Temp free space

https://dbaclass.com/article/how-to-find-the-temp-tablespace-usage/

select a.tablespace_name tablespace,
d.TEMP_TOTAL_MB,
sum (a.used_blocks * d.block_size) / 1024 / 1024 TEMP_USED_MB,
d.TEMP_TOTAL_MB - sum (a.used_blocks * d.block_size) / 1024 / 1024 TEMP_FREE_MB
from v$sort_segment a,
(
select b.name, c.block_size, sum (c.bytes) / 1024 / 1024 TEMP_TOTAL_MB
from v$tablespace b, v$tempfile c
where b.ts#= c.ts#
group by b.name, c.block_size
) d
where a.tablespace_name = d.name
group by a.tablespace_name, d.TEMP_TOTAL_MB;