Keyphrases
- xml schema
- regular expressions
- regular tree languages
- tree automata
- xml documents
- integrity constraints
- tree languages
- finite automata
- tree structure
- xml data
- data exchange
- semi structured documents
- relational databases
- object oriented
- metadata
- xml queries
- relational schema
- conceptual model
- finite state
- schema mappings
- context free grammars
- tree structures
- databases
- path expressions
- relational database systems
- database systems
- building blocks