試題詳解

24. A company’s database contains a table Sales with millions of rows, and the following SQL query is executed frequently:

Which of the following optimizations would most effectively improve the query performance?
(A) Adding an index on SalesAmount
(B) Creating a composite index on (Region, ProductID)
(C) Partitioning the table by ProductID
(D) Using HAVING SUM(SalesAmount) > 0 to filter results

(E) Adding an index on ProductID only