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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>pg_dump</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="app-pgconfig.html" title="pg_config" /><link rel="next" href="app-pg-dumpall.html" title="pg_dumpall" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">pg_dump</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="app-pgconfig.html" title="pg_config">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-client.html" title="PostgreSQL Client Applications">Up</a></td><th width="60%" align="center">PostgreSQL Client Applications</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="app-pg-dumpall.html" title="pg_dumpall">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="APP-PGDUMP"><div class="titlepage"></div><a id="id-1.9.4.12.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">pg_dump</span></h2><p>pg_dump —
extract a <span class="productname">PostgreSQL</span> database into a script file or other archive file
</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.4.12.4.1"><code class="command">pg_dump</code> [<em class="replaceable"><code>connection-option</code></em>...] [<em class="replaceable"><code>option</code></em>...] [<em class="replaceable"><code>dbname</code></em>]</p></div></div><div class="refsect1" id="PG-DUMP-DESCRIPTION"><h2>
Description
</h2><p>
<span class="application">pg_dump</span> is a utility for backing up a
<span class="productname">PostgreSQL</span> database. It makes consistent
backups even if the database is being used concurrently.
<span class="application">pg_dump</span> does not block other users
accessing the database (readers or writers).
</p><p>
<span class="application">pg_dump</span> 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 <a class="xref" href="app-pg-dumpall.html" title="pg_dumpall"><span class="refentrytitle"><span class="application">pg_dumpall</span></span></a>.
</p><p>
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 <a class="xref" href="app-psql.html" title="psql"><span class="refentrytitle"><span class="application">psql</span></span></a>. 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.
</p><p>
The alternative archive file formats must be used with
<a class="xref" href="app-pgrestore.html" title="pg_restore"><span class="refentrytitle">pg_restore</span></a> to rebuild the database. They
allow <span class="application">pg_restore</span> 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.
</p><p>
When used with one of the archive file formats and combined with
<span class="application">pg_restore</span>,
<span class="application">pg_dump</span> provides a flexible archival and
transfer mechanism. <span class="application">pg_dump</span> can be used to
backup an entire database, then <span class="application">pg_restore</span>
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 <span class="quote">“<span class="quote">custom</span>”</span> format (<code class="option">-Fc</code>) and the
<span class="quote">“<span class="quote">directory</span>”</span> format (<code class="option">-Fd</code>). They allow
for selection and reordering of all archived items, support parallel
restoration, and are compressed by default. The <span class="quote">“<span class="quote">directory</span>”</span>
format is the only format that supports parallel dumps.
</p><p>
While running <span class="application">pg_dump</span>, one should examine the
output for any warnings (printed on standard error), especially in
light of the limitations listed below.
</p></div><div class="refsect1" id="PG-DUMP-OPTIONS"><h2>Options</h2><p>
The following command-line options control the content and
format of the output.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>dbname</code></em></span></dt><dd><p>
Specifies the name of the database to be dumped. If this is
not specified, the environment variable
<code class="envar">PGDATABASE</code> is used. If that is not set, the
user name specified for the connection is used.
</p></dd><dt><span class="term"><code class="option">-a</code><br /></span><span class="term"><code class="option">--data-only</code></span></dt><dd><p>
Dump only the data, not the schema (data definitions).
Table data, large objects, and sequence values are dumped.
</p><p>
This option is similar to, but for historical reasons not identical
to, specifying <code class="option">--section=data</code>.
</p></dd><dt><span class="term"><code class="option">-b</code><br /></span><span class="term"><code class="option">--blobs</code></span></dt><dd><p>
Include large objects in the dump. This is the default behavior
except when <code class="option">--schema</code>, <code class="option">--table</code>, or
<code class="option">--schema-only</code> is specified. The <code class="option">-b</code>
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
<code class="option">--data-only</code> is used, but not
when <code class="option">--schema-only</code> is.
</p></dd><dt><span class="term"><code class="option">-B</code><br /></span><span class="term"><code class="option">--no-blobs</code></span></dt><dd><p>
Exclude large objects in the dump.
</p><p>
When both <code class="option">-b</code> and <code class="option">-B</code> are given, the behavior
is to output large objects, when data is being dumped, see the
<code class="option">-b</code> documentation.
</p></dd><dt><span class="term"><code class="option">-c</code><br /></span><span class="term"><code class="option">--clean</code></span></dt><dd><p>
Output commands to clean (drop)
database objects prior to outputting the commands for creating them.
(Unless <code class="option">--if-exists</code> is also specified,
restore might generate some harmless error messages, if any objects
were not present in the destination database.)
</p><p>
This option is only meaningful for the plain-text format. For
the archive formats, you can specify the option when you
call <code class="command">pg_restore</code>.
</p></dd><dt><span class="term"><code class="option">-C</code><br /></span><span class="term"><code class="option">--create</code></span></dt><dd><p>
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't matter which database in the
destination installation you connect to before running the script.)
If <code class="option">--clean</code> is also specified, the script drops and
recreates the target database before reconnecting to it.
</p><p>
With <code class="option">--create</code>, the output also includes the
database's comment if any, and any configuration variable settings
that are specific to this database, that is,
any <code class="command">ALTER DATABASE ... SET ...</code>
and <code class="command">ALTER ROLE ... IN DATABASE ... SET ...</code>
commands that mention this database.
Access privileges for the database itself are also dumped,
unless <code class="option">--no-acl</code> is specified.
</p><p>
This option is only meaningful for the plain-text format. For
the archive formats, you can specify the option when you
call <code class="command">pg_restore</code>.
</p></dd><dt><span class="term"><code class="option">-E <em class="replaceable"><code>encoding</code></em></code><br /></span><span class="term"><code class="option">--encoding=<em class="replaceable"><code>encoding</code></em></code></span></dt><dd><p>
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 <code class="envar">PGCLIENTENCODING</code> environment
variable to the desired dump encoding.)
</p></dd><dt><span class="term"><code class="option">-f <em class="replaceable"><code>file</code></em></code><br /></span><span class="term"><code class="option">--file=<em class="replaceable"><code>file</code></em></code></span></dt><dd><p>
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 <code class="command">pg_dump</code> and must not exist
before.
</p></dd><dt><span class="term"><code class="option">-F <em class="replaceable"><code>format</code></em></code><br /></span><span class="term"><code class="option">--format=<em class="replaceable"><code>format</code></em></code></span></dt><dd><p>
Selects the format of the output.
<em class="replaceable"><code>format</code></em> can be one of the following:
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">p</code><br /></span><span class="term"><code class="literal">plain</code></span></dt><dd><p>
Output a plain-text <acronym class="acronym">SQL</acronym> script file (the default).
</p></dd><dt><span class="term"><code class="literal">c</code><br /></span><span class="term"><code class="literal">custom</code></span></dt><dd><p>
Output a custom-format archive suitable for input into
<span class="application">pg_restore</span>.
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.
</p></dd><dt><span class="term"><code class="literal">d</code><br /></span><span class="term"><code class="literal">directory</code></span></dt><dd><p>
Output a directory-format archive suitable for input into
<span class="application">pg_restore</span>. 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 <span class="application">pg_restore</span>
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 <span class="application">gzip</span> tool.
This format is compressed by default and also supports parallel
dumps.
</p></dd><dt><span class="term"><code class="literal">t</code><br /></span><span class="term"><code class="literal">tar</code></span></dt><dd><p>
Output a <code class="command">tar</code>-format archive suitable for input
into <span class="application">pg_restore</span>. 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.
</p></dd></dl></div></dd><dt><span class="term"><code class="option">-j <em class="replaceable"><code>njobs</code></em></code><br /></span><span class="term"><code class="option">--jobs=<em class="replaceable"><code>njobs</code></em></code></span></dt><dd><p>
Run the dump in parallel by dumping <em class="replaceable"><code>njobs</code></em>
tables simultaneously. This option reduces the time of 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.
</p><p><span class="application">pg_dump</span> will open <em class="replaceable"><code>njobs</code></em>
+ 1 connections to the database, so make sure your <a class="xref" href="runtime-config-connection.html#GUC-MAX-CONNECTIONS">max_connections</a>
setting is high enough to accommodate all connections.
</p><p>
Requesting exclusive locks on database objects while running a parallel dump could
cause the dump to fail. The reason is that the <span class="application">pg_dump</span> master process
requests shared locks 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 master 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 <span class="application">pg_dump</span> worker process requests another
shared lock using the <code class="literal">NOWAIT</code> 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 <span class="application">pg_dump</span> has no choice
but to abort the dump.
</p><p>
For a consistent backup, the database server needs to support
synchronized snapshots, a feature that was introduced in
<span class="productname">PostgreSQL</span> 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.
<code class="command">pg_dump -j</code> uses multiple database connections; it
connects to the database once with the master process and once again
for each worker job. Without the synchronized snapshot feature, the
different worker jobs wouldn't be guaranteed to see the same data in
each connection, which could lead to an inconsistent backup.
</p><p>
If you want to run a parallel dump of a pre-9.2 server, you need to make sure that the
database content doesn't change from between the time the master 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
<code class="option">--no-synchronized-snapshots</code> parameter when running
<code class="command">pg_dump -j</code> against a pre-9.2 <span class="productname">PostgreSQL</span>
server.
</p></dd><dt><span class="term"><code class="option">-n <em class="replaceable"><code>schema</code></em></code><br /></span><span class="term"><code class="option">--schema=<em class="replaceable"><code>schema</code></em></code></span></dt><dd><p>
Dump only schemas matching <em class="replaceable"><code>schema</code></em>; 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 <code class="option">-n</code> switches. Also, the
<em class="replaceable"><code>schema</code></em> parameter is
interpreted as a pattern according to the same rules used by
<span class="application">psql</span>'s <code class="literal">\d</code> commands (see <a class="xref" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns">Patterns</a>),
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
<a class="xref" href="app-pgdump.html#PG-DUMP-EXAMPLES" title="Examples">Examples</a>.
</p><div class="note"><h3 class="title">Note</h3><p>
When <code class="option">-n</code> is specified, <span class="application">pg_dump</span>
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.
</p></div><div class="note"><h3 class="title">Note</h3><p>
Non-schema objects such as blobs are not dumped when <code class="option">-n</code> is
specified. You can add blobs back to the dump with the
<code class="option">--blobs</code> switch.
</p></div></dd><dt><span class="term"><code class="option">-N <em class="replaceable"><code>schema</code></em></code><br /></span><span class="term"><code class="option">--exclude-schema=<em class="replaceable"><code>schema</code></em></code></span></dt><dd><p>
Do not dump any schemas matching the <em class="replaceable"><code>schema</code></em> pattern. The pattern is
interpreted according to the same rules as for <code class="option">-n</code>.
<code class="option">-N</code> can be given more than once to exclude schemas
matching any of several patterns.
</p><p>
When both <code class="option">-n</code> and <code class="option">-N</code> are given, the behavior
is to dump just the schemas that match at least one <code class="option">-n</code>
switch but no <code class="option">-N</code> switches. If <code class="option">-N</code> appears
without <code class="option">-n</code>, then schemas matching <code class="option">-N</code> are
excluded from what is otherwise a normal dump.
</p></dd><dt><span class="term"><code class="option">-o</code><br /></span><span class="term"><code class="option">--oids</code></span></dt><dd><p>
Dump object identifiers (<acronym class="acronym">OID</acronym>s) as part of the
data for every table. Use this option if your application references
the <acronym class="acronym">OID</acronym>
columns in some way (e.g., in a foreign key constraint).
Otherwise, this option should not be used.
</p></dd><dt><span class="term"><code class="option">-O</code><br /></span><span class="term"><code class="option">--no-owner</code></span></dt><dd><p>
Do not output commands to set
ownership of objects to match the original database.
By default, <span class="application">pg_dump</span> issues
<code class="command">ALTER OWNER</code> or
<code class="command">SET SESSION AUTHORIZATION</code>
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 <code class="option">-O</code>.
</p><p>
This option is only meaningful for the plain-text format. For
the archive formats, you can specify the option when you
call <code class="command">pg_restore</code>.
</p></dd><dt><span class="term"><code class="option">-R</code><br /></span><span class="term"><code class="option">--no-reconnect</code></span></dt><dd><p>
This option is obsolete but still accepted for backwards
compatibility.
</p></dd><dt><span class="term"><code class="option">-s</code><br /></span><span class="term"><code class="option">--schema-only</code></span></dt><dd><p>
Dump only the object definitions (schema), not data.
</p><p>
This option is the inverse of <code class="option">--data-only</code>.
It is similar to, but for historical reasons not identical to,
specifying
<code class="option">--section=pre-data --section=post-data</code>.
</p><p>
(Do not confuse this with the <code class="option">--schema</code> option, which
uses the word <span class="quote">“<span class="quote">schema</span>”</span> in a different meaning.)
</p><p>
To exclude table data for only a subset of tables in the database,
see <code class="option">--exclude-table-data</code>.
</p></dd><dt><span class="term"><code class="option">-S <em class="replaceable"><code>username</code></em></code><br /></span><span class="term"><code class="option">--superuser=<em class="replaceable"><code>username</code></em></code></span></dt><dd><p>
Specify the superuser user name to use when disabling triggers.
This is relevant only if <code class="option">--disable-triggers</code> is used.
(Usually, it's better to leave this out, and instead start the
resulting script as superuser.)
</p></dd><dt><span class="term"><code class="option">-t <em class="replaceable"><code>table</code></em></code><br /></span><span class="term"><code class="option">--table=<em class="replaceable"><code>table</code></em></code></span></dt><dd><p>
Dump only tables with names matching
<em class="replaceable"><code>table</code></em>.
For this purpose, <span class="quote">“<span class="quote">table</span>”</span> includes views, materialized views,
sequences, and foreign tables. Multiple tables
can be selected by writing multiple <code class="option">-t</code> switches. Also, the
<em class="replaceable"><code>table</code></em> parameter is
interpreted as a pattern according to the same rules used by
<span class="application">psql</span>'s <code class="literal">\d</code> commands (see <a class="xref" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns">Patterns</a>),
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
<a class="xref" href="app-pgdump.html#PG-DUMP-EXAMPLES" title="Examples">Examples</a>.
</p><p>
The <code class="option">-n</code> and <code class="option">-N</code> switches have no effect when
<code class="option">-t</code> is used, because tables selected by <code class="option">-t</code> will
be dumped regardless of those switches, and non-table objects will not
be dumped.
</p><div class="note"><h3 class="title">Note</h3><p>
When <code class="option">-t</code> is specified, <span class="application">pg_dump</span>
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.
</p></div><div class="note"><h3 class="title">Note</h3><p>
The behavior of the <code class="option">-t</code> switch is not entirely upward
compatible with pre-8.2 <span class="productname">PostgreSQL</span>
versions. Formerly, writing <code class="literal">-t tab</code> would dump all
tables named <code class="literal">tab</code>, but now it just dumps whichever one
is visible in your default search path. To get the old behavior
you can write <code class="literal">-t '*.tab'</code>. Also, you must write something
like <code class="literal">-t sch.tab</code> to select a table in a particular schema,
rather than the old locution of <code class="literal">-n sch -t tab</code>.
</p></div></dd><dt><span class="term"><code class="option">-T <em class="replaceable"><code>table</code></em></code><br /></span><span class="term"><code class="option">--exclude-table=<em class="replaceable"><code>table</code></em></code></span></dt><dd><p>
Do not dump any tables matching the <em class="replaceable"><code>table</code></em> pattern. The pattern is
interpreted according to the same rules as for <code class="option">-t</code>.
<code class="option">-T</code> can be given more than once to exclude tables
matching any of several patterns.
</p><p>
When both <code class="option">-t</code> and <code class="option">-T</code> are given, the behavior
is to dump just the tables that match at least one <code class="option">-t</code>
switch but no <code class="option">-T</code> switches. If <code class="option">-T</code> appears
without <code class="option">-t</code>, then tables matching <code class="option">-T</code> are
excluded from what is otherwise a normal dump.
</p></dd><dt><span class="term"><code class="option">-v</code><br /></span><span class="term"><code class="option">--verbose</code></span></dt><dd><p>
Specifies verbose mode. This will cause
<span class="application">pg_dump</span> to output detailed object
comments and start/stop times to the dump file, and progress
messages to standard error.
</p></dd><dt><span class="term"><code class="option">-V</code><br /></span><span class="term"><code class="option">--version</code></span></dt><dd><p>
Print the <span class="application">pg_dump</span> version and exit.
</p></dd><dt><span class="term"><code class="option">-x</code><br /></span><span class="term"><code class="option">--no-privileges</code><br /></span><span class="term"><code class="option">--no-acl</code></span></dt><dd><p>
Prevent dumping of access privileges (grant/revoke commands).
</p></dd><dt><span class="term"><code class="option">-Z <em class="replaceable"><code>0..9</code></em></code><br /></span><span class="term"><code class="option">--compress=<em class="replaceable"><code>0..9</code></em></code></span></dt><dd><p>
Specify the compression level to use. Zero means no compression.
For the custom archive format, 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 <span class="application">gzip</span>; but the default is not to compress.
The tar archive format currently does not support compression at all.
</p></dd><dt><span class="term"><code class="option">--binary-upgrade</code></span></dt><dd><p>
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.
</p></dd><dt><span class="term"><code class="option">--column-inserts</code><br /></span><span class="term"><code class="option">--attribute-inserts</code></span></dt><dd><p>
Dump data as <code class="command">INSERT</code> commands with explicit
column names (<code class="literal">INSERT INTO
<em class="replaceable"><code>table</code></em>
(<em class="replaceable"><code>column</code></em>, ...) VALUES
...</code>). This will make restoration very slow; it is mainly
useful for making dumps that can be loaded into
non-<span class="productname">PostgreSQL</span> databases.
However, since this option generates a separate command for each row,
an error in reloading a row causes only that row to be lost rather
than the entire table contents.
</p></dd><dt><span class="term"><code class="option">--disable-dollar-quoting</code></span></dt><dd><p>
This option disables the use of dollar quoting for function bodies,
and forces them to be quoted using SQL standard string syntax.
</p></dd><dt><span class="term"><code class="option">--disable-triggers</code></span></dt><dd><p>
This option is relevant only when creating a data-only dump.
It instructs <span class="application">pg_dump</span> to include 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.
</p><p>
Presently, the commands emitted for <code class="option">--disable-triggers</code>
must be done as superuser. So, you should also specify
a superuser name with <code class="option">-S</code>, or preferably be careful to
start the resulting script as a superuser.
</p><p>
This option is only meaningful for the plain-text format. For
the archive formats, you can specify the option when you
call <code class="command">pg_restore</code>.
</p></dd><dt><span class="term"><code class="option">--enable-row-security</code></span></dt><dd><p>
This option is relevant only when dumping the contents of a table
which has row security. By default, <span class="application">pg_dump</span> will set
<a class="xref" href="runtime-config-client.html#GUC-ROW-SECURITY">row_security</a> 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 <span class="application">pg_dump</span> to set
<a class="xref" href="runtime-config-client.html#GUC-ROW-SECURITY">row_security</a> to on instead, allowing the user
to dump the parts of the contents of the table that they have access to.
</p><p>
Note that if you use this option currently, you probably also want
the dump be in <code class="command">INSERT</code> format, as the
<code class="command">COPY FROM</code> during restore does not support row security.
</p></dd><dt><span class="term"><code class="option">--exclude-table-data=<em class="replaceable"><code>table</code></em></code></span></dt><dd><p>
Do not dump data for any tables matching the <em class="replaceable"><code>table</code></em> pattern. The pattern is
interpreted according to the same rules as for <code class="option">-t</code>.
<code class="option">--exclude-table-data</code> 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.
</p><p>
To exclude data for all tables in the database, see <code class="option">--schema-only</code>.
</p></dd><dt><span class="term"><code class="option">--if-exists</code></span></dt><dd><p>
Use conditional commands (i.e. add an <code class="literal">IF EXISTS</code>
clause) when cleaning database objects. This option is not valid
unless <code class="option">--clean</code> is also specified.
</p></dd><dt><span class="term"><code class="option">--inserts</code></span></dt><dd><p>
Dump data as <code class="command">INSERT</code> commands (rather
than <code class="command">COPY</code>). This will make restoration very slow;
it is mainly useful for making dumps that can be loaded into
non-<span class="productname">PostgreSQL</span> databases.
However, since this option generates a separate command for each row,
an error in reloading a row causes only that row to be lost rather
than the entire table contents.
Note that
the restore might fail altogether if you have rearranged column order.
The <code class="option">--column-inserts</code> option is safe against column
order changes, though even slower.
</p></dd><dt><span class="term"><code class="option">--load-via-partition-root</code></span></dt><dd><p>
When dumping data for a table partition, make
the <code class="command">COPY</code> or <code class="command">INSERT</code> 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 reloading 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.
</p><p>
It is best not to use parallelism when restoring from an archive made
with this option, because <span class="application">pg_restore</span> will
not know exactly which partition(s) a given archive data item will
load data into. This could result in inefficiency due to lock
conflicts between parallel jobs, or perhaps even reload failures due
to foreign key constraints being set up before all the relevant data
is loaded.
</p></dd><dt><span class="term"><code class="option">--lock-wait-timeout=<em class="replaceable"><code>timeout</code></em></code></span></dt><dd><p>
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
<em class="replaceable"><code>timeout</code></em>. The timeout may be
specified in any of the formats accepted by <code class="command">SET
statement_timeout</code>. (Allowed formats vary depending on the server
version you are dumping from, but an integer number of milliseconds
is accepted by all versions.)
</p></dd><dt><span class="term"><code class="option">--no-comments</code></span></dt><dd><p>
Do not dump comments.
</p></dd><dt><span class="term"><code class="option">--no-publications</code></span></dt><dd><p>
Do not dump publications.
</p></dd><dt><span class="term"><code class="option">--no-security-labels</code></span></dt><dd><p>
Do not dump security labels.
</p></dd><dt><span class="term"><code class="option">--no-subscriptions</code></span></dt><dd><p>
Do not dump subscriptions.
</p></dd><dt><span class="term"><code class="option">--no-sync</code></span></dt><dd><p>
By default, <code class="command">pg_dump</code> will wait for all files
to be written safely to disk. This option causes
<code class="command">pg_dump</code> 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.
</p></dd><dt><span class="term"><code class="option">--no-synchronized-snapshots</code></span></dt><dd><p>
This option allows running <code class="command">pg_dump -j</code> against a pre-9.2
server, see the documentation of the <code class="option">-j</code> parameter
for more details.
</p></dd><dt><span class="term"><code class="option">--no-tablespaces</code></span></dt><dd><p>
Do not output commands to select tablespaces.
With this option, all objects will be created in whichever
tablespace is the default during restore.
</p><p>
This option is only meaningful for the plain-text format. For
the archive formats, you can specify the option when you
call <code class="command">pg_restore</code>.
</p></dd><dt><span class="term"><code class="option">--no-unlogged-table-data</code></span></dt><dd><p>
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.
</p></dd><dt><span class="term"><code class="option">--quote-all-identifiers</code></span></dt><dd><p>
Force quoting of all identifiers. This option is recommended when
dumping a database from a server whose <span class="productname">PostgreSQL</span>
major version is different from <span class="application">pg_dump</span>'s, or when
the output is intended to be loaded into a server of a different
major version. By default, <span class="application">pg_dump</span> 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 <code class="option">--quote-all-identifiers</code> prevents
such issues, at the price of a harder-to-read dump script.
</p></dd><dt><span class="term"><code class="option">--section=<em class="replaceable"><code>sectionname</code></em></code></span></dt><dd><p>
Only dump the named section. The section name can be
<code class="option">pre-data</code>, <code class="option">data</code>, or <code class="option">post-data</code>.
This option can be specified more than once to select multiple
sections. The default is to dump all sections.
</p><p>
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.
</p></dd><dt><span class="term"><code class="option">--serializable-deferrable</code></span></dt><dd><p>
Use a <code class="literal">serializable</code> 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't a risk of
the dump failing or causing other transactions to roll back with a
<code class="literal">serialization_failure</code>. See <a class="xref" href="mvcc.html" title="Chapter 13. Concurrency Control">Chapter 13</a>
for more information about transaction isolation and concurrency
control.
</p><p>
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.
</p><p>
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.
</p></dd><dt><span class="term"><code class="option">--snapshot=<em class="replaceable"><code>snapshotname</code></em></code></span></dt><dd><p>
Use the specified synchronized snapshot when making a dump of the
database (see
<a class="xref" href="functions-admin.html#FUNCTIONS-SNAPSHOT-SYNCHRONIZATION-TABLE" title="Table 9.82. Snapshot Synchronization Functions">Table 9.82</a> for more
details).
</p><p>
This option is useful when needing to synchronize the dump with
a logical replication slot (see <a class="xref" href="logicaldecoding.html" title="Chapter 49. Logical Decoding">Chapter 49</a>)
or with a concurrent session.
</p><p>
In the case of a parallel dump, the snapshot name defined by this
option is used rather than taking a new snapshot.
</p></dd><dt><span class="term"><code class="option">--strict-names</code></span></dt><dd><p>
Require that each schema
(<code class="option">-n</code>/<code class="option">--schema</code>) and table
(<code class="option">-t</code>/<code class="option">--table</code>) qualifier match at
least one schema/table in the database to be dumped. Note that if
none of the schema/table qualifiers find
matches, <span class="application">pg_dump</span> will generate an error
even without <code class="option">--strict-names</code>.
</p><p>
This option has no effect
on <code class="option">-N</code>/<code class="option">--exclude-schema</code>,
<code class="option">-T</code>/<code class="option">--exclude-table</code>,
or <code class="option">--exclude-table-data</code>. An exclude pattern failing
to match any objects is not considered an error.
</p></dd><dt><span class="term"><code class="option">--use-set-session-authorization</code></span></dt><dd><p>
Output SQL-standard <code class="command">SET SESSION AUTHORIZATION</code> commands
instead of <code class="command">ALTER OWNER</code> 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 <code class="command">SET SESSION AUTHORIZATION</code>
will certainly require superuser privileges to restore correctly,
whereas <code class="command">ALTER OWNER</code> requires lesser privileges.
</p></dd><dt><span class="term"><code class="option">-?</code><br /></span><span class="term"><code class="option">--help</code></span></dt><dd><p>
Show help about <span class="application">pg_dump</span> command line
arguments, and exit.
</p></dd></dl></div><p>
</p><p>
The following command-line options control the database connection parameters.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-d <em class="replaceable"><code>dbname</code></em></code><br /></span><span class="term"><code class="option">--dbname=<em class="replaceable"><code>dbname</code></em></code></span></dt><dd><p>
Specifies the name of the database to connect to. This is
equivalent to specifying <em class="replaceable"><code>dbname</code></em> as the first non-option
argument on the command line.
</p><p>
If this parameter contains an <code class="symbol">=</code> sign or starts
with a valid <acronym class="acronym">URI</acronym> prefix
(<code class="literal">postgresql://</code>
or <code class="literal">postgres://</code>), it is treated as a
<em class="parameter"><code>conninfo</code></em> string. See <a class="xref" href="libpq-connect.html" title="34.1. Database Connection Control Functions">Section 34.1</a> for more information.
</p></dd><dt><span class="term"><code class="option">-h <em class="replaceable"><code>host</code></em></code><br /></span><span class="term"><code class="option">--host=<em class="replaceable"><code>host</code></em></code></span></dt><dd><p>
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 <code class="envar">PGHOST</code> environment variable, if set,
else a Unix domain socket connection is attempted.
</p></dd><dt><span class="term"><code class="option">-p <em class="replaceable"><code>port</code></em></code><br /></span><span class="term"><code class="option">--port=<em class="replaceable"><code>port</code></em></code></span></dt><dd><p>
Specifies the TCP port or local Unix domain socket file
extension on which the server is listening for connections.
Defaults to the <code class="envar">PGPORT</code> environment variable, if
set, or a compiled-in default.
</p></dd><dt><span class="term"><code class="option">-U <em class="replaceable"><code>username</code></em></code><br /></span><span class="term"><code class="option">--username=<em class="replaceable"><code>username</code></em></code></span></dt><dd><p>
User name to connect as.
</p></dd><dt><span class="term"><code class="option">-w</code><br /></span><span class="term"><code class="option">--no-password</code></span></dt><dd><p>
Never issue a password prompt. If the server requires
password authentication and a password is not available by
other means such as a <code class="filename">.pgpass</code> 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.
</p></dd><dt><span class="term"><code class="option">-W</code><br /></span><span class="term"><code class="option">--password</code></span></dt><dd><p>
Force <span class="application">pg_dump</span> to prompt for a
password before connecting to a database.
</p><p>
This option is never essential, since
<span class="application">pg_dump</span> will automatically prompt
for a password if the server demands password authentication.
However, <span class="application">pg_dump</span> will waste a
connection attempt finding out that the server wants a password.
In some cases it is worth typing <code class="option">-W</code> to avoid the extra
connection attempt.
</p></dd><dt><span class="term"><code class="option">--role=<em class="replaceable"><code>rolename</code></em></code></span></dt><dd><p>
Specifies a role name to be used to create the dump.
This option causes <span class="application">pg_dump</span> to issue a
<code class="command">SET ROLE</code> <em class="replaceable"><code>rolename</code></em>
command after connecting to the database. It is useful when the
authenticated user (specified by <code class="option">-U</code>) lacks privileges
needed by <span class="application">pg_dump</span>, 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.
</p></dd></dl></div><p>
</p></div><div class="refsect1" id="id-1.9.4.12.7"><h2>Environment</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">PGDATABASE</code><br /></span><span class="term"><code class="envar">PGHOST</code><br /></span><span class="term"><code class="envar">PGOPTIONS</code><br /></span><span class="term"><code class="envar">PGPORT</code><br /></span><span class="term"><code class="envar">PGUSER</code></span></dt><dd><p>
Default connection parameters.
</p></dd></dl></div><p>
This utility, like most other <span class="productname">PostgreSQL</span> utilities,
also uses the environment variables supported by <span class="application">libpq</span>
(see <a class="xref" href="libpq-envars.html" title="34.14. Environment Variables">Section 34.14</a>).
</p></div><div class="refsect1" id="APP-PGDUMP-DIAGNOSTICS"><h2>Diagnostics</h2><p>
<span class="application">pg_dump</span> internally executes
<code class="command">SELECT</code> statements. If you have problems running
<span class="application">pg_dump</span>, make sure you are able to
select information from the database using, for example, <a class="xref" href="app-psql.html" title="psql"><span class="refentrytitle"><span class="application">psql</span></span></a>. Also, any default connection settings and environment
variables used by the <span class="application">libpq</span> front-end
library will apply.
</p><p>
The database activity of <span class="application">pg_dump</span> is
normally collected by the statistics collector. If this is
undesirable, you can set parameter <code class="varname">track_counts</code>
to false via <code class="envar">PGOPTIONS</code> or the <code class="literal">ALTER
USER</code> command.
</p></div><div class="refsect1" id="PG-DUMP-NOTES"><h2>Notes</h2><p>
If your database cluster has any local additions to the <code class="literal">template1</code> database,
be careful to restore the output of <span class="application">pg_dump</span> 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 <code class="literal">template0</code> not <code class="literal">template1</code>,
for example:
</p><pre class="programlisting">
CREATE DATABASE foo WITH TEMPLATE template0;
</pre><p>
</p><p>
When a data-only dump is chosen and the option <code class="option">--disable-triggers</code>
is used, <span class="application">pg_dump</span> 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.
</p><p>
The dump file produced by <span class="application">pg_dump</span>
does not contain the statistics used by the optimizer to make
query planning decisions. Therefore, it is wise to run
<code class="command">ANALYZE</code> after restoring from a dump file
to ensure optimal performance; see <a class="xref" href="routine-vacuuming.html#VACUUM-FOR-STATISTICS" title="24.1.3. Updating Planner Statistics">Section 24.1.3</a>
and <a class="xref" href="routine-vacuuming.html#AUTOVACUUM" title="24.1.6. The Autovacuum Daemon">Section 24.1.6</a> for more information.
</p><p>
Because <span class="application">pg_dump</span> is used to transfer data
to newer versions of <span class="productname">PostgreSQL</span>, the output of
<span class="application">pg_dump</span> can be expected to load into
<span class="productname">PostgreSQL</span> server versions newer than
<span class="application">pg_dump</span>'s version. <span class="application">pg_dump</span> can also
dump from <span class="productname">PostgreSQL</span> servers older than its own version.
(Currently, servers back to version 8.0 are supported.)
However, <span class="application">pg_dump</span> cannot dump from
<span class="productname">PostgreSQL</span> 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 <span class="application">pg_dump</span>'s output can
be loaded into a server of an older major version — 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 <code class="option">--quote-all-identifiers</code> option is recommended
in cross-version cases, as it can prevent problems arising from varying
reserved-word lists in different <span class="productname">PostgreSQL</span> versions.
</p><p>
When dumping logical replication subscriptions,
<span class="application">pg_dump</span> will generate <code class="command">CREATE
SUBSCRIPTION</code> commands that use the <code class="literal">connect = false</code>
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.
</p></div><div class="refsect1" id="PG-DUMP-EXAMPLES"><h2>Examples</h2><p>
To dump a database called <code class="literal">mydb</code> into a SQL-script file:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump mydb > db.sql</code></strong>
</pre><p>
</p><p>
To reload such a script into a (freshly created) database named
<code class="literal">newdb</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>psql -d newdb -f db.sql</code></strong>
</pre><p>
</p><p>
To dump a database into a custom-format archive file:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -Fc mydb > db.dump</code></strong>
</pre><p>
</p><p>
To dump a database into a directory-format archive:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -Fd mydb -f dumpdir</code></strong>
</pre><p>
</p><p>
To dump a database into a directory-format archive in parallel with
5 worker jobs:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -Fd mydb -j 5 -f dumpdir</code></strong>
</pre><p>
</p><p>
To reload an archive file into a (freshly created) database named
<code class="literal">newdb</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_restore -d newdb db.dump</code></strong>
</pre><p>
</p><p>
To reload an archive file into the same database it was dumped from,
discarding the current contents of that database:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_restore -d postgres --clean --create db.dump</code></strong>
</pre><p>
</p><p>
To dump a single table named <code class="literal">mytab</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -t mytab mydb > db.sql</code></strong>
</pre><p>
</p><p>
To dump all tables whose names start with <code class="literal">emp</code> in the
<code class="literal">detroit</code> schema, except for the table named
<code class="literal">employee_log</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -t 'detroit.emp*' -T detroit.employee_log mydb > db.sql</code></strong>
</pre><p>
</p><p>
To dump all schemas whose names start with <code class="literal">east</code> or
<code class="literal">west</code> and end in <code class="literal">gsm</code>, excluding any schemas whose
names contain the word <code class="literal">test</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -n 'east*gsm' -n 'west*gsm' -N '*test*' mydb > db.sql</code></strong>
</pre><p>
</p><p>
The same, using regular expression notation to consolidate the switches:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -n '(east|west)*gsm' -N '*test*' mydb > db.sql</code></strong>
</pre><p>
</p><p>
To dump all database objects except for tables whose names begin with
<code class="literal">ts_</code>:
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -T 'ts_*' mydb > db.sql</code></strong>
</pre><p>
</p><p>
To specify an upper-case or mixed-case name in <code class="option">-t</code> and related
switches, you need to double-quote the name; else it will be folded to
lower case (see <a class="xref" href="app-psql.html#APP-PSQL-PATTERNS" title="Patterns">Patterns</a>). 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
</p><pre class="screen">
<code class="prompt">$</code> <strong class="userinput"><code>pg_dump -t "\"MixedCaseName\"" mydb > mytab.sql</code></strong>
</pre></div><div class="refsect1" id="id-1.9.4.12.11"><h2>See Also</h2><span class="simplelist"><a class="xref" href="app-pg-dumpall.html" title="pg_dumpall"><span class="refentrytitle"><span class="application">pg_dumpall</span></span></a>, <a class="xref" href="app-pgrestore.html" title="pg_restore"><span class="refentrytitle">pg_restore</span></a>, <a class="xref" href="app-psql.html" title="psql"><span class="refentrytitle"><span class="application">psql</span></span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="app-pgconfig.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-client.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="app-pg-dumpall.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">pg_config </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="application">pg_dumpall</span></td></tr></table></div></body></html>
