Keyphrases
- relational algebra
- database query languages
- relational model
- relational calculus
- null values
- relational databases
- query language
- aggregate functions
- data model
- normal form
- relational data model
- functional dependencies
- relational database systems
- expressive power
- structured query language
- sql queries
- computational properties
- inclusion dependencies
- complex objects
- database design
- database technology
- conceptual model
- incomplete information
- logic programming
- object oriented databases
- sparql queries
- database queries
- databases
- database systems
- first order logic
- recursive queries
- formal semantics
- data exchange
- integrity constraints
- data types
- entity relationship
- database language
- type checking
- object oriented
- owl ontologies
- database
- logic programs
- database server
- visual basic