本文主要介绍非归档模式下offline数据文件的恢复，测试过程如下：

SQL> select * from v$version where rownum<3;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production

SQL> archive log list;
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            /u01/prod_arch
Oldest online log sequence     17
Current log sequence           19

---控件文件中的SCN
SQL> select file#,status,checkpoint_change# from v$datafile order by 1;

     FILE# STATUS  CHECKPOINT_CHANGE#
---------- ------- ------------------
         1 SYSTEM              554606
         2 ONLINE              554606
         3 ONLINE              554606
         4 ONLINE              554606
         5 ONLINE              554606

--数据文件头中的SCN

SQL> select file#,status,checkpoint_change# from v$datafile_header order by 1;

     FILE# STATUS  CHECKPOINT_CHANGE#
---------- ------- ------------------
         1 ONLINE              554606
         2 ONLINE              554606
         3 ONLINE              554606
         4 ONLINE              554606
         5 ONLINE              554606

--日志文件的情况

SQL> select * from v$Log;

    GROUP#    THREAD#  SEQUENCE#      BYTES    MEMBERS ARC   STATUS           FIRST_CHANGE#    FIRST_TIM
     ----------        ----------      ----------              ----------      ----------       ---    ----------------