Which DirectQuery-related best practice is specifically about ensuring data integrity in relationships?

• A. Set relationships to enforce integrity using the assume referential integrity property on relationships.
• B. Use a star schema as opposed to wide tables.
• C. Disable auto date/time in Power BI Desktop.
• D. Use cross-filter direction set to both.

Answer: (A)

DirectQuery relies on the data source to enforce relationships; setting relationships to assume referential integrity tells Power BI that the source guarantees that every value on the many side has a corresponding value on the one side. This lets the engine push joins and filtering efficiently and produce results that match the source constraints, improving performance while preserving correctness as long as referential integrity actually holds in the source. If there are orphaned keys or violations, avoid enabling this because it would trust constraints that aren’t guaranteed, leading to potential mismatches. The other options address modeling structure, date handling, or filter behavior, which don’t directly ensure data integrity across relationships in DirectQuery.