ORA-01135 selecting from the view

Hello,

I am getting the following error
selecting from the view

select count(*) from v_xxx;

ERROR at line 1:
ORA-01135: file 5 accessed for DML/query is offline ORA-01110: data file 5: '/db011/oradata/.dbf'

It worked fine for are very long time even earlier today too. The datafile is offline for many years already and we did not have problems before.

Please help.

Thanks.
Inessa.

--
http://www.freelists.org/webpage/oracle-l