10. MODIFICATION › 10.1 Modification Checklists › 10.1.2 Implement Incremental Update

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10.1.2 Implement Incremental Update


If you are using the TAPEfff exit to collect detail-level
data, and incremental update is active, you may need to make
a few simple but very important adjustments to your exits or
options to accommodate the way that incremental update
processes data.

This section discusses the following:

o  TAPEfff option considerations with incremental update

TAPEfff OPTION CONSIDERATIONS WITH INCREMENTAL UPDATE

  The TAPEfff option allows the creation of DETAIL timespan
  tape files for certain high volume files.

  Without incremental update, a single DETAIL timespan tape
  file is created for TAPEfff activated files during the
  DAILY run.  The general practice is to use GDGs so that the
  (+0) tape volume contains yesterday's data, (-1) contains
  the prior day's data, and so on.

  With incremental update activated, a tape is created with
  each execution of an incremental update as well as a final
  tape during the DAILY update run.  For example, three
  incremental updates followed by a final daily update run
  result in a total of four tapes created, one for each
  TAPEfff activated file.  Each tape contains only the detail
  data encountered during the individual incremental update
  or daily run.  If you are employing GDGs you will want to
  consider increasing the number of generations to encompass
  the desired time range of history.  For example, if
  previously 7 "daily" generations were maintained and you
  run 4 increments per day, you may wish to expand the
  generations kept to 28 (7 times 4 updates per day).

  The use of fewer tapes in a single update under the
  incremental feature expedites processing.  In addition, due
  to the "special study" nature of the data, separation into
  multiple pieces representing period time slices should
  allow usage to be more direct.  That is, the data is
  already subset to the period contained within the update.

  You also may consider creating a standalone job to
  consolidate these individual tapes into a single one after
  the DAILY job completes if you prefer to have a single tape
  data set contain all transactions for the time range.