Keyphrases
- conjunctive queries
- query evaluation
- data complexity
- query answering
- integrity constraints
- query language
- np complete
- query rewriting
- data exchange
- special case
- decision procedures
- containment of conjunctive queries
- boolean expressions
- probabilistic databases
- query containment
- bounded treewidth
- transitive closure
- database
- data management
- data model
- deductive databases
- primary key
- queries using views
- unions of conjunctive queries
- np hard
- databases