Keyphrases
- xml data
- xml keys
- approximate query answering
- xml documents
- xml queries
- data model
- query optimization
- xml databases
- query processing
- query evaluation
- relational databases
- relational data
- semi structured data
- keyword search
- query language
- querying xml data
- xpath queries
- xml schema
- query decomposition
- database systems
- relational and xml data
- path expressions
- native xml
- xml data sources
- database
- relational database systems
- regular expressions
- xml query languages
- xml query processing
- xml fragments
- native xml databases
- search engine