NAME
pg_restore - restore a PostgreSQL database from an archive file
created by pg_dump
SYNOPSIS
pg_restore [ option... ] [ filename ]
DESCRIPTION
pg_restore is a utility for restoring a PostgreSQL database from an
archive created by pg_dump(1) 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,
the archive is restored 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. The 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 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:
t
tar The archive is a tar archive. Using this archive format
allows reordering and/or exclusion of schema elements at
the time the database is restored. It is also possible to
limit which data is reloaded at restore time.
c
custom The archive is in the custom format of pg_dump. This is
the most flexible format in that it allows reordering of
data load as well as schema elements. This format is also
compressed by default.
-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
multi-processor 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
decreasing 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 with the -L option to restrict and reorder the items
that are restored.
-L list-file
--use-list=list-file
Restore elements in list-file only, and in the order they
appear in the file. Lines can be moved and can also be commented
out by placing a ; 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.
--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.
-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.
-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). Sequence current 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.
-T trigger
--trigger=trigger
Restore named trigger only.
-v
--verbose
Specifies verbose mode.
-x
--no-privileges
--no-acl
Prevent restoration of access privileges (grant/revoke
commands).
--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.
--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.
--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.
-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.
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
This utility, like most other PostgreSQL utilities, also uses the
environment variables supported by libpq (see in the documentation).
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(1). 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(1) 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 in the documentation and in the
documentation 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:
$ 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 Fri Jul 28 22:28:36 2000
; dbname: mydb
; TOC Entries: 74
; Compression: 0
; Dump Version: 1.4-0
; Format: CUSTOM
;
;
; Selected TOC Entries:
;
2; 145344 TABLE species postgres
3; 145344 ACL species
4; 145359 TABLE nt_header postgres
5; 145359 ACL nt_header
6; 145402 TABLE species_records postgres
7; 145402 ACL species_records
8; 145416 TABLE ss_old postgres
9; 145416 ACL ss_old
10; 145433 TABLE map_resolutions postgres
11; 145433 ACL map_resolutions
12; 145443 TABLE hs_old postgres
13; 145443 ACL hs_old
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
pg_dump(1), pg_dumpall(1), psql(1)