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'。
ContextPtr context_,
    size_t num_shards_,
    const Thresholds & min_thresholds_,
    const Thresholds & max_thresholds_,
    const Thresholds & flush_thresholds_,
    const StorageID & destination_id_,
    bool allow_materialized_)
    : IStorage(table_id_)
    , WithContext(context_->getBufferContext())
    , num_shards(num_shards_)
    , buffers(num_shards_)
    , min_thresholds(min_thresholds_)
    , max_thresholds(max_thresholds_)
    , flush_thresholds(flush_thresholds_)
    , destination_id(destination_id_)
    , allow_materialized(allow_materialized_)
    , log(&Poco::Logger::get("StorageBuffer (" + table_id_.getFullTableName() + ")"))
    , bg_pool(getContext()->getBufferFlushSchedulePool())
{
    StorageInMemoryMetadata storage_metadata;
    storage_metadata.setColumns(columns_);
    storage_metadata.setConstraints(constraints_);
    storage_metadata.setComment(comment);
    setInMemoryMetadata(storage_metadata);
    flush_handle = bg_pool.createTask(log->name() + "/Bg", [this]{ backgroundFlush(); });
}
class BufferSource : public SourceWithProgress
{
public:
    BufferSource(const Names & column_names_, StorageBuffer::Buffer & buffer_, const StorageBuffer & storage, const StorageMetadataPtr & metadata_snapshot)