gistfile1.txt

mysql> explain SELECT articles.id, articles.author_id, articles.primary_image_id, articles.hit_count, articles.blurb, articles.teaser, articles.title, articles.permalink, articles.created_at, articles.comments_count  FROM articles  inner join taggings   on tag_id=16   and taggable_type='Article'   and articles.id = taggings.taggable_id WHERE articles.deleted_at IS NULL  AND articles.created_at > '2008-10-26 00:00:00'  ORDER BY articles.id DESC  LIMIT 5;
+----+-------------+----------+--------+----------------------------------------------------------------------------------------------------------------------------+---------+---------+------------------------------------------------+------+----------------------------------------------+
| id | select_type | table    | type   | possible_keys                                                                                                              | key     | key_len | ref                                            | rows | Extra                                        |
+----+-------------+----------+--------+----------------------------------------------------------------------------------------------------------------------------+---------+---------+------------------------------------------------+------+----------------------------------------------+
|  1 | SIMPLE      | taggings | ref    | index_taggings_on_taggable_id,index_taggings_i1,index_taggings_on_tag_id_and_taggable_type,i2                              | i2      | 4       | const                                          | 7936 | Using where; Using temporary; Using filesort | 
|  1 | SIMPLE      | articles | eq_ref | PRIMARY,idx_articles_on_created_at_id,idx_deleted_at_admin_edited_regular_edited_trusted_edited_score,idx_deleted_at_score | PRIMARY | 4       | bleacherreport_production.taggings.taggable_id |    1 | Using where                                  | 
+----+-------------+----------+--------+----------------------------------------------------------------------------------------------------------------------------+---------+---------+------------------------------------------------+------+----------------------------------------------+
2 rows in set (0.01 sec)