Oracle查看表占用的空间

主要就是查dba_segments，根据Oracle存储逻辑，一个表可能会对应多个段，段名与表名相同。

OCP 体系结构_howard_shooter的博客-CSDN博客

-- 查看用户PAASTEST所有表占用的空间：

select sum(bytes)/1024/1024/1024 as "size(G)" from dba_segments where owner='PAASTEST';

-- 查看表ACT_HI_DETAIL占用的空间：

select SEGMENT_NAME, sum(BYTES)/1024/1024 MB from dba_segments where segment_name = 'ACT_HI_DETAIL' group by SEGMENT_NAME;

--查看用户PAASTEST所有的表所在的表空间

select tablespace_name from dba_segments where owner='PAASTEST' group by tablespace_name;

--数据库中所有表空间占用情况

SELECT a.tablespace_name,

         ROUND (a.total_size) "total_size(MB)",

         ROUND (a.total_size) - ROUND (b.free_size, 3) "used_size(MB)",

         ROUND (b.free_size, 3) "free_size(MB)",

         ROUND (b.free_size / total_size * 100, 2) || '%' free_rate

  FROM ( SELECT tablespace_name, SUM (bytes) / 1024 / 1024 total_size

              FROM dba_data_files

          GROUP BY tablespace_name) a,

         ( SELECT tablespace_name, SUM (bytes) / 1024 / 1024 free_size

              FROM dba_free_space

          GROUP BY tablespace_name) b

 WHERE a.tablespace_name = b.tablespace_name(+);