If a data source is only available in narrow time windows, which dataflow design best ensures the source is copied as-is and usable for later transformations?

• A. Create a linked table referencing the data from another dataflow.
• B. Create a shared dataset that can be reused by multiple Power BI reports.
• C. Create a staging dataflow that will only copy the data from the source as-is.
• D. Create a transformation dataflow that will apply all necessary transformations.

Answer: (C)

When a data source is only available in narrow time windows, you want a precise, untouched copy of what the source produced at that moment so you can use it later for any needed transformations. A staging dataflow is built for that purpose: it ingests the source and copies it as-is into a staging area, creating a persistent, raw dataset that can be transformed later without re-accessing the live source.

This decouples data capture from processing, allowing you to validate and re-process the data as needed, even if the source window is closed. It also gives you a reproducible baseline to apply transformations when you’re ready, without risking loss or drift from subsequent source changes.

Other designs don’t fit as well. A linked table depends on another dataflow and may not provide a true, standalone snapshot. A shared dataset is about consumption by reports, not about preserving a raw ingestion. A transformation dataflow applies changes during load, which means you don’t keep the original as-is copy for later use.