本节描述了不同类型备份的特性。This section describes the characteristics of different types of backups.

物理（原始）备份与逻辑备份Physical (Raw) Versus Logical Backups

物理备份包括存储数据库内容的目录和文件的原始副本。这种类型的备份适用于需要在发生问题时快速恢复的大型重要数据库。Physical backups consist of raw copies of the directories and files that store database contents. This type of backup is suitable for large, important databases that need to be recovered quickly when problems occur.

逻辑备份保存以逻辑数据库结构表示的信息（CREATE DATABASE、CREATE TABLE 语句）和内容（INSERT 语句或定界文本文件）。这种类型的备份适用于数据量较小的情况，可以编辑数据值或表结构，或者在不同的机器架构上重建数据。Logical backups save information represented as logical database structure (CREATE DATABASE, CREATE TABLE statements) and content (INSERT statements or delimited-text files). This type of backup is suitable for smaller amounts of data where you might edit the data values or table structure, or recreate the data on a different machine architecture.

物理备份方法具有以下特征：Physical backup methods have these characteristics:

逻辑备份方法具有以下特点：Logical backup methods have these characteristics:

在线备份与离线备份Online Versus Offline Backups

在线备份在 MySQL 服务器运行时进行，以便可以从服务器获取数据库信息。离线备份在服务器停止时进行。这一区别也可以描述为“热”备份与“冷”备份；“温”备份指的是服务器保持运行，但在你外部访问数据库文件时锁定以防止修改数据的备份类型。Online backups take place while the MySQL server is running so that the database information can be obtained from the server. Offline backups take place while the server is stopped. This distinction can also be described as “hot” versus “cold” backups; a “warm” backup is one where the server remains running but locked against modifying data while you access database files externally.

在线备份方法具有以下特点：Online backup methods have these characteristics:

离线备份方法具有以下特点：Offline backup methods have these characteristics:

在线和离线之间的类似区分也适用于恢复操作，并且具有类似的特征。然而，客户受到在线恢复影响的可能性比在线备份更大，因为恢复需要更强的锁定。在备份期间，客户可能在数据备份时仍能读取数据。恢复会修改数据，而不仅仅是读取数据，因此在数据恢复过程中必须阻止客户访问数据。A similar distinction between online and offline applies for recovery operations, and similar characteristics apply. However, it is more likely for clients to be affected by online recovery than by online backup because recovery requires stronger locking. During backup, clients might be able to read data while it is being backed up. Recovery modifies data and does not just read it, so clients must be prevented from accessing data while it is being restored.

本地备份与远程备份Local Versus Remote Backups

本地备份是在运行 MySQL 服务器的同一主机上执行的，而远程备份则是在不同的主机上完成的。对于某些类型的备份，即使输出写入服务器本地，也可以从远程主机启动备份。A local backup is performed on the same host where the MySQL server runs, whereas a remote backup is done from a different host. For some types of backups, the backup can be initiated from a remote host even if the output is written locally on the server. host.

快照备份Snapshot Backups

一些文件系统实现允许拍摄“快照”。这些快照在给定时间点提供文件系统的逻辑副本，而不需要物理复制整个文件系统。（例如，该实现可能使用写时复制技术，因此只需要复制快照时间之后修改的文件系统部分。）MySQL 本身不提供拍摄文件系统快照的功能。这可以通过第三方解决方案实现，例如 Veritas、LVM 或 ZFS。Some file system implementations enable “snapshots” to be taken. These provide logical copies of the file system at a given point in time, without requiring a physical copy of the entire file system. (For example, the implementation may use copy-on-write techniques so that only parts of the file system modified after the snapshot time need be copied.) MySQL itself does not provide the capability for taking file system snapshots. It is available through third-party solutions such as Veritas, LVM, or ZFS.

完整备份与增量备份Full Versus Incremental Backups

完整备份包括在特定时间点由 MySQL 服务器管理的所有数据。增量备份则包含在特定时间段内（从一个时间点到另一个时间点）对数据所做的更改。MySQL 有不同的方法来执行完整备份，例如本节前面所述的方法。通过启用服务器的二进制日志可以实现增量备份，服务器使用二进制日志来记录数据更改。A full backup includes all data managed by a MySQL server at a given point in time. An incremental backup consists of the changes made to the data during a given time span (from one point in time to another). MySQL has different ways to perform full backups, such as those described earlier in this section. Incremental backups are made possible by enabling the server's binary log, which the server uses to record data changes.

完整恢复与时间点（增量）恢复Full Versus Point-in-Time (Incremental) Recovery

完全恢复是从完整备份中恢复所有数据。这会将服务器实例恢复到备份创建时的状态。如果该状态不够当前，则在完全恢复之后，可以恢复自完整备份以来所做的增量备份，以使服务器达到更为最新的状态。A full recovery restores all data from a full backup. This restores the server instance to the state that it had when the backup was made. If that state is not sufficiently current, a full recovery can be followed by recovery of incremental backups made since the full backup, to bring the server to a more up-to-date state.

增量恢复是恢复在特定时间段内所做的更改。这也称为时间点恢复，因为它使服务器的状态达到给定时间点的最新状态。时间点恢复基于二进制日志，通常在从备份文件进行的完全恢复之后进行，从而将服务器恢复到备份创建时的状态。然后，二进制日志文件中记录的数据更改会作为增量恢复应用，以重做数据修改并将服务器恢复到所需的时间点。Incremental recovery is recovery of changes made during a given time span. This is also called point-in-time recovery because it makes a server's state current up to a given time. Point-in-time recovery is based on the binary log and typically follows a full recovery from the backup files that restores the server to its state when the backup was made. Then the data changes written in the binary log files are applied as incremental recovery to redo data modifications and bring the server up to the desired point in time.

表维护Table Maintenance

如果表损坏，数据完整性可能会受到影响。对于InnoDB表来说，这通常不是一个问题。有关程序检查MyISAM表并在发现问题时进行修复，请参见第 9.6 节，“MyISAM 表维护与崩溃恢复”。Data integrity can be compromised if tables become corrupt. For InnoDB tables, this is not a typical issue. For programs to check MyISAM tables and repair them if problems are found, see Section 9.6, “MyISAM Table Maintenance and Crash Recovery”.

备份计划、压缩和加密Backup Scheduling, Compression, and Encryption

备份调度对于自动化备份过程非常有价值。备份输出的压缩可以减少空间需求，而输出的加密则可以更好地防止未经授权访问备份数据。MySQL 本身不提供这些功能。MySQL 企业备份产品可以压缩 InnoDB 备份，而备份输出的压缩或加密可以使用文件系统实用程序来实现。其他第三方解决方案也可能存在。Backup scheduling is valuable for automating backup procedures. Compression of backup output reduces space requirements, and encryption of the output provides better security against unauthorized access of backed-up data. MySQL itself does not provide these capabilities. The MySQL Enterprise Backup product can compress InnoDB backups, and compression or encryption of backup output can be achieved using file system utilities. Other third-party solutions may be available.