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无备份的恢复是基于起始时间做的备份
 
当select * from scott.t1;时
    select * from scott.t1
    *
    ERROR at line 1:
    ORA-00376: file 5 cannot be read at this time
    ORA-01110: data file 5: '/u01/oracle/oradata/ora10g/qq.dbf'

查看哪个文件出了问题

select  *  from  v$recover_file;

     FILE# ONLINE  ONLINE_ ERROR                   CHANGE# TIME

---------- ------- ------- -------------------- ---------- ---------
         5 OFFLINE OFFLINE WRONG FILE TYPE               0

select  file#,creation_change#  from  v$datafile;

select SEQUENCE#,FIRST_CHANGE# from v$archived_log where FIRST_CHANGE#>creation_change#;

alter  database  create  datafile  数据文件号;

select * from v$recover_file;

     FILE# ONLINE  ONLINE_ ERROR                   CHANGE# TIME

---------- ------- ------- -------------------- ---------- ---------
         5 OFFLINE OFFLINE                          545331 15-APR-13

recover datafile 数据文件号;

auto

alter tablespace qq online;

select ename,sal from scott.t1;

数据恢复成功！