All Oracle ATG Web Commerce repositories provide a means for representing information in a data store as Java objects. The composite repository lets you use more than one data store as the source for a single repository. The composite repository consolidates all data sources in a single data model, making the data model flexible enough to support the addition of new data sources. Additionally, the composite repository allows all properties in each composite repository item to be queryable. Thus, from the point of view of your Oracle ATG Web Commerce application, the composite repository presents a consistent view of your data, regardless of which underlying data store the data may reside in.

The composite repository is a repository that unifies multiple data sources. Its purpose is to make any number of repositories appear in an Oracle ATG Web Commerce application as a single repository. The composite repository defines a mapping between item descriptors and properties as they appear to facilities that use the composite repository and item descriptors and properties of the data models that comprise the composite data model. A composite repository is composed of any number of composite item descriptors. Each item descriptor can draw on different data models from different repositories, and map underlying data model attributes in different ways.