[postgis-users] Point, Polygon - Does not intersects

[Andreas Forø Tollefsen]

Hi,

I am running the current setup:
 "POSTGIS="2.0.2 r10789" GEOS="3.4.0dev-CAPI-1.8.0" PROJ="Rel. 4.7.1, 23
September 2009" GDAL="GDAL 1.9.0, released 2011/12/29" LIBXML="2.7.8" (core
procs from "2.0.1 r9979" need upgrade) RASTER (raster procs from "2.0.1
r9979" need upgrade)"

I have two tables with geometries. Both include polygons representing
administrative units. One at the first level and one at the second level.
I want a table that includes all the second level polygons where available,
and where not available I want the first level polygons.

To find the level 1 polygons for filling the gaps where level 2 is N/A, I
thought about finding where the centroid of level one polygons does not
intersects with the polygons for level 2.

Hence, I tried:

SELECT g1.name, g1.geom INTO gadm2_level1_union_selected FROM
gadm2_level1_union g1, gadm2_level2_union g2 WHERE
ST_Intersects(g1.centroid, g2.geom)=FALSE;

I also tried the ST_Disjoint(g1.centroid, g2.geom).

My problem is that this is running for ages without finishing. This should
be such a simple query, but I have used half of the day running it. If I
take the two geometries into PostGIS and run a spatial query to find the
points from level 1 not intersecting with polygons of level 2, it takes 15
seconds.

What could be the issue with my query?

Thanks!
Andreas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20140217/57745874/attachment.html>