Add index to statuses_tags#status_id (#2394)

db/migrate/20170424112722_add_status_id_index_to_statuses_tags.rb

@@ -0,0 +1,5 @@
+class AddStatusIdIndexToStatusesTags < ActiveRecord::Migration[5.0]
+  def change
+    add_index :statuses_tags, :status_id
+  end
+end

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: 20170418160728) do
+ActiveRecord::Schema.define(version: 20170424112722) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -255,6 +255,7 @@ ActiveRecord::Schema.define(version: 20170418160728) do
   create_table "statuses_tags", id: false, force: :cascade do |t|
     t.bigint  "status_id", null: false
     t.integer "tag_id",    null: false
+    t.index ["status_id"], name: "index_statuses_tags_on_status_id", using: :btree
     t.index ["tag_id", "status_id"], name: "index_statuses_tags_on_tag_id_and_status_id", unique: true, using: :btree
   end