You must publish a Group By parameter in your custom transformer to enable parallel processing.

• A. Not sure
• B. It is not required
• C. True
• D. False

Answer: (C)

Grouping the input by an attribute creates separate workloads that can run at the same time on multiple workers. Publishing a Group By parameter in a custom transformer makes that grouping option visible to workspace users, so they can choose which attribute defines the groups. When configured, FME partitions the data by group and processes each group in parallel, enabling parallel processing inside the transformer. Without publishing this parameter, the transformer won't offer a user-defined grouping, so parallel execution can't be realized. This is true.