MongoDB Certified DBA Associate Exam (Based on MongoDB 4.4): C100DBA

Which of the following index would be optimum for the query?

Select all valid. db.test.find( { a : 5, c : 2 }) A. db.test.ensurelndex( { c:l, a: 1})

B. db.test.ensurelndex( { a : 1, c: 1, d: 1, b : 1})

C. CH db.test.ensurelndex( { a :1, c:l})

D. db.test.ensurelndex( { a: 1, b :1, c:l, d:l})

MongoDB is a schema-less design.

A. False

B. True

The oplog (operations log) is a special capped collection that keeps a rolling record of all operations that modify the data stored in your databases. All the replica set members contain a copy of the oplog in the following collection:

A. oplog.rs

B. ..oplog.rs

C. .oplog.rs

D. local.oplog.rs