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LI74148: DB2 INSTANCE MAY ABEND EXECUTING A QUERY PREFIXED WITH THE '.DB2SERVICE' KEYWORD.

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APAR status

  • Closed as program error.

Error description

  • A query prefixed with the DB2 support '.db2service' keyword may
    abend the instance if any of the tables used in the query has a
    dependent statistical view defined.
    
    An example of such a scenario follows:
    
    -- Table DDL
    CREATE TABLE T1 (C1 INT);
    CREATE TABLE T2 (C1 INT);
    
    -- View DDL
    CREATE VIEW STATVIEW AS (SELECT T1.C1 AS C1, T2.C1 AS C2 FROM
    T1, T2 WHERE T1.C1 = T2.C1);
    
    -- Convert view into a statistical view
    ALTER VIEW STATVIEW ENABLE QUERY OPTIMIZATION;
    
    -- Query that will abend the instance
    .db2service SELECT T1.C1 AS C1, T2.C1 AS C2 FROM T1, T2 WHERE
    T1.C1 = T2.C1;
    
    The stack trace from such an abend will look something like:
    sqlnq_mchFailList::findElem
    sqlnq_mchFailList::addElem
    sqlnq_qur::add_matchable_MQT_SV
    sqlnq_som::compute_matchinfo_opt
    sqlnr_compute_matchinfo
    sqlnr_optprep
    sqlnr_optprep_action
    sqlnr_comp
    sqlnr_seq
    sqlnr_rcc
    sqlnr_exe
    sqlnx_menuproc
    sqlnx_drv
    sqlnn_cmpl
    ...
    
    This problem will be first fixed in DB2 Version 9.1 Fix Pack 8
    and DB2 Version 9.5 Fix Pack 5.
    

Local fix

  • No feasible workaround exists aside from:
    1) Not using the '.db2service' keyword
    2) Disabling any dependent statistical views of tables used in
    the query for query optimization. For the aforementioned query,
    this may be done like so:
    
    -- Revert view from a statistical view to a normal view
    ALTER VIEW STATVIEW DISABLE QUERY OPTIMIZATION;
    

Problem summary

  • Problem Description:
    
    DB2 INSTANCE MAY ABEND EXECUTING A QUERY PREFIXED WITH THE
    '.DB2SERVICE' KEYWORD.
    Problem Summary:
    A query prefixed with the DB2 support '.db2service' keyword may
    abend the instance if any of the tables used in the query has a
    dependent statistical view defined.
    
    An example of such a scenario follows:
    
    -- Table DDL
    CREATE TABLE T1 (C1 INT);
    CREATE TABLE T2 (C1 INT);
    
    -- View DDL
    CREATE VIEW STATVIEW AS (SELECT T1.C1 AS C1, T2.C1 AS C2 FROM
    T1, T2 WHERE T1.C1 = T2.C1);
    
    -- Convert view into a statistical view
    ALTER VIEW STATVIEW ENABLE QUERY OPTIMIZATION;
    
    -- Query that will abend the instance
    .db2service SELECT T1.C1 AS C1, T2.C1 AS C2 FROM T1, T2 WHERE
    T1.C1 = T2.C1;
    
    The stack trace from such an abend will look something like:
    sqlnq_mchFailList::findElem
    sqlnq_mchFailList::addElem
    sqlnq_qur::add_matchable_MQT_SV
    sqlnq_som::compute_matchinfo_opt
    sqlnr_compute_matchinfo
    sqlnr_optprep
    sqlnr_optprep_action
    sqlnr_comp
    sqlnr_seq
    sqlnr_rcc
    sqlnr_exe
    sqlnx_menuproc
    sqlnx_drv
    sqlnn_cmpl
    ...
    
    This problem will be first fixed in DB2 Version 9.1 Fix Pack 8
    and DB2 Version 9.5 Fix Pack 5.
    
    Users Affected:
    All
    

Problem conclusion

  • Problem was first fixed in Version 9.1 Fix Pack 8
    

Temporary fix

  • No feasible workaround exists aside from:
    1) Not using the '.db2service' keyword
    2) Disabling any dependent statistical views of tables used in
    the query for query optimization. For the aforementioned query,
    this may be done like so:
    
    -- Revert view from a statistical view to a normal view
    ALTER VIEW STATVIEW DISABLE QUERY OPTIMIZATION;
    

Comments

APAR Information

  • APAR number

    LI74148

  • Reported component name

    DB2 UDE ESE LIN

  • Reported component ID

    5765F4104

  • Reported release

    910

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2009-01-23

  • Closed date

    2009-10-02

  • Last modified date

    2009-10-02

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

    LI74147

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

Fix information

  • Fixed component name

    DB2 UDE ESE LIN

  • Fixed component ID

    5765F4104

Applicable component levels

  • R910 PSY

       UP

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Document Information

Modified date:
17 October 2021