[geos-devel] Benchmark between various geometry libraries

Maxime van Noppen maxime at altribe.org
Wed Nov 18 12:18:11 EST 2009


Martin Davis wrote:
> I'm not sure that anything "went wrong" with the tests.  The results may
> be due to fundamental design differences between GGL and GEOS.  These
> include:
> 
> - GEOS uses a less efficient memory handling strategy, primarily due to
> the goal of tracking JTS closely (and also due to the substantial
> brainpower required to grok C++ template programming)
> - GEOS focuses heavily on providing robustness and ability to handle a
> wide variety of real-world geometry correctly.  This requires using some
> algorithms and extra checking which have an impact on performance
> 
> The robustness question I think is a key one.  In order for a library to
> be viable in an uncontrolled production setting such as PostGIS, it
> needs to be highly robust.  I think this needs to be considered of equal
> importance to performance for these kinds of uses.

I fully agree with your post. I'm new to geos/postgis so I obviously
miss things.

It's quite interesting to have some numbers though, as sometimes they
can lead to significant performance boost (CascadedPolygonUnion is a
good example). It might be interesting to analyze why geos is 23x slower
than other geometry libraries in some cases whereas it competes with
them elsewhere.

-- 
Maxime


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