C100DBA MongoDB Certified DBA Associate Exam (Based on MongoDB 4.4) Question and Answers

Which of the following is a valid Replica Set configuration if you want:

1-Have 3 copies of everything

2- That RS3 is never primary

2- That 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)

Which of the following is a valid insert statement in mongodb? Select all valid.

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

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.

What does the following $slice query return using the following command? db.posts.find( {}, { comments: { $slice: [ -10, 5 ] } } )

‘$set' sets the value of

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?

What is the maximum size of Index Key Limit and Number of Indexes per collection?

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?

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

Which of the following statements are true about the $match pipeline operator? Check all that apply.

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?

Consider the following example document:

{

"_id": Objectld("5360c0a0a655a60674680bbe"),

"user"

"login": "irOn"

"description": "Made of steel"

"date": ISODate("2014-04-30T09:16:45.836Z"),

}

>

and index creation command:

db.users.createlndex( { "user.login": 1, "user.date": -1 }, "mylndex" )

When performing the following query:

db.users.find( { "user.login": /Air.*/ },

{ "user":1, "_id":0 > ).sort( { "user.date":1 > )

which of the following statements correctly describe how MongoDB will handle the query? Check all that apply.

The oplog (operations log) is a special capped collection that keeps a rolling record of all operations that modify the data stored in your databases. All the replica set members contain a copy of the oplog in the following collection:

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

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?