PM55367: ENHANCEMENT TO IMPROVE THE PERFORMANCE OF DEDB HASH CHECK INVOKED BY DRF

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• With this APAR, the task CPU time consumed by the HASH check
  processing for DEDB areas will be reduced when the DEDB HASH
  check function is used in an IMS Database Recovery Facility job.
  
  This is a forward fit of IMS Fast Path Solution Pack V110 APAR
  PM55322.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users who uses HPFPU Hash Check support  *
  *                 for IMS Database Recovery Facility in Fast   *
  *                 Path Solution Pack Version 1 Release 2       *
  *                 (FMID: HAHQ120).                             *
  ****************************************************************
  * PROBLEM DESCRIPTION: Forward Fit APAR of FPSP V1R1 PM55322.  *
  *                      This APAR is an enhancement to reduce   *
  *                      the CPU time of the DRF SAS task        *
  *                      consumed by the HASH check processing   *
  *                      for IMS Database Recovery Facility.     *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  Forward Fit APAR of FPSP V1R1 PM55322.
  The DEDB Pointer Checker HASH Check that is invoked by IMS
  Database Recovery Facility(DRF) contains numerous instances of
  variables defined in close proximity to instructions that
  modify them. If the distance between variable and instruction is
  less than the amount of storage cached for instruction prefetch,
  the  modification invalidates the cache and the cache must be
  refreshed. This results in a performance degradation.
  
  This APAR reduces the CPU time of DRF SAS task consumed by the
  HASH check processing thet is invoked by IMS Database Recovery
  Facility.
  

Problem conclusion

Temporary fix

Comments

• The modules, FABAHPC0, FABAHSCA, FABAHSUB and FABAHBLD have
  been modified to exclude the save area and the data definition
  from instruction area.
  The prologs of the following modules/macros have been modified
  to indicate the copied codes.
  FABAHEXT
  FABAHDAT
  FABAHSNP
  FABABLDL
  DA#MDA51
  FABAHSP0
  FABAHRPT
  FABAHDA5
  FABAHDA0
  

APAR Information

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

  PM55322

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

  UK75562

Modules/Macros

•    FABABLDL FABAHBLD FABAHDA0 FABAHEXT FABAHPC0
  FABAHRPT FABAHSCA FABAHSNP FABAHSP0 FABAHSUB
  

Fix information

• Fixed component name

  IMS FP SOLUTION

• Fixed component ID

  5655W1400

Applicable component levels

• R120 PSY UK75562

     UP12/01/21 P F201

Fix is available

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