Fixes are available
APAR status
Closed as program error.
Error description
DB2 MAY PRODUCE INCORRECT RESULTS FOR HSJN WHEN - HSJN HAS COMPLEX PREDICATE THAT HAS CASE ( COALESCE ) - HSJN HAS NLJN OR ZZJOIN ON THE OUTER - INTERNAL OPTIMIZATION IS APPLIED Example of the Complex Predicate in HSJN from the Plan that could produce wrong results: Predicate Text: -------------- (Q8.C1 = CASE WHEN (Q1.C2 = 'X') THEN COALESCE(Q1.C3, 'Y') WHEN NOT(Q1.C4 IN ('A', 'B')) THEN CASE WHEN UPPER(COALESCE(Q2.C5, 'D')) IN ('E', 'F', 'G') THEN 'H' WHEN (UPPER(COALESCE(Q2.C5, 'D')) = 'K') THEN 'L' ELSE COALESCE(Q2.C5, 'D') END ELSE COALESCE(Q2.C5, 'D') END) Example of HSJN with NLJN on the outer: 101225 HSJN ( 6) 552757 /------/ \----\ 101225 46 NLJN ISCAN ( 7) (22) 552653 ... / \ 101224 1 SCAN ISCAN ( 8) (21) 548163 ... | ...
Local fix
db2set DB2_TCG_DEFAULT_OPTIONS="set disable_pushdown on" instance restart is needed Static packages need to be rebound.
Problem summary
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher * ****************************************************************
Problem conclusion
First fixed in Db2 11.1 Mod 4 Fixpack 5
Temporary fix
Comments
APAR Information
APAR number
IT28638
Reported component name
DB2 FOR LUW
Reported component ID
DB2FORLUW
Reported release
B10
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-04-02
Closed date
2020-01-16
Last modified date
2020-01-16
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
DB2 FOR LUW
Fixed component ID
DB2FORLUW
Applicable component levels
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]
Document Information
Modified date:
04 May 2022