MongoDB DBA Quiz Questions and Answers

Which features of relational database management systems were deliberately omitted in MongoDB and help us to obtain horizontal scalability? Check all that apply.

Answer :
  • Multi-statement transactions
  • Joins

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

Answer :
  • $project

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

Answer :
  • Skips the first five documents and returns the next five

Which of the following is supported by MongoDB?

Answer :
  • Journaling

Aggregation Pipelines have a limit of:

Answer :
  • 16 MB document and 100 MB RAM

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

Answer :
  • The query used an index to fetch the results

Which mongodb tool is used to report details on number of database operations in MongoDB?

Answer :
  • mongostat

hat RSI and RS2 can be primary? You had to see the different configurations, RS3 could be hidden or priority 0 (But not a referee because we need 3 replicas), while RSI and RS2 could NOT have priority 0 or be hidden or anything like that . In a 4-member RS RSO, RSI, RS2 and RS3 + Referee, RSO (primary) falls after some write operations that have replicated RSI and RS2 (but NOT RS3), who can get up as the new primary? The configuration comes and in it we see that RS2 has a hidden: true (or a priority: 0, (I don't remember)

Answer :
  • ORS1

Given a replica set with five data-bearing members, suppose the primary goes down with operations in its oplog that have been copied from the primary to only one secondary. Assuming no other problems occur, which of the following describes what is most likely to happen?

Answer :
  • the secondary with the most current oplog will be elected primary

In order to ensure that you can maintain high availability in the face of server failure, you should implement which of the following?

Answer :
  • Replication