Keyphrases
- conjunctive queries
- query evaluation
- query answering
- integrity constraints
- np complete
- query language
- data complexity
- special case
- query rewriting
- probabilistic databases
- query containment
- data exchange
- decision procedures
- schema mappings
- datalog programs
- boolean expressions
- unions of conjunctive queries
- relational databases
- containment of conjunctive queries
- queries using views
- answering queries using views