Overview of Backup and Recovery:

个人自行阅读时候，翻译的文档。因为比较渣，如果有更合理或者错误的地方烦劳告知，我会做修改。

This chapter explains Oracle Database backup and recovery and summarizes the Oracle solutions. This chapter contains the following topics:
• Purpose of Backup and Recovery
• Oracle Backup and Recovery Solutions
• About Oracle Flashback Technology
• About Data Recovery Advisor
• RMAN and Oracle Enterprise Manager Cloud Control
• About Zero Data Loss Recovery Appliance
• Backup and Recovery Documentation Roadmap
译文:
这篇章节涵盖了Oracle 数据库备份和恢复以及Oracle解决方案的简要概述，章节涵盖了以下主题
• 备份和恢复的目的
• Oracle备份和恢复的解决方案
• 关于Oracle 闪回技术
• 关于数据恢复建议
• RMAN和Oracle企业云管理控制
• 关于零数据丢失恢复配置
• 备份和恢复文档路线图

Purpose of Backup and Recovery
As a backup administrator, your principal duty is to devise, implement, and manage a backup and recovery strategy. In general, the purpose of a backup and recovery
strategy is to protect the database against data loss and reconstruct the database after data loss. Typically, backup administration tasks include the following:
• Planning and testing responses to different kinds of failures
• Configuring the database environment for backup and recovery
• Setting up a backup schedule
• Monitoring the backup and recovery environment
• Troubleshooting backup problems
• Recovering from data loss if the need arises
译文:
备份和恢复的目的
作为一个备份管理员,你最主要的责任就是设计,实施和管理一个备份和恢复策略.通常,备份和恢复策略是为了防止数据丢失和在数据丢失后进行重构数据库.通常，备份管理的任务包含以下
• 计划和测试响应不同的失败
• 配置数据库备份和恢复环境
• 建立一个备份计划
• 监控备份和恢复环境
• 解决备份问题
• 在需要的时候恢复数据丢失

As a backup administrator, you may also be asked to perform other duties that are
related to backup and recovery:
• Data archival, which involves creating a database copy for long-term storage
• Data transfer, which involves moving data from one database or one host to
another
The purpose of this manual is to explain how to perform the preceding tasks.

译文:
作为一个备份管理员,你也可能会被要求执行其他的备份和恢复的职责
• 数据归档,涉及到长期存储数据库的拷贝
• 数据传输,解决数据从一个数据库或者一台主机移到另一台
手册的目的是解析如何执行前面的任务

About Data Protection
As a backup administrator, your primary job is making and monitoring backups for
data protection. A backup is a copy of data of a database that you can use to
reconstruct data. A backup can be either a physical backup or a logical backup.
作为一个备份管理员，你主要的工作是对数据保护的备份进行制定和监控，拷贝数据库的备份以便你可以用它来重构数据.备份可以是物理备份或者是逻辑备份的其中一种
Physical backups are copies of the physical files used in storing and recovering a
database. These files include data files, control files, and archived redo logs.
物理备份副本的物理文件用于存储和恢复数据库，这些文件包含了数据文件,控制文件和归档重做日志
Ultimately, every physical backup is a copy of files that store database information to another location, whether on disk or on offline storage media such as tape.
最后，每一个存储数据库信息的副本文件放在另一个位置,像在磁盘或者是离线的磁带设备中
Logical backups contain logical data such as tables and stored procedures. You can use Oracle Data Pump to export logical data to binary files, which you can later import into the database. The Data Pump command-line clients expdp and impdp use the DBMS_DATAPUMP and DBMS_METADATA PL/SQL packages.
逻辑备份包含了像表和存储过程的逻辑数据.你可以使用Oracle数据泵的方式导出逻辑数据到二级制文件中，你可以在稍后导入到数据库.数据库泵的客户端指令使用PL/SQL包里的 DBMS_DATAPUMP和 DBMS_METADATA中的expdp和impdp

Physical backups are the foundation of any sound backup and recovery strategy.
Logical backups are a useful supplement to physical backups in many circumstances but are not sufficient protection against data loss without physical backups.
物理备份是在所有备份和恢复策略之中最为可靠的基础.在许多情况下，逻辑备份是物理备份的有用补充，但没有物理备份对数据丢失的保护是不足够的。
Unless otherwise specified, the term backup as used in the backup and recovery
documentation refers to a physical backup. Backing up a database is the act of making a physical backup. The focus in the backup and recovery documentation set is almost exclusively on physical backups.
除非另有规定,备份和恢复文档中使用的术语备份指的是物理备份.备份数据库是进行物理备份的行为。备份和恢复文档集中的焦点几乎完全集中在物理备份上。
While several problems can halt the normal operation of an Oracle Database or affect database I/O operations, only the following typically require DBA intervention and data recovery: media failure, user errors, and application errors. Other failures may require DBA intervention without causing data loss or requiring recovery from
backup. For example, you may need to restart the database after an instance failure or allocate more disk space after statement failure because of a full data file.
虽然一些问题可以使一个Oracle数据库正常运行停止或影响数据库的I/O操作，只有在以下情况需要DBA干预和数据恢复：介质故障、用户错误、应用程序错误。其他故障可能需要DBA干预在没有造成数据丢失或要求从备份中恢复。例如，您可能需要重启数据库在实例失败后或者由于完整的数据文件在语句失败后需要分配更多磁盘空间。
Media Failures
A media failure is a physical problem with a disk that causes a failure of a read from
or write to a disk file that is required to run the database. Any database file can be
vulnerable to a media failure. The appropriate recovery technique following a media
failure depends on the files affected and the types of backup available.
介质故障是一个磁盘的物理问题，它会导致读取或写入到需要运行数据库的磁盘文件失败。任何数据库文件都容易受到介质故障的影响。介质故障后的适当的恢复技术取决于受影响的文件和可用的备份类型。
One particularly important aspect of backup and recovery is developing a disaster
recovery strategy to protect against catastrophic data loss, for example, the loss of an entire database host.
备份和恢复的一个特别重要的方面是开发一个灾难恢复策略，以防止灾难性的数据丢失，例如，整个数据库主机的损失。
User Errors
User errors occur when, either due to an error in application logic or a manual
mistake, data in a database is changed or deleted incorrectly. User errors are estimated to be the greatest single cause of database downtime.
用户错误发生时，无论是由于应用程序逻辑错误或手册错误，数据库中的数据已经被更改或不正确的删除。用户错误估计是单一数据库停机时间最大原因。
Data loss due to user error can be either localized or widespread. An example of
localized damage is deleting the wrong person from the employees table. This type of damage requires surgical detection and repair. An example of widespread damage is a batch job that deletes the company orders for the current month. In this case, drastic action is required to avoid a extensive database downtime.
由于用户错误的数据丢失可以是局部或广泛。局部损害的一个例子是从雇员表中删除错误的人。这种类型的损伤需要外科探查和修复。一个大范围损坏的例子是一组作业，删除当前月份的公司订单。在这种情况下，需要迅速的采取行动避免大量的数据库停机时间。
While user training and careful management of privileges can prevent most user
errors, your backup strategy determines how gracefully you recover the lost data
when user error does cause data loss.
虽然用户培训和有效的管理权限可以防止大多数用户错误，您的备份策略决定了在用户错误造成数据丢失时如何优雅地恢复丢失的数据。
Application Errors
Sometimes a software malfunction can corrupt data blocks. In a physical corruption,
which is also called a media corruption, the database does not recognize the block at all: the checksum is invalid, the block contains all zeros, or the header and footer of the block do not match. If the corruption is not extensive, then you can often repair it easily with block media recovery.
有时软件故障会损坏数据块。在一个物理损坏，也就是所谓的介质损坏，数据库根本不识别所有的块：校验无效，块包含所有的零点，或块的头和尾不匹配。如果损坏不大量，那么你可以经常轻松的使用块介质恢复。
About Data Archival
Data archival is related to data protection, but serves a different purpose. For example,you may need to preserve a copy of a database as it existed at the end of a business quarter. This backup is not part of the disaster recovery strategy. The media to which these backups are written are often unavailable after the backup is complete. You may send the tape into fire storage or ship a portable hard drive to a testing facility. RMAN provides a convenient way to create a backup and exempt it from your backup retention policy. This type of backup is known as an archival backup.
数据存档与数据保护有关，但服务的目的不同。例如，您可能需要保存一个数据库的副本，因为它在业务季度结束时存在。此备份不是灾难恢复策略的一部分。备份完成后，写入这些备份的媒体通常不可用。您可以将磁带发送到消防仓库，或将便携式硬盘传送到测试设备。RMAN可以方便地创建一个备份，免除您的备份策略。这种类型的备份被称为归档备份。
About Data Transfer
In some situations you may need to take a backup of a database or database
component and move it to another location. For example, you can use Recovery
Manager (RMAN) to create a database copy, create a tablespace copy that can be
imported into another database, or move an entire database from one platform to
another. These tasks are not strictly speaking part of a backup and recovery strategy,but they do require the use of database backups, and so may be included in the duties of a backup administrator.
在某些情况下，您可能需要备份数据库或数据库组件并将其移动到另一位置。例如，你可以使用恢复管理器（RMAN）创建一个数据库副本，创建一个可以导入到另一个数据库表空间副本，或整个数据库从一个平台移动到另一个。这些任务不是严格地说是备份和恢复策略的一部分，但它们确实需要使用数据库备份，因此可以包含在备份管理员的职责中。
Oracle Backup and Recovery Solutions
When implementing a backup and recovery strategy, you have the following solutions available:
在贯彻数据备份和恢复策略中，你有以下几种可用的解决方案
• Recovery Manager (RMAN)
Recovery Manager is fully integrated with the Oracle Database to perform a range
of backup and recovery activities, including maintaining an RMAN repository of
historical data about backups. You can access RMAN through the command line or
through Oracle Enterprise Manager.
恢复管理器是完全集成的Oracle数据库执行范围备份和恢复活动,包括维护一个RMAN库历史数据备份。你可以通过命令行访问RMAN活通过 通过OEM
• Oracle Enterprise Manager Cloud Control
Oracle Enterprise Manager Cloud Control (Cloud Control) provides a graphical
front end and scheduling facilities for RMAN. You enter job parameters, specify a
job schedule, and Cloud Control runs RMAN to conduct the backup and recovery
operations.
OEM云管理提供了前端图形和RMAN调度工具,你输入一个任务参数,指定任务跳读，云控制台运行RMAN进行备份和恢复操作
• Zero Data Loss Recovery Appliance (Recovery Appliance)
Recovery Appliance is a cloud-scale Engineered System that provides data
protection for all Oracle Databases in the enterprise. Integrated with RMAN and
Cloud Control, the Recovery Appliance provides a single repository for backups of
multiple databases as described in “About Zero Data Loss Recovery Appliance”.
恢复设备是一个云规模的工程系统，提供数据企业中所有Oracle数据库的保护。RMAN和云控制集成，恢复设备提供了一个用于多个数据库备份的仓库作为在“零数据丢失恢复设备”的描述。
• User-managed backup and recovery
In this solution, you perform backup and recovery with a mixture of host operating
system commands and SQL*Plus recovery commands.You are responsible for
determining all aspects of when and how backups and recovery are done.
在这个解决方案中，您执行备份和恢复使用宿主操作系统命令和SQL * Plus恢复命令。你负责确定各方面何时以及如何备份和恢复。
These solutions are supported by Oracle and are fully documented, but RMAN is the preferred solution for database backup and recovery. RMAN provides a common interface for backup tasks across different host operating systems, and offers several backup techniques not available through user-managed methods.
这些解决方案通过Oracle的支持和丰富的文档支持，但是RMAN数据库备份和恢复是首选解决方案。RMAN提供的备份任务在不同的主机操作系统的一个通用的接口，并在无法通过用户管理的方法上提供了多种备份技术。
Most of this manual focuses on RMAN-based backup and recovery. The most
noteworthy are the following:
基于RMAN备份和恢复是手册重点。最值得注意的是以下
• Incremental backups
An incremental backup stores only blocks changed since a previous backup. Thus,
they provide more compact backups and faster recovery, thereby reducing the
need to apply redo during data file media recovery. If you enable block change
tracking, then you can improve performance by avoiding full scans of every input
data file. You use the BACKUP INCREMENTAL command to perform incremental
backups.
增量备份只存储块一次备份后改变。因此，他们提供了更紧凑的备份和更快的恢复，从而减少了需要应用重做数据文件介质恢复过程。如果你启用块更改跟踪，然后你可以通过避免每个输入数据文件的完全扫描提高性能。你使用增量备份命令执行增量备份。
• Block media recovery
You can repair a data file with only a small number of corrupt data blocks without
taking it offline or restoring it from backup. You use the RECOVER BLOCK
command to perform block media recovery.
您可以仅使用少量已损坏的数据块修复数据文件使其脱机或从备份还原。 您使用RECOVER BLOCK命令执行块介质恢复。
• Binary compression
A binary compression mechanism integrated into Oracle Database reduces the size
of backups.
集成到Oracle数据库中的二进制压缩机制减少了备份的大小。
• Encrypted backups
RMAN uses backup encryption capabilities integrated into Oracle Database to
store backup sets in an encrypted format. To create encrypted backups on disk, the
database must use the Advanced Security Option. To create encrypted backups
directly on tape, RMAN must use the Oracle Secure Backup SBT interface, but does not require the Advanced Security Option.
RMAN使用集成到Oracle数据库中的备份加密功能以加密格式存储备份集。 要在磁盘上创建加密备份，数据库必须使用高级安全选项。 创建加密备份直接在磁带上，RMAN必须使用Oracle Secure Backup SBT接口，但不需要高级安全选项。
• Automated database duplication
自动数据复制
Easily create a copy of your database, supporting various storage configurations,
including direct duplication between ASM databases.
轻松创建数据库的副本，支持各种存储配置，包括ASM数据库之间的直接复制。
• Cross-platform data conversion
跨平台数据转换
User-managed backup and recovery techniques are covered in chapters Making User-Managed Database Backups through Performing User-Managed Recovery: Advanced Scenarios.
用户管理的备份和恢复技术覆盖在使用户管理通过执行用户管理恢复的数据库备份的章节：高级方案的章节中介绍。
Whether you use RMAN or user-managed methods, you can supplement physical
backups with logical backups of schema objects made with Data Pump Export utility.
无论您使用RMAN还是用户管理的方法，都可以补充物理备份与使用数据泵导出实用程序进行的模式对象的逻辑备份。
You can later use Data Pump Import to re-create data after restore and recovery.
Logical backups are mostly beyond the scope of the backup and recovery
documentation.
你可以稍后在还原和恢复后重新创建数据时使用数据泵导入。逻辑备份大多超出了备份和恢复文档的范围
The following table summarizes the features of the different backup techniques.
一下表格总结了不同备份技术的功能

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