-<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.121 2008/11/09 17:51:15 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.122 2009/01/13 00:54:11 momjian Exp $ -->
<chapter id="backup">
<title>Backup and Restore</title>
WAL files are part of the same <application>tar</> file.
Please remember to add error handling to your backup scripts.
</para>
+
+ <para>
+ If archive storage size is a concern, use <application>pg_compresslog</>,
+ <ulink url="http://pglesslog.projects.postgresql.org"></ulink>, to
+ remove unnecessary <xref linkend="guc-full-page-writes"> and trailing
+ space from the WAL files. You can then use
+ <application>gzip</application> to further compress the output of
+ <application>pg_compresslog</>:
+<programlisting>
+archive_command = 'pg_compresslog %p - | gzip > /var/lib/pgsql/archive/%f'
+</programlisting>
+ You will then need to use <application>gunzip</> and
+ <application>pg_decompresslog</> during recovery:
+<programlisting>
+restore_command = 'gunzip < /mnt/server/archivedir/%f | pg_decompresslog - %p'
+</programlisting>
+ </para>
</sect3>
<sect3 id="backup-scripts">