MongoDB MCQ (Multiple Choice Questions) With Answers, MongoDB Online Quiz

1 .

When the introduced mongodb?

A)

2009

B)

2008

C)

2007

D)

2006

Correct Answer : 2009

Explanation : 10gen software company began developing MongoDB in 2007 as a component of a planned platform as a service product. In 2009, the company shifted to an open-source development model, with the company offering commercial support and other services. In 2013, 10gen changed its name to MongoDB Inc.

Initial release date : 11 February 2009

Founders : Kevin P. Ryan, Eliot Horowitz, Dwight Merriman

2 .

Which of the following language is MongoDB written in?

A)

C

B)

C++

C)

Javascript

D)

All of the Above

Correct Answer : All of the Above

Explanation : MongoDB (from humongous) is a cross-platform document-oriented database.

3 .

Point out the correct statement.

A)

MongoDB is column oriented database store

B)

MongoDB is classified as a NoSQL database

C)

MongoDB favours XML format more than JSON

D)

All of the Above

Correct Answer : MongoDB is classified as a NoSQL database

Explanation : MongoDB supports JSON format compared to XML.

4 .

Which of the following format is supported by MongoDB?

A)

SQL

B)

XML

C)

BSON

D)

All of the Above

Correct Answer : BSON

Explanation : MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas.

5 .

MongoDB Queries can return specific fields of documents which also include user-defined __________ functions.

A)

C

B)

C++

C)

Javascript

D)

All of the above

Correct Answer : Javascript

Explanation : MongoDB supports search by field, range queries, regular expression searches.

6 .

MongoDB has been adopted as ________ software by a number of major websites and services.

A)

frontend

B)

backend

C)

proprietary

D)

All of the above

Correct Answer : backend

Explanation : MongoDB is the most popular NoSQL database system.

7 .

MongoDB is a _________ database that provides high performance, high availability, and easy scalability.

A)

graph

B)

key value

C)

document

D)

All of the above

Correct Answer : document

Explanation : Documents (objects) map nicely to programming language data types.

8 .

Dynamic schema in MongoDB makes _____ easier for applications.

A)

inheritance

B)

encapsulation

C)

Both (A) and (B)

D)

polymorphism

Correct Answer : polymorphism

Explanation : Relational databases require that schemas be defined before you can add data.

9 .

With ________ MongoDB supports a complete backup solution and full deployment monitoring.

A)

MMS

B)

AMS

C)

CMS

D)

DMS

Correct Answer : MMS

Explanation : MMS stands for MongoDB Management Service and is available to all users in the cloud and on-premises as part of MongoDB Standard and Enterprise Subscriptions.

10 .

MongoDB provides high ____ with replica sets.

A)

availability

B)

scalability

C)

performance

D)

None of the above

Correct Answer : availability

11 .

________ replicas maintain a copy of the data on the primary using built-in replication.

A)

Primary

B)

Secondary

C)

Backup

D)

All of the above

Correct Answer : Secondary

Explanation : When a primary replica fails, the replica set automatically conducts an election process to determine which secondary should become the primary.

12 .

MongoDB scales horizontally using _________ for load balancing purpose.

A)

Partitioning

B)

Replication

C)

Sharding

D)

None of the above

Correct Answer : Sharding

Explanation : The user chooses a shard key, which determines how the data in a collection will be distributed.

13 .

MongoDB can be used as a _____ taking advantage of load balancing and data replication features over multiple machines for storing files.

A)

CMS

B)

SMS

C)

File system

D)

AMS

Correct Answer : AMS

Explanation : The data is split into ranges (based on the shard key) and distributed across multiple shards.

14 .

________ can be used for batch processing of data and aggregation operations.

A)

Hive

B)

Oozie

C)

MapReduce

D)

None of the above

Correct Answer : MapReduce

Explanation : The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used.

15 .

Which of the following sorting is not supported by MongoDB?

A)

collation

B)

heap

C)

collection

D)

None of the above

Correct Answer : collation

Explanation : MongoDB does not support collation-based sorting and is limited to byte-wise comparison via memcmp.

16 .

MongoDB uses a _____ lock that allows concurrent read access to a database but exclusive write access to a single write operation.

A)

Writer

B)

Readers

C)

Readers-writer

D)

None of the above

Correct Answer : Readers-writer

Explanation : Before version 2.2, this lock was implemented on a per-mongod basis. Since version 2.2, the lock has been implemented at the database level.

17 .

MongoDB supports fixed-size collections called ______ collections.

A)

primary

B)

capped

C)

secondary

D)

All of the above

Correct Answer : capped

Explanation : This type of collection maintains insertion order and, once the specified size has been reached, behaves like a circular queue.

18 .

Which of the following is not a NoSQL database?

A)

MongoDB

B)

Cassandra

C)

React JS

D)

SQL Server

Correct Answer : SQL Server

Explanation : Microsoft SQL Server is a relational database management system developed by Microsoft.

19 .

Which of the following is a NoSQL Database Type?

A)

SQL

B)

JSON

C)

Document databases

D)

All of the above

Correct Answer : Document databases

Explanation : Document databases pair each key with a complex data structure known as a document.

20 .

Which of the following is a wide-column store?

A)

Riak

B)

Redis

C)

MongoDB

D)

Cassandra

Correct Answer : Cassandra

Explanation : Wide-column stores such as Cassandra and HBase are optimized for queries over large datasets, and store columns of data together, instead of rows.

21 .

"Sharding" a database across many server instances can be achieved with _______

A)

SAN

B)

LAN

C)

MAN

D)

All of the above

Correct Answer : SAN

Explanation : “Sharding” a database across many server instances can be achieved with SQL databases, but usually is accomplished through SANs and other complex arrangements for making hardware act as a single server.

22 .

Most NoSQL databases support automatic __________ meaning that you get high availability and disaster recovery.

A)

scalability

B)

replication

C)

processing

D)

All of the above

Correct Answer : replication

Explanation : The storage environment is essentially virtualized from the developer’s perspective.

23 .

Which of the following are the simplest NoSQL databases?

A)

Document

B)

Key-value

C)

Wide-column

D)

All of the above

Correct Answer : Key-value

Explanation : Every single item in the database is stored as an attribute name (or “key”), together with its value in Key-value stores.

24 .

________ stores are used to store information about networks, such as social connections.

A)

Graph

B)

Document

C)

Key-value

D)

Wide-column

Correct Answer : Graph

Explanation : Graph stores include Neo4J and HyperGraphDB.

25 .

NoSQL databases is used mainly for handling large volumes of ________ data.

A)

structured

B)

semi-structured

C)

unstructured

D)

All of the above

Correct Answer : unstructured

Explanation : MongoDB is an a typical choice for unstructured data storage.

26 .

What is the interactive shell for MongoDB called?

A)

db

B)

dbmong

C)

mongodb

D)

mongo

Correct Answer : mongo

Explanation : Interactive shell lets developers view, insert, remove, and update data in their databases, as well as get replication information, set up sharding, shut down servers, execute JavaScript, and more.

27 .

Administrative information in MongoDB can also be accessed through _______

A)

psql shell

B)

web interface

C)

dashboard

D)

All of the above

Correct Answer : web interface

Explanation : Web interface is a simple webpage that serves information about the current server status. By default, this interface is 1000 ports above the database port (28017).

28 .

Which of the following is web-based client software for MongoDB?

A)

Mongo3

B)

BI Studio

C)

Fang of Mongo

D)

Database Master

Correct Answer : Database Master

Explanation : Futon4Mongo is a clone of the CouchDB-Futon-Web-Interface for MongoDB.

29 .

________ provides statistics on the per-collection level.

A)

mongotop

B)

mongofiles

C)

mongosniff

D)

mongooplog

Correct Answer : mongotop

Explanation : mongotop is a command-line tool providing a method to track the amount of time a MongoDB instance spends reading and writing data.

30 .

________ is a command-line tool that displays a summary list of status statistics for a currently running MongoDB instance.

A)

mongotop

B)

mongofiles

C)

mongostat

D)

mongooplog

Correct Answer : mongostat

Explanation : It describes how many inserts, updates, removes, queries, and commands were performed, as well as what percentage of the time the database was locked and how much memory it is using.

31 .

mongostat tool is similar to the UNIX/Linux _________ utility.

A)

vim

B)

stats

C)

vmstat

D)

All of the above

Correct Answer : vmstat

Explanation : vmstat is a computer system monitoring tool that collects and displays summary information about operating system memory, processes, interrupts, paging and block I/O.

32 .

Which of the following tool is similar to the UNIX/Linux top utility?

A)

mongofiles

B)

mongotop

C)

mongosniff

D)

mongooplog

Correct Answer : mongotop

Explanation : By default, mongotop returns values every second.

33 .

mongosniff requires the ___________ network library and is only available for Unix-like systems.

A)

Libpcap

B)

Wcap

C)

Wirecap

D)

None of the above

Correct Answer : Libpcap

Explanation : A cross-platform alternative is an open source Wireshark packet analyzer which has full support for the MongoDB wire protocol.

34 .

Which of the following is a metapackage for enterprise?

A)

mongodb-server

B)

mongodb-enterprise-server

C)

mongodb-enterprise-mongos

D)

mongodb-enterprise

Correct Answer : mongodb-enterprise

Explanation : mongodb-enterprise is a metapackage that will automatically install the four component packages.

35 .

_____ package contains the mongod daemon and associated configuration and init scripts.

A)

mongodb-enterprise

B)

mongodb-enterprise-mongos

C)

mongodb-enterprise-server

D)

None of the above

Correct Answer : mongodb-enterprise-server

Explanation : mongodb-enterprise-mongos package contains the mongos daemon.

36 .

Which of the following is not a part of mongodb-enterprise-tools?

A)

mongotop

B)

mongodown

C)

mongodump

D)

None of the above

Correct Answer : mongodown

Explanation : mongodb-enterprise-tools package contains the following MongoDB tools: mongoimport bsondump, mongodump, mongoexport, mongofiles, mongoimport, mongooplog, mongoperf, mongorestore, mongostat, and mongotop.

37 .

MongoDB only provides Enterprise packages for Ubuntu ________ LTS.

A)

12.04

B)

12.10

C)

13.04

D)

13.10

Correct Answer : 12.04

Explanation : The package structure and names have changed as of version 2.6.

38 .

Which of the following is the Ubuntu package management tool?

A)

wat

B)

dpkg

C)

capt

D)

wapt

Correct Answer : dpkg

Explanation : The Ubuntu package management tools (i.e. dpkg and apt) ensure package consistency and authenticity by requiring that distributors sign packages with GPG keys.

39 .

Command to install the latest stable version of MongoDB Enterprise in Ubuntu is _________

A)

sudo apt-get install mongodb

B)

sudo apt-get install mongodb-ent

C)

sudo apt-get install mongodb-enterprise

D)

All of the above

Correct Answer : sudo apt-get install mongodb-enterprise

Explanation : To install a specific release of MongoDB Enterprise, specify each component package individually and append the version number to the package name.

40 .

mongod process is stopped by issuing which of the following command?

A)

sudo service mongod

B)

sudo service mongod start

C)

sudo service mongod restart

D)

sudo service mongod stop

Correct Answer : sudo service mongod stop

Explanation : To stop MongoDB, press Control+C in the terminal where the mongod instance is running.

41 .

_______ does not dump the content of the local database.

A)

mongoshell

B)

mongolocaldump

C)

mongodump

D)

None of the above

Correct Answer : mongodump

Explanation : mongodump can read data from either mongod or mongos instances, in addition to reading directly from MongoDB data files without an active mongod.

42 .

To backup all the databases in a cluster via mongodump, you should have the ________ role.

A)

backup

B)

restore

C)

replication

D)

All of the above

Correct Answer : backup

Explanation : The backup role provides the required privileges for backing up all databases.

43 .

________ is a routing service for MongoDB shard configurations that processes queries from the application layer.

A)

mongod

B)

mongos

C)

mongocon

D)

None of the above

Correct Answer : mongos

Explanation : From the perspective of the application, a mongos instance behaves identically to any other MongoDB instance.

44 .

________ sends all diagnostic logging information to a log file instead of to standard output or to the host's syslog system.

A)

syslog

B)

logpath

C)

syspath

D)

syspathlog

Correct Answer : logpath

Explanation : By default, MongoDB overwrites the log file when the process restarts.

45 .

_______ is the primary daemon process for the MongoDB system.

A)

mongod

B)

logpath

C)

mongos

D)

syspathlog

Correct Answer : mongod

Explanation : It handles data requests, manages data access, and performs background management operations.

46 .

_________ utility makes it possible to manipulate files stored in your MongoDB instance in GridFS objects from the command line.

A)

mongod

B)

mongoio

C)

mongoperf

D)

mongofiles

Correct Answer : mongofiles

Explanation : All mongofiles commands have the following form:mongofiles <options> <commands> <filename>.

47 .

______ is a diagnostic tool for inspecting BSON files.

A)

jsondump

B)

bsondumpjson

C)

bsondump

D)

All of the above

Correct Answer : bsondump

Explanation : The bsondump converts BSON files into human-readable formats, including JSON.

48 .

_________ is a part of the standard MongoDB distribution and provides a full JavaScript environment.

A)

mongod

B)

mongo

C)

mongodb

D)

None of the above

Correct Answer : mongo

Explanation : mongo provides complete access to the JavaScript language and all standard functions as well as a full database interface for MongoDB.

49 .

mongo looks for a database server listening on port 27017 on the ________ interface.

A)

web

B)

web host

C)

localhost

D)

All of the above

Correct Answer : localhost

Explanation : To connect to a server on a different port or interface, use the –port and –host options.

50 .

After starting the mongo shell, your session will use the ________ database by default.

A)

test

B)

master

C)

mongo

D)

primary

Correct Answer : test

Explanation : At any time, db operation at the mongo shell is used to report the name of the current database.

51 .

Which of the following method is used to query documents in collections?

A)

find

B)

shell

C)

move

D)

replace

Correct Answer : find

Explanation : The find() method with no parameters returns all documents from a collection and returns all fields for the documents.

52 .

Which of the following also returns a list of databases?

A)

display dbs

B)

show database

C)

show databases

D)

All of the above

Correct Answer : show databases

Explanation : show databases is new in version 2.4.

53 .

Which of the following operation is used to switch to new database mydb?

A)

use db

B)

use mydb

C)

use dbs

D)

use mydbs

Correct Answer : use mydb

Explanation : Confirm that your session has the mydb database as context, by checking the value of the db object, which returns the name of the current database.

54 .

Which of the following method returns a cursor?

A)

skip

B)

find

C)

sort

D)

All of the above

Correct Answer : find

Explanation : The find() method returns a cursor. To iterate the cursor and return more documents, type it in the mongo shell.

55 .

_id is a ________ bytes hexadecimal number which assures the uniqueness of every document.

A)

10

B)

16

C)

13

D)

12

Correct Answer : 12

Explanation : You can provide _id while inserting the document.

56 .

Which of the following statement will insert 400 documents in to the testData collection?

A)

insertData("test", "testData", 400)

B)

insertData("test", "testData", 600)

C)

insertData("test", "testData", 200)

D)

All of the above

Correct Answer : insertData("test", "testData", 400)

Explanation : If the collection and database do not exist, MongoDB creates them implicitly before inserting documents.

57 .

The mongo shell loads and parses the ___________ file on startup.

A)

mongo.js

B)

mongoc.js

C)

mongorc.js

D)

All of the above

Correct Answer : mongorc.js

Explanation : Store the function in your .mongorc.js file.

58 .

To iterate the cursor and return more documents, type _________ in the mongo shell.

A)

it

B)

cursor

D)

None of the above

Correct Answer : it

Explanation : The db.collection.find() method returns a cursor. To access the documents, you need to iterate the cursor.

59 .

The order of documents returned by a query is not defined unless you specify a ______

A)

sortfind()

B)

sort()

C)

sortelse()

D)

None of the above

Correct Answer : sort()

Explanation : You can modify the query to impose limits, skips, and sort orders.

60 .

In aggregation pipeline, the _______ pipeline stage provides access to MongoDB queries.

A)

$batch

B)

$catch

C)

Both (A) and (B)

D)

$match

Correct Answer : $match

Explanation : Operations that modify existing documents (i.e. updates) use the same query syntax as queries to select documents to update.

61 .

Which of the following method returns one document?

A)

findOne1()

B)

selectOne()

C)

findOne()

D)

All of the above

Correct Answer : findOne()

Explanation : MongoDB provides a db.collection.findOne() method as a special case of find() that returns a single document.

62 .

Which of the following is the second argument to projection?

A)

find()

B)

findOne()

C)

findOne1()

D)

selectOne()

Correct Answer : find()

Explanation : Projections are the second argument to the find() method, which specifies a list of fields to return or list fields to exclude in the result documents.

63 .

Which of the following query selects documents in the records collection that match the condition { "user_id": { $lt: 42 } }?

A)

db.records.find( { â€œuser_idâ€: { $lt: 42 } }, { â€œhistoryâ€: 0 } )

B)

db.records.select( { â€œuser_idâ€: { $lt: 42 } }, { â€œhistoryâ€: 0 } )

C)

db.records.findOne( { â€œuser_idâ€: { $lt: 42 } }, { â€œhistoryâ€: 1 } )

D)

db.records.findOne( { â€œuser_idâ€: { $lt: 42 } }, { â€œhistoryâ€: 0 } )

Correct Answer : db.records.find( { â€œuser_idâ€: { $lt: 42 } }, { â€œhistoryâ€: 0 } )

Explanation : Query uses the projection { “history”: 0 } to exclude the history field from the documents in the result set.

64 .

Which of the following functionality is used for aggregation framework?

A)

$match

B)

$project

C)

$projectmatch

D)

All of the above

Correct Answer : $project

Explanation : For related projection functionality in the aggregation framework pipeline, use the $project pipeline stage.

65 .

To suppress the _id field from the result set, specify _________ in the projection document.

A)

_id: it

B)

_id: 1

C)

_id: 0

D)

None of the above

Correct Answer : _id: 0

Explanation : By default, the _id field is included in the results.

66 .

A query may include a ________ that specifies the fields from the matching documents to return.

A)

union

B)

selection

C)

projection

D)

None of the above

Correct Answer : projection

Explanation : Queries specify criteria, or conditions, that identify the documents that MongoDB returns to the clients.

67 .

MongoDB stores all documents in __________

A)

rows

B)

cols

C)

tables

D)

collections

Correct Answer : collections

Explanation : Collections are analogous to a table in relational databases.

68 .

In MongoDB _________ operations modify the data of a single collection.

A)

CRUD

B)

READ

C)

GRID

D)

All of the above

Correct Answer : CRUD

Explanation : Data modification refers to operations that create, update, or delete data.

69 .

Which of the following operation adds a new document to the users collection?

A)

add

B)

insert

C)

drop

D)

truncate

Correct Answer : insert

Explanation : For the update and delete operations, you can specify the criteria to select the documents to update or remove.

70 .

Which of the following preference determines how the client direct read operations to the set?

A)

write

B)

read

C)

delete

D)

update

Correct Answer : read

Explanation : For replica sets and sharded clusters with replica set components, applications specify read preferences.

71 .

Applications can also control the behavior of write operations using _______ concern.

A)

read

B)

truncate

C)

write

D)

All of the above

Correct Answer : write

Explanation : Write concern semantics allow clients to specify the assurance that MongoDB provides when reporting on the success of a write operation.

72 .

MongoDB process collection of documents using _________ operations.

A)

Hive

B)

Hbase

C)

Map-reduce

D)

None of the above

Correct Answer : Map-reduce

Explanation : In addition to the basic queries, MongoDB provides several data aggregation features.

73 .

Which of the following pipeline is used for aggregation in MongoDB?

A)

data processing

B)

knowledge processing

C)

information processing

D)

None of the above

Correct Answer : data processing

Explanation : MongoDB can return counts of the number of documents that match a query, or return the number of distinct values for a field.

74 .

Indexes are typically available in ______ or located sequentially on disk.

A)

RAM

B)

ROM

C)

CMOS

D)

None of the above

Correct Answer : RAM

Explanation : Querying only the index can be much faster than querying documents outside of the index.

75 .

________ is used to determine whether a query is a covered query.

A)

explainall()

B)

explain()

C)

explainstats()

D)

All of the above

Correct Answer : explain()

Explanation : db.collection.explain() provides information on the execution of other operations, such as db.collection.update().

76 .

The ________ message is used to update a document in a collection.

A)

UPDATE

B)

MB_UPDATES

C)

OP_UPDATES

D)

OP_UPDATE

Correct Answer : OP_UPDATE

Explanation : Only the OP_QUERY and OP_GET_MORE messages result in a response from the database.

77 .

____ can modify specific fields of an existing document or documents or replace an existing document entirely, depending on the update parameter.

A)

find()

B)

modify()

C)

update()

D)

None of the above

Correct Answer : update()

Explanation : By default, the update() method updates a single document.

78 .

________ is used to view statistics about the query plan for a given query.

A)

db.explain()

B)

cursor.explain()

C)

cursor.explainstats()

D)

All of the above

Correct Answer : cursor.explain()

Explanation : This information can help as you develop indexing strategies.

79 .

A ________ query plan has returned a threshold number of matching results.

A)

ordered

B)

execution

C)

unordered

D)

None of the above

Correct Answer : ordered

Explanation : An ordered query plan has returned all the matching results.

80 .

________ store the relationships between data by including links or references from one document to another.

A)

External

B)

Capped

C)

Embedded

D)

References

Correct Answer : References

Explanation : Applications can resolve these references to access the related data. Broadly, these are normalized data models.

81 .

In MongoDB, write operations are atomic at the __________ level.

A)

row

B)

collection

C)

document

D)

All of the above

Correct Answer : document

Explanation : No single write operation can atomically affect more than one document or more than one collection.

82 .

Each index in MongoDB requires at least _________ of data space.

A)

8KB

B)

28KB

C)

68KB

D)

108KB

Correct Answer : 8KB

Explanation : Adding an index has some negative performance impact for write operations.

83 .

_______ strategy is used to explicitly avoid document growth.

A)

allocation

B)

pre-allocation

C)

deallocation

D)

None of the above

Correct Answer : pre-allocation

Explanation : A data model that embeds related data in a single document facilitates atomic operations.

84 .

With MongoDB 3.0.0, the default use of the Power of _________ Allocations minimizes the occurrences of re-allocations as well as allows for the effective reuse of the freed record space.

A)

2 Sized

B)

3 Sized

C)

4 Sized

D)

5 Sized

Correct Answer : 2 Sized

Explanation : When using MMAPv1, if your applications require updates that will frequently cause document growth to exceeds the current power of 2 allocation, you may want to refactor your data model to use references between data in distinct documents rather than a denormalized data model.

85 .

For the __________ storage engine, if the document size exceeds the allocated space for that document, MongoDB relocates the document on disk.

A)

MAPv1

B)

MAPv1.5

C)

MAPv2

D)

MAPv3

Correct Answer : MAPv3

Explanation : Normalizing the data would split the data across multiple collections and would require multiple write operations that are not atomic collectively.

86 .

_______ data models allow applications to store related pieces of information in the same database record.

A)

External

B)

Reference

C)

Embedded

D)

None of the above

Correct Answer : Embedded

Explanation : As a result, applications may need to issue fewer queries and updates to complete common operations.

87 .

Embedded data model is used when you have _________ relationships between entities.

A)

isa

B)

inheritance

C)

contains

D)

All of the above

Correct Answer : contains

Explanation : Embedding provides better performance for read operations.

88 .

Normalized data models describe relationships using _______ between documents.

A)

evaluation

B)

references

C)

relativeness

D)

None of the above

Correct Answer : references

Explanation : Normalized data models can require more round trips to the server.

89 .

To interact with embedded documents, use _________ notation to "reach into" embedded documents.

A)

dot

B)

colon

C)

period

D)

comma

Correct Answer : dot

Explanation : References provides more flexibility than embedding.

90 .

MongoDB using the mmapv1 storage engine has limits on the number of _______

A)

sort

B)

documents

C)

collections

D)

namespaces

Correct Answer : namespaces

Explanation : The namespace file defaults to 16 MB.

91 .

To get the current number of namespaces in the mongo shell, use ___________

A)

db.system.namespaces.count()

B)

db.system.namespaces.countc()

C)

db.system.namespaces.count(*)

D)

All of the above

Correct Answer : db.system.namespaces.count()

Explanation : The limit on the number of namespaces depend on the <database>.ns size.

92 .

Capped collections provide __________ management of inserted documents in MongoDB.

A)

LRU

B)

MRU

C)

LIFO

D)

FIFO

Correct Answer : FIFO

Explanation : Capped collections efficiently support operations that insert and read documents based on insertion order.

93 .

Which of the following relationship uses references to describe documents between connected data?

A)

One-to-Many Relationships with Document References

B)

One-to-Many Relationships with Embedded Documents

C)

One-to-One Relationships with Embedded Documents

D)

None of the above

Correct Answer : One-to-Many Relationships with Embedded Documents

Explanation : One-to-Many Relationships with document references presents a data model that uses references to describe one-to-many relationships between documents.

94 .

Which of the following is used to avoid the repetition of data in MongoDB schema?

A)

References

B)

Cursor

C)

Collectors

D)

DeReferences

Correct Answer : References

Explanation : When using references, the growth of the relationships determine where to store the reference.

95 .

________ define what records to select for read, update, and delete operations.

A)

Query selector

B)

Query optimizer

C)

Update definitions

D)

All of the above

Correct Answer : Query selector

Explanation : Update definitions, which define what fields to modify during an update.

96 .

Which of the following statement is incorrect about documents in MongoDB?

A)

The field names cannot contain the null character

B)

The field names cannot contain the dot (.) character

C)

The field names cannot start with the dollar sign ($) character

D)

None of the mentioned

Correct Answer : None of the mentioned

Explanation : BSON documents may have more than one field with the same name.

97 .

The_____JavaScript shell and the MongoDB language drivers translate between BSON and the language-specific document representation.

A)

json

B)

mongod

C)

mongo

D)

None of the above

Correct Answer : mongo

Explanation : MongoDB stores documents on disk in the BSON serialization format. BSON is a binary representation of JSON documents, though it contains more data types than JSON.

98 .

The ________ References pattern stores each tree node in a document; in addition to the tree node, the document stores the id of the node's parent.

A)

Root

B)

Parent

C)

Child

D)

None of the above

Correct Answer : Parent

Explanation : Data model that describes a tree-like structure in MongoDB documents by storing references to “parent” nodes in children nodes.

99 .

The ________ Links pattern provides a simple solution to tree storage but requires multiple queries to retrieve subtrees.

A)

Root

B)

Child

C)

Parent

D)

All of the above

Correct Answer : Parent

Explanation : You can query by the parent field to find its immediate children nodes.

100 .

Which of the following pattern may provide a suitable solution for storing graphs?

A)

Child

B)

Root

C)

Parent

D)

None of the above

Correct Answer : Child

Explanation : Node may have multiple parents for Child Parents.

101 .

Which of the following pattern is more straightforward to use?

A)

Nested Sets

B)

String Sets

C)

Materialized Paths

D)

Array of Ancestors

Correct Answer : Array of Ancestors

Explanation : The Array of Ancestors pattern stores each tree node in a document; in addition to the tree node, document stores in an array the id(s) of the node’s ancestors or path.

102 .

The Array of Ancestors pattern is slightly slower than the ______ pattern.

A)

Materialized Paths

B)

Nested Sets

C)

Array of Ancestors

D)

None of the above

Correct Answer : Materialized Paths

Explanation : The Array of Ancestors pattern provides a fast and efficient solution to find the descendants and the ancestors of a node by creating an index on the elements of the ancestors field.

103 .

________ pattern requires additional steps of working with strings and regular expressions.

A)

Nested Sets

B)

Materialized Paths

C)

Array of Ancestors

D)

None of the above

Correct Answer : Materialized Paths

Explanation : The Materialized Paths pattern stores each tree node in a document; in addition to the tree node, document stores as a string the id(s) of the node’s ancestors or path.

104 .

Which of the following pattern is best for static trees that do not change?

A)

Root

B)

Child

C)

Parent

D)

None of the above

Correct Answer : None of the above

Explanation : The Nested Sets pattern provides a fast and efficient solution for finding subtrees but is inefficient for modifying the tree structure.

105 .

Which of the following operations are atomic on document level?

A)

update

B)

remove

C)

findAndModify

D)

All of the above

Correct Answer : All of the above

Explanation : In MongoDB, write operations, e.g. db.collection.update(), db.collection.findAndModify(), db.collection.remove(), are atomic on the level of a single document.

106 .

_______ bulk indexes may be more efficient for some kinds of content and workloads in real time.

A)

Unique

B)

Synchronous

C)

Asynchronous

D)

None of the above

Correct Answer : Asynchronous

Explanation : MongoDB can support keyword searches using specific data models and multi-key indexes;

107 .

_______ indexes can include any field whose value is a string or an array of string elements.

A)

text

B)

char

C)

string

D)

None of the above

Correct Answer : text

Explanation : MongoDB provides text indexes to support text search of string content in documents of a collection.

108 .

Which of the following is related to document that do not provide a way to weight results?

A)

Stemming

B)

Ranking

C)

Synonyms

D)

None of the above

Correct Answer : Ranking

Explanation : The keyword look ups described in this document do not provide a way to weight results.

109 .

Which of the following is related to document that provide support for synonym or related queries in the application layer?

A)

Ranking

B)

Synonyms

C)

Stemming

D)

None of the above

Correct Answer : Synonyms

Explanation : MongoDB can support keyword searches using specific data models and multi-key indexes.

110 .

To add structures to your document to support keyword-based queries add the keywords as ______ in the array.

A)

varchar

B)

number

C)

character

D)

strings

Correct Answer : strings

Explanation : You can then create a multi-key index on the array and create queries that select values from the array.

111 .

________ is a specification for storing and retrieving files that exceed the BSON-document size limit of 16MB.

A)

Grid

B)

FSpec

C)

GridFS

D)

None of the above

Correct Answer : GridFS

Explanation : Instead of storing a file in a single document, GridFS divides a file into parts, or chunks.

112 .

By default GridFS limits chunk size to ______ k.

A)

225

B)

255

C)

256

D)

None of the above

Correct Answer : 255

Explanation : GridFS is useful not only for storing files that exceed 16MB but also for storing any files for which you want access without having to load the entire file into memory.

113 .

When you query a GridFS store for a file, the _______ will reassemble the chunks as needed.

A)

client

B)

Server

C)

Agent

D)

None of the above

Correct Answer : client

Explanation : You also can access information from arbitrary sections of files, which allows you to “skip” into the middle of a video or audio file.

114 .

MongoDB represents queries as _______ objects.

A)

BSON

B)

JSON

C)

GSON

D)

None of the above

Correct Answer : BSON

Explanation : As a client program assembles a query in MongoDB, it builds a BSON object, not a string.

115 .

GridFS uses a _________ index on the chunks collection for the files_id and n fields.

A)

single

B)

double

C)

non unique

D)

unique

Correct Answer : unique

Explanation : The files_id field contains the _id of the chunk’s “parent” document.

116 .

A)

composite

B)

secondary

C)

primary

D)

All of the above

Correct Answer : primary

Explanation : Object_Id is unique and cannot be changed.

117 .

Which of the field is reserved for use as a primary key?

A)

_uid

B)

_id

C)

_uuid

D)

All of the above

Correct Answer : _id

Explanation : ID value value must be unique in the collection, is immutable, and may be of any type other than an array.

118 .

To ensure functioning replication, do not store values that are of the _______ regular expression type in the _id field.

A)

XML

B)

JSON

C)

JScript

D)

None of the above

Correct Answer : None of the above

Explanation : The _id field may contain values of any BSON data type, other than an array.

119 .

________ returns the JavaScript representation in the form of a string literal.

A)

toString()

B)

String()

C)

toStringJava()

D)

None of the above

Correct Answer : toString()

Explanation : In previous versions, toString() returns the hexadecimal string representation, which as of version 2.2 can be retrieved by the str property.

120 .

Which of the following query is used to generate a new ObjectId, use the ObjectId() constructor with no argument?

A)

x = ObjectId()

B)

x = addObjectId()

C)

x = ObjectIdAdd()

D)

None of the above

Correct Answer : x = ObjectId()

Explanation : ObjectId() constructor is used with no argument for new object.

121 .

The _____ JavaScript shell and the MongoDB language drivers translate between BSON and the language-specific document representation.

A)

iscript

B)

mongo

C)

mongod

D)

None of the above

Correct Answer : mongo

Explanation : The value of a field can be any of the BSON data types.

122 .

BSON is a binary representation of ________ documents.

A)

XML

B)

JScript

C)

JSON

D)

All of the above

Correct Answer : JSON

Explanation : BSON contains more data types than JSON.

123 .

MongoDB documents are composed of field-and-value pairs and have the following structure?

A)

field1: value1;

B)

field1:; value1

C)

field1; value1;

D)

field1: value1

Correct Answer : field1: value1

Explanation : The value of a field can be any of the BSON data types, including other documents, arrays, and arrays of documents.

124 .

To store documents larger than the maximum size, MongoDB provides the _______ API.

A)

MMS

B)

Grid

C)

GridFS

D)

None of the above

Correct Answer : Grid

Explanation : MongoDB preserves the order of the document fields following write operations.

125 .

Index keys that are of the _______ type are more efficiently stored in the index.

A)

BinData

B)

String

C)

Materialized Paths

D)

None of the above

Correct Answer : BinData

Explanation : Most MongoDB driver clients will include the _id field and generate an ObjectId before sending the insert operation to MongoDB.

126 .

To get a correct snapshot of a running mongod process, you must have _________ enabled.

A)

MMS

B)

replication

C)

journaling

D)

All of the above

Correct Answer : journaling

Explanation : Without journaling enabled, there is no guarantee that the snapshot will be consistent or valid.

127 .

The _______ tool reads data from a MongoDB database and creates high fidelity BSON files.

A)

mdump

B)

mongod

C)

mongodump

D)

All of the above

Correct Answer : mongodump

Explanation : mongodump is a utility for creating a binary export of the contents of a database.

128 .

If your storage system does not support snapshots, you can copy the files directly using _______

A)

cp

B)

copy

C)

snap

D)

None of the above

Correct Answer : cp

Explanation : Since copying multiple files is not an atomic operation, you must stop all writes to the mongod before copying the files.

129 .

The _________ tool can populate a MongoDB database with the data from these BSON files.

A)

mongod

B)

dbmongo

C)

mongostore

D)

mongorestore

Correct Answer : mongorestore

Explanation : This tool is not ideal for capturing backups of larger systems.

130 .

For replica sets, mongodump also supports a point in time feature with the ________ option.

A)

â€“op

B)

â€“oplog

C)

â€“log

D)

Correct Answer : â€“oplog

Explanation : To restore a point in time backup created with –oplog, use mongorestore with the –oplogReplay option.

131 .

If applications modify data while mongodump is creating a backup _________ will compete for resources with those applications.

A)

mongod

B)

mongostore

C)

mongorestore

D)

mongodump

Correct Answer : mongodump

Explanation : Applications may continue modifying data while mongodump captures the output.

132 .

On Linux the ______ manager can create a snapshot.

A)

MMS

B)

SVM

C)

LVM

D)

All of the above

Correct Answer : LVM

Explanation : You can create a backup by copying MongoDB’s underlying data files.

133 .

To mitigate the impact of mongodump on the performance of the replica set, use mongodump to capture backups from a _________ member of a replica set.

A)

secondary

B)

primary

C)

snaphot

D)

None of the above

Correct Answer : secondary

Explanation : Alternatively, you can shut down a secondary and use mongodump with the data files directly.

134 .

________ an on-premise solution, has similar functionality to the cloud version.

A)

Ops Manager

B)

Mongod

C)

Opscore Manager

D)

None of the above

Correct Answer : Ops Manager

Explanation : This tool is available with Enterprise Advanced subscriptions.

135 .

Ops Manager _________ provides an interface for configuring MongoDB nodes and clusters and for upgrading your MongoDB deployment.

A)

Monitoring

B)

Automation

C)

Performance

D)

None of the above

Correct Answer : Automation

Explanation : Ops Manager Monitoring provides real-time reporting, visualization, and alerting on key database and hardware indicators.

136 .

Ops Manager ______ provides scheduled snapshots and point-in-time recovery of your MongoDB replica sets and sharded clusters.

A)

Monitoring

B)

Automation

C)

Performance

D)

Backup

Correct Answer : Backup

Explanation : Backup can also create snapshots of standalones that are run as single-member replica sets.

137 .

Sharded clusters snapshots temporarily stop the balancer via _______

A)

MMS

B)

Mongod

C)

mongos

D)

MonitorMMS

Correct Answer : mongos

Explanation : Backup takes and stores snapshots based on a user-defined snapshot retention policy.

138 .

Ops Manager reads directly from the Backup Blockstore database and transfers files either through _______

A)

MMS

B)

TCP

C)

HTTPS

D)

All of the above

Correct Answer : HTTPS

Explanation : Ops Manager Backup lets you restore data from a scheduled snapshot or from a selected point between snapshots.

139 .

Ops Manager maintains one _____ database for each backed-up replica set.

A)

head

B)

tail

C)

mdump

D)

All of the above

Correct Answer : head

Explanation : The head database is consistent with the original primary up to the last oplog supplied by the agent.

140 .

Backup can also create snapshots of _________ that are run as single-member replica sets.

A)

backups

B)

standalones

C)

documents

D)

None of the above

Correct Answer : standalones

Explanation : A lightweight Backup Agent runs within your infrastructure and backs up data from the MongoDB processes you have specified.

141 .

Which of the following command returns quickly and does not impact MongoDB performance?

A)

dbStats

B)

db.stats()

C)

None of the above

D)

db.serverStatus()

Correct Answer : db.serverStatus()

Explanation : serverStatus outputs an account of the state of a MongoDB instance.

142 .

Which of the following document details the state and configuration of the replica set and statistics about its members?

A)

db.stats()

B)

db.serverStatus()

C)

replSetGetStatus

D)

None of the above

Correct Answer : None of the above

Explanation : The replSetGetStatus command (rs.status() from the shell) returns an overview of your replica set’s status.

143 .

_________ captures and returns the counts of database operations by type.

A)

mms

B)

mongod

C)

mongostat

D)

All of the above

Correct Answer : mongostat

Explanation : Use mongostat to understand the distribution of operation types and to inform capacity planning.

144 .

________ tracks and reports the current read and write activity of a MongoDB instance, and reports these statistics on a per collection basis.

A)

mongotop

B)

mongod

C)

mongostat

D)

All of the above

Correct Answer : mongotop

Explanation : Use mongotop to check if your database activity and use match your expectations.

145 .

______ method is useful tool for identifying the database instanceâ€™s in-progress operations.

A)

db.Op

B)

db.currentOp

C)

db.current

D)

None of the above

Correct Answer : db.currentOp

Explanation : MongoDB includes a number of commands that report on the state of the database.

146 .

_________ returns a general overview of the status of the database, detailing disk usage, memory use, connection, journaling, and index access.

A)

dbStats

B)

db.stats()

C)

db.serverStatus()

D)

None of the above

Correct Answer : db.serverStatus()

Explanation : This command is rarely run directly.

147 .

______ provides statistics that resemble dbStats on the collection level.

A)

collstats

B)

dbStats

C)

db.statserver()

D)

db.serverStatus()

Correct Answer : collstats

Explanation : It also includes count of the objects in the collection, the size of the collection, the amount of disk space used by the collection, and information about its indexes.

148 .

The ________ reflect the amount of storage used, the quantity of data contained in the database, and object, collection, and index counters.

A)

db.statserver()

B)

db.serverStatus()

C)

db.server()

D)

dbStats

Correct Answer : dbStats

Explanation : The dbStats command, or db.stats() from the shell, returns a document that addresses storage use and data volumes.

149 .

_______ contains a counter of the total number of clients with active operations in progress or queued.

A)

globalLock

B)

globalLock.active

C)

localLock.activeClients

D)

globalLock.activeClients

Correct Answer : globalLock.activeClients

Explanation : The activeClients data structure provides more granular information about the number of connected clients and the operation types (e.g. read or write) performed by these clients.

150 .

The ___________ collection stores custom roles that administrators create and assign to users to provide access to specific resources.

A)

admin.system.role

B)

admin.system.roles

C)

admin.system.roleasign

D)

All of the above

Correct Answer : admin.system.roles

Explanation : System collections include these collections stored in the admin database

151 .

The _________ field provides the amount of resident memory in use.

A)

mem.resident

B)

memory.resident

C)

mem.resident

D)

All of the above

Correct Answer : mem.resident

Explanation : If this exceeds the amount of system memory and there is a significant amount of data on disk that isn’t in RAM, you may have exceeded the capacity of your system.

152 .

MongoDB stores tag sets in the replica set configuration object, which is the document returned by _____

A)

rs.conf()

B)

rs.config()

C)

rs.confstats()

D)

All of the above

Correct Answer : rs.conf()

Explanation : Custom read preferences and write concerns evaluate tags sets in different ways.

153 .

On Linux, use the ______ command to check if disk I/O is a bottleneck for your database.

A)

stat

B)

iostat

C)

iostats

D)

None of the above

Correct Answer : iostat

Explanation : Specify the number of seconds when running iostat to avoid displaying stats covering the time since server boot.

154 .

Which of the following document configures the threshold which determines whether a query is â€œslowâ€ for the purpose of the logging system?

A)

systemLog

B)

systemLog.verbosity

C)

operationProfiling.mode

D)

operationProfiling.slowOpThresholdMs

Correct Answer : operationProfiling.slowOpThresholdMs

Explanation : systemLog.verbosity controls the amount of logging output that mongod write to the log.

155 .

Which of the following storage engine is supported by default?

A)

MMAPv1

B)

WiredTiger

C)

WirelessTiger

D)

All of the above

Correct Answer : MMAPv1

Explanation : MongoDB includes support for two storage engines: MMAPv1, the storage engine available in previous versions of MongoDB, and WiredTiger

156 .

All collections have a unique ________ lock that allows multiple clients to modify documents in different collections at the same time.

A)

writer

B)

readers

C)

readers-writer

D)

All of the above

Correct Answer : readers-writer

Explanation : Each database has a readers-writer lock that allows concurrent read access to a database, but gives exclusive access to a single write operation per database.

157 .

MongoDB uses ________ logging to an on-disk journal.

A)

read only

B)

write ahead

C)

write once

D)

read ahead

Correct Answer : write ahead

Explanation : Leave journaling enabled in order to ensure that mongod will be able to recover its data files and keep the data files in a valid state following a crash.

158 .

_______ concern describes the guarantee that MongoDB provides when reporting on the success of a write operation.

A)

Read

B)

SSD

C)

Write

D)

Read only

Correct Answer : Write

Explanation : The strength of the write concerns determine the level of guarantee.

159 .

The ________ command returns information regarding the number of open connections.

A)

server

B)

connStats

C)

serverstats

D)

connPoolStats

Correct Answer : connPoolStats

Explanation : To avoid overloading the connection resources of a single mongod or mongos instance, ensure that clients maintain reasonable connection pool sizes.

160 .

Which of the following should be avoided with MongoDB Deployments?

A)

RAID-0

B)

RAID-5

C)

RAID-7

D)

RAID-10

Correct Answer : RAID-0

Explanation : While RAID-0 provides good write performance, it also provides limited availability and can lead to reduced performance on read operations, particularly when using Amazon’s EBS volumes.

161 .

With the WiredTiger storage engine, use of _______ is strongly recommended to avoid performance issues.

A)

SST

B)

XFS

C)

SSD

D)

All of the above

Correct Answer : XFS

Explanation : Some Linux distributions require different versions of the kernel to support using XFS.

162 .

MongoDB requires a filesystem that supports ______ on directories.

A)

fsync()

B)

sync()

C)

fsynconce()

D)

all of the above

Correct Answer : fsync()

Explanation : HGFS and Virtual Box’s shared folders do not support this operation.

163 .

MongoDB Cloud Manager provides integration with Amazon Web Services (AWS) and lets you deploy new ______ instances directly from MongoDB Cloud Manager.

A)

ECS

B)

EC1

C)

EC2

D)

EC3

Correct Answer : EC2

Explanation : MongoDB is compatible with EC2.

164 .

WiredTiger can compress collection data using either snappy or zlib compression library.

A)

Kit

B)

Lib

C)

Zip

D)

snappy

Correct Answer : snappy

Explanation : snappy provides a lower compression rate but has little performance cost

165 .

Which of the following is especially important in Sharded Clusters?

A)

NSS

B)

NTP

C)

STP

D)

SSD

Correct Answer : NSS

Explanation : Use the Network Time Protocol (NTP) to synchronize time among your hosts.

166 .

_____ is a command-line tool for monitoring network use.

A)

bwm-n

B)

bwm-ng

C)

bwm-g

D)

bwm-ngs

Correct Answer : bwm-ng

Explanation : If you suspect a network-based bottleneck, you may use bwm-ng to begin your diagnostic process.

167 .

Which of the following setting defines what constitutes a "slow" operation?

A)

fastOpThresholdMs

B)

slowOpThresholdGs

C)

slowOpThresholdMs

D)

None of the above

Correct Answer : slowOpThresholdMs

Explanation : The operationProfiling.slowOpThresholdMs setting is available only for mongod.

168 .

________ provide the number of times the lock acquisitions encountered deadlocks.

A)

locks.deadlock

B)

lock.deadlockCount

C)

locks.deadlockCount

D)

All of the above

Correct Answer : locks.deadlockCount

Explanation : The globalLock data structure contains information regarding the database’s current lock state, historical lock status, current operation queue, and the number of active clients.

169 .

If __________ is high relative to uptime, the database has existed in a lock state for a significant amount of time.

A)

globalLock

B)

globalLock.halfTime

C)

globalLock.downTime

D)

globalLock.totalTime

Correct Answer : globalLock.totalTime

Explanation : The value of totalTime represents the time, in microseconds, since the database last started and creation of the globalLock.

170 .

The _______data structure value provides more granular information concerning the number of operations queued because of a lock.

A)

currentQu

B)

currentQueue

C)

curQueue

D)

None of the above

Correct Answer : currentQueue

Explanation : The serverStatus command returns a document that provides an overview of the database process’s state

171 .

serverStatus includes all fields by default, except _________

A)

rangeDelete

B)

rangeDEL

C)

rangeDeleter

D)

None of the above

Correct Answer : rangeDelete

Explanation : You may only dynamically include top-level fields from the serverStatus document that are not included by default.

172 .

MongoDBâ€™s _______ is a database profiling system that can help identify inefficient queries and operations.

A)

Profiler

B)

Reporter

C)

Executer

D)

None of the above

Correct Answer : Profiler

Explanation : Enable the profiler by setting the profile value using the following command in the mongo shell.

173 .

MongoDB stores additional instance-local metadata in the _______ database.

A)

Model

B)

Master

C)

Local

D)

All of the above

Correct Answer : Local

Explanation : It is stored specifically for replication purposes.

174 .

In replica sets, each ________ maintains a connection to all other members of the set.

A)

mongos

B)

mongod

C)

serverInfo

D)

None of the above

Correct Answer : mongod

Explanation : mongod uses background threads for a number of internal processes, including TTL collections, replication, and replica set health checks, which may require a small number of additional resources.

175 .

The ___________ collection stores the user's authentication credentials as well as any roles assigned to the user.

A)

admin.system

B)

admin.system.auth

C)

admin.system.usersauth

D)

admin.system.users

Correct Answer : admin.system.users

Explanation : Users may define authorization roles in the admin.system.roles collection.

176 .

Which of the following can store JavaScript functions for reuse?

A)

system.js

B)

store.js

C)

save.js

D)

system.store.js

Correct Answer : system.js

Explanation : To store a function, you can use the db.collection.save().

177 .

______ is used to load all the scripts saved in the system.js collection for the current database.

A)

db.loadScripts()

B)

db.loadServerScriptsjs()

C)

db.loadServerScripts()

D)

None of the above

Correct Answer : db.loadServerScripts()

Explanation : The documents in the system.js collection provide functions that your applications can use in any JavaScript context with MongoDB in this database.

178 .

Which of the following collection is capped?

A)

system.index

B)

system.profile

C)

system.replica

D)

All of the above

Correct Answer : system.profile

Explanation : The database profiler writes data in the system.profile collection, which is a capped collection.

179 .

The _______provides information for various lock types and lock modes held during the operation.

A)

admin.system.locks

B)

system.profile.locks

C)

admin.system.authlocks

D)

All of the above

Correct Answer : system.profile.locks

Explanation : MongoDB uses reader-writer locks that allow concurrent readers shared access to a resource, such as a database or collection, but give exclusive access to a single write operation.

180 .

Which of the following keyword represents lock on the collection?

A)