[postgis-devel] doc suggestion: move ST_GeoHash

David Fuhry dfuhry at acm.org
Fri Aug 21 11:49:13 PDT 2009


A small documentation suggestion.  ST_GeoHash, currently listed under 
the "Geometry Outputs" heading, would be better placed under "Spatial 
Relationships and Measurements" (or maybe "Geometry Accessors").

Unlike the other geometry outputs, you can't unambiguously reconstruct 
the geometry from its geohash.  As noted by the ST_GeoHash doc page, 
hashing the geometry is in some ways similar to getting an approximation 
of its envelope (ST_Envelope is in "Geometry Accessors"), but it's also 
akin to processing the coordinates of the geometry into some new value, 
like many of the functions in "Spatial Relationships and Measurements". 
  I think ST_GeoHash is more like the latter, since hashing always 
involves processing the geom's coordinates, whereas ST_Envelope is an 
exception in that it may just "Access" the envelope from the geom's 
header (not compute it).

This is not a point worth arguing if anyone has strong feelings.  I 
think it would be an improvement.  Kudos to whoever is doing such a 
great job on the documentation.  (Regina, I think.)

-Dave



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