You can use 1:

n

partitioning with Joiner transformations with sorted input. When you use 1:

n

partitioning, you create one partition for the master pipeline and more than one partition in the detail pipeline. When the Integration Service processes the join, it compares the rows in a detail partition against the rows in the master source. When processing master and detail data for outer joins, the Integration Service outputs unmatched master rows after it processes all detail partitions.