speed up rendering of data views with better json

app/views/data_views/index.json.jbuilder

 
+  home_view_id = current_user.home_data_view_id
   json.array! @data_views do |view|
     json.extract! view, *DataView.json_keys
-    json.owner current_user==view.owner
-    json.home current_user.home_data_view_id == view.id
+    json.owner current_user.id==view.user_id
+    json.home home_view_id == view.id
   end