[postgis-tickets] [PostGIS] #2422: geography regression difference

[PostGIS]

#2422: geography regression difference
---------------------+------------------------------------------------------
 Reporter:  robe     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  high     |   Milestone:  PostGIS 2.1.0
Component:  postgis  |     Version:  2.1.x        
 Keywords:           |  
---------------------+------------------------------------------------------

Comment(by robe):

 hmm even using _ST_DistanceTree combo returns the right answer with
 ST_Expand:


 {{{
 SELECT COUNT(*) FROM  face
 WHERE geog && _ST_Expand(st_setsrid(st_makepoint(-71.0636, 42.3584),
 4326)::geography, 1609.344)
 AND _ST_Expand(geog,1609.344) && st_setsrid(st_makepoint(-71.0636,
 42.3584), 4326)::geography
 AND _ST_DistanceTree(geog, st_setsrid(st_makepoint(-71.0636, 42.3584),
 4326)::geography) <  1609.344;
 }}}

 Returns:


 {{{
  count
 -------
    397
 (1 row)


 Time: 233.620 ms
 }}}


 So something must be fishy with the way _ST_DWithin is coded  I'm trying


 {{{
 SELECT COUNT(*) FROM  face
 WHERE ST_DWithin(geog, st_setsrid(st_makepoint(-71.0636, 42.3584),
 4326)::geography, 1609.344 );

 }}}
 After 112 seconds of patient waiting and it finally returned with a
 presumably WRONG answer of 395.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2422#comment:6>
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.