A Rank transformation inherits incoming fields from the upstream transformation. When you create a Rank transformation, Data Integration also creates a RANKINDEX output field.
The Rank transformation uses the following fields:
Incoming fields
Incoming fields appear on the Incoming Fields tab. By default, the Rank transformation inherits all incoming fields from the upstream transformation. If you do not need to use all of the incoming fields, you can define field rules to include or exclude certain fields. For more information about field rules, see Field rules.
RANKINDEX
After the Rank transformation identifies all rows that belong to a top or bottom rank, it assigns rank index values. Data Integration creates the RANKINDEX field to store the rank index value for each row in a group.
For example, you create a Rank transformation to identify the five retail stores in the company with the highest monthly gross sales. The store with the highest sales receives a rank index of 1. The store with the next highest sales receives a rank index of 2, and so on. If two stores have the same gross sales, they receive the same rank index, and the transformation skips the next rank index.
For example, in the following data set, the Long Beach and Anaheim stores have the same gross sales, so they are assigned the same rank index:
RANKINDEX
STORE
GROSS_SALES
1
Long Beach
100000
1
Anaheim
100000
3
Riverside
90000
4
Chula Vista
80050
When measuring a bottom rank, such as the 10 lowest priced products in the inventory, the Rank transformation assigns a rank index from lowest to highest. Therefore, the least expensive item receives a rank index of 1.
The RANKINDEX is an output field. It appears on the Incoming Fields tab of the downstream transformation.