-<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.154 2010/04/29 21:49:03 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.155 2010/05/03 09:14:16 heikki Exp $ -->
<chapter id="backup">
<title>Backup and Restore</title>
</para>
<para>
- To enable WAL archiving, set the <xref
- linkend="guc-archive-mode"> configuration parameter to <literal>on</>,
+ To enable WAL archiving, set the <xref linkend="guc-wal-level">
+ configuration parameter to <literal>archive</> (or <literal>hot_standby</>),
+ <xref linkend="guc-archive-mode"> to <literal>on</>,
and specify the shell command to use in the <xref
linkend="guc-archive-command"> configuration parameter. In practice
these settings will always be placed in the
linkend="populate-pitr">. If archiving or streaming replication were
turned on during execution of one of these statements, WAL would not
contain enough information for archive recovery. (Crash recovery is
- unaffected.) For this reason, these parameters can only be changed at
+ unaffected.) For this reason, <varname>wal_level</> can only be changed at
server start. However, <varname>archive_command</> can be changed with a
configuration file reload. If you wish to temporarily stop archiving,
one way to do it is to set <varname>archive_command</> to the empty
</para>
<para>
- To prepare for standalone hot backups, set <varname>archive_mode</> to
+ To prepare for standalone hot backups, set <varname>wal_level</> to
+ <literal>archive</> (or <literal>hot_standby</>), <varname>archive_mode</> to
<literal>on</>, and set up an <varname>archive_command</> that performs
archiving only when a <emphasis>switch file</> exists. For example:
<programlisting>
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.274 2010/05/02 11:32:53 sriggs Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.275 2010/05/03 09:14:17 heikki Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
with <literal>archive</>, plus information needed to reconstruct
the status of running transactions from the WAL. To enable read-only
queries on a standby server, <varname>wal_level</> must be set to
- <literal>hot_standby</> on the primary. It is thought that there is
+ <literal>hot_standby</> on the primary, and
+ <xref linkend="guc-hot-standby"> must be enabled in the standby. It is
+ thought that there is
little measurable difference in performance between using
<literal>hot_standby</> and <literal>archive</> levels, so feedback
is welcome if any production impacts are noticeable.