如何在類型對象上創建索引？

Question

目前我正在使用oracle 11g中的類型對象。在這方面，我有DB對象如下：

1. 表

   CREATE TABLE students 
       (rollno NUMBER(15) primary key, s_Name VARCHAR2(20), Marks type_1 
   ); 
   

2. 類型對象規範是

   CREATE OR REPLACE type type_1 
   AS 
       object 
       (
       sub_1 NUMBER, 
       sub_2 NUMBER, 
       sub_3 NUMBER, 
       member FUNCTION total 
       RETURN NUMBER, 
       member FUNCTION e_result 
       RETURN VARCHAR2); 
   

3. 它的機身

   CREATE OR REPLACE type body type_1 
   AS 
       member FUNCTION total 
       RETURN NUMBER 
   IS 
   BEGIN 
       RETURN (sub_1+sub_2+sub_3); 
   END; 
   member FUNCTION e_result 
       RETURN VARCHAR2 
   IS 
       DECLARE 
       temp NUMBER; 
       BEGIN 
       temp :=sub_1+sub_2+sub_3; 
       IF(temp>50) THEN 
        RETURN ('pass'); 
       ELSE 
        RETURN ('fail'); 
       END IF; 
       END; 
   END; 
   

創建畢竟這些事情，甚至我已經成功地使用填充

BEGIN 
FOR i IN 1..800 LOOP 
     FOR j IN 1..400 LOOP 
INSERT INTO students 
VALUES  (sequence1.NEXTVAL, 
      dbms_random.String('A', 5), 
      Type_1(Round(dbms_random.Value(10, 100)), Round(
      dbms_random.Value(10, 100)), Round(dbms_random.Value(10, 100)))); 
END LOOP; 
END LOOP; 

dbms_output.Put_line('completed'); 

COMMIT; 
END; 

/

我需要在tot列上e_result列和普通索引創建位圖索引的學生表。

我已經試過

create index id1 on students(marks.total) 

和

create bitmap index bid1 on students(marks.e-result) 

但我不能。我應該做些什麼？

Answer 1

首先，您必須將您的函數聲明爲DETERMINISTIC，以便在SQL索引中使用它們（即，您必須向給予相同輸入的Oracle斷言，它們給出相同的輸出）。

如：

SQL> CREATE OR REPLACE type type_1 
    2 AS 
    3 object 
    4 (
    5  sub_1 NUMBER, 
    6  sub_2 NUMBER, 
    7  sub_3 NUMBER, 
    8  member FUNCTION total 
    9  RETURN NUMBER deterministic, 
10  member FUNCTION e_result 
11  RETURN VARCHAR2 deterministic 
12 ); 
13/

Type created. 

SQL> CREATE OR REPLACE type body type_1 
    2 AS 
    3 member FUNCTION total 
    4 RETURN NUMBER deterministic 
    5 IS 
    6 BEGIN 
    7 RETURN (sub_1+sub_2+sub_3); 
    8 END; 
    9 member FUNCTION e_result 
10 RETURN VARCHAR2 deterministic 
11 IS 
12  temp NUMBER; 
13 BEGIN 
14  temp :=sub_1+sub_2+sub_3; 
15  IF(temp>50) THEN 
16  RETURN ('pass'); 
17  ELSE 
18  RETURN ('fail'); 
19  END IF; 
20 END; 
21 END; 
22/

其次，你必須調用函數時使用()否則會假定它命名total列：

：

SQL> create index id1 on students (marks.total()); 

Index created. 

SQL> create bitmap index bid1 on students(marks.e_result()); 

Index created. 

，那麼你應該看到所用的索引

SQL> exec dbms_stats.gather_table_stats(user, 'STUDENTS', method_opt=>'for all indexed columns size skewonly') 

PL/SQL procedure successfully completed. 

SQL> explain plan for select * from students s where s.marks.e_result() = 'fail'; 

Explained. 

SQL> @explain "" 

Plan hash value: 1595221732 

----------------------------------------------------------------------------------------- 
| Id | Operation     | Name  | Rows | Bytes | Cost (%CPU)| Time  | 
----------------------------------------------------------------------------------------- 
| 0 | SELECT STATEMENT    |   | 635 | 17780 | 109 (0)| 00:00:02 | 
| 1 | TABLE ACCESS BY INDEX ROWID | STUDENTS | 635 | 17780 | 109 (0)| 00:00:02 | 
| 2 | BITMAP CONVERSION TO ROWIDS|   |  |  |   |   | 
|* 3 | BITMAP INDEX SINGLE VALUE | BID1  |  |  |   |   | 
-----------------------------------------------------------------------------------------