wikiadmin@10.64.16.102(commonswiki)> explain SELECT /* ApiQueryLogEvents::execute  */  log_id,log_type,log_action,log_timestamp,log_deleted,page_id,log_page,actor_log_user.actor_user AS `log_user`,actor_log_user.actor_name AS `log_user_text`,log_actor,user_name,log_namespace,log_title,log_params,comment_log_comment.comment_text AS `log_comment_text`,comment_log_comment.comment_data AS `log_comment_data`,comment_log_comment.comment_id AS `log_comment_cid`,(SELECT  GROUP_CONCAT(ctd_name SEPARATOR ',')  FROM `change_tag` JOIN `change_tag_def` ON ((ct_tag_id=ctd_id))   WHERE ct_log_id=log_id  ) AS `ts_tags`  FROM `logging` JOIN `actor` `actor_log_user` ON ((actor_log_user.actor_id = log_actor)) LEFT JOIN `user` ON ((user_id=actor_log_user.actor_user)) LEFT JOIN `page` ON ((log_namespace=page_namespace) AND (log_title=page_title)) JOIN `comment` `comment_log_comment` ON ((comment_log_comment.comment_id = log_comment_id))   WHERE (log_type NOT IN ('spamblacklist','titleblacklist','abusefilterprivatedetails','suppress'))  ORDER BY log_timestamp DESC,log_id DESC LIMIT 501;
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+
| id   | select_type        | table               | type   | possible_keys                                            | key                   | key_len | ref                                                             | rows    | Extra                           |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+
|    1 | PRIMARY            | actor_log_user      | ALL    | PRIMARY                                                  | NULL                  | NULL    | NULL                                                            | 8158533 | Using temporary; Using filesort |
|    1 | PRIMARY            | user                | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | commonswiki.actor_log_user.actor_user                           |       1 | Using where                     |
|    1 | PRIMARY            | logging             | ref    | type_time,actor_time,log_actor_type_time,log_type_action | actor_time            | 8       | commonswiki.actor_log_user.actor_id                             |       4 | Using where                     |
|    1 | PRIMARY            | page                | eq_ref | name_title                                               | name_title            | 261     | commonswiki.logging.log_namespace,commonswiki.logging.log_title |       1 | Using index                     |
|    1 | PRIMARY            | comment_log_comment | eq_ref | PRIMARY                                                  | PRIMARY               | 8       | commonswiki.logging.log_comment_id                              |       1 |                                 |
|    2 | DEPENDENT SUBQUERY | change_tag          | ref    | change_tag_log_tag_id,change_tag_tag_id_id               | change_tag_log_tag_id | 5       | commonswiki.logging.log_id                                      |       1 | Using index                     |
|    2 | DEPENDENT SUBQUERY | change_tag_def      | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | commonswiki.change_tag.ct_tag_id                                |       1 |                                 |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+

wikiadmin@10.64.16.102(commonswiki)> explain SELECT * FROM logging JOIN actor ON (actor_id = log_actor)  ORDER BY log_timestamp,log_id LIMIT 501;
+------+-------------+---------+------+--------------------------------+------------+---------+----------------------------+---------+---------------------------------+
| id   | select_type | table   | type | possible_keys                  | key        | key_len | ref                        | rows    | Extra                           |
+------+-------------+---------+------+--------------------------------+------------+---------+----------------------------+---------+---------------------------------+
|    1 | SIMPLE      | actor   | ALL  | PRIMARY                        | NULL       | NULL    | NULL                       | 8158537 | Using temporary; Using filesort |
|    1 | SIMPLE      | logging | ref  | actor_time,log_actor_type_time | actor_time | 8       | commonswiki.actor.actor_id |       4 |                                 |
+------+-------------+---------+------+--------------------------------+------------+---------+----------------------------+---------+---------------------------------+

wikiadmin@10.64.16.102(commonswiki)> explain SELECT /*!STRAIGHT_JOIN*/ * FROM logging JOIN actor ON (actor_id = log_actor)  ORDER BY log_timestamp,log_id LIMIT 501;
+------+-------------+---------+--------+--------------------------------+---------+---------+-------------------------------+------+-------+
| id   | select_type | table   | type   | possible_keys                  | key     | key_len | ref                           | rows | Extra |
+------+-------------+---------+--------+--------------------------------+---------+---------+-------------------------------+------+-------+
|    1 | SIMPLE      | logging | index  | actor_time,log_actor_type_time | times   | 16      | NULL                          |  501 |       |
|    1 | SIMPLE      | actor   | eq_ref | PRIMARY                        | PRIMARY | 8       | commonswiki.logging.log_actor |    1 |       |
+------+-------------+---------+--------+--------------------------------+---------+---------+-------------------------------+------+-------+

wikiadmin@10.64.16.101(enwiki)> explain SELECT /* ApiQueryLogEvents::execute  */  log_id,log_type,log_action,log_timestamp,log_deleted,page_id,log_page,actor_log_user.actor_user AS `log_user`,actor_log_user.actor_name AS `log_user_text`,log_actor,user_name,log_namespace,log_title,log_params,comment_log_comment.comment_text AS `log_comment_text`,comment_log_comment.comment_data AS `log_comment_data`,comment_log_comment.comment_id AS `log_comment_cid`,(SELECT  GROUP_CONCAT(ctd_name SEPARATOR ',')  FROM `change_tag` JOIN `change_tag_def` ON ((ct_tag_id=ctd_id))   WHERE ct_log_id=log_id  ) AS `ts_tags`  FROM `logging` JOIN `actor` `actor_log_user` ON ((actor_log_user.actor_id = log_actor)) LEFT JOIN `user` ON ((user_id=actor_log_user.actor_user)) LEFT JOIN `page` ON ((log_namespace=page_namespace) AND (log_title=page_title)) JOIN `comment` `comment_log_comment` ON ((comment_log_comment.comment_id = log_comment_id))   WHERE (log_type NOT IN ('spamblacklist','titleblacklist','abusefilterprivatedetails','suppress'))  ORDER BY log_timestamp DESC,log_id DESC LIMIT 501;
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-------------------------------------------------------+------+-------------+
| id   | select_type        | table               | type   | possible_keys                                            | key                   | key_len | ref                                                   | rows | Extra       |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-------------------------------------------------------+------+-------------+
|    1 | PRIMARY            | logging             | index  | type_time,actor_time,log_actor_type_time,log_type_action | times                 | 16      | NULL                                                  |  799 | Using where |
|    1 | PRIMARY            | actor_log_user      | eq_ref | PRIMARY                                                  | PRIMARY               | 8       | enwiki.logging.log_actor                              |    1 |             |
|    1 | PRIMARY            | user                | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | enwiki.actor_log_user.actor_user                      |    1 | Using where |
|    1 | PRIMARY            | page                | eq_ref | name_title                                               | name_title            | 261     | enwiki.logging.log_namespace,enwiki.logging.log_title |    1 | Using index |
|    1 | PRIMARY            | comment_log_comment | eq_ref | PRIMARY                                                  | PRIMARY               | 8       | enwiki.logging.log_comment_id                         |    1 |             |
|    2 | DEPENDENT SUBQUERY | change_tag          | ref    | change_tag_log_tag_id,change_tag_tag_id_id               | change_tag_log_tag_id | 5       | enwiki.logging.log_id                                 |   36 | Using index |
|    2 | DEPENDENT SUBQUERY | change_tag_def      | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | enwiki.change_tag.ct_tag_id                           |    1 |             |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-------------------------------------------------------+------+-------------+

root@db2073.codfw.wmnet[(none)]> show explain for 6952971;
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+
| id   | select_type        | table               | type   | possible_keys                                            | key                   | key_len | ref                                                             | rows    | Extra                           |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+
|    1 | PRIMARY            | actor_log_user      | ALL    | PRIMARY                                                  | NULL                  | NULL    | NULL                                                            | 8335724 | Using temporary; Using filesort |
|    1 | PRIMARY            | user                | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | commonswiki.actor_log_user.actor_user                           |       1 | Using where                     |
|    1 | PRIMARY            | logging             | ref    | type_time,actor_time,log_actor_type_time,log_type_action | log_actor_type_time   | 8       | commonswiki.actor_log_user.actor_id                             |       3 | Using index condition           |
|    1 | PRIMARY            | page                | eq_ref | name_title                                               | name_title            | 261     | commonswiki.logging.log_namespace,commonswiki.logging.log_title |       1 | Using index                     |
|    1 | PRIMARY            | comment_log_comment | eq_ref | PRIMARY                                                  | PRIMARY               | 8       | commonswiki.logging.log_comment_id                              |       1 |                                 |
|    2 | DEPENDENT SUBQUERY | change_tag          | ref    | change_tag_log_tag_id,change_tag_tag_id_id               | change_tag_log_tag_id | 5       | commonswiki.logging.log_id                                      |       1 | Using index                     |
|    2 | DEPENDENT SUBQUERY | change_tag_def      | eq_ref | PRIMARY                                                  | PRIMARY               | 4       | commonswiki.change_tag.ct_tag_id                                |       1 |                                 |
+------+--------------------+---------------------+--------+----------------------------------------------------------+-----------------------+---------+-----------------------------------------------------------------+---------+---------------------------------+
7 rows in set, 1 warning (0.04 sec)