BenchMark Quizzes by MDFT Pro

Select The Output Mode For Structured Streaming

You work for MDFT Pro, a well-known training agency that uses Azure Databricks for real-time analytics. Mark, the Streaming Data Engineer, has asked you to build a structured streaming solution that monitors student engagement with online course materials. The solution needs to count learning events (video views, quiz submissions, document downloads) in five-minute intervals and report only the events that arrive during each specific interval. The aggregated results should be written to a Delta Lake table for further analysis by the business intelligence team. Mark wants to ensure that historical data from previous intervals is not re-emitted with each update.

Which output mode should you use?

Choose the correct answer from the options below.

Explanations for each answer:

complete is incorrect. Complete mode outputs the entire result table after each trigger, which includes all events from all intervals, not just the current interval.
append is correct. Append mode only outputs new rows added to the result table since the last trigger, which matches the requirement to report only events that arrive during each interval.
update is incorrect. Update mode outputs rows that were updated since the last trigger, which is used for aggregations that need to update previous results, not for new interval-based counts.
merge is incorrect. Merge is not a valid output mode in structured streaming. The valid modes are complete, append, and update.

Learn more about Structured Streaming With Delta Lake:

Structured Streaming With Delta Lake

Practice Exam

Select The Output Mode For Structured Streaming

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