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IT21938: DB2DART REPORT ON A COLUMN-ORGANIZED (BLU) TABLE TAKES LONG TIMETO COMPLETE

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APAR status

  • Closed as program error.

Error description

  • Db2dart takes a very long time (hours) to complete on a
    column-organized table whereas it completes in a short time
    (minutes) on a row-organized table with same data size.
    
    In db2dart processing, while accesing pages, the integrity
    checks made on column-organized tables are different than on
    row-organized tables.
    This integrity check referred to as cross data-index check is
    not done for row organized tables.
    
    In this cross data-index check function, we access data pages
    based on an index map created for column-organized tables. Due
    to a problem in the sequence of some sub-functions in it, we
    require to do some extra processing to reach next page. This
    extra processing is causing the delays in the db2dart
    performance as it needs to be done for each page find. So the
    time required for db2dart scales up depending on the size
    (number of pages) of the column-organized table.
    

Local fix

  • Run INSPECT command instead of db2dart to inspect the
    column-organized tables.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 11.1 Mod 3 Fix Pack 3 or higher               *
    ****************************************************************
    

Problem conclusion

  • First fixed in Db2 11.1 Mod 3 Fix Pack 3
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT21938

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-08-09

  • Closed date

    2018-03-19

  • Last modified date

    2018-03-19

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

    IT21149

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

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RB10 PSN

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
19 March 2018