У меня есть этот запрос, и для его завершения требуется около 10 минут.
SELECT COUNT(DISTINCT(column)) var,
column2 var2
FROM table
WHERE column<>'X' and
column2 between 'Y' and 'Z'
GROUP BY var2
ORDER BY var DESC
Есть идеи, как оптимизировать скорость?Я пытался с индексами, но все еще медленно.Возможно они не установлены должным образом.Y и Z являются временными метками, если это имеет значение, а X - это то, что вообще не нужно для этого запроса, но находится в таблице, поскольку оно необходимо для других запросов из того же приложения.Таблица очень большая - миллионы строк, и она еще не выросла.
Редактировать : Вот результат EXPLAIN из примера:
mysql> EXPLAIN SELECT COUNT(DISTINCT(ip)) v, geo n from idevaff_iptracking where geo<>'XX' and stamp between '1525122000' and '1543615199' group by n order by v desc;
+------+-------------+--------------------+-------+------------------------+--------------+---------+------+---------+-----------------------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+--------------------+-------+------------------------+--------------+---------+------+---------+-----------------------------------------------------------+
| 1 | SIMPLE | idevaff_iptracking | range | stamp,geo,geo_stamp_ip | geo_stamp_ip | 9 | NULL | 3469323 | Using where; Using index; Using temporary; Using filesort |
+------+-------------+--------------------+-------+------------------------+--------------+---------+------+---------+-----------------------------------------------------------+
1 row in set (0.00 sec)
Таблицаследующие значения:
id, acct_id, ip, reference, stamp, hit_time, hit_date, src1, src2, split, sub_id, tid1, tid2, tid3, tid4, target_url, geo.
Индексы следующие:
mysql> SHOW INDEX FROM idevaff_iptracking
-> ;
+--------------------+------------+--------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------------------+------------+--------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| idevaff_iptracking | 0 | PRIMARY | 1 | id | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_ip | 1 | acct_id | A | 2 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_ip | 2 | ip | A | 6775984 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | ip | 1 | ip | A | 6775984 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | stamp | 1 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id | 1 | acct_id | A | 4 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | geo | 1 | geo | A | 440 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | tid1 | 1 | tid1 | A | 276 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | tid2 | 1 | tid2 | A | 514 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | tid3 | 1 | tid3 | A | 34 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | tid4 | 1 | tid4 | A | 5623 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_stamp_ip | 1 | acct_id | A | 744 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_stamp_ip | 2 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_stamp_ip | 3 | ip | A | 6775984 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | geo_stamp_ip | 1 | geo | A | 22362 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | geo_stamp_ip | 2 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | geo_stamp_ip | 3 | ip | A | 6775984 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid1_stamp | 1 | acct_id | A | 658 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid1_stamp | 2 | tid1 | A | 11866 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid1_stamp | 3 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid2_stamp | 1 | acct_id | A | 2 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid2_stamp | 2 | tid2 | A | 18666 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid2_stamp | 3 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid3_stamp | 1 | acct_id | A | 2 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid3_stamp | 2 | tid3 | A | 1832 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid3_stamp | 3 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid4_stamp | 1 | acct_id | A | 2 | NULL | NULL | | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid4_stamp | 2 | tid4 | A | 5060 | NULL | NULL | YES | BTREE | | |
| idevaff_iptracking | 1 | acct_id_tid4_stamp | 3 | stamp | A | 6775984 | NULL | NULL | | BTREE | | |
+--------------------+------------+--------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
29 rows in set (0.00 sec)