IBM Support

IC81222: A QUERY WITH OLAP FUNCTION OVER(PARTITION BY ...) MAY HANG IN SQLRI_BUFFER_DISK_WRITE()

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • A query with OLAP function OVER(PARTITION BY ...) may encounter
    a hang in sqlri_buffer_disk_write() function.
    This may happen if there is not enough APPLHEAP available and
    the rows have a very high number of the same partition values
    (high data skew) .
    
    A typical stack trace obtained would show:
    
    <StackTrace>
    -------Frame------ ------Function + Offset------
    0x090000000BA5D39C
    sqlri_buffer_disk_write__FP16sqlri_buffer_mgrPP14sq
    0x090000000BA5D534
    sqlri_buffer_disk_write__FP16sqlri_buffer_mgrPP14sq
    0x090000000BA5E358
    @66@sqlri_buffer_get_new_page__FP16sqlri_buffer_mgr
    0x0900000009FFECF0
    sqlri_buffer_add__FP16sqlri_buffer_mgrP10sqlri_sqzo
    0x090000000AE2DEB4 sqlri_scalag__FP8sqlrr_cb - 0x55C
    0x090000000AE3FDC8 sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm +
    0x94
    0x090000000A52B8D8 sqlrr_dss_router__FP8sqlrr_cb + 0x230
    0x0900000009C4BC60
    sqlrr_subagent_router__FP20sqle_agent_privatecbP10s
    0x0900000009D449C8 sqleSubRequestRouter__FP13sqle_agent_cbPUiT2
    + 0x41
    0x090000000A3DFF30 sqleProcessSubRequest__FP13sqle_agent_cb +
    0x230
    0x0900000009F4899C sqleRunAgent__FPcUi + 0x8E8
    0x090000000AEEBCDC
    sqloCreateEDU__FPFPcUi_vPcUlP13SQLO_EDU_INFOPi + 0x
    0x090000000AF563E0 sqloSpawnEDU + 0x230
    0x090000000AF55F18
    sqleCreateNewAgent__FiP8sqlekrcbP17sqlcc_init_struc
    0x090000000AF57570
    sqleGetAgentFromPool__FiP17sqlcc_init_structT1P12sq
    0x090000000AF58170
    sqleGetAgent__FiP17sqlcc_init_structT1P12sqlz_app_h
    0x090000000AF69668 sqlccipcconnmgr_child__FPcUi + 0x340
    ...
    
    In addition you will observere that the db2 agent still uses CPU
    cycle.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Problem Description above.                               *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 Version 9.1 Fix Pack 12.                      *
    ****************************************************************
    

Problem conclusion

  • First fixed in DB2 Version 9.1 Fix Pack 12.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC81222

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    910

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-02-06

  • Closed date

    2012-08-02

  • Last modified date

    2012-08-02

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

  • 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

  • R910 PSN

       UP

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.1"}]

Document Information

Modified date:
19 September 2021