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 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
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).
-c --clean
Clean (drop) database objects before recreating them.
-C --create
Create the database before restoring into it. (When this
option is used, the database named with -d is
used only to issue the initial CREATE DATABASE
command. 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.
-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. Default is the standard
output.
-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 --ignore-version
A deprecated option that is now ignored.
-I index --index=index
Restore definition of named index only.
-j number-of-jobs --jobs=number-of-jobs
Run the most time-consuming parts
of pg_restore — those which load data,
create indexes, or create constraints — using multiple
concurrent jobs. This option can dramatically reduce the time
to restore a large database to a server running on a
multiprocessor machine.
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 archive format is supported with this option.
The input file must be a regular file (not, for example, a
pipe). This option is ignored when emitting a script rather
than connecting directly to a database server. Also, multiple
jobs cannot be used together with the
option --single-transaction.
-l --list
List the 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 namespace --schema=schema
Restore only objects that are in the named schema. This can be
combined with the -t option to restore just a
specific table.
-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.
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.
-R --no-reconnect
This option is obsolete but still accepted for backwards
compatibility.
-s --schema-only
Restore only the schema (data definitions), not the data (table
contents). Current sequence values will not be restored, either.
(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 only relevant if --disable-triggers is used.
-t table --table=table
Restore definition and/or data of named table only. This can be
combined with the -n option to specify a schema.
-T trigger --trigger=trigger
Restore named trigger only.
-v --verbose
Specifies verbose mode.
-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 only relevant 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.
--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-security-labels
Do not output commands to restore security labels,
even if the archive contains them.
--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.
--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 ROLErolename
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
This utility, like most other PostgreSQL utilities,
also uses the environment variables supported by libpq
(see Section 31.13).
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, psql. Also, any default connection
settings and environment variables used by the
libpq front-end library will apply.
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 pg_dump 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
Section 23.1.3 and
Section 23.1.5 for more information.
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:
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: