Keyphrases
- unions of conjunctive queries
- query evaluation
- query processing
- query language
- conjunctive queries
- finite number
- data exchange
- linear temporal logic
- answering queries
- efficient processing
- query formulation
- higher order
- response time
- complex queries
- database
- probabilistic databases
- first order logic
- user queries
- web search engines
- relational queries
- range queries
- cost model
- database queries
- description logics
- search queries
- query answering
- transitive closure
- data sources
- constraint databases
- databases