Chinaunix首页 | 论坛 | 博客
  • 博客访问: 486129
  • 博文数量: 80
  • 博客积分: 2393
  • 博客等级: 大尉
  • 技术积分: 1434
  • 用 户 组: 普通用户
  • 注册时间: 2007-12-03 21:46
个人简介

己所不欲勿施于人!

文章分类

全部博文(80)

文章存档

2017年(1)

2016年(9)

2014年(1)

2013年(17)

2012年(5)

2011年(13)

2010年(9)

2009年(8)

2008年(17)

分类: Oracle

2011-07-27 06:55:51

A fuzzy backup is a secondary (or backup) copy of data file(s) or directories that were in one state when the backup started, but in a different state by the time the backup completed. This may result in the backup copy being unusable because of the . Although the backup process might have seemed successful, the resultant copies of the files or directories could be useless because a restore would yield inconsistent and unusable data.
模糊备份,是指对一个数据文件的拷贝。备份开始和结束是处于不同的状态,由于数据处于不一致状态可能导致文件不可用。虽然备份看起来可能是成功的。但是这样的备份可能导致不一致或者完全不可用的数据。
 
SQL> archive log list;
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     73
Current log sequence           75
SQL> conn test/test
Connected.
数据库运行过程中进行的拷贝。
SQL> !cp /oradata_2/oradata/tp_test.dbf tp_test.dbf.bak
进行创建表等操作
SQL> create table after_bak(aa varchar2(20));
Table created.
SQL> insert into after_bak values('test');
1 row created.
SQL> commit;
Commit complete.
关闭数据库,并恢复之前的备份后,重新打开数据库。
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> !cp ~/tp_test.dbf.bak /oradata_2/oradata/tp_test.dbf
SQL> startup
ORACLE instance started.
Total System Global Area  285212672 bytes
Fixed Size                  1218968 bytes
Variable Size              75499112 bytes
Database Buffers          201326592 bytes
Redo Buffers                7168000 bytes
Database mounted.
ORA-01113: file 4 needs media recovery
ORA-01110: data file 4: '/oradata_2/oradata/tp_test.dbf'
注意,这里提示我们,第四个文件需要介质恢复。这个正是我们拷贝的数据文件tp_test.dbf.

SQL> recover
Media recovery complete.

SQL> alter database open;
Database altered.
SQL> select * from after_bak;
AA
--------------------
alert_orcl.log 内容:
WARNING! Recovering data file 4 from a fuzzy backup. It might be an online
backup taken without entering the begin backup command.
 
 
阅读(1132) | 评论(0) | 转发(0) |
给主人留下些什么吧!~~