Faster way of updating single field of an entity

quick_field_save.php

 <?php
function updateProductCategoryReference($product_id, $new_cat_tid) {
  $product = new stdClass();
  $product->product_id = $product_id;
  $product->type = 'product';
  $product->field_product_category[LANGUAGE_NONE][]['tid'] = $new_cat_tid;
  $transaction = db_transaction();
  try {
    field_attach_presave('commerce_product', $product);
    field_attach_update('commerce_product', $product);
    entity_get_controller('commerce_product')->resetCache([$product_id]);
  }
  catch (\Exception $e) {
    $transaction->rollback();
  }
}