Câu 13: 70-776: Perform Big Data Engineering on Microsoft Cloud Services

You have a Microsoft Azure SQL data warehouse that has a fact table named FactOrder. FactOrder contains three columns named CustomerID, OrderID, andOrderDateKey. FactOrder is hash distributed on CustomerID. OrderID is the unique identifier for FactOrder. FactOrder contains 3 million rows. Orders are distributed evenly among different customers from a table named dimCustomers that contains 2 million rows. You often run queries that join FactOrder and dimCustomers by selecting and grouping by the OrderDateKey column. You add 7 million rows to FactOrder. Most of the new records have a more recent OrderDateKey value than the previous records. You need to reduce the execution time of queries that group on OrderDateKey and that join dimCustomers and FactOrder. What should you do?

1. A. Change the distribution for the FactOrder table to round robin
2. B. Change the distribution for the FactOrder table to be based on OrderID
3. C. Update the statistics for the OrderDateKey column — đáp án hiện tại
4. D. Change the distribution for the dimCustomers table to OrderDateKey