[postgis-devel] [PostGIS] #1410: [raster] ST_Intersects doesn't seem to be using index

[PostGIS]

#1410: [raster] ST_Intersects doesn't seem to be using index
----------------------------+-----------------------------------------------
 Reporter:  robe            |       Owner:  pracine      
     Type:  defect          |      Status:  new          
 Priority:  critical        |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
----------------------------+-----------------------------------------------
 I just noticed this recently, but haven't ruled out its not something
 wrong with upgrade script.

 If I do this:

 {{{
 SELECT  Count(o.rast)
  FROM boston_test9 As o INNER JOIN
         o_2_boston_test9 AS o2 ON o.rast && o2.rast
  WHERE o2.rid = 1;

 }}}

 I see that my convex hull spatial index is being used.

 However if I do:


 {{{
 SELECT  Count(o.rast)
  FROM boston_test9 As o INNER JOIN
         o_2_boston_test9 AS o2 ON ST_Intersects(o.rast,o2.rast)
  WHERE o2.rid = 1;
 }}}

 My convex hull spatial index is no longer being used.

 I thought possibly its the fact that our _ST_Intersects for raster is
 really really low (1), but upgrading that to 10000 didn't seem to help the
 situation.

 Anyrate that cost needs to be set higher as its even lower than our &&
 raster_overlaps cost function.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1410>
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