PM82954: LOAD RESUME YES BREAKS THE DICTIONARY PAGE WHICH WAS GENERATED BY COMPRESS ON INSERT.

A fix is available

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • LOAD RESUME YES breaks the dictionary page which was generated
    by compress on insert.
    
    DSNT500I    DSNUGBAC - RESOURCE UNAVAILABLE
    REASON 00C90087
    TYPE 00000302
    NAME ********.********.X'2AC000CD'
    

Local fix

  • Affected users of this problem:
    -------------------------------
    All DB2 10 (NFM) for z/OS users of LOAD
    RESUME on compressed pageset or partition
    (whose compression dictionary was generated
    by insert), where at the time of LOAD RESUME
    the compression dictionary is at current end
    of data in the pageset or partition, meaning
    HPGZ4PNO happens to be the current end of data.
    .
    If this problem occurs, until the fix is available, the
    compression dictionary page shown in the message DSNI010I BROKEN
    PAGE ACCESSED should be recovered (e.g. from image copy),
    followed by REORG on the pageset or partition (regardless of
    whether KEEPDICTIONARY is specified or not). The REORG will
    move the compression dictionary pages to the beginning of the
    pageset/partition, in which case this problem does not exist.
    .
    If this problem has not occurred and yet HPGZ4PNO happens to be
    the current end of data, until the fix is available, a REORG can
    be run on the pageset or partition (regardless of whether
    KEEPDICTIONARY is specified or not). The REORG will move the
    compression dictionary pages to the beginning of the pageset/
    partition, in which case this problem does not exist.
    .
    As of March 25, 2013, an APARfix (++APAR) is not available yet
    because this APAR is based on a significant number of other open
    APARs.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All DB2 10 (NFM) for z/OS users of LOAD      *
    *                 RESUME on compressed pageset or partition    *
    *                 (whose compression dictionary was generated  *
    *                 by insert), where at the time of LOAD RESUME *
    *                 the compression dictionary is at current end *
    *                 of data in the pageset or partition          *
    ****************************************************************
    * PROBLEM DESCRIPTION: MSGDSNI010I - BROKEN PAGE ACCESSED      *
    *                      TYPE00000302 MODNAME DSNILPG and        *
    *                      MSGDSNT500I - RESOURCE UNAVAILABLE      *
    *                      RC00C90087 issued during LOAD RESUME    *
    *                      on COMPRESS on INSERT table space       *
    *                      whose current end of data (highest page *
    *                      in pageset or partition) is a           *
    *                      dictionary page, corrupting this        *
    *                      dictionary page                         *
    *                                                              *
    *                      Then, potentially followed by           *
    *                      MSGDSNB209I - BUFFER MANAGER CLEANUP    *
    *                      ROUTINE (DSNB1CFC) HAS BEEN SCHEDULED   *
    *                      and MSGDSNB221I - BUFFER MANAGER        *
    *                      CLEANUP PROCESS WAS NOT REQUIRED        *
    *                                                              *
    *                      In addition to the dictionary page      *
    *                      being protected by broken page status,  *
    *                      the pageset or partition is left in     *
    *                      RECP status                             *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    During LOAD RESUME into a compressed table space whose
    compression dictionary was built during the INSERT process (new
    in DB2 10 NFM) and dictionary pages are at the current end of
    data (meaning, page number HPGZ4PNO is the highest page in the
    pageset or partition), DB2 mistakenly attempted to load rows
    into the highest dictionary page, resulting in the symptoms
    mentioned above.
    
    In the affected code path, DB2 code did not account for the
    possibility that when a dictionary is built by the INSERT
    process, the dictionary pages need not be at the beginning of
    the pageset or partition. In this case, when looking for the
    current end of data for the LOAD to resume into, there were no
    pages after the dictionary pages and so DB2 mistakenly picked
    the final physical dictionary page as the resumption point.
    
    Given that this final physical dictionary page was being treated
    as a data page, the space search for a new row was relying on
    wrong information (scanning through a page "ID-map" which was
    not really an ID-map). As a result, the row was loaded into the
    dictionary page, corrupting the page's functional content.
    
    The aforementioned broken page-related messages were issued and
    the broken page status was turned on for protection, along with
    the RECP status on the pageset or partition.
    
    If this problem occurs, until the fix is available, the
    compression dictionary page shown in the message DSNI010I BROKEN
    PAGE ACCESSED should be recovered (e.g. from image copy),
    followed by REORG on the pageset or partition (regardless of
    whether KEEPDICTIONARY is specified or not). The REORG will
    move the compression dictionary pages to the beginning of the
    pageset/partition, in which case this problem does not exist.
    
    If this problem has not occurred and yet HPGZ4PNO happens to be
    the current end of data, until the fix is available, a REORG can
    be run on the pageset or partition (regardless of whether
    KEEPDICTIONARY is specified or not). The REORG will move the
    compression dictionary pages to the beginning of the pageset/
    partition, in which case this problem does not exist.
    

Problem conclusion

  • Code has been changed for LOAD RESUME to tolerate compression
    dictionary pages being at current end of data.
    
    Additional keywords: SQLINSERT SQLMERGE
    

Temporary fix

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

Comments

APAR Information

  • APAR number

    PM82954

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-02-16

  • Closed date

    2013-04-24

  • Last modified date

    2013-06-04

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

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

    UK93800

Modules/Macros

  •    DSNIHLOD DSNILPG  DSNIRLPG DSNURWBF
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RA10 PSY UK93800

       UP13/05/10 P F305

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


More support for:

DB2 for z/OS

Software version:

A10

Reference #:

PM82954

Modified date:

2013-06-04

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