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'。
{
    auto name_deps = getDependentViewsByColumn(local_context);
    for (const auto & command : commands)
    {
        if (command.type != AlterCommand::Type::ADD_COLUMN
            && command.type != AlterCommand::Type::MODIFY_COLUMN
            && command.type != AlterCommand::Type::DROP_COLUMN
            && command.type != AlterCommand::Type::COMMENT_COLUMN)
            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
                command.type, getName());
        if (command.type == AlterCommand::Type::DROP_COLUMN && !command.clear)
        {
            const auto & deps_mv = name_deps[command.column_name];
            if (!deps_mv.empty())
            {
                throw Exception(
                    "Trying to ALTER DROP column " + backQuoteIfNeed(command.column_name) + " which is referenced by materialized view "
                        + toString(deps_mv),
                    ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN);
            }
        }
    }
}
void StorageMerge::alter(