Question

我有两个巨大的表，可以从中选择大量数据。

表存储采购订单明细和产品信息。

    PURCHASE_ORDER_DETAILS.
    CREATE TABLE `PURCHASE_ORDER_DETAILS` (
    `PURCHASE_ORDER_NUMBER_PF` INT(20) NOT NULL,
    `PRODUCT_CODE_PF` VARCHAR(32) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL,
    `ORDER_QUANTITY` INT(8) DEFAULT NULL,
    `UNIT_PRICE` DECIMAL(12,2) DEFAULT NULL,
    `ORDER_FULLFILLMENT_DUE_DATE` DATETIME DEFAULT NULL,
    `DELIVERY_ADDRESS` VARCHAR(64) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL,
    `DELIVERY_CITY` VARCHAR(32) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL,
     `DELIVERY_ZIP` BIGINT(10) DEFAULT NULL,
     `other columns`
      PRIMARY KEY (`PURCHASE_ORDER_NUMBER_PF`,`PRODUCT_CODE_PF`),
      KEY `RMAPWBTX_PUCH_ORDE_DLST_INDX` (`DELIVERY_STATE_ID_FK`),
      KEY `RMAPWBTX_PUCH_ORDE_DLTY_INDX` (`DELIVERY_TYPE_FK`),
      KEY `RMAPWBTX_PUCH_ORDE_TACO_INDX` (`TAX_CODE_FK`),
      KEY `RMAPWBMS_PUOR_DETL_PDCO_FK` (`PRODUCT_CODE_PF`),
      KEY `RMAPWBTX_PUOR_DETL_TACO_FK` (`TAX_CODE_FK`),
      KEY `CREATED_DATE_INDX` (`CREATED_DATE`),
      KEY `MODIFIED_DATE_INDX` (`MODIFIED_DATE`),
      CONSTRAINT `RMAPWBMS_PUOR_DETL_PDCO_FK` FOREIGN KEY (`PRODUCT_CODE_PF`) 
      REFERENCES `PRODUCT` (`PRODUCT_CODE_PK`) ON DELETE NO ACTION ON UPDATE NO ACTION,
      CONSTRAINT `RMAPWBMS_PUOR_DETL_PONU_FK` FOREIGN KEY 
      (`PURCHASE_ORDER_NUMBER_PF`) REFERENCES `PURCHASE_ORDER` 
      (`PURCHASE_ORDER_NUMBER_PK`),
     CONSTRAINT `RMAPWBTX_PO_DETL_DSID_FK` FOREIGN KEY 
     (`DELIVERY_STATE_ID_FK`) REFERENCES `STATE` (`STATE_ID_PK`),
     CONSTRAINT `RMAPWBTX_PUOR_DETL_TACO_FK` FOREIGN KEY (`TAX_CODE_FK`) 
     REFERENCES `TAX` (`TAX_CODE_PK`) ON DELETE NO ACTION ON UPDATE NO ACTION
     ) ENGINE=INNODB DEFAULT CHARSET=latin1;


PRODUCT

    CREATE TABLE `PRODUCT` (
    `PRODUCT_CODE_PK` VARCHAR(32) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL,
    `PRODUCT_DESC` VARCHAR(256) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL,
    `FEE_BILL_CODE` VARCHAR(32) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL,
    `other columns`
     PRIMARY KEY (`PRODUCT_CODE_PK`),
     KEY `CREATED_DATE_INDX` (`CREATED_DATE`),
     KEY `MODIFIED_DATE_INDX` (`MODIFIED_DATE`),
     KEY `PRODUCT_EXCO_FK` (`EXPENSE_CODE_ID_FK`),
     KEY `FK_PRODUCT_ENTITY_TYPE` (`ENTITY_TYPE_CODE_FK`),
     CONSTRAINT `FK_PRODUCT_ENTITY_TYPE` FOREIGN KEY (`ENTITY_TYPE_CODE_FK`) REFERENCES `ENTITY_TYPE` (`ENTITY_TYPE_CODE_PK`)
     ) ENGINE=INNODB DEFAULT CHARSET=latin1

     Below query is taking ~10min to get ~1M records.

     EXPLAIN SELECT * FROM
     PURCHASE_ORDER_DETAILS POD
     JOIN PRODUCT PRD ON POD.PRODUCT_CODE_PF=PRD.PRODUCT_CODE_PK;
+----+-------------+-------+------+----------------------------+-----------------

    -----------+---------+-----------------------------------------------+-------+-------+
    | id | select_type | table | type | possible_keys              | key                        | key_len | ref                                           | rows  | Extra |
    +----+-------------+-------+------+----------------------------+----------------------------+---------+-----------------------------------------------+-------+-------+
    |  1 | SIMPLE      | PRD   | ALL  | PRIMARY                    | NULL                       | NULL    | NULL                                          | 14283 | NULL  |
    |  1 | SIMPLE      | POD   | ref  | RMAPWBMS_PUOR_DETL_PDCO_FK | RMAPWBMS_PUOR_DETL_PDCO_FK | 34      | REALREMIT_PROD_ALTISOURCE.PRD.PRODUCT_CODE_PK |    40 | NULL  |
    +----+-------------+-------+------+----------------------------+----------------------------+---------+-----------------------------------------------+-------+---

编辑1：上面的查询是一个示例，下面是我尝试获取1M记录（主表POD具有22M记录）的实际查询。

SELECT `some columns`
FROM `REALREMIT_PPIPFC_MIG`.MIGR_ORDER_DENORM MPO
INNER JOIN PURCHASE_ORDER_DETAILS POD 
ON MPO.PURCHASE_ORDER_NUMBER_PK=POD.PURCHASE_ORDER_NUMBER_PF
INNER JOIN PRODUCT PRD 
ON POD.PRODUCT_CODE_PF=PRD.PRODUCT_CODE_PK 
INNER JOIN EXPENSE_CODE EXP
ON PRD.EXPENSE_CODE_ID_FK=EXP.EXPENSE_CODE_ID_PK 
WHERE MPO.BATCH_ID=1;

解释上述查询的输出

+----+-------------+-------+--------+-------------------------------------+----------------------------+---------+--------------------------------------------------------+-------+-------------+
| id | select_type | table | type   | possible_keys                       | key                        | key_len | ref                                                    | rows  | Extra       |
+----+-------------+-------+--------+-------------------------------------+----------------------------+---------+--------------------------------------------------------+-------+-------------+
|  1 | SIMPLE      | PRD   | ALL    | PRIMARY,PRODUCT_EXCO_FK             | NULL                       | NULL    | NULL                                                   | 14283 | NULL        |
|  1 | SIMPLE      | EXP   | eq_ref | PRIMARY                             | PRIMARY                    | 4       | REALREMIT_PROD_ALTISOURCE.PRD.EXPENSE_CODE_ID_FK       |     1 | NULL        |
|  1 | SIMPLE      | POD   | ref    | PRIMARY,RMAPWBMS_PUOR_DETL_PDCO_FK  | RMAPWBMS_PUOR_DETL_PDCO_FK | 34      | REALREMIT_PROD_ALTISOURCE.PRD.PRODUCT_CODE_PK          |    40 | NULL        |
|  1 | SIMPLE      | MPO   | ref    | MIGR_PO_NBR_INDX,MIGR_BATCH_ID_INDX | MIGR_PO_NBR_INDX           | 4       | REALREMIT_PROD_ALTISOURCE.POD.PURCHASE_ORDER_NUMBER_PF |     1 | Using where |
+----+-------------+-------+--------+-------------------------------------+----------------------------+---------+--------------------------------------------------------+-------+-------------+
4 rows in set (0.20 sec)

两个数据库都具有相同的字符集连接中使用的列具有相同的排序规则两个表都有相同的字符集

我创建了一个新表，该表中的主键是连接列-PURHCASE_ORDER_NUMBER_PF和PRODUCT_CODE_PF，然后在PRODUCT_CODE_PF上添加了新索引在这种情况下将使用索引，并且/或者这是在连接中使用索引的最佳方法。

谢谢

Answer 1

这些可能会帮助您

MPO:  INDEX(BATCH_ID, PURCHASE_ORDER_NUMBER_PK)   -- in this order
EXP:  INDEX(EXPENSE_CODE_ID_PK)   -- unless it is the PRIMARY KEY

但是，在不知道“某些列”中有什么的情况下，我无法预测它们会提供多少帮助。拥有SHOW CREATE TABLE用于MPO和EXP会有所帮助。

您有多少RAM？ innodb_buffer_pool_size的值是什么？我问，因为你可能会rash打。

如果列是组合键的一部分，则不使用索引

1 个答案: