You can do this with a lateral join. SELECT * FROM A, LATERAL (SELECT * FROM B ORDER BY a.embedding <-> b.embedding LIMIT 2) AS closest_in_b ORDER BY A.id; It

You can do this with a lateral join. SELECT * FROM A, LATERAL (SELECT * FROM B ORDER BY a.embedding <-> b.embedding LIMIT 2) AS closest_in_b ORDER BY A.id; It’s going to have so-so performance. So, don’t hose your production server. Create a vector index on b.embedding. HNSW will be nice for this use case.