Keyphrases
- nested relations
- relational algebra
- recursive queries
- query language
- normal form
- relational model
- complex objects
- data model
- relational database systems
- expressive power
- transitive closure
- relational databases
- information content
- database systems
- join operations
- database technology
- query optimization
- database
- fixpoint
- object oriented
- functional dependencies
- database design
- real numbers