SQL> alter tablespace users begin backup;

Tablespace altered.

SQL> desc v$backup

 Name                       Null?    Type

 ----------------------------------------- -------- ----------------------------

 FILE#                            NUMBER

 STATUS                         VARCHAR2()

 CHANGE#                        NUMBER

 TIME                            DATE

SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME

---------- ------------------ ---------- ---------

      NOT ACTIVE

      NOT ACTIVE

      NOT ACTIVE

      ACTIVE          -NOV-

      NOT ACTIVE               

SQL> 

SQL> shutdown abort

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area   bytes

Fixed Size             bytes

Variable Size           bytes

Database Buffers       bytes

Redo Buffers             bytes

Database mounted.

ORA-: file  needs media recovery

ORA-: data file :

'/u01/app/oracle/product/10.2.0/db_2/oradata/orcl/users01.dbf'

SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME

---------- ------------------ ---------- ---------

      NOT ACTIVE

      NOT ACTIVE

      NOT ACTIVE

      ACTIVE          -NOV-

      NOT ACTIVE               

SQL> alter tablespace users end backup;

Tablespace altered.

SQL> alter database open;

Database altered.

SQL>