Keyphrases
- query processing
- database
- query expansion
- response time
- decision trees
- query evaluation
- data sources
- data structure
- relevance feedback
- maintenance cost
- query formulation
- query cost
- tree nodes
- result set
- retrieval method
- database queries
- keyword search
- memory requirements
- keywords
- range queries
- vector space
- user queries
- search queries
- communication cost
- complex queries
- query terms
- tree patterns
- retrieval systems