Keyphrases
- schema mappings
- data exchange
- data integration
- sql queries
- xml schema
- xml documents
- xml queries
- database schema
- query answering
- xml data
- twig queries
- relational database management systems
- schema matching
- xml data exchange
- schema evolution
- data model
- data management
- databases
- high level specifications
- conjunctive queries
- relational database systems
- metadata
- data transformation
- data sources
- query processing
- relational databases
- business intelligence
- query language
- np hard
- data warehouse
- high level declarative
- structured data