Examples using REDUCE

These examples show how the start time is aligned by the use of BOUNDARY.

Example 1

 
ACCOUNTING
   REDUCE
      FROM     (,09:00)
      TO       (,11:00)
      INTERVAL (30)
      BOUNDARY (60)

The data that is available for reducing is limited by the GLOBAL command. If you specified FROM and TO dates and times in GLOBAL, OMEGAMON for Db2 Performance Expert discards all records outside those dates and times before reducing. In this example no GLOBAL command is in effect, so the FROM and TO dates and times that are specified with REDUCE are used. No dates are specified, so all dates are included.

BOUNDARY(60) aligns the start time of the intervals at the start of an hour, so the first interval starts at the FROM time (09:00). Subsequent intervals start every 30 minutes. The following intervals are calculated:
  • Beginning at 9:00:00 - containing two Accounting records
  • Beginning at 9:30:00 - containing four Accounting records

No intervals are calculated at 10:00:00 or 10:30:00 because there are no Accounting records.

The interval begin and end times are reported in the job summary report. The job summary report indicates that an interval is calculated and indicates the number of records processed during the interval. It does not indicate the number of consolidated records after reducing.

Example 2

 
ACCOUNTING
   REDUCE
      INTERVAL (1440)
      BOUNDARY (60)

In this example no GLOBAL command is in effect and no dates or times have been specified in REDUCE, so the following defaults are applied:

  • The default for FROM is all dates and a time of 00:00:00.00
  • The default for TO is all dates and a time of 23:59:59.99

BOUNDARY(60) aligns the start time of the intervals at the start of an hour, so the first interval starts at the FROM time (00:00). Subsequent intervals cover 1440 minutes or one day. An interval starts at 00:00 each day. In this example, there is one interval that contains all of the Accounting records in the input data set.

The interval begin and end times are reported in the job summary report.