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 local_context,
    QueryProcessingStage::Enum to_stage,
    const StorageMetadataPtr &,
    SelectQueryInfo & query_info) const
{
    
    
    
    
    
    
    
    if (const auto * select = query_info.query->as<ASTSelectQuery>(); select && hasJoin(*select))
        return QueryProcessingStage::FetchColumns;
    auto stage_in_source_tables = QueryProcessingStage::FetchColumns;
    DatabaseTablesIterators database_table_iterators = getDatabaseIterators(local_context);
    size_t selected_table_size = 0;
    for (const auto & iterator : database_table_iterators)
    {
        while (iterator->isValid())
        {
            const auto & table = iterator->table();
            if (table && table.get() != this)
            {
                ++selected_table_size;