1.query is taking around 10mins to 1 hr to execute.
2.due to this we are getting load spikes frequently.
3.please help me to rewrite the query.
4.also help me to improve the performance of query.
Query with explain plan
explain select count(*)
from t_event eve
left join t_event_element_rel rel on rel.event_id = eve.id
left join t_object object on eve.create_object_id = object.id
left join t_keyword keyword on rel.element_id = keyword.id and rel.element_type_id = 1
left join t_target_url targeturl on rel.element_id = targeturl.id and rel.element_type_id = 2
where eve.domain_id = 522
+----+-------------+-----------+--------+-------------------------+-------------------------+---------+----------------------------+--------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-----------+--------+-------------------------+-------------------------+---------+----------------------------+--------+-------------+
| 1 | SIMPLE | eve | ref | domain_id_event_type_cd | domain_id_event_type_cd | 4 | const | 243430 | |
| 1 | SIMPLE | rel | ref | FK_event | FK_event | 4 | company.eve.id | 2 | |
| 1 | SIMPLE | user | eq_ref | PRIMARY | PRIMARY | 4 | company.eve.create_user_id | 1 | Using index |
| 1 | SIMPLE | keyword | ref | id | id | 4 | company.rel.element_id | 1 | Using index |
| 1 | SIMPLE | targeturl | ref | id | id | 4 | company.rel.element_id | 1 | Using index |
+----+-------------+-----------+--------+-------------------------+-------------------------+---------+----------------------------+--------+-------------+
5 rows in set (0.45 sec)
Table structure:
mysql> show create table t_event_element_rel\G
*************************** 1. row ***************************
Table: t_event_element_rel
Create Table: CREATE TABLE `t_event_element_rel` (
`id` int(255) NOT NULL AUTO_INCREMENT,
`element_type_id` int(11) NOT NULL,
`event_id` int(11) NOT NULL,
`element_id` int(11) NOT NULL,
`element_desc` varchar(500) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `FK_event` (`event_id`),
KEY `element_type_id_element_id` (`element_type_id`,`element_id`)
) ENGINE=InnoDB AUTO_INCREMENT=45901159 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> show create table t_object\G
*************************** 1. row ***************************
Table: t_object
Create Table: CREATE TABLE `t_object` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`password` varchar(255) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
`is_admin` int(11) DEFAULT NULL,
`phone` varchar(50) DEFAULT NULL,
`company` varchar(255) DEFAULT NULL,
`last_login` datetime DEFAULT NULL,
`state` int(11) DEFAULT NULL,
`validate_code` varchar(50) DEFAULT NULL,
`has_login` smallint(6) DEFAULT NULL COMMENT 'if null or 0 then hasn''t login, first time login',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1304 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> show create table t_event\G
*************************** 1. row ***************************
Table: t_event
Create Table: CREATE TABLE `t_event` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`create_user_id` int(11) DEFAULT NULL,
`event_create_date` date DEFAULT NULL,
`event_type_cd` int(11) NOT NULL,
`event_desc` varchar(512) NOT NULL,
`IsGlobalEvent` int(2) DEFAULT NULL,
`event_start_date` datetime NOT NULL,
`event_end_date` datetime NOT NULL,
`job_id` int(11) DEFAULT NULL,
`domain_id` int(11) NOT NULL,
PRIMARY KEY (`id`),
KEY `event_user_FK` (`create_user_id`),
KEY `domain_id_event_type_cd` (`domain_id`,`event_type_cd`)
) ENGINE=InnoDB AUTO_INCREMENT=8586007 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> show create table t_keyword\G
*************************** 1. row ***************************
Table: t_keyword
Create Table: CREATE TABLE `t_keyword` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`keyword_name` varchar(255) DEFAULT NULL,
`keyword_value` varchar(255) DEFAULT NULL,
`type` int(11) DEFAULT NULL,
`description` varchar(2000) DEFAULT NULL,
`own_domain_id` int(11) DEFAULT NULL,
`rank_check` int(11) DEFAULT NULL,
`rank1` int(11) DEFAULT NULL COMMENT 'yesterday rank value',
`rank2` int(11) DEFAULT NULL COMMENT 'the day before yesterday rank value',
`rank3` int(11) DEFAULT NULL COMMENT 'special date rank for overstock.com',
`yesterday_entrances` int(11) DEFAULT NULL COMMENT 'yesterday entrances',
`week_entrances` int(11) DEFAULT NULL COMMENT '7 days entrances',
`current_ctr` float(16,4) DEFAULT NULL COMMENT 'Current CTR',
`monthly_search_volume` int(11) DEFAULT NULL COMMENT 'Most Recent Month search volume',
`avg_monthly_search_volume` int(11) DEFAULT NULL COMMENT 'avg_monthly_search_volume',
`traffic_increase` int(11) DEFAULT NULL COMMENT 'Traffic Increase',
`rank_improvement` int(11) DEFAULT NULL COMMENT 'Rank Improvement',
`rank_update_date` date DEFAULT NULL COMMENT 'rank be updated for Special Date',
`top_rank_targeturl_id` int(11) DEFAULT NULL,
`frequency` int(10) DEFAULT '1' COMMENT '1: daily, 2: weekly, 3: monthly',
`score` float DEFAULT NULL,
`create_date` datetime DEFAULT NULL,
`bing_rank1` int(10) DEFAULT NULL,
`bing_rank2` int(10) DEFAULT NULL,
`yesterday_bing_entrances` int(11) DEFAULT NULL,
`bing_rank_improvement` int(11) DEFAULT NULL,
KEY `id` (`id`),
KEY `keyword_name` (`keyword_name`),
KEY `own_domain_id` (`own_domain_id`,`rank_check`),
KEY `rank_check` (`rank_check`)
) ENGINE=InnoDB AUTO_INCREMENT=670267018 DEFAULT CHARSET=utf8
/*!50100 PARTITION BY RANGE (`rank_check`)
(PARTITION p0 VALUES LESS THAN (0) ENGINE = InnoDB,
PARTITION p1 VALUES LESS THAN (1) ENGINE = InnoDB,
PARTITION p2 VALUES LESS THAN (2) ENGINE = InnoDB,
PARTITION pEOW VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */
1 row in set (0.00 sec)
mysql> show create table t_target_url\G
*************************** 1. row ***************************
Table: t_target_url
Create Table: CREATE TABLE `t_target_url` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`own_domain_id` int(11) DEFAULT NULL,
`url` varchar(2000) NOT NULL,
`create_date` datetime DEFAULT NULL,
`friendly_name` varchar(255) DEFAULT NULL,
`section_name_id` int(11) DEFAULT NULL,
`type` int(11) DEFAULT NULL,
`status` int(11) DEFAULT NULL,
`week_entrances` int(11) DEFAULT NULL COMMENT 'last 7 days entrances',
`week_bounces` int(11) DEFAULT NULL COMMENT 'last 7 days bounce',
`canonical_url_id` int(11) DEFAULT NULL COMMENT 'the primary URL ID, NOT allow canonical of canonical',
KEY `id` (`id`),
KEY `urlindex` (`url`(255)),
KEY `own_domain_id_type_status` (`own_domain_id`,`type`,`status`),
KEY `canonical_url_id` (`canonical_url_id`),
KEY `type` (`type`,`status`)
) ENGINE=InnoDB AUTO_INCREMENT=237034388 DEFAULT CHARSET=utf8
/*!50100 PARTITION BY RANGE (`type`)
(PARTITION p0 VALUES LESS THAN (0) ENGINE = InnoDB,
PARTITION p1 VALUES LESS THAN (1) ENGINE = InnoDB,
PARTITION p2 VALUES LESS THAN (2) ENGINE = InnoDB,
PARTITION pEOW VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */
1 row in set (0.01 sec)
The first line of your EXPLAIN shows a lot of rows for domain_id_event_type_cd, which is a compound index, yet in your query you only search on a part of the index (eve.domain_id = xxx). So unless domain 522 really has 243K entries, you can cut down on this by adding an index solely for domain_id.
Also, it seems you are trying to do an OR search by using rel.element_type_id as a “switch” for referencing different types of data. Since you are only interested in the count, I suggest you split the query in two parts, then add the results. This will cut down on the LEFT JOINS. You can even add the results within MySQL:
SELECT (SELECT COUNT (*) FROM ….) + (SELECT COUNT (*) FROM …)
(You do know you can abuse SELECT to do math, don’t you?)