For example, if you want to select the 10 most expensive items by manufacturer, you would first define a group for each manufacturer. In the

Group By

panel of the

Rank

tab, you can set one of the input, input/output, or output ports as a group by port.

For each unique value in the group port, the transformation creates a group of rows falling within the rank definition (top or bottom, and a particular number in each rank).

The Rank transformation changes the number of rows in two different ways. By filtering all but the rows falling within a top or bottom rank, you reduce the number of rows that pass through the transformation. By defining groups, you create one set of ranked rows for each group.

For example, if you create a Rank transformation that ranks the top five salespersons grouped by quarter, the rank index numbers the salespeople from 1 to 5 for each quarter:

Set the number of rows to include in a ranking on the

Advanced

tab of the

Properties

view.