Question 150
A source returns nested JSON arrays; the analyst wants each array element to become a separate record. What should be done?
Explanation
Correct Answer
Expand the list to new rows and then expand its records. List expansion creates one row per nested element before its fields are expanded.
Incorrect Answers
M expressions define row-level transformations at data preparation time. That matters for “must branch according to a null-safe status field” rather than the condition “each array element to become a separate record”.
M evaluation composes named steps whose downstream references require upstream results. The boundary it addresses is “Steps in which later steps reference earlier names”, while this case concerns “each array element to become a separate record”.
A row filter can reduce the imported dataset and may fold to the source. The deciding difference is “keeps rows with Quantity > 0” versus “each array element to become a separate record”.