read.txt

mysql> select comment_ranking, sum(story_comment_count+author_comment_count) c from hackernews where comment_ranking in (30,31,32) group by comment_ranking;
+-----------------+---------+
| comment_ranking | c       |
+-----------------+---------+
| 30              | 2290813 |
| 31              | 2051937 |
| 32              | 1882127 |
+-----------------+---------+
3 rows in set (16.01 sec)

mysql> show profiles ;
+----------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
| Query_ID | Duration    | Query                                                                                                                                                |
+----------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
|        1 | 16.01184425 | select comment_ranking, sum(story_comment_count+author_comment_count) c from hackernews where comment_ranking in (30,31,32) group by comment_ranking |
+----------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set, 1 warning (0.00 sec)

mysql> show profile ;
+----------------------+-----------+
| Status               | Duration  |
+----------------------+-----------+
| starting             |  0.000145 |
| checking permissions |  0.000017 |
| Opening tables       |  0.000026 |
| init                 |  0.000051 |
| System lock          |  0.000014 |
| optimizing           |  0.000014 |
| statistics           |  0.000036 |
| preparing            |  0.000059 |
| Sorting result       |  0.000010 |
| executing            |  0.000006 |
| Sending data         | 16.011360 |
| end                  |  0.000011 |
| query end            |  0.000009 |
| closing tables       |  0.000008 |
| freeing items        |  0.000068 |
| cleaning up          |  0.000011 |
+----------------------+-----------+
16 rows in set, 1 warning (0.00 sec)


mysql> show index from hackernews;
+------------+------------+-----------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table      | Non_unique | Key_name        | Seq_in_index | Column_name     | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+------------+------------+-----------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| hackernews |          0 | PRIMARY         |            1 | id              | A         |     1099228 |     NULL | NULL   |      | BTREE      |         |               |
| hackernews |          1 | comment_ranking |            1 | comment_ranking | A         |        1255 |     NULL | NULL   | YES  | BTREE      |         |               |
+------------+------------+-----------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.01 sec)

mysql> alter table hackernews drop index comment_ranking;


mysql> select comment_ranking, sum(story_comment_count+author_comment_count) as c from hackernews where comment_ranking in (30,31,32) group by comment_ranking;
+-----------------+---------+
| comment_ranking | c       |
+-----------------+---------+
| 30              | 2290813 |
| 31              | 2051937 |
| 32              | 1882127 |
+-----------------+---------+
3 rows in set (0.77 sec)