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IT06592: QUERY WITH MULTIPLE SUBSUMABLE SCALAR SUBQUERIES MAY CAUSE DB2 TO ABEND

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Under rare conditions, DB2 might abend if the following
    conditions are satisfied
    1) The query contains two or more scalar subqueries
    2) Atleast 2 subqueries can be proven to be subsumed by each
    other and can only be executed once
    3) Atleast one of these subqueries is used in a predicate
    4) One or more of these subqueries are part of the output column
    list.
    
    
    Similar stack will be dumped in the trap file:
    sqlnr_matchmaker::nav_assign_max_levels
    sqlnr_matchmaker::nav_assign_max_levels
    sqlnr_matchmaker::nav_assign_max_levels
    sqlnr_matchmaker::nav_init
    sqlnr_matchmaker::form_matches
    sqlnr_form_common_subexprs
    sqlnr_optprep
    sqlnr_optprep_action
    sqlnr_comp
    sqlnr_seq
    sqlnr_rcc
    sqlnr_exe
    sqlnr_exe
    sqlnn_cmpl
    sqlnn_cmpl
    sqlra_compile_var
    sqlra_find_var
    sqlra_get_var
    sqlrr_prepare
    sqljs_ddm_prpsqlstt
    sqljsParseRdbAccessed
    .sqljsParse.fdpr.clone.45__FP13sqljsDrdaAsCbP14db2UCinterfaceP8s
    qeAgentb
    sqljsSqlam
    sqljsDriveRequests
    sqljsDrdaAsInnerDriver
    sqljsDrdaAsDriver
    sqeAgent::RunEDU
    sqzEDUObj::EDUDriver
    sqloEDUEntry
    

Local fix

  • Manually rewrite the query to pushdown the subquery to the
    deepest subselect in the query.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 version 970 fixpack 11                        *
    ****************************************************************
    

Problem conclusion

  • The fix was delivered in DB2 version 970 fixpack 11
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT06592

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-01-19

  • Closed date

    2015-10-21

  • Last modified date

    2015-10-21

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

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

    IT06948

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IT06592

Modified date: 21 October 2015