RA-00979: not a GROUP BY expression

[marist89]

your error is really:

SQL> l
  1  SELECT OBJECT_NAME, STATUS, OBJECT_TYPE
  2  FROM ALL_OBJECTS
  3  WHERE OBJECT_TYPE <> 'VALID'
  4* GROUP BY OBJECT_TYPE
SQL> /
SELECT OBJECT_NAME, STATUS, OBJECT_TYPE
       *
ERROR at line 1:
ORA-00979: not a GROUP BY expression

This is telling you that "OBJECT_NAME" is not a GROUP BY expression.

I suggest you look at the group by clause in the docs at http://tahiti.oracle.com