pg_restorepg_restore1Applicationpg_restore
restore a PostgreSQL database from an
archive file created by pg_dumppg_restoreconnection-optionoptionfilenameDescriptionpg_restore is a utility for restoring a
PostgreSQL database from an archive
created by 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.
Optionspg_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.
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 .
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 is also specified.
Create the database before restoring into it.
If is also specified, drop and
recreate the target database before connecting to it.
With , 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 is specified.
When this option is used, the database named with
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.
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.
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.
Specify output file for generated script, or for the listing
when used with . Use -
for stdout.
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:
ccustom
The archive is in the custom format of
pg_dump.
ddirectory
The archive is a directory archive.
ttar
The archive is a tar archive.
Restore definition of named index only. Multiple indexes
may be specified with multiple switches.
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 .
List the table of contents of the archive. The output of this operation
can be used as input to the option. Note that
if filtering switches such as or are
used with , they will restrict the items listed.
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 or are
used with , they will further restrict the items restored.
list-file is normally created by
editing the output of a previous 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.
Restore only objects that are in the named schema. Multiple schemas
may be specified with multiple switches. This can be
combined with the option to restore just a
specific table.
Do not restore objects that are in the named schema. Multiple schemas
to be excluded may be specified with multiple switches.
When both and are given for the same
schema name, the switch wins and the schema is excluded.
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 , 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. Multiple functions may be specified with multiple
switches.
This option is obsolete but still accepted for backwards
compatibility.
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 .
It is similar to, but for historical reasons not identical to,
specifying
.
(Do not confuse this with the option, which
uses the word schema in a different meaning.)
Specify the superuser user name to use when disabling triggers.
This is relevant only if is used.
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 switches.
This option can be combined with the option to
specify table(s) in a particular schema.
When 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.
This flag does not behave identically to the
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 .
And, while pg_dump's
flag will also dump subsidiary objects (such as indexes) of the
selected table(s),
pg_restore's
flag does not include such subsidiary objects.
In versions prior to PostgreSQL 9.6, this flag
matched only tables, not any other type of relation.
Restore named trigger only. Multiple triggers may be specified with
multiple switches.
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.
Print the pg_restore version and exit.
Prevent restoration of access privileges (grant/revoke commands).
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
.
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
must be done as superuser. So you
should also specify a superuser name with or,
preferably, run pg_restore as a
PostgreSQL superuser.
This option is relevant only when restoring the contents of a table
which has row security. By default, pg_restore will set
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
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.
Use DROP ... IF EXISTS commands to drop objects
in mode. This suppresses does not
exist errors that might otherwise be reported. This
option is not valid unless is also
specified.
Do not output commands to restore comments, even if the archive
contains them.
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.
Do not output commands to restore publications, even if the archive
contains them.
Do not output commands to restore security labels,
even if the archive contains them.
Do not output commands to restore subscriptions, even if the archive
contains them.
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.
Do not output commands to select tablespaces.
With this option, all objects will be created in whichever
tablespace is the default during restore.
Only restore the named section. The section name can be
, , or .
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.
Require that each schema
(/) and table
(/) qualifier match at
least one schema/table in the backup file.
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.
Show help about pg_restore command line
arguments, and exit.
pg_restore also accepts
the following command line arguments for connection parameters:
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.
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.
User name to connect as.
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.
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 to avoid the extra
connection attempt.
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 ) 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.
EnvironmentPGHOSTPGOPTIONSPGPORTPGUSER
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 ). However, it does not read
PGDATABASE when a database name is not supplied.
Diagnostics
When a direct database connection is specified using the
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, . 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
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 ,
, or other options.
See also the 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
and
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 switch can be any database existing
in the cluster; pg_restore only uses it to issue the
CREATE DATABASE command for mydb. With
, data is always restored into the database name that appears
in the dump file.
To restore the dump into a new database called newdb:
$createdb -T template0 newdb$pg_restore -d newdb db.dump
Notice we don't use , 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.dumpSee Also