Speed up sql

core/tickets/api_v2.py

@@ -21,7 +21,7 @@ from tickets.shared_serializers import RelationSerializer
 
 class IssueViewSet(viewsets.ModelViewSet):
     serializer_class = IssueSerializer
-    queryset = IssueThread.objects.all().prefetch_related('state_changes', 'comments', 'emails', 'emails__attachments', 'assignments', 'assignments__assigned_to__username', 'related_items', 'item_relations', 'shipping_vouchers')
+    queryset = IssueThread.objects.all().prefetch_related('state_changes', 'comments', 'emails', 'emails__attachments', 'assignments', 'assignments__assigned_to__username', 'item_relation_changes', 'shipping_vouchers')
 
 
 class RelationViewSet(viewsets.ModelViewSet):

core/tickets/serializers.py

@@ -68,7 +68,7 @@ class IssueSerializer(BasicIssueSerializer):
             last_mail = max([t.timestamp for t in self.emails.all()]) if self.emails.exists() else None
             last_assignment = max([t.timestamp for t in self.assignments.all()]) if self.assignments.exists() else None
 
-            last_relation = max([t.timestamp for t in self.item_relations.all()]) if self.item_relations.exists() else None
+            last_relation = max([t.timestamp for t in self.item_relation_changes.all()]) if self.item_relation_changes.exists() else None
             args = [x for x in [last_state_change, last_comment, last_mail, last_assignment, last_relation] if
                     x is not None]
             return max(args)