public function update($query, array $options = array()) {
		$_config = $this->_config;
		$defaults = array(
			'upsert' => false,
			'multiple' => true,
			'w' => $_config['w'],
			'wTimeoutMS' => $_config['wTimeoutMS'],
			'fsync' => false
		);
		$options += $defaults;
		$this->_checkConnection();

		$params = compact('query', 'options');
		$_exp = $this->_classes['exporter'];

		return $this->_filter(__METHOD__, $params, function($self, $params) use ($_config, $_exp) {
			$options = $params['options'];
			$query  = $params['query'];
			$args   = $query->export($self, array('keys' => array('conditions', 'source', 'data')));
			$source = $args['source'];
			$data   = $args['data'];

			if ($query->entity()) {
				$data = $_exp::get('update', $data);
			}

			if ($source === "{$_config['gridPrefix']}.files" && isset($data['update']['file'])) {
				$args['data']['_id'] = $self->invokeMethod('_saveFile', array($data['update']));
			}
			$update = $query->entity() ? $_exp::toCommand($data) : $data;
			if (empty($update)) {
				return true;
			}
			if ($options['multiple'] && !preg_grep('/^\$/', array_keys($update))) {
				$update = array('$set' => $update);
			}
			$result = $self->connection->{$source}->update($args['conditions'], $update, $options);
			if ($self->invokeMethod('_ok', array($result))) {
				$query->entity() ? $query->entity()->sync() : null;
				return true;
			}
			return false;
		});
	}