Object-Relational Databases

1. The object-relational data model extends the relational model by providing rich type system including object orientation and add constructs to relational query languages to deal with added (complex) data types.
2. Such extensions attempt to preserve the relational foundations -- in particular, the declarative access to data -- while extending the modeling power.

• Nested Relations
• Complex Types and Object Orientation
  • Structured and collection types
  • Inheritance
  • Reference Types
• Querying with Complex Types
  • Relation-Valued Attributes
  • Path Expressions
  • Nesting and Unnesting
  • Functions
• Creation of Complex Values and Objects
• Comparison of Object-Oriented and Object-Relational Databases
• References