比起用其它的视图写长长的一段脚本、简便多了、据说从7.x到11g都可以用

     sm$ts_used     &    sm$ts_free

idle> select * from sm$ts_used;

TABLESPACE_NAME                     BYTES
------------------------------ ----------
SYSAUX                          256573440
UNDOTBS1                          8323072
USERS                             3211264
SYSTEM                          506789888
EXAMPLE                          71499776

idle> select * from sm$ts_free;

TABLESPACE_NAME                     BYTES
------------------------------ ----------
UNDOTBS1                         23068672
SYSAUX                           15990784
USERS                             1966080
SYSTEM                            6946816
EXAMPLE                          33292288