Object-oriented databases were originally developed as an alternative to relational database
technology for the representation storage and access of non-traditional data forms that were
increasingly found in advanced applications of database technology. After much debate regarding
object-oriented versus relational database technology object-oriented extensions were
eventually incorporated into relational technology to create object-relational databases. Both
object-oriented databases and object-relational databases collectively known as object
databases provide inherent support for object features such as object identity classes
inheritance hierarchies and associations between classes using object references. This
monograph presents the fundamentals of object databases with a specific focus on conceptual
modeling of object database designs. After an introduction to the fundamental concepts of
object-oriented data the monograph provides a review of object-oriented conceptual modeling
techniques using side-by-side Enhanced Entity Relationship diagrams and Unified Modeling
Language conceptual class diagrams that feature class hierarchies with specialization
constraints and object associations. These object-oriented conceptual models provide the basis
for introducing case studies that illustrate the use of object features within the design of
object-oriented and object-relational databases. For the object-oriented database perspective
the Object Data Management Group data definition language provides a portable
language-independent specification of an object schema together with an SQL-like object query
language. LINQ (Language INtegrated Query) is presented as a case study of an object query
language together with its use in the db4o open-source object-oriented database. For the
object-relational perspective the object-relational features of the SQL standard are presented
together with an accompanying case study of the object-relational features of Oracle. For
completeness of coverage an appendix provides a mapping of object-oriented conceptual designs
to the relational model and its associated constraints. Table of Contents: List of Figures
List of Tables Introduction to Object Databases Object-Oriented Databases
Object-Relational Databases
