Acquiring Aggregated History

Ways of accessing aggregated history differ for various aggregation methods.

Accessing Statistics in a Round-Robin Database

The Statistics function of the Utilities context returns aggregated data contained in an RRD database.

The function accepts multiple parameters:

  • Mask of source contexts and name of statistical channel

  • Aggregation period

  • Options defining which aggregates should be returned (e.g. minimums or totals)

The function returns a Data Table containing aggregates grouped by selected periods. This table can be directly used by any data processing or visualization tools.

A very similar Raw Statistics function of Utilities context returns complete data collected in a specific statistics channel pointed by context path and channel name. The returned table contains nested tables with data for different aggregation periods.

Here is how the output of the Statistics function looks:

Period Start

Period End

Aggregated Numeric Value (Average, Minimum or Maximum)



Here is an example of an expression that returns hourly averages, minimums, and maximums for a statistical channel named temperature that is defined for device users.admin.devices.meter:

{utilities:statistics("users.admin.devices.meter", "temperature", null, "hour", true, true, true, true)}

Accessing History Stored in Granules

Since granules are stored as events, they can be acquired using the Get Event History function of the Events context.

This expression returns all the randomGranule granules stored for the users.admin.devices.virtual context:

callFunction("events", "get", "users.admin.devices.virtual", "randomGranule")

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