set feedback off
set timing off
DROP TABLE scott.big_tab PURGE;
CREATE TABLE scott.big_tab AS 
SELECT ROWNUM id,  owner, object_name, subobject_name, object_id, data_object_id, object_type, created, last_ddl_time, timestamp, status, temporary, generated, secondary
FROM dba_objects a WHERE 1=0;

DECLARE
  l_cnt  NUMBER;
  l_rows NUMBER := 2000000;
BEGIN
  INSERT /*+ APPEND */ INTO scott.big_tab
  SELECT ROWNUM, owner, object_name, subobject_name, object_id,  
        data_object_id, object_type, created, last_ddl_time, timestamp,
        status, temporary, generated, secondary
  FROM dba_objects;
  l_cnt := SQL%ROWCOUNT;
  COMMIT;
  WHILE l_cnt < l_rows LOOP
    INSERT /*+ APPEND */ INTO scott.big_tab 
    SELECT ROWNUM + l_cnt, owner, object_name, subobject_name, object_id,
           data_object_id, object_type, created, last_ddl_time, timestamp,
           status, temporary, generated, secondary
    FROM scott.big_tab
    WHERE  ROWNUM <= l_rows - l_cnt;
    l_cnt  := l_cnt + SQL%ROWCOUNT;
  COMMIT;
  END LOOP;
END;
/

ALTER TABLE scott.big_tab ADD CONSTRAINT big_tab_pk PRIMARY KEY(id);
BEGIN
  DBMS_STATS.GATHER_TABLE_STATS(
             ownname => 'SCOTT', 
             tabname => 'BIG_TAB', 
    estimate_percent => 100,
             cascade => TRUE);
END;
/
set feedback on
set timing on