public function getConfig($driver = 'pgsql')
 {
     $config = parent::getConfig($driver);
     $config['parameters']['extractor_class'] = 'PgSQL';
     return $config;
 }
 public function getConfig($driver = 'common')
 {
     $config = parent::getConfig($driver);
     $config['parameters']['extractor_class'] = 'Common';
     return $config;
 }