pg\_restore

pg\_restore

1

Application

pg\_restore

restore a

PostgreSQL

database from an archive file created by

pg\_dump

pg\_restore

connection-option

option

filename

Description {#app-pgrestore-description}
===========

pg\_restore is a utility for restoring a PostgreSQL database from an
archive created by [???](#app-pgdump) 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 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.

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 {#app-pgrestore-options}
=======

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`

:   Clean (drop) database objects before recreating them. (Unless
    `--if-exists` is used, this might generate some harmless error
    messages, if any objects were not present in the destination
    database.)

`-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](#libpq-connstring). 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:

    `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.

`-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 MDASH those that
    load data, create indexes, or create constraints MDASH 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.

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

`-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 reloaded. Use this
    if you have referential integrity checks or other triggers on the
    tables that you do not want to invoke during data reload.

    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
    [???](#guc-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 [???](#guc-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 conditional commands (i.e., add an `IF EXISTS` clause) to drop
    database objects. 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.

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`.

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

Diagnostics {#app-pgrestore-diagnostics}
===========

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, [???](#app-psql). Also, any default
connection settings and environment variables used by the libpq
front-end library will apply.

Notes {#app-pgrestore-notes}
=====

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;

The limitations of pg\_restore are detailed below.

-   When restoring data to a pre-existing table and the option
    `--disable-triggers` is used, pg\_restore emits commands to disable
    triggers on user tables before inserting the data, then emits
    commands to re-enable them after the data has been inserted. If the
    restore is stopped in the middle, the system catalogs might be left
    in the wrong state.

-   pg\_restore cannot restore large objects selectively; for instance,
    only those for a specific table. If an archive contains large
    objects, then all large objects will be restored, or none of them if
    they are excluded via `-L`, `-t`, or other options.

See also the [???](#app-pgdump) documentation for details on limitations
of pg\_dump.

Once restored, it is wise to run `ANALYZE` on each restored table so the
optimizer has useful statistics; see [???](#vacuum-for-statistics) and
[???](#autovacuum) for more information.

Examples {#app-pgrestore-examples}
========

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

    $ pg_dump -Fc mydb > db.dump

To drop the database and recreate it from the dump:

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

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.

To reload the dump into a new database called `newdb`:

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

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.

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

    $ pg_restore -l db.dump > db.list

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

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

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

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
========
