Keyphrases
- expressive power
- constraint satisfaction problems
- query language
- first order logic
- relational algebra
- data complexity
- decomposition methods
- computational properties
- transitive closure
- constraint satisfaction
- aggregate functions
- relational calculus
- constraint propagation
- machine learning
- logic programming
- logic programs
- description logics
- np hard
- tree decomposition
- search algorithm
- recursive queries