An Extended Relational Algebra on Abstract Objects for Summarizing Answers to Queries.
Robert DemolombePublished in: Fundam. Informaticae (2003)
Keyphrases
- relational algebra
- query language
- query answers
- relational calculus
- relational database systems
- database query languages
- probabilistic databases
- relational model
- data model
- expressive power
- nested relational
- algebraic operations
- duplicate elimination
- relational data model
- relational operators
- normal form
- aggregate functions
- recursive queries
- first order logic
- abstract data types
- complex objects
- query evaluation
- sparql queries
- join operator
- null values
- summary tables
- object oriented
- transitive closure
- relational databases
- database systems
- database
- moving objects
- query processing
- database technology
- user defined
- data structure
- aggregate queries
- conjunctive queries
- query answering
- expert systems
- sql queries
- high level
- xml data
- universal quantification
- database management systems