33 karma · joined August 8, 2016
One sample use case would be, if you want to find which polygon (building or administrative regions like states or cities) a given location falls into, doing a point in polygon for a huge set wouldn't be the best solution. Here comes the use of geohash and s2 cells. Using GeoRaptor on the initial set of geohashes reduces the search space considerably. For instance, the entire shape of the US creates 18 million geohashes which get reduced to ~220K when compressed.
I didn't get this completely. :)
This was something that hadn't been solved using geohashes. Intention was to just bring out 'geohash'y of solution to proximity search.
Would surely go through the blog mentioned. Thanks.
On your second question, it completely depends on the problem at hand. I have been using GEORADIUS on Redis for around a year now @ > 30k QPS. The case there is to find locations that are closest to our input. ProximityHash provides you all the geohashes in a circular area for which I haven't found a library yet. Most of them provide geohashes in a BoundingBox.