Implement code style and commenting review comments

Author: AlanCoding

ansible_base/lib/utils/db.py

@@ -194,16 +194,19 @@ def psycopg_conn_string_from_settings_dict(settings_dict: dj_db_dict) -> str:
 def combine_settings_dict(settings_dict1: dj_db_dict, settings_dict2: dj_db_dict, **extra_options) -> dj_db_dict:
     """Given two Django database settings dictionaries, combine them and return a new settings_dict"""
     settings_dict = deepcopy(settings_dict1)
-    settings_dict['OPTIONS'] = deepcopy(settings_dict.get('OPTIONS', {}))
-
-    # These extra options are used by AWX to set application_name
-    settings_dict['OPTIONS'].update(extra_options)
 
     # Apply overrides specifically for the listener connection
     for k, v in settings_dict2.items():
         if k != 'OPTIONS':
             settings_dict[k] = v
 
+    # Merge the database OPTIONS
+    # https://docs.djangoproject.com/en/5.2/ref/databases/#postgresql-connection-settings
+    # These are not expected to be nested, as they are psycopg params
+    settings_dict.setdefault('OPTIONS', {})
+    # extra_options are used by AWX to set application_name, which is generally a good idea
+    settings_dict['OPTIONS'].update(extra_options)
+    # Apply overrides from nested OPTIONS for the listener connection
     for k, v in settings_dict2.get('OPTIONS', {}).items():
         settings_dict['OPTIONS'][k] = v
 
@@ -214,8 +217,9 @@ def get_pg_notify_params(alias: str = DEFAULT_DB_ALIAS, **extra_options) -> dict
     """Returns a dictionary that can be used as kwargs to create a psycopg.Connection
 
     This should use the same connection parameters as Django does.
-    However, this also allows overrides specified by the setting
-    PG_NOTIFY_DATABASES and then the LISTENER_DATABASES, deprecated AWX setting.
+    However, this also allows overrides specified by
+    - PG_NOTIFY_DATABASES, higher precedence, preferred setting
+    - LISTENER_DATABASES, lower precedence, deprecated AWX setting.
     """
     pg_notify_overrides = {}
     if hasattr(settings, 'PG_NOTIFY_DATABASES'):