[postgis-users] Possible issue with Geos on PostgreSQL 8.0 Native Windows

[Paul Ramsey]

Doh. This sounds like the original problem we had with GEOS, which is  
that the C++ exceptions are interpretted as signals by the PostgreSQL,  
in particular a signal to die, die, die. The problem appeared to be  
quietly "going away", I think as more modern gcc versions actually  
handled the exception more gracefully.  Our original workaround was to  
compile postgresql with libstdc++ linked in at the top of the DLL list  
(even ahead of libc) so that exceptions would be caught by a runtime  
library that knew what to do with them. In the absence of a windows  
native compiler that will do nice things for us, we might have to  
revert to doing our own windows native compilation with the libstdc++  
hack again in order to catch the exceptions.

P

On Wednesday, January 12, 2005, at 06:40 AM, Obe, Regina DND\MMIS wrote:

>
> I was doing a trial port of my data from Cygwin PostGreSQL 7.4   
> Postgis 0.8
>
> To Native Windows PostGreSQL  8.0.0 RC4, postgis 0.9.
>
> 2 issues -  these could be caused by something wrong with my  
> reconfiguration
> since there are so many variables that have changed so not sure if  
> they are
> problems or not.  I just wanted to know if others have run into similar
> issues.
>
> When I was testing the geom_union function on one of my tables
>
> On the cygwin install I get the following behavior
>
> SELECT geomunion(the_geom) from neighborhood;
>
>
> results in Geos throwing the below error
>
> ERROR:  GEOS union() threw an error!
>
> NOTICE:  TopologyException: side location conflict (780343,2.95405e+06)
> ---------------------------------------------------------
>
> select geomunion(the_geom) from neighborhoods where name  
> IN('Dorchester',
> 'Charlestown');
>
> Results in
> SRID=102686;MULTIPOLYGON(((778278.699002388  .........
>
> ----------------------------------------------------------------------- 
> -----
> --------------------
>
> Same Tests on the: Native Windows PostGreSQL  8.0.0 RC4, postgis 0.9.  
> (I'm
> using the PostGIS that came packaged with 8.0.0 RC4 official release)
> --------------------------------------------------------
>
> SELECT geomunion(the_geom) from neighborhood
>
> Result: The postgres connection crashes without throwing an error so I  
> need
> to reconnect.
>
> ----------------------------------------------------------------------- 
> -----
> -----
> select geomunion(the_geom) from neighborhoods where name  
> IN('Dorchester',
> 'Charlestown');
>
> Result - No SRID shows
> SRID=-1;MULTIPOLYGON(((778278.699002388
>
>
> Other functions such as collect for example return an SRID on both  
> installs
> and I checked the table and the geometry_columns table and both  
> register an
> SRID.
>
> I tried reloading the table from the original shape file using the  
> newer
> shp2pgsql and the same error still stands.
>
>
>
>
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>
      Paul Ramsey
      Refractions Research
      Email: pramsey at refractions.net
      Phone: (250) 885-0632