Keyphrases
- labeling scheme
- xml documents
- xml data
- twig queries
- relational database management systems
- xml trees
- xml queries
- xml databases
- relational tables
- transitive closure
- data model
- path expressions
- parent child
- xml schema
- relational database systems
- xpath expressions
- sql queries
- relational databases
- relational data
- efficient processing
- query optimization
- xpath queries
- graph structure
- network structure
- active learning
- database
- semi structured data
- information retrieval
- directed graph
- data integration
- object oriented
- query language
- leaf nodes
- structured data
- shortest path
- metadata
- social networks
- native xml