Flush=Buffer_End
    Flush=On_Commit

    Controls when internal RMS buffers are flushed to the unload
    file. By default, the RMU Unload command flushes any data left
    in the internal RMS file buffers only when the unload file is
    closed. The Flush qualifier changes that behavior. You must use
    one of the following options with the Flush qualifier:

    o  Buffer_End

       The Buffer_End option specifies that the internal RMS buffers
       be flushed to the unload file after each unload buffer has
       been written to the unload file.

    o  On_Commit

       The On_Commit option specifies that the internal RMS buffers
       be flushed to the unload file just before the current unload
       transaction is committed.

    If the Delete_Rows qualifier is specified, the default for this
    qualifier is Flush=On_Commit. This default is necessary to allow
    you to use the unload and record definition files to reload the
    data if an unrecoverable error has occurred after the delete of
    some of the unloaded rows has been committed.

    If the Delete_Rows qualifier is not specified, the default is to
    flush the record definition buffers only when the unload files
    are closed.

    More frequent flushing of the internal RMS buffers will avoid the
    possible loss of some unload file data if an error occurs and the
    Noerror_Delete qualifer has been specified. Additional flushing
    of the RMS internal buffers to the unload file can cause the RMU
    Unload command to take longer to complete.