1). Doesn't Oracle release the free temporary tablespace back to operating system ?NO
2). Does Oracle release free temp space back to OS when we restart the database ?NO
3) how do all the DBA pros maintain there temporary tablespace ? Do the same as we are doing currently ( create new one and delete old temp tablespace ). ?If you know that your tablespace will be filled again upto the same size then why do you want to shrink it. So, like the user above said, it generally need no maintenance. Sometime, you should be able to shrink the tempfile provided there is nothing at the end of the file.