select t.segment_name, t.segment_type, sum(t.bytes / 1024 / 1024) AS MB
from dba_segments t
where t.segment_type=‘TABLE‘ and (t.segment_name like ‘%yyy%‘ or t.segment_name like ‘%xxx%‘)
group by OWNER,t.segment_name, t.segment_type order by MB DESC
快速清空表数据保留表结构
truncate table xxx drop storage