Keyphrases
- relational schema
- xml schema
- xml documents
- xml data
- relational data
- relational databases
- extended entity relationship
- foreign key
- regular expressions
- object oriented
- xml databases
- integrity constraints
- xml queries
- data exchange
- functional dependencies
- markup language
- schema mappings
- normal form
- metadata
- relational database systems
- xml views
- data model
- relational model
- entity relationship
- database schema
- conceptual model
- query optimization
- building blocks
- query language
- user defined
- xpath queries
- transformation rules
- databases
- conceptual models
- conceptual schema
- query processing
- semantic information
- structured data
- xpath expressions