@djh@chaos.social I'm starting to remember this now.. The z curve has slightly more discontinuities iirc but its also easier to find the sub sections. My method is kinda "brute force" based on sampling a reduced resolution version of the curve in order to decide where to split up the sections before running the actual DB queries.

But in my opinion, the most important thing to call out about all of this is that you don't need different database software / you don't need to modify the database at all. The app that talks to the database just needs to Use this "one weird trick" to generate keys and query ranges.