Free MongoDB C100DEV Exam Dumps Questions & Answers

Select all true statements regarding to replication in MongoDB.

• A.In the event of failover, the nodes vote to select the new primary node.
• B.The primary node receives all new write operations, and the secondary nodes stay up to date with the primary.
• C.Replication is the primary mechanism for providing high availability in MongoDB.

Suppose you have a developers collection with the following document structure: { _id: 1, fname: 'Bob', lname: 'Smith', tech_stack: [ 'git', 'c++', 'sqlite', 'linux' ] } Select a query that can be executed without errors.

• A.db.developers.updateOne( { _id: 1 }, { $set: { fname: 'John' } } )
• B.db.developers.updateOne( { _id: 1 }, { $unset: { _id: '' } } )
• C.db.developers.updateOne( { _id: 1 }, { $set: { _id: 3, fname: 'Bob' } } )
• D.db.developers.updateOne( { _id: 1 }, { $set: { _id: 3 } } )

What is the built-in database called local in MongoDB for?

• A.The local database stores data describing the MongoDB server. For replica sets, it also stores information about the replication process.
• B.The local database is used to store information about shards in shared MongoDB cluster.
• C.The local database plays an important role in the authentication and authorization process. Certain actions performed by administrators also require access to this database.

What data structure is used to store the newly created index in MongoDB?

• A.Heap
• B.Graph
• C.B-tree
• D.Binary Tree
• E.Dictionary

Which collection method do you need to use to drop a specific collection?

• A.db.collection.dropCollection()
• B.db.collection.remove()
• C.db.collection.drop()
• D.db.collection.dropIndex()