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IT24954: SLOW INSERT PERFORMANCE IN PURESCALE BECAUSE UNCOMMITTED DELETED SLOTS AREN'T REUSED CORRECTLY

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Normally, if there are no other active transactions, deleted
    slots created by a transaction should be usable by the same
    transaction. However this doesn't always happen.
    
    Conditions for this APAR are the following:
    - pureScale
    - need to read a page from disk
    - the page needs to have a youngest_tid set (a delete by a
    different transaction occurred in the past)
    - deletes are not committed before an insert
    
    Here is a snippet of db2trc.
    db2 connect t test
    APPHNDL=`db2 -x "values MON_GET_APPLICATION_HANDLE()"`
    db2trc on -m "exit.*.*.sqldCheckPageForInsert.*" -f db2trc.dmp
    -apphdl ${APPHNDL} -t
    grep "sqldCheckPageForInsert exit" db2trc.flw |  head -n 7
    
    Good case, sqldCheckPageForInsert will return with rc = 0
    1           sqldCheckPageForInsert exit
    2           sqldCheckPageForInsert exit
    3           sqldCheckPageForInsert exit
    4           sqldCheckPageForInsert exit
    5           sqldCheckPageForInsert exit
    6           sqldCheckPageForInsert exit
    7           sqldCheckPageForInsert exit
    
    ng.case sqldCheckPageForInsert was returned with rc = 10002.
    1           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    2           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    3           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    4           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    5           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    6           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    7           sqldCheckPageForInsert exit [rc = 0x00002712 =
    10002]
    

Local fix

Problem summary

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

Problem conclusion

  • First fixed in Db2 11.1 Mod 4 Fixpack 4
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT24954

  • 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

    2018-05-04

  • Closed date

    2018-11-27

  • Last modified date

    2018-11-27

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

    IT24047

  • 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":"BU048","label":"IBM Software"},"Product":{"code":"SSEPGG","label":"DB2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
27 November 2018