Generating an RDA Report

14-4 Oracle Fusion Middleware Administrators Guide existing data in the metadata repository. It provides version history, as well as the ability to label versions so that you can access the set of metadata as it was at a given point in time. ■ Isolate metadata changes: A database-based MDS Repository has the capability to isolate metadata changes in a running environment and test them for a subset of users before committing them for all users. ■ Support for external change detection based on polling: This allows one application to detect changes that another application makes to shared metadata. For example, if you have an application deployed to Managed Servers A and B in a cluster, and you modify the customizations for the application deployed to Managed Server A, the data is written to the database-based repository. The application deployed to Managed Server B uses the updated customizations. This supports high availability in particular, activeactive scenarios. ■ Clustered updates: A database-based MDS Repository allows updates from multiple hosts to the metadata. For a file-based MDS Repository, updates can be made from only one host at a time. Multiple applications can share metadata by configuring a shared metadata repository. When you do this, changes made by one application to the metadata in this repository are seen by other applications using the shared repository, if you configure external change detection for the applications. In an MDS Repository, each application, including Oracle Fusion Middleware components, is deployed to its own partition. A partition is an independent logical repository within one physical MDS Repository, whether it is database-based or file-based. For information about deploying applications and associating them with an MDS Repository, see Chapter 10 . Note the following points about patching the MDS Repository: ■ An MDS Repository must be registered with a domain before it is patched. Otherwise, the applied patches cannot be rolled back and no additional patches can be applied. ■ You can apply patches to the following: – The MDS metadata – An MDS jar file – An MDS shared library – An MDS schema in the database-based metadata repository. The patch can include additive changes such as adding a new column or increasing the size of a column. Note that you cannot rollback this type of patch. – The MDS database PLSQL in the database-based metadata repository. The patch can include changes to a PLSQL package or new PLSQL packages and procedures. – An MDS schema or PLSQL in the database-based metadata repository that requires a corresponding MDS JAR file patch.

14.3.1.1 Databases Supported by MDS

The MDS Repository supports Oracle databases, as well as non-Oracle databases, such as SQL Server and DB2. For more information about the supported versions of these databases, see: