Free MongoDB C100DEV Exam Dumps Questions & Answers

You want to execute the following query quite often in your application: db.hotels.aggregate([ { "$match": { "stars": { "$gt": 4.5 } } }, { "$sort": { "stars": 1 } } ]) Your collection doesn't have any additional indexes. Which index should you create to support this query?

• A.db.hotels.createIndex( { "stars": 1 } )
• B.In this case, the index could not be created.
• C.db.hotels.createIndex( { "match": 1 } )

Consider a many-to-many relationship observed between courses and the students enrolled in these courses. Which of the following are true about modeling this many-to-many relationship with the document model in MongoDB?

• A.Embedding students in courses still requires a separate collection to store all students (we may have students who are not enrolled in any course).
• B.The many-to-many relationship cannot be represented in MongoDB.
• C.When using one collection for students and one collection for courses there is a need for an array of references in only one collection.
• D.Embedding students in courses duplicates student information.

Which cursor method should you use to get information about the query plan?

• A.cursor.map()
• B.cursor.hint()
• C.cursor.explain()

You have the following configuration file: net: bindIp: localhost port: 27000 security: authorization: enabled.
You have to edit this file to use new directory as the dbPath: /var/mongodb/db Select correct Answer .

• A.storage: dbPath: /data/db net: bindIp: localhost port: 27000 security: authorization: enabled
• B.dbPath: storage: /var/mongodb/db net: bindIp: localhost port: 27000 security: authorization: enabled
• C.storage: dbPath: /var/mongodb/db net: bindIp: localhost port: 27000 security: authorization: enabled

Which cursor method should you use to return the number of documents in the result set?

• A.cursor.sum()
• B.cursor.count()
• C.cursor.total()
• D.cursor.explain()