1) Failure를 확인한다.
select * from hr.employees
ERROR:
ORA-01116: error in opening database file 3
ORA-0110: data file 3: '/dba7/dba/dba9i60/users01.dbf'
ORA-27041: unable to open file
SVR4 Eroor: 2: No such file or directory
Additional information: 3

2) Recovry 시작

SQL> select d.file#,d.name,d.status,h.status from v$datafile d,v$datafile_header h where d.file#=h.file#;

SQL> alter database datafile '/dba7/dba/dba9i60/dbs/users01.dbf' offline;

SQL> !cp $HOME/ONBACK/users01.dbf $HOME/dbs/

SQL> recover datafile '$HOME/dbs/users01.dbf';
ORA-00279: change 799236 generated at 07/08/2003 22:22:31 needed for thread 1
ORA-00289: suggestion : /dba7/dba/dba9i60/arch/log/34.ARC
ORA-00280: change 799236 for thread 1 is in sequence #34

Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto    <-- auto를 입력한다.

Log applied.
Media recovery complete.

SQL>select d.file#,d.name,d.status,h.status from v$datafile d,v$datafile_header h where d.file#=h.file#;

SQL> alter database datafile '$HOME/dbs/users01.dbf' online;

3) 정상인가 확인
SQL> select count(*) from hr.emphist;