Release 10.1A: OpenEdge Getting Started:
Database Essentials

> ## Storage design overview

> The storage design of the OpenEdge RDBMS is divided into a physical model and a logical model. You manipulate the physical storage model through the Progress 4GL, OpenEdge SQL, and database administration utility interfaces. Figure 3–3 shows how areas can be stored on and span different file slices. Note that though an area’s extents can contain many disk files, an extent can only be associated with one storage area.

> Figure 3–3: Physical storage model

> The logical storage model overlays the physical model. Logical database objects are described in the database schema and include tables, indexes, and sequences that your application manipulates. Figure 3–4 illustrates how logical objects can span physical extents.

> Figure 3–4: Logical storage model

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