所有表空间使用率
select a.tablespace_name "Tablespace Name",
       b.total/1024/1024/1024 "Total Space(GB)",
       a.FREE_SPACE/1024/1024/1024 "Free Space(GB)",
       (b.total - a.FREE_SPACE)/1024/1024/1024 "Space in Use(GB)",
       ROUND((b.total - a.FREE_SPACE) / total, 4) * 100 "Use_Total Ratio(%)"
   FROM  dba_temp_free_space a,
 (select tablespace_name,sum(bytes) total from dba_temp_files
 group by tablespace_name) b
where a.tablespace_name(+)=b.TABLESPACE_NAME
union all
SELECT a.tablespace_name "Tablespace Name",
       total/1024/1024/1024 "Total Space(GB)",
       free/1024/1024/1024 "Free Space(GB)",
       (total - free)/1024/1024/1024 "Space in Use(GB)",
       ROUND((total - free) / total, 4) * 100 "Use_Total Ratio(%)"
  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;