A question that I often receive is: “What should I do to learn how to develop ETL mappings using Informatica PowerCenter?” Here are the steps that I would take to learn how to do extract, transform, and load with Informatica PowerCenter. I assume that you already have knowledge of SQL. If you don’t know SQL or need to learn more about SQL, I would recommend that you buy Learning SQL by Alan Beaulieu....
There are situations where you need to keep a source and target in sync. One method to do this is to truncate and reload. However this method is not that efficient for a table with millions of rows of data. You really only want to: insert rows from the source that don’t exist in the target update rows that have changed delete rows from the target that no longer exist in the source Can you do this efficiently in a single informatica mapping?...