Keyphrases
- relational algebra
- first order logic
- data manipulation
- relational calculus
- expressive power
- database query languages
- nested relational
- query language
- aggregate functions
- data model
- relational data model
- relational model
- normal form
- algebraic operations
- relational database systems
- complex objects
- transitive closure
- programming language
- propositional logic
- relational query languages
- knowledge representation
- modal logic
- probabilistic databases
- data types
- distributed systems
- recursive queries
- relational databases
- database systems
- high level
- summary tables
- data mining
- database