mysql> explain SELECT rc_timestamp, rc_log_action, rc_namespace, rc_title, user_name, user_editcount, rc_comment,
(unix_timestamp(rc_timestamp)-unix_timestamp(user_registration)) as user_age, log_params, ipb_expiry FROM recentchanges LEFT OUTER JOIN logging ON
log_id=rc_logid LEFT OUTER JOIN user ON user_id=rc_user LEFT OUTER JOIN ipblocks ON ipb_address=rc_user_text AND
(unix_timestamp(ipb_timestamp)-unix_timestamp(rc_timestamp))<600 ORDER BY rc_timestamp DESC LIMIT 50000;
+----+-------------+---------------+--------+---------------+---------+---------+------+---------+---------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+---------------+--------+---------------+---------+---------+------+---------+---------------------------------+
| 1 | SIMPLE | recentchanges | ALL | NULL | NULL | NULL | NULL | 6289048 | Using temporary; Using filesort |
| 1 | SIMPLE | logging | eq_ref | PRIMARY | PRIMARY | 4 | func | 1 | |
| 1 | SIMPLE | user | eq_ref | PRIMARY | PRIMARY | 4 | func | 1 | |
| 1 | SIMPLE | ipblocks | ALL | NULL | NULL | NULL | NULL | 281149 | |
+----+-------------+---------------+--------+---------------+---------+---------+------+---------+---------------------------------+
4 rows in set (0.00 sec)
