Keyphrases
- data integration
- schema mappings
- data exchange
- data model
- data sources
- data management
- databases
- query answering
- database schema
- data integration systems
- data warehouse
- data sharing
- schema matching
- data transformation
- heterogeneous data
- heterogeneous data sources
- data warehousing
- business intelligence
- xml schema
- data complexity
- finite sets
- database systems
- conjunctive queries
- query decomposition
- xml queries
- database
- data sets
- query language
- expressive power