PROCESSING STAGE

Aggregator Stage

Grouping Keys Category

Group. Specifies the input columns you are using as group keys. Repeat the property to select multiple columns as group keys. You can use the Column Selection dialog box to select several group keys at once if required. This property has a dependent property:

· Case Sensitive. Use this to specify whether each group key is case sensitive or not, this is set to True by default, i.e., the values “CASE” and “case” in would end up in different groups.

Aggregations Category

Aggregation Type. This property allows you to specify the type of aggregation operation your stage is performing. Choose from Calculate (the default), Recalculate, and Count Rows.

Column for Calculation. The Calculate aggregate type allows you to summarize the contents of a particular column or columns in your input data set by applying one or more aggregate functions to it.

Select the column to be aggregated, then select dependent properties to specify the operation to perform on it, and the output colum to carry the result. You can use the Column Selection dialog be to select several columns at once if required.

Count Output Column. The Count Rows aggregate type performs a count of the number of records within each group. Specify the column on which the count is output.

Summary Column for Recalculation. This aggregate type allows you to apply aggregate functions to a column that has already been summarized. This is like calculate but performs the specified aggregate operation on a set of data that has already been summarized. In practice this means you should have performed a calculate (or recalculate ) operation in a previous Aggregator stage with the Summary property set to produce a subrecord containing the summary data that is then included with the data set. Select the column to be aggregated, then select dependent properties to specify the operation to perform on it, and the output column to carry the result. You can use the Column Selection dialog box to select several columns at once if required.

Default To Decimal Output. The output type of a calculation or recalculation column is double. Setting this property causes it to default to decimal. You can also set a default precision and scale. (You can also specify that individual columns have decimal output while others retain the default type of double.)

Weighting column. This is a dependent property of Count Output Column or Column for Calculation. Configures the stage to increment the count for the group by the contents of the weight column for each record in the group, instead of by 1. Not available for Summary Column for Recalculation. Setting this option affects only the following options:

· Percent Coefficient of Variation.

· Mean Value

· Sum

· Sum of Weights

Uncorrected Sum of Squares