DECLARE
    l_dp_handle1 NUMBER;
BEGIN
    l_dp_handle1 := dbms_datapump.OPEN(operation => 'IMPORT',
                    job_mode => 'TABLE',
                                          remote_link => NULL,
                          job_name => 'SAMSE17_IMPORT', version
                                          => 'COMPATIBLE');

    dbms_output.Put_line('calling add_file');

    dbms_datapump.Add_file(handle => l_dp_handle1,
    filename => 'EXPDAT0122-10-2010011725.DMP', directory => 'DATA_PUMP_DIR');

    dbms_output.Put_line('calling METADATA_FILTER');

    dbms_datapump.Metadata_filter(handle => l_dp_handle1, NAME => 'NAME_LIST',
    VALUE
    => '''EMP_D''');

    dbms_output.Put_line('calling SET_PARAMETER - TABLE EXISTS action');

    dbms_datapump.Set_parameter(handle => l_dp_handle1, NAME =>
    'TABLE_EXISTS_ACTION', VALUE => 'APPEND');

    dbms_output.Put_line('starting job');

    dbms_datapump.Start_job(l_dp_handle1);

    dbms_output.Put_line('started job');

    dbms_datapump.Detach(l_dp_handle1);

    dbms_output.Put_line('detached job ');
END;  

31634, 00000, "job already exists"
// *Cause:  Job creation or restart failed because a job having the selected
//          name is currently executing.  This also generally indicates that
//          a Master Table with that job name exists in the user schema.  Refer
//          to any following error messages for clarification.
// *Action: Select a different job name, or stop the currently executing job
//          and re-try the operation (may require a DROP on the Master Table).