NAME
initdb - create a new PostgreSQL database cluster
SYNOPSIS
initdb [ option... ] [ --pgdata ] [ -D ] directory
DESCRIPTION
initdb creates a new PostgreSQL database cluster. A database cluster is
a collection of databases that are managed by a single server instance.
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 template1 and postgres databases. When you
later create a new database, everything in the template1 database is
copied. (Therefore, anything installed in template1 is automatically
copied into each database created later.) The postgres database is a
default database meant for use by users, utilities and third party
applications.
Although initdb 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 chown to assign ownership of that
directory to the database user account, then su to become the database
user to run initdb.
initdb 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 initdb creates. Since the server cannot be run as root, you must
not run initdb as root either. (It will in fact refuse to do so.)
initdb initializes the database cluster’s default locale and character
set encoding. The character set encoding, collation order (LC_COLLATE)
and character set classes (LC_CTYPE, e.g. upper, lower, digit) can be
set separately for a database when it is created. initdb determines
those settings for the template1 database, which will serve as the
default for all other databases.
To alter the default collation order or character set classes, use the
--lc-collate and --lc-ctype options. Collation orders other than C or
POSIX also have a performance penalty. For these reasons it is
important to choose the right locale when running initdb.
The remaining locale categories can be changed later when the server is
started. You can also use --locale to set the default for all locale
categories, including collation order and character set classes. All
server locale values (lc_*) can be displayed via SHOW ALL. More
details can be found in in the documentation.
To alter the default encoding, use the --encoding. More details can be
found in in the documentation.
OPTIONS
-A authmethod
--auth=authmethod
This option specifies the authentication method for local users
used in pg_hba.conf. Do not use trust unless you trust all local
users on your system. Trust is the default for ease of
installation.
-D directory
--pgdata=directory
This option specifies the directory where the database cluster
should be stored. This is the only information required by
initdb, but you can avoid writing it by setting the PGDATA
environment variable, which can be convenient since the database
server (postgres) can find the database directory later by the
same variable.
-E encoding
--encoding=encoding
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 SQL_ASCII if that does not work. The character sets supported
by the PostgreSQL server are described in in the documentation.
--locale=locale
Sets the default locale for the database cluster. If this option
is not specified, the locale is inherited from the environment
that initdb runs in. Locale support is described in in the
documentation.
--lc-collate=locale
--lc-ctype=locale
--lc-messages=locale
--lc-monetary=locale
--lc-numeric=locale
--lc-time=locale
Like --locale, but only sets the locale in the specified
category.
-X directory
--xlogdir=directory
This option specifies the directory where the transaction log
should be stored.
-U username
--username=username
Selects the user name of the database superuser. This defaults
to the name of the effective user running initdb. It is really
not important what the superuser’s name is, but one might choose
to keep the customary name postgres, even if the operating
system user’s name is different.
-W
--pwprompt
Makes initdb 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.
--pwfile=filename
Makes initdb read the database superuser’s password from a file.
The first line of the file is taken as the password.
Other, less commonly used, parameters are also available:
-d
--debug
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 initdb uses to create the
catalog tables. This option generates a tremendous amount of
extremely boring output.
-L directory
Specifies where initdb 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.
-n
--noclean
By default, when initdb 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.
ENVIRONMENT
PGDATA Specifies the directory where the database cluster is to be
stored; can be overridden using the -D option.
This utility, like most other PostgreSQL utilities, also uses the
environment variables supported by libpq (see in the documentation).
SEE ALSO
postgres(1)