Keyphrases
- query evaluation
- query processing
- deductive databases
- query language
- data management
- transitive closure
- data complexity
- conjunctive queries
- probabilistic databases
- exact and approximate
- xml data
- regular expressions
- querying xml documents
- disjunctive deductive databases
- efficient query evaluation
- database systems
- knowledge base
- tree pattern queries
- xpath queries
- query answers
- special case