Aggregation and Use Request Aggregation properties on the DataSourceBlock work together to configure the aggregation function and apply it to the data source. The aggregation function applies when
the data source resolves to multiple components in the station and determines how to combine the multiple values.
When Use Request Aggregation is false and the Aggregation property is not configured on the DataSourceBlock (set to its default value of First), the DataSourceBlock uses the aggregation function as defined in the applicable Data Definition, unless there is no Data Definition, in which case the block uses the default First function. When Use Request Aggregation is false and the Aggregation property is configured, the block uses the Aggregation property’s value.
When Use Request Aggregation is true, the block uses the Aggregation property defined in the request (analytic proxy extension, analytic binding, etc.), unless the request does not specify the
Aggregation property, in which case the block uses the algorithm's Aggregation property value.
The following table demonstrates how the actual aggregation function used by an analytic model may vary depending on how you
configure the Use Request Aggregation property on the DataSourceBlock along with the other Aggregation properties that are available for configuration.
| DataSourceBlock | Data Definition | Request | Algorithm | Actual | |
|---|---|---|---|---|---|
Use Request Aggregation
|
Aggregation |
Aggregation |
Aggregation |
Aggregation |
aggregation function used by the algorithm |
| false | not configured | not configured | Sum | Max | First (default) |
| false | Last | not configured | Sum | Max | Last |
| false | Last | Avg | Sum | Max | Avg |
| true | Last | Avg | Sum | Max | Sum |
| true | Last | Avg | not configured | Max | Max |
The bold options in the table highlight which option takes the priority based on the configuration choices in this example.