The spatiotemporal RDF store Strabon
2 likes1,463 views
Presentation of the spatiotemporal RDF store Strabon at the Linked Data Europe Workshop, co-located with the European Data Forum in Athens, Greece (21 March 2014)
The spatiotemporal RDF store Strabon
- 1. University of Athens School of Science Faculty of Informatics and Telecommunications Kostis Kyzirakos Linked Data Europe: Tools and Applications March 21, 2014 Database Architectures group Centrum Wiskunde & Informatica Netherlands
- 2. Linked Open Data Cloud 2
- 4. "POLYGON(( 38.16 23.7, 38.18 23.7, 38.18 23.8, ... 38.16 23.8, 38.16 3.7)); <http://spatialreference.org/ref/epsg/412 1/>"^^strdf:WKT stRDF: An example Spatial Literal (OpenGIS Simple Features) Spatial Data Type Well-Known Text 1 ^^xsd:int "23.7636"^^xsd:doublenoa:hasArea noa:hasID rdf:type ex:BurntArea1 noa:BurntArea geo:geometry 4
- 5. select (strdf:Difference(?RGEO, strdf:Union(?BAGEO)) AS ?BF) where { ?R rdf:type noa:Region ; geo:geometry ?RGEO ; noa:hasCorineLandCoverUse ?F . ?F rdfs:subClassOf clc:Forests . ?CITY rdf:type dbpedia:City ; geo:geometry ?CGEO . ?BA rdf:type noa:BurntArea ; geo:geometry ?BAGEO . filter( strdf:Intersect(?RGEO,?BAGEO) && strdf:Distance(?BAGEO,?CGEO, uom:km) < 10) } GROUP BY ?RGEO Find all burned forests within 10kms of a city stSPARQL: An example Spatial Functions (OGC Simple Feature Access) 5
- 6. Strabon Architecture stRDF graphs stSPARQL/ GeoSPARQL queries WKT GML 6 Time SPARQL results KML Documents GeoJSON http://strabon.di.uoa.gr/ Sesame
- 7. Real-world Workload: 500 million triples cold caches 7 Thematic selectivity: 100% number of Nodes in query region Responsetime(sec) Responsetime(sec) number of Nodes in query region Thematic selectivity: 0.1%
- 8. Geographica Synthetic Workload (Spatial Selections, cold caches) 8 Intersects Thematic Selectivity: 100% Intersects Thematic Selectivity: 0.2% http://geographica.di.uoa.gr
- 9. Results (points only) Synthetic Workload (Spatial Selections, cold caches) 9 Intersects Thematic Selectivity: 100% Intersects Thematic Selectivity: 0.1%
- 10. Geographica Synthetic Workload (Spatial Joins) Intersects 10 http://geographica.di.uoa.gr
- 11. System Language Index Geometries CRS support Geospatial Function Support Strabon stSPARQL/ GeoSPARQL* R-tree-over- GiST WKT / GML support Yes OGC-SFA Egenhofer RCC-8 Parliament GeoSPARQL* R-Tree WKT / GML support Yes OGC-SFA Egenhofer RCC-8 Oracle GeoSPARQL R-Tree, Quadtree WKT / GML support Yes OGC-SFA Egenhofer RCC-8 Brodt et al. (RDF-3X) SPARQL R-Tree WKT support No OGC-SFA Perry SPARQL-ST R-Tree GeoRSS GML Yes RCC-8 AllegroGraph Extended SPARQL Distribution sweeping technique 2D point geometries Partial Buffer Bounding Box Distance OWLIM Extended SPARQL Custom 2D point geometries No Point-in-polygon Buffer Distance Virtuoso SPARQL R-Tree 2D point geometries Yes SQL/MM (subset) uSeekM GeoSPARQL R-tree-over GiST WKT support No OGC-SFA
- 12. 12 Fire monitoring service Semantic Web Challenge 2012 - 3rd prize
- 13. 13