Only sort by IDs by default

Sorting by both "created_at" and "id" in descending order is not needed
as simply sorting by "id" in descending order will already sort rows
from new to old. Depending on the query and data involved sorting twice
can also introduce significant overhead.

app/models/concerns/sortable.rb

@@ -8,12 +8,12 @@ module Sortable
   included do
     # By default all models should be ordered
     # by created_at field starting from newest
-    default_scope { order(created_at: :desc, id: :desc) }
+    default_scope { order(id: :desc) }
 
-    scope :order_created_desc, -> { reorder(created_at: :desc, id: :desc) }
-    scope :order_created_asc, -> { reorder(created_at: :asc, id: :asc) }
-    scope :order_updated_desc, -> { reorder(updated_at: :desc, id: :desc) }
-    scope :order_updated_asc, -> { reorder(updated_at: :asc, id: :asc) }
+    scope :order_created_desc, -> { reorder(created_at: :desc) }
+    scope :order_created_asc, -> { reorder(created_at: :asc) }
+    scope :order_updated_desc, -> { reorder(updated_at: :desc) }
+    scope :order_updated_asc, -> { reorder(updated_at: :asc) }
     scope :order_name_asc, -> { reorder(name: :asc) }
     scope :order_name_desc, -> { reorder(name: :desc) }
   end