Tractable Orders for Direct Access to Ranked Answers of Conjunctive Queries.
Nofar CarmeliNikolaos TziavelisWolfgang GatterbauerBenny KimelfeldMirek RiedewaldPublished in: CoRR (2020)
Keyphrases
- conjunctive queries
- np complete
- bounded treewidth
- query answering
- queries using views
- query evaluation
- complexity of query answering
- integrity constraints
- data complexity
- hypertree decomposition
- query rewriting
- query answers
- query language
- data exchange
- special case
- decision procedures
- np hard
- probabilistic databases
- datalog programs
- query containment
- constraint satisfaction problems
- fixed parameter tractable
- conjunctive regular path queries
- unions of conjunctive queries
- regular path queries
- computational complexity
- boolean expressions
- satisfiability problem
- tree width
- schema mappings
- query processing
- containment of conjunctive queries
- data mining
- conjunctive query containment
- answering queries using views
- data sets