On the expressive power of semijoin queries
Dirk LeindersJerzy TyszkiewiczJan Van den BusschePublished in: CoRR (2003)
Keyphrases
- expressive power
- query language
- relational calculus
- pattern queries
- aggregate functions
- database query languages
- recursive queries
- data complexity
- relational algebra
- transitive closure
- relational query languages
- query evaluation
- data model
- first order logic
- monadic second order logic
- efficient processing
- query processing
- computational properties
- relational database systems
- database
- relational data model
- constraint databases
- regular expressions
- datalog queries
- join algorithms
- query types
- user queries
- xml data
- inductive databases
- query rewriting
- conjunctive queries
- relation algebra