Negative values in dba_temp_free_space

  Free Space is not calculated correctly in this example:

SQL> select * from dba_temp_free_space;

TABLESPACE_NAME                TABLESPACE_SIZE ALLOCATED_SPACE FREE_SPACE
------------------------------ --------------- --------------- ----------
TEMP                                  32505856        32505856   31457280
TEMP_TABLE_TEMPORARY                  26279936           65536   26214400
TBS_T100                              32505856       -51380224   83886080