C100DBA Premium Exam Questions

MongoDB Certified DBA Associate Exam (Based on MongoDB 4.4) Questions and Answers

Question 13

Below is a sample document in a given collection test.

{ a : 5, b : 3, c: 2, d : 1 >

Given a compound index { a: 1, b:l, c:l, d:l}, Which of the below query will not use in-memory sorting? Select

all valid.

db.test.find( { a: 5, b: 3 } ).sort( { c: 1, d : 1 } )

db.test.find( { a: 5, b: 3 } ).sort( { a: 1} )

db.test.find( { a: 5, b: 3 } ).sort( { a: 1, b: 1, c: 1 > )

db.test.find( { a: 5, b: 3 } ).sort( {c: 1 } )

Question 14

You perform the following operation in the shell: db.foo.insert( { } ); What gets inserted?

A document will be inserted with the same _id as the last document inserted

A document that matches the collection's existing schema, but with null fields

A document with an _id assigned to be an Objectld

An empty document

No document will be inserted; an error will be raised

Question 15

Which of the following commands can cause the database to be locked?

All of the above

Inserting data

Map-reduce

Issuing a query

Question 16

You have the following index on the toys collection:

{

"manufacturer" : 1,

"name" : 1,

"date" : -1

}

Which of the following is able to use the index for the query? Check all that apply.

db.toys.find( { name : "Big Rig Truck", date : "2013-02-01", manufacturer : "Tanko"

db.toys.find( { manufacturer : "Matteo", name : "Barbara", date : "2014-07-02" } )

db.toys.find( { date : "2015-03-01", manufacturer : "Loggo", name : "Brick Set" } )