It has been asked here: https://github.com/questdb/questdb/issues/261. Definitely on our road map. It would be good if you could share your story why you need arrow?

No urgent reason. I've noticed a decent of technologies have adopted it in some way or another. I could imagine it being useful for integrating QuestDB with existing internal systems which use Arrow for its in-memory/interchange format.

Appreciate the issue link :)