Improve query time by removing a check from the order by filter handler

awx/api/filters.py

@@ -277,12 +277,6 @@ class OrderByBackend(BaseFilterBackend):
                         if field not in ('type', '-type'):
                             new_order_by.append(field)
                 queryset = queryset.order_by(*new_order_by)
-                # Fetch the first result to run the query, otherwise we don't
-                # always catch the FieldError for invalid field names.
-                try:
-                    queryset[0]
-                except IndexError:
-                    pass
             return queryset
         except FieldError, e:
             # Return a 400 for invalid field names.

awx/api/views.py

@@ -15,6 +15,7 @@ import sys
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.urlresolvers import reverse
+from django.core.exceptions import FieldError
 from django.db.models import Q, Count, Sum
 from django.db import IntegrityError, transaction
 from django.shortcuts import get_object_or_404
@@ -62,6 +63,8 @@ def api_exception_handler(exc):
     '''
     if isinstance(exc, IntegrityError):
         exc = ParseError(exc.args[0])
+    if isinstance(exc, FieldError):
+        exc = ParseError(exc.args[0])
     return exception_handler(exc)