• February 20, 2019

DB2 change accumulation tool tips

Data availability is the key to ensure your customers can do business around the clock. Many times, taking data offline for DB2 utility maintenance is difficult to do. But with the DB2 Change Accumulation Tool, you can easily take SHRLEVEL REFERENCE image copies that can be used to restore data, all without touching the production DB2 object. Read more about how to leverage this technology in this short and informative article.

As always, I’m here for questions! Post them below and I’ll get right back to you!


Jennifer Nelson 4 Posts

Initially a DB2 DBA, I have 18 years experience in the mainframe industry working with DB2 for large mainframe vendors. I have also played the role of a product manager and a product specialist assisting sales with potential and existing customers on DB2 Tools. I hold a BA in Political Science from the University of Texas at Austin.


  • John Reply

    December 23, 2014 at 5:14 pm

    Just installed DB2 Change Accumulation. We’ve tried several options and they all seem to work.

    But I’m not sure I’m doing this right. Let’s say that I have a full image from 2 weeks ago, followed by 3 incrementals, followed by another full. I want to use that full and add the next 2 incrementals to produce a new full.

    I can do it using the END_LRSN parameter, but the job output indicates that it’s reading the DB2 log. Is there a way to tell it to just take the full and add the 2 incrementals and don’t bother looking at any logs?

    • Jennifer Nelson Reply

      December 29, 2014 at 3:26 pm

      Hi John,
      Change Accumulation Tool’s premise is to build SHRLEVEL REF image copies using older image copies and log data. Since the DB2 utility MERGECOPY does what you describe, Change Accumulation Tool brings additional methodologies to a DBA by creating the image copies without using your production data, and therefore not locking the table, which is the beauty of this product.

      Another option using Change Accumulation Tool is to specify the ‘END_LRSN’ option of the second full image copy with the ISPF option called ‘Force write phase for IC/WTV’. This causes a parameter called FORCE_COPIES to be generated into the JCL and, when executed, results in only the full image copy data being used for the new SHRELVEL REF image copy.

      I hope this information helps, but let me know if this sparks additional thoughts.

  • John Reply

    January 22, 2015 at 10:12 am


    I use MERGECOPY as you say, but it will only work when I’m combining the most recent full image with incrementals. You cannot use MERGECOPY to combine older images.

    For example, let’s say that I take a full image every weekend, and an incremental image every night. On Jan 3 I take a full, and then take incrementals on Jan 5, 6, and 7. I can use MERGECOPY to combine these into a new full.

    On Jan 10 I take a new full image. Now that I have a full from Jan 10, it is no longer possible to use MERGECOPY to combine Jan 3 with 5+6+7. MERGECOPY will only work with the most recent image.

    So now I use DB2 Change Accumulation to combine Jan 3 plus 5+6+7. It works fine, but I do not understand why it needs to read the DB2 log? I’m merely asking it to combine some images together — there is no need to apply any thing from the log.

    Can you tell me why DB2 Change Accum reads the log in this case? Am I doing something wrong?

    –John K

  • Ravindra Reply

    January 23, 2015 at 10:22 am

    Hello Jennifer,

    I am trying to test the newly installed CA tool and I am trying to create a FULL IC at a past point in time for tablespace DB.TS.
    This is the scenario:
    Time Description
    ===== ======================================
    T1 –> FULL image taken (let us call it FULLIC01)
    T2 –> Incremental image taken (let us call it INCRIC01)
    T3 –> Incremental image taken (let us call it INCRIC02)
    T4 –> Incremental image taken (let us call it INCRIC03)
    Tn-1 –> Image copy taken
    Tn –> Image copy taken

    FULLIC01 had a retention period 90 days and it is available today. INCRIC01/02/03 had only 15 days’ retention period and are not available/expired today i.e. T4 is older than 15 days.

    I am trying to create FULL image copy using CA at time T4 with WRITE_TO_COPIES option, but job is failing because INCR images are no more there.
    Now if you see I can recover the table at T4 using normal DB2 RECOVER utility and it will ignore the INCR images if they do not exist anymore.
    But, why the creation of image copy at T4 is failing while using CA? Should CA also not ignore/skip the missing images? Or is there an option to do this?
    I could not find any thing in manual to satisfy my needs.

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