• August 15, 2022

Db2 Cloning Tool: Enhanced App Cloning Index Processing (PI99726)

If you perform Application (Tablespace) Cloning with the Cloning Tool, chances are that you will experience a free performance boost after applying APAR PI99726 (PTF UI57180).

It is likely that indexes are included in your cloning LISTDEF definition or via the COPY parameter, ALWAYS-COPY-INDEXSPACES. With this enhancement, the Cloning Tool Source job will be able to detect several conditions which would require the index to be rebuilt by (or after) the Target job. In these cases, the index will not be copied, thereby saving page processing time in the Target job.

The conditions that the Source job can detect are:

  • IX_PGSIZE or IX_PADDED differences between the source and target indexes.
  • Version mismatches between source and target indexes.
  • Extension mismatches between the source and target index spaces.
  • The source index is in PSRBD status.
  • The index contains a column for which DATA-MASKING has been defined.
  • The clone is defined with USE-LAST-CONSISTENT-FLASHCOPY(Y), and the index is not included in the Flashcopy image copy, or the index and it’s table space are in different Flashcopy image copies.

If RTS-COPY-ENABLED is set to Y, the index statistics are still copied even if the index is not copied.

In the Source job, CKZ55505I will be followed by a report of indexes excluded from copy, with the exclude reason.

You will see messaging in the Target job, as the Source job communicates this exclusion information via the SYNCDB2 data set.

It is recommended that:

  • REBUILD-INDEXES-EXECUTE be set to Y so that the Target job can manage these REBUILD processes for you.

  • Indexes and the associated Table Spaces be cloned in the same Source Job so that INTELLIGENT-REBUILD can generate the appropriate REBUILD statements and optimize this process.

Of course, the Target Job may determine that additional indexes need to be rebuilt. Log Apply processing that changes a table space will cause the REBUILD of the associated indexes.

Additional information can be found in the APAR text and latest version of the Cloning Tool Users Guide.

If you found this helpful, please share it or comment below.

Happy Cloning!

Paul Bartak 7 Posts

Paul Bartak has been working with IBM databases since 1985, including the first version of DB2 on MVS. As an IBM customer for 14 years Paul worked in Application Development, Database Administration, and DBA. He joined IBM in 1999 as an Information Management Technical Specialist, teaming with the Sales force to present, design, install, demonstrate, and evaluate IBM Information Management solutions in a pre-sales environment; gaining multiple certifications in Database Administration, Data Replication, Blockchain, and Cloud Computing. Paul developed the four generations of the DB2 Migration Planning Workshops from DB2 V8 for z/OS, to DB2 11 for z/OS; and enablement for Db2 for z/OS pureXML and Temporal features. Currently, as a Distinguished Engineer with Rocket Software, Paul is focused on the tools used to maximize DB2 for z/OS value, with emphasis in database cloning and DevOps processes. He supports multiple Db2 User Groups, has been a speaker at several IDUG and Insight/Think conferences, is a Redbook/Redpaper author, and IBM Champion.


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