Latest C100DEV Exam Dumps MongoDB Exam from Training Expert TestKingFree [Q19-Q39]

Q19. Select all true statements regarding to unique indexes in MongoDB.

In MongoDB we cannot enforce a unique constraint on compound indexes.

A unique index ensures that the indexed fields don’t store duplicate values.

By default, MongoDB creates a unique index on the _id field.

When creating a unique index, we need to pass an additional unique option set to true. For example:

db.products.createIndex( { manufacturer_id: 1 }, { unique: true } )

Q20. Select true statement regarding to the MongoDB Atlas. (select 1)

MongoDB Atlas is a MongoDB service that can work with any database.

MongoDB Atlas includes many tools and services specifically designed for the MongoDB database.

Q21. Assign typical operational tasks to the Database Administrator.

write data, read data

read data

create index, create user

write data

Q22. Which of the following scenarios is best suited for applying the Attribute Pattern?

You need to apply document validation before inserting/modifying.

Some fields share a similar characteristics, and you want to search across those fields.

The documents in the collection are quite large.

Q23. What does IOPS stand for in database terminology?

Input/Output per Second

Internet Official Protocol Standards

Q24. Data modeling. You are considering the use of nesting or references in your data model. Documents can grow rapidly. Which option would be more appropriate?

Use of nesting.

Use of reference.

Q25. Select true statements about sorting & indexing performance.

Index prefixes cannot be used in query predicates to increase index utilization.

Indexes can be traversed both forward and backward.

Index prefixes can be used in sort predicates to prevent sort in memory.

It’s possible to have a sorted query use an index for both sorting and filtering.

Q26. Select all true statements regarding to $out stage.

$out operator creates collections in the same database as the source collection.

All indexes on an existing collection are rebuilt when $out overwrites the collection.

$out operator must be the last stage in a pipeline.

$out operator will create a new empty collection or overwrite an existing collection if the pipeline raises an error.

$out operator will overwrite an existing collection if specified.

Q27. 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.

Q28. 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( { “imdb.rating”: 8, “title”: “James Bond” } ).sort( { “imdb.votes”: -1 } )

Yes

No

Q29. Which collection method do you need to use to drop a specific collection?

db.collection.dropIndex()

db.collection.remove()

db.collection.dropCollection()

db.collection.drop()

Q30. Select all true statements regarding to replica sets in MongoDB.

We can have up to 50 replica set members, but only 7 of those will be voting members.

Replica set members have a fixed role assigned.

Replica sets use failover to provide high availability to client applications.

Q31. Select all true statements regarding to pipelines and the Aggregation Framework.

An aggregation pipeline consists of one or more stages that process documents.

The Aggregation Framework provides us many stages to filter and transform data.

The aggregation pipeline cannot operate on a sharded collection.

An aggregation pipeline is an array of stages.

Aggregation Framework does not have the group stage for grouping data.

Q32. We have the following index in a movies collection: { title: 1, genres: 1 } We want to insert the following document: { “title”: “The Immigrant”, “year”: 1917, “genres”: [ “Short”, “Comedy”, “Drama” ] } How many index entries will be created?

0

1

4

2

3

Q33. The following capped collection is given: db.createCollection(‘latest_news’, {‘capped’: true, ‘size’: 10000, ‘max’: 3}) [ { _id: ObjectId(“61e8007c9b3067e362440a88”), title: ‘COVID records broken again as weekend brings nearly 40K new cases’ }, { _id: ObjectId(“61e800989b3067e362440a89”), title: ‘Bitcoin, Ethereum, Dogecoin Face Fresh Round Of Regulatory Scrutiny’ }, { _id: ObjectId(“61e800d19b3067e362440a8a”), title: ‘Where Six Meme Stock Investors Are Now’ } ] What the latest_news collection will look like after the following operation?

db.latest_news.insertOne({title: ‘TikTok owner ByteDance dissolves its investment arm’}) [ { _id: ObjectId(“61e800989b3067e362440a89”), title: ‘Bitcoin, Ethereum, Dogecoin Face Fresh Round Of Regulatory Scrutiny’ }, { _id: ObjectId(“61e800d19b3067e362440a8a”), title: ‘Where Six Meme Stock Investors Are Now’ }, { _id: ObjectId(“61e801439b3067e362440a8b”), title: ‘TikTok owner ByteDance dissolves its investment arm’ } ]

[ { _id: ObjectId(“61e8007c9b3067e362440a88”), title: ‘COVID records broken again as weekend brings nearly 40K new cases’ }, { _id: ObjectId(“61e800989b3067e362440a89”), title: ‘Bitcoin, Ethereum, Dogecoin Face Fresh Round Of Regulatory Scrutiny’ }, { _id: ObjectId(“61e800d19b3067e362440a8a”), title: ‘Where Six Meme Stock Investors Are Now’ }, { _id: ObjectId(“61e801439b3067e362440a8b”), title: ‘TikTok owner ByteDance dissolves its investment arm’ } ]

[ { _id: ObjectId(“61e8007c9b3067e362440a88”), title: ‘COVID records broken again as weekend brings nearly 40K new cases’ }, { _id: ObjectId(“61e800989b3067e362440a89”), title: ‘Bitcoin, Ethereum, Dogecoin Face Fresh Round Of Regulatory Scrutiny’ }, { _id: ObjectId(“61e800d19b3067e362440a8a”), title: ‘Where Six Meme Stock Investors Are Now’ } ]

Q34. What stages will cause a merge on the primary shard for a database?

$out

$lookup

$group

Q35. Suppose you have a mobile_games collection with the following document structure: { game: “Fishing Clash”, company: “Ten Square Games”, platforms: [‘Android’, ‘IOS’], … release_USA: ISODate(“2017-04-09T01:00:00+01:00”), release_France: ISODate(“2017-04-09T01:00:00+01:00”), release_Italy: ISODate(“2017-08-17T01:00:00+01:00”), … } Are there any problems with this document structure?

Yes, a search for a release date will require looking across many fields at once which is inefficient.

No, everything is correct. There is no room for improvement.

Q36. 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 }]

Q37. Suppose you have a sales collection with the following document structure: { _id: ObjectId(“5bd761dcae323e45a93ccfe8”), saleDate: ISODate(“2015-03-23T21:06:49.506Z”), items: [ { name: ‘printer paper’, tags: [ ‘office’, ‘stationary’ ], price: Decimal128(“40.01”), quantity: 2 } { name: ‘pens’, tags: [ ‘writing’, ‘office’, ‘school’, ‘stationary’ ], price: Decimal128(“56.12”), quantity: 5 }, { name: ‘notepad’, tags: [ ‘office’, ‘writing’, ‘school’ ], price: Decimal128(“18.47”), quantity: 2 } ], storeLocation: ‘Denver’, couponUsed: true, purchaseMethod: ‘Online’ } Which operator should you use to extract all sales documents that have ‘notepad’ name in items field?

$in

$elemMatch

$nin

$match

$all

Q38. 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.

Q39. What does it command do in the mongo shell?

Iterates through the cursor results.

Terminates the current query execution.

it is not a mongo shell command.

Displays cluster statistics.