This concept is related to Aggregator transformation. When you have data, which in increasing but the existing data remains constant, you can utilize the incremental aggregation functionality to achieve the output faster and enhance the performance. When you select the Incremental Aggregation option in the Session properties, Informatica saves the result of the last run in the cache and replaces the value in the next run and hence enhances the performance. To understand this concept, let's look at an example.

Consider that you have a file containing the salary of employees, and you wish to get the sum of the salaries of all the employees. Then, consider that we have three employees in the month of JAN, six employees in the month of FEB, and nine employees in the month of MARCH, as shown in the following screenshot:

As you can see, the data in the file is increasing—the first file has the data of employees present in the month of JAN, the second file has the data of...