I am reading this about "Clustering on Indices" and in 25.2 says that
The geohash algorithm only works on data in geographic (longitude/latitude) coordinates, so we need to transform the geometries (to EPSG:4326, which is longitude/latitude) at the same time as we hash them.
CREATE INDEX nyc_census_blocks_geohash ON nyc_census_blocks (ST_GeoHash(ST_Transform(geom,4326)));
I was under the impression that
EPSG:4326 is available to both geometry and geography data. Also I thought that you can have geographic data by setting the column type as "geography" when creating a table or by geometry casting using the
Does the transformation to EPSG:4326 automatically turns the geometry to geography data?