incubator-jena-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Paolo Castagna <>
Subject Re: Implementing GeoSPARQL
Date Sun, 01 Apr 2012 20:12:27 GMT
Hi Chris
thanks for letting us know.

Mattmann, Chris A (388J) wrote:
> Hi Andy,
> Just to follow up on this, I went ahead and filed this issue:
> I'm going to start work on implementing the Geo SPARQL spec in SIS, maybe
> even integrating with Any23 (and Jena down the road, but Any23, I'm a tad
> more familiar with at the moment). 

I am a bit confused here.

In my head, SIS (which I do not know very well) is a low-level geo indexing
library which could be used to provide the indexing capability for a GeoSPARQL

I know that ARQ (i.e. the SPARQL query engine available in Jena) can
provide you with a SPARQL 1.1 engine and extension points to use other
custom indexes (such as SIS in this case).

What exactly do you mean with "integrating with Any23"?
Do you mean crawling the web and extract lat/long from web pages?
Where will you store those RDF statements?

How can you implement the GeoSPARQL spec without (re)using a SPARQL
query engine (such as ARQ)?

IMHO geo location (as well as free text) are two SPARQL extensions which
are very useful in loads of use cases.


> I'm CC'ing the any23-dev and jena-dev user lists (apologies for the SPAM guys)
> just to keep them in the loop.
> Cheers,
> Chris
> On Jan 31, 2012, at 4:59 AM, Andy Seaborne wrote:
>> Hi there,
>> I'm investigating what it would take to implement GeoSPARQL.
>> There is already an Apache-licensed SPARQL engine in podling Jena.
>> Of the things needed are a persistent storage layer with the right 
>> license.  Maybe the SIS project has something to use.
>> If I understand it correctly, the qtree implementation is an in-memory 
>> structure, with the ability to read from a serialized form on disk, and 
>> to be able to write it to disk in that form.
>> Is there any information on scaling for the qtree?  Memory usage?
>> California_Restaurants.csv is 54K points - is that typical usage size?
>> (yes ... there are other things needed as well such as conversion code 
>> between coodinate systems, format parsers, polygon code, ... but a start 
>> would be just for point data in one system :)
>> An open copy of the spec is available at:
>> 	Andy
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> Chris Mattmann, Ph.D.
> Senior Computer Scientist
> NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
> Office: 171-266B, Mailstop: 171-246
> Email:
> WWW:
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> Adjunct Assistant Professor, Computer Science Department
> University of Southern California, Los Angeles, CA 90089 USA
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

View raw message