~Aggregation Levels~

The Aternity database categorizes data according to the following levels of granularity (known as Aggregation Levels):

  • None: No aggregation is done. In performance queries, the raw data (i.e., every measurement) is displayed.
  • 5-Minute: Aggregation is done every 5 minutes. In performance queries, one measurement (the average of all measurements taken) for each 5 minute interval of a selected timeframe is displayed.
  • Hourly: Aggregation is done every 60 minutes. In performance queries, one measurement (the average of all measurements taken) for each hourly interval of a selected timeframe is displayed.
  • Daily: Aggregation is done every 24 hours. In performance queries, one measurement (the average of all measurements taken) for each daily interval of a selected timeframe is displayed.

Each one of those aggregation levels is retained in the history for different times, as described in the Retention Times article.

The following table shows an example of how aggregation level affects performance query results for the Outlook activity Send Mail. The sample query shows activity response for messages sent between 12:00 and 13:00. It is assumed that contextual information is identical for all the measurements (for instance, all messages are sent using the same exchange server).

Time of Message Send Aggregation Level # of Measurements Displayed

12:00:15

None

5 (Raw data is displayed.)

12:01:01

5-minute

3 (The first 3 measurements are averaged into 1 measurement.)

12:02:31

12:10:20

Hourly

1 (All 5 measurements are averaged into 1 measurement.)

12:50:00

Default Aggregation Levels

The Performance Navigator has a built-in default aggregation level setting for each timeframe option. The default aggregation levels are designed to make performance query results manageable and to display the optimal number of data points in Chart views (approximately 10 data points at a time).

The default aggregation level for each timeframe is listed in the following table.

Timeframe Default Aggregation Level

Last Hour/Last 2 Hours

5-minute

Today/Yesterday

Hourly

This Week/Last Week

Daily

This Month/Last Month

This Year/Last Year

When a given granulation level is not suitable for the purposes of a specific performance query, the default aggregation setting can be overridden. For example, if there is a performance problem within a specific, limited timeframe (such as a 1-hour interval), a user might choose to view the raw data (no aggregation) to obtain all available information.