Decidability and Undecidability of Equivalence for Linear Datalog with Applications to Normal-Form Optimizations.
Tomás FederYatin P. SaraiyaPublished in: ICDT (1992)
Keyphrases
- normal form
- query containment
- query answering
- conjunctive queries
- boolean expressions
- relational algebra
- transitive closure
- functional dependencies
- description logics
- datalog programs
- integrity constraints
- relational calculus
- nested relations
- database design
- answering queries
- recursive queries
- decision procedures
- relational databases
- relational database theory
- data complexity
- query evaluation
- information content
- query language
- data dependencies
- data exchange
- knowledge base
- query rewriting
- incomplete information
- probabilistic databases
- data integration
- dl lite
- databases
- relational model
- exptime complete
- data model
- expressive power
- database
- np complete
- schema mappings
- complex objects
- set of functional dependencies
- deductive databases