BOUNDARY subcommand option

The BOUNDARY subcommand option controls the alignment of the intervals.

Usage

The BOUNDARY subcommand option is used to control the alignment of the intervals used to summarize records in the reduction process.

Usage notes

Rules

Notes on calculating intervals

The start time of the first interval processed by REDUCE is influenced by BOUNDARY, INTERVAL, and FROM.

OMEGAMON® XE for DB2® PE attempts to reduce all data that falls between FROM and TO dates and times. The first interval processed starts at a time aligned with BOUNDARY, at or before the FROM time. If an interval cannot be aligned with the FROM time, the first properly aligned interval starting before the FROM time is used.

Although there is no restriction on the INTERVAL and BOUNDARY combination, your specification should comply with the following recommendations:

Example of interval calculation, aligning to the start of the hour

BOUNDARY(60) aligns the start time of intervals at the start of an hour, so the first interval starts at the FROM time (08:00). Subsequent intervals start every 30 minutes (08:30, 09:00, and 09:30 each day).


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REDUCE FROM (,08:00) TO (,10:00) INTERVAL (30) BOUNDARY (60)
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Example of interval calculation, covering a day

The following defaults are applied:

BOUNDARY(60) aligns the start time of intervals at the start of an hour, so the first interval starts at the FROM time (00:00). Subsequent intervals cover 1 440 minutes or one day; an interval starts at 00:00 each day.


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REDUCE INTERVAL (1440) BOUNDARY (60)
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Example of interval calculation, starting every hour

BOUNDARY(60) aligns the start time of intervals at the start of an hour, so the first interval starts at the hour of the FROM time (08:00). Subsequent intervals start every hour (09:00, 10:00, and 11:00).


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REDUCE FROM (,08:30) TO (,12:00) INTERVAL (60) BOUNDARY (60) REPORT FROM (,08:30) TO (,12:00)
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