oracle tablespace size
SELECT T1.TABLESPACE_NAME,
T1.BYTES / 1024 / 1024 as "bytes_used (Mb)",
T2.BYTES / 1024 / 1024 as "bytes_free (Mb)",
T2.largest / 1024 / 1024 as "largest (Mb)",
round(((T1.BYTES - T2.BYTES) / T1.BYTES) * 100, 2) percent_used
FROM (
select TABLESPACE_NAME,
sum(BYTES) BYTES
from dba_data_files
group by TABLESPACE_NAME
) T1,
(
select TABLESPACE_NAME,
sum(BYTES) BYTES,
max(BYTES) largest
from dba_free_space
group by TABLESPACE_NAME
) T2
where T1.TABLESPACE_NAME = T2.TABLESPACE_NAME
order by ((T1.BYTES - T2.BYTES) / T1.BYTES) desc;