PM75619: INCORRECT OUTPUT WHEN IOE AND MULTIPLE CCSID EXIST FOR A QUERY: SENSITIVITY TO CLUSTERING NOT DETECTED SO NO SUGGESTION TO REORG

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• 1) Incorrect output can occur for a query where
  Index-on-expression (IOE) is used and multiple CCSIDs exist;
  2) Sensitivity to clustering is not detected properly so
     ADMIN_UTL_MONITOR stored procedure does not issue
     RUNSTATS alerts for out-of-date statistics.
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 for z/OS V9 and V10 users who use    *
  *                 index-on-expression (IOE) and join tables    *
  *                 with multiple CCSIDs.                        *
  *                                                              *
  *              Also for all DB2 for z/OS V10 users who use DB2 *
  *              REAL-TIME STATISTICS for REORG suggestions.     *
  ****************************************************************
  * PROBLEM DESCRIPTION: There are two problem fixed by this     *
  *                      APAR.                                   *
  *                                                              *
  *                      The first problem may occur on both V9  *
  *                      and V10.  DB2 may produce incorrect     *
  *                      output when a UNICODE table joins to    *
  *                      an EBCDIC view which is a UNION ALL,    *
  *                      and at the same time, when              *
  *                      index-on-expression (IOE) is used       *
  *                      for that query.                         *
  *                                                              *
  *                      For example,                            *
  *                                                              *
  *                      CREATE VIEW MY_EBCDIC_VIEW (...) AS     *
  *                      (SELECT DISTINCT ...                    *
  *                         FROM ...                             *
  *                         WHERE ...                            *
  *                       UNION ALL                              *
  *                       SELECT DISTINCT ...                    *
  *                         FROM ...                             *
  *                         WHERE ...);                          *
  *                                                              *
  *                      SELECT ...                              *
  *                      FROM MY_UNICODE_TABLE, MY_EBCDIC_VIEW   *
  *                      WHERE ...;                              *
  *                                                              *
  *                      And for the query, DB2 chooses IOE      *
  *                      to access MY_UNICODE_TABLE.             *
  *                                                              *
  *                      The second problem is V10 only. DB2     *
  *                      may not issue a REORG suggestion as     *
  *                      it should. This problem is related to   *
  *                      DB2 V10 REAL-TIME STATISTICS.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  There are two problem fixed by this APAR.
  
  The first problem may occur on both V9 and V10.
  DB2 may produce incorrect output when a UNICODE table joins to
  an EBCDIC view which is a UNION ALL, and at the same time, when
  index-on-expression (IOE) is used for that query.
  
  It occurs because DB2 missed the multiple CCSID handling
  when IOE is used but the index access did not consume all
  the predicates on index keys for index matching or screening.
  
  The second problem is V10 only.
  DB2 may not issue a REORG suggestion as it should because the
  access path's senstivity to table clustering is not detected
  correctly.
  
  Additional Keywords:
  SQLINCORR SQLINCORROUT INCORROUT DB2INCORR/K REALTIMESTATS
  SQLCCSID SQLINDEXONEXP SQLVIEW SQLUNIONALL
  

Problem conclusion

• The two problems are fixed.
  

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:

  UK91647 UK91648

Modules/Macros

•    DSNXOGP
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UK91647

     UP13/03/01 P F302

• R910 PSY UK91648

     UP13/03/01 P F302

Fix is available

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