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IT28586: QUERY HANG IN LOADNESTEDQUERYEVALUATOR::GETCSENESTEDQUERYOUTPUT

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APAR status

  • Closed as program error.

Error description

  • Query hang when runs in a loop
    Reproduce Steps:
    
    
    ==> create_table.sql <==
    CREATE TABLE SQLTEST(ID BIGINT NOT NULL ) DISTRIBUTE BY RANDOM
    IN USERSPACE1 ORGANIZE BY COLUMN;
    
    ==> insert.sql <==
    INSERT INTO SQLTEST
    WITH TMP(C1)
    AS
    (
    VALUES(10000)
    UNION ALL
    SELECT C1+1
    FROM TMP
    WHERE C1 < 100000
    )
    SELECT C1
    FROM TMP;
    
    
    =============================
    
    run the following:
    for i in {1..30} ; do echo $i ; date ; db2 -xt " SELECT (SELECT
    COUNT(1) FROM SQLTEST), AVG(ID) FROM SQLTEST WITH UR " ; done
    
    latch will show periodically
    SQLO_LT_ibm_cde__query__NestedQueryInfo__mCseLatch
    Query hang in LoadNestedQueryEvaluator::getCseNestedQueryOutput
    

Local fix

  • db2set ?immediate DB2_EXTENDED_OPTIMIZATION=CDE_CSE_OFF
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher                *
    ****************************************************************
    

Problem conclusion

  • First fixed in Db2 11.1 Mod 4 Fixpack 5
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT28586

  • 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

    2019-03-26

  • Closed date

    2020-01-20

  • Last modified date

    2020-01-20

  • 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

  • RB10 PSN

       UP

[{"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":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
04 May 2022