oracle 查看表空间

用户表空间  select   username,default_tablespace   from   dba_users;
连接会话     select * from v$Session;
表空间大小 select tablespace_name,sum(bytes)/1024/1024 from dba_data_files   group by tablespace_name; 
未用表空间 select tablespace_name,sum(bytes)/1024/1024 from dba_free_space     group by tablespace_name;  
表空间文件 SELECT * FROM dba_data_files;