PH25628: LISTDEF PERFORMANCE IMPROVEMENT WHEN USING KEYWORDS INCLUDE INDEXSPACES TABLESPACE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• User observed the following MODIFY STATISTICS take too much
  getpages on catalog due to LISTDEF and having INCLUDE
  INDEXSPACES TABLESPACE clause:
  
  LISTDEF LISTMOD INCLUDE TABLESPACE ABCDEFG.12345678
  INCLUDE INDEXSPACES
  TABLESPACE ABCDEFG.12345678
  MODIFY STATISTICS LIST LISTMOD DELETE ALL AGE(180)
  
  When syntax is changed to the follwing, index is used instead of
  sequential scan:
  
  LISTDEF TABLESPACE INCLUDE TABLESPACE  ABCDEFG.12345678
  MODIFY STATISTICS LIST TABLESPACE DELETE ALL AGE(180)
  LISTDEF LISTMOD INCLUDE INDEXSPACES LIST TABLESPACE
  MODIFY STATISTICS LIST LISTMOD DELETE ALL AGE(180)
  
  This is applicable to any utility.
  

Local fix

• Change syntax to the LISTDEF as shown in error description
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 for z/OS users of the LISTDEF                     *
  * utility control statement.                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * List expansion for LISTDEF control                           *
  * statements that INCLUDE or EXCLUDE                           *
  * index space(s) from a table space(s)                         *
  * takes a long time to execute.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply corrective PTF when available                          *
  ****************************************************************
  The MODIFY STATISTICS utility was performed on objects
  defined by the LISTDEF utility with INCLUDE INDEXSPACES
  TABLESPACE clause:
  
    LISTDEF list1 INCLUDE TABLESPACE dbname.tsname
                  INCLUDE INDEXSPACES TABLESPACE dbname.tsname
    MODIFY STATISTICS LIST list1 DELETE ALL AGE(180)
  
  The execution of a utility that uses a list of objects
  defined with the LISTDEF control statement can have a long
  elapsed time and show a lot of get pages for catalog table
  space DSNDB06.SYSTSTAB during the list expansion.
  This can occur for LISTDEF control statements that INCLUDE
  or EXCLUDE all index spaces over one or more table space(s),
  such as:
    LISTDEF list1 INCLUDE INDEXSPACES TABLESPACE dbname.tsname
  In this example the processing of list1 can take a long
  time because a table space scan of SYSTSTAB is done.
  Additional keywords:  performance, UTILINIT phase, elapsed time
  

Problem conclusion

• The utility list expansion code has been modified not to use
  a table space scan of DSNDB06.SYSTSTAB when resolving the
  list of objects for INCLUDE or EXCLUDE clauses for all index
  spaces over one or more table space(s).
  

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:

  UI71535

Modules/Macros

• DSNUILSA
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI71535

     UP20/09/22 P F009

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.