Index: doc/src/sgml/backup.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/backup.sgml,v
retrieving revision 2.86
diff -c -r2.86 backup.sgml
*** doc/src/sgml/backup.sgml	16 Sep 2006 00:30:11 -0000	2.86
--- doc/src/sgml/backup.sgml	19 Sep 2006 14:03:32 -0000
***************
*** 1063,1068 ****
--- 1063,1081 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="startup-after-recovery" 
+                    xreflabel="startup_after_recovery">
+       <term><varname>startup_after_recovery</varname> 
+         (<type>boolean</type>)
+       </term>
+       <listitem>
+        <para>
+         Allows an incrementally updated backup to be taken.
+         See <xref linkend="backup-incremental-updated"> for discussion.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
     </variablelist>
  
     </sect3>
***************
*** 1137,1142 ****
--- 1150,1229 ----
     </para>
    </sect2>
  
+   <sect2 id="backup-incremental-updated">
+    <title>Incrementally Updated Backups</title>
+ 
+   <indexterm zone="backup">
+    <primary>incrementally updated backups</primary>
+   </indexterm>
+ 
+    <para>
+     Restartable Recovery can also be utilised to avoid the need to take
+     regular complete base backups, thus improving backup performance in
+     situations where the server is heavily loaded or the database is
+     very large.  This concept is known as incrementally updated backups.
+    </para>
+ 
+    <para>
+     If we take a backup of the server files after a recovery is partially
+     completed, we will be able to restart the recovery from the last
+     restartpoint. This backup is now further forward along the timeline
+     than the original base backup, so we can refer to it as an incrementally
+     updated backup. If we need to recover, it will be faster to recover from 
+     the incrementally updated backup than from the base backup.
+    </para>
+ 
+    <para>
+     The <xref linkend="startup-after-recovery"> option in the recovery.conf
+     file is provided to allow the recovery to complete up to the current last
+     WAL segment, yet without starting the database. This option allows us
+     to stop the server and take a backup of the partially recovered server
+     files: this is the incrementally updated backup.
+    </para>
+ 
+    <para>
+     We can use the incrementally updated backup concept to come up with a
+     streamlined backup schedule. For example:
+   <orderedlist>
+    <listitem>
+     <para>
+      Set up continuous archiving
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Take weekly base backup
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      After 24 hours, restore base backup to another server, then run a
+      partial recovery and take a backup of the latest database state to
+      produce an incrmentally updated backup.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      After next 24 hours, restore the incrementally updated backup to the
+      second server, then run a partial recovery, at the end, take a backup
+      of the partially recovered files.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Repeat previous step each day, until the end of the week.
+     </para>
+    </listitem>
+   </orderedlist>
+    </para>
+ 
+    <para>
+     A weekly backup need only be taken once per week, yet the same level of
+     protection is offered as if base backups were taken nightly. 
+    </para>
+ 
+   </sect2>
+ 
    <sect2 id="continuous-archiving-caveats">
     <title>Caveats</title>
  
Index: src/backend/access/transam/xlog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.249
diff -c -r1.249 xlog.c
*** src/backend/access/transam/xlog.c	21 Aug 2006 16:16:31 -0000	1.249
--- src/backend/access/transam/xlog.c	19 Sep 2006 14:03:36 -0000
***************
*** 182,187 ****
--- 182,188 ----
  static bool recoveryTarget = false;
  static bool recoveryTargetExact = false;
  static bool recoveryTargetInclusive = true;
+ static bool startupAfterRecovery = true;
  static TransactionId recoveryTargetXid;
  static time_t recoveryTargetTime;
  
***************
*** 2506,2514 ****
  	 * or because the administrator has specified the restore program
  	 * incorrectly.  We have to assume the former.
  	 */
! 	ereport(DEBUG2,
  		(errmsg("could not restore file \"%s\" from archive: return code %d",
  				xlogfname, rc)));
  
  	/*
  	 * if an archived file is not available, there might still be a version of
--- 2507,2520 ----
  	 * or because the administrator has specified the restore program
  	 * incorrectly.  We have to assume the former.
  	 */
! 	ereport((startupAfterRecovery ? DEBUG2 : LOG),
  		(errmsg("could not restore file \"%s\" from archive: return code %d",
  				xlogfname, rc)));
+     
+     if (startupAfterRecovery)
+     	ereport(ERROR,
+     		(errmsg("recovery ends normally with startup_after_recovery=false")));
+ 
  
  	/*
  	 * if an archived file is not available, there might still be a version of
***************
*** 4343,4348 ****
--- 4349,4366 ----
  			ereport(LOG,
  					(errmsg("recovery_target_inclusive = %s", tok2)));
  		}
+ 		else if (strcmp(tok1, "startup_after_recovery") == 0)
+ 		{
+ 			if (strcmp(tok2, "false") == 0)
+                 startupAfterRecovery = false;
+ 			else
+ 			{
+                 startupAfterRecovery = true;
+ 				tok2 = "true";
+ 			}
+ 			ereport(LOG,
+ 					(errmsg("startup_after_recovery = %s", tok2)));
+ 		}
  		else
  			ereport(FATAL,
  					(errmsg("unrecognized recovery parameter \"%s\"",