Manhattan has 50,000 restaurants. Rural Wyoming has 3 per county. A fixed-size grid wastes cells on empty space and overloads dense areas. Quadtrees adapt.

Your user is at latitude 37.7749, longitude -122.4194. Your database has 10 million locations. A full table scan comparing every coordinate pair isn’t going to work.

More indexes don’t mean faster queries. Learn when to add, remove, and optimize database indexes. Real examples of 7x performance gains through strategic indexing.