What is target load order?

Designer allows users to define target load order for all sources that pertain to a mapplet when it is used in a mapping. The target load order in which Integration Service distributes data to targets inside the mapping may be adjusted in Designer. A target load order group is just a mapping that connects source qualifiers, transformations, and targets. When working with tables that include primary and secondary keys, the target load order can be adjusted to ensure referential integrity.