Document how pglesslog can be used to reduce the storage requirements of PITR.

diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index 1c9b5cfb4bd4547c10b581c123912d8faa7cebfd..4c00ca07e1b3472d68c6bc659e379814c8e1bf20 100644 (file)
--- a/doc/src/sgml/backup.sgml
+++ b/doc/src/sgml/backup.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Backup and Restore
@@ -1337,6 +1337,23 @@ tar -rf /var/lib/pgsql/backup.tar /var/lib/pgsql/archive/
       WAL files are part of the same tar file.
       Please remember to add error handling to your backup scripts.
      
+
+     
+      If archive storage size is a concern, use pg_compresslog,
+      , to
+      remove unnecessary  and trailing
+      space from the WAL files.  You can then use
+      gzip to further compress the output of
+      pg_compresslog:
+
+archive_command = 'pg_compresslog %p - | gzip > /var/lib/pgsql/archive/%f'
+
+      You will then need to use gunzip and
+      pg_decompresslog during recovery:
+
+restore_command = 'gunzip < /mnt/server/archivedir/%f | pg_decompresslog - %p'
+
+