一、查看当前所有表空间使用情况

set pages 300

set lines 300

SELECT UPPER(F.TABLESPACE_NAME) "表空间名",

D.TOT_GROOTTE_MB "表空间大小(M)",

D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",

TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,2),'990.99') || '%' "使用比",

F.TOTAL_BYTES "空闲空间(M)",

F.MAX_BYTES "最大块(M)"

FROM (SELECT TABLESPACE_NAME,

ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,

ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES

FROM SYS.DBA_FREE_SPACE

GROUP BY TABLESPACE_NAME) F,

(SELECT DD.TABLESPACE_NAME,

ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB

FROM SYS.DBA_DATA_FILES DD

GROUP BY DD.TABLESPACE_NAME) D

WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME

ORDER BY 4 desc ;

二、通过上面的查询指定使用率过高的表空间，找出此表空间中最占空间的前20个对象

Select OWNER||','||SEGMENT_NAME||','||SEGMENT_TYPE||','||total from 

(select OWNER,SEGMENT_NAME,SEGMENT_TYPE,bytes/1024/1024 total from dba_segments 

where TABLESPACE_NAME='指定表空间的名字' order by bytes/1024/1024 desc ) where rownum <21;