Status: IN
Spatial query systems pair structurally adaptive resolution with exact distance filtering: both geohash and quadtree narrow candidates via spatial structure then filter by haversine, and the structural resolution itself is derived from query parameters (grid cell size from distance threshold, geohash precision from radius table).
spatial indexing across all implementations couples structural resolution to query parameters and refines with exact distance
Depends on (SL): both-indexes-use-haversine-filter, nearby-friends-grid-cell-size-tied-to-threshold, precision-table-descending-radius