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Datalog ±

Datalog ±. Summary of talk by Georg Gottlob http://ontolog.cim3.net/ cgi -bin/wiki.pl?ConferenceCall_2013_10_31. Datalog. Language that is based on prolog Tailored to data querying and integration Limitations to achieve decidability: No complex terms as predicates

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Datalog ±

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  1. Datalog± Summary of talk by Georg Gottlob http://ontolog.cim3.net/cgi-bin/wiki.pl?ConferenceCall_2013_10_31

  2. Datalog • Language that is based on prolog • Tailored to data querying and integration • Limitations to achieve decidability: • No complex terms as predicates • Restrictions on use of negation and recursion • A variable in the head of a clause appears in the body and in not negated • A negative appearing in the body must also exist in the body as a positive • Predicate ordering has no effect on execution

  3. ± • Extend the expressiveness of Datalog while maintaining decidability • Allow for representing popular KR languages • Requires additional language features to achieve increased expressiveness • Requires additional limitations to maintain decidability

  4. + (Extensions) • Existential Quantification • Equality predicate • Constant False

  5. - (Limitations) • Guarded Datalog: Every ‘For All’ variable in the head appears together in a single body atom • Linear Datalog: Body consists of a single atom • Sticky Datalog: Every Join variable in the head appears in a single atom of the body

  6. For Data Integration • Following can now be fully represented • UML Diagrams • F-Logic • SPARQL • Description Logics • Can now use Datalog to query and integrate data stored as these sources

  7. Representing UML

  8. Questions

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