PH14468: ABEND04E RC00D3440B DSNLXRSQ ABNDID071 AFTER ROLLBACK WHEN USINGKEEPDYNAMIC(YES) FOR ACCELERATED QUERY

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When running a Db2 12 for z/OS application where
  all of the following apply:
           - uses QUERY ACCELERATION to accelerate queries
             to the IBM Db2 Analytics Accelerator , and
           - uses the Db2 12 for z/OS feature KEEPDYNAMIC
             YES across ROLLBACK
          the Db2 DDF application abend
               DSNLXGLM.DSNLXRSQ :0071 RC00D3440B
          occurred on the OPEN cursor following the ROLLBACK
          as in the simple application scenario described
          below.
  
          Application is bound with KEEPDYNAMIC(YES) and
          specifies query acceleration either via special
          register CURRENT QUERY ACCELERATION or the
          associated Db2 subsytem parameter / zparm
  
  Application scenario example:
          EXEC SQL DECLARE C1 CURSOR FOR STMT;
  
          EXEC SQL PREPARE STMT FROM 'SELECT * FROM ...';
            -- this query is prepared for acceleration
  
          EXEC SQL OPEN C1;
  
          EXEC SQL ROLLBACK;
  
          EXEC SQL OPEN C1;
           - Abend DSNLXGLM . DSNLXRSQ :0071 RC00D3440B here
  
  The abend can also occur for cursor defined as WITH HOLD
  and is explicitly CLOSEd prior to the SQL ROLLBACK.
  
  The Db2z subsystem does not terminate; only the Db2z application
  is terminated.
  
  The customer may not have their own application that does this
  ROLLBACK scenario, but could be running a vendor application
  or tool that does.
  
  The problem does not occur when using COMMIT instead of
  ROLLBACK.
  **************************************************************
  Additional Symptoms and Keywords:
  DB2DDF IDAAV4R1/K IDAAV5R1/K IDAAV7R1/K
  ABEND04E AB04E S004E 04E
   04E-00D3440B 00D3440B
    DSNLXRSQ DSNLXRSQ:0071 0071 VRADC0071 ABNDID0071 ABID0071
  

Local fix

• If appropriate and you are able to change the application
  that encounters the abend, use COMMIT instead of ROLLBACK.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All DB2 users of the IBM Data Analytics                      *
  * Accelerator (IDAA).                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * A query offload may result in                                *
  * ABEND04E-00D3440B                                            *
  * LOC=DSNLXGLM.DSNLXRSQ:0071.                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply corrective PTF when available                          *
  ****************************************************************
  An application bound with KEEPDYNAMIC(YES) issues the
  following sequence of SQL statements to offload a dynamic
  query: PREPARE, OPEN, FETCH, CLOSE, ROLLBACK, OPEN. The OPEN
  statement following the ROLLBACK resulted in the reported
  abend.
  Beginning with Db2 12 for z/OS (V12R1M500), the
  KEEPDYNAMIC(YES) bind option keeps dynamic SQL statements
  after the point of rollback.  However, during rollback
  processing for query offloads, Db2 failed to preserve
  statement-related internal control blocks.  This can lead to
  the reported abend for any OPEN of an offloaded cursor
  following a rollback.  This issue affects both local and
  remote query offloads originating from a Db2 12 for z/OS
  system.  The issue can be bypassed by re-preparing the
  statement following a rollback.
  

Problem conclusion

• Db2 rollback processing has been changed to preserve the
  internal control blocks needed to offload queries for
  applications bound with KEEPDYNAMIC(YES).
  

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:

  UI64780

Modules/Macros

• DSNXEDSC DSNLXREL DSNXONZO DSNXOIN  DSNXONZB DSNLXSRL DSNLXCMT
  DSNLXRAX DSNXODML
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI64780

     UP19/08/30 P F908

Fix is available

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