Micro Focus XDBC relies on Extended File Descriptors (XFDs) to map your COBOL data items to database columns. An XFD file may be created either as a simple text file or as an XML file. In either case, the XFD contains a description of a COBOL indexed, sequential, or relative file based on its fields. XFDs are automatically generated when you compile your program with the CREATEXFD directive. If the default mapping described in this chapter is sufficient, there is nothing more you need to do to prepare your COBOL for Micro Focus XDBC except create the XFDs themselves. (For information on creating XFDs, see the section The Role of XFDs.)
If you want to add more detail to your database tables, you can add other directives to your program before generating the XFDs. Directives are optional comments that you can place into a File Descriptor (FD) in your COBOL source code to control how XFDs are built. (For information on adding directives, see the section Using XFD Directives.)
These concepts are described more fully later in this chapter.