DECLARE
  ind NUMBER;              -- Loop index
  h1 NUMBER;               -- Data Pump job handle
  percent_done NUMBER;     -- Percentage of job complete
  job_state VARCHAR2(30);  -- To keep track of job state
  le ku$_LogEntry;         -- For WIP and error messages
  js ku$_JobStatus;        -- The job status from get_status
  jd ku$_JobDesc;          -- The job description from get_status
  sts ku$_Status;          -- The status object returned by get_status
BEGIN

-- Create a (user-named) Data Pump job to do a schema export.

  h1 := DBMS_DATAPUMP.OPEN('EXPORT','SCHEMA',NULL,'EXAMPLE1','LATEST');

-- Specify a single dump file for the job (using the handle just returned)
-- and a directory object, which must already be defined and accessible
-- to the user running this procedure.

  DBMS_DATAPUMP.ADD_FILE(h1,'example1.dmp','DMPDIR');

-- A metadata filter is used to specify the schema that will be exported.

  DBMS_DATAPUMP.METADATA_FILTER(h1,'SCHEMA_EXPR','IN (''HR'')');

-- Start the job. An exception will be generated if something is not set up
-- properly. 

  DBMS_DATAPUMP.START_JOB(h1);

....
  dbms_output.put_line('Job has completed');
  dbms_output.put_line('Final job state = ' || job_state);
  dbms_datapump.detach(h1);
END;
  

SQL> SET SERVEROUTPUT ON SIZE 1000000
SQL> DECLARE
  2    l_dp_handle       NUMBER;
  3    l_last_job_state  VARCHAR2(30) := 'UNDEFINED';
  4    l_job_state       VARCHAR2(30) := 'UNDEFINED';
  5    l_sts             KU$_STATUS;
  6  BEGIN
  7    l_dp_handle := DBMS_DATAPUMP.open(
  8      operation   => 'EXPORT',
  9      job_mode    => 'SCHEMA',
 10      remote_link => NULL,
 11      job_name    => 'EMP_EXPORT',
 12      version     => 'LATEST');
 13
 14    DBMS_DATAPUMP.add_file(
 15      handle    => l_dp_handle,
 16      filename  => 'SCOTT.dmp',
 17      directory => 'TEST_DIR');
 18
 19    DBMS_DATAPUMP.add_file(
 20      handle    => l_dp_handle,
 21      filename  => 'SCOTT.log',
 22      directory => 'TEST_DIR',
 23      filetype  => DBMS_DATAPUMP.KU$_FILE_TYPE_LOG_FILE);
 24
 25    DBMS_DATAPUMP.metadata_filter(
 26      handle => l_dp_handle,
 27      name   => 'SCHEMA_EXPR',
 28      value  => '= ''SCOTT''');
 29
 30    DBMS_DATAPUMP.start_job(l_dp_handle);
 31
 32    DBMS_DATAPUMP.detach(l_dp_handle);
 33  END;
 34  /

PL/SQL procedure successfully completed.

ORA-39001: invalid argument value
 *Cause:  The user specified API parameters were of the wrong type or
          value range.  Subsequent messages supplied by
          DBMS_DATAPUMP.GET_STATUS will further describe the error.
 *Action: Correct the bad argument and retry the API.