Data description Ontology 2 Ontology's 2 Combined approach 1 Complete classification 1 Complexity classification 1 Computer circuits 1 Conjunctive queries 1 Conjunctive query 1 Data complexity 1 Datalog 1 Description logic 1 Existential rule 1 Existential rules 1 Fine-grained analysis 1 Formal languages 1 Formal logic 1 Guardedness 1 Linear datalog 1 Modeling languages 1 Ontological query 1 Ontologies 1 Ontology-mediated querying 1 Polynomial approximation 1 Query answering 1 Query languages 1 Query processing 1 Query rewriting 1 Query rewritings 1 Rewritability 1