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A general datalog-based framework for tractable query answering over ontologies
It is shown in particular that Datalog+/- generalizes the DL-Lite family of tractable description logics, which are the most common tractable ontology languages in the context of the Semantic Web and databases.
Taming the Infinite Chase: Query Answering under Expressive Relational Constraints
It is proved that the problems of conjunctive-query answering and query containment under TGDs are decidable and how EGDs can be incorporated into the results by providing conditions under which EGDs do not harmfully interact with TGDs and do not affect the decidability and complexity of query answering.
On the decidability and complexity of query answering over inconsistent and incomplete databases
This paper identifies the maximal class of inclusion dependencies under which query answering is decidable in the presence of key dependencies and establishes decidability and complexity results for query answering under different assumptions on data.
Towards more expressive ontology languages: The query answering problem
Datalog+/-: A Family of Logical Knowledge Representation and Query Languages for New Applications
- A. Calì, G. Gottlob, Thomas Lukasiewicz, Bruno Marnette, Andreas Pieris
- Computer Science25th Annual IEEE Symposium on Logic in Computer…
- 11 July 2010
This paper discusses three paradigms ensuring decidability: chase termination, guardedness, and stickiness, and extends plain Datalog by features such as existentially quantified rule heads and restricts the rule syntax so as to achieveDecidability and tractability.
Data Integration under Integrity Constraints
This paper shows the surprising result that, when the global schema is expressed in the relational model with integrity constraints, even of simple types, the problem of incomplete information implicitly arises, making query processing difficult in the global-as-view approach as well.
Query rewriting and answering under constraints in data integration systems
This paper addresses the problem of query answering and rewriting in global-as-view data integration systems, when key and inclusion dependencies are expressed on the global integration schema, and introduces a semantics which is able to cope with violations of constraints.
Query Answering under Non-guarded Rules in Datalog+/-
The complexity of query answering under Datalog+/- class of decidable languages is investigated, and in addition the novel class of sticky-join sets of TGDs is presented, which generalizes both sticky sets ofTGDs and so-called linear TGDs, an extension of inclusion dependencies.
Advanced processing for ontological queries
A more expressive formalism that takes joins into account, while still enjoying the same low query-answering complexity is introduced, and a highly expressive and effective ontological modeling language that unifies and generalizes both classical database constraints and important features of the most widespread tractable description logics is obtained.
Tractable Query Answering over Ontologies with Datalog+/-
It is shown that query answering under so-called guarded Datalog is PTIME-complete in data complexity, and that query Answer underSo-called linear Datalg, enriched with a special class of key constraints, generalizes the well-known DL-Lite family of tractable description logics.