Normally Redis represents positions of elements using a variation of the Geohash technique where positions are encoded using 52 bit integers. The encoding is also different compared to the standard because the initial min and max coordinates used during the encoding and decoding process are different. This command however returns a standard Geohash in the form of a string as described in the Wikipedia article and compatible with the geohash.org web site.
*Geohash string properties
The command returns 11 characters Geohash strings, so no precision is loss compared to the Redis internal 52 bit representation. The returned Geohashes have the following properties:
- They can be shortened removing characters from the right. It will lose precision but will still point to the same area.
- It is possible to use them in
geohash.orgURLs such as
http://geohash.org/<geohash-string>. This is an example of such URL.
- Strings with a similar prefix are nearby, but the contrary is not true, it is possible that strings with different prefixes are nearby too.
Array reply, specifically:
The command returns an array where each element is the Geohash corresponding to each member name passed as argument to the command.
(integer) 2redis> GEOHASH Sicily Palermo Catania
1) "sqc8b49rny0" 2) "sqdtr74hyu0"