Added commands for configuration check

change_settings.md

@@ -19,3 +19,15 @@ select pending_restart from pg_settings where name='max_wal_size';
 ```
 
 This will tell you if a restart is pending for a setting. 
+
+## How to check configuration (postgresql.conf) for configuration errors
+
+```
+select sourcefile, name,sourceline,error from pg_file_settings where error is not null;
+```
+
+## How to check pg_hba.conf for configuration errors
+
+```
+select pg_hba_file_rules();
+```