add indexes on schedules

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20161118182237) do
+ActiveRecord::Schema.define(version: 20161129040302) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -74,6 +74,8 @@
     t.datetime "created_at",   null: false
     t.datetime "updated_at",   null: false
     t.index ["course_id"], name: "index_schedules_on_course_id", using: :btree
+    t.index ["end_time"], name: "index_schedules_on_end_time", using: :btree
+    t.index ["start_time"], name: "index_schedules_on_start_time", using: :btree
     t.index ["store_id"], name: "index_schedules_on_store_id", using: :btree
   end