方法1：

select a.tablespace_name,b.space "SUM SPACE",a.space "FREE SPACE",a.space/b.space "FREE percent"

from (select sum(bytes)/1024/1024/1024 space,tablespace_name from dba_free_space  group by tablespace_name) a, (select sum(bytes)/1024/1024/1024 space,tablespace_name from dba_data_files  group by tablespace_name) b where a.tablespace_name=b.tablespace_name

 

 

方法2：

select a.tablespace_name, b.space "SUM GB",a.space "USED GB",b.space-a.space "FREE GB",(b.space-a.space)/b.space "FREE PERCENT"

from (select sum(bytes)/1024/1024/1024 space,tablespace_name from dba_segments group by tablespace_name) a, (select sum(bytes)/1024/1024/1024 space,tablespace_name from dba_data_files  group by tablespace_name) b where a.tablespace_name=b.tablespace_name

 

方法1的更准确