TEMP Tablespace Usage queries :

select total_extents, used_extents, total_extents, current_users, tablespace_name
from v$sort_segment;

select username, user, sqladdr, extents, tablespace from v$sort_usage;

SELECT b.tablespace,
       ROUND(((b.blocks*p.value)/1024/1024),2),
       a.sid||','||a.serial# SID_SERIAL,
       a.username,
       a.program
     FROM sys.v_$session a,
          sys.v_$sort_usage b,
          sys.v_$parameter p
    WHERE p.name  = 'db_block_size'
      AND a.saddr = b.session_addr
      ORDER BY b.tablespace, b.blocks;