Release 10.1A: OpenEdge Getting Started:
OpenEdge Reference Architecture

Overview

The first layer of OpenEdge RA is the Data Access Layer, as shown in Figure 2–1.

Figure 2–1: The Data Access Layer

Components within the Data Access Layer are called Data Access Objects. They are responsible for the direct interaction with data sources. All references to the physical data store and physical views of the data should be confined to the Data Access Object. Compare this with the Business Entity Object, which presents a logical view of the data to the rest of the application.