[index] index on users.remember_token

db/migrate/20210117111000_add_index_on_users_remember_token.rb

@@ -0,0 +1,7 @@
+class AddIndexOnUsersRememberToken < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def change
+    add_index :users, :remember_token, algorithm: :concurrently
+  end
+end