postgresql/doc/src/sgml/ref/initdb.sgml

634 lines
24 KiB
Plaintext

<!--
doc/src/sgml/ref/initdb.sgml
PostgreSQL documentation
-->
<refentry id="app-initdb">
<indexterm zone="app-initdb">
<primary>initdb</primary>
</indexterm>
<refmeta>
<refentrytitle><application>initdb</application></refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>Application</refmiscinfo>
</refmeta>
<refnamediv>
<refname>initdb</refname>
<refpurpose>create a new <productname>PostgreSQL</productname> database cluster</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>initdb</command>
<arg rep="repeat"><replaceable>option</replaceable></arg>
<group choice="plain">
<group choice="opt">
<arg choice="plain"><option>--pgdata</option></arg>
<arg choice="plain"><option>-D</option></arg>
</group>
<replaceable> directory</replaceable>
</group>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id="r1-app-initdb-1">
<title>Description</title>
<para>
<command>initdb</command> creates a new
<productname>PostgreSQL</productname> <glossterm linkend="glossary-db-cluster">database cluster</glossterm>.
</para>
<para>
Creating a database cluster consists of creating the
<glossterm linkend="glossary-data-directory">directories</glossterm> in
which the cluster data will live, generating the shared catalog
tables (tables that belong to the whole cluster rather than to any
particular database), and creating the <literal>postgres</literal>,
<literal>template1</literal>, and <literal>template0</literal> databases.
The <literal>postgres</literal> database is a default database meant
for use by users, utilities and third party applications.
<literal>template1</literal> and <literal>template0</literal> are
meant as source databases to be copied by later <command>CREATE
DATABASE</command> commands. <literal>template0</literal> should never
be modified, but you can add objects to <literal>template1</literal>,
which by default will be copied into databases created later. See
<xref linkend="manage-ag-templatedbs"/> for more details.
</para>
<para>
Although <command>initdb</command> 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
<command>chown</command> to assign ownership of that directory to the
database user account, then <command>su</command> to become the
database user to run <command>initdb</command>.
</para>
<para>
<command>initdb</command> 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 <command>initdb</command> creates.
Since the server cannot be run as root, you must not run
<command>initdb</command> as root either. (It will in fact refuse
to do so.)
</para>
<para>
For security reasons the new cluster created by <command>initdb</command>
will only be accessible by the cluster owner by default. The
<option>--allow-group-access</option> 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.
</para>
<para>
<command>initdb</command> initializes the database cluster's default locale
and character set encoding. These can also be set separately for each
database when it is created. <command>initdb</command> determines those
settings for the template databases, which will serve as the default for
all other databases.
</para>
<para>
By default, <command>initdb</command> uses the ICU library to provide
locale services if the server was built with ICU support; otherwise it uses
the <literal>libc</literal> locale provider (see <xref
linkend="locale-providers"/>). To choose the specific ICU locale ID to
apply, use the option <option>--icu-locale</option>. Note that for
implementation reasons and to support legacy code,
<command>initdb</command> will still select and initialize libc locale
settings when the ICU locale provider is used.
</para>
<para>
Alternatively, <command>initdb</command> can use the locale provider
<literal>libc</literal>. To select this option, specify
<literal>--locale-provider=libc</literal>, or build the server without ICU
support. The <literal>libc</literal> locale provider takes the locale
settings from the environment, and determines the encoding from the locale
settings. This is almost always sufficient, unless there are special
requirements.
</para>
<para>
To choose a different locale for the cluster, use the option
<option>--locale</option>. There are also individual options
<option>--lc-*</option> (see below) to set values for the individual locale
categories. Note that inconsistent settings for different locale
categories can give nonsensical results, so this should be used with care.
</para>
<para>
When <command>initdb</command> runs, it will print out the locale settings
it has chosen. If you have complex requirements or specified multiple
options, it is advisable to check that the result matches what was
intended.
</para>
<para>
More details about locale settings can be found in <xref
linkend="locale"/>.
</para>
<para>
To alter the default encoding, use the <option>--encoding</option>.
More details can be found in <xref linkend="multibyte"/>.
</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>
<variablelist>
<varlistentry id="app-initdb-option-auth">
<term><option>-A <replaceable class="parameter">authmethod</replaceable></option></term>
<term><option>--auth=<replaceable class="parameter">authmethod</replaceable></option></term>
<listitem>
<para>
This option specifies the default authentication method for local
users used in <filename>pg_hba.conf</filename> (<literal>host</literal>
and <literal>local</literal> lines). See <xref linkend="auth-pg-hba-conf"/>
for an overview of valid values.
</para>
<para>
<command>initdb</command> will
prepopulate <filename>pg_hba.conf</filename> entries using the
specified authentication method for non-replication as well as
replication connections.
</para>
<para>
Do not use <literal>trust</literal> unless you trust all local users on your
system. <literal>trust</literal> is the default for ease of installation.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-auth-host">
<term><option>--auth-host=<replaceable class="parameter">authmethod</replaceable></option></term>
<listitem>
<para>
This option specifies the authentication method for local users via
TCP/IP connections used in <filename>pg_hba.conf</filename>
(<literal>host</literal> lines).
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-auth-local">
<term><option>--auth-local=<replaceable class="parameter">authmethod</replaceable></option></term>
<listitem>
<para>
This option specifies the authentication method for local users via
Unix-domain socket connections used in <filename>pg_hba.conf</filename>
(<literal>local</literal> lines).
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-pgdata">
<term><option>-D <replaceable class="parameter">directory</replaceable></option></term>
<term><option>--pgdata=<replaceable class="parameter">directory</replaceable></option></term>
<listitem>
<para>
This option specifies the directory where the database cluster
should be stored. This is the only information required by
<command>initdb</command>, but you can avoid writing it by
setting the <envar>PGDATA</envar> environment variable, which
can be convenient since the database server
(<command>postgres</command>) can find the data
directory later by the same variable.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-encoding">
<term><option>-E <replaceable class="parameter">encoding</replaceable></option></term>
<term><option>--encoding=<replaceable class="parameter">encoding</replaceable></option></term>
<listitem>
<para>
Selects the encoding of the template databases. This will also be the
default encoding of any database you create later, unless you override
it then. The character sets supported by the
<productname>PostgreSQL</productname> server are described in <xref
linkend="multibyte-charset-supported"/>.
</para>
<para>
By default, the template database encoding is derived from the
locale. If <xref linkend="app-initdb-option-no-locale"/> is specified
(or equivalently, if the locale is <literal>C</literal> or
<literal>POSIX</literal>), then the default is <literal>UTF8</literal>
for the ICU provider and <literal>SQL_ASCII</literal> for the
<literal>libc</literal> provider.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-allow-group-access" xreflabel="group access">
<term><option>-g</option></term>
<term><option>--allow-group-access</option></term>
<listitem>
<para>
Allows users in the same group as the cluster owner to read all cluster
files created by <command>initdb</command>. This option is ignored
on <productname>Windows</productname> as it does not support
<acronym>POSIX</acronym>-style group permissions.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-icu-locale">
<term><option>--icu-locale=<replaceable>locale</replaceable></option></term>
<listitem>
<para>
Specifies the ICU locale when the ICU provider is used. Locale support
is described in <xref linkend="locale"/>.
</para>
<para>
If this option is not specified, the locale is inherited from the
environment in which <command>initdb</command> runs. The environment's
locale is matched to a similar ICU locale name, if possible.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-icu-rules">
<term><option>--icu-rules=<replaceable>rules</replaceable></option></term>
<listitem>
<para>
Specifies additional collation rules to customize the behavior of the
default collation. This is supported for ICU only.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-data-checksums" xreflabel="data checksums">
<term><option>-k</option></term>
<term><option>--data-checksums</option></term>
<listitem>
<para>
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. If set, checksums
are calculated for all objects, in all databases. All checksum
failures will be reported in the
<link linkend="monitoring-pg-stat-database-view">
<structname>pg_stat_database</structname></link> view.
See <xref linkend="checksums" /> for details.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-locale">
<term><option>--locale=<replaceable>locale</replaceable></option></term>
<listitem>
<para>
Sets the default locale for the database cluster. If this
option is not specified, the locale is inherited from the
environment that <command>initdb</command> runs in. Locale
support is described in <xref linkend="locale"/>.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-lc-collate">
<term><option>--lc-collate=<replaceable>locale</replaceable></option></term>
<term><option>--lc-ctype=<replaceable>locale</replaceable></option></term>
<term><option>--lc-messages=<replaceable>locale</replaceable></option></term>
<term><option>--lc-monetary=<replaceable>locale</replaceable></option></term>
<term><option>--lc-numeric=<replaceable>locale</replaceable></option></term>
<term><option>--lc-time=<replaceable>locale</replaceable></option></term>
<listitem>
<para>
Like <option>--locale</option>, but only sets the locale in
the specified category.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-no-locale">
<term><option>--no-locale</option></term>
<listitem>
<para>
Equivalent to <option>--locale=C</option>.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-locale-provider">
<term><option>--locale-provider={<literal>libc</literal>|<literal>icu</literal>}</option></term>
<listitem>
<para>
This option sets the locale provider for databases created in the new
cluster. It can be overridden in the <command>CREATE
DATABASE</command> command when new databases are subsequently
created. The default is <literal>icu</literal> if the server was
built with ICU support; otherwise the default is
<literal>libc</literal> (see <xref linkend="locale-providers"/>).
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-no-sync">
<term><option>-N</option></term>
<term><option>--no-sync</option></term>
<listitem>
<para>
By default, <command>initdb</command> will wait for all files to be
written safely to disk. This option causes <command>initdb</command>
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.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-no-instructions">
<term><option>--no-instructions</option></term>
<listitem>
<para>
By default, <command>initdb</command> will write instructions for how
to start the cluster at the end of its output. This option causes
those instructions to be left out. This is primarily intended for use
by tools that wrap <command>initdb</command> in platform-specific
behavior, where those instructions are likely to be incorrect.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-pwfile">
<term><option>--pwfile=<replaceable>filename</replaceable></option></term>
<listitem>
<para>
Makes <command>initdb</command> read the bootstrap superuser's password
from a file. The first line of the file is taken as the password.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-sync-only">
<term><option>-S</option></term>
<term><option>--sync-only</option></term>
<listitem>
<para>
Safely write all database files to disk and exit. This does not
perform any of the normal <application>initdb</application> operations.
Generally, this option is useful for ensuring reliable recovery after
changing <xref linkend="guc-fsync"/> from <literal>off</literal> to
<literal>on</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-text-search-config">
<term><option>-T <replaceable>config</replaceable></option></term>
<term><option>--text-search-config=<replaceable>config</replaceable></option></term>
<listitem>
<para>
Sets the default text search configuration.
See <xref linkend="guc-default-text-search-config"/> for further information.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-username">
<term><option>-U <replaceable class="parameter">username</replaceable></option></term>
<term><option>--username=<replaceable class="parameter">username</replaceable></option></term>
<listitem>
<para>
Selects the user name of the
<glossterm linkend="glossary-bootstrap-superuser">bootstrap superuser</glossterm>.
This defaults to the name of the
<glossterm linkend="glossary-cluster-owner">cluster owner</glossterm>.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-pwprompt">
<term><option>-W</option></term>
<term><option>--pwprompt</option></term>
<listitem>
<para>
Makes <command>initdb</command> prompt for a password
to give the bootstrap 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.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-waldir">
<term><option>-X <replaceable class="parameter">directory</replaceable></option></term>
<term><option>--waldir=<replaceable class="parameter">directory</replaceable></option></term>
<listitem>
<para>
This option specifies the directory where the write-ahead log
should be stored.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-wal-segsize">
<term><option>--wal-segsize=<replaceable>size</replaceable></option></term>
<listitem>
<para>
Set the <firstterm>WAL segment size</firstterm>, 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.
</para>
<para>
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.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
Other, less commonly used, options are also available:
<variablelist>
<varlistentry id="app-initdb-option-set">
<term><option>-c <replaceable>name</replaceable>=<replaceable>value</replaceable></option></term>
<term><option>--set <replaceable>name</replaceable>=<replaceable>value</replaceable></option></term>
<listitem>
<para>
Forcibly set the server parameter <replaceable>name</replaceable>
to <replaceable>value</replaceable> during <command>initdb</command>,
and also install that setting in the
generated <filename>postgresql.conf</filename> file,
so that it will apply during future server runs.
This option can be given more than once to set several parameters.
It is primarily useful when the environment is such that the server
will not start at all using the default parameters.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-debug">
<term><option>-d</option></term>
<term><option>--debug</option></term>
<listitem>
<para>
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 <command>initdb</command>
uses to create the catalog tables. This option generates a tremendous
amount of extremely boring output.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-discard-caches">
<term><option>--discard-caches</option></term>
<listitem>
<para>
Run the bootstrap backend with the
<literal>debug_discard_caches=1</literal> option.
This takes a very long time and is only of use for deep debugging.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-l">
<term><option>-L <replaceable class="parameter">directory</replaceable></option></term>
<listitem>
<para>
Specifies where <command>initdb</command> 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.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-no-clean">
<term><option>-n</option></term>
<term><option>--no-clean</option></term>
<listitem>
<para>
By default, when <command>initdb</command>
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.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
Other options:
<variablelist>
<varlistentry id="app-initdb-option-version">
<term><option>-V</option></term>
<term><option>--version</option></term>
<listitem>
<para>
Print the <application>initdb</application> version and exit.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-option-help">
<term><option>-?</option></term>
<term><option>--help</option></term>
<listitem>
<para>
Show help about <application>initdb</application> command line
arguments, and exit.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist>
<varlistentry id="app-initdb-environment-pgdata">
<term><envar>PGDATA</envar></term>
<listitem>
<para>
Specifies the directory where the database cluster is to be
stored; can be overridden using the <option>-D</option> option.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-environment-pg-color">
<term><envar>PG_COLOR</envar></term>
<listitem>
<para>
Specifies whether to use color in diagnostic messages. Possible values
are <literal>always</literal>, <literal>auto</literal> and
<literal>never</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry id="app-initdb-environment-tz">
<term><envar>TZ</envar></term>
<listitem>
<para>
Specifies the default time zone of the created database cluster. The
value should be a full time zone name
(see <xref linkend="datatype-timezones"/>).
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
This utility, like most other <productname>PostgreSQL</productname> utilities,
also uses the environment variables supported by <application>libpq</application>
(see <xref linkend="libpq-envars"/>).
</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
<command>initdb</command> can also be invoked via
<command>pg_ctl initdb</command>.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="app-pg-ctl"/></member>
<member><xref linkend="app-postgres"/></member>
<member><xref linkend="auth-pg-hba-conf"/></member>
</simplelist>
</refsect1>
</refentry>