CERTIFIED-DATA-ENGINEER-PROFESSIONAL Question #100: Real Exam Question with Answer & Explanation

Question

The view updates represents an incremental batch of all newly ingested data to be inserted or updated in the customers table. The following logic is used to process these records. MERGE INTO customers USING ( SELECT updates.customer_id as merge_ey, updates .* FROM updates UNION ALL SELECT NULL as merge_key, updates .* FROM updates JOIN customers ON updates.customer_id = customers.customer_id WHERE customers.current = true AND updates.address <> customers.address ) staged_updates ON customers.customer_id = mergekey WHEN MATCHED AND customers. current = true AND customers.address <> staged_updates.address THEN UPDATE SET current = false, end_date = staged_updates.effective_date WHEN NOT MATCHED THEN INSERT (customer_id, address, current, effective_date, end_date) VALUES (staged_updates.customer_id, staged_updates.address, true, staged_updates.effective_date, null) Which statement describes this implementation?

Options

• AThe customers table is implemented as a Type 2 table; old values are overwritten and new
• BThe customers table is implemented as a Type 1 table; old values are overwritten by new values
• CThe customers table is implemented as a Type 2 table; old values are maintained but marked as
• DThe customers table is implemented as a Type 0 table; all writes are append only with no