When you use dynamic partitioning, the Integration Service defines the partition-level attributes for each partition it creates at run time. It names the file and directory attributes based on session-level attribute names that you define in the session properties.

For example, you define the session reject file name as accting_detail.bad. When the Integration Service creates partitions at run time, it creates a reject file for each partition, such as accting_detail1.bad, accting_detail2.bad, accting_detail3.bad.