IT20661: WRONG RESULTS MIGHT OCCUR WHEN SCALAR SUB-QUERY IS ON THE LEFT HAND SIDE OF A NOT IN PREDICATE

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
Db2 Version 11.1 Mod4 Fix Pack4 iFix001 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• Wrong results might be observed when a scalar sub-query is on
  the left hand side of a NOT IN predicate.
  This can happen using db2 version 10.5 and later when:
  
     1. a query statement contains a NOT IN predicate;
     2. the left hand side of the NOT IN predicate is a scalar
  sub-query;
     3. the evaluation of the NOT IN predicate returns an empty
  result set
  
     The following use case can reproduce this problem:
     create table t(c1 int);
     insert into t values 1;
     create table ssq(c2 int not null);
     insert into ssq values 2;
     create table sq(c3 int not null);
     insert into sq values 2;
     select c1 from t where (select c2 from ssq) not in (select c3
  from sq);
     C1
     -----------
               1
  
       1 record(s) selected.
  

Local fix

• Please, rewrite the query
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ALL                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to DB2 11.1 Mod 2 Fix Pack 2 or higher               *
  ****************************************************************
  

Problem conclusion

• First fixed in DB2 11.1 Mod 2 Fix Pack 2
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IT20597

• 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