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IT28112: DB2 MAY TRAP IN SQLNO_PRED_BUILD_EQ_CLASSES OR SQLNQ_OPRQUNCHILDWHEN A QUERY CONTAINING THE PUSH DOWN OF A TABLE THROUGH AN OUT

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APAR status

  • Closed as duplicate of another APAR.

Error description

  • Db2 query may produce a trap when the following conditions are
    met:
    ? The query has an outer join
    ? There is a push down of a table through the outer join, to
    filter rows before the OJ
    ? Semijoin introduces an invalid correlation from the select box
    of table being pushed down, to the other arm of the OJ.
    ? Subsequent processing of the invalid correlation may fail. The
    actual location of the failure can vary based on the
    characteristics of the query, but involves the processing of the
    correlated quns. Failure may be a trap or -901.
    
    
    One Possible Symptom:
    A trap in the optimizer at sqlno_pred_build_eq_classes
    
    The stacks may look like:
    sqlno_pred_build_eq_classes
    sqlnoPropApplyPredSel_
    sqlno_prop_ff
    sqlno_prop_index_ff_lower_bound
    sqlno_prop_iscan ISCAN
    sqlno_index_scan
    sqlno_crule_index_scan
    sqlno_crule_access_root
    sqlno_crule_access
    sqlno_find_plan_chain
    sqlno_get_best_plan
    sqlno_crule_nljn_inner
    sqlno_crule_nljn
    sqlno_crule_join_choices
    sqlno_crule_join_order
    sqlno_crule_join_root
    sqlno_crule_join
    sqlno_gen_partitions_for_QTB
    sqlno_plan_end_opr
    sqlno_each_opr
    sqlno_walk_qun
    sqlno_each_opr
    
    Work around:
    Set registry variable DB2COMPOPT=NOOJSJ
    

Local fix

  • Setting the registry variable DB2COMPOPT=NOOJSJ
    

Problem summary

Problem conclusion

Temporary fix

Comments

  • This APAR is a duplicate of IT33071
    

APAR Information

  • APAR number

    IT28112

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED DUB

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-02-14

  • Closed date

    2021-03-16

  • Last modified date

    2021-03-16

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

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

    IT33270

Fix information

Applicable component levels

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

Document Information

Modified date:
18 March 2021