[postgis-tickets] [PostGIS] #3059: Allow passing per-dimension parameters in ST_Expand

[PostGIS]

#3059: Allow passing per-dimension parameters in ST_Expand
--------------------------+---------------------------
  Reporter:  strk         |      Owner:  dbaston
      Type:  enhancement  |     Status:  new
  Priority:  medium       |  Milestone:  PostGIS 2.3.0
 Component:  postgis      |    Version:  trunk
Resolution:               |   Keywords:
--------------------------+---------------------------
Changes (by dbaston):

 * owner:  strk => dbaston
 * status:  assigned => new
 * milestone:  PostGIS Future => PostGIS 2.3.0


Comment:

 This seems like a nice way to improve hackish {{{ST_DWithin}}} queries on
 WGS84 geometries stored as geometry.

 So, to find polygons within 1km of a point, you could do:
 {{{
 SELECT * FROM polygons
 WHERE geom && ST_Expand('POINT (37 52)', 1000.0/69000, 1000.0/111111, 0.0)
 AND ST_Distance_Sphere(geom, 'POINT (37 52)') < 1000
 }}}

 where 69000 m approximates 1 degree of longitude, and 111111 m
 approximates 1 degree of latitude (at 52 degrees N)

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3059#comment:3>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.