public function getColumnsWithIndex($types)
{
$columns_with_index = array();
foreach (Index::getFromTableByChoice($this->_name, $this->_db_name, $types) as $index) {
$columns = $index->getColumns();
foreach ($columns as $column_name => $dummy) {
$columns_with_index[] = $column_name;
}
}
return $columns_with_index;
}