Temp file question

From: Forte Agent <robertch_at_newscat.com>
Date: Wed, 14 Dec 2005 21:03:44 -0500
Message-ID: <mjj1q19q83p9lus4dddheuhm88sucl8iu5@4ax.com>

I have a stupid question. I did following to move a temp file:

(1) alter database tempfile '/old_dir/mytempfile1' offline;
(2) moved tempfile to new directory in OS.
(3) alter database rename file '/old_dir/mytempfile1' to
'/new_dir/mytempfile1';

When i run (3), oracle says following:
ORA-01511: error in renaming log/data files ORA-01516: nonexistent log file, datafile, or tempfile "/old_dir/mytempfile1"

What should I do? Ths database version is 10.1.0.3.0 running on HPUX Received on Wed Dec 14 2005 - 20:03:44 CST