Thankfully "partial merge join" is disabled by default.

```
milovidov-desktop :) SET max_block_size = 6, join_algorithm = 'partial_merge'

SET max_block_size = 6, join_algorithm = 'partial_merge'

Query id: 600704b7-b455-4726-8a9c-8e45b509f2fb

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) SELECT blockSize() bs FROM (SELECT 1 s) js1 ALL RIGHT JOIN (SELECT arrayJoin([2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3]) s) js2 USING (s) GROUP BY bs ORDER BY bs;

SELECT blockSize() AS bs
FROM
(
    SELECT 1 AS s
) AS js1
ALL RIGHT JOIN
(
    SELECT arrayJoin([2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3]) AS s
) AS js2 USING (s)
GROUP BY bs
ORDER BY bs ASC

Query id: ae51c589-4b69-4e90-a3a9-7ef4ead72af9

→ Progress: 2.00 rows, 2.00 B (18.21 rows/s., 18.21 B/s.)
```

Found by stress test.
{
    for (size_t i = 0; i < block.columns(); ++i)
    {
        const auto & src_column = block.getByPosition(i).column;
        columns[i]->insertRangeFrom(*src_column, start, rows_to_add);
    }
}
void copyRightRange(const Block & right_block, const Block & right_columns_to_add, MutableColumns & columns,
                    size_t row_position, size_t rows_to_add)
{
    for (size_t i = 0; i < right_columns_to_add.columns(); ++i)
    {
        const auto & src_column = right_block.getByName(right_columns_to_add.getByPosition(i).name).column;
        auto & dst_column = columns[i];
        auto * dst_nullable = typeid_cast<ColumnNullable *>(dst_column.get());
        if (dst_nullable && !isColumnNullable(*src_column))
            dst_nullable->insertManyFromNotNullable(*src_column, row_position, rows_to_add);
        else
            dst_column->insertManyFrom(*src_column, row_position, rows_to_add);
    }
}
void joinEqualsAnyLeft(const Block & right_block, const Block & right_columns_to_add, MutableColumns & right_columns, const Range & range)
{
    copyRightRange(right_block, right_columns_to_add, right_columns, range.right_start, range.left_length);
}
template <bool is_all>
bool joinEquals(const Block & left_block, const Block & right_block, const Block & right_columns_to_add,