standby_checkpoint_segments_9.1.3_fix_20120416.patch

diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 5643ec8..0ce9945 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -56,6 +56,7 @@
 #include "pgstat.h"
 #include "postmaster/bgwriter.h"
 #include "replication/syncrep.h"
+#include "replication/walreceiver.h"
 #include "storage/bufmgr.h"
 #include "storage/fd.h"
 #include "storage/ipc.h"
@@ -489,8 +490,8 @@ BackgroundWriterMain(void)
 			 * Initialize bgwriter-private variables used during checkpoint.
 			 */
 			ckpt_active = true;
-			if (!do_restartpoint)
-				ckpt_start_recptr = GetInsertRecPtr();
+			ckpt_start_recptr =	do_restartpoint ?
+				GetWalRcvWriteRecPtr(NULL) : GetInsertRecPtr();
 			ckpt_start_time = now;
 			ckpt_cached_elapsed = 0;
 
@@ -764,30 +765,32 @@ IsCheckpointOnSchedule(double progress)
 		return false;
 
 	/*
-	 * Check progress against WAL segments written and checkpoint_segments.
+	 * Check progress against WAL segments written, or replayed for
+	 * hot standby, and checkpoint_segments.
 	 *
 	 * We compare the current WAL insert location against the location
-	 * computed before calling CreateCheckPoint. The code in XLogInsert that
-	 * actually triggers a checkpoint when checkpoint_segments is exceeded
-	 * compares against RedoRecptr, so this is not completely accurate.
-	 * However, it's good enough for our purposes, we're only calculating an
-	 * estimate anyway.
+	 * computed before calling CreateCheckPoint. The code in
+	 * XLogInsert that actually triggers a checkpoint when
+	 * checkpoint_segments is exceeded compares against RedoRecptr.
+	 * Similarly, we consult WAL write location instead on hot
+	 * standbys and XLogPageRead compares it aganst RedoRecptr, too.
+	 * Altough these are not completely accurate, it's good enough for
+	 * our purposes, we're only calculating an estimate anyway.
 	 */
-	if (!RecoveryInProgress())
+	
+	recptr =
+		RecoveryInProgress() ? GetWalRcvWriteRecPtr(NULL) : GetInsertRecPtr();
+	elapsed_xlogs =
+		(((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
+		 ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
+		CheckPointSegments;
+	
+	if (progress < elapsed_xlogs)
 	{
-		recptr = GetInsertRecPtr();
-		elapsed_xlogs =
-			(((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
-			 ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
-			CheckPointSegments;
-
-		if (progress < elapsed_xlogs)
-		{
-			ckpt_cached_elapsed = elapsed_xlogs;
-			return false;
-		}
+		ckpt_cached_elapsed = elapsed_xlogs;
+		return false;
 	}
-
+	
 	/*
 	 * Check progress against time elapsed and checkpoint_timeout.
 	 */