Informatica Common components aggregator two-packet-based ports

The aggregation transformation allows you to define groups for aggregations, rather than performing aggregations across all input data. For example, instead of looking for total company sales, you can find the total sales by region group.

To define a group for an aggregate expression, select the appropriate input, input/output, output, and variable ports in the aggregation transformation. You can select multiple group by ports to create a new group for a unique combination of each group. PowerCenter will then execute the defined aggregations for each group.

After the values are grouped, PowerCenter generates a row for each group. If the values are not grouped, PowerCenter returns a row for all input rows. PowerCenter typically returns the last row of each group (or the last line received) along with the aggregated results. However, if you specify that you want to return a specific row (for example, by using the first function), PowerCenter returns a specific row.

When multiple group by ports are selected in the aggregation transformation, PowerCenter uses the port order to determine the order in which they are grouped. Because the grouping order affects your results, arranging groups by ports ensures that the appropriate groupings are in place. For example, the results from the grouping of QUANTITY after first item_id may be different from the result of grouping based on QUANTITY item_id, because the number of numbers does not have to be unique.

The following aggregation transformations are grouped by first store_id after ITEM:

Non-aggregation expressions

You can modify or replace a group by using a non-aggregated expression in the group by port. For example, if you want to replace ' AAA battery ' before grouping, you can use the following expression to create a new group by output port named Corrected_item:

IIF (item = ' AAA battery ', battery, ITEM)

Default value

You can use default values in the group by port to replace null input values. For example, if you define a default value of ' Misc ' in the following ITEM column, PowerCenter Server replaces the empty group with ' Misc '. This enables PowerCenter Server to include empty project groups in the aggregation.

Informatica Common components aggregator two-packet-based ports