[postgis-users] points in polygon

Graham Stewart graham at mobilefoundry.net
Fri Mar 31 16:31:16 PST 2006


> 8K points seem nothing to me.
> People don't do spatial analysis on 8K+ points?
>   

I have a test that compares a few hundred thousand points to the
bounding box of a polygon before performing some more complex spatial
test and it usually returns in about 100mS on my rather underpowered laptop.

I'm running the following

select * where mypoint &&
setsrid(box2d(expand(mypolygon,expansion))::box2d, 4269) and (various
other distance/area tests)

Is the slowdown in the index match or in the distance computation... I'd
try running the query against the index alone and see how many results
come back and how quickly.

SELECT  point.id
FROM    point, polygon
WHERE   (polygon.fips = '0644000')
      AND point.the_geom && polygon.the_geom

Graham

              



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