> Well, Arrow C++ does not have a notion of encoding distinct from the > data type. Adding such a notion would risk breaking compatibility for > all existing software that hasn't been upgraded to dispatch based on > encoding.
Thinking about compatibility with existing software, RLE could possibly even made an Extension Type that follows the layout of a struct of int32 and the encoded value type. I'm wondering wether this would be better for compatibility. The format is very similar to what was proposed before, exept that the indices now become an own child array, and there is in additional validity bitmap in the parent that could just be NULLPTR. Another adventage here would be that it is obvous how to add support for other run-length types than int32 if needed. Best, Tobias
