Oracle查看数据占用的空间和数据文件实际空间的信息

可以使用如下sql：

select nvl(t1.tablespace_name,t2.tablespace_name),t1.size_in_GB datafile_size_in_GB,t2.size_in_GB segment_size_in_GB,t1.size_in_GB-t2.size_in_GB table_space_free_size_in_GB from
(select tablespace_name,sum(bytes)/1024/1024/1024 size_in_GB from dba_data_files group by tablespace_name) t1
full join
(select tablespace_name,sum(bytes)/1024/1024/1024 size_in_GB from dba_segments group by tablespace_name) t2 on t2.tablespace_name=t1.tablespace_name

以上。