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From Paolo Castagna <>
Subject Re: Implementing GeoSPARQL
Date Mon, 02 Apr 2012 09:31:37 GMT
Hi Chris

Mattmann, Chris A (388J) wrote:
>> How can you implement the GeoSPARQL spec without (re)using a SPARQL
>> query engine (such as ARQ)?
> I need that too :) I just don't understand it as well (and understand the Any23/Tika
> and SIS part better). I'll have to learn Jena it looks like though, you game to 
> help me out?

ARQ has a couple of extension points which are useful here:

Filter Functions

Property Functions

You can find examples of FILTER functions here:

You can find examples of property functions here:

The GeoSPARQL spec available at
describes FILTER functions: ogcf:relate, ogcf:distance, ogc:buffer,
ogcf:convexHull, ogcf:intersection, ogcf:union, ogcf:difference,
ogcf:symDifference, ogcf:envelope and ogcf:boundary

Does GeoSPARQL requires FILTER functions only?

At the moment, I have no idea how you would deal with WKT and GML.

Also, I have no idea if SIS provides all the necessary spatial capabilities
necessary for a GeoSPARQL implementation.

It is still not clear to me, how a GeoSPARQL implementation would support
a use case such as this: "John is in Cardif and he wants to find two or
three restaurant close to where he is."?

Does anyone know if there is any GeoSPARQL implementation elsewhere?


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