Keyphrases
- conjunctive queries
- query answering
- integrity constraints
- query evaluation
- data complexity
- np complete
- query language
- decision procedures
- query rewriting
- data exchange
- special case
- query containment
- boolean expressions
- probabilistic databases
- data sets
- schema mappings
- datalog programs
- regular path queries
- spatial databases
- xml data
- dl lite
- bounded treewidth
- tuple generating dependencies
- queries using views