查看表空间使用情况

select a.tablespace_name, round(a.total_size,1) "total(M)",   
round(a.total_size)-round(nvl(b.free_size,0),1) "used(M)",    
round(nvl(b.free_size,0),1) "free(M)",                        
round(nvl(b.free_size,0)/total_size*100,1) "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(+)                
order by "free rate(%)";