One-Record File Organization
A one-record file is stored sequentially, and is therefore subject to all the restrictions that apply to sequential files (see the next section). Unlike other sequential files, however, a single-record file communicates to an APPX input process that it can expect at most one record. Based upon this information, the user interface is streamlined. For example, APPX automatically checks for the existence of a record in a file. If there is no record, APPX places the user in add mode. If there is a record in the file, APPX places the user in change mode.
A parameter file is an example of a single-record file. Using a single-record file to hold specifications that are referenced by more than one process in an application avoids unnecessary duplication, and simplifies design and maintenance.
|