Change the table comment after created the table is not supported now?
Like mysql : ALTER TABLE [tableName] COMMNET [comment]; 
The sql "ALTER TABLE `system`.tables UPDATE Comment='test' WHERE NAME='t1';" also not supported!!!
My version is '21.9.4.35'。
{
    const std::string path(disk->getPath() + relative_data_path);
    fs::create_directories(path);
    std::filesystem::directory_iterator begin(path);
    std::filesystem::directory_iterator end;
    for (auto it = begin; it != end; ++it)
    {
        const auto & dir_path = it->path();
        if (std::filesystem::is_directory(dir_path))
        {
            const auto & tmp_path = dir_path / "tmp";
            
            if (std::filesystem::is_directory(tmp_path) && std::filesystem::is_empty(tmp_path))
                std::filesystem::remove(tmp_path);
            if (std::filesystem::is_empty(dir_path))
            {
                LOG_DEBUG(log, "Removing {} (used for async INSERT into Distributed)", dir_path.string());
                
                std::filesystem::remove(dir_path);
            }
            else
            {
                requireDirectoryMonitor(disk, dir_path.filename().string(),  true);
            }
        }
    }
}
StorageDistributedDirectoryMonitor& StorageDistributed::requireDirectoryMonitor(const DiskPtr & disk, const std::string & name, bool startup)