MySQL::Eliminating redundant elements from a table?
- by Legend
I have a table like this:
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| v1 | int(11) | YES | MUL | NULL | |
| v2 | int(11) | YES | MUL | NULL | |
+-------+---------+------+-----+---------+-------+
There is a tremendous amount of duplication in this table. For instance, elements like the following:
+------+------+
| v1 | v2 |
+------+------+
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 1 | 5 |
| 1 | 6 |
| 1 | 7 |
| 1 | 8 |
| 1 | 9 |
| 2 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 1 |
+------+------+
The table is large with 1540000 entries. To remove the redundant entries (i.e. to get a table having only (1,9) and no (9,1) entries), I was thinking of doing it with a subquery but is there a better way of doing this?
