[postgis-devel] [PostGIS] #558: ST_Intersects with Large Number of Points

[PostGIS]

#558: ST_Intersects with Large Number of Points
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  Reporter:  jabts    |       Owner:  pramsey        
      Type:  defect   |      Status:  closed         
  Priority:  medium   |   Milestone:  PostGIS 1.5.2  
 Component:  postgis  |     Version:  1.5.X          
Resolution:  invalid  |    Keywords:  intersects slow
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Changes (by pramsey):

  * status:  new => closed
  * resolution:  => invalid


Comment:

 The function can return false immediately if the bounding boxes to not
 intersect. Unless you have a suggestion on how to improve performance,
 this doesn't seem like a bug to me, it seems expected: more points to test
 take longer to test. If you have large linestrings (geographically) and
 small boxes, a simple way to improve performance is to "denormalize" your
 lines: chop them into about 400-vertex segments per object and duplicate
 the attributes or provide a look-up table between them. That way the index
 can have more effect in choosing the "right" line segments to test with a
 particular box.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/558#comment:1>
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