IC83436: INCORRECT OUTPUT MIGHT BE RETURNED BY A QUERY WITH PARTITION ELIMINATION INVOLVING MULTIPLE COLUMNS AND NON-CONSTANT KEYS

DB2 Version 9.8 Fix Pack 5 for AIX and Linux

APAR status

• Closed as program error.

Error description

• You might encounter incorrect output from a SQL statement that
  references a partitioned table with a multi-column range key,
  and satisfies all the following conditions:
  
  1.  The WHERE clause contains a partition elimination eligible
  predicate, p1, with place holder variable, such as COL1=?
  2.  The WHERE clause contains a correlated subquery or a join,
  p2, that is partition elimination eligible.
  3.  The predicate p1 is applied on a leading column in the range
  key, followed by the predicate p2.
  
  For example, consider a table T1 partitioned by range on
  (COL1,COL2). If an SQL statement contains a WHERE clause as
  
  SELECT ...
  FROM ..., T1, T2, ...
  WHERE ... T1.COL1 = ? AND T1.COL2 = T2.X ...
  
  then, you might encounter incorrect output. Likewise, incorrect
  output is also possible if the predicates are within a
  correlated subquery such as
  
  WHERE T2.Y = (SELECT MAX(T1.Y) FROM T1 WHERE T1.COL1 = ? AND
  T1.COL2 = T2.Y)
  
  If the predicates on COL1 and COL2 are switched, you will get
  the correct output.
  

Local fix

• Replace the place holder variable with a constant or use the
  REOPT option.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ALL                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to DB2 Version 9.8 Fix Pack 5                        *
  ****************************************************************
  

Problem conclusion

• Problem was first fixed in Version 9.8 Fix Pack 5
  

Temporary fix

• See LOCAL FIX
  

Comments

APAR Information

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

  IC77337

• 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

• R910 PSN

     UP

• R950 PSN

     UP

• R970 PSN

     UP

• R980 PSN

     UP