On the expressive power of semijoin queries.
Dirk LeindersJerzy TyszkiewiczJan Van den BusschePublished in: Inf. Process. Lett. (2004)
Keyphrases
- expressive power
- query language
- relational calculus
- recursive queries
- database query languages
- pattern queries
- query evaluation
- relational algebra
- aggregate functions
- transitive closure
- data complexity
- relational query languages
- first order logic
- data model
- efficient processing
- computational properties
- query processing
- database
- constraint databases
- xml data
- complex objects
- range queries
- monadic second order logic
- regular expressions
- user defined aggregates
- query types
- data sources
- artificial intelligence
- relation algebra
- datalog queries
- data integration
- query containment
- aggregate queries
- conjunctive queries