Scalable Proximity Search: Why Geohashing Beats Radius Queries
TL;DR: Geohashing maps 2D coordinates to a 1D string using recursive binary partitioning and bit interleaving. By encoding these bits into a Base-32 string, we leverage B-Tree prefix matching for e...

Source: DEV Community
TL;DR: Geohashing maps 2D coordinates to a 1D string using recursive binary partitioning and bit interleaving. By encoding these bits into a Base-32 string, we leverage B-Tree prefix matching for efficient spatial lookups, bypassing the high CPU costs of Haversine distance calculations at scale. Calculating Haversine distances for 10,000 moving objects per tick is a disaster for database performance. Standard SQL radius queries aren't built for high-concurrency spatial updates; they are computationally heavy and fail to scale because they require calculating the distance between the query point and every potential candidate in the dataset. To keep latency low, you need to stop thinking in floating-point coordinates and start thinking in B-Tree friendly strings. This is where geohashing comes in, moving the heavy lifting from the CPU to the database index. How does binary partitioning resolve geographic coordinates? Binary partitioning recursively divides the map into smaller quadrants,