Ssg4env wp4
This presentation is the property of its rightful owner.
Sponsored Links
1 / 23

SSG4Env WP4 PowerPoint PPT Presentation


  • 67 Views
  • Uploaded on
  • Presentation posted in: General

SSG4Env WP4. Semantic Integrator Proposal & WP2 Collaboration. WP4. Design & implement Semantic Integrator Service D4.1 Related work on Semantic data integration, Ontology-based data access Semantic queries over streaming data

Download Presentation

SSG4Env WP4

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Ssg4env wp4

SSG4Env WP4

SemanticIntegratorProposal & WP2 Collaboration


Ssg4env wp4

WP4

  • Design & implementSemantic Integrator Service

  • D4.1

    • Related work on Semantic data integration, Ontology-based data access

    • Semantic queries over streaming data

    • Proposal of Ontology-base integration model for heterogeneous streaming and stored data


Requirements

Requirements

Sensor Network

Database Data

Decl. Query

Integrate

Integrated view

Stream Data

  • Based on use-cases

  • Integrate stored and streaming data sources

  • Integrate sources through unified view

  • Pose declarative queries over integrated view


Background

Background

  • Ontologybased data access

  • Ontology-based data integration

  • Streaming data access

  • Distributedqueryprocessing

  • SNEE/SNEEql

  • R2O/ODEMapster

  • SPARQL streamingextensions


Ontology based data access integration

Ontology-based data access & integration

SquirrelRDF

RDBToOnto

Relational.OWL

SPASQL

Virtuoso

D2RQ

MASTRO

R2O + ODEMapster

ODEMapster

MySQL

Oracle

...others

ODEMQL

Ontological query

Transform

relational query

Ontological model

Database

OWL

Mapping

R2O

OBSERVER

SIMS

Carnot

DWQ

PICSEL

MOMIS

Ontological query

Ontological model

Transform

relational query

Databases

Mappings


Streaming data access

Streaming Data Access

  • Continuously appended data

  • Potentially infinite

  • Time-stamped tuples

  • Continuous queries

  • Latest information used in queries

  • Windows: time and tuple based

  • Archival data

(t9, a1, a2, ... , an)

(t8, a1, a2, ... , an)

(t7, a1, a2, ... , an)

...

...

(t1, a1, a2, ... , an)

...

...

Window [t7 - t9]

Streaming Data

  • Sensor Networks characteristics

  • Low computational, power resources, storage

  • Distributed query execution

  • Routing, Optimization

SNEE

Query

SNEEql


Sparql streaming extensions

SPARQL streaming extensions

  • SPARQL RDF query language

  • Language limitations for streams

    • Windows, time, tuple

    • Data model

    • Aggregates, stream operators

  • Streaming SPARQL

  • C-SPARQL


Approach

Approach

  • Establish global ontological view

  • Mapping global to local views

  • Mapping ontological model to stream/stored sources

  • Define semantic streaming queries over ontological model

  • Transform semantic queries to inter-lingua streaming query language

  • Distributed query evaluation in distributed sources

  • Integration and transformation of results


Semantic integrator

SemanticIntegrator

Ontology-to-Ontologymappings

S2O mappings

Client

q

Query reconciliation

qr

Query canonisation

Qc

SNEEql (S1 S2 Sn)

SPARQLSTR (Og)

SPARQLSTR (Og)

Query Processing

Dl

Data reconciliation

Data decanonisation

[tuplel1 l2 l3]

[tuple]

d

dr

[tripleOg]

[tripleO1O2On]

Ontology-based Streaming Data Access Service


Semantic integrator1

SemanticIntegrator

S2O mappings

q

Qc

Client

Query canonisation

SNEEql (S1 S2 Sn)

SPARQLSTR (Og)

Query Processing

Data decanonisation

d

Dl

[tuple]

[tuplel1 l2 l3]

[tripleOg]

Ontology-based Streaming Data Access Service


Distributed query processing

DistributedQueryProcessing

AbstractSyntaxTree

LogicalAlgebraicForm

PhysicalAlgebraicForm

DistributedAlgebraicForm

Logical rewrite

Physicaloptimization

Partition

Leafspecific scans

Parsequerystring, usinggrammar, produce AST

Produce logical plan

Produce physical plan includingoptimizations

Identifyexchangepoints, addtothedistribute plan

Retrieve data fromexternalsources

Parse


Architecture

Architecture


Integration interface

Integration Interface

  • IntegrateAsoperation

    • Reference to sources

    • Mapping Global-to-Local ontologies

    • Sources have an ontologicalviewregistered

    • Mappingsfromontologicalviews to inter-lingua

    • Returnsreference to integrated data resource


Query interface

Query Interface

  • ExecuteQuery

    • One shotqueries

  • ExecuteQueryFactory

    • Used for most streaming queries

    • Pull/push in config document

    • Push delivery -> use Subscription

    • Pull delivery -> use Data Access

  • TypicallyStreamExecuteFactory


Cross cutting issues

Cross-cutting issues

  • Identifyqueriesfromboth use-cases

  • Characterization of queries

  • Representqueries in global querylanguage

  • Study the querysemantics of QL for RDF Streamscompared to SNEEqlsemantics


R 2 o odemapster

R2O + ODEMapster

  • Startingwith SPARQL support

  • Define «S2O » extensions for R2O

  • Define SPARQLSTRlanguagesyntax and semantics

  • Engine support for « S2O » documents, SPARQLSTR queries

  • Engine support for SNEEql translation and connection


Thanks

Thanks...

windsamples


Ssg4env wp4

conceptmap-def WindSpeedMeasurement

virtualStream<http://ssg4env.eu/Readings.srdf>

uri-asconcat('ssg4env:WindSM_',

windsamples.sensorid,windsamples.ts)

attributemap-defhasSpeed

operationconstant

has-columnwindsamples.speed

dbrelationmap-defisProducedBy

toConceptSensor

joins-viacondition equals

has-columnsensors.sensorid

has-column windsamples.sensorid

conceptmap-def Sensor

uri-asconcat('ssg4env:Sensor_',sensors.sensorid)

attributemap-defhasSensorid

operation constant

has-columnsensors.sensorid

WindSpeed

Measurement

s:windsamples

hasSpeed

sensorid: int PK

ts: datetime PK

speed: float

isProducedBy

xsd:float

Sensor

t:sensors

hasSensorid

sensorid: int PK

sensorname: st

xsd:int

Streams

S2O Mapping

Ontologies


Extras

Extras


Thru the example

Thrutheexample…

Consider a simple query: obtainthecurrentmeasuredwindspeed and direction, measurement time and sensor location.

Speed and directionretrievedfrom sensor network. Sensor locationfoundon a table.


Sparql str query

SPARQLSTRQuery

REGISTER …

PREFIX fire <http://.../integratedOntology>

SELECT ?long ?lat ?speed ?dir ?ts

FROM STREAM <integratedOntologicalView> [NOW]

WHERE { ?id a fire:WindSensor;

fire:hasLong ?long;

fire:hasLat ?lat;

fire:hasSpeed ?speed

fire:hasDir ?dir

fire:hasTS ?ts. }

Notrestrictedto C-SPARQL orStreaming SPARQL limitations (no reason)

Join of twodistributedsources

Join of stream and storedsources


Sparql str on local ontologies

SPARQLSTRon Local Ontologies

REGISTER …

PREFIX wind <http://.../WindOntology>

PREFIX loc <http://.../LocationOntology>

SELECT ?long ?lat ?speed ?dir ?ts

FROM STREAM <WindSensor> [NOW]

WHERE { ?wind a wind:Sensor;

wind:hasSpeed ?speed;

wind:hasDirection ?dir;

wind:hasTS ?ts.

?locid a loc:Location;

loc:hasLong ?long;

loc:hasLat ?lat. }


Sneeql query

SNEEql query

RSTREAM SELECT p.long, p.lat, w.speed, w.dir, w.ts

FROM Wind [NOW] as w, Placement [NOW] as p

WHERE p.id=w.id


  • Login