<application>pgAdmin</application> and other administration and management tools can

use to provide additional functionality, such as remote management

of server log files.

Use of all these functions is only allowed tothe superuser by default but may be

Use of all these functions is only allowed todatabase superusers by default, but may be

allowed to other users by using the <command>GRANT</command> command.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-bootstrap-superuser">

<glossterm>Bootstrap superuser</glossterm>

<glossdef>

<para>

The first <glossterm linkend="glossary-user">user</glossterm> initialized in a

<glossterm linkend="glossary-db-cluster">database cluster</glossterm>.

</para>

<para>

This user owns all system catalog tables in each database. It is also the role

from which all granted permissions originate. Because of these things, this

role may not be dropped.

</para>

<para>

This role also behaves as a normal

<glossterm linkend="glossary-database-superuser">database superuser</glossterm>.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-cast">

<glossterm>Cast</glossterm>

<glossdef>

</glossdef>

</glossentry>

<glossentry id="glossary-cluster-owner">

<glossterm>Cluster owner</glossterm>

<glossdef>

<para>

The operating system user that owns the

<glossterm linkend="glossary-data-directory">data directory</glossterm>

and under which the <literal>postgres</literal> process is run.

It is required that this user exist prior to creating a new

<glossterm linkend="glossary-db-cluster">database cluster</glossterm>.

</para>

<para>

On operating systems with a <literal>root</literal> user,

said user is not allowed to be the cluster owner.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-column">

<glossterm>Column</glossterm>

<glossdef>

and their common static and dynamic metadata.

Sometimes referred to as a

<firstterm>cluster</firstterm>.

A database cluster is created using the

<xref linkend="app-initdb" /> program.

</para>

<para>

In <productname>PostgreSQL</productname>, the term

<firstterm>cluster</firstterm> is also sometimes used to refer to an instance.

(Don't confuse this term with the SQL command <command>CLUSTER</command>.)

</para>

<para>

See also <glossterm linkend="glossary-cluster-owner">cluster owner</glossterm>,

the operating-system owner of a cluster,

and <glossterm linkend="glossary-bootstrap-superuser">bootstrap superuser</glossterm>,

the <productname>PostgreSQL</productname> owner of a cluster.

</para>

</glossdef>

</glossentry>

<glosssee otherterm="glossary-instance" />

</glossentry>

<glossentry id="glossary-database-superuser">

<glossterm>Database superuser</glossterm>

<glossdef>

<para>

A role having <firstterm>superuser status</firstterm>

(see <xref linkend="role-attributes"/>).

</para>

<para>

Frequently referred to as <firstterm>superuser</firstterm>.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-data-directory">

<glossterm>Data directory</glossterm>

<glossdef>

</glossdef>

</glossentry>

<glossentry id="glossary-superuser">

<glossterm>Superuser</glossterm>

<glossdef>

<para>

As used in this documentation, it is a synonym for

<glossterm linkend="glossary-database-superuser">database superuser</glossterm>.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-system-catalog">

<glossterm>System catalog</glossterm>

<glossdef>

<glossdef>

<para>

A <glossterm linkend="glossary-role">role</glossterm> that has the

<literal>LOGIN</literal> privilege.

<firstterm>login privilege</firstterm>

(see <xref linkend="role-attributes"/>).

</para>

</glossdef>

</glossentry>

<title>Description</title>

<para>

<command>initdb</command> creates a new

<productname>PostgreSQL</productname> database cluster. A database

cluster is a collection of databases that are managed by a single

server instance.

<productname>PostgreSQL</productname> <glossterm linkend="glossary-db-cluster">database cluster</glossterm>.

</para>

<para>

Creating a database cluster consists of creating the directories in

which the database data will live, generating the shared catalog

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.

<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 thedatabase

(<command>postgres</command>) can find thedata

directory later by the same variable.

</para>

</listitem>

<term><option>--pwfile=<replaceable>filename</replaceable></option></term>

<listitem>

<para>

Makes <command>initdb</command> read thedatabase superuser's password

Makes <command>initdb</command> read thebootstrap superuser's password

from a file. The first line of the file is taken as the password.

</para>

</listitem>

<term><option>--username=<replaceable class="parameter">username</replaceable></option></term>

<listitem>

<para>

Selects the user name of the database superuser. This defaults

to the name of the effective user running

<command>initdb</command>. It is really not important what the

superuser's name is, but one might choose to keep the

customary name <systemitem>postgres</systemitem>, even if the operating

system user's name is different.

Selects the user name of the

<glossterm linkend="glossary-bootstrap-superuser">boostrap superuser</glossterm>.

This defaults to the name of the

<glossterm linkend="glossary-cluster-owner">cluster owner</glossterm>.

</para>

</listitem>

</varlistentry>

<listitem>

<para>

Makes <command>initdb</command> prompt for a password

to give thedatabase superuser. If you don't plan on using password

to give thebootstrap 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.