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 >
