PI75145: ALLOCATE SYSTEM PAGES TO STORE VERSION 0 INFORMATION

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• Self describing data with allocating system pages to store
  version 0 OBDREC information.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 11 for z/OS users                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: V11 New function :                      *
  *                      Enhanced Metadata self-description      *
  *                      capability to minimize problems         *
  *                      related to schema definition changes.   *
  *                                                              *
  *                      The following APARs deliver the         *
  *                      new function and they must be applied   *
  *                      together: PI75145, PI76179,             *
  *                      PI80006 and PI81005.                    *
  *                                                              *
  *                      This APAR contains functionality of     *
  *                      storing the schema definition into      *
  *                      a page set.                             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Over the years since schema evolution was introduced, problems
  have increased for customer shops that meet these three
  conditions:
  - Table spaces containing a large number of tables.
  - Users making frequent schema changes to the tables.
  - Users regularly using the DSN1COPY utility to move or copy
    table spaces from a source DB2 subsystem to a target
    subsystem.
  
  The problems fall into two broad categories:
  - Data Integrity: After a table space is copied from a source
    DB2 subsystem to a target subsystem, mismatches between the
    metadata in the system pages of the table space and the
    information in the catalog or directory can occur.
    Due to those mismatches, the data rows cannot be properly
    processed. These problems are more frequent for tables in
    the table space that have not been altered.
  - Version Recycling: Because there are only 255 versions
    available for mapping all schema definitions for all tables
    in a table space, all versions might be used, and there is
    no effective way to drop and reuse old version numbers.
  
  This APAR contains enhancements to make table spaces
  self-describing in order to prevent problems due to a
  table's data getting out of sync with the table's catalog
  definition by saving the table schema into the pageset.
  DB2 writes information about table schema in the system pages
  of the pageset during the insert or update of a row, or
  when LOAD or REORG is run on the existing table where a
  pageset is missing schema information.
  These changes apply to simple, segmented (non-UTS),
  partitioned (non-UTS), partition-by-range
  (absolute or relative addressing), and partition-by-growth
  table spaces. These enhancements do not apply to work files,
  XML table spaces, and LOB table spaces.
  

Problem conclusion

Temporary fix

Comments

• Apply the following corrective APARs when available:
  APARs PI75145, PI76179, PI80006 and PI81005 must be applied
  together.
  
  These APARs change DB2 to allocate and update system pages for
  tables that are version 0. This change in behavior may result
  in the additional allocation of system pages for existing
  version 0 tables, when the next load, insert or update
  occurs to data within the table. In addition, these changes
  may experience an increase in CPU time due to additional
  pages being processed.
  
  ×**** PE18/12/13 PTF IN ERROR. SEE APAR PH05268  FOR DESCRIPTION
  

APAR Information

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

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

  UI53559

Modules/Macros

•    DSNIDLOD DSNIFOD  DSNIHLOD DSNILDVC DSNILPG
  DSNILREP DSNIPPHO DSNIPTYM DSNIRELK DSNIREPR DSNIROBD DSNISEGD
  DSNISEGF DSNISHPI DSNISMRT DSNISRTI DSNISUPI DSNIVOBD
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RB10 PSY UI53559

     UP18/02/16 P F802

Fix is available

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