And waits for them. That's pointless.
|| command.type == MutationCommand::Type::UPDATE)
            {
                for_interpreter.push_back(command);
            }
            else if (command.type == MutationCommand::Type::DROP_INDEX || command.type == MutationCommand::Type::DROP_PROJECTION)
            {
                for_file_renames.push_back(command);
            }
            
            
            else if (part_columns.has(command.column_name))
            {
                if (command.type == MutationCommand::Type::READ_COLUMN)
                {
                    for_interpreter.push_back(command);
                }
                else if (command.type == MutationCommand::Type::RENAME_COLUMN)
                {
                    part_columns.rename(command.column_name, command.rename_to);
                    for_file_renames.push_back(command);
                }
                else
                {
                    for_file_renames.push_back(command);
                }
            }
        }
    }
}
NameToNameVector MergeTreeDataMergerMutator::collectFilesForRenames(