'\" t
.\"     Title: pg_dump
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2023
.\"    Manual: PostgreSQL 14.8 Documentation
.\"    Source: PostgreSQL 14.8
.\"  Language: English
.\"
.TH "PG_DUMP" "1" "2023" "PostgreSQL 14.8" "PostgreSQL 14.8 Documentation"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
pg_dump \- extract a PostgreSQL database into a script file or other archive file
.SH "SYNOPSIS"
.HP \w'\fBpg_dump\fR\ 'u
\fBpg_dump\fR [\fIconnection\-option\fR...] [\fIoption\fR...] [\fIdbname\fR]
.SH "DESCRIPTION"
.PP
pg_dump
is a utility for backing up a
PostgreSQL
database\&. It makes consistent backups even if the database is being used concurrently\&.
pg_dump
does not block other users accessing the database (readers or writers)\&.
.PP
pg_dump
only dumps a single database\&. To back up an entire cluster, or to back up global objects that are common to all databases in a cluster (such as roles and tablespaces), use
\fBpg_dumpall\fR(1)\&.
.PP
Dumps can be output in script or archive file formats\&. Script dumps are plain\-text files containing the SQL commands required to reconstruct the database to the state it was in at the time it was saved\&. To restore from such a script, feed it to
\fBpsql\fR(1)\&. Script files can be used to reconstruct the database even on other machines and other architectures; with some modifications, even on other SQL database products\&.
.PP
The alternative archive file formats must be used with
\fBpg_restore\fR(1)
to rebuild the database\&. They allow
pg_restore
to be selective about what is restored, or even to reorder the items prior to being restored\&. The archive file formats are designed to be portable across architectures\&.
.PP
When used with one of the archive file formats and combined with
pg_restore,
pg_dump
provides a flexible archival and transfer mechanism\&.
pg_dump
can be used to backup an entire database, then
pg_restore
can be used to examine the archive and/or select which parts of the database are to be restored\&. The most flexible output file formats are the
\(lqcustom\(rq
format (\fB\-Fc\fR) and the
\(lqdirectory\(rq
format (\fB\-Fd\fR)\&. They allow for selection and reordering of all archived items, support parallel restoration, and are compressed by default\&. The
\(lqdirectory\(rq
format is the only format that supports parallel dumps\&.
.PP
While running
pg_dump, one should examine the output for any warnings (printed on standard error), especially in light of the limitations listed below\&.
.SH "OPTIONS"
.PP
The following command\-line options control the content and format of the output\&.
.PP
\fIdbname\fR
.RS 4
Specifies the name of the database to be dumped\&. If this is not specified, the environment variable
\fBPGDATABASE\fR
is used\&. If that is not set, the user name specified for the connection is used\&.
.RE
.PP
\fB\-a\fR
.br
\fB\-\-data\-only\fR
.RS 4
Dump only the data, not the schema (data definitions)\&. Table data, large objects, and sequence values are dumped\&.
.sp
This option is similar to, but for historical reasons not identical to, specifying
\fB\-\-section=data\fR\&.
.RE
.PP
\fB\-b\fR
.br
\fB\-\-blobs\fR
.RS 4
Include large objects in the dump\&. This is the default behavior except when
\fB\-\-schema\fR,
\fB\-\-table\fR, or
\fB\-\-schema\-only\fR
is specified\&. The
\fB\-b\fR
switch is therefore only useful to add large objects to dumps where a specific schema or table has been requested\&. Note that blobs are considered data and therefore will be included when
\fB\-\-data\-only\fR
is used, but not when
\fB\-\-schema\-only\fR
is\&.
.RE
.PP
\fB\-B\fR
.br
\fB\-\-no\-blobs\fR
.RS 4
Exclude large objects in the dump\&.
.sp
When both
\fB\-b\fR
and
\fB\-B\fR
are given, the behavior is to output large objects, when data is being dumped, see the
\fB\-b\fR
documentation\&.
.RE
.PP
\fB\-c\fR
.br
\fB\-\-clean\fR
.RS 4
Output commands to clean (drop) database objects prior to outputting the commands for creating them\&. (Unless
\fB\-\-if\-exists\fR
is also specified, restore might generate some harmless error messages, if any objects were not present in the destination database\&.)
.sp
This option is ignored when emitting an archive (non\-text) output file\&. For the archive formats, you can specify the option when you call
\fBpg_restore\fR\&.
.RE
.PP
\fB\-C\fR
.br
\fB\-\-create\fR
.RS 4
Begin the output with a command to create the database itself and reconnect to the created database\&. (With a script of this form, it doesn\*(Aqt matter which database in the destination installation you connect to before running the script\&.) If
\fB\-\-clean\fR
is also specified, the script drops and recreates the target database before reconnecting to it\&.
.sp
With
\fB\-\-create\fR, the output also includes the database\*(Aqs comment if any, and any configuration variable settings that are specific to this database, that is, any
\fBALTER DATABASE \&.\&.\&. SET \&.\&.\&.\fR
and
\fBALTER ROLE \&.\&.\&. IN DATABASE \&.\&.\&. SET \&.\&.\&.\fR
commands that mention this database\&. Access privileges for the database itself are also dumped, unless
\fB\-\-no\-acl\fR
is specified\&.
.sp
This option is ignored when emitting an archive (non\-text) output file\&. For the archive formats, you can specify the option when you call
\fBpg_restore\fR\&.
.RE
.PP
\fB\-e \fR\fB\fIpattern\fR\fR
.br
\fB\-\-extension=\fR\fB\fIpattern\fR\fR
.RS 4
Dump only extensions matching
\fIpattern\fR\&. When this option is not specified, all non\-system extensions in the target database will be dumped\&. Multiple extensions can be selected by writing multiple
\fB\-e\fR
switches\&. The
\fIpattern\fR
parameter is interpreted as a pattern according to the same rules used by
psql\*(Aqs
\ed
commands (see
Patterns), so multiple extensions can also be selected by writing wildcard characters in the pattern\&. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards\&.
.sp
Any configuration relation registered by
\fBpg_extension_config_dump\fR
is included in the dump if its extension is specified by
\fB\-\-extension\fR\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
When
\fB\-e\fR
is specified,
pg_dump
makes no attempt to dump any other database objects that the selected extension(s) might depend upon\&. Therefore, there is no guarantee that the results of a specific\-extension dump can be successfully restored by themselves into a clean database\&.
.sp .5v
.RE
.RE
.PP
\fB\-E \fR\fB\fIencoding\fR\fR
.br
\fB\-\-encoding=\fR\fB\fIencoding\fR\fR
.RS 4
Create the dump in the specified character set encoding\&. By default, the dump is created in the database encoding\&. (Another way to get the same result is to set the
\fBPGCLIENTENCODING\fR
environment variable to the desired dump encoding\&.) The supported encodings are described in
Section\ \&24.3.1\&.
.RE
.PP
\fB\-f \fR\fB\fIfile\fR\fR
.br
\fB\-\-file=\fR\fB\fIfile\fR\fR
.RS 4
Send output to the specified file\&. This parameter can be omitted for file based output formats, in which case the standard output is used\&. It must be given for the directory output format however, where it specifies the target directory instead of a file\&. In this case the directory is created by
\fBpg_dump\fR
and must not exist before\&.
.RE
.PP
\fB\-F \fR\fB\fIformat\fR\fR
.br
\fB\-\-format=\fR\fB\fIformat\fR\fR
.RS 4
Selects the format of the output\&.
\fIformat\fR
can be one of the following:
.PP
p
.br
plain
.RS 4
Output a plain\-text
SQL
script file (the default)\&.
.RE
.PP
c
.br
custom
.RS 4
Output a custom\-format archive suitable for input into
pg_restore\&. Together with the directory output format, this is the most flexible output format in that it allows manual selection and reordering of archived items during restore\&. This format is also compressed by default\&.
.RE
.PP
d
.br
directory
.RS 4
Output a directory\-format archive suitable for input into
pg_restore\&. This will create a directory with one file for each table and blob being dumped, plus a so\-called Table of Contents file describing the dumped objects in a machine\-readable format that
pg_restore
can read\&. A directory format archive can be manipulated with standard Unix tools; for example, files in an uncompressed archive can be compressed with the
gzip
tool\&. This format is compressed by default and also supports parallel dumps\&.
.RE
.PP
t
.br
tar
.RS 4
Output a
\fBtar\fR\-format archive suitable for input into
pg_restore\&. The tar format is compatible with the directory format: extracting a tar\-format archive produces a valid directory\-format archive\&. However, the tar format does not support compression\&. Also, when using tar format the relative order of table data items cannot be changed during restore\&.
.RE
.RE
.PP
\fB\-j \fR\fB\fInjobs\fR\fR
.br
\fB\-\-jobs=\fR\fB\fInjobs\fR\fR
.RS 4
Run the dump in parallel by dumping
\fInjobs\fR
tables simultaneously\&. This option may reduce the time needed to perform the dump but it also increases the load on the database server\&. You can only use this option with the directory output format because this is the only output format where multiple processes can write their data at the same time\&.
.sp
pg_dump
will open
\fInjobs\fR
+ 1 connections to the database, so make sure your
max_connections
setting is high enough to accommodate all connections\&.
.sp
Requesting exclusive locks on database objects while running a parallel dump could cause the dump to fail\&. The reason is that the
pg_dump
leader process requests shared locks (ACCESS SHARE) on the objects that the worker processes are going to dump later in order to make sure that nobody deletes them and makes them go away while the dump is running\&. If another client then requests an exclusive lock on a table, that lock will not be granted but will be queued waiting for the shared lock of the leader process to be released\&. Consequently any other access to the table will not be granted either and will queue after the exclusive lock request\&. This includes the worker process trying to dump the table\&. Without any precautions this would be a classic deadlock situation\&. To detect this conflict, the
pg_dump
worker process requests another shared lock using the
NOWAIT
option\&. If the worker process is not granted this shared lock, somebody else must have requested an exclusive lock in the meantime and there is no way to continue with the dump, so
pg_dump
has no choice but to abort the dump\&.
.sp
For a consistent backup, the database server needs to support synchronized snapshots, a feature that was introduced in
PostgreSQL
9\&.2 for primary servers and 10 for standbys\&. With this feature, database clients can ensure they see the same data set even though they use different connections\&.
\fBpg_dump \-j\fR
uses multiple database connections; it connects to the database once with the leader process and once again for each worker job\&. Without the synchronized snapshot feature, the different worker jobs wouldn\*(Aqt be guaranteed to see the same data in each connection, which could lead to an inconsistent backup\&.
.sp
If you want to run a parallel dump of a pre\-9\&.2 server, you need to make sure that the database content doesn\*(Aqt change from between the time the leader connects to the database until the last worker job has connected to the database\&. The easiest way to do this is to halt any data modifying processes (DDL and DML) accessing the database before starting the backup\&. You also need to specify the
\fB\-\-no\-synchronized\-snapshots\fR
parameter when running
\fBpg_dump \-j\fR
against a pre\-9\&.2
PostgreSQL
server\&.
.RE
.PP
\fB\-n \fR\fB\fIpattern\fR\fR
.br
\fB\-\-schema=\fR\fB\fIpattern\fR\fR
.RS 4
Dump only schemas matching
\fIpattern\fR; this selects both the schema itself, and all its contained objects\&. When this option is not specified, all non\-system schemas in the target database will be dumped\&. Multiple schemas can be selected by writing multiple
\fB\-n\fR
switches\&. The
\fIpattern\fR
parameter is interpreted as a pattern according to the same rules used by
psql\*(Aqs
\ed
commands (see
Patterns
below), so multiple schemas can also be selected by writing wildcard characters in the pattern\&. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards; see
Examples
below\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
When
\fB\-n\fR
is specified,
pg_dump
makes no attempt to dump any other database objects that the selected schema(s) might depend upon\&. Therefore, there is no guarantee that the results of a specific\-schema dump can be successfully restored by themselves into a clean database\&.
.sp .5v
.RE
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
Non\-schema objects such as blobs are not dumped when
\fB\-n\fR
is specified\&. You can add blobs back to the dump with the
\fB\-\-blobs\fR
switch\&.
.sp .5v
.RE
.RE
.PP
\fB\-N \fR\fB\fIpattern\fR\fR
.br
\fB\-\-exclude\-schema=\fR\fB\fIpattern\fR\fR
.RS 4
Do not dump any schemas matching
\fIpattern\fR\&. The pattern is interpreted according to the same rules as for
\fB\-n\fR\&.
\fB\-N\fR
can be given more than once to exclude schemas matching any of several patterns\&.
.sp
When both
\fB\-n\fR
and
\fB\-N\fR
are given, the behavior is to dump just the schemas that match at least one
\fB\-n\fR
switch but no
\fB\-N\fR
switches\&. If
\fB\-N\fR
appears without
\fB\-n\fR, then schemas matching
\fB\-N\fR
are excluded from what is otherwise a normal dump\&.
.RE
.PP
\fB\-O\fR
.br
\fB\-\-no\-owner\fR
.RS 4
Do not output commands to set ownership of objects to match the original database\&. By default,
pg_dump
issues
\fBALTER OWNER\fR
or
\fBSET SESSION AUTHORIZATION\fR
statements to set ownership of created database objects\&. These statements will fail when the script is run unless it is started by a superuser (or the same user that owns all of the objects in the script)\&. To make a script that can be restored by any user, but will give that user ownership of all the objects, specify
\fB\-O\fR\&.
.sp
This option is ignored when emitting an archive (non\-text) output file\&. For the archive formats, you can specify the option when you call
\fBpg_restore\fR\&.
.RE
.PP
\fB\-R\fR
.br
\fB\-\-no\-reconnect\fR
.RS 4
This option is obsolete but still accepted for backwards compatibility\&.
.RE
.PP
\fB\-s\fR
.br
\fB\-\-schema\-only\fR
.RS 4
Dump only the object definitions (schema), not data\&.
.sp
This option is the inverse of
\fB\-\-data\-only\fR\&. It is similar to, but for historical reasons not identical to, specifying
\fB\-\-section=pre\-data \-\-section=post\-data\fR\&.
.sp
(Do not confuse this with the
\fB\-\-schema\fR
option, which uses the word
\(lqschema\(rq
in a different meaning\&.)
.sp
To exclude table data for only a subset of tables in the database, see
\fB\-\-exclude\-table\-data\fR\&.
.RE
.PP
\fB\-S \fR\fB\fIusername\fR\fR
.br
\fB\-\-superuser=\fR\fB\fIusername\fR\fR
.RS 4
Specify the superuser user name to use when disabling triggers\&. This is relevant only if
\fB\-\-disable\-triggers\fR
is used\&. (Usually, it\*(Aqs better to leave this out, and instead start the resulting script as superuser\&.)
.RE
.PP
\fB\-t \fR\fB\fIpattern\fR\fR
.br
\fB\-\-table=\fR\fB\fIpattern\fR\fR
.RS 4
Dump only tables with names matching
\fIpattern\fR\&. Multiple tables can be selected by writing multiple
\fB\-t\fR
switches\&. The
\fIpattern\fR
parameter is interpreted as a pattern according to the same rules used by
psql\*(Aqs
\ed
commands (see
Patterns
below), so multiple tables can also be selected by writing wildcard characters in the pattern\&. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards; see
Examples
below\&.
.sp
As well as tables, this option can be used to dump the definition of matching views, materialized views, foreign tables, and sequences\&. It will not dump the contents of views or materialized views, and the contents of foreign tables will only be dumped if the corresponding foreign server is specified with
\fB\-\-include\-foreign\-data\fR\&.
.sp
The
\fB\-n\fR
and
\fB\-N\fR
switches have no effect when
\fB\-t\fR
is used, because tables selected by
\fB\-t\fR
will be dumped regardless of those switches, and non\-table objects will not be dumped\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
When
\fB\-t\fR
is specified,
pg_dump
makes no attempt to dump any other database objects that the selected table(s) might depend upon\&. Therefore, there is no guarantee that the results of a specific\-table dump can be successfully restored by themselves into a clean database\&.
.sp .5v
.RE
.RE
.PP
\fB\-T \fR\fB\fIpattern\fR\fR
.br
\fB\-\-exclude\-table=\fR\fB\fIpattern\fR\fR
.RS 4
Do not dump any tables matching
\fIpattern\fR\&. The pattern is interpreted according to the same rules as for
\fB\-t\fR\&.
\fB\-T\fR
can be given more than once to exclude tables matching any of several patterns\&.
.sp
When both
\fB\-t\fR
and
\fB\-T\fR
are given, the behavior is to dump just the tables that match at least one
\fB\-t\fR
switch but no
\fB\-T\fR
switches\&. If
\fB\-T\fR
appears without
\fB\-t\fR, then tables matching
\fB\-T\fR
are excluded from what is otherwise a normal dump\&.
.RE
.PP
\fB\-v\fR
.br
\fB\-\-verbose\fR
.RS 4
Specifies verbose mode\&. This will cause
pg_dump
to output detailed object comments and start/stop times to the dump file, and progress messages to standard error\&. Repeating the option causes additional debug\-level messages to appear on standard error\&.
.RE
.PP
\fB\-V\fR
.br
\fB\-\-version\fR
.RS 4
Print the
pg_dump
version and exit\&.
.RE
.PP
\fB\-x\fR
.br
\fB\-\-no\-privileges\fR
.br
\fB\-\-no\-acl\fR
.RS 4
Prevent dumping of access privileges (grant/revoke commands)\&.
.RE
.PP
\fB\-Z \fR\fB\fI0\&.\&.9\fR\fR
.br
\fB\-\-compress=\fR\fB\fI0\&.\&.9\fR\fR
.RS 4
Specify the compression level to use\&. Zero means no compression\&. For the custom and directory archive formats, this specifies compression of individual table\-data segments, and the default is to compress at a moderate level\&. For plain text output, setting a nonzero compression level causes the entire output file to be compressed, as though it had been fed through
gzip; but the default is not to compress\&. The tar archive format currently does not support compression at all\&.
.RE
.PP
\fB\-\-binary\-upgrade\fR
.RS 4
This option is for use by in\-place upgrade utilities\&. Its use for other purposes is not recommended or supported\&. The behavior of the option may change in future releases without notice\&.
.RE
.PP
\fB\-\-column\-inserts\fR
.br
\fB\-\-attribute\-inserts\fR
.RS 4
Dump data as
\fBINSERT\fR
commands with explicit column names (INSERT INTO \fItable\fR (\fIcolumn\fR, \&.\&.\&.) VALUES \&.\&.\&.)\&. This will make restoration very slow; it is mainly useful for making dumps that can be loaded into non\-PostgreSQL
databases\&. Any error during restoring will cause only rows that are part of the problematic
\fBINSERT\fR
to be lost, rather than the entire table contents\&.
.RE
.PP
\fB\-\-disable\-dollar\-quoting\fR
.RS 4
This option disables the use of dollar quoting for function bodies, and forces them to be quoted using SQL standard string syntax\&.
.RE
.PP
\fB\-\-disable\-triggers\fR
.RS 4
This option is relevant only when creating a data\-only dump\&. It instructs
pg_dump
to include 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\&.
.sp
Presently, the commands emitted for
\fB\-\-disable\-triggers\fR
must be done as superuser\&. So, you should also specify a superuser name with
\fB\-S\fR, or preferably be careful to start the resulting script as a superuser\&.
.sp
This option is ignored when emitting an archive (non\-text) output file\&. For the archive formats, you can specify the option when you call
\fBpg_restore\fR\&.
.RE
.PP
\fB\-\-enable\-row\-security\fR
.RS 4
This option is relevant only when dumping the contents of a table which has row security\&. By default,
pg_dump
will set
row_security
to off, to ensure that all data is dumped from the table\&. If the user does not have sufficient privileges to bypass row security, then an error is thrown\&. This parameter instructs
pg_dump
to set
row_security
to on instead, allowing the user to dump the parts of the contents of the table that they have access to\&.
.sp
Note that if you use this option currently, you probably also want the dump be in
\fBINSERT\fR
format, as the
\fBCOPY FROM\fR
during restore does not support row security\&.
.RE
.PP
\fB\-\-exclude\-table\-data=\fR\fB\fIpattern\fR\fR
.RS 4
Do not dump data for any tables matching
\fIpattern\fR\&. The pattern is interpreted according to the same rules as for
\fB\-t\fR\&.
\fB\-\-exclude\-table\-data\fR
can be given more than once to exclude tables matching any of several patterns\&. This option is useful when you need the definition of a particular table even though you do not need the data in it\&.
.sp
To exclude data for all tables in the database, see
\fB\-\-schema\-only\fR\&.
.RE
.PP
\fB\-\-extra\-float\-digits=\fR\fB\fIndigits\fR\fR
.RS 4
Use the specified value of
\fBextra_float_digits\fR
when dumping floating\-point data, instead of the maximum available precision\&. Routine dumps made for backup purposes should not use this option\&.
.RE
.PP
\fB\-\-if\-exists\fR
.RS 4
Use conditional commands (i\&.e\&., add an
IF EXISTS
clause) when cleaning database objects\&. This option is not valid unless
\fB\-\-clean\fR
is also specified\&.
.RE
.PP
\fB\-\-include\-foreign\-data=\fR\fB\fIforeignserver\fR\fR
.RS 4
Dump the data for any foreign table with a foreign server matching
\fIforeignserver\fR
pattern\&. Multiple foreign servers can be selected by writing multiple
\fB\-\-include\-foreign\-data\fR
switches\&. Also, the
\fIforeignserver\fR
parameter is interpreted as a pattern according to the same rules used by
psql\*(Aqs
\ed
commands (see
Patterns
below), so multiple foreign servers can also be selected by writing wildcard characters in the pattern\&. When using wildcards, be careful to quote the pattern if needed to prevent the shell from expanding the wildcards; see
Examples
below\&. The only exception is that an empty pattern is disallowed\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
When
\fB\-\-include\-foreign\-data\fR
is specified,
pg_dump
does not check that the foreign table is writable\&. Therefore, there is no guarantee that the results of a foreign table dump can be successfully restored\&.
.sp .5v
.RE
.RE
.PP
\fB\-\-inserts\fR
.RS 4
Dump data as
\fBINSERT\fR
commands (rather than
\fBCOPY\fR)\&. This will make restoration very slow; it is mainly useful for making dumps that can be loaded into non\-PostgreSQL
databases\&. Any error during restoring will cause only rows that are part of the problematic
\fBINSERT\fR
to be lost, rather than the entire table contents\&. Note that the restore might fail altogether if you have rearranged column order\&. The
\fB\-\-column\-inserts\fR
option is safe against column order changes, though even slower\&.
.RE
.PP
\fB\-\-load\-via\-partition\-root\fR
.RS 4
When dumping data for a table partition, make the
\fBCOPY\fR
or
\fBINSERT\fR
statements target the root of the partitioning hierarchy that contains it, rather than the partition itself\&. This causes the appropriate partition to be re\-determined for each row when the data is loaded\&. This may be useful when restoring data on a server where rows do not always fall into the same partitions as they did on the original server\&. That could happen, for example, if the partitioning column is of type text and the two systems have different definitions of the collation used to sort the partitioning column\&.
.RE
.PP
\fB\-\-lock\-wait\-timeout=\fR\fB\fItimeout\fR\fR
.RS 4
Do not wait forever to acquire shared table locks at the beginning of the dump\&. Instead fail if unable to lock a table within the specified
\fItimeout\fR\&. The timeout may be specified in any of the formats accepted by
\fBSET statement_timeout\fR\&. (Allowed formats vary depending on the server version you are dumping from, but an integer number of milliseconds is accepted by all versions\&.)
.RE
.PP
\fB\-\-no\-comments\fR
.RS 4
Do not dump comments\&.
.RE
.PP
\fB\-\-no\-publications\fR
.RS 4
Do not dump publications\&.
.RE
.PP
\fB\-\-no\-security\-labels\fR
.RS 4
Do not dump security labels\&.
.RE
.PP
\fB\-\-no\-subscriptions\fR
.RS 4
Do not dump subscriptions\&.
.RE
.PP
\fB\-\-no\-sync\fR
.RS 4
By default,
\fBpg_dump\fR
will wait for all files to be written safely to disk\&. This option causes
\fBpg_dump\fR
to return without waiting, which is faster, but means that a subsequent operating system crash can leave the dump corrupt\&. Generally, this option is useful for testing but should not be used when dumping data from production installation\&.
.RE
.PP
\fB\-\-no\-synchronized\-snapshots\fR
.RS 4
This option allows running
\fBpg_dump \-j\fR
against a pre\-9\&.2 server, see the documentation of the
\fB\-j\fR
parameter for more details\&.
.RE
.PP
\fB\-\-no\-tablespaces\fR
.RS 4
Do not output commands to select tablespaces\&. With this option, all objects will be created in whichever tablespace is the default during restore\&.
.sp
This option is ignored when emitting an archive (non\-text) output file\&. For the archive formats, you can specify the option when you call
\fBpg_restore\fR\&.
.RE
.PP
\fB\-\-no\-toast\-compression\fR
.RS 4
Do not output commands to set
TOAST
compression methods\&. With this option, all columns will be restored with the default compression setting\&.
.RE
.PP
\fB\-\-no\-unlogged\-table\-data\fR
.RS 4
Do not dump the contents of unlogged tables\&. This option has no effect on whether or not the table definitions (schema) are dumped; it only suppresses dumping the table data\&. Data in unlogged tables is always excluded when dumping from a standby server\&.
.RE
.PP
\fB\-\-on\-conflict\-do\-nothing\fR
.RS 4
Add
ON CONFLICT DO NOTHING
to
\fBINSERT\fR
commands\&. This option is not valid unless
\fB\-\-inserts\fR,
\fB\-\-column\-inserts\fR
or
\fB\-\-rows\-per\-insert\fR
is also specified\&.
.RE
.PP
\fB\-\-quote\-all\-identifiers\fR
.RS 4
Force quoting of all identifiers\&. This option is recommended when dumping a database from a server whose
PostgreSQL
major version is different from
pg_dump\*(Aqs, or when the output is intended to be loaded into a server of a different major version\&. By default,
pg_dump
quotes only identifiers that are reserved words in its own major version\&. This sometimes results in compatibility issues when dealing with servers of other versions that may have slightly different sets of reserved words\&. Using
\fB\-\-quote\-all\-identifiers\fR
prevents such issues, at the price of a harder\-to\-read dump script\&.
.RE
.PP
\fB\-\-rows\-per\-insert=\fR\fB\fInrows\fR\fR
.RS 4
Dump data as
\fBINSERT\fR
commands (rather than
\fBCOPY\fR)\&. Controls the maximum number of rows per
\fBINSERT\fR
command\&. The value specified must be a number greater than zero\&. Any error during restoring will cause only rows that are part of the problematic
\fBINSERT\fR
to be lost, rather than the entire table contents\&.
.RE
.PP
\fB\-\-section=\fR\fB\fIsectionname\fR\fR
.RS 4
Only dump the named section\&. The section name can be
\fBpre\-data\fR,
\fBdata\fR, or
\fBpost\-data\fR\&. This option can be specified more than once to select multiple sections\&. The default is to dump all sections\&.
.sp
The data section contains actual table data, large\-object contents, and sequence values\&. Post\-data items include definitions of indexes, triggers, rules, and constraints other than validated check constraints\&. Pre\-data items include all other data definition items\&.
.RE
.PP
\fB\-\-serializable\-deferrable\fR
.RS 4
Use a
serializable
transaction for the dump, to ensure that the snapshot used is consistent with later database states; but do this by waiting for a point in the transaction stream at which no anomalies can be present, so that there isn\*(Aqt a risk of the dump failing or causing other transactions to roll back with a
serialization_failure\&. See
Chapter\ \&13
for more information about transaction isolation and concurrency control\&.
.sp
This option is not beneficial for a dump which is intended only for disaster recovery\&. It could be useful for a dump used to load a copy of the database for reporting or other read\-only load sharing while the original database continues to be updated\&. Without it the dump may reflect a state which is not consistent with any serial execution of the transactions eventually committed\&. For example, if batch processing techniques are used, a batch may show as closed in the dump without all of the items which are in the batch appearing\&.
.sp
This option will make no difference if there are no read\-write transactions active when pg_dump is started\&. If read\-write transactions are active, the start of the dump may be delayed for an indeterminate length of time\&. Once running, performance with or without the switch is the same\&.
.RE
.PP
\fB\-\-snapshot=\fR\fB\fIsnapshotname\fR\fR
.RS 4
Use the specified synchronized snapshot when making a dump of the database (see
Table\ \&9.90
for more details)\&.
.sp
This option is useful when needing to synchronize the dump with a logical replication slot (see
Chapter\ \&49) or with a concurrent session\&.
.sp
In the case of a parallel dump, the snapshot name defined by this option is used rather than taking a new snapshot\&.
.RE
.PP
\fB\-\-strict\-names\fR
.RS 4
Require that each extension (\fB\-e\fR/\fB\-\-extension\fR), schema (\fB\-n\fR/\fB\-\-schema\fR) and table (\fB\-t\fR/\fB\-\-table\fR) qualifier match at least one extension/schema/table in the database to be dumped\&. Note that if none of the extension/schema/table qualifiers find matches,
pg_dump
will generate an error even without
\fB\-\-strict\-names\fR\&.
.sp
This option has no effect on
\fB\-N\fR/\fB\-\-exclude\-schema\fR,
\fB\-T\fR/\fB\-\-exclude\-table\fR, or
\fB\-\-exclude\-table\-data\fR\&. An exclude pattern failing to match any objects is not considered an error\&.
.RE
.PP
\fB\-\-use\-set\-session\-authorization\fR
.RS 4
Output SQL\-standard
\fBSET SESSION AUTHORIZATION\fR
commands instead of
\fBALTER OWNER\fR
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\&. Also, a dump using
\fBSET SESSION AUTHORIZATION\fR
will certainly require superuser privileges to restore correctly, whereas
\fBALTER OWNER\fR
requires lesser privileges\&.
.RE
.PP
\fB\-?\fR
.br
\fB\-\-help\fR
.RS 4
Show help about
pg_dump
command line arguments, and exit\&.
.RE
.PP
The following command\-line options control the database connection parameters\&.
.PP
\fB\-d \fR\fB\fIdbname\fR\fR
.br
\fB\-\-dbname=\fR\fB\fIdbname\fR\fR
.RS 4
Specifies the name of the database to connect to\&. This is equivalent to specifying
\fIdbname\fR
as the first non\-option argument on the command line\&. The
\fIdbname\fR
can be a
connection string\&. If so, connection string parameters will override any conflicting command line options\&.
.RE
.PP
\fB\-h \fR\fB\fIhost\fR\fR
.br
\fB\-\-host=\fR\fB\fIhost\fR\fR
.RS 4
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
\fBPGHOST\fR
environment variable, if set, else a Unix domain socket connection is attempted\&.
.RE
.PP
\fB\-p \fR\fB\fIport\fR\fR
.br
\fB\-\-port=\fR\fB\fIport\fR\fR
.RS 4
Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections\&. Defaults to the
\fBPGPORT\fR
environment variable, if set, or a compiled\-in default\&.
.RE
.PP
\fB\-U \fR\fB\fIusername\fR\fR
.br
\fB\-\-username=\fR\fB\fIusername\fR\fR
.RS 4
User name to connect as\&.
.RE
.PP
\fB\-w\fR
.br
\fB\-\-no\-password\fR
.RS 4
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\&.
.RE
.PP
\fB\-W\fR
.br
\fB\-\-password\fR
.RS 4
Force
pg_dump
to prompt for a password before connecting to a database\&.
.sp
This option is never essential, since
pg_dump
will automatically prompt for a password if the server demands password authentication\&. However,
pg_dump
will waste a connection attempt finding out that the server wants a password\&. In some cases it is worth typing
\fB\-W\fR
to avoid the extra connection attempt\&.
.RE
.PP
\fB\-\-role=\fR\fB\fIrolename\fR\fR
.RS 4
Specifies a role name to be used to create the dump\&. This option causes
pg_dump
to issue a
\fBSET ROLE\fR
\fIrolename\fR
command after connecting to the database\&. It is useful when the authenticated user (specified by
\fB\-U\fR) lacks privileges needed by
pg_dump, 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 dumps to be made without violating the policy\&.
.RE
.SH "ENVIRONMENT"
.PP
\fBPGDATABASE\fR
.br
\fBPGHOST\fR
.br
\fBPGOPTIONS\fR
.br
\fBPGPORT\fR
.br
\fBPGUSER\fR
.RS 4
Default connection parameters\&.
.RE
.PP
\fBPG_COLOR\fR
.RS 4
Specifies whether to use color in diagnostic messages\&. Possible values are
always,
auto
and
never\&.
.RE
.PP
This utility, like most other
PostgreSQL
utilities, also uses the environment variables supported by
libpq
(see
Section\ \&34.15)\&.
.SH "DIAGNOSTICS"
.PP
pg_dump
internally executes
\fBSELECT\fR
statements\&. If you have problems running
pg_dump, make sure you are able to select information from the database using, for example,
\fBpsql\fR(1)\&. Also, any default connection settings and environment variables used by the
libpq
front\-end library will apply\&.
.PP
The database activity of
pg_dump
is normally collected by the statistics collector\&. If this is undesirable, you can set parameter
\fItrack_counts\fR
to false via
\fBPGOPTIONS\fR
or the
ALTER USER
command\&.
.SH "NOTES"
.PP
If your database cluster has any local additions to the
template1
database, be careful to restore the output of
pg_dump
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:
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE DATABASE foo WITH TEMPLATE template0;
.fi
.if n \{\
.RE
.\}
.PP
When a data\-only dump is chosen and the option
\fB\-\-disable\-triggers\fR
is used,
pg_dump
emits commands to disable triggers on user tables before inserting the data, and then 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\&.
.PP
The dump file produced by
pg_dump
does not contain the statistics used by the optimizer to make query planning decisions\&. Therefore, it is wise to run
\fBANALYZE\fR
after restoring from a dump file to ensure optimal performance; see
Section\ \&25.1.3
and
Section\ \&25.1.6
for more information\&.
.PP
Because
pg_dump
is used to transfer data to newer versions of
PostgreSQL, the output of
pg_dump
can be expected to load into
PostgreSQL
server versions newer than
pg_dump\*(Aqs version\&.
pg_dump
can also dump from
PostgreSQL
servers older than its own version\&. (Currently, servers back to version 8\&.0 are supported\&.) However,
pg_dump
cannot dump from
PostgreSQL
servers newer than its own major version; it will refuse to even try, rather than risk making an invalid dump\&. Also, it is not guaranteed that
pg_dump\*(Aqs output can be loaded into a server of an older major version \(em not even if the dump was taken from a server of that version\&. Loading a dump file into an older server may require manual editing of the dump file to remove syntax not understood by the older server\&. Use of the
\fB\-\-quote\-all\-identifiers\fR
option is recommended in cross\-version cases, as it can prevent problems arising from varying reserved\-word lists in different
PostgreSQL
versions\&.
.PP
When dumping logical replication subscriptions,
pg_dump
will generate
\fBCREATE SUBSCRIPTION\fR
commands that use the
connect = false
option, so that restoring the subscription does not make remote connections for creating a replication slot or for initial table copy\&. That way, the dump can be restored without requiring network access to the remote servers\&. It is then up to the user to reactivate the subscriptions in a suitable way\&. If the involved hosts have changed, the connection information might have to be changed\&. It might also be appropriate to truncate the target tables before initiating a new full table copy\&.
.SH "EXAMPLES"
.PP
To dump a database called
mydb
into an SQL\-script file:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To reload such a script into a (freshly created) database named
newdb:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpsql \-d newdb \-f db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump a database into a custom\-format archive file:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-Fc mydb > db\&.dump\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump a database into a directory\-format archive:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-Fd mydb \-f dumpdir\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump a database into a directory\-format archive in parallel with 5 worker jobs:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-Fd mydb \-j 5 \-f dumpdir\fR
.fi
.if n \{\
.RE
.\}
.PP
To reload an archive file into a (freshly created) database named
newdb:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_restore \-d newdb db\&.dump\fR
.fi
.if n \{\
.RE
.\}
.PP
To reload an archive file into the same database it was dumped from, discarding the current contents of that database:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_restore \-d postgres \-\-clean \-\-create db\&.dump\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump a single table named
mytab:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-t mytab mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump all tables whose names start with
emp
in the
detroit
schema, except for the table named
employee_log:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-t \*(Aqdetroit\&.emp*\*(Aq \-T detroit\&.employee_log mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump all schemas whose names start with
east
or
west
and end in
gsm, excluding any schemas whose names contain the word
test:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-n \*(Aqeast*gsm\*(Aq \-n \*(Aqwest*gsm\*(Aq \-N \*(Aq*test*\*(Aq mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
The same, using regular expression notation to consolidate the switches:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-n \*(Aq(east|west)*gsm\*(Aq \-N \*(Aq*test*\*(Aq mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To dump all database objects except for tables whose names begin with
ts_:
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-T \*(Aqts_*\*(Aq mydb > db\&.sql\fR
.fi
.if n \{\
.RE
.\}
.PP
To specify an upper\-case or mixed\-case name in
\fB\-t\fR
and related switches, you need to double\-quote the name; else it will be folded to lower case (see
Patterns
below)\&. But double quotes are special to the shell, so in turn they must be quoted\&. Thus, to dump a single table with a mixed\-case name, you need something like
.sp
.if n \{\
.RS 4
.\}
.nf
$ \fBpg_dump \-t "\e"MixedCaseName\e"" mydb > mytab\&.sql\fR
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
\fBpg_dumpall\fR(1), \fBpg_restore\fR(1), \fBpsql\fR(1)
