DB2 FOR LUW / DB2FORLUW / A50 - DB2

This problem may be found in a SQL statement if following 
conditions are true: 
1. The query has one or more existential subquery like IN and 
EXISTS 
2. One or more of the subqueries contain a UNION operator 
3. The outer reference to the subquery is either a base table or 
a subselect joined to another base table on the same join 
columns. 
4. the UNION operator is below the CTQ (i.e. performed in CDE) 
 
Example: 
        SELECT (C.C5 || ' ' || C.C6) AS C9, C.C4 FROM S1.T1 
A,S1.T2 B, S1.T3 C WHERE A.C1 = B.C1 AND C7 = C.C4 AND C8 = 15 
AND A.C1 
          IN ( 
          SELECT C1 
          FROM S1.T1 
          WHERE C2 = ? AND C3 = 1 
          UNION OPERATOR 
            SELECT B.C1 
            FROM S1.T1 A , S1.T1 B 
            WHERE 
                A.C2 = ? AND 
                A.C3 = 1 AND 
                B.C10 = A.C1 AND 
                B.C3 = 2 
            ) 
 
Error message detail: 
SQL0901N  The SQL statement or command failed because of a 
database system 
error. (Reason "Don't know how to handle this QNC".) 
SQLSTATE=58004 
 
 
Some of the known stack traces are the following: 
sqlnn_cmpl 
sqlng_main 
sqlng_main 
sqlng_build_thread 
sqlngProcessLolepop 
sqlng_process_return_op 
sqlngProcessLolepop 
sqlng_process_pipe_op 
sqlngProcessLolepop 
sqlng_process_mate_op 
sqlngProcessLolepop 
sqlng_scan_derived_table 
sqlng_build_thread 
sqlngProcessLolepop 
sqlng_process_sort_op 
sqlngProcessLolepop 
sqlng_process_ship_op 
sqlng_build_RQOB_obj 
 
 
sqldDumpContext 
sqlrr_dump_ffdc 
sqlzeSqlCode 
sqlng_build_RQOB_obj 
sqlng_process_ship_op 
sqlngProcessLolepop 
sqlng_process_sort_op 
sqlngProcessLolepop 
sqlng_build_thread 
sqlng_scan_derived_table 
sqlng_process_scan_op 
sqlngProcessLolepop 
sqlng_process_mate_op 
sqlngProcessLolepop 
sqlng_process_pipe_op 
sqlngProcessLolepop 
sqlng_process_return_op 
sqlngProcessLolepop 
sqlng_build_thread 
sqlng_mainP9sqlnq_qur 
sqlnn_cmplP8sqeAgent 
sqlra_compile_var

**************************************************************** 
* USERS AFFECTED:                                              * 
* Users running DB2 up to 10.5 Fix Pack 7                      * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 10.5 Fix Pack 7 or later                      * 
****************************************************************

Rewrite the subquery into an inner join with a SEL distinct on 
the subquery

not known / see Local fix

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

29.09.2014
03.02.2016
03.02.2016