PM94968: ABEND04E RC00C900D0 AT DSNXROHB OFFSET 1CD6E WHEN QUERY USES HYBRID JOIN

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Abend04e rc00c900d0 at dsnxrohb offset 1cd6e could happen when
  query uses hybrid join method.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 9 and DB2 10 for z/OS users of       *
  *                 hybrid join with ROWID data.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: An ABEND04E RC00C900D0 at location      *
  *                      DSNXROHB 1CD6E (OFFSET1CD6E) can occur  *
  *                      when a query references ROWID data      *
  *                      followed by LOB data when using a       *
  *                      hybrid join access path.                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An ABEND04E RC00C900D0 can occur at location DSNXROHB 1CD6E
  (OFFSET1CD6E) when a query references ROWID data that is
  followed by LOB data when using a hybrid join access path.
  
  The following example helps to illustrate the problem.
  
  Step 1. Create two tables, each with a unique index.
  
    CREATE TABLE T1 (C1 INT,  C2 ROWID NOT NULL, C3 CLOB(100));
    CREATE TABLE T2 (C1 INT,  C2 ROWID NOT NULL, C3 CLOB(100));
  
    CREATE UNIQUE INDEX IX1 ON T1(C1);
    CREATE UNIQUE INDEX IX2 ON T2(C1) CLUSTER;
  
  
  Step 2. Insert three rows of data into each table.
  
    INSERT INTO T1 VALUES(1,DEFAULT,CLOB('ABC'));
    INSERT INTO T1 VALUES(2,DEFAULT,CLOB('ABC'));
    INSERT INTO T1 VALUES(3,DEFAULT,CLOB('ABC'));
  
    INSERT INTO T2 VALUES(1,DEFAULT,CLOB('AB2'));
    INSERT INTO T2 VALUES(2,DEFAULT,CLOB('AB2'));
    INSERT INTO T2 VALUES(3,DEFAULT,CLOB('AB2'));
  
  
  Step 3. Perform the following select statement using a hybrid
          join access path.
  
    SELECT  A.C1, HEX(A.C2), B.C2, A.C3
    FROM T1 A, T2 B
    WHERE A.C1 = B.C1 ;
  
  
  The ROWID column B.C2 is not moved correctly by DB2 and as a
  result, it eventually overlays the storage for the next column,
  CLOB column A.C3.  This leads to the above mentioned abend.
  
  Please note:  If A.C3 is replaced by another data type, an
  incorrect result for both B.C2 and the other data type or an
  unexpected abend in another DB2 module can occur due to a memory
  overlay.
  

Problem conclusion

• The code in DB2 has been modified to correctly move the ROWID
  data using the actual length instead of the declared length.
  This will prevent the above abend and the incorrect output.
  
  Additional Keywords: SQLHYBRIDJOIN SQLROWID SQLINCORR INCORROUT
                       SQLINCORROUT DB2INCORR/K DB2OVRLAY/K
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UK97483 UK97484

Modules/Macros

• DSNXRFHJ DSNXRGBJ DSNXRSFJ
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UK97483

     UP13/09/27 P F309

• R910 PSY UK97484

     UP13/09/27 P F309

Fix is available

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