Keyphrases
- query language
- expressive power
- xml data
- xml documents
- deductive databases
- relational algebra
- logic programming
- integrity constraints
- data model
- xml format
- datalog programs
- conjunctive queries
- query answering
- complex objects
- relational calculus
- xml queries
- update operations
- databases
- query rewriting
- transitive closure
- data complexity
- object oriented
- relational databases
- database
- query language for xml