TABLESPACE                                         TOTAL       USED       FREE   PCT_FREE    LARGEST  FRAGMENTS
--------------------------------------------- ---------- ---------- ---------- ---------- ---------- ----------
SYSTEM                                             78500      309.8    78190.2 99.6053503       3968      36

SQL> set lines 1000 pages 1000
SQL> select owner,segment_name,segment_type  ,bytes/(1024*1024) size_m  from dba_segments
  2  where tablespace_name = 'SYSTEM'
  3  and bytes/(1024*1024) > 1
  4  order by size_m desc;

OWNER                          SEGMENT_NAME                                                              SEGMENT_TYPE           SIZE_M
------------------------------ --------------------------------------------------------------------------------- ------------------ ------
SYS                            IDL_UB1$                                                                  TABLE                      34
SYS                            SOURCE$                                                                   TABLE                      21
SYS                            IDL_UB2$                                                                  TABLE                      17
SYS                            C_OBJ#_INTCOL#                                                            CLUSTER                    15
SYS                            SYS_LOB0000001051C00003$$                                                 LOBSEGMENT                 13
SYS                            C_TOID_VERSION#                                                           CLUSTER                    11
SYS                            C_OBJ#                                                                    CLUSTER                     7
SYS                            ARGUMENT$                                                                 TABLE                       7
SYS                            IDL_CHAR$                                                                 TABLE                       6
SYS                            VIEW$                                                                     TABLE                       5
SYS                            I_ARGUMENT1                                                               INDEX                       5
SYS                            I_SOURCE1                                                                 INDEX                       4
SYS                            I_ARGUMENT2                                                               INDEX                       4
SYS                            I_COL1                                                                    INDEX                       4
SYS                            I_H_OBJ#_COL#                                                             INDEX                       4
SYS                            I_COL2                                                                    INDEX                       3
SYS                            IDL_SB4$                                                                  TABLE                       3
SYS                            KOTAD$                                                                    TABLE                       2
SYS                            SETTINGS$                                                                 TABLE                       2
SYS                            ACCESS$                                                                   TABLE                       2
SYS                            DEPENDENCY$                                                               TABLE                       2
SYS                            I_COL3                                                                    INDEX                       2
SYS                            I_DEPENDENCY2                                                             INDEX                       2
SYS                            I_OBJ2                                                                    INDEX                       2
SYS                            HIST_HEAD$                                                                TABLE                       2
SYS                            I_OBJ5                                                                    INDEX                       2
SYS                            I_DEPENDENCY1                                                             INDEX                       2
SYS                            OBJ$                                                                      TABLE                       2

28 rows selected.

SQL>