diff --git a/django/core/management/commands/dumpdata.py b/django/core/management/commands/dumpdata.py
index d795d6f8b8..215e58605e 100644
--- a/django/core/management/commands/dumpdata.py
+++ b/django/core/management/commands/dumpdata.py
@@ -31,10 +31,10 @@ class Command(BaseCommand):
         exclude = options.get('exclude',[])
         show_traceback = options.get('traceback', False)
 
-        excluded_apps = [get_app(app_label) for app_label in exclude]
+        excluded_apps = set(get_app(app_label) for app_label in exclude)
 
         if len(app_labels) == 0:
-            app_list = SortedDict([(app, None) for app in get_apps() if app not in excluded_apps])
+            app_list = SortedDict((app, None) for app in get_apps() if app not in excluded_apps)
         else:
             app_list = SortedDict()
             for label in app_labels:
diff --git a/django/core/management/commands/syncdb.py b/django/core/management/commands/syncdb.py
index 85c1c1f4b7..31c1cb3121 100644
--- a/django/core/management/commands/syncdb.py
+++ b/django/core/management/commands/syncdb.py
@@ -59,11 +59,11 @@ class Command(NoArgsCommand):
         created_models = set()
         pending_references = {}
 
-        excluded_apps = [models.get_app(app_label) for app_label in exclude]
-        app_list = [app for app in models.get_apps() if app not in excluded_apps]
+        excluded_apps = set(models.get_app(app_label) for app_label in exclude)
+        included_apps = set(app for app in models.get_apps() if app not in excluded_apps)
 
         # Create the tables for each model
-        for app in app_list:
+        for app in included_apps:
             app_name = app.__name__.split('.')[-2]
             model_list = models.get_models(app, include_auto_created=True)
             for model in model_list:
@@ -101,7 +101,7 @@ class Command(NoArgsCommand):
 
         # Install custom SQL for the app (but only if this
         # is a model we've just created)
-        for app in app_list:
+        for app in included_apps:
             app_name = app.__name__.split('.')[-2]
             for model in models.get_models(app):
                 if model in created_models:
@@ -126,7 +126,7 @@ class Command(NoArgsCommand):
                             print "No custom SQL for %s.%s model" % (app_name, model._meta.object_name)
 
         # Install SQL indicies for all newly created models
-        for app in app_list:
+        for app in included_apps:
             app_name = app.__name__.split('.')[-2]
             for model in models.get_models(app):
                 if model in created_models:
diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 24caf67c14..966ab0354e 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -16,6 +16,7 @@ except ImportError:
     # Python 2.3 fallback
     from django.utils import _decimal as decimal
 
+from django.db import DEFAULT_DB_ALIAS
 from django.db.backends import util
 from django.utils import datetime_safe
 from django.utils.importlib import import_module
@@ -26,7 +27,7 @@ class BaseDatabaseWrapper(local):
     """
     ops = None
 
-    def __init__(self, settings_dict, alias='default'):
+    def __init__(self, settings_dict, alias=DEFAULT_DB_ALIAS):
         # `settings_dict` should be a dictionary containing keys such as
         # DATABASE_NAME, DATABASE_USER, etc. It's called `settings_dict`
         # instead of `settings` to disambiguate it from Django settings