Postgresql 中文操作指南

pg_restore

pg_restore — 通过 pg_dump 创建的存档文件还原 PostgreSQL 数据库

pg_restore — restore a PostgreSQL database from an archive file created by pg_dump

Synopsis

pg_restore [ connection-option …​] [ option …​] [ filename ]

pg_restore [connection-option…​] [option…​] [filename]

Description

pg_restore 是一个用于从 pg_dump 以非纯文本格式创建的存档中还原 PostgreSQL 数据库的实用程序。它将发出必要的命令，以将数据库恢复到其保存时的状态。存档文件还允许 pg_restore 对还原内容进行选择，甚至可以在还原之前重新排列项目。存档文件被设计为可跨体系结构移植。

pg_restore is a utility for restoring a PostgreSQL database from an archive created by pg_dump in one of the non-plain-text formats. It will issue the commands necessary to reconstruct the database to the state it was in at the time it was saved. The archive files also allow pg_restore to be selective about what is restored, or even to reorder the items prior to being restored. The archive files are designed to be portable across architectures.

pg_restore 可以以两种模式运行。如果指定了数据库名称，pg_restore 将连接到该数据库，并将存档内容直接还原到该数据库。否则，将创建一个包含用于重建数据库的 SQL 命令的脚本，并将此脚本写入文件或标准输出。此脚本输出等效于 pg_dump 的纯文本输出格式。因此，用于控制输出的一些选项与 pg_dump 的类似。

pg_restore can operate in two modes. If a database name is specified, pg_restore connects to that database and restores archive contents directly into the database. Otherwise, a script containing the SQL commands necessary to rebuild the database is created and written to a file or standard output. This script output is equivalent to the plain text output format of pg_dump. Some of the options controlling the output are therefore analogous to pg_dump options.

显而易见的是，pg_restore 无法还原存档文件中不存在的信息。例如，如果使用“将数据转储为 INSERT 命令”选项创建存档，pg_restore 将无法使用 COPY 语句加载数据。

Obviously, pg_restore cannot restore information that is not present in the archive file. For instance, if the archive was made using the “dump data as INSERT commands” option, pg_restore will not be able to load the data using COPY statements.

Options

pg_restore 接受以下命令行参数。

pg_restore accepts the following command line arguments.

  • filename

    • Specifies the location of the archive file (or directory, for a directory-format archive) to be restored. If not specified, the standard input is used.

  • -a_—​data-only_

    • Restore only the data, not the schema (data definitions). Table data, large objects, and sequence values are restored, if present in the archive.

    • This option is similar to, but for historical reasons not identical to, specifying —​section=data.

  • -c_—​clean_

    • Before restoring database objects, issue commands to DROP all the objects that will be restored. This option is useful for overwriting an existing database. If any of the objects do not exist in the destination database, ignorable error messages will be reported, unless —​if-exists is also specified.

  • -C_—​create_

    • Create the database before restoring into it. If —​clean is also specified, drop and recreate the target database before connecting to it.

    • With —​create, pg_restore also restores the database’s comment if any, and any configuration variable settings that are specific to this database, that is, any ALTER DATABASE …​ SET …​ and ALTER ROLE …​ IN DATABASE …​ SET …​ commands that mention this database. Access privileges for the database itself are also restored, unless —​no-acl is specified.

    • When this option is used, the database named with -d is used only to issue the initial DROP DATABASE and CREATE DATABASE commands. All data is restored into the database name that appears in the archive.

  • -d _dbname—​dbname=_dbname

    • Connect to database dbname and restore directly into the database. The dbname can be a connection string. If so, connection string parameters will override any conflicting command line options.

  • -e_—​exit-on-error_

    • Exit if an error is encountered while sending SQL commands to the database. The default is to continue and to display a count of errors at the end of the restoration.

  • -f _filename—​file=_filename

    • Specify output file for generated script, or for the listing when used with -l. Use - for stdout.

  • -F _format—​format=_format

    • Specify format of the archive. It is not necessary to specify the format, since pg_restore will determine the format automatically. If specified, it can be one of the following:

  • -I _index—​index=_index

    • Restore definition of named index only. Multiple indexes may be specified with multiple -I switches.

  • -j _number-of-jobs—​jobs=_number-of-jobs

    • Run the most time-consuming steps of pg_restore — those that load data, create indexes, or create constraints — concurrently, using up to number-of-jobs concurrent sessions. This option can dramatically reduce the time to restore a large database to a server running on a multiprocessor machine. This option is ignored when emitting a script rather than connecting directly to a database server.

    • Each job is one process or one thread, depending on the operating system, and uses a separate connection to the server.

    • The optimal value for this option depends on the hardware setup of the server, of the client, and of the network. Factors include the number of CPU cores and the disk setup. A good place to start is the number of CPU cores on the server, but values larger than that can also lead to faster restore times in many cases. Of course, values that are too high will lead to decreased performance because of thrashing.

    • Only the custom and directory archive formats are supported with this option. The input must be a regular file or directory (not, for example, a pipe or standard input). Also, multiple jobs cannot be used together with the option —​single-transaction.

  • -l_—​list_

    • List the table of contents of the archive. The output of this operation can be used as input to the -L option. Note that if filtering switches such as -n or -t are used with -l, they will restrict the items listed.

  • -L _list-file—​use-list=_list-file

    • Restore only those archive elements that are listed in list-file, and restore them in the order they appear in the file. Note that if filtering switches such as -n or -t are used with -L, they will further restrict the items restored.

    • list-file is normally created by editing the output of a previous -l operation. Lines can be moved or removed, and can also be commented out by placing a semicolon (;) at the start of the line. See below for examples.

  • -n _schema—​schema=_schema

    • Restore only objects that are in the named schema. Multiple schemas may be specified with multiple -n switches. This can be combined with the -t option to restore just a specific table.

  • -N _schema—​exclude-schema=_schema

    • Do not restore objects that are in the named schema. Multiple schemas to be excluded may be specified with multiple -N switches.

    • When both -n and -N are given for the same schema name, the -N switch wins and the schema is excluded.

  • -O_—​no-owner_

    • Do not output commands to set ownership of objects to match the original database. By default, pg_restore issues ALTER OWNER or SET SESSION AUTHORIZATION statements to set ownership of created schema elements. These statements will fail unless the initial connection to the database is made by a superuser (or the same user that owns all of the objects in the script). With -O, any user name can be used for the initial connection, and this user will own all the created objects.

  • -P _function-name(argtype [, …​])—​function=_function-name(argtype [, …​])

    • Restore the named function only. Be careful to spell the function name and arguments exactly as they appear in the dump file’s table of contents. Multiple functions may be specified with multiple -P switches.

  • -R_—​no-reconnect_

    • This option is obsolete but still accepted for backwards compatibility.

  • -s_—​schema-only_

    • Restore only the schema (data definitions), not data, to the extent that schema entries are present in the archive.

    • This option is the inverse of —​data-only. It is similar to, but for historical reasons not identical to, specifying —​section=pre-data --section=post-data.

    • (Do not confuse this with the —​schema option, which uses the word “schema” in a different meaning.)

  • -S _username—​superuser=_username

    • Specify the superuser user name to use when disabling triggers. This is relevant only if —​disable-triggers is used.

  • -t _table—​table=_table

    • Restore definition and/or data of only the named table. For this purpose, “table” includes views, materialized views, sequences, and foreign tables. Multiple tables can be selected by writing multiple -t switches. This option can be combined with the -n option to specify table(s) in a particular schema.

  • -T _trigger—​trigger=_trigger

    • Restore named trigger only. Multiple triggers may be specified with multiple -T switches.

  • -v_—​verbose_

    • Specifies verbose mode. This will cause pg_restore to output detailed object comments and start/stop times to the output file, and progress messages to standard error. Repeating the option causes additional debug-level messages to appear on standard error.

  • -V_—​version_

    • Print the pg_restore version and exit.

  • -x—​no-privileges_—​no-acl_

    • Prevent restoration of access privileges (grant/revoke commands).

  • -1_—​single-transaction_

    • Execute the restore as a single transaction (that is, wrap the emitted commands in BEGIN/COMMIT). This ensures that either all the commands complete successfully, or no changes are applied. This option implies —​exit-on-error.

  • —​disable-triggers

    • This option is relevant only when performing a data-only restore. It instructs pg_restore to execute commands to temporarily disable triggers on the target tables while the data is restored. Use this if you have referential integrity checks or other triggers on the tables that you do not want to invoke during data restore.

    • Presently, the commands emitted for —​disable-triggers must be done as superuser. So you should also specify a superuser name with -S or, preferably, run pg_restore as a PostgreSQL superuser.

  • —​enable-row-security

    • This option is relevant only when restoring the contents of a table which has row security. By default, pg_restore will set row_security to off, to ensure that all data is restored in to the table. If the user does not have sufficient privileges to bypass row security, then an error is thrown. This parameter instructs pg_restore to set row_security to on instead, allowing the user to attempt to restore the contents of the table with row security enabled. This might still fail if the user does not have the right to insert the rows from the dump into the table.

    • Note that this option currently also requires the dump be in INSERT format, as COPY FROM does not support row security.

  • —​if-exists

    • Use DROP …​ IF EXISTS commands to drop objects in —​clean mode. This suppresses “does not exist” errors that might otherwise be reported. This option is not valid unless —​clean is also specified.

  • —​no-comments

    • Do not output commands to restore comments, even if the archive contains them.

  • —​no-data-for-failed-tables

    • By default, table data is restored even if the creation command for the table failed (e.g., because it already exists). With this option, data for such a table is skipped. This behavior is useful if the target database already contains the desired table contents. For example, auxiliary tables for PostgreSQL extensions such as PostGIS might already be loaded in the target database; specifying this option prevents duplicate or obsolete data from being loaded into them.

    • This option is effective only when restoring directly into a database, not when producing SQL script output.

  • —​no-publications

    • Do not output commands to restore publications, even if the archive contains them.

  • —​no-security-labels

    • Do not output commands to restore security labels, even if the archive contains them.

  • —​no-subscriptions

    • Do not output commands to restore subscriptions, even if the archive contains them.

  • —​no-table-access-method

    • Do not output commands to select table access methods. With this option, all objects will be created with whichever access method is the default during restore.

  • —​no-tablespaces

    • Do not output commands to select tablespaces. With this option, all objects will be created in whichever tablespace is the default during restore.

  • —​section=_sectionname_

    • Only restore the named section. The section name can be pre-data, data, or post-data. This option can be specified more than once to select multiple sections. The default is to restore all sections.

    • The data section contains actual table data as well as large-object definitions. Post-data items consist of definitions of indexes, triggers, rules and constraints other than validated check constraints. Pre-data items consist of all other data definition items.

  • —​strict-names

    • Require that each schema (-n/—​schema) and table (-t/—​table) qualifier match at least one schema/table in the backup file.

  • —​use-set-session-authorization

    • Output SQL-standard SET SESSION AUTHORIZATION commands instead of ALTER OWNER commands to determine object ownership. This makes the dump more standards-compatible, but depending on the history of the objects in the dump, might not restore properly.

  • -?_—​help_

    • Show help about pg_restore command line arguments, and exit.

  • c__custom

    • The archive is in the custom format of pg_dump.

  • d__directory

    • The archive is a directory archive.

  • t__tar

    • The archive is a tar archive.

Note

当指定 -t 时，pg_restore 不会尝试恢复选定表可能依赖的任何其他数据库对象。因此，无法保证将特定表恢复到干净的数据库中肯定会成功。

When -t is specified, pg_restore makes no attempt to restore any other database objects that the selected table(s) might depend upon. Therefore, there is no guarantee that a specific-table restore into a clean database will succeed.

Note

此标志的行为与 pg_dump 的 -t 标志并不完全相同。目前 pg_restore 中未提供通配符匹配的规定，也无法在其 -t 中包含架构名。并且，尽管 pg_dump 的 -t 标志还会转储选定表的子对象（如索引），但 pg_restore 的 -t 标志不包括此类子对象。

This flag does not behave identically to the -t flag of pg_dump. There is not currently any provision for wild-card matching in pg_restore, nor can you include a schema name within its -t. And, while pg_dump’s -t flag will also dump subsidiary objects (such as indexes) of the selected table(s), pg_restore’s -t flag does not include such subsidiary objects.

Note

在 PostgreSQL 9.6 之前的版本中，此标志仅匹配表，不匹配任何其他类型的关联。

In versions prior to PostgreSQL 9.6, this flag matched only tables, not any other type of relation.

pg_restore 也接受以下命令行参数以用于连接参数：

pg_restore also accepts the following command line arguments for connection parameters:

  • -h _host—​host=_host

    • Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix domain socket. The default is taken from the PGHOST environment variable, if set, else a Unix domain socket connection is attempted.

  • -p _port—​port=_port

    • Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections. Defaults to the PGPORT environment variable, if set, or a compiled-in default.

  • -U _username—​username=_username

    • User name to connect as.

  • -w_—​no-password_

    • Never issue a password prompt. If the server requires password authentication and a password is not available by other means such as a .pgpass file, the connection attempt will fail. This option can be useful in batch jobs and scripts where no user is present to enter a password.

  • -W_—​password_

    • Force pg_restore to prompt for a password before connecting to a database.

    • This option is never essential, since pg_restore will automatically prompt for a password if the server demands password authentication. However, pg_restore will waste a connection attempt finding out that the server wants a password. In some cases it is worth typing -W to avoid the extra connection attempt.

  • —​role=_rolename_

    • Specifies a role name to be used to perform the restore. This option causes pg_restore to issue a SET ROLE rolename command after connecting to the database. It is useful when the authenticated user (specified by -U) lacks privileges needed by pg_restore, but can switch to a role with the required rights. Some installations have a policy against logging in directly as a superuser, and use of this option allows restores to be performed without violating the policy.

Environment

  • PGHOST_PGOPTIONS_PGPORT__PGUSER

    • Default connection parameters

  • PG_COLOR

    • Specifies whether to use color in diagnostic messages. Possible values are always, auto and never.

此实用程序与大多数其他 PostgreSQL 实用程序一样，也使用 libpq 所支持的环境变量（请参阅 Section 34.15 ）。但是，当未提供数据库名称时，它不读取 PGDATABASE 。

This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 34.15). However, it does not read PGDATABASE when a database name is not supplied.

Diagnostics

当使用 -d 选项指定直接数据库连接时，pg_restore 会在内部执行 SQL 语句。如果您在运行 pg_restore 时遇到问题，请确保您能够使用 SQL 从数据库中选择信息，例如使用 psql 。此外，libpq 前端库使用的任何默认连接设置和环境变量都将适用。

When a direct database connection is specified using the -d option, pg_restore internally executes SQL statements. If you have problems running pg_restore, make sure you are able to select information from the database using, for example, psql. Also, any default connection settings and environment variables used by the libpq front-end library will apply.

Notes

如果你的安装在 template1 数据库中有任何本地内容，请谨慎将 pg_restore 的输出加载到一个真正的空数据库中；否则，由于添加对象有重复定义，你可能会遇到错误。若要生成没有任何本地内容的空数据库，请从 template0 中复制，不要从 template1 中复制，例如：

If your installation has any local additions to the template1 database, be careful to load the output of pg_restore into a truly empty database; otherwise you are likely to get errors due to duplicate definitions of the added objects. To make an empty database without any local additions, copy from template0 not template1, for example:

CREATE DATABASE foo WITH TEMPLATE template0;

pg_restore 的局限性如下。

The limitations of pg_restore are detailed below.

另请参阅 pg_dump 文档，了解 pg_dump 的局限性详情。

See also the pg_dump documentation for details on limitations of pg_dump.

恢复后，最好对每个已恢复的表格运行 ANALYZE ，以便优化器有有用的统计信息；请参阅 Section 25.1.3 和 Section 25.1.6 了解更多信息。

Once restored, it is wise to run ANALYZE on each restored table so the optimizer has useful statistics; see Section 25.1.3 and Section 25.1.6 for more information.

Examples

假设我们已将名为 mydb 的数据库转储到自定义格式转储文件中：

Assume we have dumped a database called mydb into a custom-format dump file:

$ pg_dump -Fc mydb > db.dump

若要删除该数据库并从该转储中重新创建该数据库：

To drop the database and recreate it from the dump:

$ dropdb mydb
$ pg_restore -C -d postgres db.dump

在 -d 开关中命名的数据库可以是集群中存在的任何数据库；pg_restore 只使用它来针对 mydb 发出 CREATE DATABASE 命令。借助 -C ，数据始终恢复到转储文件中出现的数据库名称中。

The database named in the -d switch can be any database existing in the cluster; pg_restore only uses it to issue the CREATE DATABASE command for mydb. With -C, data is always restored into the database name that appears in the dump file.

若要将转储恢复到名为 newdb 的新数据库中：

To restore the dump into a new database called newdb:

$ createdb -T template0 newdb
$ pg_restore -d newdb db.dump

请注意，我们不使用 -C ，而是直接连接到要恢复到的数据库。另外请注意，我们克隆 template0 中的新数据库，而不是 template1 ，以确保它最初是空的。

Notice we don’t use -C, and instead connect directly to the database to be restored into. Also note that we clone the new database from template0 not template1, to ensure it is initially empty.

若要重新排序数据库项，首先必须转储存档的目录表：

To reorder database items, it is first necessary to dump the table of contents of the archive:

$ pg_restore -l db.dump > db.list

清单文件由一个头文件和每一项的一行组成，例如：

The listing file consists of a header and one line for each item, e.g.:

;
; Archive created at Mon Sep 14 13:55:39 2009
;     dbname: DBDEMOS
;     TOC Entries: 81
;     Compression: 9
;     Dump Version: 1.10-0
;     Format: CUSTOM
;     Integer: 4 bytes
;     Offset: 8 bytes
;     Dumped from database version: 8.3.5
;     Dumped by pg_dump version: 8.3.8
;
;
; Selected TOC Entries:
;
3; 2615 2200 SCHEMA - public pasha
1861; 0 0 COMMENT - SCHEMA public pasha
1862; 0 0 ACL - public pasha
317; 1247 17715 TYPE public composite pasha
319; 1247 25899 DOMAIN public domain0 pasha

分号开头是一个注释，行开头的数字表示分配给每一项的内部存档 ID。

Semicolons start a comment, and the numbers at the start of lines refer to the internal archive ID assigned to each item.

文件中的行可以注释掉、删除和重新排序。例如：

Lines in the file can be commented out, deleted, and reordered. For example:

10; 145433 TABLE map_resolutions postgres
;2; 145344 TABLE species postgres
;4; 145359 TABLE nt_header postgres
6; 145402 TABLE species_records postgres
;8; 145416 TABLE ss_old postgres

可用作 pg_restore 的输入，且只会依次恢复项 10 和 6：

could be used as input to pg_restore and would only restore items 10 and 6, in that order:

$ pg_restore -L db.list db.dump

See Also

pg_dump 、 pg_dumpall 、 psql

pg_dump, pg_dumpall, psql