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'。
modified_context->setSetting("max_threads", streams_num);
        modified_context->setSetting("max_streams_to_max_threads_ratio", 1);
        InterpreterSelectQuery interpreter{modified_query_info.query, modified_context, SelectQueryOptions(processed_stage)};
        pipe = QueryPipelineBuilder::getPipe(interpreter.buildQueryPipeline());
        /** Materialization is needed, since from distributed storage the constants come materialized.
          * If you do not do this, different types (Const and non-Const) columns will be produced in different threads,
          * And this is not allowed, since all code is based on the assumption that in the block stream all types are the same.
          */
        pipe.addSimpleTransform([](const Block & stream_header) { return std::make_shared<MaterializingTransform>(stream_header); });
    }
    if (!pipe.empty())
    {
        if (concat_streams && pipe.numOutputPorts() > 1)
        {
            
            
            pipe.addTransform(std::make_shared<ConcatProcessor>(pipe.getHeader(), pipe.numOutputPorts()));
        }
        
        Block pipe_header = pipe.getHeader();
        if (has_database_virtual_column && !pipe_header.has("_database"))
        {
            ColumnWithTypeAndName column;
            column.name = "_database";
            column.type = std::make_shared<DataTypeString>();
            column.column = column.type->createColumnConst(0, Field(database_name));
            auto adding_column_dag = ActionsDAG::makeAddingColumnActions(std::move(column));
            auto adding_column_actions = std::make_shared<ExpressionActions>(
                std::move(adding_column_dag),
                ExpressionActionsSettings::fromContext(modified_context, CompileExpressions::yes));