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<chapter id="installation">

<title><![%standalone-include[<productname>PostgreSQL</>]]>

]]>

<sect1 id="install-upgrading">

<title>If You AreUpgrading</title>

<title>Upgrading</title>

<indexterm zone="install-upgrading">

<primary>upgrading</primary>

</indexterm>

<para>

The internal data storage format changes with new releases of

<productname>PostgreSQL</>. Therefore, if you are upgrading an

existing installation that does not have a version number

These instructions assume that your existing installation is under the

<filename>/usr/local/pgsql</> directory, and that the data area is in

<filename>/usr/local/pgsql/data</>. Substitute your paths

appropriately.

</para>

<para>

The internal data storage format typically changes in every major

release of <productname>PostgreSQL</>. Therefore, if you are upgrading

an existing installation that does not have a version number of

<quote>&majorversion;.x</quote>, you must back up and restore your

data as shown here. These instructions assume that your existing

installation is under the <filename>/usr/local/pgsql</> directory,

and that the data area is in <filename>/usr/local/pgsql/data</>.

Substitute your paths appropriately.

data. If you are upgrading from the same major version, the new version

can use your current data files, so a backup and restore is optional.

If you wish to avoid the backup/restore, merely skip those steps below.

</para>

<procedure>

<step>

<para>

Make sure that your database is not updated during or after the

backup. This does not affect the integrity of the backup, but the

changed data would of course not be included. If necessary, edit

the permissions in the file

<filename>/usr/local/pgsql/data/pg_hba.conf</> (or equivalent) to

disallow access from everyone except you.

If making a backup, make sure that your database is being updated.

This does not affect the integrity of the backup, but the changed

data would of course not be included. If necessary, edit the

permissions in the file <filename>/usr/local/pgsql/data/pg_hba.conf</>

(or equivalent) to disallow access from everyone except you.

</para>

</step>

<step>

<para>

<indexterm>

<primary>pg_dumpall</primary>

<step>

<para>

If you are installing the new version at the same location as the

old one then shut down the old server, at the latest before you

install the new files:

Shut down the old server:

<screen>

<userinput>pg_ctl stop</>

</screen>

<step>

<para>

If you are installing in the same place as the old version then

it is also a good idea to move the old installation out of the

way, in case you have trouble and need to revert to it.

Use a command like this:

<screen>

If restoring from backup, rename or delete the old installation

directory. It is a good idea to rename the directory, rather than

delete it, in case you have trouble and need to revert to it. Keep

in mind the directory might consume significant disk space. To rename

the directory, use a command like this:

<screen>

<userinput>mv /usr/local/pgsql /usr/local/pgsql.old</>

</screen>

</para>

</step>

</procedure>

<para>

After you have installed <productname>PostgreSQL</> &version;, create a new database

directory and start the new server. Remember that you must execute

these commands while logged in to the special database user account

(which you already have if you are upgrading).

<step>

<para>

Install the new version of <productname>PostgreSQL</productname> as

outlined in <![%standalone-include[the next section.]]>

<![%standalone-ignore[<xref linkend="install-procedure">.]]>

</para>

</step>

<step>

<para>

Create a new database cluster if needed. Remember that you must

execute these commands while logged in to the special database user

account (which you already have if you are upgrading).

<programlisting>

<userinput>/usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data</>

</programlisting>

</para>

</step>

<step>

<para>

Start the database server, again from the special database user

account:

<programlisting>

<userinput>/usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data</>

</programlisting>

Finally, restore your data with

</para>

</step>

<step>

<para>

Finally, restore your data from backup with

<screen>

<userinput>/usr/local/pgsql/bin/psql -d postgres -f <replaceable>outputfile</></userinput>

</screen>

using the <emphasis>new</> <application>psql</>.

</para>

using the <emphasis>new</> <application>psql</>.

</para>

</step>

</procedure>

<para>

Further discussion appears in

<![%standalone-include[the documentation,]]>

<![%standalone-ignore[<xref linkend="migration">,]]>

which you are encouraged to read in any case.

including instructions on how the previous installation can continue

running while the new installation is installed.

</para>

</sect1>