In a mapping that converts hierarchical data to flattened data, you can read from one hierarchical input group and write to one flattened output group. You can read data from primitive fields, structs, and arrays and quickly create a fully denormalized output file. You can also flatten and denormalize only a portion of the incoming fields.

For data sources that contain sibling arrays, you can easily denormalize the output data without the need for complex joins. Select the check box next to the incoming fields you want. The Hierarchy Processor transformation adds the field to the output and creates the expression automatically.

The following image shows a mapping that uses a Hierarchy Processor transformation to convert hierarchical data to flattened data:

In this mapping, the data source is a JSON file that contains personal and vehicle data. The data flows into a flattened file that contains vehicle information. The Hierarchy Processor transformation is selected, and the

Hierarchy Processor

tab shows the structure of the incoming and output data.

For more information, see Defining flattened output with the Hierarchy Processor transformation.