Keyphrases
- path expressions
- xml documents
- xml data
- xml queries
- semi structured data
- object oriented databases
- complex objects
- xml query languages
- query language
- cost model
- xml query processing
- xpath queries
- semistructured data
- semi structured
- relational database systems
- xml schema
- relational databases
- xml databases
- structured data
- xml elements
- query evaluation
- data model
- regular expressions
- xpath expressions
- databases
- information retrieval
- database
- tree patterns
- heterogeneous data
- keyword search
- relational data
- labeling scheme
- functional dependencies
- query processing
- database systems