ARROW-14658 added support for nested field refs, but aggregations, joins, etc. cannot directly use them (you must first project, then aggregate). The node implementations resolve a field ref into a field path, but then throw away all but the first index, and so they end up referencing the wrong field (the top-level field instead of the nested one). To implement this, we should take care we don't slow down the common case of no nested field refs.

Reporter: David Li / @lidavidm

Related issues:

• [C++] Support nested FieldRefs (relates to)
• [C++] Add basic support for nested field refs in scanning (relates to)

_{Note: This issue was originally created as ARROW-15357. Please see the migration documentation for further details.}