PM66388: SQLCODE -904 WHEN OFFLOADING QUERY TO IDAA IF GROUP BY CLAUSE ITEMS ARE DIFFERENT FROM SELECT LIST

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• SQLCODE -904 when offloading query to IDAA if GROUP BY clause
  items are different from SELECT list.  For example:
  SELECT DISTINCT 3 + (C1 + C3SINT),
  C0 || ' ',
  COUNT(*)
  FROM T1
  WHERE C2=1
  GROUP BY (C1 + C3SINT)+3, C0 || ' '
  ORDER BY 2 DESC, 1, 3 DESC;
  
                                                        (d159326)
  IDAAV2R1/K
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of DB2 9 for z/OS EXPLAIN.         *
  *                 All users of DB2 9 for z/OS who are also     *
  *                 using IDAA ( IBM DB2 Analytics Accelerator ) *
  ****************************************************************
  * PROBLEM DESCRIPTION: (1) Query offload to an accelerator     *
  *                      fails when a GROUP BY expression does   *
  *                      not match the corresponding SELECT list *
  *                      expression.                             *
  *                                                              *
  *                      (2) Explain table DSN_QUERYINFO_TABLE   *
  *                      is populated for static SQL and also    *
  *                      when ACCEL=NO for both static and       *
  *                      dynamic SQL.                            *
  *                                                              *
  *                      (3) Query offload to an accelerator     *
  *                      fails when there are multiple views     *
  *                      in a complex query.                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  (1) Query offload to an accelerator fails with SQLCODE -904
  when a GROUP BY expression does not match the corresponding
  SELECT list expression. For example:
  
  SELECT 3+(C1+C2),C4
  FROM T1
  WHERE C3 >1
  GROUP BY (C1+C2)+3,C4
  ORDER BY 2,1;
  
  (2) Explain table DSN_QUERYINFO_TABLE is populated for static
  SQL and also when ACCEL=NO for both static and dynamic SQL.
  DB2 should not populate DSN_QUERYINFO_TABLE for these two
  scenarios since the queries will never offload to an
  accelerator.
  
  (3) Query offload to an accelerator fails with SQLCODE -901
  when for a complex query with multiple views.
  
  
  Additional keywords:
  SQLEXPLAIN SQLCODE904 IDAAV2R1/K SQLGROUPBY SQLCODE901 SQLVIEW
  

Problem conclusion

• (1) The converted query text used for offload is fixed so that
  the GROUP BY expression matches the SELECT list expression.
  
  (2) DB2 no longer populates DSN_QUERYINFO_TABLE for static SQL
  or when ACCEL=NO for both static and dynamic SQL.
  
  (3) The converted query text used for offload is fixed so that
  the complex query with multiple views executes successfully.
  

Temporary fix

Comments

APAR Information

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

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

  UK80822

Modules/Macros

• DSNXONZC DSNXOOP
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK80822

     UP12/08/21 P F208

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.