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IT24493: LOCK EXCLUSIVE MDC TABLE WITH LOCKSIZE SET TO BLOCKINSERT, INSERTING ROWS WILL RESULT IN ADDITIONAL LOCKS BEING ACQUIRED.

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APAR status

  • Closed as program error.

Error description

  • Lock exclusive MDC table with LockSize set to BlockInsert, then
    inserting Rows with the same dimension value consecutively will
    result in additional rows locks being acquired on this MDC
    Table.
    
    The folllowing is a simple reproduction of this issue:
    
    ----- Begin repro.ksh -----
    #!/bin/ksh
    
    export DB2OPTIONS="-ctv"
    dbName="wsdb"
    
    db2 "create db $dbName"
    db2 "connect to $dbName"
    db2 "create tablespace ts1"
    db2 "create table t1 (i1 int) organize by (i1) in ts1"
    db2 "alter table t1 locksize blockinsert"
    db2 +c "lock table t1 in exclusive mode"
    db2 +c "insert into t1 values
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
    db2pd -db $dbName -locks
    echo
    db2 "commit"
    db2 "drop tablespace ts1"
    db2 "terminate"
    ----- End of repro.ksh -----
    

Local fix

  • A workaround to this problem is to set LockSize to either Table
    or Row before the INSERT command and set it back afterwards.
    
    I.e.
    db2 +c "lock table t1 in exclusive mode"
    db2 +c "alter table t1 locksize table"
    db2 +c "insert into t1 values
    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
    db2 +c "alter table t1 locksize blockinsert"
    db2pd -db $dbName -locks
    echo
    db2 "commit"
    

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

    IT24493

  • 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

    2018-03-22

  • Closed date

    2018-11-27

  • Last modified date

    2018-11-27

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

    IT24456

  • 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":"BU053","label":"Cloud & Data Platform"},"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