PK38799: ALLOW FALLBACK OF V9 EXPLAIN TABLES TO V8 NFM/ FIX VARIOUS DSNSVBK ABENDS WHEN USING DSN_FUNCTION_TABL07/02/13 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Allow fallback of V9 Explain tables to V8 New Function Mode.
  UK90008 intended to provide fallback support from V9 to V8.
  However, fallback support for V9 Explain tables in V8 was
  missing.  This apar will allow V8 NFM to tolerate V9 Explain
  tables.
  Also, various abends could occur in DSNSVBK
  and other locations when using the DSN_FUNCTION_TABLE or
  DSN_PREDICAT_TABLE for Explain in V8 with UK20137 applied.
  .
  In addition, the use of mixed data strings or very long
  function text could encounter these abends more easily or
  cause an overlay.
  
  DB2MIGV9/K  DB2COEXIST/K
  

Local fix

• If you are not planning on migrating to V9 at this time,
  then you may BYPASS(HOLDERROR(AK33664,AK38799)) if you need
  to apply UK90008.  PK33664 and PK38799 are only applicable
  in a fallback situation (from V9 to V8).  However, you
  must remember to perform the HOLD actions in UK90008
  when you are prepared to migrate to V9 later.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Explain who either:                 *
  *                 (1) fallback from V9 to V8, or               *
  *                 (2) use DSN_PREDICAT_TABLE and mixed data    *
  *                     on their system, or                      *
  *                 (3) use DSN_FUNCTION_TABLE                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: (1) If a user migrates to V9 and        *
  *                          creates V9 Explain tables, then     *
  *                          after fallback to V8 the user will  *
  *                          no longer be able to do Explain.    *
  *                          SQLCODE -220 may occur during       *
  *                          Explain.  UK90008 was missing       *
  *                          fallback support for Explain.       *
  *                      (2) Various abends in DSNSVBK or        *
  *                          other modules may occur after       *
  *                          applying UK20137 when Explain is    *
  *                          performed and DSN_PREDICAT_TABLE    *
  *                          or DSN_FUNCTION_TABLE exists.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  If a user migrates to V9 and creates V9 Explain tables, then
  falls back to V8 New Function Mode, Explain will fail with
  SQLCODE -220.
  Also, various abends may occur in DSNSVBK and other modules
  when Explain is performed and DSN_PREDICAT_TABLE or
  DSN_FUNCTION_TABLE are defined.  Specifically, the use of
  mixed data strings could encounter these abends more easily.
  When a mixed data string (a combination of single-byte and
  multi-byte characters) appears in one of the character fields
  of the DSN_PREDICAT_TABLE or DSN_FUNCTION_TABLE, the string
  could be too long to fit in the field, and cause an overlay
  resulting in various abends.  This may also occur for very
  long function text without mixed data when the
  DSN_FUNCTION_TABLE is defined and the function text does not
  fit in the field.
  
  Additional Keywords:
  SQLCODE220 SQLEXPLAIN PREDICATE TABLE FUNCTION TABLE
  SQLSTORAGE ABEND0C4 ABEND04E RC00E20006 SMCOVERLAY
  

Problem conclusion

• V8 will support the V9 Explain tables in NFM only and insert
  default values for the new V9 columns.  Code is changed for
  DSN_PREDICAT_TABLE and DSN_FUNCTION_TABLE so that long
  strings will not go beyond the end of the fields and cause
  overlays when Explain is issued.
  

Temporary fix

Comments

APAR Information

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

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

  UK24425

Modules/Macros

• DSNDOPLA DSNXEXP  DSNXIEPL DSNXNTRY DSNXOCCH
  DSNXODCH DSNXOD0  DSNXOD0A DSNXOD0P DSNXOD0Z DSNXOD1  DSNXOD10
  DSNXOD12 DSNXOD13 DSNXOD2  DSNXOD3  DSNXOD4  DSNXOD7  DSNXOD8
  DSNXOD9  DSNXOLX1 DSNXOLX2 DSNXOOP  DSNXOPTH DSNXOPTI DSNXOPTJ
  DSNXOTS  HDB8810J
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R810 PSY UK24425

     UP07/04/27 P F704

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.