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Jiahui Zhang, Xiaowang Zhang, and Zhiyong Feng
Tianjin University
zhangjiahui@tju.edu.cn xiaowangzhang@tju.edu.cn zyfeng@tju.edu.cn
A Path Querying Language for Federation of RDF and Relational - - PowerPoint PPT Presentation
A Path Querying Language for Federation of RDF and Relational - - PowerPoint PPT Presentation
A Path Querying Language for Federation of RDF and Relational Database Jiahui Zhang, Xiaowang Zhang, and Zhiyong Feng Tianjin University zhangjiahui@tju.edu.cn xiaowangzhang@tju.edu.cn zyfeng@tju.edu.cn Outline n Introduction n Federated
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Introduction
n SPARQL
The standard language for querying RDF data since 2008.
n Navigational Capability
Versa: using XPath over the XML of RDF graphs SPARQLeR: adding path variables CPSPARQL: allowing constraints over regular expressions nSPARQL: applying nested regular expressions SPARQL 1.1: appending property paths
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Introduction
Q : Go from Rouen to Reims. Rouen→Dreux→Paris→Reims Rouen→Paris→Reims
Rouen Dreux Paris Reims Figure: Geographical map.
Driver
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Introduction
ID Time Passenger Driver Start Point End Point 1 6:40 a.m. B E Rouen Reims 2 6:50 a.m. C ? Dreux Paris
shorter
Rouen Dreux Paris Reims Figure: Geographical map.
Q' : Go from Dreux to Paris. Rouen→Dreux→Paris→Reims Rouen→Paris→Reims
more orders
Table: Taxi-hailing orders.
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Introduction
ID Time Passenger Driver Start Point End Point 1 6:40 a.m. B E Rouen Reims 2 6:50 a.m. C E Dreux Paris
n RDF Rouen→Paris→Reims n RDF+Relational Database Rouen→Dreux→Paris→Reims
Rouen Dreux Paris Reims Figure: Geographical map. Table: Taxi-hailing orders.
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n Introduction n A Path Querying Language for
Federation
- f RDF and Relational Database
n Expressiveness of FPQ n Experiment and Evaluation
Outline
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FPQ
n Federated Path Querying Language(FPQ)
Conjuction
); , , ( : ) , (
1 i i i n i
v e u v u q
where
- q is the name of FPQ;
- is a conjunctive combination of relations;
- each for is a NRE triple pattern.
) , , (
i i i
v e u
} ,..., 1 { n i
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FPQ
n Query: At a certain time, whether a passenger take a ride?
Conjuction
)] ? , , (? ) ? , , (? ) ? , , [(? )] ( ) ( [ ) ? , (? y exp x y exp x y exp x e R v R y x q
3 2 1
where
- R(v) := Position(Time, ?x, ?y, ?driverId);
- R(e) := Orders(Time, lonUp, latUp, ?x, ?y, ?driverId);
- exp1 : next-1 :: lon;
- exp2 : next :: lat;
- exp3 : next :: nd / next :: ref / next-1 :: id.
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n Introduction n Federated Path Querying Language(FPQ) n Expressiveness of FPQ n Experiment and Evaluation
Outline
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Expressiveness of FPQ
| : Disjunctive operator; N : Nesting operator; ∧ : Conjunctive operator; R : Federated operator; ∨ : Union Operator. UFCNRPQ FCNRPQ CNRPQ NRPQ The query evaluation of FCNRPQ: Data complexity → Polynomial time Combined complexity → NP-complete time
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n Introduction n Federation Path Querying Language n Expressiveness of FPQ n Experiment and Evaluation
l Query and Result l Extention
Outline
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Query
n Query 1: At a certain time, where did the passengers get
- n vehicles or off?
n Query 2: At a certain time, did the passengers visit tourist attractions on the map? n Query 3: At a certain time, which roads did the passengers go down from the vehicles?
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Query
n Query 1: At a certain time, where did the passengers get on vehicles or off? n Query 2: At a certain time, did the passengers visit tourist attractions on the map? n Query 3: At a certain time, which roads did the passengers go down from the vehicles?
ID Time Passenger Driver Start Point End Point 1 6:40 a.m. B E Rouen Reims 2 6:50 a.m. C E Dreux Paris RDF
Conjuction
Relational Database Rouen Dreux Paris Reims Figure: Geographical map. Table: Taxi-hailing orders.
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Result
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n Distributed environment to solve the memory overflow n Streaming data to process the real time query
Extention
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