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 re-generate all user-defined types, functions, tables, indexes, aggregates, and operators, as well as the data in the tables.
The archive files contain information for pg_restore to rebuild the database, but 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), similar to the ones created by the pg_dump plain text format. Some of the options controlling the script 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 INSERTs" option, pg_restore will not be able to load the data using COPY statements.
pg_restore accepts the following command line arguments. (Long option forms are only available on some platforms.)
Specifies the location of the archive file to be restored. If not specified, the standard input is used.
Restore only the data, no schema (definitions).
Clean (drop) database objects before recreating them.
Create the database before restoring into it. (When this switch appears, 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.)
Connect to database dbname and restore directly into the database. Large objects can only be restored by using a direct database connection.
Specify output file for generated script, or for the listing when used with -l. Default is the standard output.
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:
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.
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.
Ignore database version checks.
Restore definition for named index only.
List the contents of the archive. The output of this command can be used with the -L option to restrict and reorder the items that are restored.
Restore elements in list-file only, and in the order they appear in the file. Lines can be moved and may also be commented out by placing a ; at the start of the line.
Restore items in the original dump order. By default pg_dump will dump items in an order convenient to pg_dump, then save the archive in a modified OID order. This option overrides the OID ordering.
Restore items in the OID order. By default pg_dump will dump items in an order convenient to pg_dump, then save the archive in a modified OID order. This option enforces strict OID ordering.
Prevent any attempt to restore original object ownership. Objects will be owned by the user name used to attach to the database.
Specify a procedure or function to be restored.
Restore items in modified OID order. By default pg_dump will dump items in an order convenient to pg_dump, then save the archive in a modified OID order. Most objects will be restored in OID order, but some things (e.g., rules and indexes) will be restored at the end of the process irrespective of their OIDs. This option is the default.
While restoring an archive, pg_restore typically has to reconnect to the database several times with different user names to set the correct ownership of the created objects. If this is undesirable (e.g., because manual interaction (passwords) would be necessary for each reconnection), this option prevents pg_restore from issuing any reconnection requests. (A connection request while in plain text mode, not connected to a database, is made by putting out a psql \connect command.) However, this option is a rather blunt instrument because it makes pg_restore lose all object ownership information, unless you use the -X use-set-session-authorization option.
Restore the schema (definitions), no data. Sequence values will be reset.
Specify the superuser user name to use when disabling triggers. This is only relevant if --disable-triggers is used.
Restore schema/data for table only.
Restore definition of trigger only.
Specifies verbose mode.
Prevent restoration of access privileges (grant/revoke commands).
Normally, if restoring an archive requires altering the current database user (e.g., to set correct object ownerships), a new connection to the database must be opened, which might require manual interaction (e.g., passwords). If you use the -X use-set-session-authorization option, then pg_restore will instead use the SET SESSION AUTHORIZATION command. This has the same effect, but it requires that the user restoring the archive is a database superuser. This option effectively overrides the -R option.
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 specify --use-set-session-authorization and run pg_restore as a PostgreSQL superuser.
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 host begins with a slash, it is used as the directory for the Unix domain socket.
Specifies the Internet TCP/IP port or local Unix domain socket file extension on which the server is listening for connections. The port number defaults to 5432, or the value of the PGPORT environment variable (if set).
Connect as the given user
Force a password prompt. This should happen automatically if the server requires password authentication.
Connection to database 'template1' failed. connectDBStart() -- connect() failed: No such file or directory Is the postmaster running locally and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?
pg_restore could not attach to the PostgreSQL server process on the specified host and port. If you see this message, ensure that the server is running on the proper host and that you have specified the proper port. If your site uses an authentication system, ensure that you have obtained the required authentication credentials.
Note: 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.
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, pg_restore emits queries to disable triggers on user tables before inserting the data then emits queries to re-enable them after the data has been inserted. If the restore is stopped in the middle, the system catalogs may be left in the wrong state.
pg_restore will not restore large objects for a single table. If an archive contains large objects, then all large objects will be restored.
See also the pg_dump documentation for details on limitations of pg_dump.
To dump a database:
$ pg_dump mydb > db.out
To reload this database:
$ psql -d database -f db.out
To dump a database called mydb that contains large objects to a tar file:
$ pg_dump -Ft -b mydb > db.tar
To reload this database (with large objects) to an existing database called newdb:
$ pg_restore -d newdb db.tar
To reorder database items, it is first necessary to dump the table of contents of the archive:
$ pg_restore -l archive.file > archive.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: birds ; 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
Semi-colons are comment delimiters, 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 archive.list archive.file