--allow-pk-changes

当此选项设置为1时，ndb_restore 允许表定义中的主键与备份中相同表的主键不同。当在一个或多个表上主键发生更改时，在不同模式版本之间进行备份和恢复时，这可能是可取的，并且使用 ndb_restore 执行恢复操作通常比在恢复表模式和数据后执行多个ALTER TABLE语句更简单或更高效。When this option is set to 1, ndb_restore allows the primary keys in a table definition to differ from that of the same table in the backup. This may be desirable when backing up and restoring between different schema versions with primary key changes on one or more tables, and it appears that performing the restore operation using ndb_restore is simpler or more efficient than issuing many ALTER TABLE statements after restoring table schemas and data.

--allow-pk-changes 支持如下主键定义的更改：The following changes in primary key definitions are supported by --allow-pk-changes:

这些差异可以与ndb_restore支持的其他模式差异结合使用，包括需要使用临时表的 blob 和 text 列的更改。These differences can be combined with other schema differences supported by ndb_restore, including changes to blob and text columns requiring the use of staging tables.

使用主键模式更改的典型场景中的基本步骤如下：Basic steps in a typical scenario using primary key schema changes are listed here:

在扩展主键时，ndb_restore 可能需要在恢复操作中使用临时的二级唯一索引，以将旧主键映射到新主键。仅在将备份日志中的事件应用于具有扩展主键的表时才创建这样的索引。该索引名为 NDB$RESTORE_PK_MAPPING，并在每个需要的表上创建；如果有必要，它可以被多个并行运行的 ndb_restore 实例共享。（在恢复过程结束时运行 ndb_restore --rebuild-indexes 会导致该索引被删除。）When extending the primary key, it may be necessary for ndb_restore to use a temporary secondary unique index during the restore operation to map from the old primary key to the new one. Such an index is created only when necessary to apply events from the backup log to a table which has an extended primary key. This index is named NDB$RESTORE_PK_MAPPING, and is created on each table requiring it; it can be shared, if necessary, by multiple instances of ndb_restore instances running in parallel. (Running ndb_restore --rebuild-indexes at the end of the restore process causes this index to be dropped.)

--append

当与 --tab 和 --print-data 选项一起使用时，这会将数据追加到任何具有相同名称的现有文件中。When used with the --tab and --print-data options, this causes the data to be appended to any existing files having the same names.

--backup-path=dir_name

需要提供备份目录的路径；这是通过 ndb_restore 使用 --backup-path 选项提供的，并且必须包含对应于要恢复的备份 ID 的子目录。例如，如果数据节点的 DataDir 是 /var/lib/mysql-cluster，那么备份目录就是 /var/lib/mysql-cluster/BACKUP，ID 为 3 的备份文件可以在 /var/lib/mysql-cluster/BACKUP/BACKUP-3 中找到。该路径可以是绝对路径，也可以是相对于 ndb_restore 可执行文件所在目录的相对路径，并且可以选择性地加上 backup-path= 前缀。The path to the backup directory is required; this is supplied to ndb_restore using the --backup-path option, and must include the subdirectory corresponding to the ID backup of the backup to be restored. For example, if the data node's DataDir is /var/lib/mysql-cluster, then the backup directory is /var/lib/mysql-cluster/BACKUP, and the backup files for the backup with the ID 3 can be found in /var/lib/mysql-cluster/BACKUP/BACKUP-3. The path may be absolute or relative to the directory in which the ndb_restore executable is located, and may be optionally prefixed with backup-path=.

可以将备份恢复到与其创建时配置不同的数据库。例如，假设一个备份 ID 为 12 的备份，是在具有两个存储节点（节点 ID 分别为 2 和 3）的集群中创建的，现在要将其恢复到一个有四个节点的集群中。那么必须运行 ndb_restore 两次——每次对应备份时所在集群的一个存储节点。然而，ndb_restore 并不总是能将一个 MySQL 版本的集群创建的备份恢复到运行不同 MySQL 版本的集群。有关更多信息，请参见 第 25.3.7 节“升级和降级 NDB 集群”。It is possible to restore a backup to a database with a different configuration than it was created from. For example, suppose that a backup with backup ID 12, created in a cluster with two storage nodes having the node IDs 2 and 3, is to be restored to a cluster with four nodes. Then ndb_restore must be run twice—once for each storage node in the cluster where the backup was taken. However, ndb_restore cannot always restore backups made from a cluster running one version of MySQL to a cluster running a different MySQL version. See Section 25.3.7, “Upgrading and Downgrading NDB Cluster”, for more information.

为了更快速的恢复，数据可以并行恢复，前提是有足够数量的集群连接可用。也就是说，当并行恢复到多个节点时，您必须为每个并发的 ndb_restore 进程在集群 config.ini 文件中拥有一个 [api] 或 [mysqld] 节。然而，数据文件必须始终在日志之前应用。For more rapid restoration, the data may be restored in parallel, provided that there is a sufficient number of cluster connections available. That is, when restoring to multiple nodes in parallel, you must have an [api] or [mysqld] section in the cluster config.ini file available for each concurrent ndb_restore process. However, the data files must always be applied before the logs.

--backup-password=password

此选项用于指定在使用 --decrypt 选项解密加密备份时使用的密码。此密码必须与用于加密备份的密码相同。This option specifies a password to be used when decrypting an encrypted backup with the --decrypt option. This must be the same password that was used to encrypt the backup.

密码长度必须为 1 到 256 个字符，并且必须用单引号或双引号括起来。它可以包含 ASCII 码为 32、35、38、40-91、93、95 和 97-126 的任意字符；换句话说，它可以使用任何可打印的 ASCII 字符，但不能使用 !、'、"、$、%、\ 和 ^。The password must be 1 to 256 characters in length, and must be enclosed by single or double quotation marks. It can contain any of the ASCII characters having character codes 32, 35, 38, 40-91, 93, 95, and 97-126; in other words, it can use any printable ASCII characters except for !, ', ", $, %, \, and ^.

可以省略密码，在这种情况下，ndb_restore 会等待从 stdin 提供密码，就像使用 --backup-password-from-stdin 时一样。It is possible to omit the password, in which case ndb_restore waits for it to be supplied from stdin, as when using --backup-password-from-stdin.

--backup-password-from-stdin[=TRUE|FALSE]

当用来替代 --backup-password 时，此选项允许从系统 shell (stdin) 输入备份密码，类似于在交互式向 mysql 提供密码时的方式，当使用 --password 且不在命令行上提供密码时。When used in place of --backup-password, this option enables input of the backup password from the system shell (stdin), similar to how this is done when supplying the password interactively to mysql when using the --password without supplying the password on the command line.

--backupid=#, -b

此选项是必需的；用于指定备份的 ID 或序列号，并且该编号与管理客户端在备份完成时显示的 Backup backup_id completed 消息中显示的编号相同。（参见 第 25.6.8.2 节，“使用 NDB 集群管理客户端创建备份”。）This option is required; it is used to specify the ID or sequence number of the backup, and is the same number shown by the management client in the Backup backup_id completed message displayed upon completion of a backup. (See Section 25.6.8.2, “Using The NDB Cluster Management Client to Create a Backup”.)

--character-sets-dir

包含字符集的目录。Directory containing character sets.

--connect, -c

是 --ndb-connectstring 的别名。Alias for --ndb-connectstring.

--connect-retries

放弃之前重试连接的次数。Number of times to retry connection before giving up.

--connect-retry-delay

尝试联系管理服务器之间等待的秒数。Number of seconds to wait between attempts to contact management server.

--connect-string

与 --ndb-connectstring 相同。Same as --ndb-connectstring.

--core-file

错误时生成核心文件；用于调试。Write core file on error; used in debugging.

--decrypt

使用通过--backup-password选项提供的密码解密备份。Decrypt an encrypted backup using the password supplied by the --backup-password option.

--defaults-extra-file

在读取全局文件之后读取给定文件。Read given file after global files are read.

--defaults-file

仅从指定文件读取默认选项。Read default options from given file only.

--defaults-group-suffix

也读取组合了 concat(group, suffix) 的组。Also read groups with concat(group, suffix).

--disable-indexes

在从原生 NDB 备份恢复数据时禁用索引的恢复。之后，您可以使用多线程索引构建通过 --rebuild-indexes 一次性为所有表恢复索引，这对于非常大的表比同时重建索引更快。Disable restoration of indexes during restoration of the data from a native NDB backup. Afterwards, you can restore indexes for all tables at once with multithreaded building of indexes using --rebuild-indexes, which should be faster than rebuilding indexes concurrently for very large tables.

此选项还会删除备份中指定的任何外键。This option also drops any foreign keys specified in the backup.

MySQL 可以打开一个 NDB 表，即使找不到一个或多个索引，只要查询不使用任何受影响的索引；否则查询将被拒绝，并显示 ER_NOT_KEYFILE。在后一种情况下，你可以通过执行如下 ALTER TABLE 语句暂时解决问题：MySQL can open an NDB table for which one or more indexes cannot be found, provided the query does not use any of the affected indexes; otherwise the query is rejected with ER_NOT_KEYFILE. In the latter case, you can temporarily work around the problem by executing an ALTER TABLE statement such as this one:

ALTER TABLE tbl ALTER INDEX idx INVISIBLE;

这会导致 MySQL 忽略表 tbl 上的索引 idx。有关更多信息，请参阅 主键和索引，以及 第 10.3.12 节，“不可见索引”。This causes MySQL to ignore the index idx on table tbl. See Primary Keys and Indexes, for more information, as well as Section 10.3.12, “Invisible Indexes”.

--dont-ignore-systab-0, -f

通常，在恢复表数据和元数据时，ndb_restore 会忽略备份中存在的 NDB 系统表的副本。--dont-ignore-systab-0 会导致系统表被恢复。此选项仅用于实验和开发目的，不建议在生产环境中使用。Normally, when restoring table data and metadata, ndb_restore ignores the copy of the NDB system table that is present in the backup. --dont-ignore-systab-0 causes the system table to be restored. This option is intended for experimental and development use only, and is not recommended in a production environment.

--exclude-databases=db-list

以逗号分隔的一个或多个数据库列表，这些数据库不应被恢复。Comma-delimited list of one or more databases which should not be restored.

此选项通常与 --exclude-tables 一起使用；有关更多信息和示例，请参阅该选项的描述。This option is often used in combination with --exclude-tables; see that option's description for further information and examples.

--exclude-intermediate-sql-tables[=TRUE|FALSE]

在执行复制 ALTER TABLE 操作时，mysqld 会创建中间表（其名称以 #sql- 为前缀）。当 TRUE 时，--exclude-intermediate-sql-tables 选项会阻止 ndb_restore 恢复可能由这些操作遗留下来的此类表。此选项默认值为 TRUE。When performing copying ALTER TABLE operations, mysqld creates intermediate tables (whose names are prefixed with #sql-). When TRUE, the --exclude-intermediate-sql-tables option keeps ndb_restore from restoring such tables that may have been left over from these operations. This option is TRUE by default.

--exclude-missing-columns

使用此选项可以仅恢复选定的表列，这会导致ndb_restore忽略与备份中表的版本相比，在恢复的表中缺失的任何列。此选项适用于所有正在恢复的表。如果您希望仅对选定的表或数据库应用此选项，可以将其与本节其他地方描述的一个或多个--include-*或--exclude-*选项组合使用，然后使用这些选项的互补组合将数据恢复到其余表中。It is possible to restore only selected table columns using this option, which causes ndb_restore to ignore any columns missing from tables being restored as compared to the versions of those tables found in the backup. This option applies to all tables being restored. If you wish to apply this option only to selected tables or databases, you can use it in combination with one or more of the --include-* or --exclude-* options described elsewhere in this section to do so, then restore data to the remaining tables using a complementary set of these options.

--exclude-missing-tables

可以使用此选项仅恢复选定的表，这会导致 ndb_restore 忽略在目标数据库中未找到的备份表。It is possible to restore only selected tables using this option, which causes ndb_restore to ignore any tables from the backup that are not found in the target database.

--exclude-tables=table-list

要排除的一个或多个表的列表；每个表引用必须包括数据库名称。通常与 --exclude-databases 一起使用。List of one or more tables to exclude; each table reference must include the database name. Often used together with --exclude-databases.

当使用 --exclude-databases 或 --exclude-tables 时，只有选项中指定的那些数据库或表会被排除；所有其他数据库和表将由 ndb_restore 恢复。When --exclude-databases or --exclude-tables is used, only those databases or tables named by the option are excluded; all other databases and tables are restored by ndb_restore.

此表显示了几次使用 ndb_restore 的调用，并使用 --exclude-* 选项（为了清晰可能省略了其他必需选项），以及这些选项对从 NDB Cluster 备份恢复的影响：This table shows several invocations of ndb_restore using --exclude-* options (other options possibly required have been omitted for clarity), and the effects these options have on restoring from an NDB Cluster backup:

你可以将这两个选项一起使用。例如，下面的操作会导致恢复所有数据库中的表，除了 数据库 db1 和 db2，以及数据库 db3 中的表 t1 和 t2：You can use these two options together. For example, the following causes all tables in all databases except for databases db1 and db2, and tables t1 and t2 in database db3, to be restored:

$> ndb_restore [...] --exclude-databases=db1,db2 --exclude-tables=db3.t1,db3.t2

（同样，为了清晰和简洁，上述示例中省略了其他可能必要的选项。）(Again, we have omitted other possibly necessary options in the interest of clarity and brevity from the example just shown.)

你可以同时使用 --include-* 和 --exclude-* 选项，但需遵循以下规则：You can use --include-* and --exclude-* options together, subject to the following rules:

例如，以下选项集会导致 ndb_restore 从数据库 db1 中恢复除 db1.t1 以外的所有表，同时不恢复任何其他数据库的表：For example, the following set of options causes ndb_restore to restore all tables from database db1 except db1.t1, while restoring no other tables from any other databases:

--include-databases=db1 --exclude-tables=db1.t1

然而，仅仅颠倒刚才给出的选项顺序，会导致恢复来自数据库 db1 的所有表（包括 db1.t1，但不会有任何其他数据库的表），因为最靠右的 --include-databases 选项首先匹配数据库 db1，因此优先于任何其他匹配 db1 或 db1 中的表的选项：However, reversing the order of the options just given simply causes all tables from database db1 to be restored (including db1.t1, but no tables from any other database), because the --include-databases option, being farthest to the right, is the first match against database db1 and thus takes precedence over any other option that matches db1 or any tables in db1:

--exclude-tables=db1.t1 --include-databases=db1

--fields-enclosed-by=char

每个列值都被传递给此选项的字符串包围（无论数据类型如何；参见 --fields-optionally-enclosed-by 的描述）。Each column value is enclosed by the string passed to this option (regardless of data type; see the description of --fields-optionally-enclosed-by).

--fields-optionally-enclosed-by

传递给此选项的字符串用于包围包含字符数据的列值（例如 CHAR、VARCHAR、BINARY、TEXT 或 ENUM）。The string passed to this option is used to enclose column values containing character data (such as CHAR, VARCHAR, BINARY, TEXT, or ENUM).

--fields-terminated-by=char

传递给此选项的字符串用于分隔列值。默认值是制表符 (\t)。The string passed to this option is used to separate column values. The default value is a tab character (\t).

--help

显示帮助文本并退出。Display help text and exit.

--hex

如果使用此选项，所有二进制值将以十六进制格式输出。If this option is used, all binary values are output in hexadecimal format.

--ignore-extended-pk-updates

使用 --allow-pk-changes 时，成为表主键部分的列在备份进行时不得更新；这些列应保持从插入数据起到包含这些值的行被删除之间的值不变。如果 ndb_restore 在恢复备份时遇到这些列的更新，恢复将失败。由于某些应用程序在更新行时可能会为所有列设置值，即使某些列值未被更改，备份可能会包含看似更新了实际上未修改的列的日志事件。在这种情况下，您可以将 --ignore-extended-pk-updates 设置为 1，强制 ndb_restore 忽略这些更新。When using --allow-pk-changes, columns which become part of a table's primary key must not be updated while the backup is being taken; such columns should keep the same values from the time values are inserted into them until the rows containing the values are deleted. If ndb_restore encounters updates to these columns when restoring a backup, the restore fails. Because some applications may set values for all columns when updating a row, even when some column values are not changed, the backup may include log events appearing to update columns which are not in fact modified. In such cases you can set --ignore-extended-pk-updates to 1, forcing ndb_restore to ignore such updates.

更多信息，请参阅 --allow-pk-changes 的描述。For more information, see the description of --allow-pk-changes.

--include-databases=db-list

以逗号分隔的一个或多个要还原的数据库列表。通常与--include-tables一起使用；有关进一步信息和示例，请参阅该选项的说明。Comma-delimited list of one or more databases to restore. Often used together with --include-tables; see the description of that option for further information and examples.

--include-stored-grants

ndb_restore 默认不会恢复共享用户和权限（参见 第 25.6.13 节，“权限同步与 NDB_STORED_USER”）到 ndb_sql_metadata 表。指定此选项会使其执行恢复。ndb_restore does not by default restore shared users and grants (see Section 25.6.13, “Privilege Synchronization and NDB_STORED_USER”) to the ndb_sql_metadata table. Specifying this option causes it to do so.

--include-tables=table-list

要恢复的表的逗号分隔列表；每个表引用必须包含数据库名称。Comma-delimited list of tables to restore; each table reference must include the database name.

当使用 --include-databases 或 --include-tables 时，只有那些由选项指定的数据库或表会被恢复；所有其他数据库和表会被 ndb_restore 排除，并且不会被恢复。When --include-databases or --include-tables is used, only those databases or tables named by the option are restored; all other databases and tables are excluded by ndb_restore, and are not restored.

下表显示了几种使用 ndb_restore 时使用 --include-* 选项的实例（为清楚起见，可能需要的其他选项已略去），以及这些选项对从 NDB Cluster 备份恢复的影响：The following table shows several invocations of ndb_restore using --include-* options (other options possibly required have been omitted for clarity), and the effects these have on restoring from an NDB Cluster backup:

您也可以将这两个选项一起使用。例如，以下操作会恢复数据库 db1 和 db2 中的所有表，以及数据库 db3 中的表 t1 和 t2（且不恢复其他任何数据库或表）：You can also use these two options together. For example, the following causes all tables in databases db1 and db2, together with the tables t1 and t2 in database db3, to be restored (and no other databases or tables):

$> ndb_restore [...] --include-databases=db1,db2 --include-tables=db3.t1,db3.t2

（同样，我们在上面的示例中省略了其他可能需要的选项。）(Again we have omitted other, possibly required, options in the example just shown.)

还可以仅恢复选定的数据库，或者从单个数据库中恢复选定的表，而无需任何 --include-*（或 --exclude-*）选项，使用此处显示的语法：It also possible to restore only selected databases, or selected tables from a single database, without any --include-* (or --exclude-*) options, using the syntax shown here:

ndb_restore other_options db_name,[db_name[,...] | tbl_name[,tbl_name][,...]]

换句话说，您可以指定下列任何一种进行恢复：In other words, you can specify either of the following to be restored:

--lines-terminated-by=char

指定用于结束每行输出的字符串。默认是换行符字符 (\n)。Specifies the string used to end each line of output. The default is a linefeed character (\n).

--login-path

从登录文件读取给定路径。Read given path from login file.

--no-login-paths

跳过从登录路径文件读取选项。Skips reading options from the login path file.

--lossy-conversions, -L

此选项旨在补充--promote-attributes选项。使用--lossy-conversions允许在从备份恢复数据时对列值进行有损转换（类型降级或符号变化）。在某些例外情况下，降级规则与 MySQL 复制相同；有关属性降级当前支持的特定类型转换的信息，请参见第 19.5.1.9.2 节，“具有不同数据类型的列的复制”。This option is intended to complement the --promote-attributes option. Using --lossy-conversions allows lossy conversions of column values (type demotions or changes in sign) when restoring data from backup. With some exceptions, the rules governing demotion are the same as for MySQL replication; see Section 19.5.1.9.2, “Replication of Columns Having Different Data Types”, for information about specific type conversions currently supported by attribute demotion.

此选项还可以将 NULL 列恢复为 NOT NULL。该列不能包含任何 NULL 条目；否则 ndb_restore 会报错并停止。This option also makes it possible to restore a NULL column as NOT NULL. The column must not contain any NULL entries; otherwise ndb_restore stops with an error.

ndb_restore 会在对每个属性和列进行有损转换时，报告其执行的任何数据截断。ndb_restore reports any truncation of data that it performs during lossy conversions once per attribute and column.

--no-binlog

此选项可防止任何已连接的 SQL 节点将由 ndb_restore 恢复的数据写入它们的二进制日志。This option prevents any connected SQL nodes from writing data restored by ndb_restore to their binary logs.

--no-restore-disk-objects, -d

此选项阻止 ndb_restore 恢复任何 NDB 集群磁盘数据对象，例如表空间和日志文件组；有关这些内容的更多信息，请参见 第 25.6.11 节，“NDB 集群磁盘表”。This option stops ndb_restore from restoring any NDB Cluster Disk Data objects, such as tablespaces and log file groups; see Section 25.6.11, “NDB Cluster Disk Data Tables”, for more information about these.

--no-upgrade, -u

在使用 ndb_restore 恢复备份时，使用旧固定格式创建的 VARCHAR 列会被调整大小并使用现在采用的可变宽格式重新创建。通过指定 --no-upgrade 可以覆盖此行为。When using ndb_restore to restore a backup, VARCHAR columns created using the old fixed format are resized and recreated using the variable-width format now employed. This behavior can be overridden by specifying --no-upgrade.

--ndb-connectstring

设置用于连接到 ndb_mgmd 的连接字符串。语法：[nodeid=id;][host=]hostname[:port]。覆盖 NDB_CONNECTSTRING 和 my.cnf 中的条目。Set connection string for connecting to ndb_mgmd. Syntax: [nodeid=id;][host=]hostname[:port]. Overrides entries in NDB_CONNECTSTRING and my.cnf.

--ndb-mgm-tls

设置连接到管理服务器所需的 TLS 支持级别；可以是 relaxed 或 strict。relaxed（默认）表示尝试建立 TLS 连接，但不要求成功；strict表示连接必须使用 TLS。Sets the level of TLS support required to connect to the management server; one of relaxed or strict. relaxed (the default) means that a TLS connection is attempted, but success is not required; strict means that TLS is required to connect.

--ndb-mgmd-host

与 --ndb-connectstring 相同。Same as --ndb-connectstring.

--ndb-nodegroup-map=map, -z

为此选项设置的任何值将被忽略，并且该选项本身不执行任何操作。Any value set for this option is ignored, and the option itself does nothing.

--ndb-nodeid

为此节点设置节点 ID，覆盖--ndb-connectstring 设置的任何 ID。Set node ID for this node, overriding any ID set by --ndb-connectstring.

--ndb-optimized-node-selection

启用事务节点选择的优化。默认启用；使用 --skip-ndb-optimized-node-selection 来禁用。Enable optimizations for selection of nodes for transactions. Enabled by default; use --skip-ndb-optimized-node-selection to disable.

--ndb-tls-search-path

指定用于搜索 CA 文件的目录列表。在 Unix 平台上，目录名称用冒号 (:) 分隔；在 Windows 系统上，使用分号 (;) 作为分隔符。目录引用可以是相对路径或绝对路径；它可以包含一个或多个环境变量，每个变量以美元符号 ($) 开头，并在使用前进行展开。Specify a list of directories to search for a CA file. On Unix platforms, the directory names are separated by colons (:); on Windows systems, the semicolon character (;) is used as the separator. A directory reference may be relative or absolute; it may contain one or more environment variables, each denoted by a prefixed dollar sign ($), and expanded prior to use.

搜索从最左边的命名目录开始，按从左到右的顺序进行，直到找到文件。空字符串表示空搜索路径，这会导致所有搜索失败。由单个点 (.) 组成的字符串表示搜索路径仅限于当前工作目录。Searching begins with the leftmost named directory and proceeds from left to right until a file is found. An empty string denotes an empty search path, which causes all searches to fail. A string consisting of a single dot (.) indicates that the search path limited to the current working directory.

如果未提供搜索路径，则使用编译时的默认值。此值取决于所使用的平台：在 Windows 上，它是 \ndb-tls；在其他平台（包括 Linux）上，它是 $HOME/ndb-tls。可以通过使用 -DWITH_NDB_TLS_SEARCH_PATH 编译 NDB Cluster 来覆盖该值。If no search path is supplied, the compiled-in default value is used. This value depends on the platform used: On Windows, this is \ndb-tls; on other platforms (including Linux), it is $HOME/ndb-tls. This can be overridden by compiling NDB Cluster using -DWITH_NDB_TLS_SEARCH_PATH.

--no-defaults

除了登录文件之外，不从任何配置文件读取默认选项。Do not read default options from any option file other than login file.

--nodeid=#, -n

指定备份时所在的数据节点的节点 ID；必填。Specify the node ID of the data node on which the backup was taken; required.

当恢复到的数据节点数量与备份时的数量不同的集群时，此信息有助于确定需要恢复到指定节点的正确文件集。（在这种情况下，通常需要将多个文件恢复到单个数据节点。）有关更多信息和示例，请参见 恢复到不同数量的数据节点。When restoring to a cluster with different number of data nodes from that where the backup was taken, this information helps identify the correct set or sets of files to be restored to a given node. (In such cases, multiple files usually need to be restored to a single data node.) See Restoring to a different number of data nodes, for additional information and examples.

--num-slices=#

在通过切片恢复备份时，此选项设置将备份划分为多少个切片。这样可以让多个 ndb_restore 实例并行恢复不重叠的子集，可能减少执行恢复操作所需的时间。When restoring a backup by slices, this option sets the number of slices into which to divide the backup. This allows multiple instances of ndb_restore to restore disjoint subsets in parallel, potentially reducing the amount of time required to perform the restore operation.

一个 片 是给定备份中数据的一个子集；也就是说，它是一组具有相同片 ID 的片段，可以使用 --slice-id 选项来指定。这两个选项必须始终一起使用，并且 --slice-id 设置的值必须始终小于片的数量。A slice is a subset of the data in a given backup; that is, it is a set of fragments having the same slice ID, specified using the --slice-id option. The two options must always be used together, and the value set by --slice-id must always be less than the number of slices.

ndb_restore 遇到碎片时，会为每个碎片分配一个碎片计数器。按切片恢复时，会为每个碎片分配一个切片 ID；该切片 ID 的范围从 0 到切片数减 1。对于非 BLOB 表的表，某个碎片所属的切片是使用此处显示的公式确定的：ndb_restore encounters fragments and assigns each one a fragment counter. When restoring by slices, a slice ID is assigned to each fragment; this slice ID is in the range 0 to 1 less than the number of slices. For a table that is not a BLOB table, the slice to which a given fragment belongs is determined using the formula shown here:

[slice_ID] = [fragment_counter] % [number_of_slices]

对于一个BLOB 表，不使用片段计数器；而是使用片段号，以及 BLOB 表的主表 ID（回想一下，NDB 内部将 BLOB 值存储在单独的表中）。在这种情况下，给定片段的切片 ID 计算方法如下所示：For a BLOB table, a fragment counter is not used; the fragment number is used instead, along with the ID of the main table for the BLOB table (recall that NDB stores BLOB values in a separate table internally). In this case, the slice ID for a given fragment is calculated as shown here:

[slice_ID] =
([main_table_ID] + [fragment_ID]) % [number_of_slices]

因此，通过 N 个切片进行恢复意味着运行 N 个 ndb_restore 实例，所有实例都使用 --num-slices=N（以及任何其他必要的选项），并且每个实例分别使用 --slice-id=1、--slice-id=2、--slice-id=3，依此类推，直到 slice-id=N-1。Thus, restoring by N slices means running N instances of ndb_restore, all with --num-slices=N (along with any other necessary options) and one each with --slice-id=1, --slice-id=2, --slice-id=3, and so on through slice-id=N-1.

示例。 假设您想要恢复一个名为 BACKUP-1 的备份，该备份位于每个数据节点文件系统的默认目录 /var/lib/mysql-cluster/BACKUP/BACKUP-3 中，将其恢复到一个拥有节点 ID 为 1、2、3 和 4 的四数据节点集群。要使用五个切片执行此操作，请执行下列命令集：Example.  Assume that you want to restore a backup named BACKUP-1, found in the default directory /var/lib/mysql-cluster/BACKUP/BACKUP-3 on the node file system on each data node, to a cluster with four data nodes having the node IDs 1, 2, 3, and 4. To perform this operation using five slices, execute the sets of commands shown in the following list:

您应该使用切片来仅恢复集群数据；在恢复元数据、索引或时期信息时，不必使用 --num-slices 或 --slice-id。如果在控制这些内容恢复的 ndb_restore 选项中使用了其中一个或两个选项，程序会忽略它们。You should use slicing to restore the cluster data only; it is not necessary to employ --num-slices or --slice-id when restoring the metadata, indexes, or epoch information. If either or both of these options are used with the ndb_restore options controlling restoration of these, the program ignores them.

The effects of using the --parallelism option on the speed of restoration are independent of those produced by slicing or parallel restoration using multiple instances of ndb_restore (--parallelism specifies the number of parallel transactions executed by a single ndb_restore thread), but it can be used together with either or both of these. You should be aware that increasing --parallelism causes ndb_restore to impose a greater load on the cluster; if the system can handle this, restoration should complete even more quickly.

--num-slices 的值不直接依赖于硬件相关的值，例如 CPU 数量或 CPU 核心数、内存大小等，也不依赖于 LDM 的数量。The value of --num-slices is not directly dependent on values relating to hardware such as number of CPUs or CPU cores, amount of RAM, and so forth, nor does it depend on the number of LDMs.

在同一恢复过程中，在不同的数据节点上使用不同的此选项值是可能的；仅此本身不应产生任何不良影响。It is possible to employ different values for this option on different data nodes as part of the same restoration; doing so should not in and of itself produce any ill effects.

--parallelism=#, -p

ndb_restore 使用单行事务以并发方式应用多行。此参数确定 ndb_restore 实例尝试使用的并行事务（并发行）数量。默认值为 128；最小值为 1，最大值为 1024。ndb_restore uses single-row transactions to apply many rows concurrently. This parameter determines the number of parallel transactions (concurrent rows) that an instance of ndb_restore tries to use. By default, this is 128; the minimum is 1, and the maximum is 1024.

执行插入操作的工作在参与的数据节点的线程之间并行化。该机制用于从 .Data 文件恢复批量数据——也就是数据的模糊快照；它不用于构建或重建索引。变更日志是串行应用的；索引删除和构建是 DDL 操作，并单独处理。恢复操作的客户端侧没有线程级并行。The work of performing the inserts is parallelized across the threads in the data nodes involved. This mechanism is employed for restoring bulk data from the .Data file—that is, the fuzzy snapshot of the data; it is not used for building or rebuilding indexes. The change log is applied serially; index drops and builds are DDL operations and handled separately. There is no thread-level parallelism on the client side of the restore.

--preserve-trailing-spaces, -P

在将固定宽度的字符数据类型提升为其可变宽度等效类型时保留尾随空格——也就是说，当将 CHAR 列值提升为 VARCHAR，或者将 BINARY 列值提升为 VARBINARY 时。否则，当将这些列值插入到新列中时，任何尾随空格都将被删除。Cause trailing spaces to be preserved when promoting a fixed-width character data type to its variable-width equivalent—that is, when promoting a CHAR column value to VARCHAR, or a BINARY column value to VARBINARY. Otherwise, any trailing spaces are dropped from such column values when they are inserted into the new columns.

--print

使 ndb_restore 将所有数据、元数据和日志打印到 stdout。等同于同时使用 --print-data、--print-meta 和 --print-log 选项。Causes ndb_restore to print all data, metadata, and logs to stdout. Equivalent to using the --print-data, --print-meta, and --print-log options together.

--print-data

使 ndb_restore 将其输出定向到 stdout。通常与一个或多个 --tab、--fields-enclosed-by、--fields-optionally-enclosed-by、--fields-terminated-by、--hex 以及 --append 一起使用。Cause ndb_restore to direct its output to stdout. Often used together with one or more of --tab, --fields-enclosed-by, --fields-optionally-enclosed-by, --fields-terminated-by, --hex, and --append.

TEXT 和 BLOB 列值总是被截断。这些值在输出中被截断为前 256 字节。目前在使用 --print-data 时无法覆盖此设置。TEXT and BLOB column values are always truncated. Such values are truncated to the first 256 bytes in the output. This cannot currently be overridden when using --print-data.

--print-defaults

打印程序参数列表然后退出。Print program argument list and exit.

--print-log

让 ndb_restore 将其日志输出到 stdout。Cause ndb_restore to output its log to stdout.

--print-meta

将所有元数据打印到 stdout。Print all metadata to stdout.

print-sql-log

将 SQL 语句记录到 stdout。使用此选项以启用；通常此行为是禁用的。该选项在尝试记录之前会检查所有正在恢复的表是否都明确定义了主键；对于仅由 NDB 实现的隐藏主键的表上的查询，无法转换为有效的 SQL。Log SQL statements to stdout. Use the option to enable; normally this behavior is disabled. The option checks before attempting to log whether all the tables being restored have explicitly defined primary keys; queries on a table having only the hidden primary key implemented by NDB cannot be converted to valid SQL.

此选项不适用于具有 BLOB 列的表。This option does not work with tables having BLOB columns.

--progress-frequency=N

在备份进行时，每 N 秒打印一次状态报告。0（默认值）表示不打印状态报告。最大值为 65535。Print a status report each N seconds while the backup is in progress. 0 (the default) causes no status reports to be printed. The maximum is 65535.

--promote-attributes, -A

ndb_restore 支持有限的属性提升，方式类似于 MySQL 复制中支持的方式；也就是说，从某一类型的列备份的数据通常可以恢复到使用“更大、相似”类型的列。例如，可以将 CHAR(20) 列的数据恢复到声明为 VARCHAR(20)、VARCHAR(30) 或 CHAR(30) 的列；将 MEDIUMINT 列的数据恢复到 INT 或 BIGINT 类型的列。有关属性提升当前支持的类型转换表，请参见 第 19.5.1.9.2 节，“不同数据类型列的复制”。ndb_restore supports limited attribute promotion in much the same way that it is supported by MySQL replication; that is, data backed up from a column of a given type can generally be restored to a column using a “larger, similar” type. For example, data from a CHAR(20) column can be restored to a column declared as VARCHAR(20), VARCHAR(30), or CHAR(30); data from a MEDIUMINT column can be restored to a column of type INT or BIGINT. See Section 19.5.1.9.2, “Replication of Columns Having Different Data Types”, for a table of type conversions currently supported by attribute promotion.

此选项还可以将一个 NOT NULL 列恢复为 NULL。This option also makes it possible to restore a NOT NULL column as NULL.

必须显式启用 ndb_restore 的属性提升，如下所示：Attribute promotion by ndb_restore must be enabled explicitly, as follows:

在字符数据类型与TEXT或BLOB之间进行转换时，只能同时进行字符类型（CHAR 和 VARCHAR）与二进制类型（BINARY 和 VARBINARY）之间的转换。例如，您不能在同一次调用 ndb_restore 时，同时将 INT 列提升为 BIGINT 并将 VARCHAR 列提升为 TEXT。When converting between character data types and TEXT or BLOB, only conversions between character types (CHAR and VARCHAR) and binary types (BINARY and VARBINARY) can be performed at the same time. For example, you cannot promote an INT column to BIGINT while promoting a VARCHAR column to TEXT in the same invocation of ndb_restore.

不支持在使用不同字符集的 TEXT 列之间进行转换，并且明确禁止这样做。Converting between TEXT columns using different character sets is not supported, and is expressly disallowed.

在使用 ndb_restore 将字符或二进制类型转换为 TEXT 或 BLOB 时，您可能会注意到它会创建并使用一个或多个名为 table_name$STnode_id 的临时表。这些表之后不再需要，通常在成功恢复后会由 ndb_restore 删除。When performing conversions of character or binary types to TEXT or BLOB with ndb_restore, you may notice that it creates and uses one or more staging tables named table_name$STnode_id. These tables are not needed afterwards, and are normally deleted by ndb_restore following a successful restoration.

--rebuild-indexes

在恢复本地 NDB 备份时启用有序索引的多线程重建。使用此选项时，由 ndb_restore 构建有序索引的线程数量由 BuildIndexThreads 数据节点配置参数以及 LDM 数量控制。Enable multithreaded rebuilding of the ordered indexes while restoring a native NDB backup. The number of threads used for building ordered indexes by ndb_restore with this option is controlled by the BuildIndexThreads data node configuration parameter and the number of LDMs.

仅在首次运行 ndb_restore 时才有必要使用此选项；这会导致所有有序索引在恢复后续节点时重建，而无需再次使用 --rebuild-indexes。你应该在向数据库插入新行之前使用此选项；否则，有可能插入的某行在稍后尝试重建索引时导致唯一约束冲突。It is necessary to use this option only for the first run of ndb_restore; this causes all ordered indexes to be rebuilt without using --rebuild-indexes again when restoring subsequent nodes. You should use this option prior to inserting new rows into the database; otherwise, it is possible for a row to be inserted that later causes a unique constraint violation when trying to rebuild the indexes.

默认情况下，有序索引的构建会根据 LDM 的数量并行化。在节点和系统重启期间执行的离线索引构建可以使用 BuildIndexThreads 数据节点配置参数加快；该参数对在线执行的 ndb_restore 删除和重建索引无效。Building of ordered indices is parallelized with the number of LDMs by default. Offline index builds performed during node and system restarts can be made faster using the BuildIndexThreads data node configuration parameter; this parameter has no effect on dropping and rebuilding of indexes by ndb_restore, which is performed online.

重建唯一索引会使用磁盘写入带宽用于重做日志记录和本地检查点。如果该带宽不足，可能会导致重做缓冲区过载或日志过载错误。在这种情况下，您可以再次运行 ndb_restore --rebuild-indexes；该过程会从错误发生的点继续。您也可以在遇到临时错误时执行此操作。您可以无限次重复执行 ndb_restore --rebuild-indexes；通过降低 --parallelism 的值，您可能能够阻止此类错误。如果问题是空间不足，您可以增加重做日志的大小（FragmentLogFileSize 节点配置参数），或者可以增加执行 LCP 的速度（MaxDiskWriteSpeed 及相关参数），以便更快释放空间。Rebuilding of unique indexes uses disk write bandwidth for redo logging and local checkpointing. An insufficient amount of this bandwidth can lead to redo buffer overload or log overload errors. In such cases you can run ndb_restore --rebuild-indexes again; the process resumes at the point where the error occurred. You can also do this when you have encountered temporary errors. You can repeat execution of ndb_restore --rebuild-indexes indefinitely; you may be able to stop such errors by reducing the value of --parallelism. If the problem is insufficient space, you can increase the size of the redo log (FragmentLogFileSize node configuration parameter), or you can increase the speed at which LCPs are performed (MaxDiskWriteSpeed and related parameters), in order to free space more quickly.

--remap-column=db.tbl.col:fn:args

与 --restore-data 一起使用时，此选项会将函数应用于指定列的值。参数字符串中的值列在这里：When used together with --restore-data, this option applies a function to the value of the indicated column. Values in the argument string are listed here:

This option can be useful when you wish to merge data stored in multiple source instances of NDB Cluster (all using the same schema) into a single destination NDB Cluster, using NDB native backup (see Section 25.6.8.2, “Using The NDB Cluster Management Client to Create a Backup”) and ndb_restore to merge the data, where primary and unique key values are overlapping between source clusters, and it is necessary as part of the process to remap these values to ranges that do not overlap. It may also be necessary to preserve other relationships between tables. To fulfill such requirements, it is possible to use the option multiple times in the same invocation of ndb_restore to remap columns of different tables, as shown here:

$> ndb_restore --restore-data --remap-column=hr.employee.id:offset:1000 \
    --remap-column=hr.manager.id:offset:1000 --remap-column=hr.firstaiders.id:offset:1000

（这里未显示的其他选项也可以使用。）(Other options not shown here may also be used.)

--remap-column 也可以用于更新同一表的多个列。可以组合多个表和列的操作。不同的列也可以使用不同的偏移值，如下所示：--remap-column can also be used to update multiple columns of the same table. Combinations of multiple tables and columns are possible. Different offset values can also be used for different columns of the same table, like this:

$> ndb_restore --restore-data --remap-column=hr.employee.salary:offset:10000 \
    --remap-column=hr.employee.hours:offset:-10

当源备份包含不应合并的重复表时，可以使用 --exclude-tables、--exclude-databases，或者通过应用程序中的其他方式来处理。When source backups contain duplicate tables which should not be merged, you can handle this by using --exclude-tables, --exclude-databases, or by some other means in your application.

可以使用 SHOW CREATE TABLE、ndb_desc 工具，以及 MAX()、MIN()、LAST_INSERT_ID() 和其他 MySQL 函数，获取要合并的表的结构和其他特性信息。Information about the structure and other characteristics of tables to be merged can obtained using SHOW CREATE TABLE; the ndb_desc tool; and MAX(), MIN(), LAST_INSERT_ID(), and other MySQL functions.

在 NDB Cluster 的不同实例中，不支持将已合并表的变更复制到未合并表，或将未合并表的变更复制到已合并表。Replication of changes from merged to unmerged tables, or from unmerged to merged tables, in separate instances of NDB Cluster is not supported.

--restore-data, -r

输出 NDB 表数据和日志。Output NDB table data and logs.

--restore-epoch, -e

向集群复制状态表添加（或恢复）epoch 信息。这对于在 NDB 集群副本上启动复制非常有用。当使用此选项时，如果mysql.ndb_apply_status表中id列为0的行已存在，则对其进行更新；如果该行不存在，则插入该行。（见第 25.7.9 节，“具有 NDB 集群复制的 NDB 集群备份”。）Add (or restore) epoch information to the cluster replication status table. This is useful for starting replication on an NDB Cluster replica. When this option is used, the row in the mysql.ndb_apply_status having 0 in the id column is updated if it already exists; such a row is inserted if it does not already exist. (See Section 25.7.9, “NDB Cluster Backups With NDB Cluster Replication”.)

--restore-meta, -m

此选项会使 ndb_restore 打印 NDB 表元数据。This option causes ndb_restore to print NDB table metadata.

第一次运行 ndb_restore 恢复程序时，你还需要恢复元数据。换句话说，你必须重新创建表——这可以通过使用 --restore-meta (-m) 选项运行来完成。元数据的恢复只需在单个数据节点上进行，这就足以将其恢复到整个集群。The first time you run the ndb_restore restoration program, you also need to restore the metadata. In other words, you must re-create the database tables—this can be done by running it with the --restore-meta (-m) option. Restoring the metadata need be done only on a single data node; this is sufficient to restore it to the entire cluster.

ndb_restore 使用目标集群的默认分区数，除非本地数据管理器线程数也从原集群的数据节点设置修改过。ndb_restore uses the default number of partitions for the target cluster, unless the number of local data manager threads is also changed from what it was for data nodes in the original cluster.

使用此选项时，建议通过设置 ndb_metadata_check=OFF 禁用自动同步，直到 ndb_restore 完成元数据恢复，然后可以重新启用它以同步 NDB 字典中新创建的对象。When using this option, it is recommended that auto synchronization be disabled by setting ndb_metadata_check=OFF until ndb_restore has completed restoring the metadata, after which it can it turned on again to synchronize objects newly created in the NDB dictionary.

--restore-privilege-tables

不再使用。No longer used.

--rewrite-database=olddb,newdb

此选项可以将数据恢复到名称与备份中使用的名称不同的数据库。例如，如果对名为 products 的数据库进行了备份，您可以将其包含的数据恢复到名为 inventory 的数据库中，如下所示使用此选项（省略可能需要的其他选项）：This option makes it possible to restore to a database having a different name from that used in the backup. For example, if a backup is made of a database named products, you can restore the data it contains to a database named inventory, use this option as shown here (omitting any other options that might be required):

$> ndb_restore --rewrite-database=product,inventory

该选项可以在单次调用 ndb_restore 时使用多次。因此，可以使用 db1 同时将名为 db2 的数据库恢复到名为 db3 的数据库，并将名为 db4 的数据库恢复到名为 --rewrite-database=db1,db2 --rewrite-database=db3,db4 的数据库。在多次出现的 --rewrite-database 之间，还可以使用其他 ndb_restore 选项。The option can be employed multiple times in a single invocation of ndb_restore. Thus it is possible to restore simultaneously from a database named db1 to a database named db2 and from a database named db3 to one named db4 using --rewrite-database=db1,db2 --rewrite-database=db3,db4. Other ndb_restore options may be used between multiple occurrences of --rewrite-database.

在多个 --rewrite-database 选项之间发生冲突的情况下，从左到右使用的最后一个 --rewrite-database 选项将生效。例如，如果使用 --rewrite-database=db1,db2 --rewrite-database=db1,db3，则仅 --rewrite-database=db1,db3 会被采纳，而 --rewrite-database=db1,db2 将被忽略。也可以将多个数据库恢复到同一个数据库，因此 --rewrite-database=db1,db3 --rewrite-database=db2,db3 会将数据库 db1 和 db2 的所有表和数据恢复到数据库 db3。In the event of conflicts between multiple --rewrite-database options, the last --rewrite-database option used, reading from left to right, is the one that takes effect. For example, if --rewrite-database=db1,db2 --rewrite-database=db1,db3 is used, only --rewrite-database=db1,db3 is honored, and --rewrite-database=db1,db2 is ignored. It is also possible to restore from multiple databases to a single database, so that --rewrite-database=db1,db3 --rewrite-database=db2,db3 restores all tables and data from databases db1 and db2 into database db3.

--skip-broken-objects

此选项会导致 ndb_restore 在读取原生 NDB 备份时忽略损坏的表，并继续恢复任何剩余的表（没有损坏的表）。当前，--skip-broken-objects 选项仅在缺少 blob 部件表的情况下有效。This option causes ndb_restore to ignore corrupt tables while reading a native NDB backup, and to continue restoring any remaining tables (that are not also corrupted). Currently, the --skip-broken-objects option works only in the case of missing blob parts tables.

--skip-fk-checks

此选项修改ndb_restore --rebuild-indexes 的行为，以便在重新启用外键时，不检查表中现有数据的一致性。This option modifies the behavior of ndb_restore --rebuild-indexes so that, when foreign keys are re-enabled, the existing data in the table is not checked for consistency.

--skip-table-check, -s

可以在不恢复表元数据的情况下恢复数据。默认情况下，在执行此操作时，如果表数据与表模式不匹配，ndb_restore 会因错误而失败；此选项会覆盖该行为。It is possible to restore data without restoring table metadata. By default when doing this, ndb_restore fails with an error if a mismatch is found between the table data and the table schema; this option overrides that behavior.

在使用ndb_restore恢复数据时，对列定义不匹配的一些限制有所放宽；当遇到这些类型的不匹配时，ndb_restore不会像以前那样立即报错停止，而是接受数据并将其插入目标表，同时向用户发出警告，提示正在进行此操作。无论是否使用--skip-table-check选项或--promote-attributes选项，此行为都会发生。列定义的这些差异类型如下：Some of the restrictions on mismatches in column definitions when restoring data using ndb_restore are relaxed; when one of these types of mismatches is encountered, ndb_restore does not stop with an error as it did previously, but rather accepts the data and inserts it into the target table while issuing a warning to the user that this is being done. This behavior occurs whether or not either of the options --skip-table-check or --promote-attributes is in use. These differences in column definitions are of the following types:

--skip-unknown-objects

此选项使 ndb_restore 在读取本地 NDB 备份时忽略其不识别的任何模式对象。这可以用于将来自运行（例如）NDB 7.6 的集群的备份恢复到运行 NDB 集群 7.5 的集群。This option causes ndb_restore to ignore any schema objects it does not recognize while reading a native NDB backup. This can be used for restoring a backup made from a cluster running (for example) NDB 7.6 to a cluster running NDB Cluster 7.5.

--slice-id=#

在按片恢复时，这是要恢复的片的 ID。此选项总是与 --num-slices 一起使用，其值必须始终小于 --num-slices 的值。When restoring by slices, this is the ID of the slice to restore. This option is always used together with --num-slices, and its value must be always less than that of --num-slices.

有关更多信息，请参见本节其他地方对 --num-slices 的描述。For more information, see the description of the --num-slices elsewhere in this section.

--tab=dir_name, -T dir_name

使 --print-data 创建转储文件，每个表一个文件，每个文件命名为 tbl_name.txt。它需要一个参数，即要保存文件的目录路径；使用 . 表示当前目录。Causes --print-data to create dump files, one per table, each named tbl_name.txt. It requires as its argument the path to the directory where the files should be saved; use . for the current directory.

--timestamp-printouts

使信息、错误和调试日志消息带有时间戳前缀。Causes info, error, and debug log messages to be prefixed with timestamps.

此选项默认启用。使用 --timestamp-printouts=false 可禁用。This option is enabled by default. Disable it with --timestamp-printouts=false.

--usage

显示帮助文本并退出；与 --help 相同。Display help text and exit; same as --help.

--verbose=#

设置输出的详细程度。最小值为 0；最大值为 255。默认值为 1。Sets the level for the verbosity of the output. The minimum is 0; the maximum is 255. The default value is 1.

--version

显示版本信息并退出。Display version information and exit.

--with-apply-status

从备份的ndb_apply_status表中恢复所有行（除server_id = 0的行外，该行是使用--restore-epoch生成的）。此选项需要同时使用--restore-data。Restore all rows from the backup's ndb_apply_status table (except for the row having server_id = 0, which is generated using --restore-epoch). This option requires that --restore-data also be used.

如果备份中的 ndb_apply_status 表已经包含 server_id = 0 的行，ndb_restore --with-apply-status 会将其删除。因此，我们建议在使用 ndb_restore --with-apply-status 选项恢复后，再使用 ndb_restore --restore-epoch。你也可以在任何一次使用 ndb_restore --with-apply-status 恢复集群的最后一次调用时，同时使用 --restore-epoch。If the ndb_apply_status table from the backup already contains a row with server_id = 0, ndb_restore --with-apply-status deletes it. For this reason, we recommend that you use ndb_restore --restore-epoch after invoking ndb_restore with the --with-apply-status option. You can also use --restore-epoch concurrently with the last of any invocations of ndb_restore --with-apply-status used to restore the cluster.

欲了解更多信息，请参见 ndb_apply_status 表。For more information, see ndb_apply_status Table.