函数索引 ORA-30553: The function is not deterministic 解决方法

建函数索引的时候报错：ORA-30553: The function is not deterministic， 这个函数是自定义的。

SQL>create index mobileIndex on mobile(getmobilearea (callerno));

Google 一下：

ORA-30553:	The function is not deterministic
Cause:	The function on which the index is defined is not deterministic
Action:	If the function is deterministic, mark it DETERMINISTIC. If it is not deterministic (it depends on package state, database state, current time, or anything other than the function inputs) then do not create the index. The values returned by a deterministic function should not change even when the function is rewritten or recompiled.

解决如下：

在创建基于自定义函数时, 指定deterministic参数，在创建函数索引，就没有问题了。

CREATE OR REPLACE FUNCTION ICD.getmobilearea (mobileno VARCHAR2)

RETURN VARCHAR2 deterministic

IS

s VARCHAR2 (20);

i INTEGER;

c INTEGER;

BEGIN

FOR i IN 4 .. 11

LOOP

SELECT COUNT (*)

INTO c

FROM mobilearea

WHERE shortno LIKE SUBSTR (mobileno, 1, i) || '%';

s := '000';

IF c = 0

THEN

EXIT;

ELSE

IF c = 1

THEN

SELECT areacode

INTO s

FROM mobilearea

WHERE shortno LIKE SUBSTR (mobileno, 1, i) || '%';

EXIT;

END IF;

END IF;

END LOOP;

RETURN s;

END getmobilearea;

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