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官方文档备份指南一 Introduction to Backup and Recovery

2024-07-09 17:25:41   227人阅读

1.备份分为:物理备份和逻辑备份

   物理备份:备份数据文件  控制文件  归档日志文件
    逻辑备份:EXP EXPDP备份等
物理备份为主,逻辑做补充
 
 
2.错误的类型
        media failure :介质失败.磁盘不能读写
        user error: 操作错误
        application error:应用程序错误
 
 
3.备份的方式
       RMAN                                :RMAN备份
       User managed backup      :用户手工备份
        
4. 关于RMAN备份的一些东西
     Incremental backups            :只备份用过的块,在恢复的时候只使用这些块对应的redo
    Block media recovery           :可以只修复某些块而不是整个数据文件,命令recover block
    Binary compression              :减少备份所占的空间
    Encrypted backups              :加密备份,必须有advance security操作(?).如果是加密备份到磁带,则需要Oracle Secure Backup SBT实例(?)不再需要advance security
    Automated database duplication :复制数据库,可以使用不同的存储结构,可以在ASM间复制
    Cross-platform data conversion    :跨平台的转换数据
 
5.不同的备份区别

Table 1-1 Feature Comparison of Backup Techniques

FeatureRecovery ManagerUser-ManagedData Pump Export

Closed database backups

Supported. Requires instance to be mounted.

Supported.

Not supported.

Open database backups

Supported. No need to use BEGIN/ENDBACKUP statements.

Supported. Must use BEGIN/END BACKUPstatements.

Requires rollback or undo segments to generate consistent backups.

Incremental backups

Supported.

Not supported.

Not supported.

Corrupt block detection

Supported. Identifies corrupt blocks and logs in V$DATABASE_BLOCK_CORRUPTION.

Not supported.

Supported. Identifies corrupt blocks in the export log.

Automatic specification of files to include in a backup(备份信息)

Supported. Establishes the name and locations of all files to be backed up (whole database, tablespaces, data files, control files, and so on).

Not supported. Files to be backed up must be located and copied manually.

Not applicable.

Backup repository

Supported. Backups are recorded in the control file, which is the main repository of RMAN metadata. Additionally, you can store this metadata in a recovery catalog, which is a schema in a different database.

Not supported. DBA must keep own records of backups.

Not supported.

Backups to a media manager

Supported. Interfaces with a media manager. RMAN also supports proxy copy, a feature that allows a media manager to manage completely the transfer of data between disk and backup media.

Supported. Backup to tape is manual or controlled by a media manager.(需要手动或备份管理器)

Not supported.

Backup of initialization parameter file

Supported.

Supported.

Not supported.

Backup of password and networking files

Not supported.

Supported.

Not supported.

Platform-independent language for backups(平台依赖的语言?)

Supported.

Not supported.

Supported.

 
 
 
5.FLASHBACK(闪回)
   1)逻辑的闪回:
        除了flashback drop外,其它的闪回技能需要使用undo表空间的信息    
        有以下几种逻辑闪回方式 :
                Oracle Flashback Query:闪回查询. as to timestamp....
            Oracle Flashback Version Query:闪回版本查询.在特定时间段内行的所有版本,包括start and end time, operation, and transaction ID等
            Oracle Flashback Transaction Query:闪回事务查询.查询一个事务或一段时间内的所有事务做的更改
            Oracle Flashback Transaction        :闪回事务.把事务闪回,并且把依赖的事务也闪回,就像这些事务没有做过一样.
                Oracle Flashback Drop                :表删除闪回.从回收站把表还原
            flashback data archive            :通过补充日志,把表的更改记录下来.补充日志放在表空间中.数据库自动删除过期的闪回归档.
    2)数据库闪回
            将数据库闪回到某个SCN,有点像POINT-IN-TIME-RECOVER(基于时间点的恢复),但经PITR快,不需要用备份还原,所使用的的redo也比较少.ORACLE使用flashback log(闪回日志)来获取
     数据块的历史版本和日志信息.闪回日志放在fast recover area(快速闪回区),默认不开启FRA(在DBCA创建数据库时可以配置).
            ORACLE在FLASHBACK和BACK AND RESOTRE上支持还原点.还原点(restore point)对应一个SCN.可以任何时候创建还原点,可以将数据库闪回到某个已经存在的还原点上.
 
6.DATA RECOVERY ADVISOR(DRA数据恢复顾问)
          DAR自动诊断数据库错误(如文件丢失),并且生成恢复建议.可以使用EM或GRID CONTROL或RMAN命令来使用DRA.DRA会显示错误的严重程度,critical, high, or low.DRA生成的建议包括data file restore and recovery, media recovery, Flashback Database等.在修复完成后,DRA会删除错误提示.DAR使用的顺序为list failure-advisor failure-repair failure
 
 
 
7.Backup and Recovery Documentation Roadmap(恢复备份的文档路径图)
 
 
 



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