Parts of a DEDB area

A DEDB area consists of three parts.

The parts are:

The following figure shows these parts of a DEDB area.

Figure 1. Parts of a DEDB area in storage
A DEDB area has 3 parts: a root addressable part, an independent overflow part, and a sequential dependent part. Each part has CIs. The root addressable part has base and dependent overflow sections.

When a DEDB data set is initialized by the DEDB initialization utility (DBFUMIN0), additional CIs are created for internal use, so the DEDB area will actually contain more CIs than are shown in the preceding figure. These extra CIs are referred to as the Reorganization UOW. Although IMS does not use the extra CIs, DBFUMIN0 creates them for compatibility purposes.