select d.tablespace_name,
space||'M' "SUM_SPACE(M")",
blocks "SUM_BLOCKS",
space - nvl(free_space, 0) || ‘M’ “USED_SPACE(M)",
round((1-nvl(free_space, 0)/space) * 100 , 2)|| '%'
"USED_RATE(%)",
free_space || 'M' "FREE_SPACE(M)"
from (select tablespace_name,
round(sum(bytes)/(1024*1024),2) space,
sum(blocks) blocks
from dba_data_files
group by tablespace_name) d,
(select tablespace_name, round(sum(bytes)/(1024*1024),2) free_space
from dba_free_space
group by tablespace_name) f
where d.tablespace_name=f.tablespace_name(+);