MongoDB C100DBA Online Practice Questions and Exam Preparation

MongoDB C100DBA Online Questions & Answers

• Question 121:

  MongoDB is

  A. None of the above
  B. Object-oriented DBMS
  C. Relational DBMS
  D. Document-oriented DBMS
  D. Document-oriented DBMS

• Question 122:

  You have designed a web application with mongoDB. You have configured replication. The replica set is in place and function properly. What happens in case of failure?

  A. Switchover needs to be done manually
  B. Failover happens automatically
  C. Switchover happens automatically
  D. Failover needs to be done manually
  B. Failover happens automatically

• Question 123:

  Addding the index {a:l} can potentially decrease the speed of which of the following operations? Check all that apply.

  A. db.collection.update({b:456>, {$inc: {a:l> })
  B. db.collection.find( {a : 232} )
  C. db.collection.insert( { a:341})
  A. db.collection.update({b:456>, {$inc: {a:l> })
  C. db.collection.insert( { a:341})

• Question 124:

  Using an arbiter allows one to easily ensure an odd number of voters in replica sets. Why is this important?

  A. To help in disaster recovery
  B. To protect agains network partitions
  C. To enable certain read preference settings
  D. To add greather redundancy
  E. For more efficient backup operations
  B. To protect agains network partitions

• Question 125:

  As per the aggregation pipeline optimization concepts, if you have a $sort followed by a $match:

  A. Providing these parameters in any order does not impact the performance
  B. $sort moves before $match
  C. MongoDB does not do any movements by default and will use the order provided
  D. $match moves before $sort
  D. $match moves before $sort

• Question 126:

  Which of the following does MongoDB use to provide High Scalability?

  A. Replication
  B. Write Concern
  C. Indexing
  D. Sharding
  D. Sharding

• Question 127:

  Which of the following about Capped Collections is correct?

  A. Fixed Size
  B. Only "Fixed Size" and "High-throughput operations that insert and retrieve documents based on insertion order"
  C. High-throughput operations that insert and retrieve documents based on insertion order
  D. If the allocated space for a capped collection exceeds, it stops inserting new documents
  B. Only "Fixed Size" and "High-throughput operations that insert and retrieve documents based on insertion order"

• Question 128:

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

  A. All of the above
  B. Inserting data
  C. Map-reduce
  D. Issuing a query
  A. All of the above

• Question 129:

  What is the maximum size of a MongoDB document

  A. 16 MB
  B. 12 MB
  C. 2 MB
  D. There is no maximum size. It depends on the RAM.
  A. 16 MB

• Question 130:

  In a collection that contains 100 post documents, what does the following command do? db. posts. find().skip(5).limit(5)

  A. Skip and limit nullify each other. Hence returning the first five documents
  B. Limits the first five documents and then return them in reverse order
  C. Skips the first five documents and returns the sixth document five times
  D. Skips the first five documents and returns the next five
  D. Skips the first five documents and returns the next five