Keyphrases
- relational schema
- semantic constraints
- xml schema
- xml documents
- xml data
- relational data
- relational databases
- regular expressions
- functional dependencies
- integrity constraints
- entity relationship
- relational database systems
- object oriented
- data model
- metadata
- schema mappings
- data exchange
- relational model
- database schema
- normal form
- conceptual model
- transformation rules
- database
- user defined
- structured data
- building blocks
- software engineering
- knowledge representation
- high level
- knowledge base