Hello,
https://github.com/apache/arrow/issues/50515 and its associated PR
https://github.com/apache/arrow/pull/50546 raise the question of what
the `nullable` flag in the IPC format means exactly for non-trivial fields.
For example:
1) a non-nullable child field in a struct with some nulls in the parent
(implying that some child elements are logically null)
2) a dictionary array with nulls in the dictionary (but no nulls in the
indices)
3) a union or run-end-encoded array with nulls in the child values
Arrow C++ has historically not been very considerate of the `nullable`
flag internally, treating it as mere metadata with no semantic implications.
What do other implementations do / what do you suggest implementations
*should* do?
Regards
Antoine.
