DB2 FOR LUW / DB2FORLUW / B10 - DB2

DB2 can return wrong query result when all of the following 
conditions are satisfied 
 
1. DPF (Data Partitioning Feature) environment. 
2. The query has a outer join, and the outer join has a 
predicate of the form COLUMN1=COLUMN2, where both columns are 
from the outer table. 
3. Either DB2COMPOPT=OJLOCALPRDPLANNING is set, or the 
NULL-producing side of the outer join is a CSE (Common 
SubExpression), UNION, GROUP-BY, or another outer join. 
4. The query has a key requirement or order requirement on one 
of the columns in the COLUMN1=COLUMN2 predicate. 
 
For example: 
 
The following query can possibly produce a wrong result in DPF 
environment, because the query has an outer join predicate of 
TT.T1_C1 = TT.T1_C2, the NULL-producing side of the outer join 
is another outer join, and the query requires "DISTINCT 
TT.T1_C2" 
 
SELECT DISTINCT TT.T1_C2 FROM T1 TT LEFT OUTER JOIN 
(SELECT T2.T2_C4 FROM T2 FULL OUTER JOIN T1 ON T1.T1_C1 = 
T2.T2_C2) TT2 on TT.T1_C1 = TT.T1_C2 
 
The following query can possibly produce a wrong result in DPF 
environment and when DB2COMPOPT=OJLOCALPRDPLANNING is set, 
because the query has an outer join predicate of 
T1.T1_C1=T1.T1_C2, and the query requires "ORDER BY TT.T1_C2" 
 
SELECT * FROM T2 TT1, (SELECT * FROM T1 LEFT JOIN T2 on 
T1.T1_C1=T1.T1_C2 ) TT 
WHERE TT1.T2_C4 = TT.T1_C1 
ORDER BY TT.T1_C2

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* USERS AFFECTED:                                              * 
* DB2 DPF                                                      * 
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* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 11.1.1.1                              * 
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DB2 Version 11.1 Mod1 Fix Pack1 iFix001 for Linux, UNIX, and Windows
 DB2 Version 11.1 Mod 2 Fix Pack 2 for Linux, UNIX, and Windows
 Db2 Version 11.1 Mod2 Fix Pack2 iFix001 for Linux, UNIX, and Windows
 Db2 Version 11.1 Mod2 Fix Pack2 iFix002 for Linux, UNIX, and Windows
 Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows
 Db2 Version 11.1 Mod3 Fix Pack3 iFix001 for Linux, UNIX, and Windows
 Db2 Version 11.1 Mod3 Fix Pack3 iFix002 for Linux, UNIX, and Windows
 

First fixed in DB2 Version 11.1.1.1

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

12.10.2016
20.12.2016
20.12.2016