Oracle备份/恢复案例04——不完全恢复
Oracle备份/恢复案例04——不完全恢复
一、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、基于撤消的恢复，这里以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*Plus: Release 9.2.0.1.0 - Production on Tue Jan 13 10:03:27 2009
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
SQL> connect sys/sys 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
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，这里最好备份所有的数据文件，包括临时数据文件
SQL> @ D:\test\hotbak.sql
注：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
-------------------
2009-01-14 08:41:11
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:\DATABASE\BACK \ *.DBF D:\ORACLE\ORADATA\DODO
注：此处需要copy所有文件，因为会涉及到系统数据字典
6、启动到mount下
SQL> startup mount;
ORACLE instance started.
Total System Global Area 135338868 bytes
Fixed Size 453492 bytes
Variable Size 109051904 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
Fixed Size 453492 bytes
Variable Size 109051904 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
7、开始不完全恢复数据库到T1时间
SQL> recover database until time 2009-01-14 08:41:11';
ORA-00279: change 5966020159195 generated at 01/13/2009 10:37:39 needed for thread 1
ORA-00289: suggestion : D:\ORACLE\ORADATA\DODO\ARCHIVE\1_39.DBF
ORA-00280: change 5966020159195 for thread 1 is in sequence #39
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
二、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*Plus: Release 9.2.0.1.0 - Production on Tue Jan 13 10:03:27 2009
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
SQL> connect sys/sys 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
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
C:> rman
Recovery Manager: Release 9.2.0.1.0 - Production
Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
RMAN> connect rcvcat rman/rman
RMAN> run{
2> allocate channel c1 type disk;
3> backup full tag 'dbfull' format 'd:backupfull _%u_%s_%p' database
4> include current controlfile;
5> sql 'alter system archive log current';
6> release channel c1;
7> }
allocated channel: c1
channel c1: sid=18 devtype=DISK
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
---------------
5966020192446
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;
ORACLE instance started.
5、开始恢复到改变点SCN 5966020192446
RMAN> run{
2> allocate channel c1 type disk;
3> restore database;
4> recover database until scn 5966020192446;
5> sql 'ALTER DATABASE OPEN RESETLOGS';
6> release channel c1;
7> }
allocated channel: c1
channel c1: sid=12 devtype=DISK
6、检查数据
SQL> select * from test;
A
---------------------
1
2
可以看到，表依然存在
RMAN> connect rcvcat rman/rman
connected to recovery catalog database
RMAN> connect target sys/sys
connected to target database: DODO (DBID=472976704)
RMAN> connect target sys/sys
connected to target database: DODO (DBID=472976704)
RMAN> run{
2> allocate channel c1 type disk;
3> backup full tag 'dbfull' format 'd:backupfull _%u_%s_%p' database
4> include current controlfile;
5> sql 'alter system archive log current';
6> release channel c1;
7> }
allocated channel: c1
channel c1: sid=18 devtype=DISK
Starting backup at 2009-01-14
channel c1: starting full datafile backupset
channel c1: specifying datafile(s) in backupset
including current controlfile in backupset
input datafile fno=00008 name=D:\ORACLE\ORADATA\DODO\WXQ_TBS.ORA
input datafile fno=00006 name=D:\ORACLE\ORADATA\DODO\USERS01.DBF
input datafile fno=00001 name=D:\ORACLE\ORADATA\DODO\SYSTEM01.DBF
input datafile fno=00002 name=D:\ORACLE\ORADATA\DODO\UNDOTBS01.DBF
input datafile fno=00007 name=D:\ORACLE\ORADATA\DODO\XDB01.DBF
input datafile fno=00004 name=D:\ORACLE\ORADATA\DODO\INDX01.DBF
input datafile fno=00003 name=D:\ORACLE\ORADATA\DODO\DRSYS01.DBF
input datafile fno=00009 name=D:\ORACLE\ORADATA\DODO\RECOVERY_TBS.ORA
input datafile fno=00005 name=D:\ORACLE\ORADATA\DODO\TOOLS01.DBF
channel c1: starting piece 1 at 2009-01-14
channel c1: finished piece 1 at 2009-01-14
piece handle=D:\DATABASE\RMAN\FULL_1UK4PBLD_62_1 comment=NONE
channel c1: backup set complete, elapsed time: 00:02:35
Finished backup at 2009-01-14
channel c1: starting full datafile backupset
channel c1: specifying datafile(s) in backupset
including current controlfile in backupset
input datafile fno=00008 name=D:\ORACLE\ORADATA\DODO\WXQ_TBS.ORA
input datafile fno=00006 name=D:\ORACLE\ORADATA\DODO\USERS01.DBF
input datafile fno=00001 name=D:\ORACLE\ORADATA\DODO\SYSTEM01.DBF
input datafile fno=00002 name=D:\ORACLE\ORADATA\DODO\UNDOTBS01.DBF
input datafile fno=00007 name=D:\ORACLE\ORADATA\DODO\XDB01.DBF
input datafile fno=00004 name=D:\ORACLE\ORADATA\DODO\INDX01.DBF
input datafile fno=00003 name=D:\ORACLE\ORADATA\DODO\DRSYS01.DBF
input datafile fno=00009 name=D:\ORACLE\ORADATA\DODO\RECOVERY_TBS.ORA
input datafile fno=00005 name=D:\ORACLE\ORADATA\DODO\TOOLS01.DBF
channel c1: starting piece 1 at 2009-01-14
channel c1: finished piece 1 at 2009-01-14
piece handle=D:\DATABASE\RMAN\FULL_1UK4PBLD_62_1 comment=NONE
channel c1: backup set complete, elapsed time: 00:02:35
Finished backup at 2009-01-14
Starting Control File and SPFILE Autobackup at 2009-01-14
piece handle=D:\ORACLE\ORADATA\DODO\RMANBACK\CTL_C-472976704-20090114-01 comment=NONE
Finished Control File and SPFILE Autobackup at 2009-01-14
piece handle=D:\ORACLE\ORADATA\DODO\RMANBACK\CTL_C-472976704-20090114-01 comment=NONE
Finished Control File and SPFILE Autobackup at 2009-01-14
sql statement: alter system archive log current
released channel: c1
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
---------------
5966020192446
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;
ORACLE instance started.
Total System Global Area 135338868 bytes
Fixed Size 453492 bytes
Variable Size 109051904 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
Fixed Size 453492 bytes
Variable Size 109051904 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
5、开始恢复到改变点SCN 5966020192446
RMAN> run{
2> allocate channel c1 type disk;
3> restore database;
4> recover database until scn 5966020192446;
5> sql 'ALTER DATABASE OPEN RESETLOGS';
6> release channel c1;
7> }
allocated channel: c1
channel c1: sid=12 devtype=DISK
Starting restore at 2009-01-14
channel c1: starting datafile backupset restore
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to D:\ORACLE\ORADATA\DODO\SYSTEM01.DBF
restoring datafile 00002 to D:\ORACLE\ORADATA\DODO\UNDOTBS01.DBF
restoring datafile 00003 to D:\ORACLE\ORADATA\DODO\DRSYS01.DBF
restoring datafile 00004 to D:\ORACLE\ORADATA\DODO\INDX01.DBF
restoring datafile 00005 to D:\ORACLE\ORADATA\DODO\TOOLS01.DBF
restoring datafile 00006 to D:\ORACLE\ORADATA\DODO\USERS01.DBF
restoring datafile 00007 to D:\ORACLE\ORADATA\DODO\XDB01.DBF
restoring datafile 00008 to D:\ORACLE\ORADATA\DODO\WXQ_TBS.ORA
restoring datafile 00009 to D:\ORACLE\ORADATA\DODO\RECOVERY_TBS.ORA
channel c1: restored backup piece 1
piece handle=D:\DATABASE\RMAN\FULL_1UK4PBLD_62_1 tag=DBFULL params=NULL
channel c1: restore complete
Finished restore at 2009-01-14
channel c1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to D:\ORACLE\ORADATA\DODO\SYSTEM01.DBF
restoring datafile 00002 to D:\ORACLE\ORADATA\DODO\UNDOTBS01.DBF
restoring datafile 00003 to D:\ORACLE\ORADATA\DODO\DRSYS01.DBF
restoring datafile 00004 to D:\ORACLE\ORADATA\DODO\INDX01.DBF
restoring datafile 00005 to D:\ORACLE\ORADATA\DODO\TOOLS01.DBF
restoring datafile 00006 to D:\ORACLE\ORADATA\DODO\USERS01.DBF
restoring datafile 00007 to D:\ORACLE\ORADATA\DODO\XDB01.DBF
restoring datafile 00008 to D:\ORACLE\ORADATA\DODO\WXQ_TBS.ORA
restoring datafile 00009 to D:\ORACLE\ORADATA\DODO\RECOVERY_TBS.ORA
channel c1: restored backup piece 1
piece handle=D:\DATABASE\RMAN\FULL_1UK4PBLD_62_1 tag=DBFULL params=NULL
channel c1: restore complete
Finished restore at 2009-01-14
Starting recover at 2009-01-14
starting media recovery
archive log thread 1 sequence 55 is already on disk as file D:\ORACLE\ORADATA\DODO\ARCHIVE\1_55.DBF
archive log thread 1 sequence 56 is already on disk as file D:\ORACLE\ORADATA\DODO\ARCHIVE\1_56.DBF
archive log thread 1 sequence 57 is already on disk as file D:\ORACLE\ORADATA\DODO\ARCHIVE\1_57.DBF
archive log filename=D:\ORACLE\ORADATA\DODO\ARCHIVE\1_55.DBF thread=1 sequence=55
media recovery complete
Finished recover at 2009-01-14
archive log thread 1 sequence 56 is already on disk as file D:\ORACLE\ORADATA\DODO\ARCHIVE\1_56.DBF
archive log thread 1 sequence 57 is already on disk as file D:\ORACLE\ORADATA\DODO\ARCHIVE\1_57.DBF
archive log filename=D:\ORACLE\ORADATA\DODO\ARCHIVE\1_55.DBF thread=1 sequence=55
media recovery complete
Finished recover at 2009-01-14
sql statement: ALTER DATABASE OPEN RESETLOGS
released channel: c1
6、检查数据
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。
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。