MongoDB MongoDB Certifications C100DBA Questions & Answers

• Question 71:

  Which option can be used with update command so that a new document gets created if no matching document is found based on the query condition?

  A. upsert command instead of update command

  B. This has to be handled in application code (Node.js, PHP, JAVA, C#, etc.) and cannot be handled in mongo shell query

  C. {update: true, insert: true} as the third parameter of update command

  D. Specify {upsert : true } as the third parameter of update command

  Correct Answer: D

• Question 72:

  You perform the following query on the sayings collection, which has the index { quote : "text" }: Assuming the documents below are in the collection, which ones will the following query return? Check all

  that apply.

  A. db.sayings.find( { $text : { $search : "fact find" } } )

  B. { _id : 3, quote : "Nobody will ever catch me." }

  C. { _id : 1, quote : "That's a fact, Jack." }

  D. { _id : 2, quote : "Find out if that fact is correct." }

  Correct Answer: BC

• Question 73:

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

  A. mapReduce

  B. group

  C. aggregate

  D. All of the above

  Correct Answer: C

• Question 74:

  `$set' sets the value of

  A. Code block

  B. Name/value pair

  C. Key

  D. None of the above

  Correct Answer: C

• Question 75:

  Which of the following is incorrect statement about find and findOne operations in MongoDB?

  A. findQ returns all the documents in a collection while findOne() retrieves only the first one.

  B. find.limit(l) is not the same query as findOne()

  C. findOneQ returns the actual first document retrieved from a collection

  D. findQ and findOneQ returns cursors to the collection documents

  Correct Answer: D

• Question 76:

  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.

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

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

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

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

  Correct Answer: AD

• Question 77:

  Mongodb does provide high availability via which option?

  A. Replication

  B. Indexing

  C. Sharding

  D. Journaling

  Correct Answer: A

• Question 78:

  You are in a sharded cluster. What will you do prior to initiating backup in sharded cluster?

  A. db.stopBalancer()

  B. db.stopserver()

  C. sh.stopBalancer()

  D. sh.stopserverQ

  Correct Answer: C

• Question 79:

  You are comparing values of different BSON types in mongodb. You want to compare from lowest to highest. Which comparison order is used?

  A. MinKey, Null, Numbers,Symbol, String,Object,Array,BinData

  B. MinKey, Null, Numbers,Object,Array,BinData,Symbol, String

  C. Object/Array^inData/Symbol,MinKey, Null, Numbers,String

  D. Objec^Array^inData,Symbol, String,MinKey, Null, Numbers

  Correct Answer: A

• Question 80:

  If you have created a compound index on (A,B, C) which of the following access pattern will not be able to utilize the index?

  A. A, B, C

  B. A

  C. B, C

  D. A, B

  Correct Answer: C