Keyphrases
- query language
- expressive power
- data model
- sparql queries
- relational algebra
- query answering
- rdf data
- deductive databases
- database
- relational calculus
- linked data
- semantic web
- datalog programs
- query evaluation
- conjunctive queries
- object oriented
- transitive closure
- rdf graphs
- ontology based data access
- relational query languages
- logic programming
- data complexity
- integrity constraints
- data mining
- neural network
- complex objects
- query optimization
- query processing
- xml documents
- data sets