public function checkBackupIsPossible()
    {
        $size = 0;
        if (preg_match('/^(\d+)(.)$/', ini_get('memory_limit'), $matches)) {
            switch (strtolower($matches[2])) {
                case 'k':
                    $size = $matches[1] / 1024;
                    break;
                case 'm':
                    $size = $matches[1];
                    break;
                case 'g':
                    $size = $matches[1] * 1024;
                    break;
            }
        }

        if ($this->getDataBaseSize() > ($size - 64) / 8) {
            return false;
        }

        return true;
    }