查询数据库表空间大小

SELECT A.TABLESPACE_NAME "表空间名",
       TOTAL / 1024 / 1024 表空间大小,
       FREE / 1024 / 1024 表空间剩余大小,
       (TOTAL - FREE) / 1024 / 1024 表空间使用大小,
       ROUND((TOTAL - FREE) / TOTAL, 4) * 100 "使用率 %"
  FROM (SELECT TABLESPACE_NAME, SUM(BYTES) FREE
          FROM DBA_FREE_SPACE
         GROUP BY TABLESPACE_NAME) A,
       (SELECT TABLESPACE_NAME, SUM(BYTES) TOTAL
          FROM DBA_DATA_FILES
         GROUP BY TABLESPACE_NAME) B
WHERE A.TABLESPACE_NAME = B.TABLESPACE_NAME
   AND A.TABLESPACE_NAME = '查询的表空间名称';