DBMS_METADATA.GET_DDL

Hello,

How one can retrieve definition of all objects not in sys schema?

The following for tables is failing:

sql / as sysdba

SQL> SELECT DBMS_METADATA.GET_DDL('TABLE', TABLE_NAME) FROM dba_tables  where owner not in ('SYS');

ERROR:

ORA-31603: object "OL$" of type TABLE not found in schema "SYS"

ORA-06512: at "SYS.DBMS_METADATA", line 4018

ORA-06512: at "SYS.DBMS_METADATA", line 5843

ORA-06512: at line 1

Thank You