The first database developed in mathematical terminology is relational model database. Its basic assumption is that data can be expressed in mathematical n-array relations either as Cartesian product of n domains or in subsets. Object / relational database model add new object storage ability to the relational models at the foundation levels of modern information systems. Applying encapsulating techniques, complex analytical and data manipulation functions can be executed. As an emerging, technology, the object/relational (OR) approach has gained strong transaction and performance-management features of its relational ancestor and the flexibility of object-oriented .
An object-relational database is a database analogous to the relational database. It also offers a middle ground between relational database and object oriented database. However, object oriented relational data base has additional features which support database schema and also the structured query language. Some of features include:
OR database is initially developed to bridge up the gap between data modelling techniques like entity-relationship diagram and object-relational modelling techniques that are used in programming C ++ and Java. Also, this type of database aims at raising the level of abstracting a problem domain.
- Object oriented data bases are mainly developed for complex data types,
- object abstraction (easier real-world modelling, better resolvability and reusability), encapsulation behaviour (Data objects and their respective operations and methods are considered together – close the gap between utilization of data in the and querying of data in the software)
- For performing high presentation application programs .