Wikimedia Bugzilla is closed!

Split from bug 16112 comment 47 as this is a problem in the script itself.

(Reedy said in bug 16112 comment 48)
> The original queries take an age, and isn't going to attempt to load it all.
> 
> mysql> explain select DISTINCT pl_from from pagelinks LEFT JOIN page ON
> pl_from=page_id;
> +----+-------------+-----------+--------+---------------+---------+---------+--------------------------+-----------+------------------------------+
> | id | select_type | table     | type   | possible_keys | key     | key_len |
> ref                      | rows      | Extra                        |
> +----+-------------+-----------+--------+---------------+---------+---------+--------------------------+-----------+------------------------------+
> |  1 | SIMPLE      | pagelinks | index  | NULL          | pl_from | 265     |
> NULL                     | 624327870 | Using index; Using temporary |
> |  1 | SIMPLE      | page      | eq_ref | PRIMARY       | PRIMARY | 4       |
> enwiki.pagelinks.pl_from |         1 | Using index; Distinct        |
> +----+-------------+-----------+--------+---------------+---------+---------+--------------------------+-----------+------------------------------+
> 2 rows in set (0.01 sec)
> 
> Removing the distinct would make things simpler.. If kept a client side count,
> and removed the distint... Would this work for us..