Keyphrases
- data integration systems
- query answering
- data sources
- data integration
- query rewriting
- schema mappings
- datalog programs
- data exchange
- logic programming
- integrity constraints
- query interface
- logic programs
- regular path queries
- conjunctive queries
- data analysis
- incomplete information
- data model
- data complexity
- relational databases
- answering queries
- data sets
- spatial databases