Keyphrases
- lower bound
- upper bound
- database
- worst case
- np hard
- query processing
- constant factor
- objective function
- branch and bound algorithm
- response time
- branch and bound
- query evaluation
- lower and upper bounds
- user queries
- databases
- query formulation
- data structure
- complex queries
- information retrieval systems
- query expansion
- sample complexity
- vector space
- query terms
- optimal solution
- lower bounding
- statistical queries
- min sum
- retrieval method
- range queries
- retrieval systems
- user interaction
- data sources
- relational databases
- wide range
- keywords
- information retrieval