0003_v9_reload_wal_receiver_create_temp_slot.patch

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index f1d2a77043..eb6b3fb876 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4170,7 +4170,11 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
         Specifies whether a WAL receiver should create a temporary replication
         slot on the remote instance when no permanent replication slot to use
         has been configured (using <xref linkend="guc-primary-slot-name"/>).
-        The default is off.  This parameter can only be set at server start.
+        The default is off.  This parameter can only be set in the 
+        <filename>postgresql.conf</filename> file or on the server command line.
+       </para>
+       <para>
+        The WAL receiver is restarted after an update of <varname>wal_receiver_create_temp_slot</varname>.
        </para>
       </listitem>
      </varlistentry>
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index e1f3e905bb..47d69d92d2 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -12278,8 +12278,10 @@ ProcessStartupSigHup(void)
 {
 	char	   *conninfo = pstrdup(PrimaryConnInfo);
 	char	   *slotname = pstrdup(PrimarySlotName);
+	bool		tempSlot = wal_receiver_create_temp_slot;
 	bool		conninfoChanged;
 	bool		slotnameChanged;
+	bool		tempSlotChanged = false;
 
 	ProcessConfigFile(PGC_SIGHUP);
 
@@ -12289,10 +12291,17 @@ ProcessStartupSigHup(void)
 	conninfoChanged = (strcmp(conninfo, PrimaryConnInfo) != 0);
 	slotnameChanged = (strcmp(slotname, PrimarySlotName) != 0);
 
+	/*
+	 * wal_receiver_create_temp_slot is used only when we have no slot
+	 * configured. We do not need to track this change if it has no effect.
+	 */
+	if (!slotnameChanged && strcmp(PrimarySlotName, "") == 0)
+		tempSlotChanged = (tempSlot != wal_receiver_create_temp_slot);
+
 	pfree(conninfo);
 	pfree(slotname);
 
-	if ((conninfoChanged || slotnameChanged) &&
+	if ((conninfoChanged || slotnameChanged || tempSlotChanged) &&
 		currentSource == XLOG_FROM_STREAM
 		&& WalRcvRunning())
 	{
@@ -12300,14 +12309,16 @@ ProcessStartupSigHup(void)
 			ereport(LOG,
 					(errmsg("The WAL receiver is going to be shut down due to change of %s",
 							"primary_conninfo")));
-		else if (conninfoChanged && slotnameChanged)
+		else if (conninfoChanged && (slotnameChanged || tempSlotChanged))
 			ereport(LOG,
 					(errmsg("The WAL receiver is going to be restarted due to change of %s and %s",
-							"primary_conninfo", "primary_slot_name")));
+							"primary_conninfo",
+							slotnameChanged ? "primary_slot_name" : "wal_receiver_create_temp_slot")));
 		else
 			ereport(LOG,
 					(errmsg("The WAL receiver is going to be restarted due to change of %s",
-							conninfoChanged ? "primary_conninfo" : "primary_slot_name")));
+							conninfoChanged ? "primary_conninfo"
+							: (slotnameChanged ? "primary_slot_name" : "wal_receiver_create_temp_slot"))));
 
 		pendingWalRcvRestart = true;
 	}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 8d9bdc0eaf..a3650518c4 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2030,7 +2030,7 @@ static struct config_bool ConfigureNamesBool[] =
 	},
 
 	{
-		{"wal_receiver_create_temp_slot", PGC_POSTMASTER, REPLICATION_STANDBY,
+		{"wal_receiver_create_temp_slot", PGC_SIGHUP, REPLICATION_STANDBY,
 			gettext_noop("Sets whether a WAL receiver should create a temporary replication slot if no permanent slot is configured."),
 		},
 		&wal_receiver_create_temp_slot,
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 31096725fd..f01e43b818 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -321,7 +321,6 @@
 					# -1 allows indefinite delay
 #wal_receiver_create_temp_slot = off	# Create temp slot if primary_slot_name
 					# is not set.
-					# (change requires restart)
 #wal_receiver_status_interval = 10s	# send replies at least this often
 					# 0 disables
 #hot_standby_feedback = off		# send info from standby to prevent