[postgis-devel] [PostGIS] #962: ST_Within not using prepared geometries

PostGIS trac at osgeo.org
Wed May 18 09:50:39 PDT 2011


#962: ST_Within not using prepared geometries
---------------------+------------------------------------------------------
 Reporter:  strk     |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 2.0.0
Component:  postgis  |     Version:  trunk        
 Keywords:           |  
---------------------+------------------------------------------------------

Comment(by chodgson):

 I had a look and agree. Is there any reason to not just map within(x,y) to
 contains(y,x)? Either by a direct function call in the postgis C code or a
 change at the postgis SQL level... I wonder if there is other, similarly
 duplicate code in other predicates?

 Are Disjoint and intersects also inverses? Because again, it looks like
 intersects is using prepared geoms and disjoint is not. I'm wondering if
 the prepgeom stuff was intentionally integrated into only half the
 functions, with the intention of eventually killing off the other half and
 remapping them over?

 Save with covers (has prep) and coveredby (doesn't).

 Also, overlaps, crosses, and the relate functions don't seem to use
 prepared geoms either, it seems like they could? Did we just not really
 finish implementing prepared geoms? Stopped after the first few most
 common cases to make sure it was actually helping?

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/962#comment:1>
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.


More information about the postgis-devel mailing list