SQL>  Begin
  2    Dbms_Redefinition.Can_Redef_Table(USER, 'TB_HXL_USER');
  3   End;
  4  /

PL/SQL procedure successfully completed.

SQL> BEGIN
  2    dbms_redefinition.start_redef_table(
  3      uname      => USER,
  4      orig_table => 'TB_HXL_USER',
  5      int_table  => 'TB_HXL_USER_MID',
  6      options_flag => DBMS_REDEFINITION.cons_use_pk);
  7  END;
  8  /
BEGIN
*
ERROR at line 1:
ORA-01031: insufficient privileges
ORA-06512: at "SYS.DBMS_REDEFINITION", line 52
ORA-06512: at "SYS.DBMS_REDEFINITION", line 1646
ORA-06512: at line 2

ALTER ANY TABLE
CREATE ANY TABLE
DROP ANY TABLE
LOCK ANY TABLE
SELECT ANY TABLE

One cannot redefine Materialized Views (MViews) and tables with MViews or MView Logs defined on them.
One cannot redefine Temporary and Clustered Tables
One cannot redefine tables with BFILE, LONG or LONG RAW columns
One cannot redefine tables belonging to SYS or SYSTEM
One cannot redefine Object tables
Table redefinition cannot be done in NOLOGGING mode (watch out for heavy archiving)
Cannot be used to add or remove rows from a table