1、查找特定表大小
select round(BYTES/1024/1024,2)||'M' from Dba_Segments where segment_name=upper('表名');
2、查找数据库中占用空间较大的对象
SELECT OWNER,SEGMENT_NAME,SUM(bytes/1024/1024/1024 ) sum from Dba_Segments group by owner,segment_name having sum(bytes/1024/1024/1024 )>2 order by 3 desc;
3、统计Oracle数据库用户所有表的大小
SELECT OWNER as "用户名", sum(BYTES) / 1024 / 1024 / 1024 as "所有表的大小(GB)"
FROM DBA_SEGMENTS
WHERE SEGMENT_NAME in (select t2.OBJECT_NAME
from dba_objects t2
where t2.OBJECT_TYPE = 'TABLE')
group by OWNER order by 2 desc;
4、查看每个表空间的大小
Select Tablespace_Name,Sum(bytes)/1024/1024 From Dba_Segments Group By Tablespace_Name order by 2 desc;