The slowly growing target mapping filters source rows based on user-defined comparisons, and then inserts only those found to be

new

to the target. Use the slowly growing target mapping to determine which source rows are new and to load them to an existing target table. In the slowly growing target mapping, all rows are current.

Use the slowly growing target mapping to load a slowly growing fact or dimension table, one in which existing data does not require updates.

For example, you have a site code dimension table that contains only a store name and a corresponding site code that you update only after the company opens a new store. Although listed stores might close, you want to keep the store code and name in the dimension for historical analysis. With the slowly growing target mapping, you can load new source rows to the site code dimension table without deleting historical sites.