IT10059: WRONG RESULTS USING AGGREGATION AND SAME COLUMN TWICE IN DIFFERENT AGGREGATION FUNCTIONS

DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• A complex query might produce wrong results with the following
  conditions:
  
  - using aggregation
  - the same column is used twice in different aggregation
  functions
  - internal optimization is done (this can only be checked by DB2
  support looking at the section dumps for the query)
  
  Example:
  select  a11.ART_DAN  ART_DAN_S,
          max(a13.ART_ARTBEZ)  ART_ARTBEZ,
          a14.DAT_JJJJMM  DAT_JJJJMM,
          max(a14.DAT_MON_KBEZ)  DAT_MON_KBEZ,
          a12.DAT_JJJJMM  DAT_JJJJMM0,
          min(a12.DAT_MON_KBEZ)  DAT_MON_KBEZ0,
          sum((a11.WB_MENGE * a11.WB_C_FIL))  WJXBFS1
  from    dpermv.F3WB_A_L_M       a11,
          dpermv.D1TAGMON a12,
          dpermv.D1DANDAN a13,
          dpermv.D1TAGMON a14
  where   a11.DAT_JJJJMM = a12.DAT_VJM and
          a11.ART_DAN = a13.ART_DAN
   and    (a13.ART_HLNR in (14)
   and a12.DAT_JJJJMM in (201312, 201311, 201310, 201309, 201308,
  201307,
  201306, 201305, 201304, 201303, 201302, 201301)
   and a12.DAT_JJJJMM = a14.DAT_JJJJMM
   and a11.BWART_BWART in ('S02', 'S14', 'S15', 'S11', 'S03', 'S08
  ',
  'I02  ', 'I03  ', 'S72  ', 'S81  ', 'S73  ', 'S78  ', 'S23  ',
  'S20  ',
  'S21  ', 'S22  '))
  group by        a11.ART_DAN,
          a14.DAT_JJJJMM,
          a12.DAT_JJJJMM;
  
  Note:
  
  max(a14.DAT_MON_KBEZ) DAT_MON_KBEZ,
     min(a12.DAT_MON_KBEZ) DAT_MON_KBEZ0,
  
  are coming from the same column in the same table:
      dpermv.D1TAGMON a12,
      dpermv.D1TAGMON a14
  

Local fix

• db2set DB2_TCG_DEFAULT_OPTIONS="set disable_pushdown on"
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ALL                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to DB2 10.1 Fix Pack 6                               *
  ****************************************************************
  

Problem conclusion

• First fixed in DB2 10.1 Fix Pack 6
  

Temporary fix

Comments

APAR Information

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

  IT10009

• 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

• RA10 PSN UP

     FIX