PM66040: LOOP IN DSNXEBR AT OFFSETS +5FC8, +5FCC, +6084, and +608C when running a V10 Native Stored Proc on a V9 subsystem

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• At the first attempt to run a V10 Native Stored Procedure on a
  V9 system, it hung/looped with high CPU usage. This was due to a
  loop in DSNXEBR at offsets  +5FC8, +5FCC, +6084, +608C during
  internal ALTER PROCEDURE REPLACE VERSION processing.
  

Local fix

• Explicitly issue ALTER PROCEDURE REPLACE VERSION for the
  V10 native SQL Stored Proc on V9.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 9 for z/OS users of native stored    *
  *                 procedures or packages bound before DB2 for  *
  *                 z/OS V8.                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: An infinite loop may occur in CSECT     *
  *                      DSNXGRDS DSNXEBR when executing a       *
  *                      statement from a native SQLPL procedure *
  *                      or a package bound before DB2 V8.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Scenario  1:
  For a native stored procedure, the problem may occur if the
  stored procedure has a statement that references one of the
  following special registers :
  (CURRENT PACKAGESET,CURRENT PATH,CURRENT SQLID,CURRENT USER or
  CURRENT OPTIMIZATION HINT)
  and the package for the stored procedure has been rebound.
  The problem occurs when the stored procedure statements are
  executed.
  
  Scenario 2 : Any package bound on a release prior to Version 8
  that has an SQL statement that references one of the following
  special registers :
  (CURRENT PACKAGESET,CURRENT PATH,CURRENT SQLID,CURRENT USER or
  CURRENT OPTIMIZATION HINT)
  The problem occurs when the package is executed on Version 9.
  
  
  An example of a native stored procedure which may encounter the
  problem follows :
  
  CREATE PROCEDURE SP1
           (IN P1 TIMESTAMP,
            OUT P2 CHAR(128))
  BEGIN
  
      SET P2 = CURRENT SQLID;
  
  END!
  
  REBIND PACKAGE(SYSADM.SP1.(V1))
  Call the stored procedure so that it is executed and the
  infinite loop may occur.  Other symptoms such an ABEND0C4 are
  possible.
  

Problem conclusion

• DB2 has been changed to set the internal variable correctly
  which will prevent DB2 from looping.
  
  ADDITIONAL KEYWORDS : LOOPDSNXEBR SQLNATIVESQLPL
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

• ž**** PE12/10/24 FIX IN ERROR. SEE APAR PM74477  FOR DESCRIPTION
  

APAR Information

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

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

  UK80992

Modules/Macros

• DSNXEBR
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK80992

     UP12/08/29 P F208

Fix is available

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