Keyphrases
- integrity constraints
- databases
- inclusion dependencies
- active rules
- null values
- functional dependencies
- database integrity
- deductive databases
- constraint language
- query answering
- integrity checking
- federated databases
- conjunctive queries
- database transactions
- modal logic
- logical rules
- schema integration
- database systems
- relational databases
- database schema
- constraint checking
- foreign key
- active databases
- consistent answers
- multi valued
- data model
- database integration
- database queries
- np complete
- logic programming
- data management
- consistent query answering