/substrait/relation_internal.cc#L851 https://github.com/substrait-io/substrait/blob/main/proto/substrait/algebra.proto#L209 Looks like in subtrait, AggregateRel can have multiple groupings and each grouping can have multiple expressions. Let's say now I want to "compute sum and mean on column A group by column B, C, D" (for Acero to execute). Is the right way to create one grouping with 3 expressions (direct reference) for "column B, C, D"? Thanks, Li
