Keyphrases
- query evaluation
- query language
- data model
- conjunctive queries
- relational algebra
- transitive closure
- query processing
- deductive databases
- xml data
- data complexity
- data management
- expressive power
- disjunctive deductive databases
- efficient query evaluation
- aggregate functions
- database systems
- constraint databases
- regular expressions
- database
- knowledge representation
- probabilistic databases
- search engine
- query answers
- querying xml documents
- probabilistic xml
- inverted lists
- signature file
- machine learning
- data mining
- databases