Database (DBMS) - MCQ Practice Questions

For a sales database, to get top 5 products by revenue in each region, which window function approach is suitable?

In an e-commerce platform with orders table, which index structure is best for frequently filtering by customer_id AND order_date?

Which of the following is a valid correlated subquery for finding employees earning more than their department average?

In a bank database with accounts table, which query correctly identifies dormant accounts (no transactions in 2 years)?

Which anomaly in unnormalized database allows insertion of duplicate partial information without main entity?

For a multi-million row analytics database, which data type is most storage-efficient for storing yes/no values?