When you run data preview in the Data Viewer view, you can
perform tasks, such as viewing the structure and data of a hierarchy field and
filtering ports to view. You can also export the results to a JSON file.
Before you preview
data, verify that Spark is configured as the mapping run-time environment. If
you are previewing hierarchical data in a complex file object, add the complex
file object to a mapping to preview the data.
To preview data on the Spark engine, perform the following tasks:
Open a mapping in the Developer tool and select a preview point.
To run the data preview, click Run in the Data Viewer view.
The output of the data preview can be viewed in the Data
Viewer view.
To filter ports in the output, choose the ports you want to view.
To view the structure and the data in a hierarchy field, select
the field.
The details of the hierarchy field appears on the
hierarchical type panel.
To export the results to a JSON file, right-click the hierarchy
field and select