[postgis-users] Side Location Conflict

[Markus Schaber]

Hi,

During debugging one of our apps, I discovered the following problem:

It seems that I have valid geometry data as input:

logigis=# SELECT distinct
isvalid(intersection(buffer(geom,'0.00005'),'BOX3D (8.554829000000002
47.370963,8.573829 47.379963000000004)'::box3d)) from badgeoms; 

isvalid 
---------
 t
(1 Zeile)


However, trying to union those valid geometries, I get the following
error message:

logigis=#  SELECT geomunion(intersection(buffer(geom,'0.00005'),'BOX3D
(8.554829000000002 47.370963,8.573829 47.379963000000004)'::box3d)) from
badgeoms;      

NOTICE:  TopologyException: side location conflict (8.56235,47.3777) 
ERROR:  GEOS union() threw an error!


I attached the output of "COPY badgeoms TO stdout;" so you can try to
reproduce the problem.

I use a postgis debian package created by a co-worker of mine that
identifies itsself as postgis 0.8.1, the output of postgis_version is:

logigis=# select postgis_version();
            postgis_version            
---------------------------------------
 0.8 USE_GEOS=1 USE_PROJ=1 USE_STATS=1
(1 Zeile)


Can anyone reproduce or explain the problem? Is there a workaround or
fix available?

Thanks,
Markus

-- 
markus schaber | dipl. informatiker
logi-track ag | rennweg 14-16 | ch 8001 zürich
phone +41-43-888 62 52 | fax +41-43-888 62 53
mailto:schabios at logi-track.com | www.logi-track.com
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