There are several elements of COBOL FDs that require special handling when XFDs are built. These include multiple record definitions, REDEFINES, FILLER, and OCCURS. This section describes how the compiler handles each of these situations.
As described earlier, in many instances you can override the default behavior described below by placing directives in the FDs of your COBOL code. (Directives are described in the section Using XFD Directives.) For example, the WHEN directive enables you to use multiple definitions for a single set of data by specifying when each definition should be used.
Like most data sources, Micro Focus XDBC does not support the notion of multiple definitions for the same column. As the following sections explain, whenever a COBOL program gives more than one definition for the same data, the compiler makes a choice about which definition to use in the XFD. Then it disregards the rest.