时间戳

首页 > 解决方案 > Oracle-加速查询

sql - Oracle-加速查询

问题描述

此查询查找 K2 的 W_G 是什么（例如：'L_E' 由'E1' 找到）。然后它找到K1是什么（例如：'IS'被'E1'找到）。然后它根据 K1，K2（'30'，'10' by 'IS' 和 'C01A'）找到 K4，K5。

为了加快这个查询，有什么东西可以修改这个查询吗？

执行计划如下。

----------------------------------------------------------------------------------------------------------                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
| Id  | Operation                    | Name                      | Rows  | Bytes | Cost (%CPU)| Time     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
----------------------------------------------------------------------------------------------------------                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   0 | SELECT STATEMENT             |                           |     1 |       |     5   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   1 |  VIEW                        |                           |     1 |    13 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   2 |   TABLE ACCESS FULL          | SYS_TEMP_0FD9D6617_CD798E |     1 |    26 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   3 |    TEMP TABLE TRANSFORMATION |                           |       |       |            |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   4 |     LOAD AS SELECT           | SYS_TEMP_0FD9D6618_CD798E |       |       |            |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|*  5 |      TABLE ACCESS FULL       | C_W_B                     |     1 |   273 |     3   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   6 |       VIEW                   |                           |     1 |    13 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   7 |        TABLE ACCESS FULL     | SYS_TEMP_0FD9D6617_CD798E |     1 |    26 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|*  8 |     VIEW                     |                           |     1 |    39 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|   9 |      TABLE ACCESS FULL       | SYS_TEMP_0FD9D6618_CD798E |     1 |   273 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  10 |      SORT AGGREGATE          |                           |     1 |    13 |            |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  11 |       VIEW                   |                           |     1 |    13 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  12 |        TABLE ACCESS FULL     | SYS_TEMP_0FD9D6618_CD798E |     1 |   273 |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  13 |  TEMP TABLE TRANSFORMATION   |                           |       |       |            |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  14 |   LOAD AS SELECT             | SYS_TEMP_0FD9D6617_CD798E |       |       |            |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|* 15 |    TABLE ACCESS FULL         | C_W_B                     |     1 |    78 |     3   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|  16 |   FAST DUAL                  |                           |     1 |       |     2   (0)| 00:00:01 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
----------------------------------------------------------------------------------------------------------



Statistics
----------------------------------------------------------                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
          4  recursive calls                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
         16  db block gets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
         30  consistent gets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
          2  physical reads                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
       1156  redo size                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
        682  bytes sent via SQL*Net to client                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
        416  bytes received via SQL*Net from client                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
          2  SQL*Net roundtrips to/from client                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
          0  sorts (memory)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
          0  sorts (disk)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
          1  rows processed

表如下

CREATE TABLE C_W_B  (  
      HE VARCHAR2(22),
      WE VARCHAR2(22),
      G_D VARCHAR2(22),
      W_G VARCHAR2(22),
      W_V VARCHAR2(22),
      K1 VARCHAR2(22),
      K2 VARCHAR2(22),
      K3 VARCHAR2(22),
      K4 VARCHAR2(22),
      K5 VARCHAR2(22),
      K6 VARCHAR2(22),
      K7 VARCHAR2(22),
      K8 VARCHAR2(22),
      K9 VARCHAR2(22),
      K10 VARCHAR2(22),
      K11 VARCHAR2(22),
      K12 VARCHAR2(22),
      K13 VARCHAR2(22),
      K14 VARCHAR2(22),
      K22 VARCHAR2(22),
      K16 VARCHAR2(22) 
      );

数据如下

 INSERT INTO C_W_B(HE,WE,G_D,W_G,W_V,K1,K3,K4,K6) VALUES 
('C6','61','R3','L_C_F','1','IS','C01A','30','10');
INSERT INTO C_W_B(HE,WE,G_D,W_G,K1,K2) VALUES 
('C6','61','R3','L_E','IS','E1');

查询如下

WITH G_S AS (
  SELECT /*+FIRST_ROWS(1)*/
  A.W_G, A.K1
  FROM C_W_B A
  WHERE 1=1
  AND A.HE = 'C6'AND A.WE = '61'  AND A.G_D ='R3'  AND A.K2='E1'
 )
 SELECT CASE
 WHEN (SELECT A.W_G FROM G_S A)='L_E'
 THEN (
    WITH SEO AS (        
 SELECT A.K1 FROM G_S A
          ),
     SE AS (SELECT *
         FROM C_W_B B
         WHERE B.W_G = 'L_C_F'
         AND B.HE = 'C6'
         AND B.WE = '61'
         AND B.G_D ='R3'
         AND B.K1 = (SELECT K1 FROM SEO)
         AND B.K3 LIKE 'C01A'
        ) 
SELECT (L_T /QT*1000) 
      FROM ( SELECT NVL(TO_NUMBER(K4),0)  AS  L_T,
        NVL(TO_NUMBER(K6),0)  AS  QT
       FROM SE
       WHERE W_V IN (SELECT TO_CHAR(MAX(TO_NUMBER(W_V))) FROM SE )
        )
          )
   WHEN 1=2
     THEN TO_NUMBER(0)
  ELSE TO_NUMBER(0)
  END
 FROM DUAL;

标签： sqloraclequery-performance

解决方案

您的查询可以简化，并可能提供如下性能：

SELECT CASE
       WHEN W_G ='L_E' 
            AND K6 IS NOT NULL -- ADDED K6 IS NOT NULL CONDITION TO AVOID NUMBER DIVIDE BY 0 ERROR
       THEN NVL(K4,0) / (K6*1000)
       ELSE 0 
       END  
 FROM (SELECT A.W_G, B.K6, B.K4,
           ROW_NUMBER() 
           OVER (ORDER BY TO_NUMBER(W_V) DESC NULLS LAST) AS RN
      FROM C_W_B A JOIN C_W_B S ON (A.K1=S.K1)
     WHERE A.HE = 'C6'
       AND A.WE = '61'
       AND A.G_D ='R3'
       AND A.K2='E1'
       AND S.W_G = 'L_C_F'
       AND S.HE = 'C6'
       AND S.WE = '61'
       AND S.G_D ='R3'
       AND S.K3 LIKE 'C01A')
WHERE RN = 1;

干杯！！

推荐阅读