AggregationPhase: AGGREGATION_PHASE_UNSPECIFIED not understood substrait-java

[mbwhite]

The protobuf defines the AGGREGATION_PHASE_UNSPECIFIED but does say it implies INTERMEDIATE_TO_RESULT

https://github.com/substrait-io/substrait/blob/55683fb1078bd50b9fe711a8e0084910f34199e6/proto/substrait/algebra.proto#L1582

substrait-java treats this as unknown, when it isn't really. (in fact duckdb produces this)

testing fix for this locally

[EpsilonPrime]

AGGREGATION_PHASE_UNSPECIFIED is the default value. So if the field is not set consumers will encounter it (although one could argue that it should always be set). As stated above, consumers should likely deal with it in some manner.

[mbwhite]

Just to clairfy - that the substrait-java throws an exception if it encounters this field; this is part that is being fixed.

Up to consumers as you say to handle the actually meaning.

[Blizzara]

Hmm, given the proto docs say

// Implies `INTERMEDIATE_TO_RESULT`.

does it make sense to let consumers handle it, or should we just treat it as INTERMEDIATE_TO_RESULT directly in substrait-java?

[mbwhite]

@Blizzara the pr just enables the the value to be correctly returned to the user to do as they wish.

The issue was that an exception was thrown;

The PR has approval and is waiting for merge