Q
Problem solve Get help with specific problems with your technologies, process and projects.

What factors could affect DB2 batch performance?

After our DB2 4.1 to DB2 5.1 migration, all batch DB2 jobs now have excessive run times. What types of performance factors could affect DB2 batch performance?

Well, that is a very open-ended question, so here are some high-level thoughts on the matter.

First off, you just migrated from a rather old version of DB2. Version 4 went GA in September 1994 -- that is about nine years ago! You ought to consider bringing your subsystem up to a more recent version of DB2 -- at least V6. That way you can be more sure that your system is taking advantage of more recent performance techniques.

Secondly, whenever you move to a new version of DB2 you should consider rebinding your application programs. New versions typically add optimization features that your programs cannot take advantage of unless they were rebound. Before rebinding, consider running RUNSTATS on your DB2 objects to get the most up-to-date statistics in the catalog. This will ensure that DB2 is formulating access paths for the SQL in your programs based on the most current information about your data.

My third, and final thought on the matter is to ask, "What else changed?" If the answer is honestly and truly nothing, then your only recourse is to REBIND (and/or migrate to a newer version of DB2). If something else also changed, anything else, then you should take a look at that as another possible mitigating factor in your performance degradation. For example, did any of these "things" change:

  • new version of the operating system

  • additional (or less) memory

  • new hardware (CPU, DASD, etc.)

  • new version of other system software (CICS, IMS/TM, TSO, etc.)

  • changes to MVS, OS/390 system parameters

  • and so on
  • Make sure that none of these changes could have a negative effect on performance. And good luck!

    This was last published in January 2003

    Dig Deeper on IBM DB2 management

    PRO+

    Content

    Find more PRO+ content and other member only offers, here.

    Have a question for an expert?

    Please add a title for your question

    Get answers from a TechTarget expert on whatever's puzzling you.

    You will be able to add details on the next page.

    Start the conversation

    Send me notifications when other members comment.

    By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

    Please create a username to comment.

    -ADS BY GOOGLE

    SearchBusinessAnalytics

    SearchAWS

    SearchContentManagement

    SearchOracle

    SearchSAP

    SearchSQLServer

    Close