[postgis-tickets] [PostGIS] #2614: Prepared geometry support for ST_DWithin

[PostGIS]

#2614: Prepared geometry support for ST_DWithin
-------------------------+--------------------------------------------------
 Reporter:  robe         |       Owner:  pramsey      
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.2.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
-------------------------+--------------------------------------------------
 In some cases, despite what we tell people, doing an
 {{{
 ST_Intersects(geom1, ST_Buffer(geom2,radius))
 }}}


 is sometimes faster than ST_DWithin(geom1,geom2)

 Granted ST_DWithin is faster.

 I'll come up with a small self-standing example to demonstrate the point.
 The one I have currently is kind of hefty.

 But basic assumption is if you have a fairly large constant geometry then
 ST_Intersects(ST_Buffer..) often out performs ST_DWithin.  I assume this
 is because ST_Intersects takes advantage of prepared geometries and
 ST_DWithin does not.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2614>
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.