Of course in code we can always mix and match.

but we should also track some of the discussion here:

https://github.com/opengeospatial/ogc-geosparql/milestone/1

I prefer to focus on the basics for Jena but possibly going forward keeping
an eye on 1.2 and 2.0

I think it's Important to take a look at the issues with Apache Jena
GeoSPARQL that Milos has mentioned at the Semantic GeoSpatial Web - Use
Cases Workshop 2021 last week.

maybe we do another follow up session on this to make sure we have
addressed the show stoppers.



On Sat, Feb 27, 2021 at 9:51 AM Jean-Marc Vanel <jeanmarc.va...@gmail.com>
wrote:

> About performance, all I can say is that indexing 2 dbPedia cities takes
> 608 ms elapsed time from scratch,
> and re-indexing after loading one more city takes 4 ms .
> This is acceptable, and hopefully the re-indexing  time is mostly dependent
> on the increment, not on the overall size of already indexed spatial data.
>
> I'll try GeoSPARQL + Lucene, to see for myself; I see no fundamental reason
> preventing having two different indices on a database (actually altogether
> 16 , the 12 TDB/*.idn plus Lucene plus GeoSparql ).
>
> Time permitting, I also want to try 4.0.0-SNAPSHOT.
>
> Jean-Marc Vanel
> <
> http://semantic-forms.cc:9112/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me
> >
> +33
> (0)6 89 16 29 52
>
>
> Le sam. 27 févr. 2021 à 10:14, Marco Neumann <marco.neum...@gmail.com> a
> écrit :
>
> > On Sat, Feb 27, 2021 at 8:48 AM Jean-Marc Vanel <
> jeanmarc.va...@gmail.com>
> > wrote:
> >
> > > The result is now correct. The missing call is
> > > GeoSPARQLConfig.setupMemoryIndex()
> > > source code updated:
> > >
> > >
> >
> https://github.com/jmvanel/semantic_forms/blob/master/scala/forms/src/main/scala/deductions/runtime/jena/GeoSPARLtest.scala#L11
> > >
> > > NOTES
> > >
> > >    -     but need to re-index after RDF addition;
> > >    -     setupMemoryIndex()  actually registers special SPARQL
> > predicates,
> > >    which is not apparent in method name;
> > >    -     QUESTIONS:
> > >       -  how expensive in terms of CPU, elapsed time and storage is
> > >       re-indexing?
> > >
> > you will have to test that yourself
> > did you check out the
> >
> >   https://github.com/galbiston/geosparql-benchmarking
> >
> > and
> >
> >  https://github.com/OpenLinkSoftware/GeoSPARQLBenchmark
> >
> > would be nice to compare them
> >
> >
> >       -  how to make re-index automatic?
> > >
> >
> > they should be, of course it depends on your conformance requirements
> with
> > OGC Geosparql as well. query rewriting requires inferencing. try the
> > standalone implementations for your tests first,
> >
> >
> > >       - is GeoSPARQL indexing compatible with Lucene indexing?
> > >
> >
> > no, the geospatial modul uses a different approach to indexing. The
> lucene
> > index is not directly resusably in the Apache Jena geosparql module. But
> > Andy mentioned a resurrection of our lucene spatial integration with Jena
> > 4.
> >
> > we may approach this integration with a compliance register in mind in
> the
> > future from a OGC GeoSPARQL 1,0 conformance level point of view.
> >
> >
> > >
> > > Jean-Marc Vanel
> > > <
> > >
> >
> http://semantic-forms.cc:9112/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me
> > > >
> > > +33
> > > (0)6 89 16 29 52
> > >
> > >
> > > Le mer. 24 févr. 2021 à 09:17, Jean-Marc Vanel <
> jeanmarc.va...@gmail.com
> > >
> > > a
> > > écrit :
> > >
> > > > The Scala code is here;
> > > >
> > > >
> > >
> >
> https://github.com/jmvanel/semantic_forms/blob/master/scala/forms/src/main/scala/deductions/runtime/jena/GeoSPARLtest.scala#L11
> > > > starting with empty TDB 1; just load 2 dbPedia cities with geo:
> > > > coordinates, initialize with
> > > >   GeoSPARQLConfig.setupSpatialIndex(dataset)
> > > > and query with spatial:withinBox .
> > > > Alas, the result is empty (see bold line).
> > > >
> > > > Log output :
> > > > 2021-02-24T08:04:14.609Z [run-main-6] INFO
> > o.a.j.g.c.GeoSPARQLOperations
> > > > - Find Mode SRS - Started
> > > > 2021-02-24T08:04:14.633Z [run-main-6] INFO
> > o.a.j.g.c.GeoSPARQLOperations
> > > > - Find Mode SRS - Completed
> > > > 2021-02-24T08:04:14.634Z [run-main-6] INFO
> > > >  o.a.j.geosparql.spatial.SpatialIndex - Building Spatial Index -
> > Started
> > > > 2021-02-24T08:04:14.634Z [run-main-6] INFO
> > > >  o.a.j.geosparql.spatial.SpatialIndex - Geo predicate statements
> found.
> > > > févr. 24, 2021 8:04:14 AM
> > > > org.apache.sis.referencing.factory.sql.EPSGFactory <init>
> > > >
> > > > *AVERTISSEMENT: La variable environnementale « SIS_DATA » n’est pas
> > > > définie.*2021-02-24T08:04:14.973Z [run-main-6] INFO
> > > >  o.a.j.geosparql.spatial.SpatialIndex - Building Spatial Index -
> > > Completed
> > > >
> > > > *?feature*[success] Total time: 5 s, completed 24 févr. 2021 à
> 08:04:15
> > > >
> > > > If someone wants Java code to try, send me a private mail and I'll
> > write
> > > > it :) .
> > > >
> > > > Jean-Marc Vanel
> > > > <
> > >
> >
> http://semantic-forms.cc:1952/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me
> > > >
> > > > +33 (0)6 89 16 29 52
> > > > Twitter: @jmvanel , @jmvanel_fr ; chat: irc://
> > irc.freenode.net#eulergui
> > > >  Chroniques jardin
> > > > <
> > >
> >
> http://semantic-forms.cc:1952/history?uri=http%3A%2F%2Fdbpedia.org%2Fresource%2FChronicle
> > > >
> > > >
> > > >
> > >
> >
> >
> > --
> >
> >
> > ---
> > Marco Neumann
> > KONA
> >
>


-- 


---
Marco Neumann
KONA

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