MongoDB MongoDB Certifications C100DBA Questions & Answers

• Question 81:

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

  A. When the many is not very large

  B. When the many is very large

  C. Always D. Never

  Correct Answer: A

• Question 82:

  Which of the following command is used to get all the indexes on a collection?

  A. db.collection.showIndexes()

  B. db.collection.findlndexes()

  C. db.showIndexes()

  D. db.collection.getlndexesQ

  Correct Answer: D

• Question 83:

  What is the use of mongodump and mongorestore tools?

  A. backup mongodb deployment

  B. audit mongodb deployment

  C. performance tune mongodb deployment

  D. replicate mongodb deployments

  Correct Answer: A

• Question 84:

  Which of the following are common uses of the mongo shell? Check all that apply

  A. Perform queries against MongoDB collections

  B. Perform administrative tasks

  C. Use as a JavaScript framework for your production system

  Correct Answer: AB

• Question 85:

  Write the command(s) are correct to enable sharding on a database "testdb" and shard a collection "testCollection" with _id as shard key.

  

  A. sh.enableSharding("testdb") and sh.shardCollection("testdb.testCollection", {_id : 1 }, true )

  Correct Answer: A

• Question 86:

  Which of the following is true about aggregation framework?

  A. Each aggregation operator need to return atleast one of more documents as a result

  B. the aggregate command operates on a multiple collection

  C. A single aggregation framework operator can be used more than once in a query

  D. Pipeline expressions are stateless except accumulator expressions used with $group operator

  Correct Answer: ACD

• Question 87:

  Which of the following operator can be used to limit the number of documents in an array field of a document after an update is performed?

  A. $arrayLimit

  B. $push along with $each, $sort and $slice

  C. $removeFromSet

  D. None of the above

  Correct Answer: B

• Question 88:

  Which mongodb tools allow us to work with our data in a human readable format?

  A. mongoexport

  B. mongostat

  C. mongoimport

  D. mongodump

  Correct Answer: AC

• Question 89:

  Consider that you have a collection called population which has fields state and city. Which of the following query will calculate the population grouped by state and city?

  A. db.population.aggregate( [{ $group: { _id: { state: "$state", city: "$city" },pop: { $pop: 1 } } }] )

  B. db.population.aggregate( [{ $group: { _id: { city: "$city" },pop: { $sum: "$pop" } } }] )Multi Document Transaction is not supported by MongoDB

  C. db.population.aggregate( [{ $group: { _id: { state: Estate", city: "$city" },pop: { $sum: "$pop" } } }] )

  D. db.population.aggregate( [{ $group: { _id: { state: Estate", city: "$city" },pop: { $sum: 1 > > >] )

  Correct Answer: C

• Question 90:

  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?

  A. 7

  B. 03

  C. 04

  D. 06

  Correct Answer: C