PH33061: DB2 12 FOR Z/OS NEW FUNCTION TO SUPPORT IBM DB2 ANALYTICS ACCELERATOR

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• Db2 12 for z/OS new function to support IBM Db2 Analytics
  Accelerator
  
  Additional Keywords:
  IDAAV7R5/K
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 for z/OS users who use IBM Db2                    *
  * Analytics Accelerator V7.                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Support query offloading to IBM Db2                          *
  * Analytics Accelerator V7 when the                            *
  * query references a column with column                        *
  * mask but the column mask does not have                       *
  * to be applied.                                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Column mask is a DB2 10 feature that describes a specific
  column access control rule for a column. In the form of an SQL
  CASE expression, the rule specifies the condition under which
  a user, group, or role can receive the masked values that are
  returned for a column.
  Before this APAR, there is no offloading support for a query
  referencing a column with column mask. When there exists a
  column mask on any of the columns referenced by the query, it
  is not offloadable with SQLCODE-4742 and rsn15.
  This APAR helps a subset of queries referencing a column with
  column mask to be offloadable to IBM Db2 Analytics Accelerator
  V7, i.e. When the column mask does not need to be applied.
  Although the query contains a column with column mask, as long
  as the MASKED column does not need to be returned in the
  outermost result select list, the query is able to be
  offloaded.
  For example:
    TABLE USRT003.T1(C1,C2,C3), column mask on T1.C1,T1.C2,T1.C3
    TABLE USRT003.T3(C1,C2), column mask on T3.C1 only
  
    Query #1
      SELECT         TT3.C2
        FROM TABLE
             (SELECT RIGHT(C1, 4), C2 + C3
              FROM USRT003.T1
             ) AS Y(C1, C2),USRT003.T3 TT3
      FOR READ ONLY;
  
    Query #2
      SELECT  Y.C1 || TT3.C2
        FROM TABLE
             (SELECT RIGHT(C1, 4), C2 + C3
              FROM USRT003.T1
             ) AS Y(C1, C2),USRT003.T3 TT3
      FOR READ ONLY;
    For Query #1, it will be offloadable to IBM Db2 Analytics
    Accelerator V7 with this APAR and server level 7.5.6.
    Although the query references USRT003.T1.C1,
    USRT003.T1.C2, USRT003.T1.C3, there is only TT3.C2 in the
    outermost SELECT list, i.e. there is no need to apply the
    column mask of USRT003.T1.C1, USRT003.T1.C2, USRT003.T1.C3
    and return the value of USRT003.T1.C1, USRT003.T1.C2,
    USRT003.T1.C3. Thus Query #1 will be offloadable.
    For Query #2, it's not offloadable because Y.C1 is in the
    outermost SELECT list and it's actually referencing
    USRT003.T1.C1 on which there is a column mask. So SQLCODE
   -4742 rsn 15 will be returned as before.
  IBM Db2 Analytics Accelerator for z/OS Version 7.5.6 or above
  is required to support this new feature. The support level in
  SYSACCELS.SYSACCELERATEDTABLES for the acceleated tables will
  be 7 after tables are loaded with this IBM Db2 Analytics
  Accelerator for z/OS Version 7.5.6.
  Additional Keywords:
      IDAAV7R1/K IDAAV7R5/K
      SQLCODE4742 SQLMASK SQLCOLUMNMASK
  

Problem conclusion

Temporary fix

Comments

• The support of offloading query with column masks require
  both this APAR and IBM Db2 Analytics Accelerator for z/OS
  Version 7.5.6 or above.
  

APAR Information

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

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

  UI74917

Modules/Macros

• DSNXODML DSNXONZO DSNXONZA DSNXOACA DSNXOIN  DSNXOBZB DSNXONZB
  DSNXOBZO DSNXOBZA
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI74917

     UP21/04/22 P F104

Fix is available

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