The Oracle Enterprise Repository provides a flexible meta model for cataloguing all assets within the SOA ecosystem and their dependencies. It is primarily used during the plan, design, and build phase of the lifecycle as a single source of truth for service and composite application development.
The Oracle Service Registry is a reference point for services that have been deployed into the runtime environment. It is primarily used for programmatic, dynamic discovery and binding by elements of the SOA infrastructure. The Oracle Service Registry typically contains a subset of the metadata from the Oracle Enterprise Repository for runtime discovery.
A major use case for Oracle Service Registry is to provide a UDDI interface by which selected Oracle Enterprise Repository content may be accessed or published. The Oracle Service Registry also serves as an integration point for runtime tooling such as Oracle Service Bus (OSB), Oracle SOA Suite 11g and JDeveloper. OSB can automatically publish and subscribe to new or modified assets. Registries can also be federated - configurations of systems with single logical repository, and multiple registries (one for each major environment or stage in the lifecycle) are common. The Oracle Enterprise Repository and the Oracle Service Registry are synchronized using the Oracle Registry Repository Exchange Utility.
The enterprise metadata repository capabilities of Oracle Enterprise Repository together with the comprehensive support for UDDI v3 in Oracle Service Registry provide customers with the capability for managing and governing the full SOA lifecycle. Together, Oracle Enterprise Repository and Oracle Service Registry provide organizations with a system of record for managing their enterprise assets in order to provide visibility, reusability, and traceability throughout the enterprise.
For more information about integrating Oracle Enterprise Repository with OER Exchange Utility and Oracle Service Registry, see their OTN pages http://otn.oracle.com/goto/oer and http://otn.oracle.com/goto/registry respectively.