Question 1

What does the output x of the following MongoDB aggregation query result into; db.posts.aggregate( [ { $group: { _id; '$author', x: { $sum: $likes } } } ] )

Options :

A : Average of likes on all the posts of an author, grouped by author

B : Number of posts by an author

C : Sum of likes on all the posts by all the authors

D : Sum of likes on all the posts by an author, grouped by author

Answer: D

Question 2

'mongoimport' command is used for

Options :

A : Batch data insertion

B : None of the above

C : Multiple command import

D : Multiple command insertion

Answer: A

Question 3

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

Options :

A : All of the above

B : Inserting data

C : Map-reduce

D : Issuing a query

Answer: A

Question 4

Which mongodb tool is used to report details on number of database operations in MongoDB?

Options :

A : mongostat

B : mongotop

C : mongorestore

D : mongodump

Answer: A

Question 5

You have a replicated cluster with 1 primary, 3 secondary, 1 arbiter. One of the secondary is hidden. What is the replication factor of this replicated cluster?

Options :

A : 7

B : 03

C : 04

D : 06

Answer: C

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