DB2 10 for zOS Migration: More Tips from the IDUG Conference

The International DB2 User Group (IDUG) conference was a great success with more attendees than the past few years and great DB2 technical educational information.  As I talked about during the week through Twitter, and in my blog last week, IDUG had many technical presentations, good vendor and IBM networking opportunities.

There was a great deal of information about the DB2 10 for LUW, DB2 working in the cloud, DB2 big data applications and especially DB2 10 for zOS migration tips.   Many shops have already migrated to DB2 10 for zOS in their production environments, but there were many that still were planning their DB2 10 for zOS migration.

Additional tips for the best DB2 10 for zOS migration experience were given during many different conference presentations.  Following are three of the most important DB2 10 for zOS migration tips that I heard in several of the IDUG conference sessions.     

First, rebind all your applications before any of the DB2 10 for zOS migration process is started.  This point was stressed in many sessions because DB2 10 for zOS requires a rebind to leverage all the improvements, including DB2 performance improvements.  It is much better to understand and rebind access path changes before any migration activity and without the pressure of a new release migration turnover.  Resolve your access path rebind issues before anything is done within the DB2 10 for zOS migration process.

Next, understand and maybe remove any of your special application SQL put in years ago to improve DB2 performance.  A DB2 10 for zOS migration rebind enhances all the application access paths such as the improvements of Prefetch, Hash Access and all the new optimizer algorithms with the improved DB2 optimizer to increase DB2 performance.  Scan your application source code for any SELECT SQL statements with old optimizer tricks or techniques such as WHERE 0 = 1, OPTIMIZE FOR 1 ROW. Look for any high RID Pool usage SQL such as Hybrid Joins, large IN lists and other high RID usage SQL applications.  The DB2 10 for zOS usage of OPTIMIZE FOR 1 ROW is affected by APAR PM56845 and needs to be handled appropriately for your shop’s unique requirements.

Lastly, DB2 10 for zOS optimizer improvements provided more SQL parallelism opportunities within your applications.  Previous versions of DB2 had limitations on parallelism when using Multi-Row fetch, some SQL that produced work files, and SQL that went against key and dynamic record range partitioning operations.  All of these areas have been enhanced to provide more parallelism and DB2 can offload more of the workload to the zIIP CPU processors to improve DB2 performance.  If your shop does not desire these new SQL parallelism opportunities, analyze your SQL for where parallelism is currently used before your DB2 10 for zOS migration. 

Again there was a tremendous amount of great DB2 10 for zOS and DB2 10 for LUW information at this year’s IDUG conference.  Start your budget planning and campaigning to go to next year’s IDUG conference in Orlando, April 29 through May 3.  Thank you to all my Twitter followers and blog readers for all your wonderful comments; it’s nice to hear from all of you.


Dave Beulke is an internationally recognized DB2 consultant, DB2 training and DB2 education instructor.  Dave helps his clients improve their strategic direction, dramatically improve DB2 performance and reduce their CPU demand, saving millions in their systems, databases and application areas within their mainframe, UNIX and Windows environments.

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>