MongoDB C100DBA Exam Questions Instant Access

Question 1

Which type of indexes does MongoDB support?

AAll of the above

BCompound Indexes

CMultikey Indexes

DGeospatial Indexes

Answer : A

Question 2

Which is the default mode in which the explain() command runs?

AallPlansExecution

BcustomExecutionStats

CqueryPlanner

DexecutionStats

Answer : C

Question 3

When should we consider representing a one-to-many relationship in an embedded collection instead of separate collection?

AWhen the many is not very large

BWhen the many is very large

CAlways

DNever

Answer : A

Question 4

Which of the following about Capped Collections is correct?

AFixed Size

BOnly 'Fixed Size' and 'High-throughput operations that insert and retrieve documents based on insertion order'

CHigh-throughput operations that insert and retrieve documents based on insertion order

DIf the allocated space for a capped collection exceeds, it stops inserting new documents

Answer : B

Question 5

Which of the following aggregate commands in MongoDB uses a pipeline approach with the goals of improving the aggregation performance?

AmapReduce

Bgroup

Caggregate

DAll of the above

Answer : C

Question 6

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

AAverage of likes on all the posts of an author, grouped by author

BNumber of posts by an author

CSum of likes on all the posts by all the authors

DSum of likes on all the posts by an author, grouped by author

Answer : D

Question 7

Given a collection posts as shown below having a document array comments, which of the following command will create an index on the comment author descending?

Adb.posts.createIndex({^comments.$.author':-l});

Bdb. posts.createIndex({^comments.author' :1});

Cdb.posts.createIndex({^commerits.author';-!});

Answer : C

MongoDB Certified DBA Associate C100DBA Exam Questions