PH27716: GOC - ALTER COLUMN IMPLICIT TABLESPACE NOT NULL TO WITH DEFAULT NULL UNLOAD ALTERED TABLE YES DATA LOSS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• GOC - ALTER COLUMN IMPLICIT TABLESPACE NOT NULL TO WITH DEFAULT
  NULL UNLOAD ALTERED TABLE YES DATA LOSS
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of the Db2 Administration Tool for     *
  *                 z/OS and Object Comparison Tool for z/OS     *
  *                 who alter the NULLS attribute of a           *
  *                 column.                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: Executing a work statement list (WSL)   *
  *                      from Object Compare or CM Batch might   *
  *                      result in data loss when altering       *
  *                      the NULLS attribute of a                *
  *                      column (the NULLS value                 *
  *                      in the SYSCOLUMNS catalog               *
  *                      table).                                 *
  ****************************************************************
  When altering a column's NULLS attribute with the option "Unload
  Altered Tables" set to YES, the resulting WSL contains the
  following sequence of operations:
  
  ALTER TABLE DROP COL col1
  REORG
  ALTER TABLE ADD COL col1
  
  Running this sequence of operations results in data loss
  for the column, because the data is not saved before the
  DROP COL operation.
  

Problem conclusion

• A new "Recreate for NULLS Change" option is added to
  control how the NULLS change is implemented. This
  field provides the option either to perform UNLOAD, DROP,
  CREATE and LOAD operations to preserve the column's
  data, or to use the existing ALTER, REORG, and ALTER
  sequence of operations if the column's data does not
  need to be preserved.
  
  A new CM batch parameter RECREATE_FOR_NULLS_CHANGE
  is also added:
  
  recreate_for_nulls_change
  
  Specifies whether to drop and recreate a table when altering
  whether a column can contain null values
  (the NULLS value in the SYSCOLUMNS catalog table).
  
  This parameter is applicable only if the unload_altered_tables
  CM batch parameter is set to YES.
  
  Values:
  
  YES  or Y   The table is dropped and recreated
  (by using UNLOAD, DROP, CREATE, and LOAD operations) so that the
  column data is preserved. YES is the default value.
  
  NO or N   The column is altered by using ALTER TABLE
  statements, which might result in data loss.
  Specify NO only if the column's data does not
  need to be preserved.
  
  Default:
  YES
  
  When an invalid combination of recreate_for_nulls_change and
  unload_altered_tables is specified, informational message
  ADB7385I is included in the compare report:
  
  ADB7385I ADB2CMP Option "Recreate for NULLS Change" is only
  applicable when "Unload Altered tables" is set to YES.
  

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:

  UI71179

Modules/Macros

• GOCCMP   GOCGCMP
  

Fix information

• Fixed component name

  DB2 OBJECT COMP

• Fixed component ID

  5697G6400

Applicable component levels

• RC10 PSY UI71179

     UP20/08/25 P F008

Fix is available

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