5.3.1 Defaults Used in XFD Files
There are several elements of COBOL that require special handling when data
dictionaries are built. These include multiple record definitions, REDEFINES,
FILLER, and OCCURS. This section describes how ACUCOBOL-GT handles each of these
situations.
Note that in many instances you can override the default behavior described below
by placing special comment lines in the FDs of your COBOL code. These comments
are called directives, and are described in section 5.3.2. For example, the WHEN directive allows you to use multiple definitions for
a single set of data by specifying when each definition should be used.
Databases generally do not support the notion of multiple definitions for the
same column. (In a similar sense, when you are editing a data file, it makes
sense to see and change only one view of the data, rather than multiple views.)
As the following paragraphs 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 data dictionary. Then it disregards the rest.
More:
KEY IS phrase
REDEFINES clause
Multiple record definitions
Group items
FILLER data items
OCCURS clauses
Summary of dictionary fields
Identical field names
Long field names
Naming the XFD
Examples of XFD names