Print wal_log_hints in the rm_desc routing of a parameter-change record.

It was an oversight in the original commit.

Also note in the sample config file that changing wal_log_hints requires a
restart.

Michael Paquier. Backpatch to 9.4, where wal_log_hints was added.

src/backend/access/rmgrdesc/xlogdesc.c

@@ -108,12 +108,15 @@ xlog_desc(StringInfo buf, XLogReaderState *record)
 			}
 		}
 
-		appendStringInfo(buf, "max_connections=%d max_worker_processes=%d max_prepared_xacts=%d max_locks_per_xact=%d wal_level=%s",
+		appendStringInfo(buf, "max_connections=%d max_worker_processes=%d "
+						 "max_prepared_xacts=%d max_locks_per_xact=%d "
+						 "wal_level=%s wal_log_hints=%s",
 						 xlrec.MaxConnections,
 						 xlrec.max_worker_processes,
 						 xlrec.max_prepared_xacts,
 						 xlrec.max_locks_per_xact,
-						 wal_level_str);
+						 wal_level_str,
+						 xlrec.wal_log_hints ? "on" : "off");
 	}
 	else if (info == XLOG_FPW_CHANGE)
 	{

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

@@ -187,6 +187,7 @@
 					#   open_sync
 #full_page_writes = on			# recover from partial page writes
 #wal_log_hints = off			# also do full page writes of non-critical updates
+					# (change requires restart)
 #wal_buffers = -1			# min 32kB, -1 sets based on shared_buffers
 					# (change requires restart)
 #wal_writer_delay = 200ms		# 1-10000 milliseconds