[ARROW-18205] [C++] Substrait consumer is not converting right side references correctly on joins

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 11.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/33391
• Assignee: Vibhatha Lakmal Abeykoon
• Reporter: Weston Pace
• Created: 31/Oct/22 18:59
• Updated: 11/Jan/23 11:58
• Resolved: 01/Nov/22 17:29

Description

The Substrait plan expresses a join condition as a logical expression like:

field(0) == field(3) where 0 and 3 are indices into the combined schema. These are then passed down to Acero which expects:

HashJoinNodeOptions(std::vector<FieldRef> in_left_keys, std::vector<FieldRef> in_right_keys)

However, in_left_keys are field references into the left schema and in_right_keys are field references into the right schema.

In other words, given the above expression (field(0) == field(3) if the schema were:

left:
key: int32
y: int32
z: int32

right:
key: int32
x: int32

Then in_left_keys should be field(0) (works correct today) and in_right_keys should be field(0) (today we are sending in field(3)).

Issue Links

• links to: GitHub Pull Request #14558