Author: Bryan.TongMinh
Description:
See https://wikitech.leuksman.com/index.php?title=Server_admin_log&diff=17574&oldid=17573
An explain on the example query in the code gives:
mysql> EXPLAIN SELECT page_id, page_title, page_namespace, page_is_redirect, pl_title, pl_namespace FROM pagelinks, page WHERE pl_from=page_id AND (pl_title='Foo' AND pl_namespace=0) OR (pl_title='Bar' AND pl_namespace=1) ORDER BY pl_namespace, pl_title, pl_from LIMIT 500;
+----+-------------+-----------+-------+----------------------+--------------+---------+------+----------+-----------------------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-----------+-------+----------------------+--------------+---------+------+----------+-----------------------------------------------------------+
| 1 | SIMPLE | pagelinks | range | pl_from,pl_namespace | pl_namespace | 261 | NULL | 557 | Using where; Using index; Using temporary; Using filesort |
| 1 | SIMPLE | page | ALL | PRIMARY | NULL | NULL | NULL | 15734439 | Using where |
+----+-------------+-----------+-------+----------------------+--------------+---------+------+----------+-----------------------------------------------------------+
2 rows in set (0.01 sec)
A filesort of 557 rows does not seem much, but I don't know how the row number is related to the requested page.
Version: 1.14.x
Severity: enhancement