Hash partitioning: Use hash partitioning when you want the PowerCenter Integration Service to distribute rows to the partitions by group. For example, you need to sort items by item ID, but you do not know how many items have a particular ID number.
You can use the following types of hash partitioning:
Hash auto-keys: The PowerCenter Integration Service uses all grouped or sorted ports as a compound partition key. You may need to use hash auto-keys partitioning at Rank,Sorter, and unsorted Aggregator transformations.
Hash user keys: The PowerCenter Integration Service uses a hash function to group rows of data among partitions. You define the number of ports to generate the partition key.