Oracle 冷备份
--======================
-- Oracle 冷备份
--======================
一、冷备份
数据库在关闭状态下完成所有物理系统文件拷贝的过程，也称脱机备份
适合于非归档模式下，数据库处于一致性状态
二、步骤
首先在运行的库中得到数据库运行的所有的物理文件位置，然后在计划内关闭数据库(shutdown)
再执行拷贝物理文家到备份路径或备份设备
备份完成后立即启动数据库让其提供正常的服务
三、冷备脚本的写法
首先应该在相关视图里查出数据库的数据文件，日志文件，控制文件，临时文件所在的位置
注意：不要直接把oradata下的cp就行了，因为生产库里各个文件通常分布在不同的磁盘，不同的地方，所以在去视图里获得真实路径
--查看实例和数据库的相关信息
SQL> select instance_name,version,status,archiver,database_status from v$instance;
INSTANCE_NAME VERSION STATUS ARCHIVE DATABASE_STATUS
---------------- ----------------- ------------ ------- -----------------
orcl 10.2.0.1.0 OPEN STOPPED ACTIVE
SQL> select dbid,name,log_mode from v$database;
DBID NAME LOG_MODE
---------- --------- ------------
1242732291 ORCL NOARCHIVELOG
--查看数据文件及状态信息
SQL> select file_name,tablespace_name,status,online_status from dba_data_files;
FILE_NAME TABLESPACE STATUS ONLINE_
------------------------------------------------------- ---------- --------- -------
/u01/app/oracle/oradata/orcl/undotbs01.dbf UNDOTBS1 AVAILABLE ONLINE
/u01/app/oracle/oradata/orcl/system01.dbf SYSTEM AVAILABLE SYSTEM
/u01/app/oracle/oradata/orcl/sysaux01.dbf SYSAUX AVAILABLE ONLINE
/u01/app/oracle/oradata/orcl/users01.dbf USERS AVAILABLE ONLINE
/u01/app/oracle/oradata/orcl/example01.dbf EXAMPLE AVAILABLE ONLINE
/u01/app/oracle/oradata/orcl/tbs1_1.dbf TBS1 AVAILABLE ONLINE
/u01/app/oracle/oradata/orcl/tbs1_2.dbf TBS1 AVAILABLE ONLINE
--查看数据文件
SQL> select name from v$datafile;
NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/orcl/system01.dbf
/u01/app/oracle/oradata/orcl/undotbs01.dbf
/u01/app/oracle/oradata/orcl/sysaux01.dbf
/u01/app/oracle/oradata/orcl/users01.dbf
/u01/app/oracle/oradata/orcl/example01.dbf
/u01/app/oracle/oradata/orcl/tbs1_1.dbf
/u01/app/oracle/oradata/orcl/tbs1_2.dbf
--查看临时文件
SQL> select name from v$tempfile;
NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/orcl/temp01.dbf
--查看日志文件
SQL> select member from v$logfile;
MEMBER
------------------------------------------------------------
/u01/app/oracle/oradata/orcl/redo2a.rdo
/u01/app/oracle/oradata/orcl/redo2b.rdo
/u01/app/oracle/oradata/orcl/redo1a.rdo
/u01/app/oracle/oradata/orcl/redo3a.rdo
/u01/app/oracle/oradata/orcl/redo3b.rdo
/u01/app/oracle/oradata/orcl/redo1b.rdo
--查看控制文件
SQL> select name from v$controlfile;
NAME
------------------------------------------------------------
/u01/app/oracle/oradata/orcl/control01.ctl
/u01/app/oracle/oradata/orcl/control02.ctl
--创建备份目录
SQL> ho mkdir /u01/app/oracle/coolbak
--使用连接符生成复制文件命令
SQL> select 'ho cp ' || name || ' /u01/app/oracle/coolbak' from v$controlfile;
'HOCP'||NAME||'/U01/APP/ORACLE/COOLBAK'
----------------------------------------------------------------------------------
ho cp /u01/app/oracle/oradata/orcl/control01.ctl /u01/app/oracle/coolbak
ho cp /u01/app/oracle/oradata/orcl/control02.ctl /u01/app/oracle/coolbak
SQL> save /tmp/tmpbak.sql; --将上面的输入保存为tmpbak.sql
Created file /tmp/tmpbak.sql
SQL> ho vim /tmp/tmpbak.sql --编辑tmpbak.sql,将下面的内容输入到tmpbak.sql
set feedback off
set heading off
set verify off
set trimspool off
set pagesize 0
set linesize 200
define dir = '/u01/app/oracle/coolbak'
define script = '/tmp/coolbak.sql'
spool &script
select 'ho cp ' || name || ' &dir' from v$controlfile
union all
select 'ho cp ' || name || ' &dir' from v$datafile
union all
select 'ho cp ' || member || ' &dir' from v$logfile
union all
select 'ho cp ' || name || ' &dir' from v$tempfile
/
create pfile = '&dir/initorcl.ora' from spfile;
ho cp /u01/app/oracle/10g/dbs/orapworcl &dir
spool off
shutdown immediate
start &script
ho rm &script
startup
--执行tmpbak.sql
SQL> @/tmp/tmpbak.sql;
--执行过程及数据库启动略
--启动后查看备份的文件
SQL> ho ls /u01/app/oracle/coolbak
control01.ctl orapworcl redo2b.rdo system01.dbf users01.dbf
control02.ctl redo1a.rdo redo3a.rdo tbs1_1.dbf
example01.dbf redo1b.rdo redo3b.rdo tbs1_2.dbf
initorcl.ora redo2a.rdo sysaux01.dbf undotbs01.dbf
四、总结
优点
冷备模式下概念易于理解，即将需要备份的文件复制到安全的位置
操作比较简单，不需要太多的干预
容易恢复到某个时间点上(只需将文件再拷贝回去)
能与归档方法相结合，作数据库“最新状态”的恢复。
缺点
备份时，数据库必须处于一致性关闭状态
只能提供到某一时间点的恢复
备份时速度比较慢，尤其是数据量大性能影响比较大
不能实现基于表和用户级别的数据恢复
五、更多参考
Oracle 联机重做日志文件(ONLINE LOG FILE)
