MongoDB Online Quiz

Q 1 - Which of the following is correct explanation of MongoDB processes?

A - mongod.exe is the shell process and mongo.exe is the actual database process

B - mongo.exe is the shell process and mongod.exe is the actual database process

C - mongos.exe is the MongoDB server process needed to run database

D - mongodump.exe can be used to import database backup dump

Q 2 - What is the maximum size of a MongoDB document?

A - 2 MB

B - 16 MB

C - 12 MB

D - There is no maximum size. It depends on the RAM.

Q 3 - Which of the following commands can cause the database to be locked?

A - Issuing a query

B - Inserting data

C - Map-reduce

D - All of the above

Q 4 - Which option should be used to update all the documents with the specified condition in the MongoDB query?

A - updateAll instead of update

B - specify {multi : true} as the third parameter of update command

C - specify {all: true} as the third parameter of update command

D - specify {updateAll: true} as the third parameter of update command

Q 5 - Which option should be used with findAndModify() command to return the modified document instead of the pre-modification document?

A - findAndModify by default returns the pre-modification document

B - Set {new : true}

C - Use the POST version of findAndModify called findAndModifyPost

D - Both b and c are valid

Q 6 - What is the equivalent command in MongoDB for the following SQL query?

SELECT * FROM posts WHERE author like "%john%"

A - db.posts.find( { author: /john/ } )

B - db.posts.find( { author: {$like: /john/} } )

C - db.posts.find( { $like: {author: /john/} } )

D - db.posts.find( { author: /^john^/ } )

Q 7 - Consider that you have a collection called population which has fields state and city. Which of the following query will calculate the population grouped by state and city?

A - db.population.aggregate( [{ $group: { _id: { state: "$state", city: "$city" },pop: { $sum: "$pop" } } }] )

B - db.population.aggregate( [{ $group: { _id: { state: "$state", city: "$city" },pop: { $sum: 1 } } }] )

C - db.population.aggregate( [{ $group: { _id: { state: "$state", city: "$city" },pop: { “$pop”: 1 } } }] )

D - db.population.aggregate( [{ $group: { _id: { city: "$city" },pop: { $sum: "$pop" } } }] )Multi Document Transaction is not supported by MongoDB

Q 8 - Given a collection posts as shown below having a document array comments, which of the following command will create an index on the comment author descending?

{
		“_id”:1,
		“post_text”:”This is a sample post”,
		“author”:”Tom”,
		“comments”:[
			{
				“author”:”Joe”,
				“comment_text”:”This is comment 1”
			},
			{
				“author”:”Leo”,
				“comment_text”:”This is comment 2”
			}
		]	
}

A - db.posts.createIndex({“comments.$.author":-1});

B - db.posts.createIndex({“comments.author":-1});

C - db.posts.createIndex({“comments.author":1});

D - db.posts.createIndex({“comments.$.author": {“$desc”:1}});

Q 9 - Which of the tags in a replica set configuration specify the operations to be read from the node with the least network latency?

A - primaryPreferred

B - secondaryPreferred

C - nearest

D - netLatency

Q 10 - When should we consider representing a one-to-many relationship in an embedded collection instead of separate collection?

A - When the many is very large

B - When the many is not very large

C - Never

D - Always