To obtain expected results and get best performance when partitioning a sorted Joiner transformation, you must group and sort data. To group data, ensure that rows with the same key value are routed to the same partition. The best way to ensure that data is grouped and distributed evenly among partitions is to add a hash auto-keys or key-range partition point before the sort origin. Placing the partition point before you sort the data ensures that you maintain grouping and sort the data within each group.