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/access/nbtree/nbtsort.c

@@ -56,7 +56,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtsort.c,v 1.83 2004/07/11 18:01:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/nbtree/nbtsort.c,v 1.84 2004/07/19 02:47:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -64,6 +64,7 @@
 #include "postgres.h"
 
 #include "access/nbtree.h"
+#include "access/xlog.h"
 #include "miscadmin.h"
 #include "storage/smgr.h"
 #include "utils/tuplesort.h"
@@ -222,15 +223,9 @@ _bt_leafbuild(BTSpool *btspool, BTSpool *btspool2)
 	/*
 	 * We need to log index creation in WAL iff WAL archiving is enabled
 	 * AND it's not a temp index.
-	 *
-	 * XXX when WAL archiving is actually supported, this test will likely
-	 * need to change; and the hardwired extern is cruddy anyway ...
 	 */
-	{
-		extern char XLOG_archive_dir[];
+	wstate.btws_use_wal = XLogArchivingActive() && !wstate.index->rd_istemp;
 
-		wstate.btws_use_wal = XLOG_archive_dir[0] && !wstate.index->rd_istemp;
-	}
 	/* reserve the metapage */
 	wstate.btws_pages_alloced = BTREE_METAPAGE + 1;
 	wstate.btws_pages_written = 0;

src/backend/access/transam/recovery.conf.sample

@@ -0,0 +1,70 @@
+# -------------------------------
+# PostgreSQL recovery config file
+# -------------------------------
+#
+# Edit this file to provide the parameters that PostgreSQL
+# needs to perform an archive recovery of a database
+#
+# If "recovery.conf" is present in the PostgreSQL data directory, it is
+# read on postmaster startup.  After successful recovery, it is renamed
+# to "recovery.done" to ensure that we do not accidentally re-enter archive
+# recovery mode.
+#
+# This file consists of lines of the form:
+#
+#   name = 'value'
+#
+# (The quotes around the value are NOT optional, but the "=" is.)
+#
+# Comments are introduced with '#'.
+#
+# The complete list of option names and
+# allowed values can be found in the PostgreSQL documentation. The
+# commented-out settings shown below are sample values.
+#
+#---------------------------------------------------------------------------
+# REQUIRED PARAMETERS
+#---------------------------------------------------------------------------
+#
+# restore command
+#
+# specifies the shell command that is executed to copy log files
+# back from archival storage.  The command string may contain %f,
+# which is replaced by the name of the desired log file, and %p,
+# which is replaced by the absolute path to copy the log file to.
+#
+# It is important that the command return nonzero exit status on failure.
+# The command *will* be asked for log files that are not present in the
+# archive; it must return nonzero when so asked.
+#
+# NOTE that the basename of %p will be different from %f; do not
+# expect them to be interchangeable.
+#
+#
+#restore_command = 'cp /mnt/server/archivedir/%f %p'
+#
+#
+#---------------------------------------------------------------------------
+# OPTIONAL PARAMETERS
+#---------------------------------------------------------------------------
+#
+# By default, recovery will rollforward to the end of the WAL log.
+# If you want to stop rollforward before that point, you
+# MUST set a recovery target.
+#
+# You may set a recovery target either by transactionId, or
+# by timestamp. Recovery may either include or exclude the
+# records with the recovery target value (ie, stop either just
+# after or just before the given target).
+#
+#recovery_target_time = '2004-07-14 22:39:00'
+#
+# note: target time is interpreted by strptime() and must therefore be
+# given in your system's default timezone.
+#
+#recovery_target_xid = '11000'
+#
+# true or false
+#recovery_target_inclusive = 'true'
+#
+#---------------------------------------------------------------------------