Câu 14: C100DBA: MongoDB Associate Database Administrator

A MongoDB database administrator needs to improve the performance of the following query: What index should the administrator use to achieve this goal?

1. A. db.employees.createIndex({salary: 1, name: 1, department: 0 });
2. B. db.employees.createIndex({ department: 1, salary: -1 }); — đáp án hiện tại
3. C. db.employees.createIndex({department: 1, salary: 1, name: 1 });
4. D. db.employees.createIndex({ name: 1, department: 1, salary: -1 });