FWIW, I tried going back to bed and it didn't help.

Hey @U015879P2F8 short of a more helpful answer from someone else on the team, I can at least confirm that ChatGPT agrees it's not straightforward https://chat.openai.com/share/f4ec32ec-163c-4563-9535-2cc3e684ef2b

well, as long as it's hard for the overlords too 🙂...I agree that the REE with dict-encoded child makes more sense, now to see about getting it done. It's odd to me that Arrow provides builders in most of different language implementations for dictionary encoding an array as you go, but run end encoding is provided as a function to post-process an existing array if it's provided at all.

hey @U015879P2F8 👋 we've not used Arrow's REE in practice I'm afraid, we haven't upgraded to Arrow 15 yet. the https://lists.apache.org/[email protected] is pretty active though, maybe someone on there can give you a pointer?

thanks, I wasn't familiar with the mailing lists. I got back to it this afternoon and I think I've just about hacked something together using the Go implementation, but I'll head there if I end up stuck.