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，对于非凡情况，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非凡频繁的数据文件，可以单独加大备份频率）；
3、假如在恢复过程中，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、假如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.
SQLr
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 Area102020364 bytes
Fixed Size70924 bytes
Variable Size85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers77824 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，假如在open方式下恢复，可以减少down机时间;
2、假如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
