第四章. 数据库恢复案例
4.1
非归档模式下的备份与恢复
备份方案:采用
OS
冷备份
1.
连接数据库并创建测试表
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2.
备份数据库
SQL> @coldbak.sql
或在
DOS
下
svrmgrl @coldbak.sql
3.
再插入记录
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
-------------------
1
2
4.
关闭数据库
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down.
5.
毁坏一个或多个数据文件,如删除
user01.dbf
C:\>del D:\Oracle\ORADATA\TEST\USERS01.DBF
模拟媒体毁坏。
6.
重新启动数据库,会发现如下错误
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: 'D:\Oracle\ORADATA\TEST\USERS01.DBF'
在报警文件中,会有更详细的信息
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: 'D:\Oracle\ORADATA\TEST\USERS01.DBF'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2)
系统找不到指定的文件。
7.
拷贝备份复原到原来位置
(restore
过程
)
C:\>xcopy d:\database\*.* d:\Oracle\oradata\test/H/R/S
8.
打开数据库,检查数据
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
这里可以发现,数据库恢复成功,但在备份之后与崩溃之前的数据丢失了。
说明:
1
、非归档模式下的恢复方案可选性很小,一般情况下只能有一种恢复方式,就是数据库的冷备
份的完全恢复,仅仅需要拷贝原来的备份就可以
(restore)
,不需要
recover
;
2
、这种情况下的恢复,可以完全恢复到备份的点上,但是可能是丢失数据的,在备份之后与崩溃之前的数据将全部丢失;
3
、不管毁坏了多少数据文件或是联机日志或是控制文件,都可以通过这个办法恢复,因为这个恢复过程是
Restore
所有的冷备份文件,而这个备份点上的所有文件是一致的,与最新的数据库没有关系,就好比把数据库又放到了一个以前的
"
点
"
上;
4
、对于非归档模式下,最好的办法就是采用
OS
的冷备份,建议不要用
RMAN
来作冷备份,效果不好,因为
RMAN
不备份联机日志,
restore
不能根本解决问题;
5
、如果没有备份联机日志,如
RMAN
的备份,就需要利用不完全恢复
(until cancel)
的方法来重新创建联机日志文件。
4.2
归档模式下丢失或损坏一个数据文件
4.2.1
OS
备份方案
在归档方式下损坏或丢失一个数据文件,如果存在相应的备份与该备份以来的归档日志,恢复还是比较简单的,可以作到尽量少的
Down
机时间,并能作到数据库的完全恢复。
1
、
连接数据库,创建测试表并插入记录
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int) tablespace users;
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、
备份数据库
SQL> @hotbak.sql
或在
DOS
下
svrmgrl @hotbak.sql
3
、
继续在测试表中插入记录
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
--------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL> alter system switch logfile;
System altered.
4
、
关闭数据库,模拟丢失数据文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\USERS01.DBF
模拟媒体毁坏。
5
、
启动数据库错误,脱机该数据文件:
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: 'D:\Oracle\ORADATA\TEST\USERS01.DBF'
还可以查看报警文件(见上一个恢复案例)或动态视图
v$recover_file
如
SQL> select * from v$recover_file;
FILE# ONLINE ERROR CHANGE# TIME
---------- ------- ------------------ ---------- -----------
3 ONLINE 1013500 2003-05-07
脱机数据文件
SQL> alter database datafile 3 offline drop;
Database altered.
6
、
打开数据库,拷贝备份回来
(restore)
,恢复
(recover)
该数据文件,并联机
:
SQL> alter database open;
Database altered.
拷贝备份从备份处
copy d:\databak\ users01.dbf d:\Oracle\oradata\test;
恢复该数据文件
SQL> recover datafile 3;
ORA-00279: change 1053698 generated at 05/07/2003 17:51:26 needed for
thread 1
ORA-00289: suggestion :
D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC
ORA-00280: change 1053698 for thread 1 is in sequence #304
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
AUTO
ORA-00279: change 1053701 generated at 05/07/2003 17:51:39 needed for
thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00305.ARC
ORA-00280: change 1053701 for thread 1 is in sequence #305
ORA-00278: log file 'D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC' no longer needed for this recovery Log applied.
Media recovery complete.
恢复成功,联机该数据文件
SQL> alter database datafile 3 online;
Database altered.
7
、
检查数据库的数据(完全恢复)
SQL> select * from test;
A
--------------------------------
1
2
说明:
1
、采用热备份,需要运行在归档模式下,可以实现数据库的完全恢复,也就是说,从备份后到数据库崩溃时的数据都不会丢失
;
2
、可以采用全备份数据库的方式备份,对于特殊情况,也可以只备份特定的数据文件,如只备份用户表空间(一般情况下对于某些写特别频繁的数据文件,可以单独加大备份频率);
3
、如果在恢复过程中,发现损坏的是多个数据文件,即可以采用一个一个数据文件的恢复方法(第
5
步中需要对数据文件一一脱机,第
6
步中需要对数据文件分别恢复),也可以采用整个数据库的恢复方法;
4
、如果是系统表空间的损坏,不能采用此方法。
4.2.2
RMAN
备份方案
RMAN
也可以进行联机备份,而且备份与恢复方法将比
OS
备份更简单可靠。
1
、连接数据库,创建测试表并插入记录
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int) tablespace users;
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、
备份数据库表空间
users
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN> run{
2> allocate channel c1 type disk;
3> backup tag 'tsuser' format 'd:\backup\tsuser_%u_%s_%p'
4> tablespace users;
5> release channel c1;
6> }
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=16 devtype=DISK
RMAN-03022: compiling command: backup
RMAN-03025: performing implicit partial resync of recovery catalog
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03023: executing command: backup
RMAN-08008: channel c1: starting full datafile backupset
RMAN-08502: set_count=5 set_stamp=494177612 creation_time=16-MAY-03
RMAN-08010: channel c1: specifying datafile(s) in backupset
RMAN-08522: input datafile fno=00003 name=D:\Oracle\ORADATA\TEST\USER01.DBF
RMAN-08013: channel c1: piece 1 created
RMAN-08503: piece handle=D:\BACKUP\TSUSER_05EN93AC_5_1 comment=NONE
RMAN-08525: backup set complete, elapsed time: 00:00:01
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
RMAN-08031: released channel: c1
RMAN>
3
、
继续在测试表中插入记录
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL>r
1* alter system switch logfile;
System altered.
4
、
关闭数据库,模拟丢失数据文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\USER01.DBF
5
、
启动数据库,检查错误
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: 'D:\Oracle\ORADATA\TEST\USER01.DBF'
6
、
先打开数据库
SQL> alter database datafile 3 offline drop;
Database altered.
SQL> alter database open;
Database altered.
7
、
恢复该表空间
恢复脚本可以是恢复单个数据文件
run{
allocate channel c1 type disk;
restore datafile 3;
recover datafile 3;
sql 'alter database datafile 3 online';
release channel c1;
}
也可以是
,
恢复表空间
run{
allocate channel c1 type disk;
restore tablespace users;
recover tablespace users;
sql 'alter database datafile 3 online';
release channel c1;
}
过程如下:
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN> run{
2> allocate channel c1 type disk;
3> restore datafile 3;
4> recover datafile 3;
5> sql 'alter database datafile 3 online';
6> release channel c1;
7> }
//
输出内容冗长,省略
--
编者
RMAN>
8
、
检查数据是否完整
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
说明:
1
、
RMAN
也可以实现单个表空间或数据文件的恢复,恢复过程可以在
mount
下或
open
方式下,如果在
open
方式下恢复,可以减少
down
机时间
;
2
、如果损坏的是一个数据文件,建议
offline
并在
open
方式下恢复
;
3
、这里可以看到,
RMAN
进行数据文件与表空间恢复的时候,代码都比较简单,而且能保证备份与恢复的可靠性,所以建议采用
RMAN
的备份与恢复
.
4.3
丢失多个数据文件,实现整个数据库的恢复
.
4.3.1
OS
备份方案
OS
备份归档模式下损坏(丢失)多个数据文件,进行整个数据库的恢复
1
、
连接数据库,创建测试表并插入记录
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、
备份数据库,备份除临时数据文件后的所数据文件
SQL> @hotbak.sql
或在
DOS
下
svrmgrl @hotbak.sql
3
、
继续在测试表中插入记录
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL> alter system switch logfile;
System altered.
4
、
关闭数据库,模拟丢失数据文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
C:\>del D:\Oracle\ORADATA\TEST\INDX01.DBF
C:\>del D:\Oracle\ORADATA\TEST\TOOLS01.DBF
C:\>del D:\Oracle\ORADATA\TEST\RBS01.DBF
模拟媒体毁坏(这里删除多个数据文件)
5
、
启动数据库,检查错误
SQL> STARTUP
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: 'D:\Oracle\ORADATA\TEST\SYSTEM01.DBF'
详细信息可以查看报警文件
ORA-1157 signalled during: ALTER DATABASE OPEN...
Thu May 08 09:39:36 2003
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: 'D:\Oracle\ORADATA\TEST\SYSTEM01.DBF'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2)
系统找不到指定的文件。
Thu May 08 09:39:36 2003
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 2 - see DBWR trace file
ORA-01110: data file 2: 'D:\Oracle\ORADATA\TEST\RBS01.DBF'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2)
系统找不到指定的文件。
Thu May 08 09:39:36 2003
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 5 - see DBWR trace file
ORA-01110: data file 5: 'D:\Oracle\ORADATA\TEST\TOOLS01.DBF'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2)
系统找不到指定的文件。
Thu May 08 09:39:36 2003
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 6 - see DBWR trace file
ORA-01110: data file 6: 'D:\Oracle\ORADATA\TEST\INDX01.DBF'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2)
系统找不到指定的文件。
通过查询
v$recover_file
可以看到
SQL> select * from v$recover_file;
FILE# ONLINE ERROR CHANGE# TIME
---------- ------- ------------------ ---------- -----------
1 ONLINE FILE NOT FOUND 0
2 ONLINE FILE NOT FOUND 0
5 ONLINE FILE NOT FOUND 0
6 ONLINE FILE NOT FOUND 0
有四个数据文件需要恢复
6
、
拷贝备份回到原地点
(restore)
,开始恢复数据库
(recover)
restore
过程
:
C:\>copy D:\DATABAK\SYSTEM01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\INDX01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\TOOLS01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\RBS01.DBF.DBF D:\Oracle\ORADATA\TEST\
Recover
过程
:
SQL> recover database
[0001191]
;
ORA-00279: change 1073849 generated at 05/08/2003 08:58:35 needed for thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00311.ARC
ORA-00280: change 1073849 for thread 1 is in sequence #311
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
ORA-00279: change 1073856 generated at 05/08/2003 09:03:27 needed for thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00312.ARC
ORA-00280: change 1073856 for thread 1 is in sequence #312
ORA-00278: log file 'D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00311.ARC' no
longer needed for this recovery
ORA-00279: change 1073858 generated at 05/08/2003 09:11:43 needed for thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00313.ARC
ORA-00280: change 1073858 for thread 1 is in sequence #313
ORA-00278: log file 'D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00312.ARC' no
longer needed for this recovery
ORA-00279: change 1073870 generated at 05/08/2003 09:11:46 needed for thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00314.ARC
ORA-00280: change 1073870 for thread 1 is in sequence #314
ORA-00278: log file 'D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00313.ARC' no
longer needed for this recovery
Log applied.
Media recovery complete.
7
、
打开数据库,检查数据库的数据(完全恢复)
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
说明:
1
、只要有备份与归档存在,就可以实现数据库的完全恢复(不丢失数据)
;
2
、适合于丢失大量数据文件,或包含系统数据文件在内的数据库的恢复
;
3
、恢复过程在
mount
下进行,如果恢复成功,再打开数据库,
down
机时间可能比较长一些。
4.3.2
RMAN
备份方案
RMAN
备份归档模式下损坏(丢失)多个数据文件,进行整个数据库的恢复
1
、连接数据库,创建测试表并插入记录
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、备份数据库
DOS
下
C:>\ rman cmdfile=bakup.rcv msglog=backup.log;
以下是
backup.log
内容。
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> # script:bakup.rcv
2> # creater:chenjiping
3> # date:5.8.2003
4> # desc:backup all database datafile in archive with rman
5>
6> #connect database
7> connect rcvcat rman/rman@back;
8> connect target internal/virpure;
9>
10> #start backup database
11> run{
12> allocate channel c1 type disk;
13> backup full tag 'dbfull' format 'd:\backup\full%u_%s_%p' database
14> include current controlfile;
15> sql 'alter system archive log current';
16> release channel c1;
17> }
18> #end
19>
RMAN-06008: connected to recovery catalog database
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=15 devtype=DISK
RMAN-03022: compiling command: backup
RMAN-03023: executing command: backup
RMAN-08008: channel c1: starting full datafile backupset
RMAN-08502: set_count=4 set_stamp=494074368 creation_time=15-MAY-03
RMAN-08010: channel c1: specifying datafile(s) in backupset
RMAN-08522: input datafile fno=00002 name=D:\Oracle\ORADATA\TEST\RBS01.DBF
RMAN-08522: input datafile fno=00001 name=D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
RMAN-08011: including current controlfile in backupset
RMAN-08522: input datafile fno=00005 name=D:\Oracle\ORADATA\TEST\TOOLS01.DBF
RMAN-08522: input datafile fno=00004 name=D:\Oracle\ORADATA\TEST\TEMP01.DBF
RMAN-08522: input datafile fno=00006 name=D:\Oracle\ORADATA\TEST\INDX01.DBF
RMAN-08522: input datafile fno=00003 name=D:\Oracle\ORADATA\TEST\USER01.DBF
RMAN-08013: channel c1: piece 1 created
RMAN-08503: piece handle=D:\BACKUP\FULL04EN5UG0_4_1 comment=NONE
RMAN-08525: backup set complete, elapsed time: 00:01:16
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: sql
RMAN-06162: sql statement: alter system archive log current
RMAN-03023: executing command: sql
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
RMAN-08031: released channel: c1
Recovery Manager complete.
到这里表示备份成功。
3
、
继续在测试表中插入记录
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL>alter system switch logfile;
System altered.
SQL> alter system switch logfile;
System altered.
4
、
关闭数据库,模拟丢失数据文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
C:\>del D:\Oracle\ORADATA\TEST\INDX01.DBF
C:\>del D:\Oracle\ORADATA\TEST\TOOLS01.DBF
C:\>del D:\Oracle\ORADATA\TEST\RBS01.DBF
5
、启动数据库,检查错误
SQL> STARTUP
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: 'D:\Oracle\ORADATA\TEST\SYSTEM01.DBF'
查询
v$recover_file
SQL> select * from v$recover_file;
FILE# ONLINE ERROR CHANGE# TIME
---------- ------- ------------------ ---------- -----------
1 ONLINE FILE NOT FOUND 0
2 ONLINE FILE NOT FOUND 0
5 ONLINE FILE NOT FOUND 0
6 ONLINE FILE NOT FOUND 0
可以知道有四个数据文件需要恢复
.
6
、利用
RMAN
进行恢复
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN> run{
2> allocate channel c1 type disk;
3> restore database;
4> recover database;
5> sql 'alter database open';
6> release channel c1;
7> }
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=17 devtype=DISK
RMAN-03022: compiling command: restore
RMAN-03025: performing implicit partial resync of recovery catalog
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: IRESTORE
RMAN-03023: executing command: IRESTORE
RMAN-08016: channel c1: starting datafile backupset restore
RMAN-08502: set_count=4 set_stamp=494074368 creation_time=15-MAY-03
RMAN-08089: channel c1: specifying datafile(s) to restore from backup set
RMAN-08523: restoring datafile 00001 to D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
RMAN-08523: restoring datafile 00002 to D:\Oracle\ORADATA\TEST\RBS01.DBF
RMAN-08523: restoring datafile 00003 to D:\Oracle\ORADATA\TEST\USER01.DBF
RMAN-08523: restoring datafile 00004 to D:\Oracle\ORADATA\TEST\TEMP01.DBF
RMAN-08523: restoring datafile 00005 to D:\Oracle\ORADATA\TEST\TOOLS01.DBF
RMAN-08523: restoring datafile 00006 to D:\Oracle\ORADATA\TEST\INDX01.DBF
RMAN-08023: channel c1: restored backup piece 1
RMAN-08511: piece handle=D:\BACKUP\FULL04EN5UG0_4_1 tag=DBFULL params=NULL
RMAN-08024: channel c1: restore complete
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: recover
RMAN-03022: compiling command: recover(1)
RMAN-03022: compiling command: recover(2)
RMAN-03022: compiling command: recover(3)
RMAN-03023: executing command: recover(3)
RMAN-08054: starting media recovery
RMAN-03022: compiling command: recover(4)
RMAN-06050: archivelog thread 1 sequence 327 is already on disk as file D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00327.ARC
RMAN-06050: archivelog thread 1 sequence 328 is already on disk as file D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00328.ARC
RMAN-06050: archivelog thread 1 sequence 329 is already on disk as file D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00329.ARC
RMAN-06050: archivelog thread 1 sequence 330 is already on disk as file D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00330.ARC
RMAN-03023: executing command: recover(4)
RMAN-08515: archivelog filename=D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00327.ARC thread=1 sequence=327
RMAN-08515: archivelog filename=D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00328.ARC thread=1 sequence=328
RMAN-08055: media recovery complete
RMAN-03022: compiling command: sql
RMAN-06162: sql statement: alter database open
RMAN-03023: executing command: sql
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
RMAN-08031: released channel: c1
RMAN>
7
、
检查数据库的数据(完全恢复)
SQL> select * from test;
A
---------------------------------------
1
2
说明:
1
、只要有备份与归档存在,
RMAN
也可以实现数据库的完全恢复(不丢失数据)
;
2
、同
OS
备份数据库恢复,适合于丢失大量数据文件,或包含系统数据文件在内的数据库的恢复
;
3
、目标数据库在
mount
下进行,如果恢复成功,再打开数据库
;
4
、
RMAN
的备份与恢复命令相对比较简单并可靠,建议有条件的话,都采用
RMAN
进行数据库的备份。
4.4
不完全恢复案例
4.4.1
OS
备份下的基于时间的恢复
不完全恢复可以分为基于时间的恢复,基于改变的恢复与基于撤消的恢复,这里已基于时间的恢复为例子来说明不完全恢复过程。
基于时间的恢复可以不完全恢复到现在时间之前的某一个时间,对于某些误操作,如删除了一个数据表,可以在备用恢复环境上恢复到表的删除时间之前,然后把该表导出到正式环境,避免一个人为的错误。
1
、
连接数据库,创建测试表并插入记录
:
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、
备份数据库,这里最好备份所有的数据文件,包括临时数据文件
:
SQL> @hotbak.sql
或在
DOS
下
svrmgrl @hotbak.sql
或冷备份也可以
3
、
删除测试表,假定删除前的时间为
T1
,在删除之前,便于测试,继续插入数据并应用到归
档。
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
Statement processed.
SQL> alter system switch logfile;
Statement processed.
SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual;
TO_CHAR(SYSDATE,'YY
-------------------
2003-05-21 14:43:01
SQL> drop table test;
Table dropped.
4
、
准备恢复到时间点
T1
,找回删除的表,先关闭数据库
:
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down.
5
、
拷贝刚才备份的所有数据文件回来
C:\>copy D:\DATABAK\*.DBF D:\Oracle\ORADATA\TEST\
6
、
启动到
mount
下
SQL> startup mount;
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
7
、
开始不完全恢复数据库到
T1
时间
SQL> recover database until time '2003-05-21:14:43:01';
ORA-00279: change 30944 generated at 05/21/2003 14:40:06 needed for thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00191.ARC
ORA-00280: change 30944 for thread 1 is in sequence #191
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
Log applied.
Media recovery complete.
8
、
打开数据库,检查数据
SQL> alter database open resetlogs;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
说明:
1
、不完全恢复最好备份所有的数据,冷备份亦可,因为恢复过程是从备份点往后恢复的,如果因为其中一个数据文件的时间戳
(SCN)
大于要恢复的时间点,那么恢复都是不可能成功的
;
2
、不完全恢复有三种方式,过程都一样,仅仅是
recover
命令有所不一样,这里用基于时间的恢复作为示例
;
3
、不完全恢复之后,都必须用
resetlogs
的方式打开数据库,建议马上再做一次全备份,因为
resetlogs
之后再用以前的备份恢复是很难了
;
4
、以上是在删除之前获得时间,但是实际应用中,很难知道删除之前的实际时间,但可以采用大致时间即可,或可以采用分析日志文件
(logmnr)
,取得精确的需要恢复的时间
;
5
、一般都是在测试机后备用机器上采用这种不完全恢复,恢复之后导出
/
导入被误删的表回生产系统
.
4.4.2
RMAN
备份下的基于改变的恢复
以上用
OS
备份说明了一个基于时间的恢复,现在用
RMAN
说明一个基于改变的恢复
1
、
连接数据库,创建测试表并插入记录
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2
、
备份数据库
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=874705288)
RMAN> run{
2> allocate channel c1 type disk;
3> backup full tag 'dbfull' format 'd:\backup\full%u_%s_%p' database
4> include current controlfile;
5> sql 'alter system archive log current';
6> release channel c1;
7> }
//
屏幕输出内容冗长,省略
--
编辑
RMAN>
3
、
删除测试表,在删除之前,便于测试,继续插入数据并应用到归档,并获取删除前的
scn
号。
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
Statement processed.
SQL> alter system switch logfile;
Statement processed.
SQL> select max(ktuxescnw * power(2, 32) + ktuxescnb) scn from x$ktuxe;
SCN
----------
31014
SQL> drop table test;
Table dropped.
4
、
准备恢复到
SCN 31014
,先关闭数据库,然后启动到
mount
下
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down.
SQL> startup mount;
5
、
开始恢复到改变点
SCN 31014
RMAN> run{
2> allocate channel c1 type disk;
3> restore database;
4> recover database until scn 31014;
5> sql 'ALTER DATABASE OPEN RESETLOGS';
6> release channel c1;
7> }
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=10 devtype=DISK
RMAN-03022: compiling command: restore
RMAN-03022: compiling command: IRESTORE
RMAN-03023: executing command: IRESTORE
RMAN-08016: channel c1: starting datafile backupset restore
RMAN-08502: set_count=1 set_stamp=494613682 creation_time=21-MAY-03
RMAN-08089: channel c1: specifying datafile(s) to restore from backup set
RMAN-08523: restoring datafile 00001 to D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
RMAN-08523: restoring datafile 00002 to D:\Oracle\ORADATA\TEST\RBS01.DBF
RMAN-08523: restoring datafile 00003 to D:\Oracle\ORADATA\TEST\USERS01.DBF
RMAN-08523: restoring datafile 00004 to D:\Oracle\ORADATA\TEST\TEMP01.DBF
RMAN-08523: restoring datafile 00005 to D:\Oracle\ORADATA\TEST\TOOLS01.DBF
RMAN-08523: restoring datafile 00006 to D:\Oracle\ORADATA\TEST\INDX01.DBF
RMAN-08023: channel c1: restored backup piece 1
RMAN-08511: piece handle=D:\BACKUP\FULL01ENMD5I_1_1 tag=DBFULL params=NULL
RMAN-08024: channel c1: restore complete
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: recover
RMAN-03022: compiling command: recover(1)
RMAN-03022: compiling command: recover(2)
RMAN-03022: compiling command: recover(3)
RMAN-03023: executing command: recover(3)
RMAN-08054: starting media recovery
RMAN-03022: compiling command: recover(4)
RMAN-06050: archivelog thread 1 sequence 191 is already on disk as file D:\ORACL
E\ORADATA\TEST\ARCHIVE\TESTT001S00191.ARC
RMAN-06050: archivelog thread 1 sequence 192 is already on disk as file D:\ORACL
E\ORADATA\TEST\ARCHIVE\TESTT001S00192.ARC
RMAN-03023: executing command: recover(4)
RMAN-08515: archivelog filename=D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00191.AR
C thread=1 sequence=191
RMAN-08515:archivelog filename=D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00192.ARC
Thread=1 sequence=192
RMAN-08055: media recovery complete
RMAN-03022: compiling command: sql
RMAN-06162: sql statement: ALTER DATABASE OPEN RESETLOGS
RMAN-03023: executing command: sql
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
RMAN-08031: released channel: c1
6
、
检查数据
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
可以看到,表依然存在。
说明:
1
、
RMAN
也可以实现不完全恢复,方法比
OS
备份恢复的方法更简单可靠;
2
、
RMAN
可以基于时间,基于改变与基于日志序列的不完全恢复,基于日志序列的恢复可以指定恢复到哪个日志序列,如
run {
allocate channel ch1 type disk;
allocate channel ch2 type 'sbt_tape';
set until logseq 1234 thread 1;
restore controlfile to '$Oracle_HOME/dbs/cf1.f' ;
replicate controlfile from '$Oracle_HOME/dbs/cf1.f';
alter database mount;
restore database;
recover database;
sql "ALTER DATABASE OPEN RESETLOGS";
}
3
、
与所有的不完全恢复一样,必须在
mount
下,
restore
所有备份数据文件,需要
resetlogs
;
4
、
基于改变的恢复比基于时间的恢复更可靠,但是可能也更复杂,需要知道需要恢复到哪一个改变号
(SCN)
,在正常生产中,获取
SCN
的办法其实也有很多,如查询数据库字典表
(V$archived_log or v$log_history)
,或分析归档与联机日志
(logmnr)
等