Tablespace used rate monitor：

col used_space(M) for a15
col sum_space(M) for a20
col used_rate(%) for a20
col tablespace_name for a20
set linesize 150
SELECT D.TABLESPACE_NAME,  
       SPACE || 'M' "SUM_SPACE(M)",  
       BLOCKS "SUM_BLOCKS",  
       SPACE - NVL (FREE_SPACE, 0) || 'M' "USED_SPACE(M)",  
       ROUND ( (1 - NVL (FREE_SPACE, 0) / SPACE) * 100, 2) || '%'  
          "USED_RATE(%)",  
       FREE_SPACE || 'M' "FREE_SPACE(M)"  
  FROM (  SELECT TABLESPACE_NAME,  
                 ROUND (SUM (BYTES) / (1024 * 1024), 2) SPACE,  
                 SUM (BLOCKS) BLOCKS  
            FROM DBA_DATA_FILES  
        GROUP BY TABLESPACE_NAME) D,  
       (  SELECT TABLESPACE_NAME,  
                 ROUND (SUM (BYTES) / (1024 * 1024), 2) FREE_SPACE  
            FROM DBA_FREE_SPACE  
        GROUP BY TABLESPACE_NAME) F  
 WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+)  
UNION ALL                                                           --如果有临时表空间  
SELECT D.TABLESPACE_NAME,  
       SPACE || 'M' "SUM_SPACE(M)",  
       BLOCKS SUM_BLOCKS,  
       USED_SPACE || 'M' "USED_SPACE(M)",  
       ROUND (NVL (USED_SPACE, 0) / SPACE * 100, 2) || '%' "USED_RATE(%)",  
       NVL (FREE_SPACE, 0) || 'M' "FREE_SPACE(M)"  
  FROM (  SELECT TABLESPACE_NAME,  
                 ROUND (SUM (BYTES) / (1024 * 1024), 2) SPACE,  
                 SUM (BLOCKS) BLOCKS  
            FROM DBA_TEMP_FILES  
        GROUP BY TABLESPACE_NAME) D,  
       (  SELECT TABLESPACE_NAME,  
                 ROUND (SUM (BYTES_USED) / (1024 * 1024), 2) USED_SPACE,  
                 ROUND (SUM (BYTES_FREE) / (1024 * 1024), 2) FREE_SPACE  
            FROM V$TEMP_SPACE_HEADER  
        GROUP BY TABLESPACE_NAME) F  
 WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+)  
ORDER BY 1;