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PH63250: AN UNLOAD COMMAND WITH AT LEAST TWO UNLOAD STATEMENTS REQUESTINGTO UNLOAD FROM THE SAME TABLE PROCESSED IN NATIVE MODE FAILS

A fix is available

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APAR status

  • Closed as program error.

Error description

  • (HPU 5.2)
    An unload:
    - either fails with ABENDS0C7 with the following symptom dump:
    DATA AT PSW 3C8FF20C - DF1FD35A D2F0B946 00109240
    AR/GR 0: 00000000/3CA97000 1: 00000000/3C8F6379
    2: 00000000/3CA97000 3: 00000000/3BA87820
    4: 00000000/3CA970F2 5: 00000000/3C90C048
    6: 3C8E1348/00000010 7: E9D3D6C7/3C90BC76
    8: 00000000/3C8FF18A 9: 00000000/3C90BC70
    A: 00000000/3C8EE4E8 B: 00000000/3BA859A2
    C: 00000000/3C8EE198 D: 00000000/3C8F6000
    E: 00000005/3BA85960 F: 00000000/3C8FF180
    - or produces incorrect and unpredictably incorrect unloaded
      data
    
    This occurs if the unload step specifies at least two logical
    unloads that fulfills all the following conditions:
    - both unload data from the same tablespace
    - both are processed in native mode
    - both are candidate to optimization
    - they are specified under distinct UNLOAD statements
    - the first one is processed with an optimized algorithm
      dedicated to unloads satisfying the conditions referred to
      as type 1 unloads
    - the second one (affected by or triggering the issue) is
      processed with an optimized algorithm dedicated to unloads
      satisfying the conditions referred to as type 2 unloads
    
    An unload is a type 1 unload if it is a logical unload (SELECT
    statant and OUTDDN option) that does not unload the data from
    all the columns of the involved table
    
    An unload is a type 2 unload if at least one of the following
    conditions applies:
    - to the unload in question
       . the unload is a physical unload
       . the unload is a logical unload specifying either of the
         following
       . an ORDER clause with an order criterion involving a
         VARCHAR column or columns placed after a VARCHAR column
       . the OUTEXIT option
       . the SPANNED YES option
    - to the input data source (tablespace or image copy)
        . the tablespace is a CLONE (for DB2 v12 and later versions)
        . an input dataset (either an input Image Copy or an LDS
          from the unloaded tablespace) i has the BRF format
    - to the involved table
       . the table contains a lob column
       . the table definition specifies a fieldproc
    

Local fix

  • try the following solutions and choose the one that gives the
    best performance:
    a) run the failing unload in SQL mode by specifying the DB2
       FORCE option.
    b) add OPTIM_LEVEL(3) to a GLOBAL option
    c) rewrite the Db2 HPU command (SYSIN) to gather all the
       logical unloads involving the same tablespace under a single
       UNLOAD statement (this is also advisable to improve the
       unload performance)
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of Db2 High Performance Unload for     *
    *                 z/OS                                         *
    ****************************************************************
    * PROBLEM DESCRIPTION: (HPU 5.2)                               *
    *                      An unload:                              *
    *                      - either fails with ABENDS0C7 with the  *
    *                      following symptom dump:                 *
    *                      DATA AT PSW 3C8FF20C - DF1FD35A         *
    *                      D2F0B946 00109240                       *
    *                      AR/GR                                   *
    *                      0: 00000000/3CA97000                    *
    *                      1: 00000000/3C8F6379                    *
    *                      2: 00000000/3CA97000                    *
    *                      3: 00000000/3BA87820                    *
    *                      4: 00000000/3CA970F2                    *
    *                      5: 00000000/3C90C048                    *
    *                      6: 3C8E1348/00000010                    *
    *                      7: E9D3D6C7/3C90BC76                    *
    *                      8: 00000000/3C8FF18A                    *
    *                      9: 00000000/3C90BC70                    *
    *                      A: 00000000/3C8EE4E8                    *
    *                      B: 00000000/3BA859A2                    *
    *                      C: 00000000/3C8EE198                    *
    *                      D: 00000000/3C8F6000                    *
    *                      E: 00000005/3BA85960                    *
    *                      F: 00000000/3C8FF180                    *
    *                      - or produces incorrect and             *
    *                      unpredictably incorrect unloaded data   *
    *                                                              *
    *                      This occurs if the unload step          *
    *                      specifies at least two logical unloads  *
    *                      that fulfills all the following         *
    *                      conditions:                             *
    *                      - both unload data from the same        *
    *                        tablespace                            *
    *                      - both are processed in native mode     *
    *                      - both are candidate to optimization    *
    *                      - they are specified under distinct     *
    *                        UNLOAD statements                     *
    *                      - the first one is processed with an    *
    *                        optimized algorithm dedicated to      *
    *                        unloads satisfying the conditions     *
    *                        referred to as type 1 unloads         *
    *                      - the second one (affected by or        *
    *                        triggering the issue) is processed    *
    *                        with an optimized algorithm           *
    *                        dedicated to unloads satisfying the   *
    *                        conditions referred to as type 2      *
    *                        unloads                               *
    *                                                              *
    *                      An unload is a type 1 unload if it is   *
    *                      a logical unload (SELECT statant and    *
    *                      OUTDDN option) that does not unload     *
    *                      the data from all the columns of the    *
    *                      involved table                          *
    *                                                              *
    *                      An unload is a type 2 unload if at      *
    *                      least one of the following conditions   *
    *                      applies:                                *
    *                      - to the unload in question             *
    *                         . the unload is a physical unload    *
    *                         . the unload is a logical unload     *
    *                           specifying either of the following *
    *                         . an ORDER clause with an order      *
    *                           criterion involving a VARCHAR      *
    *                           column or columns placed after     *
    *                           a VARCHAR column                   *
    *                         . the OUTEXIT option                 *
    *                         . the SPANNED YES option             *
    *                      - to the input data source (tablespace  *
    *                        or image copy)                        *
    *                          . the tablespace is a CLONE (for    *
    *                            DB2 v12 and later versions)       *
    *                          . an input dataset (either an       *
    *                            input Image Copy or an LDS from   *
    *                            the unloaded tablespace) i has    *
    *                            the BRF format                    *
    *                      - to the involved table                 *
    *                         . the table contains a lob column    *
    *                         . the table definition specifies a   *
    *                           fieldproc                          *
    *                                                              *
    *                      Local fix: try the following solutions  *
    *                      and choose the one that gives the best  *
    *                      performance:                            *
    *                      a) run the failing unload in SQL mode   *
    *                         by specifying the DB2 FORCE option.  *
    *                      b) add OPTIM_LEVEL(3) to a GLOBAL       *
    *                         option                               *
    *                      c) rewrite the Db2 HPU command (SYSIN)  *
    *                        to gather all the logical unloads     *
    *                        involving the same tablespace under   *
    *                        a single UNLOAD statement (this is    *
    *                        also advisable to improve the unload  *
    *                        performance)                          *
    ****************************************************************
    * RECOMMENDATION: Apply the PTF                                *
    ****************************************************************
    an unload command with at least two UNLOAD statements
    requesting to unload from the same table processed in native
    mode fails in ABENDS0C7 or produces incorrect unloaded data
    

Problem conclusion

  • Code has been changed to fix this problem
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH63250

  • Reported component name

    DB2 HI PERF UNL

  • Reported component ID

    5697F4400

  • Reported release

    520

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2024-09-16

  • Closed date

    2024-11-20

  • Last modified date

    2024-12-03

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

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

Modules/Macros

  • INZ$$PRM INZCHECK INZTDSC  INZTPMEM INZUTILK
    

Fix information

  • Fixed component name

    DB2 HI PERF UNL

  • Fixed component ID

    5697F4400

Applicable component levels

  • R520 PSY UI99095

       UP24/11/23 P F411

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
03 December 2024