Free MongoDB C100DEV Exam Dumps Questions & Answers

Select all true statements regarding to the _id field in MongoDB documents. (select 4)

• A.When inserting a document, the _id value is already generated as an ObjectId type, if not directly specified.
• B.We can select a non ObjectId type value for _id field when inserting a new document.
• C.The _id can be an array data type.
• D.The _id values must be unique for the collection.
• E.MongoDB adds an _id field to any inserted document if it doesn't have one.

Select all true statements regarding to scaling.

• A.When scaling vertically our scaling cost increases linearly.
• B.Scaling horizontally is generally cheaper than scaling vertically.
• C.When scaling horizontally our scaling cost increases linearly.

In your database there is a collection named trips with the following document structure: { '_id': ObjectId("572bb8222b288919b68abf6d"), 'trip_duration': 858, 'start_station id': 532, 'end_station_id': 401, 'bike_id': 17057, 'start_station_location': { type: 'Point', coordinates: [ -73.960876, 40.710451 ] }, 'end_station_location': { type: 'Point', coordinates: [ -73.98997825, 40.72019576 ] }, 'start_time': ISODate("2016-01-01T00:09:31.000Z"), 'stop_time': ISODate("2016-01-01T00:23:49.000Z") } How can you extract all trips from this collection ended at stations that are to the west of the -73.5 longitude coordinate?

• A.db.trips.find( { 'end_station_location.coordinates.0': { $lt: -73.5 } } )
• B.db.trips.find( { 'end_station_location.coordinates.0': { $gt: -73.5 } } )
• C.db.trips.find( { 'end_station_location.coordinates.1': { $lt: -73.5 } } )
• D.db.trips.find( { 'coordinates': { $lt: -73.5 } } )

Which of the following methods executes a database command? (mongo shell)

• A.db.runCommand({ <command> })
• B.db.ommand({ <command> })
• C.db.runThisCommand({ <command> })
• D.db.execute({ <command> })

Data modeling. You are considering the use of nesting or references in your data model. Your data may change frequently. Which option would be more appropriate?

• A.Use of nesting.
• B.Use of reference.