丢失数据文件恢复操作(有备份)
恢复的前提条件
1.必须是在归档模式下
2.必须拥有一个可用的全备，并且拥有该全备以后知道数据文件丢失以后所有的归档日志文件，
及数据文件丢失后的联机重做日志文件
场景：
SQL> create tablespace tbs1 datafile '/oracle/app/oracle/oradata/orcl/tbs01.dbf' size 5m;
Tablespace created.
SQL> create table t(id number) tablespace tbs1;
Table created.
SQL> insert into t values(1);
1 row created.
SQL> commit;
Commit complete.
SQL> select * from t;
ID
----------
1
RMAN> backup database;
[oracle@redhat5 orcl]$ rm tbs01.dbf
SQL> shutdown immediate;
ORA-01116: error in opening database file 7
ORA-01110: data file 7: '/oracle/app/oracle/oradata/orcl/tbs01.dbf'
ORA-27041: unable to open file
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
恢复步骤
a.
SQL> startup force mount;
b.
RMAN> restore tablespace tbs1;
也可直接存取要恢复的数据文件:restore datafile '/oracle/app/oracle/oradata/orcl/tbs01.dbf'
c.recover tablespace tbs1
d.alter database open;
其实就算不做rman备份也是可以恢复的，因为利用重做日志就可以恢复。
比如：
SQL> create table t tablespace mytbs1 as select * from all_objects where rownum<10;
Table created.
[oracle@redhat5 orcl]$ rm mytbs*
SQL> startup force mount;
RMAN> list failure;
using target database control file instead of recovery catalog
List of Database Failures
=========================
Failure ID Priority Status Time Detected Summary
---------- -------- --------- ------------- -------
382 HIGH OPEN 28-MAR-16 One or more non-system datafiles are offline
RMAN> restore tablespace mytbs1;
Starting restore at 29-MAR-16
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=18 device type=DISK
creating datafile file number=6 name=/oracle/app/oracle/oradata/orcl/mytbs01.dbf
restore not done; all files read only, offline, or already restored
Finished restore at 29-MAR-16
RMAN> recover tablespace mytbs1;
Starting recover at 29-MAR-16
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:00
Finished recover at 29-MAR-16
RMAN> sql 'alter database open';
RMAN> list failure;