MongoDB Online Test

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Initial release of MongoDB was in the year?

2000
2005
2009
2011

Correct Answer : C

As per the aggregation pipeline optimization concepts, if you have a $sort followed by a $match:

$match moves before $sort
$sort moves before $match
MongoDB does not do any movements by default and will use the order provided
Providing these parameters in any order does not impact the performance

Correct Answer : A

Object_Id is similar to _________ key in Relational Databases

primary
secondary
composite
all of the mentioned

Correct Answer : A

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

find
move
shell
replace

Correct Answer : A

____________ works similar to HAVING clause in SQL

$setcon
$group
$match
None of the mentioned

Correct Answer : C

MongoDB applies the _____ phase to each input document in mapreduce.

map
reduce
mapper
all of the mentioned

Correct Answer : A

Point out the wrong statement

Variables can hold any BSON type data
Aggregation expressions can use both user-defined and system variables
To access the value of the variable, use a string with the variable name prefixed with double dollar signs ($$)
None of the mentioned

Correct Answer : C

Which of the following method returns one document?

findOne()
findOne1()
selectOne()
all of the mentioned

Correct Answer : A

Which of the following functionality is used for aggregation framework?

$match
$project
$projectmatch
All of the mentioned

Correct Answer : B

Which of the following mode defaults to false?

jsMode
scope
finalize
min

Correct Answer : A

______ can be used to iterate the cursor of document results returned by db.collection.find()

it
next
cur
none of the mentioned

Correct Answer : A

Which index is used to index the content stored in arrays?

Multikey Index
Compound Index
Text Index
Sparse Index

Correct Answer : A

__________ is a diagnostic tool for inspecting BSON files

jsondump
bsondump
bsondumpjson
all of the mentioned

Correct Answer : B

Which of the following provides similar functionality to join?

$unwindelem
$unwind
$unwin
None of the mentioned

Correct Answer : C

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

$catch
$match
$batch
All of the mentioned

Correct Answer : B

____________ does not dump the content of the local database

mongoshell
mongodump
mongolocaldump
none of the mentioned

Correct Answer : B

A collection and a document in MongoDB is equivalent to which of the SQL concepts respectively?

Table and Row
Table and Column
Column and Row
Database and Table

Correct Answer : A

___________ is the primary daemon process for the MongoDB system

mongos
mongod
logpath
syspathlog

Correct Answer : B

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

selection
projection
union
none of the mentioned

Correct Answer : B

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

Correct Answer : C

__________ returns the JavaScript representation in the form of a string literal

toStringJava()
toString()
String()
none of the mentioned

Correct Answer : B

Which of the following flag can be set by mongo shell?

Timeout
noTimeout
Time
None of the mentioned

Correct Answer : B

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

mongo
master
test
primary

Correct Answer : C

A query _______ consists of a combination of query, sort, and projection specifications

plan
shape
stats
all of the mentioned

Correct Answer : B

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

db.explain()
cursor.explain()
cursor.explainstats()
all of the mentioned

Correct Answer : B

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

read
write
update
delete

Correct Answer : A

_______ groups documents by some specified expression and outputs to the next stage a document for each distinct grouping

$setcon
$group
$match
None of the mentioned

Correct Answer : B

Point out the correct statement

Queries specify criteria, or conditions, that identify the documents that MongoDB returns to the clients
Write operations, or queries, retrieve data stored in the database
The selection limits the amount of data that MongoDB returns to the client over the network
All of the mentioned

Correct Answer : A

Point out the wrong statement

Aggregation pipeline have some limitations on value types and result size
The aggregation pipeline is a framework for data aggregation modeled on the concept of data processing pipelines
Documents enter a multi-stage pipeline that transforms the documents into an aggregated results
All of the mentioned

Correct Answer : D

Which of the following language is MongoDB written in?

Javascript
C
C++
All of the mentioned

Correct Answer : D