initdb
INITDB(1) PostgreSQL Server Applications INITDB(1)
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 database. When you
later create a new database, everything in the template1 database is
copied. It contains catalog tables filled in for things like the
built-in types.
initdb initializes the database cluster’s default locale and character
set encoding. Some locale categories are fixed for the lifetime of the
cluster, so it is important to make the right choice when running
initdb. Other locale categories can be changed later when the server
is started. initdb will write those locale settings into the post-
gresql.conf configuration file so they are the default, but they can
be changed by editing that file. To set the locale that initdb uses,
see the description of the --locale option. The character set encoding
can be set separately for each database as it is created. initdb
determines the encoding for the template1 database, which will serve
as the default for all other databases. To alter the default encoding
use the --encoding option.
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 may not be run as root, you
must not run initdb as root either. (It will in fact refuse to do so.)
Although initdb will attempt to create the specified data directory,
often it won’t have permission to do so, since the parent of the
desired data directory is often a root-owned directory. To set up an
arrangement like this, create an empty data directory as root, then
use chown to hand over ownership of that directory to the database
user account, then su to become the database user, and finally run
initdb as the database user.
OPTIONS
-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 (postmaster) 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 SQL_ASCII.
--locale=locale
Sets the default locale for the database cluster. If this
option is not specified, the locale is inherited from the envi-
ronment that initdb runs in.
--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 cate-
gory.
-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 operat-
ing system user’s name is different.
-W
--pwprompt
Makes initdb prompt for a password to give the database supe-
ruser. 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.
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 cat-
alog tables. This option generates a tremendous amount of
extremely boring output.
-L directory
Specifies where initdb should find its input files to initial-
ize 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 may have created before discovering that it can’t fin-
ish 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; may be overridden using the -D option.
SEE ALSO
postgres(1), postmaster(1)
Application 2008-01-03 INITDB(1)
