public function update($query, array $options = []) {
		$this->_checkConnection();

		$defaults = [
			'upsert' => false,
			'multiple' => true,
			'w' => $this->_config['w'],
			'wTimeoutMS' => $this->_config['wTimeoutMS'],
			'fsync' => false
		];
		$options += $defaults;

		$params = compact('query', 'options');

		return Filters::run($this, __FUNCTION__, $params, function($params) {
			$exporter = $this->_classes['exporter'];
			$prefix = $this->_config['gridPrefix'];

			$options = $params['options'];
			$query  = $params['query'];
			$args   = $query->export($this, ['keys' => ['conditions', 'source', 'data']]);
			$source = $args['source'];
			$data   = $args['data'];

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

			if ($source === "{$prefix}.files" && isset($data['update']['file'])) {
				$args['data']['_id'] = $this->_saveFile($data['update']);
			}
			$update = $query->entity() ? $exporter::toCommand($data) : $data;

			if (empty($update)) {
				return true;
			}
			if ($options['multiple'] && !preg_grep('/^\$/', array_keys($update))) {
				$update = ['$set' => $update];
			}
			$result = $this->connection->{$source}->update($args['conditions'], $update, $options);

			if ($this->_ok($result)) {
				$query->entity() ? $query->entity()->sync() : null;
				return true;
			}
			return false;
		});
	}