EclipseLink Solutions Guide for EclipseLink
Release 2.5
  Go To Table Of Contents

9 Using Multiple Databases with a Composite Persistence Unit

With EclipseLink, you can expose multiple persistence units (each with unique sets of entity types) as a single persistence context by using a composite persistence unit. Individual persistence units that are part of this composite persistence unit are called composite member persistence units.


EclipseLink also supports multiple databases through partitioning. See Chapter 10, "Scaling Applications in Clusters" for more information.

This chapter contains the following sections:

Use Case

Users need to map expose multiple persistence units as a single persistence context within an application.


EclipseLink supports a "composite" persistence unit which can include multiple member persistence units.



See the following EclipseLink examples for related information: