PostgreSQL 7.4 Documentation
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# initdb

## 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 `postgresql.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 environment 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 category.

-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.

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 may have created before discovering that it can't 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; may be overridden using the -D option.

## See Also

postgres, postmaster

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