Geo joins look innocent: SELECT * FROM A JOIN B ON ST_Intersects(A.geo, B.geo); …but at scale they can become the query that ruins your day. Geospatial functions are expensive, and they often force a loop join that starts to feel quadratic as your tables grow. The core idea in this post is simple: we’ll see how Floe automatically rewrites this kind of query and takes advantage of H3 indexes for dramatic speedup. What’s a geo join A geo join is any join whose ON clause is a spatial predicate: ST_...