在使用自定义聚集函数时出现了一个ORA-1467错误。

根据Oracle文档上的描述，1467错误是由于排序的键值超过了DB_BLOCK_SIZE。

但是出现错误的SQL似乎并不满足这个条件。下面简单构造这个错误：

SQL> CREATE OR REPLACE TYPE T_LINK AS OBJECT (
2 STR VARCHAR2(30000),
3 STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT T_LINK) RETURN NUMBER,
4 MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT T_LINK, VALUE IN VARCHAR2) RETURN NUMBER,
5 MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF IN T_LINK, RETURNVALUE OUT VARCHAR2, FLAGS IN NUMBER) RETURN NUMBER,
6 MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT T_LINK, CTX2 IN T_LINK) RETURN NUMBER
7 )
8 /

Type created.

SQL> CREATE OR REPLACE TYPE BODY T_LINK IS
2 STATIC FUNCTION ODCIAGGREGATEINITIALIZE(SCTX IN OUT T_LINK) RETURN NUMBER IS
3 BEGIN
4 SCTX := T_LINK(NULL);
5 RETURN ODCICONST.SUCCESS;
6 END;
7
8 MEMBER FUNCTION ODCIAGGREGATEITERATE(SELF IN OUT T_LINK, VALUE IN VARCHAR2) RETURN NUMBER IS
9 BEGIN
10 SELF.STR := SELF.STR || VALUE || ',';
11 RETURN ODCICONST.SUCCESS;
12 END;
13
14 MEMBER FUNCTION ODCIAGGREGATETERMINATE(SELF IN T_LINK, RETURNVALUE OUT VARCHAR2, FLAGS IN NUMBER) RETURN NUMBER IS
15 BEGIN
16 RETURNVALUE := SUBSTR(SELF.STR, 1, LENGTH(SELF.STR) - 1);
17 RETURN ODCICONST.SUCCESS;
18 END;
19
20 MEMBER FUNCTION ODCIAGGREGATEMERGE(SELF IN OUT T_LINK, CTX2 IN T_LINK) RETURN NUMBER IS
21 BEGIN
22 NULL;
23 RETURN ODCICONST.SUCCESS;
24 END;
25 END;
26 /

Type body created.

SQL> CREATE OR REPLACE FUNCTION F_LINK(P_STR VARCHAR2) RETURN VARCHAR2
2 AGGREGATE USING T_LINK;
3 /

Function created.

首先是构造自定义聚集函数，关于这个函数的详细说明，可以参考：http://yangtingkun.itpub.net/post/468/3380

SQL> CREATE TABLE T AS SELECT * FROM DBA_OBJECTS;

Table created.

SQL> SELECT OWNER, F_LINK(OBJECT_NAME), F_LINK(SUBOBJECT_NAME), F_LINK(OBJECT_ID)
2 FROM T
3 GROUP BY OWNER;
SELECT OWNER, F_LINK(OBJECT_NAME), F_LINK(SUBOBJECT_NAME), F_LINK(OBJECT_ID)
*
ERROR at line 1:
ORA-01467: sort key too long

SQL> DESC T
Name Null? Type
--------------------------------- -------- --------------
OWNER VARCHAR2(30)
OBJECT_NAME VARCHAR2(128)
SUBOBJECT_NAME VARCHAR2(30)
OBJECT_ID NUMBER
DATA_OBJECT_ID NUMBER
OBJECT_TYPE VARCHAR2(18)
CREATED DATE
LAST_DDL_TIME DATE
TIMESTAMP VARCHAR2(19)
STATUS VARCHAR2(7)
TEMPORARY VARCHAR2(1)
GENERATED VARCHAR2(1)
SECONDARY VARCHAR2(1)

OWNER列的长度只有30，而且即使换成长度为1的列也没有作用。

SQL> SELECT TEMPORARY, F_LINK(OBJECT_NAME), F_LINK(SUBOBJECT_NAME), F_LINK(OBJECT_ID)
2 FROM T
3 GROUP BY TEMPORARY;
SELECT TEMPORARY, F_LINK(OBJECT_NAME), F_LINK(SUBOBJECT_NAME), F_LINK(OBJECT_ID)
*
ERROR at line 1:
ORA-01467: sort key too long

既然和GROUP BY列没有太大的关系，那么是否与F_LINK输入列的长度有关：

SQL> SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
2 FROM T
3 GROUP BY OWNER;
SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
*
ERROR at line 1:
ORA-01467: sort key too long

即使将F_LINK的输入参数变成常数1、2、3，问题仍然会出现，看来和F_LINK输入参数的长度也没有关系。

虽然与F_LINK输入参数长度没有关系，但是和F_LINK函数调用次数有关，将F_LINK三次调用变为两次调用，就可以得到结果：

SQL> SELECT OWNER, F_LINK(1), F_LINK(2)
2 FROM T
3 WHERE ROWNUM < 10
4 GROUP BY OWNER;

OWNER F_LINK(1) F_LINK(2)
------------------------------ ------------------------------ -----------------
SYS 1,1,1,1,1,1,1,1,1 2,2,2,2,2,2,2,2,2

这个问题在9i上就会出现，而且与DB_BLOCK_SIZE的大小没有关系。在DB_BLOCK_SIZE为8K和16K的环境下测试，得到的结果完全一样。

SQL> CREATE TABLE T AS SELECT * FROM ALL_OBJECTS;

Table created.

SQL> SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
2 FROM T
3 GROUP BY OWNER;
SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
*
ERROR at line 1:
ORA-01467: sort key too long

SQL> SET SERVEROUT ON
SQL> DECLARE
2 V_NUMBER NUMBER;
3 V_STR VARCHAR2(4000);
4 V_RES NUMBER;
5 BEGIN
6 V_RES := DBMS_UTILITY.GET_PARAMETER_VALUE('db_block_size', V_NUMBER, V_STR);
7 DBMS_OUTPUT.PUT_LINE(V_NUMBER);
8 END;
9 /
8192

PL/SQL procedure successfully completed.

SQL> CONN TEST@GPODB
Enter password:
Connected.
SQL> SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
2 FROM T
3 GROUP BY OWNER;
SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3)
*
ERROR at line 1:
ORA-01467: sort key too long

SQL> SHOW PARAMETER DB_BLOCK_SIZE

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_block_size integer 16384

而这个问题在10g已经得到了解决，测试发现即使有30多个F_LINK的调用，也没有出现ORA-1467错误。

SQL> CONN YANGTK/YANGTK@YTK已连接。
SQL> SELECT * FROM V$VERSION;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

SQL> COL F_LINK(1) FORMAT A20
SQL> COL F_LINK(2) FORMAT A20
SQL> COL F_LINK(3) FORMAT A20
SQL> COL F_LINK(4) FORMAT A20
SQL> SELECT OWNER, F_LINK(1), F_LINK(2), F_LINK(3), F_LINK(4)
2 FROM T
3 WHERE ROWNUM < 5
4 GROUP BY OWNER;

OWNER F_LINK(1) F_LINK(2) F_LINK(3) F_LINK(4)
-------------------- -------------------- -------------------- -------------------- ------
SYS 1,1,1,1 2,2,2,2 3,3,3,3 4,4,4,4

在9i上如果碰到这个问题，可以考虑使用变通的方法解决。比如使用CONNECT BY语句来代替自定义聚集函数。

SQL> SELECT OWNER, MAX(LTRIM(SYS_CONNECT_BY_PATH(OBJECT_NAME, ','), ',')) OBJECT_NAME,
2 MAX(LTRIM(SYS_CONNECT_BY_PATH(SUBOBJECT_NAME, ','), ',')) SUBOBJECT_NAME,
3 MAX(LTRIM(SYS_CONNECT_BY_PATH(OBJECT_ID, ','), ',')) OBJECT_ID
4 FROM
5 (
6 SELECT OWNER, OBJECT_NAME, SUBOBJECT_NAME, OBJECT_ID,
7 ROW_NUMBER() OVER(PARTITION BY OWNER ORDER BY OBJECT_NAME) RN
8 FROM T
9 WHERE OBJECT_ID BETWEEN 30014 AND 30017
10 )
11 START WITH RN = 1
12 CONNECT BY PRIOR RN + 1 = RN
13 AND PRIOR OWNER = OWNER
14 GROUP BY OWNER;

OWNER OBJECT_NAME SUBOBJECT_NAM OBJECT_ID
-------- ---------------------------------------------------- ------------- ---------------
OLAPSYS ALL$OLAP1_CUBES,ALL$OLAPMR_DIM_LEVELS_KEYMAPS 30016,30017
PUBLIC CWM2_OLAP_AW_ACCESS,CWM2_OLAP_INSTALLER 30014,30015

如果无法聚集函数函数无法代替，可以使用下面的办法：

SQL> SELECT A.OWNER, A.OBJECT_NAME, A.SUBOBJECT_NAME, B.OBJECT_ID
2 FROM
3 (
4 SELECT OWNER, F_LINK(OBJECT_NAME) OBJECT_NAME,
5 F_LINK(SUBOBJECT_NAME) SUBOBJECT_NAME
6 FROM T
7 WHERE OBJECT_ID BETWEEN 30014 AND 30017
8 GROUP BY OWNER
9 ) A,
10 (
11 SELECT OWNER, F_LINK(OBJECT_ID) OBJECT_ID
12 FROM T
13 WHERE OBJECT_ID BETWEEN 30014 AND 30017
14 GROUP BY OWNER
15 ) B
16 WHERE A.OWNER = B.OWNER;

OWNER OBJECT_NAME SUBOBJECT_NAM OBJECT_ID
-------- ---------------------------------------------------- ------------- ---------------
OLAPSYS ALL$OLAP1_CUBES,ALL$OLAPMR_DIM_LEVELS_KEYMAPS 30016,30017
PUBLIC CWM2_OLAP_AW_ACCESS,CWM2_OLAP_INSTALLER 30014,30015

只要避免在同一个子查询中自定义聚集函数不要超过限定数量就可以了。

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