efficient join based on non-constant range condition?

Hi,
I have a query that is extremely inefficient involving a join based
on a range condition, as follows:

mysql> select * from sorted;
+----+----------+
| id | position |
+----+----------+
| 0 | 2426 |
| 1 | 2782 |
| 2 | 3095 |
| 3 | 3522 |
| 4 | 5363 |
| 5 | 6166 |
| 6 | 7834 |
| 7 | 8304 |
| 8 | 8732 |
| 9 | 9131 |
| 10 | 10711 |
| 11 | 11413 |
| 12 | 12275 |
| 13 | 12474 |
| 14 | 13420 |
| 15 | 15360 |
| 16 | 15925 |
| 17 | 16405 |
| 18 | 16701 |
| 19 | 16962 |
+----+----------+
20 rows in set (0.00 sec)

mysql> show index from sorted;
+--------+------------+----------+--------------+-------------
+-----------+-------------+----------+--------+------+------------
+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name |
Collation | Cardinality | Sub_part | Packed | Null | Index_type |
Comment |
+--------+------------+----------+--------------+-------------
+-----------+-------------+----------+--------+------+------------
+---------+
| sorted | 1 | pos | 1 | position |
A | NULL | NULL | NULL | | BTREE
| |
+--------+------------+----------+--------------+-------------
+-----------+-------------+----------+--------+------+------------
+---------+
1 row in set (0.00 sec)

mysql> explain select s1.id as id1, s2.id as id2 from sorted s1,
sorted s2 where (s2.position between s1.position + 10 and s1.position
+ 1000);
+----+-------------+-------+------+---------------+------+---------
+------+------+------------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len |
ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------
+------+------+------------------------------------------------+
| 1 | SIMPLE | s1 | ALL | NULL | NULL | NULL |
NULL | 20 | |
| 1 | SIMPLE | s2 | ALL | pos | NULL | NULL |
NULL | 20 | Range checked for each record (index map: 0x1) |
+----+-------------+-------+------+---------------+------+---------
+------+------+------------------------------------------------+
2 rows in set (0.00 sec)


it seems like mysql should know to only scan a small subset of rows of
s2 for each row of s1. There is however no discussion in the
documentation on using non-constant range constraints.

Has anyone else encountered this and found a solution, such that the
'explain' command would show 20 rows scanned for s1 and about 2 for
s2?

Thanks in advance!

Henry