In a mapping that converts hierarchical data to relational output, you can optionally generate unique keys for the hierarchical input group.
The following image shows the option to generate unique keys in the
Hierarchy Processor
tab:
When you generate unique keys, you generate a primary key for the input group and a key for every array element within the input group. Each key is a combination of a global unique ID and a value that increases for each additional field. You can map the generated keys to the output groups just like any other incoming field.
When you map key fields from an input parent element to the output group of the child data set, the output data or output group has a primary key and foreign key relationship. This relationship is generated on the output side, based on how you mapped the generated keys.