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If past time is used in the scope of interest time the Information
Manager returns historical data with time stamps from the requested time
interval as well as one just before starting point of this interval and
one just after ending point of this interval.
In your case the following schema applies:
-------*----------*----------*----------*---------> time
recorded data 15:29 15:44 15:59 16:14
^ ^ ^ ^
:1 interval:2 interval:3 interval:
For the first interval historical data returned:
- 15:29 - just before starting point;
- 15:44 - inside requested interval;
- 15:59 - just after end point.
For the second interval historical data returned:
- 15:44 - just before starting point;
- 15:59 - inside requested interval;
- 16:14 - just after end point.
To avoid this you should specify the scope of interest time like:
a. if you want to see all historical data between 15:30:00 and
16:30:00:
for start 15:30:00 duration 01:00:00
b. if you want to see historical data only with fixed intervals:
for start 15:30:00 every 00:30:00
Please, note that b. works only if data have been recorded with frequency
twice bigger that requested "every". In general you can have the following
situation:
----*----------*----------*----------*----------*----------*-----> time
recorded 10:00 10:10 10:20 10:30 10:40 10:50
data
scope of ^ ^ ^ ^
interest 10:01 10:16 10:31 10:46
In this example data have been recorded with polling period 10 minutes and
scope of interest time has been specified as "for start 10:01 every 00:15:00".
The Show returns data with the following time stamps:
10:00, 10:10, 10:10, 10:20, 10:30, 10:40, 10:40, 10:50 ....
For statistics partitions the duration is used to define an interval for
which statistics are calculated.
Hope this helps,
Sam
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