[postgis-users] Intersects() and large datasets: error?

[Hubert Fröhlich]

Hi list,

I am working with PostgreSQL 7.4.1, Postgis 0.8.2 and GEOS 1.0.0 .

I have a table with some columns and a geometry column for MULTIPOLYGONs

I try to test the scenario "give me the geometry containing a point with 
given coordinates (borders included)" with some SQL statement like

select col1, col2  from table1 where pgpoly && 
geometryfromtext('POINT(4427268.73 5477865.96))', 31494) and 
intersects(geometryfromtext('POINT(4427268.73 5477865.96))', 31494), 
pgpoly);

When the table is filled with a sub-dataset (ca. 80 000 multipolygons) 
of my final data, everything works fine.

When I use my dataset (ca. 10 mill. multipolygons) , I get errors like

NOTICE:  TopologyException: side location conflict (4.42661e+06,5.47702e+06)
ERROR:  GEOS intersects() threw an error!

The box overlap alone

select col1, col2  from table1 where pgpoly && 
geometryfromtext('POINT(4427268.73 5477865.96))', 31494)

works properly.
What has gone wrong?

Regards,
Hubert

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Dr.-Ing. Hubert Fröhlich			
Bezirksfinanzdirektion München 			
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hubert dot froehlich at bvv dot bayern dot de