索引的执行计划变化

Mon Jan  6 18:48:26 2020
autopilot@10.10.10.11 ((none)) > use event;
Database changed
Mon Jan  6 18:48:30 2020
autopilot@10.10.10.11 (event) > explain SELECT a.* FROM event as a INNER JOIN current as b on a.`event_id` = b.`event_id` AND a.`event_ts` = b.`event_ts` INNER JOIN event_receiver as c on  a.`id` = c.`event_id` WHERE (c.`username` = ‘zhaolilei‘ AND a.`priority` in (‘0‘, ‘1‘, ‘2‘) AND b.`status` = ‘PROBLEM‘) GROUP BY a.`id` ORDER BY c.`event_ts` desc LIMIT 100 OFFSET 0;
+----+-------------+-------+--------+-----------------------------------+--------------+---------+------------------+---------+----------------------------------------------+
| id | select_type | table | type   | possible_keys                     | key          | key_len | ref              | rows    | Extra                                        |
+----+-------------+-------+--------+-----------------------------------+--------------+---------+------------------+---------+----------------------------------------------+
|  1 | SIMPLE      | c     | ref    | idx_username,idx_event_id         | idx_username | 98      | const            | 1721438 | Using where; Using temporary; Using filesort |
|  1 | SIMPLE      | a     | eq_ref | PRIMARY,idx_event_id,idx_event_ts | PRIMARY      | 8       | event.c.event_id |       1 | Using where                                  |
|  1 | SIMPLE      | b     | eq_ref | PRIMARY,idx_event_ts              | PRIMARY      | 194     | event.a.event_id |       1 | Using where                                  |
+----+-------------+-------+--------+-----------------------------------+--------------+---------+------------------+---------+----------------------------------------------+
3 rows in set (0.00 sec)

Mon Jan  6 18:48:32 2020
autopilot@10.10.10.11 (event) > show index from event;
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name     | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| event |          0 | PRIMARY      |            1 | id          | A         |    29439482 |     NULL | NULL   |      | BTREE      |         |               |
| event |          1 | idx_pdl      |            1 | pdl         | A         |          17 |     NULL | NULL   |      | BTREE      |         |               |
| event |          1 | idx_event_id |            1 | event_id    | A         |      588789 |     NULL | NULL   | YES  | BTREE      |         |               |
| event |          1 | idx_event_ts |            1 | event_ts    | A         |     2943948 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
4 rows in set (0.01 sec)

Mon Jan  6 18:48:35 2020
autopilot@10.10.10.11 (event) > 



Mon Jan  6 18:38:40 2020
autopilot@10.10.10.10 (event) >  explain SELECT a.* FROM event as a INNER JOIN current as b on a.`event_id` = b.`event_id` AND a.`event_ts` = b.`event_ts` INNER JOIN event_receiver as c on  a.`id` = c.`event_id` WHERE (c.`username` = ‘zhaolilei‘ AND a.`priority` in (‘0‘, ‘1‘, ‘2‘) AND b.`status` = ‘PROBLEM‘) GROUP BY a.`id` ORDER BY c.`event_ts` desc LIMIT 100 OFFSET 0;
+----+-------------+-------+------+-----------------------------------+--------------+---------+------------------+--------+----------------------------------------------+
| id | select_type | table | type | possible_keys                     | key          | key_len | ref              | rows   | Extra                                        |
+----+-------------+-------+------+-----------------------------------+--------------+---------+------------------+--------+----------------------------------------------+
|  1 | SIMPLE      | b     | ALL  | PRIMARY,idx_event_ts              | NULL         | NULL    | NULL             | 175557 | Using where; Using temporary; Using filesort |
|  1 | SIMPLE      | a     | ref  | PRIMARY,idx_event_id,idx_event_ts | idx_event_ts | 99      | event.b.event_ts |      4 | Using where                                  |
|  1 | SIMPLE      | c     | ref  | idx_username,idx_event_id         | idx_event_id | 8       | event.a.id       |      2 | Using where                                  |
+----+-------------+-------+------+-----------------------------------+--------------+---------+------------------+--------+----------------------------------------------+
3 rows in set (0.00 sec)

Mon Jan  6 18:39:38 2020
autopilot@10.10.10.10 (event) > show index from event;
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name     | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| event |          0 | PRIMARY      |            1 | id          | A         |    30352590 |     NULL | NULL   |      | BTREE      |         |               |
| event |          1 | idx_pdl      |            1 | pdl         | A         |          19 |     NULL | NULL   |      | BTREE      |         |               |
| event |          1 | idx_event_id |            1 | event_id    | A         |     3035259 |     NULL | NULL   | YES  | BTREE      |         |               |
| event |          1 | idx_event_ts |            1 | event_ts    | A         |     7588147 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
4 rows in set (0.01 sec)

Mon Jan  6 18:39:41 2020
autopilot@10.10.10.10 (event) > 





autopilot@10.10.10.10 (event) > show create table event\G;
*************************** 1. row ***************************
       Table: event
Create Table: CREATE TABLE `event` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `event_id` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
  `status` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
  `endpoint` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
  `hostname` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT ‘‘,
  `is_customize` int(1) NOT NULL DEFAULT ‘1‘,
  `pdl` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT ‘‘,
  `idc` varchar(16) COLLATE utf8_unicode_ci NOT NULL DEFAULT ‘‘,
  `current_step` int(11) DEFAULT NULL,
  `event_ts` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
  `metric` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
  `pushed_tags` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
  `left_val` double DEFAULT NULL,
  `func` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
  `op` varchar(4) COLLATE utf8_unicode_ci DEFAULT NULL,
  `right_val` double DEFAULT NULL,
  `max_step` int(11) DEFAULT NULL,
  `priority` int(11) DEFAULT NULL,
  `note` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
  `tpl_id` bigint(20) DEFAULT NULL,
  `action_id` bigint(20) DEFAULT NULL,
  `expression_id` bigint(20) DEFAULT NULL,
  `strategy_id` bigint(20) DEFAULT NULL,
  `strategy_group_id` bigint(20) DEFAULT NULL,
  `last_values` varchar(1024) COLLATE utf8_unicode_ci DEFAULT NULL,
  `db_ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_pdl` (`pdl`),
  KEY `idx_event_id` (`event_id`),
  KEY `idx_event_ts` (`event_ts`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=125698572 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
1 row in set (0.00 sec)

ERROR: 
No query specified