[geos-devel] Progress on #837 - TopologyException in UnaryUnion

Martin Davis mtnclimb at gmail.com
Tue Apr 16 08:06:41 PDT 2019


That's good to know, Darafei.   Can you provide a data example that we can
use for doing performance testing?

I'm not seeing that JTS buffer(0) is slower than union() on a random
triangulation.  So perhaps either your dataset has some different
characteristic, or possibly GEOS buffer has different performance
characteristics to JTS.

On Tue, Apr 16, 2019 at 5:27 AM Darafei "Komяpa" Praliaskouski <
me at komzpa.net> wrote:

> Hello,
>
>
>> Ultimately I think the ideal approach is going to be abandoning
>> CascadedUnion and switch to a full union algorithm (which will essentially
>> be the same as running buffer(0).  This should have very good performance.
>>
>
>  We're using PostGIS's ST_Union to dissolve a clipped TIN into a polygon.
> Current ST_Union implementation handles this measurably faster than
> ST_Buffer(ST_Collect(geom),0). Please keep this case in mind.
>
>
> --
> Darafei Praliaskouski
> Support me: http://patreon.com/komzpa
> _______________________________________________
> geos-devel mailing list
> geos-devel at lists.osgeo.org
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