Keyphrases
- database
- response time
- query processing
- query evaluation
- query expansion
- data structure
- range queries
- user queries
- query formulation
- information retrieval
- data sources
- user interaction
- user defined
- databases
- query terms
- retrieval systems
- relevance feedback
- vector space
- image database
- data model
- data objects
- complex queries
- query execution
- keywords
- original query
- heterogeneous databases
- answering queries