Oracle-手工恢复的案例（1）

场景案例1：

数据文件手工备份 - 创建了表空间 - 备份了控制文件 - 当前控制文件损坏，新创建的表空间数据文件损坏，归档模式，日志都可用（手工备份中没有该表空间的备份）

案例环境部署：
SYS@prod>shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

手工备份数据文件：
[oracle@service3 prod]$ cp *.dbf /u01/backup/

SYS@prod>startup;
ORACLE instance started.

Total System Global Area 835104768 bytes
Fixed Size 2257840 bytes
Variable Size 490736720 bytes
Database Buffers 335544320 bytes
Redo Buffers 6565888 bytes
Database mounted.
Database opened.

创建一个表空间：
SYS@prod>create tablespace test datafile ‘/u01/app/oracle/oradata/prod/test.dbf’ size 50M;

在表空间上建表：
SYS@prod>create table test tablespace test as select * from hr.employees;

备份控制文件：
SYS@prod>alter database backup controlfile to ‘/u01/backup/con.ctl’;

开始破坏数据文件，控制文件：
[oracle@service3 prod]$ cp /etc/passwd control01.ctl
[oracle@service3 prod]$ cp /etc/passwd test.dbf
[oracle@service3 prod]$ cp /etc/passwd /u01/app/oracle/fast_recovery_area/prod/control02.ctl

SYS@prod>alter system switch logfile;
alter system switch logfile
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Process ID: 5790
Session ID: 125 Serial number: 9

开始恢复：
使用备份的控制文件恢复：
[oracle@service3 prod]$ cp /u01/backup/con.ctl control01.ctl
[oracle@service3 prod]$ cp control01.ctl /u01/app/oracle/fast_recovery_area/prod/control02.ctl

SYS@prod>startup mount;
ORACLE instance started.

Total System Global Area 835104768 bytes
Fixed Size 2257840 bytes
Variable Size 490736720 bytes
Database Buffers 335544320 bytes
Redo Buffers 6565888 bytes
Database mounted.

SYS@prod>alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01157: cannot identify/lock data file 6 - see DBWR trace file
ORA-01110: data file 6: ‘/u01/app/oracle/oradata/prod/test.dbf’

创建一个空的数据文件让控制文件识别该数据文件已存在：
SYS@prod>alter database create datafile 6 as ‘/u01/app/oracle/oradata/prod/test.dbf’;

Database altered.

使用备份的控制文件进行recover时，
需要加上using backup controlfile。
SYS@prod>recover database using backup controlfile;
ORA-00279: change 1196472 generated at 05/12/2020 22:24:02 needed for thread 1
ORA-00289: suggestion :
/u01/app/oracle/fast_recovery_area/PROD/archivelog/2020_05_12/o1_mf_1_28_%u_.arc
ORA-00280: change 1196472 for thread 1 is in sequence #28
Specify log: {=suggested | filename | AUTO | CANCEL}
auto
ORA-00308: cannot open archived log
‘/u01/app/oracle/fast_recovery_area/PROD/archivelog/2020_05_12/o1_mf_1_28_%u_.ar
c’
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

查看一下28号日志文件的情况：
SYS@prod>select group#,sequence#,status from v$log;

GROUP#  SEQUENCE# STATUS

1	   28 CURRENT
3	   27 INACTIVE
2	   26 INACTIVE

再执行一下recover 指定当前日志文件名：
SYS@prod>recover database using backup controlfile;
ORA-00279: change 1196472 generated at 05/12/2020 22:24:02 needed for thread 1
ORA-00289: suggestion :
/u01/app/oracle/fast_recovery_area/PROD/archivelog/2020_05_12/o1_mf_1_28_%u_.arc
ORA-00280: change 1196472 for thread 1 is in sequence #28

Specify log: {=suggested | filename | AUTO | CANCEL}
/u01/app/oracle/oradata/prod/redo01.log
Log applied.
Media recovery complete.

SYS@prod>alter database open resetlogs;

进行恢复校验：
SYS@prod>select tablespace_name,status from dba_tablespaces;

TABLESPACE_NAME STATUS

SYSTEM ONLINE
SYSAUX ONLINE
UNDOTBS1 ONLINE
TEMP ONLINE
USERS ONLINE
EXAMPLE ONLINE
TEST ONLINE

SYS@prod>select count(*) from test;

107

恢复成功。