The post discusses how to perform bulk nearest neighbor queries using CartoDB, a geographic information system (GIS) platform. To achieve this, the author uses a lateral join, which allows for iterating a PostGIS ordering operation once for each input row. The query calculates the distance between each parcel and its nearest fire hydrant by performing a geography type calculation on the spheroid. The resulting map is colored according to the distance, providing an attractive visualization of parcels by their proximity to fire hydrants. However, the author notes that this approach may not be suitable for large datasets due to performance limitations.