/**
  * Returns array of main table columns names of $field
  *
  * @param  moscomprofilerFields  $field
  * @return array
  */
 function getMainTableColumns(&$field)
 {
     global $_CB_database;
     $fieldXML =& $this->_loadFieldXML($field);
     if ($fieldXML) {
         $db =& $fieldXML->getElementByPath('database');
         if ($db !== false) {
             cbimport('cb.sql.upgrader');
             $sqlUpgrader = new CBSQLupgrader($_CB_database);
             $columnsNames = $sqlUpgrader->getMainTableColumnsNames($db, $field->name);
             if ($columnsNames !== false) {
                 return $columnsNames;
             }
         }
     }
     return array($field->name);
 }