added change_settings.md

change_settings.md

@@ -0,0 +1,15 @@
+# Does changing a config setting require a restart of postgresql or just a reload (SIGHUP)?
+
+This can be archived by simply selecting the setting from pg_settings. 
+
+```
+select context from pg_settings where name='max_wal_size';
+```
+
+# Is a restart of postgresql required?
+
+```
+select pending_restart from pg_settings where name='max_wal_size';
+```
+
+This will tell you if a restart is pending for a setting.