Question

我正在MySQL中运行查询，但它需要花费很多时间。当我对此做一个解释时，我可以说它没有使用索引。

select distinct substring(r.promotion_code,5,CHAR_LENGTH(r.promotion_code)- 4) promotion_code, 
numeric_code, 
tier, 
issue_date, 
expire_date, 
type, 
reward, 
r.status, 
description, 
if(r.status=2,if(t.issuance_date is null,'1900-01-01 00:00:00',t.issuance_date),'') redemption_date, 
if(r.status=2,'Y','N') redeemed 
from 
rewards r join 
status_enumeration s 
on r.status = s.keyvalue 
left join 
trips t 
on (r.promotion_code=t.promotion_code 
or substring(r.promotion_code,5,CHAR_LENGTH(r.promotion_code)-4)=t.promotion_code) 
where r.member_id=164631400 
and table_name='rewards' order by issue_date desc;


+----+-------------+-------+------+-------------------------------------------------------------+--------------------------+---------+---------------------------------+---------+--------------------------------------------------+
| id | select_type | table | type | possible_keys                                               | key                      | key_len | ref                             | rows    | Extra                                            |
+----+-------------+-------+------+-------------------------------------------------------------+--------------------------+---------+---------------------------------+---------+--------------------------------------------------+
|  1 | SIMPLE      | s     | ALL  | idx_keyvalue                                                | NULL                     | NULL    | NULL                            |      41 | Using where; Using temporary; Using filesort     |
|  1 | SIMPLE      | r     | ref  | NCIDX_type_reward_memberID_issDate,rewards$member_id$status | rewards$member_id$status | 13      | const,CUST_GHPROD_DB.s.keyvalue |       1 | NULL                                             |
|  1 | SIMPLE      | t     | ALL  | idx_promotion_code                                          | NULL                     | NULL    | NULL                            | 3192871 | Range checked for each record (index map: 0x400) |
+----+-------------+-------+------+-------------------------------------------------------------+--------------------------+---------+---------------------------------+---------+--------------------------------------------------+

有没有更好的方法来编写此查询？

我的桌子奖励，status_enumeration和旅行都有以下DDL。

CREATE TABLE `rewards` (
  `rewards_id` int(11) NOT NULL AUTO_INCREMENT,
  `member_id` bigint(20) DEFAULT NULL,
  `promotion_code` varchar(50) DEFAULT NULL,
  `numeric_code` int(11) NOT NULL,
  `tier` varchar(2) NOT NULL,
  `type` varchar(2) NOT NULL,
  `reward` varchar(2) NOT NULL,
  `status` int(11) NOT NULL,
  `reward_source_type` char(1) DEFAULT 'B',
  `description` varchar(100) DEFAULT NULL,
  `issue_date` datetime NOT NULL,
  `expire_date` datetime NOT NULL,
  `RowGUID` varchar(64) DEFAULT NULL,
  `created_date` datetime DEFAULT CURRENT_TIMESTAMP,
  `updated_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`rewards_id`),
  KEY `NCIDX_status_expireDate_rewardID` (`rewards_id`,`member_id`,`status`,`expire_date`),
  KEY `NCIDX_status_rewardsID_promCode` (`rewards_id`,`promotion_code`,`status`),
  KEY `NCIDX_type_desc_memberID_issDate` (`rewards_id`,`member_id`,`type`,`description`,`issue_date`,`status`,`expire_date`),
  KEY `NCIDX_type_reward_memberID_issDate` (`member_id`,`issue_date`,`type`,`reward`),
  KEY `rewards$member_id$status` (`member_id`,`status`),
  KEY `idx_promotion_code_rewards` (`promotion_code`,`status`)
) ENGINE=InnoDB AUTO_INCREMENT=15253716 DEFAULT CHARSET=latin1


CREATE TABLE `status_enumeration` (
  `table_name` varchar(50) NOT NULL,
  `field_name` varchar(50) NOT NULL,
  `keyvalue` int(11) NOT NULL,
  `datavalue` varchar(50) NOT NULL,
  `RowGUID` varchar(64) DEFAULT NULL,
  KEY `idx_keyvalue` (`keyvalue`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1


    CREATE TABLE `trips` (
  `trip_number` int(11) NOT NULL AUTO_INCREMENT,
  `member_id` bigint(20) DEFAULT NULL,
  `confirmation_number` varchar(50) NOT NULL,
  `departure_city` varchar(100) NOT NULL DEFAULT '',
  `departure_state` varchar(2) NOT NULL DEFAULT '',
  `arrival_city` varchar(100) NOT NULL DEFAULT '',
  `arrival_state` varchar(2) NOT NULL DEFAULT '',
  `issuance_date` datetime NOT NULL,
  `departure_date` datetime NOT NULL,
  `arrival_date` datetime NOT NULL,
  `number_of_passengers` tinyint(3) unsigned NOT NULL DEFAULT '0',
  `fare_type` varchar(50) NOT NULL DEFAULT '',
  `mileage` int(11) NOT NULL DEFAULT '0',
  `status` tinyint(3) unsigned NOT NULL DEFAULT '0',
  `credits` int(11) NOT NULL DEFAULT '0',
  `promotion_code` varchar(50) NOT NULL DEFAULT '',
  `reference_id` varchar(50) NOT NULL DEFAULT '',
  `purchase_price` decimal(19,4) DEFAULT NULL,
  `RowGUID` varchar(64) DEFAULT NULL,
  `reward_points` decimal(10,0) NOT NULL DEFAULT '1',
  `created_date` datetime DEFAULT CURRENT_TIMESTAMP,
  `updated_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`trip_number`),
  KEY `NCIDX_issuanceDate_memberID` (`member_id`,`issuance_date`),
  KEY `NCIDX_refID_tripNum_status` (`trip_number`,`status`,`reference_id`),
  KEY `NCIDX_status_tripNum_status_memberID_depGate_promCode` (`trip_number`,`member_id`,`departure_date`,`promotion_code`,`status`),
  KEY `trips$issuance_date` (`issuance_date`),
  KEY `trips$member_id$reference_id$arrival_city$departure_city$issua1` (`member_id`,`reference_id`,`arrival_city`,`departure_city`,`issuance_date`),
  KEY `trips$promCode$Status` (`status`,`promotion_code`),
  KEY `reference_id` (`reference_id`),
  KEY `member_id` (`member_id`,`status`,`departure_date`),
  KEY `reference_id_2` (`reference_id`),
  KEY `idx_promotion_code` (`promotion_code`)
) ENGINE=InnoDB AUTO_INCREMENT=32406357 DEFAULT CHARSET=latin1

查询不使用MySQL中的索引

0 个答案: