PH31684: NEW FUNCTION FOR SORT EXPLOITATION

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• New function for sort exploitation.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 for z/OS users that require Db2                   *
  * sort.                                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * IBM z15 processor introduced new                             *
  * capability, Integrated Accelerator for                       *
  * Z Sort to improve the performance of                         *
  * sort processing.  The capability                             *
  * includes the SORT LISTS (SORTL)                              *
  * instruction.  Db2 for z/OS exploits                          *
  * SORT LISTS in Db2 RDS sort operations                        *
  * through this APAR.                                           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Today, Db2 for z/OS uses a tournament sort within RDS to
  perform sorting routines. This tournament sort is used during
  both the input and merge phases of sort.  RDS sort can be
  invoked by ORDER BY or GROUP BY clause explicitly or implicitly
  by Db2 based on the access path.
  IBM z15 Integrated Accelerator for Z Sort provides a means to
  sort multiple lists of unsorted input data into one or more
  lists of sorted output data.  The facility also provides a
  means to merge multiples lists of sorted input data into a
  single list of sorted output data.  The facility includes the
  SORT LISTS (SORTL) instruction.
  By utilizing Z Sort capability, based on specific limits to
  both the key size and data size, Db2 will now have a second
  method of sorting to be used during the input phase only for
  Db2 sort.
  As a result, Db2 for z/OS users can enjoy reduced CPU and
  elapsed time from sort intensive SQL operations when the SQL
  is executed on z15 when the necessary conditions are met.
  The enhancement will be triggered automatically without user
  control when all conditions are met.
  The enhancement will limit on the sort key size of up to 136
  bytes and sort record size of up to 256 bytes and when the
  execution is done on z15 processors and above.
  This item will provide two new statistics in IFCID 2 to count
  the number of Db2 sorts and to count the number of Db2 sorts
  that use the IBM Integrated Accelerator for Z Sort (SORTL).
  Also, 2 new records will be added to IFCID 96 for sort that
  include the key size and data size for the SORTL since the
  sizes will be different and larger than the current Db2
  tournament sort.  IFCID 96 will also add a 2 new type of sorts
  to differentiate ORDER BY and GROUP BY.  Originally these would
  be defined as ESA or ESAG.  In the future if SORTL is used, it
  will now include STLO and STLG for ORDER BY and GROUP BY,
  respectively.
  

Problem conclusion

Temporary fix

Comments

• Db2 has been modified to enhance the sort processing on the
  IBM Z 15 processor, if available.
  

APAR Information

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

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

  UI73254

Modules/Macros

• DSNXSTSG DSNXTAD  DSNXSORI DSNXSTSE DSNXECWA DSNXSFTP DSNXSING
  DSNXSMRG DSNXSINE DSNXSMRE DSNXECL  DSNXSTM  DSNXECWU DSNXSMIR
  DSNXRRC  DSNXECLF DSNDQXST DSNXECW  DSNXSRME DSNDQW01 DSNXSMIG
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI73254

     UP20/12/31 P F012

Fix is available

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