The Best C100DEV Exam Study Material Premium Files and Preparation Tool (Mar-2023) [Q68-Q91]

4.6/5 - (5 votes)

The Best C100DEV Exam Study Material Premium Files and Preparation Tool (Mar-2023)

Get Instant Access to C100DEV Practice Exam Questions

QUESTION 68
Suppose we have a shipwrecks collection with the following document structure: { _id: ObjectId(“578f6fa2df35c7fbdbaed8ce”), feature_type: ‘Wrecks – Visible’, watlev: ‘always dry’, coordinates: [ -79.9469681, 9.3729954 ] } Your application will often query based on the coordinates field. How to create a 2dsphere geospatial index for the coordinates field?

db.shipwrecks.createIndex({‘coordinates’: ‘2d’})

db.shipwrecks.createIndex({‘coordinates’: ‘2dsphere’})

db.shipwrecks.createIndex({‘coordinates’: ‘1’})

db.shipwrecks.createIndex({‘coordinates’: ‘text’})

QUESTION 69
What is a document in MongoDB?

It’s an ordered collection of keys (fields) with assigned values. The keys in each document are strings of characters. Documents in MongoDB cannot contain duplicate keys.

It’s a text file containing the configuration of the MongoDB instance.

It’s a table that contains information about all collections in the database.

QUESTION 70
We have a movies collection with the following document structure: { _id: ObjectId(“573a1390f29313caabcd6223”), genres: [ ‘Comedy’, ‘Drama’, ‘Family’ ], title: ‘The Poor Little Rich Girl’, released: ISODate(“1917-03-05T00:00:00.000Z”), year: 1917, imdb: { rating: 6.9, votes: 884, id: 8443 } } We need to use Aggregation Framework to fetch all movies from this collection where ‘Drama’ is not in genres list and the minimum ‘imdb.votes’ is at least 100. Additionally, in the projection stage, we want to leave only the following fields: -> title -> genres -> imdb.votes We also want to sort the result set by decreasing imdb votes and limit the number of documents retuned to 5. Example output: [ { imdb: { votes: 1294646 }, genres: [ ‘Action’, ‘Mystery’, ‘Sci-Fi’ ], title: ‘Inception’ }, { imdb: { votes: 1109724 }, genres: [ ‘Adventure’, ‘Fantasy’ ], title: ‘The Lord of the Rings: The Fellowship of the Ring’ }, { imdb: { votes: 1081144 }, genres: [ ‘Adventure’, ‘Fantasy’ ], title: ‘The Lord of the Rings: The Return of the King’ }, { imdb: { votes: 1080566 }, genres: [ ‘Action’, ‘Sci-Fi’ ], title: ‘The Matrix’ }, { imdb: { votes: 1004805 }, genres: [ ‘Action’, ‘Thriller’ ], title: ‘The Dark Knight Rises’ } ] Which pipeline should you use?

[{ $match: { genres: { $nin: [‘Drama’] }, ‘imdb.votes’: { $gte: 100 } } }, { $project: { _id: 0, title: 1, genres: 1, ‘imdb.votes’: 1 } }, { $sort: { ‘imdb.votes’: -1 } }, { $limit: 5 }]

[{ $match: { genres: { $in: [‘Drama’] }, ‘imdb.votes’: { $gte: 100 } } }, { $project: { _id: 0, title: 1, genres: 1, ‘imdb.votes’: 1 } }, { $sort: { ‘imdb.votes’: -1 } }, { $limit: 5 }]

[{ $match: { genres: { $nin: [‘Drama’] }, ‘imdb.votes’: { $gte: 100 } } }, { $project: { _id: 0, title: 1, genres: 1, ‘imdb.votes’: 1 } }, { $sort: { ‘imdb.votes’: -1 } }]

QUESTION 71
Select all true statements regarding to Aggregation Framework.

The Aggregation Framework will automatically reorder stages in a certain conditions (for optimization).

The query in a $match stage can not be entirely covered by an index.

QUESTION 72
Why adding indexes may lead to slower write operations?

Because we also need to update the index.

Because we have less and less disk space.

QUESTION 73
Which of the following roles provides minimal privileges needed for backing up data in MongoDB?

backup

restore

update

QUESTION 74
You have the following index in a movies collection: { “title”: 1, “imdb.rating”: -1, “imdb.votes”: -1, “type”: 1 } Can the following query use the given index for both filtering and sorting?
db.movies.find( { “title”: “James Bond”, “imdb.rating”: { “$gt”: 8} } ).sort( { “imdb.rating”: 1 } )

Yes

QUESTION 75
Select all true statements about the differences between mongoexport and mongodump.

mongoexport outputs BSON file, but mongodump outputs JSON file.

mongoexport outputs JSON file, but mongodump outputs BSON file.

mongodump can create a data file and a metadata file, but mongoexport just creates a data file.

By default, mongodump sends output to stdout, but mongoexport writes to a file.

mongodump is typically faster than mongoexport

QUESTION 76
Select all options when you should deploy a MongoDB deployment with security enabled.

Deployment of the development environment.

Deployment of the evaluation environment.

Deployment of the staging environment.

Deployment of the production environment.

QUESTION 77
We have an accounts collection with the following document structure:
{ _id: ObjectId(“61af47c6e29861661d063714”), account_id: 1010, type: ‘investment’, limit: 1000000 }
And the following query:
db.accounts.find({ “$or”: [ { “type”: { “$in”: [ “investment”, “derivatives” ] } }, { “limit”: { “$gt”: 500000 } } ] })
Which of the documents below will be retrieved by this query?

{ _id: ObjectId(“61af47c6e29861661d067825”), account_id: 7355, type: ‘commodity’, limit: 500000 }

{ _id: ObjectId(“61af47c6e29861661d063357”), account_id: 1752, type: ‘commodity’, limit: 1000 }

{ _id: ObjectId(“61af47c6e29861661d063714”), account_id: 1010, type: ‘investment’, limit: 1000000 }

{ _id: ObjectId(“61af47c6e29861661d063715”), account_id: 4336, type: ‘derivatives’, limit: 100000 }

QUESTION 78
We have a restaurants collection with the following document structure: { _id: ObjectId(“5eb3d668b31de5d588f42a7d”), address: { building: ‘605’, coord: [ -74.0060152, 40.7372653 ], street: ‘Hudson Street’, zipcode: ‘10014’ }, cuisine: ‘French’, grades: [ { date: ISODate(“2014-06-30T00:00:00.000Z”), grade: ‘A’, score: 10 }, { date: ISODate(“2013-05-20T00:00:00.000Z”), grade: ‘A’, score: 13 }, { date: ISODate(“2012-12-11T00:00:00.000Z”), grade: ‘A’, score: 9 } ], name: ‘La Ripaille Restaurant’ } We need to use Aggregation Framework to calculate the total number of restaurants for top 5 cuisine (sorted in descending order by the number of restaurants). Expected output: [ { _id: ‘American’, total_restaurants: 6183 }, { _id: ‘Chinese’, total_restaurants: 2418 }, { _id: ‘Cafao/Coffee/Tea’, total_restaurants: 1214 }, { _id: ‘Pizza’, total_restaurants: 1163 }, { _id: ‘Italian’, total_restaurants: 1069 } ] Which pipeline should you use?

[{ $group: { _id: “$cuisine”, total_restaurants: { $sum: 1 } } }, { $sort: { total_restaurants: -1 } }, { $limit: 5 }]

[{ $group: { _id: “$cuisine”, total_restaurants: { $sum: 1 } } }, { $sort: { total_restaurants: 1 } }, { $limit: 5 }]

[{ $group: { _id: “$cuisine”, total_restaurants: { $sum: 1 } } }, { $limit: 5 }, { $sort: { total_restaurants: -1 } }]

[{ $group: { _id: “cuisine”, total_restaurants: { $sum: 1 } } }, { $sort: { total_restaurants: -1 } }, { $limit: 5 }]

QUESTION 79
You have the following index in a movies collection: { “title”: 1, “imdb.rating”: -1, “imdb.votes”: -1, “type”: 1 }
Can the following query use the given index for both filtering and sorting?
db.movies.find( { “title”: “James Bond” } ).sort( { “imdb.rating”: 1, “imdb.votes”: 1 } )

Yes

QUESTION 80
Which of the following commands will delete a collection named restaurants?

db.restaurants.dropCollection()

db.restaurants.delete()

db.restaurants.remove()

db.restaurants.drop()

QUESTION 81
We have an accounts collection with only one document: { _id: 54657, account_id: 557378, products: [ ‘InvestmentStock’, ‘Commodity’, ‘CurrencyService’ ] } We need to use Aggregation Framework to unwind the products Array to obtain new documents with only one product per document (see below). Expected output: [ { _id: 54657, account_id: 557378, products: ‘InvestmentStock’ }, { _id: 54657, account_id: 557378, products: ‘Commodity’ }, { _id: 54657, account_id: 557378, products: ‘CurrencyService’ } ] Which pipeline should you use?

[{ $facet: { path: “$products”, } }]

[{ $unwind: { path: “$products”, } }]

[{ $unset: { path: “$products”, } }]

[{ $project: { path: “$products”, } }]

QUESTION 82
You have the following config file: storage: dbPath: /data/db systemLog: destination: file path: /var/log/mongod.log net: bindIp: localhost,192.168.168.62 security: keyFile: /var/pki/keyfile processManagement: fork: true Select all the directories that MongoDB must have access to

/var/log

/data/db

/var/pki

QUESTION 83
Given a movies collection where each document has the following structure: { _id: ObjectId(‘573a1390f29313caabcd60e4’), genres: [ ‘Short’, ‘Comedy’, ‘Drama’ ], title: ‘The Immigrant’, year: 1917, imdb: { rating: 7.8, votes: 4680, id: 8133 }, countries: [ ‘USA’ ] } Which of the following queries will find all the movies that have more votes than the year in which they were released?

db.movies.find({ $expr: { $gt: [“imdb.votes”, “year”] } } )

db.movies.find({ $expr: { $lt: [“$imdb.votes”, “$year”] } } )

db.movies.find({ $expr: { $gt: [“$imdb.votes”, “$year”] } } )

QUESTION 84
Which cursor method should you use to force MongoDB to use a specific index for a query?

cursor.index()

cursor.hint()

cursor.explain()

cursor.use()

QUESTION 85
What is data modeling in MongoDB world?

A way to organize fields in a document to support your application performance and querying capabilities.

A way to build your application based on how your data is stored.

A way to show your database with graphs.

A way to decide whether to store your data in the cloud or locally.

QUESTION 86
Select all true statements regarding to the role of fields and values in a MongoDB document. (select 2)

A field is a unique identifier for a specific data point.

You can have duplicate field names within the same level of a single document.

Values don’t need to be attached to fields and can be standalone data points.

Each field has a value associated with it.

QUESTION 87
Is MongoDB a NoSQL database?

Yes

QUESTION 88
Suppose you insert the following documents into a companies collection:
db.companies.insertMany([ {“name”: “Facebook”}, {“name”: “Twitter”} ])
Select all true statements about this command. (select 3)

The _id field is not specified in any of these documents.

This command will insert one document into the collection.

This command will insert two documents into the collection.

MongoDB will automatically create an _id field for each document and it will be unique.

QUESTION 89
Given a companies collection where each document has the following structure:
{ _id: ObjectId(’61a8b90c6d5ce6a7d8fef95e’), name: ‘Facebook’, tag_list: [‘facebook’, ‘college’, ‘students’, ‘network’], description: ‘Social network’ }
Which of the following commands will add new fields to the updated documents?

db.companies.updateMany({ “name”: “Facebook” }, { “$push”: { “tag_list”: “media” } })

db.companies.updateMany({ “name”: “Facebook” }, { “$set”: { “description”: “Social media” } })

db.companies.updateMany({ “name”: “Facebook” }, { “$set”: { “country”: “USA” } })

QUESTION 90
Use case: e-learning platform Which of the following scenarios is the best candidate to use the Subset Pattern?

Our app needs to retrieve a course and its ten most recent reviews.

Our app needs to retrieve a course and information about its instructor.

A course model needs to store references to image of the course that are kept in an external location outside the database.

A course model needs to store a counter representing the number of times it was purchased.

QUESTION 91
You have the following index in a products collection: { product_category: 1, product_name: 1, origin_country: -1 } Which of the following queries can use this index? Check all that apply.

db.products.find({ origin_country: ‘Bangladesh’, product_name: ‘AIR MAX 90’, product_category: ‘shoes’ })

db.products.find({ product_name: ‘AIR MAX 90’, product_category: ‘shoes’, origin_country: ‘Bangladesh’ })

db.products.find({ product_category: ‘shoes’, product_name: ‘AIR MAX 90’, origin_country: ‘Bangladesh’ })

db.products.find({ product_name: ‘AIR MAX 90’, origin_country: ‘Bangladesh’ })

Validate your Skills with Updated C100DEV Exam Questions & Answers and Test Engine: https://www.testsimulate.com/C100DEV-study-materials.html

Leave a Reply Cancel reply