Use 1:

n

partitions when you have one flat file in the master pipeline and multiple flat files in the detail pipeline. When you use 1:

n

partitions, the Integration Service maintains the sort order because it does not redistribute data among partitions. When you have one large flat file in each master and detail pipeline, use

n

:

n

partitions and add a pass-through or hash auto-keys partition at the Joiner transformation. When you add a hash auto-keys partition point, you must configure partitions to pass all sorted data in the first partition to maintain the sort order.