{"id":"geohash-nearby-prefix-scan-is-linear","text":"GeohashIndex.nearby iterates all keys in `_index` to match prefixes, making it O(buckets) per query rather than O(1) — a deliberate simplification vs. a sorted/trie structure","truth_value":"IN","source":"entries/2026/06/05/proximity-service-proximity_service.md","source_url":"","source_hash":"","justifications":[],"dependents":["brute-force-acceptable-at-pedagogical-scale"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"geohash-nearby-prefix-scan-is-linear","truth_value":"IN","reason":"premise"}]}}