PDI allows you to do the basic operations that modify the data in your tables, that is: insert, update, and delete records. For each of those operations you have at least one step that allows you to do the task. It may happen that you have to do one or another operation depending on the value of a field. That is possible with a rather unknown step named Synchronize after merge.
Suppose you have a database with books. You received a file with a list of books. In that list there are books you already have, and there are books you don't have.
For the books you already have, you intend to update the prices.
Among the other books, you will insert in your database only those which have been ...