For AcuXDBC to map your COBOL data file to an SQL table format, descriptive information must be written to an XFD file for each data file. An XFD typically has the same name as the COBOL data file, but its extension is .xfd. When you distribute your application, you don't need to include the XFD with the executable files and data files. The XFDs are used only one time to populate your system catalog.
This help section describes the information included in an XFD and how it is mapped to a system catalog format that is easily recognized by your ODBC or JDBC application. See Using XFD Directives for a description of how you can take control of the XFDs using directives. Because this material is relevant during compilation, it applies only to COBOL developers.