XLOG file archiving and point-in-time recovery. There are still some

loose ends and a glaring lack of documentation, but it basically works.

Simon Riggs with some editorialization by Tom Lane.

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.219 2004/07/12 02:22:51 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.220 2004/07/19 02:47:10 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -1371,6 +1371,15 @@ static struct config_real ConfigureNamesReal[] =
 
 static struct config_string ConfigureNamesString[] =
 {
+ 	{
+ 		{"archive_command", PGC_SIGHUP, WAL_SETTINGS,
+ 			gettext_noop("WAL archiving command."),
+ 			gettext_noop("The shell command that will be called to archive a WAL file.")
+ 		},
+ 		&XLogArchiveCommand,
+ 		"", NULL, NULL
+ 	},
+
 	{
 		{"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
 			gettext_noop("Sets the client's character set encoding."),

src/backend/utils/misc/postgresql.conf.sample

@@ -111,6 +111,16 @@
 #commit_delay = 0		# range 0-100000, in microseconds
 #commit_siblings = 5		# range 1-1000
 
+# - Archiving -
+
+#archive_command = ''		# command to use to archive a logfile segment
+
+# If archive_command is '' then archiving is disabled.  Otherwise, set it
+# to a command to copy a file to the proper place.  A simplistic example
+# is 'cp %p /mnt/server/archivedir/%f'.  Any %p in the string is replaced
+# by the absolute path of the file to archive, while any %f is replaced by
+# the file name only.  NOTE: it is important for the command to return
+# zero exit status if and only if it succeeded.
 
 #---------------------------------------------------------------------------
 # QUERY TUNING