Querying Incomplete Information Using Bag Relational Algebra.
Lubomir StanchevPublished in: eKNOW (2010)
Keyphrases
- incomplete information
- relational algebra
- relational model
- query language
- first order logic
- sparql queries
- relational database systems
- expressive power
- data model
- relational calculus
- partial information
- database
- complex objects
- normal form
- missing information
- query evaluation
- null values
- nested relations
- database query languages
- query answering
- autonomous agents
- databases
- user defined
- query processing
- relational databases
- universal relation
- transitive closure
- entity relationship
- data types
- answering queries
- xml data
- object oriented
- recursive queries