steps to perform table-reorganization using DBMS_REDEFINITION on oracle table

1.DETERMINE IF THE TABLE CAN BE REDEFINED ONLINE

BEGIN
   DBMS_REDEFINITION.CAN_REDEF_TABLE('schema_name','original_TABLE', DBMS_REDEFINITION.CONS_USE_ROWID);
END;
/

2.CREATE THE INTERIM TABLE

CREATE TABLE "schema_name"."original_TABLE_INTERIM" AS SELECT * FROM "schema_name"."original_TABLE" WHERE 1=2;

3.PARALLELISM FOR LARGE TABLES

ALTER SESSION FORCE PARALLEL DML PARALLEL 8;
ALTER SESSION FORCE PARALLEL QUERY PARALLEL 8;

4.START THE REDEFINITION

BEGIN
   DBMS_REDEFINITION.START_REDEF_TABLE(
                 uname => 'schema_name',
                 orig_table => 'original_TABLE',
                 int_table => 'original_TABLE_INTERIM',
                 options_flag => DBMS_REDEFINITION.CONS_USE_ROWID);
END;
/

5.COPY THE TABLE DEPENDENTS FROM THE ORIGINAL TABLE TO THE INTERIM TABLE

DECLARE
   error_count pls_integer := 0;
BEGIN
   DBMS_REDEFINITION.COPY_TABLE_DEPENDENTS('schema_name', 'original_TABLE', 'original_TABLE_INTERIM', dbms_redefinition.cons_orig_params, TRUE,TRUE,TRUE,FALSE, error_count);
   DBMS_OUTPUT.PUT_LINE('errors := ' || TO_CHAR(error_count));
END;
/


6.check for invalid objects

select count(*),status from dba_objects where owner='schema_name' group by status;

select object_name from DBA_OBJECTS where owner='schema_name' and status='INVALID';

7.DO ONE FINAL SYNCHRONIZE BEFORE FINISHING THE REDEFINITION

BEGIN
   DBMS_REDEFINITION.SYNC_INTERIM_TABLE('schema_name', 'original_TABLE', 'original_TABLE_INTERIM');
END;
/

8.FINISH THE REDEFINITION

exec DBMS_REDEFINITION.FINISH_REDEF_TABLE('schema_name', 'original_TABLE', 'original_TABLE_INTERIM');

9.Drop the interim table
drop TABLE "schema_name"."original_TABLE_INTERIM"