I cann’t be better than what is written at help.sap.com site. So here is the straight dope from there. Read it and marvel upon 😀
UME also supports data partitioning. This means that you can configure UME to use different data sources for different user sets or attribute sets. You can partition data in two ways:
- Attribute-based data partitioning: Different sets of attributes are written to different data sources. For example, global user attributes, such as telephone number, email address, and so on, are written to a corporate directory while SAP-specific data is written to a database.
- User-based data partitioning: Different sets of users are written to different data sources. For example, in a collaboration scenario, where both users internal to your company and users from other companies work together in the same application, the external users need a user account as well. In this case you can configure the persistence manager to store company internal users in the corporate directory, whereas external users are stored in a separate directory.