/**
  * Check unique url_key value in catalog_category_entity_url_key table.
  *
  * @param Mage_Catalog_Model_Abstract $object
  * @return bool
  * @throws Mage_Core_Exception
  */
 protected function _isAvailableUrl($object)
 {
     $select = $this->_connection->select()->from($this->getAttribute()->getBackendTable(), array('entity_id', 'store_id'))->where('value = ?', $object->getUrlKey())->limit(1);
     $row = $this->_connection->fetchRow($select);
     // we should allow save same url key for product in current store view
     // but not allow save existing url key in current store view from another store view
     if (empty($row)) {
         return true;
     } elseif ($object->getId() && $object->getStoreId() !== null && ($row['store_id'] == $object->getStoreId() && $row['entity_id'] == $object->getId())) {
         return true;
     }
     return false;
 }