</para>

<para>

A second database,

<literal>template1</literal>,<indexterm><primary>template1</primary></indexterm>

is also created during database cluster initialization. Whenever a

Two additional databases,

<literal>template1</literal><indexterm><primary>template1</primary></indexterm>

and

<literal>template0</literal>,<indexterm><primary>template0</primary></indexterm>

are also created during database cluster initialization. Whenever a

new database is created within the

cluster, <literal>template1</literal> is essentially cloned.

This means that any changes you make in <literal>template1</literal> are

propagated to all subsequently created databases. Because of this,

avoid creating objects in <literal>template1</literal> unless you want them

propagated to every newly created database. More details

propagated to every newly created database.

<literal>template0</literal> is meant as a pristine copy of the original

contents of <literal>template1</literal>. It can be cloned instead

of <literal>template1</literal> when it is important to make a database

without any such site-local additions. More details

appear in <xref linkend="manage-ag-templatedbs"/>.

</para>

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 <literal>template1</literal>

and <literal>postgres</literal> databases. When you later create a

new database, everything in the <literal>template1</literal> database is

copied. (Therefore, anything installed in <literal>template1</literal>

is automatically copied into each database created later.)

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>

collation order (<literal>LC_COLLATE</literal>) and character set classes

(<literal>LC_CTYPE</literal>, e.g., upper, lower, digit) can be set separately

for a database when it is created. <command>initdb</command> determines

those settings for the<literal>template1</literal> database, which will

those settings for thetemplate databases, which will

serve as the default for all other databases.

</para>

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

<listitem>

<para>

Selects the encoding of the templatedatabase. This will also

Selects the encoding of the templatedatabases. This will also

be the default encoding of any database you create later,

unless you override itthere. The default is derived from the locale, or

unless you override itthen. The default is derived from the locale, or

<literal>SQL_ASCII</literal> if that does not work. The character sets supported by

the <productname>PostgreSQL</productname> server are described

in <xref linkend="multibyte-charset-supported"/>.

which is meant as a default database for use by utilities, users and third

party applications. The database server itself does not require the

<literal>postgres</literal> database to exist, but many external utility

programs assume it exists.Another database created within each cluster

during initialization is called

<literal>template1</literal>. As thename suggests, this will be used

asa templatefor subsequentlycreated databases;it should not be

programs assume it exists.There are two more databases created within

each clusterduring initialization, named <literal>template1</literal>

and<literal>template0</literal>. As thenames suggest, these will be

usedastemplatesfor subsequently-created databases;they should not be

used for actual work. (See <xref linkend="managing-databases"/> for

information about creating new databases within a cluster.)

</para>