Tap an asset to run a live downstream blast-radius — a
recursive CTE in PostgreSQL, master record hydrated from the same row.
Or pick a Region query shape — circle, rectangle,
or free-form polygon — one exact GiST-indexed query, no prefilter, no refine.
Compose them: select an asset first, then draw a shape — the answer is
downstream of it ∩ inside your shape, in one SQL statement.