What are Rank and Dense Rank transformations in Informatica and how do they differ from each other?

Rank vs. Dense Rank Transformations in Informatica

Rank and Dense Rank are two commonly used transformations in Informatica for sorting and ranking data. While both transformations are used to assign numerical rankings to data based on certain criteria, they differ in how they handle ties.

Rank Transformation:

The Rank transformation assigns unique rankings to each row of data based on the specified sorting criteria. In case of ties (i.e., multiple rows with the same value), the Rank transformation may skip numbers and create gaps in the ranking sequence.

Dense Rank Transformation:

The Dense Rank transformation also assigns rankings to data rows based on the specified criteria, but unlike the Rank transformation, it does not create gaps in the ranking sequence in case of ties. Instead, it assigns consecutive rankings to tied rows.

Therefore, the key difference between Rank and Dense Rank transformations in Informatica lies in how they handle ties in data ranking, with Rank allowing gaps in the ranking sequence and Dense Rank assigning consecutive rankings to tied rows.

When using these transformations in Informatica, it is important to consider the specific requirements of the task at hand and choose the appropriate transformation based on how ties should be handled in the ranking process.