问题
Is this an Oracle 12c bug?
I run 64-bit Oracle 12.1.0.2 on Oracle Linux.
Came across a strange thing: when the execution plan switches to using "PARTITION LIST SUBQUERY" then the package used in the affected query is loosing all of its variable's values. It looks like something de-instantiates the package just like after running DBMS_SESSION.RESET_PACKAGE.
The query uses a partitioned table which partitions are limited by joining with another table limited using a variable from the package read using a deterministic "getter" function.
If I change the function not to be deterministic, or change anything so the explain plan is not using "PARTITION LIST SUBQUERY" the problem does not appear.
See the synthetic example that produces the explain plan with "PARTITION LIST SUBQUERY" on my databases (tried on 4):
-- Clean-up ----------------------------------------------------------------------------------------------------------------------------------------------------
DROP TABLE facts CASCADE CONSTRAINTS;
DROP TABLE DIM_CALENDAR CASCADE CONSTRAINTS;
DROP PACKAGE Parameters_PKG;
-- First, partitioned table ----------------------------------------------------------------------------------------------------------------------------------
CREATE TABLE factS
( mth VARCHAR2(6 BYTE) NOT NULL
, just_data VARCHAR2(120 BYTE) NOT NULL
)
PARTITION BY LIST (mth)
(
PARTITION M01 VALUES ('M01')
, PARTITION M02 VALUES ('M02')
, PARTITION M03 VALUES ('M03')
, PARTITION M04 VALUES ('M04')
, PARTITION M05 VALUES ('M05')
, PARTITION MAX_VALUE VALUES (DEFAULT)
LOGGING
ROW STORE COMPRESS BASIC
)
;
INSERT INTO facts SELECT 'M' || TO_CHAR(LEVEL, 'FM09'), STANDARD_HASH(LEVEL, 'SHA384' ) FROM dual connect BY LEVEL < 4;
COMMIT;
-- Second table to iterate the partitions of the first table ------------------------------------------------------------------------------------------------
CREATE TABLE DIM_CALENDAR
(
CLIENT_ID VARCHAR2(10 BYTE) NOT NULL,
mth VARCHAR2(6 BYTE) NOT NULL
)
;
INSERT INTO DIM_CALENDAR SELECT 'TEST', 'M' || TO_CHAR(LEVEL, 'FM09') FROM dual connect BY LEVEL < 2;
INSERT INTO DIM_CALENDAR SELECT 'OTHER', 'M' || TO_CHAR(LEVEL, 'FM009') FROM dual connect BY LEVEL < 10;
INSERT INTO DIM_CALENDAR SELECT 'ANOTHER', 'M' || TO_CHAR(LEVEL, 'FM09') FROM dual connect BY LEVEL < 2;
COMMIT;
-- Analyzing both tables to get to the desired explain plan ----------------------------------------------------------------------------------------------------
EXECUTE DBMS_STATS.GATHER_SCHEMA_STATS (NULL, NULL);
-- A package with deterministic ffunction ---------------------------------------------------------------------------------------------------------------------
CREATE OR REPLACE PACKAGE Parameters_PKG
AUTHID DEFINER
AS
FUNCTION get_Client_ID RETURN VARCHAR2 deterministic;
PROCEDURE Set_Client_ID (p_Client_ID VARCHAR2);
END Parameters_PKG
;
CREATE OR REPLACE PACKAGE BODY Parameters_PKG
AS
Client_ID VARCHAR2(255);
FUNCTION get_Client_ID RETURN VARCHAR2
AS
PRAGMA UDF;
BEGIN
IF Client_ID IS NULL THEN
RAISE_APPLICATION_ERROR(-20001, 'Fatal error.');
END IF;
RETURN Client_ID;
END get_Client_ID;
PROCEDURE Set_Client_ID (P_Client_ID VARCHAR2)
IS
BEGIN
Client_ID := UPPER(TRIM(p_Client_ID));
END Set_Client_ID;
END Parameters_PKG
;
----------------------------------------------------------------------------------------------------------------------------------------------------------------
-- The test ----------------------------------------------------------------------------------------------------------------------------------------------------
-- exec Parameters_PKG.Set_Client_ID('TEST') -- this should return 2 rows
exec Parameters_PKG.Set_Client_ID('wrong_value_to_have_0_rows_returned')
SELECT Parameters_PKG.Get_Client_ID FROM dual; -- a check that the value is really set.
SELECT f.mth, f.just_data
FROM facts f, DIM_CALENDAR c
WHERE c.CLIENT_ID = Parameters_PKG.Get_Client_ID
AND F.mth = C.mth
;
/* Failing explain plan with "PARTITION LIST SUBQUERY"
SELECT STATEMENT ALL_ROWSCost: 43.194 Bytes: 336 Cardinality: 3
4 HASH JOIN Cost: 43.194 Bytes: 336 Cardinality: 3
2 PARTITION LIST SUBQUERY Cost: 43.107 Bytes: 303 Cardinality: 3 Partition #: 2 Partitions accessed #KEY(SUBQUERY)
1 TABLE ACCESS FULL TABLE FACTS Cost: 43.107 Bytes: 303 Cardinality: 3 Partition #: 2 Partitions accessed #KEY(SUBQUERY)
3 TABLE ACCESS FULL TABLE DIM_CALENDAR Cost: 87 Bytes: 44 Cardinality: 4
*/
回答1:
Remove the 'deterministic' keyword. DETERMINISTIC means for the same set of inputs I can return the same output without evaluating the function again. You have no inputs to that function, so we never need to run it. So we'll return null, eg (with your setup code omitted)
--
-- with deterministic
--
SQL> CREATE OR REPLACE PACKAGE Parameters_PKG
2 AUTHID DEFINER
3 AS
4 FUNCTION get_Client_ID RETURN VARCHAR2 deterministic;
5 PROCEDURE Set_Client_ID (p_Client_ID VARCHAR2);
6 END Parameters_PKG
7 ;
8 /
Package created.
SQL> CREATE OR REPLACE PACKAGE BODY Parameters_PKG
2 AS
3 Client_ID VARCHAR2(255);
4 FUNCTION get_Client_ID RETURN VARCHAR2
5 AS
6 PRAGMA UDF;
7 BEGIN
8 IF Client_ID IS NULL THEN
9 RAISE_APPLICATION_ERROR(-20001, 'Fatal error.');
10 END IF;
11 RETURN Client_ID;
12 END get_Client_ID;
13 PROCEDURE Set_Client_ID (P_Client_ID VARCHAR2)
14 IS
15 BEGIN
16 Client_ID := UPPER(TRIM(p_Client_ID));
17 END Set_Client_ID;
18 END Parameters_PKG;
19 /
Package body created.
SQL>
SQL>
SQL> exec Parameters_PKG.Set_Client_ID('TEST')
PL/SQL procedure successfully completed.
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = Parameters_PKG.Get_Client_ID
4 AND F.mth = C.mth
5 ;
FROM facts f, DIM_CALENDAR c
*
ERROR at line 2:
ORA-00604: error occurred at recursive SQL level 1
ORA-20001: Fatal error.
ORA-06512: at "MCDONAC.PARAMETERS_PKG", line 9
SQL>
SQL> exec Parameters_PKG.Set_Client_ID('wrong_value_to_have_0_rows_returned')
PL/SQL procedure successfully completed.
SQL>
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = Parameters_PKG.Get_Client_ID
4 AND F.mth = C.mth
5 ;
SELECT f.mth, f.just_data
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-20001: Fatal error.
ORA-06512: at "MCDONAC.PARAMETERS_PKG", line 9
--
-- without deterministic
--
SQL>
SQL> CREATE OR REPLACE PACKAGE Parameters_PKG
2 AUTHID DEFINER
3 AS
4 FUNCTION get_Client_ID RETURN VARCHAR2;
5 PROCEDURE Set_Client_ID (p_Client_ID VARCHAR2);
6 END Parameters_PKG
7 ;
8 /
Package created.
SQL> CREATE OR REPLACE PACKAGE BODY Parameters_PKG
2 AS
3 Client_ID VARCHAR2(255);
4 FUNCTION get_Client_ID RETURN VARCHAR2
5 AS
6 PRAGMA UDF;
7 BEGIN
8 IF Client_ID IS NULL THEN
9 RAISE_APPLICATION_ERROR(-20001, 'Fatal error.');
10 END IF;
11 RETURN Client_ID;
12 END get_Client_ID;
13 PROCEDURE Set_Client_ID (P_Client_ID VARCHAR2)
14 IS
15 BEGIN
16 Client_ID := UPPER(TRIM(p_Client_ID));
17 END Set_Client_ID;
18 END Parameters_PKG;
19 /
Package body created.
SQL>
SQL>
SQL> exec Parameters_PKG.Set_Client_ID('TEST')
PL/SQL procedure successfully completed.
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = Parameters_PKG.Get_Client_ID
4 AND F.mth = C.mth
5 ;
MTH JUST_DATA
------ ------------------------------------------------------------------------------------------------------------------------
M01 C6537FE410CFA617AFE7F17E6DD72BD9A6EF9ED08CA1216A811320A31A1FE0F9E57D832061B1A7EAA3534D8473098CBF
1 row selected.
SQL>
SQL> exec Parameters_PKG.Set_Client_ID('wrong_value_to_have_0_rows_returned')
PL/SQL procedure successfully completed.
SQL>
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = Parameters_PKG.Get_Client_ID
4 AND F.mth = C.mth
5 ;
no rows selected
SQL>
SQL>
And here is an alternative using a CONTEXT variable
SQL> CREATE TABLE factS
2 ( mth VARCHAR2(6 BYTE) NOT NULL
3 , just_data VARCHAR2(120 BYTE) NOT NULL
4 )
5 PARTITION BY LIST (mth)
6 (
7 PARTITION M01 VALUES ('M01')
8 , PARTITION M02 VALUES ('M02')
9 , PARTITION M03 VALUES ('M03')
10 , PARTITION M04 VALUES ('M04')
11 , PARTITION M05 VALUES ('M05')
12 , PARTITION MAX_VALUE VALUES (DEFAULT)
13 LOGGING
14 ROW STORE COMPRESS BASIC
15 )
16 ;
Table created.
SQL> INSERT INTO facts SELECT 'M' || TO_CHAR(LEVEL, 'FM09'), STANDARD_HASH(LEVEL, 'SHA384' ) FROM dual connect BY LEVEL < 4;
3 rows created.
SQL> COMMIT;
Commit complete.
SQL>
SQL> CREATE TABLE DIM_CALENDAR
2 (
3 CLIENT_ID VARCHAR2(10 BYTE) NOT NULL,
4 mth VARCHAR2(6 BYTE) NOT NULL
5 )
6 ;
Table created.
SQL> INSERT INTO DIM_CALENDAR SELECT 'TEST', 'M' || TO_CHAR(LEVEL, 'FM09') FROM dual connect BY LEVEL < 2;
1 row created.
SQL> INSERT INTO DIM_CALENDAR SELECT 'OTHER', 'M' || TO_CHAR(LEVEL, 'FM009') FROM dual connect BY LEVEL < 10;
9 rows created.
SQL> INSERT INTO DIM_CALENDAR SELECT 'ANOTHER', 'M' || TO_CHAR(LEVEL, 'FM09') FROM dual connect BY LEVEL < 2;
1 row created.
SQL> COMMIT;
Commit complete.
SQL> create context my_context using Parameters_PKG;
Context created.
SQL> CREATE OR REPLACE PACKAGE Parameters_PKG AS
2 PROCEDURE Set_Client_ID (p_Client_ID VARCHAR2);
3 END Parameters_PKG;
4 /
Package created.
SQL> CREATE OR REPLACE PACKAGE BODY Parameters_PKG AS
2
3 PROCEDURE Set_Client_ID (P_Client_ID VARCHAR2)
4 IS
5 BEGIN
6 dbms_session.set_context('MY_CONTEXT','CLIENT_ID',UPPER(TRIM(p_Client_ID)));
7 END Set_Client_ID;
8 END Parameters_PKG;
9 /
Package body created.
SQL> exec Parameters_PKG.Set_Client_ID('TEST')
PL/SQL procedure successfully completed.
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = sys_context('MY_CONTEXT','CLIENT_ID')
4 AND F.mth = C.mth
5 ;
MTH
------
JUST_DATA
----------------------------------------------------------------------------------------------------
M01
C6537FE410CFA617AFE7F17E6DD72BD9A6EF9ED08CA1216A811320A31A1FE0F9E57D832061B1A7EAA3534D8473098CBF
1 row selected.
SQL>
SQL> exec Parameters_PKG.Set_Client_ID('wrong_value_to_have_0_rows_returned')
PL/SQL procedure successfully completed.
SQL>
SQL> SELECT f.mth, f.just_data
2 FROM facts f, DIM_CALENDAR c
3 WHERE c.CLIENT_ID = sys_context('MY_CONTEXT','CLIENT_ID')
4 AND F.mth = C.mth
5 ;
no rows selected
SQL>
来源：https://stackoverflow.com/questions/50907322/when-partition-list-subquery-is-in-the-execution-plan-something-a-bug-de-in