[gdal-dev] Open source vector geoprocessing libraries?

[Mateusz Loskot]

Frank Warmerdam wrote:
> Jan Hartmann wrote:
>> On 13-1-2010 21:19, Mateusz Loskot wrote:
>>>
>>> IMHO, it's misunderstanding to consider OGR fully featured data model
>>> and I/O engine to read, write, process and analyse spatial vector data,
>>> especially if performance is a critical factor. IMHO, there are too
>>> many
>>> compromises in OGR.
>>>
>>>
>> OK, that is a very clear statement. I must say that I always thought of
>> OGR as an independant GIS data model, the most encompassing of all, and
>> that it could (in principle anyway) be used in some sort of stand-alone
>> fashion.. I certainly can imagine, however, that for real applications
>> it is not as optimal as more specialized formats.
>
> [...]
> Also, as I think Mateusz is suggesting, the performance characteristics
> of different OGR drivers varies greatly.

Yes. Also, most applications I've seen using OGR do define their own
data models and translate OGRFeature to features of their own types.
Perhaps it would be interesting to know why they don't use OGRFeature
as a part of their data model, what's missing...

> There is of course some non-trivial overhead converting underlying
> features into OGRFeatures, and as was noted there is some performance
> impedance between OGR and GEOS due to the need to translate
> geometries frequently.

There usually is yet another step (cost), it is translation from
OGRFeature to feature of application's data model.

An example:

http://trac.osgeo.org/qgis/browser/trunk/qgis/src/providers/ogr/

Best regards,
-- 
Mateusz Loskot
http://mateusz.loskot.net