#27685
{
    if (column.type->lowCardinality())
    {
        
        const auto & dict_type = typeid_cast<const DataTypeLowCardinality *>(column.type.get())->getDictionaryType();
        column.type = std::make_shared<DataTypeLowCardinality>(removeNullable(dict_type));
        if (column.column && column.column->lowCardinality())
        {
            auto mut_col = IColumn::mutate(std::move(column.column));
            ColumnLowCardinality * col_as_lc = typeid_cast<ColumnLowCardinality *>(mut_col.get());
            if (col_as_lc && col_as_lc->nestedIsNullable())
                col_as_lc->nestedRemoveNullable();
            column.column = std::move(mut_col);
        }
    }
    else
    {
        column.type = removeNullable(column.type);
        if (column.column && column.column->isNullable())
        {
            const auto * nullable_column = checkAndGetColumn<ColumnNullable>(*column.column);
            ColumnPtr nested_column = nullable_column->getNestedColumnPtr();
            MutableColumnPtr mutable_column = IColumn::mutate(std::move(nested_column));
            column.column = std::move(mutable_column);
        }
    }
}
void changeColumnRepresentation(const ColumnPtr & src_column, ColumnPtr & dst_column)