PK79312: THIS APAR ENABLES A V9 DB2 SYSTEM TO PROVIDE INDEX COMPRESSION SUPPORT FOR VERSIONED INDEXES.

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• This APAR enables a V9 DB2 system to provide the index
  compression support for those indexes that contain versioned
  keys.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 users that use index compression     *
  *                 and want to perform schema changes.          *
  ****************************************************************
  * PROBLEM DESCRIPTION: When index compression is used, any     *
  *                      schema change affecting the index key   *
  *                      will result in the index being marked   *
  *                      REBUILD-pending. The ALTER statement    *
  *                      receives SQLCODE610, indicating the     *
  *                      object was placed in REBUILD-pending    *
  *                      state.                                  *
  ****************************************************************
  * RECOMMENDATION: In addition to the text below, read the      *
  *                 ++HOLD information in the PTF for further    *
  *                 installation requirements and information.   *
  ****************************************************************
  Currently, if an index is compressed and a user
  does an ALTER that affects the index key in a way that
  results in a new index key version, the index will be
  placed in REBUILD-pending state, and the ALTER will receive
  SQLCODE610 warning, indicating the index was placed in
  REBUILD-pending state.
  
  An example:
     For a compressed index where the datatype of
     col_name is CHAR(50), and col_name is part of index IX1,
     the following ALTER statement would return SQLCODE610
     and set index IX1 to REBUILD-pending:
  
        ALTER TABLE T1 ALTER col_name SET DATA TYPE CHAR(75);
  
  To remove the REBUILD-pending state, users need to run
  REBUILD INDEX utility or DROP the affected index(es) and CREATE
  the index(es) again.
  

Problem conclusion

Temporary fix

Comments

• APAR PK79312 enhances ALTER schema support for compressed
  indexes (indexes marked COMPRESS YES). The types of ALTERs
  that place a compressed index into REBUILD-pending are reduced.
  Compressed indexes will behave like uncompressed indexes.
  An example:
     For a compressed index where the datatype of col_name
     is CHAR(50), and col_name is part of index IX1, the following
     ALTER statement would no longer mark the index IX1 in
     REBUILD-pending or return SQLCODE610:
      ALTER TABLE T1 ALTER col_name SET DATA TYPE CHAR(75);
  
  By allowing versioned keys in a COMPRESS YES index, it is
  important to note that index compression may be less efficient
  until the index is rebuilt. As a result, AREO* status will
  still be set on the index, as it is on the table space if a
  column of a table is altered.
  
  
  USERS ARE ADVISED OF THE FOLLOWING:
  
  All DB2 V9 members of the data sharing group must be restarted
  with the preconditioning APARs PK75002(UK45395) and
  PM00088(UK52414) before PK79312 is applied to any member.
  
  PTFs for APARs PK75002(UK45395) and PM00088(UK52414)
  must be applied to all members of a DB2 V9 data sharing
  group and all active members must be restarted before applying
  PTF for PK79312. The PTFs may be applied to each member
  individually. There is no need to restart all members at the
  same time.
  If procedure is not followed,
  ABEND04E RC00C90101 in DSNKPGCM ERQUAL5008, ERQUAL5006,
  MSGDSNU086I in DSNUCDA1 (WRITE I/O ERRORS),
  or other abends may result during or following access of the
  affected index(es) or using the RECOVER utility.
  
  If the PTF for PK79312 has been applied to at least one member
  of a data sharing group and the PTF for PK75002(UK45395) is
  removed from any member(s), then the PTF for PK79312 must be
  removed from all members and run REBUILD INDEX utility on the
  affected index(es).
  If procedure is not followed,
  ABEND04E RC00C90101 in DSNKPGEX ERQUAL5004,
  or other abends may result during or following access of the
  affected index(es).
  
  Likewise, if the PTF for PK79312 has been applied to at least
  one member of a data sharing group and the PTF for
  PM00088(UK52414) is removed from any member(s), then the
  PTF for PK79312 must be removed from all members and run
  REBUILD INDEX utility on the affected index(es).
  If procedure is not followed,
  ABEND04E RC00C90101 in DSNKPGCM ERQUAL5008, ERQUAL5006,
  MSGDSNU086I in DSNUCDA1 (WRITE I/O ERRORS),
  or other abends may result during or following access of the
  affected index(es) or using the RECOVER utility.
  

APAR Information

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

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

  UK52416

Modules/Macros

• DSNGDAIX DSNGDART DSNIPPS  DSNKISPL DSNKPGCM
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK52416

     UP09/12/16 P F912

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.