PH60916: CARDF IN SYSIBM.SYSTABLES IS RESET TO ZERO WHEN A REORG WITH INLINE STATISTICS AND PAGE SAMPLING ADDS A NEW PBG PARTITION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A REORG with INLINE STATISTICS is executed on a PBG tablespace
  in a Db2 v13 subsystem with ZPARM STATPGSAMP=SYSTEM .
  During REORG process a PBG partition is added
  (DSNU2910I) and statistics are collected using
  page sampling (DSNU1374I).
  After REORG completion the user finds that REORG has reset CARDF
  in SYSIBM.SYSTABLES to a value of zero.
  

Local fix

• BYPASS/CIRCUMVENTION:
  Set ZPARM STATPGSAMP=NO
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Db2 13 for z/OS users of REORG           *
  *                 TABLESPACE or LOAD REPLACE STATISTICS        *
  *                 utility with page sampling active on         *
  *                 PBG table space                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Incorrect catalog statistics updated    *
  *                      by a REORG TABLESPACE STATISTICS        *
  *                      utility execution on a PBG table        *
  *                      space with page sampling active after   *
  *                      PBG growth in the RELOAD phase          *
  ****************************************************************
  * RECOMMENDATION: Apply corrective PTF when available          *
  ****************************************************************
  User ran a REORG TABLESPACE STATISTICS against a
  partition-by-growth table space, which utilized page sampling
  to collect the catalog statistics.  A new PBG partition was
  grown during the RELOAD phase of REORG, and it was noticed that
  the catalog statistics used for access path selection was
  updated with incorrect values, including a value of 0 for the
  CARDF column in SYSTABLES despite many records were reloaded.
  
  The reported problem was caused by incorrect program logic
  in REORG for determining whether page sampling is being used or
  not after PBG growth has happened during the RELOAD phase.
  A similar problem can happen for LOAD REPLACE STATISTICS after
  PBG growth in the RELOAD phase with page sampling active.
  
  Additional keywords:
  - TABLESAMPLE SYSTEM STATPGSAMP
  - DSNU2910I MSGDSNU2910I
  

Problem conclusion

• Code has been modified to correct the catalog statistics
  gathered in the aforementioned LOAD and REORG scenarios
  involving page sampling and PBG growth.
  

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:

  UI97203

Modules/Macros

• DSNURWIR
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RD10 PSY UI97203

     UP24/06/14 P F406

Fix is available

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