MongoDB C100DBA Online Practice Questions and Exam Preparation

MongoDB C100DBA Online Questions & Answers

• Question 11:

  Which of the following command inside aggregate command is used in MongoDB aggregation to filter the documents to pass only the documents that match the specified condition(s) to the next pipeline stage.

  A. $aggregate
  B. $sum
  C. $match
  D. $group
  C. $match

• Question 12:

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

• Question 13:

  Which of the following index would be optimum for the query? Select all valid. db.test.find( { a : 5, c : 2 })

  A. db.test.ensurelndex( { c:l, a: 1})
  B. db.test.ensurelndex( { a : 1, c: 1, d: 1, b : 1})
  C. CH db.test.ensurelndex( { a :1, c:l})
  D. db.test.ensurelndex( { a: 1, b :1, c:l, d:l})
  B. db.test.ensurelndex( { a : 1, c: 1, d: 1, b : 1})
  C. CH db.test.ensurelndex( { a :1, c:l})

• Question 14:

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

• Question 15:

  If the value of totalKeysExamined is 30000 and the value of totalDocsExamined is 0, which of the following option is correct?

  A. None of the above
  B. The query used an index to fetch the results
  C. The query returned 0 documents
  D. The query returned 30000 documents after scanning the documents
  B. The query used an index to fetch the results

• Question 16:

  What does the following query do when performed on the posts collection? db.posts.update({_id:l},{Title:This is post with ID 1"})

  A. Syntax error
  B. Replaces the complete document with _id as 1 with the document specified in second parameter
  C. Updates the Title of the post
  D. Updating a document is possible only with $set
  B. Replaces the complete document with _id as 1 with the document specified in second parameter

• Question 17:

  The following aggregation option is used to specify the specific fields that needs to be passed to the next stage of the aggregation pipeline:

  A. $project
  B. $aggregate
  C. $match
  D. $group
  A. $project

• Question 18:

  Below is a sample document of "orders" collection

  

  A. $project
  A. $project

• Question 19:

  Update If Correct is an approach for which of the following concepts in MongoDB:

  A. Concurrency Control
  B. Atomicity
  C. Performance Management
  D. Transaction Management
  A. Concurrency Control

• Question 20:

  Mongodb does provide high availability via which option?

  A. Replication
  B. Indexing
  C. Sharding
  D. Journaling
  A. Replication