新特性：CDB/PDB的维护命令：查看CDB、PDB的所有的表空间

在CDB查看所有的表空间，使用cdb_tablespaces这个视图

SQL> col TABLESPACE_NAME format a30
SQL> col CONTENTS format a12
SQL> select TABLESPACE_NAME,contents,con_id from cdb_tablespaces;

TABLESPACE_NAME                CONTENTS         CON_ID
------------------------------ ------------ ----------
SYSTEM                         PERMANENT             1
SYSAUX                         PERMANENT             1
UNDOTBS1                       UNDO                  1
TEMP                           TEMPORARY             1
USERS                          PERMANENT             1
UNDOTBS2                       UNDO                  1
SYSTEM                         PERMANENT             5
SYSAUX                         PERMANENT             5
UNDOTBS1                       UNDO                  5
TEMP                           TEMPORARY             5
USERS                          PERMANENT             5

TABLESPACE_NAME                CONTENTS         CON_ID
------------------------------ ------------ ----------
UNDOTBS2                       UNDO                  5
SYSTEM                         PERMANENT             3
SYSAUX                         PERMANENT             3
UNDOTBS1                       UNDO                  3
TEMP                           TEMPORARY             3
UNDO_2                         UNDO                  3
USERS                          PERMANENT             3

18 rows selected.