https://blog.csdn.net/lebron3v/article/details/80992969
http://blog.itpub.net/29618264/viewspace-2140729/
SELECT
owner,
segment_name,
round( sum( bytes / 1024 / 1024 / 1024 ), 2 ) gb_size
FROM
dba_segments
WHERE
owner = ‘用户名‘
AND segment_type = ‘TABLE‘ -- 如果是分区表, 则 segment_type = ‘TABLE PARTITION‘
GROUP BY
owner,
segment_name
ORDER BY
3 DESC;
原文：https://www.cnblogs.com/xiaoL/p/11511815.html