PROCESSING STAGE

Aggregator Stage

OUTPUT TAB

The Outputs page allows you to specify details about data output from the Aggregator stage. The Aggregator stage can have only one output link.

The General tab allows you to specify an optional description of the output link. The Columns tab specifies the column definitions of incoming data. The Mapping tab allows you to specify the relationship between the processed data being produced by the Aggregator stage and the Output columns. The Advanced tab you to change the default buffering settings for the output link.

OUTPUT MAPPING TAB

For the Aggregator stage the Mapping tab allows you to specify how the output columns are derived, i.e., what input columns map onto them or how they are generated.

In the example the left pane represents the data after it has been grouped and summarized. The Expression field shows how the column has been derived. The right pane represents the data being output by the stage after the grouping and summarizing. In this example key carries the value of the key field on which the data was grouped (for example, if you were grouping by date it would contain each date grouped on). Column am1mean carries the mean of all the values in the group, am1min the minimum value, and am1sum the sum.