II09434: UN90139 (PT.1)- THIS INFOAPAR PROVIDES COMMENTS TO FURTHER INTRODUCE AND EXPLAIN THE SUPPORT PROVIDED BY APAR PN71337

APAR status

• Closed as canceled.

Error description

• For DFSORT Release 13.0, PN71337 provides significant
  performance improvements, powerful new Year 2000 features
   (YR2000) and floating point for SUM support, as follows:
  
     * Performance Improvements for FLR and VLR Blockset Sorts
  
       Dataspace sorting can now be used for variable-length
       record sort applications.
  
      Dynamic storage adjustment is a new feature that allows
      DFSORT to automatically use more storage than the TMAXLIM
      value for a Blockset sort application if DFSORT
      determines that doing so should improve performance.
      New installation option DSA=n has been added to enable
      you to specify the dynamic storage adjustment limit.
  
      The upper limit for the amount of main storage that can be
      specified and used by DFSORT has been raised from 32M to
      2000M.  Specifying more main storage allows DFSORT to
      improve performance in some cases, such as for very large
      sort applications, or to extend the range of sort
      applications that can be done entirely in main storage.
      It also increases the maximum amount of data DFSORT can
      process in a single sort application.
  
      New installation option IOMAXBF=n has been added to enable
      you to specify the upper limit for the amount of storage
      to be used for SORTIN and SORTOUT data set buffers, which
      in turn limits the amount of data that can be transferred
      in a single I/O operation.
  
      The upper limit for the number of JCL and dynamically
      allocated work data sets that can be specified and used
      by DFSORT's Blockset technique has been raised from 32
      to 100.  The use of more work data sets increases the
      maximum amount of data DFSORT can process in a single
      sort application.
  
      DFSORT can now use NOEQUALS for VLR Blockset applications
      if EQUALS=NO is specified at installation or NOEQUALS is
      specified at run-time.  The use of NOEQUALS can improve
      performance and is recommended for applications for which
      the order of records that collate identically need not be
      preserved from input to output.  To minimize migration
      concerns, the IBM-supplied default for the ICEMAC EQUALS
      option is the new value VLBLKSET, which is equivalent to
      EQUALS=YES for VLR Blockset applications and to EQUALS=NO
      for all other applications.
  
    * Year 2000 features (YR2000)
  
      New Y2C, Y2Z, Y2P and Y2D formats, in conjunction with a
      new Y2PAST installation and run-time option, allow you to
      handle two-digit year data in the following ways:
      - Set the appropriate century window for your applications
        (for example, 1915-2014 or 1950-2049).
      - Order two-digit character, zoned decimal, packed decimal
        or decimal year data according to the century window
        using Blockset SORT or MERGE (for example, order 96
        representing 1996 before 00 representing 2000 in
        ascending sequence, or order 00 before 96 in descending
        sequence).
      - Transform two-digit character, zoned decimal, packed
        decimal or decimal year data to four-digit character
        year data according to the century window using
        OUTFIL OUTREC (for example, transform 96 to 1996 and
        00 to 2000).
  
      A new PD0 format allows you to order and transform
      parts of packed decimal fields (for example, month
      and day in date fields) using SORT, MERGE and OUTFIL.
  
    * Floating point for SUM
  
      FL format can now be used with the SUM control statement
      for short (4-byte), long (8-byte) and extended (16-byte)
      floating point data.
  
    * EXCPVR processing removed
  
      To enhance DFSORT's protection of system integrity,
      EXCPVR processing will no longer be used.  EXCPVR
      parameter values will continue to be accepted, but will
      have no effect on DFSORT processing.  In general, the
      performance improvements provided by EXCPVR processing
      have diminished with newer technologies and will be
      more than offset by the performance improvements provided
      by PN71337.
  **************************************************************
  For more details on all functions see one of the following:
  World Wide Web site:
    Visit the DFSORT/MVS World Wide Web home page at URL:
    http://www.storage.ibm.com/storage/software/sort/srtmhome.htm
  
  FTP server
     You can obtain DFSORT articles and examples via anonymous
     FTP to:
      lscftp.kgn.ibm.com/pub/mvs/docs/
  
  MKTTOOLS (Marketing Tools disk)
    Additional information can be found on the IBM Marketing
    tools disk for subjects introduced by this apar.
  
   General Description of Enhancements
   * Dynamic Storage Adjustment
  
    ICEMAC DSA=n
      specifies the maximum amount of storage available to DFSORT
      for dynamic storage adjustment of a Blockset sort
      application when SIZE/MAINSIZE=MAX is in effect.  If you
      specify a DSA value greater than the TMAXLIM value, you
      allow DFSORT to use more storage than the TMAXLIM value if
      doing so should improve performance.  The amount of storage
      DFSORT uses is subject to the DSA value as well as system
      limits such as region size.  However, whereas DFSORT always
      tries to obtain as much storage as it can up to the TMAXLIM
      value, DFSORT only tries to obtain as much storage as
      needed to improve performance up to the DSA value.
  
      The performance improvement from dynamic storage adjustment
      usually provides a good tradeoff against the increased
      storage used by DFSORT.  On storage constrained systems,
      however, the DSA value should be set low enough to prevent
      unacceptable paging.
  
       n
         specifies that DFSORT can dynamically adjust storage to
         improve performance, subject to a limit of n megabytes.
         n must be a value between 0 and 2000.  If n is less than
         or equal to the value specified for TMAXLIM, n is set
         to 0 to indicate that storage will not be dynamically
         adjusted.
  
       Applicable Systems: MVS/ESA and MVS/XA
  
      Default: 16
  
    New ICEMAC MNOTEs
      *,  x MEGABYTES IS THE LIMIT FOR DSA
      *,  0 MEGABYTES IS THE LIMIT FOR DSA BECAUSE DSA
          IS LESS THAN OR EQUAL TO TMAXLIM
      *,  16 MEGABYTES IS THE LIMIT FOR DSA
  
      8,***ICESM1098 DSA VALUE x INVALID
          The value x specified for DSA is not a valid decimal
          number or is not in the valid range for DSA.
  
    New SMF Type-16 Record Field
      Dec.  Hex   Name     Length   Format   Description
      +64   +40   ICEDSA        2   binary   DSA value in effect
                                             (in megabytes)
  
    Changed Message
  
      ICE131I OPTIONS: TMAXLIM=n,ARESALL=n,ARESINV=n,OVERRGN=n,
                       CINV=x,CFW=x,DSA=n
  
  * Increase main storage size limit
  
    ICEMAC SIZE=n
      The limit for n is raised from 33554416 (32 megabytes
      minus 16 bytes) to 2097152000 (2000 megabytes).
  
      The limit for n is raised from 33554424 (32 megabytes
      minus 16 bytes) to 2097152000 (2000 megabytes).
  
    EXEC PARM SIZE=n and OPTION MAINSIZE=n
      The limit for n is raised from 8 digits to 10 digits.
      If more than 2097152000 is specified, 2097152000 is used.
  
    EXEC PARM SIZE=nK and OPTION MAINSIZE=nK
      The limit for n is raised from 5 digits to 7 digits.
      If more than 2048000K is specified, 2048000K is used.
  
    EXEC PARM SIZE=nM and OPTION MAINSIZE=nM
      The limit for n is raised from 2 digits to 4 digits.
      If more than 2000M is specified, 2000M is used.
  
    ICEIEXIT Maximum Storage Run-Time Option
      If more than 2097152000 is specified, 2097152000 is used.
  
    Note:  Sufficient virtual storage must be available in the
    primary address space in order for DFSORT to use the amount
    of main storage specified.  Also, DFSORT and system
    performance can degrade if insufficient processor storage
    is available to back the specified amount of main storage.
  
    ICEMAC IOMAXBF=n
      specifies the maximum buffer space DFSORT can use for the
      SORTIN and SORTOUT data sets.  This, in turn, will limit
      the amount of data that can be transferred in a single I/O
      operation.  The actual amount of buffer space used for the
      SORTIN and SORTOUT data sets is subject to the IOMAXBF
      limit as well as the system storage limits (for example,
      IEFUSI and REGION) and the DFSORT storage limits (that is,
      SIZE, MAXLIM and TMAXLIM).  DFSORT attempts to use
      storage above 16-megabyte virtual for SORTIN and SORTOUT
      data set processing whenever possible.
  
      DFSORT uses the IOMAXBF value as the limit for the SORTIN
      data set buffers and as the limit for the SORTOUT data set
      buffers.  For example, if IOMAXBF is set to 8388608
      (8 megabytes), DFSORT uses an 8M limit for SORTIN and an
      8M limit for SORTOUT.  The buffer space for each data set
      will not exceed the IOMAXBF limit, but can be less than
      the limit.
  
      The IOMAXBF value can be adjusted up or down to fit the
      needs of your devices and system load.  At a transfer
      rate of 3M per second, the IBM shipped default of 33554432
      (32M) for IOMAXBF engages the channel for a maximum of
      about 11 seconds at any one time.  This is well below the
      IBM supplied missing interrupt handler (MIH) value of
      15 seconds for most direct access devices.  Exceeding this
      MIH value can result in I/O terminations of DFSORT
      applications.  IBM recommends that this MIH value be
      raised for newer devices, such as 3390 and RAMAC DASD.
      With higher MIH values, or higher transfer rates, it is
      possible to use higher values of IOMAXBF without risk of
      MIH termination.
  
      The IOMAXBF value can be reduced or increased using the
      following formula as a guideline:
  
        IOMAXBF =
          (transfer rate per second) * (channel seconds allowed)
  
      For example, if you have a channel transfer rate of
      3M per second, and you wish to limit DFSORT to a
      maximum channel connect time of 8 seconds, set IOMAXBF
      to 25165824 (24M).  Likewise, with a channel transfer rate
      of 4M per second and an MIH value of 30 seconds, limiting
      DFSORT to no more than 25 seconds of channel connect time
      by setting IOMAXBF to 104857600 (100M), will prevent
      MIH terminations.
  
      Lowering IOMAXBF below the default value of
      33554432 (32MB) can cause performance degradation.
  
      n
        specifies the maximum bytes of storage to be used for
        the SORTIN and SORTOUT data set buffers as a decimal
        value within the range of 8388608 (8M) to 268435456
        (256M).
  
      Applicable Systems: MVS/ESA and MVS/XA
  
      Default: 33554432 (32M)
  
      Example 1
  
          IOMAXBF=37748736
  
        Limits the storage used for the SORTIN and SORTOUT data
        set buffers to 36 megabytes.  At a transfer rate of
        3M per second, this IOMAXBF value limits DFSORT to a
        maximum connect time of 12 seconds.
  
      Example 2
  
          IOMAXBF=20971520
  
        Limits the storage used for the SORTIN and SORTOUT data
        set buffers to 20 megabytes.  At a transfer rate of
        4M per second, this IOMAXBF value limits DFSORT to a
        maximum connect time of 5 seconds.
  
    New ICEMAC MNOTEs
      *,  x BYTES IS LIMIT FOR SORTIN/SORTOUT BUFFER SPACE
      *,  32768K BYTES IS LIMIT FOR SORTIN/SORTOUT BUFFER SPACE
  
      8,***ICESM1103 IOMAXBF VALUE x INVALID
          The value x specified for IOMAXBF is not a valid
          decimal number or is not in the valid range for
          IOMAXBF.
  
    Changed Messages
  
      MSGICE061A Programmer Response.  Add the following new
      paragraph after the first paragraph:
  
        If ICE061A contains ECB=41 and CSW=0006, and you receive
        an accompanying IOS000I simulated I/O error message, you
        could be experiencing a missing interrupt timeout on the
        corresponding channel due to a large data transfer.  If
        this is the case, either reduce the value set for the
        IOMAXBF installation option or raise the missing
        interrupt handler (MIH) value for the device associated
        with the error.
  
  ADDITIONAL KEYWORDS:
   5740SM105 SPE INFOAPAR INFO APAR RF00 Y2K
  

Local fix

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Temporary fix

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• This is a info apar
  

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