Sometimes you need an empty database, particularly in an online environment.
Because IMS does not allow the creation of a database online, the database must be created offline. Creating an empty database offline usually involves inserting one root segment and deleting it. The Reorg function allows you to initialize the database so it can be used online.
You can execute the REORG command to perform this initialization function with a JCL statement modification. To create a usable empty database, specify a DFSUINPT DD statement that points to an empty sequential data set. You cannot specify DFSUINPT DD DUMMY. Include the INPUT(UNLDFILE) keyword in the PLUSIN control statement data set. For more information, see INPUT.