O

Object

A Java object in memory.

See also Datastore object.

Object model

The classes of objects and the relationships of objects in memory.

See also Persistent object model.

ODBMS

Acronym for object-oriented database management system, also called an object database.

ODMG

Object Data Management Group, a standards body for specifying an API for object-oriented databases.

Optimistic transaction

A JDO transaction that implements its transactional boundaries by using multiple transactions in the datastore and a concurrency value for the persistent objects.

O/R mapping

Object-to-relational mapping, a software that maps persistent state of an object-oriented language, such as Java, to a relational database.