Semantic Data

Chapter 9 : Data integration and ontology-based data access

Jean-Louis Binot

1 01/04/2020Semantic Data

Sources and recommended readings

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Agenda

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Graph DBs and triple stores3

RDBMS and data integration challenges2

RDF-based data integration1

Case Study in Oil & Gaz4

Ontology based data access5

Oil and Gaz data context

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A data integration example : EPIM

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Solution architecture: RDF database for data integration

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Solution : RDF database for data integration

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Background questions

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Agenda

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Graph DBs and triple stores3

RDBMS and data integration challenges2

RDF-based data integration1

Case Study in Oil & Gaz4

Ontology based data access5

Data integration ?

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The IT environments

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What do we find in production?

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Performance and velocity challenges in production

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Operational complexity

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Live data

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Is OLAP the solution for data ?

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RDBMS challenges summary

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Integration challenges : data silos

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Silo issues summary

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Agenda

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Graph DBs and triple stores3

RDBMS and data integration challenges2

RDF-based data integration1

Case Study in Oil & Gaz4

Ontology based data access5

NoSQL databases

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Aggregate NoSQL databases

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Value

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Aggregate NoSQL databases

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Graph databases

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Graph databases versus RDF triple stores

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Graph databases versus RDF triple stores

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Implementation of RDF stores

Subject Predicate Object

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Implementation of RDF stores ./.

Subject Predicate Object

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Dictionary

A ranking of graph databases and RDF stores

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The main commercial systems are also active

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Reasoning with RDF stores

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Agenda

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Graph DBs and triple stores3

RDBMS and data integration challenges2

RDF-based data integration1

Case Study in Oil & Gaz4

Ontology based data access5

What do we mean by a case study ?

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Statoil: case study paper

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Looking at the abstract

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The problem

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Business needs

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Existing situation: architecture and data

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Existing situation : p

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Solution architecture : ontology-based data access

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Solution implemented: innovative aspects

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Evaluation

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Agenda

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Graph DBs and triple stores3

RDBMS and data integration challenges2

RDF-based data integration1

Case Study in Oil & Gaz4

Ontology based data access5

OBDA main ideas

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DB3

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OBDA main ideas ./.

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Differences between OBDA and databases

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A quiz

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Database ABox OntologyQuery

NonBelgianUniv(Oxford)

Student(André)

University(ULiège)

Institution ⊓ ¬University(KUL) Yes Don’t Know Don’t Know

No Don’t Know Yes

No Don’t Know Yes

Yes Yes Yes

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Questions to be adressed

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Choices of languages

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❑ Ԧ𝑥 ∃ Ԧ𝑦 φ Ԧ𝑥 Ԧ𝑦

◼ φ Ԧ𝑥 Ԧ𝑦

Ԧ𝑥 or Ԧ𝑦

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◼ x,

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Choices of languages ./.

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Ontology language for OBDA : OLW 2 QL / DL Lite

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⊆ NLOGSPACE ⊆ ⊆ ⊆ ⊆ ⊆ EXPSPACE

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DL Lite logics

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Certain answers

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❑ O Ԧ𝑥 OO

Ԧ𝑥 Ԧ𝑥 Ԧ𝑥 O

O ⊨ Ԧ𝑥

I I ⊨ O→ I ⊨ Ԧ𝑥

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Dealing with the TBox

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A T ⊆ ∀

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Classical approach for dealing with the TBox: query rewrite

O T A

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Example of query rewriting from the case study

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❑ Query rewriten qr :

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Example of query rewriting from the case study

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OBDA status

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Summary

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References

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THANK YOU

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