Add recovery_target='immediate' option.

This allows ending recovery as a consistent state has been reached. Without
this, there was no easy way to e.g restore an online backup, without
replaying any extra WAL after the backup ended.

MauMau and me.

3 files changed, 53 insertions, 2 deletions

diff --git a/src/backend/access/transam/recovery.conf.sample b/src/backend/access/transam/recovery.conf.sample
index 673605cfc66..6f7b38eb197 100644
--- a/src/backend/access/transam/recovery.conf.sample
+++ b/src/backend/access/transam/recovery.conf.sample
@@ -81,6 +81,12 @@
 #recovery_target_inclusive = true
 #
 #
+# Alternatively, you can request stopping as soon as a consistent state
+# is reached, by uncommenting this option.
+#
+#recovery_target = 'immediate'
+#
+#
 # If you want to recover into a timeline other than the "main line" shown in
 # pg_control, specify the timeline number here, or write 'latest' to get
 # the latest branch for which there's a history file.
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 9559d6d6aef..b333d820c72 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5434,6 +5434,19 @@ readRecoveryCommandFile(void)
 					(errmsg_internal("recovery_target_name = '%s'",
 									 recoveryTargetName)));
 		}
+		else if (strcmp(item->name, "recovery_target") == 0)
+		{
+			if (strcmp(item->value, "immediate") == 0)
+				recoveryTarget = RECOVERY_TARGET_IMMEDIATE;
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("invalid recovery_target parameter"),
+						 errhint("The only allowed value is 'immediate'")));
+			ereport(DEBUG2,
+					(errmsg_internal("recovery_target = '%s'",
+									 item->value)));
+		}
 		else if (strcmp(item->name, "recovery_target_inclusive") == 0)
 		{
 			/*
@@ -5676,7 +5689,20 @@ recoveryStopsBefore(XLogRecord *record)
 	bool		isCommit;
 	TimestampTz recordXtime = 0;
 
-	/* We only consider stopping before COMMIT or ABORT records. */
+	/* Check if we should stop as soon as reaching consistency */
+	if (recoveryTarget == RECOVERY_TARGET_IMMEDIATE && reachedConsistency)
+	{
+		ereport(LOG,
+				(errmsg("recovery stopping after reaching consistency")));
+
+		recoveryStopAfter = false;
+		recoveryStopXid = InvalidTransactionId;
+		recoveryStopTime = 0;
+		recoveryStopName[0] = '\0';
+		return true;
+	}
+
+	/* Otherwise we only consider stopping before COMMIT or ABORT records. */
 	if (record->xl_rmid != RM_XACT_ID)
 		return false;
 	record_info = record->xl_info & ~XLR_INFO_MASK;
@@ -5825,6 +5851,19 @@ recoveryStopsAfter(XLogRecord *record)
 		}
 	}
 
+	/* Check if we should stop as soon as reaching consistency */
+	if (recoveryTarget == RECOVERY_TARGET_IMMEDIATE && reachedConsistency)
+	{
+		ereport(LOG,
+				(errmsg("recovery stopping after reaching consistency")));
+
+		recoveryStopAfter = true;
+		recoveryStopXid = InvalidTransactionId;
+		recoveryStopTime = 0;
+		recoveryStopName[0] = '\0';
+		return true;
+	}
+
 	return false;
 }
 
@@ -6246,6 +6285,9 @@ StartupXLOG(void)
 			ereport(LOG,
 					(errmsg("starting point-in-time recovery to \"%s\"",
 							recoveryTargetName)));
+		else if (recoveryTarget == RECOVERY_TARGET_IMMEDIATE)
+			ereport(LOG,
+					(errmsg("starting point-in-time recovery to earliest consistent point")));
 		else
 			ereport(LOG,
 					(errmsg("starting archive recovery")));
@@ -7125,6 +7167,8 @@ StartupXLOG(void)
 			snprintf(reason, sizeof(reason),
 					 "at restore point \"%s\"",
 					 recoveryStopName);
+		else if (recoveryTarget == RECOVERY_TARGET_IMMEDIATE)
+			snprintf(reason, sizeof(reason), "reached consistency");
 		else
 			snprintf(reason, sizeof(reason), "no recovery target specified");
 
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 281f51629e4..47e302276b4 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -173,7 +173,8 @@ typedef enum
 	RECOVERY_TARGET_UNSET,
 	RECOVERY_TARGET_XID,
 	RECOVERY_TARGET_TIME,
-	RECOVERY_TARGET_NAME
+	RECOVERY_TARGET_NAME,
+	RECOVERY_TARGET_IMMEDIATE
 } RecoveryTargetType;
 
 extern XLogRecPtr XactLastRecEnd;