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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>initdb</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="reference-server.html" title="PostgreSQL Server Applications" /><link rel="next" href="pgarchivecleanup.html" title="pg_archivecleanup" /></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">initdb</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="reference-server.html" title="PostgreSQL Server Applications">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-server.html" title="PostgreSQL Server Applications">Up</a></td><th width="60%" align="center">PostgreSQL Server 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="pgarchivecleanup.html" title="pg_archivecleanup">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="APP-INITDB"><div class="titlepage"></div><a id="id-1.9.5.3.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">initdb</span></h2><p>initdb — create a new <span class="productname">PostgreSQL</span> database cluster</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.5.3.4.1"><code class="command">initdb</code> [<em class="replaceable"><code>option</code></em>...] [ <code class="option">--pgdata</code> | <code class="option">-D</code> ]<em class="replaceable"><code> directory</code></em> </p></div></div><div class="refsect1" id="R1-APP-INITDB-1"><h2>
Description
</h2><p>
<code class="command">initdb</code> creates a new
<span class="productname">PostgreSQL</span> database cluster. A database
cluster is a collection of databases that are managed by a single
server instance.
</p><p>
Creating a database cluster consists of creating the directories in
which the database data will live, generating the shared catalog
tables (tables that belong to the whole cluster rather than to any
particular database), and creating the <code class="literal">template1</code>
and <code class="literal">postgres</code> databases. When you later create a
new database, everything in the <code class="literal">template1</code> database is
copied. (Therefore, anything installed in <code class="literal">template1</code>
is automatically copied into each database created later.)
The <code class="literal">postgres</code> database is a default database meant
for use by users, utilities and third party applications.
</p><p>
Although <code class="command">initdb</code> will attempt to create the
specified data directory, it might not have permission if the parent
directory of the desired data directory is root-owned. To initialize
in such a setup, create an empty data directory as root, then use
<code class="command">chown</code> to assign ownership of that directory to the
database user account, then <code class="command">su</code> to become the
database user to run <code class="command">initdb</code>.
</p><p>
<code class="command">initdb</code> must be run as the user that will own the
server process, because the server needs to have access to the
files and directories that <code class="command">initdb</code> creates.
Since the server cannot be run as root, you must not run
<code class="command">initdb</code> as root either. (It will in fact refuse
to do so.)
</p><p>
For security reasons the new cluster created by <code class="command">initdb</code>
will only be accessible by the cluster owner by default. The
<code class="option">--allow-group-access</code> option allows any user in the same
group as the cluster owner to read files in the cluster. This is useful
for performing backups as a non-privileged user.
</p><p>
<code class="command">initdb</code> initializes the database cluster's default
locale and character set encoding. The character set encoding,
collation order (<code class="literal">LC_COLLATE</code>) and character set classes
(<code class="literal">LC_CTYPE</code>, e.g. upper, lower, digit) can be set separately
for a database when it is created. <code class="command">initdb</code> determines
those settings for the <code class="literal">template1</code> database, which will
serve as the default for all other databases.
</p><p>
To alter the default collation order or character set classes, use the
<code class="option">--lc-collate</code> and <code class="option">--lc-ctype</code> options.
Collation orders other than <code class="literal">C</code> or <code class="literal">POSIX</code> also have
a performance penalty. For these reasons it is important to choose the
right locale when running <code class="command">initdb</code>.
</p><p>
The remaining locale categories can be changed later when the server
is started. You can also use <code class="option">--locale</code> to set the
default for all locale categories, including collation order and
character set classes. All server locale values (<code class="literal">lc_*</code>) can
be displayed via <code class="command">SHOW ALL</code>.
More details can be found in <a class="xref" href="locale.html" title="23.1. Locale Support">Section 23.1</a>.
</p><p>
To alter the default encoding, use the <code class="option">--encoding</code>.
More details can be found in <a class="xref" href="multibyte.html" title="23.3. Character Set Support">Section 23.3</a>.
</p></div><div class="refsect1" id="id-1.9.5.3.6"><h2>Options</h2><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-A <em class="replaceable"><code>authmethod</code></em></code><br /></span><span class="term"><code class="option">--auth=<em class="replaceable"><code>authmethod</code></em></code></span></dt><dd><p>
This option specifies the default authentication method for local
users used in <code class="filename">pg_hba.conf</code> (<code class="literal">host</code>
and <code class="literal">local</code> lines). <code class="command">initdb</code> will
prepopulate <code class="filename">pg_hba.conf</code> entries using the
specified authentication method for non-replication as well as
replication connections.
</p><p>
Do not use <code class="literal">trust</code> unless you trust all local users on your
system. <code class="literal">trust</code> is the default for ease of installation.
</p></dd><dt><span class="term"><code class="option">--auth-host=<em class="replaceable"><code>authmethod</code></em></code></span></dt><dd><p>
This option specifies the authentication method for local users via
TCP/IP connections used in <code class="filename">pg_hba.conf</code>
(<code class="literal">host</code> lines).
</p></dd><dt><span class="term"><code class="option">--auth-local=<em class="replaceable"><code>authmethod</code></em></code></span></dt><dd><p>
This option specifies the authentication method for local users via
Unix-domain socket connections used in <code class="filename">pg_hba.conf</code>
(<code class="literal">local</code> lines).
</p></dd><dt><span class="term"><code class="option">-D <em class="replaceable"><code>directory</code></em></code><br /></span><span class="term"><code class="option">--pgdata=<em class="replaceable"><code>directory</code></em></code></span></dt><dd><p>
This option specifies the directory where the database cluster
should be stored. This is the only information required by
<code class="command">initdb</code>, but you can avoid writing it by
setting the <code class="envar">PGDATA</code> environment variable, which
can be convenient since the database server
(<code class="command">postgres</code>) can find the database
directory later by the same variable.
</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>
Selects the encoding of the template database. This will also
be the default encoding of any database you create later,
unless you override it there. The default is derived from the locale, or
<code class="literal">SQL_ASCII</code> if that does not work. The character sets supported by
the <span class="productname">PostgreSQL</span> server are described
in <a class="xref" href="multibyte.html#MULTIBYTE-CHARSET-SUPPORTED" title="23.3.1. Supported Character Sets">Section 23.3.1</a>.
</p></dd><dt id="APP-INITDB-ALLOW-GROUP-ACCESS"><span class="term"><code class="option">-g</code><br /></span><span class="term"><code class="option">--allow-group-access</code></span></dt><dd><p>
Allows users in the same group as the cluster owner to read all cluster
files created by <code class="command">initdb</code>. This option is ignored
on <span class="productname">Windows</span> as it does not support
<acronym class="acronym">POSIX</acronym>-style group permissions.
</p></dd><dt id="APP-INITDB-DATA-CHECKSUMS"><span class="term"><code class="option">-k</code><br /></span><span class="term"><code class="option">--data-checksums</code></span></dt><dd><p>
Use checksums on data pages to help detect corruption by the
I/O system that would otherwise be silent. Enabling checksums
may incur a noticeable performance penalty. This option can only
be set during initialization, and cannot be changed later. If
set, checksums are calculated for all objects, in all databases.
</p></dd><dt><span class="term"><code class="option">--locale=<em class="replaceable"><code>locale</code></em></code></span></dt><dd><p>
Sets the default locale for the database cluster. If this
option is not specified, the locale is inherited from the
environment that <code class="command">initdb</code> runs in. Locale
support is described in <a class="xref" href="locale.html" title="23.1. Locale Support">Section 23.1</a>.
</p></dd><dt><span class="term"><code class="option">--lc-collate=<em class="replaceable"><code>locale</code></em></code><br /></span><span class="term"><code class="option">--lc-ctype=<em class="replaceable"><code>locale</code></em></code><br /></span><span class="term"><code class="option">--lc-messages=<em class="replaceable"><code>locale</code></em></code><br /></span><span class="term"><code class="option">--lc-monetary=<em class="replaceable"><code>locale</code></em></code><br /></span><span class="term"><code class="option">--lc-numeric=<em class="replaceable"><code>locale</code></em></code><br /></span><span class="term"><code class="option">--lc-time=<em class="replaceable"><code>locale</code></em></code></span></dt><dd><p>
Like <code class="option">--locale</code>, but only sets the locale in
the specified category.
</p></dd><dt><span class="term"><code class="option">--no-locale</code></span></dt><dd><p>
Equivalent to <code class="option">--locale=C</code>.
</p></dd><dt><span class="term"><code class="option">-N</code><br /></span><span class="term"><code class="option">--no-sync</code></span></dt><dd><p>
By default, <code class="command">initdb</code> will wait for all files to be
written safely to disk. This option causes <code class="command">initdb</code>
to return without waiting, which is faster, but means that a
subsequent operating system crash can leave the data directory
corrupt. Generally, this option is useful for testing, but should not
be used when creating a production installation.
</p></dd><dt><span class="term"><code class="option">--pwfile=<em class="replaceable"><code>filename</code></em></code></span></dt><dd><p>
Makes <code class="command">initdb</code> read the database superuser's password
from a file. The first line of the file is taken as the password.
</p></dd><dt><span class="term"><code class="option">-S</code><br /></span><span class="term"><code class="option">--sync-only</code></span></dt><dd><p>
Safely write all database files to disk and exit. This does not
perform any of the normal <span class="application">initdb</span> operations.
</p></dd><dt><span class="term"><code class="option">-T <em class="replaceable"><code>config</code></em></code><br /></span><span class="term"><code class="option">--text-search-config=<em class="replaceable"><code>config</code></em></code></span></dt><dd><p>
Sets the default text search configuration.
See <a class="xref" href="runtime-config-client.html#GUC-DEFAULT-TEXT-SEARCH-CONFIG">default_text_search_config</a> for further information.
</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>
Selects the user name of the database superuser. This defaults
to the name of the effective user running
<code class="command">initdb</code>. It is really not important what the
superuser's name is, but one might choose to keep the
customary name <span class="systemitem">postgres</span>, even if the operating
system user's name is different.
</p></dd><dt><span class="term"><code class="option">-W</code><br /></span><span class="term"><code class="option">--pwprompt</code></span></dt><dd><p>
Makes <code class="command">initdb</code> prompt for a password
to give the database superuser. If you don't plan on using password
authentication, this is not important. Otherwise you won't be
able to use password authentication until you have a password
set up.
</p></dd><dt><span class="term"><code class="option">-X <em class="replaceable"><code>directory</code></em></code><br /></span><span class="term"><code class="option">--waldir=<em class="replaceable"><code>directory</code></em></code></span></dt><dd><p>
This option specifies the directory where the write-ahead log
should be stored.
</p></dd><dt><span class="term"><code class="option">--wal-segsize=<em class="replaceable"><code>size</code></em></code></span></dt><dd><p>
Set the <em class="firstterm">WAL segment size</em>, in megabytes. This
is the size of each individual file in the WAL log. The default size
is 16 megabytes. The value must be a power of 2 between 1 and 1024
(megabytes). This option can only be set during initialization, and
cannot be changed later.
</p><p>
It may be useful to adjust this size to control the granularity of
WAL log shipping or archiving. Also, in databases with a high volume
of WAL, the sheer number of WAL files per directory can become a
performance and management problem. Increasing the WAL file size
will reduce the number of WAL files.
</p></dd></dl></div><p>
</p><p>
Other, less commonly used, options are also available:
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-d</code><br /></span><span class="term"><code class="option">--debug</code></span></dt><dd><p>
Print debugging output from the bootstrap backend and a few other
messages of lesser interest for the general public.
The bootstrap backend is the program <code class="command">initdb</code>
uses to create the catalog tables. This option generates a tremendous
amount of extremely boring output.
</p></dd><dt><span class="term"><code class="option">-L <em class="replaceable"><code>directory</code></em></code></span></dt><dd><p>
Specifies where <code class="command">initdb</code> should find
its input files to initialize the database cluster. This is
normally not necessary. You will be told if you need to
specify their location explicitly.
</p></dd><dt><span class="term"><code class="option">-n</code><br /></span><span class="term"><code class="option">--no-clean</code></span></dt><dd><p>
By default, when <code class="command">initdb</code>
determines that an error prevented it from completely creating the database
cluster, it removes any files it might have created before discovering
that it cannot finish the job. This option inhibits tidying-up and is
thus useful for debugging.
</p></dd></dl></div><p>
</p><p>
Other options:
</p><div class="variablelist"><dl class="variablelist"><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">initdb</span> version and exit.
</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">initdb</span> command line
arguments, and exit.
</p></dd></dl></div><p>
</p></div><div class="refsect1" id="id-1.9.5.3.7"><h2>Environment</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">PGDATA</code></span></dt><dd><p>
Specifies the directory where the database cluster is to be
stored; can be overridden using the <code class="option">-D</code> option.
</p></dd><dt><span class="term"><code class="envar">TZ</code></span></dt><dd><p>
Specifies the default time zone of the created database cluster. The
value should be a full time zone name
(see <a class="xref" href="datatype-datetime.html#DATATYPE-TIMEZONES" title="8.5.3. Time Zones">Section 8.5.3</a>).
</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="id-1.9.5.3.8"><h2>Notes</h2><p>
<code class="command">initdb</code> can also be invoked via
<code class="command">pg_ctl initdb</code>.
</p></div><div class="refsect1" id="id-1.9.5.3.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="app-pg-ctl.html" title="pg_ctl"><span class="refentrytitle"><span class="application">pg_ctl</span></span></a>, <a class="xref" href="app-postgres.html" title="postgres"><span class="refentrytitle"><span class="application">postgres</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="reference-server.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-server.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="pgarchivecleanup.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">PostgreSQL Server Applications </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_archivecleanup</span></td></tr></table></div></body></html>
