Generalizing Database Relational Algebra for the Treatment of Incomplete/Uncertain Information and Vague Queries.
Henri PradeClaudette TestemalePublished in: Inf. Sci. (1984)
Keyphrases
- uncertain information
- relational algebra
- query language
- relational calculus
- database
- null values
- relational database systems
- relational data model
- database query languages
- data model
- incomplete information
- relational model
- expressive power
- probabilistic databases
- uncertain data
- relational operators
- normal form
- query evaluation
- relational databases
- complex objects
- aggregate functions
- relational algebra expressions
- belief functions
- first order logic
- database systems
- transitive closure
- recursive queries
- object oriented
- answering queries
- database queries
- vague sets
- query processing
- database technology
- data management