How is OJB related to ODMG and JDO?
ODMG is a standard API for Object Persistence specified by the ODMG consortium (www.odmg.org). JDO is Sun’s API specification for Object Persistence. ODMG may well be regarded as a Precursor to JDO. In fact JDO incorporates many ideas from ODMG and several people who have been involved in the ODMG spec are now in the JDO team. I assume JDO will have tremendous influence on OODBMS-, RDBMS-, J2EE-server and O/R-tool-vendors to provide compliant products. OJB wants to provide first class support for JDO and ODMG APIs. OJB currently contains of four main layers, each with its own API: • A low-level PersistenceBroker API which serves as the OJB persistence kernel. The PersistenceBroker also provides a scalable multi-server architecture that allows to used it in heavy-duty app-server scenarios. This API can also be used directly by applications that don’t need full fledged object level transactions (see tutorial1 for details). • An Object Transaction Manager (OTM) layer that contains all fea
