Keyphrases
- data model
- query language
- data sources
- database
- query evaluation
- wide variety
- xml data
- query processing
- xml documents
- answering queries
- response time
- web search engines
- information retrieval systems
- semantically similar
- efficient processing
- database queries
- retrieval systems
- metadata
- data objects
- data structure
- complex queries
- search engine
- boolean queries
- real world